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Sample records for schistosome ova inactivation

  1. Leveraging rural energy investment for parasitic disease control: schistosome ova inactivation and energy co-benefits of anaerobic digesters in rural China.

    Science.gov (United States)

    Remais, Justin; Chen, Lin; Seto, Edmund

    2009-01-01

    Cooking and heating remain the most energy intensive activities among the world's poor, and thus improved access to clean energies for these tasks has been highlighted as a key requirement of attaining the major objectives of the UN Millennium Development Goals. A move towards clean energy technologies such as biogas systems (which produce methane from human and animal waste) has the potential to provide immediate benefits for the control of neglected tropical diseases. Here, an assessment of the parasitic disease and energy benefits of biogas systems in Sichuan Province, China, is presented, highlighting how the public health sector can leverage the proliferation of rural energy projects for infectious disease control. First, the effectiveness of biogas systems at inactivating and removing ova of the human parasite Schistosoma japonicum is experimentally evaluated. Second, the impact of biogas infrastructure on energy use and environmental quality as reported by surveyed village populations is assessed, as is the community acceptance of the technology. No viable eggs were recovered in the effluent collected weekly from biogas systems for two months following seeding with infected stool. Less than 1% of ova were recovered viable from a series of nylon bags seeded with ova, a 2-log removal attributable to biochemical inactivation. More than 90% of Ascaris lumbricoides ova (used as a proxy for S. japonicum ova) counted at the influent of two biogas systems were removed in the systems when adjusted for system residence time, an approximate 1-log removal attributable to sedimentation. Combined, these inactivation/removal processes underscore the promise of biogas infrastructure for reducing parasite contamination resulting from nightsoil use. When interviewed an average of 4 years after construction, villagers attributed large changes in fuel usage to the installation of biogas systems. Household coal usage decreased by 68%, wood by 74%, and crop waste by 6%. With

  2. Leveraging rural energy investment for parasitic disease control: schistosome ova inactivation and energy co-benefits of anaerobic digesters in rural China.

    Directory of Open Access Journals (Sweden)

    Justin Remais

    Full Text Available Cooking and heating remain the most energy intensive activities among the world's poor, and thus improved access to clean energies for these tasks has been highlighted as a key requirement of attaining the major objectives of the UN Millennium Development Goals. A move towards clean energy technologies such as biogas systems (which produce methane from human and animal waste has the potential to provide immediate benefits for the control of neglected tropical diseases. Here, an assessment of the parasitic disease and energy benefits of biogas systems in Sichuan Province, China, is presented, highlighting how the public health sector can leverage the proliferation of rural energy projects for infectious disease control.First, the effectiveness of biogas systems at inactivating and removing ova of the human parasite Schistosoma japonicum is experimentally evaluated. Second, the impact of biogas infrastructure on energy use and environmental quality as reported by surveyed village populations is assessed, as is the community acceptance of the technology. No viable eggs were recovered in the effluent collected weekly from biogas systems for two months following seeding with infected stool. Less than 1% of ova were recovered viable from a series of nylon bags seeded with ova, a 2-log removal attributable to biochemical inactivation. More than 90% of Ascaris lumbricoides ova (used as a proxy for S. japonicum ova counted at the influent of two biogas systems were removed in the systems when adjusted for system residence time, an approximate 1-log removal attributable to sedimentation. Combined, these inactivation/removal processes underscore the promise of biogas infrastructure for reducing parasite contamination resulting from nightsoil use. When interviewed an average of 4 years after construction, villagers attributed large changes in fuel usage to the installation of biogas systems. Household coal usage decreased by 68%, wood by 74%, and crop waste

  3. Full scale validation of helminth ova (Ascaris suum) inactivation by different sludge treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Paulsrud, B.; Gjerde, B.; Lundar, A.

    2003-07-01

    The Norwegian sewage sludge regulation requires disinfection (hygienisation) of all sludges for land application, and one of the criteria is that disinfected sludge should not contain viable helminth ova. All disinfection processes have to be designed and operated in order to comply with this criteria, and four processes employed in Norway (thermophilic aerobic pre-treatment, pre-pasteurisation, thermal vacuum drying in membrane filter presses and lime treatment) have been tested in full scale by inserting semipermeable bags of Ascaris suum eggs into the processes for certain limes. For lime treatment supplementary laboratory tests have been conducted. The paper presents the results of the experiments, and it could be concluded that all processes, except lime treatment, could be operated at less stringent time-temperature regimes than commonly experienced at Norwegian plants today. (author)

  4. Assessing the fate of Ascaris suum ova during mesophilic anaerobic digestion.

    Science.gov (United States)

    Manser, Nathan D; Wald, Ileana; Ergas, Sarina J; Izurieta, Ricardo; Mihelcic, James R

    2015-03-03

    There is limited knowledge about the survival of geohelminths, which are soil-transmitted human pathogens, in mesophilic anaerobic digestion processes. This study examined the fate of embryonated and unembryonated Ascaris suum ova in six laboratory-scale mesophilic (35 °C) anaerobic digesters processing swine manure to identify their survival strategies and investigate potential mechanisms to enhance their destruction. There was no significant difference in inactivation of Ascaris suum ova in digesters operated at different solids residence times (SRT) or feeding frequencies. Ova exposed to an anaerobic environment became dormant, or remained unembryonated throughout their residence in the reactors. Approximately 65% of ova were able to retain their viability for up to 16 days, after which the rate of inactivation increased until nearly all ova were nonviable by day 24. In contrast, ova exposed to aerobic conditions did not become dormant and progressed through several developmental stages until day 16, after which nearly all ova were observed to be nonviable. In addition, only 35% of fully developed ova exposed to the anaerobic environment retained their viability by day 16 compared to 65% for dormant ova. Results suggest that some ova are physically destroyed during digestion and ova can be inactivated faster if their development cycle is aerobically triggered before entering the anaerobic digestion process. Results also suggest that transfer of resource recovery technologies such as mesophilic anaerobic digestion to developing world settings must account for local climatic and health conditions so mutually beneficial outcomes can be attained.

  5. TRP channels in schistosomes

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    Swarna Bais

    2016-12-01

    Full Text Available Praziquantel (PZQ is effectively the only drug currently available for treatment and control of schistosomiasis, a disease affecting hundreds of millions of people worldwide. Many anthelmintics, likely including PZQ, target ion channels, membrane protein complexes essential for normal functioning of the neuromusculature and other tissues. Despite this fact, only a few classes of parasitic helminth ion channels have been assessed for their pharmacological properties or for their roles in parasite physiology. One such overlooked group of ion channels is the transient receptor potential (TRP channel superfamily. TRP channels share a common core structure, but are widely diverse in their activation mechanisms and ion selectivity. They are critical to transducing sensory signals, responding to a wide range of external stimuli. They are also involved in other functions, such as regulating intracellular calcium and organellar ion homeostasis and trafficking. Here, we review current literature on parasitic helminth TRP channels, focusing on those in schistosomes. We discuss the likely roles of these channels in sensory and locomotor activity, including the possible significance of a class of TRP channels (TRPV that is absent in schistosomes. We also focus on evidence indicating that at least one schistosome TRP channel (SmTRPA has atypical, TRPV1-like pharmacological sensitivities that could potentially be exploited for future therapeutic targeting.

  6. 9 CFR 590.440 - Processing ova.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Processing ova. 590.440 Section 590... into Official Egg Products Plants § 590.440 Processing ova. (a) Ova from slaughtered poultry may be brought into the official plant for processing: Provided, That the ova is from wholesome poultry inspected...

  7. Schistosome feeding and regurgitation.

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    Patrick J Skelly

    2014-08-01

    Full Text Available Schistosomes are parasitic flatworms that infect >200 million people worldwide, causing the chronic, debilitating disease schistosomiasis. Unusual among parasitic helminths, the long-lived adult worms, continuously bathed in blood, take up nutrients directly across the body surface and also by ingestion of blood into the gut. Recent proteomic analyses of the body surface revealed the presence of hydrolytic enzymes, solute, and ion transporters, thus emphasising its metabolic credentials. Furthermore, definition of the molecular mechanisms for the uptake of selected metabolites (glucose, certain amino acids, and water establishes it as a vital site of nutrient acquisition. Nevertheless, the amount of blood ingested into the gut per day is considerable: for males ∼100 nl; for the more actively feeding females ∼900 nl, >4 times body volume. Ingested erythrocytes are lysed as they pass through the specialized esophagus, while leucocytes become tethered and disabled there. Proteomics and transcriptomics have revealed, in addition to gut proteases, an amino acid transporter in gut tissue and other hydrolases, ion, and lipid transporters in the lumen, implicating the gut as the site for acquisition of essential lipids and inorganic ions. The surface is the principal entry route for glucose, whereas the gut dominates amino acid acquisition, especially in females. Heme, a potentially toxic hemoglobin degradation product, accumulates in the gut and, since schistosomes lack an anus, must be expelled by the poorly understood process of regurgitation. Here we place the new observations on the proteome of body surface and gut, and the entry of different nutrient classes into schistosomes, into the context of older studies on worm composition and metabolism. We suggest that the balance between surface and gut in nutrition is determined by the constraints of solute diffusion imposed by differences in male and female worm morphology. Our conclusions have

  8. BIOCHEMICAL ASPECTS OF SCHISTOSOME BEHAVIOUR ...

    African Journals Online (AJOL)

    BIOCHEMICAL ASPECTS OF SCHISTOSOME BEHAVIOUR. P.J.FRIPP. Bilharzia. Research Unit, South African Institute for Medical Research, Johannesburg. ABSTRACT. The haematophagous blood trematodes that comprise the genus SchistolJlOmIl live in a stable environment with an adequate food supply and an ...

  9. Trans Ova Genetics, L.C.

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Trans Ova Genetics, L.C., a business located at 2938 380th Street Sioux Center, IA 51250, for alleged violations at the Trans Ova Genetics, L.C.’s facility located in 12425

  10. Schistosomal glomerular disease (a review

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    Zilton A. Andrade

    1984-12-01

    Full Text Available In this review paper schistosomal glomerulopathy is defined as an immune-complex disease. The disease appears in 12-15 per cent of the individuals with hepatosplenic schistosomiasis. Portal hypertension with collateral circulation helps the by pass of the hepatic clearance process and the parasite antigens can bind to antibodies in the circulation and be trapped in the renal glomerulus. Chronic membranousproliferative glomerulonephritis is the most commom lesion present and the nephrotic syndrome is the usual form of clinical presentation. The disease can be experimentally produced, and schistosomal antigens and antibodies, as well as complement, can be demonstrated in the glomerular lesions. Specific treatment of schistosomiasis does not seem to alter the clinical course of schistosomal nephropathy.A glomerulopatia esquistossomotica e um exemplo de doenca causada por complexos imunes. Ela se manifesta em 12 a 15% dos portadores de forma hepato-eplenica da esquistossomose. A hipertensao porta, com circulacao colateral, facilita a ultrapassagem do filtro hepatico e os antigenos esquistossomoticos podem se acoplar aos anticorpos na circulacao e vir a se depositar nos glomerulos. O tipo histologico mais frequente e a glomerulonefrite cronica membrano-proliferativa, geralmente com sindrome nefrotica. A doenca e passivel de reproducao experimental e os antigenos esquistossomoticos, os anticorpos e fracoes do complemento podem ser demonstrados nas lesoes glomerulares. O tratamento especifico da esquistossomose nao mostrou ate o momento a capacidade de alterar o curso da nefropatia.

  11. Acute Perforated Schistosomal Appendicitis: A Case Report ...

    African Journals Online (AJOL)

    Appendicitis is occasionally the first clinical manifestation of schistosomal infestation which may require treatment. A rare case of perforated schistosomal appendicitis in a 12 –year old Nigerian boy diagnosed on the basis of histological evaluation of the appendectomy specimen is reported to highlight the clinical ...

  12. Deciphering the glycogenome of schistosomes

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    Megan Lee Mickum

    2014-08-01

    Full Text Available Schistosoma mansoni and other Schistosoma sp. are multicellular parasitic helminths (worms that infect humans and mammals worldwide. Infection by these parasites, which results in developmental maturation and sexual differentiation over a period of five to six weeks, induces antibodies to glycan antigens expressed in surface and secreted glycoproteins and glycolipids. There is growing interest in defining these unusual parasite-synthesized glycan antigens and using them to understand immune responses, their roles in immunomodulation, and in using glycan antigens as potential vaccine targets. A key problem in this area, however, has been the lack of information about the enzymes involved in elaborating the complex repertoire of glycans represented by the schistosome glycome. Recent availability of the nuclear genome sequences for Schistosoma sp. has created the opportunity to define the glycogenome, which represents the specific genes and cognate enzymes that generate the glycome. Here we describe the current state of information in regard to the schistosome glycogenome and glycome and highlight the important classes of glycans and glycogenes that may be important in their generation.

  13. Indian Schistosomes: A Need for Further Investigations

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    M. C. Agrawal

    2011-01-01

    Full Text Available India is uniquely positioned with regard to schistosomes and schistosomiasis—discovering seven new mammalian species with the existence of three more schistosome species: Orientobilharzia turkestanicum, O. harinasutai, and Schistosoma haematobium(?. An endemic focus of urinary schistosomiasis was reported from Gimvi village of Ratnagiri, Maharashtra with infrequent occurrence of schistosome eggs in human stools. Cercarial dermatitis has been reported to be more abundant in rural population using ponds, tanks, and so forth, for their domestic purposes. Few dermatitis cases were tested positive by CHR. Schistosome antigen was also detected in urine of five cases suggesting existence of active schistosomiasis in India. Nevertheless, human kind does not appear to be the usual host for Indian schistosomes in contrast to S. haematobium, S. mansoni, or S. japonicum. Various reasons for this phenomenon are discussed including evolution of Indian schistosomes, immune mechanisms, and environmental conditions. These and other aspects such as seasonal effect on the prevalence, snail infectivity, heterologous mating, existence of hybrids, and number of schistosomes in heterologous infections need further investigations with application of molecular techniques. Joint efforts by the national as well as international scientific community would be much more rewarding for better understanding of the parasite and the infection.

  14. Fundamental cryobiology of mouse ova and embryos

    Energy Technology Data Exchange (ETDEWEB)

    Leibo, S. P.

    1977-01-01

    An increasing fraction of mouse ova and embryos are killed as the rate at which they are cooled to -196/sup 0/C is increased. The survival of these cells depends not only on cooling rate, but also on the minimum subzero temperature to which the cells are cooled. Low temperature microscopy demonstrates that lethal cooling rates are coincident with those that produce intracellular ice formation, and that the lethal temperature appears to be that at which intracellular ice forms. Furthermore, the microscopy shows that ova do not dehydrate when cooled at rates that produce intracellular ice and cell death, but undergo substantial shrinkage when cooled at rates that produce little intracellular ice and high survival. Measurements of the water permeability of mouse ova and the temperature coefficient of that permeability can be used to test a mathematical model formulated to describe the kinetics of water loss at subzero temperatures from a hypothetical cell. The observed dehydration of ova cooled to subzero temperatures at given rates is approximately predicted by the mathematical model, although there is some quantitative discrepancy between the observed and calculated responses.

  15. Purinergic signaling in schistosomal infection

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    Claudia Lucia Martins Silva

    2016-10-01

    Full Text Available Human schistosomiasis is a chronic inflammatory disease caused by blood fluke worms belonging to the genus Schistosoma. Health metrics indicate that the disease is related to an elevated number of years lost-to-disability and years lost-to-life. Schistosomiasis is an intravascular disease that is related to a Th1 and Th2 immune response polarization, and the degree of polarization affects the outcome of the disease. The purinergic system is composed of adenosine and nucleotides acting as key messenger molecules. Moreover, nucleotide-transforming enzymes and cell-surface purinergic receptors are obligatory partners of this purinergic signaling. In mammalian cells, purinergic signaling modulates innate immune responses and inflammation among other functions; conversely purinergic signaling may also be modulated by inflammatory mediators. Moreover, schistosomes also express some enzymes of the purinergic system, and it is possible that worms modulate host purinergic signaling. Current data obtained in murine models of schistosomiasis support the notion that the host purinergic system is altered by the disease. The dysfunction of adenosine receptors, metabotropic P2Y and ionotropic P2X7 receptors, and NTPDases likely contributes to disease morbidity. Keywords: Purinergic receptor, NTPDases, Schistosomiasis, Macrophages, Endothelial cell, Inflammation

  16. Prevalence of Helminths Ova in Faeces of Patients Attending State ...

    African Journals Online (AJOL)

    Prevalence of Helminths Ova in Faeces of Patients Attending State Specialist Hospital, Maiduguri, Borno State, Nigeria. ... 2(2.0%) young patients had hookworm and 1 (1.0%) taenid ova whereas 4(4.0%) adults had hookworm with no taenid ova. The helminths identified could be of great medical and economic importance.

  17. Schistosomes and snails: a molecular encounter

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    Matty eKnight

    2014-07-01

    Full Text Available Biomphalaria glabrata snails play an integral role in the transmission of Schistosoma mansoni, the causative agent for human schistosomiasis in the Western hemisphere. For the past two decades, tremendous advances have been made in research aimed at elucidating the molecular basis of the snail/parasite interaction. The growing concern that there is no vaccine to prevent schistosomiasis and only one effective drug in existence provides the impetus to develop new control strategies based on eliminating schistosomes at the snail-stage of the life cycle. To elucidate why a given snail is not always compatible to each and every schistosome it encounters, B. glabrata that are either resistant or susceptible to a given strain of S. mansoni have been employed to track molecular mechanisms governing the snail/schistosome relationship. With such snails, genetic markers for resistance and susceptibility were identified. Additionally, differential gene expression studies have led to the identification of genes that underlie these phenotypes. Lately, the role of schistosomes in mediating non-random relocation of gene loci has been identified for the first time, making B. glabrata a model organism where chromatin regulation by changes in nuclear architechture, known as spatial epigenetics, orchestrated by a major human parasite can now be investigated. This review will highlight the progress that has been made in using molecular approaches to describe snail/schistosome compatibility issues. Uncovering the signaling networks triggered by schistosomes that provide the impulse to turn genes on and off in the snail host, thereby controlling the outcome of infection, could also yield new insights into anti-parasite mechanism(s that operate in the human host as well.

  18. Polypyridylruthenium(II complexes exert anti-schistosome activity and inhibit parasite acetylcholinesterases.

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    Madhu K Sundaraneedi

    2017-12-01

    Full Text Available Schistosomiasis affects over 200 million people and there are concerns whether the current chemotherapeutic control strategy (periodic mass drug administration with praziquantel (PZQ-the only licenced anti-schistosome compound is sustainable, necessitating the development of new drugs.We investigated the anti-schistosome efficacy of polypyridylruthenium(II complexes and showed they were active against all intra-mammalian stages of S. mansoni. Two compounds, Rubb12-tri and Rubb7-tnl, which were among the most potent in their ability to kill schistosomula and adult worms and inhibit egg hatching in vitro, were assessed for their efficacy in a mouse model of schistosomiasis using 5 consecutive daily i.v. doses of 2 mg/kg (Rubb12-tri and 10 mg/kg (Rubb7-tnl. Mice treated with Rubb12-tri showed an average 42% reduction (P = 0.009, over two independent trials, in adult worm burden. Liver egg burdens were not significantly decreased in either drug-treated group but ova from both of these groups showed significant decreases in hatching ability (Rubb12-tri-68%, Rubb7-tnl-56% and were significantly morphologically altered (Rubb12-tri-62% abnormal, Rubb7-tnl-35% abnormal. We hypothesize that the drugs exerted their activity, at least partially, through inhibition of both neuronal and tegumental acetylcholinesterases (AChEs, as worms treated in vitro showed significant decreases in activity of these enzymes. Further, treated parasites exhibited a significantly decreased ability to uptake glucose, significantly depleted glycogen stores and withered tubercules (a site of glycogen storage, implying drug-mediated interference in this nutrient acquisition pathway.Our data provide compelling evidence that ruthenium complexes are effective against all intra-mammalian stages of schistosomes, including schistosomula (refractory to PZQ and eggs (agents of disease transmissibility. Further, the results of this study suggest that schistosome AChE is a target of

  19. Developmental expression and antigenicity of schistosome glycans

    NARCIS (Netherlands)

    Smit, C.H.

    2016-01-01

    Schistosomiasis is a tropical disease affecting over 230 million people worldwide. Although effective drug treatment is available, reinfections are common, and development of immunity is slow. Most antibodies raised during schistosome infection are directed against glycans, some of which are thought

  20. Schistosomal infestation: under investigation with attendant surgical ...

    African Journals Online (AJOL)

    Schistosomal infestation: under investigation with attendant surgical complications. Barnabas M Mandong, Abio JK Madaki. Abstract. No Abstract. Nigerian Medical Practitioner Vol. 48(5-6) 2005: 117-119. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  1. Evaluation of schistosome promoter expression for transgenesis and genetic analysis.

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    Shuang Liang

    Full Text Available Schistosome worms of the genus Schistosoma are the causative agents of schistosomiasis, a devastating parasitic disease affecting more than 240 million people worldwide. Schistosomes have complex life cycles, and have been challenging to manipulate genetically due to the dearth of molecular tools. Although the use of gene overexpression, gene knockouts or knockdowns are straight-forward genetic tools applied in many model systems, gene misexpression and genetic manipulation of schistosome genes in vivo has been exceptionally challenging, and plasmid based transfection inducing gene expression is limited. We recently reported the use of polyethyleneimine (PEI as a simple and effective method for schistosome transfection and gene expression. Here, we use PEI-mediated schistosome plasmid transgenesis to define and compare gene expression profiles from endogenous and nonendogenous promoters in the schistosomula stage of schistosomes that are potentially useful to misexpress (underexpress or overexpress gene product levels. In addition, we overexpress schistosome genes in vivo using a strong promoter and show plasmid-based misregulation of genes in schistosomes, producing a clear and distinct phenotype--death. These data focus on the schistosomula stage, but they foreshadow strong potential for genetic characterization of schistosome molecular pathways, and potential for use in overexpression screens and drug resistance studies in schistosomes using plasmid-based gene expression.

  2. Human Schistosome Infection and Allergic Sensitisation

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    Nadine Rujeni

    2012-01-01

    Full Text Available Several field studies have reported an inverse relationship between the prevalence of helminth infections and that of allergic sensitisation/atopy. Recent studies show that immune responses induced by helminth parasites are, to an extent, comparable to allergic sensitisation. However, helminth products induce regulatory responses capable of inhibiting not only antiparasite immune responses, but also allergic sensitisation. The relative effects of this immunomodulation on the development of protective schistosome-specific responses in humans has yet to be demonstrated at population level, and the clinical significance of immunomodulation of allergic disease is still controversial. Nonetheless, similarities in immune responses against helminths and allergens pose interesting mechanistic and evolutionary questions. This paper examines the epidemiology, biology and immunology of allergic sensitisation/atopy, and schistosome infection in human populations.

  3. IN VITRO CULTURE OF FROZEN AND THAWED MOUSE OVA

    OpenAIRE

    KANAGAWA, Hiroshi

    1980-01-01

    Seventy mouse ova at the 4--8-cell stages were collected at room temperature from mice treated with pregnant mare's serum gonadotrophin and human chorionic gonadotrophin. Seventy ova were divided into 5 groups, and each group was placed in a 0.5 ml plastic straw with 0.2 ml of Brinster's medium. Then, the straws were immersed into an ice bath (0℃) for 5 minutes. Next, an equal volume of 2 M dimethyl sulfoxide was added to the sample straw. The medium with ova was then seeded at -6℃ and cooled...

  4. Effects of ultraviolet light on Hymenolepis diminuta ova and cysticercoids

    Energy Technology Data Exchange (ETDEWEB)

    McGavock, W.D.; Howard, K.E.

    1980-07-01

    The ova and cysticercoids of Hymenolepis diminuta were exposed to a 2537 A wave length of ultraviolet light for various time periods. Development was extremely impaired in the cysts which had been irradiated for 30 and 60 minutes. When these were administered to the final host no tapeworms developed. From 113 intermediate host beetle larvae fed with irradiated ova, only three cysticercoids were recovered. Development was impaired in both cases and the infective rate of irradiated ova and cysts of the least exposed groups was lower than that of the controls.

  5. Sanitary survey of residential areas using Ascaris lumbricoides ova ...

    African Journals Online (AJOL)

    Administrator

    high in temperate and tropical environments. Objective: To assess the sanitary conditions of soil using the presence of Ascaris lumbricoides ova as an indicator. ... an environmental health indicator could contribute to the development of surveillance tools and health protection measures in this area. A large scale study on ...

  6. Interference with the host haemostatic system by schistosomes.

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    Mirjam M Mebius

    Full Text Available Schistosomes, parasitic flatworms that cause the tropical disease schistosomiasis, are still a threat. They are responsible for 200 million infections worldwide and an estimated 280,000 deaths annually in sub-Saharan Africa alone. The adult parasites reside as pairs in the mesenteric or perivesicular veins of their human host, where they can survive for up to 30 years. The parasite is a potential activator of blood coagulation according to Virchow's triad, because it is expected to alter blood flow and endothelial function, leading to hypercoagulability. In contrast, hepatosplenic schistosomiasis patients are in a hypocoagulable and hyperfibrinolytic state, indicating that schistosomes interfere with the haemostatic system of their host. In this review, the interactions of schistosomes with primary haemostasis, secondary haemostasis, fibrinolysis, and the vascular tone will be discussed to provide insight into the reduction in coagulation observed in schistosomiasis patients. Interference with the haemostatic system by pathogens is a common mechanism and has been described for other parasitic worms, bacteria, and fungi as a mechanism to support survival and spread or enhance virulence. Insight into the mechanisms used by schistosomes to interfere with the haemostatic system will provide important insight into the maintenance of the parasitic life cycle within the host. This knowledge may reveal new potential anti-schistosome drug and vaccine targets. In addition, some of the survival mechanisms employed by schistosomes might be used by other pathogens, and therefore, these mechanisms that interfere with host haemostasis might be a broad target for drug development against blood-dwelling pathogens. Also, schistosome antithrombotic or thrombolytic molecules could form potential new drugs in the treatment of haemostatic disorders.

  7. Receptor tyrosine kinases and schistosome reproduction: new targets for chemotherapy

    Directory of Open Access Journals (Sweden)

    Marion eMorel

    2014-07-01

    Full Text Available Schistosome parasites still represent a serious public health concern and a major economic problem in developing countries. Pathology of schistosomiasis is mainly due to massive egg production by these parasites and to inflammatory responses raised against the eggs which are trapped in host tissues. Tyrosine kinases (TKs are key molecules that control cell differentiation and proliferation and they already represent important targets in cancer therapy. During the recent years, it has been shown that receptor tyrosine kinases (RTK signaling was active in reproductive organs and that it could regulate sexual maturation of schistosomes and egg production. This opens interesting perspectives for the control of transmission and pathogenesis of schistosomiasis based on new therapies targeting schistosome RTKs. This review relates the numerous data showing the major roles of kinase signaling in schistosome reproduction. It describes the conserved and particular features of schistosome RTKs, their implication in gametogenesis and reproduction processes and summarizes recent works indicating that RTKs and their signaling partners are interesting chemotherapeutical targets in new programs of control.

  8. Immunomodulation of experimental autoimmune encephalomyelitis by helminth ova immunization.

    Science.gov (United States)

    Sewell, Diane; Qing, Zhu; Reinke, Emily; Elliot, David; Weinstock, Joel; Sandor, Matyas; Fabry, Zsuzsa

    2003-01-01

    Experimental autoimmune encephalomyelitis (EAE) is an animal model for multiple sclerosis (MS) characterized by chronic inflammatory demyelination of the central nervous system (CNS). The pathology of EAE involves autoimmune CD4(+) T(h)1 cells. There is a striking inverse correlation between the occurrence of parasitic and autoimmune diseases. We demonstrate that in mice with Schistosoma mansoni ova immunization, the severity of EAE is reduced as measured by decreased clinical scores and CNS cellular infiltrates. Disease suppression is associated with immune deviation in the periphery and the CNS, demonstrated by decreased IFN-gamma and increased IL-4, transforming growth factor-beta and IL-10 levels in the periphery, and increased frequency of IL-4 producing neuroantigen-specific T cells in the brain. S. mansoni helminth ova treatment influenced the course of EAE in wild-type mice, but not in STAT6-deficient animals. This indicates that STAT6 plays a critical role in regulating the ameliorating effect of S. mansoni ova treatment on the autoimmune response, and provides the direct link between helminth treatment, T(h)2 environment and improved EAE. As some intestinal helminthic infections induce minimal pathology, they might offer a safe and inexpensive therapy to prevent and/or ameliorate MS.

  9. Exposure to Chlorine Dioxide Gas for 4 Hours Renders Syphacia Ova Nonviable

    OpenAIRE

    Czarra, Jane A; Adams, Joleen K; Carter, Christopher L; Hill, William A; Coan, Patricia N

    2014-01-01

    The purpose of our study was to evaluate the efficacy of chlorine dioxide gas for environmental decontamination of Syphacia spp. ova. We collected Syphacia ova by perianal cellophane tape impression of pinworm-infected mice. Tapes with attached ova were exposed to chlorine dioxide gas for 1, 2, 3, or 4 h. After gas exposure, ova were incubated in hatching medium for 6 h to promote hatching. For controls, tapes with attached ova were maintained at room temperature for 1, 2, 3, and 4 h without ...

  10. schistosomal appendicitis in a sliding hernia (case report)

    African Journals Online (AJOL)

    uncommonly found in the appendix (2). We report a sliding right inguinal hernia that contained an appendix with histological evidence of intense Schistosoma haematobium ovideposition. The case is presented to highlight the importance of early anti- schistosomal treatment. CASE REPORT. J. A., a 47-year-old male farmer, ...

  11. Molecular diversity of avian schistosomes in Danish freshwater snails

    DEFF Research Database (Denmark)

    Christiansen, Anne Ø.; Olsen, Annette; Buchmann, Kurt

    2016-01-01

    to identify the parasites at species level. In order to do that, 499 pulmonate freshwater snails (Radix sp., Lymnaea stagnalis, Stagnicola sp. and Planorbarius corneus) were sampled from 12 lakes, ponds, and marshes in the greater Copenhagen area. Avian schistosome cercariae were identified by microscopy...

  12. schistosomal appendicitis in a sliding hernia (case report)

    African Journals Online (AJOL)

    We report a rare case of a forty-seven year old Nigeria male with schistosomal appendicitis in a sliding hernia. The clinical and pathological features of the case are discussed, followed by a review of the literature. It is concluded that a high index of suspicion is necessary to diagnose unusual presentations of ...

  13. Interference with the Host Haemostatic System by Schistosomes

    NARCIS (Netherlands)

    R.E. Mebius (Reina); P.J.J. van Genderen (Perry); J. Urbanus (Jos); A.G.M. Tielens (Aloysius); P.G. de Groot; J.J. van Hellemond (Jaap)

    2013-01-01

    textabstractSchistosomes, parasitic flatworms that cause the tropical disease schistosomiasis, are still a threat. They are responsible for 200 million infections worldwide and an estimated 280,000 deaths annually in sub-Saharan Africa alone. The adult parasites reside as pairs in the mesenteric or

  14. Andrographolide ameliorates OVA-induced lung injury in mice by suppressing ROS-mediated NF-κB signaling and NLRP3 inflammasome activation.

    Science.gov (United States)

    Peng, Shuang; Gao, Jian; Liu, Wen; Jiang, Chunhong; Yang, Xiaoling; Sun, Yang; Guo, Wenjie; Xu, Qiang

    2016-12-06

    In this study, we attempted to explore the effect and possible mechanism of Andrographolide on OVA-induced asthma. OVA challenge induced significant airway inflammatory cell recruitment and lung histological alterations, which were ameliorated by Andrographolide. The protein levels of cytokines in bron-choalveolar fluid (BALF) and serum were reduced by Andrographolide administration as well as the mRNA levels in lung tissue. Mechanically, Andrographolide markedly hampered the activation of nuclear factor-κB (NF-κB) and NLRP3 inflammasome both in vivo and vitro thus decreased levels of TNF-α and IL-1β. Finally, we confirmed that ROS scavenging was responsible for Andrographolide's inactivation of NF-κB and NLRP3 inflammasome signaling. Our study here revealed the effect and possible mechanism of Andrographolide on asthma, which may represent a new therapeutic approach for treating this disease.

  15. OVA-specific CD8(+)T cells do not express granzyme B during anterior chamber associated immune deviation

    NARCIS (Netherlands)

    Ren, Y.; Yang, P.; Li, B.; Gao, Y.; Zhou, H.; Huang, X.; Zhu, L.; Kijlstra, A.

    2006-01-01

    To examine antigen (Ag)-specific CTL response during anterior chamber associated immune deviation (ACAID). Methods OVA or OVA257-264 peptide was injected into the anterior chamber (AC) of C57BL/6 mice. There were 16 mice in each ACAID group induced with OVA or OVA257-264 peptide. The mice were

  16. Exposure to chlorine dioxide gas for 4 hours renders Syphacia ova nonviable.

    Science.gov (United States)

    Czarra, Jane A; Adams, Joleen K; Carter, Christopher L; Hill, William A; Coan, Patricia N

    2014-07-01

    The purpose of our study was to evaluate the efficacy of chlorine dioxide gas for environmental decontamination of Syphacia spp. ova. We collected Syphacia ova by perianal cellophane tape impression of pinworm-infected mice. Tapes with attached ova were exposed to chlorine dioxide gas for 1, 2, 3, or 4 h. After gas exposure, ova were incubated in hatching medium for 6 h to promote hatching. For controls, tapes with attached ova were maintained at room temperature for 1, 2, 3, and 4 h without exposure to chlorine dioxide gas and similarly incubated in hatch medium for 6 h. Ova viability after incubation was assessed by microscopic examination. Exposure to chlorine dioxide gas for 4 h rendered 100% of Syphacia spp. ova nonviable. Conversely, only 17% of ova on the 4-h control slide were nonviable. Other times of exposure to chlorine dioxide gas resulted in variable effectiveness. These data suggest that exposure to chlorine dioxide gas for at least 4 h is effective for surface decontamination of Syphacia spp. ova.

  17. Transplacental transfer of schistosomal circulating anodic antigens in cows

    OpenAIRE

    Gabriël, Sarah; De Bont, J; Phiri, IK; Masuku, M; Riveau, G; Schacht, AM; DEELDER, AM; Van Dam, GJ; Vercruysse, Jozef

    2002-01-01

    The present work investigated the transplacental passage of circulating anodic schistosome antigens (CAA) and the production of foetal antibodies in response to antigenic stimulation in Schistosoma mattheei infected cows. Three groups were available: six calves born to non-infected cows received colostrum from a pool from non-infected cows (group 1), six calves born to non-infected cows (group 2) and six calves born to infected cows (group 3) received colostrum from a pool from infected cows....

  18. Molecular Detection of Schistosome Infections with a Disposable Microfluidic Cassette.

    Directory of Open Access Journals (Sweden)

    Jinzhao Song

    2015-12-01

    Full Text Available Parasitic helminths such as schistosomes, as well as filarial and soil-transmitted nematodes, are estimated to infect at least a billion people worldwide, with devastating impacts on human health and economic development. Diagnosis and monitoring of infection dynamics and efficacy of treatment depend almost entirely on methods that are inaccurate, labor-intensive, and unreliable. These shortcomings are amplified and take on added significance in mass drug administration programs, where measures of effectiveness depend on accurate monitoring of treatment success (or failure, changes in disease transmission rates, and emergence of possible drug resistance. Here, we adapt isothermal molecular assays such as loop-mediated isothermal amplification (LAMP to a simple, hand-held, custom-made field-ready microfluidic device that allows sensitive and specific detection of schistosome cell-free nucleic acids in serum and plasma (separated with a point-of-care plasma separator from Schistosoma mansoni-infected mice. Cell-free S. mansoni DNA was detected with our device without prior extraction from blood. Our chip exhibits high sensitivity (~2 x 10(-17 g/μL, with a positive signal for S. mansoni DNA detectable as early as one week post infection, several weeks before parasite egg production commences. These results indicate that incorporation of isothermal amplification strategies with our chips could represent a strategy for rapid, simple, low-cost diagnosis of both pre-patent and chronic schistosome infections as well as potential monitoring of treatment efficacy.

  19. Molecular diversity of avian schistosomes in Danish freshwater snails.

    Science.gov (United States)

    Christiansen, Anne Ø; Olsen, Annette; Buchmann, Kurt; Kania, Per W; Nejsum, Peter; Vennervald, Birgitte J

    2016-03-01

    Avian schistosomes are widespread parasites of snails and waterfowl and may cause cercarial dermatitis (swimmer's itch) in humans, a disease that is frequently reported in European countries. These parasites are known to occur in Denmark, but here, we applied a new approach using molecular tools to identify the parasites at species level. In order to do that, 499 pulmonate freshwater snails (Radix sp., Lymnaea stagnalis, Stagnicola sp. and Planorbarius corneus) were sampled from 12 lakes, ponds, and marshes in the greater Copenhagen area. Avian schistosome cercariae were identified by microscopy and subjected to molecular investigation by sequencing and phylogenetic analysis of the 5.8S and ITS2 ribosomal DNA for species identification. Additionally, snail hosts belonging to the genus Radix were identified by sequencing and phylogenetic analysis of partial ITS2 ribosomal DNA. Three out of 499 snails shed different species of Trichobilharzia cercariae: Trichobilharzia szidati was isolated from L. stagnalis, Trichobilharzia franki from Radix auricularia and Trichobilharzia regenti from Radix peregra. In the light of the public health risk represented by bird schistosomes, these findings are of concern and, particularly, the presence of the potentially neuro-pathogenic species, T. regenti, in Danish freshwaters calls for attention.

  20. Trans Ova Genetics, L.C. - Clean Water Act Public Notice

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Trans Ova Genetics, L.C., a business located at 2938 380th Street Sioux Center, IA 51250, for alleged violations at the Trans Ova Genetics, L.C.’s facility located in 12425

  1. Immunologic activity of schistosomal and bacterial TLR2 ligands in Gabonese children

    NARCIS (Netherlands)

    Retra, K.; Riet, E. van; Adegnika, A.A.; Everts, B.; Geest, S. van; Kremsner, P.G.; Hellemond, J.J. van; Kleij, D. van der; Tielens, A.G.M.; Yazdanbakhsh, M.

    2008-01-01

    Schistosomes carry lipid moieties that interact with the immune system. To understand the consequence of interactions in terms of polarizing the cytokine profiles, the effect of two Toll-like receptor-2 (TLR2) activating schistosomal lipid fractions was studied on whole blood from Gabonese children

  2. Sleep-related breathing disorders in patients with schistosomal cor-pulmonale

    Directory of Open Access Journals (Sweden)

    Yehia Khalil

    2012-07-01

    Conclusion: SRBD are highly prevalent in patients with schistosomal pulmonary hypertension (PH. Also, the SA severity was correlated with more advanced PH and more severe cardiovascular impairment. Therefore in the evaluation of patients with schistosomal PH, polysomnography or an ambulatory cardiorespiratory sleep study seems justified to identify potentially treatable SRBD that may additionally challenge the already compromised cardiovascular system in these patients.

  3. Schistosome serine protease inhibitors: parasite defense or homeostasis?

    Directory of Open Access Journals (Sweden)

    Landys A. Lopez Quezada

    2011-06-01

    Full Text Available Serpins are a structurally conserved family of macromolecular inhibitors found in numerous biological systems. The completion and annotation of the genomes of Schistosoma mansoni and Schistosoma japonicum has enabled the identification by phylogenetic analysis of two major serpin clades. S. mansoni shows a greater multiplicity of serpin genes, perhaps reflecting adaptation to infection of a human host. Putative targets of schistosome serpins can be predicted from the sequence of the reactive center loop (RCL. Schistosome serpins may play important roles in both post-translational regulation of schistosome-derived proteases, as well as parasite defense mechanisms against the action of host proteases.Serpinas são uma família de inibidores macromoleculares estruturalmente conservados encontrados em inúmeros sistemas biológicos. O término e a anotação dos genomas de Schistosoma mansoni e de Schistosoma japonicum permitiram a identificação por análise filogenética de dois principais clados de serpinas. S. mansoni mostra uma multiplicidade maior de genes de serpinas, talvez refletindo uma adaptação à infecção de um hospedeiro humano. Alvos putativos das serpinas de esquistossomos podem ser preditos a partir da sequência do "loop" do centro reativo. Serpinas de esquistossomos podem ter importantes papeis tanto na regulação pós-traducional de proteases derivadas do esquistossoma, quanto nos mecanismos de defesa contra a ação de proteases do hospedeiro.

  4. Schistosome infections induce significant changes in the host biliary proteome.

    Science.gov (United States)

    de la Torre-Escudero, Eduardo; Pérez-Sánchez, Ricardo; Manzano-Román, Raúl; Oleaga, Ana

    2015-01-30

    Schistosomiasis is a disease caused by blood trematodes affecting man and animals that represents an important human health and veterinary problem. Main damages caused by this infection are a consequence of the host inflammatory reaction against the parasite eggs trapped inside the liver. Despite that the hepatic pathology of schistosomiasis is very well known, there are no specific studies dealing with the schistosome infection effects on the biliary function. The purpose of this work was to analyse the changes induced by Schistosoma bovis infection in the biliary proteome. For this, whole gallbladders from S. bovis-infected and non-infected mice were dissected, homogenized and fractionated by differential centrifugation. The resulting protein fractions were resolved by SDS-PAGE, the gels were sliced, and the gel pieces analysed by LC-MS/MS. Altogether, we identified 1937 proteins, which were classified according to their "protein class" and "molecular function", and then subjected to an "Enrichment analysis". The differences found in gallbladder proteomes between S. bovis-infected and non-infected mice are analysed. We show that chronic schistosome infections cause significant changes in the biliary proteome that may produce physiological alterations and affect the therapeutic actions of drugs when administered to human patients and animals with schistosomiasis. To identify the changes induced by the schistosome infection in bile protein composition, and therefore in bile function, we compared the proteome of the gallbladders collected from non-infected healthy mice and from mice infected with S. bovis during 4months. For this, gallbladders from both groups of mice were homogenized and these homogenates were fractionated by serial centrifugation and acrylamide gel electrophoresis. The proteins were in gel digested and analysed by LC-MS/MS for identification. The present work reports the first data on the proteome of the mouse gallbladder and provides a

  5. Effects of Angelicin on Ovalbumin (OVA)-Induced Airway Inflammation in a Mouse Model of Asthma.

    Science.gov (United States)

    Wei, Da-Zhen; Guo, Xian-Yang; Lin, Li-Na; Lin, Meng-Xiang; Gong, Yu-Qiang; Ying, Bin-Yu; Huang, Ming-Yuan

    2016-12-01

    Angelicin, a furocoumarin found in Psoralea corylifolia L. fruit, has been reported to have anti-inflammatory activity. The purpose of this study was to determine the protective effects of angelicin on allergic asthma induced by ovalbumin (OVA) in mice. Mice were sensitized to OVA (on days 0 and 14) and challenged with OVA three times (on days 21 to 23). Angelicin (2.5, 5, 10 mg/kg) was given intraperitoneally 1 h before OVA treatment after the initial OVA sensitization. The production of IL-4, IL-5, and IL-13 in BALF and IgE in the serum were measured by ELISA. Lung histological changes were detected by using hematoxylin and eosin (H&E) stain. The results showed that angelicin significantly inhibited inflammatory cells infiltration into the lungs. Histological studies showed that angelicin significantly attenuated OVA-induced lung injury. Meanwhile, treatment of angelicin dose-dependently inhibited OVA-induced the production of IL-4, IL-5, and IL-13 in BALF and IgE in the serum. Furthermore, angelicin was found to inhibit airway hyperresponsiveness and NF-kB activation. In conclusion, our results suggested that angelicin inhibited allergic airway inflammation and hyperresponsiveness by inhibiting NF-kB activation.

  6. Evaluating the efficacy of a centrifugation-flotation method for extracting Ascaris ova from soil

    DEFF Research Database (Denmark)

    Cranston, Imogen; Teoh, Penelope J.; baker, Sarah M.

    2016-01-01

    Background: Soil transmitted helminths (STH) continue to be associated with high burdens of disease, with an estimated 1.45 billion people infected with STH globally. The promotion and construction of latrines is considered the first barrier to prevent transmission of STH. The absence of a reliable...... method to extract STH ova from soil makes it challenging to examine whether the use of latrines may or may not have an effect on environmental contamination with ova. The present study evaluated the recovery rate of a method developed to extract STH ova from soil. Methods: The adapted centrifugation...

  7. Chronic Schistosome Infection Leads to Modulation of Granuloma Formation and Systemic Immune Suppression

    Directory of Open Access Journals (Sweden)

    Steven K. Lundy

    2013-02-01

    Full Text Available Schistosome worms have been infecting humans for millennia, but it is only in the last half century that we have begun to understand the complexities of this inter-relationship. As our sophistication about the inner workings of every aspect of the immune system has increased, it has also become obvious that schistosome infections have broad ranging effects on nearly all of the innate and adaptive immune response mechanisms. Selective pressures on both the worms and their hosts, has no doubt led to co-evolution of protective mechanisms, particularly those that favor granuloma formation around schistosome eggs and immune suppression during chronic infection. The immune modulatory effects that chronic schistosome infection and egg deposition elicit have been intensely studied, not only because of their major implications to public health issues, but also due to the emerging evidence that schistosome infection may protect humans from severe allergies and autoimmunity. Mouse models of schistosome infection have been extremely valuable for studying immune modulation and regulation, and in the discovery of novel aspects of immunity. A progression of immune reactions occurs during granuloma formation ranging from innate inflammation, to activation of each branch of adaptive immune response, and culminating in systemic immune suppression and granuloma fibrosis. Although molecular factors from schistosome eggs have been identified as mediators of immune modulation and suppressive functions of T and B cells, much work is still needed to define the mechanisms of the immune alteration and determine whether therapies for asthma or autoimmunity could be developed from these pathways.

  8. Comparison of concentration methods for rapid detection of hookworm ova in wastewater matrices using quantitative PCR.

    Science.gov (United States)

    Gyawali, P; Ahmed, W; Jagals, P; Sidhu, J P S; Toze, S

    2015-12-01

    Hookworm infection contributes around 700 million infections worldwide especially in developing nations due to increased use of wastewater for crop production. The effective recovery of hookworm ova from wastewater matrices is difficult due to their low concentrations and heterogeneous distribution. In this study, we compared the recovery rates of (i) four rapid hookworm ova concentration methods from municipal wastewater, and (ii) two concentration methods from sludge samples. Ancylostoma caninum ova were used as surrogate for human hookworm (Ancylostoma duodenale and Necator americanus). Known concentration of A. caninum hookworm ova were seeded into wastewater (treated and raw) and sludge samples collected from two wastewater treatment plants (WWTPs) in Brisbane and Perth, Australia. The A. caninum ova were concentrated from treated and raw wastewater samples using centrifugation (Method A), hollow fiber ultrafiltration (HFUF) (Method B), filtration (Method C) and flotation (Method D) methods. For sludge samples, flotation (Method E) and direct DNA extraction (Method F) methods were used. Among the four methods tested, filtration (Method C) method was able to recover higher concentrations of A. caninum ova consistently from treated wastewater (39-50%) and raw wastewater (7.1-12%) samples collected from both WWTPs. The remaining methods (Methods A, B and D) yielded variable recovery rate ranging from 0.2 to 40% for treated and raw wastewater samples. The recovery rates for sludge samples were poor (0.02-4.7), although, Method F (direct DNA extraction) provided 1-2 orders of magnitude higher recovery rate than Method E (flotation). Based on our results it can be concluded that the recovery rates of hookworm ova from wastewater matrices, especially sludge samples, can be poor and highly variable. Therefore, choice of concentration method is vital for the sensitive detection of hookworm ova in wastewater matrices. Crown Copyright © 2015. Published by Elsevier

  9. Heat-induced structural changes affect OVA-antigen processing and reduce allergic response in mouse model of food allergy.

    Directory of Open Access Journals (Sweden)

    Jaroslav Golias

    Full Text Available BACKGROUND AND AIMS: The egg protein ovalbumin (OVA belongs to six most frequent food allergens. We investigated how thermal processing influences its ability to induce allergic symptoms and immune responses in mouse model of food allergy. METHODOLOGY/PRINCIPAL FINDINGS: Effect of increased temperature (70°C and 95°C on OVA secondary structure was characterized by circular dichroism and by the kinetics of pepsin digestion with subsequent HPLC. BALB/c mice were sensitized intraperitoneally and challenged with repeated gavages of OVA or OVA heated to 70°C (h-OVA. Levels of allergen-specific serum antibodies were determined by ELISA (IgA and IgGs or by β-hexosaminidase release test (IgE. Specific activities of digestive enzymes were determined in brush border membrane vesicles of jejunal enterocytes. Cytokine production and changes in regulatory T cells in mesenteric lymph nodes and spleen were assessed by ELISA and FACS. Heating of OVA to 70°C caused mild irreversible changes in secondary structure compared to boiling to 95°C (b-OVA, but both OVA treatments led to markedly different digestion kinetics and Tregs induction ability in vitro, compared to native OVA. Heating of OVA significantly decreased clinical symptoms (allergic diarrhea and immune allergic response on the level of IgE, IL-4, IL-5, IL-13. Furthermore, h-OVA induced lower activities of serum mast cell protease-1 and enterocyte brush border membrane alkaline phosphatase as compared to native OVA. On the other hand h-OVA stimulated higher IgG2a in sera and IFN-γ secretion by splenocytes. CONCLUSIONS: Minor irreversible changes in OVA secondary structure caused by thermal processing changes both its digestion and antigenic epitopes formation, which leads to activation of different T cell subpopulations, induces shift towards Th1 response and ultimately reduces its allergenicity.

  10. Hyperplasia of elastic tissue in hepatic schistosomal fibrosis

    Directory of Open Access Journals (Sweden)

    Zilton A. Andrade

    1991-12-01

    Full Text Available Elastic tissue hyperplasia, revealed by means of histological, immunocytochemical and ultrastructural methods, appeared as a prominent change in surgical liver biopsies taken from 61 patients with schistosomal periportal and septal fibrosis. Such hyperplasia was absent in ecperimental murine schistosomiasis, including mice with "pipe-stem" fibrosis. Displaced connective tissue cells in periportal areas, such as smooth muscle cells, more frequently observed in human material, could be the site of excessive elastin synthesis, and could explain the differences observed in human and experimental materials. Elastic tissue, sometimes represented by its microfibrillar components, also appeared to be more condensed in areas of matrix (collagen degradation, suggesting a participation of this tissue in the remodelling of the extracellular matrix. By its rectratile properties elastic tissue hyperplasia in hepatic schistosomiasis can cause vascular narrowing and thus play a role in the pathogenesis of portal hypeertension.

  11. Bidirectional introgressive hybridization between a cattle and human schistosome species.

    Directory of Open Access Journals (Sweden)

    Tine Huyse

    2009-09-01

    Full Text Available Schistosomiasis is a disease of great medical and veterinary importance in tropical and subtropical regions, caused by parasitic flatworms of the genus Schistosoma (subclass Digenea. Following major water development schemes in the 1980s, schistosomiasis has become an important parasitic disease of children living in the Senegal River Basin (SRB. During molecular parasitological surveys, nuclear and mitochondrial markers revealed unexpected natural interactions between a bovine and human Schistosoma species: S. bovis and S. haematobium, respectively. Hybrid schistosomes recovered from the urine and faeces of children and the intermediate snail hosts of both parental species, Bulinus truncatus and B. globosus, presented a nuclear ITS rRNA sequence identical to S. haematobium, while the partial mitochondrial cox1 sequence was identified as S. bovis. Molecular data suggest that the hybrids are not 1st generation and are a result of parental and/or hybrid backcrosses, indicating a stable hybrid zone. Larval stages with the reverse genetic profile were also found and are suggested to be F1 progeny. The data provide indisputable evidence for the occurrence of bidirectional introgressive hybridization between a bovine and a human Schistosoma species. Hybrid species have been found infecting B. truncatus, a snail species that is now very abundant throughout the SRB. The recent increase in urinary schistosomiasis in the villages along the SRB could therefore be a direct effect of the increased transmission through B. truncatus. Hybridization between schistosomes under laboratory conditions has been shown to result in heterosis (higher fecundity, faster maturation time, wider intermediate host spectrum, having important implications on disease prevalence, pathology and treatment. If this new hybrid exhibits the same hybrid vigour, it could develop into an emerging pathogen, necessitating further control strategies in zones where both parental species

  12. Bidirectional introgressive hybridization between a cattle and human schistosome species.

    Science.gov (United States)

    Huyse, Tine; Webster, Bonnie L; Geldof, Sarah; Stothard, J Russell; Diaw, Oumar T; Polman, Katja; Rollinson, David

    2009-09-01

    Schistosomiasis is a disease of great medical and veterinary importance in tropical and subtropical regions, caused by parasitic flatworms of the genus Schistosoma (subclass Digenea). Following major water development schemes in the 1980s, schistosomiasis has become an important parasitic disease of children living in the Senegal River Basin (SRB). During molecular parasitological surveys, nuclear and mitochondrial markers revealed unexpected natural interactions between a bovine and human Schistosoma species: S. bovis and S. haematobium, respectively. Hybrid schistosomes recovered from the urine and faeces of children and the intermediate snail hosts of both parental species, Bulinus truncatus and B. globosus, presented a nuclear ITS rRNA sequence identical to S. haematobium, while the partial mitochondrial cox1 sequence was identified as S. bovis. Molecular data suggest that the hybrids are not 1st generation and are a result of parental and/or hybrid backcrosses, indicating a stable hybrid zone. Larval stages with the reverse genetic profile were also found and are suggested to be F1 progeny. The data provide indisputable evidence for the occurrence of bidirectional introgressive hybridization between a bovine and a human Schistosoma species. Hybrid species have been found infecting B. truncatus, a snail species that is now very abundant throughout the SRB. The recent increase in urinary schistosomiasis in the villages along the SRB could therefore be a direct effect of the increased transmission through B. truncatus. Hybridization between schistosomes under laboratory conditions has been shown to result in heterosis (higher fecundity, faster maturation time, wider intermediate host spectrum), having important implications on disease prevalence, pathology and treatment. If this new hybrid exhibits the same hybrid vigour, it could develop into an emerging pathogen, necessitating further control strategies in zones where both parental species overlap.

  13. Class B Alkaline Stabilization to Achieve Pathogen Inactivation

    Directory of Open Access Journals (Sweden)

    Giovanni Widmer

    2007-03-01

    Full Text Available Liming is a cost-effective treatment currently employed in many Class B biosolids production plants in the United States. A bench scale model of lime stabilization was designed to evaluate the persistence of viral, bacterial and parasitic pathogens. The survival of fecal coliforms, Salmonella, adenovirus type 5, rotavirus Wa, bacteriophage MS-2, Cryptosporidium parvum oocysts, Giardia lamblia cysts, and Ascaris lumbricoides ova was evaluated under lime stabilization conditions in a water matrix. Fecal coliforms and Salmonella were undetectable following 2 hours of lime stabilization, demonstrating a 7-log reduction. Adenovirus, MS-2 and rotavirus were below detectable levels following 2 h of liming, demonstrating a 4-log reduction. G. lamblia cysts were also inactivated. A. lumbricoides ova remained viable following 72 hours of liming as did C. parvum oocysts. While this study confirmed that Ascaris ova are resistant to liming, their scarcity in sludge and low recovery efficiencies limit their use as indicator. The persistence of C. parvum oocysts after exposure to lime, suggests that this parasite would be a better choice as indicator for evaluating biosolids intended for land application. The studies done with adenovirus Type 5, rotavirus Wa and male specific bacteriophage provided preliminary data demonstrating similar inactivation rates. Monitoring anthropogenic viruses is a time consuming, labor intensive and expensive process. If further studies could demonstrate that phage could be used as an indicator of other enteric viruses, enhanced monitoring could result in greater acceptance of land application of biosolids while demonstrating no increased public health threat.

  14. Thymol attenuates allergic airway inflammation in ovalbumin (OVA)-induced mouse asthma.

    Science.gov (United States)

    Zhou, Ershun; Fu, Yunhe; Wei, Zhengkai; Yu, Yuqiang; Zhang, Xichen; Yang, Zhengtao

    2014-07-01

    Thymol, a naturally occurring monocyclic phenolic compound derived from Thymus vulgaris (Lamiaceae), has been reported to exhibit anti-inflammatory property in vivo and vitro. However, the mechanism of thymol is not clear. The aim of the present study was to investigate the effects of thymol on allergic inflammation in OVA-induced mice asthma and explore its mechanism. The model of mouse asthma was established by the induction of OVA. Thymol was orally administered at a dose of 4, 8, and 16 mg/kg body weight 1h before OVA challenge. At 24h after the last challenge, mice were sacrificed, and the data were collected by various experimental methods. The results revealed that pretreatment with thymol reduced the level of OVA-specific IgE, inhibited recruitment of inflammatory cells into airway, and decreased the levels of IL-4, IL-5, and IL-13 in BALF. Moreover, the pathologic changes of lung tissues were obviously ameliorated and goblet cell hyperplasia was effectively inhibited by the pretreatment of thymol. In addition, thymol reduced the development of airway hyperresponsiveness and blocked the activation of NF-κB pathway. All data suggested that thymol ameliorated airway inflammation in OVA-induced mouse asthma, possibly through inhibiting NF-κB activation. These findings indicated that thymol may be used as an alternative agent for treating allergic asthma. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Introgressive hybridization of Schistosoma haematobium group species in Senegal: species barrier break down between ruminant and human schistosomes

    National Research Council Canada - National Science Library

    Webster, Bonnie L; Diaw, Oumar T; Seye, Mohmoudane M; Webster, Joanne P; Rollinson, David

    2013-01-01

    .... Schistosomes undergo a sexual reproductive stage within their mammalian host enabling interactions between different species, which may result in hybridization if the species involved are phylogenetically close...

  16. The susceptibility of adult schistosomes to immune attrition

    Directory of Open Access Journals (Sweden)

    A. M. Agnew

    1992-01-01

    Full Text Available Mouse infection models are described that demonstrate reduction of egg production in Schistosoma haematobium infections and both worm loss and reduced fecundity in S. bovis infections. Neither phenomenum could be shown in S. mansoni infected mice. The immunological basis for these anti-adult responses was inferred by comparison with infections in T-cell deprived mice and by the serum transfer of the ability to reduce a S. bovis worm burden into immunocompromised hosts. Vaccination with irradiation attenuated parasites was also shown to have consequences for the adults of a challenge infections of S. haematobium and S. bovis specifically. Prior vaccination resulted in an abrogation of the anti-fecundity and adult worm elimination that occurred in non-vaccinated similary infected mice. hese models are being used to define the targets and mechanisms involved in anti-adult attrition. A serological assay, quantitation of a circulating antigen (CAA has been assessed for its ability to measure worm burdens of different species of schistosome in mice. This assay will be used to question whether anti-adult immunity contributes to the pattern of infection with S. mansoni and S. haematobium in man.

  17. IMPROVEMENT OF SCHISTOSOMAL PORTAL HYPERTENSIVE COLOPATHY AFTER SURGICAL TREATMENT

    Directory of Open Access Journals (Sweden)

    Maria Angelina Carvalho MIRANDA

    2013-04-01

    Full Text Available Context Data on vascular alterations in patients with hepatosplenic schistosomiasis and portal hypertensive colopathy and changes in these after surgery to decrease portal hypertension are limited. Objective The purpose of this study was to analyse the alterations of portal hypertensive colopathy previously and 6-12 months after splenectomy and gastric devascularization. Methods Twelve patients with hepatosplenic schistosomiasis who also had upper gastrointestinal bleeding were studied prospectively. Their endoscopic findings before and 6-12 months after the surgery were analysed. In addition, mucosal biopsies from ascending colon, sigmoid colon and rectum at these time points were subjected to histological and histomorphometric assessment. It was used a control group due to lack of normal pattern of the histomorphometric measures of vessels in individuals without portal hypertension. The critical level of significance adopted in all tests was of a maximum probability error of 5%. Results Surgery did not lead to significant improvement in histological and endoscopic findings. However, on histomorphometry, there was a significant decrease in the area, diameter and thickness of the vessels in mucosa at all colonic sites. Conclusion Surgery for decompression of schistosomal portal hypertension has a beneficial effect on the associated colopathy, being best indicated in patients with gastrointestinal bleeding and esophageal varices.

  18. Some further observations on schistosome transmission in the Eastern Transvaal*

    Science.gov (United States)

    Pitchford, R. J.; Visser, P. S.

    1965-01-01

    By immersing groups of rodents into several types of natural waters at Malelane, Eastern Transvaal, and subsequently recovering schistosomes from them, the authors have shown that there is seasonal transmission, which is more marked with Schistosoma mansoni than with S. mattheei. Laboratory confirmation of this periodicity was obtained by infecting groups of snails with the appropriate parasite and studying the pattern of sporocyst development and cercarial shedding under outdoor conditions. It was also found that, apart from seasonal periodicity, the amount of transmission is dependent on the density of human population, the proximity of the definitive host to the immersion site, the degree to which the water is protected from pollution and the distance downstream from the polluting source. Negligible numbers of S. haematobium adults were recovered; possible reasons for this are discussed. The authors consider that an annual transmission cycle may be more common in bilharziasis than is generally supposed—although not exclusively or necessarily for the reasons given in this paper—and suggest that such a cycle be taken into consideration in the planning of control schemes. PMID:14292065

  19. Phylogenetic Placement of a Schistosome from an Unusual Marine Snail Host, the False Limpet (Siphonaria lessoni) and Gulls (Larus dominicanus) from Argentina with a Brief Review of Marine Schistosomes from Snails.

    Science.gov (United States)

    Brant, Sara V; Loker, Eric S; Casalins, Laura; Flores, Veronica

    2017-02-01

    In the blood fluke family Schistosomatidae, marine snails are well known as intermediate hosts. Eight families of marine snails have thus far been reported to host schistosomes across the world, most of which have been implicated in human cercarial dermatitis (HCD) outbreaks. As part of our larger effort to define the species diversity and biology of schistosomes in Argentina, in particular their role in causing HCD, we searched in the marine pulmonate snail (Siphonaria lessoni) for a schistosome species described previously from S. lessoni from southern Argentina. Additionally, gulls (Larus dominicanus) collected from a different project locality (inland) were examined, because they are known to spend time in the intertidal regions. Schistosome sporocysts were found in S. lessoni, and a small worm fragment was retrieved from a gull. Molecular phylogenies for 28S, ITS1-5.8S-ITS2, and cox1 genes revealed that the specimens from the gull and S. lessoni grouped closely together, suggesting they are conspecifics. Also, ITS1-5.8S-ITS2 sequences suggested one of the schistosomes from S. lessoni and a schistosome from a South African penguin were also conspecifics. Further study is needed to verify if these specimens comprise a distinct marine clade within the larger avian schistosome clade that is comprised mostly of species using freshwater snail hosts. Thus far, it appears this group of marine schistosomes may be more likely found in the southern hemisphere. It is unclear if the observed distribution pattern of schistosomes in Siphonaria is a result of sampling bias and/or indicative of a specific bird-snail-schistosome association. It is clear they are sharply differentiated from the basal marine clade of avian schistosomes that includes Austrobilharzia.

  20. Ova collection in Japan: making visible women’s experience in male spaces

    NARCIS (Netherlands)

    Kato, M.; Sleeboom-Faulkner, M.

    2013-01-01

    The role of women is essential in embryo creation and donation, as they undergo in vitro fertilisation (IVF) treatment for ova collection. Yet, it has often been pointed out that in the process of embryo donation women's role is largely neglected, as if embryos come from nowhere. The procedure of

  1. Enhancement of anti-OVA IgG2c production in vivo by enalapril

    Directory of Open Access Journals (Sweden)

    L.C. Almeida

    2016-01-01

    Full Text Available Angiotensin-converting enzyme (ACE inhibitors have non-hemodynamic, pleiotropic effects on the immune response. The effects of ACE inhibitors on the production of cytokines and T-cell functions are well established. However, little is known on the effects of these medicines on humoral response to foreign antigens. In this study, we investigated the effect of enalapril treatment on ovalbumin (OVA-specific IgG1 and IgG2c production in mice determined by ELISA. Two groups of 8-week-old C57BL/6 females mice (3–4/group were subcutaneously immunized with OVA (10 μg/animal in presence of Alhydrogel (1 mg/mouse and boosted at day 21. The mice were treated with enalapril (5 mg/kg daily, po or were left without treatment for one month. The animals were bled from the orbital plexus on days 0, 7, 14, 21, and 28 after the first immunization and the sera were stored at –20°C until usage. OVA-specific serum IgG1 and IgG2c were determined by ELISA using serum from each individual animal. The results showed that enalapril significantly increased anti-OVA serum IgG2c in the secondary response without affecting IgG1 synthesis. These data expand our understanding on the properties of enalapril on the immune response, including antibody production.

  2. Presence of parasitic ova, cysts and larva on common fresh fruits ...

    African Journals Online (AJOL)

    ... 2.15% and 1.67% for Ascaris lumbricoides eggs, Strongyloides stercoralis larvae, hookworm eggs, Oocysts of Cryptosporidium , immature cyst of Entamoeba histolytica/dispar, trichuris trichuira eggs, Taenia species egg and oocyst of Isospora species respectively. Tomatoes had the highest percentage with parasites' ova ...

  3. Transmission of Armillifer armillatus ova at snake farm, The Gambia, West Africa.

    Science.gov (United States)

    Tappe, Dennis; Meyer, Michael; Oesterlein, Anett; Jaye, Assan; Frosch, Matthias; Schoen, Christoph; Pantchev, Nikola

    2011-02-01

    Visceral pentastomiasis caused by Armillifer armillatus larvae was diagnosed in 2 dogs in The Gambia. Parasites were subjected to PCR; phylogenetic analysis confirmed relatedness with branchiurans/crustaceans. Our investigation highlights transmission of infective A. armillatus ova to dogs and, by serologic evidence, also to 1 human, demonstrating a public health concern.

  4. [Optimization of time of artificial population schistosome infected Oncomelania hupensis snails].

    Science.gov (United States)

    Xiong, Chun-Rong; Yao, Yun-Yi; Yang, Kun

    2013-12-01

    To explore the optimizational time of artificial population schistosome infected Oncomelania hupensis snails. Under laboratory conditions, the snails were infected with the miracidia of Schistosoma japonicum for 2 h, 3 h and 4 h respectively, and the death rates and the infection rates of the snails, and the quantities of cercariae of each group were observed 60-120 d after the infection, and all the data observed were analyzed to get the optimizational time of artificial population schistosome infected snails. Of the 3 h group, the snail infection rate was the highest and the mortality was the lowest among the 3 groups (P0.05). Under laboratory conditions, the optimizational time is 3 h in artificial population schistosome infected O. hupensis snails.

  5. Morphological Specifications of the Bird Schistosome Cercariae and Surface Carbohydrates as Receptors for Lectins

    Directory of Open Access Journals (Sweden)

    I Moebedi

    2007-04-01

    Full Text Available Background: To determine the morphological specifications of the bird schistosomes cercaria from Lymnaea gedrosiana and to detect the surface carbohydrates as receptors for host lectins in the host-parasite relationship systems such as avian schistosomiasis and human cercarial dermatitis. Methods: One hundred ninety two snails collected from Dezful areas in Khuzestan Province, in the south west of Iran, during 2005-2006 were examined for cercariae using shedding and crushing methods. In addition, surface carbohydrates on the cercariae were detected by lentil (Lens culinaris lectins. Results: From the total number of Lymnaea gedrosiana, which examined for bird schistosomes cercaria, 9(4% snails were found to be infected with furcocercus cercaria of the bird schistosomes (probably Gigantobilharzia sp.. Mannose monosaccharide CH2OH (CHOH4CHO as surface carbohydrate was also detected on the cercariae. Conclusion: Mannose carbohydrate on these cercariae may be used as receptor by lectins.

  6. Transplacental transfer of schistosomal circulating anodic antigens in cows.

    Science.gov (United States)

    Gabriël, S; De Bont, J; Phiri, I K; Masuku, M; Riveau, G; Schacht, A M; Deelder, A M; Van Dam, G J; Vercruysse, J

    2002-01-01

    The present work investigated the transplacental passage of circulating anodic schistosome antigens (CAA) and the production of foetal antibodies in response to antigenic stimulation in Schistosoma mattheei infected cows. Three groups were available: six calves born to non-infected cows received colostrum from a pool from non-infected cows (group 1), six calves born to non-infected cows (group 2) and six calves born to infected cows (group 3) received colostrum from a pool from infected cows. Schistosoma-specific IgG1 antibody and CAA levels were measured in the colostrum pools, the sera collected from the cows, and the sera collected from the calves at birth, after intake of colostrum and at day 30. The specific IgG1 antibody levels were significantly higher in the sera from cows of group 3. In four cows of group 3 high CAA levels were detected. The specific IgG1 antibody levels were 0.646 and 0.176 OD for the infected and non-infected colostrum pool, respectively, and the CAA levels were 5667 and 2557 pg CAA/mL, respectively. At birth high levels of specific IgG1 antibody and CAA were detected in 4 calves of group 3; levels in the other two calves were negligible. After intake of colostrum, specific IgG1 antibody levels of group 1 increased slightly at day 1 to become again insignificant at day 30. In group 2 specific IgG1 antibody levels increased significantly between days 0 and 1, to decrease, although not significantly, at day 30. Finally, in group 3 the delta OD values increased at day 1 and remained high until day 30. After intake of colostrum the CAA level increased very slightly for groups 1 and 2 to become again undetectable at day 30. In group 3 a nonsignificant decrease in CAA levels was observed at day 1 followed by a further significant decrease to reach low levels at day 30. The suggested intrauterine antigenic stimulation may be important not only for generating immune responses to natural early infections, but also for enhancing the immunogenicity

  7. Schistosome syntenin partially protects vaccinated mice against Schistosoma mansoni infection.

    Directory of Open Access Journals (Sweden)

    Barbara C Figueiredo

    2014-08-01

    Full Text Available Schistosomiasis is a neglected tropical disease caused by several species of trematode of the genus Schistosoma. The disease affects more than 200 million people in the world and causes up to 280,000 deaths per year, besides having high morbidity due to chronic illness that damages internal organs. Current schistosomiasis control strategies are mainly based on chemotherapy, but many researchers believe that the best long-term strategy to control disease is a combination of drug treatment and immunization with an anti-schistosome vaccine. Among the most promising molecules as vaccine candidates are the proteins present in the tegument and digestive tract of the parasite.In this study, we describe for the first time Schistosoma mansoni syntenin (SmSynt and we evaluate its potential as a recombinant vaccine. We demonstrate by real-time PCR that syntenin is mainly expressed in intravascular life stages (schistosomula and adult worms of the parasite life cycle and, by confocal microscopy, we localize it in digestive epithelia in adult worms and schistosomula. Administration of siRNAs targeting SmSynt leads to the knock-down of syntenin gene and protein levels, but this has no demonstrable impact on parasite morphology or viability, suggesting that high SmSynt gene expression is not essential for the parasites in vitro. Mice immunization with rSmSynt, formulated with Freund's adjuvant, induces a Th1-type response, as suggested by the production of IFN-γ and TNF-α by rSmSynt-stimulated cultured splenocytes. The protective effect conferred by vaccination with rSmSynt was demonstrated by 30-37% reduction of worm burden, 38-43% reduction in the number, and 35-37% reduction in the area, of liver granulomas.Our report is the first characterization of syntenin in Schistosoma mansoni and our data suggest that this protein is a potential candidate for the development of a multi-antigen vaccine to control schistosomiasis.

  8. Expression of costimulatory molecules in antigen-activated peritoneal macrophages treated with either ovalbumin or palmitoyl-ova conjugates

    Directory of Open Access Journals (Sweden)

    Flávia Márcia Oliveira

    2013-12-01

    Full Text Available One of the mechanisms by which adjuvants are believed to promote T-cell activation and prevent induction of oral tolerance is by up-regulating the expression of co-stimulatory molecules on antigen presenting cells. Mice treated orally with palmitoyl-ovalbumin conjugates become immunized, while those treated with native ovalbumin (Ova become tolerant. Cells from the peritoneal cavity of B6D2F1 mice were cultured in the presence of 0.01, or 0.1 mg/100ml of either Ova, or palmitoyl-Ova and tested for the presence of cell markers. PE-conjugated anti-mouse CD80, CD86, and CD11b antibodies as well as biotin-PE were used to stain the antigen-activated peritoneal cells. A significant increase in the expression of CD86 and CD80 was observed following in vitro stimulation with palmitoyl-Ova; additionally, both Ova and palmitoyl-Ova induced the basal expression of CD11b. These findings could be related with the strong T-cell proliferative response induced by palmitoyl-Ova.

  9. Phenotypic differences in Schistosoma mattheei ova from populations sympatric and allopatric to S. haematobium.

    Science.gov (United States)

    Kruger, F J; Schutte, C H; Visser, P S; Evans, A C

    1986-06-01

    Schistosoma mattheei ova were collected from cattle in different localities in South Africa and after hatching, miracidia were used to infest Bulinus (Physopsis) globosus. Cercariae harvested from these snails were used to infest the definitive host Praomys (Mastomys) coucha and eggs from the resulting female S. mattheei were collected. These ova were compared with a Schistosoma haematobium X S. mattheei hybrid similarly collected from an infested P. (M.) coucha. The results indicate that S. mattheei populations which are sympatric to S. haematobium possess S. haematobium characteristics. It is suggested that the gene pools of populations of the parasite in these areas are infiltrated with S. haematobium genes via the S. mattheei X S. haematobium hybrid originating from human hosts.

  10. In vitro efflux of lactic acid by schistosomes cultured in varying ...

    African Journals Online (AJOL)

    While residing in the mammalian bloodstream, adult schistosomes consume large quantities of glucose and metabolize it to lactic acid. The accumulating load of this end product in the parasite tissue lowers the cellular pH, hence the need for a system to flux it out to avoid compromising metabolic processes. In the present ...

  11. Copro-PCR based detection of bovine schistosome infection in India.

    Science.gov (United States)

    Lakshmanan, B; Devada, K; Joseph, S; Aravindakshan, T V; Sabu, L

    2016-01-01

    Schistosomosis and amphistomosis are the two economically important and widely prevalent snail-borne trematode infections in grazing cattle of southern India. Acute infections are symptomatically similar and difficult to detect by routine microscopy for eggs. The present study was directed towards the development of a copro-polymerase chain reaction (copro-PCR) for detection of bovine schistosome species, using custom-designed primers targeting 18S and 28S ribosomal RNA as well as mitochondrial DNA. The study demonstrated the enhanced diagnostic specificity of mitochondrial DNA markers over ribosomal RNA genes as genus-specific probes to detect schistosomes. We developed a sensitive PCR assay using primers designed from mitochondrial DNA sequences targeting the partial rrnl (16S rRNA), tCys (transfer RNA for cysteine) and partial rrnS (12S rRNA) genes of Schistosoma spindale to specifically detect schistosome infection from faecal samples of naturally infected bovines. The salient findings of the work also throw light on to the high similarity of the ribosomal RNA gene sequences of schistosomes with those of Gastrothylax crumenifer and Fischoederius elongatus, the most prevalent pouched amphistomes of the region. Further investigation has to be directed towards unravelling the complete gene sequences of 18S and 28S ribosomal RNA as well as mitochondrial DNA sequences of amphistome isolates from India.

  12. Effect of praziquantel treatment during pregnancy on cytokine responses to schistosome antigens

    DEFF Research Database (Denmark)

    Tweyongyere, Robert; Mawa, Patrice A.; Ngom-Wegi, Sophy

    2008-01-01

    . Cytokine responses to S. mansoni worm and egg antigens were measured in whole blood culture before and 6 weeks after each treatment. RESULTS: Schistosome-specific cytokine responses were suppressed during pregnancy. Praziquantel treatment during pregnancy caused significant boosts in interferon-gamma (IFN...

  13. Th2 related markers in milk allergic inflammatory mice model, versus OVA

    Directory of Open Access Journals (Sweden)

    Lamia El-housseiny

    2017-12-01

    Full Text Available Experimental studies on allergic asthma are limited by the high cost of the administrated allergens. In this study we tested the allergic potency of low fat milk as a cheap substitute to the widely used standard allergen, ovalbumin (OVA. BALB/c female mice (4 weeks old were sensitized intraperitoneally with low fat milk/or OVA followed by intranasal challenge with the two allergens on days 28 and 29. At day 31, serum, bronchoalveolar lavage fluid (BALF, and lungs were harvested. Mice of the low fat milk model showed infiltration of eosinophils, macrophages, lymphocytes, and neutrophils in BALF comparable to that of the OVA model. Both allergic protocols led to the production of similar numbers of Th2 cells and induced comparable expression of Th2 cytokine (IL-13 as evident by real time PCR for IL-13 and GATA3 (Th2 transcription factor and confirmed by immunofluorescence for Th2 surface markers (T1/ST2. In addition, both mouse models had similar elevated levels of allergen specific antibody, IgG1 and IgE. Notably, HE, PAS, and LUNA stained lung sections from low fat milk treated mice had higher average pathological scores as compared to OVA treated mice. In conclusion, this study suggests that the low fat milk-induced inflammation showed hallmarks of allergic airway inflammatory model such as eosinophilic influx in BALF, increased numbers of Th2 cells, augmented expression of IL-13, elevated levels of circulatory IgG1 and IgE, signs of robust pulmonary inflammation, and most importantly it is a cheap and promising model for studying acute allergic airway inflammation and acute asthma.

  14. Napájecí zdroj elektrostatického odlučovače

    OpenAIRE

    Broďák, Kamil

    2015-01-01

    Diplomová práce je zaměřena na seznámení s problematikou napájení elektrických odlučovačů. Vzhledem k doposud dominantnímu postavení jednofázových transformátorů pracujících na síťové frekvenci 50 Hz řízených tyristory, se práce zaměřuje právě na tyto zdroje. První část popisuje princip elektrického odlučování a popis vlastního elektrického odlučovače. Na to navazuje stručné seznámení s teorií návrhu elektrického odlučovače. Dále se práce zabývá popisem zdroje velmi vysokého napětí, který je ...

  15. Allergic immune-regulatory effects of adlay bran on an OVA-immunized mice allergic model.

    Science.gov (United States)

    Chen, Hong-Jhang; Hsu, Hsin-Yi; Chiang, Wenchang

    2012-10-01

    Allergy is an inflammation associated with an elevated T helper (Th) 2 lymphocyte responses to allergens and elevated serum IgE levels and cytokines. In one of our previous studies using a cell model, various flavonoids were found to be involved the anti-inflammatory effects of adlay bran. The present study investigated the effect of the ethyl-acetate fraction of ethanolic extract of adlay bran (ABE-EtOAc) in an ovalbumin (OVA)-immunized murine model. Six-week-old female BALB/c mice underwent OVA sensitization and were used as an allergy model. An orogastric gavage was used to force feed these mice with 240 mg/kg ABE-EtOAc from their sixth week through their twelfth week. Immune reactions were determined by measuring changes in Th2-type cytokine (IL-4 and IL-5) levels and production of antibodies. ABE-EtOAc was found capable of regulating the Th1/Th2 immune reaction through its regulation of IL-2 and IL-4. It also significantly reduced the production of anti-OVA IgE antibodies (10%), increased the secretion of IFN-γ and decreased the secretion of IL-6 (38%). These results suggest that adlay bran extract can reduce an allergic reaction by balancing Th1/Th2 immune responses and that it might be used in the treatment of this condition. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  16. Vestibular Evoked Myogenic Potential (VEMP Triggered by Galvanic Vestibular Stimulation (GVS: A Promising Tool to Assess Spinal Cord Function in Schistosomal Myeloradiculopathy.

    Directory of Open Access Journals (Sweden)

    Júlia Fonseca de Morais Caporali

    2016-04-01

    Full Text Available Schistosomal myeloradiculopathy (SMR, the most severe and disabling ectopic form of Schistosoma mansoni infection, is caused by embolized ova eliciting local inflammation in the spinal cord and nerve roots. The treatment involves the use of praziquantel and long-term corticotherapy. The assessment of therapeutic response relies on neurological examination. Supplementary electrophysiological exams may improve prediction and monitoring of functional outcome. Vestibular evoked myogenic potential (VEMP triggered by galvanic vestibular stimulation (GVS is a simple, safe, low-cost and noninvasive electrophysiological technique that has been used to test the vestibulospinal tract in motor myelopathies. This paper reports the results of VEMP with GVS in patients with SMR.A cross-sectional comparative study enrolled 22 patients with definite SMR and 22 healthy controls that were submitted to clinical, neurological examination and GVS. Galvanic stimulus was applied in the mastoid bones in a transcranial configuration for testing VEMP, which was recorded by electromyography (EMG in the gastrocnemii muscles. The VEMP variables of interest were blindly measured by two independent examiners. They were the short-latency (SL and the medium-latency (ML components of the biphasic EMG wave.VEMP showed the components SL (p = 0.001 and ML (p<0.001 delayed in SMR compared to controls. The delay of SL (p = 0.010 and of ML (p = 0.020 was associated with gait dysfunction.VEMP triggered by GVS identified alterations in patients with SMR and provided additional functional information that justifies its use as a supplementary test in motor myelopathies.

  17. Inactivation Data.xlsx

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data set is a spreadsheet that contains results of inactivation experiments that were conducted to to determine the effectiveness of chlorine in inactivating B....

  18. Heat-induced structural changes affect OVA-antigen processing and reduce allergic response in mouse model of food allergy

    National Research Council Canada - National Science Library

    Golias, Jaroslav; Schwarzer, Martin; Wallner, Michael; Kverka, Miloslav; Kozakova, Hana; Srutkova, Dagmar; Klimesova, Klara; Sotkovsky, Petr; Palova-Jelinkova, Lenka; Ferreira, Fatima; Tuckova, Ludmila

    2012-01-01

    The egg protein ovalbumin (OVA) belongs to six most frequent food allergens. We investigated how thermal processing influences its ability to induce allergic symptoms and immune responses in mouse model of food allergy...

  19. Comparison of culture-based, vital stain and PMA-qPCR methods for the quantitative detection of viable hookworm ova.

    Science.gov (United States)

    Gyawali, P; Sidhu, J P S; Ahmed, W; Jagals, P; Toze, S

    2017-06-01

    Accurate quantitative measurement of viable hookworm ova from environmental samples is the key to controlling hookworm re-infections in the endemic regions. In this study, the accuracy of three quantitative detection methods [culture-based, vital stain and propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR)] was evaluated by enumerating 1,000 ± 50 Ancylostoma caninum ova in the laboratory. The culture-based method was able to quantify an average of 397 ± 59 viable hookworm ova. Similarly, vital stain and PMA-qPCR methods quantified 644 ± 87 and 587 ± 91 viable ova, respectively. The numbers of viable ova estimated by the culture-based method were significantly (P methods. Therefore, both PMA-qPCR and vital stain methods appear to be suitable for the quantitative detection of viable hookworm ova. However, PMA-qPCR would be preferable over the vital stain method in scenarios where ova speciation is needed.

  20. Interplay between CKS2, N-cadherin, and PD-ECGF in Non-Schistosomal and Schistosomal-Associated Bladder Cancer: A Prospective Comparative Study in the Egyptian Population

    Directory of Open Access Journals (Sweden)

    Sanaa Shawky

    2017-01-01

    Full Text Available Background: The current study investigated the possible role of the cell cycle regulator, cyclin-dependent kinases regulatory subunit-2; the angiogenic factor, plateletderived endothelial cell growth factor; and the cell adhesive molecule, neural cadherin, as prognostic factors in schistosomal and non-schistosomal-associated urothelial carcinomas. We also investigated the possible correlation between cyclin-dependent kinases regulatory subunit-2, platelet-derived endothelial cell growth factor, neural cadherin, tumor grade, and stage. Methods: The study included 40 patients with primary bladder cancer (25 nonschistosomal- associated and 15 schistosomal-associated who had no prior anticancer treatment. Tumor specimens were collected at the time of the transurethral resection. The vivid portions of the resected tumors were subjected to routine pathological examinations to determine stage, grade, and schistosomal infestation. Control bladder tissues (5 cases were obtained by cystoscopic biopsies from patients who underwent transurethral resection of the prostate. Platelet-derived endothelial cell growth factor and neural cadherin protein expressions were evaluated by immunohistochemical staining. RNA was extracted, reverse transcribed, and amplified by PCR using cyclindependent kinases regulatory subunit-2 specific primers. Relative expression was detected by a comparison of the expression in normal and tumor samples relative to GAPDH (housekeeping gene expression. Results:We detected a positive correlation between neural cadherin and plateletderived endothelial cell growth factor proteins in schistosomal-associated and non-schistosomal-associated bladder cancer. Significant overexpression of relative cyclin-dependent kinases regulatory subunit-2 gene, neural cadherin, and plateletderived endothelial cell growth factor proteins were detected in invasive stages and higher grades of bladder cancer. Differential expressions of neural cadherin and

  1. Introgressive Hybridization of Schistosoma haematobium Group Species in Senegal: Species Barrier Break Down between Ruminant and Human Schistosomes

    OpenAIRE

    WEBSTER, B. L.; Diaw, O. T.; Seye, M M; Webster, J. P.; Rollinson, D

    2013-01-01

    BACKGROUND: Schistosomes are dioecious parasitic flatworms, which live in the vasculature of their mammalian definitive hosts. They are the causative agent of schistosomiasis, a disease of considerable medical and veterinary importance in tropical and subtropical regions. Schistosomes undergo a sexual reproductive stage within their mammalian host enabling interactions between different species, which may result in hybridization if the species involved are phylogenetically close. In Senegal, ...

  2. Host immunity, nutrition and coinfection alter longitudinal infection patterns of schistosomes in a free ranging African buffalo population

    Science.gov (United States)

    Jolles, Anna E.; Ezenwa, Vanessa O.; Smith, Mireya; Steinauer, Michelle L.

    2017-01-01

    Schistosomes are trematode parasites of global importance, causing infections in millions of people, livestock, and wildlife. Most studies on schistosomiasis, involve human subjects; as such, there is a paucity of longitudinal studies investigating parasite dynamics in the absence of intervention. As a consequence, despite decades of research on schistosomiasis, our understanding of its ecology in natural host populations is centered around how environmental exposure and acquired immunity influence acquisition of parasites, while very little is known about the influence of host physiology, coinfection and clearance in the absence of drug treatment. We used a 4-year study in free-ranging African buffalo to investigate natural schistosome dynamics. We asked (i) what are the spatial and temporal patterns of schistosome infections; (ii) how do parasite burdens vary over time within individual hosts; and (iii) what host factors (immunological, physiological, co-infection) and environmental factors (season, location) explain patterns of schistosome acquisition and loss in buffalo? Schistosome infections were common among buffalo. Microgeographic structure explained some variation in parasite burdens among hosts, indicating transmission hotspots. Overall, parasite burdens ratcheted up over time; however, gains in schistosome abundance in the dry season were partially offset by losses in the wet season, with some hosts demonstrating complete clearance of infection. Variation among buffalo in schistosome loss was associated with immunologic and nutritional factors, as well as co-infection by the gastrointestinal helminth Cooperia fuelleborni. Our results demonstrate that schistosome infections are surprisingly dynamic in a free-living mammalian host population, and point to a role for host factors in driving variation in parasite clearance, but not parasite acquisition which is driven by seasonal changes and spatial habitat utilization. Our study illustrates the power of

  3. Host immunity, nutrition and coinfection alter longitudinal infection patterns of schistosomes in a free ranging African buffalo population.

    Directory of Open Access Journals (Sweden)

    Brianna R Beechler

    2017-12-01

    Full Text Available Schistosomes are trematode parasites of global importance, causing infections in millions of people, livestock, and wildlife. Most studies on schistosomiasis, involve human subjects; as such, there is a paucity of longitudinal studies investigating parasite dynamics in the absence of intervention. As a consequence, despite decades of research on schistosomiasis, our understanding of its ecology in natural host populations is centered around how environmental exposure and acquired immunity influence acquisition of parasites, while very little is known about the influence of host physiology, coinfection and clearance in the absence of drug treatment. We used a 4-year study in free-ranging African buffalo to investigate natural schistosome dynamics. We asked (i what are the spatial and temporal patterns of schistosome infections; (ii how do parasite burdens vary over time within individual hosts; and (iii what host factors (immunological, physiological, co-infection and environmental factors (season, location explain patterns of schistosome acquisition and loss in buffalo? Schistosome infections were common among buffalo. Microgeographic structure explained some variation in parasite burdens among hosts, indicating transmission hotspots. Overall, parasite burdens ratcheted up over time; however, gains in schistosome abundance in the dry season were partially offset by losses in the wet season, with some hosts demonstrating complete clearance of infection. Variation among buffalo in schistosome loss was associated with immunologic and nutritional factors, as well as co-infection by the gastrointestinal helminth Cooperia fuelleborni. Our results demonstrate that schistosome infections are surprisingly dynamic in a free-living mammalian host population, and point to a role for host factors in driving variation in parasite clearance, but not parasite acquisition which is driven by seasonal changes and spatial habitat utilization. Our study illustrates

  4. OVAS: an open-source variant analysis suite with inheritance modelling.

    Science.gov (United States)

    Mozere, Monika; Tekman, Mehmet; Kari, Jameela; Bockenhauer, Detlef; Kleta, Robert; Stanescu, Horia

    2018-02-08

    The advent of modern high-throughput genetics continually broadens the gap between the rising volume of sequencing data, and the tools required to process them. The need to pinpoint a small subset of functionally important variants has now shifted towards identifying the critical differences between normal variants and disease-causing ones. The ever-increasing reliance on cloud-based services for sequence analysis and the non-transparent methods they utilize has prompted the need for more in-situ services that can provide a safer and more accessible environment to process patient data, especially in circumstances where continuous internet usage is limited. To address these issues, we herein propose our standalone Open-source Variant Analysis Sequencing (OVAS) pipeline; consisting of three key stages of processing that pertain to the separate modes of annotation, filtering, and interpretation. Core annotation performs variant-mapping to gene-isoforms at the exon/intron level, append functional data pertaining the type of variant mutation, and determine hetero/homozygosity. An extensive inheritance-modelling module in conjunction with 11 other filtering components can be used in sequence ranging from single quality control to multi-file penetrance model specifics such as X-linked recessive or mosaicism. Depending on the type of interpretation required, additional annotation is performed to identify organ specificity through gene expression and protein domains. In the course of this paper we analysed an autosomal recessive case study. OVAS made effective use of the filtering modules to recapitulate the results of the study by identifying the prescribed compound-heterozygous disease pattern from exome-capture sequence input samples. OVAS is an offline open-source modular-driven analysis environment designed to annotate and extract useful variants from Variant Call Format (VCF) files, and process them under an inheritance context through a top-down filtering schema of

  5. Detection of Schistosoma spindale ova and associated risk factors among Malaysian cattle through coprological survey

    OpenAIRE

    Tan, Tiong Kai; Low, Van Lun; Lee, Soo Ching; Panchadcharam, Chandrawathani; Kho, Kai Ling; Koh, Fui Xian; Sharma, Reuben Sunil Kumar; Jaafar, Tariq; Lim, Yvonne Ai Lian

    2015-01-01

    The present study was conducted to determine the occurrence of Schistosoma spindale ova and its associated risk factors in Malaysian cattle through a coprological survey. A total of 266 rectal fecal samples were collected from six farms in Peninsular Malaysia. The overall infection rate of S. spindale was 6% (16 of 266). Schistosoma spindale infection was observed in two farms, with a prevalence of 5.4% and 51.9%, respectively. This trematode was more likely to co-occur with other gastro-inte...

  6. Elaboracion de un objeto virtual de aprendizaje (ova) sobre “tecnicas de facilitacion neuromuscular propioceptiva”

    OpenAIRE

    Gomez Diaz, Isabel Cristina

    2010-01-01

    El presente resumen corresponde a un ejercicio de innovación en el aula que se constituye en un aporte en el marco de los “productos electrónicos” los cuales se refieren a libros o contenidos en formato digital diseñados para la educación facilitada con objetos virtuales de aprendizaje. El propósito de elaborar un OVA sobre “Técnicas de Facilitación Neuromuscular Propioceptiva - TFNP” fue proporcionar al fisioterapeuta (profesional o en formación) una herramienta que le facilite el apr...

  7. The morphological changes of Ascaris lumbricoides ova in sewage sludge water treated by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shamma, M. E-mail: atom@sy.net; Al-Adawi, M.A

    2002-10-01

    Untreated wastewater sampled from Damascus sewage water treatment plant containing nematode Ascaris lumbricoides ova were treated using gamma irradiation (doses between 1.5 and 8 kGy), immediately after irradiation the morphological and developmental status of eggs was examined microscopically. Major morphological changes of the contents of the eggs were detected. These eggs were incubated for 8 weeks, after this period no larvae 'inside the eggs' were observed. Thus the morphological changes can be used as a viable parameter.

  8. Effects of schistosomal mansoni infection on Calomys callosus coelom-associated lymphomyeloid tissue (milky spots).

    Science.gov (United States)

    Lenzi, J A; Pelajo-Machado, M; Mota, E M; Oliveira, D N; Panasco, M S; Andrade, Z A; Lenzi, H L

    1998-01-01

    Calomys callosus Rengger, 1830 (Rodentia: Cricetidae) is a mouse-like South American wild rodent, which is permissive to Schistosoma mansoni infection. In this paper we studied the effect of schistosomal infection in C. callosus mesenteric and omental milky spots (MS), subsidiary foci of coelom-associated lymphomyeloid tissue (CALT), during the acute, transitional (acute to chronic), and chronic phases of the infection. MS were morphologically analyzed by histological methods, using brightfield and confocal laser scanning microscopies. The MS of infected animals were mainly of lymphomyelocytic (42 to 90 days) and lymphoplasmacytic (160 days of infection) types and showed frequent presence of lymphoid follicles with germinal centers, plasmacytogenesis and plasmacytosis, mastocytosis, megakaryopoiesis, erythropoiesis and less pronounced eosinopoiesis. These results indicate that MS are a preferential site of germinal-center-dependent and independent plasmacytogenesis, and a bone marrow-like organ, committed with various cellular lineages. The consequence of C. callosus MS reactivity for schistosomal infection is still unknown and is under investigation.

  9. Effects of Schistosomal mansoni infection on Calomys callosus coelom-associated lymphomyeloid tissue (milky spots)

    OpenAIRE

    Lenzi Jane A; Pelajo-Machado Marcelo; Mota Ester M; Oliveira Denise N; Panasco Mônica S; Andrade Zilton A; Lenzi Henrique L.

    1998-01-01

    Calomys callosus Rengger, 1830 (Rodentia: Cricetidae) is a mouse-like South American wild rodent, which is permissive to Schistosoma mansoni infection. In this paper we studied the effect of schistosomal infection in C. callosus mesenteric and omental milky spots (MS), subsidiary foci of coelom-associated lymphomyeloid tissue (CALT), during the acute, transitional (acute to chronic), and chronic phases of the infection. MS were morphologically analyzed by histological methods, using brigthfie...

  10. Neurotransmitter transporters in schistosomes: structure, function and prospects for drug discovery.

    Science.gov (United States)

    Ribeiro, Paula; Patocka, Nicholas

    2013-12-01

    Neurotransmitter transporters (NTTs) play a fundamental role in the control of neurotransmitter signaling and homeostasis. Sodium symporters of the plasma membrane mediate the cellular uptake of neurotransmitter from the synaptic cleft, whereas proton-driven vesicular transporters sequester the neurotransmitter into synaptic vesicles for subsequent release. Together these transporters control how much transmitter is released and how long it remains in the synaptic cleft, thereby regulating the intensity and duration of signaling. NTTs have been the subject of much research in mammals and there is growing interest in their activities among invertebrates as well. In this review we will focus our attention on NTTs of the parasitic flatworm Schistosoma mansoni. Bloodflukes of the genus Schistosoma are the causative agents of human schistosomiasis, a devastating disease that afflicts over 200 million people worldwide. Schistosomes have a well-developed nervous system and a rich diversity of neurotransmitters, including many of the small-molecule ("classical") neurotransmitters that normally employ NTTs in their mechanism of signaling. Recent advances in schistosome genomics have unveiled numerous NTTs in this parasite, some of which have now been cloned and characterized in vitro. Moreover new genetic and pharmacological evidence suggests that NTTs are required for proper control of neuromuscular signaling and movement of the worm. Among these carriers are proteins that have been successfully targeted for drug discovery in other organisms, in particular sodium symporters for biogenic amine neurotransmitters such as serotonin and dopamine. Our goal in this chapter is to review the current status of research on schistosome NTTs, with emphasis on biogenic amine sodium symporters, and to evaluate their potential for anti-schistosomal drug targeting. Through this discussion we hope to draw attention to this important superfamily of parasite proteins and to identify new

  11. DIFFERENTIATION OF SCHISTOSOMA HAEMATOBIUM FROM RELATED SCHISTOSOMES BY PCR AMPLIFYING AN INTER-REPEAT SEQUENCE

    OpenAIRE

    Abbasi, Ibrahim; King, Charles H.; Sturrock,Robert F.; Kariuki, Curtis; Muchiri, Eric; HAMBURGER, JOSEPH

    2007-01-01

    Schistosoma haematobium infects nearly 150 million people, primarily in Africa, and is transmitted by select species of local bulinid snails. These snails can host other related trematode species as well, so that effective detection and monitoring of snails infected with S. haematobium requires a successful differentiation between S. haematobium and any closely related schistosome species. To enable differential detection of S. haematobium DNA by simple polymerase chain reaction (PCR), we des...

  12. Accelerated evolution of schistosome genes coding for proteins located at the host-parasite interface.

    Science.gov (United States)

    Philippsen, Gisele S; Wilson, R Alan; DeMarco, Ricardo

    2015-01-06

    Study of proteins located at the host-parasite interface in schistosomes might provide clues about the mechanisms utilized by the parasite to escape the host immune system attack. Micro-exon gene (MEG) protein products and venom allergen-like (VAL) proteins have been shown to be present in schistosome secretions or associated with glands, which led to the hypothesis that they are important components in the molecular interaction of the parasite with the host. Phylogenetic and structural analysis of genes and their transcripts in these two classes shows that recent species-specific expansion of gene number for these families occurred separately in three different species of schistosomes. Enrichment of transposable elements in MEG and VAL genes in Schistosoma mansoni provides a credible mechanism for preferential expansion of gene numbers for these families. Analysis of the ratio between synonymous and nonsynonymous substitution rates (dN/dS) in the comparison between schistosome orthologs for the two classes of genes reveals significantly higher values when compared with a set of a control genes coding for secreted proteins, and for proteins previously localized in the tegument. Additional analyses of paralog genes indicate that exposure of the protein to the definitive host immune system is a determining factor leading to the higher than usual dN/dS values in those genes. The observation that two genes encoding S. mansoni vaccine candidate proteins, known to be exposed at the parasite surface, also display similar evolutionary dynamics suggests a broad response of the parasite to evolutionary pressure imposed by the definitive host immune system. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  13. The developing schistosome worms elicit distinct immune responses in different tissue regions.

    Science.gov (United States)

    McWilliam, Hamish E G; Driguez, Patrick; Piedrafita, David; Maupin, Kevin A; Haab, Brian B; McManus, Donald P; Meeusen, Els N T

    2013-08-01

    Schistosome parasites follow a complex migration path through various tissues, changing their antigenic profile as they develop. A thorough understanding of the antibody response in each tissue region could help unravel the complex immunology of these developing parasites and aid vaccine design. Here we used a novel strategy for analysing the local antibody responses induced by Schistosoma japonicum infection at each site of infection. Cells from rat lymph nodes draining the sites of larval migration (the skin and lungs), the liver-lymph nodes where adults reside and the spleens were cultured to allow the in vivo-induced antibody-secreting cells to release antibody into the media. The amount and isotype of antibodies secreted in the supernatants differed significantly in the different lymph nodes and spleen, corresponding with the migration path of the schistosome worms. In addition, there were significant differences in binding specificity, as determined by surface labelling, western blots and by screening a glycan array. Through capturing the local antibody response, this study has revealed dramatic differences in the quality and specificity of the immune response at different tissue sites, and highlighted the existence of stage-specific protein and carbohydrate antigens. This will provide a valuable tool for the isolation of novel vaccine targets against the larval stages of schistosomes.

  14. Differentiation of Schistosoma haematobium from related schistosomes by PCR amplifying an inter-repeat sequence.

    Science.gov (United States)

    Abbasi, Ibrahim; King, Charles H; Sturrock, Robert F; Kariuki, Curtis; Muchiri, Eric; Hamburger, Joseph

    2007-05-01

    Schistosoma haematobium infects nearly 150 million people, primarily in Africa, and is transmitted by select species of local bulinid snails. These snails can host other related trematode species as well, so that effective detection and monitoring of snails infected with S. haematobium requires a successful differentiation between S. haematobium and any closely related schistosome species. To enable differential detection of S. haematobium DNA by simple polymerase chain reaction (PCR), we designed and tested primer pairs from numerous newly identified Schistosoma DNA repeat sequences. However, all pairs tested were found unsuitable for this purpose. Differentiation of S. haematobium from S. bovis, S. mattheei, S. curassoni, and S. intercalatum (but not from S. margrebowiei) was ultimately accomplished by PCR using one primer from a newly identified repeat, Sh110, and a second primer from a known schistosomal splice-leader sequence. For evaluation of residual S. haematobium transmission after control interventions, this differentiation tool will enable accurate monitoring of infected snails in areas where S. haematobium is sympatric with the most prevalent other schistosome species.

  15. Studies on transmission and schistosome interactions in Senegal, Mali and Zambia.

    Science.gov (United States)

    Vercruysse, J; Southgate, V R; Rollinson, D; De Clercq, D; Sacko, M; De Bont, J; Mungomba, L M

    1994-01-01

    The transmission and interaction of schistosomes in the Senegal River Basin in Mali and Zambia are reviewed and some preliminary field data are presented. In the Senegal River Basin four species of schistosomes are prevalent: Schistosoma mansoni, S. haematobium, S. bovis and S. curassoni as well as the following potential intermediate hosts: Biomphalaria pfeifferi, Bulinus globosus, B. umbilicatus, B. truncatus, B. senegalensis and B. forskalii. The role of each of these species in the transmission of schistosomes in man and domestic stock is discussed. Recent ecological changes caused by the construction of dams at Diama and Mananatali on the Senegal River, such as reduction in salinity, more stable water flow, creation of irrigation canals and development and extension of rice culture, have contributed towards the occurrence of new outbreaks of both intestinal and urinary schistosomiasis in the Senegal River Basin. In Mali, the four main areas of high prevalence of S. haematobium are Office du Niger (irrigation areas), Bandiagara (small dams), Selingué (dam areas) and Baguineda (irrigation areas). Apart from the Office du Niger, S. mansoni infections are rare. Surveys were carried out in the Dogon Country (Bandiagara District) in an attempt to confirm the recent independent reports of the presence of S. intercalatum. Data based on egg morphology and Ziehl Neelsen staining of egg shells suggested the possible occurrence of S. haematobium x S. intercalatum hybrids. Potential factors affecting the focal endemicity of S. haematobium in Mali are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Natural infection with schistosomes of the Schistosoma haematobium group in a dog in Zambia.

    Science.gov (United States)

    Chiti, L; De Bont, J; Fransen, J; Kane, R A; Mwase, M; Southgate, V R; Vercruysse, J

    2000-01-01

    Post-mortem examination of an adult male Jack Russell dog from Zambia revealed that it was heavily infected with schistosomes. The dog had been admitted, with a history of retching, 4 days before its death. At necropsy, the liver was found to be enlarged, with multiple pin-point yellowish-white foci scattered diffusely throughout the organ. Multiple pin-point recent and old haemorrhages were seen on the mucosal surface of the gastrointestinal tract, particularly in the stomach and proximal duodenum. Large numbers of schistosome worm pairs and eggs were found in all mesenteric, gastric and hepatic veins. Histological examination of the intestines, mesenteric lymph nodes, liver, spleen, pancreas, stomach and lungs revealed numerous strongly fibrotic, encapsulated, epithelioid-giant cell granulomata containing dead, degenerating and viable eggs. A few examples of the Splendore-Hoeppli phenomenon were also detected. The eggs collected at necropsy had a terminal spine and an average length and breadth of 187.6+/-14.1 microm and 57. 3+/-4.1 microm, respectively. DNA analysis of female worms indicated that the schistosomes were either Schistosoma haematobium or a hybrid of Schistosoma mattheei and S. haematobium. Copyright 2000 Harcourt Publishers Ltd.

  17. Comparison of Schistosoma mansoni soluble cercarial antigens and soluble egg antigens for serodiagnosing schistosome infections.

    Science.gov (United States)

    Smith, Huw; Doenhoff, Mike; Aitken, Cara; Bailey, Wendi; Ji, Minjun; Dawson, Emily; Gilis, Henk; Spence, Grant; Alexander, Claire; van Gool, Tom

    2012-01-01

    A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid--SmCTF) was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA) in an indirect enzyme-immunoassay (ELISA) antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA) in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis.

  18. Comparison of Schistosoma mansoni soluble cercarial antigens and soluble egg antigens for serodiagnosing schistosome infections.

    Directory of Open Access Journals (Sweden)

    Huw Smith

    Full Text Available A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid--SmCTF was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA in an indirect enzyme-immunoassay (ELISA antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis.

  19. Exploring the function of protein kinases in schistosomes: perspectives from the laboratory and from comparative genomics

    Directory of Open Access Journals (Sweden)

    Anthony John Walker

    2014-07-01

    Full Text Available Eukaryotic protein kinases are well conserved through evolution. The genome of Schistosoma mansoni, which causes intestinal schistosomiasis, encodes over 250 putative protein kinases with all of the main eukaryotic groups represented. However, unraveling functional roles for these kinases is a considerable endeavour, particularly as protein kinases regulate multiple and sometimes overlapping cell and tissue functions in organisms. In this article, elucidating protein kinase signal transduction and function in schistosomes is considered from the perspective of the state-of-the-art methodologies used and comparative organismal biology, with a focus on current advances and future directions. Using the free-living nematode Caenorhabditis elegans as a comparator we predict roles for various schistosome protein kinases in processes vital for host invasion and successful parasitism such as sensory behaviour, growth and development. It is anticipated that the characterization of schistosome protein kinases in the context of parasite function will catalyze cutting edge research into host-parasite interactions and will reveal new targets for developing drug interventions against human schistosomiasis.

  20. Inhibition of Asthma in OVA Sensitized Mice Model by a Traditional Uygur Herb Nepeta bracteata Benth.

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2016-01-01

    Full Text Available Asthma is a chronic lung inflammation which affects many people. As current therapies for asthma mainly rely on administration of glucocorticoids and have many side effects, new therapy is needed. In this study, we investigated Nepeta bracteata Benth., a traditional Uygur Herb, for its therapeutics effect in OVA induced asthmatic mice model. Treatment of OVA sensitized asthma mice with extract from Nepeta bracteata Benth. demonstrated improved lung pathology, as well as reduced infiltration of eosinophil and neutrophil. Nepeta bracteata Benth. extract also contributed to the rebalance of Th17/Treg cell via decreasing the Th17 cell and increasing the Treg, which was corresponding with the inhibited Th17 cytokine response and increased IL-10 level. Moreover, the reduced TGF-β level and Smad2/3 protein level also suggested that Nepeta bracteata Benth. extract could inhibit TGF-β mediated airway remodelling as well. Taken together, these data suggested that Nepeta bracteata Benth. may be a novel candidate for future antiasthma drug development.

  1. Phosphocholine-specific antibodies improve T-dependent antibody responses against OVA encapsulated into phosphatidylcholine-containing liposomes.

    Directory of Open Access Journals (Sweden)

    Yoelys Cruz-Leal

    2016-09-01

    Full Text Available Liposomes containing phosphatidylcholine have been widely used as adjuvants. Recently, we demonstrated that B-1 cells produce dipalmitoyl phosphatidylcholine (DPPC-specific IgM upon immunization of BALB/c mice with DPPC-liposomes encapsulating ovalbumin (OVA. Although this preparation enhanced the OVA-specific humoral response, the contribution of anti-DPPC antibodies to this effect was unclear. Here, we demonstrate that these antibodies are secreted by B-1 cells independently of the presence of OVA in the formulation. We also confirm that these antibodies are specific for phosphocholine. The anti-OVA humoral response was partially restored in B-1 cells-deficient BALB/xid mice by immunization with the liposomes opsonized with the serum total immunoglobulin (Ig fraction containing anti-phosphocholine antibodies, generated in wild type animals. This result could be related to the increased phagocytosis by peritoneal macrophages of the particles opsonized with the serum total Ig or IgM fractions, both containing anti-phosphocholine antibodies. In conclusion, in the present work it has been demonstrated that phosphocholine-specific antibodies improve T-dependent antibody responses against OVA carried by DPPC-liposomes.

  2. Development of sensitisation or tolerance following repeated OVA inhalation in BALB/cJ mice. Dose-dependency and modulation by the Al(OH)3 adjuvant

    DEFF Research Database (Denmark)

    Clausen, Susanne Knoth; Bergqvist, Mette; Poulsen, Lars K.

    2003-01-01

    days with ovalbumin (OVA) solution, 25 mg/l-10 g/l (0.0025-1%) for 20 min/day, with and without the Al(OH)(3) adjuvant (0.5%). Four days after the last aerosol exposure, no OVA specific IgE and only low IgG1 were produced. Subsequent parenteral OVA administration showed that the 10 g/l solution induced...

  3. Human U6 promoter drives stronger shRNA activity than its schistosome orthologue in Schistosoma mansoni and human fibrosarcoma cells

    Science.gov (United States)

    Duvoisin, Raphaël; Ayuk, Mary A.; Rinaldi, Gabriel; Suttiprapa, Sutas; Mann, Victoria H.; Lee, Clarence M.; Harris, Nicola; Brindley, Paul J.

    2011-01-01

    Blood flukes or schistosomes are the causative agents of human schistosomiasis, one of the major neglected tropical diseases. Draft genome sequences have been reported for schistosomes, but functional genomics tools are needed to investigate the role and essentiality of the newly reported genes. Vector based RNA interference can contribute to functional genomics analysis for schistosomes. Using mRNA encoding reporter firefly luciferase as a model target, we compared the performance of a schistosome and a human promoter from the U6 gene in driving shRNA in human fibrosarcoma cells and in cultured schistosomes. Further, both a retroviral (Murine leukemia virus [MLV]) and plasmid (piggyBac, pXL-Bac II) vector were utilized. The schistosome U6 gene promoter was 270 bp in length, the human U6 gene promoter was 264 bp; they shared 41% identity. Following transduction of both HT1080 fibrosarcoma cells and schistosomules of Schistosoma mansoni with pseudotyped MLV virions, stronger knockdown of luciferase activity was seen with the virions encoding the human U6 promoter driven shRNA than the schistosome U6 promoter. A similar trend was seen after transfection of HT1080 cells and schistosomules with the pXL-Bac-II constructs – stronger knockdown of luciferase activity was seen with constructs encoding the human compared to schistosome U6 promoter. The findings indicate that a human U6 gene promoter drives stronger shRNA activity than its schistosome orthologue, not only in a human cancer cell line but also in larval schistosomes. This RNA polymerase III promoter represents a potentially valuable component for vector based RNA interference studies in schistosomes and related platyhelminth parasites. PMID:21953124

  4. Proteomic analysis of human skin treated with larval schistosome peptidases reveals distinct invasion strategies among species of blood flukes.

    Directory of Open Access Journals (Sweden)

    Jessica Ingram

    2011-09-01

    Full Text Available Skin invasion is the initial step in infection of the human host by schistosome blood flukes. Schistosome larvae have the remarkable ability to overcome the physical and biochemical barriers present in skin in the absence of any mechanical trauma. While a serine peptidase with activity against insoluble elastin appears to be essential for this process in one species of schistosomes, Schistosoma mansoni, it is unknown whether other schistosome species use the same peptidase to facilitate entry into their hosts.Recent genome sequencing projects, together with a number of biochemical studies, identified alternative peptidases that Schistosoma japonicum or Trichobilharzia regenti could use to facilitate migration through skin. In this study, we used comparative proteomic analysis of human skin treated with purified cercarial elastase, the known invasive peptidase of S. mansoni, or S. mansoni cathespin B2, a close homolog of the putative invasive peptidase of S. japonicum, to identify substrates of either peptidase. Select skin proteins were then confirmed as substrates by in vitro digestion assays.This study demonstrates that an S. mansoni ortholog of the candidate invasive peptidase of S. japonicum and T. regenti, cathepsin B2, is capable of efficiently cleaving many of the same host skin substrates as the invasive serine peptidase of S. mansoni, cercarial elastase. At the same time, identification of unique substrates and the broader species specificity of cathepsin B2 suggest that the cercarial elastase gene family amplified as an adaptation of schistosomes to human hosts.

  5. Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

    CERN Document Server

    Shamma, M A; Sharabi, N

    2002-01-01

    The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays.

  6. Late Bronze Age in Alcáçova de Santarém (Portugal

    Directory of Open Access Journals (Sweden)

    Arruda, Ana Margarida

    2015-06-01

    Full Text Available The field work that took place in the restaurant area in Jardim das Portas do Sol (Alcáçova de Santarém recovered well-preserved archaeological layers dated to the Late Bronze Age, lying directly underneath the Iron Age phase. The excavation made it possible to collect an important set of ceramics that incorporate printed and incised decoration, which can be easily decoration related to the Cogotas 1 cultural background. Burnished decorations, with grooves on the inner surface and outer strips, are less common. The formal repertoire does not deviate from what is known about the Late Bronze Age in central and southern Iberian Peninsula. The data allow us to propose a chronology centered in the early 1st millennium BCE for this occupation.Durante los trabajos de campo, realizados en el área del restaurante del Jardim das Portas do Sol, se documentaron, por primera vez en Alcáçova de Santarém, niveles conservados del final de la Edad del Bronce, inmediatamente infrapuestos a los de la Edad del Hierro. Su excavación permitió recoger un conjunto de materiales cerámicos que incorpora varios fragmentos decorados por impresión e incisión, que pueden ser fácilmente relacionados con el universo cultural de Cogotas 1. Las decoraciones bruñidas con surcos en la superficie interna y con franjas al exterior son mucho menos frecuentes. El repertorio formal no difiere del conocido para el Bronce Final del centro y sur de la Península Ibérica. Los datos permiten proponer una cronologia del inicio del 1 milenio a.n.e. (siglo IX para esta ocupación.

  7. In ova angiogenesis analgesic and anti inflammatory potency of Aerva monsoniae (Amaranthaceae

    Directory of Open Access Journals (Sweden)

    Sandhya S

    2012-10-01

    Full Text Available Objective: To evaluate the wound healing potency of aqueous extract of Aerva monsoniae (A. monsoniae by in vitro method using fertilized eggs, in vivo analgesic and anti inflammatory activity in rodents and the anti bacterial activity on the bacterial strains that infect the wound. Methods: The whole plant of A. monsoniae was extracted with water and then subjected to preliminary chemical screening. It was then evaluated for in ova angiogenesis on fertilized white leg horn eggs using the concentrations of 200-600 毺 g/mL. The analgesic activity was evaluated in mice using the dose 100 and 250 mg/kg. The anti inflammatory activity was evaluated in rats using the dose 250 mg/kg and 500 mg/kg. In both the parameters water was used as the control and diclofenac was used the standard. The anti bacterial activity on Staphylococcus aureus and Pseudomonas aerugenosa was performed. Results: The phytochemical screening revealed the presence of tannins, flavonoids and saponins. The in ova angiogenesis revealed a dose dependent activity which proves the wound healing claim of the plant as more number of blood capillaries were formed at the site of the drug. The plant proved to be a potent analgesic and anti inflammatory agent at doses 1 00 mg/kg and 250 mg/kg. The anti bacterial activity was present but at higher doses. Conclusions: The parameters studied in the present investigation proved that the plant is a potent wound healer. Further in vivo wound healing studies on animal model is desired. As the extract showed potent analgesic, anti inflammatory and anti bacterial properties, it can be considered that when formulated into suitable formulation, and it can reduce the pain, inflammation and infections related to wound very well.

  8. Effect of praziquantel treatment of Schistosoma mansoni during pregnancy on immune responses to schistosome antigens among the offspring

    DEFF Research Database (Denmark)

    Tweyongyere, Robert; Mawa, Patrice A.; Kihembo, Macklyn

    2011-01-01

    Offspring of women with schistosomiasis may exhibit immune responsiveness to schistosomes due to in utero sensitisation or trans-placental transfer of antibodies. Praziquantel treatment during pregnancy boosts maternal immune responses to schistosome antigens and reduces worm burden. Effects of p...

  9. In vivo imaging of schistosomes to assess disease burden using positron emission tomography (PET).

    Science.gov (United States)

    Salem, Nicolas; Balkman, Jason D; Wang, Jing; Wilson, David L; Lee, Zhenghong; King, Christopher L; Basilion, James P

    2010-09-21

    Schistosomes are chronic intravascular helminth parasites of humans causing a heavy burden of disease worldwide. Diagnosis of schistosomiasis currently requires the detection of schistosome eggs in the feces and urine of infected individuals. This method unreliably measures disease burden due to poor sensitivity and wide variances in egg shedding. In vivo imaging of schistosome parasites could potentially better assess disease burden, improve management of schistosomiasis, facilitate vaccine development, and enhance study of the parasite's biology. Schistosoma mansoni (S. mansoni) have a high metabolic demand for glucose. In this work we investigated whether the parasite burden in mice could be assessed by positron emission tomography (PET) imaging with 2-deoxy-2[(18)F]fluoro-D-glucose (FDG). Live adult S. mansoni worms FDG uptake in vitro increased with the number of worms. Athymic nude mice infected with S. mansoni 5-6 weeks earlier were used in the imaging studies. Fluorescence molecular tomography (FMT) imaging with Prosense 680 was first performed. Accumulation of the imaging probe in the lower abdomen correlated with the number of worms in mice with low infection burden. The total FDG uptake in the common portal vein and/or regions of elevated FDG uptake in the liver linearly correlated to the number of worms recovered from infected animals (R(2) =0.58, Pworm burden in mice with more than 50 worms (R(2) = 0.85, Pworms in a mouse with a high infection burden were in the portal vein, but not in a mouse with a low infection burden. FDG uptake in recovered worms measured by well counting closely correlated with worm number (R(2) = 0.85, Pworm burden in schistosomiasis-infected animals. Future investigations aiming at minimizing non-specific FDG uptake and to improve the recovery of signal from worms located in the lower abdomen will include the development of more specific radiotracers.

  10. Schistosome infection is negatively associated with mite atopy, but not wheeze and asthma in Ghanaian schoolchildren.

    Science.gov (United States)

    Obeng, B B; Amoah, A S; Larbi, I A; de Souza, D K; Uh, H-W; Fernández-Rivas, M; van Ree, R; Rodrigues, L C; Boakye, D A; Yazdanbakhsh, M; Hartgers, F C

    2014-07-01

    Epidemiological evidence suggests that helminth infection and rural living are inversely associated with allergic disorders. The aim of the study was to investigate the effect of helminth infections and urban versus rural residence on allergy in schoolchildren from Ghana. In a cross-sectional study of 1385 children from urban-high socio-economic status (SES), urban-low SES and rural schools, associations between body mass index (BMI), allergen-specific IgE (sIgE), parasitic infections and allergy outcomes were analysed. Allergy outcomes were skin prick test (SPT) reactivity, reported current wheeze and asthma. Helminth infections were found predominantly among rural subjects, and the most common were hookworm (9.9%) and Schistosoma spp (9.5%). Being overweight was highest among urban-high SES (14.6%) compared to urban-low SES (5.5%) and rural children (8.6%). The prevalence of SPT reactivity to any allergen was 18.3%, and this was highest among rural children (21.4%) followed by urban-high SES (20.2%) and urban-low SES (10.5%) children. Overall, SPT reactivity to mite (12%) was most common. Wheeze and asthma were reported by 7.9% and 8.3%, respectively. In multivariate analyses, factors associated with mite SPT were BMI (aOR 2.43, 95% CI 1.28-4.60, P = 0.007), schistosome infection (aOR 0.15, 95% CI 0.05-0.41) and mite sIgE (aOR 7.40, 95% CI 5.62-9.73, P asthma. Infection with schistosomes appeared to protect against mite SPT reactivity. This needs to be confirmed in future studies, preferably in a longitudinal design where schistosome infections are treated and allergic reactions reassessed. © 2014 John Wiley & Sons Ltd.

  11. Studies on animal schistosomes in Peninsular Malaysia: record of naturally infected animals and additional hosts of Schistosoma spindale.

    Science.gov (United States)

    Inder Singh, K; Krishnasamy, M; Ambu, S; Rasul, R; Chong, N L

    1997-06-01

    Surveillance studies on cercarial dermatitis were carried out in paddy growing areas in Peninsular Malaysia. It was observed that dermatitis in paddy planters occurred in paddy fields which were cultivated using animals such as bafflos or fields where domestic animals were allowed to graze during the off planting season as these animals harbored the parasite. The causative agent of cercarial dermatitis was Schistosoma spindale. A total of 215 small mammals trapped from Alor Setar and 126 trapped from Labu were examined for the schistosome. In Alor Setar Bandicota indica, Rattus argentiventer and Rattus rattus diardii were the only wild mammals found to be infected with the parasite, while in the Labu areas only Rattus tiomanicus jalorensis was positive for the schistosome. The occurrence of S. spindale in R. argentiventer and R.r. diardii in Alor Setar and in R.t. jalorensis in Labu constitute new host and geographic distribution records of the schistosome.

  12. Boron nanoparticles inhibit turnour growth by boron neutron capture therapy in the murine B16-OVA model

    DEFF Research Database (Denmark)

    Petersen, Mikkel Steen; Petersen, Charlotte Christie; Agger, Ralf

    2008-01-01

    Background: Boron neutron capture therapy usually relies on soluble, rather than particulate, boron compounds. This study evaluated the use of a novel boron nanoparticle for boron neutron capture therapy. Materials and Methods: Two hundred and fifty thousand B16-OVA tumour cells, pre...

  13. Effect of histamine, phencyclidine, phenoxybenzamine and gamma-aminobutyric acid on ovulation and quality of ova in rats.

    Science.gov (United States)

    Batta, S K

    1980-01-01

    The gonadotropin-stimulated prepuberal female rat is a good model for the study of drugs affecting ovulation and the quality of ova released. Various pharmacological agents, such as histamine, phencyclidine, phenoxybenzamine (PBZ) and gamma-aminobutyric acid (GABA), were tested in this paradigm for evaluation on incidence of ovulation, number of ova released and degeneration in the ova shed. A dose of 25 iu of pregnant mare serum gonadotropin (PMS) was found to be most effective in inducing superovulation in these rats. The percentage of degenerative eggs obtained was least in this dose group. Histamine and GABA appeared to cause an increased number of oocytes to be released, while phencyclidine reduced the number of animals responding to PMS treatment. PBZ was effective in completely blocking ovulation only when given before the LH surge occurred in the treated animals. The quality of ova released was affected by GABA, phencyclidine and PBZ. GABA and phencyclidine reduced the incidence of degenerative oocytes while treatment of animals with PBZ at the time of PMS administration increased the degenerative oocytes. It is suggested that more studies be carried out to observe the effect of various drugs, administered shortly before ovulation, on ovum quality.

  14. [Polymorphism of the cox1 gene in bird schistosome cercaria isolates (Trematoda, Schistosomatidae) from ponds of Moscow and Moscow oblast].

    Science.gov (United States)

    Lopatkin, A A; Khrisanfova, G G; Voronin, M V; Zazornova, O P; Beér, S A; Semenova, S K

    2010-07-01

    Polymorphism of a 8 10-bp mitochondrial cox1 gene region was studied in 16 cercaria isolates of bird schistosomes (family Schistosomatidae), which were collected in water bodies of Moscow and Moscow oblast and represented three species: Trichobilharzia szidati, T. franki, and T. regenti. A substantial predominance of AT (65.4%) was characteristic of the cox1 sequences in all three species. Rare single nucleotide substitutions determined low (0.2-0.9%) intraspecific nucleotide and amino acid sequence diversity. Haplotype diversity h was high (80-100%) in all three species, suggesting a unique character for almost all cox1 sequences in the sample. Phylogenetic trees based on the nucleotide and amino acid sequence variations were constructed to study the relationships of the three schistosome species. A high support was observed for the main branching node that reflects differentiation of the monophyletic group Trichobilharzia and species of the genera Bilharziella (B. polonica), Dendritobilharzia (D. pulverulenta), and Gigantobilharzia (G. huronensis). Based on the nucleotide substitutions and amino acid polymorphisms, two groups of isolates, which infect Lymnaea stagnalis (T. szidati) and snails of the group Radix (T. franki and T. regenti) respectively, were isolated in the genus Trichobilharzia. The time of divergence between the two schistosome groups infecting snails of the genera Radix and Lymnaea was calculated from the cox1 nucleotide substitution rate, which is known for Asian and Indian blood flukes from the genus Schistosoma and is 2-3% per million years on average. Divergence of the three bird schistosome species under study and divergence of the Asian species of mammalian schistosome were almost concurrent, dating back to 2.5-3.8 Myr ago. Factors responsible for the lack of intraspecific subdivision with respect to the cox1 gene in bird schistosomes and the lack of separation between two species (T. franki and T. regenti) are discussed.

  15. Enterobius vermicularis as a Novel Surrogate for the Presence of Helminth Ova in Tertiary Wastewater Treatment Plants.

    Science.gov (United States)

    Rudko, Sydney P; Ruecker, Norma J; Ashbolt, Nicholas J; Neumann, Norman F; Hanington, Patrick C

    2017-06-01

    Significant effort has gone into assessing the fate and removal of viruses, bacteria, and protozoan parasites during wastewater treatment to provide data addressing potential health risks associated with reuse options. Comparatively less is known about the fate of parasitic worm species ova in these complex systems. It is largely assumed that these helminths settle, are removed with the sludge, and consequently represent a relatively low risk for wastewater reuse applications. However, helminths are a highly diverse group of organisms that display a wide range of physical properties that complicate the application of a single treatment for helminth reduction during wastewater treatment. Moreover, their diverse biological and physical properties make some ova highly resistant to both disinfection (i.e., with chlorine or UV treatment) and physical removal (settling) through the wastewater treatment train, indicating that there may be reason to broaden the scope of our investigations into whether parasitic worm eggs can be identified in treated wastewater. The ubiquitous human parasitic nematode Enterobius vermicularis (pinworm) produces small, buoyant ova. Utilizing a novel diagnostic quantitative PCR (qPCR), this study monitored E. vermicularis presence at two full-scale wastewater treatment plants over the course of 8 months and demonstrated incomplete physical removal of E. vermicularis ova through tertiary treatment, with removal efficiencies approximating only 0.5 and 1.6 log 10 at the two wastewater treatment plants based on qPCR. These findings demonstrate the need for more-diverse surrogates of helminthic ova to fully assess treatment performance with respect to reclaimed wastewaters. IMPORTANCE Helminths, despite being a diverse and environmentally resistant class of pathogens, are often underestimated and ignored when treatment performance at modern wastewater treatment plants is considered. A one-size-fits-all surrogate for removal of helminth ova may be

  16. Pattern of cercarial emergence of Schistosoma curassoni from Niger and comparison with three sympatric species of schistosomes.

    Science.gov (United States)

    Mouchet, F; Théron, A; Brémond, P; Sellin, E; Sellin, B

    1992-02-01

    The emergence pattern of Schistosoma curassoni cercariae from Bulinus umbilicatus, whose adult worms parasitize bovine, caprine, and ovine ungulates in Niger, is of a circadian type with a mean emission time at 0855 hr +/- 1 hr 6 min, characteristic of the schistosome species parasitizing domestic or wild cattle. The comparison of this cercarial emergence pattern with those of the other 3 sympatric species of schistosomes (Schistosoma haematobium, Schistosoma bovis, and Schistosoma mansoni) shows a significant difference between the chronobiology of the cercariae infective for human and those infective for bovine hosts. This difference may improve epidemiological surveys based on snail prevalences by allowing the distinction between bulinids infected with human and bovine parasites.

  17. Rapid concentration and sensitive detection of hookworm ova from wastewater matrices using a real-time PCR method.

    Science.gov (United States)

    Gyawali, P; Sidhu, J P S; Ahmed, W; Jagals, P; Toze, S

    2015-12-01

    The risk of human hookworm infections from land application of wastewater matrices could be high in regions with high hookworm prevalence. A rapid, sensitive and specific hookworm detection method from wastewater matrices is required in order to assess human health risks. Currently available methods used to identify hookworm ova to the species level are time consuming and lack accuracy. In this study, a real-time PCR method was developed for the rapid, sensitive and specific detection of canine hookworm (Ancylostoma caninum) ova from wastewater matrices. A. caninum was chosen because of its morphological similarity to the human hookworm (Ancylostoma duodenale and Necator americanus). The newly developed PCR method has high detection sensitivity with the ability to detect less than one A. caninum ova from 1 L of secondary treated wastewater at the mean threshold cycle (CT) values ranging from 30.1 to 34.3. The method is also able to detect four A. caninum ova from 1 L of raw wastewater and from ∼4 g of treated sludge with mean CT values ranging from 35.6 to 39.8 and 39.8 to 39.9, respectively. The better detection sensitivity obtained for secondary treated wastewater compared to raw wastewater and sludge samples could be attributed to sample turbidity. The proposed method appears to be rapid, sensitive and specific compared to traditional methods and has potential to aid in the public health risk assessment associated with land application of wastewater matrices. Furthermore, the method can be adapted to detect other helminth ova of interest from wastewater matrices. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  18. Effects of Schistosomal mansoni infection on Calomys callosus coelom-associated lymphomyeloid tissue (milky spots

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    Jane A Lenzi

    1998-01-01

    Full Text Available Calomys callosus Rengger, 1830 (Rodentia: Cricetidae is a mouse-like South American wild rodent, which is permissive to Schistosoma mansoni infection. In this paper we studied the effect of schistosomal infection in C. callosus mesenteric and omental milky spots (MS, subsidiary foci of coelom-associated lymphomyeloid tissue (CALT, during the acute, transitional (acute to chronic, and chronic phases of the infection. MS were morphologically analyzed by histological methods, using brigthfield and confocal laser scanning microscopies. The MS of infected animals were mainly of lymphomyelocytic (42 to 90 days and lymphoplasmacytic (160 days of infection types and showed frequent presence of lymphoid follicles with germinal centers, plasmacytogenesis and plasmacytosis, mastocytosis, megakaryopoiesis, erythropoiesis and less pronounced eosinopoiesis. These results indicate that MS are a preferential site of germinal-center-dependent and independent plasmacytogenesis, and a bone marrow-like organ, committed with various cellular lineages. The consequence of C. callosus MS reactivity for schistosomal infection is still unknown and is under investigation.

  19. Immunological Consequences of Antihelminthic Treatment in Preschool Children Exposed to Urogenital Schistosome Infection

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    Nadine Rujeni

    2013-01-01

    Full Text Available Urogenital schistosomiasis, due to Schistosoma haematobium, is endemic in sub-Saharan Africa. Control is by targeted treatment with praziquantel but preschool age children are excluded from control programs. Immunological studies on the effect of treatment at this young age are scarce. In light of studies in older individuals showing that praziquantel alters antischistosome immune responses and responses to bystander antigens, this study aims to investigate how these responses would be affected by treatment at this young age. Antibody responses directed against schistosome antigens, Plasmodium falciparum crude and recombinant antigens, and the allergen house dust mite were measured in children aged 3 to 5 years before and 6 weeks after treatment. The change in serological recognition of schistosome proteins was also investigated. Treatment augmented antischistosome IgM and IgE responses. The increase in IgE responses directed against adult worm antigens was accompanied by enhanced antigen recognition by sera from the children. Antibody responses directed against Plasmodium antigens were not significantly affected by praziquantel treatment nor were levels of allergen specific responses. Overall, praziquantel treatment enhanced, quantitatively and qualitatively, the antiworm responses associated with protective immunity but did not alter Plasmodium-specific responses or allergen-specific responses which mediate pathology in allergic disease.

  20. Schistosome infection intensity is inversely related to auto-reactive antibody levels.

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    Francisca Mutapi

    Full Text Available In animal experimental models, parasitic helminth infections can protect the host from auto-immune diseases. We conducted a population-scale human study investigating the relationship between helminth parasitism and auto-reactive antibodies and the subsequent effect of anti-helminthic treatment on this relationship. Levels of antinuclear antibodies (ANA and plasma IL-10 were measured by enzyme linked immunosorbent assay in 613 Zimbabweans (aged 2-86 years naturally exposed to the blood fluke Schistosoma haematobium. ANA levels were related to schistosome infection intensity and systemic IL-10 levels. All participants were offered treatment with the anti-helminthic drug praziquantel and 102 treated schoolchildren (5-16 years were followed up 6 months post-antihelminthic treatment. ANA levels were inversely associated with current infection intensity but were independent of host age, sex and HIV status. Furthermore, after allowing for the confounding effects of schistosome infection intensity, ANA levels were inversely associated with systemic levels of IL-10. ANA levels increased significantly 6 months after anti-helminthic treatment. Our study shows that ANA levels are attenuated in helminth-infected humans and that anti-helminthic treatment of helminth-infected people can significantly increase ANA levels. The implications of these findings are relevant for understanding both the aetiology of immune disorders mediated by auto-reactive antibodies and in predicting the long-term consequences of large-scale schistosomiasis control programs.

  1. A molecular genetic study of the variations in metabolic function during schistosome development

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    Patrick J. Skelly

    1995-04-01

    Full Text Available During their complex life cycle schistosomes alternate between the use of stored glycogen and reliance on host glucose to provide for their energy needs. In addition, there is dramatic variation between the relative contribution of aerobic versus anaerobic glucose metabolism during development. We have cloned a set of representative cDNAs that encode proteins involved in glucose uptake, glycolysis, Kreb's cycle and oxidative phosphorylation. The different cDNAs were used as probes to examine the expression of glucose metabolism genes during the schistosome life cycle. Steady state mRNA levels from whole cercariae, isolated cercarial tails, schistosomula and adult worms were analysed on Northern blots and dot blots which were quantified using storage phosphor technology. These studies reveal: (1 Transcripts encoding glycogen metabolic enzymes are expressed to much higher levels in cercarial tails than whole cercariae or schistosomula while the opposite pattern is found for glucose transporters and hexokinase transcripts; (2 Schistosomula contain low levels of transcripts encoding respiratory enzymes but regain the capacity for aerobic glucose metabolism as they mature to adulthood; (3 Male and female adults contain similar levels of the different transcripts involved in glucose metabolism.

  2. Mobile Diagnostics Based on Motion? A Close Look at Motility Patterns in the Schistosome Life Cycle

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    Ewert Linder

    2016-06-01

    Full Text Available Imaging at high resolution and subsequent image analysis with modified mobile phones have the potential to solve problems related to microscopy-based diagnostics of parasitic infections in many endemic regions. Diagnostics using the computing power of “smartphones” is not restricted by limited expertise or limitations set by visual perception of a microscopist. Thus diagnostics currently almost exclusively dependent on recognition of morphological features of pathogenic organisms could be based on additional properties, such as motility characteristics recognizable by computer vision. Of special interest are infectious larval stages and “micro swimmers” of e.g., the schistosome life cycle, which infect the intermediate and definitive hosts, respectively. The ciliated miracidium, emerges from the excreted egg upon its contact with water. This means that for diagnostics, recognition of a swimming miracidium is equivalent to recognition of an egg. The motility pattern of miracidia could be defined by computer vision and used as a diagnostic criterion. To develop motility pattern-based diagnostics of schistosomiasis using simple imaging devices, we analyzed Paramecium as a model for the schistosome miracidium. As a model for invasive nematodes, such as strongyloids and filaria, we examined a different type of motility in the apathogenic nematode Turbatrix, the “vinegar eel.” The results of motion time and frequency analysis suggest that target motility may be expressed as specific spectrograms serving as “diagnostic fingerprints.”

  3. Detecting hybridization in African schistosome species: does egg morphology complement molecular species identification?

    Science.gov (United States)

    Boon, Nele A M; Fannes, Wouter; Rombouts, Sara; Polman, Katja; Volckaert, Filip A M; Huyse, Tine

    2017-06-01

    Hybrid parasites may have an increased transmission potential and higher virulence compared to their parental species. Consequently, hybrid detection is critical for disease control. Previous crossing experiments showed that hybrid schistosome eggs have distinct morphotypes. We therefore compared the performance of egg morphology with molecular markers with regard to detecting hybridization in schistosomes. We studied the morphology of 303 terminal-spined eggs, originating from 19 individuals inhabiting a hybrid zone with natural crosses between the human parasite Schistosoma haematobium and the livestock parasite Schistosoma bovis in Senegal. The egg sizes showed a high variability and ranged between 92·4 and 176·4 µm in length and between 35·7 and 93·0 µm in width. No distinct morphotypes were found and all eggs resembled, to varying extent, the typical S. haematobium egg type. However, molecular analyses on the same eggs clearly showed the presence of two distinct partial mitochondrial cox1 profiles, namely S. bovis and S. haematobium, and only a single nuclear ITS rDNA profile (S. haematobium). Therefore, in these particular crosses, egg morphology appears not a good indicator of hybrid ancestry. We conclude by discussing strengths and limitations of molecular methods to detect hybrids in the context of high-throughput screening of field samples.

  4. The p53 gene expression and its developmental regulation in schistosomes

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    Manami Tanaka

    1992-01-01

    Full Text Available We have studied the gene expression, especially of the oncoproteins, and its regulation in schistosomes. Schistosomes have a complex life cycle with defined dimorphic lifestyle. The parasite are so far unique in biology in expressing oncogene products in their adult stage. In order to characterize the expression and developmental regulation, a lambda gt 11 cDNA library and lambda EMBL4 genomic DNA library of each growth stage of Schistosoma mansoni and S. japonicum was constructed, and was screened with various monoclonal antibodies against ongogene products. One positive plaque reacted to anti-p53 antibody (Ab-2, Oncogene Science, Inc. was further analyzed. This fusion protein was about 120 KDa in molecular weights, and expressed as 1.4 Kb RNA in the adult stage. P53 gene is well-known as the negative regulator of the cell cicle, and the mutations in the gene are turning out to be the most common genetic alterations in human cancers. The comparison of the gene structure among species and stages were being conducted. Chromosome structures, C-band formation, and the results of in situ hybridization using the phage probe would be discussed.

  5. Pidotimod exacerbates allergic pulmonary infection in an OVA mouse model of asthma.

    Science.gov (United States)

    Fu, Luo-Qin; Li, Ya-Li; Fu, Ai-Kun; Wu, Yan-Ping; Wang, Yuan-Yuan; Hu, Sheng-Lan; Li, Wei-Fen

    2017-10-01

    Pidotimod is a synthetic dipeptide with biological and immuno‑modulatory properties. It has been widely used for treatment and prevention of recurrent respiratory infections. However, its impact on the regulation of allergic pulmonary inflammation is still not clear. In the current study, an ovalbumin (OVA)‑induced allergic asthma model was used to investigate the immune‑modulating effects of pidotimod on airway eosinophilia, mucus metaplasia and inflammatory factor expression compared with dexamethasone (positive control). The authors determined that treatment with pidotimod exacerbated pulmonary inflammation as demonstrated by significantly increased eosinophil infiltration, dramatically elevated immunoglobulin E production, and enhanced T helper 2 response. Moreover, treatment failed to attenuate mucus production in lung tissue, and did not reduce OVA‑induced high levels of FIZZ1 and Arg1 expression in asthmatic mice. In contrast, administration of dexamethasone was efficient in alleviating allergic airway inflammation in OVA‑induced asthmatic mice. These data indicated that pidotimod as an immunotherapeutic agent should be used cautiously and the effectiveness for controlling allergic asthma needs further evaluation and research.

  6. Detection of Schistosoma spindale ova and associated risk factors among Malaysian cattle through coprological survey.

    Science.gov (United States)

    Tan, Tiong Kai; Low, Van Lun; Lee, Soo Ching; Panchadcharam, Chandrawathani; Tay, Sun Tee; Ngui, Romano; Bathmanaban, Premaalatha; Kho, Kai Ling; Koh, Fui Xian; Sharma, Reuben Sunil Kumar; Jaafar, Tariq; Nizam, Quaza Nizamuddin Hassan; Lim, Yvonne Ai Lian

    2015-05-01

    The present study was conducted to determine the occurrence of Schistosoma spindale ova and its associated risk factors in Malaysian cattle through a coprological survey. A total of 266 rectal fecal samples were collected from six farms in Peninsular Malaysia. The overall infection rate of S. spindale was 6% (16 of 266). Schistosoma spindale infection was observed in two farms, with a prevalence of 5.4% and 51.9%, respectively. This trematode was more likely to co-occur with other gastro-intestinal parasites (i.e., Dicrocoelium spp., Paramphistomum spp., strongyle, Eimeria spp. and Entamoeba spp.). Chi-square analysis revealed that female cattle are less likely to get S. spindale infection as compared to male cattle (OR = 0.3; 95% CI = 0.08-1.06; p < 0.05), and cattle weighing lower than 200 kg, were significantly at higher risk than those higher than 200 kg (OR = 5; 95% CI = 1.07-24.79; p < 0.05) to the infection. Multivariate analysis confirmed that among the cattle in Malaysia, the age (cattle with two year old and higher: OR = 21; 95% CI = 2.48-179.44; p < 0.05) and weight (weighing 200 kg and lower: OR = 17; 95% CI = 3.38-87.19; p < 0.05) were risk factors for S. spindale infection among Malaysian cattle.

  7. Archaeometric studies of Byzantine pottery from Hârşova-Carsium, Romania

    Energy Technology Data Exchange (ETDEWEB)

    Bugoi, Roxana, E-mail: bugoi@nipne.ro [Horia Hulubei National Institute for Nuclear Physics and Engineering, Mǎgurele 077125 (Romania); Talmaţchi, Cristina, E-mail: ctalmatchi@gmail.com [Museum of National History and Archaeology, Constanţa 900745 (Romania); Haitǎ, Constantin, E-mail: costel_haita@yahoo.com [National Museum of Romania History, Bucharest 030026 (Romania); Ceccato, Daniele, E-mail: daniele.ceccato@lnl.infn.it [Università di Padova, Dipartimento di Fisica e Astronomia “Galileo Galilei”, Padova 35131 (Italy); INFN – LNL, Legnaro 35020 (Italy)

    2015-04-01

    A set of 36 ceramic shards excavated at Hârşova, Romania, dated to the 11th century A.D., was investigated using Optical Microscopy (OM) and PIXE (Particle Induced X-ray Emission). The study aimed at revealing the raw materials and the manufacturing techniques employed by the potters from the Lower Danube zone during the Byzantine period and to distinguish the local products from the supposedly imported ones. The division of the ceramic shards based on stylistic grounds was refined by the petrographic observations that identified four types of fabrics. Principal Component Analysis (PCA) of the PIXE data singled out two categories of ceramic: one made from kaolinitic clays and another produced from local sedimentary resources, with or without temper addition. Micro-PIXE scans of the interfaces between the green glaze and the underlying ceramic body indicated a high Pb content in the decorative layers. Glazing was made through the application of PbO onto a non-calcareous clay body. The petrographic and compositional data interpreted in correlation with archaeological information led to the characterization of a representative assemblage of ceramic finds from the Byzantine period, subject rarely tackled in the scientific literature.

  8. Exposure of ova to cortisol pre-fertilisation affects subsequent behaviour and physiology of brown trout.

    Science.gov (United States)

    Sloman, Katherine A

    2010-08-01

    Even before fertilisation, exposure of ova to high levels of stress corticosteroids can have significant effects on offspring in a variety of animals. In fish, high levels of cortisol in ovarian fluid can elicit morphological changes and reduce offspring survival. Whether there are other more subtle effects, including behavioural effects, of exposure to cortisol pre-fertilisation in fish is unclear. Here I demonstrate that a brief (3h) exposure of brown trout eggs to a physiologically relevant ( approximately 500 microg l(-)(1)) concentration of cortisol pre-fertilisation resulted in changes to developing offspring. Embryos exposed to cortisol pre-fertilisation displayed elevated oxygen consumption and ammonia excretion rates during development. After hatch, in contrast to the effects of cortisol exposure in juvenile fish, fish exposed to cortisol as eggs were more aggressive than control individuals and responded differently within a maze system. Thus, a transient exposure to corticosteroids in unfertilised eggs results in both physiological and behavioural alterations in fish. Copyright 2010 Elsevier Inc. All rights reserved.

  9. Distribution of freshwater snails in the river Niger basin in Mali with special reference to the intermediate hosts of schistosomes

    DEFF Research Database (Denmark)

    Madsen, Henry; Coulibaly, Godefroy; Furu, Peter

    1987-01-01

    Snail surveys were carried out in various parts of Mali. All areas surveyed are part of the Niger basin being either affluents or irrigation schemes fed by this river. The snail species present varied greatly between areas. The following potential hosts of schistosomes were recorded: Biomphalaria...

  10. Schistosomes of small mammals from the Lake Victoria Basin, Kenya: new species, familiar species, and implications for schistosomiasis control.

    Science.gov (United States)

    Hanelt, B; Mwangi, I N; Kinuthia, J M; Maina, G M; Agola, L E; Mutuku, M W; Steinauer, M L; Agwanda, B R; Kigo, L; Mungai, B N; Loker, E S; Mkoji, G M

    2010-06-01

    Recent schistosomiasis control efforts in sub-Saharan Africa have focused nearly exclusively on treatment of humans with praziquantel. However, the extent to which wild mammals act as reservoirs for Schistosoma mansoni and therefore as sources of renewed transmission following control efforts is poorly understood. With the objective to study the role of small mammals as reservoir hosts, 480 animals belonging to 9 rodent and 1 insectivore species were examined for infection with schistosomes in Kisumu, in the Lake Victoria Basin, Kenya. Animals were collected from 2 sites: near the lakeshore and from Nyabera Marsh draining into the lake. A total of 6.0% of the animals captured, including 5 murid rodent species and 1 species of shrew (Crocidura olivieri) were infected with schistosomes. Four schistosome species were recovered and identified using cox1 DNA barcoding: S. mansoni, S. bovis, S. rodhaini and S. kisumuensis, the latter of which was recently described from Nyabera Marsh. Schistosoma mansoni and S. rodhaini were found infecting the same host individual (Lophuromys flavopunctatus), suggesting that this host species could be responsible for the production of hybrid schistosomes found in the area. Although the prevalence of S. mansoni infection in these reservoir populations was low (1.5%), given their potentially vast population size, their impact on transmission needs further study. Reservoir hosts could perpetuate snail infections and favour renewed transmission to humans once control programmes have ceased.

  11. Polyethyleneimine mediated DNA transfection in schistosome parasites and regulation of the WNT signaling pathway by a dominant-negative SmMef2.

    Directory of Open Access Journals (Sweden)

    Shuang Liang

    Full Text Available Schistosomiasis is a serious global problem and the second most devastating parasitic disease following malaria. Parasitic worms of the genus Schistosoma are the causative agents of schistosomiasis and infect more than 240 million people worldwide. The paucity of molecular tools to manipulate schistosome gene expression has made an understanding of genetic pathways in these parasites difficult, increasing the challenge of identifying new potential drugs for treatment. Here, we describe the use of a formulation of polyethyleneimine (PEI as an alternative to electroporation for the efficacious transfection of genetic material into schistosome parasites. We show efficient expression of genes from a heterologous CMV promoter and from the schistosome Sm23 promoter. Using the schistosome myocyte enhancer factor 2 (SmMef2, a transcriptional activator critical for myogenesis and other developmental pathways, we describe the development of a dominant-negative form of the schistosome Mef2. Using this mutant, we provide evidence that SmMef2 may regulate genes in the WNT pathway. We also show that SmMef2 regulates its own expression levels. These data demonstrate the use of PEI to facilitate effective transfection of nucleic acids into schistosomes, aiding in the study of schistosome gene expression and regulation, and development of genetic tools for the characterization of molecular pathways in these parasites.

  12. Application of DNA-based diagnostics in detection of schistosomal DNA in early infection and after drug treatment

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    Ji Minjun

    2011-08-01

    Full Text Available Abstract Background Research is now focused on identification of sensitive and specific diagnostic tests for early identification of schistosomal infection and evaluation of chemotherapy in field situations in China. Results This study compared loop-mediated isothermal amplification (LAMP with conventional PCR as DNA-based diagnostic techniques for the early detection of schistosomal DNA and the evaluation of chemotherapy. The results showed that both PCR and LAMP assays targeting a 301 base pair (bp sequence of the highly repetitive retrotransposon, SjR2, amplified DNA from schistosomes but were unable to distinguish between schistosome species. LAMP and conventional PCR were shown to amplify the target sequence of the SjR2-pCR2.1 recombinant plasmid template with limits of detection of 10-4 ng and 10-2 ng, respectively, thus demonstrating the superior sensitivity of the LAMP method. Schistosoma japonicum DNA was detected in all serum samples obtained from the three experimental groups at 1 week post-infection by LAMP assay, while the rate of detection by conventional PCR ranged from 50% to 66%. The potential application of PCR and LAMP assays for the evaluation of artesunate and praziquantel chemotherapy was investigated. PCR was shown to be less sensitive for detection of schistosomal DNA in drug-treated rabbit sera than the LAMP method. Conclusions The data presented here indicate that LAMP is suitable for the detection of early infection in the groups primarily infected with Schistosoma japonicum, such as migrants, travellers, military personnel and the younger age groups. However, it is less suitable for evaluation of the efficacy of chemotherapy in the early stages because of its high sensitivity.

  13. Recent studies on the reproductive biology of the schistosomes and their relevance to speciation in the Digenea.

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    Southgate, V R; Jourdane, J; Tchuenté, L A

    1998-08-01

    The members of the family Schistosomatidae, dioecious Digenea, are discussed with regard to their distribution, intermediate and definitive host-parasite relationships. The biological species concept is considered together with the difficulties of its application to Schistosoma spp. and the Digenea. The correlation between pairing of adult schistosomes, physical and sexual development and the maintenance of reproductive potential is emphasised. Development of the female reproductive system does not depend upon species-specific pairing. In some combinations, e.g., Schistosoma haematobium/Schistosoma intercalatum and Schistosoma bovis/Schistosoma curassoni, a specific mate choice system apparently does not exist, whereas it does in other combinations, e.g., Schistosoma mansoni/Schistosoma intercalatum. In mixed infections change of mate may occur and when the opportunity arises heterospecific pairs of worms will change partners to conspecific pairs. Interspecific pairing in adult schistosomes will lead to either hybridisation or parthenogenesis. Yet the majority of schistosomes that inhabit the same definitive host maintain their genetic identity: specific mate recognition, site selection within the host and heterologous immunity have been suggested as isolating mechanisms. Experimental intraspecific crosses have enabled evaluation of the degree to which some populations separated and became reproductively isolated through pre-mating isolating mechanisms, indicative of incipient speciation, e.g., the Lower Guinea and Zaire strains of S. intercalatum. The occurrence and significance of parthenogenesis in schistosomes and other species of Digenea are discussed. The consequences of interspecific mating interactions in schistosomes with regard to parasite epidemiology, interspecific competition and genetic heterogeneity are debated. Geographical isolation and host specificity represent important pre-zygotic isolating mechanisms. It is suggested that site selection within

  14. In vivo imaging of schistosomes to assess disease burden using positron emission tomography (PET.

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    Nicolas Salem

    2010-09-01

    Full Text Available Schistosomes are chronic intravascular helminth parasites of humans causing a heavy burden of disease worldwide. Diagnosis of schistosomiasis currently requires the detection of schistosome eggs in the feces and urine of infected individuals. This method unreliably measures disease burden due to poor sensitivity and wide variances in egg shedding. In vivo imaging of schistosome parasites could potentially better assess disease burden, improve management of schistosomiasis, facilitate vaccine development, and enhance study of the parasite's biology. Schistosoma mansoni (S. mansoni have a high metabolic demand for glucose. In this work we investigated whether the parasite burden in mice could be assessed by positron emission tomography (PET imaging with 2-deoxy-2[(18F]fluoro-D-glucose (FDG.Live adult S. mansoni worms FDG uptake in vitro increased with the number of worms. Athymic nude mice infected with S. mansoni 5-6 weeks earlier were used in the imaging studies. Fluorescence molecular tomography (FMT imaging with Prosense 680 was first performed. Accumulation of the imaging probe in the lower abdomen correlated with the number of worms in mice with low infection burden. The total FDG uptake in the common portal vein and/or regions of elevated FDG uptake in the liver linearly correlated to the number of worms recovered from infected animals (R(2 =0.58, P<0.001, n = 40. FDG uptake showed a stronger correlation with the worm burden in mice with more than 50 worms (R(2 = 0.85, P<0.001, n = 17. Cryomicrotome imaging confirmed that most of the worms in a mouse with a high infection burden were in the portal vein, but not in a mouse with a low infection burden. FDG uptake in recovered worms measured by well counting closely correlated with worm number (R(2 = 0.85, P<0.001, n = 21. Infected mice showed a 32% average decrease in total FDG uptake after three days of praziquantel treatment (P = 0.12. The total FDG uptake in untreated mice increased

  15. Hsp70 May Be a Molecular Regulator of Schistosome Host Invasion.

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    Kenji Ishida

    2016-09-01

    Full Text Available Schistosomiasis is a debilitating disease that affects over 240 million people worldwide and is considered the most important neglected tropical disease following malaria. Free-swimming freshwater cercariae, one of the six morphologically distinct schistosome life stages, infect humans by directly penetrating through the skin. Cercariae identify and seek the host by sensing chemicals released from human skin. When they reach the host, they burrow into the skin with the help of proteases and other contents released from their acetabular glands and transform into schistosomula, the subsequent larval worm stage upon skin infection. Relative to host invasion, studies have primarily focused on the nature of the acetabular gland secretions, immune response of the host upon exposure to cercariae, and cercaria-schistosomulum transformation methods. However, the molecular signaling pathways involved from host-seeking through the decision to penetrate skin are not well understood. We recently observed that heat shock factor 1 (Hsf1 is localized to the acetabular glands of infectious schistosome cercariae, prompting us to investigate a potential role for heat shock proteins (HSPs in cercarial invasion. In this study, we report that cercarial invasion behavior, similar to the behavior of cercariae exposed to human skin lipid, is regulated through an Hsp70-dependent process, which we show by using chemical agents that target Hsp70. The observation that biologically active protein activity modulators can elicit a direct and clear behavioral change in parasitic schistosome larvae is itself interesting and has not been previously observed. This finding suggests a novel role for Hsp70 to act as a switch in the cercaria-schistosomulum transformation, and it allows us to begin elucidating the pathways associated with cercarial host invasion. In addition, because the Hsp70 protein and its structure/function is highly conserved, the model that Hsp70 acts as a

  16. Immunomodulatory Activity of Lactococcus lactis A17 from Taiwan Fermented Cabbage in OVA-Sensitized BALB/c Mice

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    Hui-Ching Mei

    2013-01-01

    Full Text Available From fermented Taiwan foods, we have isolated numerous lactic acid bacteria (LAB of plant origin and investigated their biological activities. This study aimed to investigate the immunomodulatory effect and mechanism of Lactococcus lactis A17 (A17, isolated from Taiwan fermented cabbage, on ovalbumin (OVA-sensitized mice. Human peripheral blood mononuclear cells were used to verify immune responses of A17 by IFN-γ production. Live (A17-A and heat-killed A17 (A17-H were orally administered to OVA-sensitized BALB/c mice to investigate their effects on immunoglobulin (Ig and cytokine production. The mRNA expression of Toll-like receptors (TLR and nucleotide binding oligomerization domain (NOD-like protein receptors in spleen cells was analyzed by real-time RT-PCR. Both live and heat-killed A17 modulate OVA-induced allergic effects. B-cell response was modulated by diminishing IgE production and raising OVA-specific IgG2a production, while T-cell response was modulated by increasing IFN-γ production and decreasing IL-4 production. The mRNA expression of NOD-1, NOD-2, and TLR-4 was down-regulated by A17 as well. This is the first report to describe a naïve Lactococcus lactis A17 strain as a promising candidate for prophylactic and therapeutic treatments of allergic diseases via oral administration. Our results suggest the ameliorative effects of A17 may be caused by modulating NOD-1 NOD-2, and TLR-4 expression.

  17. Terminal Restriction Fragment Length Polymorphism for the Identification of Spirorchiid Ova in Tissues from the Green Sea Turtle, Chelonia mydas.

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    Phoebe A Chapman

    Full Text Available Blood flukes are among the most common disease causing pathogens infecting vertebrates, including humans and some of the world's most globally endangered fauna. Spirorchiid blood flukes are parasites of marine turtles, and are associated with pathology, strandings and mortalities worldwide. Their ova embolize in tissues and incite significant inflammatory responses, however attempts to draw correlations between species and lesions are frustrated by difficulties in identifying ova beyond the genus level. In this study, a newly developed terminal restriction fragment length polymorphism (T-RFLP method was validated as a tool for differentiating between mixed spirorchiid ova in turtle tissue. Initially, a multiplex PCR was used to differentiate between the five genera of spirorchiid flukes. Following this, PCR was performed using genus/genera-specific fluorescently tagged primer pairs and PCR products digested analysis using restriction endonucleases. Using capillary electrophoresis, this T-RFLP method could differentiate between twelve species and genotypes of spirorchiid flukes in turtles. It was applied to 151 tissue samples and successfully identified the spirorchiid species present. It was found to be more sensitive than visual diagnosis, detecting infections in 28 of 32 tissues that were negative on histology. Spirorchiids were present in 96.7% of tissues tested, with Neospirorchis genotype 2 being the most prevalent, present in 93% of samples. Mixed infections were common, being present in 60.7% of samples tested. The method described here is, to our knowledge, the first use of the T-RFLP technique on host tissues or in an animal ecology context, and describes a significant advancement in the clinical capacity to diagnose a common cause of illness in our environment. It is proven as a sensitive, specific and cost-efficient means of identifying spirorchiid flukes and ova in turtles, with the potential to contribute valuable information to

  18. Ex ova chick chorioallantoic membrane as a novel model for evaluation of tissue responses to biomaterials and implants.

    Science.gov (United States)

    Klueh, Ulrike; Dorsky, David I; Moussy, Francis; Kreutzer, Don L

    2003-12-01

    One of the major obstacles in developing rationale strategies to control inflammation and fibrosis surrounding implants is the lack of a simple and inexpensive in vivo model to screen tissue reactions to various biomaterials and implants. To begin to fill this gap, we have developed an ex ova model of the chick embryo chorioallantoic membrane (CAM) for testing of tissue reaction to biomaterials and implants. For these studies, we evaluated tissue reactions (inflammation and fibrosis) to two commonly used biomaterials (nylon and silastic) grossly and histologically in the ex ova CAM. Nylon mesh was incorporated within the CAM tissue 4 days postplacement. After 8 days postplacement, the nylon mesh was totally incorporated into the CAM. Histologically, little or no inflammation was seen associated with the incorporated nylon mesh at any time point. In the case of silastic tubing, significant incorporation of the CAM was seen grossly by 1-2 days postplacement. Incorporation of the tubing continued at day 8 postplacement of the silastic tubing, with ingrowth of the CAM into the lumen of the tubing. Histological evaluation of CAMs indicated that no significant tissue reactions (inflammation or fibrosis) occurred in the CAM tissue surrounding the silastic tubing or in the CAM tissue and vasculature that had grown into the silastic tubing. To our knowledge, this report represents the first investigation of the usage of the ex ova CAM model, a shell-less chick embryo model (ex ova), as an in vivo model to test the tissue reactions to biomaterials and implants. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 838-843, 2003

  19. Effect of volatile fatty acids in anaerobic conditions on viability of helminth ova (Ascaris suum) in sanitization of municipal sludge.

    Science.gov (United States)

    Rojas-Oropeza, Marcelo; Hernández-Uresti, Alejandro S; Ortega-Charleston, Luis S; Cabirol, Nathalie

    2017-09-01

    The present work aimed at evaluating the effect of four different mixtures of diverse volatile fatty acids (VFAs) on the viability of helminth ova (Ascaris suum), under mesophilic (35°C) anaerobic conditions and at different incubation times, in order to reproduce the process of two-phase anaerobic digestion. The mixtures of VFAs contained acetic, propionic, butyric, valeric, and isovaleric acids, used at concentrations normally found in acidogenic anaerobic digesters. The four treatments all showed a reduction in Ascaris suum ova viability, among which Treatment III (4.2 g-acetic acid L(-1) +  2.2 g-propionic acid L(-1) + 0.6 g-valeric acid L(-1) + 0.6 g-isovaleric acid L(-1)) resulted the most efficient. We found that the full effect of VFAs on the viability loss of Ascaris suum ova in mesophilic conditions requires a minimum incubation time of 3 days. The highest efficiency in the loss of viability was observed with Treatment III and 4-day incubation. Interestingly, the proportion of acetic acid was three times as much in this treatment than in the other ones and resulted in an effect in a minimum time of 3 days. The mesophilic condition, however, was not sufficient to induce a complete loss of viability.

  20. Numerical investigations of fault-induced seawater circulation in the Seferihisar-Balçova Geothermal system, western Turkey

    Science.gov (United States)

    Magri, F.; Akar, T.; Gemici, U.; Pekdeger, A.

    2012-02-01

    The Seferihisar-Balçova Geothermal system (SBG), Turkey, is characterized by temperature and hydrochemical anomalies along the faults: thermal waters in northern Balçova are heated meteoric freshwater, whereas the hot springs of the southern Seferihisar region have a strong seawater contribution. Previous numerical simulations of fluid flow and heat transport indicated that focused upsurge of hot water in faults induces a convective-like flow motion in surrounding units. Salt transport is fully coupled to thermally driven flow to study whether fault-induced convection cells could be responsible for seawater encroachment in the SBG. Isotope data are presented to support the numerical findings. The results show that fault-induced convection cells generate seawater plumes that extend from the seafloor toward the faults. At fault intersections, seawater mixes with rising hot thermal waters. The resulting saline fluids ascend to the surface along the fault, driven by buoyant forces. In Balçova, thick alluvium, minor faults and regional flow prevent ascending salty water from spreading at the surface, whereas the weak recharge flow in the thin alluvium of the southern SBG is not sufficient to flush the ascending hot salty waters. These mechanisms could develop in any faulted geothermal system, with implications for minerals and energy migration in sedimentary basins.

  1. Trichuris suis ova therapy in relapsing multiple sclerosis is safe but without signals of beneficial effect.

    Science.gov (United States)

    Voldsgaard, A; Bager, P; Garde, E; Åkeson, P; Leffers, A M; Madsen, C G; Kapel, C; Roepstorff, A; Thamsborg, S M; Melbye, M; Siebner, H; Søndergaard, H B; Sellebjerg, F; Sørensen, P Soelberg

    2015-11-01

    An observational study has suggested that relapsing-remitting multiple sclerosis patients with helminth infections have lower disease activity and progression than uninfected multiple sclerosis patients. To evaluate the safety and efficacy on MRI activity of treatment with TSO in relapsing MS. The study was an open-label, magnetic resonance imaging assessor-blinded, baseline-to-treatment study including ten patients with relapsing forms of multiple sclerosis. Median (range) age was 41 (24-55) years, disease duration 9 (4-34) years, Expanded Disability Status Scale score 2.5 (1-5.0), and number of relapses within the last two years 3 (2-5). Four patients received no disease modifying therapy, while six patients received IFN-β. After an observational period of 8 weeks, patients received 2500 ova from the helminth Trichuris suis orally every second week for 12 weeks. Patients were followed with serial magnetic resonance imaging, neurological examinations, laboratory safety tests and expression of immunological biomarker genes. Treatment with Trichuris suis orally was well-tolerated apart from some gastrointestinal symptoms. Magnetic resonance imaging revealed 6 new or enlarged T2 lesions in the run-in period, 7 lesions in the early period and 21 lesions in the late treatment period. Two patients suffered a relapse before treatment and two during treatment. Eight patients developed eosinophilia. The expression of cytokines and transcription factors did not change. In a small group of relapsing multiple sclerosis patients, Trichuris suis oral therapy was well tolerated but without beneficial effect. © The Author(s), 2015.

  2. [Spatial regression analysis of relationship between schistosome infection rate of Oncomelania hupensis snails and climate factors].

    Science.gov (United States)

    Chen, Yan-yan; Iu, Jian-bing; Xiao, Ying; Zhou, Xiao-rong; Jiang, Yong; Dai, Ling-feng; Cai, Shun-xiang

    2015-04-01

    To explore the relationship between the schistosome infection rate of O. hupensis snails and the climate factors in endemic areas of schistosomiasis, so as to provide the evidence for improving the snail control. The snail and climate data of 18 counties in Hubei Province in 2009 were collected to obtain the infection rate of O. hupensis snails and to fit the spatial regression models. The multiple linear regression model showed that the residuals were autocorrelated (Moran's I = 0.182 8, P snails was positively correlated with the annual average temperature (P 0.05). The spatial regression models could be well applied in the analysis of the relationship between the O. hupensis snails and climate factors. The annual average temperature is the primary climate factor influencing the infection of O. hupensis snails.

  3. Hyperdiverse gene cluster in snail host conveys resistance to human schistosome parasites.

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    Jacob A Tennessen

    2015-03-01

    Full Text Available Schistosomiasis, a neglected global pandemic, may be curtailed by blocking transmission of the parasite via its intermediate hosts, aquatic snails. Elucidating the genetic basis of snail-schistosome interaction is a key to this strategy. Here we map a natural parasite-resistance polymorphism from a Caribbean population of the snail Biomphalaria glabrata. In independent experimental evolution lines, RAD genotyping shows that the same genomic region responds to selection for resistance to the parasite Schistosoma mansoni. A dominant allele in this region conveys an 8-fold decrease in the odds of infection. Fine-mapping and RNA-Seq characterization reveal a 25% haplotypes across the GRC, a significantly non-neutral pattern, suggests that balancing selection maintains diversity at the GRC. Thus, the GRC resembles immune gene complexes seen in other taxa and is likely involved in parasite recognition. The GRC is a potential target for controlling transmission of schistosomiasis, including via genetic manipulation of snails.

  4. Extensive spinal cord involvement in magnetic resonance imaging evaluation on schistosomal myelitis

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    Claudio Henrique Fernandes Vidal

    2012-03-01

    Full Text Available The diagnosis of schistosomal myelitis (SM is frequently presumptive because no findings from any complementary examination are pathognomonic for this disease. The present report describes some abnormalities seen on magnetic resonance imaging (MRI evaluation of a series of SM patients and discusses their etiopathogenesis. Methods: This study evaluated SM patients at the time of their diagnosis. These patients routinely underwent MRI on all segments of the spinal cord. Results: Thirteen patients were evaluated. The MRI was abnormal in 12 (92.3% of them. In 11 patients (84.61%, the damage reached two or more spinal segments. Conclusions: MRI was an important diagnostic aid in this sample, because of the high rate of abnormalities detected. The tissue damage observed on MRI was extensive in the majority of the patients.

  5. Host determinants of reinfection with schistosomes in humans: a systematic review and meta-analysis.

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    Evaristus Chibunna Mbanefo

    2014-09-01

    Full Text Available Schistosomiasis is still a major public health burden in the tropics and subtropics. Although there is an effective chemotherapy (Praziquantel for this disease, reinfection occurs rapidly after mass drug administration (MDA. Because the entire population do not get reinfected at the same rate, it is possible that host factors may play a dominant role in determining resistance or susceptibility to reinfection with schistosomes. Here, we systematically reviewed and meta-analyzed studies that reported associations between reinfection with the principal human-infecting species (S. mansoni, S. japonicum and S. haematobium and host socio-demographic, epidemiological, immunological and genetic factors.PubMed, Scopus, Google Scholar, Cochrane Review Library and African Journals Online public databases were searched in October 2013 to retrieve studies assessing association of host factors with reinfection with schistosomes. Meta-analysis was performed to generate pooled odds ratios and standardized mean differences as overall effect estimates for dichotomous and continuous variables, respectively. Quality assessment of included studies, heterogeneity between studies and publication bias were also assessed. Out of the initial 2739 records, 109 studies were included in the analyses, of which only 32 studies with 37 data sets were eligible for quantitative data synthesis. Among several host factors identified, strong positive association was found with age and pre-treatment intensity, and only slightly for gender. These factors are major determinants of exposure and disease transmission. Significant positive association was found with anti-SWA IgG4 level, and a negative overall effect for association with IgE levels. This reconfirmed the concept that IgE/IgG4 balance is a major determinant of protective immunity against schistosomiasis. Other identified determinants were reported by a small number of studies to enable interpretation.Our data contribute to

  6. Schistosomes with wings: how host phylogeny and ecology shape the global distribution of Trichobilharzia querquedulae (Schistosomatidae).

    Science.gov (United States)

    Ebbs, Erika T; Loker, Eric S; Davis, Norm E; Flores, Veronica; Veleizan, Aylen; Brant, Sara V

    2016-09-01

    Migratory waterfowl play an important role in the maintenance and spread of zoonotic diseases worldwide. An example is cercarial dermatitis, caused when larval stages of schistosomes that normally develop in birds penetrate human skin. Members of the genus Trichobilharzia (Schistosomatidae), transmitted mainly by ducks, are considered to be major etiological agents of cercarial dermatitis globally. To better understand the diversity and distribution of Trichobilharzia spp., we surveyed ducks from the United States, eastern Canada, Argentina, South Africa and New Zealand. To aid in species identification of the Trichobilharzia worms recovered, regions of the Cox1, ND4 and ITS1 were sequenced. Furthermore, we provide molecular phylogenetic evidence for the cosmopolitan distribution and trans-hemispheric gene flow for one species, Trichobilharzia querquedulae, previously thought to be restricted to North America. These new samples from endemic non-migratory duck species indicate that T. querquedulae transmission occurs within each of the regions we sampled and that it is specific to the blue-winged+silver teal duck clade. Prevalence within this host group is >95% across the known range of T. querquedulae, indicating that transmission is common. Genetic divergence is evenly distributed among continents, and no phylogenetic structure associated with geography was observed. The results provide strong support for the global distribution and transmission of T. querquedulae and represent, to our knowledge, the first report of a cosmopolitan schistosome confirmed by genetic data. These data are the first known to support trans-hemispheric genetic exchange in a species responsible for causing cercarial dermatitis, indicating that the epidemiology of this group of poorly known zoonotic parasites is more complex than previously expected. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

  7. Inactivation of rabies virus.

    Science.gov (United States)

    Wu, Guanghui; Selden, David; Fooks, Anthony R; Banyard, Ashley

    2017-05-01

    Rabies virus is a notifiable pathogen that must be handled in high containment facilities where national and international guidelines apply. For the effective inactivation of rabies virus, a number of reagents were tested. Virkon S (1%) solution caused more than 4log reduction of rabies virus in culture medium supplemented with 10% foetal calf serum within 1min. Isopropyl alcohol (70%) treatment resulted in >3log reduction of rabies virus within 20s when applied at a ratio of 19:1, making it a suitable agent for surface decontamination whereas 70% ethanol was ineffective. Rabies virus (from 102.33 to 103ffu/ml) was also inactivated when cell cultures were fixed with 3% or 4% paraformaldehyde for 30min. Regardless of inactivation procedure, when taking inactivated virus preparations out of a biological containment envelope, proof of inocuity must be demonstrated to cover any possible error/deviation from procedure. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  8. Expression of schistosomal cathepsin l1 in Escherichia coli and evaluation of its protective capacity in an animal challenge

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    PA Miyasato

    2009-01-01

    Full Text Available Schistosomes utilize proteinases to accomplish several activities such as tissue penetration, tissue digestion and evasion of host immune responses. Cathepsin L is a cysteine proteinase of the papain superfamily detected in their gut lumen which indicates that this enzyme contributes to the proteolysis of ingested hemoglobin. Due to the roles played in the schistosome biology, proteolytic enzymes are considered potential targets for developing and guiding antischistosomal therapies. In the present work, the cathepsin L1 cDNA coding of Schistosoma mansoni was cloned into the pAE vector that provides high-level expression of heterologous proteins in Escherichia coli. The recombinant protein was expressed as inclusion bodies, purified under denaturing conditions through nickel-charged chromatography and used for experimental animal vaccination. ELISA was performed with the pooled sera. Although this protein was shown to be immunogenic, mice immunized with three doses of recombinant protein plus aluminum hydroxide as adjuvant were not protected against S. mansoni infection.

  9. Schistosome-induced portacaval haemodynamic changes in Rattus rattus are associated with translocation of adult worms to the lungs

    OpenAIRE

    Imbert-Establet, D.; Mone, H.; Coulson, P.S.; Wilson, R A

    1998-01-01

    The presence of naturally portacaval shunts has been investigated in the vasculature of normal and Schistosoma mansoni-infected Rattus rattus. Using the technique of injecting Polystyrene microspheres in the superior mesenteric vein, we demonstrated that the presence of adult schistosomes in the lungs of R. rattus was not due to an innate anomaly of the rat vasculature but resulted from the formation of portacaval shunts during infection. In rats harbouring a bisexual infection, microspheres ...

  10. Isolation and preservation of schistosome eggs and larvae in RNAlater® facilitates genetic profiling of individuals

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    Webster Bonnie L

    2009-10-01

    Full Text Available Abstract Although field-sampling procedures to capture gDNA from individual schistosome larval stages directly from their natural hosts exist, they do pose some technical and logistical challenges hampering certain epidemiological studies. The aim of this study was to develop, refine and evaluate an alternative methodology, which enables better preservation of large numbers of individual schistosome larval stages and eggs collected in low resource endemic areas, to provide PCR-quality DNA for multi-locus genetic analysis. The techniques reported here present simple and effective short-term field and long-term laboratory preservation and storage systems for individually sampled schistosome eggs and larval stages using a commercially available aqueous stabilisation reagent, RNAlater® eliminating the need for more cumbersome resources such as refrigerators, heaters and centrifuge equipment for immediate specimen processing. Adaptations to a general gDNA extraction method are described, that enables the acquisition of a gDNA extract (~50 μl, facilitating multiple molecular analyses of each sampled schistosome. The methodology provided PCR-quality mitochondrial and nuclear DNA from laboratory cercariae, miracidia and eggs that had been stored at up to 37°C for 2 weeks and at 4°C for 6 months and also from field collected samples. This present protocol provides significant epidemiological, ethical and practical advantages over existing sampling methods and has the potential to be transferred to studies on other organisms, especially where specimens are unable to be seen by the naked eye, are difficult to handle and need to be obtained from a field environment.

  11. Infection with schistosome parasites in snails leads to increased predation by prawns: implications for human schistosomiasis control.

    Science.gov (United States)

    Swartz, Scott J; De Leo, Giulio A; Wood, Chelsea L; Sokolow, Susanne H

    2015-12-01

    Schistosomiasis - a parasitic disease that affects over 200 million people across the globe - is primarily transmitted between human definitive hosts and snail intermediate hosts. To reduce schistosomiasis transmission, some have advocated disrupting the schistosome life cycle through biological control of snails, achieved by boosting the abundance of snails' natural predators. But little is known about the effect of parasitic infection on predator-prey interactions, especially in the case of schistosomiasis. Here, we present the results of laboratory experiments performed on Bulinus truncatus and Biomphalaria glabrata snails to investigate: (i) rates of predation on schistosome-infected versus uninfected snails by a sympatric native river prawn, Macrobrachium vollenhovenii, and (ii) differences in snail behavior (including movement, refuge-seeking and anti-predator behavior) between infected and uninfected snails. In predation trials, prawns showed a preference for consuming snails infected with schistosome larvae. In behavioral trials, infected snails moved less quickly and less often than uninfected snails, and were less likely to avoid predation by exiting the water or hiding under substrate. Although the mechanism by which the parasite alters snail behavior remains unknown, these results provide insight into the effects of parasitic infection on predator-prey dynamics and suggest that boosting natural rates of predation on snails may be a useful strategy for reducing transmission in schistosomiasis hotspots. © 2015. Published by The Company of Biologists Ltd.

  12. Association between Micronutrients (Vitamin A, D, Iron and Schistosome-Specific Cytokine Responses in Zimbabweans Exposed to Schistosoma haematobium

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    Liam Reilly

    2012-01-01

    Full Text Available Micronutrients play an important role in the development of effective immune responses. This study characterised a populations exposed to schistosome infections in terms of the relationship between micronutrients and immune responses. Levels of retinol binding protein (RBP; vitamin A marker, vitamin D, ferritin and soluble transferrin receptor (sTfR, and C reactive protein (CRP were related to levels of schistosome specific cytokines (IFN-γ, IL-4/5/10 in 40 Zimbabweans (7–54 years exposed to Schistosoma haematobium infection. 67.2% of the participants were deficient in vitamin D. RBP levels were within normal ranges but declined with age. The two indicators of iron levels suggested that although levels of stored iron were within normal levels (normal ferritin levels, levels of functional iron (sTfR levels were reduced in 28.6% of the population. Schistosome infection alone was not associated with levels of any of the micronutrients, but altered the relationship between parasite-specific IL-4 and IL-5 and levels of ferritin and sTfR.

  13. School Water, Sanitation, and Hygiene, Soil-Transmitted Helminths, and Schistosomes: National Mapping in Ethiopia.

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    Jack E T Grimes

    2016-03-01

    Full Text Available It is thought that improving water, sanitation, and hygiene (WASH might reduce the transmission of schistosomes and soil-transmitted helminths, owing to their life cycles. However, few large-scale studies have yet assessed the real extent of associations between WASH and these parasites.In the 2013-2014 Ethiopian national mapping of infections with these parasites, school WASH was assessed alongside infection intensity in children, mostly between 10 and 15 years of age. Scores were constructed reflecting exposure to schistosomes arising from water collection for schools, from freshwater sources, and the adequacy of school sanitation and hygiene facilities. Kendall's τb was used to test the WASH scores against the school-level arithmetic mean intensity of infection with each parasite, in schools with at least one child positive for the parasite in question. WASH and parasitology data were available for 1,645 schools. More frequent collection of water for schools, from open freshwater sources was associated with statistically significantly higher Schistosoma mansoni infection intensity (Kendall's τb = 0.097, 95% confidence interval, CI: 0.011 to 0.18, better sanitation was associated with significantly lower Ascaris lumbricoides intensity (Kendall's τb = -0.067, 95% CI: -0.11 to -0.023 and borderline significant lower hookworm intensity (Kendall's τb = -0.039, 95% CI: -0.090 to 0.012, P = 0.067, and better hygiene was associated with significantly lower hookworm intensity (Kendall's τb = -0.076, 95% CI: -0.13 to -0.020. However, no significant differences were observed when comparing sanitation and infection with S. mansoni or Trichuris trichiura, or hygiene and infection with A. lumbricoides or T. trichiura.Improving school WASH may reduce transmission of these parasites. However, different forms of WASH appear to have different effects on infection with the various parasites, with our analysis finding the strongest associations between

  14. School Water, Sanitation, and Hygiene, Soil-Transmitted Helminths, and Schistosomes: National Mapping in Ethiopia.

    Science.gov (United States)

    Grimes, Jack E T; Tadesse, Gemechu; Mekete, Kalkidan; Wuletaw, Yonas; Gebretsadik, Abeba; French, Michael D; Harrison, Wendy E; Drake, Lesley J; Gardiner, Iain A; Yard, Elodie; Templeton, Michael R

    2016-03-01

    It is thought that improving water, sanitation, and hygiene (WASH) might reduce the transmission of schistosomes and soil-transmitted helminths, owing to their life cycles. However, few large-scale studies have yet assessed the real extent of associations between WASH and these parasites. In the 2013-2014 Ethiopian national mapping of infections with these parasites, school WASH was assessed alongside infection intensity in children, mostly between 10 and 15 years of age. Scores were constructed reflecting exposure to schistosomes arising from water collection for schools, from freshwater sources, and the adequacy of school sanitation and hygiene facilities. Kendall's τb was used to test the WASH scores against the school-level arithmetic mean intensity of infection with each parasite, in schools with at least one child positive for the parasite in question. WASH and parasitology data were available for 1,645 schools. More frequent collection of water for schools, from open freshwater sources was associated with statistically significantly higher Schistosoma mansoni infection intensity (Kendall's τb = 0.097, 95% confidence interval, CI: 0.011 to 0.18), better sanitation was associated with significantly lower Ascaris lumbricoides intensity (Kendall's τb = -0.067, 95% CI: -0.11 to -0.023) and borderline significant lower hookworm intensity (Kendall's τb = -0.039, 95% CI: -0.090 to 0.012, P = 0.067), and better hygiene was associated with significantly lower hookworm intensity (Kendall's τb = -0.076, 95% CI: -0.13 to -0.020). However, no significant differences were observed when comparing sanitation and infection with S. mansoni or Trichuris trichiura, or hygiene and infection with A. lumbricoides or T. trichiura. Improving school WASH may reduce transmission of these parasites. However, different forms of WASH appear to have different effects on infection with the various parasites, with our analysis finding the strongest associations between water and S

  15. Rigidity and resistance of larval- and adult schistosomes-medium interface

    Energy Technology Data Exchange (ETDEWEB)

    Migliardo, Federica, E-mail: fmigliardo@unime.it [Department of Physics and Earth Sciences, University of Messina, 98166 Messina (Italy); Tallima, Hatem; El Ridi, Rashika [Zoology Department, Faculty of Science, Cairo University, Cairo 12613 (Egypt)

    2014-03-28

    Graphical abstract: - Highlights: • Schistosoma larvae and worms are studied by neutron scattering. • Measurements on larvae were repeated after one day and by increasing temperature. • The flexibility properties of larvae and adult parasites are compared. • The parasite rigidity is related to their resistance to the hostile environment. • Insight into the parasite defense mechanisms to the immune system attack is achieved. - Abstract: Schistosomiasis is second only to malaria in prevalence and severity, and is still a major health problem in many tropical countries worldwide with about 200–300 million cases and with more than 800 million people at risk of infection. Based on these data, the World Health Organization recommends fostering research efforts for understanding at any level the mechanisms of the infection and then decreasing the social and economical impact of schistosomiasis. A key role is played by the parasite apical lipid membrane, which is entirely impervious to the surrounding elements of the immune system. We have previously demonstrated that the interaction between schistosomes and surrounding medium is governed by a parasite surface membrane sphingomyelin-based hydrogen barrier. In the present article, the elastic contribution to the total motion as a function of the exchanged wave-vector Q and the mean square displacement values for Schistosoma mansoni larvae and worms and Schistosomahaematobium worms have been evaluated by quasi elastic neutron scattering (QENS). The results point out that S. mansoni larvae show a smaller mean square displacement in comparison to S. mansoni and S. haematobium worms. These values increased by repeating the measurements after one day. These differences, which are analogous to those observed for the diffusion coefficient we previously evaluated, are interpreted in terms of rigidity of the parasite-medium interaction. S. mansoni larvae are the most rigid systems, while S. haematobium worms are the most

  16. Single classifier, OvO, OvA and RCC multiclass classification method in handheld based smartphone gait identification

    Science.gov (United States)

    Raziff, Abdul Rafiez Abdul; Sulaiman, Md Nasir; Mustapha, Norwati; Perumal, Thinagaran

    2017-10-01

    Gait recognition is widely used in many applications. In the application of the gait identification especially in people, the number of classes (people) is many which may comprise to more than 20. Due to the large amount of classes, the usage of single classification mapping (direct classification) may not be suitable as most of the existing algorithms are mostly designed for the binary classification. Furthermore, having many classes in a dataset may result in the possibility of having a high degree of overlapped class boundary. This paper discusses the application of multiclass classifier mappings such as one-vs-all (OvA), one-vs-one (OvO) and random correction code (RCC) on handheld based smartphone gait signal for person identification. The results is then compared with a single J48 decision tree for benchmark. From the result, it can be said that using multiclass classification mapping method thus partially improved the overall accuracy especially on OvO and RCC with width factor more than 4. For OvA, the accuracy result is worse than a single J48 due to a high number of classes.

  17. Oral Administration of MBG to Modulate Immune Responses and Suppress OVA-Sensitized Allergy in a Murine Model

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    Yu-Sheng Wu

    2014-01-01

    Full Text Available Recently studies performed on mushroom isolated polysaccharides demonstrated that β-(1,3-glucan may affect the balance of Th1/Th2 cell response. Using ovalbumin (OVA as a hypersensitivity inducer, we evaluated the ability of mushroom beta-glucan (MBG in modulating Th1/Th2 cell responses in B6 mice. As compared to the control group, administration of MBG resulted in an increase of phagocytic activities, Th1 cytokine productions, immunoglobulins including IgG2A and IgA, and a significant expression of the splenic surface markers including CD3, CD4, CD8, and F4/80. In contrast, administration of MBG has significantly suppressed IgE and IgG1 levels and Th2 cytokines including IL-4, IL-5, and IL-6. Histopathological observation of MBG-treated followed by OVA-treated mice showed less filtration of eosinophil in pulmonary tissue sections. Our data suggested that administration of MBG treatments alters the natural course of the IgE-mediated hypersensitivities. In this investigation, we realize the mushroom beta glucan alter the Th2 response toward the Th1 in the allergic, resulting in a reduction in IgE productions which played a substantive role in reducing the severity of IgE-mediated hypersensitivity.

  18. Pharmacological profiling an abundantly expressed schistosome serotonergic GPCR identifies nuciferine as a potent antagonist

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    John D. Chan

    2016-12-01

    Full Text Available 5-hydroxytryptamine (5-HT is a key regulator of muscle contraction in parasitic flatworms. In Schistosoma mansoni, the myoexcitatory action of 5-HT is effected through activation of a serotonergic GPCR (Sm.5HTRL, prioritizing pharmacological characterization of this target for anthelmintic drug discovery. Here, we have examined the effects of several aporphine alkaloids on the signaling activity of a heterologously expressed Sm.5HTRL construct using a cAMP biosensor assay. Four structurally related natural products – nuciferine, D-glaucine, boldine and bulbocapnine – were demonstrated to block Sm.5HTRL evoked cAMP generation with the potency of GPCR blockade correlating well with the ability of each drug to inhibit contractility of schistosomule larvae. Nuciferine was also effective at inhibiting both basal and 5-HT evoked motility of adult schistosomes. These data advance our understanding of structure-affinity relationships at Sm.5HTRL, and demonstrate the effectiveness of Sm.5HTRL antagonists as hypomotility-evoking drugs across different parasite life cycle stages.

  19. Three-dimensional structure of a schistosome serpin revealing an unusual configuration of the helical subdomain

    Energy Technology Data Exchange (ETDEWEB)

    Granzin, Joachim [Institute of Complex Systems, ICS-6: Structural Biochemistry, Forschungszentrum Jülich, 52425 Jülich (Germany); Huang, Ying; Topbas, Celalettin [Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195 (United States); Huang, Wenying [Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195 (United States); Wu, Zhiping [Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195 (United States); Misra, Saurav [Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195 (United States); Hazen, Stanley L. [Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195 (United States); Blanton, Ronald E. [Department of Infectious Diseases, Case Western Reserve University, Cleveland, OH 44190 (United States); Lee, Xavier [Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195 (United States); Weiergräber, Oliver H., E-mail: o.h.weiergraeber@fz-juelich.de [Institute of Complex Systems, ICS-6: Structural Biochemistry, Forschungszentrum Jülich, 52425 Jülich (Germany)

    2012-06-01

    The crystal structure of ShSPI, a serpin from the blood fluke S. haematobium, reveals some peculiar features of the helical subdomain which have not been observed previously in the serpin superfamily. Parasitic organisms are constantly challenged by the defence mechanisms of their respective hosts, which often depend on serine protease activities. Consequently, protease inhibitors such as those belonging to the serpin superfamily have emerged as protective elements that support the survival of the parasites. This report describes the crystal structure of ShSPI, a serpin from the trematode Schistosoma haematobium. The protein is exposed on the surface of invading cercaria as well as of adult worms, suggesting its involvement in the parasite–host interaction. While generally conforming to the well established serpin fold, the structure reveals several distinctive features, mostly concerning the helical subdomain of the protein. It is proposed that these peculiarities are related to the unique biological properties of a small serpin subfamily which is conserved among pathogenic schistosomes.

  20. Potential schistosome-vector snails and associated trematodes in ricefields of Corrients province, Argentina: preliminary results

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    Alejandra Rumi

    1990-09-01

    Full Text Available Considering the possibility of introduction of schistosomiasis mansoni into Argentina as a consequence of dam construction on the Rio De La Plata basin, preliminary studies have been carried out on agrosystems such as ricefields in Corrientes province with the following purposes: 1 to survey and estimate the relative abundance of planorbids and identify potential vector species; 2 to identify environmental factors capable of influencing Biomphalaria population dynamics; and 3 to find out snail-parasite associations and estimate snail infection rates in order to detect possible competitive interactions between larval stages of native trematodes that could be used in biological control of Schistosoma mansoni. Three potential schistosome vectors were detected in ricefields, namely Biomphalaria straminea, B. tenagophila and B. peregrina, although B. orbignyi, a species refractory to infection with S. mansoni, proved the most frequent and abundant. Positive correlations (P0.05 was found in total iron, phosphates (SRP, pH and soil granulometry. Echinocercariae developed from rediae and belonging to Petasiger sp., Paryphostomum sp., and other undetermined species were found.

  1. Haematological and biochemical characteristics of the splenic effluent blood in schistosomal patients undergoing splenectomy

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    Andy Petroianu

    Full Text Available OBJECTIVE: To assess hematological and biochemical features of splenic effluent blood and their influence on the rise of hematological values after splenectomy. METHODS: we studied 20 patients undergoing surgical treatment for schistosomatic portal hypertension. We collected blood samples for CBC, coagulation, bilirubin and albumin in the splenic vein (perioperative and peripheral blood (immediately pre and postoperative periods. RESULTS: the splenic blood showed higher values of red blood cells, hemoglobin, hematocrit, platelet count, total leukocytes, neutrophils, lymphocytes, monocytes, eosinophils and basophils, as well as reduction of laboratory coagulation parameters in relation to peripheral blood collected preoperatively. In the postoperative peripheral blood there was an increase in the overall leukocytes and in their neutrophil component, and decreased levels of basophils, eosinophils and lymphocytes. The other postoperative variables of complete blood count and coagulation tests were not different compared with the splenic blood. The albumin values were lower postoperatively when compared to preoperative and splenic blood. There were higher values of direct bilirubin in the postoperative period when compared with the preoperative and splenic blood. Postoperative indirect bilirubin was lower compared to its value in the splenic blood. CONCLUSION: hematological and biochemical values of splenic effluent blood are higher than those found in peripheral blood in the presence of schistosomal splenomegaly. However, the splenic blood effluent is not sufficient to raise the blood levels found after splenectomy.

  2. Clinical-epidemiologic profile of the schistosomal myeloradiculopathy in Pernambuco, Brazil

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    Karina Conceição GM de Araújo

    2010-07-01

    Full Text Available This was a retrospective descriptive study on a series of cases of schistosomal myeloradiculopathy (SMR and the aim was to investigate the incidence of this disease and its clinical and epidemiological characteristics in cases diagnosed at three healthcare units in Pernambuco, Brazil between 1994-2006. The data were collected by reviewing the medical records from both the neurological and paediatric outpatient clinics and wards of the Hospital Clinics, Hospital of the Restoration and Pernambuco Mother and Child Institute. To gather the data, a spinal cord schistosomiasis evaluation protocol was used. The diagnoses were based on positive epidemiological evidence of schistosomiasis, clinical findings and laboratory tests (stool parasitological examination or rectal biopsies, magnetic resonance imaging findings and cerebrospinal fluid investigations. A total of 139 cases aged between 2-83 years were found. The most important determinants of SMR were male sex (66.2%, contact with fresh water (91%, origin in endemic regions (39.5%, lower-limb muscle weakness (100%, sensory level at the lower thoracic medulla (40.3%, myeloradicular form (76% and presence of eggs in the stool parasitological examination (48%. This sample indicates the need for intervention policies guided by diagnostic standardization, thereby avoiding disease under-notification.

  3. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem]. E-mail: ar.leao@uol.com.br; Colleoni, Ramiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Gastroenterologia

    2008-09-15

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  4. Genetic dissimilarity between mates, but not male heterozygosity, influences divorce in schistosomes.

    Science.gov (United States)

    Beltran, Sophie; Cézilly, Frank; Boissier, Jérôme

    2008-10-08

    Correlational studies strongly suggest that both genetic similarity and heterozygosity can influence female mate choice. However, the influence of each variable has usually been tested independently, although similarity and heterozygosity might be correlated. We experimentally determined the relative influence of genetic similarity and heterozygosity in divorce and re-mating in the monogamous endoparasite Schistosoma mansoni. We performed sequential infections of vertebrate hosts with controlled larval populations of parasites, where sex and individual genetic diversity and similarity were predetermined before infection. Divorce rate increased significantly when females were given the opportunity to increase genetic dissimilarity through re-mating with a new partner, independently of the intensity of male-male competition. We found however no evidence for females attempting to maximize the level of heterozygosity of their reproductive partner through divorce. Female preference for genetically dissimilar males should result in more heterozygous offspring. Because genetic heterozygosity might partly determine the ability of parasites to counter host resistance, adaptive divorce could be an important factor in the evolutionary arms race between schistosomes and their hosts.

  5. Genetic dissimilarity between mates, but not male heterozygosity, influences divorce in schistosomes.

    Directory of Open Access Journals (Sweden)

    Sophie Beltran

    Full Text Available BACKGROUND: Correlational studies strongly suggest that both genetic similarity and heterozygosity can influence female mate choice. However, the influence of each variable has usually been tested independently, although similarity and heterozygosity might be correlated. We experimentally determined the relative influence of genetic similarity and heterozygosity in divorce and re-mating in the monogamous endoparasite Schistosoma mansoni. METHODOLOGY/PRINCIPAL FINDINGS: We performed sequential infections of vertebrate hosts with controlled larval populations of parasites, where sex and individual genetic diversity and similarity were predetermined before infection. Divorce rate increased significantly when females were given the opportunity to increase genetic dissimilarity through re-mating with a new partner, independently of the intensity of male-male competition. We found however no evidence for females attempting to maximize the level of heterozygosity of their reproductive partner through divorce. CONCLUSIONS/SIGNIFICANCE: Female preference for genetically dissimilar males should result in more heterozygous offspring. Because genetic heterozygosity might partly determine the ability of parasites to counter host resistance, adaptive divorce could be an important factor in the evolutionary arms race between schistosomes and their hosts.

  6. Estrogen alters gonadal soma-derived factor (Gsdf)/Foxl2 expression levels in the testes associated with testis-ova differentiation in adult medaka, Oryzias latipes.

    Science.gov (United States)

    Kobayashi, Tohru; Chiba, Ayaka; Sato, Tadashi; Myosho, Taijun; Yamamoto, Jun; Okamura, Tetsuro; Onishi, Yuta; Sakaizumi, Mitsuru; Hamaguchi, Satoshi; Iguchi, Taisen; Horie, Yoshifumi

    2017-10-01

    Testis-ova differentiation in sexually mature male medaka (Oryzias latipes) is easily induced by estrogenic chemicals, indicating that spermatogonia persist in sexual bipotentiality, even in mature testes in medaka. By contrast, the effects of estrogen on testicular somatic cells associated with testis-ova differentiation in medaka remain unclear. In this study, we focused on the dynamics of sex-related genes (Gsdf, Dmrt1, and Foxl2) expressed in Sertoli cells in the mature testes of adult medaka during estrogen-induced testis-ova differentiation. When mature male medaka were exposed to estradiol benzoate (EB; 800ng/L), testis-ova first appeared after EB treatment for 14days (observed as the first oocytes of the leptotene-zygotene stage). However, the testis remained structurally unchanged, even after EB treatment for 28days. Although Foxl2 is a female-specific sex gene, EB treatment for 7days induced Foxl2/FOXL2 expression in all Sertoli cell-enclosed spermatogonia before testis-ova first appeared; however, Foxl2 was not detected in somatic cells in control testes. Conversely, Sertoli-cell-specific Gsdf mRNA expression levels significantly decreased after EB treatment for 14days, and no changes were observed in DMRT1 localization following EB treatment, whereas Dmrt1 mRNA levels increased significantly. Furthermore, after EB exposure, FOXl2 and DMRT1 were co-localized in Sertoli cells during testis-ova differentiation, although FOXL2 localization was undetectable in Sertoli-cell-enclosed apoptotic testis-ova, whereas DMRT1 remained localized in Sertoli cells. These results indicated for the first time that based on the expression of female-specific sex genes, feminization of Sertoli cells precedes testis-ova differentiation induced by estrogen in mature testes in medaka; however, complete feminization of Sertoli cells was not induced in this study. Additionally, it is suggested strongly that Foxl2 and Gsdf expression constitute potential molecular markers for

  7. Thermal Inactivation of Viruses

    Science.gov (United States)

    1977-10-01

    S) VIKU3FS THERMAL RESISTANCE FOODS FLUIDS FOOD PROCESSING FOOD PRESERVATION CONTAMINATION HEAT VIRAL NUCLEIC ACIDS ao’.AjUsTNACT (Conilnum...an rm**— •**» It nmc +nmy m>d Id+atttr by M«o* fmbm) A review of the literature pertaining to thermal inactivation of virus in fluid media» fluid...vacuum packaged in cans or in flexible pouches , frozen to ca. -40 C, and irradiated within a temperature range of -40 C to -8 C to obtain the

  8. Effect of oral administration of Propionibacterium acnes on growth performance, DTH response and anti-OVA titers in goat kids

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    Luis Miguel Ferrer

    2013-01-01

    Full Text Available Immunostimulants are susbstances that stimuli the response of effector cells to activate the immune response such as antigen uptake, cytokine release or antibody response. These substances can increase resistence to infection by different types of microorganisms, reducing dependence of antibiotics used in livestock animals. Recent reports have demonstrated the positive effect of Propionibacterium acnes (P. acnes to control animal diseases. In this study, we evaluated the effect of the non-specific immunostimulant P. acnes on immunological functions and growth performance in goat kids. Twenty five goat kids served as control group (A and another 25 animals received P. acnes being the experimental group (B. Kids were challenged with ovalbumin (OVA to assess humoral immunity. To assess in vivo cell immunity, delayed type hypersensitivity (DTH test with phytohemagglutinin (PHA was used, clinical signs and body weight were recorded each week until 9 weeks of age when the experiment ended. Blood samples were obtained to analyze serum proteins fractions and anti-OVA specific antibodies. No clinical signs of disease and no differences (p>0.05 on body weight between groups were recorded (7.32±0.81 kg in group A, 7.13±0.65 kg in group B. Goat kids from group B had more total protein (59.8±5g/l and albumin levels (32.8±3.3g/l than goat kids from group A (56.6±5.7 g/l, 29.6±3.9 g/l respectively (p<0.05. DTH response in goat kids from group B on day 42 was higher (p<0.05 than group A. At day 63, goat kids from group receiving P. acnes had higher percentage (85.4 of anti-OVA IgM titers (p<0.05 than control group (57.7. In conclusion, the results showed that oral administration of P. acnes to goat kids improved some aspects of the immune system of the animals and it could be used to control goat diseases.

  9. Inactivation of Microorganisms

    Science.gov (United States)

    Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

    Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

  10. The iron distribution and magnetic properties of schistosome eggshells: implications for improved diagnostics.

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    Stephan Karl

    Full Text Available BACKGROUND: Schistosoma mansoni and Schistosoma japonicum are the most frequent causative agents of human intestinal schistosomiasis. Approximately 200 million people in the world are infected with schistosomes. Diagnosis of schistosomiasis is often difficult. High percentages of low level infections are missed in routine fecal smear analysis and current diagnostic methodologies are inadequate to monitor the progress of parasite control, especially in areas with low transmission. Improved diagnostic methods are urgently needed to evaluate the success of elimination programs. Recently, a magnetic fractionation method for isolation of parasite eggs from feces was described, which uses magnetic microspheres to form parasite egg - magnetic microsphere conjugates. This approach enables screening of larger sample volumes and thus increased diagnostic sensitivity. The mechanism of formation of the conjugates remains unexplained and may either be related to specific surface characteristics of eggs and microspheres or to their magnetic properties. METHODS/PRINCIPAL FINDINGS: Here, we investigated iron localization in parasite eggs, specifically in the eggshells. We determined the magnetic properties of the eggs, studied the motion of eggs and egg-microsphere conjugates in magnetic fields and determined species specific affinity of parasite eggs to magnetic microspheres. Our study shows that iron is predominantly localized in pores in the eggshell. Parasite eggs showed distinct paramagnetic behaviour but they did not move in a magnetic field. Magnetic microspheres spontaneously bound to parasite eggs without the presence of a magnetic field. S. japonicum eggs had a significantly higher affinity to bind microspheres than S. mansoni eggs. CONCLUSIONS/SIGNIFICANCE: Our results suggest that the interaction of magnetic microspheres and parasite eggs is unlikely to be magnetic in origin. Instead, the filamentous surface of the eggshells may be important in

  11. Regulation of schistosome egg production by HMG CoA reductase

    Energy Technology Data Exchange (ETDEWEB)

    VandeWaa, E.A.; Bennett, J.L.

    1986-03-05

    Hydroxymethylglutaryl coenzyme A reductase (HMG CoA reductase) catalyzes the conversion of HMG CoA to mevalonate in the synthesis of steroids, isoprenoids and terpenes. Mevinolin, an inhibitor of this enzyme, decreased egg production in Schistosoma mansoni during in vitro incubations. This was associated with a reduction in the incorporation of /sup 14/C-acetate into polyisoprenoids and a reduction in the formation of a lipid-linked oligosaccharide. In vivo, mevinolin in daily doses of 50 mg/kg (p.o., from days 30-48 post-infection) caused no change in gross liver pathology in S. mansoni infected mice. However, when parasites exposed to mevinolin or its vehicle in vivo were cultured in vitro, worms from mevinolin-treated mice produced six times more eggs than control parasites. When infected mice were dosed with 250 mg/kg mevinolin daily (p.o., from days 35-45 post-infection), liver pathology was reduced in comparison to control mice. Thus, during in vivo exposure to a high dose of the drug egg production is decreased, while at a lower dose it appears unaffected until the parasites are cultured in a drug-free in vitro system wherein egg production is stimulated to extraordinarily high levels. It may be that at low doses mevinolin, by inhibiting the enzyme, is blocking the formation of a product (such as an isoprenoid) which normally acts to down-regulate enzyme synthesis, resulting in enzyme induction. Induction of HMG CoA reductase is then expressed as increased egg production when the worms are removed from the drug. These data suggest that HMG CoA reductase plays a role in schistosome egg production.

  12. Epidermal keratinocytes initiate wound healing and pro-inflammatory immune responses following percutaneous schistosome infection.

    Science.gov (United States)

    Bourke, Claire D; Prendergast, Catriona T; Sanin, David E; Oulton, Tate E; Hall, Rebecca J; Mountford, Adrian P

    2015-03-01

    Keratinocytes constitute the majority of cells in the skin's epidermis, the first line of defence against percutaneous pathogens. Schistosome larvae (cercariae) actively penetrate the epidermis to establish infection, however the response of keratinocytes to invading cercariae has not been investigated. Here we address the hypothesis that cercariae activate epidermal keratinocytes to promote the development of a pro-inflammatory immune response in the skin. C57BL/6 mice were exposed to Schistosoma mansoni cercariae via each pinna and non-haematopoietic cells isolated from epidermal tissue were characterised for the presence of different keratinocyte sub-sets at 6, 24 and 96 h p.i. We identified an expansion of epidermal keratinocyte precursors (CD45(-), CD326(-), CD34(+)) within 24 h of infection relative to naïve animals. Following infection, cells within the precursor population displayed a more differentiated phenotype (α6integrin(-)) than in uninfected skin. Parallel immunohistochemical analysis of pinnae cryosections showed that this expansion corresponded to an increase in the intensity of CD34 staining, specifically in the basal bulge region of hair follicles of infected mice, and a higher frequency of keratinocyte Ki67(+) nuclei in both the hair follicle and interfollicular epidermis. Expression of pro-inflammatory cytokine and stress-associated keratin 6b genes was also transiently upregulated in the epidermal tissue of infected mice. In vitro exposure of keratinocyte precursors isolated from neonatal mouse skin to excretory/secretory antigens released by penetrating cercariae elicited IL-1α and IL-1β production, supporting a role for keratinocyte precursors in initiating cutaneous inflammatory immune responses. Together, these observations indicate that S.mansoni cercariae and their excretory/secretory products act directly upon epidermal keratinocytes, which respond by initiating barrier repair and pro-inflammatory mechanisms similar to those

  13. Introgressive hybridization of Schistosoma haematobium group species in Senegal: species barrier break down between ruminant and human schistosomes.

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    Bonnie L Webster

    Full Text Available BACKGROUND: Schistosomes are dioecious parasitic flatworms, which live in the vasculature of their mammalian definitive hosts. They are the causative agent of schistosomiasis, a disease of considerable medical and veterinary importance in tropical and subtropical regions. Schistosomes undergo a sexual reproductive stage within their mammalian host enabling interactions between different species, which may result in hybridization if the species involved are phylogenetically close. In Senegal, three closely related species in the Schistosoma haematobium group are endemic: S. haematobium, which causes urogenital schistosomiasis in humans, and S. bovis and S. curassoni, which cause intestinal schistosomiasis in cows, sheep and goats. METHODOLOGY/PRINCIPAL FINDINGS: Large-scale multi-loci molecular analysis of parasite samples collected from children and domestic livestock across Senegal revealed that interactions and hybridization were taking place between all three species. Evidence of hybridization between S. haematobium/S. curassoni and S. haematobium/S. bovis was commonly found in children from across Senegal, with 88% of the children surveyed in areas of suspected species overlap excreting hybrid miracidia. No S. haematobium worms or hybrids thereof were found in ruminants, although S. bovis and S. curassoni hybrid worms were found in cows. Complementary experimental mixed species infections in laboratory rodents confirmed that males and females of each species readily pair and produce viable hybrid offspring. CONCLUSIONS/SIGNIFICANCE: THESE DATA PROVIDE INDISPUTABLE EVIDENCE FOR: the high occurrence of bidirectional hybridization between these Schistosoma species; the first conclusive evidence for the natural hybridisation between S. haematobium and S. curassoni; and demonstrate that the transmission of the different species and their hybrids appears focal. Hybridization between schistosomes has been known to influence the disease epidemiology

  14. The impact of schistosomes and schistosomiasis on murine blood coagulation and fibrinolysis as determined by thromboelastography (TEG).

    Science.gov (United States)

    Da'dara, Akram A; de Laforcade, Armelle M; Skelly, Patrick J

    2016-05-01

    Schistosomes are parasitic platyhelminths that currently infect over 200 million people and cause the chronic debilitating disease schistosomiasis. While these large intravascular parasites can disturb blood flow, surprisingly they do not appear to provoke thrombus formation around them in vivo. In order to determine if the worms can alter their local environment to impede coagulation, we incubated adult worms (50 pairs) in murine blood (500 µl) for 1 h at 37 °C and, using thromboelastography (TEG), we compared the coagulation profile of the blood with control blood that never contained worms. Substantial differences were apparent between the two profiles. Blood that had been exposed to schistosomes clotted more slowly and yielded relatively poor, though stable, thrombi; all TEG measures of blood coagulation (R, K, α-angle, MA, G and TMA) differed significantly between conditions. No fibrinolysis (as determined by LY30 and LY60 values) was detected in either case. The observed TEG profile suggests that the worms are acting as local anti-coagulants. Blood recovered from schistosome-infected mice, however, does not behave in this way. At an early time point post infection (4-weeks), the TEG profile of infected murine blood is essentially the same as that of control blood. However at a later time point (7-weeks) infected murine blood clots significantly faster than control blood but these clots also break down faster. The R, K, α-angle, and TMA measures of coagulation are all significantly different between the control versus infected mice as are the LY30 and LY60 values. This profile is indicative of a hypercoagulable state with fibrinolysis and is akin to that seen in human patients with advanced schistosomiasis.

  15. Introgressive hybridization of Schistosoma haematobium group species in Senegal: species barrier break down between ruminant and human schistosomes.

    Science.gov (United States)

    Webster, Bonnie L; Diaw, Oumar T; Seye, Mohmoudane M; Webster, Joanne P; Rollinson, David

    2013-01-01

    Schistosomes are dioecious parasitic flatworms, which live in the vasculature of their mammalian definitive hosts. They are the causative agent of schistosomiasis, a disease of considerable medical and veterinary importance in tropical and subtropical regions. Schistosomes undergo a sexual reproductive stage within their mammalian host enabling interactions between different species, which may result in hybridization if the species involved are phylogenetically close. In Senegal, three closely related species in the Schistosoma haematobium group are endemic: S. haematobium, which causes urogenital schistosomiasis in humans, and S. bovis and S. curassoni, which cause intestinal schistosomiasis in cows, sheep and goats. Large-scale multi-loci molecular analysis of parasite samples collected from children and domestic livestock across Senegal revealed that interactions and hybridization were taking place between all three species. Evidence of hybridization between S. haematobium/S. curassoni and S. haematobium/S. bovis was commonly found in children from across Senegal, with 88% of the children surveyed in areas of suspected species overlap excreting hybrid miracidia. No S. haematobium worms or hybrids thereof were found in ruminants, although S. bovis and S. curassoni hybrid worms were found in cows. Complementary experimental mixed species infections in laboratory rodents confirmed that males and females of each species readily pair and produce viable hybrid offspring. THESE DATA PROVIDE INDISPUTABLE EVIDENCE FOR: the high occurrence of bidirectional hybridization between these Schistosoma species; the first conclusive evidence for the natural hybridisation between S. haematobium and S. curassoni; and demonstrate that the transmission of the different species and their hybrids appears focal. Hybridization between schistosomes has been known to influence the disease epidemiology and enhance phenotypic characteristics affecting transmission, morbidity and drug

  16. Impact of schistosome infection on Plasmodium falciparum Malariometric indices and immune correlates in school age children in Burma Valley, Zimbabwe.

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    Davison T Sangweme

    2010-11-01

    Full Text Available A group of children aged 6-17 years was recruited and followed up for 12 months to study the impact of schistosome infection on malaria parasite prevalence, density, distribution and anemia. Levels of cytokines, malaria specific antibodies in plasma and parasite growth inhibition capacities were assessed. Baseline results suggested an increased prevalence of malaria parasites in children co-infected with schistosomiasis (31% compared to children infected with malaria only (25% (p = 0.064. Moreover, children co-infected with schistosomes and malaria had higher sexual stage geometric mean malaria parasite density (189 gametocytes/µl than children infected with malaria only (73/µl gametocytes (p = 0.043. In addition, a larger percentage of co-infected children (57% had gametocytes as observed by microscopy compared to the malaria only infected children (36% (p = 0.06. There was no difference between the two groups in terms of the prevalence of anemia, which was approximately 64% in both groups (p = 0.9. Plasma from malaria-infected children exhibited higher malaria antibody activity compared to the controls (p = 0.001 but was not different between malaria and schistosome plus malaria infected groups (p = 0.44 and malaria parasite growth inhibition activity at baseline was higher in the malaria-only infected group of children than in the co-infected group though not reaching statistical significance (p = 0.5. Higher prevalence and higher mean gametocyte density in the peripheral blood may have implications in malaria transmission dynamics during co-infection with helminths.

  17. Interactions between natural populations of human and rodent schistosomes in the Lake Victoria region of Kenya: a molecular epidemiological approach.

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    Michelle L Steinauer

    2008-04-01

    Full Text Available Schistosoma mansoni exists in a complex environmental milieu that may select for significant evolutionary changes in this species. In Kenya, the sympatric distribution of S. mansoni with S. rodhaini potentially influences the epidemiology, ecology, and evolutionary biology of both species, because they infect the same species of snail and mammalian hosts and are capable of hybridization.Over a 2-year period, using a molecular epidemiological approach, we examined spatial and temporal distributions, and the overlap of these schistosomes within snails, in natural settings in Kenya. Both species had spatially and temporally patchy distributions, although S. mansoni was eight times more common than S. rodhaini. Both species were overdispersed within snails, and most snails (85.2% for S. mansoni and 91.7% for S. rodhaini only harbored one schistosome genotype. Over time, half of snails infected with multiple genotypes showed a replacement pattern in which an initially dominant genotype was less represented in later replicates. The other half showed a consistent pattern over time; however, the ratio of each genotype was skewed. Profiles of circadian emergence of cercariae revealed that S. rodhaini emerges throughout the 24-hour cycle, with peak emergence before sunrise and sometimes immediately after sunset, which differs from previous reports of a single nocturnal peak immediately after sunset. Peak emergence for S. mansoni cercariae occurred as light became most intense and overlapped temporally with S. rodhaini. Comparison of schistosome communities within snails against a null model indicated that the community was structured and that coinfections were more common than expected by chance. In mixed infections, cercarial emergence over 24 hours remained similar to single species infections, again with S. rodhaini and S. mansoni cercarial emergence profiles overlapping substantially.The data from this study indicate a lack of obvious spatial or

  18. Dual targeting of insulin and venus kinase Receptors of Schistosoma mansoni for novel anti-schistosome therapy.

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    Mathieu Vanderstraete

    Full Text Available BACKGROUND: Chemotherapy of schistosomiasis relies on a single drug, Praziquantel (PZQ and mass-use of this compound has led to emergence of resistant strains of Schistosoma mansoni, therefore pointing out the necessity to find alternative drugs. Through their essential functions in development and metabolism, receptor tyrosine kinases (RTK could represent valuable drug targets for novel anti-schistosome chemotherapies. Taking advantage of the similarity between the catalytic domains of S. mansoni insulin receptors (SmIR1 and SmIR2 and Venus Kinase Receptors (SmVKR1 and SmVKR2, we studied the possibility to fight schistosomes by targeting simultaneously the four receptors with a single drug. METHODOLOGY/PRINCIPAL FINDINGS: Several commercial RTK inhibitors were tested for their potential to inhibit the kinase activities of SmIR1, SmIR2, SmVKR1 and SmVKR2 intracellular domains (ICD expressed in Xenopus oocytes. We measured the inhibitory effect of chemicals on meiosis resumption induced by the active ICD of the schistosome kinases in oocytes. The IR inhibitor, tyrphostin AG1024, was the most potent inhibitory compound towards SmIR and SmVKR kinases. In vitro studies then allowed us to show that AG1024 affected the viability of both schistosomula and adult worms of S. mansoni. At micromolar doses, AG1024 induced apoptosis and caused schistosomula death in a dose-dependent manner. In adult worms, AG1024 provoked alterations of reproductive organs, as observed by confocal laser scanner microscopy. With 5 µM AG1024, parasites were no more feeding and laying eggs, and they died within 48 h with 10 µM. CONCLUSION/SIGNIFICANCE: IRs and VKRs are essential in S. mansoni for key biological processes including glucose uptake, metabolism and reproduction. Our results demonstrate that inhibiting the kinase potential and function of these receptors by a single chemical compound AG1024 at low concentrations, leads to death of schistosomula and adult worms

  19. Dual targeting of insulin and venus kinase Receptors of Schistosoma mansoni for novel anti-schistosome therapy.

    Science.gov (United States)

    Vanderstraete, Mathieu; Gouignard, Nadège; Cailliau, Katia; Morel, Marion; Lancelot, Julien; Bodart, Jean-François; Dissous, Colette

    2013-01-01

    Chemotherapy of schistosomiasis relies on a single drug, Praziquantel (PZQ) and mass-use of this compound has led to emergence of resistant strains of Schistosoma mansoni, therefore pointing out the necessity to find alternative drugs. Through their essential functions in development and metabolism, receptor tyrosine kinases (RTK) could represent valuable drug targets for novel anti-schistosome chemotherapies. Taking advantage of the similarity between the catalytic domains of S. mansoni insulin receptors (SmIR1 and SmIR2) and Venus Kinase Receptors (SmVKR1 and SmVKR2), we studied the possibility to fight schistosomes by targeting simultaneously the four receptors with a single drug. Several commercial RTK inhibitors were tested for their potential to inhibit the kinase activities of SmIR1, SmIR2, SmVKR1 and SmVKR2 intracellular domains (ICD) expressed in Xenopus oocytes. We measured the inhibitory effect of chemicals on meiosis resumption induced by the active ICD of the schistosome kinases in oocytes. The IR inhibitor, tyrphostin AG1024, was the most potent inhibitory compound towards SmIR and SmVKR kinases. In vitro studies then allowed us to show that AG1024 affected the viability of both schistosomula and adult worms of S. mansoni. At micromolar doses, AG1024 induced apoptosis and caused schistosomula death in a dose-dependent manner. In adult worms, AG1024 provoked alterations of reproductive organs, as observed by confocal laser scanner microscopy. With 5 µM AG1024, parasites were no more feeding and laying eggs, and they died within 48 h with 10 µM. IRs and VKRs are essential in S. mansoni for key biological processes including glucose uptake, metabolism and reproduction. Our results demonstrate that inhibiting the kinase potential and function of these receptors by a single chemical compound AG1024 at low concentrations, leads to death of schistosomula and adult worms. Thus, AG1024 represents a valuable hit compound for further design of anti

  20. Dual Targeting of Insulin and Venus Kinase Receptors of Schistosoma mansoni for Novel Anti-schistosome Therapy

    Science.gov (United States)

    Vanderstraete, Mathieu; Gouignard, Nadège; Cailliau, Katia; Morel, Marion; Lancelot, Julien; Bodart, Jean-François; Dissous, Colette

    2013-01-01

    Background Chemotherapy of schistosomiasis relies on a single drug, Praziquantel (PZQ) and mass-use of this compound has led to emergence of resistant strains of Schistosoma mansoni, therefore pointing out the necessity to find alternative drugs. Through their essential functions in development and metabolism, receptor tyrosine kinases (RTK) could represent valuable drug targets for novel anti-schistosome chemotherapies. Taking advantage of the similarity between the catalytic domains of S. mansoni insulin receptors (SmIR1 and SmIR2) and Venus Kinase Receptors (SmVKR1 and SmVKR2), we studied the possibility to fight schistosomes by targeting simultaneously the four receptors with a single drug. Methodology/Principal Findings Several commercial RTK inhibitors were tested for their potential to inhibit the kinase activities of SmIR1, SmIR2, SmVKR1 and SmVKR2 intracellular domains (ICD) expressed in Xenopus oocytes. We measured the inhibitory effect of chemicals on meiosis resumption induced by the active ICD of the schistosome kinases in oocytes. The IR inhibitor, tyrphostin AG1024, was the most potent inhibitory compound towards SmIR and SmVKR kinases. In vitro studies then allowed us to show that AG1024 affected the viability of both schistosomula and adult worms of S. mansoni. At micromolar doses, AG1024 induced apoptosis and caused schistosomula death in a dose-dependent manner. In adult worms, AG1024 provoked alterations of reproductive organs, as observed by confocal laser scanner microscopy. With 5 µM AG1024, parasites were no more feeding and laying eggs, and they died within 48 h with 10 µM. Conclusion/Significance IRs and VKRs are essential in S. mansoni for key biological processes including glucose uptake, metabolism and reproduction. Our results demonstrate that inhibiting the kinase potential and function of these receptors by a single chemical compound AG1024 at low concentrations, leads to death of schistosomula and adult worms. Thus, AG1024

  1. LF-15 & T7, synthetic peptides derived from tumstatin, attenuate aspects of airway remodelling in a murine model of chronic OVA-induced allergic airway disease.

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    Karryn T Grafton

    Full Text Available BACKGROUND: Tumstatin is a segment of the collagen-IV protein that is markedly reduced in the airways of asthmatics. Tumstatin can play an important role in the development of airway remodelling associated with asthma due to its anti-angiogenic properties. This study assessed the anti-angiogenic properties of smaller peptides derived from tumstatin, which contain the interface tumstatin uses to interact with the αVβ3 integrin. METHODS: Primary human lung endothelial cells were exposed to the LF-15, T3 and T7 tumstatin-derived peptides and assessed for cell viability and tube formation in vitro. The impact of the anti-angiogenic properties on airways hyperresponsiveness (AHR was then examined using a murine model of chronic OVA-induced allergic airways disease. RESULTS: The LF-15 and T7 peptides significantly reduced endothelial cell viability and attenuated tube formation in vitro. Mice exposed to OVA+ LF-15 or OVA+T7 also had reduced total lung vascularity and AHR was attenuated compared to mice exposed to OVA alone. T3 peptides reduced cell viability but had no effect on any other parameters. CONCLUSION: The LF-15 and T7 peptides may be appropriate candidates for use as novel pharmacotherapies due to their small size and anti-angiogenic properties observed in vitro and in vivo.

  2. Clinical-epidemiological profile of children with schistosomal myeloradiculopathy attended at the Instituto Materno-Infantil de Pernambuco.

    Science.gov (United States)

    Araújo, Karina Conceição G M; Rosa e Silva, Cristiana da; Barbosa, Constança Simões; Ferrari, Teresa C A

    2006-09-01

    The most critical phase of exposure to schistosomal infection is the infancy, because of the more frequent contact with contaminated water and the immaturity of the immune system. One of the most severe presentations of this parasitosis is the involvement of the spinal cord, which prognosis is largely dependent on early diagnosis and treatment. Reports on this clinical form of schistosomiasis in children are rare in the literature. We present here the clinical-epidemiological profile of schistosomal myeloradiculopathy (SMR) from ten children who were admitted at the Instituto Materno-Infantil de Pernambuco over a five-year period. They were evaluated according to an investigation protocol. Most of these patients presented an acute neurological picture which included as the main clinical manifestations: sphincteral disorders, low back and lower limbs pain, paresthesia, lower limbs muscle weakness and absence of deep tendon reflex, and impairment of the gait. The diagnosis was presumptive in the majority of the cases. This study emphasizes the importance of considering the diagnosis of SMR in pediatric patients coming from endemic areas who present a low cord syndrome, in order to start the appropriate therapy and avoid future complications.

  3. Genetic differentiation of cercariae infrapopulations of the avian schistosome Trichobilharzia szidati based on RAPD markers and mitochondrial cox1 gene.

    Science.gov (United States)

    Korsunenko, Anna; Chrisanfova, Galina; Lopatkin, Anton; Beer, Sergey A; Voronin, Mikhail; Ryskov, Alexey P; Semyenova, Seraphima K

    2012-02-01

    Avian schistosome Trichobilharzia szidati is a member of the largest genus within the family Schistosomatidae (Trematoda). Population genetic structure of Trichobilharzia spp. schistosomes, causative agents of cercarial dermatitis in humans, has not been studied yet. The knowledge of the genetic structure of trichobilharzian populations is essential for understanding the host-parasite coevolutionary dynamics and epidemiology strategies. Here we examined genetic diversity in three geographically isolated local populations of T. szidati cercariae inhabiting Russia based on nuclear (randomly amplified polymorphic DNA, RAPD) and mt (cox1) markers. We analyzed T. szidati cercariae shed from seven naturally infected snails of Lymnaea stagnalis. Using three random primers, we demonstrated genetic variation among populations, thus posing genetic structure across geographic sites. Moreover, T. szidati cercariae have been genetically structured among hosts (infrapopulations). Molecular variance analysis was performed to test the significance of genetic differentiation within and between local populations. Of total parasitic diversity, 18.8% was partitioned between populations, whereas the higher contribution (48.9%) corresponds to the differences among individual cercariae within infrapopulations. In contrast to RAPD markers, a 1,125-bp fragment of cox1 mt gene failed to provide any significant within-species structure. The lack of geographic structuring was detected using unique haplotypes which were determined in the current work for Moscow and Western Siberian local populations as well as obtained previously for European isolates (Czech Republic and Germany). All T. szidati/Trichobilharzia ocellata haplotypes were found to be mixed across their geographical origin.

  4. A genetically distinct Schistosoma from Radix luteola from Nepal related to Schistosoma turkestanicum: A phylogenetic study of schistosome and snail host.

    Science.gov (United States)

    Devkota, Ramesh; Brant, Sara V; Loker, Eric S

    2016-12-01

    During a survey of freshwater snails in the Terai region of southern Nepal, 16 of 2588 specimens of Radix luteola from 4 different habitats were found to be shedding schistosome cercariae. None of the 1411 specimens of Radix acuminata we collected were positive for schistosomes. Analysis of 28S, cox1, 16S and 12S sequences indicated that all the R. luteola-derived schistosomes were genetically very similar to one another and, although unambiguously grouping most closely to the widespread Asian species Schistosoma turkestanicum, were clearly genetically distinct from it. We lack information from other life cycle stages to verify the specific identity of these cercariae, but it is possible they are of Schistosoma bomfordi or Schistosoma dattai, both species previously known only from northern India, the latter species known to infect R. luteola. This study provides sequence evidence for a third genetically distinct lymnaeid-transmitted Schistosoma lineage in Asia (to go along with S. turkestanicum and S. incognitum). As a close relative of S. turkestanicum, it provides the first direct molecular evidence to accompany morphological results from earlier studies for the presence of a S. turkestanicum species group in Asia. It increases to five the number of known or suspected mammalian schistosome species to be present in the Terai region of Nepal. Radix luteola and R. acuminata were identified and differentiated using conchological features and by molecular phylogenetic analyses of cox1 and 16S genes. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. In vivo micro-CT assessment of airway remodeling in a flexible OVA-sensitized murine model of asthma.

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    Mathieu Lederlin

    Full Text Available Airway remodeling is a major pathological feature of asthma. Up to now, its quantification still requires invasive methods. In this study, we aimed at determining whether in vivo micro-computed tomography (micro-CT is able to demonstrate allergen-induced airway remodeling in a flexible mouse model of asthma. Sixty Balb/c mice were challenged intranasally with ovalbumin or saline at 3 different endpoints (Days 35, 75, and 110. All mice underwent plethysmography at baseline and just prior to respiratory-gated micro-CT. Mice were then sacrificed to assess bronchoalveolar lavage and lung histology. From micro-CT images (voxel size = 46×46×46 µm, the numerical values of total lung attenuation, peribronchial attenuation (PBA, and PBA normalized by total lung attenuation were extracted. Each parameter was compared between OVA and control mice and correlation coefficients were calculated between micro-CT and histological data. As compared to control animals, ovalbumin-sensitized mice exhibited inflammation alone (Day 35, remodeling alone (Day 110 or both inflammation and remodeling (Day 75. Normalized PBA was significantly greater in mice exhibiting bronchial remodeling either alone or in combination with inflammation. Normalized PBA correlated with various remodeling markers such as bronchial smooth muscle size or peribronchial fibrosis. These findings suggest that micro-CT may help monitor remodeling non-invasively in asthmatic mice when testing new drugs targeting airway remodeling in pre-clinical studies.

  6. Phenylbutazone radicals inactivate creatine kinase.

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    Miura, T; Muraoka, S; Fujimoto, Y

    2001-02-01

    Creatine kinase (CK) was used as a marker molecule to examine the side effect of damage to tissues by phenylbutazone (PB), an effective drug to treat rheumatic and arthritic diseases, with horseradish peroxidase and hydrogen peroxide (HRP-H(2)O2). PB inactivated CK during its interaction with HRP-H(2) O(2), and inactivated CK in rat heart homogenate. PB carbon-centered radicals were formed during the interaction of PB with HRP-H(2)O2. The CK efficiently reduced electron spin resonance signals of the PB carbon-centered radicals. The spin trap agent 2-methyl-2-nitrosopropane strongly prevented CK inactivation. These results show that CK was inactivated through interaction with PB carbon-centered radicals. Sulfhydryl groups and tryptophan residues in CK were lost during the interaction of PB with HRP-H(2)O2, suggesting that cysteine and tryptophan residues are oxidized by PB carbon-centered radicals. Other enzymes, including alcohol dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, but not lactate dehydrogenase, were also inactivated. Sulfhydryl enzymes seem to be sensitive to attack by PB carbon-centered radicals. Inhibition of SH enzymes may explain some of the deleterious effects induced by PB.

  7. 'Death and axes': unexpected Ca²⁺ entry phenologs predict new anti-schistosomal agents.

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    John D Chan

    2014-02-01

    Full Text Available Schistosomiasis is a parasitic flatworm disease that infects 200 million people worldwide. The drug praziquantel (PZQ is the mainstay therapy but the target of this drug remains ambiguous. While PZQ paralyses and kills parasitic schistosomes, in free-living planarians PZQ caused an unusual axis duplication during regeneration to yield two-headed animals. Here, we show that PZQ activation of a neuronal Ca²⁺ channel modulates opposing dopaminergic and serotonergic pathways to regulate 'head' structure formation. Surprisingly, compounds with efficacy for either bioaminergic network in planarians also displayed antischistosomal activity, and reciprocally, agents first identified as antischistocidal compounds caused bipolar regeneration in the planarian bioassay. These divergent outcomes (death versus axis duplication result from the same Ca²⁺ entry mechanism, and comprise unexpected Ca²⁺ phenologs with meaningful predictive value. Surprisingly, basic research into axis patterning mechanisms provides an unexpected route for discovering novel antischistosomal agents.

  8. Susceptibility of Snails to Infection with Schistosomes is influenced by Temperature and Expression of Heat Shock Proteins

    Science.gov (United States)

    Knight, Matty; Elhelu, O; Smith, M; Haugen, B; Miller, A; Raghavan, N; Wellman, C; Cousin, C; Dixon, F; Mann, V; Rinaldi, G; Ittiprasert, W; Brindley, PJ

    2015-01-01

    The freshwater snail, Biomphalaria glabrata is the obligate intermediate host for the transmission of the parasitic trematode, Schistosoma mansoni the causative agent of the chronic debilitating neglected tropical disease, schistosomiasis. We showed previously that in juvenile snails, early and significant induction of stress manifested by the expression of stress proteins, Hsp 70, Hsp 90 and reverse transcriptase (RT) of the non- LTR retrotransposon, nimbus, is a characteristic feature of juvenile susceptible NMRI but not resistant BS-90 snails. These latter, however, could be rendered susceptible after mild heat shock at 32°C, revealing that resistance in the BS-90 resistant snail to schistosomes is a temperature dependent trait. Here we tested the hypothesis that maintenance of BS-90 resistant snails at the permissive temperature for several generations affects the resistance phenotype displayed at the non-permissive temperature of 25°C. The progeny of BS-90 snails bred and maintained through several generations (F1 to F4) at 32°C were susceptible to the schistosome infection when returned to room temperature, shedding cercariae at four weeks post-infection. Moreover, the study of expression levels of the heat shock protein (Hsp) 70 protein by ELISA and western blot analysis, showed that this protein is also differentially expressed between susceptible and resistant snails, with susceptible snails expressing more protein than their resistant counterparts after early exposure to wild-type but not to radiation-attenuated miracidia. These data suggested that in the face of global warming, the ability to sustain a reduction in schistosomiasis by using refractory snails as a strategy to block transmission of the disease might prove challenging since non-lethal elevation in temperature, affects snail susceptibility to S. mansoni. PMID:26504668

  9. Ovariectomized OVA-sensitized mice display increased frequency of CD4(+Foxp3(+ T regulatory cells in the periphery.

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    Ana Paula Ligeiro de Oliveira

    Full Text Available It is well established that female sex hormones have a pivotal role in inflammation. For instance, our group has previously reported that estradiol has proinflammatory actions during allergic lung response in animal models. Based on these findings, we have decided to further investigate whether T regulatory cells are affected by female sex hormones absence after ovariectomy. We evaluated by flow cytometry the frequencies of CD4(+Foxp3(+ T regulatory cells (Tregs in central and peripheral lymphoid organs, such as the thymus, spleen and lymph nodes. Moreover, we have also used the murine model of allergic lung inflammation a to evaluate how female sex hormones would affect the immune response in vivo. To address that, ovariectomized or sham operated female Balb/c mice were sensitized or not with ovalbumin 7 and 14 days later and subsequently challenged twice by aerosolized ovalbumin on day 21. Besides the frequency of CD4(+Foxp3(+ T regulatory cells, we also measured the cytokines IL-4, IL-5, IL-10, IL-13 and IL-17 in the bronchoalveolar lavage from lungs of ovalbumine challenged groups. Our results demonstrate that the absence of female sex hormones after ovariectomy is able to increase the frequency of Tregs in the periphery. As we did not observe differences in the thymus-derived natural occurring Tregs, our data may indicate expansion or conversion of peripheral adaptive Tregs. In accordance with Treg suppressive activity, ovariectomized and ovalbumine-sensitized and challenged animals had significantly reduced lung inflammation. This was observed after cytokine analysis of lung explants showing significant reduction of pro-inflammatory cytokines, such as IL-4, IL-5, IL-13 and IL-17, associated to increased amount of IL-10. In summary, our data clearly demonstrates that OVA sensitization 7 days after ovariectomy culminates in reduced lung inflammation, which may be directly correlated with the expansion of Tregs in the periphery and further

  10. Composición de ácidos grasos en ovas de trucha arco iris (Oncorhynchus mykiss, Walbaum, 1792

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    Rafael Rosado Puccini

    2012-06-01

    Full Text Available En este artículo se analizan con parámetros de composición 58 puestas de trucha arcoiris obtenidas, manejadas y monitoreadas individualmente en desempeño desde la fertilización hasta finalizar la etapa de reabsorción de vesícula. Además de los valores reproductivos, el contenido de ácidos grasos en las ovas se determinó en fresco, mediante cromatografía de gases. En el perfil medio se destacan los ácidos palmítico (C16, oleico (C18:1n-9 y docosahexaenoico (C22:6n-3 como los más representativos, con casi el 60% del total y, en general, en concentraciones estables entre las hembras. Tanto para cada ácido determinado como para el conjunto de contenidos integrados de las series n-3 y n-6, y los colectivos de saturados (SAF, monoinsaturados (MUFA y poliinsaturados (PUFA, se define un patrón de composición similar al reportado para la especie en otros esquemas de manejo y bajo regímenes nutricionales variables. Se analizó la condición conservativa en la incorporación de ácidos grasos al huevo, y se discutió su utilidad como posibles definitorios de calidad, teniendo como referente la alta variabilidad registrada en la supervivencia al final del proceso de incubación.

  11. Influenza Vaccine, Inactivated or Recombinant

    Science.gov (United States)

    ... die from flu, and many more are hospitalized.Flu vaccine can:keep you from getting flu, make flu ... What is inactivated or recombinant influenza vaccine?A dose of flu vaccine is recommended every flu season. Children 6 months through 8 years of age may need two ...

  12. Inactivation of rabies virus by hydrogen peroxide.

    Science.gov (United States)

    Abd-Elghaffar, Asmaa A; Ali, Amal E; Boseila, Abeer A; Amin, Magdy A

    2016-02-03

    Development of safe and protective vaccines against infectious pathogens remains a challenge. Inactivation of rabies virus is a critical step in the production of vaccines and other research reagents. Beta-propiolactone (βPL); the currently used inactivating agent for rabies virus is expensive and proved to be carcinogenic in animals. This study aimed to investigate the ability of hydrogen peroxide (H2O2) to irreversibly inactivate rabies virus without affecting its antigenicity and immunogenicity in pursuit of finding safe, effective and inexpensive alternative inactivating agents. H2O2 3% rapidly inactivated a Vero cell adapted fixed rabies virus strain designated as FRV/K within 2h of exposure without affecting its antigenicity or immunogenicity. No residual infectious virus was detected and the H2O2-inactivated vaccine proved to be safe and effective when compared with the same virus harvest inactivated with the classical inactivating agent βPL. Mice immunized with H2O2-inactivated rabies virus produced sufficient level of antibodies and were protected when challenged with lethal CVS virus. These findings reinforce the idea that H2O2 can replace βPL as inactivating agent for rabies virus to reduce time and cost of inactivation process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Artesunate effect on schistosome thioredoxin glutathione reductase and cytochrome c peroxidase as new molecular targets in schistosoma mansoni-infected mice.

    Science.gov (United States)

    Abdin, Amany A; Ashour, Dalia S; Shoheib, Zeinab S

    2013-12-01

    To investigate the possible effect of artesunate (ART) on schistosome thioredoxin glutathione reductase (TGR) and cytochrome c peroxidase (CcP) in Schistosoma mansoni-infected mice. A total of 200 laboratory bred male Swiss albino mice were divided into 4 groups (50 mice in each group). Group I: infected untreated group (Control group) received a vehicle of 1% sodium carbonyl methylcellulose (CMC-Na); Group II: infected then treated with artesunate; Group III: infected then treated with praziquantel, and group IV: infected then treated with artesunate then praziquantel. Adult S. mansoni worms were collected by Animal Perfusion Method, tissue egg counted, TGR, and CcP mRNA Expression were estimated of in S. mansoni adult worms by semi-quantitative rt-PCR. Semi-quantitative rt-PCR values revealed that treatment with artesunate caused significant decrease in expression of schistosome TGR and CcP in comparison to the untreated group. In contrast, the treatment with praziquantel did not cause significant change in expression of these genes. The results showed more reduction in total worm and female worm count in combined ART-PZQ treated group than in monotherapy treated groups by either ART or PZQ. Moreover, complete disappearance (100%) of tissue eggs was recorded in ART-PZQ treated group with a respective reduction rate of 95.9% and 68.4% in ART- and PZQ-treated groups. The current study elucidated for the first time that anti-schistosomal mechanisms of artesunate is mediated via reduction in expression of schistosome TGR and CcP. Linking these findings, addition of artesunate to praziquantel could achieve complete cure outcome in treatment of schistosomiasis. Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  14. Differentiating Schistosoma haematobium from Schistosoma magrebowiei and other closely related schistosomes by polymerase chain reaction amplification of a species specific mitochondrial gene

    OpenAIRE

    Olaoluwa P Akinwale; Hock, Tang T.; Chia-Kwung, Fan; ZHENG Qi; Haimo, Shen; Ezeh, Charles; Gyang, Pam V

    2014-01-01

    Introduction: Schistosoma haematobium infection afflicts about 150 million people in 53 countries in Africa and the Middle East. In many endemic areas, S. haematobium is sympatric with Schistosoma bovis, Schistosoma mattheei, Schistosoma curassoni, Schistosoma intercalatum and Schistosoma magrebowiei, its closely related species. In addition, they also develop in the same intermediate snail hosts. Since these schistosome species often infect snails inhabiting the same bodies of water, examini...

  15. Impact of density of schistosomal antigen expression in urinary bladder tissue on the stratification, cell type, and staging, and prognosis of carcinoma of the bladder in Egyptian patients

    OpenAIRE

    Wishahi, Mohamed; Zakarya, Ahmed; Hamamm, Olfat; Abdel-Rasol, Mohamed; Badawy, Hisham; Elganzoury, Hossam; Ismail, Mohamed; Elkhouly, Amr; Meheina, Ahmed

    2014-01-01

    Background Infection with urinary schistosomiasis and its severity are oncogenic factors for developing carcinoma of the bladder, whether it is urothelial carcinoma (UC) of a transitional cell type (TCC) or non-urothelial of squamous cell carcinoma (SCC). In UC it is not defined whether it is schistosomal or not. This led to controversial results in expression of tumour markers, tumour prognosis, and response to therapy. Objectives We assessed the application by immunohistochemistry method (I...

  16. Molecular approaches to the identification of Bulinus species in south-west Nigeria and observations on natural snail infections with schistosomes.

    Science.gov (United States)

    Akinwale, O P; Kane, R A; Rollinson, D; Stothard, J R; Ajayi, M B; Akande, D O; Ogungbemi, M O; Duker, C; Gyang, P V; Adeleke, M A

    2011-09-01

    The current study considers the distribution of a small sample of 138 Bulinus snails, across 28 localities within eight Nigerian states. Snails were identified using a combination of molecular methods involving both DNA sequencing of a partial cytochrome oxidase subunit 1 (cox1) fragment and restriction profiles obtained from ribosomal internal transcribed spacer (its) amplicons. The results showed that the majority of Bulinus samples tested belonged to the species Bulinus truncatus while only two were Bulinus globosus. The use of RsaI restriction endonuclease to cleave the ribosomal its of Bulinus, as a method of species identification, was adopted for the majority of samples, this being a quicker and cheaper method better suited to small laboratory environments. Polymerase chain reaction (PCR) amplification of the schistosome Dra1 repeat within each of the collected Bulinus samples was employed to determine the extent and distribution of infected snails within the sample areas. Successful amplification of the Dra1 repeat demonstrated that 29.7% of snails were infected with schistosomes. Sequencing of the partial schistosome its from a small subset of snail samples suggested that some snails were either penetrated by both Schistosoma haematobium and Schistosoma bovis miracidia or hybrid miracidia formed from the two species.

  17. Inactivation of allergens and toxins.

    Science.gov (United States)

    Morandini, Piero

    2010-11-30

    Plants are replete with thousands of proteins and small molecules, many of which are species-specific, poisonous or dangerous. Over time humans have learned to avoid dangerous plants or inactivate many toxic components in food plants, but there is still room for ameliorating food crops (and plants in general) in terms of their allergens and toxins content, especially in their edible parts. Inactivation at the genetic rather than physical or chemical level has many advantages and classical genetic approaches have resulted in significant reduction of toxin content. The capacity, offered by genetic engineering, of turning off (inactivating) specific genes has opened up the possibility of altering the plant content in a far more precise manner than previously available. Different levels of intervention (genes coding for toxins/allergens or for enzymes, transporters or regulators involved in their metabolism) are possible and there are several tools for inactivating genes, both direct (using chemical and physical mutagens, insertion of transposons and other genetic elements) and indirect (antisense RNA, RNA interference, microRNA, eventually leading to gene silencing). Each level/strategy has specific advantages and disadvantages (speed, costs, selectivity, stability, reversibility, frequency of desired genotype and regulatory regime). Paradigmatic examples from classical and transgenic approaches are discussed to emphasize the need to revise the present regulatory process. Reducing the content of natural toxins is a trade-off process: the lesser the content of natural toxins, the higher the susceptibility of a plant to pests and therefore the stronger the need to protect plants. As a consequence, more specific pesticides like Bt are needed to substitute for general pesticides. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Secretory glands in cercaria of the neuropathogenic schistosome Trichobilharzia regenti - ultrastructural characterization, 3-D modelling, volume and pH estimations

    Directory of Open Access Journals (Sweden)

    Koberna Karel

    2011-08-01

    Full Text Available Abstract Background Cercariae of schistosomes employ bioactive molecules for penetration into their hosts. These are released from specialized unicellular glands upon stimuli from host skin. The glands were previously well-described in the human pathogen Schistosoma mansoni. As bird schistosomes can also penetrate human skin and cause cercarial dermatitis, our aim was to characterize the architecture and ultrastructure of glands in the neurotropic bird schistosome Trichobilharzia regenti and compare it with S. mansoni. In the context of different histolytic enzymes used by these two species, we focused also on the estimations of gland volumes and pH in T. regenti. Results The architecture and 3-D models of two types of acetabular penetration glands, their ducts and of the head gland are shown here. We characterized secretory vesicles in all three gland types by means of TEM and confirmed accuracy of the models obtained by confocal microscopy. The results of two independent approaches showed that the glands occupy ca. one third of cercarial body volume (postacetabular glands ca. 15%, circumacetabular 12% and head gland 6%. The inner environment within the two types of acetabular glands differed significantly as evidenced by dissimilar ability to bind fluorescent markers and by pH value which was higher in circumacetabular (7.44 than in postacetabular (7.08 glands. Conclusions As far as we know, this is the first presentation of a 3-D model of cercarial glands and the first exact estimation of the volumes of the three gland types in schistosomes. Our comparisons between T. regenti and S. mansoni implied that the architecture and ultrastructure of the glands is most likely conserved within the family. Only minor variations were found between the two species. It seems that the differences in molecular composition have no effect on general appearance of the secretory cells in TEM. Fluorescent markers employed in this study, distinguishing between

  19. Regulatory dendritic cell expression of MHCII and IL-10 are jointly requisite for induction of tolerance in a murine model of OVA-asthma.

    Science.gov (United States)

    Huang, H; Dawicki, W; Lu, M; Nayyar, A; Zhang, X; Gordon, J R

    2013-09-01

    Allergen-presenting dendritic cells differentiated with IL-10 (DC10) reverse the asthma phenotype in mice by converting their Th2 cells to regulatory T cells (Tregs). DC10 express elevated levels of IL-10, but substantially reduced levels of MHCII and costimulatory molecules, so the relationships between these factors with each other and tolerogenicity have not been clearly elucidated. We assessed the roles of these inputs in DC10 reversal of OVA-associated asthma-like disease by treating affected mice with OVA-pulsed DC10 generated from wild-type or IL-10-sufficient MHCII(-/-) or CD80/CD86(-/-) mice, or with MHCII-intact IL-10-silenced DC10. IL-10 silencing did not discernibly affect the cells' immunobiology (e.g., costimulatory molecules, chemokines), but it eliminated IL-10 secretion and the cell's abilities to induce tolerance, as determined by assessments of airway hyper-responsiveness, eosinophilia, and Th2 responses to recall OVA challenge. MHCII(-/-) DC10 expressed normal levels of IL-10, but, nevertheless, were unable to induce allergen tolerance in asthma phenotype mice, while tolerance induced by CD80/CD86(-/-) DC10 was attenuated but not eliminated. We also assessed the induction of multiple Treg cell markers (e.g., ICOS, PD-1, GITR) on pulmonary CD25(+) Foxp3(+) cells in the treated mice. Wild-type DC10 treatments upregulated expression of each marker, while neither IL-10-silenced nor MHCII(-/-) DC10 did so, and the CD80/86(-/-) DC10 induced an intermediate Treg cell activation phenotype. Both IL-10 and MCHII expression by DC10 are requisite, but not sufficient for tolerance induction, suggesting that DC10 and Th2 effector T cells must be brought together in a cognate fashion in order for their IL-10 to induce tolerance. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Affinities between Asian non-human Schistosoma species, the S. indicum group, and the African human schistosomes.

    Science.gov (United States)

    Agatsuma, T; Iwagami, M; Liu, C X; Rajapakse, R P V J; Mondal, M M H; Kitikoon, V; Ambu, S; Agatsuma, Y; Blair, D; Higuchi, T

    2002-03-01

    Schistosoma species have traditionally been arranged in groups based on egg morphology, geographical origins, and the genus or family of snail intermediate host. One of these groups is the 'S. indicum group' comprising species from Asia that use pulmonate snails as intermediate hosts. DNA sequences were obtained from the four members of this group (S. indicum, S. spindale, S. nasale and S. incognitum) to provide information concerning their phylogenetic relationships with other Asian and African species and species groups. The sequences came from the second internal transcribed spacer (ITS2) of the ribosomal gene repeat, part of the 28S ribosomal RNA gene (28S), and part of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene. Tree analyses using both distance and parsimony methods showed the S. indicum group not to be monophyletic. Schistosoma indicum, S. spindale and S. nasale were clustered among African schistosomes, while S. incognitum was placed as sister to the African species (using ITS2 and 28S nucleotide sequences and CO1 amino acid sequences), or as sister to all other species of Schistosoma (CO1 nucleotide sequences). Based on the present molecular data, a scenario for the evolution of the S. indicum group is discussed.

  1. Expression profile of the Schistosoma japonicum degradome reveals differential protease expression patterns and potential anti-schistosomal intervention targets.

    Science.gov (United States)

    Liu, Shuai; Cai, Pengfei; Piao, Xianyu; Hou, Nan; Zhou, Xiaosu; Wu, Chuang; Wang, Heng; Chen, Qijun

    2014-10-01

    Blood fluke proteases play pivotal roles in the processes of invasion, nutrition acquisition, immune evasion, and other host-parasite interactions. Hundreds of genes encoding putative proteases have been identified in the recently published schistosome genomes. However, the expression profiles of these proteases in Schistosoma species have not yet been systematically analyzed. We retrieved and culled the redundant protease sequences of Schistosoma japonicum, Schistosoma mansoni, Echinococcus multilocularis, and Clonorchis sinensis from public databases utilizing bioinformatic approaches. The degradomes of the four parasitic organisms and Homo sapiens were then comparatively analyzed. A total of 262 S. japonicum protease sequences were obtained and the expression profiles generated using whole-genome microarray. Four main clusters of protease genes with different expression patterns were identified: proteases up-regulated in hepatic schistosomula and adult worms, egg-specific or predominantly expressed proteases, cercaria-specific or predominantly expressed proteases, and constantly expressed proteases. A subset of protease genes with different expression patterns were further validated using real-time quantitative PCR. The present study represents the most comprehensive analysis of a degradome in Schistosoma species to date. These results provide a firm foundation for future research on the specific function(s) of individual proteases and may help to refine anti-proteolytic strategies in blood flukes.

  2. Differentiating Schistosoma haematobium from related animal schistosomes by PCR amplifying inter-repeat sequences flanking newly selected repeated sequences.

    Science.gov (United States)

    Abbasi, Ibrahim; Hamburger, Joseph; Kariuki, Curtis; Mungai, Peter L; Muchiri, Eric M; King, Charles H

    2012-12-01

    In schistosomiasis elimination programs, successful discrimination of Schistosoma haematobium from the related animal Schistosoma parasites will be essential for accurate detection of human parasite transmission. Polymerase chain reaction assays employing primers from two newly selected repeated sequences, named Sh73 and Sh77, did not discriminate S. haematobium when amplifying Sh73-77 intra- or inter-repeats. However, amplification between Sh73 and the previously described DraI repeat exhibited discriminative banding patterns for S. haematobium and Schistosoma bovis (sensitivity 1 pg and 10 pg, respectively). It also enabled banding pattern discrimination of Schistosoma curassoni and Schistosoma intercalatum, but Schistosoma mattheei and Schistosoma margrebowiei did not yield amplicons. Similar inter-repeat amplification between Sh77 and DraI yielded amplicons with discriminative banding for S. haematobium, and S. bovis; however, S. mattheei was detected only at low sensitivity (1 ng). The Sh73/DraI assay detected snails infected with S. haematobium, S. bovis, or both, and should prove useful for screening snails where discrimination of S. haematobium from related schistosomes is required.

  3. Vaccination of goats against the trematode Schistosoma bovis with a recombinant homologous schistosome-derived glutathione S-transferase.

    Science.gov (United States)

    Boulanger, D; Trottein, F; Mauny, F; Bremond, P; Couret, D; Pierce, R J; Kadri, S; Godin, C; Sellin, E; Lecocq, J P

    1994-08-01

    We assayed the vaccine potentialities of a recombinant S. bovis-derived glutathione S-transferase (rSb28GST), member of a molecular family already shown to have protective capacities in the S. mansoni and S. japonicum models. Injection of the rSb28GST in Freund's Complete Adjuvant resulted in good specific IgG responses allowing all the animals to display high antibody titres on the day of experimental challenge with S. bovis cercariae. No statistically significant differences were observed in the faecal egg output. Although tissue egg counts in vaccinated animals were lower than in controls, the difference was not statistically significant, apart from the number of eggs trapped in the liver (P bovis, by affecting worm viability but not fecundity. These results also point to the striking differences in the effect of vaccination according to animal species. Because it has the capacity to prevent growth impairment due to schistosome pathogenicity, the molecule can be proposed as a valuable tool in the development of vaccine-based control programs in endemic areas.

  4. Neutrophil Inhibitory Factor Selectively Inhibits the Endothelium-Driven Transmigration of Eosinophils In Vitro and Airway Eosinophilia in OVA-Induced Allergic Lung Inflammation

    Directory of Open Access Journals (Sweden)

    Silvia Schnyder-Candrian

    2012-01-01

    Full Text Available Leukocyte adhesion molecules are involved in cell recruitment in an allergic airway response and therefore provide a target for pharmaceutical intervention. Neutrophil inhibitory factor (NIF, derived from canine hookworm (Ancylostoma caninum, binds selectively and competes with the A-domain of CD11b for binding to ICAM-1. The effect of recombinant NIF was investigated. Intranasal administration of rNIF reduced pulmonary eosinophilic infiltration, goblet cell hyperplasia, and Th2 cytokine production in OVA-sensitized mice. In vitro, transendothelial migration of human blood eosinophils across IL-4-activated umbilical vein endothelial cell (HUVEC monolayers was inhibited by rNIF (IC50: 4.6±2.6 nM; mean ± SEM, but not across TNF or IL-1-activated HUVEC monolayers. Treatment of eosinophils with rNIF together with mAb 60.1 directed against CD11b or mAb 107 directed against the metal ion-dependent adhesion site (MIDAS of the CD11b A-domain resulted in no further inhibition of transendothelial migration suggesting shared functional epitopes. In contrast, rNIF increased the inhibitory effect of blocking mAbs against CD18, CD11a, and VLA-4. Together, we show that rNIF, a selective antagonist of the A-domain of CD11b, has a prominent inhibitory effect on eosinophil transendothelial migration in vitro, which is congruent to the in vivo inhibition of OVA-induced allergic lung inflammation.

  5. Regulation of hypothalamic-pituitary-adrenal axis activity and immunologic function contributed to the anti-inflammatory effect of acupuncture in the OVA-induced murine asthma model.

    Science.gov (United States)

    Wei, Ying; Dong, Ming; Zhong, Ling; Liu, Jiaqi; Luo, Qingli; Lv, Yubao; Mo, Shuming; Sun, Jing; Liu, Feng; Xu, Fei; Yan, Chen; Dong, Jingcheng

    2017-01-01

    Asthma is a complex inflammatory disease of the airways and acupuncture is one of the effective therapies widely used to treat asthma in China. The aim of the study was to evaluate the regulatory role of acupuncture in airway inflammation and the hypothalamic-pituitary-adrenal (HPA) axis activity in OVA-induced murine asthma model. Our results demonstrated that acupuncture was effective in suppression of AHR, inhibition of total leukocyte, neutrophil, lymphocyte and eosinophil counts in BALF, attenuation of airway inflammation and TNF-α, IL-1β, IL-5 and eotaxin secretion. Furthermore, the HPA axis activity was also regulated by acupuncture, which included promotion of adrenocorticotropic hormone and cortisol secretion in the plasma. Our findings revealed that acupuncture could attenuate airway inflammation and regulate HPA axis and immunologic function in the OVA-induced murine asthma model, which may provide support to better understand the contribution of acupuncture to the regulation of airway inflammation and HPA axis activity in asthma. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

    Directory of Open Access Journals (Sweden)

    Liliana Costa

    2012-06-01

    Full Text Available Photodynamic inactivation (PDI has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

  7. The Schistosoma indicum species group in Nepal: presence of a new lineage of schistosome and use of the Indoplanorbis exustus species complex of snail hosts✯

    OpenAIRE

    Devkota, Ramesh; Brant, Sara V.; Loker, Eric S.

    2015-01-01

    From 2007–2014, 19,360 freshwater snails from the Terai and hilly regions of Nepal were screened for cercariae of mammalian schistosomes. Based on analysis of mitochondrial cytochrome oxidase I (cox1), 12S, 16S and 28S sequences (3,675 bp) of the cercariae recovered, we provide, to our knowledge, the first report of the Schistosoma indicum species group in Nepal. Five samples of Schistosoma nasale, nine of Schistosoma spindale and 17 of Schistosoma sp. were recovered, all from the snail Indop...

  8. Inactivation of poliovirus by chloramine-T.

    Science.gov (United States)

    Gowda, N M; Trieff, N M; Stanton, G J

    1981-01-01

    Since concern has recently been expressed about the presence of genotoxic substances due to chlorination of water and wastewater, chloramine-T (CAT) is proposed as an alternative disinfectant to chlorine. The viricidal properties of chlorine and CAT were compared. Kinetics of inactivation of poliovirus type 2 by chlorine and CAT in chlorine demand-free water were investigated by using a kinetic apparatus. Inactivation of the virus by chlorine and CAT occurred in two steps. The initial linear part of the inactivation curve followed a pseudo-first-order reaction with the virus. An obvious dose-response relationship was demonstrated with CAT. The rate of inactivation of the virus by CAT was faster in acid medium than in alkaline medium. Inactivation kinetic studies were performed at different temperatures, and the kinetic, Arrhenius, and thermodynamic parameters were evaluated. The rate of inactivation of poliovirus type 2 by chlorine was faster than that by CAT under identical conditions. A mechanism for the viral inactivation in acid conditions was proposed which led to a rate equation consistent with the experimental results. The results indicate that CAT may be an effective viricide against poliovirus type 2 in an acid medium. PMID:6271058

  9. Prereproductive stress to female rats alters corticotropin releasing factor type 1 expression in ova and behavior and brain corticotropin releasing factor type 1 expression in offspring.

    Science.gov (United States)

    Zaidan, Hiba; Leshem, Micah; Gaisler-Salomon, Inna

    2013-11-01

    Human and animal studies indicate that vulnerability to stress may be heritable and that changes in germline may mediate some transgenerational effects. Corticotropin releasing factor type 1 (CRF1) is a key component in the stress response. We investigated changes in CRF1 expression in brain and ova of stressed female rats and in the brain of their neonate and adult offspring. Behavioral changes in adulthood were also assessed. Adult female rats underwent chronic unpredictable stress. We extracted mature oocytes and brain regions from a subset of rats and mated the rest 2 weeks following the stress procedure. CRF1 expression was assessed using quantitative reverse-transcription polymerase chain reaction. Tests of anxiety and aversive learning were used to examine behavior of offspring in adulthood. We show that chronic unpredictable stress leads to an increase in CRF1 messenger RNA expression in frontal cortex and mature oocytes. Neonatal offspring of stressed female rats show an increase in brain CRF1 expression. In adulthood, offspring of stressed female rats show sex differences in both CRF1 messenger RNA expression and behavior. Moreover, CRF1 expression patterns in frontal cortex of female offspring depend upon both maternal and individual adverse experience. Our findings demonstrate that stress affects CRF1 expression in brain but also in ova, pointing to a possible mechanism of transgenerational transmission. In offspring, stress-induced changes are evident at birth and are thus unlikely to result from altered maternal nurturance. Finally, brain CRF1 expression in offspring depends upon gender and upon maternal and individual exposure to adverse environment. © 2013 Society of Biological Psychiatry.

  10. The occurrence of schistosomin, an antagonist of female gonadotropic hormones, is a general phenomenon in haemolymph of schistosome-infected freshwater snails.

    Science.gov (United States)

    De Jong-Brink, M; Elsaadany, M; Soto, M S

    1991-12-01

    In haemolymph of Lymnaea stagnalis, parasitized with the digenetic trematode parasite Trichobilharzia ocellata, a neuropeptide (schistosomin) occurs which antagonizes female gonadotropic hormones, e.g. calfluxin (CaFl). By means of an ultracytochemical hormone-assay, the CaFl assay, it was demonstrated that the occurrence of schistosomin is a general phenomenon in schistosome-infected freshwater snails. Haemolymph of the schistosomiasis-transmitting snail species Biomphalaria glabrata and B. pfeifferi, parasitized with Schistosoma mansoni, also appeared to contain an antagonizing factor, i.e. schistosomin. In contrast, in haemolymph of L. stagnalis parasitized with Diplostomum spathaceum (Diplostomatidae) no schistosomin could be found. This suggests that schistosomin may only occur in snails infected with parasites belonging to the Schistosomatidae. The effect of schistosomin is rather specific. Haemolymph of B. glabrata parasitized with S. mansoni had not the capacity to inhibit the response to CaFl in the target organs for CaFl, the albumen glands of L. stagnalis and Bulinus truncatus. The same holds true for haemolymph of infected L. stagnalis: it did not inhibit the CaFl response in glands of B. glabrata and B. truncatus and even not in those of a related species (L. ovata). Schistosomins in haemolymph of infected B. glabrata and B. pfeifferi, on the other hand, seem more related. Both appeared to inhibit the hormone response in glands of the two Biomphalaria species studied. The results indicate that schistosomin in haemolymph of schistosome-infected pulmonate snails, although functionally related, may differ structurally.

  11. Cigarette smoking induced liver insult concomitant with inflammatory mediators in serum crevicular fluid and bronchio alveolar lavage of schistosomal diabetic subjects with history of bronchial asthma.

    Science.gov (United States)

    El-Dardiry, Samia A; Shafik, Sherine R; Wagih, Ayman; Amir, El-Amir M; Kassem, Gamal K; Atef, Ghada; El-Toukhy, Heba

    2007-08-01

    Forty five smokers were classified into schistosomal cases with type-2 diabetis mellitus (GI) and with associated history of bronchial asthma (GII) and without T-2 DM (GIII). A control group (GIV) of non-diabetic non schistosomal age matched subjects who quitted smoking for >6 months were included. Assessed parameters included indices of glycemic status (glycated hemoglobin), angiogenesis (vascular endothelial growth factor) hepatic and bronchoalveolar disposition (Liver function test, metallothionein, serum levels of cotinine, cadmium selenium, copper & zinc) and bronchoalveolar lavage) (BAL) levels of surfactant proteins A & D, zinc and copper oxidative stress and fibrogenesis (total antioxidant capacity thiobarbituric acid reactive substance) and vasculopathy (angiotensin converting enzyme, P-selectin, nitrate) and periodontitis (collagenase and elastase in GCF) impact of cigarette smoking associated with trace element disbalance and enzymatic changes in crevicular fluid on altered parameters collaborative out-come. The study reflected the collaborative outcome of immune mediated mechanisms initiated by liver affection, glycemic status and history of predisposed bronchial integrity induced by oxidative stress.

  12. Silence of the fathers: early X inactivation.

    Science.gov (United States)

    Cheng, Mimi K; Disteche, Christine M

    2004-08-01

    X chromosome inactivation is the mammalian answer to the dilemma of dosage compensation between males and females. The study of this fascinating form of chromosome-wide gene regulation has yielded surprising insights into early development and cellular memory. In the past few months, three papers reported unexpected findings about the paternal X chromosome (X(p)). All three studies agree that the X(p) is imprinted to become inactive earlier than ever suspected during embryonic development. Although apparently incomplete, this early form of inactivation insures dosage compensation throughout development. Silencing of the X(p) persists in cells of extraembryonic tissues, but it is erased and followed by random X inactivation in cells of the embryo proper. These findings challenge several aspects of the current view of X inactivation during early development and may have profound impact on studies of pluripotency and epigenetics.

  13. Microbial Inactivation by Ultrasound Assisted Supercritical Fluids

    Science.gov (United States)

    Benedito, Jose; Ortuño, Carmen; Castillo-Zamudio, Rosa Isela; Mulet, Antonio

    A method combining supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) has been developed and tested for microbial/enzyme inactivation purposes, at different process conditions for both liquid and solid matrices. In culture media, using only SC-CO2, the inactivation rate of E. coli and S. cerevisiae increased with pressure and temperature; and the total inactivation (7-8 log-cycles) was attained after 25 and 140 min of SC-CO2 (350 bar, 36 °C) treatment, respectively. Using SC-CO2+HPU, the time for the total inactivation of both microorganisms was reduced to only 1-2 min, at any condition selected. The SC-CO2+HPU inactivation of both microorganisms was slower in juices (avg. 4.9 min) than in culture media (avg. 1.5 min). In solid samples (chicken, turkey ham and dry-cured pork cured ham) treated with SC-CO2 and SC-CO2+HPU, the inactivation rate of E. coli increased with temperature. The application of HPU to the SC-CO2 treatments accelerated the inactivation rate of E. coli and that effect was more pronounced in treatments with isotonic solution surrounding the solid food samples. The application of HPU enhanced the SC-CO2 inactivation mechanisms of microorganisms, generating a vigorous agitation that facilitated the CO2 solubilization and the mass transfer process. The cavitation generated by HPU could damage the cell walls accelerating the extraction of vital constituents and the microbial death. Thus, using the combined technique, reasonable industrial processing times and mild process conditions could be used which could result into a cost reduction and lead to the minimization in the food nutritional and organoleptic changes.

  14. Photodynamic-induced inactivation of Propionibacterium acnes

    Science.gov (United States)

    Koenig, Karsten; Teschke, M.; Eick, Stephen G.; Pfister, W.; Meyer, Herbert; Halbhuber, Karl-Juergen

    1998-05-01

    We report on photodynamically induced inactivation of the skin bacterium Propionibacterium acnes (P. acnes) using endogenous as well as exogenous photosensitizers and red light sources. P. acnes is involved in the pathogenesis of the skin disease acne vulgaris. The skin bacterium is able to synthesize the metal-free fluorescent porphyrins protoporphyrin IX (PP) and coproporphyrin (CP) as shown by in situ spectrally-resolved detection of natural autofluorescence of human skin and bacteria colonies. These naturally occurring intracellular porphyrins act as efficient endogenous photosensitizers. Inactivation of P. acnes suspensions was achieved by irradiation with He-Ne laser light in the red spectral region (632.8 nm). We monitored the photodynamically-induced death of single bacteria using a fluorescent viability kit in combination with confocal laser scanning microscopy. In addition, the photo-induced inactivation was calculated by CFU (colony forming units) determination. We found 633 nm-induced inactivation (60 mW, 0.12 cm2 exposure area, 1 hour irradiation) of 72% in the case of non-incubated bacteria based on the destructive effect of singlet oxygen produced by red light excited endogenous porphyrins and subsequent energy transfer to molecular oxygen. In order to achieve a nearly complete inactivation within one exposure procedure, the exogenous photosensitizer Methylene Blue (Mb) was added. Far red exposure of Mb-labeled bacteria using a krypton ion laser at 647 nm and 676 nm resulted in 99% inactivation.

  15. Experimental pulmonary schistosomiasis: lack of morphological evidence of modulation in schistosomal pulmonary granulomas Esquistossomose pulmonar experimental: falta de evidência morfológica de modulação nos granulomas esquistosomóticos pulmonares

    OpenAIRE

    Maura R. F. Souza Vidal; Barbosa Jr.,Aryon A.; Zilton A. ANDRADE

    1993-01-01

    Numerous pulmonary schistosome egg granulomas were present in mice submitted to partial portal vein ligation (Warren's model). The granulomas were characterized by cellular aggregations formed within alveolar tissue. Main cellular types were macrophages (epithelioid cells), eosinophils, plasma cells and lymphocytes. These cells were supported by scanty fibrous stroma and exhibited close membrane contact points amongst themselves, but without forming specialized adhesion apparatus. When granul...

  16. Differentiating Schistosoma haematobium from Schistosoma magrebowiei and other closely related schistosomes by polymerase chain reaction amplification of a species specific mitochondrial gene.

    Science.gov (United States)

    Akinwale, Olaoluwa P; Hock, Tang T; Chia-Kwung, Fan; Zheng, Qi; Haimo, Shen; Ezeh, Charles; Gyang, Pam V

    2014-01-01

    Schistosoma haematobium infection afflicts about 150 million people in 53 countries in Africa and the Middle East. In many endemic areas, S. haematobium is sympatric with Schistosoma bovis, Schistosoma mattheei, Schistosoma curassoni, Schistosoma intercalatum and Schistosoma magrebowiei, its closely related species. In addition, they also develop in the same intermediate snail hosts. Since these schistosome species often infect snails inhabiting the same bodies of water, examining cercariae or infected snails for estimating transmission of S. haematobium is always confounded by the need to differentially identify S. haematobium from these other species. Recently, differentiating S. haematobium by polymerase chain reaction (PCR) from S. bovis, S. mattheei, S. curassoni and S. intercalatum, but not from S. magrebowiei was reported. However, to be able to evaluate residual S. haematobium transmission after control interventions in areas where S. haematobium may be sympatric with S. magrebowiei, a differential tool for accurate monitoring of infected snails is needed. Thus in this study, we developed a new PCR assay using a pair of primers, ShND-1/ShND-2, to amplify a target sequence of 1117 bp (GenBank accession number KF834975) from S. haematobium mitochondrion complete genome (GenBank accession number DQ157222). Sensitivity of the assay was determined by PCR amplification of different concentrations of S. haematobium gDNA serially diluted from 10ng to 0.1pg. For assay specificity, different concentrations of gDNA from S. haematobium and the other schistosome species, 20 positive urine samples and five controls as well as 20 infected snails were subjected to PCR amplification, while some of the PCR products were sequenced. The assay detected up to 1pg of S. haematobium gDNA, while a differential identification of S. haematobium DNA content from other closely related species was achieved when applied to urine and naturally infected snails. When a protein-protein blast

  17. Inactivation of pathogenic bacteria in food matrices: high pressure processing, photodynamic inactivation and pressure-assisted photodynamic inactivation

    Science.gov (United States)

    Cunha, A.; Couceiro, J.; Bonifácio, D.; Martins, C.; Almeida, A.; Neves, M. G. P. M. S.; Faustino, M. A. F.; Saraiva, J. A.

    2017-09-01

    Traditional food processing methods frequently depend on the application of high temperature. However, heat may cause undesirable changes in food properties and often has a negative impact on nutritional value and organoleptic characteristics. Therefore, reducing the microbial load without compromising the desirable properties of food products is still a technological challenge. High-pressure processing (HPP) can be classified as a cold pasteurization technique, since it is a non-thermal food preservation method that uses hydrostatic pressure to inactivate spoilage microorganisms. At the same time, it increases shelf life and retains the original features of food. Photodynamic inactivation (PDI) is also regarded as promising approach for the decontamination of food matrices. In this case, the inactivation of bacterial cells is achieved by the cytotoxic effects of reactive oxygens species (ROS) produced from the combined interaction of a photosensitizer molecule, light and oxygen. This short review examines some recent developments on the application of HPP and PDI with food-grade photosensitizers for the inactivation of listeriae, taken as a food pathogen model. The results of a proof-of-concept trial of the use of high-pressure as a coadjutant to increase the efficiency of photodynamic inactivation of bacterial endospores is also addressed.

  18. Beta-2 adrenergic receptors increase TREG cell suppression in an OVA-induced allergic asthma mouse model when mice are moderate aerobically exercised.

    Science.gov (United States)

    Dugger, Kari J; Chrisman, Taylor; Sayner, Sarah L; Chastain, Parker; Watson, Kacie; Estes, Robert

    2018-02-17

    The potency of T regulatory (TREG) cells to inhibit T helper (Th)-driven immune cell responses has been linked to increased intracellular cyclic-AMP (cAMP) levels of TREG cells. In an ovalbumin (OVA)-driven allergic asthma mouse model, moderate aerobic exercise increases TREG cell function in a contact-dependent manner that leads to a significant reduction in chronic inflammation and restoration of lung function. However, the mechanism, whereby exercise increases TREG function, remains unknown and was the focus of these investigations. Exercise can communicate with TREG cells by their expression of β2-adrenergic receptors (β2-AR). Activation of these receptors results in an increase in intracellular levels of cyclic-AMP, potentially creating a potent inhibitor of Th cell responses. For the allergic asthma model, female wildtype BALB/c mice were challenged with OVA, and exercised (13.5 m/min for 45 min) 3×/week for 4 weeks. TREG cells were isolated from all mouse asthma/exercise groups, including β2-AR -/- mice, to test suppressive function and intracellular cAMP levels. In these studies, cAMP levels were increased in TREG cells isolated from exercised mice. When β2-AR expression was absent on TREG cells, cAMP levels were significantly decreased. Correlatively, their suppressive function was compromised. Next, TREG cells from all mouse groups were tested for suppressive function after treatment with either a pharmaceutical β2-adrenergic agonist or an effector-specific cAMP analogue. These experiments showed TREG cell function was increased when treated with either a β2-adrenergic agonist or effector-specific cAMP analogue. Finally, female wildtype BALB/c mice were antibody-depleted of CD25 + CD4 + TREG cells (anti-CD25). Twenty-four hours after TREG depletion, either β2-AR -/- or wildtype TREG cells were adoptively transferred. Recipient mice underwent the asthma/exercise protocols. β2-AR -/- TREG cells isolated from these mice showed no increase in

  19. Evolution of schistosomiasis-induced pathology after therapy and interruption of exposure to schistosomes: a review of ultrasonographic studies.

    Science.gov (United States)

    Richter, J

    2000-10-23

    urogenital lesions led to complications many years after exposure. Contrary to hepatosplenic and urinary pathology, knowlegde on the evolution of other organic abnormalities is very limited: studies on the evolution of biliary abnormalities or intestinal pathology have not been published. Genital pathology may be induced by all Schistosoma spp. Post-therapy evolution of genital schistosomiasis is largely ignored. In some European travellers partial regression of prostatic fibrosis has been described. Schistosomal adnexitis leading to infertility and/or ectopic pregnancy has been reported occurring many years after interruption of exposure. Ultrasonography (US) has never been used to study the influence of schistosomiasis on pregnancy. Concluding, current knowlegde on the evolution of pathology after treatment and/or interruption of exposure is still fragmentary. Frequently, fibrosis reverses after therapy, but advanced pathology may persist for long. Therefore, the possibility of severe clinical complications has to be taken into account, even if the infection is inactive since many years. In interventions aimed at controlling schistosomiasis-related morbidity, evolution of pathology must be monitored by US in representative patient cohorts. Further systematic US-studies are needed not only on the evolution of hepatosplenic and urinary pathology but also on that of intestinal, biliary and genital pathology induced by schistosomiasis, as well as on the influence of schistosomiasis on the outcome of pregnancy.

  20. Kinetics of Hydrothermal Inactivation of Endotoxins ▿

    Science.gov (United States)

    Li, Lixiong; Wilbur, Chris L.; Mintz, Kathryn L.

    2011-01-01

    A kinetic model was established for the inactivation of endotoxins in water at temperatures ranging from 210°C to 270°C and a pressure of 6.2 × 106 Pa. Data were generated using a bench scale continuous-flow reactor system to process feed water spiked with endotoxin standard (Escherichia coli O113:H10). Product water samples were collected and quantified by the Limulus amebocyte lysate assay. At 250°C, 5-log endotoxin inactivation was achieved in about 1 s of exposure, followed by a lower inactivation rate. This non-log-linear pattern is similar to reported trends in microbial survival curves. Predictions and parameters of several non-log-linear models are presented. In the fast-reaction zone (3- to 5-log reduction), the Arrhenius rate constant fits well at temperatures ranging from 120°C to 250°C on the basis of data from this work and the literature. Both biphasic and modified Weibull models are comparable to account for both the high and low rates of inactivation in terms of prediction accuracy and the number of parameters used. A unified representation of thermal resistance curves for a 3-log reduction and a 3 D value associated with endotoxin inactivation and microbial survival, respectively, is presented. PMID:21193667

  1. Trichobilharzia anseri n. sp. (Schistosomatidae: Digenea), a new visceral species of avian schistosomes isolated from greylag goose (Anser anser L.) in Iceland and France.

    Science.gov (United States)

    Jouet, D; Kolářová, L; Patrelle, C; Ferté, H; Skírnisson, K

    2015-08-01

    Parasitological investigations carried out on birds in Iceland and France highlight the presence of four species of avian schistosomes from greylag geese (Anser anser L.): the european nasal species Trichobilharzia regenti and three visceral species, among which an unknown species isolated from blood vessels of the large intestine and liver. Morphological and molecular analyzes of different parasite stages (eggs, adults) revealed new species of Trichobilharzia genus – Trichobilharzia anseri sp. nov. Studies on host-parasite relationship under natural conditions, showed that the life-cycle includes the snail Radix balthica (syn. R. peregra) as intermediate host. The cercariae, already isolated in Iceland from two ponds of the Reykjavik capital area – the Family park and Tjörnin Lake – are the same as those isolated in 1999 by Kolářová et al. during the first study on Icelandic parasitic agents of cercarial dermatitis. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. DNA barcoding of schistosome cercariae reveals a novel sub-lineage within Schistosoma rodhaini from Ngamba Island Chimpanzee Sanctuary, Lake Victoria.

    Science.gov (United States)

    Standley, C J; Stothard, J R

    2012-10-01

    While Schistosoma rodhaini is typically considered a parasite of small mammals and is very scantly distributed in the Lake Victoria basin, it is known to hybridize with the more widespread Schistosoma mansoni, the causative agent of intestinal schistosomiasis. As part of broader parasitological and malacological surveys for S. mansoni across Lake Victoria, schistosome cercariae were harvested from a field-caught Biomphalaria choanomphala taken on Ngamba Island Chimpanzee Sanctuary, Uganda. Upon DNA barcoding, these cercariae were found to be a mixture of both S. rodhaini and S. mansoni, with further phylogenetic analysis revealing a hitherto unknown sub-lineage within S. rodhaini. Despite repeated sampling for eggs and miracidia from both chimpanzees and staff on Ngamba Island Sanctuary, detection of S. rodhaini within local definitive hosts awaits additional efforts, which should be mindful of a potential host role of spotted-necked otters.

  3. Differences in the egg morphology and certain biological characteristics of some African and Middle Eastern schistosomes, genus Schistosoma, with terminal-spined eggs*

    Science.gov (United States)

    Pitchford, R. J.

    1965-01-01

    There is some confusion regarding the differentiation of African and Middle Eastern schistosomes with terminal-spined eggs. In an attempt to clarify the situation, the author has separated the members of the genus Schistosoma that have terminal-spined eggs into three broad groups and five species on the basis of egg morphology and certain biological characteristics. The groups are: the haematobium group, with one species (S. haematobium); the bovis group, with three species (S. bovis, S. mattheei and S. leiperi); and the intercalatum group, with one species (S. intercalatum). Further species separation is not thought to be justified yet, and reasons are given for considering S. capense and S. curassoni as synonymous with S. haematobium and S. mattheei respectively. PMID:14292062

  4. DIFFERENCES IN THE EGG MORPHOLOGY AND CERTAIN BIOLOGICAL CHARACTERISTICS OF SOME AFRICAN AND MIDDLE EASTERN SCHISTOSOMES, GENUS SCHISTOSOMA, WITH TERMINAL-SPINED EGGS.

    Science.gov (United States)

    PITCHFORD, R J

    1965-01-01

    There is some confusion regarding the differentiation of African and Middle Eastern schistosomes with terminal-spined eggs. In an attempt to clarify the situation, the author has separated the members of the genus Schistosoma that have terminal-spined eggs into three broad groups and five species on the basis of egg morphology and certain biological characteristics.THE GROUPS ARE: the haematobium group, with one species (S. haematobium); the bovis group, with three species (S. bovis, S. mattheei and S. leiperi); and the intercalatum group, with one species (S. intercalatum). Further species separation is not thought to be justified yet, and reasons are given for considering S. capense and S. curassoni as synonymous with S. haematobium and S. mattheei respectively.

  5. Differences in the gene expression profiles of haemocytes from schistosome-susceptible and -resistant biomphalaria glabrata exposed to Schistosoma mansoni excretory-secretory products.

    Directory of Open Access Journals (Sweden)

    Zahida Zahoor

    Full Text Available During its life cycle, the helminth parasite Schistosoma mansoni uses the freshwater snail Biomphalaria glabrata as an intermediate host to reproduce asexually generating cercariae for infection of the human definitive host. Following invasion of the snail, the parasite develops from a miracidium to a mother sporocyst and releases excretory-secretory products (ESPs that likely influence the outcome of host infection. To better understand molecular interactions between these ESPs and the host snail defence system, we determined gene expression profiles of haemocytes from S. mansoni-resistant or -susceptible strains of B. glabrata exposed in vitro to S. mansoni ESPs (20 μg/ml for 1 h, using a 5K B. glabrata cDNA microarray. Ninety-eight genes were found differentially expressed between haemocytes from the two snail strains, 57 resistant specific and 41 susceptible specific, 60 of which had no known homologue in GenBank. Known differentially expressed resistant-snail genes included the nuclear factor kappa B subunit Relish, elongation factor 1α, 40S ribosomal protein S9, and matrilin; known susceptible-snail specific genes included cathepsins D and L, and theromacin. Comparative analysis with other gene expression studies revealed 38 of the 98 identified genes to be uniquely differentially expressed in haemocytes in the presence of ESPs, thus identifying for the first time schistosome ESPs as important molecules that influence global snail host-defence cell gene expression profiles. Such immunomodulation may benefit the schistosome, enabling its survival and successful development in the snail host.

  6. A Recombinant DNA Plasmid Encoding the sIL-4R-NAP Fusion Protein Suppress Airway Inflammation in an OVA-Induced Mouse Model of Asthma.

    Science.gov (United States)

    Liu, Xin; Fu, Guo; Ji, Zhenyu; Huang, Xiabing; Ding, Cong; Jiang, Hui; Wang, Xiaolong; Du, Mingxuan; Wang, Ting; Kang, Qiaozhen

    2016-08-01

    Asthma is a chronic inflammatory airway disease. It was prevalently perceived that Th2 cells played the crucial role in asthma pathogenesis, which has been identified as the important target for anti-asthma therapy. The soluble IL-4 receptor (sIL-4R), which is the decoy receptor for Th2 cytokine IL-4, has been reported to be effective in treating asthma in phase I/II clinical trail. To develop more efficacious anti-asthma agent, we attempt to test whether the Helicobacter pylori neutrophil-activating protein (HP-NAP), a novel TLR2 agonist, would enhance the efficacy of sIL-4R in anti-asthma therapy. In our work, we constructed a pcDNA3.1-sIL-4R-NAP plasmid, named PSN, encoding fusion protein of murine sIL-4R and HP-NAP. PSN significantly inhibited airway inflammation, decreased the serum OVA-specific IgE levels and remodeled the Th1/Th2 balance. Notably, PSN is more effective on anti-asthma therapy comparing with plasmid only expressing sIL-4R.

  7. Localization of ubiquitin C-terminal hydrolase L1 in mouse ova and its function in the plasma membrane to block polyspermy.

    Science.gov (United States)

    Sekiguchi, Satoshi; Kwon, Jungkee; Yoshida, Etsuko; Hamasaki, Hiroko; Ichinose, Shizuko; Hideshima, Makoto; Kuraoka, Mutsuki; Takahashi, Akio; Ishii, Yoshiyuki; Kyuwa, Shigeru; Wada, Keiji; Yoshikawa, Yasuhiro

    2006-11-01

    Protein degradation is essential for oogenesis and embryogenesis. The ubiquitin-proteasome system regulates many cellular processes via the rapid degradation of specific proteins. Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) is exclusively expressed in neurons, testis, ovary, and placenta, each of which has unique biological activities. However, the functional role of UCH-L1 in mouse oocytes remains unknown. Here, we report the expression pattern of UCH-L1 and its isozyme UCH-L3 in mouse ovaries and embryos. Using immunocytochemistry, UCH-L1 was selectively detected on the plasma membrane, whereas UCH-L3 was mainly detected in the cytoplasm, suggesting that these isozymes have distinct functions in mouse eggs. To further investigate the functional role of UCH-L1 in mouse eggs, we analyzed the fertilization rate of UCH-L1-deficient ova of gad female mice. Female gad mice had a significantly increased rate of polyspermy in in vitro fertilization assays, although the rate of fertilization did not differ significantly from wild-type mice. In addition, the litter size of gad female mice was significantly reduced compared with wild-type mice. These results may identify UCH-L1 as a candidate for a sperm-oocyte interactive binding or fusion protein on the plasma membrane that functions during the block to polyspermy in mouse oocytes.

  8. Inactivation of glutathione peroxidase by benzaldehyde.

    Science.gov (United States)

    Tabatabaie, T; Floyd, R A

    1996-12-01

    Chronic benzaldehyde exposure is known to cause central nervous system (CNS) disturbances. Previous studies have shown that benzaldehyde causes the formation of reactive oxygen species (ROS) in rat synaptosomal fractions. Benzaldehyde has also been implicated in ROS formation in the CNS of rats treated with toluene. We have found that benzaldehyde effectively inactivates the antioxidant enzyme glutathione peroxidase (Ki approximately 15 microM), but has no effect on the other antioxidant enzymes tested: catalase, superoxide dismutase, and glutathione reductase. This effect has been found to be specific to benzaldehyde since other structurally related and unrelated aldehydes tested were found to be devoid of inactivating capacity toward glutathione peroxidase. Since glutathione peroxidase is the main enzyme responsible for removal of hydrogen peroxide and organic hydroperoxides in brain, its inactivation by benzaldehyde may be a main contributor to the observed ROS formation and the observed neurotoxicity caused by either benzaldehyde or toluene exposure.

  9. Kinetics of Hydrothermal Inactivation of Endotoxins ▿

    OpenAIRE

    Li, Lixiong; Wilbur, Chris L.; Mintz, Kathryn L.

    2011-01-01

    A kinetic model was established for the inactivation of endotoxins in water at temperatures ranging from 210°C to 270°C and a pressure of 6.2 × 106 Pa. Data were generated using a bench scale continuous-flow reactor system to process feed water spiked with endotoxin standard (Escherichia coli O113:H10). Product water samples were collected and quantified by the Limulus amebocyte lysate assay. At 250°C, 5-log endotoxin inactivation was achieved in about 1 s of exposure, followed by a lower ina...

  10. X-chromosome inactivation and escape

    Indian Academy of Sciences (India)

    2015-11-06

    Nov 6, 2015 ... She predicted many of the features of X inactivation, for e.g., .... feature that locks silencing, i.e. DNA methylation at CpG islands of X-linked ..... 1996 XIST RNA paints the inactive X chromosome at interphase: evidence for a novel RNA involved in nuclear/chromosome structure. J. Cell Biol. 132, 259–275.

  11. Inactivation of Bacillus atrophaeus by OH radicals

    Science.gov (United States)

    Ono, Ryo; Yonetamari, Kenta; Tokumitsu, Yusuke; Yonemori, Seiya; Yasuda, Hachiro; Mizuno, Akira

    2016-08-01

    The inactivation of Bacillus atrophaeus by OH radicals is measured. This study aims to evaluate the bactericidal effects of OH radicals produced by atmospheric-pressure nonthermal plasma widely used for plasma medicine; however, in this study, OH radicals are produced by vacuum ultraviolet (VUV) photolysis of water vapor instead of plasma to allow the production of OH radicals with almost no other reactive species. A 172 nm VUV light from a Xe2 excimer lamp irradiates a He-H2O mixture flowing in a quartz tube to photodissociate H2O to produce OH, H, O, HO2, H2O2, and O3. The produced reactive oxygen species (ROS) flow out of the quartz tube nozzle to the bacteria on an agar plate and cause inactivation. The inactivation by OH radicals among the six ROS is observed by properly setting the experimental conditions with the help of simulations calculating the ROS densities. A 30 s treatment with approximately 0.1 ppm OH radicals causes visible inactivation.

  12. Bioinactivation: Software for modelling dynamic microbial inactivation.

    Science.gov (United States)

    Garre, Alberto; Fernández, Pablo S; Lindqvist, Roland; Egea, Jose A

    2017-03-01

    This contribution presents the bioinactivation software, which implements functions for the modelling of isothermal and non-isothermal microbial inactivation. This software offers features such as user-friendliness, modelling of dynamic conditions, possibility to choose the fitting algorithm and generation of prediction intervals. The software is offered in two different formats: Bioinactivation core and Bioinactivation SE. Bioinactivation core is a package for the R programming language, which includes features for the generation of predictions and for the fitting of models to inactivation experiments using non-linear regression or a Markov Chain Monte Carlo algorithm (MCMC). The calculations are based on inactivation models common in academia and industry (Bigelow, Peleg, Mafart and Geeraerd). Bioinactivation SE supplies a user-friendly interface to selected functions of Bioinactivation core, namely the model fitting of non-isothermal experiments and the generation of prediction intervals. The capabilities of bioinactivation are presented in this paper through a case study, modelling the non-isothermal inactivation of Bacillus sporothermodurans. This study has provided a full characterization of the response of the bacteria to dynamic temperature conditions, including confidence intervals for the model parameters and a prediction interval of the survivor curve. We conclude that the MCMC algorithm produces a better characterization of the biological uncertainty and variability than non-linear regression. The bioinactivation software can be relevant to the food and pharmaceutical industry, as well as to regulatory agencies, as part of a (quantitative) microbial risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Pulsed electric field inactivation in a microreactor

    NARCIS (Netherlands)

    Fox, M.B.

    2006-01-01

    Pulsed electric fields (PEF) is a novel, non-thermal pasteurization method which uses short, high electric field pulses to inactivate microorganisms. The advantage of a pasteurization method like PEF compared to regular heat pasteurization is that the taste, flavour, texture and nutritional value

  14. Inactivation of human norovirus using chemical sanitizers

    Science.gov (United States)

    The porcine gastric mucin binding magnetic bead (PGM-MB) assay was used to evaluate the ability of chlorine, chlorine dioxide, peroxyacetic acid, hydrogen peroxide, and trisodium phosphate to inactivate human norovirus within 10 percent stool filtrate. One min free chlorine treatments at concentrat...

  15. Photodynamic Inactivation of Food Pathogen Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Irina Buchovec

    2010-01-01

    Full Text Available The aim of this study is to examine the possibility to inactivate food pathogen Listeria monocytogenes by nonthermal antimicrobial treatment – photosensitization. L. monocytogenes was incubated with 5-aminolevulinic acid (ALA (7.5 mM for 0–2 h to produce endogenous photosensitizers and then illuminated with visible light. The LED-based light source used for the illumination of L. monocytogenes emitted light at λ=400 nm with energy density of 20 mW/cm2. The illumination time varied from 0 to 20 min, and a total energy dose reached 0–24 J/cm2. The obtained results reveal that L. monocytogenes can effectively produce endogenous porphyrins after incubation with 7.5 mM ALA. Subsequent illumination of cells with visible light significantly decreased their viability in vitro (4 log. After adhesion of Listeria to the surface of packaging material and following photosensitization, the surface-attached bacterial population was inactivated by 3.7 log. In addition, most resistant Listeria biofilms are susceptible to this treatment. Their inactivation reached 3.1 log under certain experimental conditions. The cells and biofilms of Gram-positive bacteria L. monocytogenes ATCL3C 7644 could be effectively inactivated by ALA-based photosensitization in the solution as well as adhered onto the surface of packaging material in a nonthermal way.

  16. Inactivation of prion infectivity by ionizing rays

    Energy Technology Data Exchange (ETDEWEB)

    Gominet, M. [Ionisos, ZI les Chatinieres, F01120 Dagneux (France); Vadrot, C.; Austruy, G. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France); Darbord, J.C. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France)], E-mail: darbord@pharmacie.univ-paris5.fr

    2007-11-15

    Inactivation of prion deposits on medical devices or prion contamination in pharmaceutical raw materials is considered as impossible by using gamma irradiation. Early, the guideline WHO/CDS/CSR/APH/2000 has described irradiation as an ineffective process. But, in 2003, S. Miekka et al. noted radiation inactivation of prions in a particular application to purify human albumin, shown by the physical denaturation of the infectious protein (PrP). The aim of our study was to determine the inactivation of prions with a scrapie model (strain C506M3) by irradiating standardised preparations. Results: Gamma irradiation was partially effective, showing a 4-5 log reduction on exposure to 50 kGy. A characteristic effect-dose curve was not observed (25, 50 and 100 kGy), only an increase in the incubation period of the murine disease (229 days with 25 kGy to 290 days with 100 kGy) compared with 170 days without irradiation. Since the inactivation was not a total one, the observed effect is significant. It is proposed that further work be undertaken with the model to investigate the application of gamma radiation known levels of prion contamination.

  17. Inactivation of Escherichia coli by citral.

    Science.gov (United States)

    Somolinos, M; García, D; Condón, S; Mackey, B; Pagán, R

    2010-06-01

    The aim was to evaluate (i) the resistance of Escherichia coli BJ4 to citral in a buffer system as a function of citral concentration, treatment medium pH, storage time and initial inoculum size, (ii) the role of the sigma factor RpoS on citral resistance of E. coli, (iii) the role of the cell envelope damage in the mechanism of microbial inactivation by citral and (iiii) possible synergistic effects of mild heat treatment and pulsed electric fields (PEF) treatment combined with citral. The initial inoculum size greatly affected the efficacy of citral against E. coli cells. Exposure to 200 microl l(-1) of citral at pH 4.0 for 24 h at 20 degrees C caused the inactivation of more than 5 log(10) cycles of cells starting at an inoculum size of 10(6) or 10(7) CFU ml(-1), whereas increasing the cell concentration to 10(9) CFU ml(-1) caused citral at pH 4.0 than pH 7.0. The rpoS null mutant strain E. coli BJ4L1 was less resistant to citral than the wild-type strain. Occurrence of sublethal injury to both the cytoplasmic and outer membranes was demonstrated by adding sodium chloride or bile salts to the recovery media. The majority of sublethally injured cells by citral required energy and lipid synthesis for repair. A strongly synergistic lethal effect was shown by mild heat treatment combined with citral but the presence of citral during the application of a PEF treatment did not show any advantage. This work confirms that cell envelope damage is an important event in citral inactivation of bacteria, and it describes the key factors on the inactivation of E. coli cells by citral. Knowledge about the mechanism of microbial inactivation by citral helps establish successful combined preservation treatments.

  18. Treatment with 1,25(OH){sub 2}D{sub 3}induced HDAC2 expression and reduced NF-κB p65 expression in a rat model of OVA-induced asthma

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.; Wang, G.F.; Yang, L.; Liu, F.; Kang, J.Q.; Wang, R.L.; Gu, W.; Wang, C.Y. [Department of Gerontology Medicine, Xinhua Hospital, Shanghai Jiatong University School of Medicine, Shanghai (China)

    2015-04-28

    Recent evidence indicates that a deficiency of 1,25-dihydroxyvitamin D{sub 3} (1,25[OH]{sub 2}D{sub 3}) may influence asthma pathogenesis; however, its roles in regulating specific molecular transcription mechanisms remain unclear. We aimed to investigate the effect of 1,25(OH){sub 2}D{sub 3} on the expression and enzyme activity of histone deacetylase 2 (HDAC2) and its synergistic effects with dexamethasone (Dx) in the inhibition of inflammatory cytokine secretion in a rat asthma model. Healthy Wistar rats were randomly divided into 6 groups: control, asthma, 1,25(OH){sub 2}D{sub 3} pretreatment, 1,25(OH){sub 2}D{sub 3} treatment, Dx treatment, and Dx and 1,25(OH){sub 2}D{sub 3} treatment. Pulmonary inflammation was induced by ovalbumin (OVA) sensitization and challenge (OVA/OVA). Inflammatory cells and cytokines in the bronchoalveolar lavage (BAL) fluid and histological changes in lung tissue were examined. Nuclear factor kappa B (NF-κB) p65 and HDAC2 expression levels were assessed with Western blot analyses and quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Enzyme activity measurements and immunohistochemical detection of HDAC2 were also performed. Our data demonstrated that 1,25(OH){sub 2}D{sub 3} reduced the airway inflammatory response and the level of inflammatory cytokines in BAL. Although NF-κB p65 expression was attenuated in the pretreatment and treatment groups, the expression and enzyme activity of HDAC2 were increased. In addition, 1,25(OH){sub 2}D{sub 3} and Dx had synergistic effects on the suppression of total cell infusion, cytokine release, and NF-κB p65 expression, and they also increased HDAC2 expression and activity in OVA/OVA rats. Collectively, our results indicated that 1,25(OH){sub 2}D{sub 3}might be useful as a novel HDAC2 activator in the treatment of asthma.

  19. Stool ova and parasites exam

    Science.gov (United States)

    ... Management by Laboratory Methods . 23rd ed. Philadelphia, PA: Elsevier; 2017:chap 64. DuPont HL. Approach to the ... AI, eds. Goldman's Cecil Medicine . 25thed. Philadelphia, PA: Elsevier Saunders; 2016:chap 283. Haines CF, Sears CL. ...

  20. Effects of Bacterial Inactivation Methods on Downstream Proteomic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Andy; Merkley, Eric D.; Clowers, Brian H.; Hutchison, Janine R.; Kreuzer, Helen W.

    2015-05-01

    Inactivation of pathogenic microbial samples is often necessary for the protection of researchers and to comply with local and federal regulations. By its nature, biological inactivation causes changes to microbial samples, potentially affecting observed experimental results. While inactivation induced damage to materials such as DNA has been evaluated, the effect of various inactivation strategies on proteomic data, to our knowledge, has not been discussed. To this end, we inactivated samples of Yersinia pestis and Escherichia coli by autoclave, ethanol, or irradiation treatment to determine how inactivation changes liquid chromatography tandem mass spectrometry data quality as well as apparent protein content of cells. Proteomic datasets obtained from aliquots of samples inactivated by different methods were highly similar, with Pearson correlation coefficients ranging from 0.822 to 0.985 and 0.816 to 0.985 for E. coli and Y. pestis, respectively, suggesting that inactivation had only slight impacts on the set of proteins identified. In addition, spectral quality metrics such as distributions of various database search algorithm scores remained constant across inactivation methods, indicating that inactivation does not appreciably degrade spectral quality. Though overall changes resulting from inactivation were small, there were detectable trends. For example, one-sided Fischer exact tests determined that periplasmic proteins decrease in observed abundance after sample inactivation by autoclaving (α = 1.71x10-2 for E. coli, α = 4.97x10-4 for Y. pestis) and irradiation (α = 9.43x10-7 for E. coli, α = 1.21x10-5 for Y. pestis) when compared to controls that were not inactivated. Based on our data, if sample inactivation is necessary, we recommend inactivation with ethanol treatment with secondary preference given to irradiation.

  1. Inactivation of a Norovirus by High-Pressure Processing▿

    Science.gov (United States)

    Kingsley, David H.; Holliman, Daniel R.; Calci, Kevin R.; Chen, Haiqiang; Flick, George J.

    2007-01-01

    Murine norovirus (strain MNV-1), a propagable norovirus, was evaluated for susceptibility to high-pressure processing. Experiments with virus stocks in Dulbecco's modified Eagle medium demonstrated that at room temperature (20°C) the virus was inactivated over a pressure range of 350 to 450 MPa, with a 5-min, 450-MPa treatment being sufficient to inactivate 6.85 log10 PFU of MNV-1. The inactivation of MNV-1 was enhanced when pressure was applied at an initial temperature of 5°C; a 5-min pressure treatment of 350 MPa at 30°C inactivated 1.15 log10 PFU of virus, while the same treatment at 5°C resulted in a reduction of 5.56 log10 PFU. Evaluation of virus inactivation as a function of treatment times ranging from 0 to 150 s and 0 to 900 s at 5°C and 20°C, respectively, indicated that a decreasing rate of inactivation with time was consistent with Weibull or log-logistic inactivation kinetics. The inactivation of MNV-1 directly within oyster tissues was demonstrated; a 5-min, 400-MPa treatment at 5°C was sufficient to inactivate 4.05 log10 PFU. This work is the first demonstration that norovirus can be inactivated by high pressure and suggests good prospects for inactivation of nonpropagable human norovirus strains in foods. PMID:17142353

  2. The Schistosoma indicum species group in Nepal: presence of a new lineage of schistosome and use of the Indoplanorbis exustus species complex of snail hosts.

    Science.gov (United States)

    Devkota, Ramesh; Brant, Sara V; Loker, Eric S

    2015-11-01

    From 2007-2014, 19,360 freshwater snails from the Terai and Hilly regions of Nepal were screened for cercariae of mammalian schistosomes. Based on analysis of mitochondrial cytochrome oxidase I, 12S, 16S and 28S sequences (3,675bp) of the cercariae recovered, we provide, to our knowledge, the first report of the Schistosoma indicum species group in Nepal. Five samples of Schistosoma nasale, nine of Schistosoma spindale and 17 of Schistosoma sp. were recovered, all from the snail Indoplanorbis exustus. The last-mentioned lineage failed to group in any of our analyses with S. nasale, S. spindale or S. indicum. It diverged in cox1 sequence from them by 16%, 13% and 13%, respectively, levels of difference comparable to well-studied species pairs of Schistosoma. Analysis of cox1, 16S and internal transcribed spacer 1 sequences (1,874bp) for Nepalese specimens of I. exustus was also surprising in revealing the presence of four genetically distinct clades. They diverged from one another at levels comparable to those noted for species pairs in the sister genus Bulinus. There was no obvious pattern of use by Nepalese Schistosoma of the Indoplanorbis clades. We found high support for a close relationship between S. indicum and Schistosoma haematobium groups, but failed to retrieve support for a clean separation of the two, with a tendency for S. nasale to fall as the most basal representative. If this pattern holds, hypotheses for the origin of the Asian Indoplanorbis-transmitted S. indicum group from the Bulinus-transmitted S. haematobium group may require modification, including consideration of more contemporaneous origins of the two groups. The Indian subcontinent is under-studied with respect to schistosome diversity and our current knowledge of the S. indicum and I. exustus species groups is inadequate. Further study is warranted given the ability of indicum group species to cause veterinary problems and cercarial dermatitis, with a worrisome potential in the future to

  3. Cathepsin D inactivates cysteine proteinase inhibitors, cystatins.

    Science.gov (United States)

    Lenarcic, B; Kos, J; Dolenc, I; Lucovnik, P; Krizaj, I; Turk, V

    1988-07-29

    The formation of inactive complexes in excess molar amounts of human cathepsins H and L with their protein inhibitors human stefin A, human stefin B and chicken cystatin at pH 5.6 has been shown by measurement of enzyme activity coupled with reverse-phase HPLC not to involve covalent cleavage of the inhibitors. Inhibition must be the direct result of binding. On the contrary the interaction of cystatins with aspartic proteinase cathepsin D at pH 3.5 for 60 min followed by HPLC resulted in their inactivation accompanied by peptide bond cleavage at several sites, preferentially those involving hydrophobic amino acid residues. The released peptides do not inhibit papain and cathepsin L. These results explain reported elevated levels of cysteine proteinases and lead to the proposal that cathepsin D exerts an important function, through inactivation of cystatins, in the increased activities of cysteine proteinases in human diseases including muscular distrophy.

  4. Female meiotic sex chromosome inactivation in chicken.

    Directory of Open Access Journals (Sweden)

    Sam Schoenmakers

    2009-05-01

    Full Text Available During meiotic prophase in male mammals, the heterologous X and Y chromosomes remain largely unsynapsed, and meiotic sex chromosome inactivation (MSCI leads to formation of the transcriptionally silenced XY body. In birds, the heterogametic sex is female, carrying Z and W chromosomes (ZW, whereas males have the homogametic ZZ constitution. During chicken oogenesis, the heterologous ZW pair reaches a state of complete heterologous synapsis, and this might enable maintenance of transcription of Z- and W chromosomal genes during meiotic prophase. Herein, we show that the ZW pair is transiently silenced, from early pachytene to early diplotene using immunocytochemistry and gene expression analyses. We propose that ZW inactivation is most likely achieved via spreading of heterochromatin from the W on the Z chromosome. Also, persistent meiotic DNA double-strand breaks (DSBs may contribute to silencing of Z. Surprisingly, gammaH2AX, a marker of DSBs, and also the earliest histone modification that is associated with XY body formation in mammalian and marsupial spermatocytes, does not cover the ZW during the synapsed stage. However, when the ZW pair starts to desynapse, a second wave of gammaH2AX accumulates on the unsynapsed regions of Z, which also show a reappearance of the DSB repair protein RAD51. This indicates that repair of meiotic DSBs on the heterologous part of Z is postponed until late pachytene/diplotene, possibly to avoid recombination with regions on the heterologously synapsed W chromosome. Two days after entering diplotene, the Z looses gammaH2AX and shows reactivation. This is the first report of meiotic sex chromosome inactivation in a species with female heterogamety, providing evidence that this mechanism is not specific to spermatogenesis. It also indicates the presence of an evolutionary force that drives meiotic sex chromosome inactivation independent of the final achievement of synapsis.

  5. Chlorine Inactivation of Spores of Encephalitozoon spp.

    OpenAIRE

    Johnson, C. H.; Marshall, M. M.; DeMaria, L. A.; Moffet, J. M.; Korich, D. G.

    2003-01-01

    This report is an extension of a preliminary investigation on the use of chlorine to inactivate spores of Encephalitozoon intestinalis and to investigate the effect of chlorine on two other species, E cuniculi and E. hellem, associated with human infection. The 50% tissue culture infective doses of these three species were also determined. On the basis of the results obtained, it appears that chlorination of water is an effective means of controlling spores of these organisms in the aquatic e...

  6. Hyaluronan decreases surfactant inactivation in vitro.

    Science.gov (United States)

    Lu, Karen W; Goerke, Jon; Clements, John A; Taeusch, H William

    2005-02-01

    Hyaluronan (HA) is an anionic polymer and a constituent of alveolar fluid that can bind proteins, phospholipids, and water. Previous studies have established that nonionic polymers improve the surface activity of pulmonary surfactants by decreasing inactivation of surfactant. In this work, we investigate whether HA can also have beneficial effects when added to surfactants. We used a modified pulsating bubble surfactometer to measure mixtures of several commercially available pulmonary surfactants or native calf surfactant with and without serum inactivation. Surface properties such as equilibrium surface tension, minimum and maximum surface tensions on compression and expansion of a surface film, and degree of surface area reduction required to reach a surface tension of 10 mN/m were measured. In the presence of serum, addition of HA dramatically improved the surface activities of all four surfactants and in some cases in the absence of serum as well. These results indicate that HA reduces inactivation of surfactants caused by serum and add evidence that endogenous HAs may interact with alveolar surfactant under normal and abnormal conditions.

  7. Rapid inactivation of SARS-like coronaviruses.

    Energy Technology Data Exchange (ETDEWEB)

    Kapil, Sanjay (Kansas State University, Manhattan, KS); Oberst, R. D. (Kansas State University, Manhattan, KS); Bieker, Jill Marie; Tucker, Mark David; Souza, Caroline Ann; Williams, Cecelia Victoria

    2004-03-01

    Chemical disinfection and inactivation of viruses is largely understudied, but is very important especially in the case of highly infectious viruses. The purpose of this LDRD was to determine the efficacy of the Sandia National Laboratories developed decontamination formulations against Bovine Coronavirus (BCV) as a surrogate for the coronavirus that causes Severe Acute Respiratory Syndrome (SARS) in humans. The outbreak of SARS in late 2002 resulted from a highly infectious virus that was able to survive and remain infectious for extended periods. For this study, preliminary testing with Escherichia coli MS-2 (MS-2) and Escherichia coli T4 (T4) bacteriophages was conducted to develop virucidal methodology for verifying the inactivation after treatment with the test formulations following AOAC germicidal methodologies. After the determination of various experimental parameters (i.e. exposure, concentration) of the formulations, final testing was conducted on BCV. All experiments were conducted with various organic challenges (horse serum, bovine feces, compost) for results that more accurately represent field use condition. The MS-2 and T4 were slightly more resistant than BCV and required a 2 minute exposure while BCV was completely inactivated after a 1 minute exposure. These results were also consistent for the testing conducted in the presence of the various organic challenges indicating that the test formulations are highly effective for real world application.

  8. Antithrombin inactivation by neutrophil elastase requires heparin.

    Science.gov (United States)

    Jordan, R E; Nelson, R M; Kilpatrick, J; Newgren, J O; Esmon, P C; Fournel, M A

    1989-09-11

    In certain thrombotic states, large declines in the levels of functional circulating antithrombin occur, which may reflect the highly active nature of the endothelial surface in suppressing excessive amounts of activated coagulation enzymes. Alternatively, we have recently observed an unexpected and paradoxical in vitro functioning of heparin that could result in the inactivation of antithrombin in pathologic conditions. Specifically, antithrombin was rendered nonfunctional as an inhibitor of clotting enzymes as a result of a limited, heparin-dependent cleavage by neutrophil elastase. This inactivation occurred only in the presence of the active anticoagulant heparin fraction, which suggested that the heparin-antithrombin complex was the substrate for elastase attack. Interestingly, neutrophil elastase was found to bind tightly to heparin and heparin-like materials. Neutrophil elastase has been previously linked to nonspecific proteinolysis occurring in inflammatory thrombotic reactions. This affinity of both antithrombin and elastase for heparin suggests a novel mechanism of potential specificity. An important component of this hypothesis is the localization of the elastase/antithrombin reaction away from the high circulating levels of elastase inhibitors. The proposed inactivation of antithrombin on the vascular surface would likely occur only in pathologic states associated with neutrophil sequestration and activation. Nevertheless, this mechanism could lead to a localized reversal of the nonthrombogenic nature of the endothelium and potentially lead to significant reductions of functional antithrombin in certain disease states.

  9. CD209a Synergizes with Dectin-2 and Mincle to Drive Severe Th17 Cell-Mediated Schistosome Egg-Induced Immunopathology

    Directory of Open Access Journals (Sweden)

    Parisa Kalantari

    2018-01-01

    Full Text Available The immunopathology caused by schistosome helminths varies greatly in humans and among mouse strains. A severe form of parasite egg-induced hepatic granulomatous inflammation, seen in CBA mice, is driven by Th17 cells stimulated by IL-1β and IL-23 produced by dendritic cells that express CD209a (SIGNR5, a C-type lectin receptor (CLR related to human DC-SIGN. Here, we show that CD209a-deficient CBA mice display decreased Th17 responses and are protected from severe immunopathology. In vitro, CD209a augments the egg-induced IL-1β and IL-23 production initiated by the related CLRs Dectin-2 and Mincle. While Dectin-2 and Mincle trigger an FcRγ-dependent signaling cascade that involves the tyrosine kinase Syk and the trimolecular Card9-Bcl10-Malt1 complex, CD209a promotes the sustained activation of Raf-1. Our findings demonstrate that CD209a drives severe Th17 cell-mediated immunopathology in a helminthic disease based on synergy between DC-SIGN- and Dectin-2-related CLRs.

  10. Murine eosinophils labeled with indium-111 oxine: localization to delayed hypersensitivity reactions against a schistosomal antigen and to lymphokine in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Rand, T.H.; Clanton, J.A.; Runge, V.; English, D.; Colley, D.G.

    1983-04-01

    We have evaluated a method for quantitation of eosinophil migration to stimuli in vivo. Upon transfusion into normal syngeneic mice, 111In-labeled eosinophils had an intravascular half-life of 9.5 hr and distributed predominantly into spleen, bone marrow, and liver. In either Schistosoma mansoni-infected mice or recipients of lymphoid cells from infected mice, intradermal (ear pinna) injection of the schistosomal egg antigenic preparation (SEA) elicited time-dependent accumulation of 111In-labeled eosinophils detectable by either gamma scintillation counting of tissue samples or by nuclear medicine external imaging. Intradermal administration of a lymphokine fraction (containing eosinophil stimulation promoter activity) similarly caused accumulation of 111In-labeled eosinophils. Both reactions depended on the concentration of stimulus (SEA or lymphokine). 111In-labeled neutrophils or macrophages or 125I-albumin did not preferentially accumulate at the reactions examined to the extent found with 111In-labeled eosinophils, indicating that localization of label depends on an active process and is due to eosinophils rather than a contaminating cell type. The method was used to estimate how long eosinotactic lymphokine remained at dermal sites: 60% of initial activity was present 12 hr after injection. The model is discussed with regard to the role of lymphokines in hypersensitivity reactions with eosinophil involvement, such as the granulomatous response to S. mansoni eggs.

  11. Polymerase chain reaction assay based on a highly repeated sequence of Schistosoma haematobium: a potential tool for monitoring schistosome-infested water.

    Science.gov (United States)

    Hamburger, J; He-Na; Abbasi, I; Ramzy, R M; Jourdane, J; Ruppel, A

    2001-12-01

    We have cloned from Schistosoma haematobium genome a repeated sequence, the DraI repeated sequence, which consists of tandemly arranged 121-bp-long units and which is highly abundant (approximately 15% of the S. haematobium genome). By these features, the DraI repeat is similar to the Sm1-7 sequence of Schistosoma mansoni previously described by us. However, their nucleotide sequences are profoundly different. Polymerase chain reaction (PCR) primers were designed on the basis of the DraI sequence information and were used in a PCR assay by which as little as 10 fg of schistosomal DNA as well as individual cercariae were detected. The DraI repeat cross-hybridized with DNA from Schistosoma bovis, Schistosoma magrebowiei, Schistosoma mattheei, Schistosoma curassoni, and Schistosoma intercalatum, but not with DNA from S. mansoni nor from Trichobilharzia ocellata and Echinostoma sp. A potential value of this PCR assay is suggested for monitoring free-living cercariae and infected snails only in bodies free of cross-hybridizing species.

  12. Chlorine inactivation of Tubifex tubifex in drinking water and the synergistic effect of sequential inactivation with UV irradiation and chlorine.

    Science.gov (United States)

    Nie, Xiao-Bao; Li, Zhi-Hong; Long, Yuan-Nan; He, Pan-Pan; Xu, Chao

    2017-06-01

    The inactivation of Tubifex tubifex is important to prevent contamination of drinking water. Chlorine is a widely-used disinfectant and the key factor in the inactivation of T. tubifex. This study investigated the inactivation kinetics of chlorine on T. tubifex and the synergistic effect of the sequential use of chlorine and UV irradiation. The experimental results indicated that the Ct (concentration × timereaction) concept could be used to evaluate the inactivation kinetics of T. tubifex with chlorine, thus allowing for the use of a simpler Ct approach for the assessment of T. tubifex chlorine inactivation requirements. The inactivation kinetics of T. tubifex by chlorine was found to be well-fitted to a delayed pseudo first-order Chick-Watson expression. Sequential experiments revealed that UV irradiation and chlorine worked synergistically to effectively inactivate T. tubifex as a result of the decreased activation energy, Ea, induced by primary UV irradiation. Furthermore, the inactivation effectiveness of T. tubifex by chlorine was found to be affected by several drinking water quality parameters including pH, turbidity, and chemical oxygen demand with potassium permanganate (CODMn) concentration. High pH exhibited pronounced inactivation effectiveness and the decrease in turbidity and CODMn concentrations contributed to the inactivation of T. tubifex. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. X Inactivation and Progenitor Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ruben Agrelo

    2011-04-01

    Full Text Available In mammals, silencing of one of the two X chromosomes is necessary to achieve dosage compensation. The 17 kb non-coding RNA called Xist triggers X inactivation. Gene silencing by Xist can only be achieved in certain contexts such as in cells of the early embryo and in certain hematopoietic progenitors where silencing factors are present. Moreover, these epigenetic contexts are maintained in cancer progenitors in which SATB1 has been identified as a factor related to Xist-mediated chromosome silencing.

  14. Modeling the pressure inactivation dynamics of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Yamamoto K.

    2005-01-01

    Full Text Available Escherichia coli, as a model microorganism, was treated in phosphate-buffered saline under high hydrostatic pressure between 100 and 300 MPa, and the inactivation dynamics was investigated from the viewpoint of predictive microbiology. Inactivation data were curve fitted by typical predictive models: logistic, Gompertz and Weibull functions. Weibull function described the inactivation curve the best. Two parameters of Weibull function were calculated for each holding pressure and their dependence on holding pressure was obtained by interpolation. With the interpolated parameters, inactivation curves were simulated and compared with the experimental data sets.

  15. Inactivation of virus in solution by cold atmospheric pressure plasma: identification of chemical inactivation pathways

    Science.gov (United States)

    Aboubakr, Hamada A.; Gangal, Urvashi; Youssef, Mohammed M.; Goyal, Sagar M.; Bruggeman, Peter J.

    2016-05-01

    Cold atmospheric pressure plasma (CAP) inactivates bacteria and virus through in situ production of reactive oxygen and nitrogen species (RONS). While the bactericidal and virucidal efficiency of plasmas is well established, there is limited knowledge about the chemistry leading to the pathogen inactivation. This article describes a chemical analysis of the CAP reactive chemistry involved in the inactivation of feline calicivirus. We used a remote radio frequency CAP produced in varying gas mixtures leading to different plasma-induced chemistries. A study of the effects of selected scavengers complemented with positive control measurements of relevant RONS reveal two distinctive pathways based on singlet oxygen and peroxynitrous acid. The first mechanism is favored in the presence of oxygen and the second in the presence of air when a significant pH reduction is induced in the solution by the plasma. Additionally, smaller effects of the H2O2, O3 and \\text{NO}2- produced were also found. Identification of singlet oxygen-mediated 2-imidazolone/2-oxo-His (His  +14 Da)—an oxidative modification of His 262 comprising the capsid protein of feline calicivirus links the plasma induced singlet oxygen chemistry to viral inactivation.

  16. Photodynamic inactivation of pathogens causing infectious keratitis

    Science.gov (United States)

    Simon, Carole; Wolf, G.; Walther, M.; Winkler, K.; Finke, M.; Hüttenberger, D.; Bischoff, Markus; Seitz, B.; Cullum, J.; Foth, H.-J.

    2014-03-01

    The increasing prevalence of antibiotic resistance requires new approaches also for the treatment of infectious keratitis. Photodynamic Inactivation (PDI) using the photosensitizer (PS) Chlorin e6 (Ce6) was investigated as an alternative to antibiotic treatment. An in-vitro cornea model was established using porcine eyes. The uptake of Ce6 by bacteria and the diffusion of the PS in the individual layers of corneal tissue were investigated by fluorescence. After removal of the cornea's epithelium Ce6-concentrations keratitis patients were tested in liquid culture against different concentrations of Ce6 (1 - 512 μM) using 10 minutes irradiation (E = 18 J/cm2 ). This demonstrated that a complete inactivation of the pathogen strains were feasible whereby SA was slightly more susceptible than PA. 3909 mutants of the Keio collection of Escherichia coli (E.coli) were screened for potential resistance factors. The sensitive mutants can be grouped into three categories: transport mutants, mutants in lipopolysaccharide synthesis and mutants in the bacterial SOS-response. In conclusion PDI is seen as a promising therapy concept for infectious keratitis.

  17. Efficacy of select disinfectants at inactivating Ranavirus.

    Science.gov (United States)

    Bryan, Laura K; Baldwin, Charles A; Gray, Matthew J; Miller, Debra L

    2009-04-06

    Ranavirus can cause disease in reptiles and amphibians. Because survival time outside of a host remains uncertain, equipment must be disinfected to prevent transmission of ranaviruses. However, disinfectant efficacy against amphibian ranaviruses has not been investigated for chlorhexidine (Nolvasan), sodium hypochlorite (bleach), or potassium compounds. Our goal was to determine the efficacy of Nolvasan (0.25, 0.75 and 2.0%), bleach (0.2, 1.0, 3.0 and 5.0%), and Virkon S (1.0%) at inactivating Ranavirus at 1 and 5 min contact durations. Potassium permanganate (KMnO4) (2.0 and 5.0 ppm) was also tested with a 60 min contact time. Nolvasan at 0.75 and 2.0% and bleach at 3.0 and 5.0% concentration were effective for both contact durations. Virkon S was effective for both durations, but KMnO4 was not effective at either concentration. Concentrations of Nolvasan, bleach and Virkon S that are at least 0.75, 3.0 and 1.0%, respectively, are effective at inactivating Ranavirus after 1 min exposure time.

  18. X-changing information on X inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Barakat, Tahsin Stefan; Jonkers, Iris; Monkhorst, Kim [Department of Reproduction and Development, Room Ee 09-71, Erasmus MC, PO Box 2040, 3000 CA Rotterdam (Netherlands); Gribnau, Joost, E-mail: j.gribnau@erasmusmc.nl [Department of Reproduction and Development, Room Ee 09-71, Erasmus MC, PO Box 2040, 3000 CA Rotterdam (Netherlands)

    2010-03-10

    In female somatic cells of mammalian species one X chromosome is inactivated to ensure dosage equality of X-encoded genes between females and males, during development and adulthood. X chromosome inactivation (XCI) involves various epigenetic mechanisms, including RNA mediated gene silencing in cis, DNA methylation, and changes in chromatin modifications and composition. XCI therefore provides an attractive paradigm to study epigenetic gene regulation in a more general context. The XCI process starts with counting of the number of X chromosomes present in a nucleus, and initiation of XCI follows if this number exceeds one per diploid genome. Recently, X-encoded RNF12 has been identified as a dose-dependent activator of XCI. In addition, other factors, including the pluripotency factors OCT4, SOX2 and Nanog, have been implicated to play a role in suppression of initiation of XCI. In this review, we highlight and explain these new and old findings in the context of a stochastic model for X chromosome counting and XCI initiation.

  19. Gonad RNA-specific qRT-PCR analyses identify genes with potential functions in schistosome reproduction such as SmFz1 and SmFGFRs

    Science.gov (United States)

    Hahnel, Steffen; Quack, Thomas; Parker-Manuel, Sophia J.; Lu, Zhigang; Vanderstraete, Mathieu; Morel, Marion; Dissous, Colette; Cailliau, Katia; Grevelding, Christoph G.

    2014-01-01

    In the search for new strategies to fight schistosomiasis, the unique reproductive biology of Schistosoma mansoni has come into the focus of research. The development of the gonads and the ability of egg production are fundamental not only for continuing the life cycle but also for pathogenicity. Previous studies of schistosome biology demonstrated an influence of pairing on gonad development of the female and on gene expression profiles in both genders. Due to the limited access to specific tissues, however, most of these studies were done at the level of whole worms neglecting individual tissues that may be targets of pairing-dependent processes. Recently, we established a protocol allowing the isolation of testes and ovaries from adult S. mansoni. Here, we describe tissue-specific qRT-PCR analyses comparing transcript levels of selected genes on the basis of RNA from gonads and whole worms. Gene expression in ovary and testes was in some cases found to be significantly influenced by pairing, which was not traceable in whole worms. Among the candidate genes identified as regulated by pairing in gonads were the frizzled homolog SmFz1 and the two fibroblast growth factor receptor homologs SmFGFR-A and SmFGFR-B. First functional characterizations were done, including comparative qRT-PCR analyses, in situ-localization experiments, heterologous expression in Xenopus oocytes (SmFGFR-A/B), and inhibitor studies using the Fz/Dvl-pathway inhibitor 3289-8625, or BIBF1120 blocking FGFR-signaling. Besides confirming gonad localization and receptor functions, inhibitor-induced phenotypes were observed in vitro such as decreased egg production as well as drastic effects on gonad differentiation, morphology, embryogenesis, and survival of adult worms. In summary, these results emphasise the usefulness of tissue-specific qRT-PCRs for selection of candidate genes with important roles in reproduction, allowing subsequent studies to determine their suitability as drug targets. PMID

  20. Prevalence and effect of schistosome and soil-transmitted helminth infection on labour input in rice-growing communities of Ogun State, Nigeria

    Directory of Open Access Journals (Sweden)

    Sammy Olufemi Sam-Wobo

    2013-06-01

    Full Text Available Schistosomiasis and soil-transmitted helminthiasis (STH are public health problems in communities which lack basic social amenities with poor hygienic conditions. Studies were carried out to determine the prevalence and effect of schistosomes and soil-transmitted helminths infection on labour input on rice production in 9 rice-growing communities of Ogun State. Parasitological examinations of urine and faecal samples, and structured questionnaires were conducted on 243 consented individuals from May 2009 to March 2010. The results showed an overall prevalence of 17% for Ascaris lumbricoides, 12% for hookworms, 2% for Trichuris trichiura, 1% for Schistosoma haematobium and 1% for Schistosoma mansoni. A. lumbricoides and hookworms were more prevalent in Agbajege (25%, and varied in the other 8 communities. T. trichiura was prevalent in three communities, Agbajege (5%, Akodu (4.2%, and Moloko-Asipa (4.8 %; S. haematobium was prevalent only in Ayedere (2.6% and Lufoko (8%, while S. mansoni was prevalent only in Moloko-Asipa (9.5%. Infections among the gender were varied as 26.3 % of males and 33.8 % of females had an overall prevalence of: A. lumbricoides (16.8%, hookworms (11.8%, T. trichiura (1.6%, S. haematobium (1.1% and S. mansoni (1.1%. On frequency of infection to incapacitation per year, 45% of respondents were incapacitated 1-2 times, 27% 3-4 times and 19% were incapacitated more than 4 times. Understanding the effect of these two diseases will not only improve the health status of residents but also increase their productivity and ensure food security.

  1. Gonad RNA-specific qRT-PCR analyses identify genes with potential functions in schistosome reproduction such as SmFz1 and SmFGFRs

    Directory of Open Access Journals (Sweden)

    Steffen eHahnel

    2014-06-01

    Full Text Available In the search for new strategies to fight schistosomiasis, the unique reproductive biology of Schistosoma mansoni has come into the focus of research. The development of the gonads and the ability of egg production are fundamental not only for continuing the life cycle but also for pathogenicity.Previous studies of schistosome biology demonstrated an influence of pairing on gonad development of the female and on gene expression profiles in both genders. Due to the limited access to specific tissues, however, most of these studies were done at the level of whole worms neglecting individual tissues that may be targets of pairing-dependent processes.Recently, we established a protocol allowing the isolation of testes and ovaries from adult S. mansoni. Here, we describe tissue-specific qRT-PCR analyses comparing transcript levels of selected genes on the basis of RNA from gonads and whole worms. Gene expression in ovary and testes was in some cases found to be significantly influenced by pairing, which was not traceable in whole worms. Among the candidate genes identified as regulated by pairing in gonads were the frizzled homolog SmFz1 and the two fibroblast growth factor receptor homologs SmFGFR-A and SmFGFR-B. First functional characterizations were done, including comparative qRT-PCR analyses, in situ-localization experiments, heterologous expression in Xenopus oocytes (SmFGFR-A/B, and inhibitor studies using the Fz/Dvl-pathway inhibitor 3289-8625, or BIBF1120 blocking FGFR-signaling. Besides confirming gonad localization and receptor functions, inhibitor-induced phenotypes were observed in vitro such as decreased egg production as well as drastic effects on gonad differentiation, morphology, embryogenesis, and survival of adult worms.In summary, these results emphasise the usefulness of tissue specific qRT-PCRs for selection of candidate genes with important roles in reproduction, allowing subsequent studies to determine their suitability as

  2. [Polyphenolic antioxidants efficiently protect urease from inactivation by ultrasonic cavitation].

    Science.gov (United States)

    Metelitsa, D I; Tarun, E I; Losev, Iu P

    2002-01-01

    Inactivation of urease (25 nM) in aqueous solutions (pH 5.0-6.0) treated with low-frequency ultrasound (LFUS; 27 kHz, 60 Wt/cm2, 36-56 degrees C) or high-frequency ultrasound (HFUS; 2.64 MHz, 1 Wt/cm2, 36 or 56 degrees C) has been characterized quantitatively, using first-order rate constants: kin, aggregate inactivation; kin*, thermal inactivation; and kin* (US), ultrasonic inactivation. Within the range from 1 nM to 10 microM, propyl gallate (PG) decreases approximately threefold the rate of LFUS-induced inactivation of urease (56 degrees C), whereas resorcinol poly-2-disulfide prevents this process at 1 nM or higher concentrations. PG completely inhibits HFUS-induced inactivation of urease at 1 nM (36 degrees C) or 10 nM (56 degrees C). At 0.2-10 microM, human serum albumin (HSA) increases the resistance of urease (at 56 degrees C) treated with HFUS to temperature- and cavitation-induced inactivation. Complexes of gallic acid polydisulfide (GAPDS) with HSA (GAPDS-HSA), formed by conjugation of 1.0 nM PGDS with 0.33 nM HSA, prevent HFUS-induced urease inactivation (56 degrees C).

  3. Scale down of the inactivated polio vaccine production process

    NARCIS (Netherlands)

    Thomassen, Y.E.; Oever, van 't R.; Vinke, C.M.; Spiekstra, A.; Wijffels, R.H.; Pol, van der L.A.; Bakker, W.A.M.

    2013-01-01

    The anticipated increase in the demand for inactivated polio vaccines resulting from the success in the polio eradication program requires an increase in production capacity and cost price reduction of the current inactivated polio vaccine production processes. Improvement of existing production

  4. Suicide inactivation of horseradish peroxidase by excess hydrogen ...

    African Journals Online (AJOL)

    In reactions carried out in sodium acetate buffer, higher inactivation rates were observed when the buffer ion concentration was increased, an indication that peroxidase might be generating reactive radicals from the buffer molecules. Promethazine exerted a modest protective effect against inactivation; however, higher ...

  5. Effects of electrolytes on virus inactivation by acidic solutions.

    Science.gov (United States)

    Nishide, Mitsunori; Tsujimoto, Kazuko; Uozaki, Misao; Ikeda, Keiko; Yamasaki, Hisashi; Koyama, A Hajime; Arakawa, Tsutomu

    2011-06-01

    Acidic pH is frequently used to inactivate viruses. We have previously shown that arginine synergizes with low pH in enhancing virus inactivation. Considering a potential application of the acid inactivation of viruses for the prevention and treatment of superficial virus infection at body surfaces and fixtures, herein we have examined the effects of various electrolytes on the acid-induced inactivation of the herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), the influenza A virus (IAV) and the poliovirus upon their incubation at 30˚C for 5 min. Eight electrolytes, i.e., phosphate, NaCl, glutamate, aspartate, pyrrolidone carboxylate, citrate, malate and acetate were tested. No detectable inactivation of the poliovirus was observed under the conditions examined, reflecting its acid-resistance. HSV-1 and HSV-2 responded similarly to the acid-treatment and electrolytes. Some electrolytes showed a stronger virus inactivation than others at a given pH and concentration. The effects of the electrolytes were virus-dependent, as IAV responded differently from HSV-1 and HSV-2 to these electrolytes, indicating that certain combinations of the electrolytes and a low pH can exert a more effective virus inactivation than other combinations and that their effects are virus-specific. These results should be useful in designing acidic solvents for the inactivation of viruses at various surfaces.

  6. Ebola Virus Inactivation by Detergents Is Annulled in Serum

    NARCIS (Netherlands)

    van Kampen, Jeroen J. A.; Tintu, Andrei; Russcher, Henk; Fraaij, Pieter L. A.; Reusken, Chantal B. E. M.; Rijken, Mikel; van Hellemond, Jaap J.; van Genderen, Perry J. J.; Koelewijn, Rob; de Jong, Menno D.; Haddock, Elaine; Fischer, Robert J.; Munster, Vincent J.; Koopmans, Marion P. G.

    2017-01-01

    Treatment of blood samples from hemorrhagic fever virus (HFV)-infected patients with 0.1% detergents has been recommended for virus inactivation and subsequent safe laboratory testing. However, data on virus inactivation by this procedure are lacking. Here we show the effect of this procedure on

  7. Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

    Science.gov (United States)

    Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

    2016-03-01

    Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

  8. Kinetic modelling of enzyme inactivation : kinetics of heat inactivation of the extracellular proteinase from Pseudomonas fluorescens 22F

    NARCIS (Netherlands)

    Schokker, E.P.

    1997-01-01

    The kinetics of heat inactivation of the extracellular proteinase from Pseudomonas fluorescens 22F was studied. It was established, by making use of kinetic modelling, that heat inactivation in the temperature range 35 - 70 °C was most likely caused

  9. Development of thermostable lyophilized inactivated polio vaccine.

    Science.gov (United States)

    Kraan, Heleen; van Herpen, Paul; Kersten, Gideon; Amorij, Jean-Pierre

    2014-10-01

    The aim of current study was to develop a dried inactivated polio vaccine (IPV) formulation with minimal loss during the drying process and improved stability when compared with the conventional liquid IPV. Extensive excipient screening was combined with the use of a Design of Experiment (DoE) approach in order to achieve optimal results with high probability. Although it was shown earlier that the lyophilization of a trivalent IPV while conserving its antigenicity is challenging, we were able to develop a formulation that showed minimal loss of potency during drying and subsequent storage at higher temperatures. This study showed the potential of a highly stable and safe lyophilized polio vaccine, which might be used in developing countries without the need of a cold-chain.

  10. Inactivation of Coxiella burnetti by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, G.H.; McCaul, T.F.; Williams, J.C.

    1989-01-01

    The gamma radiation inactivation kinetics for Coxiella burnetii at - 79 C were exponential. The radiation dose needed to reduce the number of infective C. burnetii by 90% varied from 0-64 to 1.2 kGy depending on the phase of hte micro-organism, purity of the culture and composition of suspending menstruum. The viability of preparations containing C. burnetti was completely abolished by 10 kGy without diminishing antigenicity or ability to elicit a protective immune response in vaccinated mice. Immunocytochemical examinations using monoclonal antibodies and electron microscopy demonstrated that radiation doses of 20 kGy did not alter cell-wall morphology or cell-surface antigenic epitopes.

  11. Inactivation of Coxiella burnetii by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, G.H.; McCaul, T.F. (Army Medical Research Inst. of Infectious Diseases, Fort Detrick, Frederick, MD (USA)); Williams, J.C. (National Inst. of Allergy and Infectious Diseases, Bethesda, MD (USA))

    1989-12-01

    The gamma radiation inactivation kinetics for Coxiella burnetii at - 79{sup 0}C were exponential. The radiation dose needed to reduce the number of infective C. burnetii by 90% varied from 0.64 to 1.2 kGy depending on the phase of the micro-organism, purity of the culture and composition of suspending menstruum. The viability of preparations containing 10{sup 11} C. burnetii ml{sup -1} was completely abolished by 10 kGy without diminishing antigenicity or ability to elicit a protective immune response in vaccinated mice. Immunocytochemical examinations using monoclonal antibodies and electron microscopy demonstrated that radiation doses of 20 kGy did not alter cell-wall morphology or cell-surface antigenic epitopes. (author).

  12. Esterase resistant to inactivation by heavy metals

    KAUST Repository

    El, Dorry Hamza

    2014-09-25

    EstATII is an esterase that a halotolerant, thermophilic and resistant to a spectrum of heavy metals including toxic concentration of metals. It was isolated from the lowest convective layer of the Atlantis II Red Sea brine pool. The Atlantis II brine pool is an extreme environment that possesses multiple harsh conditions such as; high temperature, salinity, pH and high concentration of metals, including toxic heavy metals. A fosmid metagenomic library using DNA isolated from the lowest convective layer this pool was used to identify EstATII. Polynucleotides encoding EstATII and similar esterases are disclosed and can be used to make EstATII. EstATII or compositions or apparatuses that contain it may be used in various processes employing lipases/esterases especially when these processes are performed under harsh conditions that inactivate other kinds of lipases or esterases.

  13. Human male meiotic sex chromosome inactivation.

    Directory of Open Access Journals (Sweden)

    Marieke de Vries

    Full Text Available In mammalian male gametogenesis the sex chromosomes are distinctive in both gene activity and epigenetic strategy. At first meiotic prophase the heteromorphic X and Y chromosomes are placed in a separate chromatin domain called the XY body. In this process, X,Y chromatin becomes highly phosphorylated at S139 of H2AX leading to the repression of gonosomal genes, a process known as meiotic sex chromosome inactivation (MSCI, which has been studied best in mice. Post-meiotically this repression is largely maintained. Disturbance of MSCI in mice leads to harmful X,Y gene expression, eventuating in spermatocyte death and sperm heterogeneity. Sperm heterogeneity is a characteristic of the human male. For this reason we were interested in the efficiency of MSCI in human primary spermatocytes. We investigated MSCI in pachytene spermatocytes of seven probands: four infertile men and three fertile controls, using direct and indirect in situ methods. A considerable degree of variation in the degree of MSCI was detected, both between and within probands. Moreover, in post-meiotic stages this variation was observed as well, indicating survival of spermatocytes with incompletely inactivated sex chromosomes. Furthermore, we investigated the presence of H3K9me3 posttranslational modifications on the X and Y chromatin. Contrary to constitutive centromeric heterochromatin, this heterochromatin marker did not specifically accumulate on the XY body, with the exception of the heterochromatic part of the Y chromosome. This may reflect the lower degree of MSCI in man compared to mouse. These results point at relaxation of MSCI, which can be explained by genetic changes in sex chromosome composition during evolution and candidates as a mechanism behind human sperm heterogeneity.

  14. X chromosome inactivation in women with alcoholism.

    Science.gov (United States)

    Manzardo, Ann M; Henkhaus, Rebecca; Hidaka, Brandon; Penick, Elizabeth C; Poje, Albert B; Butler, Merlin G

    2012-08-01

    All female mammals with 2 X chromosomes balance gene expression with males having only 1 X by inactivating one of their X chromosomes (X chromosome inactivation [XCI]). Analysis of XCI in females offers the opportunity to investigate both X-linked genetic factors and early embryonic development that may contribute to alcoholism. Increases in the prevalence of skewing of XCI in women with alcoholism could implicate biological risk factors. The pattern of XCI was examined in DNA isolated in blood from 44 adult women meeting DSM-IV criteria for an alcohol use disorder and 45 control women with no known history of alcohol abuse or dependence. XCI status was determined by analyzing digested and undigested polymerase chain reaction (PCR) products of the polymorphic androgen receptor (AR) gene located on the X chromosome. Subjects were categorized into 3 groups based upon the degree of XCI skewness: random (50:50 to 64:36%), moderately skewed (65:35 to 80:20%), and highly skewed (>80:20%). XCI status from informative women with alcoholism was found to be random in 59% (n = 26), moderately skewed in 27% (n = 12), or highly skewed in 14% (n = 6). Control subjects showed 60, 29, and 11%, respectively. The distribution of skewed XCI observed among women with alcoholism did not differ statistically from that of control subjects (χ(2) test = 0.14, 2 df, p = 0.93). Our data did not support an increase in XCI skewness among women with alcoholism or implicate early developmental events associated with embryonic cell loss or unequal (nonrandom) expression of X-linked gene(s) or defects in alcoholism among women. Copyright © 2012 by the Research Society on Alcoholism.

  15. Virus-specific thermostability and heat inactivation profiles of alphaviruses.

    Science.gov (United States)

    Park, So Lee; Huang, Yan-Jang S; Hsu, Wei-Wen; Hettenbach, Susan M; Higgs, Stephen; Vanlandingham, Dana L

    2016-08-01

    Serological diagnosis is a critical component for disease surveillance and is important to address the increase in incidence and disease burden of alphaviruses, such as the chikungunya (CHIKV) and Ross River (RRV) viruses. The gold standard for serological diagnosis is the plaque reduction neutralization test (PRNT), which demonstrates the neutralizing capacity of serum samples after the removal of complement activity and adventitious viruses. This procedure is normally performed following inactivation of the virus at 56°C for 30min. Although this protocol has been widely accepted for the inactivation of envelope RNA viruses, recent studies have demonstrated that prolonged heat inactivation is required to completely inactivate two alphaviruses, Western equine encephalitis virus and CHIKV. Incomplete inactivation of viruses poses a laboratory biosafety risk and can also lead to spurious test results. Despite its importance in ensuring the safety of laboratory personnel as well as test integrity, systematic investigation on the thermostability of alphaviruses has not been performed. In this study, the temperature tolerance and heat inactivation profiles of RRV, Barmah Forest, and o'nyong-nyong viruses were determined. Variations in thermostability were observed within the Semliki forest serocomplex. Therefore, evidence-based heat inactivation procedures for alphaviruses are recommended. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Relative Inactivation by Staphylococcus aureus of Eight Cephalosporin Antibiotics

    Science.gov (United States)

    Fong, Ignatius W.; Engelking, Elin R.; Kirby, William M. M.

    1976-01-01

    These studies extend the recent observation that cefazolin is inactivated to a greater extent than cephaloridine by some strains of penicillinase-producing Staphylococcus aureus, whereas cephalothin undergoes little if any inactivation. In Mueller-Hinton broth (inoculum, 3 × 106) 100 recently isolated strains had minimal inhibitory concentrations (MICs) ≤ 2 μg/ml for cephalothin and cephaloridine, whereas in Trypticase soy broth (TSB) 50% had MICs > 2 μg/ml and 10% (designated “resistant” strains) were >8 μg/ml for cephaloridine but remained ≤2 μg/ml for cephalothin. A large inoculum (3 × 107) of strains with high MICs in TSB almost completely inactivated 50 μg of cefazolin per ml in 6 h, with progressively less inactivation, in the following order, of cephaloridine, cephalexin, cephradine, cephapirin, and cefamandole; cefoxitin and cephalothin underwent little if any inactivation. The greater inactivation in TSB than in Mueller-Hinton broth appeared to be due to a greater production of β-lactamases by each colony-forming unit, since the inoculum size in the two broths was not significantly different. In contrast, “susceptible” strains (MICs ≤ 2 μg/ml in both broths) inactivated cephaloridine more than cefazolin, and equal amounts of powdered bacterial extracts confirmed the fact that qualitatively different β-lactamases were produced by the susceptible and resistant strains. Disk diffusion tests were unreliable in separating the two groups of staphylococci. The clinical significance of inactivation by strains with high MICs is not known but, unless susceptibility can be clearly established, cephalothin appears preferable for severe staphylococcal infections, since it undergoes little if any inactivation by any strains of staphylococci. PMID:938023

  17. Thermoradiation inactivation of naturally occurring organisms in soil

    Science.gov (United States)

    Reynolds, M. C.; Lindell, K. F.; David, T. J.

    1973-01-01

    Samples of soil collected from Kennedy Space Center near spacecraft assembly facilities were found to contain microorganisms very resistant to conventional sterilization techniques. The inactivation behavior of the naturally occurring spores in soil was investigated using dry heat and ionizing radiation, first separately, then in combination. Dry heat inactivation rates of spores were determined for 105 and 125 C. Radiation inactivation rates were determined for dose rates of 660 and 76 krad/hr at 25 C. Simultaneous combinations of heat and radiation were then investigated at 105, 110, 115, 120, and 125 C. Combined treatment was found to be highly synergistic requiring greatly reduced radiation doses to accomplish sterilization.

  18. Aβ seeds resist inactivation by formaldehyde.

    Science.gov (United States)

    Fritschi, Sarah K; Cintron, Amarallys; Ye, Lan; Mahler, Jasmin; Bühler, Anika; Baumann, Frank; Neumann, Manuela; Nilsson, K Peter R; Hammarström, Per; Walker, Lary C; Jucker, Mathias

    2014-10-01

    Cerebral β-amyloidosis can be exogenously induced by the intracerebral injection of brain extracts containing aggregated β-amyloid (Aβ) into young, pre-depositing Aβ precursor protein- (APP) transgenic mice. Previous work has shown that the induction involves a prion-like seeding mechanism in which the seeding agent is aggregated Aβ itself. Here we report that the β-amyloid-inducing activity of Alzheimer's disease (AD) brain tissue or aged APP-transgenic mouse brain tissue is preserved, albeit with reduced efficacy, after formaldehyde fixation. Moreover, spectral analysis with amyloid conformation-sensitive luminescent conjugated oligothiophene dyes reveals that the strain-like properties of aggregated Aβ are maintained in fixed tissues. The resistance of Aβ seeds to inactivation and structural modification by formaldehyde underscores their remarkable durability, which in turn may contribute to their persistence and spread within the body. The present findings can be exploited to establish the relationship between the molecular structure of Aβ aggregates and the variable clinical features and disease progression of AD even in archived, formalin-fixed autopsy material.

  19. Inactivation of RNA viruses by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nonomiya, Takashi; Morimoto, Akinori; Iwatsuki, Kazuo; Tsutsumi, Takamasa (Ministry of Agriculture, Forestry and fisheries, Yokohama, Kanagawa (Japan). Animal Quarantine Service); Ito, Hitoshi; Yamashiro, Tomio; Ishigaki, Isao

    1992-09-01

    Four kinds of RNA viruses, Bluetongue virus (BT), Bovine Virus Diarrhea-Mucosal Disease virus (BVD[center dot]MD), Bovine Respiratory Syncytial virus (RS), Vesicular Stmatitis virus (VS), were subjected to various doses of gamma irradiation to determine the lethal doses. The D[sub 10] values, which are the dose necessary to decimally reduce infectivity, ranged from 1.5 to 3.4 kGy under frozen condition at dry-ice temperature, and they increased to 2.6 to 5.0 kGy under frozen condition at dry-ice temperature. Serum neutralzing antibody titer of Infectious Bovine Rhinotracheitis (IBR) was not adversely changed by the exposure to 36 kGy of gamma-rays under frozen condition. Analysis of electrophoresis patterns of the bovine serum also reveales that the serum proteins were not remarkably affected, even when exposed to 36 kGy of gamma radiation under frozen condition. The results suggested that gamma irradiation under frozen condition is an effective means for inactivating both DNA and RNA viruses without adversely affecting serum proteins and neutralizing antibody titer. (author).

  20. CHLORINE INACTIVATION OF CATEGORY "A" BIO-TERRORISM AGENTS

    Science.gov (United States)

    This poster presents information on the inactivation of select bioterrorist agents. Information will be presented on chlorine disinfection of vegetative cells of Brucella suis, Brucella melitensis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis and endos...

  1. Use of genetic algorithms for high hydrostatic pressure inactivation ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    ) for high hydrostatic pressure (HHP) inactivation of Bacillus cereus spores, Bacillus subtilis spores and cells,. Staphylococcus aureus and Listeria monocytogenes, all in milk buffer, were used to demonstrate the utility of ...

  2. Inactivation Strategies for Clostridium perfringens Spores and Vegetative Cells.

    Science.gov (United States)

    Talukdar, Prabhat K; Udompijitkul, Pathima; Hossain, Ashfaque; Sarker, Mahfuzur R

    2017-01-01

    Clostridium perfringens is an important pathogen to human and animals and causes a wide array of diseases, including histotoxic and gastrointestinal illnesses. C. perfringens spores are crucial in terms of the pathogenicity of this bacterium because they can survive in a dormant state in the environment and return to being live bacteria when they come in contact with nutrients in food or the human body. Although the strategies to inactivate C. perfringens vegetative cells are effective, the inactivation of C. perfringens spores is still a great challenge. A number of studies have been conducted in the past decade or so toward developing efficient inactivation strategies for C. perfringens spores and vegetative cells, which include physical approaches and the use of chemical preservatives and naturally derived antimicrobial agents. In this review, different inactivation strategies applied to control C. perfringens cells and spores are summarized, and the potential limitations and challenges of these strategies are discussed. Copyright © 2016 American Society for Microbiology.

  3. Inactivation of rabies diagnostic reagents by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, W.C.; Chappell, W.A.; George, E.H.

    1980-11-01

    Treatment of CVS-11 rabies adsorbing suspensions and street rabies infected mouse brains with gamma radiation resulted in inactivated reagents that are safer to distribute and use. These irradiated reagents were as sensitive and reactive as the nonirradiated control reagents.

  4. Biocontrol interventions for inactivation of foodborne pathogens on produce

    Science.gov (United States)

    Post-harvest interventions for control of foodborne pathogens on minimally processed foods are crucial for food safety. Biocontrol interventions have the primary objective of developing novel antagonists in combinations with physical and chemical interventions to inactivate pathogenic microbes. Ther...

  5. Enzyme inactivation kinetics: Coupled effects of temperature and moisture content

    NARCIS (Netherlands)

    Perdana, J.A.; Fox, M.B.; Schutyser, M.A.I.; Boom, R.M.

    2012-01-01

    Enzymes are often dried for stability reasons and to facilitate handling. However, they are often susceptible to inactivation during drying. It is generally known that temperature and moisturecontent influence the enzymeinactivation kinetics. However, the coupledeffect of both variables on

  6. Enterococcus faecalis and pathogenic streptococci inactivate daptomycin by releasing phospholipids.

    Science.gov (United States)

    Ledger, Elizabeth V K; Pader, Vera; Edwards, Andrew M

    2017-10-01

    Daptomycin is a lipopeptide antibiotic with activity against Gram-positive bacteria. We showed previously that Staphylococcus aureus can survive daptomycin exposure by releasing membrane phospholipids that inactivate the antibiotic. To determine whether other pathogens possess this defence mechanism, phospholipid release and daptomycin activity were measured after incubation of Staphylococcus epidermidis, group A or B streptococci, Streptococcus gordonii or Enterococcus faecalis with the antibiotic. All bacteria released phospholipids in response to daptomycin, which resulted in at least partial inactivation of the antibiotic. However, E. faecalis showed the highest levels of lipid release and daptomycin inactivation. As shown previously for S. aureus, phospholipid release by E. faecalis was inhibited by the lipid biosynthesis inhibitor platensimycin. In conclusion, several pathogenic Gram-positive bacteria, including E. faecalis, inactivate daptomycin by releasing phospholipids, which may contribute to the failure of daptomycin to resolve infections caused by these pathogens.

  7. Evaluation of the Efficacy of Inactivated Oil-Emulsion Newcastle ...

    African Journals Online (AJOL)

    Evaluation of the Efficacy of Inactivated Oil-Emulsion Newcastle Disease Komarov Vaccine against Clinical Disease, Lesions and Immune Response, Following Challenge with Velogenic Newcastle Disease Virus in Laying Chickens.

  8. 21 CFR 610.11a - Inactivated influenza vaccine, general safety test.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Inactivated influenza vaccine, general safety test... Inactivated influenza vaccine, general safety test. For inactivated influenza vaccine, the general safety test... subcutaneous or intraperitoneal injection of 5.0 milliliters of inactivated influenza vaccine into each guinea...

  9. Shaker IR T449 mutants separate C- from U-type inactivation.

    Science.gov (United States)

    Jamieson, Quentin; Jones, Stephen W

    2014-04-01

    Previous studies demonstrated that slow inactivation of the Shaker potassium channel can be made ~100-fold faster or slower by point mutations at a site in the outer pore (T449). However, the discovery that two forms of slow inactivation coexist in Shaker raises the question of which inactivation process is affected by mutation. Equivalent mutations in K(V)2.1, a channel exhibiting only U-type inactivation, have minimal effects on inactivation, suggesting that mutation of Shaker T449 acts on C-type inactivation alone, a widely held yet untested hypothesis. This study reexamines mutations at Shaker T449, confirming that T449A speeds inactivation and T449Y/V slow it. T449Y and T449V exhibit U-type inactivation that is enhanced by high extracellular potassium, in contrast to C-type inactivation in T449A which is inhibited by high potassium. Automated parameter estimation for a 12-state Markov model suggests that U-type inactivation occurs mainly from closed states upon weak depolarization, but primarily from the open state at positive voltages. The model also suggests that WT channels, which in this study exhibit mostly C-type inactivation, recover from inactivation through closed-inactivated states, producing voltage-dependent recovery. This suggests that both C-type and U-type inactivation involve both open-inactivated and closed-inactivated states.

  10. Introgressive hybridizations of Schistosoma haematobium by Schistosoma bovis at the origin of the first case report of schistosomiasis in Corsica (France, Europe).

    Science.gov (United States)

    Moné, Hélène; Holtfreter, Martha C; Allienne, Jean-François; Mintsa-Nguéma, Rodrigue; Ibikounlé, Moudachirou; Boissier, Jérôme; Berry, Antoine; Mitta, Guillaume; Richter, Joachim; Mouahid, Gabriel

    2015-11-01

    This study concerns the first urinary schistosomiasis case observed in Corsica (France, Europe) occurring in a 12-year-old German boy. The aim was to identify the relationship between this Schistosoma haematobium infection and other schistosomes of the Schistosoma group with terminal-spined ova. Morphological and molecular analyses were conducted on the ova. The results showed that the schistosome responsible for the emergence of schistosomiasis in Corsica was due to S. haematobium introgressed by genes from S. bovis.

  11. Non-thermal plasma for inactivated-vaccine preparation.

    Science.gov (United States)

    Wang, Guomin; Zhu, Ruihao; Yang, Licong; Wang, Kaile; Zhang, Qian; Su, Xia; Yang, Bing; Zhang, Jue; Fang, Jing

    2016-02-17

    Vaccines are of great importance in controlling the spread of infectious diseases in poultry farming. The safety and efficacy of vaccines are also essential. To explore the feasibility of a novel technology (non-thermal plasma) in inactivated vaccine preparation, an alternating current atmospheric pressure non-thermal plasma (NTP) jet with Ar/O2/N2 as the operating gas was used to inactivate a Newcastle disease virus (NDV, LaSota) strain and H9N2 avian influenza virus (AIV, A/Chicken/Hebei/WD/98) for vaccine preparation. The results showed that complete inactivation could be achieved with 2 min of NTP treatment for both NDV and AIV. Moreover, a proper NTP treatment time is needed for inactivation of a virus without destruction of the antigenic determinants. Compared to traditional formaldehyde-inactivated vaccine, the vaccine made from NDV treated by NTP for 2 min (NTP-2 min-NDV-vaccine) could induce a higher NDV-specific antibody titer in specific pathogen-free (SPF) chickens, and the results of a chicken challenge experiment showed that NTP-2 min-NDV-vaccine could protect SPF chickens from a lethal NDV challenge. Vaccines made from AIV treated by NTP for 2 min (NTP-2 min-AIV-vaccine) also showed a similar AIV-specific antibody titer compared with traditional AIV vaccines prepared using formaldehyde inactivation. Studies of the morphological changes of the virus, chemical analysis of NDV allantoic fluid and optical emission spectrum analysis of NTP suggested that reactive oxygen species and reactive nitrogen species produced by NTP played an important role in the virus inactivation process. All of these results demonstrated that it could be feasible to use non-thermal NTP as an alternative strategy to prepare inactivated vaccines for Newcastle disease and avian influenza. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Stochastic and deterministic model of microbial heat inactivation.

    Science.gov (United States)

    Corradini, Maria G; Normand, Mark D; Peleg, Micha

    2010-03-01

    Microbial inactivation is described by a model based on the changing survival probabilities of individual cells or spores. It is presented in a stochastic and discrete form for small groups, and as a continuous deterministic model for larger populations. If the underlying mortality probability function remains constant throughout the treatment, the model generates first-order ("log-linear") inactivation kinetics. Otherwise, it produces survival patterns that include Weibullian ("power-law") with upward or downward concavity, tailing with a residual survival level, complete elimination, flat "shoulder" with linear or curvilinear continuation, and sigmoid curves. In both forms, the same algorithm or model equation applies to isothermal and dynamic heat treatments alike. Constructing the model does not require assuming a kinetic order or knowledge of the inactivation mechanism. The general features of its underlying mortality probability function can be deduced from the experimental survival curve's shape. Once identified, the function's coefficients, the survival parameters, can be estimated directly from the experimental survival ratios by regression. The model is testable in principle but matching the estimated mortality or inactivation probabilities with those of the actual cells or spores can be a technical challenge. The model is not intended to replace current models to calculate sterility. Its main value, apart from connecting the various inactivation patterns to underlying probabilities at the cellular level, might be in simulating the irregular survival patterns of small groups of cells and spores. In principle, it can also be used for nonthermal methods of microbial inactivation and their combination with heat.

  13. Pathogen Inactivation Technologies for Cellular Blood Components: an Update

    Science.gov (United States)

    Schlenke, Peter

    2014-01-01

    Summary Nowadays patients receiving blood components are exposed to much less transfusion-transmitted infectious diseases than three decades before when among others HIV was identified as causative agent for the acquired immunodeficiency syndrome and the transmission by blood or coagulation factors became evident. Since that time the implementation of measures for risk prevention and safety precaution was socially and politically accepted. Currently emerging pathogens like arboviruses and the well-known bacterial contamination of platelet concentrates still remain major concerns of blood safety with important clinical consequences, but very rarely with fatal outcome for the blood recipient. In contrast to the well-established pathogen inactivation strategies for fresh frozen plasma using the solvent-detergent procedure or methylene blue and visible light, the bench-to-bedside translation of novel pathogen inactivation technologies for cell-containing blood components such as platelets and red blood cells are still underway. This review summarizes the pharmacological/toxicological assessment and the inactivation efficacy against viruses, bacteria, and protozoa of each of the currently available pathogen inactivation technologies and highlights the impact of the results obtained from several randomized clinical trials and hemovigilance data. Until now in some European countries pathogen inactivation technologies are in in routine use for single-donor plasma and platelets. The invention and adaption of pathogen inactivation technologies for red blood cell units and whole blood donations suggest the universal applicability of these technologies and foster a paradigm shift in the manufacturing of safe blood. PMID:25254027

  14. Thermal inactivation kinetics of β-galactosidase during bread baking.

    Science.gov (United States)

    Zhang, Lu; Chen, Xiao Dong; Boom, Remko M; Schutyser, Maarten A I

    2017-06-15

    In this study, β-galactosidase was utilized as a model enzyme to investigate the mechanism of enzyme inactivation during bread baking. Thermal inactivation of β-galactosidase was investigated in a wheat flour/water system at varying temperature-moisture content combinations, and in bread during baking at 175 or 205°C. In the wheat flour/water system, the thermostability of β-galactosidase increased with decreased moisture content, and a kinetic model was accurately fitted to the corresponding inactivation data (R 2 =0.99). Interestingly, the residual enzyme activity in the bread crust (about 30%) was hundredfold higher than that in the crumb (about 0.3%) after baking, despite the higher temperature in the crust throughout baking. This result suggested that the reduced moisture content in the crust increased the thermostability of the enzyme. Subsequently, the kinetic model reasonably predicted the enzyme inactivation in the crumb using the same parameters derived from the wheat flour/water system. However, the model predicted a lower residual enzyme activity in the crust compared with the experimental result, which indicated that the structure of the crust may influence the enzyme inactivation mechanism during baking. The results reported can provide a quantitative understanding of the thermal inactivation kinetics of enzyme during baking, which is essential to better retain enzymatic activity in bakery products supplemented with heat-sensitive enzymes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Kinetic analysis of Legionella inactivation using ozone in wastewater.

    Science.gov (United States)

    Li, Jun; Li, Kunquan; Zhou, Yan; Li, Xuebin; Tao, Tao

    2017-02-01

    Legionella inactivation using ozone was studied in wastewater using kinetic analysis and modeling. The experimental results indicate that the relationship between the ozone concentration, germ concentration, and chemical oxygen demand (COD) can be used to predict variations in germ and COD concentrations. The ozone reaction with COD and inactivation of Legionella occurred simultaneously, but the reaction with COD likely occurred at a higher rate than the inactivation, as COD is more easily oxidized by ozone than Legionella. Higher initial COD concentrations resulted in a lower inactivation rate and higher lnN/N0. Higher temperature led to a higher inactivation efficiency. The relationship of the initial O3 concentration and Legionella inactivation rate was not linear, and thus, the Ct value required for a 99.99% reduction was not constant. The initial O3 concentration was more important than the contact time, and a reduction of the initial O3 concentration could not be compensated by increasing the contact time. The Ct values were compared over a narrow range of initial concentrations; the Ct values could only be contrasted when the initial O3 concentrations were very similar. A higher initial O3 concentration led to a higher inflection point value for the lnN/N0 vs C0t curve. Energy consumption using a plasma corona was lower than when using boron-doped diamond electrodes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Oxidation of multiple methionine residues impairs rapid sodium channel inactivation

    Science.gov (United States)

    Kassmann, Mario; Hansel, Alfred; Leipold, Enrico; Birkenbeil, Jan; Lu, Song-Qing; Hoshi, Toshinori; Heinemann, Stefan H.

    2010-01-01

    Reactive oxygen species (ROS) readily oxidize the sulfur-containing amino acids cysteine and methionine (Met). The impact of Met oxidation on the fast inactivation of the skeletal muscle sodium channel NaV1.4 expressed in human embryonic kidney cells was studied by applying the Met-preferring oxidant chloramine-T (ChT) or by irradiating the ROS-producing dye Lucifer Yellow in the patch pipettes. Both interventions dramatically slowed down inactivation of the sodium channels. Replacement of Met in the Ile-Phe-Met inactivation motif with Leu (M1305L) strongly attenuated the oxidizing effect on inactivation but did not eliminate it completely. Mutagenesis of conserved Met residues in the intracellular linkers connecting the membrane-spanning segments of the channel (M1469L and M1470L) also markedly diminished the oxidation sensitivity of the channel, while that of other conserved Met residues (442, 1139, 1154, 1316) were without any noticeable effect. The results of mutagenesis of results, assays of other NaV channel isoforms (NaV1.2, NaV1.5, NaV1.7) and the kinetics of the oxidation-induced removal of inactivation collectively indicate that multiple Met target residues need to be oxidized to completely impair inactivation. This arrangement using multiple Met residues confers a finely graded oxidative modulation of NaV channels and allows organisms to adapt to a variety of oxidative stress conditions, such as ischemic reperfusion. PMID:18369661

  17. Thermal Inactivation of Feline Calicivirus in Pet Food Processing.

    Science.gov (United States)

    Haines, J; Patel, M; Knight, A I; Corley, D; Gibson, G; Schaaf, J; Moulin, J; Zuber, S

    2015-12-01

    Extrusion is the most common manufacturing process used to produce heat-treated dry dog and cat food (pet food) for domestic use and international trade. Due to reoccurring outbreaks of notifiable terrestrial animal diseases and their impact on international trade, experiments were undertaken to demonstrate the effectiveness of heat-treated extruded pet food on virus inactivation. The impact of extrusion processing in a pet food matrix on virus inactivation has not been previously reported and very few inactivation studies have examined the thermal inactivation of viruses in complex food matrices. The feline calicivirus vaccine strain FCV F-9 was used as a surrogate model RNA virus pathogen. Small-scale heat inactivation experiments using animal-derived pet food raw materials showed that a > 4 log10 reduction (log10 R) in infectivity occurred at 70 °C prior to reaching the minimum extrusion manufacturing operating temperature of 100 °C. As anticipated, small-scale pressure studies at extrusion pressure (1.6 MPa) showed no apparent effect on FCV F-9 inactivation. Additionally, FCV F-9 was shown not to survive the acidic conditions used to produce pet food palatants of animal origin that are typically used as a coating after the extrusion process.

  18. High pressure inactivation of Brettanomyces bruxellensis in red wine.

    Science.gov (United States)

    van Wyk, Sanelle; Silva, Filipa V M

    2017-05-01

    Brettanomyces bruxellensis ("Brett") is a major spoilage concern for the wine industry worldwide, leading to undesirable sensory properties. Sulphur dioxide, is currently the preferred method for wine preservation. However, due to its negative effects on consumers, the use of new alternative non-thermal technologies are increasingly being investigated. The aim of this study was to determine and model the effect of high pressure processing (HPP) conditions and yeast strain on the inactivation of "Brett" in Cabernet Sauvignon wine. Processing at 200 MPa for 3 min resulted in 5.8 log reductions. However higher pressure is recommended to achieve high throughput in the wine industry, for example >6.0 log reductions were achieved after 400 MPa for 5 s. The inactivation of B. bruxellensis is pressure and time dependent, with increased treatment time and pressure leading to increased yeast inactivation. It was also found that yeast strain had a significant effect on HPP inactivation, with AWRI 1499 being the most resistant strain. The Weibull model successfully described the HPP "Brett" inactivation. HPP is a viable alternative for the inactivation of B. bruxellensis in wine, with the potential to reduce the industry's reliance on sulphur dioxide. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Viral inactivation in hemotherapy: systematic review on inactivators with action on nucleic acids

    Directory of Open Access Journals (Sweden)

    Patricia Marial Sobral

    2012-01-01

    Full Text Available The aim of this study was to conduct a systematic review on the photoinactivators used in hemotherapy, with action on viral genomes. The SciELO, Science Direct, PubMed and Lilacs databases were searched for articles. The inclusion criterion was that these should be articles on inactivators with action on genetic material that had been published between 2000 and 2010. The key words used in identifying such articles were "hemovigilance", "viral inactivation", "photodynamics", "chemoprevention" and "transfusion safety". Twenty-four articles on viral photoinactivation were found with the main photoinactivators covered being: methylene blue, amotosalen HCl, S-303 frangible anchor linker effector (FRALE, riboflavin and inactin. The results showed that methylene blue has currently been studied least, because it diminishes coagulation factors and fibrinogen. Riboflavin has been studied most because it is a photoinactivator of endogenous origin and has few collateral effects. Amotosalen HCl is effective for platelets and is also used on plasma, but may cause changes both to plasma and to platelets, although these are not significant for hemostasis. S-303 FRALE may lead to neoantigens in erythrocytes and is less indicated for red-cell treatment; in such cases, PEN 110 is recommended. Thus, none of the methods for pathogen reduction is effective for all classes of agents and for all blood components, but despite the high cost, these photoinactivators may diminish the risk of blood-transmitted diseases.

  20. Laser-induced inactivation of Plasmodium falciparum.

    Science.gov (United States)

    LeBlanc, Danielle; Story, Robert; Gross, Eitan

    2012-08-08

    Haemozoin crystals, produced by Plasmodium during its intra-erythrocytic asexual reproduction cycle, can generate UV light via the laser-induced, non-linear optical process of third harmonic generation (THG). In the current study the feasibility of using haemozoin, constitutively stored in the parasite's food vacuole, to kill the parasite by irradiation with a near IR laser was evaluated. Cultured Plasmodium parasites at different stages of development were irradiated with a pulsed NIR laser and the viability of parasites at each stage was evaluated from their corresponding growth curves using the continuous culture method. Additional testing for germicidal effects of haemozoin and NIR laser was performed by adding synthetic haemozoin crystals to Escherichia coli in suspension. Cell suspensions were then irradiated with the laser and small aliquots taken and spread on agar plates containing selective agents to determine cell viability (CFU). Parasites in the late-trophozoites form as well as trophozoites in early-stage of DNA synthesis were found to be the most sensitive to the treatment with -4-log reduction in viability after six passes through the laser beam; followed by parasites in ring phase (-2-log reduction). A -1-log reduction in E. coli viability was obtained following a 60 min irradiation regimen of the bacteria in the presence of 1 μM synthetic haemozoin and a -2-log reduction in the presence of 10 μM haemozoin. Minimal (≤ 15%) cell kill was observed in the presence of 10 μM haemin. Laser-induced third-harmonic generation by haemozoin can be used to inactivate Plasmodium. This result may have clinical implications for treating severe malaria symptoms by irradiating the patient's blood through the skin or through dialysis tubing with a NIR laser.

  1. Laser-induced inactivation of Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    LeBlanc Danielle

    2012-08-01

    Full Text Available Abstract Background Haemozoin crystals, produced by Plasmodium during its intra-erythrocytic asexual reproduction cycle, can generate UV light via the laser-induced, non-linear optical process of third harmonic generation (THG. In the current study the feasibility of using haemozoin, constitutively stored in the parasite’s food vacuole, to kill the parasite by irradiation with a near IR laser was evaluated. Methods Cultured Plasmodium parasites at different stages of development were irradiated with a pulsed NIR laser and the viability of parasites at each stage was evaluated from their corresponding growth curves using the continuous culture method. Additional testing for germicidal effects of haemozoin and NIR laser was performed by adding synthetic haemozoin crystals to Escherichia coli in suspension. Cell suspensions were then irradiated with the laser and small aliquots taken and spread on agar plates containing selective agents to determine cell viability (CFU. Results Parasites in the late-trophozoites form as well as trophozoites in early-stage of DNA synthesis were found to be the most sensitive to the treatment with ~4-log reduction in viability after six passes through the laser beam; followed by parasites in ring phase (~2-log reduction. A ~1-log reduction in E. coli viability was obtained following a 60 min irradiation regimen of the bacteria in the presence of 1 μM synthetic haemozoin and a ~2-log reduction in the presence of 10 μM haemozoin. Minimal (≤15% cell kill was observed in the presence of 10 μM haemin. Conclusions Laser-induced third-harmonic generation by haemozoin can be used to inactivate Plasmodium. This result may have clinical implications for treating severe malaria symptoms by irradiating the patient’s blood through the skin or through dialysis tubing with a NIR laser.

  2. Green Tea Catechin-Inactivated Viral Vaccine Platform

    Directory of Open Access Journals (Sweden)

    Yun H. Lee

    2017-12-01

    Full Text Available Traditionally, chemical agents such as formalin (FA and β-propiolactone (BPL have long been used for the preparation of inactivated vaccines or toxoids. It has been shown that FA extensively modifies vaccine antigens and thus affects immunogenicity profiles, sometimes compromising the protective efficacy of the vaccines or even exacerbating the disease upon infection. In this study, we show that natural catechins from green tea extracts (GT can be used as an inactivating agent to prepare inactivated viral vaccines. GT treatment resulted in complete and irreversible inactivation of influenza virus as well as dengue virus. In contrast to FA that reacted extensively with multiple amino acids including lysine, a major anchor residue for epitope binding to MHC molecules, GT catechin epigallocatechin-3-gallate (EGCG crosslinked primarily with cysteine residues and thus preserved the major epitopes of the influenza hemagglutinin. In a mouse model, vaccination with GT-inactivated influenza virus (GTi virus elicited higher levels of viral neutralizing antibodies than FA-inactivated virus (FAi virus. The vaccination completely protected the mice from a lethal challenge and restricted the challenge viral replication in the lungs. Of note, the quality of antibody responses of GTi virus was superior to that with FAi virus, in terms of the magnitude of antibody titer, cross-reactivity to hetero-subtypes of influenza viruses, and the avidity to viral antigens. As the first report of using non-toxic natural compounds for the preparation of inactivated viral vaccines, the present results could be translated into a clinically relevant vaccine platform with improved efficacy, safety, productivity, and public acceptance.

  3. Infective and inactivated filamentous phage as carriers for immunogenic peptides.

    Science.gov (United States)

    Samoylova, Tatiana I; Norris, Mandy D; Samoylov, Alexandre M; Cochran, Anna M; Wolfe, Karen G; Petrenko, Valery A; Cox, Nancy R

    2012-07-01

    The focus of this study is on development of vaccines using filamentous phage as a delivery vector for immunogenic peptides. The use of phage as a carrier for immunogenic peptides provides significant benefits such as high immunogenicity, low production costs, and high stability of phage preparations. However, introduction of live recombinant phage into the environment might represent a potential ecological problem. This, for example, may occur when vaccines are used in oral or nasal formulations in field conditions for wild and feral animals. To address this issue, comparative studies of antigenic properties of live and inactivated (non-viable) phage were accomplished. Inactivated phage, if released, will not propagate and will degrade as any other protein. In these experiments, a model phage clone that was previously selected from a phage display library and shown to stimulate production of anti-sperm antibodies with contraceptive properties was used. Multiple methods of phage inactivation were tested, including drying, freezing, autoclaving, heating, and UV irradiation. Under studied conditions, heating at 76°C for 3h, UV irradiation, and autoclaving resulted in complete phage inactivation. Phage samples treated by heat and UV were characterized by spectrophotometry and electron microscopy. To test antigenicity, live and inactivated phage preparations were injected into mice and antibody responses assayed by ELISA. It was found that phage killed by heat causes little to no immune responses, probably due to destruction of phage particles. In contrast, UV-inactivated phage stimulated production of IgG serum antibodies at the levels comparable to live phage. Thus, vaccines formulated to include UV-inactivated filamentous phage might represent environmentally safe alternatives to live phage vaccines. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. ERADIKASI POLIO DAN IPV (INACTIVATED POLIO VACCINE

    Directory of Open Access Journals (Sweden)

    Gendrowahyuhono Gendrowahyuhono

    2012-09-01

    Full Text Available In the year 1988, World Health Organization (WHO claims that polio viruses should be eradicated after year 2000. However, until year 2010 the world have not been free from polio viruses circulation. So many effort had been achieved and it is estimated that the world will be free from polio virus after the year 2013. Control of poliomyelitis in Indonesia has been commenced since 1982 with routine immunization of polio program and the National Immunization Days (NID has been commenced since 1995,1996,2005 and 2006. When the world is free from polio virus, WHO suggests several alternative effort to maintain the world free from polio viruses : I stop the OPV (Oral Polio Vaccine and no polio immunization, 2 stop OPV and stock pile mOPV (monovalent OPV, 3 use OPV and IPV (Inactivated Polio Vaccine in a certain times, 4 use IPV only in a certain times. IPV has been used routinely in develop countries but has not been used in the developing countries. Several studies in development countries has been conducted, but had not been done in the developing countries. Indonesia collaboration with WHO has conducted the study of IPV in Yogyakarta Province since year 2002 until year 2010. The overall aim of the study is to compile the necessary data that will inform global and national decision-making regarding future polio immunization policies for the OPV cessation era. The data generated from the study will be particularly important to make decisions regarding optimal IPV use in developing tropical countries. It is unlikely that this data can be assembled through other means than through this study. The tentative result of the study shows that OPV immunization coverage in the year 2004 is 99% in four district and 93 % in the Yogyakarta city. Environment surveillance shows that there are 65.7% polio virus detected from 137 sewage samples pre IPV swich, and 4.8% polio virus detected from 83 sewage samples post IPV swich. Survey polio antibody serologis shows

  5. Inactivation of viruses in labile blood derivatives. II. Physical methods

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, B.; Wiebe, M.E.; Lippin, A.; Vandersande, J.; Stryker, M.H.

    1985-11-01

    The thermal inactivation of viruses in labile blood derivatives was evaluated by addition of marker viruses (VSV, Sindbis, Sendai, EMC) to anti-hemophilic factor (AHF) concentrates. The rate of virus inactivation at 60 degrees C was decreased by at least 100- to 700-fold by inclusion of 2.75 M glycine and 50 percent sucrose, or 3.0 M potassium citrate, additives which contribute to retention of protein biologic activity. Nonetheless, at least 10(4) infectious units of each virus was inactivated within 10 hours. Increasing the temperature from 60 to 70 or 80 degrees C caused a 90 percent or greater loss in AHF activity. An even greater decline in the rate of virus inactivation was observed on heating AHF in the lyophilized state, although no loss in AHF activity was observed after 72 hours of heating at 60 degrees C. Several of the proteins present in lyophilized AHF concentrates displayed an altered electrophoretic mobility as a result of exposure to 60 degrees C for 24 hours. Exposure of lyophilized AHF to irradiation from a cobalt 60 source resulted in an acceptable yield of AHF at 1.0, but not at 2.0, megarads. At 1 megarad, greater than or equal to 6.0 logs of VSV and 3.3 logs of Sindbis virus were inactivated.

  6. Effect of heat on virus inactivation by ammonia.

    Science.gov (United States)

    Burge, W D; Cramer, W N; Kawata, K

    1983-08-01

    The rate of inactivation of bacteriophage f2 and poliovirus 1 (CHAT) by NH3 was strongly influenced by temperature. The process was pseudo-first order at all temperatures and NH3 concentrations. Poliovirus was inactivated at a greater rate than f2, but the change in the rate of inactivation with increasing temperature in the range of approximately 10 to 40 degrees C was greater for f2 than for poliovirus. At higher temperatures, the rate of change was greater for poliovirus. Arrhenius plots of the data were biphasic, indicating that two inactivation processes were occurring, one for the low temperature range and another for the high temperature range. However, the magnitudes of the thermodynamic variables for f2 were low enough, as calculated for the low (10 to 35 degrees C) and high (35 to 60 degrees C) phases, that inactivation could have occurred by breakage of nucleic acid chains. For poliovirus, the sizes indicated possible involvement of nucleic acid at the low temperatures (10 to 40 degrees C) but some unknown mechanism for the high temperatures (40 and 50 degrees C).

  7. Efficacy of chlorine dioxide tablets on inactivation of cryptosporidium oocysts.

    Science.gov (United States)

    Murphy, Jennifer L; Haas, Charles N; Arrowood, Michael J; Hlavsa, Michele C; Beach, Michael J; Hill, Vincent R

    2014-05-20

    The ability of chlorine dioxide (ClO2) to achieve 2-log inactivation of Cryptosporidium in drinking water has been documented. No studies have specifically addressed the effects of ClO2 on C. parvum oocyst infectivity in chlorinated recreational water venues (e.g., pools). The aim of this research was to determine the efficacy of ClO2 as an alternative to existing hyperchlorination protocols that are used to achieve a 3-log inactivation of Cryptosporidium in such venues. To obtain a 3-log inactivation of C. parvum Iowa oocysts, contact times of 105 and 128 min for a solution containing 5 mg/L ClO2 with and without the addition of 2.6 mg/L free chlorine, respectively, were required. Contact times of 294 and 857 min for a solution containing 1.4 mg/L ClO2 with and without the addition of 3.6 mg/L free chlorine, respectively, were required. The hyperchlorination control (21 mg/L free chlorine only) required 455 min for a 3-log inactivation. Use of a solution containing 5 mg/L ClO2 and solutions containing 5 or 1.4 mg/L ClO2 with the addition of free chlorine appears to be a promising alternative to hyperchlorination for inactivating Cryptosporidium in chlorinated recreational water venues, but further studies are required to evaluate safety constraints on use.

  8. Thermal inactivation of the wine spoilage yeasts Dekkera/Brettanomyces.

    Science.gov (United States)

    Couto, José António; Neves, Filipe; Campos, Francisco; Hogg, Tim

    2005-10-25

    The heat resistance of three strains of Dekkera/Brettanomyces (Dekkera anomala PYCC 5,153, Dekkera bruxellensis PYCC 4,801 and Dekkera/Brettanomyces 093) was evaluated at different temperatures between 32.5 and 55 degrees C. Thermal inactivation tests were performed in tartrate buffer solution (pH 4.0) and in wines. In the studies employing buffer as the heating menstruum, measurable thermal inactivation began only at temperatures of 50 degrees C. When heating was performed in wine, significant inactivation begins at 35 degrees C. Subsequent thermal inactivation tests were performed in buffer at various levels of pH, ethanol concentration, and various phenolic acids. Results from experiments in buffer with added ethanol suggest that the greater heat sensitivity shown in wines can be largely attributed to ethanol, although potentiation of this effect might be due to the phenolic content, particularly from ferulic acid. In the range of pH values tested (2.5-4.5), this factor had no influence in the heat inactivation kinetics. Relevant data, in the form of D and Z values calculated in the various environments, potentially useful for the establishment of regimes of thermal control of Dekkera/Brettanomyces yeasts in wine and contaminated equipment is presented.

  9. Inactivation of citrus tristeza virus by gamma ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ieki, Hiroyuki; Yamaguchi, Akira

    1984-12-01

    The total exposure of gamma ray and the intensity of gamma ray per hour for the inactivation of citrus tristeza virus (CTV) and also the effect on citrus tissues are described. The budwoods of Morita navel orange infected with a severe seedling-yellow strain of CTV were irradiated with gamma ray from a /sup 60/Co source for 20 - 52 hours. The buds or small tissue pieces of the irradiated budwoods were subsequently grafted onto Mexcan lime. CTV was easily inactivated by the irradiation from 10 to 18 kR for from 20 to 52 hours. The higher the total exposure, the higher the rate of inactivation. The CTV in the budwoods was almost inactivated after the irradiation with 20 kR. When the total exposure to gamma ray on budwoods was the same, CTV was more efficiently inactivated by the irradiation for long period with low intensity of gamma ray per hour than that for short period with high intensity per hour. Gamma ray irradiation was effective to eliminate CTV from citrus tissues. (Mori, K.).

  10. Comparative innocuity and efficacy of live and inactivated sheeppox vaccines.

    Science.gov (United States)

    Boumart, Zineb; Daouam, Samira; Belkourati, Imane; Rafi, Lamya; Tuppurainen, Eeva; Tadlaoui, Khalid Omari; El Harrak, Mehdi

    2016-06-29

    Sheeppox (SPP) is one of the priorities, high-impact animal diseases in many developing countries, where live attenuated vaccines are routinely used against sheeppox virus (SPPV). In an event of an SPP outbreak, historically disease-free countries would hesitate to use of live vaccines against SPPVdue to the safety and trade reasons. Currently no killed SPPV vaccines are commercially available. In this study, we developed an inactivated Romanian SPPVvaccine and assessed its efficacy and potency in comparison with a live attenuated Romanian SPPV vaccine. Four naïve sheep were vaccinated once with the Romanian SPPV live attenuated vaccine and16 sheep were vaccinated twice with the inactivated vaccine. All sheep in the live vaccine group were included in the challenge trial, which was conducted using a highly virulent Moroccan SPPV field strain. Eight sheep of the inactivated vaccine group were challenged and the remaining sheep were monitored for seroconversion. Experimental animals were closely monitored for the appearance of clinical signs, body temperature and inflammation at the injection site. Two naïve sheep were used as unvaccinated controls. The inactivated Romanian SPPV vaccine was found to be safe and confer a good protection, similar to the live vaccine. Specific antibodies appeared from seven days post vaccination and remained up to nine months. This study showed that the developed inactivated Romanian SPPV vaccine has a potential to replace attenuated vaccine to control and prevent sheep pox in disease-free or endemic countries.

  11. Raman spectroscopy-compatible inactivation method for pathogenic endospores.

    Science.gov (United States)

    Stöckel, S; Schumacher, W; Meisel, S; Elschner, M; Rösch, P; Popp, J

    2010-05-01

    Micro-Raman spectroscopy is a fast and sensitive tool for the detection, classification, and identification of biological organisms. The vibrational spectrum inherently serves as a fingerprint of the biochemical composition of each bacterium and thus makes identification at the species level, or even the subspecies level, possible. Therefore, microorganisms in areas susceptible to bacterial contamination, e.g., clinical environments or food-processing technology, can be sensed. Within the scope of point-of-care-testing also, detection of intentionally released biosafety level 3 (BSL-3) agents, such as Bacillus anthracis endospores, or their products is attainable. However, no Raman spectroscopy-compatible inactivation method for the notoriously resistant Bacillus endospores has been elaborated so far. In this work we present an inactivation protocol for endospores that permits, on the one hand, sufficient microbial inactivation and, on the other hand, the recording of Raman spectroscopic signatures of single endospores, making species-specific identification by means of highly sophisticated chemometrical methods possible. Several physical and chemical inactivation methods were assessed, and eventually treatment with 20% formaldehyde proved to be superior to the other methods in terms of sporicidal capacity and information conservation in the Raman spectra. The latter fact has been verified by successfully using self-learning machines (such as support vector machines or artificial neural networks) to identify inactivated B. anthracis-related endospores with adequate accuracies within the range of the limited model database employed.

  12. Inactivation of complement by Loxosceles reclusa spider venom.

    Science.gov (United States)

    Gebel, H M; Finke, J H; Elgert, K D; Cambell, B J; Barrett, J T

    1979-07-01

    Zymosan depletion of serum complement in guinea pigs rendered them highly resistant to lesion by Loxosceles reclusa spider venom. Guinea pigs deficient in C4 of the complement system are as sensitive to the venom as normal guinea pigs. The injection of 35 micrograms of whole recluse venom intradermally into guinea pigs lowered their complement level by 35.7%. Brown recluse spider venom in concentrations as slight as 0.02 micrograms protein/ml can totally inactivate one CH50 of guinea pig complement in vitro. Bee, scorpion, and other spider venoms had no influence on the hemolytic titer of complement. Fractionation of recluse spider venom by Sephadex G-200 filtration separated the complement-inactivating property of the venom into three major regions which could be distinguished on the basis of heat stability as well as size. None was neutralized by antivenom. Polyacrylamide gel electrophoresis of venom resolved the complement inactivators into five fractions. Complement inactivated by whole venom or the Sephadex fractions could be restored to hemolytic activity by supplements of fresh serum but not by heat-inactivated serum, pure C3, pure C5, or C3 and C5 in combination.

  13. Thermal and high pressure inactivation kinetics of blueberry peroxidase.

    Science.gov (United States)

    Terefe, Netsanet Shiferaw; Delon, Antoine; Versteeg, Cornelis

    2017-10-01

    This study for the first time investigated the stability and inactivation kinetics of blueberry peroxidase in model systems (McIlvaine buffer, pH=3.6, the typical pH of blueberry juice) during thermal (40-80°C) and combined high pressure-thermal processing (0.1-690MPa, 30-90°C). At 70-80°C, the thermal inactivation kinetics was best described by a biphasic model with ∼61% labile and ∼39% stable fractions at temperature between 70 and 75°C. High pressure inhibited the inactivation of the enzyme with no inactivation at pressures as high as 690MPa and temperatures less than 50°C. The inactivation kinetics of the enzyme at 60-70°C, and pressures higher than 500MPa was best described by a first order biphasic model with ∼25% labile fraction and 75% stable fraction. The activation energy values at atmospheric pressure were 548.6kJ/mol and 324.5kJ/mol respectively for the stable and the labile fractions. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  14. Inactivation of Heterosigma akashiwo in ballast water by circular orifice plate-generated hydrodynamic cavitation.

    Science.gov (United States)

    Feng, Daolun; Zhao, Jie; Liu, Tian

    2016-01-01

    The discharge of alien ballast water is a well-known, major reason for marine species invasion. Here, circular orifice plate-generated hydrodynamic cavitation was used to inactivate Heterosigma akashiwo in ballast water. In comparison with single- and multihole orifice plates, the conical-hole orifice plate yielded the highest inactivation percentage, 51.12%, and consumed only 6.84% energy (based on a 50% inactivation percentage). Repeating treatment, either using double series-connection or circling inactivation, elevated the inactivation percentage, yet consumed much more energy. The results indicate that conical-hole-generated hydrodynamic cavitation shows great potential as a pre-inactivation method for ballast water treatment.

  15. Microbial inactivation by microwave radiation in the home environment.

    Science.gov (United States)

    Park, Dong-Kyoo; Bitton, Gabriel; Melker, Richard

    2006-12-01

    The study reported here looked at the survival of microorganisms (heterotrophic plate counts, total coliforms, E. coli, and bacterial spores) in a consumer-type microwave oven. Kitchen sponges, scrubbing pads, and syringes were experimentally contaminated with wastewater and subsequently exposed to microwave radiation. At 100 percent power level, it was found that the heterotrophic plate count (i.e., total bacterial count) of the wastewater was reduced by more that 99 percent within 1 to 2 minutes, and the total coliform and E. coli were totally inactivated after 30 seconds of microwave radiation. Bacterial phage MS2 was totally inactivated within 1 to 2 minutes. Spores of Bacillus cereus were more resistant than the other microorganisms tested, and were completely eradicated only after 4-minute irradiation. Similar inactivation rates were obtained in wastewater-contaminated scrubbing pads. Microorganisms attached to plastic syringes were more resistant to microwave irradiation than those associated with kitchen sponges or scrubbing pads. It took 10 minutes for total inactivation of the heterotrophic plate count and 4 minutes for total inactivation of total coliform and E. coli. A 4-log reduction of phage MS2 was obtained after 2 minutes; 97.4 percent reduction was observed after 12 minutes. The authors also observed a higher inactivation of B. cereus spores in syringes placed in a ceramic container than of spores in syringes placed in a glass container. This finding could have some implications for the design of containers to be used in exposure of medical devices to microwave radiation. The article discusses the implications of these findings for consumer safety in the home environment.

  16. Assessing the efficacy of an inactivated chicken anemia virus vaccine.

    Science.gov (United States)

    Zhang, Xinheng; Wu, Boliang; Liu, Yuanjia; Chen, Weiguo; Dai, Zhenkai; Bi, Yingzuo; Xie, Qingmei

    2015-04-15

    Chicken anemia virus (CAV) is an immunosuppressive virus that causes chicken infectious anemia (CIA) which is a highly contagious avian disease. CAV causes major economic losses in the poultry industry worldwide. The current CAV vaccine is a live attenuated strain administered in the drinking water that risks horizontal infection of other chickens. The purpose of this study was to develop a novel vaccine against CAV that can be administered safely using a highly pathogenic isolate inactivated with β-propiolactone hydrolysis that would protect chicks from CAV. Hens were vaccinated twice intramuscularly with a novel CAV GD-G-12 inactivated vaccine and the humoral immune responses of the hens and offspring were monitored by ELISA. A heterologous intramuscular challenge using the CAV strain GD-E-12 was conducted in the chicks hatched from vaccinated or unvaccinated hens. The vaccine strain, GD-G-12, was shown to be highly pathogenic prior to inactivation evidenced by thymic atrophy and bleeding, and weight loss. The inactivated vaccine was considered safe and showed no signs of pathogenicity. High titers of CAV specific antibodies were detected in the vaccinated hens and in their chicks, indicating vertical transfer of maternal antibodies. Furthermore, the chicks hatched from vaccinated hens were resistant to a heterologous CAV challenge and showed no signs of weight loss and thymic atrophy and bleeding. Our studies are proof of principle that inactivated GD-G-12 might be a novel vaccine candidate to prevent CAV infection, and highlight the utility of using an inactivated virus for this vaccine. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Genetic architecture of skewed X inactivation in the laboratory mouse.

    Directory of Open Access Journals (Sweden)

    John D Calaway

    Full Text Available X chromosome inactivation (XCI is the mammalian mechanism of dosage compensation that balances X-linked gene expression between the sexes. Early during female development, each cell of the embryo proper independently inactivates one of its two parental X-chromosomes. In mice, the choice of which X chromosome is inactivated is affected by the genotype of a cis-acting locus, the X-chromosome controlling element (Xce. Xce has been localized to a 1.9 Mb interval within the X-inactivation center (Xic, yet its molecular identity and mechanism of action remain unknown. We combined genotype and sequence data for mouse stocks with detailed phenotyping of ten inbred strains and with the development of a statistical model that incorporates phenotyping data from multiple sources to disentangle sources of XCI phenotypic variance in natural female populations on X inactivation. We have reduced the Xce candidate 10-fold to a 176 kb region located approximately 500 kb proximal to Xist. We propose that structural variation in this interval explains the presence of multiple functional Xce alleles in the genus Mus. We have identified a new allele, Xce(e present in Mus musculus and a possible sixth functional allele in Mus spicilegus. We have also confirmed a parent-of-origin effect on X inactivation choice and provide evidence that maternal inheritance magnifies the skewing associated with strong Xce alleles. Based on the phylogenetic analysis of 155 laboratory strains and wild mice we conclude that Xce(a is either a derived allele that arose concurrently with the domestication of fancy mice but prior the derivation of most classical inbred strains or a rare allele in the wild. Furthermore, we have found that despite the presence of multiple haplotypes in the wild Mus musculus domesticus has only one functional Xce allele, Xce(b. Lastly, we conclude that each mouse taxa examined has a different functional Xce allele.

  18. Inactivation of VHSV by Percolation and Salt Under Experimental Conditions

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Olesen, Niels Jørgen; Jørgensen, Claus

    2012-01-01

    At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by percolation. To evaluate the inactivation effect of percolation on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid...... method to sanitize VHSV infected water. Changes in temperature, pH, earth types in the area used for percolation etc. may change the virus reduction, though. As some of the fish cutting plants are also smoking rainbow trout fillets, the question arose whether a brine solution will inactivate VHSV...

  19. Inactivation of VHSV by infiltration and salt under experimental conditions

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Jørgensen, Claus; Olesen, Niels Jørgen

    2014-01-01

    At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by infiltration. To evaluate the inactivation effect of infiltration on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid...... be a valuable method to sanitize VHSV infected water. Changes in temperature, pH, earth types in the area used for infiltration etc. may change the virus reduction, though. As some of the fish cutting plants are also smoking rainbow trout fillets, the question arose whether a brine solution will inactivate VHSV...

  20. Inactivation of Herpes Simplex Viruses by Nonionic Surfactants

    Science.gov (United States)

    Asculai, Samuel S.; Weis, Margaret T.; Rancourt, Martha W.; Kupferberg, A. B.

    1978-01-01

    Nonionic surface-active agents possessing ether or amide linkages between the hydrophillic and hydrophobic portions of the molecule rapidly inactivated the infectivity of herpes simplex viruses. The activity stemmed from the ability of nonionic surfactants to dissolve lipid-containing membranes. This was confirmed by observing surfactant destruction of mammalian cell plasma membranes and herpes simplex virus envelopes. Proprietary vaginal contraceptive formulations containing nonionic surfactants also inactivated herpes simplex virus infectivity. This observation suggests that nonionic surfactants in appropriate formulation could effectively prevent herpes simplex virus transmission. Images PMID:208460

  1. An insight on bacterial cellular targets of photodynamic inactivation.

    Science.gov (United States)

    Alves, Eliana; Faustino, Maria Af; Neves, Maria Gpms; Cunha, Angela; Tome, Joao; Almeida, Adelaide

    2014-02-01

    The emergence of microbial resistance is becoming a global problem in clinical and environmental areas. As such, the development of drugs with novel modes of action will be vital to meet the threats created by the rise in microbial resistance. Microbial photodynamic inactivation is receiving considerable attention for its potentialities as a new antimicrobial treatment. This review addresses the interactions between photosensitizers and bacterial cells (binding site and cellular localization), the ultrastructural, morphological and functional changes observed at initial stages and during the course of photodynamic inactivation, the oxidative alterations in specific molecular targets, and a possible development of resistance.

  2. Influenza (flu) vaccine (Inactivated or Recombinant): What you need to know

    Science.gov (United States)

    ... taken in its entirety from the CDC Inactivated Influenza Vaccine Information Statement (VIS) www.cdc.gov/vaccines/hcp/vis/vis-statements/flu.html CDC review information for Inactivated Influenza VIS: ...

  3. High pressure processing's potential to inactivate norovirus and other fooodborne viruses

    Science.gov (United States)

    High pressure processing (HPP) can inactivate human norovirus. However, all viruses are not equally susceptible to HPP. Pressure treatment parameters such as required pressure levels, initial pressurization temperatures, and pressurization times substantially affect inactivation. How food matrix ...

  4. X inactivation in Rett syndrome: A preliminary study showing partial preferential inactivation of paternal X with the M27{beta} probe

    Energy Technology Data Exchange (ETDEWEB)

    Camus, P.; Abbadi, N.; Gilgenkrantz, S. [Laboratoire de Genetique, Vandoeuvre les Nancy (France)

    1994-04-15

    Rett syndrome (RS) is a severe progressive neurological disorder occurring exclusively in females. Most cases are sporadic. The few familial cases (less than 1%) cannot be explained by a simple mode of inheritance. Several hypotheses have been proposed: X-linked male lethal mutation, maternal uniparental disomy, fresh mutation on the X chromosome, involvement of mitochondrial DNA and differential inactivation with metabolic interference of X-borne alleles. The authors have examined the pattern of X inactivation in 10 affected girls who were selected according to the clinical criteria previously described and accepted by the French Rett Scientific Committee. The X inactivation pattern was studied by analysis of methylation at the hypervariable locus DXS255 with the M27{beta} probe. The results show a more-or-less skewed inactivation of paternal X in 8 Rett females, and 2 cases of symmetrical inactivation. In control girls, inactivation was symmetrical cases and the maternal X has been preferentially inactivated in the other 2 cases. In no case was a total skewed inactivation observed. Though there was clear evidence for a preferential paternal X inactivation that was statistically significant further studies are necessary to establish a relationship between X inactivation pattern and Rett syndrome.

  5. Měkkýši Hončovy hůrky u Příbora (Slezsko, Česká republika Molluscs of the Hončova Hůrka hill near Příbor (Silesia, Czech Republic

    Directory of Open Access Journals (Sweden)

    Lenka Kotarová

    2011-11-01

    Full Text Available Hončova Hůrka hill in Skotnice near Příbor is important mineralogical locality. It is formed by rocks of the te­schenite association. It was opened as relatively small picrite quarry with further enlargement due to gravel mi­ning up to present status. Quarries in general possess wide range of habitats. Moreover, teschenite rock association with its high calcium content is favourable environment for land snails. Altogether, 27 land snail species were found in Hončova Hůrka hill, of which four are concerned as near threatened (Ena montana, Vertigo pygmaea, Daudebardia rufa and Pupilla muscorum. This site thus has a potential as local refugium for endangered species and deserves our attention.

  6. Inactivation of Ascaris suum by short-chain fatty acids

    Science.gov (United States)

    Ascaris suum eggs were inactivated in distilled water and digested sludge by butanoic, pentanoic and hexanoic acids. The fatty acids (FA) were only effective when protonated and at sufficient concentration. The conjugate bases were not effective at the concentrations evaluated. Predictions from an ...

  7. Testing household disinfectants for the inactivation of helminth eggs ...

    African Journals Online (AJOL)

    2016-10-04

    Oct 4, 2016 ... Keywords: Ascaris, carbolic acid, disinfectant, eggs, inactivation, pit latrine, sanitation, sodium hypochlorite. INTRODUCTION. The lack of ... ronment providing temperature (25°C) and humidity (> 55%) are optimal. ...... The pH of the stomach is strongly acidic, but pH of the gas- trointestinal tract is in the ...

  8. 40 CFR 141.720 - Inactivation toolbox components.

    Science.gov (United States)

    2010-07-01

    ... Cryptosporidium, Giardia lamblia, and virus treatment credits for ultraviolet (UV) light reactors by achieving the... unfiltered systems. UV Dose Table for Cryptosporidium, Giardia lamblia, and Virus Inactivation Credit Log credit Cryptosporidium UV dose (mJ/cm2) Giardia lamblia UV dose (mJ/cm2) VirusUV dose (mJ/cm2) (i) 0.5 1...

  9. Inactivation of human and simian rotaviruses by chlorine dioxide.

    Science.gov (United States)

    Chen, Y S; Vaughn, J M

    1990-01-01

    The inactivation of single-particle stocks of human (type 2, Wa) and simian (SA-11) rotaviruses by chlorine dioxide was investigated. Experiments were conducted at 4 degrees C in a standard phosphate-carbonate buffer. Both virus types were rapidly inactivated, within 20 s under alkaline conditions, when chlorine dioxide concentrations ranging from 0.05 to 0.2 mg/liter were used. Similar reductions of 10(5)-fold in infectivity required additional exposure time of 120 s at 0.2 mg/liter for Wa and at 0.5 mg/liter for SA-11, respectively, at pH 6.0. The inactivation of both virus types was moderate at neutral pH, and the sensitivities to chlorine dioxide were similar. The observed enhancement of virucidal efficiency with increasing pH was contrary to earlier findings with chlorine- and ozone-treated rotavirus particles, where efficiencies decreased with increasing alkalinity. Comparison of 99.9% virus inactivation times revealed ozone to be the most effective virucidal agent among these three disinfectants. PMID:2160222

  10. Application of electrolysis to inactivation of antibacterials in clinical use.

    Science.gov (United States)

    Nakano, Takashi; Hirose, Jun; Kobayashi, Toyohide; Hiro, Naoki; Kondo, Fumitake; Tamai, Hiroshi; Tanaka, Kazuhiko; Sano, Kouichi

    2013-04-01

    Contamination of surface water by antibacterial pharmaceuticals (antibacterials) from clinical settings may affect aquatic organisms, plants growth, and environmental floral bacteria. One of the methods to decrease the contamination is inactivation of antibacterials before being discharged to the sewage system. Recently, we reported the novel method based on electrolysis for detoxifying wastewater containing antineoplastics. In the present study, to clarify whether the electrolysis method is applicable to the inactivation of antibacterials, we electrolyzed solutions of 10 groups of individual antibacterials including amikacin sulfate (AMK) and a mixture (MIX) of some commercial antibacterials commonly prescribed at hospitals, and measured their antibacterial activities. AMK was inactivated in its antibacterial activities and its concentration decreased by electrolysis in a time-dependent manner. Eighty to ninety-nine percent of almost all antibacterials and MIX were inactivated within 6h of electrolysis. Additionally, cytotoxicity was not detected in any of the electrolyzed solutions of antibacterials and MIX by the Molt-4-based cytotoxicity test. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Expression of a ribosome inactivating protein (curcin 2) in Jatropha ...

    Indian Academy of Sciences (India)

    Expression of a ribosome inactivating protein (curcin 2) in Jatropha curcas is induced by stress ... In addition, the 32 kDa band is nearly the molecular weight of curcin 2. ... curcin 2. The presence of this protein molecular marker under stresses may provide an experimental foundation to study the stress proteins in J. curcas.

  12. Significance of cobalamin inactivation in normal and malignant hematopoiesis

    NARCIS (Netherlands)

    A.A.M. Ermens (Anton)

    1990-01-01

    textabstractThis thesis deals with several aspects of the effects of cobalamin inactivation by nitrous oxide on cellular folate metabolism and the consequences on normal and malignant hematopoiesis. Kroes et al. demonstrated the antileukemic effects of nitrous oxide either or not in combination

  13. Inactivation of pathogens on pork by steam-ultrasound treatment

    DEFF Research Database (Denmark)

    Morild, Rikke K; Christiansen, Pia; Sørensen, Anders Morten Hay

    2011-01-01

    The objective of the study was to evaluate a new pathogen inactivation concept that combines application of pressurized steam simultaneously with high-power ultrasound through a series of nozzles. On skin and meat surfaces of pork jowl samples, counts of total viable bacteria were reduced by 1...

  14. Inactivation of bacteria in sewage sludge by gamma radiation.

    Science.gov (United States)

    Pandya, G A; Kapila, S; Kelkar, V B; Negi, S; Modi, V V

    1987-01-01

    The survival of certain bacterial cultures suspended in sewage sludge and exposed to gamma-radiation was studied. The inactivation patterns of most of the organisms were significantly different when irradiation was performed using sewage samples collected in the summer and monsoon seasons. The summer sample collected from the anaerobic digestor afforded significant protection to both Gram negative and Gram positive organisms. This was evident by the increase in dose required to bring about a 6 log cycle reduction in viable count of the bacterial cultures, when suspended in sewage samples instead of phosphate buffer. The observations made using monsoon digestor samples were quite different. This sewage sludge greatly enhanced inactivation by gamma-radiation in most cases. The effects of certain chemicals on the inactivation patterns of two organisms-Salmonella typhi and Shigella flexneri-were examined. Arsenate, mercury and lead salts sensitised S. typhi, while barium acetate and sodium sulphide protected this culture against gamma-radiation. In the case of Sh. flexneri, barium acetate and iodacetamide proved to be radioprotectors. The effects of some chemicals on the inactivation pattern of Sh. flexneri cells irradiated in sludge are also discussed.

  15. Use of genetic algorithms for high hydrostatic pressure inactivation ...

    African Journals Online (AJOL)

    Use of genetic algorithms for high hydrostatic pressure inactivation of microorganisms. ... Depending on the properties of HHP equipment (maximum operating pressure) or the type of the food product (heat-sensitive), it could be possible to select the suitable P-T-t trio among the alternatives. This study reveals that GAs could ...

  16. Inactivation of enveloped virus by laser-driven protein aggregation

    Science.gov (United States)

    Tsen, Shaw-Wei D.; Chapa, Travis; Beatty, Wandy; Tsen, Kong-Thon; Yu, Dong; Achilefu, Samuel

    2012-12-01

    Ultrafast lasers in the visible and near-infrared range have emerged as a potential new method for pathogen reduction of blood products and pharmaceuticals. However, the mechanism of enveloped virus inactivation by this method is unknown. We report the inactivation as well as the molecular and structural effects caused by visible (425 nm) femtosecond laser irradiation on murine cytomegalovirus (MCMV), an enveloped, double-stranded DNA virus. Our results show that laser irradiation (1) caused a 5-log reduction in MCMV titer, (2) did not cause significant changes to the global structure of MCMV virions including membrane and capsid, as assessed by electron microscopy, (3) produced no evidence of double-strand breaks or crosslinking in MCMV genomic DNA, and (4) caused selective aggregation of viral capsid and tegument proteins. We propose a model in which ultrafast laser irradiation induces partial unfolding of viral proteins by disrupting hydrogen bonds and/or hydrophobic interactions, leading to aggregation of closely associated viral proteins and inactivation of the virus. These results provide new insight into the inactivation of enveloped viruses by visible femtosecond lasers at the molecular level, and help pave the way for the development of a new ultrafast laser technology for pathogen reduction.

  17. Inactivation of a transgene due to transposition of insertion ...

    Indian Academy of Sciences (India)

    Agrobacterium strains harbour insertion sequences, which are known to transpose into genomes as well as into Ti plasmids. In this study we report the inactivation of a transgene due to transposition of the A. tumefaciens insertion sequence IS136. The transposition was discovered following transformation of plant tissues, ...

  18. Photoactivated polycationic bioactive chitosan nanoparticles inactivate bacterial endotoxins.

    Science.gov (United States)

    Shrestha, Annie; Cordova, Martha; Kishen, Anil

    2015-05-01

    The current root canal disinfection protocols fail to markedly inactivate bacterial endotoxins from infected root dentin. This study aimed to evaluate the ability of antibacterial photodynamic therapy with chitosan-conjugated rose bengal nanoparticles (CSRBnps) to selectively inactivate endotoxins/lipopolysaccharides (LPSs). Antimicrobial agents such as calcium hydroxide (Ca[OH]2), chitosan nanoparticles (CSnps), CSRBnps, and methylene blue (MB) were assessed for their ability to neutralize LPSs obtained from Pseudomonas aeruginosa in a time-dependent interaction with/without photoactivation (20 and 40 J/cm(2)). The inflammatory potential of the treated/untreated LPSs was assessed on macrophage cells (RAW 267.4) using nitric oxide- and enzyme-linked immunosorbent assay (tumor necrosis factor α and interleukin-6 expression)-based analysis. These antimicrobials were tested directly on macrophage cells for cytotoxicity using the mitochondrial activity assay and light microscopy. The data were analyzed using 1-way analysis of variance and the Tukey test. CSnps were least effective in LPS inactivation. Interluekin-6 expression was reduced only with CSRBnp treatment. CSnps and CSRBnps were completely nontoxic, and MB showed slight toxicity to macrophage cells. Ca(OH)2 was highly cytotoxic (P endotoxins and the subsequent reduction of all tested inflammatory markers from activated macrophages. Antimicrobial CSRBnps in combination with photodynamic therapy showed the potential to effectively inactivate bacterial endotoxins. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Inactivation of dairy manure-borne pathogens by anaerobic digestion

    Science.gov (United States)

    Background: Anaerobic digestion of animal manure has the potential to inactivate enteric pathogens, thereby reducing exposures to livestock and humans when the products of digestion are disposed by land-spreading or irrigation or returned to livestock uses such as bedding. Data on digester effectiv...

  20. Photodynamic inactivation of fibroblasts by a cationic porphyrin

    NARCIS (Netherlands)

    Lambrechts, Saskia A. G.; Schwartz, Kevin R.; Aalders, Maurice C. G.; Dankert, Jacob B.

    2005-01-01

    An important determinant of the clinical applicability and value of antimicrobial photodynamic inactivation (PDI) is the cytotoxicity of the treatment to human cells. We evaluated the in vitro cytotoxicity of PDI to human dermal fibroblasts using 5-phenyl-10,15,20-tris(N-methyl-4-pyridyl)porphyrin

  1. Drying of liquid food droplets : enzyme inactivation and multicomponent diffusion

    NARCIS (Netherlands)

    Meerdink, G.

    1993-01-01

    In this thesis the drying of liquid food droplets is studied from three different points of view: drying kinetics, enzyme inactivation and multicomponent diffusion. Mathematical models are developed and validated experimentally.

    Drying experiments are performed with suspended

  2. Evaluation of the Efficacy of Inactivated Oil-Emulsion Newcastle ...

    African Journals Online (AJOL)

    Since the first recognition of Newcastle disease (ND) in Nigeria, it has been observed to be enzootic despite the intensive vaccination policy, leading to significant economic losses in the poultry industry. This study evaluated the ability of inactivated oil-emulsion ND Komarov vaccine to protect laying chickens from challenge ...

  3. Indicators for suicide substrate inactivation: A kinetic investigation

    Indian Academy of Sciences (India)

    Suicide substrate kinetic pathway and a proposed set of indicators, some theoretical and a few practical ones, that can decisively conclude enzyme inactivation are considered. Steady-state approximation is assumed not only when a catalytic amount of enzyme is used but also for any substrate-enzyme ratio. In each ...

  4. Photodynamic inactivation of Aspergillus flavus mediated by Bidens ...

    African Journals Online (AJOL)

    Occurrence of mycotoxins in food and animal feeds poses major health risks to human and animals, and effective control requires integration of crop management strategies both in the field and during post-harvest storage and processing. Photodynamic inactivation is a novel light-based approach which offers a promising ...

  5. Strategy to inactivate Clostridium perfringens spores in meat products.

    Science.gov (United States)

    Akhtar, Saeed; Paredes-Sabja, Daniel; Torres, J Antonio; Sarker, Mahfuzur R

    2009-05-01

    The current study aimed to develop an inactivation strategy for Clostridium perfringens spores in meat through a combination of spore activation at low pressure (100-200 MPa, 7 min) and elevated temperature (80 degrees C, 10 min); spore germination at high temperatures (55, 60 or 65 degrees C); and inactivation of germinated spores with elevated temperatures (80 and 90 degrees C, 10 and 20 min) and high pressure (586 MPa, at 23 and 73 degrees C, 10 min). Low pressures (100-200 MPa) were insufficient to efficiently activate C. perfringens spores for germination. However, C. perfringens spores were efficiently activated with elevated temperature (80 degrees C, 10 min), and germinated at temperatures lethal for vegetative cells (>or= 55 degrees C) when incubated for 60 min with a mixture of L-asparagine and KCl (AK) in phosphate buffer (pH 7) and in poultry meat. Inactivation of spores (approximately 4 decimal reduction) in meat by elevated temperatures (80-90 degrees C for 20 min) required a long germination period (55 degrees C for 60 min). However, similar inactivation level was reached with shorter germination period (55 degrees C for 15 min) when spore contaminated-meat was treated with pressure-assisted thermal processing (568 MPa, 73 degrees C, 10 min). Therefore, the most efficient strategy to inactivate C. perfringens spores in poultry meat containing 50 mM AK consisted: (i) a primary heat treatment (80 degrees C, 10 min) to pasteurize and denature the meat proteins and to activate C. perfringens spores for germination; (ii) cooling of the product to 55 degrees C in about 20 min and further incubation at 55 degrees C for about 15 min for spore germination; and (iii) inactivation of germinated spores by pressure-assisted thermal processing (586 MPa at 73 degrees C for 10 min). Collectively, this study demonstrates the feasibility of an alternative and novel strategy to inactivate C. perfringens spores in meat products formulated with germinants specific for C

  6. 21 CFR 866.5250 - Complement C2 inhibitor (inactivator) immunological test system.

    Science.gov (United States)

    2010-04-01

    ... Test Systems § 866.5250 Complement C2 inhibitor (inactivator) immunological test system. (a) Identification. A complement C1 inhibitor (inactivator) immunological test system is a device that consists of... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Complement C2 inhibitor (inactivator...

  7. Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

    Directory of Open Access Journals (Sweden)

    Takashi Furukawa

    2017-07-01

    Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.

  8. Randomized Trials Comparing Inactivated Vaccine after Medium- or High-titer Measles Vaccine with Standard Titer Measles Vaccine after Inactivated Vaccine

    DEFF Research Database (Denmark)

    Aaby, Peter; Ravn, Henrik; Benn, Christine S.

    2016-01-01

    Background: Observational studies have suggested that girls have higher mortality if their most recent immunization is an inactivated vaccine rather than a live vaccine. We therefore reanalyzed 5 randomized trials of early measles vaccine (MV) in which it was possible to compare an inactivated...... vaccines [after medium-titer MV (MTMV) or high-titer MV (HTMV)] and a live standard titer MV (after an initial inactivated vaccine). Methods: The trials were conducted in Sudan, Senegal, The Gambia and Guinea-Bissau. The intervention group received live MTMV or HTMV from 4 to 5 months...... and then an inactivated vaccine from 9 to 10 months of age; the control children received inactivated vaccine/placebo from 4 to 5 months and standard titer MV from 9 to 10 months of age. We compared mortality from 9 months until end of study at 3 to 5 years of age for children who received inactivated vaccine (after MTMV...

  9. The assessment of efficacy of porcine reproductive respiratory syndrome virus inactivated vaccine based on the viral quantity and inactivation methods

    Directory of Open Access Journals (Sweden)

    Lee Byeongchun

    2011-06-01

    Full Text Available Abstract Background There have been many efforts to develop efficient vaccines for the control of porcine reproductive and respiratory syndrome virus (PRRSV. Although inactivated PRRSV vaccines are preferred for their safety, they are weak at inducing humoral immune responses and controlling field PRRSV infection, especially when heterologous viruses are involved. Results In all groups, the sample to positive (S/P ratio of IDEXX ELISA and the virus neutralization (VN titer remained negative until challenge. While viremia did not reduce in the vaccinated groups, the IDEXX-ELISA-specific immunoglobulin G increased more rapidly and to significantly greater levels 7 days after the challenge in all the vaccinated groups compared to the non-vaccinated groups (p 6 PFU/mL PRRSV vaccine-inoculated and binary ethylenimine (BEI-inactivated groups 22 days after challenge (p Conclusions The inactivated vaccine failed to show the humoral immunity, but it showed different immune response after the challenge compared to mock group. Although the 106 PFU/mL-vaccinated and BEI-inactivated groups showed significantly greater VN titers 22 days after challenge, all the groups were already negative for viremia.

  10. Transient inactivation of myostatin induces muscle hypertrophy and overcompensatory growth in zebrafish via inactivation of the SMAD signaling pathway.

    Science.gov (United States)

    Fuentes, Eduardo N; Pino, Katherine; Navarro, Cristina; Delgado, Iselys; Valdés, Juan Antonio; Molina, Alfredo

    2013-12-01

    Myostatin (MSTN) is the main negative regulator of muscle growth and development in vertebrates. In fish, little is known about the molecular mechanisms behind how MSTN inactivation triggers skeletal muscle enhancement, particularly regarding the signaling pathways involved in this process. Moreover, there have not been reports on the biotechnological applications of MSTN and its signal transduction. In this context, zebrafish underwent compensatory growth using fasting and refeeding trials, and MSTN activity was inactivated with dominant negative LAPD76A recombinant proteins during the refeeding period, when a rapid, compensatory muscle growth was observed. Treated fish displayed an overcompensation of growth characterized by higher muscle hypertrophy and growth performance than constantly fed, control fish. Treatment with LAPD76A recombinant proteins triggered inactivation of the SMAD signaling pathway in skeletal muscle, the main signal transduction used by MSTN to achieve its biological actions. Therefore, transient inactivation of MSTN during the compensatory growth of zebrafish led to a decrease in the SMAD signaling pathway in muscle, triggering muscle hypertrophy and finally improving growth performance, thus, zebrafish achieved an overcompensation of growth. The present study shows an attractive strategy for improving muscle growth in a fish species by mixing a classical strategy, such as compensatory growth, and a biotechnological approach, such as the use of recombinant proteins for inhibiting the biological actions of MSTN. The mix of both strategies may represent a method that could be applied in order to improve growth in commercial fish of interest for aquaculture. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Cytolytic T lymphocyte responses to metabolically inactivated stimulator cells. I. Metabolic inactivation impairs both CD and LD antigen signals

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, A.; Boyle, W.

    1982-03-01

    The effects of metabolic inactivation of spleen cells on antigen presentation to precursors of alloreactive cytolytic T lymphocytes (T/sub c/) were examined. By serological methods, populations inactivated by ultraviolet irradiation, glutaraldehyde fixation or plasma membrane isolation were found to retain normal levels of H-2K/D and Ia antigens. However, comparison of the antigen doses required to stimulate secondary T/sub c/ responses in mixed leukocyte culture showed that the inactivated preparations were approximately 10-fold less immunogenic than X-irradiated spleen cells. Their total inability to stimulate primary cytolytic responses pointed to at least a 100-fold impairment of immunogenicity for unprimed T/sub c/ precursors in the case of uv-irradiated and glutaraldehyde-treated stimulator cells, and at least a 10-fold impairment for membrane fragments. Experiments showing that the capacity of cell monolayers to absorb precursor T/sub c/ from unprimed spleen populations was reduced following uv-irradiation or glutaraldehyde treatment provided direct evidence that this loss of immunogenicity was due in part to suboptimal antigen presentation to precursor T/sub c/. It is concluded that, in addition to the traditional view that these treatments damage the ''LD'' signal to helper T lymphocytes, metabolic inactivation also impairs recognition of ''CD'' determinants by precursor T/sub c/.

  12. Experimental pulmonary schistosomiasis: lack of morphological evidence of modulation in schistosomal pulmonary granulomas Esquistossomose pulmonar experimental: falta de evidência morfológica de modulação nos granulomas esquistosomóticos pulmonares

    Directory of Open Access Journals (Sweden)

    Maura R. F. Souza Vidal

    1993-10-01

    Full Text Available Numerous pulmonary schistosome egg granulomas were present in mice submitted to partial portal vein ligation (Warren's model. The granulomas were characterized by cellular aggregations formed within alveolar tissue. Main cellular types were macrophages (epithelioid cells, eosinophils, plasma cells and lymphocytes. These cells were supported by scanty fibrous stroma and exhibited close membrane contact points amongst themselves, but without forming specialized adhesion apparatus. When granulomas involved arterial structures, proliferation of cndothelial and smooth muscle cells occurred and fibrosis associated with angiogenesis became more evident. Granulomas formed around mature eggs in the pulmonary alveolar tissue presented approximately the same size and morphology regardless of the time of infection, the latter being 10, 18 and 25 weeks after cercarial exposure. This persistence of morphological appearance suggests that pulmonary granulomas do not undergo immunological modulation, as is the case with the granulomas in the liver and, to a lesser extent, in the intestines. Probably, besides general immunological factors, local (stromal factors play an important role in schistosomal granuloma modulation.Em camundongos submetidos à ligadura parcial da veia porta e infecção pelo Schistosoma mansoni, os granulomas periovulares apareceram em grande número nos pulmões, comprovando a validade do modelo de Warren. Histologicamente os granulomas eram representados por agregados celulares compactos no seio de escasso estroma. Os macrófagos (células epitelióides e eosinófilos eram os elementos celulares predominantes, vindo em seguida os linfóticos e plasmócitos. Ultraestruturalmenle, as células do granuloma exibiam íntimo contacto de suas membranas, com varios pontos de adesão, mas sem formar estruturas juncionais mais específicas. Os granulomas formados em torno a ovos maduros tinham tamanho, forma e composição celular similares ap

  13. Calcium current-dependent and voltage-dependent inactivation of calcium channels in Helix aspersa

    Science.gov (United States)

    Brown, A. M.; Morimoto, K.; Tsuda, Y.; Wilson, D. L.

    1981-01-01

    1. Inactivation of the Ca channels has been examined in isolated nerve cell bodies of Helix aspersa using the suction pipette method for voltage clamp and internal perfusion. 2. Satisfactory suppression of outward currents was essential. This was achieved over most of the voltage range by substitution of Cs ion for K ion and by the use of TEA intra- and extracellularly and 4-AP extracellularly. A small time- and voltage-dependent non-specific current remained at potentials above +60 mV. 3. In these solutions, Ca current approaches ECa but cannot be detected in the outward direction. The Ca channel appears to be impermeable to Cs and Tris ions. 4. Inactivation of Ca currents occurs as a bi-exponential process. The faster rate is 10-20 times the slower rate and is about one twentieth the rate of activation. The development of inactivation during a single voltage-clamp step and the onset of inactivation produced by prepulses followed after brief intervals by a test pulse, have roughly similar time courses. 5. The rates of inactivation increase monotonically at potentials more positive than about -25 mV. The amount of steady-state inactivation increases with membrane depolarizations to potentials of about +50 mV. At more positive potentials, steady-state inactivation is reduced. 6. Intracellular EGTA slows the faster rate of inactivation of ICa and reduces the amount of steady-state inactivation measured with a standard two pulse protocol. The effect is specifically related to Ca chelation and hydrogen ions are not involved. This component of inactivation is referred to as Ca current-dependent inactivation and is consistent with observations that increased Cai inactivates the Ca channel. The process does not depend upon current flow alone since Ba currents of comparable or greater magnitude have smaller initial rates of inactivation. Furthermore, application of Ba ion intracellularly in large concentrations has no effect on steady-state inactivation. 7. The bi

  14. Photochemical inactivation of pathogenic bacteria in human platelet concentrates.

    Science.gov (United States)

    Lin, L; Londe, H; Janda, J M; Hanson, C V; Corash, L

    1994-05-01

    Platelet concentrates (PC) may be infrequently contaminated with low levels of bacteria that can cause septicemia and death in patients receiving transfusion therapy. We evaluated the efficacy of a photochemical decontamination (PCD) technique using 8-methoxypsoralen (8-MOP) and long wavelength UV light (UVA) to inactivate bacteria in standard therapeutic PC. Twelve phylogenetically distinct pathogenic bacteria, 5 gram-positive and 7 gram-negative organisms, were seeded into PC to a final challenge dose ranging from 10(5) to 10(7) colony-forming units (CFU)/mL. Contaminated PC were treated with 8-MOP (5 micrograms/mL) and 5 J/cm2 of UVA, a PCD treatment regimen found to adequately preserve in vitro platelet function. Greater than 10(5) CFU/mL of all 5 gram-positive (Staphylococcus aureus, Streptococcus epidermidis, Streptococcus pyogenes, Listeria monocytogenes, and Corynebacterium minutissimum) and 2 of the gram-negative (Escherichia coli and Yersinia enterocolitica) organisms were inactivated. The remaining 5 gram-negative organisms were more resistant, with less than 10(1) to 10(3.7) CFU/mL inactivated under these conditions. The inactivation efficiency for this resistant group of gram-negative organisms was improved when PC were resuspended in a synthetic storage medium with reduced plasma protein concentration (15%) and an increased 8-MOP concentration (23.4 micrograms/mL). Illumination with 3 J/cm2 of UVA in this system inactivated greater than 10(5) CFU/mL of 4 resistant gram-negative organisms (Salmonella choleraesuis, Enterobacter cloacae, Serratia marcescens, and Klebsiella pneumoniae) and 10(4.1) CFU/mL of the most resistant gram-negative organism (Pseudomonas aeruginosa). This level of PCD treatment did not adversely affect in vitro platelet function. These results demonstrate that PCD using 8-MOP (5 to 23.4 micrograms/mL) effectively inactivated high levels of pathogenic bacteria in PC with adequate preservation of in vitro platelet properties.

  15. Modeling of human factor Va inactivation by activated protein C

    Directory of Open Access Journals (Sweden)

    Bravo Maria

    2012-05-01

    Full Text Available Abstract Background Because understanding of the inventory, connectivity and dynamics of the components characterizing the process of coagulation is relatively mature, it has become an attractive target for physiochemical modeling. Such models can potentially improve the design of therapeutics. The prothrombinase complex (composed of the protease factor (FXa and its cofactor FVa plays a central role in this network as the main producer of thrombin, which catalyses both the activation of platelets and the conversion of fibrinogen to fibrin, the main substances of a clot. A key negative feedback loop that prevents clot propagation beyond the site of injury is the thrombin-dependent generation of activated protein C (APC, an enzyme that inactivates FVa, thus neutralizing the prothrombinase complex. APC inactivation of FVa is complex, involving the production of partially active intermediates and “protection” of FVa from APC by both FXa and prothrombin. An empirically validated mathematical model of this process would be useful in advancing the predictive capacity of comprehensive models of coagulation. Results A model of human APC inactivation of prothrombinase was constructed in a stepwise fashion by analyzing time courses of FVa inactivation in empirical reaction systems with increasing number of interacting components and generating corresponding model constructs of each reaction system. Reaction mechanisms, rate constants and equilibrium constants informing these model constructs were initially derived from various research groups reporting on APC inactivation of FVa in isolation, or in the presence of FXa or prothrombin. Model predictions were assessed against empirical data measuring the appearance and disappearance of multiple FVa degradation intermediates as well as prothrombinase activity changes, with plasma proteins derived from multiple preparations. Our work integrates previously published findings and through the cooperative

  16. O&P (Ova and Parasite) Test

    Science.gov (United States)

    ... States are the single-cell parasites Giardia species , Entamoeba histolytica , and Cryptosporidium species. Found throughout the world ... recreational water-related disease outbreaks in the U.S. Entamoeba histolytica is common but only causes illness in ...

  17. O&P (Ova and Parasite) Test

    Science.gov (United States)

    ... States are the single-cell parasites Giardia species , Entamoeba histolytica , and Cryptosporidium species. Found throughout the world in ... recreational water-related disease outbreaks in the U.S. Entamoeba histolytica is common but only causes illness in about ...

  18. Fast- or slow-inactivated state preference of Na+ channel inhibitors: a simulation and experimental study.

    Directory of Open Access Journals (Sweden)

    Robert Karoly

    2010-06-01

    Full Text Available Sodium channels are one of the most intensively studied drug targets. Sodium channel inhibitors (e.g., local anesthetics, anticonvulsants, antiarrhythmics and analgesics exert their effect by stabilizing an inactivated conformation of the channels. Besides the fast-inactivated conformation, sodium channels have several distinct slow-inactivated conformational states. Stabilization of a slow-inactivated state has been proposed to be advantageous for certain therapeutic applications. Special voltage protocols are used to evoke slow inactivation of sodium channels. It is assumed that efficacy of a drug in these protocols indicates slow-inactivated state preference. We tested this assumption in simulations using four prototypical drug inhibitory mechanisms (fast or slow-inactivated state preference, with either fast or slow binding kinetics and a kinetic model for sodium channels. Unexpectedly, we found that efficacy in these protocols (e.g., a shift of the "steady-state slow inactivation curve", was not a reliable indicator of slow-inactivated state preference. Slowly associating fast-inactivated state-preferring drugs were indistinguishable from slow-inactivated state-preferring drugs. On the other hand, fast- and slow-inactivated state-preferring drugs tended to preferentially affect onset and recovery, respectively. The robustness of these observations was verified: i by performing a Monte Carlo study on the effects of randomly modifying model parameters, ii by testing the same drugs in a fundamentally different model and iii by an analysis of the effect of systematically changing drug-specific parameters. In patch clamp electrophysiology experiments we tested five sodium channel inhibitor drugs on native sodium channels of cultured hippocampal neurons. For lidocaine, phenytoin and carbamazepine our data indicate a preference for the fast-inactivated state, while the results for fluoxetine and desipramine are inconclusive. We suggest that

  19. Cometabolic degradation of chlorinated solvents: Bacterial inhibition, inactivation, and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Ely, R.L.; Williamson, K.J.; Hyman, M.R.; Arp, D.J. [Oregon State Univ., Corvallis, OR (United States). Dept. of Civil Engineering

    1995-12-31

    This paper summarizes an approach for quantifying degradation kinetics and bacterial activity changes during cometabolic degradation of chlorinated solvents, results from trichloroethylene (TCE) degradation experiments, and a mathematical model addressing fluctuations in activity caused by enzyme inhibition, inactivation, and respondent enzyme synthesis. Using Nitrosomonas duropaea as a slow-growing exemplar capable of effecting cometabolic transformations, quasi-steady-state ammonia oxidation was established in a small bioreactor. A chlorinated solvent was injected to perturb the system, and bacterial activity and solvent degradation were monitored. At TCE concentrations to about 3.5 mg/L, from slight to nearly complete ammonia monooxygenase (AMO) inactivation occurred without causing immediate cell death. Results suggested cellular injury was limited primarily to AMO, most metabolic systems remained functional, and bacterial recovery processes, independent of cell growth, were initiated while degrading TCE.

  20. Polio endgame: the global introduction of inactivated polio vaccine.

    Science.gov (United States)

    Patel, Manish; Zipursky, Simona; Orenstein, Walt; Garon, Julie; Zaffran, Michel

    2015-05-01

    In 2013, the World Health Assembly endorsed a plan that calls for the ultimate withdrawal of oral polio vaccines (OPV) from all immunization programs globally. The withdrawal would begin in a phased manner with removal of the type 2 component of OPV in 2016 through a global switch from trivalent OPV to bivalent OPV (containing only types 1 and 3). To mitigate risks associated with immunity gaps after OPV type 2 withdrawal, the WHO Strategic Advisory Group of Experts has recommended that all 126 OPV-only using countries introduce at least one dose of inactivated polio vaccine into routine immunization programs by end-2015, before the trivalent OPV-bivalent OPV switch. The introduction of inactivated polio vaccine would reduce risks of reintroduction of type 2 poliovirus by providing some level of seroprotection, facilitating interruption of transmission if outbreaks occur, and accelerating eradication by boosting immunity to types 1 and 3 polioviruses.

  1. [Survey on Schistosomes of man and livestock in Senegal using specific identification given by chetotaxy of cercaria. I. New arguments for the validation of S. curassoni Brumpt, 1931, parasite of man and domestic Bovidae].

    Science.gov (United States)

    Albaret, J L; Picot, H; Diaw, O T; Bayssade-Dufour, C; Vassiliades, G; Adamson, M; Luffau, G; Chabaud, A G

    1985-01-01

    Study of Senegal cercariae emitted by naturally infected snails or by snails experimentally infected using eggs from human urine or from sheep liver, and study of the corresponding eggs. The relative position of the dorsal sensillae of cercariae is described by an "AD index" and the ratio length/width of eggs by an "L/l index." At the present time, we have not finished the epidemiological studies, certain experiments are imperfect and the isoenzyme analysis of the corresponding adults is incomplete. Nevertheless information given by the indices AD and L/l agree and lead us to admit the existence of a Schistosome different to mattheei, haematobium and bovis and which, following Brumpt and Gretillat we refer to as Schistosoma curassoni. If one relies on the indices, the study indicates that: a) S. mattheei has not been found in Senegal, b) S. bovis is quite rare, c) S. haematobium apparently exists in pure infections in Casamance and in mixed infections with S. curassoni in man in the north and in the east, d) S. curassoni is apparently the dominant species in domestic ruminants and in man in the north and in the east, e) Bulinus umbilicatus is the principal vector of S. curassoni and S. haematobium.

  2. Lesions of the enteric nervous system and the possible role of mast cells in the pathogenic mechanisms of migration of schistosome eggs in the small intestine of cattle during Schistosoma bovis infection.

    Science.gov (United States)

    Balemba, O B; Mbassa, G K; Assey, R J; Kahwa, C K; Makundi, A E; Hay-Schmidt, A; Dantzer, V; Semuguruka, W D

    2000-06-10

    The enteric nervous system in the small intestine of cattle during Schistosoma bovis infection was studied by histological stains and immunohistochemical methods. Lesions due to migration of schistosoma eggs were located mainly in the mucous and the submucous layer overlaying the submucous vascular arcades. Granulomas destroyed ganglia, neurons, nerves fibre strands and nerve fibres. Ganglia situated within or near granulomas were infiltrated by mast cells, eosinophils, lymphocytes, globule leukocytes, neutrophils and macrophages. Mast cells were in close contact with degenerating neuronal perikarya. Whereas vasoactive intestinal peptide-like immunoreactivity in the nerves and neurons in the ganglia within and around granulomas was increased, the neurofilament-like immunoreactivity was reduced. Compared to the myenteric and external submucous plexuses, the internal submucous and mucous plexuses were the most damaged. These changes imply reduced functional capacity in the nervous tissue which might cause reduced motility, malabsorption and partly account for the loss of body weight and condition and failure to thrive which occur in schistosomosis. Biotinylated affinity purified swine anti-rabbit and mouse anti-rabbit immunoglobulins reacted nonspecifically with a subset of mast cells. The reaction revealed many mast cells in early forming granulomas and around schistosome egg tracts and infiltration of mast cells into the ganglia of intestinal nerve plexuses. The observation shows a localized, Type I hypersensitivity reaction suggesting for the release of mast cell-derived chemical mediators in the intestinal reaction to trap or evict S. bovis eggs and to cause diarrhoea.

  3. Nonthermal Plasma Inactivation of Food-Borne Pathogens

    OpenAIRE

    Misra, N.; Tiwari, B.; Rahavarao, K.; Cullen, Patrick

    2011-01-01

    Non-thermal plasma (NTP) is electrically energized matter, composed of highly reactive species including gas molecules, charged particles in the form of positive ions, negative ions, free radicals, electrons and quanta of electromagnetic radiation (photons) at near-room temperature. NTP is an emerging nonthermal technology with potential applications for decontamination in the food industries. An upsurge in the research activities for plasma based inactivation of food borne pathogens is evide...

  4. Inactivation of norovirus on dry copper alloy surfaces.

    Science.gov (United States)

    Warnes, Sarah L; Keevil, C William

    2013-01-01

    Noroviruses (family Caliciviridae) are the primary cause of viral gastroenteritis worldwide. The virus is highly infectious and touching contaminated surfaces can contribute to infection spread. Although the virus was identified over 40 years ago the lack of methods to assess infectivity has hampered the study of the human pathogen. Recently the murine virus, MNV-1, has successfully been used as a close surrogate. Copper alloys have previously been shown to be effective antimicrobial surfaces against a range of bacteria and fungi. We now report rapid inactivation of murine norovirus on alloys, containing over 60% copper, at room temperature but no reduction of infectivity on stainless steel dry surfaces in simulated wet fomite and dry touch contamination. The rate of inactivation was initially very rapid and proportional to copper content of alloy tested. Viral inactivation was not as rapid on brass as previously observed for bacteria but copper-nickel alloy was very effective. The use of chelators and quenchers of reactive oxygen species (ROS) determined that Cu(II) and especially Cu(I) ions are still the primary effectors of toxicity but quenching superoxide and hydroxyl radicals did not confer protection. This suggests Fenton generation of ROS is not important for the inactivation mechanism. One of the targets of copper toxicity was the viral genome and a reduced copy number of the gene for a viral encoded protein, VPg (viral-protein-genome-linked), which is essential for infectivity, was observed following contact with copper and brass dry surfaces. The use of antimicrobial surfaces containing copper in high risk closed environments such as cruise ships and care facilities could help to reduce the spread of this highly infectious and costly pathogen.

  5. Drying of liquid food droplets : enzyme inactivation and multicomponent diffusion

    OpenAIRE

    Meerdink, G.

    1993-01-01

    In this thesis the drying of liquid food droplets is studied from three different points of view: drying kinetics, enzyme inactivation and multicomponent diffusion. Mathematical models are developed and validated experimentally.

    Drying experiments are performed with suspended droplets and with free falling droplets under spray-drying conditions. The experiments with the free falling droplets are performed in a specially designed drying tower using a resonance nozzle. The reso...

  6. Thermal inactivation of eight Salmonella serotypes on dry corn flour.

    OpenAIRE

    VanCauwenberge, J E; Bothast, R J; Kwolek, W F

    1981-01-01

    Dry heat was used to inactivate Salmonella newington, Salmonella typhimurium, Salmonella anatum, Salmonella kentucky, Salmonella cubana, Salmonella seftenberg, Salmonella thompson, and Salmonella tennessee in corn flour at 10 and 15% moisture. The flour was spray inoculated at 10(5) Salmonella cells per g and then stored at 49 degrees C (120 degrees F); viable Salmonella cells were counted on Trypticase (BBL Microbiology Systems) soy agar plates every 30 min for the first 4 h and then at 4-h ...

  7. Mechanism for Mutational Inactivation of the Tumor Suppressor Smad2

    OpenAIRE

    Prunier, Celine; Ferrand, Nathalie; Frottier, Bertrand; Pessah, Marcia; Atfi, Azeddine

    2001-01-01

    Transforming growth factor β (TGF-β) is a potent natural antiproliferative agent that plays an important role in suppressing tumorigenicity. In numerous tumors, loss of TGF-β responsiveness is associated with inactivating mutations that can occur in components of this signaling pathway, such as the tumor suppressor Smad2. Although a general framework for how Smads transduce TGF-β signals has been proposed, the physiological relevance of alterations of Smad2 functions in promoting tumorigenesi...

  8. Significance of cobalamin inactivation in normal and malignant hematopoiesis

    OpenAIRE

    Ermens, Anton

    1990-01-01

    textabstractThis thesis deals with several aspects of the effects of cobalamin inactivation by nitrous oxide on cellular folate metabolism and the consequences on normal and malignant hematopoiesis. Kroes et al. demonstrated the antileukemic effects of nitrous oxide either or not in combination with other drugs interfering with the folate metabolism (132-136). Especially the potentiation of methotrexate activity in the employed rat model for myeloid leukemia (BNML) after preexposure to nitrou...

  9. The efficacy of preservation methods to inactivate foodborne viruses.

    Science.gov (United States)

    Baert, L; Debevere, J; Uyttendaele, M

    2009-05-31

    During the last decade an increased incidence of infections and outbreaks attributed to foodborne viruses, in particular noroviruses (NoV), was observed world wide. The awareness of the presence of viruses on food emphasized the need to acquire knowledge regarding the effect of preservation methods upon viruses. Most foodborne viruses cannot be cultured in the laboratory, which hinders studies of their stability in food. Cultivable surrogate viruses, genetically related to the human infecting strains, are taken as a substitute to define inactivation rates. The last years, the number of survival and inactivation studies using various surrogate viruses increased. In this review, state-of-the-art information regarding the efficacy of preservation methods to reduce the level of viruses on food is compiled. In the first place, the effect of preservation methods establishing microbial growth inhibition (chilling, freezing, acidification, reduced water activity and modified atmosphere packaging) upon foodborne viruses is described. Secondly, the use of preservation methods establishing microbial inactivation such as heat treatment, high hydrostatic pressure processing and irradiation to eliminate viruses is discussed. In the third place, the efficacy of decontamination methods on fresh produce and purification procedures applied on live bivalve shellfish to reduce the viral load is included. These studies indicate that viruses persist well on chilled, acidified, frozen foods and foods packed under modified atmosphere or in dried conditions. Intervention strategies inducing microbial inactivation are required to achieve a 3 log reduction of the level of viruses. Decontamination of fresh produce reduces viruses with a maximum of 1 to 2 log while purification of live bivalves is not adequate to prevent viral outbreaks. It was noted that the effect of a particular food preservation method is dependent upon the virus tested and type of food.

  10. Patulin reduction in apple juice by inactivated Alicyclobacillus spp.

    Science.gov (United States)

    Yuan, Y; Wang, X; Hatab, S; Wang, Z; Wang, Y; Luo, Y; Yue, T

    2014-12-01

    This study aimed to investigate the reduction of patulin (PAT) in apple juice by 12 inactivated Alicyclobacillus strains. The reduction rate of PAT by each strain was determined by high-performance liquid chromatography (HPLC). The results indicated that the removal of PAT was strain specific. Alicyclobacillus acidoterrestris 92 and A. acidoterrestris 96 were the most effective ones among the 12 tested strains in the removal of PAT. Therefore, these two strains were selected to study the effects of incubation time, initial PAT concentration and bacteria powder amount on PAT removal abilities of Alicyclobacillus. The highest PAT reduction rates of 88·8 and 81·6% were achieved after 24-h incubation with initial PAT concentration of 100 μg l(-1) and bacteria powder amount of 40 g l(-1) , respectively. Moreover, it was found that the treatment by these 12 inactivated Alicyclobacillus strains had no negative effect on the quality parameters of apple juice. Similar assays were performed in supermarket apple juice, where inactivated Alicyclobacillus cells could efficiently reduce PAT content. Taken together, these data suggest the possible application of this strategy as a means to detoxify PAT-contaminated juices. Inactivated Alicyclobacillus cells can efficiently reduce patulin concentration in apple juice. It provides a theoretical foundation for recycling of Alicyclobacillus cells from spoiled apple juice to reduce the source of pollution and the cost of juice industry. This is the first report on the use of Alicyclobacillus to remove patulin from apple juice. © 2014 The Society for Applied Microbiology.

  11. Inactivation of murine norovirus by chemical biocides on stainless steel

    Directory of Open Access Journals (Sweden)

    Steinmann Jörg

    2009-07-01

    Full Text Available Abstract Background Human norovirus (NoV causes more than 80% of nonbacterial gastroenteritis in Europe and the United States. NoV transmission via contaminated surfaces may be significant for the spread of viruses. Therefore, measures for prevention and control, such as surface disinfection, are necessary to interrupt the dissemination of human NoV. Murine norovirus (MNV as a surrogate for human NoV was used to study the efficacy of active ingredients of chemical disinfectants for virus inactivation on inanimate surfaces. Methods The inactivating properties of different chemical biocides were tested in a quantitative carrier test with stainless steel discs without mechanical action. Vacuum-dried MNV was exposed to different concentrations of alcohols, peracetic acid (PAA or glutaraldehyde (GDA for 5 minutes exposure time. Detection of residual virus was determined by endpoint-titration on RAW 264.7 cells. Results PAA [1000 ppm], GDA [2500 ppm], ethanol [50% (v/v] and 1-propanol [30% (v/v] were able to inactivate MNV under clean conditions (0.03% BSA on the carriers by ≥ 4 log10 within 5 minutes exposure time, whereas 2-propanol showed a reduced effectiveness even at 60% (v/v. Furthermore, there were no significant differences in virus reduction whatever interfering substances were used. When testing with ethanol, 1- and 2-propanol, results under clean conditions were nearly the same as in the presence of dirty conditions (0.3% BSA plus 0.3% erythrocytes. Conclusion Products based upon PAA, GDA, ethanol and 1-propanol should be used for NoV inactivation on inanimate surfaces. Our data provide valuable information for the development of strategies to control NoV transmission via surfaces.

  12. Inactivation of Bacillus Anthracis Spores Using Carbon Nanotubes

    Science.gov (United States)

    2014-10-30

    AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6. AUTHORS 7. PERFORMING ORGANIZATION NAMES AND ADDRESSES 15. SUBJECT...2010 31-May-2014 Approved for Public Release; Distribution Unlimited Final Report: (Life Science Division/Biochemistry) Inactivation of Bacillus ...S) AND ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Bacillus Anthracis, Spores, Biofilm, Inhibition

  13. Inactivation of norovirus on dry copper alloy surfaces.

    Directory of Open Access Journals (Sweden)

    Sarah L Warnes

    Full Text Available Noroviruses (family Caliciviridae are the primary cause of viral gastroenteritis worldwide. The virus is highly infectious and touching contaminated surfaces can contribute to infection spread. Although the virus was identified over 40 years ago the lack of methods to assess infectivity has hampered the study of the human pathogen. Recently the murine virus, MNV-1, has successfully been used as a close surrogate. Copper alloys have previously been shown to be effective antimicrobial surfaces against a range of bacteria and fungi. We now report rapid inactivation of murine norovirus on alloys, containing over 60% copper, at room temperature but no reduction of infectivity on stainless steel dry surfaces in simulated wet fomite and dry touch contamination. The rate of inactivation was initially very rapid and proportional to copper content of alloy tested. Viral inactivation was not as rapid on brass as previously observed for bacteria but copper-nickel alloy was very effective. The use of chelators and quenchers of reactive oxygen species (ROS determined that Cu(II and especially Cu(I ions are still the primary effectors of toxicity but quenching superoxide and hydroxyl radicals did not confer protection. This suggests Fenton generation of ROS is not important for the inactivation mechanism. One of the targets of copper toxicity was the viral genome and a reduced copy number of the gene for a viral encoded protein, VPg (viral-protein-genome-linked, which is essential for infectivity, was observed following contact with copper and brass dry surfaces. The use of antimicrobial surfaces containing copper in high risk closed environments such as cruise ships and care facilities could help to reduce the spread of this highly infectious and costly pathogen.

  14. Degradation and inactivation of Shiga toxins by nitrogen gas plasma.

    Science.gov (United States)

    Sakudo, Akikazu; Imanishi, Yuichiro

    2017-12-01

    Shiga toxin (Stx)-producing Escherichia coli (STEC) leads to food poisoning by causing hemorrhagic colitis and hemolytic uremic syndrome. Some STEC produce Shiga toxin 1 (Stx1) and/or Shiga toxin 2 (Stx2), a relatively stable protein toxin, necessitating the development of an efficient inactivation method. Here we applied a nitrogen gas plasma apparatus to the inactivation of Stx. Samples of Stx1 and Stx2 were treated with a nitrogen gas plasma generated by a plasma device using a short high-voltage pulse applied by a static induction thyristor power supply at 1.5 kpps (kilo pulse per second). The recovered Stx samples were then analyzed for immunological and biological activities. Immunochromatography demonstrated that Stx1 and Stx2 were degraded by the gas plasma. Quantification by enzyme-linked immunosorbent assay (ELISA) showed that both toxins were efficiently degraded to less than 1/10th of their original concentration within 5 min of treatment. Western blotting further showed the gas plasma treatment degraded the A subunit, which mediates the toxicity of Stx. Moreover, an assay using HEp-2 cells as an index of cytotoxicity showed that gas plasma treatment reduced the toxic activity of Stx. Therefore, nitrogen gas plasma might be an efficient method for the inactivation of Stx.

  15. Influenza Vaccination Strategies: Comparing Inactivated and Live Attenuated Influenza Vaccines

    Science.gov (United States)

    Sridhar, Saranya; Brokstad, Karl A.; Cox, Rebecca J.

    2015-01-01

    Influenza is a major respiratory pathogen causing annual outbreaks and occasional pandemics. Influenza vaccination is the major method of prophylaxis. Currently annual influenza vaccination is recommended for groups at high risk of complications from influenza infection such as pregnant women, young children, people with underlying disease and the elderly, along with occupational groups such a healthcare workers and farm workers. There are two main types of vaccines available: the parenteral inactivated influenza vaccine and the intranasal live attenuated influenza vaccine. The inactivated vaccines are licensed from 6 months of age and have been used for more than 50 years with a good safety profile. Inactivated vaccines are standardized according to the presence of the viral major surface glycoprotein hemagglutinin and protection is mediated by the induction of vaccine strain specific antibody responses. In contrast, the live attenuated vaccines are licensed in Europe for children from 2–17 years of age and provide a multifaceted immune response with local and systemic antibody and T cell responses but with no clear correlate of protection. Here we discuss the immunological immune responses elicited by the two vaccines and discuss future work to better define correlates of protection. PMID:26343192

  16. Raman spectroscopy of Bacillus thuringiensis physiology and inactivation

    Science.gov (United States)

    Morrow, J. B.; Almeida, J.; Cole, K. D.; Reipa, V.

    2012-12-01

    The ability to detect spore contamination and inactivation is relevant to developing and determining decontamination strategy success for food and water safety. This study was conducted to develop a systematic comparison of nondestructive vibrational spectroscopy techniques (Surface-Enhanced Raman Spectroscopy, SERS, and normal Raman) to determine indicators of Bacillus thuringiensis physiology (spore, vegetative, outgrown, germinated and inactivated spore forms). SERS was found to provide better resolution of commonly utilized signatures of spore physiology (dipicolinic acid at 1006 cm-1 and 1387 cm-1) compared to normal Raman and native fluorescence indigenous to vegetative and outgrown cell samples was quenched in SERS experiment. New features including carotenoid pigments (Raman features at 1142 cm-1, 1512 cm-1) were identified for spore cell forms. Pronounced changes in the low frequency region (300 cm-1 to 500 cm-1) in spore spectra occurred upon germination and inactivation (with both free chlorine and by autoclaving) which is relevant to guiding decontamination and detection strategies using Raman techniques.

  17. Pulsed light inactivation of horseradish peroxidase and associated structural changes.

    Science.gov (United States)

    Pellicer, José Antonio; Gómez-López, Vicente M

    2017-12-15

    Pulsed light (PL) is a non-thermal preservation method in which foods are subjected to one or several intense pulses of wide-spectrum light. Peroxidase (POD) is an enzyme that needs to be inactivated or inhibited because of its deleterious effects on the quality of fruits and vegetables. The feasibility of using PL to inactivate POD was tested and results explained based on measurements of UV-vis spectrum, far-UV circular dichroism and tryptophan fluorescence, and the phase-diagram method. PL reduced the activity of POD by more than 95% after applying 128Jcm -2 . There was observed a decrease in the Reinheitzahl value and ellipticity and an increase in tryptophan fluorescence at incremental fluences, as well as linear phase diagrams. The study indicates that the inactivation of POD by PL is an all-or-none process related to loss of helical structure, weak unfolding and ejection of the prostetic group. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Photosensitized inactivation of infectious blood-borne human parasites

    Science.gov (United States)

    Judy, Millard M.; Sogandares-Bernal, Franklin M.; Matthews, James Lester

    1995-05-01

    Blood-borne viruses and protozoan parasites that are infectious to humans pose risk world-wide of infection transmission through blood and blood product transfusion. Blood-borne infectious viruses include human immunodeficiency virus (HIV-I), which causes AIDS; hepatitis C virus, which can cause chronic hepatitis; and cytomegalovirus, which can be dangerous to immunocompromised patients, e.g., the newborn, transplant recipients, and AIDS patients. Infectious blood-borne protozoan parasites include Trypanosoma cruzi, which causes Chagas' disease, endemic throughout Central and South America; the Trypanosoma species causing African sleeping sickness endemic in Central Africa; and Plasmodium falciparum, which causes malignant and increasingly drug- resistant human malaria prevalent throughout the tropics. Some researchers have focused on using photosensitizers to inactivate HIV-I and other viruses in whole blood, packed red cells, and platelet concentrates without compromising blood product function. Our group previously has reported photosensitized in vitro inactivation of P. falciparum and the mouse malaria organism Plasmodium berghei in whole blood using hematoporphyrin derivative (HPD) and of T. cruzi using benzoporphyrin derivatives BPDMA and BPDDA, dihematoporphyrin ether (DHE), and hydroxyethylvinyldeuteroporphyrin (HEVD). These results suggest that continued investigation is warranted to evaluate the potential for photosensitized inactivation of blood-borne parasites in blood banking.

  19. Influenza Vaccination Strategies: Comparing Inactivated and Live Attenuated Influenza Vaccines

    Directory of Open Access Journals (Sweden)

    Saranya Sridhar

    2015-04-01

    Full Text Available Influenza is a major respiratory pathogen causing annual outbreaks and occasional pandemics. Influenza vaccination is the major method of prophylaxis. Currently annual influenza vaccination is recommended for groups at high risk of complications from influenza infection such as pregnant women, young children, people with underlying disease and the elderly, along with occupational groups such a healthcare workers and farm workers. There are two main types of vaccines available: the parenteral inactivated influenza vaccine and the intranasal live attenuated influenza vaccine. The inactivated vaccines are licensed from 6 months of age and have been used for more than 50 years with a good safety profile. Inactivated vaccines are standardized according to the presence of the viral major surface glycoprotein hemagglutinin and protection is mediated by the induction of vaccine strain specific antibody responses. In contrast, the live attenuated vaccines are licensed in Europe for children from 2–17 years of age and provide a multifaceted immune response with local and systemic antibody and T cell responses but with no clear correlate of protection. Here we discuss the immunological immune responses elicited by the two vaccines and discuss future work to better define correlates of protection.

  20. Thermal inactivation kinetics of hepatitis A virus in spinach.

    Science.gov (United States)

    Bozkurt, Hayriye; Ye, Xiaofei; Harte, Federico; D'Souza, Doris H; Davidson, P Michael

    2015-01-16

    Leafy vegetables have been recognized as important vehicles for the transmission of foodborne viral pathogens. To control hepatitis A viral foodborne illness outbreaks associated with mildly heated (e.g., blanched) leafy vegetables such as spinach, generation of adequate thermal processes is important both for consumers and the food industry. Therefore, the objectives of this study were to determine the thermal inactivation behavior of hepatitis A virus (HAV) in spinach, and provide insights on HAV inactivation in spinach for future studies and industrial applications. The D-values calculated from the first-order model (50-72 °C) ranged from 34.40 ± 4.08 to 0.91 ± 0.12 min with a z-value of 13.92 ± 0.87 °C. The calculated activation energy value was 162 ± 11 kJ/mol. Using the information generated in the present study and the thermal parameters of industrial blanching conditions for spinach as a basis (100 °C for 120-180 s), the blanching of spinach in water at 100 °C for 120-180 s under atmospheric conditions will provide greater than 6 log reduction of HAV. The results of this study may be useful to the frozen food industry in designing blanching conditions for spinach to inactivate or control hepatitis A virus outbreaks. Copyright © 2014. Published by Elsevier B.V.

  1. Method for flow cytometric monitoring of Renibacterium salmoninarum inactivation

    Science.gov (United States)

    Pascho, R.J.; Ongerth, J.E.

    2000-01-01

    The slow growth of Renibacterium salmoninarum limits the usefulness of culture as a research tool. Development of a 2-color flow cytometric assay to quantify the proportions of live and dead R. salmoninarum in a test population is described. Bacteria were simultaneously stained with fluorescein isothiocyanate-conjugated immunoglobulin and exposed to the exclusion dye propidium iodide. Propidium iodide red fluorescence profiles of control groups of untreated and killed R. salmoninarum were compared with those for bacteria exposed to chlorine. Bacterial inactivation was based on mean red fluorescence intensity, and analyzed by high-red fluorescence intensity (HRFI) and curve subtraction (CS) analyses. When the concentration of R. salmoninarum was 8.65 x 106 bacteria ml-1 and the bacteria exposed to chlorine at 1 mg l-1 for periods from 1 to 20 min (high-Rs assessment), the mean red fluorescence intensity of the profile for each chlorine-exposure group was higher than that for the untreated control (p mean red fluorescence intensities of the exposure groups were higher than that for the untreated control only when the R. salmoninarum was exposed to chlorine for at least 1 min (p ??? 0.01). On the basis of red fluorescence intensity, the proportion of dead cells generally increased with the duration of chlorine exposure. Whereas the rates of inactivation derived from the HRFI and CS analyses did not correlate with the duration of exposure in the high-Rs assessment (r2 ??? 0.27), there was a correlation between these estimates and the duration of exposure in the reduced-Rs assessment (r2 ??? 0.92). Because of the rapid loss of culturable R. salmoninarum in both assessments following chlorine exposure, neither the duration of exposure nor the inactivation estimates correlated with bacteriological culture (r2 ??? 0.22). In both assessments, there was a correlation between the estimates of inactivation based upon HRFI and CS analyses (r2 > 0.99). These results suggest that

  2. Inactivation of B. subtilis spores by low pressure plasma—influence of optical filters and photon/particle fluxes on the inactivation efficiency

    Science.gov (United States)

    Fiebrandt, Marcel; Hillebrand, Bastian; Lackmann, Jan-Wilm; Raguse, Marina; Moeller, Ralf; Awakowicz, Peter; Stapelmann, Katharina

    2018-01-01

    Inactivation experiments were performed with Bacillus subtilis spores in a low pressure double inductively coupled plasma (DICP) system. Argon, nitrogen and oxygen at 5 Pa were used as feed gas to change the emission spectrum in the range of 100 nm to 400 nm, as well as between radical and metastable densities. Optical filters were applied, to block particles and selected wavelengths from the spores. By determining absolute photon fluxes, the sporicidal efficiency of various wavelength ranges was evaluated. The results showed good agreement with other plasma experiments, as well as with monochromatic light inactivation experiments from a synchrotron. The findings indicated that the inactivation rate constants of broadband plasma emission and monochromatic light were identical, and that no synergistic effect exists. Furthermore, the influence of radicals, ions and metastables on the inactivation efficiency was of minor importance in the set-up used, and radiation was the main reason for spore inactivation.

  3. Influence of activation and germination on high pressure inactivation of ascospores of the mould Eurotium repens.

    Science.gov (United States)

    Eicher, R; Ludwig, H

    2002-03-01

    We investigated heat activation and germination of Eurotium repens ascospores to follow high pressure inactivation. Activation energy and entropy values strengthen the idea of protein denaturation as the underlying mechanism of heat activation. Preceding activation, germination or a combination of both affected high pressure inactivation in different ways. Activation followed immediately by high pressure treatment led to the most efficient improvement in inactivation. However, a pause after activation caused a partial re-establishment of the spores' stability and less efficient high pressure inactivation. Germination stabilized the spores against high pressure. A combined treatment of activation and germination led to an initially fast inactivation, but compared to high pressure treatment of only activated spores the time course of inactivation was slowed down.

  4. A mutation in segment I-S6 alters slow inactivation of sodium channels.

    Science.gov (United States)

    Wang, S Y; Wang, G K

    1997-01-01

    Slow inactivation occurs in voltage-gated Na+ channels when the membrane is depolarized for several seconds, whereas fast inactivation takes place rapidly within a few milliseconds. Unlike fast inactivation, the molecular entity that governs the slow inactivation of Na+ channels has not been as well defined. Some regions of Na+ channels, such as mu1-W402C and mu1-T698M, have been reported to affect slow inactivation. A mutation in segment I-S6 of mu1 Na+ channels, N434A, shifts the voltage dependence of activation and fast inactivation toward the depolarizing direction. The mutant Na+ current at +50 mV is diminished by 60-80% during repetitive stimulation at 5 Hz, resulting in a profound use-dependent phenomenon. This mutant phenotype is due to the enhancement of slow inactivation, which develops faster than that of wild-type channels (tau = 0.46 +/- 0.01 s versus 2.11 +/- 0.10 s at +30 mV, n = 9). An oxidant, chloramine-T, abolishes fast inactivation and yet greatly accelerates slow inactivation in both mutant and wild-type channels (tau = 0.21 +/- 0.02 s and 0.67 +/- 0.05 s, respectively, n = 6). These findings together demonstrate that N434 of mu1 Na+ channels is also critical for slow inactivation. We propose that this slow form of Na+ channel inactivation is analogous to the "C-type" inactivation in Shaker K+ channels. PMID:9083667

  5. Inhibition of bone resorption by selective inactivators of cysteine proteinases.

    Science.gov (United States)

    Hill, P A; Buttle, D J; Jones, S J; Boyde, A; Murata, M; Reynolds, J J; Meikle, M C

    1994-09-01

    Inactivators of cysteine proteinases (CPs) were tested as inhibitors of bone resorption in vitro and in vivo. The following four CP inactivators were tested: Ep475, a compound with low membrane permeability which inhibits cathepsins B, L, S, H, and calpain; Ep453, the membrane-permeant prodrug of Ep475; CA074, a compound with low membrane permeability which selectively inactivates cathepsin B; and CA074Me, the membrane-permeant prodrug of CA074. The test systems consisted of 1) monitoring the release of radioisotope from prelabelled mouse calvarial explants and 2) assessing the extent of bone resorption in an isolated osteoclast assay using confocal laser microscopy. Ep453, Ep475, and CA074Me inhibited both stimulated and basal bone resorption in vitro while CA074 was without effect; the inhibition was reversible and dose dependent. None of the inhibitors affected protein synthesis, DNA synthesis, the PTH-enhanced secretion of beta-glucuronidase, and N-acetyl-beta-glucosaminidase, or the spontaneous release of lactate dehydrogenase. Ep453, Ep475, and CA074Me dose-dependently inhibited the resorptive activity of isolated rat osteoclasts cultured on bone slices with a maximal effect at 50 microM. The number of resorption pits and their mean volume was reduced, whilst the mean surface area remained unaffected. Again, CA074 was without effect. Ep453, Ep475, and CA074Me, but not CA074, when administered subcutaneously at a dose of 60 micrograms/g body weight inhibited bone resorption in vivo as measured by an in vivo/in vitro assay, by about 20%. This study demonstrates that cathepsins B, L, and/or S are involved in bone resorption in vitro and in vivo. Whilst cathepsin L and/or S act extracellularly, and possibly intracellularly, cathepsin B mediates its effects intracellularly perhaps through the activation of other proteinases involved in subosteoclastic collagen degradation.

  6. Inactivation of foodborne microorganisms using engineered water nanostructures (EWNS).

    Science.gov (United States)

    Pyrgiotakis, Georgios; Vasanthakumar, Archana; Gao, Ya; Eleftheriadou, Mary; Toledo, Eduardo; DeAraujo, Alice; McDevitt, James; Han, Taewon; Mainelis, Gediminas; Mitchell, Ralph; Demokritou, Philip

    2015-03-17

    Foodborne diseases caused by the consumption of food contaminated with pathogenic microorganisms or their toxins have very serious economic and public health consequences. Here, we explored the effectiveness of a recently developed intervention method for inactivation of microorganisms on fresh produce, and food production surfaces. This method utilizes Engineered Water Nanostructures (EWNS) produced by electrospraying of water vapor. EWNS possess unique properties; they are 25 nm in diameter, remain airborne in indoor conditions for hours, contain Reactive Oxygen Species (ROS) and have very strong surface charge (on average 10 e/structure). Here, their efficacy in inactivating representative foodborne bacteria such as Escherichia coli, Salmonella enterica, and Listeria innocua, on stainless steel surfaces and on organic tomatoes, was assessed. The inactivation was facilitated using two different exposure approaches in order to optimize the delivery of EWNS to bacteria: (1) EWNS were delivered on the surfaces by diffusion and (2) a "draw through" Electrostatic Precipitator Exposure System (EPES) was developed and characterized for EWNS delivery to surfaces. Using the diffusion approach and an EWNS concentration of 24,000 #/cm3, the bacterial concentrations on the surfaces were reduced, depending on the bacterium and the surface type, by values ranging between 0.7 to 1.8 logs. Using the EPES approach and for an aerosol concentration of 50,000 #/cm3 at 90 min of exposure, results show a 1.4 log reduction for E. coli on organic tomato surfaces, as compared to the control (same conditions in regards to temperature and Relative Humidity). Furthermore, for L. innocua, the dose-response relationship was demonstrated and found to be a 0.7 and 1.2 logs removal at 12,000 and 23,000 #/cm3, respectively. The results presented here indicate that this novel, chemical-free, and environmentally friendly intervention method holds potential for development and application in the

  7. Inactivation of Salmonella during cocoa roasting and chocolate conching.

    Science.gov (United States)

    Nascimento, Maristela da Silva do; Brum, Daniela Merlo; Pena, Pamela Oliveira; Berto, Maria Isabel; Efraim, Priscilla

    2012-10-15

    The high heat resistance of Salmonella in foods with low water activity raises particular issues for food safety, especially chocolate, where outbreak investigations indicate that few colony-forming units are necessary to cause salmonellosis. This study evaluated the efficiency of cocoa roasting and milk chocolate conching in the inactivation of Salmonella 5-strain suspension. Thermal resistance of Salmonella was greater in nibs compared to cocoa beans upon exposure at 110 to 130°C. The D-values in nibs were 1.8, 2.2 and 1.5-fold higher than those calculated for cocoa beans at 110, 120 and 130°C. There was no significant difference (p>0.05) between the matrices only at 140°C. Since in the conching of milk chocolate the inactivation curves showed rapid death in the first 180 min followed by a lower inactivation rate, and two D-values were calculated. For the first time interval (0-180 min) the D-values were 216.87, 102.27 and 50.99 min at 50, 60 and 70°C, respectively. The other D-values were determined from the second time interval (180-1440 min), 1076.76 min at 50°C, 481.94 min at 60°C and 702.23 min at 70°C. The results demonstrated that the type of matrix, the process temperature and the initial count influenced the Salmonella resistance. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Combination of endolysins and high pressure to inactivate Listeria monocytogenes.

    Science.gov (United States)

    van Nassau, Tomas J; Lenz, Christian A; Scherzinger, Anna S; Vogel, Rudi F

    2017-12-01

    Outbreaks of listeriosis are often related to the consumption of low-processed ready-to-eat food products (e.g. soft cheeses or smoked fish) contaminated with Listeria monocytogenes. Traditional preservation techniques, such as heat treatment, cannot eliminate Listeria from these products without strongly affecting the quality of the foods. We therefore investigated the use of endolysin (PlyP40, Ply511, or PlyP825) in combination with high hydrostatic pressure processing to kill L. monocytogenes in buffer. The results demonstrated a more than additive effect when both treatments were combined. For example, whereas 0.16 μg/mL PlyP825 or 300 MPa (1 min, 30 °C) applied individually reduced the cell count by 0.2 and 0.3 log cfu, respectively, a combined treatment resulted in a reduction of 5.5 log cfu. Similar results were obtained for the other endolysins combined with high pressure processing. We also showed that the synergistic inactivation of cells by endolysin and HHP is possible at a pressure level of only 200 MPa (2 min, 30 °C). Thus, the application of endolysins did not only substantially increase the bactericidal effect of high pressure, but it also enabled the inactivation of bacterial cells at much lower pressure levels. This shows the potential of using such combined processes for the inactivation of L. monocytogenes and food preservation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Inactivation of porcine epidemic diarrhea virus using heated water

    Directory of Open Access Journals (Sweden)

    Michele M. Zentkovich

    2016-12-01

    Full Text Available Porcine epidemic diarrhea virus (PEDV is a very contagious swine pathogen that spreads easily via the fecal-oral route, notably from contaminated fomites. The present study investigated heated water as a method for rapid thermal inactivation of PEDV. Cell-culture adapted PEDV was treated with water at varying temperatures and viral titers were measured at multiple time points post-treatment. Viable PEDV was not recovered after a ten second or longer treatment with water heated to ≥76 °C; however, PEDV nucleic acid was detected in all samples regardless of treatment. Hot water decontamination could be considered in settings where chemical disinfection is impractical.

  10. Inactivation of Prions and Amyloid Seeds with Hypochlorous Acid.

    Directory of Open Access Journals (Sweden)

    Andrew G Hughson

    2016-09-01

    Full Text Available Hypochlorous acid (HOCl is produced naturally by neutrophils and other cells to kill conventional microbes in vivo. Synthetic preparations containing HOCl can also be effective as microbial disinfectants. Here we have tested whether HOCl can also inactivate prions and other self-propagating protein amyloid seeds. Prions are deadly pathogens that are notoriously difficult to inactivate, and standard microbial disinfection protocols are often inadequate. Recommended treatments for prion decontamination include strongly basic (pH ≥~12 sodium hypochlorite bleach, ≥1 N sodium hydroxide, and/or prolonged autoclaving. These treatments are damaging and/or unsuitable for many clinical, agricultural and environmental applications. We have tested the anti-prion activity of a weakly acidic aqueous formulation of HOCl (BrioHOCl that poses no apparent hazard to either users or many surfaces. For example, BrioHOCl can be applied directly to skin and mucous membranes and has been aerosolized to treat entire rooms without apparent deleterious effects. Here, we demonstrate that immersion in BrioHOCl can inactivate not only a range of target microbes, including spores of Bacillus subtilis, but also prions in tissue suspensions and on stainless steel. Real-time quaking-induced conversion (RT-QuIC assays showed that BrioHOCl treatments eliminated all detectable prion seeding activity of human Creutzfeldt-Jakob disease, bovine spongiform encephalopathy, cervine chronic wasting disease, sheep scrapie and hamster scrapie; these findings indicated reductions of ≥103- to 106-fold. Transgenic mouse bioassays showed that all detectable hamster-adapted scrapie infectivity in brain homogenates or on steel wires was eliminated, representing reductions of ≥~105.75-fold and >104-fold, respectively. Inactivation of RT-QuIC seeding activity correlated with free chlorine concentration and higher order aggregation or destruction of proteins generally, including prion

  11. Inactivation of oenological lactic acid bacteria (Lactobacillus hilgardii and Pediococcus pentosaceus) by wine phenolic compounds

    National Research Council Canada - National Science Library

    García-Ruiz, A; Bartolomé, B; Cueva, C; Martín-Alvarez, P J; Moreno-Arribas, M V

    2009-01-01

    To investigate the inactivation properties of different classes of phenolic compounds present in wine against two wine isolates of Lactobacillus hilgardii and Pediococcus pentosaceus, and to explore...

  12. Pathogen Inactivation Technologies: The Advent of Pathogen-Reduced Blood Components to Reduce Blood Safety Risk.

    Science.gov (United States)

    Devine, Dana V; Schubert, Peter

    2016-06-01

    Pathogen inactivation technologies represent a shift in blood safety from a reactive approach to a proactive protective strategy. Commercially available technologies demonstrate effective killing of most viruses, bacteria, and parasites and are capable of inactivating passenger leukocytes in blood products. The use of pathogen inactivation causes a decrease in the parameters of products that can be readily measured in laboratory assays but that do not seem to cause any alteration in hemostatic effect of plasma or platelet transfusions. Effort needs to be made to further develop these technologies so that the negative quality impact is ameliorated without reducing the pathogen inactivation effectiveness. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Inactivation of E. Coli in Water Using Photocatalytic, Nanostructured Films Synthesized by Aerosol Routes

    Directory of Open Access Journals (Sweden)

    Pratim Biswas

    2013-03-01

    Full Text Available TiO2 nanostructured films were synthesized by an aerosol chemical vapor deposition (ACVD method with different controlled morphologies: columnar, granular, and branched structures for the photocatalytic inactivation of Escherichia coli (E. coli in water. Effects of film morphology and external applied voltage on inactivation rate were investigated. As-prepared films were characterized using scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffractometry (XRD, and UV-VIS. Photocatalytic and photoelectrochemical inactivation of E. coli using as-prepared TiO2 films were performed under irradiation of UVA light (note: UVA has a low efficiency to inactivate E. coli. Inactivation rate constants for each case were obtained from their respective inactivation curve through a 2 h incubation period. Photocatalytic inactivation rate constants of E. coli are 0.02/min (using columnar films, and 0.08/min (using branched films. The inactivation rate constant for the columnar film was enhanced by 330% by applied voltage on the film while that for the branched film was increased only by 30%. Photocatalytic microbial inactivation rate of the columnar and the branched films were also compared taking into account their different surface areas. Since the majority of the UV radiation that reaches the Earth’s surface is UVA, this study provides an opportunity to use sunlight to efficiently decontaminate drinking water.

  14. Influenza (Flu) Vaccine (Inactivated or Recombinant): What You Need to Know

    Science.gov (United States)

    VACCINE INFORMATION STATEMENT Influenza (Flu) Vaccine (Inactivated or Recombinant): What you need to know Many Vaccine Information Statements are available in Spanish and other languages. See www. immunize. ...

  15. Effects of heat inactivation on HIV antibody screening and confirmatory test systems.

    Science.gov (United States)

    Fipps, D R; Damato, J J; Burke, D S

    1988-06-01

    In order to evaluate the effect of heat inactivation on serum undergoing testing for HIV antibody, 100 heat-inactivated and nonheat-inactivated serum samples were tested by two modifications of Abbott's screening assays for human T-cell lymphotropic virus type-III (lot numbers 1037 and 3036) and by two confirmatory assays (Cambridge BioScience CBre3-EIA; Damon Corporation Western blot). The samples consisted of 75 HIV antibody-negative and 25 HIV antibody-positive sera. The specimens were divided into two equal aliquots. One set was not subjected to heat inactivation, while the others were subjected to heat inactivation at 56 degrees C for 30 min. Heat inactivation had no significant effect on the HIV-position sera; however, heat-inactivated, negative sera evaluated by Abbott lot numbers 1037 and 3036 resulted in false-positive rates of 8% and 7%, respectively. No false positives were generated by the two confirmatory assays; however, the CBre3-EIA recombinant envelope protein assay had a significantly increased optical density reading following heat inactivation of the negative sera. The Western blot procedure used in the study was not affected by heat inactivation.

  16. Inactivation of RNA Viruses by Gamma Irradiation: A Study on Mitigating Factors

    Directory of Open Access Journals (Sweden)

    Adam J. Hume

    2016-07-01

    Full Text Available Effective inactivation of biosafety level 4 (BSL-4 pathogens is vital in order to study these agents safely. Gamma irradiation is a commonly used method for the inactivation of BSL-4 viruses, which among other advantages, facilitates the study of inactivated yet morphologically intact virions. The reported values for susceptibility of viruses to inactivation by gamma irradiation are sometimes inconsistent, likely due to differences in experimental protocols. We analyzed the effects of common sample attributes on the inactivation of a recombinant vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein and green fluorescent protein. Using this surrogate virus, we found that sample volume and protein content of the sample modulated viral inactivation by gamma irradiation but that air volume within the sample container and the addition of external disinfectant surrounding the sample did not. These data identify several factors which alter viral susceptibility to inactivation and highlight the usefulness of lower biosafety level surrogate viruses for such studies. Our results underscore the need to validate inactivation protocols of BSL-4 pathogens using “worst-case scenario” procedures to ensure complete sample inactivation.

  17. Rapid inactivation of Penicillium digitatum spores using high-density nonequilibrium atmospheric pressure plasma

    Science.gov (United States)

    Iseki, Sachiko; Ohta, Takayuki; Aomatsu, Akiyoshi; Ito, Masafumi; Kano, Hiroyuki; Higashijima, Yasuhiro; Hori, Masaru

    2010-04-01

    A promising, environmentally safe method for inactivating fungal spores of Penicillium digitatum, a difficult-to-inactivate food spoilage microorganism, was developed using a high-density nonequilibrium atmospheric pressure plasma (NEAPP). The NEAPP employing Ar gas had a high electron density on the order of 1015 cm-3. The spores were successfully and rapidly inactivated using the NEAPP, with a decimal reduction time in spores (D value) of 1.7 min. The contributions of ozone and UV radiation on the inactivation of the spores were evaluated and concluded to be not dominant, which was fundamentally different from the conventional sterilizations.

  18. Lack of X inactivation associated with maternal X isodisomy: Evidence for a counting mechanism prior to X inactivation during human embryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Migeon, B.R.; Torchia, B.S.; Fu, S. [Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States)] [and others

    1996-01-01

    We have previously reported functional disomy for X-linked genes in females with tiny ring X chromosomes and a phenotype significantly more abnormal than Turner syndrome. In such cases the disomy results from failure of these X chromosomes to inactivate because they lack DNA sequences essential for cis X inactivation. Here we describe a novel molecular mechanism for functional X disomy that is associated with maternal isodisomy. In this case, the severe mental retardation and multiple congenital abnormalities in a female with a mosaic 45,X/46,X,del(X) (q21.3-qter)/46X,r(X) karyotype are associated with overexpression of the genes within Xpter to Xq21.31 in many of her cells. Her normal X, ring X, and deleted linear X chromosomes originate from the same maternal X chromosome, and all are transcriptionally active. None expresses X inactive specific transcript (XIST), although the locus and region of the putative X inactivation center (XIC) are present on both normal and linear deleted X chromosomes. To our knowledge, this is the first report of a functional maternal X isodisomy, and the largest X chromosome to escape inactivation. In addition, these results (1) show that cis inactivation does not invariably occur in human females with two X chromosomes, even when the XIC region is present on both of them; (2) provide evidence for a critical time prior to the visible onset of X inactivation in the embryo when decisions about X inactivation are made; and (3) support the hypothesis that the X chromosome counting mechanism involves chromosomal imprinting, occurs prior to the onset of random inactivation, and is required for subsequent inactivation of the chromosome. 41 refs., 4 figs., 2 tabs.

  19. Randomized Trials Comparing Inactivated Vaccine After Medium- or High-titer Measles Vaccine With Standard Titer Measles Vaccine After Inactivated Vaccine: A Meta-analysis.

    Science.gov (United States)

    Aaby, Peter; Ravn, Henrik; Benn, Christine S; Rodrigues, Amabelia; Samb, Badara; Ibrahim, Salah A; Libman, Michael D; Whittle, Hilton C

    2016-11-01

    Observational studies have suggested that girls have higher mortality if their most recent immunization is an inactivated vaccine rather than a live vaccine. We therefore reanalyzed 5 randomized trials of early measles vaccine (MV) in which it was possible to compare an inactivated vaccines [after medium-titer MV (MTMV) or high-titer MV (HTMV)] and a live standard titer MV (after an initial inactivated vaccine). The trials were conducted in Sudan, Senegal, The Gambia and Guinea-Bissau. The intervention group received live MTMV or HTMV from 4 to 5 months and then an inactivated vaccine from 9 to 10 months of age; the control children received inactivated vaccine/placebo from 4 to 5 months and standard titer MV from 9 to 10 months of age. We compared mortality from 9 months until end of study at 3 to 5 years of age for children who received inactivated vaccine (after MTMV or HTMV) and standard titer MV (after inactivated vaccine), respectively. The original datasets were analyzed using a Cox proportional hazards model stratified by trial. The mortality rate ratio (MRR) was 1.38 (95% confidence interval: 1.05-1.83) after an inactivated vaccine (after MTMV or HTMV) compared with a standard titer MV (after inactivated vaccine). Girls had a MRR of 1.89 (1.27-2.80), whereas there was no effect for boys, the sex-differential effect being significant (P = 0.02). Excluding measles cases did not alter these conclusions, the MRR after inactivated vaccines (after MTMV or HTMV) being 1.40 (1.06-1.86) higher overall and 1.92 (1.29-2.86) for girls. Control for variations in national immunization schedules for other vaccines did not modify these results. After 9 months of age, all children had been immunized against measles, and mortality in girls was higher when they had received inactivated vaccines (after MTMV or HTMV) rather than live standard titer MV (after an inactivated vaccine).

  20. Evidence update: GlaxoSmithKline's inactivated quadrivalent influenza vaccines.

    Science.gov (United States)

    Bekkat-Berkani, Rafik; Ray, Riju; Jain, Varsha K; Chandrasekaran, Vijayalakshmi; Innis, Bruce L

    2016-01-01

    Inactivated trivalent influenza vaccines (IIV3s) are designed to protect against illness caused by two influenza A virus subtypes and one influenza B virus lineage. They may provide inadequate protection due to the co-circulation of viruses from two antigenically distinct influenza B lineages. Incorporating strains from both B lineages as in inactivated quadrivalent influenza vaccines (IIV4s) reduces this risk. We summarize the evidence supporting two IIV4s manufactured by GSK Vaccines. Compared to IIV3s, these two IIV4s demonstrated noninferior immunogenicity against the shared influenza strains and superior immunogenicity for the strain of the additional B lineage, particularly in subjects who were seronegative for that B strain. One IIV4's efficacy in children aged 3-8 years was 55.4% against influenza of any severity and 73.1% against moderate-to-severe influenza. Both IIV4s were well-tolerated with a similar safety profile to IIV3s. These IIV4s are more likely than IIV3s to protect against the added influenza B strain.

  1. Role of Merlin/NF2 inactivation in tumor biology.

    Science.gov (United States)

    Petrilli, A M; Fernández-Valle, C

    2016-02-04

    Merlin (Moesin-ezrin-radixin-like protein, also known as schwannomin) is a tumor suppressor protein encoded by the neurofibromatosis type 2 gene NF2. Loss of function mutations or deletions in NF2 cause neurofibromatosis type 2 (NF2), a multiple tumor forming disease of the nervous system. NF2 is characterized by the development of bilateral vestibular schwannomas. Patients with NF2 can also develop schwannomas on other cranial and peripheral nerves, as well as meningiomas and ependymomas. The only potential treatment is surgery/radiosurgery, which often results in loss of function of the involved nerve. There is an urgent need for chemotherapies that slow or eliminate tumors and prevent their formation in NF2 patients. Interestingly NF2 mutations and merlin inactivation also occur in spontaneous schwannomas and meningiomas, as well as other types of cancer including mesothelioma, glioma multiforme, breast, colorectal, skin, clear cell renal cell carcinoma, hepatic and prostate cancer. Except for malignant mesotheliomas, the role of NF2 mutation or inactivation has not received much attention in cancer, and NF2 might be relevant for prognosis and future chemotherapeutic approaches. This review discusses the influence of merlin loss of function in NF2-related tumors and common human cancers. We also discuss the NF2 gene status and merlin signaling pathways affected in the different tumor types and the molecular mechanisms that lead to tumorigenesis, progression and pharmacological resistance.

  2. Inactivation of adenovirus types 5 and 6 by Virkon S.

    Science.gov (United States)

    McCormick, Lisa; Maheshwari, Gargi

    2004-10-01

    Throughout the pharmaceutical industry, adenovirus-based products are being developed for human use as vaccine vectors and gene therapy delivery vehicles. The implementation of effective decontamination procedures is critical to the successful manufacture of these products to minimize the risk of personnel exposure and prevent product cross-contamination in the manufacturing facility. In this investigation, we have conducted small-scale decontamination studies to determine the efficacy of Virkon S on the inactivation of adenovirus types 5 and 6 in suspension. Virkon S is a commercially available oxidative disinfectant used against a variety of bacteria, spores, fungi, and viruses. A cytotoxicity-based endpoint dilution assay was used to quantify adenovirus potency before and after Virkon S treatment. We show that the level of organic content in the inactivation sample matrix has a significant impact on Virkon S activity. The potency of adenovirus types 5 and 6 was reduced by greater than six logs upon a five minute exposure to the appropriate concentration of Virkon S. Based on these results, we propose that Virkon S liquid decontamination procedures for adenovirus types 5 and 6 use 0.9% Virkon S for contact times greater than five minutes.

  3. Demeanor of rivaroxaban in activated/inactivated FXa

    Directory of Open Access Journals (Sweden)

    Kaname Seki

    2017-03-01

    Full Text Available Activated factor X (FXa plays an important role in thrombin generation and inflammation. Factor X is not converted constitutively to FXa, but only after intrinsic clotting factors are activated and/or cellular injury occurs. Although rivaroxaban is one of direct FXa inhibitors, its function in the inactivated coagulation cascade is unclear. In human umbilical vein endothelial cells that natively express protease-activated receptor-1 and -2, high dose rivaroxaban did not alter gene transcripts including pro-inflammatory genes in DNA microarray. Upon FXa stimulation, the expressions of pro-inflammatory genes such as monocyte chemoattractant protein-1 (MCP-1, intracellular adhesion molecule-1, and interleukin-8 were maximally increased at 4 h after stimulation, and were suppressed by rivaroxaban. To confirm these results, quantitative polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA for MCP-1 were performed. FXa evoked the expression of MCP-1 maximally at 4 h after stimulation, whereas MCP-1 displayed a different temporal activation in ELISA. Interestingly, rivaroxaban inhibited both time courses of MCP-1 expression. These results suggest that rivaroxaban may not influence gene modulation in the inactivated coagulation state, but can attenuate the endothelial damage evoked by FXa and pro-inflammatory cytokine genes.

  4. Assaying the Stability and Inactivation of AAV Serotype 1 Vectors.

    Science.gov (United States)

    Howard, Douglas B; Harvey, Brandon K

    2017-02-01

    Adeno-associated virus (AAV) vectors are a commonplace tool for gene delivery ranging from cell culture to human gene therapy. One feature that makes AAV a desirable vector is its stability, in regard to both the duration of transgene expression and retention of infectivity as a viral particle. This study examined the stability of AAV serotype 1 (AAV1) vectors under different conditions. First, transducibility after storage at 4°C decreased 20% over 7 weeks. Over 10 freeze-thaw cycles, the resulting transduction efficiency became variable at 60-120% of a single thaw. Using small stainless steel slugs to mimic a biosafety cabinet or metal lab bench surface, it was found that an AAV1 vector can be reconstituted after 6 days of storage at room temperature. The stability of AAV is a desired feature, but effective decontamination procedures must be available for safety and experimental integrity. Multiple disinfectants commonly used in the laboratory for ability to inactivate an AAV1 vector were tested, and it was found that autoclaving, 0.25% peracetic acid, iodine, or 10% Clorox bleach completely prevented AAV-mediated transgene expression. These data suggest that peracetic acid should be used for inactivating AAV1 vectors on metal-based surfaces or instruments in order to avoid inadvertent transgene expression in human cells or cross-contamination of instruments.

  5. Pulsed light inactivation of naturally occurring moulds on wheat grain.

    Science.gov (United States)

    Aron Maftei, Nicoleta; Ramos-Villarroel, Ana Y; Nicolau, Anca I; Martín-Belloso, Olga; Soliva-Fortuny, Robert

    2014-03-15

    Pulsed light (PL) is emerging as a non-thermal technology with excellent prospects for the decontamination of foods and food contact surfaces. Its application for mould inactivation on cereal grains would allow a reduction of storage losses as well as the prevention of mycotoxin contamination at a post-harvest level. The potential of PL for the decontamination of naturally occurring moulds on wheat grain was investigated in this study. Treatments of up to 40 flashes of a fluence of 0.4 J cm⁻² per pulse were applied to both sides of the grain, with an overall energy release ranging from 6.4 to 51.2 J g⁻¹. The most powerful treatment applied to wheat in this study (51.2 J g⁻¹) resulted in a mould reduction of approximately 4 log cycles on samples displaying an initial mould contamination level of 2.2 × 10⁵ CFU g⁻¹. At the same time, the seed germination percentage was only slightly affected. For PL treatments causing an inactivation of 3-4 log cycles, only 14-15% of the germination power of the wheat seeds was lost. The PL treatments attained greater microbial reductions for higher treatment times and lower initial mould loads. The absence of the UV portion of the radiation spectrum was found to significantly reduce the treatment effectiveness. © 2013 Society of Chemical Industry.

  6. Inactivation of enveloped viruses by anthraquinones extracted from plants.

    Science.gov (United States)

    Sydiskis, R J; Owen, D G; Lohr, J L; Rosler, K H; Blomster, R N

    1991-01-01

    To determine the extent of antiviral activity present in a number of plant extracts, hot glycerin extracts were prepared from Rheum officinale, Aloe barbadensis, Rhamnus frangula, Rhamnus purshianus, and Cassia angustifolia and their virucidal effects were tested against herpes simplex virus type 1. All the plant extracts inactivated the virus. The active components in these plants were separated by thin-layer chromatography and identified as anthraquinones. A purified sample of aloe emodin was prepared from aloin, and its effects on the infectivity of herpes simplex virus type 1 and type 2, varicella-zoster virus, pseudorabies virus, influenza virus, adenovirus, and rhinovirus were tested by mixing virus with dilutions of aloe emodin for 15 min at 37 degrees C, immediately diluting the sample, and assaying the amount of infectious virus remaining in the sample. The results showed that aloe emodin inactivated all of the viruses tested except adenovirus and rhinovirus. Electron microscopic examination of anthraquinone-treated herpes simplex virus demonstrated that the envelopes were partially disrupted. These results show that anthraquinones extracted from a variety of plants are directly virucidal to enveloped viruses. PMID:1810179

  7. Removal of inactivation causes time-invariant sodium current decays

    Science.gov (United States)

    1988-01-01

    The kinetic properties of the closing of Na channels were studied in frog skeletal muscle to obtain information about the dependence of channel closing on the past history of the channel. Channel closing was studied in normal and modified channels. Chloramine-T was used to modify the channels so that inactivation was virtually removed. A series of depolarizing prepulse potentials was used to activate Na channels, and a -140-mV postpulse was used to monitor the closing of the channels. Unmodified channels decay via a biexponential process with time constants of 72 and 534 microseconds at 12 degrees C. The observed time constants do not depend upon the potential used to activate the channels. The contribution of the slow component to the total decay increases as the activating prepulse is lengthened. After inactivation is removed, the biexponential character of the decay is retained, with no change in the magnitude of the time constants. However, increases in the duration of the activating prepulse over the range where the current is maximal 1-75 ms) produce identical biexponential decays. The presence of biexponential decays suggests that either two subtypes of Na channels are found in muscle, or Na channels can exist in one of two equally conductive states. The time- invariant decays observed suggest that channel closure does not depend upon their past history. PMID:2852208

  8. The eag domain regulates hERG channel inactivation gating via a direct interaction

    Science.gov (United States)

    Gustina, Ahleah S.

    2013-01-01

    Human ether-á-go-go (eag)-related gene (hERG) potassium channel kinetics are characterized by rapid inactivation upon depolarization, along with rapid recovery from inactivation and very slow closing (deactivation) upon repolarization. These factors combine to create a resurgent hERG current, where the current amplitude is paradoxically larger with repolarization than with depolarization. Previous data showed that the hERG N-terminal eag domain regulated deactivation kinetics by making a direct interaction with the C-terminal region of the channel. A primary mechanism for fast inactivation depends on residues in the channel pore; however, inactivation was also shown to be slower after deletion of a large N-terminal region. The mechanism for N-terminal region regulation of inactivation is unclear. Here, we investigated the contributions of the large N-terminal domains (amino acids 1–354), including the eag domain (amino acids 1–135), to hERG channel inactivation kinetics and steady-state inactivation properties. We found that N-deleted channels lacking just the eag domain (Δ2–135) or both the eag domain and the adjacent proximal domain (Δ2–354) had less rectifying current–voltage (I-V) relationships, slower inactivation, faster recovery from inactivation, and lessened steady-state inactivation. We coexpressed genetically encoded N-terminal fragments for the eag domain (N1–135) or the eag domain plus the proximal domain (N1–354) with N-deleted hERG Δ2–135 or hERG Δ2–354 channels and found that the resulting channels had more rectifying I-V relationships, faster inactivation, slower recovery from inactivation, and increased steady-state inactivation, similar to those properties measured for wild-type (WT) hERG. We also found that the eag domain–containing fragments regulated the time to peak and the voltage at the peak of a resurgent current elicited with a ramp voltage protocol. The eag domain–containing fragments effectively converted N

  9. Effects of inactivated Enterococcus faecalis on the proliferation and osteogenic induction of osteoblasts.

    Science.gov (United States)

    Tong, Zhongchun; Ma, Jinglei; Tan, Jiali; Huang, Lijia; Ling, Junqi

    2016-12-01

    The present study aimed to evaluate the effects of Enterococcus faecalis, inactivated by the common intracanal irrigants sodium hypochlorite (NaOCl) and chlorhexidine (CHX), on osteoblasts. E. faecalis was inactivated with 2% CHX or 5.25% NaOCl. Subsequently, the Cell Counting kit‑8 assay was used to examine the effects of CHX‑ and NaOCl-inactivated E. faecalis on MC3T3‑E1 osteoblast cell proliferation. Alizarin red staining was used to determine osteoblast mineralization, and osteogenic induction was quantified by determining the optical density of the dye solution. The relative expression levels of osteogenic genes were detected after 1, 4, 7 and 14 days of stimulation with CHX‑ and NaOCl-inactivated E. faecalis by reverse transcription‑quantitative polymerase chain reaction. The results indicated that CHX‑inactivated E. faecalis inhibited osteoblast proliferation, whereas NaOCl‑inactivated E. faecalis did not suppress cell proliferation. Various concentrations of CHX‑ and NaOCl‑inactivated E. faecalis induced different degrees of osteoblast mineralization. The expression levels of osteocalcin, alkaline phosphatase, runt‑related transcription factor 2, osteopontin and osterix were upregulated in cells following stimulation with 107 and 105 colony‑forming units/ml E. faecalis inactivated by CHX and NaOCl; the upregulation of these osteogenic genes occurred at various time points. In conclusion, the present study demonstrated that CHX‑inactivated E. faecalis exerted more of an effect on osteoblast proliferation compared with NaOCl‑inactivated E. faecalis. In addition, CHX‑ and NaOCl‑inactivated E. faecalis was able to induce mineralization and relevant osteogenic gene expression in osteoblast cells.

  10. Effects of inactivated Enterococcus faecalis on the proliferation and osteogenic induction of osteoblasts

    Science.gov (United States)

    Tong, Zhongchun; Ma, Jinglei; Tan, Jiali; Huang, Lijia; Ling, Junqi

    2016-01-01

    The present study aimed to evaluate the effects of Enterococcus faecalis, inactivated by the common intracanal irrigants sodium hypochlorite (NaOCl) and chlorhexidine (CHX), on osteoblasts. E. faecalis was inactivated with 2% CHX or 5.25% NaOCl. Subsequently, the Cell Counting kit-8 assay was used to examine the effects of CHX- and NaOCl-inactivated E. faecalis on MC3T3-E1 osteoblast cell proliferation. Alizarin red staining was used to determine osteoblast mineralization, and osteogenic induction was quantified by determining the optical density of the dye solution. The relative expression levels of osteogenic genes were detected after 1, 4, 7 and 14 days of stimulation with CHX- and NaOCl-inactivated E. faecalis by reverse transcription-quantitative polymerase chain reaction. The results indicated that CHX-inactivated E. faecalis inhibited osteoblast proliferation, whereas NaOCl-inactivated E. faecalis did not suppress cell proliferation. Various concentrations of CHX- and NaOCl-inactivated E. faecalis induced different degrees of osteoblast mineralization. The expression levels of osteocalcin, alkaline phosphatase, runt-related transcription factor 2, osteopontin and osterix were upregulated in cells following stimulation with 107 and 105 colony-forming units/ml E. faecalis inactivated by CHX and NaOCl; the upregulation of these osteogenic genes occurred at various time points. In conclusion, the present study demonstrated that CHX-inactivated E. faecalis exerted more of an effect on osteoblast proliferation compared with NaOCl-inactivated E. faecalis. In addition, CHX- and NaOCl-inactivated E. faecalis was able to induce mineralization and relevant osteogenic gene expression in osteoblast cells. PMID:27840919

  11. Cost-effectiveness of pathogen inactivation for platelet transfusions in the Netherlands

    NARCIS (Netherlands)

    Postma, MJ; van Hulst, M; De Wolf, JTM; Botteman, M; Staginnus, U

    2005-01-01

    The objective of this study is to estimate cost-effectiveness of pathogen inactivation for platelet transfusions in the Netherlands. We used decision tree analysis to evaluate the cost-effectiveness of the addition of pathogen inactivation of pooled platelets to standard procedures for platelet

  12. The inactivating and mutagenic effect of hydroxylamine on bacteriophage φX174

    NARCIS (Netherlands)

    Pol, J.H. van de; Arkel, G.A. van

    1965-01-01

    The inactivation of bacteriophage ΦXI74 by the mutagenic agents nitrous acid and ultraviolet irradiation proceeds according to a single-hit kinetics. However, treatment of purified ΦXI74 by hydroxylamine (HA) at pH 6 and 25° results in an inactivation that is not strictly exponential. The

  13. Curing conditions to inactivate Trichinella spiralis muscle larvae in ready-to-eat pork sausage

    Science.gov (United States)

    Curing processes for ready to eat (RTE) pork products currently require individual validation of methods to demonstrate inactivation of Trichinella spiralis. This is a major undertaking for each process; currently no model of meat chemistry exists that can be correlated with inactivation of Trichin...

  14. ASSESSING THE EFFECTIVENESS OF LOW PRESSURE ULTRAVIOLET LIGHT FOR INACTIVATING HELICOBACTER PYLORI

    Science.gov (United States)

    Three strains of Helicobacter pylori were exposed to ultraviolet (UV) light from a low-pressure source to determine log inactivation versus applied fluence. Results indicate that H. pylori is readily inactivated at UV fluences typically used in water treatment r...

  15. Inactivation of porcine endogenous retrovirus in pigs using CRISPR-Cas9

    DEFF Research Database (Denmark)

    Niu, Dong; Wei, Hong-Jiang; Lin, Lin

    2017-01-01

    of this approach. Earlier, we demonstrated the feasibility of inactivating PERV activity in an immortalized pig cell line. Here, we confirmed that PERVs infect human cells, and observed the horizontal transfer of PERVs among human cells. Using CRISPR-Cas9, we inactivated all the PERVs in a porcine primary cell...

  16. A systematic approach to determine global thermal inactivation parameters for various food pathogens

    NARCIS (Netherlands)

    Asselt, van E.D.; Zwietering, M.H.

    2006-01-01

    Thermal inactivation of pathogens has been studied extensively, which has resulted in a wide range of D- and z-values. Estimating the inactivation rate for a specific condition based on these reported values is difficult, since one has to select representative conditions, and data obtained exactly

  17. Inactivation of 12 viruses by heating steps applied during manufacture of a hepatitis B vaccine

    NARCIS (Netherlands)

    Lelie, P. N.; Reesink, H. W.; Lucas, C. J.

    1987-01-01

    The efficacy of two heating cycles (90 sec at 103 degrees C and 10 hr at 65 degrees C) used during manufacture of a plasma-derived hepatitis-B vaccine was validated for the inactivation of 12 virus families. A period of 15 min warming up to 65 degrees C had already completely inactivated

  18. Inactivation of soybean trypsin inhibitors and lipoxygenases by high-pressure processing

    NARCIS (Netherlands)

    Ven, van der C.; Matser, A.M.; Berg, van den R.W.

    2005-01-01

    Trypsin inhibitors (TIA), one of the antinutritional factors of soy milk, are usually inactivated by heat treatment. In the current study, high-pressure processing (HPP) was evaluated as an alternative for the inactivation of TIA in soy milk. Moreover, the effect of HPP on lipoxygenase (LOX) in

  19. Modelling fungal solid-state fermentation: The role of inactivation kinetics

    NARCIS (Netherlands)

    Smits, J.P.; Sonsbeek, H.M. van; Knol, W.; Tramper, J.; Geelhoed, W.; Peeters, M.; Rinzema, A.

    1999-01-01

    The theoretical mathematical models described in this paper are used to evaluate the effects of fungal biomass inactivation kinetics on a non- isothermal tray solid-state fermentation (SSF). The inactivation kinetics, derived from previously reported experiments done under isothermal conditions and

  20. Inactivation of recombinant bacteriophage lambda by use of chemical agents and UV radiation.

    Science.gov (United States)

    Clark, Ewan M; Wright, Harry; Lennon, Kelly-Anne; Craik, Vicki A; Clark, Jason R; March, John B

    2012-04-01

    Several approaches for the inactivation of bacteriophage lambda, including UV germicidal irradiation (UVGI) and the chemical agents Virkon-S, Chloros, Decon-90, and sodium hydroxide (NaOH), were compared. Virkon, NaOH, and UVGI caused a ≥7-log(10) reduction in phage titers. This study successfully describes several methods with potential for bacteriophage inactivation in industrial settings.

  1. Chemical-free inactivated whole influenza virus vaccine prepared by ultrashort pulsed laser treatment

    Science.gov (United States)

    Tsen, Shaw-Wei David; Donthi, Nisha; La, Victor; Hsieh, Wen-Han; Li, Yen-Der; Knoff, Jayne; Chen, Alexander; Wu, Tzyy-Choou; Hung, Chien-Fu; Achilefu, Samuel; Tsen, Kong-Thon

    2015-05-01

    There is an urgent need for rapid methods to develop vaccines in response to emerging viral pathogens. Whole inactivated virus (WIV) vaccines represent an ideal strategy for this purpose; however, a universal method for producing safe and immunogenic inactivated vaccines is lacking. Conventional pathogen inactivation methods such as formalin, heat, ultraviolet light, and gamma rays cause structural alterations in vaccines that lead to reduced neutralizing antibody specificity, and in some cases, disastrous T helper type 2-mediated immune pathology. We have evaluated the potential of a visible ultrashort pulsed (USP) laser method to generate safe and immunogenic WIV vaccines without adjuvants. Specifically, we demonstrate that vaccination of mice with laser-inactivated H1N1 influenza virus at about a 10-fold lower dose than that required using conventional formalin-inactivated influenza vaccines results in protection against lethal H1N1 challenge in mice. The virus, inactivated by the USP laser irradiation, has been shown to retain its surface protein structure through hemagglutination assay. Unlike conventional inactivation methods, laser treatment did not generate carbonyl groups in protein, thereby reducing the risk of adverse vaccine-elicited T helper type 2 responses. Therefore, USP laser treatment is an attractive potential strategy to generate WIV vaccines with greater potency and safety than vaccines produced by current inactivation techniques.

  2. Mechanism of Bacillus subtilis spore inactivation by and resistance to supercritical CO2 plus peracetic acid

    National Research Council Canada - National Science Library

    Setlow, B; Korza, G; Blatt, K.M.S; Fey, J.P; Setlow, P

    2016-01-01

    Determine how supercritical CO2 (scCO2 ) plus peracetic acid (PAA) inactivates Bacillus subtilis spores, factors important in spore resistance to scCO2 -PAA, and if spores inactivated by scCO2 -PAA are truly dead...

  3. The non-enzymatic inactivation of thirteen β-lactam antibiotics in human faeces

    NARCIS (Netherlands)

    Jansen, G; Weissing, F; de Vries Hospers, H; Tonk, R; van der Waaij, D

    1992-01-01

    In order to obtain a method that could predict the in vitro inactivation of an antibiotic in the digestive tract, the non-enzymatic inactivation of 13 beta-lactam antibiotics by human faeces was investigated. Benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin,

  4. The non-enzymatic inactivation of thirteen beta-lactam antibiotics in human faeces

    NARCIS (Netherlands)

    Jansen, G; Weissing, F; de Vries-Hospers, H; Tonk, R; van der Waaij, D

    1992-01-01

    In order to obtain a method that could predict the in vitro inactivation of an antibiotic in the digestive tract, the non-enzymatic inactivation of 13 beta-lactam antibiotics by human faeces was investigated. Benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin,

  5. Inactivation of Escherichia coli by superoxide radicals and their dismutation products

    NARCIS (Netherlands)

    Hemmen, J.J. van; Meuling, W.J.A.

    1977-01-01

    E. coli cells are inactivated by the products of the reaction between dialuric acid and oxygen, of which the primary product is superoxide. The rate of inactivation is decreased by superoxide dismutase, by catalase, and by EDTA, whereas it is increased by addition of cupric ions or hydrogen

  6. 21 CFR 866.5260 - Complement C3b inactivator immunological test system.

    Science.gov (United States)

    2010-04-01

    ... Systems § 866.5260 Complement C3b inactivator immunological test system. (a) Identification. A complement... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Complement C3b inactivator immunological test system. 866.5260 Section 866.5260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND...

  7. Thermal inactivation of infectious hematopoietic necrosis and infectious pancreatic necrosis virus

    Science.gov (United States)

    Gosting, L.; Gould, R.W.

    1981-01-01

    A plaque assay was used to follow the inactivation kinetics of infectious hematopoietic necrosis virus and infectious pancreatic necrosis virus in cell culture media at various temperatures. Inactivation of infectious hematopoietic necrosis virus in a visceral organ slurry was compared with that in culture media.

  8. Growth and inactivation of Salmonella at low refrigerated storage temperatures and thermal inactivation on raw chicken meat and laboratory media: mixed effect meta-analysis.

    Science.gov (United States)

    Smadi, Hanan; Sargeant, Jan M; Shannon, Harry S; Raina, Parminder

    2012-12-01

    Growth and inactivation regression equations were developed to describe the effects of temperature on Salmonella concentration on chicken meat for refrigerated temperatures (⩽10°C) and for thermal treatment temperatures (55-70°C). The main objectives were: (i) to compare Salmonella growth/inactivation in chicken meat versus laboratory media; (ii) to create regression equations to estimate Salmonella growth in chicken meat that can be used in quantitative risk assessment (QRA) modeling; and (iii) to create regression equations to estimate D-values needed to inactivate Salmonella in chicken meat. A systematic approach was used to identify the articles, critically appraise them, and pool outcomes across studies. Growth represented in density (Log10CFU/g) and D-values (min) as a function of temperature were modeled using hierarchical mixed effects regression models. The current meta-analysis analysis found a significant difference (P⩽0.05) between the two matrices - chicken meat and laboratory media - for both growth at refrigerated temperatures and inactivation by thermal treatment. Growth and inactivation were significantly influenced by temperature after controlling for other variables; however, no consistent pattern in growth was found. Validation of growth and inactivation equations against data not used in their development is needed. Copyright © 2012 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

  9. Inactivation of hepatitis A virus and norovirus surrogate in suspension and on food-contact surfaces using pulsed UV light (pulsed light inactivation of food-borne viruses).

    Science.gov (United States)

    Jean, Julie; Morales-Rayas, Rocío; Anoman, Marie-Natacha; Lamhoujeb, Safaa

    2011-05-01

    This study was conducted to evaluate the inactivation of murine norovirus (MNV-1) and hepatitis A virus (HAV) by pulsed ultraviolet (UV) light. MNV-1 was used as a model for human norovirus. Viral suspensions of about 10(6) PFU/ml were exposed to pulses of UV light for different times and at different distances in a Xenon Steripulse device (model RS-3000C). Inactivation studies were also carried out on 1-cm(2) stainless steel and polyvinyl chloride disks with 10(5) PFU/ml. Inactivation of MNV-1 and HAV at 10.5 cm from the UV source was greater on inert surfaces than in suspension. The presence of organic matter (fetal bovine serum) reduced the effectiveness of pulsed light both in suspension and on surfaces. However, 2-s treatment in the absence of FBS completely inactivated (5 log reduction) the viral load at different distances tested, whether in suspension (MNV-1) or on disks (MNV-1 and HAV). The same treatment in the presence of fetal bovine serum (5%) allowed a reduction of about 3 log. This study showed that short duration pulses represent an excellent alternative for inactivation of food-borne viruses. This technology could be used to inactivate viruses in drinking water or on food-handling surfaces. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Calcium dependence of inactivation of calcium release from the sarcoplasmic reticulum in skeletal muscle fibers.

    Science.gov (United States)

    Simon, B J; Klein, M G; Schneider, M F

    1991-03-01

    The steady-state calcium dependence of inactivation of calcium release from the sarcoplasmic reticulum was studied in voltage-clamped, cut segments of frog skeletal muscle fibers containing two calcium indicators, fura-2 and anti-pyrylazo III (AP III). Fura-2 fluorescence was used to monitor resting calcium and relatively small calcium transients during small depolarizations. AP III absorbance signals were used to monitor larger calcium transients during larger depolarizations. The rate of release (Rrel) of calcium from the sarcoplasmic reticulum was calculated from the calcium transients. The equilibrium calcium dependence of inactivation of calcium release was determined using 200-ms prepulses of various amplitudes to elevate [Ca2+] to various steady levels. Each prepulse was followed by a constant test pulse. The suppression of peak Rrel during the test pulse provided a measure of the extent of inactivation of release at the end of the prepulse. The [Ca2+] dependence of inactivation indicated that binding of more than one calcium ion was required to inactivate each release channel. Half-maximal inactivation was produced at a [Ca2+] of approximately 0.3 microM. Variation of the prepulse duration and amplitude showed that the suppression of peak release was consistent with calcium-dependent inactivation of calcium release but not with calcium depletion. The same calcium dependence of inactivation was obtained using different amplitude test pulses to determine the degree of inactivation. Prepulses that produced near maximal inactivation of release during the following test pulse produced no suppression of intramembrane charge movement during the test pulse, indicating that inactivation occurred at a step beyond the voltage sensor for calcium release. Three alternative set of properties that were assumed for the rapidly equilibrating calcium-binding sites intrinsic to the fibers gave somewhat different Rrel records, but gave very similar calcium dependence of

  11. Differential effects of deep cerebellar nuclei inactivation on reaching and adaptive control.

    Science.gov (United States)

    Martin, J H; Cooper, S E; Hacking, A; Ghez, C

    2000-04-01

    This study examined the effects of selective inactivation of the cerebellar nuclei in the cat on the control of multijoint trajectories and trajectory adaptation to avoid obstacles. Animals were restrained in a hammock and trained to perform a prehension task in which they reached to grasp a small cube of meat from a narrow food well. To examine trajectory adaptation, reaching was obstructed by placing a horizontal bar in the limb's path. Inactivation was produced by microinjection of the GABA agonist muscimol (0.25-1.0 microg in 1 microL saline). Fastigial nucleus inactivation produced a severe impairment in balance and in head and trunk control but no effect on reaching and grasping. Dentate inactivation slowed movements significantly and produced a significant increase in tip path curvature but did not impair reaching and grasping. Selective inactivation of the anterior and posterior interpositus nuclei did not impair grasping but severely decreased the accuracy of reaching movements and produced different biases in wrist and paw paths. Anterior interpositus inactivation produced movement slowing (wrist speed) and under-reaching to the food well. Wrist and tip paths showed anterior biases and became more curved. Also animals could no longer make anticipatory adjustments in limb kinematics to avoid obstructions but sensory-evoked corrective responses were preserved. Posterior interpositus inactivation produced a significant increase in wrist speed and overreaching. Wrist and tip paths showed a posterior bias and became more curved, although in a different way than during anterior interpositus inactivation. Posterior interpositus inactivation did not impair trajectory adaptation to reach over the obstacle. During inactivation of either interpositus nucleus, all measures of kinematic temporal and spatial variability increased with somewhat greater effects being produced by anterior interpositus inactivation. We discuss our results in relation to the hypothesis that

  12. Proton transfer unlocks inactivation in cyclic nucleotide-gated A1 channels.

    Science.gov (United States)

    Marchesi, Arin; Arcangeletti, Manuel; Mazzolini, Monica; Torre, Vincent

    2015-02-15

    Desensitization and inactivation provide a form of short-term memory controlling the firing patterns of excitable cells and adaptation in sensory systems. Unlike many of their cousin K(+) channels, cyclic nucleotide-gated (CNG) channels are thought not to desensitize or inactivate. Here we report that CNG channels do inactivate and that inactivation is controlled by extracellular protons. Titration of a glutamate residue within the selectivity filter destabilizes the pore architecture, which collapses towards a non-conductive, inactivated state in a process reminiscent of the usual C-type inactivation observed in many K(+) channels. These results indicate that inactivation in CNG channels represents a regulatory mechanism that has been neglected thus far, with possible implications in several physiological processes ranging from signal transduction to growth cone navigation. Ion channels control ionic fluxes across biological membranes by residing in any of three functionally distinct states: deactivated (closed), activated (open) or inactivated (closed). Unlike many of their cousin K(+) channels, cyclic nucleotide-gated (CNG) channels do not desensitize or inactivate. Using patch recording techniques, we show that when extracellular pH (pHo ) is decreased from 7.4 to 6 or lower, wild-type CNGA1 channels inactivate in a voltage-dependent manner. pHo titration experiments show that at pHo  < 7 the I-V relationships are outwardly rectifying and that inactivation is coupled to current rectification. Single-channel recordings indicate that a fast mechanism of proton blockage underlines current rectification while inactivation arises from conformational changes downstream from protonation. Furthermore, mutagenesis and ionic substitution experiments highlight the role of the selectivity filter in current decline, suggesting analogies with the C-type inactivation observed in K(+) channels. Analysis with Markovian models indicates that the non-independent binding of two

  13. Virus-inactivated plasma - Plasmasafe: a one-year experience

    Science.gov (United States)

    De Silvestro, Giustina; Bagatella, Paola; Tison, Tiziana; Quaino, Vania; Carraro, Paolo; Tenderini, Maria Luisa; Lazzaro, Annarosa; Marotti, Alberto

    2007-01-01

    Background Fresh-frozen plasma (FFP) is a widely used blood transfusion product. The transfusion safety of this product is ensured by legally obligatory tests, but can be further improved by using some technical procedures, such as methylene blue (MB) and solvent-detergent (SD) viral inactivation methods. Mainly organisational criteria led us to introduce the SD viral inactivation technique as a service activity. In this report we describe our first year of experience, following the introduction of the SD technique, and thus the use of SD-virally inactivated plasma (PlasmaSafe). Materials and methods In order to evaluate the appropriate use and the therapeutic efficacy of PlasmaSafe in our Blood Transfusion Unit, the following programme was planned: quality control [prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen] of the FFP units (N=312); evaluation of the clinical effectiveness on 490 patients (879 transfusion events); pre- and post-treatment monitoring of indicators of coagulation (PT, aPTT, fibrinogen, proteins S and C, factor VIII) on 15 patients; treatment of three patients with thrombotic thrombocytopenic purpura (TTP) undergoing plasma-exchange; haemovigilance of adverse reactions provoked by SD-plasma. Results The indicators of coagulation in the FFP units varied greatly: the PT ranged from 50–120%, the aPTT from 24–41 seconds and the fibrinogen concentration from 1.42–6.84 g/L. Seventy-six percent of the patients responded to the plasma administration; moreover, two of 15 patients in whom protein S was assayed, showed no increase of this haemostatic protein. The TTP patients responded to plasma exchange treatment following four sessions of apheresis. During the observation period 8,422 PlasmaSafe units were transfused and no adverse reactions were recorded. Conclusion PlasmaSafe, a pharmaceutical-like product with a standardised content of coagulation factors, was found to be effective at correcting coagulation

  14. Inactivation of C4orf26 in toothless placental mammals.

    Science.gov (United States)

    Springer, Mark S; Starrett, James; Morin, Phillip A; Lanzetti, Agnese; Hayashi, Cheryl; Gatesy, John

    2016-02-01

    Previous studies have reported inactivated copies of six enamel-related genes (AMBN, AMEL, AMTN, ENAM, KLK4, MMP20) and one dentin-related gene (DSPP) in one or more toothless vertebrates and/or vertebrates with enamelless teeth, thereby providing evidence that these genes are enamel or tooth-specific with respect to their critical functions that are maintained by natural selection. Here, we employ available genome sequences for edentulous and enamelless mammals to evaluate the enamel specificity of four genes (WDR72, SLC24A4, FAM83H, C4orf26) that have been implicated in amelogenesis imperfecta, a condition in which proper enamel formation is abrogated during tooth development. Coding sequences for WDR72, SCL24A4, and FAM83H are intact in four edentulous taxa (Chinese pangolin, three baleen whales) and three taxa (aardvark, nine-banded armadillo, Hoffmann's two-toed sloth) with enamelless teeth, suggesting that these genes have critical functions beyond their involvement in tooth development. By contrast, genomic data for C4orf26 reveal inactivating mutations in pangolin and bowhead whale as well as evidence for deletion of this gene in two minke whale species. Hybridization capture of exonic regions and PCR screens provide evidence for inactivation of C4orf26 in eight additional baleen whale species. However, C4orf26 is intact in all three species with enamelless teeth that were surveyed, as well as in 95 additional mammalian species with enamel-capped teeth. Estimates of selection intensity suggest that dN/dS ratios on branches leading to taxa with enamelless teeth are similar to the dN/dS ratio on branches leading to taxa with enamel-capped teeth. Based on these results, we conclude that C4orf26 is tooth-specific, but not enamel-specific, with respect to its essential functions that are maintained by natural selection. A caveat is that an alternative splice site variant, which translates exon 3 in a different reading frame, is putatively functional in

  15. Rapid Bedside Inactivation of Ebola Virus for Safe Nucleic Acid Tests

    DEFF Research Database (Denmark)

    Rosenstierne, Maiken Worsøe; Karlberg, Helen; Bragstad, Karoline

    2016-01-01

    for nucleic acid extraction inactivates Ebola virus. A rapid bedside inactivation method for nucleic acid tests is obtained by simply adding Magna Pure lysis/binding buffer directly into vacuum blood collection EDTA tubes using a thin needle and syringe prior to sampling. The ready-to-use inactivation vacuum......Rapid bedside inactivation of Ebola virus would be a solution for the safety of medical and technical staff, risk containment, sample transport, and high-throughput or rapid diagnostic testing during an outbreak. We show that the commercially available Magna Pure lysis/binding buffer used...... tubes are stable for more than 4 months, and Ebola virus RNA is preserved in the Magna Pure lysis/binding buffer for at least 5 weeks independent of the storage temperature. We also show that Ebola virus RNA can be manually extracted from Magna Pure lysis/binding buffer-inactivated samples using...

  16. MECHANISM OF FUSARIUM TRICINCTUM (CORDA SACC. SPORE INACTIVATION BY CHLORINE DIOXIDE

    Directory of Open Access Journals (Sweden)

    Zhao Chen

    2015-06-01

    Full Text Available The mechanism of Fusarium tricinctum (Corda Sacc. spore inactivation by chlorine dioxide (ClO2 was investigated. During F. tricinctum spore inactivation by ClO2, protein, DNA, and metal ion leakage, enzyme activity, and cell ultrastructure were examined. Protein and DNA leakages were not detected, while there were metal ion leakages of K+, Ca2+, and Mg2+, which were well-correlated with the inactivation rate. The enzyme activities of glucose-6-phosphate dehydrogenase, citrate synthase, and phosphofructokinase were inhibited and were also well-correlated with the inactivation rate. Electron micrographs showed the ultrastructural modifications of spores and demonstrated that spores were heavily distorted and collapsed from their regular structure. Spore surface damage and disruption in inner components was also severe. The metal ion leakage, the inhibition of enzyme activities, and the damage of spore structure were significant in F. tricinctum spore inactivation by ClO2.

  17. Inactivation disinfection property of Moringa Oleifera seed extract: optimization and kinetic studies

    Science.gov (United States)

    Idris, M. A.; Jami, M. S.; Hammed, A. M.

    2017-05-01

    This paper presents the statistical optimization study of disinfection inactivation parameters of defatted Moringa oleifera seed extract on Pseudomonas aeruginosa bacterial cells. Three level factorial design was used to estimate the optimum range and the kinetics of the inactivation process was also carried. The inactivation process involved comparing different disinfection models of Chicks-Watson, Collins-Selleck and Homs models. The results from analysis of variance (ANOVA) of the statistical optimization process revealed that only contact time was significant. The optimum disinfection range of the seed extract was 125 mg/L, 30 minutes and 120rpm agitation. At the optimum dose, the inactivation kinetics followed the Collin-Selleck model with coefficient of determination (R2) of 0.6320. This study is the first of its kind in determining the inactivation kinetics of pseudomonas aeruginosa using the defatted seed extract.

  18. Distinct molecular sites of anaesthetic action: pentobarbital block of human brain sodium channels is alleviated by removal of fast inactivation

    NARCIS (Netherlands)

    Wartenberg, H. C.; Urban, B. W.; Duch, D. S.

    1999-01-01

    Fast inactivation of sodium channel function is modified by anaesthetics. Its quantitative contribution to the overall anaesthetic effect is assessed by removing the fast inactivation mechanism enzymatically. Sodium channels from human brain cortex were incorporated into planar lipid bilayers. After

  19. Net energy production associated with pathogen inactivation during mesophilic and thermophilic anaerobic digestion of sewage sludge.

    Science.gov (United States)

    Ziemba, Christopher; Peccia, Jordan

    2011-10-15

    The potential for anaerobic digester energy production must be balanced with the sustainability of reusing the resultant biosolids for land application. Mesophilic, thermophilic, temperature-phased, and high temperature (60 or 70 °C) batch pre-treatment digester configurations have been systematically evaluated for net energy production and pathogen inactivation potential. Energy input requirements and net energy production were modeled for each digester scheme. First-order inactivation rate coefficients for Escherichia coli, Enterococcus faecalis and bacteriophage MS-2 were measured at each digester temperature and full-scale pathogen inactivation performance was estimated for each indicator organism and each digester configuration. Inactivation rates were found to increase dramatically at temperatures above 55 °C. Modeling full-scale performance using retention times based on U.S. EPA time and temperature constraints predicts a 1-2 log inactivation in mesophilic treatment, and a 2-5 log inactivation in 50-55 °C thermophilic and temperature-phased treatments. Incorporating a 60 or 70 °C batch pre-treatment phase resulted in dramatically higher potency, achieving MS-2 inactivation of 14 and 16 logs respectively, and complete inactivation (over 100 log reduction) of E. coli and E. faecalis. For temperatures less than 70 °C, viability staining of thermally-treated E. coli showed significantly reduced inactivation relative to standard culture enumeration. Due to shorter residence times in thermophilic reactors, the net energy production for all digesters was similar (less than 20% difference) with the 60 or 70 °C batch treatment configurations producing the most net energy and the mesophilic treatment producing the least. Incorporating a 60 or 70 °C pre-treatment phase can dramatically increase pathogen inactivation performance without decreasing net energy capture from anaerobic digestion. Energy consumption is not a significant barrier against

  20. Inactivation of Zika virus in platelet components using amotosalen and ultraviolet A illumination.

    Science.gov (United States)

    Santa Maria, Felicia; Laughhunn, Andrew; Lanteri, Marion C; Aubry, Maite; Musso, Didier; Stassinopoulos, Adonis

    2017-08-01

    Concerned over the risk of Zika virus (ZIKV) transfusion transmission, public health agencies recommended the implementation of mitigation strategies for its prevention. Those strategies included the use of pathogen inactivation for the treatment of plasma and platelets. The efficacy of amotosalen/ultraviolet A to inactivate ZIKV in plasma had been previously demonstrated, and the efficacy of inactivation in platelets with the same technology was assumed. These studies quantify ZIKV inactivation in platelet components using amotosalen/ultraviolet A. Platelet components were spiked with ZIKV, and ZIKV infectious titers and RNA loads were measured by cell culture-based assays and real-time polymerase chain reaction in spiked platelet components before and after photochemical treatment using amotosalen/ultraviolet A. The mean ZIKV infectivity titers and RNA loads in platelet components before inactivation were either 4.9 log10 plaque forming units per milliliter, or 4.4 log10 50% tissue culture infective dose per milliliter and 7.5 log10 genome equivalents per milliliter, respectively. No infectivity was detected immediately after amotosalen/ultraviolet A treatment. No replicative virus remained after treatment, as demonstrated by multiple passages on Vero cell cultures; and ZIKV RNA was not detected from the first passage after inactivation. Additional experiments in this study demonstrated efficient inactivation to the limit of detection in platelets manufactured in 65% platelet additive solution, 35% plasma, or 100% plasma. As previously demonstrated for plasma, robust levels of ZIKV inactivation were achieved in platelet components. With inactivation of higher levels of ZIKV than those reported in asymptomatic, RNA-reactive blood donors, the pathogen-inactivation system using amotosalen/ultraviolet A offers the potential to mitigate the risk of ZIKV transmission by plasma and platelet transfusion. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc

  1. Modification of C-type inactivating Shaker potassium channels by chloramine-T.

    Science.gov (United States)

    Schlief, T; Schönherr, R; Heinemann, S H

    1996-02-01

    Shaker potassium channels undergo a slow C-type inactivation which can be hastened dramatically by single-point mutations in or near the pore region. We found that the oxidizing agent chloramine-T (Chl-T) causes an irreversible loss of current for those mutants which show C-type inactivation. For several mutants at position T449, which show a wide spectrum of inactivation time constants, the time constant of current rundown induced by Chl-T correlated with the speed of inactivation. Rundown was accelerated when the channels were in the inactivated state but rundown also occurred when channels were not opened or inactivated. Apparently, only those channels which can undergo C-type inactivation are accessible to Chl-T. In order to gain information about the target amino-acid residue for the action of Chl-T and the structural rearrangements occurring during C-type inactivation, several mutant channel proteins were compared with respect to their response to Chl-T. Since Chl-T can oxidize cysteine and methionine residues, we mutated the possible targets in and close to the pore region, namely C462 to A, and M440 and M448 to I. While the residues M440 and C462 were not important for channel rundown, mutation of M448 to I made the channels more resistant to Chl-T by about one order of magnitude. While inactivation was accelerated upon application of Chl-T in most mutants, mutation of M448 to I abolished this effect on the time course of inactivation, indicating that M448 is one of the target residues for Chl-T.

  2. Nanoscale Structural and Mechanical Analysis of Bacillus anthracis Spores Inactivated with Rapid Dry Heating

    Science.gov (United States)

    Felker, Daniel L.; Burggraf, Larry W.

    2014-01-01

    Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using atomic force microscopy (AFM). Our results revealed significant changes in spore morphology and nanomechanical properties after heat inactivation. In addition, we also found that these changes were different under different heating conditions that produced similar inactivation probabilities (high temperature for short exposure time versus low temperature for long exposure time). We attributed the differences to the differential thermal and mechanical stresses in the spore. The buildup of internal thermal and mechanical stresses may become prominent only in ultrafast, high-temperature heat inactivation when the experimental timescale is too short for heat-generated vapor to efficiently escape from the spore. Our results thus provide direct, visual evidences of the importance of thermal stresses and heat and mass transfer to spore inactivation by very rapid dry heating. PMID:24375142

  3. Inactivation of microorganisms with microwaves at reduced temperatures.

    Science.gov (United States)

    Kozempel, M F; Annous, B A; Cook, R D; Scullen, O J; Whiting, R C

    1998-05-01

    We developed a pilot-plant nonthermal flow process using microwave energy to inactivate microorganisms. The process consists of multiple passes through the microwave generator. Each passed material goes to a receiving tank for subsequent passes. The flow rate was 0.96 to 1.26 kg/min and the dwell time per pass was 1.1 to 1.5 min. Five passes were used. The microwave energy is instantaneously and simultaneously applied to the system, and thermal energy is removed by a cooling tube within the process line in the microwave generator. The cooling tube maintains the temperature below 40 degrees C. There was significant reduction in microorganisms in water, 10% glucose solution, and apple juice, and in yeast in beer. There was a slight decrease in microorganisms in tomato juice, pineapple juice, apple cider, and beer; and no effect in skim milk.

  4. Experience of vaccination with inactivated poliomyelitis vaccines in Iceland.

    Science.gov (United States)

    Gudnadóttir, M

    1981-01-01

    Iceland, as a few other European countries, has used inactivated vaccine against poliomyelitis from the beginning in 1956. No cases of paralytic polio occurred since 1960. For 17 years neither isolations of poliovirus nor suspected cases of the clinical disease have been recorded. Studies on neutralizing antibodies in sera of vaccinees were not too encouraging after 4 injections. A 5th vaccination of IPV was therefore given to those children who lacked antibodies to any type of poliovirus. One month after the 5th injection 70% had antibodies against all 3 types of poliovirus and only 2% lacked antibodies against both types 1 and 3. In countries where no virus to boost immunity exists any longer during the life of an individual it may be necessary to secure booster effects at regular intervals after primary vaccination and later in life. This will be included in the vaccination schedule against polio in Iceland.

  5. Enzyme stability in downstream processing. Part 2: quantification of inactivation.

    Science.gov (United States)

    Weijers, S R; Van't Riet, K

    1992-01-01

    In biotechnological recovery processes the instability of the product can lead to large losses in the sequence of recovery processes needed to purify the product. As the cost of the final active product is strongly dependent on the recovery yield, this will lead to an increase in product cost. Therefore knowledge of factors that influence stability is important. This Part 2 provides the basic principles for design and operation of processes in which inactivation takes place. Simple kinetics and reactor modelling are discussed. These are applied to a number of unit operations: cell disruption, membrane filtration, drying and reversed micellar extraction. It is thus shown that the basic tools for modeling of biochemical processes provide us with the data needed for optimal process design and operation.

  6. Inactivation pathogenic microorganisms in water by laser methods

    Science.gov (United States)

    Iakovlev, Alexey; Grishkanich, Aleksandr; Kascheev, Sergey; Ruzankina, Julia; Afanasyev, Mikhail; Hafizov, Nail

    2017-02-01

    As a result of the research the following methods have been proposed for controlling harmful microorganisms: sterilization of water by laser radiation at wavelengths of 425 nm, 355 nm and 308 nm. The results of theoretical and experimental studies on the development and establishment of a system of ultraviolet disinfection of water for injection (UFOVI) intended for research sterilized water for injections. The pipe created a strong turbulent water flow. Performance irradiation laminar flow of 1.5 liters per second. Irradiation was carried out at three wavelengths 425 nm, 355 nm and 308 nm with energies semiconductor laser diode arrays to 4 MJ / cm3. Wavelength tuning implemented current in the range of 10 nm. For large capacities, we have developed a miniature solid state laser, which was used in fluid microorganisms inactivator. In the water treatment process breaks up to 98% of microbes, but can be left among pathogenic viruses destruction which requires special handling.

  7. New developments in gold-catalyzed manipulation of inactivated alkenes

    Directory of Open Access Journals (Sweden)

    Michel Chiarucci

    2013-11-01

    Full Text Available Over the recent years, the nucleophilic manipulation of inactivated carbon–carbon double bonds has gained remarkable credit in the chemical community. As a matter of fact, despite lower reactivity with respect to alkynyl and allenyl counterparts, chemical functionalization of isolated alkenes, via carbon- as well as hetero atom-based nucleophiles, would provide direct access to theoretically unlimited added value of molecular motifs. In this context, homogenous [Au(I] and [Au(III] catalysis continues to inspire developments within organic synthesis, providing reliable responses to this interrogative, by combining crucial aspects such as chemical selectivity/efficiency with mild reaction parameters. This review intends to summarize the recent progresses in the field, with particular emphasis on mechanistic details.

  8. Influence of bacterial interactions on the susceptibility to photodynamic inactivation

    Science.gov (United States)

    Upadya, M. H.; Tegos, G.; Hamblin, M.; Kishen, A.

    2009-06-01

    Photodynamic therapy has emerged as a possible supplement to the existing protocols for endodontic disinfection. Microbes are known to gain significant ecological advantage when they survive as coaggregates and biofilms in an infected tissue. Such microbial coaggregates and biofilms have been confirmed to play a key role in the pathogenicity of many infections. So far, not many studies have correlated the efficacy of antimicrobial photodynamic inactivation (APDI) to the different modes of bacterial growth. This study aims to evaluate the APDI of 3 strains of Enterococcus faecalis in planktonic phase, in a co-aggregated suspension and in a 4-day old biofilm. The results showed that the biofilm mode of growth offered the greatest resistance to APDI and the inclusion of an efflux pump inhibitor significantly increased the APDI of biofilm bacteria. From this study, we conclude that APDI of bacteria in biofilms is the most challenging and that the use of bacterial efflux pump inhibitors enhances its photodynamic antibiofilm efficacy.

  9. Ribosome-Inactivating Proteins: From Plant Defense to Tumor Attack

    Directory of Open Access Journals (Sweden)

    Maria Serena Fabbrini

    2010-11-01

    Full Text Available Ribosome-inactivating proteins (RIPs are EC3.2.32.22 N-glycosidases that recognize a universally conserved stem-loop structure in 23S/25S/28S rRNA, depurinating a single adenine (A4324 in rat and irreversibly blocking protein translation, leading finally to cell death of intoxicated mammalian cells. Ricin, the plant RIP prototype that comprises a catalytic A subunit linked to a galactose-binding lectin B subunit to allow cell surface binding and toxin entry in most mammalian cells, shows a potency in the picomolar range. The most promising way to exploit plant RIPs as weapons against cancer cells is either by designing molecules in which the toxic domains are linked to selective tumor targeting domains or directly delivered as suicide genes for cancer gene therapy. Here, we will provide a comprehensive picture of plant RIPs and discuss successful designs and features of chimeric molecules having therapeutic potential.

  10. Adsorption and inactivation of proteolytic enzymes by Triaenophorus nodulosus (Cestoda

    Directory of Open Access Journals (Sweden)

    Izvekova G.I.

    2017-03-01

    Full Text Available The proteolytic activity in washings off the Triaenophorus nodulosus cestode tegument and the ability of the worms to inactivate proteolytic enzymes were studied. It was found that the major proteolytic activity in the washing samples is represented by the easily desorbed fraction most probably characterizing the activity of the host’s enzymes. Serine proteinases are an essential part of these enzymes. It was shown that the worms’ incubation medium and their homogenates can inhibit host proteinases and commercial trypsin samples. Suppressive activity of the incubation medium suggests that the inhibitors are rather spontaneously produced by the worms than induced by the presence of proteinases in the surrounding medium. The inhibitor produced by the cestode is hypothesized to be trypsin-specific.

  11. Evaluation of an inactivated vaccine for nephropathogenic infectious bronchitis virus

    Directory of Open Access Journals (Sweden)

    T. R. Gopalakrishnamurthy

    2013-06-01

    Full Text Available Aim: To evaluate an inactivated vaccine for nephropathogenic infectious bronchitis in broiler with special reference to its ability for passing maternal antibodies to broiler chicks. Materials and Methods: An inactivated vaccine against nephropathogenic infectious bronchitis (NIB, prepared using an isolate obtained from natural outbreak of NIB was administered to broiler parents at the point of lay, leaving the control birds unvaccinated. Eggs laid below the desired weight (> 52 g by vaccinated hens were utilized for yolk serology. Chicks obtained from hens of both group were subjected for serology and challenge with wild type of nephropathogenic IB isolates. Serology of the yolk and serum was carried out using haemagglutination (HI test and ELISA. Results: Yolk serology revealed a geometric mean titre of 415.9 and 15188±768 in HI test and ELISA respectively on 28 days post vaccination (dpv as against 16.0 and 1881±86 in yolk from unvaccinated hens. The HI test and ELISA indicated that the level of maternal antibody (MAb in the chicks obtained from vaccinated hens was significantly (P< 0.01 higher on seven days of age than that of chicks from unvaccinated hens. However, the level of Mab of the chicks obtained from vaccinated hens decreased to below the level of protection at two weeks of age. Wild isolate and another isolate obtained from different geographical area were used for challenge dividing the chicks from vaccinated and unvaccinated hens equally. Mortality was observed in the challenged chicks from vaccinated (one in heterologus challenge and unvaccinated (two hens. Examination of kidney specimens collected from dead chicks revealed mottling and severe congestion grossly and inflammatory, degenerative and necrotic changes microscopically. Conclusion: The partial cross-protection against heterologous challenge and incomplete protection against homologous challenge with wild isolates were noticed. [Vet World 2013; 6(3.000: 134-138

  12. Role of FAAH-like anandamide transporter in anandamide inactivation.

    Directory of Open Access Journals (Sweden)

    Kwannok Leung

    Full Text Available The endocannabinoid system modulates numerous physiological processes including nociception and reproduction. Anandamide (AEA is an endocannabinoid that is inactivated by cellular uptake followed by intracellular hydrolysis by fatty acid amide hydrolase (FAAH. Recently, FAAH-like anandamide transporter (FLAT, a truncated and catalytically-inactive variant of FAAH, was proposed to function as an intracellular AEA carrier and mediate its delivery to FAAH for hydrolysis. Pharmacological inhibition of FLAT potentiated AEA signaling and produced antinociceptive effects. Given that endocannabinoids produce analgesia through central and peripheral mechanisms, the goal of the current work was to examine the expression of FLAT in the central and peripheral nervous systems. In contrast to the original report characterizing FLAT, expression of FLAT was not observed in any of the tissues examined. To investigate the role of FLAT as a putative AEA binding protein, FLAT was generated from FAAH using polymerase chain reaction and further analyzed. Despite its low cellular expression, FLAT displayed residual catalytic activity that was sensitive to FAAH inhibitors and abolished following mutation of its catalytic serine. Overexpression of FLAT potentiated AEA cellular uptake and this appeared to be dependent upon its catalytic activity. Immunofluorescence revealed that FLAT localizes primarily to intracellular membranes and does not contact the plasma membrane, suggesting that its capability to potentiate AEA uptake may stem from its enzymatic rather than transport activity. Collectively, our data demonstrate that FLAT does not serve as a global intracellular AEA carrier, although a role in mediating localized AEA inactivation in mammalian tissues cannot be ruled out.

  13. MSA prions exhibit remarkable stability and resistance to inactivation.

    Science.gov (United States)

    Woerman, Amanda L; Kazmi, Sabeen A; Patel, Smita; Freyman, Yevgeniy; Oehler, Abby; Aoyagi, Atsushi; Mordes, Daniel A; Halliday, Glenda M; Middleton, Lefkos T; Gentleman, Steve M; Olson, Steven H; Prusiner, Stanley B

    2018-01-01

    In multiple system atrophy (MSA), progressive neurodegeneration results from the protein α-synuclein misfolding into a self-templating prion conformation that spreads throughout the brain. MSA prions are transmissible to transgenic (Tg) mice expressing mutated human α-synuclein (TgM83+/-), inducing neurological disease following intracranial inoculation with brain homogenate from deceased patient samples. Noting the similarities between α-synuclein prions and PrP scrapie (PrPSc) prions responsible for Creutzfeldt-Jakob disease (CJD), we investigated MSA transmission under conditions known to result in PrPSc transmission. When peripherally exposed to MSA via the peritoneal cavity, hind leg muscle, and tongue, TgM83+/- mice developed neurological signs accompanied by α-synuclein prions in the brain. Iatrogenic CJD, resulting from PrPSc prion adherence to surgical steel instruments, has been investigated by incubating steel sutures in contaminated brain homogenate before implantation into mouse brain. Mice studied using this model for MSA developed disease, whereas wire incubated in control homogenate had no effect on the animals. Notably, formalin fixation did not inactivate α-synuclein prions. Formalin-fixed MSA patient samples also transmitted disease to TgM83+/- mice, even after incubating in fixative for 244 months. Finally, at least 10% sarkosyl was found to be the concentration necessary to partially inactivate MSA prions. These results demonstrate the robustness of α-synuclein prions to denaturation. Moreover, they establish the parallel characteristics between PrPSc and α-synuclein prions, arguing that clinicians should exercise caution when working with materials that might contain α-synuclein prions to prevent disease.

  14. Radiation inactivation target size of rat adipocyte glucose transporter

    Energy Technology Data Exchange (ETDEWEB)

    Jung, C.Y.; Jacobs, D.B.; Berenski, C.J.; Spangler, R.A.

    1987-05-01

    In situ assembly states of rat adipocyte glucose transport protein in plasma membrane (PM) and in microsomal pool (MM) were assessed by measuring target size (TS) of D glucose-sensitive, cytochalasin B binding activity. High energy radiation inactivated the binding in both PM and MM by reducing the total capacity of the binding (B/sub T/) without affecting the dissociation constant (K/sub D/). The reduction in B/sub T/ as a function of radiation dose was analyzed based on classical target theory, from which TS was calculated. TS in the PM of insulin-treated adipocytes was 58 KDa. TS in the MM of noninsulin-treated and insulin-treated adipocytes were 112 and 109 KDa, respectively. With MM, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses showing a shoulder in the semilog plots, which may be due to an interaction with a radiation sensitive inhibitor. With these results, they propose the following model: Adipocyte glucose transporter, while exists as a monomer (T) in PM, occurs in MM either as a homodimer (T/sub 2/) or as a heterodimer (TX) with a protein X of a similar size. These dimers (T/sub 2/ or TX) in MM, furthermore, may form a multi-molecular assembly with another, large (300-400 KDa) protein Y, and insulin increases this assembly formation. These putative, transporter-associated proteins X and Y may play an important role in control of transporter distribution between PM and MM, particularly in response to insulin.

  15. Calcium current inactivation in identified neurones of Helix aspersa.

    Science.gov (United States)

    Plant, T D; Standen, N B

    1981-01-01

    1. A two-electrode voltage clamp method was used to study Ca inward currents in identified Helix aspersa neurones bathed in 25 mM-Ca, Na-free saline with TEA and 4-AP. 2. Inward currents were blocked by CdCl2. In Cd delayed outward currents appeared at +30 mV. When two identical depolarizations were separated by a gap inward current turned off to the same level during the two pulses up to +20 mV; above this potential the records cross over. 3. The turn-off of inward current at potentials up to +20 mV was not affected by 0.2 mM-quinine, which reduced outward currents at more depolarized potentials. Inward currents declined exponentially over the first 100 msec with a time constant around 60 msec at 0 mV. Double-pulse experiments gave the same time course of turn-off. 4. When Ca inward current was reduced by lowering [Ca]o or by partial block by Cd the rate and extent of turn-off was reduced. 5. The inactivation curve (obtained using a double pulse with gap method) was U-shaped. The curve was not significantly changed by addition of quinine (0.2 mM) or by changing test pulse size. 6. Recovery of inward currents after a depolarizing prepulse was a double-exponential process, with time constants of 120 msec and 9.4 sec at 10--11 degrees C. 7. Our results are discussed in terms of possible Ca-dependent Ca inactivation and in terms of the possibility of development of an outward Ca-dependent K current. PMID:7338811

  16. Visual fixation as equilibrium: Evidence from superior colliculus inactivation

    Science.gov (United States)

    Goffart, Laurent; Hafed, Ziad M.; Krauzlis, Richard J.

    2012-01-01

    During visual fixation, the image of an object is maintained within the fovea. Previous studies have shown that such maintenance involves the deep superior colliculus (dSC). However, the mechanisms by which the dSC supports visual fixation remain controversial. According to one view, activity in the rostral dSC maintains gaze direction by preventing neurons in the caudal dSC from issuing saccade commands. An alternative hypothesis proposes that gaze direction is achieved through equilibrium of target position signals originating from the two dSC. Here we show in monkeys that artificially reducing activity in the rostral half of one dSC results in a biased estimate of target position during fixation, consistent with the second hypothesis, rather than an inability to maintain gaze fixation as predicted by the first hypothesis. After injection of muscimol at rostral sites in the dSC, fixation became more stable since microsaccade rate was reduced rather than increased. Moreover, the scatter of eye positions was offset relative to pre-inactivation baselines. The magnitude and the direction of the offsets depended upon both the target size and the injected site in the collicular map. Other oculomotor parameters, such as the accuracy of saccades to peripheral targets and the amplitude and velocity of fixational saccades, were largely unaffected. These results suggest that the rostral half of the dSC supports visual fixation through a distributed representation of behaviorally-relevant target position signals. The inactivation-induced fixation offset establishes the foveal visual stimulation that is required to restore the balance of activity between the two dSC. PMID:22855812

  17. Porinas as an adyuvant of inactivated Newcastle vaccine in broilers

    Directory of Open Access Journals (Sweden)

    Francisco Bustos M.

    2005-05-01

    Full Text Available Three groups of 25 broilers were vaccinated on two opportunities by aerosol using inactivated NC (Newcastle virus and different helper concentrations of porinas (20 ìg, 50 ìg, 125 ìg. A fourth group was injected with live B1 virus (12 and 28 days of age nasally. The NC inactivated virus (La Sota strain was concentrated 10 times with PEG with a final titer of 1:2.056. Twenty serums for each group were taken in order to evaluate NC antibodies using the HI and double immuno-difusion tests for IgA detection at 1, 12, 28 and 42 days of age. During the study the chickens were on a restricted diet in order to control ascites (2.640 mosl. On day 42, two broilers of the fourth group (live virus presented ascites and 1 broiler of group 1 presented lung edema (20 ìg. The geometric mean for NC antibodies titers at 42 days of age was 2 in the groups 1,2,3 and 5.7 in the group 4 (Log 2. For IgA, 180 mg/dl, 135 mg/dl, 120 mg/dl and 176 mg/dl respectively. Three broilers of each group were challenged with a pathogenic strain of NC, at 42 day of age, without signs of disease after 72 hours when the positive control group was dead. Gross and microscopic lesions were not detected in the bursa of Fabricius or thymo. [thymo sounds like short hand for something that should be properly named.] Very good animal weight, conversion and efficiency results were observed in all the groups. New studies using a fixed dose of porinas, larger numbers of broilers and the establishment of protective levels of IgA against NC challenge are recommended.

  18. A novel method for bacterial inactivation using electrosprayed water nanostructures

    Science.gov (United States)

    Pyrgiotakis, Georgios; McDevitt, James; Yamauchi, Toshiyuki; Demokritou, Philip

    2012-08-01

    This is a study focusing on the potential to deactivate biological agents (bacteria and endospores) using engineered water nanostructures (EWNS). The EWNS were generated using an electrospray device that collects water by condensing atmospheric water vapor on a Peltier-cooled electrode. A high voltage is applied between the collection electrode and a grounded electrode resulting in aerosolization of the condensed water and a constant generation of EWNS. Gram-negative Serratia marcescens, gram-positive Staphylococcus aureus, and Bacillus atrophaeus endospores were placed on stainless steel coupons and exposed to generated EWNS at multiple time intervals. Upon exposures, the bacteria were recovered and placed on nutrient agar to grow, and the colony forming units were counted. Ozone levels as well as air temperature and relative humidity were monitored during the experiments. Qualitative confirmation of bacterial destruction was also obtained by transmission electron microscopy. In addition, important EWNS aerosol properties such as particle number concentration as a function of size as well as the average surface charge of the generated EWNS were measured using real-time instrumentation. It was shown that the novel electrospray method can generate over time a constant flux of EWNS. EWNS have a peak number concentration of 8,000 particles per cubic centimeter with a modal peak size around 20 nm. The average surface charge of the generated EWNS was found to be 10 ± 2 electrons per particle. In addition, it was shown that the EWNS have the potential to deactivate both bacteria types from surfaces. At the same administrate dose, however, the endospores were not inactivated. This novel method and the unique properties of the generated EWNS could potentially be used to develop an effective, environmentally friendly, and inexpensive method for bacteria inactivation.

  19. A novel method for bacterial inactivation using electrosprayed water nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Pyrgiotakis, Georgios, E-mail: gpyrgiot@hsph.harvard.edu; McDevitt, James [Harvard School of Public Health, Center for Nanotechnology and Nanotoxicology (United States); Yamauchi, Toshiyuki [Panasonic Corporation, Appliances Company (Japan); Demokritou, Philip [Harvard School of Public Health, Center for Nanotechnology and Nanotoxicology (United States)

    2012-08-15

    This is a study focusing on the potential to deactivate biological agents (bacteria and endospores) using engineered water nanostructures (EWNS). The EWNS were generated using an electrospray device that collects water by condensing atmospheric water vapor on a Peltier-cooled electrode. A high voltage is applied between the collection electrode and a grounded electrode resulting in aerosolization of the condensed water and a constant generation of EWNS. Gram-negative Serratia marcescens, gram-positive Staphylococcus aureus, and Bacillusatrophaeus endospores were placed on stainless steel coupons and exposed to generated EWNS at multiple time intervals. Upon exposures, the bacteria were recovered and placed on nutrient agar to grow, and the colony forming units were counted. Ozone levels as well as air temperature and relative humidity were monitored during the experiments. Qualitative confirmation of bacterial destruction was also obtained by transmission electron microscopy. In addition, important EWNS aerosol properties such as particle number concentration as a function of size as well as the average surface charge of the generated EWNS were measured using real-time instrumentation. It was shown that the novel electrospray method can generate over time a constant flux of EWNS. EWNS have a peak number concentration of {approx}8,000 particles per cubic centimeter with a modal peak size around 20 nm. The average surface charge of the generated EWNS was found to be 10 {+-} 2 electrons per particle. In addition, it was shown that the EWNS have the potential to deactivate both bacteria types from surfaces. At the same administrate dose, however, the endospores were not inactivated. This novel method and the unique properties of the generated EWNS could potentially be used to develop an effective, environmentally friendly, and inexpensive method for bacteria inactivation.

  20. How helminth lipid-binding proteins offload their ligands to membranes: differential mechanisms of fatty acid transfer by the ABA-1 polyprotein allergen and Ov-FAR-1 proteins of nematodes and Sj-FABPc of schistosomes.

    Science.gov (United States)

    McDermott, Lindsay; Kennedy, Malcolm W; McManus, Donald P; Bradley, Jan E; Cooper, Alan; Storch, Judith

    2002-05-28

    Three different classes of small lipid-binding protein (LBP) are found in helminth parasites. Although of similar size, the ABA-1A1 (also designated As-NPA-A1) and Ov-FAR-1 (formerly known as Ov20) proteins of nematodes are mainly alpha-helical and have no known structural counterparts in mammals, whereas Sj-FABPc of schistosomes is predicted to form a beta-barrel structure similar to the mammalian family of intracellular fatty acid binding proteins. The parasites that produce these proteins are unable to synthesize their own complex lipids and, instead, rely entirely upon their hosts for supply. As a first step in elucidating whether these helminth proteins are involved in the acquisition of host lipid, the process by which these LBPs deliver their ligands to acceptor membranes was examined, by comparing the rates and mechanisms of ligand transfer from the proteins to artificial phospholipid vesicles using a fluorescence resonance energy transfer assay. All three proteins bound the fluorescent fatty acid 2-(9-anthroyloxy)palmitic acid (2AP) similarly, but there were clear differences in the rates and mechanisms of fatty acid transfer. Sj-FABPc displayed a collisional mechanism; 2AP transfer rates increased with acceptor membrane concentration, were modulated by acceptor membrane charge, and were not diminished in the presence of increasing salt concentrations. In contrast, transfer of ligand from Ov-FAR-1 and ABA-1A1 involved an aqueous diffusion step; transfer rates from these proteins were not modulated by acceptor membrane concentration or charge but did decrease with the ionic strength of the buffer. Despite these differences, all of the proteins interacted directly with membranes, as determined using a cytochrome c competition assay, although Sj-FABPc interacted to a greater extent than did Ov-FAR-1 or rABA-1A1. Together, these results suggest that Sj-FABPc is most likely to be involved in the intracellular targeted transport and metabolism of fatty acids

  1. Elective Inactivation of Total Artificial Heart Technology in Non-Futile Situations: Inpatients, Outpatients and Research Participants

    Science.gov (United States)

    Bramstedt, Katrina A.

    2004-01-01

    Total artificial heart technology as a potential clinical therapy raises the issue of elective device inactivation in both futile and non-futile situations. This article explores elective device inactivation in non-futile situations. In reply to such requests for inactivation, the medical team should reflect on the individual's decision-making…

  2. Safety and immunogenicity of a quadrivalent inactivated influenza vaccine compared to licensed trivalent inactivated influenza vaccines in adults.

    Science.gov (United States)

    Greenberg, David P; Robertson, Corwin A; Noss, Michael J; Blatter, Mark M; Biedenbender, Rex; Decker, Michael D

    2013-01-21

    To evaluate the safety and immunogenicity of a prototype quadrivalent inactivated influenza vaccine (QIV) containing two influenza B strains, one of each lineage, compared with licensed trivalent inactivated influenza vaccines (TIVs) containing either a Victoria B-lineage strain (2009-2010 TIV) or a Yamagata B-lineage strain (2008-2009 TIV). Healthy adults ≥18 years of age were eligible to participate in this phase II, open-label, randomized, controlled, multicenter study conducted in the US. Participants received a single dose of 2009-2010 TIV, 2008-2009 TIV, or QIV. Sera were collected before and 21 days after vaccine administration to test for hemagglutination inhibition (HAI) antibodies to each of the four influenza strains. Immunogenicity endpoints included geometric mean HAI antibody titers (GMTs) and rates of seroprotection (titer ≥1:40) and seroconversion (4-fold rise pre- to post-vaccination). Safety endpoints included frequency of solicited injection-site and systemic reactions occurring within 3 days of vaccination, and unsolicited non-serious adverse events (AEs) and serious AEs (SAEs) within 21 days of vaccination. One hundred and ninety participants were enrolled to each vaccine group. QIV induced GMTs to each A and B strain that were noninferior to those induced by the 2009-2010 and 2008-2009 TIVs (i.e., lower limit of the two-sided 95% confidence interval of the ratio of GMT(QIV)/GMT(TIV)>0.66 for each strain). Rates of seroprotection and seroconversion were similar in all groups. Incidence and severity of solicited injection-site and systemic reactions, AEs, and SAEs were similar among groups. QIV, containing two B strains (one from each B lineage), was as safe and immunogenic as licensed TIV. QIV has the potential to be a useful alternative to TIV and offer protection against both B lineages. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Inactivation of oenological lactic acid bacteria (Lactobacillus hilgardii and Pediococcus pentosaceus) by wine phenolic compounds.

    Science.gov (United States)

    García-Ruiz, A; Bartolomé, B; Cueva, C; Martín-Alvarez, P J; Moreno-Arribas, M V

    2009-09-01

    To investigate the inactivation properties of different classes of phenolic compounds present in wine against two wine isolates of Lactobacillus hilgardii and Pediococcus pentosaceus, and to explore their inactivation mechanism. After a first screening of the inactivation potency of 21 phenolic compounds (hydroxybenzoic and hydroxycinnamic acids, phenolic alcohols, stilbenes, flavan-3-ols and flavonols) at specific concentrations, the survival parameters (MIC and MBC) of the most active compounds were determined. For the L. hilgardii strain, the flavonols morin and kaempferol showed the strongest inactivation (MIC values of one and 5 mg l(-1), and MBC values of 7.5 and 50 mg l(-1), respectively). For the P. pentosaceus strain, flavonols also showed the strongest inactivation effects, with MIC values between one and 10 mg l(-1) and MBC values between 7.5 and 300 mg l(-1). Observations by epifluorescence and scanning electron microscopy revealed that the phenolics damaged the cell membrane and promoted the subsequent release of the cytoplasm material into the medium. The antibacterial activity of wine phenolics against L. hilgardii and P. pentosaceus was dependent on the phenolic compound tested, and led not only to bacteria inactivation, but also to the cell death. New information about the inactivation properties of wine lactic acid bacteria by phenolic compounds is presented. It opens up a new area of study for selecting/obtaining wine phenolic preparations with potential applications as a natural alternative to SO(2) in winemaking.

  4. X inactivation in females with X-linked Charcot-Marie-Tooth disease.

    LENUS (Irish Health Repository)

    Murphy, Sinéad M

    2012-07-01

    X-linked Charcot-Marie-Tooth disease (CMT1X) is the second most common inherited neuropathy, caused by mutations in gap junction beta-1 (GJB1). Males have a uniformly moderately severe phenotype while females have a variable phenotype, suggested to be due to X inactivation. We aimed to assess X inactivation pattern in females with CMT1X and correlate this with phenotype using the CMT examination score to determine whether the X inactivation pattern accounted for the variable phenotype in females with CMT1X. We determined X inactivation pattern in 67 females with CMT1X and 24 controls using the androgen receptor assay. We were able to determine which X chromosome carried the GJB1 mutation in 30 females. There was no difference in X inactivation pattern between patients and controls. In addition, there was no correlation between X inactivation pattern in blood and phenotype. A possible explanation for these findings is that the X inactivation pattern in Schwann cells rather than in blood may explain the variable phenotype in females with CMT1X.

  5. MS2 inactivation by TiO2 nanoparticles in the presence of quartz sand

    Science.gov (United States)

    Syngouna, Vasiliki I.; Chrysikopoulos, Constantinos V.

    2017-04-01

    Virus inactivation by nanoparticles (NPs) is hypothesized to affect virus fate and transport in the subsurface. This study examines the interactions of viruses with titanium dioxide (TiO2) anatase NPs, which is a good disinfectant with unique physiochemical properties, using three different virus concentrations. The bacteriophage MS2 was used as a model virus. A series of batch experiments of MS2 inactivation by TiO2 NPs were conducted at room temperature (25 °C), in the presence of quartz sand, with and without ambient light. The virus inactivation experimental data were satisfactorily fitted with a pseudo-first order expression with a time dependent rate coefficient. Quartz sand was shown to affect MS2 inactivation by TiO2 NPs both in the presence and absence of ambient light, because, under the experimental conditions of this study, the quartz sand offers a protection to the attached MS2 against inactivation. Moreover, in most cases similar inactivation rates were observed in reactor and control tubes (absence of TiO2 NPs) suggesting that low TiO2 concentration (10 mg/L) affects only slightly MS2 inactivation with and without ambient light.

  6. Identifying possible non-thermal effects of radio frequency energy on inactivating food microorganisms.

    Science.gov (United States)

    Kou, Xiaoxi; Li, Rui; Hou, Lixia; Zhang, Lihui; Wang, Shaojin

    2018-02-01

    Radio frequency (RF) heating has been successfully used for inactivating microorganisms in agricultural and food products. Athermal (non-thermal) effects of RF energy on microorganisms have been frequently proposed in the literature, resulting in difficulties for developing effective thermal treatment protocols. The purpose of this study was to identify if the athermal inactivation of microorganisms existed during RF treatments. Escherichia coli and Staphylococcus aureus in apple juice and mashed potato were exposed to both RF and conventional thermal energies to compare their inactivation populations. A thermal death time (TDT) heating block system was used as conventional thermal energy source to simulate the same heating treatment conditions, involving heating temperature, heating rate and uniformity, of a RF treatment at a frequency of 27.12 MHz. Results showed that a similar and uniform temperature distribution in tested samples was achieved in both heating systems, so that the central sample temperature could be used as representative one for evaluating thermal inactivation of microorganisms. The survival patterns of two target microorganisms in two food samples were similar both for RF and heating block treatments since their absolute difference of survival populations was  0.05) in inactivating bacteria between the RF and the heating block treatments at each set of temperatures. The solid temperature and microbial inactivation data demonstrated that only thermal effect of RF energy at 27.12 MHz was observed on inactivating microorganisms in foods. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Weed seed inactivation in soil mesocosms via biosolarization with mature compost and tomato processing waste amendments.

    Science.gov (United States)

    Achmon, Yigal; Fernández-Bayo, Jesús D; Hernandez, Katie; McCurry, Dlinka G; Harrold, Duff R; Su, Joey; Dahlquist-Willard, Ruth M; Stapleton, James J; VanderGheynst, Jean S; Simmons, Christopher W

    2017-05-01

    Biosolarization is a fumigation alternative that combines passive solar heating with amendment-driven soil microbial activity to temporarily create antagonistic soil conditions, such as elevated temperature and acidity, that can inactivate weed seeds and other pest propagules. The aim of this study was to use a mesocosm-based field trial to assess soil heating, pH, volatile fatty acid accumulation and weed seed inactivation during biosolarization. Biosolarization for 8 days using 2% mature green waste compost and 2 or 5% tomato processing residues in the soil resulted in accumulation of volatile fatty acids in the soil, particularly acetic acid, and >95% inactivation of Brassica nigra and Solanum nigrum seeds. Inactivation kinetics data showed that near complete weed seed inactivation in soil was achieved within the first 5 days of biosolarization. This was significantly greater than the inactivation achieved in control soils that were solar heated without amendment or were amended but not solar heated. The composition and concentration of organic matter amendments in soil significantly affected volatile fatty acid accumulation at various soil depths during biosolarization. Combining solar heating with organic matter amendment resulted in accelerated weed seed inactivation compared with either approach alone. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Selective inactivation of various acyl-CoA dehydrogenases by (methylenecyclopropyl)acetyl-CoA.

    Science.gov (United States)

    Ikeda, Y; Tanaka, K

    1990-04-19

    Inactivation of five distinct acyl-CoA dehydrogenases by (methylenecyclopropyl)acetyl-CoA (MCPA-CoA), the toxic metabolite of hypoglycin from unripe ackee fruit, was investigated using purified enzyme preparations. Short-chain acyl-CoA (SCADH), medium-chain acyl-CoA (MCADH) and isovaleryl-CoA (IVDH) dehydrogenases were severely and irreversibly inactivated by MCPA-CoA, while 2-methyl-branched chain acyl-CoA dehydrogenase (2-meBCADH) was only slowly and mildly inactivated. Long-chain acyl-CoA dehydrogenase (LCADH) was not significantly inactivated, even after prolonged incubation with MCPA-CoA. Inactivation of SCADH, MCADH and IVDH was effectively prevented by the addition of substrate. This mode of inactivation by MCPA-CoA explains the urinary metabolite profile in hypoglycin treated-rats, which includes large amounts of metabolites from fatty acids and leucine, and relatively small amounts of those from valine and isoleucine. Spectrophotometric titration of SCADH and MCADH with MCPA-CoA, together with the protective effects of substrate, indicates that MCPA-CoA is acted upon by, and exerts in turn irreversible inactivation of, SCADH and MCADH, confirming that MCPA-CoA is a suicide inhibitor (Wenz et al. (1981) J. Biol. Chem. 256, 9809-9812). Spectrophotometric titration data of LCADH and MCPA-CoA is typical of non-reacting CoA ester.

  9. Evaluation of Virus Inactivation by Formaldehyde to Enhance Biosafety of Diagnostic Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Lars Möller

    2015-02-01

    Full Text Available Formaldehyde (FA fixation of infectious samples is a well-established protocol in diagnostic electron microscopy of viruses. However, published experimental data that demonstrate virus inactivation by these fixation procedures are lacking. Usually, fixation is performed immediately before the sample preparation for microscopy. The fixation procedure should transform viruses in a non–infectious but nonetheless structurally intact form in order to allow a proper diagnosis based on morphology. FA provides an essential advantage in comparison to other disinfectants, because it preserves the ultrastructure of biological material without interfering significantly with the preparation (i.e., the negative staining and the detection of viruses. To examine the efficiency of FA inactivation, we used Vaccinia virus, Human adenovirus and Murine norovirus as models and treated them with FA under various conditions. Critical parameters for the inactivation efficiency were the temperature, the duration of the FA treatment, and the resistance of the virus in question. Our results show that FA inactivation at low temperature (4 °C bears a high risk of incomplete inactivation. Higher temperatures (25 °C are more efficient, although they still require rather long incubation times to fully inactivate a complex and highly robust virus like Vaccinia. A protocol, which applied 2% buffered FA for 60 min and a temperature–shift from 25 to 37 °C after 30 min was efficient for the complete inactivation of all test viruses, and therefore has the potential to improve both biosafety and speed of diagnostic electron microscopy.

  10. Sunlight inactivation of human viruses and bacteriophages in coastal waters containing natural photosensitizers.

    Science.gov (United States)

    Silverman, Andrea I; Peterson, Britt M; Boehm, Alexandria B; McNeill, Kristopher; Nelson, Kara L

    2013-02-19

    Sunlight inactivation of poliovirus type 3 (PV3), adenovirus type 2 (HAdV2), and two bacteriophage (MS2 and PRD1) was investigated in an array of coastal waters to better understand solar inactivation mechanisms and the effect of natural water constituents on observed inactivation rates (k(obs)). Reactor scale inactivation experiments were conducted using a solar simulator, and k(obs) for each virus was measured in a sensitizer-free control and five unfiltered surface water samples collected from different sources. k(obs) values varied between viruses in the same water matrix, and for each virus in different matrices, with PV3 having the fastest and MS2 the slowest k(obs) in all waters. When exposed to full-spectrum sunlight, the presence of photosensitizers increased k(obs) of HAdV2, PRD1 and MS2, but not PV3, which provides evidence that the exogenous sunlight inactivation mechanism, involving damage by exogenously produced reactive intermediates, played a greater role for these viruses. While PV3 inactivation was observed to be dominated by endogenous mechanisms, this may be due to a masking of exogenous k(obs) by significantly faster endogenous k(obs). Results illustrate that differences in water composition can shift absolute and relative inactivation rates of viruses, which has important implications for natural wastewater treatment systems, solar disinfection (SODIS), and the use of indicator organisms for monitoring water quality.

  11. Hemozoin as a novel adjuvant for inactivated whole virion influenza vaccine.

    Science.gov (United States)

    Uraki, Ryuta; Das, Subash C; Hatta, Masato; Kiso, Maki; Iwatsuki-Horimoto, Kiyoko; Ozawa, Makoto; Coban, Cevayir; Ishii, Ken J; Kawaoka, Yoshihiro

    2014-09-15

    Because vaccination is an effective means to protect humans from influenza viruses, extensive efforts have been made to develop not only new vaccines, but also for new adjuvants to enhance the efficacy of existing inactivated vaccines. Here, we examined the adjuvanticity of synthetic hemozoin, a synthetic version of the malarial by-product hemozoin, on the vaccine efficacy of inactivated whole influenza viruses in a mouse model. We found that mice immunized twice with hemozoin-adjuvanted inactivated A/California/04/2009 (H1N1pdm09) or A/Vietnam/1203/2004 (H5N1) virus elicited higher virus-specific antibody responses than did mice immunized with non-adjuvanted counterparts. Furthermore, mice immunized with hemozoin-adjuvanted inactivated viruses were better protected from lethal challenge with influenza viruses than were mice immunized with non-adjuvanted inactivated vaccines. Our results show that hemozoin improves the immunogenicity of inactivated influenza viruses, and is thus a promising adjuvant for inactivated whole virion influenza vaccines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Enveloped virus inactivation using neutral arginine solutions and applications in therapeutic protein purification processes.

    Science.gov (United States)

    McCue, Justin T; Selvitelli, Keith; Cecchini, Doug; Brown, Rhonda

    2014-01-01

    For the manufacturing of recombinant protein therapeutics produced from mammalian cell culture, demonstrating the capacity of the purification process to effectively clear infectious viruses is a regulatory requirement. At least two process steps, using different mechanisms of virus removal and/or inactivation, should be validated in support of the regulatory approval process. For example, exposure of the product stream to low pH, detergents or solvent/detergent combinations is commonly incorporated in protein purification processes for the inactivation of lipid-enveloped viruses. However, some proteins have limited stability at low pH or in the presence of the detergents, and alternative techniques for achieving the inactivation of enveloped viruses would be beneficial. We present here an alternative and novel approach for the rapid inactivation of enveloped viruses using pH-neutral buffer solutions containing arginine. The implementation of this approach in a monoclonal antibody or Fc-fusion protein purification process is described and illustrated with several different therapeutic proteins. The use of the neutral pH arginine solution was able to effectively inactivate two enveloped model viruses, with no measurable effect on the product quality of the investigated proteins. Thus, the use of pH-neutral arginine containing buffer solutions provides an alternative means of virus inactivation where other forms of virus inactivation, such as low pH and/or solvent/detergent treatments are not possible or undesirable due to protein stability limitations. © 2013 American Institute of Chemical Engineers.

  13. Pathogens Inactivated by Low-Energy-Electron Irradiation Maintain Antigenic Properties and Induce Protective Immune Responses

    Science.gov (United States)

    Fertey, Jasmin; Bayer, Lea; Grunwald, Thomas; Pohl, Alexandra; Beckmann, Jana; Gotzmann, Gaby; Casado, Javier Portillo; Schönfelder, Jessy; Rögner, Frank-Holm; Wetzel, Christiane; Thoma, Martin; Bailer, Susanne M.; Hiller, Ekkehard; Rupp, Steffen; Ulbert, Sebastian

    2016-01-01

    Inactivated vaccines are commonly produced by incubating pathogens with chemicals such as formaldehyde or β-propiolactone. This is a time-consuming process, the inactivation efficiency displays high variability and extensive downstream procedures are often required. Moreover, application of chemicals alters the antigenic components of the viruses or bacteria, resulting in reduced antibody specificity and therefore stimulation of a less effective immune response. An alternative method for inactivation of pathogens is ionizing radiation. It acts very fast and predominantly damages nucleic acids, conserving most of the antigenic structures. However, currently used irradiation technologies (mostly gamma-rays and high energy electrons) require large and complex shielding constructions to protect the environment from radioactivity or X-rays generated during the process. This excludes them from direct integration into biological production facilities. Here, low-energy electron irradiation (LEEI) is presented as an alternative inactivation method for pathogens in liquid solutions. LEEI can be used in normal laboratories, including good manufacturing practice (GMP)- or high biosafety level (BSL)-environments, as only minor shielding is necessary. We show that LEEI efficiently inactivates different viruses (influenza A (H3N8), porcine reproductive and respiratory syndrome virus (PRRSV), equine herpesvirus 1 (EHV-1)) and bacteria (Escherichia coli) and maintains their antigenicity. Moreover, LEEI-inactivated influenza A viruses elicit protective immune responses in animals, as analyzed by virus neutralization assays and viral load determination upon challenge. These results have implications for novel ways of developing and manufacturing inactivated vaccines with improved efficacy. PMID:27886076

  14. Buffer AVL Alone Does Not Inactivate Ebola Virus in a Representative Clinical Sample Type.

    Science.gov (United States)

    Smither, Sophie J; Weller, Simon A; Phelps, Amanda; Eastaugh, Lin; Ngugi, Sarah; O'Brien, Lyn M; Steward, Jackie; Lonsdale, Steve G; Lever, Mark S

    2015-10-01

    Rapid inactivation of Ebola virus (EBOV) is crucial for high-throughput testing of clinical samples in low-resource, outbreak scenarios. The EBOV inactivation efficacy of Buffer AVL (Qiagen) was tested against marmoset serum (EBOV concentration of 1 × 10(8) 50% tissue culture infective dose per milliliter [TCID50 · ml(-1)]) and murine blood (EBOV concentration of 1 × 10(7) TCID50 · ml(-1)) at 4:1 vol/vol buffer/sample ratios. Posttreatment cell culture and enzyme-linked immunosorbent assay (ELISA) analysis indicated that treatment with Buffer AVL did not inactivate EBOV in 67% of samples, indicating that Buffer AVL, which is designed for RNA extraction and not virus inactivation, cannot be guaranteed to inactivate EBOV in diagnostic samples. Murine blood samples treated with ethanol (4:1 [vol/vol] ethanol/sample) or heat (60°C for 15 min) also showed no viral inactivation in 67% or 100% of samples, respectively. However, combined Buffer AVL and ethanol or Buffer AVL and heat treatments showed total viral inactivation in 100% of samples tested. The Buffer AVL plus ethanol and Buffer AVL plus heat treatments were also shown not to affect the extraction of PCR quality RNA from EBOV-spiked murine blood samples. © Crown copyright 2015.

  15. Hippocampal inactivation with TTX impairs long-term spatial memory retrieval and modifies brain metabolic activity.

    Directory of Open Access Journals (Sweden)

    Nélida María Conejo

    Full Text Available Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions.

  16. Sex-differential selection and the evolution of X inactivation strategies.

    Directory of Open Access Journals (Sweden)

    Tim Connallon

    2013-04-01

    Full Text Available X inactivation--the transcriptional silencing of one X chromosome copy per female somatic cell--is universal among therian mammals, yet the choice of which X to silence exhibits considerable variation among species. X inactivation strategies can range from strict paternally inherited X inactivation (PXI, which renders females haploid for all maternally inherited alleles, to unbiased random X inactivation (RXI, which equalizes expression of maternally and paternally inherited alleles in each female tissue. However, the underlying evolutionary processes that might account for this observed diversity of X inactivation strategies remain unclear. We present a theoretical population genetic analysis of X inactivation evolution and specifically consider how conditions of dominance, linkage, recombination, and sex-differential selection each influence evolutionary trajectories of X inactivation. The results indicate that a single, critical interaction between allelic dominance and sex-differential selection can select for a broad and continuous range of X inactivation strategies, including unequal rates of inactivation between maternally and paternally inherited X chromosomes. RXI is favored over complete PXI as long as alleles deleterious to female fitness are sufficiently recessive, and the criteria for RXI evolution is considerably more restrictive when fitness variation is sexually antagonistic (i.e., alleles deleterious to females are beneficial to males relative to variation that is deleterious to both sexes. Evolutionary transitions from PXI to RXI also generally increase mean relative female fitness at the expense of decreased male fitness. These results provide a theoretical framework for predicting and interpreting the evolution of chromosome-wide expression of X-linked genes and lead to several useful predictions that could motivate future studies of allele-specific gene expression variation.

  17. Development and Preclinical Evaluation of a Trivalent, Formalin-Inactivated Shigella Whole-Cell Vaccine

    Science.gov (United States)

    Kaminski, R. W.; Wu, M.; Turbyfill, K. R.; Clarkson, K.; Tai, B.; Bourgeois, A. L.; Van De Verg, L. L.; Walker, R. I.

    2014-01-01

    Studies were undertaken to manufacture a multivalent Shigella inactivated whole-cell vaccine that is safe, effective, and inexpensive. By using several formalin concentrations, temperatures, and incubation periods, an optimized set of inactivation conditions was established for Shigella flexneri 2a, S. sonnei, and S. flexneri 3a to produce inactivated whole cells expressing a full repertoire of Ipa proteins and lipopolysaccharide (LPS). The inactivation conditions selected were treatment with 0.2% formalin (S. flexneri 2a and 3a) or 0.6% formalin (S. sonnei) for 48 h at 25°C. Vaccine formulations prepared under different inactivation conditions, in different doses (10E5, 10E7, and 10E9 cells), and with or without the inclusion of double-mutant heat-labile toxin (dmLT) were evaluated in mice. Two intranasal immunizations with ≥10E7 inactivated whole cells resulted in high levels of anti-Invaplex and moderate levels of LPS-specific IgG and IgA in serum and in lung and intestinal wash samples. Addition of dmLT to the vaccine formulations did not significantly enhance humoral immunogenicity. Minimal humoral responses for IpaB, IpaC, or IpaD were detected after immunization with inactivated whole Shigella cells regardless of the vaccine inactivation conditions. In guinea pigs, monovalent formulations of S. flexneri 2a of 3a or S. sonnei consisting of 10E8, 10E9, or 10E10 cells were protective in a keratoconjunctivitis assay. A trivalent formulation provided protection against all three serotypes (S. flexneri 2a, P = 0.018; S. flexneri 3a, P = 0.04; S. sonnei, P inactivated Shigella whole-cell vaccine approach incorporates an uncomplicated manufacturing process that is compatible with multivalency and the future development of a broadly protective Shigella vaccine. PMID:24403527

  18. Paternal X inactivation does not correlate with X chromosome evolutionary strata in marsupials.

    Science.gov (United States)

    Rodríguez-Delgado, Claudia L; Waters, Shafagh A; Waters, Paul D

    2014-12-24

    X chromosome inactivation is the transcriptional silencing of one X chromosome in the somatic cells of female mammals. In eutherian mammals (e.g. humans) one of the two X chromosomes is randomly chosen for silencing, with about 15% (usually in younger evolutionary strata of the X chromosome) of genes escaping this silencing. In contrast, in the distantly related marsupial mammals the paternally derived X is silenced, although not as completely as the eutherian X. A chromosome wide examination of X inactivation, using RNA-seq, was recently undertaken in grey short-tailed opossum (Monodelphis domestica) brain and extraembryonic tissues. However, no such study has been conduced in Australian marsupials, which diverged from their American cousins ~80 million years ago, leaving a large gap in our understanding of marsupial X inactivation. We used RNA-seq data from blood or liver of a family (mother, father and daughter) of tammar wallabies (Macropus eugenii), which in conjunction with available genome sequence from the mother and father, permitted genotyping of 42 expressed heterozygous SNPs on the daughter's X. These 42 SNPs represented 34 X loci, of which 68% (23 of the 34) were confirmed as inactivated on the paternally derived X in the daughter's liver; the remaining 11 X loci escaped inactivation. Seven of the wallaby loci sampled were part of the old X evolutionary stratum, of which three escaped inactivation. Three loci were classified as part of the newer X stratum, of which two escaped inactivation. A meta-analysis of previously published opossum X inactivation data revealed that 5 of 52 genes in the old X stratum escaped inactivation. We demonstrate that chromosome wide inactivation of the paternal X is common to an Australian marsupial representative, but that there is more escape from inactivation than reported for opossum (32% v 14%). We also provide evidence that, unlike the human X chromosome, the location of loci within the oldest evolutionary stratum on

  19. The Eag domain regulates the voltage-dependent inactivation of rat Eag1 K+ channels.

    Directory of Open Access Journals (Sweden)

    Ting-Feng Lin

    Full Text Available Eag (Kv10 and Erg (Kv11 belong to two distinct subfamilies of the ether-à-go-go K+ channel family (KCNH. While Erg channels are characterized by an inward-rectifying current-voltage relationship that results from a C-type inactivation, mammalian Eag channels display little or no voltage-dependent inactivation. Although the amino (N-terminal region such as the eag domain is not required for the C-type inactivation of Erg channels, an N-terminal deletion in mouse Eag1 has been shown to produce a voltage-dependent inactivation. To further discern the role of the eag domain in the inactivation of Eag1 channels, we generated N-terminal chimeras between rat Eag (rEag1 and human Erg (hERG1 channels that involved swapping the eag domain alone or the complete cytoplasmic N-terminal region. Functional analyses indicated that introduction of the homologous hERG1 eag domain led to both a fast phase and a slow phase of channel inactivation in the rEag1 chimeras. By contrast, the inactivation features were retained in the reverse hERG1 chimeras. Furthermore, an eag domain-lacking rEag1 deletion mutant also showed the fast phase of inactivation that was notably attenuated upon co-expression with the rEag1 eag domain fragment, but not with the hERG1 eag domain fragment. Additionally, we have identified a point mutation in the S4-S5 linker region of rEag1 that resulted in a similar inactivation phenotype. Biophysical analyses of these mutant constructs suggested that the inactivation gating of rEag1 was distinctly different from that of hERG1. Overall, our findings are consistent with the notion that the eag domain plays a critical role in regulating the inactivation gating of rEag1. We propose that the eag domain may destabilize or mask an inherent voltage-dependent inactivation of rEag1 K+ channels.

  20. The inactivation of eggs of helminthes under the action of narrowband ultraviolet radiation of excilamps

    Science.gov (United States)

    Lipatov, Evgeniy I.; Sosnin, Edward A.; Avdeev, Sergey M.

    2015-12-01

    The inactivation of eggs of Opisthorchis felineus and Diphyllobothrium latum in the water under the action of UV excilamps at 222 and 282 nm in dependence on the surface dose of radiation was studied. It was observed that the water disinfection from eggs of helminthes was more efficient at 222 nm, than at 282 nm. At the surface dose up to 5 mJ/cm2 of UV radiation at 222 nm up to 85 % of Opisthorchis felineus eggs were inactivated. At the comparable surface dose of UV radiation at 222 nm up to 56 % of Diphyllobothrium latum eggs were inactivated.

  1. Inactivation of possible microorganism food contaminants on packaging foils using nonthermal plasma and hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Scholtz, V., E-mail: Vladimir.Scholtz@vscht.cz; Khun, J. [Institute of Chemical Technology in Prague, Department of Physics and Measurements, Faculty of Chemical Engineering (Czech Republic); Soušková, H. [Institute of Chemical Technology in Prague, Department of Computing and Control Engineering, Faculty of Chemical Engineering (Czech Republic); Čeřovský, M. [Institute of Chemical Technology in Prague, Department of Food Preservation, Faculty of Food and Biochemical Technology (Czech Republic)

    2015-07-15

    The inactivation effect of nonthermal plasma generated in electric discharge burning in air atmosphere with water or hydrogen peroxide aerosol for the application to the microbial decontamination of packaging foils is studied. The microbial inactivation is studied on two bacterial, two yeasts, and two filamentous micromycete species. The inactivation of all contaminating microorganisms becomes on the area of full 8.5 cm in diameter circular sample after short times of several tens of seconds. Described apparatus may present a possible alternative method of microbial decontamination of food packaging material or other thermolabile materials.

  2. Inactivation of batrachotoxin-modified Na+ channels in GH3 cells. Characterization and pharmacological modification

    Science.gov (United States)

    1992-01-01

    Batrachotoxin (BTX)-modified Na+ currents were characterized in GH3 cells with a reversed Na+ gradient under whole-cell voltage clamp conditions. BTX shifts the threshold of Na+ channel activation by approximately 40 mV in the hyperpolarizing direction and nearly eliminates the declining phase of Na+ currents at all voltages, suggesting that Na+ channel inactivation is removed. Paradoxically, the steady-state inactivation (h infinity) of BTX-modified Na+ channels as determined by a two-pulse protocol shows that inactivation is still present and occurs maximally near -70 mV. About 45% of BTX-modified Na+ channels are inactivated at this voltage. The development of inactivation follows a sum of two exponential functions with tau d(fast) = 10 ms and tau d(slow) = 125 ms at -70 mV. Recovery from inactivation can be achieved after hyperpolarizing the membrane to voltages more negative than -120 mV. The time course of recovery is best described by a sum of two exponentials with tau r(fast) = 6.0 ms and tau r(slow) = 240 ms at -170 mV. After reaching a minimum at -70 mV, the h infinity curve of BTX-modified Na+ channels turns upward to reach a constant plateau value of approximately 0.9 at voltages above 0 mV. Evidently, the inactivated, BTX-modified Na+ channels can be forced open at more positive potentials. The reopening kinetics of the inactivated channels follows a single exponential with a time constant of 160 ms at +50 mV. Both chloramine-T (at 0.5 mM) and alpha-scorpion toxin (at 200 nM) diminish the inactivation of BTX-modified Na+ channels. In contrast, benzocaine at 1 mM drastically enhances the inactivation of BTX-modified Na+ channels. The h infinity curve reaches minimum of less than 0.1 at -70 mV, indicating that benzocaine binds preferentially with inactivated, BTX-modified Na+ channels. Together, these results imply that BTX-modified Na+ channels are governed by an inactivation process. PMID:1311019

  3. Modification of sodium channel inactivation in single myelinated nerve fibers by methionine-reactive chemicals.

    Science.gov (United States)

    Wang, G K

    1984-01-01

    Several methionine-reactive reagents, including N-bromoacetamide, N-bromosuccinimide, chloramine-T, and N-chlorosuccinimide, irreversibly slowed and prevented Na channel inactivation in single myelinated nerve fibers, whereas sulfhydryl- or tyrosine-modifying reagents had little effect. The activation process was not modified by the reagents that altered inactivation and could be modulated normally by Ca++ ions and Centruroides scorpion toxin II alpha. These results suggest that externally applied N-bromoacetamide and its related compounds specifically affect Na channel inactivation by modifying methionine residues of the channel. PMID:6331542

  4. Bim nuclear translocation and inactivation by viral interferon regulatory factor.

    Directory of Open Access Journals (Sweden)

    Young Bong Choi

    2010-08-01

    Full Text Available Viral replication efficiency is in large part governed by the ability of viruses to counteract pro-apoptotic signals induced by infection of the host cell. Human herpesvirus 8 (HHV-8 uses several strategies to block the host's innate antiviral defenses via interference with interferon and apoptotic signaling. Contributors include the four viral interferon regulatory factors (vIRFs 1-4, which function in dominant negative fashion to block cellular IRF activities in addition to targeting IRF signaling-induced proteins such as p53 and inhibiting other inducers of apoptosis such as TGFbeta receptor-activated Smad transcription factors. Here we identify direct targeting by vIRF-1 of BH3-only pro-apoptotic Bcl-2 family member Bim, a key negative regulator of HHV-8 replication, to effect its inactivation via nuclear translocation. vIRF-1-mediated relocalization of Bim was identified in transfected cells, by both immunofluorescence assay and western analysis of fractionated cell extracts. Also, co-localization of vIRF-1 and Bim was detected in nuclei of lytically infected endothelial cells. In vitro co-precipitation assays using purified vIRF-1 and Bim revealed direct interaction between the proteins, and Bim-binding residues of vIRF-1 were mapped by deletion and point mutagenesis. Generation and experimental utilization of Bim-refractory vIRF-1 variants revealed the importance of vIRF-1:Bim interaction, specifically, in pro-replication and anti-apoptotic activity of vIRF-1. Furthermore, blocking of the interaction with cell-permeable peptide corresponding to the Bim-binding region of vIRF-1 confirmed the relevance of vIRF-1:Bim association to vIRF-1 pro-replication activity. To our knowledge, this is the first report of an IRF protein that interacts with a Bcl-2 family member and of nuclear sequestration of Bim or any other member of the family as a means of inactivation. The data presented reveal a novel mechanism utilized by a virus to control

  5. Low pH inactivation for xenotropic gamma retrovirus in recombinant human TNF-α receptor immunoglobulin G and mechanism of inactivation.

    Science.gov (United States)

    Ma, Rong; Cui, Xiaolan

    2014-01-01

    CHO-derived recombinant proteins for human therapeutic are used commonly. There are noninfectious endogenous retroviruses in CHO cells. Validation study for inactivation process is required. Murine xenotropic gamma retrovirus (X-MulV) is a model virus in validation study. In our previous study, optimum conditions for X-MulV inactivation were sifted. In this study, we performed a further research on low pH inactivation for evaluation of X-MulV clearance in manufacturing of recombinant human TNF-α receptor immunoglobulin G fusion proteins (rhTNF-α) for injection. Cell-based infectivity assay was used for the evaluation of X-MulV clearance. RhTNF-α were spiked with X-MulV and were inactivated at pH 3.60 ∼ 3.90, 25 ± 2 °C, and 0 ∼ 240 min, respectively. Samples incubated at the conditions for 15 ∼ 180 min were not inactivated effectively. For 4 h incubation, log10 reductions were achieved 5.0 log10. Biological activity of rhTNF-α incubated at pH 3.60, 25 °C for 4 h, which was assayed on murine L929 fibroblasts cells, was not affected by low pH. Env gene of X-MulV, which was detected by conventional PCR method for the first time, was not detected after incubation at pH 3.60, and it may be the mechanism of low pH inactivation. Copyright © 2013. Published by Elsevier Ltd.

  6. Strategies to optimize photosensitizers for photodynamic inactivation of bacteria.

    Science.gov (United States)

    Tim, Maisch

    2015-09-01

    The Infectious Diseases Society of America (IDSA) highlights that over the past several years, the number of new antibacterial drugs approved continues to decrease (Boucher et al., 2009) [1]. Bacteria are very good in developing resistance against antibiotics in a short time. Therefore new approaches like antibacterial photodynamic inactivation of bacteria (aPDI) will become more important in the future as antimicrobial resistance is expected to continue to increase. This review summarises the potential of the susceptibility of bacteria to aPDI and the strategies to optimize leading photosensitizers which are useful for aPDI. The most appropriate photosensitizers belonging to the chemical classes of phenothiazinium, porphyrine, fullerene and perinaphthenone. They all share the following characteristics: positively-charged, water-soluble and photostable. Taken together the most promising clinical applications of aPDI are (i) decolonization of pathogens on skin, (ii) treatments of the oral cavity like periodontitis and root canal infection and (iii) superinfected burn wounds, because these are relatively accessible for photosensitizer application and illumination. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Structures and Ribosomal Interaction of Ribosome-Inactivating Proteins.

    Science.gov (United States)

    Shi, Wei-Wei; Mak, Amanda Nga-Sze; Wong, Kam-Bo; Shaw, Pang-Chui

    2016-11-21

    Ribosome-inactivating proteins (RIPs) including ricin, Shiga toxin, and trichosanthin, are RNA N-glycosidases that depurinate a specific adenine residue (A-4324 in rat 28S ribosomal RNA, rRNA) in the conserved α-sarcin/ricin loop (α-SRL) of rRNA. RIPs are grouped into three types according to the number of subunits and the organization of the precursor sequences. RIPs are two-domain proteins, with the active site located in the cleft between the N- and C-terminal domains. It has been found that the basic surface residues of the RIPs promote rapid and specific targeting to the ribosome and a number of RIPs have been shown to interact with the C-terminal regions of the P proteins of the ribosome. At present, the structural basis for the interaction of trichosanthin and ricin-A chain toward P2 peptide is known. This review surveys the structural features of the representative RIPs and discusses how they approach and interact with the ribosome.

  8. Advances in antimicrobial photodynamic inactivation at the nanoscale

    Science.gov (United States)

    Kashef, Nasim; Huang, Ying-Ying; Hamblin, Michael R.

    2017-08-01

    The alarming worldwide increase in antibiotic resistance amongst microbial pathogens necessitates a search for new antimicrobial techniques, which will not be affected by, or indeed cause resistance themselves. Light-mediated photoinactivation is one such technique that takes advantage of the whole spectrum of light to destroy a broad spectrum of pathogens. Many of these photoinactivation techniques rely on the participation of a diverse range of nanoparticles and nanostructures that have dimensions very similar to the wavelength of light. Photodynamic inactivation relies on the photochemical production of singlet oxygen from photosensitizing dyes (type II pathway) that can benefit remarkably from formulation in nanoparticle-based drug delivery vehicles. Fullerenes are a closed-cage carbon allotrope nanoparticle with a high absorption coefficient and triplet yield. Their photochemistry is highly dependent on microenvironment, and can be type II in organic solvents and type I (hydroxyl radicals) in a biological milieu. Titanium dioxide nanoparticles act as a large band-gap semiconductor that can carry out photo-induced electron transfer under ultraviolet A light and can also produce reactive oxygen species that kill microbial cells. We discuss some recent studies in which quite remarkable potentiation of microbial killing (up to six logs) can be obtained by the addition of simple inorganic salts such as the non-toxic sodium/potassium iodide, bromide, nitrite, and even the toxic sodium azide. Interesting mechanistic insights were obtained to explain this increased killing.

  9. Mechanism for Mutational Inactivation of the Tumor Suppressor Smad2

    Science.gov (United States)

    Prunier, Celine; Ferrand, Nathalie; Frottier, Bertrand; Pessah, Marcia; Atfi, Azeddine

    2001-01-01

    Transforming growth factor β (TGF-β) is a potent natural antiproliferative agent that plays an important role in suppressing tumorigenicity. In numerous tumors, loss of TGF-β responsiveness is associated with inactivating mutations that can occur in components of this signaling pathway, such as the tumor suppressor Smad2. Although a general framework for how Smads transduce TGF-β signals has been proposed, the physiological relevance of alterations of Smad2 functions in promoting tumorigenesis is still unknown. Here, we show that expression of Smad2.P445H, a tumor-derived mutation of Smad2 found in human cancer, suppresses the ability of the Smads to mediate TGF-β-induced growth arrest and transcriptional responses. Smad2.P445H is phosphorylated by the activated TGF-β receptor at the carboxy-terminal serine residues and associates with Smad3 and Smad4 but is unable to dissociate from the receptor. Upon ligand-induced phosphorylation, Smad2.P445H interacts stably with wild-type Smad2, thereby blocking TGF-β-induced nuclear accumulation of wild-type Smad2 and Smad2-dependent transcription. The ability of the Smad2.P445H to block the nuclear accumulation of wild-type Smad2 protein reveals a new mechanism for loss of sensitivity to the growth-inhibitory functions of TGF-β in tumor development. PMID:11313456

  10. Photodynamic inactivation of Gram-positive bacteria employing natural resources.

    Science.gov (United States)

    Mamone, L; Di Venosa, G; Gándara, L; Sáenz, D; Vallecorsa, P; Schickinger, S; Rossetti, M V; Batlle, A; Buzzola, F; Casas, A

    2014-04-05

    The aim of this paper was to investigate a collection of plant extracts from Argentina as a source of new natural photosensitizers (PS) to be used in Photodynamic Inactivation (PDI) of bacteria. A collection of plants were screened for phototoxicity upon the Gram-positive species Staphylococcus epidermidis. Three extracts turned out to be photoactive: Solanum verbascifolium flower, Tecoma stans flower and Cissus verticillata root. Upon exposure to a light dose of 55J/cm(2), they induced 4, 2 and 3logs decrease in bacterial survival, respectively. Photochemical characterisation of S. verbascifolium extract was carried out. PDI reaction was dependent mainly on singlet oxygen and to a lesser extent, on hydroxyl radicals, through type II and I reactions. Photodegradation experiments revealed that the active principle of the extract was not particularly photolabile. It is noticeable that S. verbascifolium -PDI was more efficient under sunlight as compared to artificial light (total eradication vs. 4 logs decrease upon 120min of sunlight). The balance between oxidant and antioxidant compounds is likely to be masking or unmasking potential PS of plant extracts, but employing the crude extract, the level of photoactivity of S. verbascifolium is similar to some artificial PS upon exposure to sunlight, demonstrating that natural resources can be employed in PDI of bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Characterization and inactivation of an agmatine deiminase from Helicobacter pylori

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Justin E.; Causey, Corey P.; Lovelace, Leslie; Knuckley, Bryan; Flick, Heather; Lebioda, Lukasz; Thompson, Paul R. (SC)

    2010-11-12

    Helicobacter pylori encodes a potential virulence factor, agmatine deiminase (HpAgD), which catalyzes the conversion of agmatine to N-carbamoyl putrescine (NCP) and ammonia - agmatine is decarboxylated arginine. Agmatine is an endogenous human cell signaling molecule that triggers the innate immune response in humans. Unlike H. pylori, humans do not encode an AgD; it is hypothesized that inhibition of this enzyme would increase the levels of agmatine, and thereby enhance the innate immune response. Taken together, these facts suggest that HpAgD is a potential drug target. Herein we describe the optimized expression, isolation, and purification of HpAgD (10-30 mg/L media). The initial kinetic characterization of this enzyme has also been performed. Additionally, the crystal structure of wild-type HpAgD has been determined at 2.1 {angstrom} resolution. This structure provides a molecular basis for the preferential deimination of agmatine, and identifies Asp198 as a key residue responsible for agmatine recognition, which has been confirmed experimentally. Information gathered from these studies led to the development and characterization of a novel class of haloacetamidine-based HpAgD inactivators. These compounds are the most potent AgD inhibitors ever described.

  12. Effect of Activated Plastic Films on Inactivation of Foodborne Pathogens

    Directory of Open Access Journals (Sweden)

    Belén Soriano Cuadrado

    2016-07-01

    Full Text Available In the present study, low density polyethylene films were activated by co-extrusion with zinc oxide, zinc acetate or potassium sorbate. Films were also surface-activated with tyrosol singly or in combination with lactic acid or p-hydroxybenzoic acid. Activated films were tested on Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella enterica and Pseudomonas fluorescens. The combinations showing greatest inhibition zones and broadest inhibitory spectrum were the films activated with tyrosol plus p-hydroxybenzoic acid. A small delay in growth of Listeria innocua was observed on seabream packed in ZnO-activated films during refrigerated storage for 7 days. When films activated with 2.5% tyrosol or with 1.5% tyrosol plus 0.5 p-hydroxybenzoic acid were used for vacuum packaging of smoked salmon and smoked tuna challenged with cocktails of S. enterica and L. monocytogenes strains, the combination of tyrosol and p-hydroxybenzoic acid improved inactivation of both pathogens during chill storage compared to films singly activated with tyrosol. The best results were obtained in smoked salmon, since no viable pathogens were detected after 7 days of chill storage for the activated film. Results from the study highlight the potential of plastic films surface-activated with tyrosol and p-hydroxybenzoic acid in the control of foodborne pathogens in smoked seafood.

  13. Field trials of an inactivated virus vaccine against porcine parvovirus.

    Science.gov (United States)

    Castro, J M; del Pozo, M; Simarro, I

    1992-07-01

    Serological response and reproductive performance were estimated in field trials of an inactivated virus vaccine against porcine parvovirus. Experiments were carried out in 10 selected pig breeding herds. A total of 277 seronegative gilts were used. Two hundred and twenty animals were vaccinated twice before mating, fourteen days apart and revaccinated after farrowing. Blood samples were obtained from both vaccinated and non-vaccinated (57 animal) control gilts, one week after the 2nd dose of vaccination, at farrowing time and one week after revaccination. Although there were considerable variations among the herds, the number of returns to oestrus in all herds was higher in vaccinated gilts (11.81%) than in the controls (10.52%). This difference, however, was not statistically significant. The reproductive performance results revealed the absence of an increase in the total born, as pooled values, in vaccinated gilts compared to controls. However, when these results are interpreted in relation to serological data, many control gilts were already seropositive before mating, or remained seronegative at farrowing. According to our results, the duration of immunity with this vaccine is apparently short, as there is a clear decrease in the titres between the 1st and the 2nd sampling times (2.35 +/- 0.14 and 1.97 +/- 0.08, respectively).

  14. Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas.

    Science.gov (United States)

    Kim, Hyobi; Yum, Bora; Yoon, Sung-Sik; Song, Kyoung-Ju; Kim, Jong-Rak; Myeong, Donghoon; Chang, Byungjoon; Choe, Nong-Hoon

    2016-01-01

    Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO2 gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO2 each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry.

  15. Potentiation of antimicrobial photodynamic inactivation by inorganic salts.

    Science.gov (United States)

    Hamblin, Michael R

    2017-11-01

    Antimicrobial photodynamic inactivation (aPDI) involves the use of non-toxic dyes excited with visible light to produce reactive oxygen species (ROS) that can destroy all classes of microorganisms including bacteria, fungi, parasites, and viruses. Selectivity of killing microbes over host mammalian cells allows this approach (antimicrobial photodynamic therapy, aPDT) to be used in vivo as an alternative therapeutic approach for localized infections especially those that are drug-resistant. Areas covered: We have discovered that aPDI can be potentiated (up to 6 logs of extra killing) by the addition of simple inorganic salts. The most powerful and versatile salt is potassium iodide, but potassium bromide, sodium thiocyanate, sodium azide and sodium nitrite also show potentiation. The mechanism of potentiation with iodide is likely to be singlet oxygen addition to iodide to form iodine radicals, hydrogen peroxide and molecular iodine. Another mechanism involves two-electron oxidation of iodide/bromide to form hypohalites. A third mechanism involves a one-electron oxidation of azide anion to form azide radical. Expert commentary: The addition of iodide has been shown to improve the performance of aPDT in several animal models of localized infection. KI is non-toxic and is an approved drug for antifungal therapy, so its transition to clinical use in aPDT should be straightforward.

  16. Advances in antimicrobial photodynamic inactivation at the nanoscale

    Directory of Open Access Journals (Sweden)

    Kashef Nasim

    2017-08-01

    Full Text Available The alarming worldwide increase in antibiotic resistance amongst microbial pathogens necessitates a search for new antimicrobial techniques, which will not be affected by, or indeed cause resistance themselves. Light-mediated photoinactivation is one such technique that takes advantage of the whole spectrum of light to destroy a broad spectrum of pathogens. Many of these photoinactivation techniques rely on the participation of a diverse range of nanoparticles and nanostructures that have dimensions very similar to the wavelength of light. Photodynamic inactivation relies on the photochemical production of singlet oxygen from photosensitizing dyes (type II pathway that can benefit remarkably from formulation in nanoparticle-based drug delivery vehicles. Fullerenes are a closed-cage carbon allotrope nanoparticle with a high absorption coefficient and triplet yield. Their photochemistry is highly dependent on microenvironment, and can be type II in organic solvents and type I (hydroxyl radicals in a biological milieu. Titanium dioxide nanoparticles act as a large band-gap semiconductor that can carry out photo-induced electron transfer under ultraviolet A light and can also produce reactive oxygen species that kill microbial cells. We discuss some recent studies in which quite remarkable potentiation of microbial killing (up to six logs can be obtained by the addition of simple inorganic salts such as the non-toxic sodium/potassium iodide, bromide, nitrite, and even the toxic sodium azide. Interesting mechanistic insights were obtained to explain this increased killing.

  17. Inactivation of Pseudomonas aeruginosa by Chitosan Coated Iron Oxide Nanoparticles.

    Science.gov (United States)

    Mukherjee, Munmun; De, Sirshendu

    2016-01-01

    Pseudomonas aeruginosa is one of the potent opportunistic pathogens associated with respiratory and urinary tract infection. The bacterium owes its pathogenicity due to the intrinsic resistance to antibiotics and disinfectants. The present study is focused on the synthesis of antibacterial chitosan coated iron oxide nanoparticles for rapid inactivation of Pseudomonas aeruginosa. We have discussed the relevant patents on synthesis and antibacterial potential of metallic nanoparticles and chitosan. Chitosan coated iron oxide nanoparticles were synthesized by coprecipitation method at room temperature using non-toxic chitosan and iron salts in alkali media. The particles were characterized and evaluated for antibacterial property against Pseudomonas aeruginosa. The average size of the particles was measured as 52 nm. The surface area of the coated particles was as high as 90 ±5 m2/g. FTIR spectra confirmed the coating of chitosan on nanoparticles. The coated particles showed excellent antibacterial activity against the bacteria. The minimum inhibitory concentration of the coated particles was 105)µg mol-1. The morphological alteration and cytoplasmic leakage of bacteria were confirmed by SEM image and release of intracellular constituents, respectively. Higher 260 nm absorbance value confirmed stronger antibacterial activity of the coated nanoparticles as compared to pure chitosan and bare iron oxide nanoparticles. The study indicated that chitosan coated iron oxide nanoparticles have superior antibacterial property as compared to pure chitosan and iron oxide nanoparticles.

  18. Probing Mercaptobenzamides as HIV Inactivators via Nucleocapsid Protein 7.

    Science.gov (United States)

    Saha, Mrinmoy; Scerba, Michael T; Shank, Nathaniel I; Hartman, Tracy L; Buchholz, Caitlin A; Buckheit, Robert W; Durell, Stewart R; Appella, Daniel H

    2017-05-22

    Human immunodeficiency virus type 1 (HIV-1) nucleocapsid protein 7 (NCp7), a zinc finger protein, plays critical roles in viral replication and maturation and is an attractive target for drug development. However, the development of drug-like molecules that inhibit NCp7 has been a significant challenge. In this study, a series of novel 2-mercaptobenzamide prodrugs were investigated for anti-HIV activity in the context of NCp7 inactivation. The molecules were synthesized from the corresponding thiosalicylic acids, and they are all crystalline solids and stable at room temperature. Derivatives with a range of amide side chains and aromatic substituents were synthesized and screened for anti-HIV activity. Wide ranges of antiviral activity were observed, with IC 50 values ranging from 1 to 100 μm depending on subtle changes to the substituents on the aromatic ring and side chain. Results from these structure-activity relationships were fit to a probable mode of intracellular activation and interaction with NCp7 to explain variations in antiviral activity. Our strategy to make a series of mercaptobenzamide prodrugs represents a general new direction to make libraries that can be screened for anti-HIV activity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Inactivation of food spoilage fungi by ultra violet (UVC) irradiation.

    Science.gov (United States)

    Begum, Mariam; Hocking, Ailsa D; Miskelly, Di

    2009-01-31

    The effect of ultraviolet irradiation (254 nm, UVC) on Aspergillus flavus, Aspergillus niger, Penicillium corylophilum and Eurotium rubrum was investigated using three different exposure techniques. Survival was determined for spores suspended in liquid medium after 1, 2 and 3 min UVC exposure at 4644 J/m(2)/min. The same UVC dose was applied to spores on the surface of agar plates for 5, 10, 15, 30, 60 and 120 s. Spores of A. niger were dried onto a membrane filter, then exposed to UVC treatment. In the liquid medium, treatments from 1-3 min significantly (P<0.001) reduce the number of viable spores. On the surface of agar plates, after a 15 s exposure, a 80-99% reduction of viable spores was observed for all species except A. niger, for which the reduction was only 62%. For spores dried onto filter membranes, a 3.5 log(10) reduction was achieved for A. niger after 180 s exposure. These observations suggest that UVC irradiation can effectively inactivate spores of A. flavus, P. corylophilum, E. rubrum and A. niger but the efficacy of UVC radiation against fungal spores varies significantly according to methods of exposure to the irradiation, and among genera.

  20. Diltiazem and verapamil preferentially block inactivated cardiac calcium channels.

    Science.gov (United States)

    Kanaya, S; Arlock, P; Katzung, B G; Hondeghem, L M

    1983-02-01

    Diltiazem has been proposed to act by blocking calcium channels of cardiac and smooth muscle since it has pharmacological [12-14] and clinical [10] effects that resemble those of verapamil, an agent that has been shown to block these channels [3]. However, block of the slow inward current by diltiazem has not been directly demonstrated. In fact, it has been suggested that diltiazem has an entirely different mechanism of action [7]. We therefore studied the blocking effects of diltiazem and verapamil on cardiac calcium channels by measuring the slow inward current in voltage-clamped ferret myocardium. Both drugs blocked the slow inward current in a use-dependent fashion, i.e. the block was enhanced by increased frequency of activating clamps and by more positive holding potentials. However, we found that short single activating clamps resulted in minimal block, whereas prolonging the clamp step progressively enhanced the blockade. Thus, a single long clamp caused as much blockade as a train of shorter pulses. These results demonstrate that diltiazem and verapamil block the slow inward current by binding to calcium channels in a state-dependent fashion, i.e. inactivated channels have a high affinity for the drugs, while rested and open channels have a lower affinity.