Structural, Bioinformatic, and In Vivo Analyses of Two Treponema pallidum Lipoproteins Reveal a Unique TRAP Transporter

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Deka, Ranjit K.; Brautigam, Chad A.; Goldberg, Martin; Schuck, Peter; Tomchick, Diana R.; Norgard, Michael V. (NIH); (UTSMC)

2012-05-25

Treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite ATP-independent periplasmic transporter (TRAP-T). TRAP-Ts typically employ a periplasmic substrate-binding protein (SBP) to deliver the cognate ligand to the transmembrane symporter. Herein, we demonstrate that the genes encoding the putative TRAP-T components from T. pallidum, tp0957 (the SBP), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. We determined the crystal structure of recombinant Tp0956; the protein is trimeric and perforated by a pore. Part of Tp0956 forms an assembly similar to those of 'tetratricopeptide repeat' (TPR) motifs. The crystal structure of recombinant Tp0957 was also determined; like the SBPs of other TRAP-Ts, there are two lobes separated by a cleft. In these other SBPs, the cleft binds a negatively charged ligand. However, the cleft of Tp0957 has a strikingly hydrophobic chemical composition, indicating that its ligand may be substantially different and likely hydrophobic. Analytical ultracentrifugation of the recombinant versions of Tp0956 and Tp0957 established that these proteins associate avidly. This unprecedented interaction was confirmed for the native molecules using in vivo cross-linking experiments. Finally, bioinformatic analyses suggested that this transporter exemplifies a new subfamily of TPATs (TPR-protein-associated TRAP-Ts) that require the action of a TPR-containing accessory protein for the periplasmic transport of a potentially hydrophobic ligand(s).

Specific and sensitive diagnosis of syphilis using a real-time PCR for Treponema pallidum

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Koek, A. G.; Bruisten, S. M.; Dierdorp, M.; van Dam, A. P.; Templeton, K.

2006-01-01

A real-time PCR assay with a Taqman probe was developed that targeted the polA gene of Treponema pallidum. The test was validated using an analytical panel (n = 140) and a clinical panel of genital samples (n = 112) from patients attending a sexually transmitted infections clinic. High sensitivities

Detección de Treponema pallidum subespecie pallidum para el diagnóstico de sífilis congénita mediante reacción en cadena de la polimerasa anidada.

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Pinilla, Gladys; Campos, Lesly; Durán, Andrea; Navarrete, Jeannette; Muñoz, Liliana

2018-03-15

Introducción. La sífilis es una enfermedad producida por Treponema pallidum subespecie pallidum cuya incidencia mundial es de 12 millones de casos por año, aproximadamente; de estos, más de dos millones se presentan en mujeres gestantes, siendo la sífilis congénita la complicación más grave de esta infección en el embarazo.Objetivo. Detectar la presencia de T. pallidum subespecie pallidum en muestras clínicas para el diagnóstico de sífilis congénita mediante reacción en cadena de la polimerasa (PCR) anidada y determinar su concordancia con las pruebas serológicas.Materiales y métodos. Mediante PCR convencional y anidada, se amplificaron tres genes diana (polA, 16S ADNr y TpN47) y se confirmaron los productos de amplificación de los genes TpN47 y polA por secuenciación. Las pruebas serológicas empleadas fueron la VDRL (Venereal Disease Research Laboratory), la de reagina plasmática rápida (Rapid Plasma Reagin, RPR) y la de aglutinación de partículas para Treponema pallidum (Treponema pallidum Particle Agglutination Assay, TPPA).Resultados. La sensibilidad para la PCR convencional fue de 52 pg y, para la PCR anidada, de 0,52 pg. La especificidad con los iniciadores TpN47 y polA fue de 100 %; los resultados de la secuenciación mostraron una identidad de 97 % con T. pallidum. En 70 % de las muestras, los resultados de las pruebas serológicas y la PCR anidada concordaron.Conclusión. El gen TpN47 resultó ser el mejor blanco molecular para la identificación de T. pallidum. La PCR anidada se presenta como una alternativa de diagnóstico molecular promisoria para el diagnóstico de sífilis congénita.

Treponema pallidum 3-Phosphoglycerate Mutase Is a Heat-Labile Enzyme That May Limit the Maximum Growth Temperature for the Spirochete

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Benoit, Stéphane; Posey, James E.; Chenoweth, Matthew R.; Gherardini, Frank C.

2001-01-01

In the causative agent of syphilis, Treponema pallidum, the gene encoding 3-phosphoglycerate mutase, gpm, is part of a six-gene operon (tro operon) that is regulated by the Mn-dependent repressor TroR. Since substrate-level phosphorylation via the Embden-Meyerhof pathway is the principal way to generate ATP in T. pallidum and Gpm is a key enzyme in this pathway, Mn could exert a regulatory effect on central metabolism in this bacterium. To study this, T. pallidum gpm was cloned, Gpm was purified from Escherichia coli, and antiserum against the recombinant protein was raised. Immunoblots indicated that Gpm was expressed in freshly extracted infective T. pallidum. Enzyme assays indicated that Gpm did not require Mn2+ while 2,3-diphosphoglycerate (DPG) was required for maximum activity. Consistent with these observations, Mn did not copurify with Gpm. The purified Gpm was stable for more than 4 h at 25°C, retained only 50% activity after incubation for 20 min at 34°C or 10 min at 37°C, and was completely inactive after 10 min at 42°C. The temperature effect was attenuated when 1 mM DPG was added to the assay mixture. The recombinant Gpm from pSLB2 complemented E. coli strain PL225 (gpm) and restored growth on minimal glucose medium in a temperature-dependent manner. Increasing the temperature of cultures of E. coli PL225 harboring pSLB2 from 34 to 42°C resulted in a 7- to 11-h period in which no growth occurred (compared to wild-type E. coli). These data suggest that biochemical properties of Gpm could be one contributing factor to the heat sensitivity of T. pallidum. PMID:11466272

Evaluation of the HISCL Anti-Treponema pallidum Assay as a Screening Test for Syphilis.

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An, Jingna; Chen, Qixia; Liu, Qianqian; Rao, Chenli; Li, Dongdong; Wang, Tingting; Tao, Chuanmin; Wang, Lanlan

2015-07-01

The resurgence of syphilis in recent years has become a serious threat to public health worldwide, and the serological detection of specific antibodies against Treponema pallidum remains the most reliable method for laboratory diagnosis of syphilis. This study examined the performance of the recently launched HISCL anti-Treponema pallidum (anti-TP) assay as a screening test for syphilis in a high-volume laboratory. The HISCL anti-TP assay was tested in 300 preselected syphilis-positive samples, 704 fresh syphilis-negative samples, 48 preselected potentially interfering samples, and 30 "borderline" samples and was compared head to head with the commercially available Lumipulse G TP-N. In this study, the HISCL anti-TP assay was in perfect agreement with the applied testing algorithms with an overall agreement of 100%, comparable to that of Lumipulse G TP-N (99.63%). The sensitivity and specificity of the HISCL anti-TP assay were 100% (95% confidence interval [CI], 98.42% to 100%) and 100% (95% CI, 99.37% to 100%), respectively. Considering the excellent ease of use and automation, high throughput, and its favorable sensitivity and specificity, the HISCL anti-TP assay may represent a new choice for syphilis screening in high-volume laboratories. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Evaluation of two automated chemiluminescence immunoassays, the LIAISON Treponema Screen and the ARCHITECT Syphilis TP, and the Treponema pallidum particle agglutination test for laboratory diagnosis of syphilis.

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Wellinghausen, Nele; Dietenberger, Hanna

2011-08-01

Automated Treponema pallidum-specific chemi-luminescence immunoassays (CLIA) run on random-access analyzers allow for rapid diagnosis of syphilis infection. We evaluated the LIAISON Treponema Screen (LIA) and the ARCHITECT Syphilis TP (ARCH) in comparison to the Treponema pallidum particle agglutination (TPPA) test, as a screening test for syphilis. We performed a prospective study using 577 sera submitted for diagnosis of syphilis, including 318 samples from pregnant women. In addition, 42 stored sera from 32 patients with clinically and serologically characterized syphilis infection were investigated. In the prospective study, the sensitivity and specificity of LIA, ARCH, and TPPA were 100% (18/18), 100% (17/17), and 100% (18/18), and 100% (558/558), 99.8% (552/553), and 99.6% (556/558), respectively. In pregnant women, the specificity of LIA and ARCH was 100% (317/317) and of TPPA 99.7% (316/317). One sample from a child with assumed exposure to maternal antitreponemal antibodies was omitted from analysis. LIA, ARCH, and TPPA were also positive in all investigated sera from patients with known syphilis. Both automated CLIA demonstrated excellent diagnostic sensitivity and specificity when evaluated as a screening test for syphilis under routine conditions of a diagnostic laboratory. Thus, these may be used independently as an alternative to the manual TPPA screen.

The Tp0684 (MglB-2 Lipoprotein of Treponema pallidum: A Glucose-Binding Protein with Divergent Topology.

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Chad A Brautigam

Full Text Available Treponema pallidum, the bacterium that causes syphilis, is an obligate human parasite. As such, it must acquire energy, in the form of carbon sources, from the host. There is ample evidence that the principal source of energy for this spirochete is D-glucose acquired from its environment, likely via an ABC transporter. Further, there is genetic evidence of a D-glucose chemotaxis system in T. pallidum. Both of these processes may be dependent on a single lipidated chemoreceptor: Tp0684, also called TpMglB-2 for its sequence homology to MglB of Escherichia coli. To broaden our understanding of this potentially vital protein, we determined a 2.05-Å X-ray crystal structure of a soluble form of the recombinant protein. Like its namesake, TpMglB-2 adopts a bilobed fold that is similar to that of the ligand-binding proteins (LBPs of other ABC transporters. However, the protein has an unusual, circularly permuted topology. This feature prompted a series of biophysical studies that examined whether the protein's topological distinctiveness affected its putative chemoreceptor functions. Differential scanning fluorimetry and isothermal titration calorimetry were used to confirm that the protein bound D-glucose in a cleft between its two lobes. Additionally, analytical ultracentrifugation was employed to reveal that D-glucose binding is accompanied by a significant conformational change. TpMglB-2 thus appears to be fully functional in vitro, and given the probable central importance of the protein to T. pallidum's physiology, our results have implications for the viability and pathogenicity of this obligate human pathogen.

The Tp0684 (MglB-2) Lipoprotein of Treponema pallidum: A Glucose-Binding Protein with Divergent Topology.

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Brautigam, Chad A; Deka, Ranjit K; Liu, Wei Z; Norgard, Michael V

2016-01-01

Treponema pallidum, the bacterium that causes syphilis, is an obligate human parasite. As such, it must acquire energy, in the form of carbon sources, from the host. There is ample evidence that the principal source of energy for this spirochete is D-glucose acquired from its environment, likely via an ABC transporter. Further, there is genetic evidence of a D-glucose chemotaxis system in T. pallidum. Both of these processes may be dependent on a single lipidated chemoreceptor: Tp0684, also called TpMglB-2 for its sequence homology to MglB of Escherichia coli. To broaden our understanding of this potentially vital protein, we determined a 2.05-Å X-ray crystal structure of a soluble form of the recombinant protein. Like its namesake, TpMglB-2 adopts a bilobed fold that is similar to that of the ligand-binding proteins (LBPs) of other ABC transporters. However, the protein has an unusual, circularly permuted topology. This feature prompted a series of biophysical studies that examined whether the protein's topological distinctiveness affected its putative chemoreceptor functions. Differential scanning fluorimetry and isothermal titration calorimetry were used to confirm that the protein bound D-glucose in a cleft between its two lobes. Additionally, analytical ultracentrifugation was employed to reveal that D-glucose binding is accompanied by a significant conformational change. TpMglB-2 thus appears to be fully functional in vitro, and given the probable central importance of the protein to T. pallidum's physiology, our results have implications for the viability and pathogenicity of this obligate human pathogen.

First Report of the 23S rRNA Gene A2058G Point Mutation Associated With Macrolide Resistance in Treponema pallidum From Syphilis Patients in Cuba.

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Noda, Angel A; Matos, Nelvis; Blanco, Orestes; Rodríguez, Islay; Stamm, Lola Virginia

2016-05-01

This study aimed to assess the presence of macrolide-resistant Treponema pallidum subtypes in Havana, Cuba. Samples from 41 syphilis patients were tested for T. pallidum 23S rRNA gene mutations. Twenty-five patients (61%) harbored T. pallidum with the A2058G mutation, which was present in all 8 subtypes that were identified. The A2059G mutation was not detected.

Complete Genome Sequence of Treponema paraluiscuniculi, Strain Cuniculi A: The Loss of Infectivity to Humans Is Associated with Genome Decay

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Šmajs, David; Zobaníková, Marie; Strouhal, Michal; Čejková, Darina; Dugan-Rocha, Shannon; Pospíšilová, Petra; Norris, Steven J.; Albert, Tom; Qin, Xiang; Hallsworth-Pepin, Kym; Buhay, Christian; Muzny, Donna M.; Chen, Lei; Gibbs, Richard A.; Weinstock, George M.

2011-01-01

Treponema paraluiscuniculi is the causative agent of rabbit venereal spirochetosis. It is not infectious to humans, although its genome structure is very closely related to other pathogenic Treponema species including Treponema pallidum subspecies pallidum, the etiological agent of syphilis. In this study, the genome sequence of Treponema paraluiscuniculi, strain Cuniculi A, was determined by a combination of several high-throughput sequencing strategies. Whereas the overall size (1,133,390 bp), arrangement, and gene content of the Cuniculi A genome closely resembled those of the T. pallidum genome, the T. paraluiscuniculi genome contained a markedly higher number of pseudogenes and gene fragments (51). In addition to pseudogenes, 33 divergent genes were also found in the T. paraluiscuniculi genome. A set of 32 (out of 84) affected genes encoded proteins of known or predicted function in the Nichols genome. These proteins included virulence factors, gene regulators and components of DNA repair and recombination. The majority (52 or 61.9%) of the Cuniculi A pseudogenes and divergent genes were of unknown function. Our results indicate that T. paraluiscuniculi has evolved from a T. pallidum-like ancestor and adapted to a specialized host-associated niche (rabbits) during loss of infectivity to humans. The genes that are inactivated or altered in T. paraluiscuniculi are candidates for virulence factors important in the infectivity and pathogenesis of T. pallidum subspecies. PMID:21655244

Complete genome sequence of Treponema paraluiscuniculi, strain Cuniculi A: the loss of infectivity to humans is associated with genome decay.

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David Šmajs

Full Text Available Treponema paraluiscuniculi is the causative agent of rabbit venereal spirochetosis. It is not infectious to humans, although its genome structure is very closely related to other pathogenic Treponema species including Treponema pallidum subspecies pallidum, the etiological agent of syphilis. In this study, the genome sequence of Treponema paraluiscuniculi, strain Cuniculi A, was determined by a combination of several high-throughput sequencing strategies. Whereas the overall size (1,133,390 bp, arrangement, and gene content of the Cuniculi A genome closely resembled those of the T. pallidum genome, the T. paraluiscuniculi genome contained a markedly higher number of pseudogenes and gene fragments (51. In addition to pseudogenes, 33 divergent genes were also found in the T. paraluiscuniculi genome. A set of 32 (out of 84 affected genes encoded proteins of known or predicted function in the Nichols genome. These proteins included virulence factors, gene regulators and components of DNA repair and recombination. The majority (52 or 61.9% of the Cuniculi A pseudogenes and divergent genes were of unknown function. Our results indicate that T. paraluiscuniculi has evolved from a T. pallidum-like ancestor and adapted to a specialized host-associated niche (rabbits during loss of infectivity to humans. The genes that are inactivated or altered in T. paraluiscuniculi are candidates for virulence factors important in the infectivity and pathogenesis of T. pallidum subspecies.

Purification, crystallization and preliminary X-ray analysis of TP0435 (Tp17) from the syphilis spirochete Treponema pallidum

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Brautigam, Chad A.; Deka, Ranjit K.; Norgard, Michael V.

2013-01-01

The soluble portion of TP0435, a putative periplasmic lipoprotein from the syphilis spirochete T. pallidum, has been purified and crystallized in a rhombohedral space group. A complete native data set has been collected to 2.4 Å resolution. Syphilis, caused by the bacterial spirochete Treponema pallidum, remains a prominent sexually transmitted infection worldwide. Despite sequencing of the genome of this obligate human pathogen 15 years ago, the functions of a large number of the gene products of T. pallidum are still unknown, particularly with respect to those of the organism’s periplasmic lipoproteins. To better understand their functions, a structural biology approach has been pursued. To this end, the soluble portion of the T. pallidum TP0435 lipoprotein (also known as Tp17) was cloned, hyper-expressed in Escherichia coli and purified to apparent homogeneity. The protein crystals obtained from this preparation diffracted to 2.4 Å resolution and had the symmetry of space group R3. In the hexagonal setting, the unit-cell parameters were a = b = 85.7, c = 85.4 Å

A longitudinal evaluation of Treponema pallidum PCR testing in early syphilis

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Shields Matt

2012-12-01

Full Text Available Abstract Background Syphilis is a growing public health problem among men who have sex with men (MSM globally. Rapid and accurate detection of syphilis is vital to ensure patients and their contacts receive timely treatment and reduce ongoing transmission. Methods We evaluated a PCR assay for the diagnosis of Treponema pallidum using swabs of suspected early syphilis lesions in longitudinally assessed MSM. Results We tested 260 MSM for T pallidum by PCR on 288 occasions: 77 (26.7% had early syphilis that was serologically confirmed at baseline or within six weeks, and 211 (73.3% remained seronegative for syphilis. Of 55 men with primary syphilis, 49 were PCR positive, giving a sensitivity of 89.1% (95% CI: 77.8%-95.9% and a specificity of 99.1% (95% CI: 96.5%-99.9%. Of 22 men with secondary syphilis, 11 were PCR positive, giving a sensitivity of 50% (95% CI: 28.2%-71.8% and a specificity of 100% (95% CI: 66.4%-71.8%. Of the 77 syphilis cases, 43 (56% were HIV positive and the sensitivity and specificity of the PCR test did not vary by HIV status. The PCR test was able to detect up to five (10% primary infections that were initially seronegative, including one HIV positive man with delayed seroconversion to syphilis (72 to 140 days and one HIV positive man who did not seroconvert to syphilis over 14 months follow-up. Both men had been treated for syphilis within a week of the PCR test. Conclusions T pallidum PCR is a potentially powerful tool for the early diagnosis of primary syphilis, particularly where a serological response has yet to develop.

Multiple primary syphilis on the lip, nipple-areola and penis: An immunohistochemical examination of Treponema pallidum localization using an anti-T. pallidum antibody.

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Fukuda, Hidetsugu; Takahashi, Misaki; Kato, Keiichi; Oharaseki, Toshiaki; Mukai, Hideki

2015-05-01

Primary syphilis caused by Treponema pallidum usually develops after sexual contact as an initial solitary sclerosis or hard chancre in the genital region. We describe a case of primary syphilis at three sites in genital and extragenital regions of a man who had sex with men. A 29-year-old man visited our hospital for skin lesions on his lower lip, nipple-areola and penis. A positive syphilis serological test for rapid plasma reagin had a titer of 1:16; the patient also tested positive for specific antibodies against T. pallidum, with a cut-off index of 39.0. Histopathological examination of a nipple-areola biopsy specimen revealed a thickened epidermis and dense infiltration of inflammatory cells extending from the upper dermal layers to the deep dermis. The inflammatory cells were composed of abundant lymphocytes, plasma cells, histiocytes and neutrophils. Immunohistochemical staining for T. pallidum using an anti-T. pallidum antibody showed numerous spirochetes in the lower portion of the epidermis, scattered inside inflammatory cell infiltrate and perivascular sites throughout the dermis. Based on these findings, the patient was diagnosed with primary syphilis. Treatment with oral amoxicillin hydrate was started. Five days after starting treatment, a diffuse maculopapular rash (syphilitic roseola) occurred on his trunk and extremities. Perivascular cuffing due to T. pallidum was present throughout the dermis in the biopsy specimen of a localized lesion of primary syphilis. Moreover, syphilitic roseola, which indicates generalized dissemination of T. pallidum, developed during the course of treatment for primary syphilis. Therefore, we considered perivascular cuffing to be indicative of the dissemination phase. © 2015 Japanese Dermatological Association.

Prevalencia de la infección por el VIH y de Treponema pallidum en mujeres trabajadoras sexuales de Argentina Prevalence of HIV infection and Treponema pallidum in Argentine female sex workers

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María de los Ángeles Pando

2011-10-01

Full Text Available OBJETIVO: Estimar la prevalencia de infección por el virus de la inmunodeficiencia humana (VIH y de Treponema pallidum en mujeres trabajadoras sexuales (MTS de Argentina, y describir las características sociodemográficas de este grupo de población asociadas a la transmisión del VIH. MÉTODOS: Entre octubre de 2006 y diciembre de 2009 se realizó un estudio de corte transversal y un muestreo por conveniencia en MTS mayores de 18 años de nueve ciudades de Argentina. Un total de 1 255 mujeres participaron en este estudio. Se capacitó especialmente a un grupo de MTS para convocar a las otras mujeres a participar en talleres y a realizarse el diagnóstico del VIH y T. pallidum. RESULTADOS: Las características socio-epidemiológicas más destacadas de las MTS incluyeron un alto porcentaje de abuso sexual, escaso uso de preservativos con parejas sexuales no comerciales y un alto porcentaje de situaciones de violencia. La prevalencia del VIH fue de 2% (25/1 255, intervalo de confianza de 95% [IC95%]:1,2-2,8 y la de T. pallidum, de 22,4% (245/ 1 094, IC95%: 19,9-24,9. En las MTS de la ciudad de La Plata, la prevalencia del VIH fue significativamente más baja comparada con las participantes del resto del país (0,3% vs 2,7%, P OBJECTIVE: Estimate the prevalence of human immunodeficiency virus (HIV infection and Treponema pallidum in Argentine female sex workers (FSW, and describe the sociodemographic characteristics of this population group associated with HIV transmission. METHODS: A cross-sectional study and convenience sampling were conducted in FSW over 18 years of age in nine Argentine cities from October 2006 to December 2009. A total of 1 255 women participated in this study. A group of FSW was especially trained to invite other women to participate in the workshops and undergo screening for HIV and T. pallidum. RESULTS: The most noteworthy socioepidemiological characteristics of the FSW included a high percentage of sexual abuse, limited

Development of a Multilocus Sequence Typing (MLST) scheme for Treponema pallidum subsp. pertenue: Application to yaws in Lihir Island, Papua New Guinea.

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Godornes, Charmie; Giacani, Lorenzo; Barry, Alyssa E; Mitja, Oriol; Lukehart, Sheila A

2017-12-01

Yaws is a neglected tropical disease, caused by Treponema pallidum subsp. pertenue. The disease causes chronic lesions, primarily in young children living in remote villages in tropical climates. As part of a global yaws eradication campaign initiated by the World Health Organization, we sought to develop and evaluate a molecular typing method to distinguish different strains of T. pallidum subsp. pertenue for disease control and epidemiological purposes. Published genome sequences of strains of T. pallidum subsp. pertenue and pallidum were compared to identify polymorphic genetic loci among the strains. DNA from a number of existing historical Treponema isolates, as well as a subset of samples from yaws patients collected in Lihir Island, Papua New Guinea, were analyzed using these targets. From these data, three genes (tp0548, tp0136 and tp0326) were ultimately selected to give a high discriminating capability among the T. pallidum subsp. pertenue samples tested. Intragenic regions of these three target genes were then selected to enhance the discriminating capability of the typing scheme using short readily amplifiable loci. This 3-gene multilocus sequence typing (MLST) method was applied to existing historical human yaws strains, the Fribourg-Blanc simian isolate, and DNA from 194 lesion swabs from yaws patients on Lihir Island, Papua New Guinea. Among all samples tested, fourteen molecular types were identified, seven of which were found in patient samples and seven among historical isolates or DNA. Three types (JG8, TD6, and SE7) were predominant on Lihir Island. This MLST approach allows molecular typing and differentiation of yaws strains. This method could be a useful tool to complement epidemiological studies in regions where T. pallidum subsp. pertenue is prevalent with the overall goals of improving our understanding of yaws transmission dynamics and helping the yaws eradication campaign to succeed.

Development of a Multilocus Sequence Typing (MLST) scheme for Treponema pallidum subsp. pertenue: Application to yaws in Lihir Island, Papua New Guinea

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Godornes, Charmie; Giacani, Lorenzo; Barry, Alyssa E.; Mitja, Oriol

2017-01-01

Background Yaws is a neglected tropical disease, caused by Treponema pallidum subsp. pertenue. The disease causes chronic lesions, primarily in young children living in remote villages in tropical climates. As part of a global yaws eradication campaign initiated by the World Health Organization, we sought to develop and evaluate a molecular typing method to distinguish different strains of T. pallidum subsp. pertenue for disease control and epidemiological purposes. Methods and principal findings Published genome sequences of strains of T. pallidum subsp. pertenue and pallidum were compared to identify polymorphic genetic loci among the strains. DNA from a number of existing historical Treponema isolates, as well as a subset of samples from yaws patients collected in Lihir Island, Papua New Guinea, were analyzed using these targets. From these data, three genes (tp0548, tp0136 and tp0326) were ultimately selected to give a high discriminating capability among the T. pallidum subsp. pertenue samples tested. Intragenic regions of these three target genes were then selected to enhance the discriminating capability of the typing scheme using short readily amplifiable loci. This 3-gene multilocus sequence typing (MLST) method was applied to existing historical human yaws strains, the Fribourg-Blanc simian isolate, and DNA from 194 lesion swabs from yaws patients on Lihir Island, Papua New Guinea. Among all samples tested, fourteen molecular types were identified, seven of which were found in patient samples and seven among historical isolates or DNA. Three types (JG8, TD6, and SE7) were predominant on Lihir Island. Conclusions This MLST approach allows molecular typing and differentiation of yaws strains. This method could be a useful tool to complement epidemiological studies in regions where T. pallidum subsp. pertenue is prevalent with the overall goals of improving our understanding of yaws transmission dynamics and helping the yaws eradication campaign to succeed

Seroprevalence of the Hepatitis B, Hepatitis C, and Human Immunodeficiency Viruses and Treponema pallidum at the Beijing General Hospital from 2010 to 2014: A Cross-Sectional Study.

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Shaoxia Xu

Full Text Available The hepatitis B, hepatitis C, human immunodeficiency viruses and Treponema pallidum are important causes of infectious diseases concern to public health.Between 2010 and 2014, we used an automated chemiluminescence microparticle immunoassay to detect the hepatitis B, hepatitis C, and human immunodeficiency viruses as well as Treponema pallidum (the rapid plasma regain test was used in 2010-2011. Positive human immunodeficiency virus tests were confirmed via western blotting.Among 416,130 subjects, the seroprevalences for hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and Treponema pallidum were 5.72%, 1.23%, 0.196%, and 0.76%, respectively. Among 671 patients with positive human immunodeficiency virus results, 392 cases were confirmed via western blotting. Hepatitis B and human immunodeficiency virus infections were more frequent in men (7.78% and 0.26%, respectively than in women (4.45% and 0.021%, respectively. The hepatitis B and C virus seroprevalences decreased from 6.21% and 1.58%, respectively, in 2010, to 5.37% and 0.988%, respectively, in 2014. The human immunodeficiency virus seroprevalence increased from 0.04% in 2010 to 0.17% in 2014, and was elevated in the Infectious Disease (2.65%, Emergency (1.71%, and Dermatology and Sexually Transmitted Diseases (1.12% departments. The specificity of the human immunodeficiency virus screening was 71.4%. The false positive rates for the Treponema pallidum screening tests increased in patients who were 60-70 years old. The co-infection rates for the hepatitis C and human immunodeficiency viruses were 0.47% in hepatitis C virus-positive patients and 7.33% in human immunodeficiency virus-positive patients.During 2010-2014, hepatitis B virus and human immunodeficiency virus infections were more frequent among men at our institution. Although the seroprevalences of hepatitis B and C viruses decreased, the seroprevalence of human immunodeficiency virus infection increased (with

Protection against Syphilis Correlates with Specificity of Antibodies to the Variable Regions of Treponema pallidum Repeat Protein K

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Morgan, Cecilia A.; Lukehart, Sheila A.; Van Voorhis, Wesley C.

2003-01-01

Syphilis has been recognized as a disease since the late 1400s, yet there is no practical vaccine available. One impediment to the development of a vaccine is the lack of understanding of multiple reinfections in humans despite the development of robust immune responses during the first episode. It has been shown that the Treponema pallidum repeat protein K (TprK) differs in seven discrete variable (V) regions in isolates and that the antibody response during infection is directed to these V ...

Evaluation of macrolide resistance and enhanced molecular typing of Treponema pallidum in patients with syphilis in Taiwan: a prospective multicenter study.

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Wu, Hsiu; Chang, Sui-Yuan; Lee, Nan-Yao; Huang, Wen-Chi; Wu, Bing-Ru; Yang, Chia-Jui; Liang, Shiou-Haur; Lee, Chen-Hsiang; Ko, Wen-Chien; Lin, Hsi-Hsun; Chen, Yen-Hsu; Liu, Wen-Chun; Su, Yi-Ching; Hsieh, Chia-Yin; Wu, Pei-Ying; Hung, Chien-Ching

2012-07-01

Studies of macrolide resistance mutations and molecular typing using the newly proposed enhanced typing system for Treponema pallidum isolates obtained from HIV-infected patients in the Asia-Pacific region are scarce. Between September 2009 and December 2011, we conducted a survey to detect T. pallidum using a PCR assay using clinical specimens from patients with syphilis at six major designated hospitals for HIV care in Taiwan. The T. pallidum strains were genotyped by following the enhanced molecular typing methodology, which analyzed the number of 60-bp repeats in the acidic repeat protein (arp) gene, T. pallidum repeat (tpr) polymorphism, and the sequence of base pairs 131 to 215 in the tp0548 open reading frame of T. pallidum. Detection of A2058G and A2059G point mutations in the T. pallidum 23S rRNA was performed with the use of restriction fragment length polymorphism (RFLP). During the 2-year study period, 211 clinical specimens were obtained from 136 patients with syphilis. T. pallidum DNA was isolated from 105 (49.8%) of the specimens, with swab specimens obtained from chancres having the highest yield rate (63.2%), followed by plasma (49.4%), serum (35.7%), and cerebrospinal fluid or vitreous fluid (18.2%) specimens. Among the 40 fully typed specimens, 11 subtypes of T. pallidum were identified. Subtype 14f/f (18 isolates) was the most common isolates, followed by 14f/c (3), 14b/c (3), and 14k/f (3). Among the isolates examined for macrolide resistance, none had the A2058G or A2059G mutation. In conclusion, we found that type 14 f/f was the most common T. pallidum strain in this multicenter study on syphilis in Taiwan and that none of the isolates exhibited 23S rRNA mutations causing resistance to macrolides.

Rapid Treponema pallidum clearance from blood and ulcer samples following single dose benzathine penicillin treatment of early syphilis.

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Tipple, Craig; Jones, Rachael; McClure, Myra; Taylor, Graham

2015-02-01

Currently, the efficacy of syphilis treatment is measured with anti-lipid antibody tests. These can take months to indicate cure and, as a result, syphilis treatment trials require long periods of follow-up. The causative organism, Treponema pallidum (T. pallidum), is detectable in the infectious lesions of early syphilis using DNA amplification. Bacteraemia can likewise be identified, typically in more active disease. We hypothesise that bacterial clearance from blood and ulcers will predict early the standard serology-measured treatment response and have developed a qPCR assay that could monitor this clearance directly in patients with infectious syphilis. Patients with early syphilis were given an intramuscular dose of benzathine penicillin. To investigate the appropriate sampling timeframe samples of blood and ulcer exudate were collected intensively for T. pallidum DNA (tpp047 gene) and RNA (16S rRNA) quantification. Sampling ended when two consecutive PCRs were negative. Four males were recruited. The mean peak level of T. pallidum DNA was 1626 copies/ml whole blood and the mean clearance half-life was 5.7 hours (std. dev. 0.53). The mean peak of 16S rRNA was 8879 copies/ml whole blood with a clearance half-life of 3.9 hours (std. dev. 0.84). From an ulcer, pre-treatment, 67,400 T. pallidum DNA copies and 7.08 x 107 16S rRNA copies were detected per absorbance strip and the clearance half-lives were 3.2 and 4.1 hours, respectively. Overall, T. pallidum nucleic acids were not detected in any sample collected more than 56 hours (range 20-56) after treatment. All patients achieved serologic cure. In patients with active early syphilis, measuring T. pallidum levels in blood and ulcer exudate may be a useful measure of treatment success in therapeutic trials. These laboratory findings need confirmation on a larger scale and in patients receiving different therapies.

Rapid Treponema pallidum clearance from blood and ulcer samples following single dose benzathine penicillin treatment of early syphilis.

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Craig Tipple

2015-02-01

Full Text Available Currently, the efficacy of syphilis treatment is measured with anti-lipid antibody tests. These can take months to indicate cure and, as a result, syphilis treatment trials require long periods of follow-up. The causative organism, Treponema pallidum (T. pallidum, is detectable in the infectious lesions of early syphilis using DNA amplification. Bacteraemia can likewise be identified, typically in more active disease. We hypothesise that bacterial clearance from blood and ulcers will predict early the standard serology-measured treatment response and have developed a qPCR assay that could monitor this clearance directly in patients with infectious syphilis. Patients with early syphilis were given an intramuscular dose of benzathine penicillin. To investigate the appropriate sampling timeframe samples of blood and ulcer exudate were collected intensively for T. pallidum DNA (tpp047 gene and RNA (16S rRNA quantification. Sampling ended when two consecutive PCRs were negative. Four males were recruited. The mean peak level of T. pallidum DNA was 1626 copies/ml whole blood and the mean clearance half-life was 5.7 hours (std. dev. 0.53. The mean peak of 16S rRNA was 8879 copies/ml whole blood with a clearance half-life of 3.9 hours (std. dev. 0.84. From an ulcer, pre-treatment, 67,400 T. pallidum DNA copies and 7.08 x 107 16S rRNA copies were detected per absorbance strip and the clearance half-lives were 3.2 and 4.1 hours, respectively. Overall, T. pallidum nucleic acids were not detected in any sample collected more than 56 hours (range 20-56 after treatment. All patients achieved serologic cure. In patients with active early syphilis, measuring T. pallidum levels in blood and ulcer exudate may be a useful measure of treatment success in therapeutic trials. These laboratory findings need confirmation on a larger scale and in patients receiving different therapies.

Enhanced Molecular Typing of Treponema pallidum subspecies pallidum Strains From 4 Italian Hospitals Shows Geographical Differences in Strain Type Heterogeneity, Widespread Resistance to Macrolides, and Lack of Mutations Associated With Doxycycline Resistance.

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Giacani, Lorenzo; Ciccarese, Giulia; Puga-Salazar, Christian; Dal Conte, Ivano; Colli, Laura; Cusini, Marco; Ramoni, Stefano; Delmonte, Sergio; DʼAntuono, Antonietta; Gaspari, Valeria; Drago, Francesco

2018-04-01

Although syphilis rates have been relatively high in Italy for more than 15 years, no data on the molecular types of Treponema pallidum subspecies pallidum circulating in this country are yet available. Likewise, no data on how widespread is resistance to macrolide or tetracycline antibiotics in these strains exist. Such data would, however, promote comprehensive studies on the molecular epidemiology of syphilis infections in Italy and inform future interventions aiming at syphilis control in this and other European countries. Swabs from oral, genital, cutaneous, or anal lesions were obtained from 60 syphilis patients attending dermatology clinics in Milan, Turin, Genoa, and Bologna. Molecular typing of T. pallidum DNA was performed to provide a snapshot of the genetic diversity of strains circulating in Northern Italy. Samples were also screened for mutations conferring resistance to macrolides and tetracyclines. T. pallidum DNA was detected in 88.3% (53/60) of the specimens analyzed. Complete and partial T. pallidum typing data were obtained for 77.3% (41/53) and 15.0% (8/53) of samples, respectively, whereas 4 samples could not be typed despite T. pallidum DNA being detected. The highest strain type heterogeneity was seen in samples from Bologna and Milan, followed by Genoa. Minimal diversity was detected in samples from Turin, despite the highest number of typeable samples collected there. Resistance to macrolides was detected in 94.3% (50/53) of the strains, but no known mutations associated with tetracycline resistance were found. Genetic diversity among T. pallidum strains circulating in Northern Italy varies significantly among geographical areas regardless of physical distance. Resistance to macrolides is widespread.

Sensitive detection of Treponema pallidum DNA from the whole blood of patients with syphilis by the nested PCR assay.

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Wang, Cuini; Cheng, Yuanyuan; Liu, Biao; Wang, Yuanyuan; Gong, Weiming; Qian, Yihong; Guan, Zhifang; Lu, Haikong; Gu, Xin; Shi, Mei; Zhou, Pingyu

2018-05-09

The aim of this work was to investigate the application of the nested PCR assay for the detection of Treponema pallidum (TP) DNA from the blood of patients with different stages of syphilis. In this study, a nested PCR method targeting the Tpp47 and polA genes (Tpp47-Tp-PCR and polA-Tp-PCR) was developed to detect TP-DNA in whole blood samples collected from 262 patients with different stages of syphilis (84 primary syphilis, 97 secondary syphilis, and 81 latent syphilis patients). The PCR assay detected T. pallidum DNA in 53.6% and 62.9% of the patients with primary and secondary syphilis, respectively, which was much higher than the detection levels in patients with latent syphilis (7.4%) (both p PCR in the early phase of the latent infection. Thus, blood RPR titers were correlated with the blood T. pallidum burden, but the correlations varied with primary and secondary syphilis. The results indicate that nested PCR is a sensitive method for detecting blood TP-DNA and is especially useful for detecting early syphilis including primary syphilis and secondary syphilis. The findings also suggest that the PCR assay may be used to complement other methods to enhance the diagnosis of syphilis.

Molecular typing of Treponema pallidum isolates from Buenos Aires, Argentina: Frequent Nichols-like isolates and low levels of macrolide resistance.

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Lucía Gallo Vaulet

Full Text Available A total of 54 clinical samples, including genital lesion swabs, whole blood and cerebrospinal fluid from patients diagnosed with syphilis were collected in 2006 and in 2013 in Buenos Aires, Argentina. Treponemal DNA was detected in 43 of the analyzed samples (79.6% and further analyzed using Sequencing-based molecular typing (SBMT and Enhanced CDC-typing (ECDCT. By SBMT, 10 different Treponema pallidum subsp. pallidum (TPA genotypes were found, of which six were related to the TPA SS14 strain, and four to the TPA Nichols strain. The 23S rRNA gene was amplified in samples isolated from 42 patients, and in six of them (14.3%, either the A2058G (four patients, 9.5% or the A2059G (two patients, 4.8% mutations were found. In addition to Taiwan, Madagascar and Peru, Argentina is another country where the prevalence of Nichols-like isolates (26.8% is greater than 10%.

Seroprevalence of Human Immunodeficiency Virus, Hepatitis B Virus, Hepatitis C Virus, and Treponema pallidum Infections among Blood Donors on Bioko Island, Equatorial Guinea.

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Dong-De Xie

Full Text Available Regular screening of transfusion-transmissible infections (TTIs, such as human immunodeficiency virus (HIV, hepatitis B and hepatitis C virus (HBV and HCV, respectively, and Treponema pallidum, in blood donors is essential to guaranteeing clinical transfusion safety. This study aimed to determine the seroprevalence of four TTIs among blood donors on Bioko Island, Equatorial Guinea (EG.A retrospective survey of blood donors from January 2011 to April 2013 was conducted to assess the presence of HIV, HBV, HCV and T. pallidum. The medical records were analyzed to verify the seroprevalence of these TTIs among blood donations stratified by gender, age and geographical region.Of the total 2937 consecutive blood donors, 1098 (37.39% had a minimum of one TTI and 185 (6.29% harbored co-infections. The general seroprevalence of HIV, HBV, HCV and T. pallidum were 7.83%, 10.01%, 3.71% and 21.51%, respectively. The most frequent TTI co-infections were HBV-T. pallidum 60 (2.04% and HIV-T. pallidum 46 (1.57%. The seroprevalence of HIV, HBV, HCV and T. pallidum were highest among blood donors 38 to 47 years, 18 to 27 years and ≥ 48 years age, respectively (P<0.05. The seroprevalence of TTIs varied according to the population from which the blood was collected on Bioko Island.Our results firstly provide a comprehensive overview of TTIs among blood donors on Bioko Island. Strict screening of blood donors and improved hematological examinations using standard operating procedures are recommended.

A double-edged sword: does highly active antiretroviral therapy contribute to syphilis incidence by impairing immunity to Treponema pallidum?

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Rekart, Michael L; Ndifon, Wilfred; Brunham, Robert C; Dushoff, Jonathan; Park, Sang Woo; Rawat, Sanjana; Cameron, Caroline E

2017-08-01

Recently, the world has experienced a rapidly escalating outbreak of infectious syphilis primarily affecting men who have sex with men (MSM); many are taking highly active antiretroviral therapy (HAART) for HIV-1 infection. The prevailing hypothesis is that HAART availability and effectiveness have led to the perception among both individuals who are HIV-1 infected and those who are uninfected that HIV-1 transmission has become much less likely, and the effects of HIV-1 infection less deadly. This is expected to result in increased sexual risk-taking, especially unprotected anal intercourse, leading to more non-HIV-1 STDs, including gonorrhoea, chlamydia and syphilis. However, syphilis incidence has increased more rapidly than other STDs. We hypothesise that HAART downregulates the innate and acquired immune responses to Treponema pallidum and that this biological explanation plays an important role in the syphilis epidemic. We performed a literature search and developed a mathematical model of HIV-1 and T. pallidum confection in a population with two risk groups with assortative mixing to explore the consequence on syphilis prevalence of HAART-induced changes in behaviour versus HAART-induced biological effects. Since rising syphilis incidence appears to have outpaced gonorrhoea and chlamydia, predominantly affecting HIV-1 positive MSM, behavioural factors alone may be insufficient to explain the unique, sharp increase in syphilis incidence. HAART agents have the potential to alter the innate and acquired immune responses in ways that may enhance susceptibility to T. pallidum . This raises the possibility that therapeutic and preventative HAART may inadvertently increase the incidence of syphilis, a situation that would have significant and global public health implications. We propose that additional studies investigating the interplay between HAART and enhanced T. pallidum susceptibility are needed. If our hypothesis is correct, HAART should be combined with

Whole Genome Sequences of Three Treponema pallidum ssp. pertenue Strains: Yaws and Syphilis Treponemes Differ in Less than 0.2% of the Genome Sequence

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Chen, Lei; Pospíšilová, Petra; Strouhal, Michal; Qin, Xiang; Mikalová, Lenka; Norris, Steven J.; Muzny, Donna M.; Gibbs, Richard A.; Fulton, Lucinda L.; Sodergren, Erica; Weinstock, George M.; Šmajs, David

2012-01-01

Background The yaws treponemes, Treponema pallidum ssp. pertenue (TPE) strains, are closely related to syphilis causing strains of Treponema pallidum ssp. pallidum (TPA). Both yaws and syphilis are distinguished on the basis of epidemiological characteristics, clinical symptoms, and several genetic signatures of the corresponding causative agents. Methodology/Principal Findings To precisely define genetic differences between TPA and TPE, high-quality whole genome sequences of three TPE strains (Samoa D, CDC-2, Gauthier) were determined using next-generation sequencing techniques. TPE genome sequences were compared to four genomes of TPA strains (Nichols, DAL-1, SS14, Chicago). The genome structure was identical in all three TPE strains with similar length ranging between 1,139,330 bp and 1,139,744 bp. No major genome rearrangements were found when compared to the four TPA genomes. The whole genome nucleotide divergence (dA) between TPA and TPE subspecies was 4.7 and 4.8 times higher than the observed nucleotide diversity (π) among TPA and TPE strains, respectively, corresponding to 99.8% identity between TPA and TPE genomes. A set of 97 (9.9%) TPE genes encoded proteins containing two or more amino acid replacements or other major sequence changes. The TPE divergent genes were mostly from the group encoding potential virulence factors and genes encoding proteins with unknown function. Conclusions/Significance Hypothetical genes, with genetic differences, consistently found between TPE and TPA strains are candidates for syphilitic treponemes virulence factors. Seventeen TPE genes were predicted under positive selection, and eleven of them coded either for predicted exported proteins or membrane proteins suggesting their possible association with the cell surface. Sequence changes between TPE and TPA strains and changes specific to individual strains represent suitable targets for subspecies- and strain-specific molecular diagnostics. PMID:22292095

Evaluation of FlaB1, FlaB2, FlaB3, and Tp0463 of Treponema pallidum for serodiagnosis of syphilis.

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Jiang, Chuanhao; Xiao, Jinhong; Xie, Yafeng; Xiao, Yongjian; Wang, Chuan; Kuang, Xingxing; Xu, Man; Li, Ranhui; Zeng, Tiebing; Liu, Shuanquan; Yu, Jian; Zhao, Feijun; Wu, Yimou

2016-02-01

Syphilis is a multistage disease caused by the invasive spirochete Treponema pallidum subsp. pallidum, and accurate diagnosis is important for the prevention and treatment of syphilis. Here, to identify appropriate diagnostic antigens for serodiagnosis of syphilis, 6 recombinant proteins were expressed in Escherichia coli and purified, including flagellins (FlaB1 [Tp0868], FlaB2 [Tp0792], and FlaB3 [Tp0870]), Tp0463, Tp0751, and Tp1038. The sensitivities were determined by screening sera from individuals with primary (n=82), secondary (n=115), latent (n=105), and congenital (n=65) syphilis. The specificities were determined by screening sera from uninfected controls (n=30) and potentially cross-reactive infections including Lyme disease (n=30), leptospirosis (n=5), and hepatitis B (n=30). Our data showed that FlaB1, FlaB2, FlaB3, Tp0463, and Tp1038 exhibited higher overall sensitivities and specificities for detecting IgG antibody, with 95.4% and 98.9%, 92.6% and 95.8%, 95.1% and 95.8%, 92.6% and 97.9%, and 95.9% and 98.9%, respectively. In contrast, Tp0751 demonstrated only an overall sensitivity of 39.2%. For comparison, the sensitivity and specificity of Architect Syphilis TP were determined to be 98.1% and 93.7%, respectively. In addition, FlaB1, FlaB2, FlaB3, and Tp0463 demonstrated excellent performance for detecting IgM antibody in primary and congenital syphilis, with sensitivities of 76.8% and 83.1%, 72.0% and 87.7%, 74.4% and 89.2%, and 64.6% and 75.3%, respectively. These results indicate that FlaB1, FlaB2, FlaB3, and Tp0463 could be as novel diagnostic candidates for serodiagnosis of syphilis. Copyright © 2016 Elsevier Inc. All rights reserved.

Diagnostic value of recombinant Tp0821 protein in serodiagnosis for syphilis.

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Xie, Y; Xu, M; Wang, C; Xiao, J; Xiao, Y; Jiang, C; You, X; Zhao, F; Zeng, T; Liu, S; Kuang, X; Wu, Y

2016-04-01

Syphilis is a multistage sexually transmitted disease that remains a serious public health concern worldwide. The coexistence of Treponema pallidum with other closely related members of spirochaeta, such as Leptospira spp. and Borrelia burgdorferi, has complicated the serodiagnosis due to cross-reactive antigens. In this study, recombinant Tp0821 protein was expressed in Escherichia coli and purified by metal affinity chromatography. Then enzyme-linked immunosorbent assays (ELISAs) based on Tp0821 for the detection of specific antibodies were established. The relative positive rates of the IgM ELISA and the IgG ELISA were found to be 91·0 and 98·3%, respectively, when screening 578 syphilis specimens. The specificities were 94·3 and 100%, respectively, when cross-checking with serum samples obtained from 30 patients with Lyme disease, five patients with leptospirosis, and 52 uninfected controls. In addition, relative positive rates and specificities of Tp0821 for human sera were all 100% in Western blotting. When compared to the syphilis diagnostic tests commonly used in clinical settings, we found that the results of Tp0821-based ELISAs correlated well with the results of the treponemal tests, specifically the T. pallidum particle agglutination (TP-PA) test and the chemiluminescent immunoassay (CIA). Thus, these findings identify Tp0821 as a novel serodiagnostic candidate for syphilis. In this study, we expressed and purified the Treponema pallidum protein Tp0821 and developed Tp0821-based enzyme-linked immunosorbent assays (ELISAs) for the detection of specific antibodies. The serodiagnostic performance of the recombinant protein was then evaluated. When compared to the results of syphilis diagnostic tests commonly used in clinical settings, we found that the reactivities of syphilitic sera with the recombinant antigen correlated well with the results of the treponemal tests, specifically the T. pallidum particle agglutination (TP-PA) test and the

Protection against syphilis correlates with specificity of antibodies to the variable regions of Treponema pallidum repeat protein K.

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Morgan, Cecilia A; Lukehart, Sheila A; Van Voorhis, Wesley C

2003-10-01

Syphilis has been recognized as a disease since the late 1400s, yet there is no practical vaccine available. One impediment to the development of a vaccine is the lack of understanding of multiple reinfections in humans despite the development of robust immune responses during the first episode. It has been shown that the Treponema pallidum repeat protein K (TprK) differs in seven discrete variable (V) regions in isolates and that the antibody response during infection is directed to these V regions. Immunization with TprK confers significant protection against infection with the homologous strain. We hypothesize that the antigenic diversity of TprK is involved in immune evasion, which contributes to the lack of heterologous protection. Here, using the rabbit model, we show a correlation between limited heterologous protection and tprK diversity in the challenge inoculum. We demonstrate that antibody responses to the V regions of one TprK molecule show limited cross-reactivity with heterologous TprK V regions.

Development of a colloidal gold-immunochromatography assay to detect immunoglobulin G antibodies to Treponema pallidum with TPN17 and TPN47.

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Lin, Li-Rong; Fu, Zuo-Gen; Dan, Bing; Jing, Guang-Jun; Tong, Man-li; Chen, De-Teng; Yu, Yang; Zhang, Chang-Gong; Yang, Tian-Ci; Zhang, Zhong-Ying

2010-11-01

Syphilis remains a worldwide public health problem; it is necessary to develop a new diagnostic approach that is easier and faster than conventional tests. Here, we report a new testing method named colloidal gold-immunochromatography assay (GICA) to detect syphilis instead of fluorescent treponemal antibody-absorption (FTA-Abs). Syphilis-specific immunoglobulin G (IgG) antibody was detected with GICA established on syphilis-specific recombinant proteins, TPN17 and TPN47. FTA-Abs Treponema pallidum (TP)-IgG was set as the gold standard. A GICA test was performed to detect the serum of 14 967 subjects who took a serologic test for syphilis at the Xiamen Center of Clinical Laboratory, Fujian, China, from March 2009 to February 2010, among which 1326 cases were diagnosed as syphilitic. The results showed that the sensitivity, specificity, and positive predictive value were 99.38% (1279/1287), 99.96% (12,975/12,980), and 99.61% (1279/1284), respectively. The positive rate between the 2 test methods had no significant difference (χ(2) = 0.003, P > 0.05). Detection on 500 interference specimens indicated that the biologic false-positive rate of the GICA test was extremely low and free from other biologic and chemical factors. The characteristics of GICA TP-IgG correspond to that of FTA-Abs TP-IgG (EUROIMMUN Medizinische Labordiagnostika, Germany). The GICA test is convenient, fast, and inexpensive, and it can be used both as a confirmatory test and a screening indicator, instead of FTA-Abs TP-IgG. Copyright © 2010 Elsevier Inc. All rights reserved.

Molecular Characterization of Syphilis in Patients in Canada: Azithromycin Resistance and Detection of Treponema pallidum DNA in Whole-Blood Samples versus Ulcerative Swabs▿

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Martin, Irene E.; Tsang, Raymond S. W.; Sutherland, Karen; Tilley, Peter; Read, Ron; Anderson, Barbara; Roy, Colleen; Singh, Ameeta E.

2009-01-01

Although detection of Treponema pallidum DNA in whole-blood specimens of syphilis patients has been reported, it is uncertain at what stage of the disease such specimens are most suitable for the molecular diagnosis of syphilis. Also, few studies have directly compared the different gene targets for routine laboratory diagnostic usage in PCR assays. We examined 87 specimens from 68 patients attending two urban sexually transmitted disease clinics in Alberta, Canada. PCR was used to amplify the T. pallidum tpp47, bmp, and polA genes as well as a specific region of the 23S rRNA gene linked to macrolide antibiotic susceptibility. In primary syphilis cases, PCR was positive exclusively (75% sensitivity rate) in ulcerative swabs but not in blood specimens, while in secondary syphilis cases, 50% of the blood specimens were positive by PCR. Four out of 14 (28.6%) of our PCR-positive syphilis cases were found to be caused by an azithromycin-resistant strain(s). Our results confirmed that swabs from primary ulcers are the specimens of choice for laboratory diagnostic purposes. However, further research is required to determine what specimen(s) would be most appropriate for molecular investigation of syphilis in secondary and latent syphilis. PMID:19339468

Further evaluation of the characteristics of Treponema pallidum-specific IgM antibody in syphilis serofast reaction patients.

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Lin, Li-Rong; Zheng, Wei-Hong; Tong, Man-Li; Fu, Zuo-Gen; Liu, Gui-Li; Fu, Jian-Guo; Zhang, Dai-Wei; Yang, Tian-Ci; Liu, Li-Li

2011-11-01

Syphilis serofast reaction (SSR) is common in clinical work. From June 2005 to May 2009, 1208 syphilis patients were chosen for research by the Xiamen Center of Clinical Laboratory in China. Serologic tests were performed with toluidine red unheated serum test (TRUST) and Treponema pallidum particle agglutination (TPPA). Then, T. pallidum-specific IgM antibody (TP-IgM) was detected with fluorescent treponemal antibody absorption (FTA-Abs) and TPPA. In this study, patients were divided into the following experimental groups according to the results of TRUST and TPPA: (1) the SSR group consisted of 411 cases with (+) TRUST and (+) TPPA, and without clinical manifestations after 1 year of recommended syphilis treatment; (2) the serum cure group, which was further subdivided into group A consisting of 251cases with (-) TRUST and (+) TPPA; (3) group B consisting of 546 cases with (-) TRUST and (-) TPPA; and (4) the blood donor control group which consisted of 100 cases. We demonstrated that a total of 136 cases (33.09%) of 411 SSR patients were TP-IgM positive by TPPA, and this percentage was markedly higher than that in serum cure group A (9.16%). FTA-Abs analyses revealed similar results. All samples in serum cure group B and the control group were TP-IgM negative, which is identical to our previous report. The present study also indicated that the TP-IgM positive rate was not significantly different among patients with different ages, genders, and clinical phases after 1 year of recommended therapy. From the total of 1208 syphilis patients, 289 were randomly selected for TP-DNA detection by fluorescence quantitative polymerase chain reaction, and the positive rate of TP-DNA was 32.53%, which was slightly higher than that of FTA-Abs TP-IgM, and no statistically significant difference by chi-square tests, indicating the TP-DNA result is preferably consistent with FTA-Abs and supporting our deduction that TP-IgM could be used as a serologic marker for the relapse and

Complete genome sequences of two strains of Treponema pallidum subsp. pertenue from Ghana, Africa: Identical genome sequences in samples isolated more than 7 years apart.

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Michal Strouhal

2017-09-01

Full Text Available Treponema pallidum subsp. pertenue (TPE is the causative agent of yaws, a multi-stage disease, endemic in tropical regions of Africa, Asia, Oceania, and South America. To date, four TPE strains have been completely sequenced including three TPE strains of human origin (Samoa D, CDC-2, and Gauthier and one TPE strain (Fribourg-Blanc isolated from a baboon. All TPE strains are highly similar to T. pallidum subsp. pallidum (TPA strains. The mutation rate in syphilis and related treponemes has not been experimentally determined yet.Complete genomes of two TPE strains, CDC 2575 and Ghana-051, that infected patients in Ghana and were isolated in 1980 and 1988, respectively, were sequenced and analyzed. Both strains had identical consensus genome nucleotide sequences raising the question whether TPE CDC 2575 and Ghana-051 represent two different strains. Several lines of evidence support the fact that both strains represent independent samples including regions showing intrastrain heterogeneity (13 and 5 intrastrain heterogeneous sites in TPE Ghana-051 and TPE CDC 2575, respectively. Four of these heterogeneous sites were found in both genomes but the frequency of alternative alleles differed. The identical consensus genome sequences were used to estimate the upper limit of the yaws treponeme evolution rate, which was 4.1 x 10-10 nucleotide changes per site per generation.The estimated upper limit for the mutation rate of TPE was slightly lower than the mutation rate of E. coli, which was determined during a long-term experiment. Given the known diversity between TPA and TPE genomes and the assumption that both TPA and TPE have a similar mutation rate, the most recent common ancestor of syphilis and yaws treponemes appears to be more than ten thousand years old and likely even older.

Clinical comparison of the Treponema pallidum CAPTIA syphilis-G enzyme immunoassay with the fluorescent treponemal antibody absorption immunoglobulin G assay for syphilis testing.

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Halling, V W; Jones, M F; Bestrom, J E; Wold, A D; Rosenblatt, J E; Smith, T F; Cockerill, F R

1999-10-01

Recently, a treponema-specific immunoglobulin G (IgG) enzyme immunoassay (EIA), the CAPTIA Syphilis-G (Trinity Biotech, Jamestown, N.Y.), has become available as a diagnostic test for syphilis. A total of 89 stored sera previously tested by the fluorescent treponemal antibody absorption (FTA-ABS) IgG assay were evaluated by the CAPTIA EIA. The FTA-ABS IgG procedure was performed by technologists unblinded to results of rapid plasmid reagin (RPR) testing of the same specimens. Borderline CAPTIA-positive samples (antibody indices of >/=0.650 and 0.900, the sample was considered positive. Thirteen of 89 (15%) samples had discrepant results. Compared to the FTA-ABS assay, the CAPTIA EIA had a sensitivity and specificity and positive and negative predictive values of 70.7, 97.9, 96.7, and 79.7%, respectively. In another analysis, discrepancies between results were resolved by repeated FTA-ABS testing (technologists were blinded to previous RPR results) and patient chart reviews. Seven CAPTIA-negative samples which were previously interpreted (unblinded) as minimally reactive by the FTA method were subsequently interpreted (blinded) as nonreactive. One other discrepant sample (CAPTIA negative and FTA-ABS positive [at an intensity of 3+], unblinded) was FTA negative with repeated testing (blinded). For the five remaining discrepant samples, chart reviews indicated that one patient (CAPTIA negative and FTA-ABS positive [minimally reactive], blinded) had possible syphilis. These five samples were also evaluated and found to be negative by another treponema-specific test, the Treponema pallidum microhemagglutination assay. Therefore, after repeated testing and chart reviews, 2 of the 89 (2%) samples had discrepant results; the adjusted sensitivity, specificity, and positive and negative predictive values were 96.7, 98.3, 96.7, and 98.3%, respectively. This study demonstrates that the CAPTIA IgG EIA is a reliable method for syphilis testing and that personnel performing tests

Clinical Evaluation of Fully Automated Elecsys® Syphilis Assay for the Detection of Antibodies of Treponema pallidum.

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Li, Dongdong; An, Jingna; Wang, Tingting; Tao, Chuanmin; Wang, Lanlan

2016-11-01

The resurgence of syphilis in recent years has become a serious threat to the public health worldwide, and the serological detection of specific antibodies against Treponema pallidum (TP) remains the most reliable method for laboratory diagnosis of syphilis. The performance of the Elecsys ® Syphilis assay, a brand new electrochemiluminescene immunoassay (ECLIA), was assessed by large amounts of samples in this study. In comparison with InTec assay, the Elecsys ® Syphilis assay was evaluated in 146 preselected samples from patients with syphilis, 1803 clinical routine samples, and 175 preselected samples from specific populations with reportedly increased rates of false-positive syphilis test results. Discrepancy samples must be investigated by Mikrogen Syphilis recomline assay. There was an overall agreement of 99.58% between two assays (Kappa = 0.975). The sensitivity and specificity of the Elecsys ® Syphilis assay were 100.0% (95% CI, 96.8-100.0%) and 99.8% (95% CI, 99.5-100.0%), respectively. The Elecsys syphilis assay displays better sensitivity (100%), specificity (99.8%), PPV (98.7%), and NPV (100%) in 2124 samples enrolled, compared with the InTec assay. Considering the excellent ease of use and automation, high throughput, and its superior sensitivity, especially in primary syphilis, the Elecsys ® Syphilis assay could represent an outstanding choice for screening of syphilis in high-volume laboratories. However, more attention was still needed, or the results must be confirmed by other treponemal immunoassays. The new Elecsys ® Syphilis assay is applied to patients with malignant neoplasm or HIV infection. © 2016 Wiley Periodicals, Inc.

Multilocus sequence analysis of Treponema denticola strains of diverse origin

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Mo Sisu

2013-02-01

Full Text Available Abstract Background The oral spirochete bacterium Treponema denticola is associated with both the incidence and severity of periodontal disease. Although the biological or phenotypic properties of a significant number of T. denticola isolates have been reported in the literature, their genetic diversity or phylogeny has never been systematically investigated. Here, we describe a multilocus sequence analysis (MLSA of 20 of the most highly studied reference strains and clinical isolates of T. denticola; which were originally isolated from subgingival plaque samples taken from subjects from China, Japan, the Netherlands, Canada and the USA. Results The sequences of the 16S ribosomal RNA gene, and 7 conserved protein-encoding genes (flaA, recA, pyrH, ppnK, dnaN, era and radC were successfully determined for each strain. Sequence data was analyzed using a variety of bioinformatic and phylogenetic software tools. We found no evidence of positive selection or DNA recombination within the protein-encoding genes, where levels of intraspecific sequence polymorphism varied from 18.8% (flaA to 8.9% (dnaN. Phylogenetic analysis of the concatenated protein-encoding gene sequence data (ca. 6,513 nucleotides for each strain using Bayesian and maximum likelihood approaches indicated that the T. denticola strains were monophyletic, and formed 6 well-defined clades. All analyzed T. denticola strains appeared to have a genetic origin distinct from that of ‘Treponema vincentii’ or Treponema pallidum. No specific geographical relationships could be established; but several strains isolated from different continents appear to be closely related at the genetic level. Conclusions Our analyses indicate that previous biological and biophysical investigations have predominantly focused on a subset of T. denticola strains with a relatively narrow range of genetic diversity. Our methodology and results establish a genetic framework for the discrimination and phylogenetic

Prevalencia de anticuerpos antitreponémicos y características sociodemográficas de la población mexicana adulta en el año 2000 Anti-Treponema pallidum seroprevalence and sociodemographic characteristics in Mexican adult population, 2000

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Carlos J Conde-González

2007-01-01

Full Text Available OBJETIVO: Determinar la frecuencia de anticuerpos antitreponémicos en mexicanos adultos de ambos sexos y las características de la población relacionadas con la infección sifilítica. MATERIAL Y MÉTODOS: Se analizaron para anti-Treponema pallidum 12 010 sueros seleccionados de forma aleatoria de la Encuesta Nacional de Salud 2000, con aplicación de un algoritmo conformado por técnicas serológicas treponémicas y no treponémicas, de tamizaje y confirmatorias, y se realizó un análisis estadístico para identificar los factores vinculados con la seropositividad. RESULTADOS: La seroprevalencia de anticuerpos antitreponémicos fue de 3.1% (IC95% 2.5-3.7. Las características relacionadas de modo significativo con la exposición a la infección fueron la mayor edad (RM 3.3, sexo masculino (RM 1.3, residencia en la región geográfica sur del país (RM 1.7, vivir en unión libre (RM 2.7 o ser viudo (RM 1.8, inicio de relaciones sexuales a edad temprana (RM 6.3 y, en las mujeres en particular, se identificó el antecedente de mortinatos (RM 1.8 y el informe de falta de uso del condón como método anticonceptivo (RM 14.1. CONCLUSIONES: Los hallazgos del estudio demuestran que la magnitud del antecedente de la infección por el treponema en la población mexicana adulta es considerablemente mayor respecto del que permite calcular la notificación oficial de casos de la enfermedad. Como sucede con otras infecciones de transmisión sexual, aspectos sociodemográficos, de género y las prácticas sexuales no seguras incrementan la transmisión del agente etiológico. En México existe la necesidad de reforzar la vigilancia de la infección sifilítica a través de un diagnóstico oportuno y eficaz de los casos, más su adecuado tratamiento, para coadyuvar al control del padecimiento.OBJECTIVE: To measure for the first time in a population based study the prevalence of antibodies against Treponema pallidum among the Mexican adult population and

Comparative evaluation of the INNO-LIA syphilis score and the MarDx Treponema pallidum immunoglobulin G Marblot test assays for the serological diagnosis of syphilis.

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Lam, T K; Lau, H Y; Lee, Y P; Fung, S M; Leung, W L; Kam, K M

2010-02-01

We evaluated the performance of two immunoblot assays: the INNO-LIA Syphilis Score (LIA) and the MarDx T. pallidum IgG Marblot Test (TWB), as compared with that of the Murex ICE Syphilis enzyme immunoassay (EIA), the Serodia Treponema pallidum particle agglutination (TPPA) assay and the fluorescent treponemal antibody-absorption (FTA-abs) assay, for the serological diagnosis of syphilis using serum samples of 135 attendees of the social hygiene clinics of the Department of Health in Hong Kong newly diagnosed with syphilis and provided with clinical stages (39 in primary, 20 in secondary, 18 in early latent and 58 in latent of unknown duration) and of 43 normal healthy subjects between October and December 2004. The differences in the overall sensitivities of the LIA assay and the EIA/TPPA/FTA-abs assays were not statistically significant (P > 0.05) whereas the overall sensitivity of the TWB assay was significantly lower (P FTA-abs assays. The LIA assay had an overall sensitivity of 94.1% (95% CI 88.7-97.0%) whereas the TWB assay 65.2% (95% CI 56.8-72.7%). Both the LIA and the TWB assays have a specificity of 100%. When consensus results were derived from the most predominant results of the EIA, the TPPA and the FTA-abs assays, the LIA assay had a positive agreement with the consensus results of 98.5% (95% CI 94.5-99.6%) whereas the TWB assay 68.2% (95% CI 59.8-75.6%). Therefore, the LIA assay performed significantly better (P < 0.05) than the TWB assay. The LIA assay can be considered to be a valid alternative confirmatory test for the serological diagnosis of syphilis.

Superoxide reductase from the syphilis spirochete Treponema pallidum: crystallization and structure determination using soft X-rays

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Santos-Silva, Teresa; Trincão, José; Carvalho, Ana L.; Bonifácio, Cecília; Auchère, Françoise; Moura, Isabel; Moura, José J. G.; Romão, Maria J., E-mail: mromao@dq.fct.unl.pt [REQUIMTE Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

2005-11-01

Superoxide reductase is a non-haem iron-containing protein involved in resistance to oxidative stress. The oxidized form of the protein has been crystallized and its three-dimensional structure solved. A highly redundant X-ray diffraction data set was collected on a rotating-anode generator using Cu Kα X-ray radiation. Four Fe atoms were located in the asymmetric unit corresponding to four protein molecules arranged as a dimer of homodimers. Superoxide reductase is a 14 kDa metalloprotein containing a catalytic non-haem iron centre [Fe(His){sub 4}Cys]. It is involved in defence mechanisms against oxygen toxicity, scavenging superoxide radicals from the cell. The oxidized form of Treponema pallidum superoxide reductase was crystallized in the presence of polyethylene glycol and magnesium chloride. Two crystal forms were obtained depending on the oxidizing agents used after purification: crystals grown in the presence of K{sub 3}Fe(CN){sub 6} belonged to space group P2{sub 1} (unit-cell parameters a = 60.3, b = 59.9, c = 64.8 Å, β = 106.9°) and diffracted beyond 1.60 Å resolution, while crystals grown in the presence of Na{sub 2}IrCl{sub 6} belonged to space group C2 (a = 119.4, b = 60.1, c = 65.6 Å, β = 104.9°) and diffracted beyond 1.55 Å. A highly redundant X-ray diffraction data set from the C2 crystal form collected on a copper rotating-anode generator (λ = 1.542 Å) clearly defined the positions of the four Fe atoms present in the asymmetric unit by SAD methods. A MAD experiment at the iron absorption edge confirmed the positions of the previously determined iron sites and provided better phases for model building and refinement. Molecular replacement using the P2{sub 1} data set was successful using a preliminary trace as a search model. A similar arrangement of the four protein molecules could be observed.

Superoxide reductase from the syphilis spirochete Treponema pallidum: crystallization and structure determination using soft X-rays

International Nuclear Information System (INIS)

Santos-Silva, Teresa; Trincão, José; Carvalho, Ana L.; Bonifácio, Cecília; Auchère, Françoise; Moura, Isabel; Moura, José J. G.; Romão, Maria J.

2005-01-01

Superoxide reductase is a non-haem iron-containing protein involved in resistance to oxidative stress. The oxidized form of the protein has been crystallized and its three-dimensional structure solved. A highly redundant X-ray diffraction data set was collected on a rotating-anode generator using Cu Kα X-ray radiation. Four Fe atoms were located in the asymmetric unit corresponding to four protein molecules arranged as a dimer of homodimers. Superoxide reductase is a 14 kDa metalloprotein containing a catalytic non-haem iron centre [Fe(His) 4 Cys]. It is involved in defence mechanisms against oxygen toxicity, scavenging superoxide radicals from the cell. The oxidized form of Treponema pallidum superoxide reductase was crystallized in the presence of polyethylene glycol and magnesium chloride. Two crystal forms were obtained depending on the oxidizing agents used after purification: crystals grown in the presence of K 3 Fe(CN) 6 belonged to space group P2 1 (unit-cell parameters a = 60.3, b = 59.9, c = 64.8 Å, β = 106.9°) and diffracted beyond 1.60 Å resolution, while crystals grown in the presence of Na 2 IrCl 6 belonged to space group C2 (a = 119.4, b = 60.1, c = 65.6 Å, β = 104.9°) and diffracted beyond 1.55 Å. A highly redundant X-ray diffraction data set from the C2 crystal form collected on a copper rotating-anode generator (λ = 1.542 Å) clearly defined the positions of the four Fe atoms present in the asymmetric unit by SAD methods. A MAD experiment at the iron absorption edge confirmed the positions of the previously determined iron sites and provided better phases for model building and refinement. Molecular replacement using the P2 1 data set was successful using a preliminary trace as a search model. A similar arrangement of the four protein molecules could be observed

Evaluation of a colloidal gold immunochromatography assay in the detection of Treponema pallidum specific IgM antibody in syphilis serofast reaction patients: a serologic marker for the relapse and infection of syphilis.

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Lin, Li-Rong; Tong, Man-Li; Fu, Zuo-Gen; Dan, Bing; Zheng, Wei-Hong; Zhang, Chang-Gong; Yang, Tian-Ci; Zhang, Zhong-Ying

2011-05-01

Syphilis remains as a worldwide public health problem; hence, it is necessary to develop a new diagnostic approach that is easier and faster than conventional tests. A new testing method to detect Treponema pallidum IgM (TP-IgM), named colloidal gold immunochromatography assay (GICA), is presented in place of fluorescent treponemal antibody absorption (FTA-Abs). TP-IgM was detected using GICA developed on syphilis-specific recombinant proteins TPN17 and TPN47. The FTA-Abs IgM test was set as the gold standard. A GICA TP-IgM test was performed to detect syphilis in 1208 patients who received recommended therapy for syphilis for more than 1 year at the Xiamen Center of Clinical Laboratory in China from June 2005 to May 2009. One hundred blood donors were set up as control. The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 98.21%, 99.04%, 93.75%, 99.73%, 102.3, and 0.018, respectively. Detection on 500 interference specimens indicated that the biological false-positive rate of the GICA test was extremely low and was free from other biological and chemical factors. The patients were divided into the following experimental groups based on the results of toluidine red unheated serum test (TRUST) and treponemal pallidum particle agglutination (TPPA): (1) the syphilis serofast reaction (SSR) group consisted of 411 cases with (+) TRUST and (+) TPPA, which exhibited no clinical manifestations of syphilis after 1 year of recommended syphilis treatment; (2) the serum cure group, which was further subdivided into group A, a group that consisted of 251 cases with (-) TRUST and (+) TPPA, and (3) group B, a group that consisted of 546 cases with (-) TRUST and (-) TPPA; and (4) the blood donor control group, which consisted of 100 healthy persons with (-) ELISA-TP and (-) TPPA. We used the FTA-Abs method and the GICA method to detect TP-IgM; the positive rate of TP-IgM in 411 SSR

Assessment of the rapid test based on an immunochromatography technique for detecting anti-Treponema pallidum antibodies Avaliação do teste rápido para a detecção de anticorpos anti-Treponema pallidum baseado na técnica de imunocromatografia

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Neuza Satomi Sato

2003-12-01

Full Text Available A rapid test based on an immunochromatography assay - Determine™ Syphilis TP (Abbott Lab. for detecting specific antibodies to Treponema pallidum was evaluated against serum samples from patients with clinical, epidemiological and serological diagnosis of syphilis, patients with sexually transmitted disease other than syphilis, and individuals with negative serology for syphilis. The Determine™ test presented the sensitivity of 93.6%, specificity of 92.5%, and positive predictive value and negative predictive value of 95.2% and 93.7%, respectively. One serum sample from patient with recent latent syphilis showed a prozone reaction. Determine™ is a rapid assay, highly specific and easy to perform. This technique obviates the need of equipment and its diagnostic features demonstrate that it may be applicable as an alternative assay for syphilis screening under some emergency conditions or for patients living in remote localities.O desempenho do teste rápido imunocromatográfico de procedência comercial Determine™ Syphilis TP (Abbott Lab. para detectar anticorpos específicos contra antígenos treponêmicos foi avaliado com soros de pacientes tendo diagnóstico epidemiológico, clínico e laboratorial de sífilis, de pacientes com outras doenças sexualmente transmissíveis e de indivíduos clinicamente sadios ou com resultados negativos nos testes sorológicos para sífilis. Os valores de sensibilidade e de especificidade do teste Determine™ foram respectivamente de 93,6% e 95,2%, o valor preditivo positivo foi de 95,2% e o valor preditivo negativo 93,6%. O fenômeno de prozona foi observado em uma amostra de paciente com sífilis recente latente. O teste é de fácil e rápida execução, sem necessidade de equipamentos e o resultado pode ser obtido em 15 minutos, que de acordo com suas características diagnósticas poderá ser utilizado como teste alternativo de triagem em determinadas situações de emergência ou em pacientes que vivem

A Retrospective Study on Genetic Heterogeneity within Treponema Strains: Subpopulations Are Genetically Distinct in a Limited Number of Positions.

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Darina Čejková

Full Text Available Pathogenic uncultivable treponemes comprise human and animal pathogens including agents of syphilis, yaws, bejel, pinta, and venereal spirochetosis in rabbits and hares. A set of 10 treponemal genome sequences including those of 4 Treponema pallidum ssp. pallidum (TPA strains (Nichols, DAL-1, Mexico A, SS14, 4 T. p. ssp. pertenue (TPE strains (CDC-2, Gauthier, Samoa D, Fribourg-Blanc, 1 T. p. ssp. endemicum (TEN strain (Bosnia A and one strain (Cuniculi A of Treponema paraluisleporidarum ecovar Cuniculus (TPLC were examined with respect to the presence of nucleotide intrastrain heterogeneous sites.The number of identified intrastrain heterogeneous sites in individual genomes ranged between 0 and 7. Altogether, 23 intrastrain heterogeneous sites (in 17 genes were found in 5 out of 10 investigated treponemal genomes including TPA strains Nichols (n = 5, DAL-1 (n = 4, and SS14 (n = 7, TPE strain Samoa D (n = 1, and TEN strain Bosnia A (n = 5. Although only one heterogeneous site was identified among 4 tested TPE strains, 16 such sites were identified among 4 TPA strains. Heterogeneous sites were mostly strain-specific and were identified in four tpr genes (tprC, GI, I, K, in genes involved in bacterial motility and chemotaxis (fliI, cheC-fliY, in genes involved in cell structure (murC, translation (prfA, general and DNA metabolism (putative SAM dependent methyltransferase, topA, and in seven hypothetical genes.Heterogeneous sites likely represent both the selection of adaptive changes during infection of the host as well as an ongoing diversifying evolutionary process.

A Retrospective Study on Genetic Heterogeneity within Treponema Strains: Subpopulations Are Genetically Distinct in a Limited Number of Positions.

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Čejková, Darina; Strouhal, Michal; Norris, Steven J; Weinstock, George M; Šmajs, David

2015-01-01

Pathogenic uncultivable treponemes comprise human and animal pathogens including agents of syphilis, yaws, bejel, pinta, and venereal spirochetosis in rabbits and hares. A set of 10 treponemal genome sequences including those of 4 Treponema pallidum ssp. pallidum (TPA) strains (Nichols, DAL-1, Mexico A, SS14), 4 T. p. ssp. pertenue (TPE) strains (CDC-2, Gauthier, Samoa D, Fribourg-Blanc), 1 T. p. ssp. endemicum (TEN) strain (Bosnia A) and one strain (Cuniculi A) of Treponema paraluisleporidarum ecovar Cuniculus (TPLC) were examined with respect to the presence of nucleotide intrastrain heterogeneous sites. The number of identified intrastrain heterogeneous sites in individual genomes ranged between 0 and 7. Altogether, 23 intrastrain heterogeneous sites (in 17 genes) were found in 5 out of 10 investigated treponemal genomes including TPA strains Nichols (n = 5), DAL-1 (n = 4), and SS14 (n = 7), TPE strain Samoa D (n = 1), and TEN strain Bosnia A (n = 5). Although only one heterogeneous site was identified among 4 tested TPE strains, 16 such sites were identified among 4 TPA strains. Heterogeneous sites were mostly strain-specific and were identified in four tpr genes (tprC, GI, I, K), in genes involved in bacterial motility and chemotaxis (fliI, cheC-fliY), in genes involved in cell structure (murC), translation (prfA), general and DNA metabolism (putative SAM dependent methyltransferase, topA), and in seven hypothetical genes. Heterogeneous sites likely represent both the selection of adaptive changes during infection of the host as well as an ongoing diversifying evolutionary process.

Recombinant antigen-based immuno-slot blot method for serodiagnosis of syphilis

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N.S. Sato

2004-07-01

Full Text Available Three recombinant antigens of Treponema pallidum Nichols strain were fused with GST, cloned and expressed in Escherichia coli, resulting in high levels of GST-rTp47 and GST-rTp17 expression, and supplementation with arginine tRNA for the AGR codon was needed to obtain GST-rTp15 overexpression. Purified fusion protein yields were 1.9, 1.7 and 5.3 mg/l of cell culture for GST-rTp47, GST-rTp17 and GST-rTp15, respectively. The identities of the antigens obtained were confirmed by automated DNA sequencing using ABI Prism 310 and peptide mapping by Finningan LC/MS. These recombinant antigens were evaluated by immuno-slot blot techniques applied to 137 serum samples from patients with a clinical and laboratory diagnosis of syphilis (61 samples, from healthy blood donors (50 samples, individuals with sexually transmitted disease other than syphilis (3 samples, and from individuals with other spirochetal diseases such as Lyme disease (20 samples and leptospirosis (3 samples. The assay had sensitivity of 95.1% (95% CI, 86.1 to 98.7% and a specificity of 94.7% (95% CI, 87.0 to 98.7%; a stronger reactivity was observed with fraction rTp17. The immunoreactivity results showed that fusion recombinant antigens based-immuno-slot blot techniques are suitable for use in diagnostic assays for syphilis.

Serological survey of HIV and syphilis in pregnant women in Madagascar.

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Frickmann, Hagen; Schwarz, Norbert G; Girmann, Mirko; Hagen, Ralf M; Poppert, Sven; Crusius, Sabine; Podbielski, Andreas; Heriniaina, Jean N; Razafindrabe, Tsiriniaina; Rakotondrainiarivelo, Jean P; May, Jürgen; Rakotozandrindrainy, Raphaël

2013-01-01

Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow-up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow-up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission. © 2012 Blackwell Publishing Ltd.

Ventral pallidum roles in reward and motivation.

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Smith, Kyle S; Tindell, Amy J; Aldridge, J Wayne; Berridge, Kent C

2009-01-23

In recent years the ventral pallidum has become a focus of great research interest as a mechanism of reward and incentive motivation. As a major output for limbic signals, the ventral pallidum was once associated primarily with motor functions rather than regarded as a reward structure in its own right. However, ample evidence now suggests that ventral pallidum function is a major mechanism of reward in the brain. We review data indicating that (1) an intact ventral pallidum is necessary for normal reward and motivation, (2) stimulated activation of ventral pallidum is sufficient to cause reward and motivation enhancements, and (3) activation patterns in ventral pallidum neurons specifically encode reward and motivation signals via phasic bursts of excitation to incentive and hedonic stimuli. We conclude that the ventral pallidum may serve as an important 'limbic final common pathway' for mesocorticolimbic processing of many rewards.

A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis.

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Xu, Man; Xie, Yafeng; Jiang, Chuanhao; Xiao, Yongjian; Kuang, Xingxing; Zhao, Feijun; Zeng, Tiebing; Liu, Shuangquan; Liang, Mingxing; Li, Li; Wang, Chuan; Wu, Yimou

2016-02-01

The lack of Treponema pallidum-specific antigens with highly accurate diagnosis makes the diagnosis of syphilis challenging. A soluble recombinant version of a new diagnostic protein Tp0663 has been produced. The serodiagnostic potential of this protein was assessed by screening 3326 serum samples simultaneously evaluated by rapid plasma reagin and T. pallidum particle agglutination tests. Kappa (κ) coefficients were used to compare the concordance between clinical diagnosis and the Tp0663-based ELISA or the ARCHITECT Syphilis TP chemiluminescent immunoassay (Abbott GmbH and Co. KG). Using the results of clinical diagnosis as the gold standard, the sensitivity and specificity of Tp0663 were found to be 98.83% (95% confidence interval (CI) 96.61-99.60%) and 100% (95% CI 99.88-100%), respectively. In comparison, the ARCHITECT Syphilis TP assay was found to have a lower sensitivity (97.27%, 95% CI 94.46-98.67%) and specificity (99.61%, 95% CI 99.32-99.78%). In particular, the ARCHITECT Syphilis TP exhibited a false-positive rate of 0.39%. Moreover, the ELISA was in perfect agreement with the gold standard, with a κ value of 0.99, comparable to that of ARCHITECT Syphilis TP (0.96). These results identified Tp0663 as a novel serodiagnostic candidate with great potential for developing novel tests for the diagnosis of syphilis. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Are Treponema pallidum specific rapid and point-of-care tests for syphilis accurate enough for screening in resource limited settings? Evidence from a meta-analysis.

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Yalda Jafari

Full Text Available Rapid and point-of-care (POC tests for syphilis are an invaluable screening tool, yet inadequate evaluation of their diagnostic accuracy against best reference standards limits their widespread global uptake. To fill this gap, a systematic review and meta-analysis was conducted to evaluate the sensitivity and specificity of rapid and POC tests in blood and serum samples against Treponema pallidum (TP specific reference standards.Five electronic databases (1980-2012 were searched, data was extracted from 33 articles, and Bayesian hierarchical models were fit.In serum samples, against a TP specific reference standard point estimates with 95% credible intervals (CrI for the sensitivities of popular tests were: i Determine, 90.04% (80.45, 95.21, ii SD Bioline, 87.06% (75.67, 94.50, iii VisiTect, 85.13% (72.83, 92.57, and iv Syphicheck, 74.48% (56.85, 88.44, while specificities were: i Syphicheck, 99.14% (96.37, 100, ii Visitect, 96.45% (91.92, 99.29, iii SD Bioline, 95.85% (89.89, 99.53, and iv Determine, 94.15% (89.26, 97.66. In whole blood samples, sensitivities were: i Determine, 86.32% (77.26, 91.70, ii SD Bioline, 84.50% (78.81, 92.61, iii Syphicheck, 74.47% (63.94, 82.13, and iv VisiTect, 74.26% (53.62, 83.68, while specificities were: i Syphicheck, 99.58% (98.91, 99.96, ii VisiTect, 99.43% (98.22, 99.98, iii SD Bioline, 97.95%(92.54, 99.33, and iv Determine, 95.85% (92.42, 97.74.Rapid and POC treponemal tests reported sensitivity and specificity estimates comparable to laboratory-based treponemal tests. In resource limited settings, where access to screening is limited and where risk of patients lost to follow up is high, the introduction of these tests has already been shown to improve access to screening and treatment to prevent stillbirths and neonatal mortality due to congenital syphilis. Based on the evidence, it is concluded that rapid and POC tests are useful in resource limited settings with poor access to laboratories or screening

Reatividade do anticorpo IgM anti-Treponema pallidum na soroconversão e na resposta sorológica ao tratamento de sífilis IgM antibody reactivity to Treponema pallidum in seroconversion and in the serologic response to syphilis treatment

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Neuza Satomi Sato

2012-12-01

Full Text Available INTRODUÇÃO: A utilidade da detecção de anticorpos da imunoglobulina da classe M (IgM no diagnóstico da sífilis tem sido discutida há tempos. OBJETIVO: No presente estudo foi analisada a ocorrência de anticorpo IgM anti-T. pallidum (Tp-IgMAc nas amostras de pacientes com sífilis recente, na fase de soroconversão e no monitoramento da resposta sorológica pós-tratamento. MÉTODOS: Amostras séricas de 11 indivíduos. RESULTADOS: Na soroconversão, o Tp-IgMAc foi detectado nas amostras de 10 indivíduos, e em um paciente a reatividade IgM ocorreu anteriormente ao Venereal Disease Research Laboratory (VDRL. A sororreversão foi evidenciada nas amostras de três pacientes com sífilis secundária tratada, e em um indivíduo com reinfecção. CONCLUSÃO: A detecção de Tp-IgMAc mostrou ser um potencial marcador diagnóstico de sífilis ativa e o desempenho do ensaio imunoenzimático de captura de IgM (ELISA-IgM para o monitoramento pós-tratamento foi similar ao da VDRL.INTRODUCTION: The appropriateness of IgM antibody detection in the diagnosis of syphilis has been extensively discussed. OBJECTIVE: This study aimed at assessing the detection of anti-T. pallidum IgM antibody (TP-IgMAb in serum samples from patients with recent syphilis in seroconversion and in the monitoring of post-treatment serological response. METHODS: Serum samples from 11 individuals. RESULTS: At seroconversion, positive Tp-IgMAb was detected in 10 samples and IgM reactivity previous to Venereal Disease Research Laboratory (VDRL was detected in one sample. Seroreversion was found in samples from three treated patients with secondary syphilis and in one individual with reinfection. CONCLUSION: Tp-IgMAb detection proved to be a potential diagnostic marker for active syphilis, and IgM capture enzyme linked immunosorbent assay (ELISA-IgM performance was similar to VDRL in post-treatment monitoring.

Vitreitis and movement disorder associated with neurosyphilis and human immunodeficiency virus (HIV infection: case report Vitreíte e distúrbio motor associados à neurosífilis e infecção pelo vírus da imunodeficiência humana (HIV: relato de caso

Directory of Open Access Journals (Sweden)

Luciano Sousa Pereira

2008-10-01

Full Text Available In this report, we describe an unusual patient with a choreiform movement disorder, misdiagnosed as Huntington disease, who later developed dense vitreitis leading to the identification of Treponema pallidum as the underlying pathogen of both abnormalities.Neste relato descrevemos um caso infreqüente de um paciente com quadro de distúrbio motor coreiforme diagnosticado equivocadamente como doença de Huntington, o qual posteriormente desenvolveu quadro de intensa vitreíte, possibilitando a identificação do Treponema pallidum como o patógeno causador de ambas anormalidades.

Clinical Comparison of the Treponema pallidum CAPTIA Syphilis-G Enzyme Immunoassay with the Fluorescent Treponemal Antibody Absorption Immunoglobulin G Assay for Syphilis Testing

OpenAIRE

Halling, V. W.; Jones, M. F.; Bestrom, J. E.; Wold, A. D.; Rosenblatt, J. E.; Smith, T. F.; Cockerill, F. R.

1999-01-01

Recently, a treponema-specific immunoglobulin G (IgG) enzyme immunoassay (EIA), the CAPTIA Syphilis-G (Trinity Biotech, Jamestown, N.Y.), has become available as a diagnostic test for syphilis. A total of 89 stored sera previously tested by the fluorescent treponemal antibody absorption (FTA-ABS) IgG assay were evaluated by the CAPTIA EIA. The FTA-ABS IgG procedure was performed by technologists unblinded to results of rapid plasmid reagin (RPR) testing of the same specimens. Borderline CAPTI...

Canadian Public Health Laboratory Network Laboratory Guidelines for the Use of Direct Tests to Detect Syphilis in Canada

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Raymond SW Tsang

2015-01-01

Full Text Available Treponema pallidum subsp. pallidum and/or its nucleic acid can be detected by various methods such as microscopy, rabbit infectivity test or polymerase chain reaction (PCR tests. The rabbit infectivity test for T. pallidum, although very sensitive, has been discontinued from most laboratories due to ethical issues related to the need for animal inoculation with live T. pallidum, the technically demanding procedure and long turnaround time for results, thus making it impractical for routine diagnostic use. Dark-field and phase-contrast microscopy are still useful at clinic- or hospital-based laboratories for near-bedside detection of T. pallidum in genital, skin or mucous lesions although their availability is decreasing. The lack of reliable and specific anti-T. pallidum antibodies and its inferior sensitivity to PCR may explain why the direct fluorescent antibody test for T. pallidum is not widely available for clinical use. Immunohistochemical staining for T. pallidum also depends on the availability of specific antibodies, and the method is only applicable for histopathological examination of biopsy and autopsy specimens necessitating an invasive specimen collection approach. With recent advances in molecular diagnostics, PCR is considered to be the most reliable, versatile and practical for laboratories to implement. In addition to being an objective and sensitive test for direct detection of Treponema pallidum subsp. pallidum DNA in skin and mucous membrane lesions, the resulting PCR amplicons from selected gene targets can be further characterized for antimicrobial (macrolide susceptibility testing, strain typing and identification of T. pallidum subspecies.

Identification of Treponema pedis as the predominant Treponema species in porcine skin ulcers by fluorescence in situ hybridization and high-throughput sequencing

DEFF Research Database (Denmark)

Karlsson, Frida; Schou, Kirstine Klitgaard; Jensen, Tim Kåre

2014-01-01

Skin lesions often seen in pig production are of great animal welfare concern. To study the potential role of Treponema bacteria in porcine skin ulcers, we investigated the presence and distribution of these organisms in decubital shoulder ulcers (n=51) and ear necroses (n=54) by fluorescence...... probes targeting 16S rRNA were used, specific for domain bacterium, Treponema spp. and species T. pedis. Screening showed that two cases each of facial and other ulcers, 35 (69%) of shoulder ulcers and 32 (59%) of ear necroses were positive for Treponema spp. T. pedis was the unequivocally, predominant...

Treponema putidum sp. nov., a medium-sized proteolytic spirochaete isolated from lesions of human periodontitis and acute necrotizing ulcerative gingivitis.

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Wyss, C; Moter, A; Choi, B-K; Dewhirst, F E; Xue, Yi; Schüpbach, P; Göbel, U B; Paster, B J; Guggenheim, B

2004-07-01

So far, little phenotypic heterogeneity has been detected in cultured oral treponemes with trypsin-like proteolytic activity, and all have been assigned to the species Treponema denticola. However, comparisons of protein patterns and antigen expression in our collection of proteolytic oral treponemes occasionally identified isolates with a unique phenotype; e.g. strain OMZ 830 (=ATCC 700768), which qualified as a 'pathogen-related oral spirochaete' due to the presence of a approximately 37 kDa protein reactive with the Treponema pallidum FlaA-specific mAb H9-2. In addition to such single isolates, a homogeneous group of seven independent strains is described that were highly motile, medium-sized, proteolytic but asaccharolytic spirochaetes and were cultured from human gingivitis, periodontitis and acute necrotizing ulcerative gingivitis in medium OMIZ-Pat supplemented with 1% human serum and antibiotics. Growth of these spirochaetes in OMIZ-Pat was not dependent on, but was stimulated by, human or bovine serum. Carbohydrates were neither required nor stimulatory for growth. The protein and antigen patterns of total cell extracts of these organisms separated by SDS-PAGE were distinct from those of all previously cultured spirochaetes, with highest similarity to T. denticola. The novel spirochaete has a 2 : 4 : 2 arrangement of the periplasmic flagella, similar to T. denticola. However, the flagellin pattern as detected by immunostaining or glycan staining of Western blots readily distinguished the novel group from T. denticola. Also, distinct from reference strains of T. denticola, none of the novel isolates displayed sialidase or dentilisin activities, both of which are expressed by most strains of T. denticola. Trypsin-like activity and other enzymes as detected by API ZYM test were similar to those of T. denticola. The status of a novel species is supported by the 16S rRNA gene sequence, with 98.5% similarity to its closest cultured relative, T. denticola. The

Detecção de Treponema denticola em casos de abscesso perirradicular agudo Detection of Treponema denticola in cases of acute periradicular abscesses

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Isabela das Neves RÔÇAS

2000-09-01

Full Text Available Nosso objetivo foi detectar Treponema denticola em casos de abscesso perirradicular agudo. O DNA extraído das amostras de pus foi examinado pelo método da "Polymerase Chain Reaction" direcionada para o gene do RNAr (fração 16S. A amplificação usando o "primer" da espécie Treponema denticola permitiu detectá-la em 5 dos 6 casos de abscessos examinados. Apenas uma banda de tamanho esperado foi observada para as amostras positivas para esta bactéria, o que foi confirmado pela comparação com o DNA de referência do Treponema denticola (controle positivo. Até o momento, este é o primeiro relato da presença desta espiroqueta, considerada um importante patógeno periodontal em infecções endodônticas. Os resultados sugerem que Treponema denticola também pode ser um importante patógeno endodôntico.The purpose of this study was to report the detection of Treponema denticola in five out of six cases of acute periradicular abscesses. The 16S rRNA gene directed Polymerase Chain Reaction was the method utilized. This is probably the first report hitherto of the occurrence of this spirochete in acute periradicular abscesses.

Pulmonary involvement of secondary syphilis.

Science.gov (United States)

Ogawa, Yoshihiko; Imai, Yuichiro; Yoshihara, Shingo; Fujikura, Hiroyuki; Hirai, Nobuyasu; Sato, Masatoshi; Ogawa, Taku; Uno, Kenji; Kasahara, Kei; Yano, Hisakazu; Mikasa, Keiichi

2018-01-01

Pulmonary involvement in secondary syphilis is considered a rare occurrence; however, the number of cases has increased in the 2000s. This is likely due to the increased use of computed tomography scans and molecular diagnostic testing. We report a case of an HIV-positive man with pleural chest pain and bilateral subpleural nodules on chest computed tomography. His rapid plasma reagin and Treponema pallidum hemagglutination tests were positive, and the specimen of one of the pulmonary nodules obtained by transthoracic biopsy was positive for the polA gene of Treponema pallidum. Since clinical manifestations of syphilis are highly variable, clinicians should bear in mind that pleural chest pain with bilateral subpleural nodules can be caused by pulmonary syphilis.

Occurrence of two newly named oral treponemes - Treponema parvum and Treponema putidum - in primary endodontic infections.

Science.gov (United States)

Rôças, I N; Siqueira, J F

2005-12-01

Recent evidence from molecular genetic studies has revealed that oral Treponema species are involved in infections of endodontic origin. This study assessed the occurrence of two newly named oral treponemes - Treponema parvum and Treponema putidum - in primary endodontic infections using a culture-independent identification technique. Genomic DNA was isolated directly from clinical samples, and a 16S rRNA gene-based nested polymerase chain reaction (PCR) assay was used to determine the presence of T. parvum and T. putidum. Species-specific primer pairs were developed by aligning closely related 16S rRNA gene sequences. The specificity for each primer pair was validated by running PCR against a panel of oral bacteria and by sequence analysis of PCR products from positive clinical samples. T. parvum was detected in 52% of the root canals associated with chronic apical periodontitis, in 20% of the cases diagnosed as acute apical periodontitis, and in no abscessed case. In general, T. parvum was detected in 26% of the samples from primary endodontic infections. T. putidum was found in only one case of acute apical periodontitis (2% of the total number of cases investigated). The devised nested PCR protocol was able to identify both T. parvum and T. putidum directly in clinical samples and demonstrated that these two treponemes can take part in endodontic infections.

Performance Evaluation of a Novel Chemiluminescence Assay Detecting Treponema Pallidum Antibody as a Syphilis Screening Method.

Science.gov (United States)

Chen, Qixia; An, Jingna; Rao, Chenli; Wang, Tingting; Li, Dongdong; Feng, Shu; Tao, Chuanmin

2016-01-01

Syphilis is a major concern to global public health with increasing incidence. So its screening test should have sufficient sensitivity and specificity. We evaluated the performance of the Lumipulse G TP-N assay detection for syphilis screening and compared it with the InTec ELISA test kit for TP, which is widely used. Samples of several patient groups including 133 clinical and serologically characterized syphilitic sera, 175 samples containing potentially interfering agents, and 2290 unselected samples submitted for routine screening were detected by both the Lumipulse G TP-N assay and the InTec ELISA test kit for TP. Inconsistent samples were confirmed by RecomLine Treponema IgG, IgM immunoblot. Coefficient of variations of the Lumipulseo G TP-N assay at both levels were below 5% and of the InTec ELISA test kit for TP both over 5%. The sensitivity of the Lumipulse G TP-N assay and the InTec ELISA test kit for TP were 100% for all stages of syphilis. The two methods had consistent analytical specificity of 100% (95% CI: 97.21 - 100.00), while the clinical specificity was 100% (95% CI: 99.79 - 100.00) and 99.82% (95% CI: 99.51 - 99.94), respectively. Between them, Spearman's correlation coefficient was 0.455 and kappa value was 0.986. The overall sensitivity and specificity of the Lumipulse G TP-N assay was higher than the InTec ELISA test kit for TP (sensitivity: 100.0 versus 99.5, specificity: 100.0 versus 99.8). The automated Lumipulse G TP-N assay demonstrated excellent diagnostic sensitivity and specificity when evaluated as a screening test for syphilis. Thus, it can be an alternative to the treponemal screening test.

Sensibility of the hamster (Cricetus auratus to the Treponema pertenue

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F. Nery-Guimarães

1955-05-01

Full Text Available In two experiments, 8 Hamsters inoculated with material from yaws lesions (Treponema pertenue, developed skin lesions considered specific by their clinical and histopathological aspects and by the presence of treponemae. These lesions appeared on the scrotumm, testicle, prepuce, anus, tail, muzzle, back and hinders paws (palm surface. In the internal organs no treponemae were found in direct examinations and inoculation of brain, spleen and lymph node. The incubation period was of 35 days for the testicle, 55 days for the scrotum and 107 days for peritoneal cavity inoculation. Positive sub-inoculations were obtained. The serum reactions (Qasserman's and Kahn's were negative in all 5 tested Hamsters. Out of 4 normal females matched to infected males two developed nasal lesions resulting from direct contact. Apparently the genital lesions hindered copulation. Hamsters are very well suited for an experimental study of yaws.Em 2 experiências, 8 Hamsters inoculados com material direto de lesões boubáticas (Treponema pertenue, desenvolveram lesões cutâneas consideradas específicas, pelo aspecto clínico e histopatológico e pela presentça de treponemas. Essas lesões se manifestaram no escrôto, testículo, prepúcio, anus, cauda, focinho, dorso e patas posteriores (face palmar. Nos órgãos internos não foram vistos treponemas ao exame direto e, uma vez, por inoculação de cérebro, baço e gânglio linfático. O período incubativo foi de 35 dias pela via testicular, 55 dias pela via escrotal e 107 dias pela via peritonial. Foram obtidas sub-inoculações positivas para Hamsters normais. As experiências continuam. De 4 fêmeas normais, acasaladas com 4 hamsters infectados apenas 2 mostraram lesões positivas resultantes de contágio direto. Aparentemente, não houve copulação e, se esta ocorreu, não determinou fecundação.

Congenital syphilis: literature review

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Eduardo Chaida Sonda

2013-01-01

Full Text Available Syphilis is an infectious disease caused by Treponema pallidum and has high rates of vertical transmission, which can reach 100% depending on the maternal disease and stage of pregnancy. The diagnosis of gestational syphilis is simple and its screening is required during the prenatal period. However, this disease still has a high prevalence, affecting two million pregnant women worldwide. The procedures performed in newborns with congenital syphilis represent costs that are three-fold higher than the ones spent with a baby without this infection. The treatment is generally carried out with penicillin and must be extended to sexual partners. Inadequate or lack of treatment of congenital syphilis can result in miscarriage, premature birth, acute complications and other fetal sequelae. KEYWORDS: Congenital syphilis. Treponema pallidum. Vertical transmission.

Performance of Syphilis Sentinel Surveillance in the context of endemic Treponematoses: experience from Ghana.

Science.gov (United States)

Dassah, Edward Tieru; Adu-Sarkodie, Yaw; Mayaud, Philippe

2016-12-09

Use of treponemal tests to screen for syphilis (caused by Treponema pallidum pallidum) poses challenges with infection status classification, especially in settings where other treponemal infections are endemic. This study aimed to determine the validity of the syphilis surveillance testing strategy implemented since 2004 using two treponemal tests, and estimate the seroprevalence of active syphilis infection in Ghana where yaws (caused by Treponema pallidum pertenue) is endemic. We retested sera from the 2007 HIV sentinel survey (HSS) using a traditional algorithm, quantitative rapid plasma reagin test followed by qualitative Treponema pallidum haemagglutination assay. The adjusted seroprevalence of active syphilis was calculated by applying the proportions of active syphilis within identified categories of HSS samples during the retesting, to the entire population of HSS samples. The 95% confidence intervals (CIs) were calculated for each proportion, and the t-test was used to assess differences in proportions. Of 2,214 samples that were retested, 203 (9.2%) had active syphilis infection, 21 (0.9%) were biological false reactions, 640 (28.9%) were past or treated syphilis infections, and 1,350 (61%) were uninfected. The current syphilis testing strategy overestimated the seroprevalence of active syphilis infection by a third (HSS versus traditional algorithm: 6.0% (95% CI: 5.6-6.3) vs. 4.5% (95% CI: 4.2-4.8); p syphilis infection. More than half (51.9%) of HSS syphilis positive cases were actually past/treated treponemal infections, possibly previous exposure to yaws. There is an urgent need to review the current syphilis sentinel surveillance testing strategy in Ghana in the context of concurrent endemic treponematoses, to better inform policy.

Neurosyphilis

Science.gov (United States)

... research laboratory ( VDRL ) test Fluorescent treponemal antibody absorption ( FTA-ABS ) Rapid plasma reagin ( RPR ) Treponema pallidum particle ... MD, Infectious Diseases Medical Practice of NY and Clinical Research Centers of CT. Review provided by VeriMed ...

First report of tertiary syphilis presenting as lipoatrophic panniculitis in an immunocompetent patient.

Science.gov (United States)

Drago, Francesco; Ciccarese, Giulia; Tomasini, Carlo F; Calamaro, Paola; Boggio, Maurizio; Rebora, Alfredo; Parodi, Aurora

2017-03-01

We describe herein a woman who developed subcutaneous gummas in her trochanteric regions, bilaterally, although she had been treated for syphilis two decades earlier. Evidence of Treponema pallidum latent late infection was the presence of IgG antibodies against T. pallidum and the positive non-treponemal and treponemal tests. Moreover, immunohistochemical staining for T. pallidum detected some spirochetes close to the atrophic adipocytes allowing the diagnosis of lypo-atrophic panniculitis tertiary syphilis. This is the first case of tertiary syphilis presenting as panniculitis in an immunocompetent patient, demonstrating that subcutaneous fat may be another organ infected in tertiary syphilis.

Evaluation of Elecsys Syphilis Assay for Routine and Blood Screening and Detection of Early Infection

OpenAIRE

Kremastinou, J.; Polymerou, V.; Lavranos, D.; Aranda Arrufat, A.; Harwood, J.; Mart?nez Lorenzo, M. J.; Ng, K. P.; Queiros, L.; Vereb, I.; Cusini, M.

2016-01-01

Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T. pallidum. The performance of this assay was investigated previously in a multicenter study. The current study expands on that evaluation in a variety of diagnostic settings and patient popul...

FTA-ABS test

Science.gov (United States)

... Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. St Louis, MO: Elsevier Saunders; 2013:533-534. Radolf JD, Tramont EC, Salazar JC. Syphilis ( Treponema pallidum ). In: Bennett JE, Dolin R, Blaser ...

Molecular Typing of Treponema pallidum in Denmark

DEFF Research Database (Denmark)

Salado-Rasmussen, Kirsten; Cowan, Susan; Gerstoft, Jan

2016-01-01

The aim of this nationwide study is to determine the strain type diversity among patients diagnosed with syphilis by PCR during a 4-year period in Denmark. Epidemiological data, including HIV status, for all patients were obtained from the Danish national syphilis registration system. Molecular...

Screening assays to find out late latent syphilis cases – which is the ...

African Journals Online (AJOL)

non-treponemal) such as Rapid Plasma Reagin (RPR), and specific (treponemal) such as Treponema pallidum hemagglutination test (TPHA) and Enzyme-linked immunosorbent assay IgG, IgM (ELISA IgG, IgM) tests. The aim of this ...

Genome-wide relatedness of Treponema pedis, from gingiva and necrotic skin lesions of pigs, with the human oral pathogen Treponema denticola.

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Olov Svartström

Full Text Available Treponema pedis and T. denticola are two genetically related species with different origins of isolation. Treponema denticola is part of the human oral microbiota and is associated with periodontitis while T. pedis has been isolated from skin lesions in animals, e.g., digital dermatitis in cattle and necrotic ulcers in pigs. Although multiple Treponema phylotypes may exist in ulcerative lesions in pigs, T. pedis appears to be a predominant spirochete in these lesions. Treponema pedis can also be present in pig gingiva. In this study, we determined the complete genome sequence of T. pedis strain T A4, isolated from a porcine necrotic ear lesion, and compared its genome with that of T. denticola. Most genes in T. pedis were homologous to those in T. denticola and the two species were similar in general genomic features such as size, G+C content, and number of genes. In addition, many homologues of specific virulence-related genes in T. denticola were found in T. pedis. Comparing a selected pair of strains will usually not give a complete picture of the relatedness between two species. We therefore complemented the analysis with draft genomes from six T. pedis isolates, originating from gingiva and necrotic ulcers in pigs, and from twelve T. denticola strains. Each strain carried a considerable amount of accessory genetic material, of which a large part was strain specific. There was also extensive sequence variability in putative virulence-related genes between strains belonging to the same species. Signs of lateral gene-transfer events from bacteria known to colonize oral environments were found. This suggests that the oral cavity is an important habitat for T. pedis. In summary, we found extensive genomic similarities between T. pedis and T. denticola but also large variability within each species.

Fast growing penis ulcer: an unusual coincidence.

Science.gov (United States)

Brunasso, Alexandra Maria Giovanna; Bandelloni, Roberto; Massone, Cesare

2012-07-01

A 57-year-old man was seen with a 2-week history of progressive enlargement of an asymptomatic genital ulcer associated with bilateral inguinal lymphadenomegaly. Multiple unprotected heterosexual contacts were reported. The family doctor misdiagnosed primary syphilis with the following laboratory results: negative findings on the Venereal Disease Research Laboratory test, positive findings on the Treponema pallidum particle agglutination assay (titer 1:1280), and IgM negative on the Treponema pallidum particle agglutination assay. The patient was treated with penicillin G for the diagnosis of indeterminate latent syphilis and initially denied authorization for a skin biopsy. After 2 weeks, fast enlargement of the lesion was documented. He underwent skin biopsy, and the histopathologic examination revealed squamous cell carcinoma, and polymerase chain reaction for human papillomavirus 16 was positive. Copyright © 2012 Elsevier Inc. All rights reserved.

In vitro susceptibility of contagious ovine digital dermatitis associated Treponema spp. isolates to antimicrobial agents in the UK

OpenAIRE

Angell, Joseph W.; Clegg, Simon R.; Sullivan, Leigh E.; Duncan, Jennifer S.; Grove?White, Dai H.; Carter, Stuart D.; Evans, Nicholas J.

2015-01-01

Background: Contagious ovine digital dermatitis (CODD) is an important cause of infectious lameness in sheep in the UK and Ireland and has a severe impact on the welfare of affected individuals. The three treponemal phylogroups Treponema medium/Treponema vincentii-like, Treponema phagedenis-like and Treponema pedis spirochaetes have been associated with clinical CODD lesions and are considered to be a necessary cause of disease. There are scant data on the antimicrobial susceptibility of the ...

Diagnostic aspects of infections with Chlamydia trachomatis, Neisseria gonorrhoeae and herpes simplex virus

NARCIS (Netherlands)

J. Ulsen (Josina)

1994-01-01

textabstractThe sexually transmitted diseases (STOs) constitute a worldwide problem of major significance in terms of health. economic and social consequences. The most important STOs are Ihe bacterial infections syphilis (causative agent Treponema pal/idum sub·species pallidum), gonorrhoea

Caractéristiques sociodémographiques associées au risque de ...

African Journals Online (AJOL)

Caractéristiques sociodémographiques associées au risque de transmission du VIH, du VHC et de Treponema pallidum par les donneurs de sang de premier don de Libreville (Gabon) : dynamique trisannuelle des infections de 2009 à 2015.

68 ORIGINAL ARTICLE

African Journals Online (AJOL)

Dr Oboro VO

transmitted through blood transfusion. These include. Treponema pallidum,. Plasmodium sp., human T-lymphotrophic virus (HTLV), Babesia, Leishmania,. Trypanosoma cruzi, variant Creutzfeldt-Jacob. Disease (vCJD) agent, cytomegalovirus. (CMV)and Epstein Barr virus (EBV). Therefore, the need to render donated blood.

Coronavirus-like particles in laboratory rabbits with different syndromes in The Netherlands (Coronavirus-like particles in rabbits).

NARCIS (Netherlands)

A.D.M.E. Osterhaus (Albert); J.S. Teppema; G. van Steenis (Bert)

1982-01-01

textabstractVirus-like particles were identified from the plasma of rabbits which developed pleural effusion disease after inoculation with different strains of Treponema pallidum. These particles were considered coronavirus-like on the basis of their size, morphology, and buoyant density. Clinical

Atypical extensive genital ulcer in full blown aids with slim disease ...

African Journals Online (AJOL)

Direct immunofluorescence detection on genital ulcer scraping was negative for Chlamydia trachomatis and Treponema pallidum. Furthermore, the infections with Haemophilus ducreyi and Chlamydia trachomatis were excluded by PCR on genital swabs.Genital PCR was positive for herpes simplex virus (HSV) type 2.

[Neurosyphilis, the great imitator: a diagnostic challenge

NARCIS (Netherlands)

Hogebrug, J.; Koopmans †, P.P.; Oostrom, I.I.H. van; Schellekens, A.F.A.

2013-01-01

BACKGROUND: Neurosyphilis is a tertiary form of syphilis and is caused by the spirochete Treponema pallidum. Today, more than one type of neurosyphilis often manifest simultaneously, which can pose difficulties to the diagnostic process. CASE DESCRIPTION: A 45-year-old man presented with an attack

Non-plaque-induced gingival lesions

DEFF Research Database (Denmark)

Holmstrup, P

1999-01-01

infections. Specific bacterial infections of gingiva may be due to Neisseria gonorrhea, Treponema pallidum, streptococci, and other organisms. The most important viral infections of gingiva are herpes simplex virus type 1 and 2 and varicella-zoster virus. Fungal infections may be caused by several fungi...

2018-05-01T16:46:18Z https://www.ajol.info/index.php/index/oai oai ...

African Journals Online (AJOL)

The incidence rates are Staphylococcus aureus (20%), followed by Chlamydia trachomatis (6.7%) while Klebsiellia spp, Treponema pallidum, Human Immunodeficiency Virus (HIV), Escherichia coli and Hepatitis B Virus were detected with incidence rate of 3.3% each respectively. Ten percent (10%) of the prospective ...

TprK gene regions are not suitable for epidemiological syphilis typing

NARCIS (Netherlands)

Heymans, R.; Kolader, M.-E.; van der Helm, J. J.; Coutinho, R. A.; Bruisten, S. M.

2009-01-01

Given reports of increasing syphilis incidence in Western countries, we used molecular typing and epidemiological data to elucidate Treponema pallidum transmission networks. Samples and data were collected, dating from 2002 to 2005, from a well-defined population of patients with an ulcus and a

Cutaneous papules in a patient with AIDS

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Pascale Quatresooz

2010-01-01

Full Text Available During the past decade or so, the incidence of syphilis has increased in most parts of the world. In some urban regions, a coinfection with human immunodeficiency virus is disclosed in nearly 50% of the cases. Owing to the polymorphism of the lesions, the clinical diagnosis may be puzzling. The homing patterns and migration paths of Treponema pallidum in the skin during early syphilis represent the preliminary steps preceding dissemination to other organs. Immunohistochemistry directed to T. pallidum is a convenient means for reaching the diagnosis and for exploring the dissemination process. The present case illustrates the dermal clustering and the vascular spread of T. pallidum in a woman with acquired immu­no deficiency syndrome.

Enabulele, OI

African Journals Online (AJOL)

Seroevidence Of Chlamydia Trachomatis Infection In Infertile Male And Its Association With Semen Quality In University Of Benin Teaching Hospital, Benin City, Nigeria Abstract PDF · Vol 11, No 1 (2009): Supplementary Issue - Articles Serodynamics Of Treponema Pallidum In Serum Of Pregnant Women In Benin City

Author Details

African Journals Online (AJOL)

Seroevidence Of Chlamydia Trachomatis Infection In Infertile Male And Its Association With Semen Quality In University Of Benin Teaching Hospital, Benin City, Nigeria Abstract PDF · Vol 11, No 1 (2009): Supplementary Issue - Articles Serodynamics Of Treponema Pallidum In Serum Of Pregnant Women In Benin City

A Three Year Retrospective Study on Seroprevalence of Syphilis ...

African Journals Online (AJOL)

2014-03-01

Mar 1, 2014 ... Introduction. Sexually transmitted infections (STIs) are a serious public health problem in developing countries, including. Ethiopia (1). Syphilis is STIs caused by the spirochete. Treponema pallidum and constitutes a major public health problem worldwide (2). Syphilis is an important cause of morbidity and ...

Syphilis: using modern approaches to understand an old disease

Science.gov (United States)

Ho, Emily L.; Lukehart, Sheila A.

2011-01-01

Syphilis is a fascinating and perplexing infection, with protean clinical manifestations and both diagnostic and management ambiguities. Treponema pallidum subsp. pallidum, the agent of syphilis, is challenging to study in part because it cannot be cultured or genetically manipulated. Here, we review recent progress in the application of modern molecular techniques to understanding the biological basis of this multistage disease and to the development of new tools for diagnosis, for predicting efficacy of treatment with alternative antibiotics, and for studying the transmission of infection through population networks. PMID:22133883

Prevalence Of Syphilis ( Treponema pallidum ) – An Emerging ...

African Journals Online (AJOL)

Abstract. Background: In general,the risk of transfusion transmitted infections has been greatly reduced today. However, blood borne bacterial, viral as well as parasitic infections and emerging infections transmitted through transfusion are an area of increasing concern. More recently, there has been a resurgence of syphilis ...

Characterization of Treponema spp. isolates from pigs with ear necrosis and shoulder ulcers.

Science.gov (United States)

Svartström, Olov; Karlsson, Frida; Fellström, Claes; Pringle, Märit

2013-10-25

Ear necrosis and shoulder ulcers in pigs are animal welfare problems and ethical issues that can cause economic losses for producers. Spirochetes have been observed microscopically in scrapings from pig ulcers since the early 1900s, but have until recently not been cultured and therefore not characterized. In this study, 12 Treponema spp. isolates were acquired from porcine ear necrosis, shoulder ulcers and gingiva. DNA analysis of the 16S rRNA-tRNA(Ile) intergenic spacer region (ISR2) or the 16S rRNA gene revealed relatedness to oral treponemes found in dogs and humans. All isolates except one aligned into two clusters, Treponema pedis and Treponema sp. OMZ 840-like. The 16S rRNA gene of the remaining isolate shared 99% nucleotide identity with Treponema parvum. Genetic fingerprinting of the isolates was performed through random amplification of polymorphic DNA (RAPD). In addition, the isolates were characterized by biochemical tests, including api(®)ZYM, tryptophanase and hippuricase activity, and by testing the antimicrobial susceptibility to tiamulin, valnemulin, tylosin, tylvalosin, lincomycin and doxycycline using broth dilution. All isolates except two showed unique RAPD fingerprints, whereas metabolic activity tests could not differentiate between the isolates. The MICs of all antimicrobial agents tested were low. Copyright © 2013 Elsevier B.V. All rights reserved.

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African Journals Online (AJOL)

Dongang, NRR. Vol 12, No 3 (2011) - Articles Risk factors of cervical intraepithelial lesion in Douala-Cameroon: Implications of Herpes Simplex Virus Type 2, Chlamydia Trachomatis and Treponema Pallidum Abstract PDF. ISSN: 1595-689X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for ...

Prevalence of treponema species detected in endodontic infections: systematic review and meta-regression analysis.

Science.gov (United States)

Leite, Fábio R M; Nascimento, Gustavo G; Demarco, Flávio F; Gomes, Brenda P F A; Pucci, Cesar R; Martinho, Frederico C

2015-05-01

This systematic review and meta-regression analysis aimed to calculate a combined prevalence estimate and evaluate the prevalence of different Treponema species in primary and secondary endodontic infections, including symptomatic and asymptomatic cases. The MEDLINE/PubMed, Embase, Scielo, Web of Knowledge, and Scopus databases were searched without starting date restriction up to and including March 2014. Only reports in English were included. The selected literature was reviewed by 2 authors and classified as suitable or not to be included in this review. Lists were compared, and, in case of disagreements, decisions were made after a discussion based on inclusion and exclusion criteria. A pooled prevalence of Treponema species in endodontic infections was estimated. Additionally, a meta-regression analysis was performed. Among the 265 articles identified in the initial search, only 51 were included in the final analysis. The studies were classified into 2 different groups according to the type of endodontic infection and whether it was an exclusively primary/secondary study (n = 36) or a primary/secondary comparison (n = 15). The pooled prevalence of Treponema species was 41.5% (95% confidence interval, 35.9-47.0). In the multivariate model of meta-regression analysis, primary endodontic infections (P apical abscess, symptomatic apical periodontitis (P < .001), and concomitant presence of 2 or more species (P = .028) explained the heterogeneity regarding the prevalence rates of Treponema species. Our findings suggest that Treponema species are important pathogens involved in endodontic infections, particularly in cases of primary and acute infections. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Fibronectin tetrapeptide is target for syphilis spirochete cytadherence

International Nuclear Information System (INIS)

Thomas, D.D.; Baseman, J.B.; Alderete, J.F.

1985-01-01

The syphilis bacterium, Treponema pallidum, parasitizes host cells through recognition of fibronectin (Fn) on cell surfaces. The active site of the Fn molecule has been identified as a four-amino acid sequence, arg-gly-asp-ser (RGDS), located on each monomer of the cell-binding domain. The synthetic heptapeptide gly-arg-gly-asp-ser-pro-cys (GRGDSPC), with the active site sequence RGDS, specifically competed with 125 I-labeled cell-binding domain acquisition by T. pallidum. Additionally, the same heptapeptide with the RGDS sequence diminished treponemal attachment to HEp-2 and HT1080 cell monolayers. Related heptapeptides altered in one key amino acid within the RGDS sequence failed to inhibit Fn cell-binding domain acquisition or parasitism of host cells by T. pallidum. The data support the view that T. pallidum cytadherence of host cells is through recognition of the RGDS sequence also important for eukaryotic cell-Fn binding

Research

African Journals Online (AJOL)

abp

2017-10-06

Oct 6, 2017 ... South Africa). Seropositivity for syphilis in turn uses a completely screening by a Rapid-Plasma-Réagin test (syphilis RPR test, Human. Gesellschaft für Biochemicaund Diagnostic amb H, Germany) then the positive samples were passed to the TPHA (Treponema Pallidum. Hemagglutination Assay) and the ...

Risk factors of cervical intraepithelial lesion in Douala-Cameroon ...

African Journals Online (AJOL)

Infection with high risk oncogenic human papillomavirus (HPV) such as HPVs 16 and 18 is the main cause of cervical cancer. The objective of this study was to determine the impact of Chlamydia trachomatis, Herpes simplex virus 2 (HSV 2), Treponema pallidum and some sexual behaviour on malignant progression of ...

ROUTINE ANTENATAL SYPHILIS SCREENING IN SOUTH WEST ...

African Journals Online (AJOL)

INTRODUCTION. Syphilis, caused by infection with Treponema pallidum, is a muco-cutaneous sexually transmitted infection (STI) with high infectivity in the early stages. It may also be passed transplacentally from the ninth week of gesta- tion onwards1. The basic pathology in all stages is vas- culitis2.Untreated maternal ...

Bovine digital dermatitis: Possible pathogenic consortium consisting of Dichelobacter nodosus and multiple Treponema species

DEFF Research Database (Denmark)

Rasmussen, Marianne; Capion, Nynne; Schou, Kirstine Klitgaard

2012-01-01

not colonized by bacteria while only four samples were found normal. We hypothesise that external noxious stimuli allow D. nodosus to break down the epidermal barrier creating a suitable environment for the secondary invaders, Treponema species, which gradually take over the infection site. The variety...... and different distribution of treponemes in the DD lesions observed in this study, suggests that most of the Treponema phylotypes have the potential to be pathogenic....

Clovamide-rich extract from Trifolium pallidum reduces oxidative stress-induced damage to blood platelets and plasma.

Science.gov (United States)

Kolodziejczyk, Joanna; Olas, Beata; Wachowicz, Barbara; Szajwaj, Barbara; Stochmal, Anna; Oleszek, Wieslaw

2011-09-01

Numerous plants (including clovers) have been widely used in folk medicine for the treatment of different disorders. This in vitro study was designed to examine the antioxidative effects of the clovamide-rich fraction, obtained from aerial parts of Trifolium pallidum, in the protection of blood platelets and plasma against the nitrative and oxidative damage, caused by peroxynitrite (ONOO(-)). Carbonyl groups and 3-nitrotyrosine in blood platelet and plasma proteins were determined by ELISA tests. Thiol groups level was estimated by using 5,5'-dithio-bis(2-nitro-benzoic acid, DTNB). Plasma lipid peroxidation was measured spectrophotometrically as the production of thiobarbituric acid reactive substances. The results from our work indicate that clovamide-rich T. pallidum extract may reveal the protective properties in the prevention against oxidative stress. The presence of clovamide-rich T. pallidum extract (12.5-100 μg/ml) partly inhibited ONOO(-)-mediated protein carbonylation and nitration. All the used concentrations of T. pallidum extract reduced lipid peroxidation in plasma. The antioxidative action of the tested extract in the protection of blood platelet lipids was less effective; the extract at the lowest final concentration (12.5 μg/ml) had no protective effect against lipid peroxidation. The present results indicate that the extract from T. pallidum is likely to be a source of compounds with the antioxidative properties, useful in the prevention against the oxidative stress-related diseases.

Advances in diagnostic tests for bacterial STDs Avances en las pruebas diagnósticas de ETS bacterianas

Directory of Open Access Journals (Sweden)

Stephen A Morse

2003-01-01

Full Text Available Because of their asymptomatic nature and nonspecific symptoms, laboratory tests are often required to diagnose a sexually transmitted infection. Over the past few years, there have been advances in technology, such as the development of nucleic acid amplification assays, which have improved our ability to diagnose infections caused by Chlamydia trachomatis. The finding that nucleic acid amplification tests can detect more infected individuals and are useful in screening low prevalence populations, has led to the development of strategies designed to reduce the cost of these assays without significantly impacting their sensitivity. The development of new tests for the diagnosis of syphilis has gained momentum from the report of a synthetic VDRL antigen, which will result in better nontreponemal antibody tests for syphilis. In spite of the completion of the genome sequence of Treponema pallidum and its annotation, we are still unable to cultivate this microorganism in vitro. However, the molecular revolution has resulted in the development of PCR assays for detecting Treponema pallidum in various types of clinical specimens, and to the production of recombinant antigens for use in tests that detect treponemal-specific antibodies. Further research will improve the availability of low cost, sensitive tests for the diagnosis of sexually transmitted infections.Las pruebas de laboratorio son necesarias a menudo para el diagnóstico de las infecciones transmitidas sexualmente, debido a la naturaleza asintomática o a la presencia de síntomas inespecíficos de esas infecciones. En este sentido, durante los años relativamente recientes se han registrado importantes avances tecnológicos, como por ejemplo los ensayos de amplificación de ácidos nucleicos que han permitido una mejora en la posibilidad de diagnosticar las infecciones causadas por Chlamydia trachomatis. El descubrimiento de que las pruebas de amplificación de ácidos nucleicos permiten

Evaluation of the diagnostic performance and operational ...

African Journals Online (AJOL)

The objectives of the study were (i) to assess the sensitivity and specificity of four on site rapid tests in comparison with Treponema pallidum haemagglutination assay (TPHA) as a gold standard and (ii) to evaluate the operational characteristics of those tests among health workers in a maternity unit. Methods: Four rapid ...

Neurosífilis meningovascular con trombosis de la arteria basilar

Directory of Open Access Journals (Sweden)

Jorge Andrés Jiménez

2012-03-01

La neurosífilis es el compromiso del sistema nervioso central por Treponema pallidum subespecie pallidum en cualquier estadio de la entidad e incluye las formas asintomáticas y sintomáticas de la infección; sus formas de presentación son diversas y dependen de la localización y la extensión de las lesiones. La recomendación actual es el tratamiento con 4 millones de unidades de penicilina cristalina cada 4 horas por 14 días.   doi: http://dx.doi.org/10.7705/biomedica.v32i1.586

[HIV infection and syphilis prevalence among men who have sex with men receiving voluntary counseling and testing appointed through a web-based registering system and related factors].

Science.gov (United States)

Wu, Qiongmiao; Cheng, Weibin; Zhong, Fei; Xu, Huifang; Liu, Qi; Lin, Peng

2015-05-01

To understand the human immunodeficiency virus (HIV) infection status and syphilis prevalence among men who have sex with men (MSM) receiving voluntary counseling and testing appointed through a web-based registering system and related factors. The MSM receiving web appointed HIV counseling and testing from 2011 to 2012 in Guangzhou were recruited and a questionnaire survey was conduct among them to obtain the information about their demographic characteristics and sexual behavior. Binary and multivariate logistic regression model were used to identify the factors associated with HIV infection or syphilis prevalence. A total of 4,904 MSM were enrolled in the study, the average age of the MSM was (28.77±7.24) years, and 70.3% of them had high education level; the unmarried MSM accounted for 72.7%. The HIV infection rate and syphilis prevalence were 8.7% and 4.4% respectively. The co-infection rate of HIV and Treponema pallidum was 1.2% (59/4 904). About one in three MSM did not use condom at latest homosexual behavior, 43.5% did not use condoms at each homosexual behavior in the past three months. Lower education level, occupation (worker or farmer), non-consistent condom use at each sex with men in the past three months, receiving HIV test or not and Treponema pallidum infection were associated with HIV infection. Age≥40 years, lower education level, multi male sex partners in the past three months and HIV infection were associated with Treponema pallidum infection. MSM receiving web appointed HIV counseling and testing had high prevalence of risk behaviors and high HIV infection rate, but had low previous HIV testing rate. It is necessary to strengthen the promotion of HIV test through web based appointment and conduct target behavior intervention in older MSM with lower education level.

Reducing risks of Transfusion-transmitted infections in a resource-limited hospital-based blood bank: the case of the Yaoundé University Teaching Hospital, Cameroon

Science.gov (United States)

Tagny, C. T.; Ndoumba, A.; Laperche, S.; Murphy, E.; Mbanya, D.

2016-01-01

Background and Objectives Although interest in assessing risk of TTIs, very few trends in blood safety epidemiological data from resource-limited blood services are reported in the literature. This analysis aims at reporting trends in seroprevalences of TTIs in blood donations in the Yaoundé University Teaching Hospital (UTH) from 2011 to 2015 and to describe reasons for these changes. Materials and Methods All donations of 2015 were tested for HIV 1&2 antibodies and the P24 antigen, HBsAg, HCV antibody and the Treponema pallidum antibody. Screening for HIV uses a national algorithm based on the systematic use of two assays of different principles: a rapid determination testing assay and an EIA HIV 1 & 2 Ab-Ag. The tests used for HBsAg and HCVAb screening were all based on EIA techniques. Treponema pallidum antibody screening was based on Treponema Pallidum hemagglutination assay (TPHA) and rapid immunochromatographic test (RIT). Screening techniques and results from 2015 were compared to retrospective data from 2011, 2012, 2013 and 2014. Results In 2015, 13·4% (n = 214) of 1,596 blood donations were seropositive for at least one screened TTIs. The most frequent serological marker was HBsAg with 123 (7·7%) blood units contaminated. Nineteen (1·2%) and 18 (1·1%) blood units was positive for HIV and syphilis, respectively. There was a significant decrease in the total number of blood donations (P < 10−4) and HIV, HBsAg and syphilis seroprevalences and an increase in the proportion of voluntary non-remunerated blood donor (P < 0·05). HCVAb seroprevalence was 3·8% in 2015 and has not decreased significantly over the years (P = 0·09). Conclusion Significant progress is noted in reduction in seroprevalences of HIV, HBV, HCV and syphilis since the beginning of a regular registration of data in 1990. PMID:28484511

Subacute Hypophysitis with Panhypopituitarism as First Presentation of HIV and Syphilis Coinfection.

Science.gov (United States)

Alves, Rute; França, Margarida

2017-01-01

Infection by Treponema pallidum still represents a clinical challenge due to its various forms of presentation. HIV coinfection added diversity and changed the natural history of syphilis as a systemic infection. We present a rare case of subacute hypophysitis and panhypopituitarism due to an early active neurosyphilis in a previously unknown HIV coinfected patient.

ENCUESTAS SEROEPIDEMIOLÓGICAS EN ENFERMEDADES NO INMUNOPREVENIBLES Y SU INTERÉS EN SALUD PÚBLICA

Directory of Open Access Journals (Sweden)

Fernando de Ory Manchón

2009-01-01

de estudios de seroprevalencia realizados en España en relación con enfermedades no inmunoprevenibles de transmisión vertical (Toxoplasma gondii, Treponema pallidum, citomegalovirus, virus herpes simple tipo 2, y parvovirus humano B19, enfermedades de transmisión sanguínea (virus de la hepatitis C, virus de la inmunodeficiencia humana y Trypanosoma cruzi y enfermedades emergentes (Virus del Nilo occidental, virus Toscana, y virus de la coriomeningitis linfocitaria. Se observa reducción en la seroprevalencia en la población autóctona española frente a Toxoplasma gondii, Treponema pallidum, citomegalovirus y virus de la inmunodeficiencia humana. Los patrones obtenidos en población inmigrante reflejan la situación de estas enfermedades en sus países de origen; pudiendo ser causa de situaciones de impacto en la salud pública (Trypanosoma cruzi, en relación con la donación de sangre. Se pone en evidencia la circulación en España de virus del Nilo Occidental, y la importancia de la infección por virus Toscana.

Genome sequence of the thermophilic fresh-water bacterium Spirochaeta caldaria type strain (H1T), reclassification of Spirochaeta caldaria, Spirochaeta stenostrepta, and Spirochaeta zuelzerae in the genus Treponema as Treponema caldaria comb. nov., Treponema stenostrepta comb. nov., and Treponema zuelzerae comb. nov., and emendation of the genus Tr

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Abt, Birte [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Scheuner, Carmen [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Han, Cliff [Los Alamos National Laboratory (LANL); Lu, Megan [Los Alamos National Laboratory (LANL); Misra, Monica [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Deshpande, Shweta [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Gronow, Sabine [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany

2013-01-01

Spirochaeta caldaria Pohlschroeder et al. 1995 is an obligately anaerobic, spiral-shaped bac- terium that is motile via periplasmic flagella. The type strain, H1T, was isolated in 1990 from cyanobacterial mat samples collected at a freshwater hot spring in Oregon, USA, and is of in- terest because it enhances the degradation of cellulose when grown in co-culture with Clos- tridium thermocellum. Here we provide a taxonomic re-evaluation for S. caldaria based on phylogenetic analyses of 16S rRNA sequences and whole genomes, and propose the reclassi- fication of S. caldaria and two other Spirochaeta species as members of the emended genus Treponema. Whereas genera such as Borrelia and Sphaerochaeta possess well-distinguished genomic features related to their divergent lifestyles, the physiological and functional ge- nomic characteristics of Spirochaeta and Treponema appear to be intermixed and are of little taxonomic value. The 3,239,340 bp long genome of strain H1T with its 2,869 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

Subacute Hypophysitis with Panhypopituitarism as First Presentation of HIV and Syphilis Coinfection

Directory of Open Access Journals (Sweden)

Rute Alves

2017-01-01

Full Text Available Infection by Treponema pallidum still represents a clinical challenge due to its various forms of presentation. HIV coinfection added diversity and changed the natural history of syphilis as a systemic infection. We present a rare case of subacute hypophysitis and panhypopituitarism due to an early active neurosyphilis in a previously unknown HIV coinfected patient.

On the origin of the treponematoses: a phylogenetic approach.

Directory of Open Access Journals (Sweden)

Kristin N Harper

2008-01-01

Full Text Available Since the first recorded epidemic of syphilis in 1495, controversy has surrounded the origins of the bacterium Treponema pallidum subsp. pallidum and its relationship to the pathogens responsible for the other treponemal diseases: yaws, endemic syphilis, and pinta. Some researchers have argued that the syphilis-causing bacterium, or its progenitor, was brought from the New World to Europe by Christopher Columbus and his men, while others maintain that the treponematoses, including syphilis, have a much longer history on the European continent.We applied phylogenetics to this problem, using data from 21 genetic regions examined in 26 geographically disparate strains of pathogenic Treponema. Of all the strains examined, the venereal syphilis-causing strains originated most recently and were more closely related to yaws-causing strains from South America than to other non-venereal strains. Old World yaws-causing strains occupied a basal position on the tree, indicating that they arose first in human history, and a simian strain of T. pallidum was found to be indistinguishable from them.Our results lend support to the Columbian theory of syphilis's origin while suggesting that the non-sexually transmitted subspecies arose earlier in the Old World. This study represents the first attempt to address the problem of the origin of syphilis using molecular genetics, as well as the first source of information regarding the genetic make-up of non-venereal strains from the Western hemisphere.

Etiologic pattern of genital ulcers in Lusaka, Zambia: has chancroid been eliminated?

Science.gov (United States)

Makasa, Mpundu; Buve, Anne; Sandøy, Ingvild Fossgard

2012-10-01

Genital ulcers are a public health problem in developing countries. The World Health Organization recommends the use of syndromic guidelines for sexually transmitted infection treatment in resource-constrained countries. Monitoring local etiologies provides information that may aid policy for sexually transmitted infection treatment. We investigated the etiology of genital ulcer disease among outpatients in Lusaka, Zambia. Swabs from genital ulcers of 200 patients were tested using polymerase chain reaction for Treponema pallidum, herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), Haemophilus ducreyi, and Chlamydia trachomatis. The prevalence of the detected pathogens was as follows; HSV-2, 28%; T. pallidum, 11.5%; C. trachomatis, 3%; HSV-1, 0.5%; and H. ducreyi, 0%. Coinfection with HSV-2 and T. pallidum was 1.5%, and coinfection of HSV-2 and C. trachomatis was 1%. In 55% of the patients, no etiologic diagnosis could be established. H. ducreyi was not detected, whereas HSV-2 and T. pallidum were the commonest pathogens. Nondetection of H. ducreyi requires further studies. If the present findings are validated, treatment guidelines would require to be revised in Zambia.

Focal lesions within the ventral striato-pallidum abolish attraction for male chemosignals in female mice.

Science.gov (United States)

Agustín-Pavón, Carmen; Martínez-García, Fernando; Lanuza, Enrique

2014-02-01

In rodents, socio-sexual behaviour is largely mediated by chemosensory cues, some of which are rewarding stimuli. Female mice display an innate attraction towards male chemosignals, dependent on the vomeronasal system. This behaviour likely reflects the hedonic value of sexual chemosignals. The anteromedial aspect of the olfactory tubercle, along with its associated islands of Calleja, receives vomeronasal inputs and sexually-dimorphic vasopressinergic innervation. Thus, we hypothesised that this portion of the ventral striato-pallidum, known to be involved in reward processing, might be important for sexual odorant-guided behaviours. In this study, we demonstrate that lesions of this region, but not of regions in the posterolateral striato-pallidum, abolish the attraction of female mice for male chemosignals, without affecting significantly their preference for a different natural reward (a sucrose solution). These results show that, at least in female mice, the integrity of the anterior aspect of the medioventral striato-pallidum, comprising a portion of the olfactory tubercle and associated islands of Calleja, is necessary for the attraction for male chemosignals. We suggest that this region contributes to the processing of the hedonic properties of biologically significant odorants. Copyright © 2013 Elsevier B.V. All rights reserved.

Syphilitic hepatitis: An uncommon manifestation of a common disease

Directory of Open Access Journals (Sweden)

Sukriti Baveja

2014-01-01

Full Text Available Hepatitis being first manifestation of secondary syphilis is rare. Here in we report a case of 39 years old male who was being treated for hepatitis and presented to us subsequently with itchy maculopapular rash. Venereal disease research laboratory (VDRL titre was 1:16. Treponema pallidum hemagglutination assay (TPHA was positive. He was treated with intramuscular Benzathine Penicillin. His hepatitis improved rapidly.

Secondary syphilis: The great imitator can't be forgotten.

Science.gov (United States)

Reinehr, Clarissa Prieto Herman; Kalil, Célia Luiza Petersen Vitello; Reinehr, Vinícius Prieto Herman

2017-06-01

Syphilis is an infection caused by Treponema pallidum, mainly transmitted by sexual contact. Since 2001, primary and secondary syphilis rates started to rise, with an epidemic resurgence. The authors describe an exuberant case of secondary syphilis, presenting with annular and lichen planus-like lesions, as well as one mucocutaneous lesion. Physicians must be aware of syphilis in daily practice, since the vast spectrum of its cutaneous manifestations is rising worldwide.

Condylomata lata on the ankle: an unusual location.

Science.gov (United States)

Ikeda, Eri; Goto, Akane; Suzaki, Reiko; Sawada, Mizuki; Dekio, Itaru; Ishizaki, Sumiko; Fujibayashi, Mariko; Takahashi, Hayato; Tanaka, Masaru

2016-04-01

A 43-year-old Japanese man presented with reddish nodules on the ankle. The nodules had a yellowish crust and eroded surface. Dermoscopy revealed red to milky-red globules at the periphery and some glomerular vessels in the center and a whitish-pink network, which corresponded to capillary dilatation in the papillary dermis and prominent acanthosis, respectively. These structures were surrounded by a yellowish peripheral structureless area and multiple white, small, round structures in the center, corresponding to the macerated horny layer and keratin plugs. Blood samples were positive for rapid plasma reagin (1:64), Treponema pallidum hemagglutination assay (1:20480), and fluorescent treponemal antibody-absorption (1:1280). A lesional skin biopsy specimen showed irregular acanthosis and papillomatosis. The Warthin-Starry and anti-Treponema pallidum antibody stains on the biopsy specimen revealed many spirochetes in the lower epidermis and the papillary dermis. A diagnosis of secondary syphilis with condylomata lata was made. After one week of treatment with oral benzylpenicillin benzathine hydrate (Bicillin(®) G granules 400,000 units; Banyu Pharmaceutical Co., Ltd, Tokyo, Japan), 1.6 million units (U) daily, the ankle lesions had resolved with a small ulcer and pigmentation. Although syphilis is a relatively common disease, this case study reports an unusual presentation as well as dermoscopy findings.

Isolation and characterization of Treponema phagedenis-like spirochetes from digital dermatitis lesions in Swedish dairy cattle.

Science.gov (United States)

Pringle, Märit; Bergsten, Christer; Fernström, Lise-Lotte; Höök, Helena; Johansson, Karl-Erik

2008-10-20

Digital dermatitis in cattle is an emerging infectious disease. Ulcerative lesions are typically located on the plantar skin between the heel bulbs and adjacent to the coronet. Spirochetes of the genus Treponema are found in high numbers in the lesions and are likely to be involved in the pathogenesis. The aim of this study was to obtain pure cultures of spirochetes from cattle with digital dermatitis and to describe them further. Tissue samples and swabs from active digital dermatitis lesions were used for culturing. Pure isolates were subjected to, molecular typing through 16S rRNA gene sequencing, pulsed-field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD) and an intergenic spacer PCR developed for Treponema spp. as well as API-ZYM and antimicrobial susceptibility tests. The antimicrobial agents used were tiamulin, valnemulin, tylosin, aivlosin, lincomycin and doxycycline. Seven spirochete isolates from five herds were obtained. Both 16S rRNA gene sequences, which were identical except for three polymorphic nucleotide positions, and the intergenic spacer PCR indicated that all isolates were of one yet unnamed species, most closely related to Treponema phagedenis. The enzymatic profile and antimicrobial susceptibility pattern were also similar for all isolates. However it was possible to separate the isolates through their PFGE and RAPD banding pattern. This is the first report on isolation of a Treponema sp. from cattle with digital dermatitis in Scandinavia. The phylotype isolated has previously been cultured from samples from cattle in the USA and the UK and is closely related to T. phagedenis. While very similar, the isolates in this study were possible to differentiate through PFGE and RAPD indicating that these methods are suitable for subtyping of this phylotype. No antimicrobial resistance could be detected among the tested isolates.

Isolation and characterization of Treponema phagedenis-like spirochetes from digital dermatitis lesions in Swedish dairy cattle

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Höök Helena

2008-10-01

Full Text Available Abstract Background Digital dermatitis in cattle is an emerging infectious disease. Ulcerative lesions are typically located on the plantar skin between the heel bulbs and adjacent to the coronet. Spirochetes of the genus Treponema are found in high numbers in the lesions and are likely to be involved in the pathogenesis. The aim of this study was to obtain pure cultures of spirochetes from cattle with digital dermatitis and to describe them further. Methods Tissue samples and swabs from active digital dermatitis lesions were used for culturing. Pure isolates were subjected to, molecular typing through 16S rRNA gene sequencing, pulsed-field gel electrophoresis (PFGE, random amplified polymorphic DNA (RAPD and an intergenic spacer PCR developed for Treponema spp. as well as API-ZYM and antimicrobial susceptibility tests. The antimicrobial agents used were tiamulin, valnemulin, tylosin, aivlosin, lincomycin and doxycycline. Results Seven spirochete isolates from five herds were obtained. Both 16S rRNA gene sequences, which were identical except for three polymorphic nucleotide positions, and the intergenic spacer PCR indicated that all isolates were of one yet unnamed species, most closely related to Treponema phagedenis. The enzymatic profile and antimicrobial susceptibility pattern were also similar for all isolates. However it was possible to separate the isolates through their PFGE and RAPD banding pattern. Conclusion This is the first report on isolation of a Treponema sp. from cattle with digital dermatitis in Scandinavia. The phylotype isolated has previously been cultured from samples from cattle in the USA and the UK and is closely related to T. phagedenis. While very similar, the isolates in this study were possible to differentiate through PFGE and RAPD indicating that these methods are suitable for subtyping of this phylotype. No antimicrobial resistance could be detected among the tested isolates.

Reiter haemagglutination test: a screening test for syphilis.

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Al-Qudah, A A; Mostratos, A

1982-01-01

Using an ultrasonicate of the Reiter treponeme as antigen the Reiter haemagglutination test (RHA) was evaluated as a serological test for syphilis. Comparison of the results of the cardiolipin Wassermann reaction, Reiter protein complement-fixation test, the fluorescent treponemal antibody-absorbed (FTA-ABS) test, the Treponema pallidum haemagglutination test (TPHA) (at dilutions of 1/16 and 1/80), and the Venereal Disease Research Laboratory test with those of the RHA showed that the RHA was...

Manifestaciones orales de la sífilis. Caso clínico

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Navazo-eguía, Ana Isabel; Rioja-peñaranda, Elena; Echevarria-iturbe, Celina; Terán-muñoz, Danilo; Cordero-civantos, Cristina; Ibañez-muñoz, Cristina

2017-01-01

Introduction: Syphilis is a sexually transmitted disease caused by the bacterium Treponema pallidum. Oral manifestations of syphilis are not frequent but may occur in all stages simulating other diseases, delaying diagnosis and treatment. We describe the case of a patient with oral lesions as a manifestation of secondary syphilis. Discussion: oral manifestations of syphilis may mimic other more common oral mucosa lesions, going undiagnosed and with no proper treatment. Although oral lesions m...

Malignant syphilis with human immunodeficiency virus infection

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Jiby Rajan

2011-01-01

Full Text Available Malignant syphilis or Lues maligna, commonly reported in the pre-antibiotic era, has now seen a resurgence with the advent of human immunodeficiency virus (HIV. Immunosuppression and sexual promiscuity set the stage for this deadly association of HIV and Treponema pallidum that can manifest atypically and can prove to cause diagnostic problems. We report one such case in a 30-year-old female who responded favorably to treatment with penicillin.

Secondary syphilis: The great imitator can't be forgotten

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Clarissa Prieto Herman Reinehr

Full Text Available Summary Syphilis is an infection caused by Treponema pallidum, mainly transmitted by sexual contact. Since 2001, primary and secondary syphilis rates started to rise, with an epidemic resurgence. The authors describe an exuberant case of secondary syphilis, presenting with annular and lichen planus-like lesions, as well as one mucocutaneous lesion. Physicians must be aware of syphilis in daily practice, since the vast spectrum of its cutaneous manifestations is rising worldwide.

Activation of Murine Macrophages by Lipoprotein and Lipooligosaccharide of Treponema denticola

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Rosen, Graciela; Sela, Michael N.; Naor, Ronit; Halabi, Amal; Barak, Vivian; Shapira, Lior

1999-01-01

We have recently demonstrated that the periodontopathogenic oral spirochete Treponema denticola possesses membrane-associated lipoproteins in addition to lipooligosaccharide (LOS). The aim of the present study was to test the potential of these oral spirochetal components to induce the production of inflammatory mediators by human macrophages, which in turn may stimulate tissue breakdown as observed in periodontal diseases. An enriched lipoprotein fraction (dLPP) from T. denticola ATCC 35404 ...

Adjuvant Activity of Sargassum pallidum Polysaccharides against Combined Newcastle Disease, Infectious Bronchitis and Avian Influenza Inactivated Vaccines

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Li-Jie Li

2012-11-01

Full Text Available This study evaluates the effects of Sargassum pallidum polysaccharides (SPP on the immune responses in a chicken model. The adjuvanticity of Sargassum pallidum polysaccharides in Newcastle disease (ND, infectious bronchitis (IB and avian influenza (AI was investigated by examining the antibody titers and lymphocyte proliferation following immunization in chickens. The chickens were administrated combined ND, IB and AI inactivated vaccines containing SPP at 10, 30 and 50 mg/mL, using an oil adjuvant vaccine as a control. The ND, IB and AI antibody titers and the lymphocyte proliferation were enhanced at 30 mg/mL SPP. In conclusion, an appropriate dose of SPP may be a safe and efficacious immune stimulator candidate that is suitable for vaccines to produce early and persistent prophylaxis.

In vitro susceptibility of contagious ovine digital dermatitis associated Treponema spp. isolates to antimicrobial agents in the UK.

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Angell, Joseph W; Clegg, Simon R; Sullivan, Leigh E; Duncan, Jennifer S; Grove-White, Dai H; Carter, Stuart D; Evans, Nicholas J

2015-12-01

Contagious ovine digital dermatitis (CODD) is an important cause of infectious lameness in sheep in the UK and Ireland and has a severe impact on the welfare of affected individuals. The three treponemal phylogroups Treponema medium/Treponema vincentii-like, Treponema phagedenis-like and Treponema pedis spirochaetes have been associated with clinical CODD lesions and are considered to be a necessary cause of disease. There are scant data on the antimicrobial susceptibility of the treponemes cultured from CODD lesions. The aim of this study was to determine in vitro the miniumum inhibitory concentration/ minimum bactericidal concentration (MIC/MBC) of antimicrobials used in the sheep industry for isolates of the three CODD associated treponeme phylogroups T. medium/T. vincentii-like, T. phagedenis-like and T. pedis. Twenty treponeme isolates; from 19 sheep with clinical CODD lesions. A microdilution method was used to determine in vitro the MIC/MBC of 10 antimicrobial agents for 20 treponeme isolates (five T. medium/T. vincentii-like, 10 T. phagedenis-like and five T. pedis). The antimicrobials tested were penicillin G, amoxicillin, oxytetracycline, tilmicosin, lincomycin, spectinomycin, tylosin, tildipirosin, tulathromycin and gamithromycin. The treponeme isolates tested showed low MICs and MBCs to all 10 antimicrobials tested. They were most susceptible to gamithromycin and tildipirosin (MIC90: 0.0469 mg/L), and were least susceptible to lincomycin, spectinomycin and oxytetracycline (MIC90: 48 mg/L, 24 mg/L and 3 mg/L, respectively). These data are comparable to in vitro antimicrobial susceptibility data for treponemes cultured from bovine digital dermatitis lesions. Dependent on local licensing, penicillin and tilmicosin appear to be the best candidates for future in vivo studies. © 2015 The Authors. Veterinary Dermatology published by John Wiley & Sons Ltd on behalf of the ESVD and ACVD.

Correlates of Bacterial Ulcers and Acute HSV-2 Infection among Men with Genital Ulcer Disease in South Africa: Age, Recent Sexual Behaviors, and HIV

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Leichliter, Jami S.; Lewis, David A.; Paz-Bailey, Gabriela

2016-01-01

Data from baseline surveys and STI/HIV laboratory tests (n=615 men) were used to examine correlates of bacterial ulcers (Treponema pallidum, Haemophilus ducreyi, or Chlamydia trachomatis L1–L3 detected in ulcer) and acute HSV-2 ulcers (HSV-2 positive ulcer specimen, HSV-2 sero-negative, and negative for bacterial pathogens) vs. recurrent HSV-2 ulcers (sero-positive), separately. Compared to men with recurrent HSV-2 ulcers, men with bacterial ulcers had larger ulcers but were less likely to be...

Vaccine development for syphilis.

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Lithgow, Karen V; Cameron, Caroline E

2017-01-01

Syphilis, caused by the spirochete Treponema pallidum subspecies pallidum, continues to be a globally prevalent disease despite remaining susceptible to penicillin treatment. Syphilis vaccine development is a viable preventative approach that will serve to complement public health-oriented syphilis prevention, screening and treatment initiatives to deliver a two-pronged approach to stemming disease spread worldwide. Areas covered: This article provides an overview of the need for development of a syphilis vaccine, summarizes significant information that has been garnered from prior syphilis vaccine studies, discusses the critical aspects of infection that would have to be targeted by a syphilis vaccine, and presents the current understanding within the field of the correlates of protection needed to be achieved through vaccination. Expert commentary: Syphilis vaccine development should be considered a priority by industry, regulatory and funding agencies, and should be appropriately promoted and supported.

A retrospective cross-sectional quantitative molecular approach in biological samples from patients with syphilis.

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Pinto, Miguel; Antelo, Minia; Ferreira, Rita; Azevedo, Jacinta; Santo, Irene; Borrego, Maria José; Gomes, João Paulo

2017-03-01

Syphilis is the sexually transmitted disease caused by Treponema pallidum, a pathogen highly adapted to the human host. As a multistage disease, syphilis presents distinct clinical manifestations that pose different implications for diagnosis. Nevertheless, the inherent factors leading to diverse disease progressions are still unknown. We aimed to assess the association between treponemal loads and dissimilar disease outcomes, to better understand syphilis. We retrospectively analyzed 309 DNA samples distinct anatomic sites associated with particular syphilis manifestations. All samples had previously tested positive by a PCR-based diagnostic kit. An absolute quantitative real-time PCR procedure was used to precisely quantify the number of treponemal and human cells to determine T. pallidum loads in each sample. In general, lesion exudates presented the highest T. pallidum loads in contrast with blood-derived samples. Within the latter, a higher dispersion of T. pallidum quantities was observed for secondary syphilis. T. pallidum was detected in substantial amounts in 37 samples of seronegative individuals and in 13 cases considered as syphilis-treated. No association was found between treponemal loads and serological results or HIV status. This study suggests a scenario where syphilis may be characterized by: i) heterogeneous and high treponemal loads in primary syphilis, regardless of the anatomic site, reflecting dissimilar duration of chancres development and resolution; ii) high dispersion of bacterial concentrations in secondary syphilis, potentially suggesting replication capability of T. pallidum while in the bloodstream; and iii) bacterial evasiveness, either to the host immune system or antibiotic treatment, while remaining hidden in privileged niches. This work highlights the importance of using molecular approaches to study uncultivable human pathogens, such as T. pallidum, in the infection process. Copyright © 2017 Elsevier Ltd. All rights

Topography and chemoarchitecture of the striatum and pallidum in a monotreme, the short-beaked echidna (Tachyglossus aculeatus).

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Ashwell, K W S

2008-09-01

The topography and chemoarchitecture of the striatum and pallidum in a monotreme, the short-beaked echidna (Tachyglossus aculeatus) have been studied using Nissl staining in conjunction with myelin staining, enzyme reactivity to acetylcholinesterase and NADPH diaphorase, and immunoreactivity to parvalbumin, calbindin, calretinin, tyrosine hydroxylase, neuropeptide Y, and neurofilament protein (SMI-32 antibody). All those components of the striatum and pallidum found in eutherian mammals could also be identified in the echidna's brain, with broad chemoarchitectural similarities to those regions in eutherian brains also apparent. There was a clear chemoarchitectural gradient visible with parvalbumin immunoreactivity of neurons and fibers, suggesting a subdivision of the echidna caudatoputamen into weakly reactive rostrodorsomedial and strongly reactive caudoventrolateral components. This may, in turn, relate to subdivision into associative versus sensorimotor CPu and reflect homology to the caudate and putamen of primates. Moreover, the chemoarchitecture of the echidna striatum suggested the presence of striosome-matrix architecture. The morphology of identified neuronal groups (i.e., parvalbumin, calbindin, and neuropeptide Y immunoreactive) in the echidna striatum and pallidum showed many similarities to those seen in eutherians, although the pattern of distribution of calbindin immunoreactive neurons was more uniform in the caudatoputamen of the echidna than in therians. These observations indicate that the same broad features of striatal and pallidal organization apply across all mammals and suggest that these common features may have arisen before the divergence of the monotreme and therian lineages.

[The key role of the pathologist in the diagnosis of syphilis: A case report].

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Picard, Cécile; Fontaine, Juliette; Chouvet, Brigitte; Balme, Brigitte; Traverse-Glehen, Alexandra

2018-02-01

Syphilis is a resurging sexually transmitted infection linked to Treponema Pallidum. Syphilitic lymphadenitis can be present during the 3 stages of the disease. Its histological diagnosis remains challenging for the pathologist given its possible misleading aspect and its ability to mimic as well as reactional as tumoral conditions. We report the case of an HIV-infected young patient referred for suspicion of an aggressive lymphoma. Histological and immunohistochemical analysis of cervical lymphadenopathy revealed secondary syphilis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A 16-kilodalton lipoprotein of the outer membrane of Serpulina (Treponema) hyodysenteriae.

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Thomas, W; Sellwood, R; Lysons, R J

1992-01-01

Serpulina (Treponema) hyodysenteriae P18A and VS1 were extracted by using the detergent Triton X-114 and separated into detergent and aqueous phases. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western immunoblot analysis confirmed that a membrane-associated 16-kDa antigen was hydrophobic, since it was found in the detergent phase. A 45-kDa antigen partitioned into the aqueous phase, suggesting that it was hydrophilic and may be of periplasmic origin. When spirochetes were g...

Evaluation of the diagnostic performance and operational characteristics of four rapid immunochromatographic syphilis tests in Burkina Faso.

Science.gov (United States)

Bocoum, Fadima Yaya; Ouédraogo, Henri; Tarnagda, Grissoum; Kiba, Alice; Tiendrebeogo, Simon; Bationo, Fabrice; Liestman, Benjamin; Diagbouga, Serge; Zarowsky, Christina; Traoré, Ramata Ouédraogo; Kouanda, Séni

2015-06-01

Little information is available on the rapid diagnostic testing for syphilis in Burkina Faso. The objectives of the study were (i) to assess the sensitivity and specificity of four on site rapid tests in comparison with Treponema pallidum haemagglutination assay (TPHA) as a gold standard and (ii) to evaluate the operational characteristics of those tests among health workers in a maternity unit. Four rapid syphilis tests commercially available in Burkina Faso were evaluated using archived serum samples and Treponema pallidum hemagglutination assay (TPHA) as the gold standard. Blood samples were collected between November 2011 and June 2012 from blood donors at the Regional Blood Transfusion Center of Ouagadougou. The sensitivity and specificity of the tests were calculated. Evaluation of operational characteristics such as clarity of pamphlet, complexity of technique, duration, was conducted in a first-level healthcare center with health workers in maternity unit. Alere DetermineTM Syphilis was the most sensitive of the four rapid syphilis tests evaluated. It was followed by SD Bioline Syphilis 3.0, Cypress Diagnostics Syphilis Quick test and Accu-Tell ® Rapid Anti-TP, which was the least sensitive. The four tests demonstrated a good diagnostic specificity for syphilis (95-98%), and healthcare workers found them easy to use. The study allowed confirming the good performance of three of four rapid syphilis tests in Burkina Faso. More research will be conducted to assess the feasibility of introducing selected rapid tests for syphilis in antenatal care services.

The development and validation of dried blood spots for external quality assurance of syphilis serology

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Smit Pieter W

2013-02-01

Full Text Available Abstract Background Syphilis causes up to 1,500,000 congenital syphilis cases annually. These could be prevented if all pregnant women were screened, and those with syphilis treated with a single dose of penicillin before 28 weeks gestation. In recent years, rapid point-of-care tests have allowed greater access to syphilis screening, especially in rural or remote areas, but the lack of quality assurance of rapid testing has been a concern. We determined the feasibility of using dried blood spots (DBS as specimens for quality assurance of syphilis serological assays. Methods We developed DBS extraction protocols for use with Treponema pallidum particle agglutination assay (TPPA, Treponema pallidum haemagglutination assay (TPHA and an enzyme immunoassay (EIA and compared the results with those using matching plasma samples from the same patient. Results Since DBS samples showed poor performance with TPHA and EIA (TPHA sensitivity was 50.5% (95% confidence interval: 39.9–61.2% and EIA specificity was 50.4% (95% CI: 43.7–57.1%, only the DBS TPPA was used in the final evaluation. DBS TPPA showed an sensitivity of 95.5% (95% CI: 91.3–98.0% and a specificity of 99.0% (95% CI: 98.1–99.5% compared to TPPA using plasma samples as a reference. Conclusion DBS samples can be recommended for use with TPPA, and may be of value for external quality assurance of point-of-care syphilis testing.

Host-Symbiont Cospeciation of Termite-Gut Cellulolytic Protists of the Genera Teranympha and Eucomonympha and their Treponema Endosymbionts.

Science.gov (United States)

Noda, Satoko; Shimizu, Daichi; Yuki, Masahiro; Kitade, Osamu; Ohkuma, Moriya

2018-03-29

Cellulolytic flagellated protists inhabit the hindgut of termites. They are unique and essential to termites and related wood-feeding cockroaches, enabling host feeding on cellulosic matter. Protists of two genera in the family Teranymphidae (phylum Parabasalia), Eucomonympha and Teranympha, are phylogenetically closely related and harbor intracellular endosymbiotic bacteria from the genus Treponema. In order to obtain a clearer understanding of the evolutionary history of this triplex symbiotic relationship, the molecular phylogenies of the three symbiotic partners, the Teranymphidae protists, their Treponema endosymbionts, and their host termites, were inferred and compared. Strong congruence was observed in the tree topologies of all interacting partners, implying their cospeciating relationships. In contrast, the coevolutionary relationship between the Eucomonympha protists and their endosymbionts was more complex, and evidence of incongruence against cospeciating relationships suggested frequent host switches of the endosymbionts, possibly because multiple Eucomonympha species are present in the same gut community. Similarities in the 16S rRNA and gyrB gene sequences of the endosymbionts were higher among Teranympha spp. (>99.25% and >97.2%, respectively), whereas those between Teranympha and Eucomonympha were lower (<97.1% and <91.9%, respectively). In addition, the endosymbionts of Teranympha spp. formed a phylogenetic clade distinct from those of Eucomonympha spp. Therefore, the endosymbiont species of Teranympha spp., designated here as "Candidatus Treponema teratonymphae", needs to be classified as a species distinct from the endosymbiont species of Eucomonympha spp.

Sífilis secundária com acometimento pulmonar Secondary syphilis with pulmonary involvement

OpenAIRE

Ederson Valei Lopes de Oliveira; José Alves Rocha-Filho; Andreia Américo Monteiro; Eurides Maria de Oliveira Pozzeti; João Roberto Antonio

2007-01-01

Sífilis é doença sistêmica e infectocontagiosa causada pelo Treponema pallidum. Relata-se caso de sífilis secundária em homem de 37 anos com queixas relacionadas ao trato respiratório. Manifestações clínicas e exames de imagens, incluindo radiografia e tomografia computadorizada de tórax, sugeriram neoplasia. A avaliação dermatológica e os exames complementares (sorologia e anatomopatológico de pele) confirmaram o diagnóstico. Paciente foi tratado com aplicação semanal de penicilina G benzati...

FRITZ SCHAUDINN, SU ÉPOCA Y SU RELACIÓN CON AMIBIASIS, MALARIA Y SÍFILIS | FRITZ SCHAUDINN, YOUR TIME AND ITS RELATIONSHIP WITH AMOEBIASIS, MALARIA AND SYPHILIS

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Luis Eduardo Traviezo Valles

2014-02-01

Full Text Available A brief history of Fritz Schaudinn, the time of his birth (1871 and his death (1906 is described, highlighting their achievements in Parasitology and Microbiology, such as the description first, Entamoeba histolytica 1903, the Spirochaeta pallida (Treponema pallidum 1905 , confirmation of the life cycle of hookworms, the penetration of larvae through the skin, (1895, designing a solution for fixing base mercuric chloride for protozoa and the introduction of terms such as schizogony, schizont, merozoite, macro and microgametocyte, sporogony, ookinete, sporozoite, oociste and would include in the cycle of Plasmodium of the malaria.

Várias máscaras, a mesma doença

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Santos, C; Ramalho, M; Pedrosa, C; Coutinho, I; Mota, M; Amaral, N; Bernardo, M

2014-01-01

Introdução: a sífilis é uma doença sistémica sexualmente transmissível, causada pela bactéria Treponema pallidum. Conhecida como a grande imitadora, pode afectar qualquer estrutura ocular, sendo que muitas vezes as manifestações oftalmológicas apontam no sentido do diagnóstico. Materiais e Métodos: Análise retrospectiva dos processos clínicos de casos confirmados e presuntivos de sifilis ocular observados na Consulta de Inflamação Ocular do Hospital Prof. Doutor Fernando da Fonseca, EPE en...

Soroprevalência e fatores de risco para sífilis em população carcerária de Goiás

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Andrade,Ana Lúcia Sampaio Sgambatti de; Martelli,Celina Maria Turchi; Sousa,Luiz Carlos Silva; Sousa,Marta Antunes de; Zicker,Fabio

1989-01-01

Com o objetivo de dimensionar a prevalência da infecção pelo Treponema pallidum e determinar fatores de risco relacionados a soropositividade foram rastreados 299 presidiários no Centro Penitenciário de Atividades Industriais de Goiás (CEPAI-GO), 20 Km de Goiânia. O rastreamento sorológico foi realizado utilizando-se como critério de positividade, qualquer resultado sororeagente ao VDRL independentemente do título. Através de um questionário padronizado foram avaliados os seguintes fatores de...

Production, purification and molecular weight determination of the haemolysin of Treponema hyodysenteriae.

Science.gov (United States)

Kent, K A; Lemcke, R M; Lysons, R J

1988-11-01

The production of haemolysin from Treponema hyodysenteriae was increased by an improved culture method and by repeated incubation of spirochaetes suspended in a buffer containing RNA-core. Ion exchange chromatography on DEAE cellulose followed by gel filtration on Sephadex G100 yielded purified haemolysin free from extraneous protein, as judged by silver-stained polyacrylamide gels. The mol. wt of the purified haemolysin, determined by gel filtration was 19,000, a value similar to that of streptolysin S, but much lower than that previously reported.

Abrogation of genetically controlled resistance of mice to Treponema pallidum by irradiation

International Nuclear Information System (INIS)

Klein, J.R.; Monjan, A.A.; Hardy, P.H. Jr.; Cole, G.A.

1980-01-01

On intradermal infection, transient primary lesions, characteristic of those seen in naturally acquired human syphilis, can be produced regularly in some strains of mice but not others, indicating a genetic basis for host susceptibility. However strains of mice which normally fail to develop lesions, do so after exposure to ionising radiation. Here the importance of an intact immune system in the outcome of local infection is illustrated by the use of radiation-induced immunosuppression. The mice were exposed to lethal doses of total body irradiation from a 137 Ce source (137 rad per min), 850-1,050 rad depending on mouse strain. (UK)

Swine dysentery: protection of pigs by oral and parenteral immunisation with attenuated Treponema hyodysenteriae.

Science.gov (United States)

Hudson, M J; Alexander, T J; Lysons, R J; Prescott, J F

1976-11-01

An attenuated strain of Treponema hyodysenteriae was used to immunise 18 pigs in three experiments. Live attenuated spirochaetes were dosed orally and injected intra-peritoneally, and killed spirochaetes were injected intramuscularly with adjuvant. The vaccinated pigs, which developed high serum agglutination titres against T hyodysenteriae, and 18 unvaccinated litter-mates were repeatedly challenged with virulent T hyodysenteriae. Nine vaccinated pigs and 16 control pigs developed typical swine dysentery.

A cross-sectional study of 'yaws' in districts of Ghana which have previously undertaken azithromycin mass drug administration for trachoma control.

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Rosanna Ghinai

2015-01-01

Full Text Available Yaws, caused by Treponema pallidum ssp. pertenue, is reportedly endemic in Ghana. Mass distribution of azithromycin is now the cornerstone of the WHO yaws eradication campaign. Mass distribution of azithromycin at a lower target dose was previously undertaken in two regions of Ghana for the control of trachoma. Ongoing reporting of yaws raises the possibility that resistance may have emerged in T. pallidum pertenue, or that alternative infections may be responsible for some of the reported cases. We conducted a cross-sectional survey in thirty communities in two districts of Ghana where MDA for trachoma had previously been conducted. Children aged 5-17 years with ulcerative lesions compatible with yaws were enrolled. Samples for treponemal serology and lesion PCR were collected from all children. 90 children with 98 lesions were enrolled. Syphilis serology was negative in all of them. PCR for T. pallidum ssp pertenue was negative in all children, but Haemophilus ducreyi DNA was detected in 9 lesions. In these communities, previously treated for trachoma, we found no evidence of ongoing transmission of yaws. H. ducreyi was associated with a proportion of skin lesions, but the majority of lesions remain unexplained. Integration of diagnostic testing into both pre and post-MDA surveillance systems is required to better inform yaws control programmes.

Sexually Transmitted Infections in Women Participating in a Biomedical Intervention Trial in Durban: Prevalence, Coinfections, and Risk Factors.

Science.gov (United States)

Abbai, Nathlee Samantha; Wand, Handan; Ramjee, Gita

2013-01-01

Background. Sexually transmitted infections (STIs) continue to be a significant public health problem especially among women of reproductive age in Africa. Methods. A total of 2236 women that had enrolled in the MDP301 vaginal microbicide trial were tested for the presence of Chlamydia trachomatis (CT), Neisseria gonorrhea (NG), Treponema pallidum, and Trichomonas vaginalis (TV). Results. CT was identified as the most prevalent STI (11%) followed by TV (10%), NG, and Syphilis (3%). The highest prevalence of coinfection was reported between T. pallidum and TV (19.67%, P = 0.004), followed by CT and TV (13.52%, P ≤ 0.001). Risk factors that were significantly associated with STI acquisition were women of 23 years of age or younger (HR: 1.50, 95% CI 1.17, 1.93), baseline STI with CT (HR: 1.77, 95% CI 1.32, 2.35), TV (HR: 1.58, 95% CI, 1.20, 2.10), and T. pallidum (HR: 5.13, 95% CI 3.65, 7.22), and a low education level (HR: 1.30, 95% CI 1.02, 1.66). Conclusion. Young women with lower education and a history of STIs are at high risk of multiple STIs. Prevention programs should consider target approach to STI prevention among young women. This trial is registered with ISRCTN64716212.

Surveying infections among pregnant women in the Niger Delta, Nigeria

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F I Buseri

2010-01-01

Full Text Available Background: There is paucity of epidemiological data on infectious diseases among antenatal mothers in Bayelsa State of the Niger Delta, Nigeria. Aims: The aim of this study was to determine the seroprevalence of the serological markers Human immunodeficiency virus-antibody (HIV-Ab, Hepatitis B surface antigen(HBsAg, Hepatitis C virus antibody(HCV-Aand antibodies to T.pallidum among pregnant women in Yenagoa, Bayelsa State, South-South Nigeria. Settings and Design: This is a cross-sectional study which was carried out in Yenagoa city, the heart of the Niger Delta, Nigeria. Materials and Methods: Human immunodeficiency virus (HIV antibodies were detected by using "Determine" HIV-1/2 test strip (Abbott Laboratories, Japan; hepatitis B surface antigen (HBsAg, antibodies to hepatitis C virus (anti-HCV and antibodies to T. pallidum were carried out using ACON rapid test strips (ACON Laboratories, USA. All positive samples for HIV, HBV and HCV were confirmed using the Clinotech diagnostic enzyme-linked immunosorbent assay (ELISA test kits (Clinotech Laboratories, USA, while all reactive samples to Treponema pallidum antibodies were confirmed by the Treponema pallidum hemagglutination (TPHA test (Lorne Laboratories Ltd., UK. All test procedures were carried out according to the manufacturers′ instructions. Statistical Analysis Used: The data generated were coded, entered, validated and analyzed using Statistical Package for Social Science (SPSS, version 12.0, and Epi info. The seroprevalence of syphilis, HBsAg, HCV and HIV was expressed for the entire study group by age, sex and other demographic features using Pearson chi-square analysis. Values below 0.05 were considered statistically significant. Results: A total of 1,000 apparently healthy pregnant women aged between 15 and 44 years with a mean of 27.34΁5.43 years were screened. In terms of percentage, 89.4% of the subjects were married, and 10.6% were without formal husbands. The overall

Squamous cell carcinoma of penis in patient with incipient neurosyphilis

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D. V. Zaslavsky

2016-01-01

Full Text Available Squamous cell carcinoma of the skin (SSCC is one of the most common malignant skin tumors. Syphilis is a sexually transmitted disease caused by Treponema pallidum, with human beings as the only host. The combination of syphilis and squamous cell carcinoma of the skin is not uncommon, particularly if the lesions are located on different parts of the body. However, simultaneous development of the chancre and squamous cell carcinoma of the glans penis seems exceptional. Considering rarity of the manifestation observed we feel the rare case of combined syphilis and squamous cell skin cancer is of interest.

The clinical study of cerebral blood flow imaging in patients with early syphilis

International Nuclear Information System (INIS)

Liu Zengli; Shi Xin; Wu Jinchang; Tang Jun; Zhong Jijun

2003-01-01

Objective: To study the clinical value of cerebral blood flow imaging for evaluation of patients with early syphilis. Methods: Fifty-three patients with early syphilis underwent cerebral blood flow imaging using 99 Tc m -ethylenecysteinate dimer(ECD). Regional cerebral blood flow (rCBF) changes were analyzed. Results: The acquired images of 53 patients were graded as 5 types. The rCBF was significantly depressed in 48 of 53 patients mainly in the areas dominated by anterior cerebral artery and middle cerebral artery. Conclusion: Treponema pallidum (TP) could start invading central nervous system at the early stage of infection

Cell-mediated immunity during syphilis. A review

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Pavia, Charles S.; Folds, James D.; Baseman, Joel B.

1978-01-01

Evidence is presented which reinforces the complexity of the host-parasite interaction during the course of syphilis. Infection with Treponema pallidum evokes a complicated antibody response and an assortment of cell-mediated immune reactions in the host. It appears that humoral immunity plays a minor role towards the complete elimination of syphilitic infection while the cellular limb of the immune response may be an important host defence mechanism. Information now available indicates that a state of anergy, or immunosuppression, exists in the early stages of human and experimental rabbit syphilis based upon negative skin reactions to T. pallidum antigen(s), the abnormal histological appearance of lymphoid organs, and impaired in vitro lymphocyte reactivity. It is also evident that in the later stages of the disease cellular immunity becomes activated as delayed type skin reactions can normally be elicited in tertiary syphilitics and lymphocyte behaviour in cell culture appears normal. Several mechanisms have been invoked to explain the delay in an effective immune response against syphilitic infection and the duration of the disease: (1) a capsule-like substance on the outer surface of virulant T. pallidum may act as a barrier against treponemicidal antibody; (2) this material and other biological properties of virulent treponemes could enable spirochaetes to escape being engulfed by macrophages and other phagocytic cells; (3) antigenic competition among different treponemal antigens causing partial tolerance; (4) T. pallidum infection may bring about the elaboration of immunosuppressive substances of host or treponemal origin which inhibit the proper function of lymphocytes, macrophages, and other cell types. PMID:350348

Current status of syphilis vaccine development: need, challenges, prospects.

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Cameron, Caroline E; Lukehart, Sheila A

2014-03-20

Syphilis is a multistage disease caused by the invasive spirochete Treponema pallidum subsp. pallidum. Despite inexpensive and effective antibiotic therapy, syphilis remains a prevalent disease in developing countries and has re-emerged as a public health threat in developed nations. In addition to the medical burden imparted by infectious syphilis, congenital syphilis is considered the most significant infectious disease affecting fetuses and newborns worldwide, and individuals afflicted with syphilis have an enhanced risk for HIV transmission and acquisition. The global disease burden of syphilis and failure of decades of public health efforts to stem the incidence of disease highlight the need for an effective syphilis vaccine. Although challenges associated with T. pallidum research have impeded understanding of this pathogen, the existence of a relevant animal model has enabled insight into the correlates of disease protection. Complete protection against infection has been achieved in the animal model using an extended immunization regimen of γ-irradiated T. pallidum, demonstrating the importance of treponemal surface components in generation of protective immunity and the feasibility of syphilis vaccine development. Syphilis is a prime candidate for development of a successful vaccine due to the (1) research community's accumulated knowledge of immune correlates of protection; (2) existence of a relevant animal model that enables effective pre-clinical analyses; (3) universal penicillin susceptibility of T. pallidum which enhances the attractiveness of clinical vaccine trials; and (4) significant public health benefit a vaccine would have on reduction of infectious/congenital syphilis and HIV rates. Critical personnel, research and market gaps need to be addressed before the goal of a syphilis vaccine can be realized, including recruitment of additional researchers to the T. pallidum research field with a proportional increase in research funding

Canadian Public Health Laboratory Network laboratory Guidelines for the Diagnosis of Neurosyphilis in Canada

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Tom Wong

2015-01-01

Full Text Available Neurosyphilis refers to infection of the central nervous system by Treponema pallidum, which may occur at any stage. Neurosyphilis has been categorized in many ways including early and late, asymptomatic versus symptomatic and infectious versus non-infectious. Late neurosyphilis primarily affects the central nervous system parenchyma, and occurs beyond early latent syphilis, years to decades after the initial infection. Associated clinical syndromes include general paresis, tabes dorsalis, vision loss, hearing loss and psychiatric manifestations. Unique algorithms are recommended for HIV-infected and HIV-uninfected patients, as immunocompromised patients may present with serologic and cerebrospinal fluid findings that are different from immunocompetent hosts. Antibody assays include a VDRL assay and the FTA-Abs, while polymerase chain reaction for T. pallidum can be used as direct detection assays for some specimens. This chapter reviews guidelines for specimen types and sample collection, and identifies two possible algorithms for use with immunocompromised and immunocompetent hosts using currently available tests in Canada, along with a review of treatment response and laboratory testing follow-up.

Bacteria and vampirism in cinema.

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Castel, O; Bourry, A; Thévenot, S; Burucoa, C

2013-09-01

A vampire is a non-dead and non-alive chimerical creature, which, according to various folklores and popular superstitions, feeds on blood of the living to draw vital force. Vampires do not reproduce by copulation, but by bite. Vampirism is thus similar to a contagious disease contracted by intravascular inoculation with a suspected microbial origin. In several vampire films, two real bacteria were staged, better integrated than others in popular imagination: Yersinia pestis and Treponema pallidum. Bacillus vampiris was created for science-fiction. These films are attempts to better define humans through one of their greatest fears: infectious disease. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Syphilis: Neologisms, social impact and development of research on its nature and etiology = Sífilis: neologismos, impacto social y desarrollo de la investigación de su naturaleza y etiología

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Volcy, Charles

2014-01-01

Full Text Available Perhaps originating from the Hispaniola Island, an epidemic of syphilis arose in 1495 in the Old Continent, and ravaged it for 20-25 consecutive years. Given the proliferation of vernacular and medical names assigned to Morbus Gallicus, this review addresses the discriminatory and racist role of these synonyms, and the implementation of public health legislation and quarantine to contain its spread. Also the controversy about its geographical origin and its possible presence in Europe before the discovery of America are discussed, as well as the disputes and mistakes concerning the nature, etiology and taxonomy of the newly discovered pathogen -Treponema pallidum-.

A cytotoxic haemolysin from Treponema hyodysenteriae--a probable virulence determinant in swine dysentery.

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Lysons, R J; Kent, K A; Bland, A P; Sellwood, R; Robinson, W F; Frost, A J

1991-02-01

The haemolysin from a virulent strain of Treponema hyodysenteriae was extracted and injected into ligated loops of the ileum and colon of germ-free pigs. It caused severe epithelial damage, especially to the differentiated cells at the tips of the villi in the ileum and the cells in the intercrypt zones of the colon; goblet cells were less affected. The changes in the colon were similar to those seen in natural cases of swine dysentery. The ligated loop offers a means of investigating pathogenic mechanisms and the mode of action of the toxin. This study demonstrated that the haemolysin was a potent cytotoxin for pig enterocytes, and a probable virulence determinant in swine dysentery.

Oscillatory reactivity to effortful cognitive processing in the subthalamic nucleus and internal pallidum: a depth electrode EEG study

Czech Academy of Sciences Publication Activity Database

Bočková, M.; Chládek, Jan; Jurák, Pavel; Halámek, Josef; Rapcsak, S.Z.; Baláž, M.; Chrastina, J.; Rektor, I.

2017-01-01

Roč. 124, č. 7 (2017), s. 841-852 ISSN 0300-9564 R&D Projects: GA MZd(CZ) NV16-33798A; GA ČR GAP103/11/0933; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : subthalamic nucleus * internal globus pallidum * complex cognitive functions * lateralization * deep brain stimulation * erd/s Subject RIV: FS - Medical Facilities ; Equipment OBOR OECD: Medical engineering Impact factor: 2.392, year: 2016

Diagnosis of swine dysentery: spirochaetes which may be confused with Treponema hyodysenteriae.

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Hudson, M J; Alexander, T J; Lysons, R J

Spirochaetes, designated PWS, microscopically resembling Treponema hyodysenteriae, were isolated from the colon contents of pigs with post-weaning scours from three herds, which on clinical and epidemiological grounds were thought to be free from swine dysentery. One of the isolates was fed to pigs experimentally but no evidence of disease was noted. Their cultural characteristics differed from those of T hyodysenteriae but they were similar to those of a non-pathogenic spirachaete (4/71) which had been isolated previously from the laboratory's dysentery-free herd. Smears prepared from cultures of the PWS spirochaete, 4/71 and two virulent and one avirulent strain of T hyodysenteriae were all positive to a fluorescent antibody test which was in use as an aid to the diagnosis of swine dysentery in the United Kingdom.

Using standard serology blood tests to diagnose latent syphilis

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G. L. Katunin

2016-01-01

Full Text Available Goal. To conduct a comparative assessment of the results of regulated serological tests obtained as a result of blood tests in patients suffering from latent syphilis. Materials and methods. The authors examined 187 patient medical records with newly diagnosed latent syphilis in FGBU GNTsDK (State Research Center for Dermatology, Venereology and Cosmetology, Health Ministry of the Russian Federation, in 2006-2015. The results of patient blood tests were analyzed with the use of non-treponemal (microprecipitation test/RPR and treponemal (passive hemagglutination test, immune-enzyme assay (IgA, IgM, IgG, IFabs, immunofluorescence test and Treponema pallidum immobilization test serology tests. Results. According to the results of blood tests of latent syphilis patients, the largest number of positive results was obtained as a result of treponemal serology tests such as immune-enzyme assay (100%, passive hemagglutination test (100% and IFabs (100%. The greatest number of negative results was observed in non-treponemal (microprecipitation test/RPR serology tests: in 136 (72.7% patients; evidently positive results (4+ test results were obtained in 8 (4.3% patients only. According to the results of a comparative analysis of blood tests in patients suffering from latent syphilis obtained with the use of treponemal serology tests, the greatest number of evidently positive results (4+ was noted for the passive hemagglutination test (67.9%. Negative treponemal test results were obtained with the use of the immunofluorescence test and Treponema pallidum immobilization test (21.9% and 11.8% of cases, respectively. Moreover, weakly positive results prevailed for the immunofluorescence test: in 65 (34.7% patients. Conclusion. These data confirm that the following treponemal tests belong to the most reliable ones for revealing patients suffering from latent syphilis: immune-enzyme assay, passive hemagglutination test and IFabs.

Evaluation of the Lumipulse G TP-N Chemiluminescent Immunoassay as a Syphilis Screening Test.

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Ortiz, Daniel A; Loeffelholz, Michael J

2017-11-01

A syphilis diagnosis is often aided by the detection of treponemal and nontreponemal antibodies. Automated treponemal antibody detection systems enable high-volume clinical laboratories to perform syphilis screening at a faster pace with lower labor costs. The Lumipulse G TP-N chemiluminescent immunoassay is an automated system that qualitatively detects IgG and IgM antibodies against Treponema pallidum antigens in human serum and plasma. To assess performance characteristics and workflow efficiency, the Lumipulse G TP-N assay was compared to the Bioplex 2200 Syphilis IgG multiplex flow immunoassay. Among the 4,134 routine and HIV samples tested by the two automated assays, the percentage of agreement was excellent at 99.0% (95% confidence interval [CI], 98.6% to 99.2%; κ, 0.89), with the Lumipulse G TP-N having a shorter time to first and subsequent results. All specimens with reactive syphilis screening results were further tested by rapid plasma reagin (RPR) and Treponema pallidum particle agglutination (TP·PA) testing ( n = 231). The results from the RPR-reactive samples ( n = 82) showed complete concordance with the two automated assays, while the TP·PA assay displayed some discrepancies. The positive percent agreement (PPA) and negative percent agreement (NPA) between the TP·PA test and the Lumipulse G TP-N test were 98.9% and 77.3%, respectively. The Bioplex 2200 Syphilis IgG immunoassay displayed a similar PPA (100%) but a substantially lower NPA (15.9%). Patient chart reviews of discrepant results suggested that the Lumipulse G TP-N assay produced 27 fewer falsely reactive results and can reduce the amount of additional confirmatory RPR and TP·PA testing needed. The analogous performance characteristics of the two automated systems indicate that the Lumipulse G TP-N assay is suitable for high-throughput syphilis screening. Copyright © 2017 American Society for Microbiology.

Comparison of Six Automated Treponema-Specific Antibody Assays.

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Park, Borae G; Yoon, Jihoon G; Rim, John Hoon; Lee, Anna; Kim, Hyon-Suk

2016-01-01

Six different Treponema (TP)-specific immunoassays were compared to the fluorescent treponemal antibody absorption (FTA-ABS) test. A total of 615 samples were tested. The overall percent agreement, analytical sensitivity, and analytical specificity of each assay compared to the FTA-ABS test were as follows: Architect Syphilis TP, 99.2%, 96.8%, and 100%; Cobas Syphilis, 99.8%, 99.4%, and 100%; ADVIA Centaur Syphilis, 99.8%, 99.4%, and 100%; HISCL Anti-TP assay kit, 99.7%, 98.7%, and 100%; Immunoticles Auto3 TP, 99.0%, 97.5%, and 99.6%; Mediace TPLA, 98.0%, 98.1%, and 98.0%. All results that were discrepant between the TP-specific assays were associated with samples from noninfectious cases (11 immunoassay false positives and 7 from previous syphilis cases). Our study demonstrated that TP-specific immunoassays generally showed high sensitivities, specificities, and percentages of agreement compared to FTA-ABS, with rare cases of false-positive or false-negative results. Therefore, most TP-specific immunoassays are acceptable for use in screening for syphilis. However, it is important to perform a thorough review of a patient's clinical and treatment history for interpreting the results of syphilis serology. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Diagnostic approaches in unsuspected oral lesions of syphilis.

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Siqueira, C S; Saturno, J L; de Sousa, S C O M; da Silveira, F R X

2014-12-01

Awareness of the increased prevalence of syphilis is essential for early diagnosis and treatment, and to prevent the spread of the disease. Although serological studies are the primary tool used to confirm the diagnosis of secondary syphilis, biopsy of unsuspected oral lesions is not uncommon in the routine oral pathology laboratory. In these cases, histopathological characteristics are likely to indicate the possibility of syphilis, and an immunohistochemical reaction can confirm it. The aim of the present study was to highlight the histological features and test the efficacy of immunohistochemistry in the detection of Treponema pallidum in oral lesions biopsied with the assumption of a non-syphilitic disease. Thirty-nine tissue samples from patients for whom the possibility of syphilis was suggested on the basis of histopathological findings, were retrieved from the surgical oral pathology service files and submitted to immunohistochemical staining for T. pallidum. The study was approved by the institutional ethics committee. Eighteen of the tissue samples were positive for T. pallidum. Following this, the contributing clinicians were contacted to check whether they had asked for serological examinations when the diagnostic report was received; for all 18 positive cases, the clinicians confirmed that the patients had tested positive at that time. This study shows the importance of clinical-pathological correlation and the value of immunohistochemistry in the diagnosis of unsuspected syphilis. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Correlates of Bacterial Ulcers and Acute HSV-2 Infection among Men with Genital Ulcer Disease in South Africa: Age, Recent Sexual Behaviors, and HIV.

Science.gov (United States)

Leichliter, Jami S; Lewis, David A; Paz-Bailey, Gabriela

2016-01-01

Data from baseline surveys and STI/HIV laboratory tests (n=615 men) were used to examine correlates of bacterial ulcers ( Treponema pallidum , Haemophilus ducreyi , or Chlamydia trachomatis L1-L3 detected in ulcer) and acute HSV-2 ulcers (HSV-2 positive ulcer specimen, HSV-2 sero-negative, and negative for bacterial pathogens) vs. recurrent HSV-2 ulcers (sero-positive), separately. Compared to men with recurrent HSV-2 ulcers, men with bacterial ulcers had larger ulcers but were less likely to be HIV-positive whereas men with acute HSV-2 ulcers were younger with fewer partners. Acute HIV was higher among men with bacterial and acute HSV-2 ulcers; the difference was not statistically significant.

Cost utility analysis of diagnostic method of syphilis

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Viroj Wiwanitkit

2008-04-01

Full Text Available Presently, the diagnosis of syphilis is dependent mainly on serological tests. The most widely used screening tests for syphilis are the VDRL and the rapid plasma reagin (RPR and for confirmation, the fluorescent treponemal antibody (FTA and the treponema pallidum hemagglutination (TPHA tests. The four alternative modes for diagnosis of syphilis can be a VDRL + FTA, b VDRL + TPHA, c RPR + FTA and d RPR + TPHA. Here the author reports an evaluation of cost utility of these tests in medical practice. It is shown that the cost per accurate diagnosis with VDRL + TPH is the least expensive choice. Therefore, this alternative is the best method for serological diagnosis for syphilis, based on medical laboratory economics principles

Optogenetic Inhibition of Ventral Pallidum Neurons Impairs Context-Driven Salt Seeking.

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Chang, Stephen E; Smedley, Elizabeth B; Stansfield, Katherine J; Stott, Jeffrey J; Smith, Kyle S

2017-06-07

Salt appetite, in which animals can immediately seek out salt when under a novel state of sodium deprivation, is a classic example of how homeostatic systems interface with learned associations to produce an on-the-fly updating of motivated behavior. Neural activity in the ventral pallidum (VP) has been shown to encode changes in the value of salt under such conditions, both the value of salt itself (Tindell et al., 2006) and the motivational value of its predictive cues (Tindell et al., 2009; Robinson and Berridge, 2013). However, it is not known whether the VP is necessary for salt appetite in terms of seeking out salt or consuming salt following sodium depletion. Here, we used a conditioned place-preference procedure to investigate the effects of optogenetically inhibiting the VP on context-driven salt seeking and the consumption of salt following deprivation. Male rats learned to associate one context with sucrose and another context with less-desirable salt. Following sodium depletion, and in the absence of either sucrose or salt, we found that inhibiting the VP selectively reduced the elevation in time spent in the salt-paired context. VP inhibition had minimal effects on the consumption of salt once it was made available. To our knowledge, this is the first evidence that the VP or any brain region is necessary for the ability to use contextual cues to guide salt seeking. These results highlight a dissociation between deficit-driven reward seeking and reward consumption to replenish those deficits, with the former process being particularly sensitive to on-line VP activity. SIGNIFICANCE STATEMENT Salt appetite, in which rats will immediately seek out a once-undesirable concentrated salt solution after being depleted of bodily sodium despite never having tasted salt as a positive reward, is a phenomenon showing how animals can update their motivational goals without any new learning or conditioning. This salt-seeking behavior is also observed when the animal

Type of female sex worker and other risk factors of syphilis

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Roselinda Roselinda

2016-03-01

Full Text Available AbstrakLatar belakang: Sifilis termasuk salah satu dari penyakit infeksi menular seksual kronis disebabkankuman Treponema pallidum yang dapat menyebabkan kecacatan pada penderita dan anak yang dilahirkan.Tujuan analisis ini adalah untuk melihat hubungan tipe dan lama kerja sebagai Wanita Pekerja Seks(WPS dengan kejadian penyakit sifilis di 7 kota di Indonesia.Metode: Data dari Survei WPS menggunakan kuesioner terstruktur di 7 kota (Kupang, Samarinda,Pontianak, Yogyakarta, Timika, Makassar dan Tangerang di Indonesia tahun 2007, desain potong lintangdan responden dipilih secara cluster random sampling dari WPS langsung dan tidak langsung yangmemenuhi kriteria definisi operasional. Diagnosa Sifilis ditegakkan dengan pemeriksaan laboratoriumRapid Plasma Reagent (RPR dan Treponema pallidum Haemaglutination Assay (TPHA.Hasil: Sebanyak 1750 responden ikut dalam penelitian dan 12.2% terindikasi sifilis. Kota Makassar mempunyaiprevalensi yang tertinggi sebesar 55,2%. WPS yang berlokasi di luar pulau Jawa memiliki risiko terinfeksi sifilis3,16 kali lebih tinggi dibandingkan dengan WPS yang berlokasi dipulau Jawa [risiko relatif suaian (RRa = 3,16 ;P= 0,000]. Tipe WPS tidak langsung memiliki risiko 46% lebih banyak untuk terinfeksi sifilis dibandingkan denganWPS langsung (RRa = 1,46 ; 95%; P = 0,002, sedangkan WPS yang mencari pengobatan ke dokter memiliki risiko58% lebih besar dibandingkan yang berobat ke sarana kesehatan langsung (RRa = 1,58; P = 0.006.Kesimpulan: Lokasi WPS yang berada di luar pulau Jawa, tipe WPS tidak langsung memiliki risiko lebihtinggi untuk terinfeksi penyakit sifilis. Wanita pekerja seks yang mencari pengobatan ke dokter menyebabkanpenyakit terindikasi lebih tinggi dibandingkan jika berobat ke sarana pelayanan kesehatan lainnya. (HealthScience Journal of Indonesia 2015;6:132-6Kata kunci: sifilis, wanita pekerja seks, Indonesia AbstractBackground: Syphilis is one of the chronicle sexual transmission diseases which is caused by

Seroprevalence and risk factors of syphilis among HIV/AIDS patients in Istanbul, Turkey.

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Aydin, Özlem Altuntaş; Karaosmanoğlu, Hayat Kumbasar; Sayan, Murat; İnce, Emine Rahşan; Nazlıcan, Özcan

2015-03-01

Data on syphilis seroprevalence among human immunodeficiency virus (HIV)/Acquired immunodeficiency syndrome (AIDS) patients are unavailable in Turkey although they have common transmission routes. Our study is oriented towards the assessment of the seroprevalence of syphilis and the related risk factors in the HIV/AIDS patients followed in our outpatient clinic. Newly diagnosed HIV/AIDS cases (n = 308) who attended our outpatient clinic between January 2006 and April 2013 were included in the study. Patient characteristics, medical history, physical examination findings, CD4+ T lymphocyte count, HIV RNA level, rapid plasma reagent (RPR) and Treponema pallidum hemagglutination (TPHA) test results were analyzed retrospectively. TPHA positivity was considered indicative of syphilis-causing T pallidum exposure. HIV infection was transmitted through heterosexual (n = 176) or homosexual (n =131) contact (266 male, 86.3%; age 38.3 ± 11.7 years; CD4+ T lymphocyte count, 330.6 ± 15.17/mm3). 50.7% of the patients attained only primary education. Out of the 245 cases, who were asked about the number of their sexual partners, 40 patients (26 women) lived in a monogamous relationship. Condom usage was not practiced (57.2%) or was only occasional (34.4% - particularly with their legal spouses and for contraception). Physical exam revealed no signs of syphilis or other STIs. TPHA (+/- RPR) positivity was determined in 40 patients (12.9%), indicating T pallidum exposure. All patients with positive syphilis serology were male (p= 0.0026). T pallidum exposure was determined in 21.3% of homosexual and 6.8% of heterosexual cases (p = 0.0003). Since sexual contact is the most common route of transmission for both infections, syphilis seroprevalence was relatively high in our HIV/AIDS patients. Male and homosexual HIV/AIDS patients constituted a group at the highest risk for syphilis.

Absence of infection with human immunodeficiency virus in Peruvian prostitutes.

Science.gov (United States)

Golenbock, D T; Guerra, J; Pfister, J; Golubjatnikov, R; Tejada, A; Abugattas, J; Kemper, R; Maki, D G

1988-12-01

We serologically tested 140 female prostitutes (mean age, 30 years) from the port city of Callao, Peru, for evidence of infection with human immunodeficiency virus (HIV), Chlamydia trachomatis, Treponema pallidum, herpes simplex viruses (HSV) I and II, and hepatitis B virus. The women had worked as prostitutes for an average of 5 years; one-fourth serviced foreign visitors exclusively, mainly sailors. Only 4 women used condoms, and only 1 woman gave a history of parenteral narcotic abuse, although 53% were regularly exposed to unsterile needles outside the medical setting for injections of vitamins, antibiotics, or steroids; another 29% are thought to probably use unsterile needles. None of the 140 prostitutes screened was seropositive for HIV, despite a very high prevalence of antibody to T. pallidum (24%), C. trachomatis (97%), HSV I and II (100%), and hepatitis B (51%); 5% were HbsAg positive. These data indicate that HIV has not yet been introduced into female prostitutes in the Peruvian port city. We believe that widespread use of unsterile needles in developing countries, such as Peru, represents a serious health threat and will amplify the spread of HIV, once introduced.

In vitro and in vivo activities of sedecamycin against Treponema hyodysenteriae.

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Hayashi, T; Suenaga, I; Narukawa, N; Yamazaki, T

1988-01-01

Sedecamycin (lankacidin A), one of the lankacidin-group antibiotics, showed potent activity against Treponema hyodysenteriae. The MICs of sedecamycin against 79 field isolates of T. hyodysenteriae ranged from 0.78 to 12.5 micrograms/ml, the MIC for 90% of the strains tested (MIC90) being 3.13 micrograms/ml. The protective and therapeutic effects of sedecamycin were compared with those of carbadox, tiamulin, and lincomycin against experimental infection with T. hyodysenteriae in mice. The protective effect of sedecamycin was similar to that of carbadox, two times more potent than that of tiamulin, and three times greater than that of lincomycin. In the therapeutic test, sedecamycin showed activity similar to that of carbadox and was two times more active than both tiamulin and lincomycin. At doses of 10 mg or more of sedecamycin per kg, the recurrence of shedding of T. hyodysenteriae into the feces of mice was not detected for at least 8 weeks postmedication. Images PMID:3377458

Antibody production by the pig colon during infection with Treponema hyodysenteriae.

Science.gov (United States)

Rees, A S; Lysons, R J; Stokes, C R; Bourne, F J

1989-09-01

When 47 pigs were dosed orally with cultures of Treponema hyodysenteriae, 44 (94 per cent) developed swine dysentery. Of those which recovered and were rechallenged, nine of 21 (43 per cent) showed clinical signs, as did one of 10 (10 per cent) challenged on a third occasion. Clinical disease was associated with development of specific IgG, IgA and IgM antibodies in serum and the local production of IgA in gut mucosal tissues. The appearance of antibody was not directly related to protection but rather indicated either prolonged exposure (in the case of serum IgG) or recent exposure to T hyodysenteriae (for secretory IgA). Infection also resulted in the appearance of IgG and IgA memory cells in gut-associated lymphoid tissue. However, these studies indicated that humoral immunity alone is not responsible for the onset of a protective response to T hyodysenteriae in the colon.

Biochemical characterization of a D-psicose 3-epimerase from Treponema primitia ZAS-1 and its application on enzymatic production of D-psicose.

Science.gov (United States)

Zhang, Wenli; Zhang, Tao; Jiang, Bo; Mu, Wanmeng

2016-01-15

The rare sugar D-psicose is a hexoketose monosaccharide and a C-3 epimer of D-fructose. D-Psicose is a novel functional sweetener with 70% of the sweetness but only 0.3% of the energy content of sucrose. Generally, the industrial production of D-psicose involves a bioconversion from D-fructose induced by ketose 3-epimerases. The D-psicose 3-epimerase (DPEase) gene from Treponema primitia ZAS-1 (Trpr-DPEase) was cloned and overexpressed in Escherichia coli BL21 (DE3). The recombinant enzyme was purified with a molecular mass of 33 kDa. Trpr-DPEase exhibited optimal activity at pH 8.0 and 70 °C and was sensitive to temperature, with relative thermal stability below 50 °C. It was strictly metal-dependent and displayed maximum catalytic activity with 450 µmol L(-1) Co(2+). The Km values of the enzyme for D-psicose and D-fructose were 209 and 279 mmol L(-1) respectively. The D-psicose/D-fructose equilibrium ratio of Trpr-DPEase was 28:72. A novel DPEase from T. primitia ZAS-1 was characterized that could catalyze the formation of D-psicose from D-fructose. D-Psicose was produced at a yield of 137.5 g L(-1) from 500 g L(-1) D-fructose, suggesting that Trpr-DPEase might be appropriate for the industrial production of D-psicose. © 2015 Society of Chemical Industry.

Enhanced target-specific signal detection using an Escherichia coli lysate in multiplex microbead immunoassays with E. coli-derived recombinant antigens.

Science.gov (United States)

Crestani, Sandra; Leitolis, Amanda; Lima, Lucianna Freitas Oliveira; Krieger, Marco A; Foti, Leonardo

2016-08-01

Diverse techniques have been developed to analyze antibody-mediated responses to infections. However, the most common tests, i.e., enzyme-linked immunosorbent assays, require separate reactions for each antigen and consequently necessitate large sample volumes. Luminex technology allows the detection of multiple antibodies in a single experiment, but nonspecific binding can impair the results. Therefore, we examined the use of Escherichia coli lysates to reduce nonspecific binding and improve the results of liquid microarrays based on Luminex technology. Anti-bacteria antibodies were detected in human serum samples, as evidenced by high median fluorescence intensity (MFI) in assays performed with paramagnetic microspheres coupled with E. coli lysates. Moreover, the addition of an E. coli lysate as a blocker reduced the nonspecific binding of antigens produced by E. coli in a concentration-dependent manner. Tris-HCl reduced MFI values in negative samples, but did not affect MFI for positive samples. For microspheres coupled with different antigens, an E. coli lysate blocker significantly improved the fluorescence signals from positive samples. The addition of Tris-HCl and the E. coli lysate induced antigen-specific differences in MFI. This combination of the E. coli lysate blocker and Tris-HCl yielded a statistically significant improvement in MFI in the assays for Chagas disease and hepatitis C virus samples. However, for the Treponema pallidum p47 antigen improvement in MFI was only observed for the preparation with the E. coli blocker at a concentration of 3%. In conclusion, the addition of an E. coli lysate and Tris-HCl to the microarray assay reduced the nonspecific binding of human anti-bacteria antibodies and, therefore, increased the specific MFI. Copyright © 2016 Elsevier B.V. All rights reserved.

Porphyromonas gingivalis and Treponema denticola synergistic polymicrobial biofilm development.

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Ying Zhu

Full Text Available Chronic periodontitis has a polymicrobial biofilm aetiology and interactions between key bacterial species are strongly implicated as contributing to disease progression. Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia have all been implicated as playing roles in disease progression. P. gingivalis cell-surface-located protease/adhesins, the gingipains, have been suggested to be involved in its interactions with several other bacterial species. The aims of this study were to determine polymicrobial biofilm formation by P. gingivalis, T. denticola and T. forsythia, as well as the role of P. gingivalis gingipains in biofilm formation by using a gingipain null triple mutant. To determine homotypic and polymicrobial biofilm formation a flow cell system was employed and the biofilms imaged and quantified by fluorescent in situ hybridization using DNA species-specific probes and confocal scanning laser microscopy imaging. Of the three species, only P. gingivalis and T. denticola formed mature, homotypic biofilms, and a strong synergy was observed between P. gingivalis and T. denticola in polymicrobial biofilm formation. This synergy was demonstrated by significant increases in biovolume, average biofilm thickness and maximum biofilm thickness of both species. In addition there was a morphological change of T. denticola in polymicrobial biofilms when compared with homotypic biofilms, suggesting reduced motility in homotypic biofilms. P. gingivalis gingipains were shown to play an essential role in synergistic polymicrobial biofilm formation with T. denticola.

Evidence for an ABC-Type Riboflavin Transporter System in Pathogenic Spirochetes

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Deka, Ranjit K.; Brautigam, Chad A.; Biddy, Brent A.; Liu, Wei Z.; Norgard, Michael V.

2013-01-01

ABSTRACT Bacterial transporter proteins are involved in the translocation of many essential nutrients and metabolites. However, many of these key bacterial transport systems remain to be identified, including those involved in the transport of riboflavin (vitamin B2). Pathogenic spirochetes lack riboflavin biosynthetic pathways, implying reliance on obtaining riboflavin from their hosts. Using structural and functional characterizations of possible ligand-binding components, we have identified an ABC-type riboflavin transport system within pathogenic spirochetes. The putative lipoprotein ligand-binding components of these systems from three different spirochetes were cloned, hyperexpressed in Escherichia coli, and purified to homogeneity. Solutions of all three of the purified recombinant proteins were bright yellow. UV-visible spectra demonstrated that these proteins were likely flavoproteins; electrospray ionization mass spectrometry and thin-layer chromatography confirmed that they contained riboflavin. A 1.3-Å crystal structure of the protein (TP0298) encoded by Treponema pallidum, the syphilis spirochete, demonstrated that the protein’s fold is similar to the ligand-binding components of ABC-type transporters. The structure also revealed other salient details of the riboflavin binding site. Comparative bioinformatics analyses of spirochetal genomes, coupled with experimental validation, facilitated the discovery of this new ABC-type riboflavin transport system(s). We denote the ligand-binding component as riboflavin uptake transporter A (RfuA). Taken together, it appears that pathogenic spirochetes have evolved an ABC-type transport system (RfuABCD) for survival in their host environments, particularly that of the human host. PMID:23404400

Porphyromonas gingivalis and Treponema denticola exhibit metabolic symbioses.

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Kheng H Tan

2014-03-01

Full Text Available Porphyromonas gingivalis and Treponema denticola are strongly associated with chronic periodontitis. These bacteria have been co-localized in subgingival plaque and demonstrated to exhibit symbiosis in growth in vitro and synergistic virulence upon co-infection in animal models of disease. Here we show that during continuous co-culture a P. gingivalis:T. denticola cell ratio of 6∶1 was maintained with a respective increase of 54% and 30% in cell numbers when compared with mono-culture. Co-culture caused significant changes in global gene expression in both species with altered expression of 184 T. denticola and 134 P. gingivalis genes. P. gingivalis genes encoding a predicted thiamine biosynthesis pathway were up-regulated whilst genes involved in fatty acid biosynthesis were down-regulated. T. denticola genes encoding virulence factors including dentilisin and glycine catabolic pathways were significantly up-regulated during co-culture. Metabolic labeling using 13C-glycine showed that T. denticola rapidly metabolized this amino acid resulting in the production of acetate and lactate. P. gingivalis may be an important source of free glycine for T. denticola as mono-cultures of P. gingivalis and T. denticola were found to produce and consume free glycine, respectively; free glycine production by P. gingivalis was stimulated by T. denticola conditioned medium and glycine supplementation of T. denticola medium increased final cell density 1.7-fold. Collectively these data show P. gingivalis and T. denticola respond metabolically to the presence of each other with T. denticola displaying responses that help explain enhanced virulence of co-infections.

The growth of Treponema hyodysenteriae and other porcine intestinal spirochaetes in a liquid medium.

Science.gov (United States)

Lemcke, R M; Bew, J; Burrows, M R; Lysons, R J

1979-05-01

A new simple method for the preparation of a liquid medium containing rabbit serum for the propagation of Treponema hyodysenteriae and other porcine intestinal spirochaetes is described. The medium, when dispensed in shallow layers and sealed under 10 per cent CO2 in nitrogen, had a redox potential not greater than -125mV and an initial pH of about 6.9 when buffered with bicarbonate. Growth of T hyodysenteriae developed more rapidly and viable counts reached higher levels at 42 degrees C than at 37 degrees C. Viable counts increased at least 10,000-fold after two to five days' incubation, depending on the temperature. Growth could be initiated from small inocula that failed to produce colonies on blood agar. Using a 1 per cent inoculum, the medium supported the growth of two strains of T hyodysenteriae through 10 serial passages.

[Evaluation of the Performance of Two Kinds of Anti-TP Enzyme-Linked Immunosorbent Assay].

Science.gov (United States)

Gao, Nan; Huang, Li-Qin; Wang, Rui; Jia, Jun-Jie; Wu, Shuo; Zhang, Jing; Ge, Hong-Wei

2018-06-01

To evaluate the accuracy and precision of 2 kinds of anti-treponema pallidum (anti-TP) ELISA reagents in our laboratory for detecting the anti-TP in voluntary blood donors, so as to provide the data support for use of ELISA reagents after introduction of chemiluminescene immunoassay (CLIA). The route detection of anti-TP was performed by using 2 kinds of ELISA reagents, then 546 responsive positive samples detected by anti-TP ELISA were collected, and the infections status of samples confirmed by treponema pallidum particle agglutination (TPPA) test was identified. The confirmed results of responsive samples detected by 2 kinds of anti-TP ELISA reagents were compared, the accuracy of 2 kinds of anti-TP ELISA reagents was analyzed by drawing ROC and comparing area under curve (AUC), and precision of 2 kinds of anti-TP ELISA reagents was compared by statistical analysis of quality control data from 7.1 2016 to 6.30 2017. There were no statistical difference in confirmed positive rate of responsive samples and weak positive samples between 2 kinds of anti-TP ELISA reagents. The responsive samples detected by 2 kinds of anti-TP ELISA reagents accounted for 85.53%(467/546) of all responsive samples, the positive rate confirmed by TPPA test was 82.87%. 44 responsive samples detected by anti-TP ELISA reagent A and 35 responsive samples detected by anti-TP ELISA reagent B were confirmed to be negative by TPPA test. Comparison of AUC showed that the accuracy of 2 kinds of anti-TP ELISA reagents was more high, the difference between 2 reagents was not statistically significant. The coefficient of variation (CV) of anti-TP ELISA reagent A and B was 14.98% and 18.04% respectively, which met the precision requirement of ELISA test. The accuracy and precision of 2 kinds of anti-TP ELISA reagents used in our laboratory are similar, and using any one of anti-TP ELISA reagents all can satisfy the requirements of blood screening.

Analysis of the axial filaments of Treponema hyodysenteriae by SDS-PAGE and immunoblotting.

Science.gov (United States)

Kent, K A; Sellwood, R; Lemcke, R M; Burrows, M R; Lysons, R J

1989-06-01

Purified axial filaments from eight serotypes of Treponema hyodysenteriae and two non-pathogenic intestinal spirochaetes were characterized by SDS-PAGE and Western blotting. Axial filaments of all ten strains had similar SDS-PAGE profiles; five major axial filament polypeptides were identified, with molecular masses of 43.8, 38, 34.8, 32.8 and 29.4 kDa. Hyperimmune gnotobiotic pig serum raised against purified axial filaments of strain P18A (serotype 4) cross-reacted with all other serotypes and with the non-pathogens, and convalescent serum taken from a pig with persistent swine dysentery also showed a strong response to the axial filament polypeptides. Hyperimmune gnotobiotic pig serum raised against axial filaments failed to agglutinate viable organisms and did not inhibit growth in vitro. Hence, the axial filaments of T. hyodysenteriae have been identified as major immunodominant antigens, although the role that antibodies to these antigens play in protection has yet to be established.

A 16-kilodalton lipoprotein of the outer membrane of Serpulina (Treponema) hyodysenteriae.

Science.gov (United States)

Thomas, W; Sellwood, R; Lysons, R J

1992-08-01

Serpulina (Treponema) hyodysenteriae P18A and VS1 were extracted by using the detergent Triton X-114 and separated into detergent and aqueous phases. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western immunoblot analysis confirmed that a membrane-associated 16-kDa antigen was hydrophobic, since it was found in the detergent phase. A 45-kDa antigen partitioned into the aqueous phase, suggesting that it was hydrophilic and may be of periplasmic origin. When spirochetes were grown in the presence of [3H]palmitic acid, a predominant 16-kDa antigen was labeled; from the results of immunoprecipitation experiments, this antigen appeared to be the same as that recognized by both polyclonal and monoclonal antisera to a previously described 16-kDa antigen. This antigen was proteinase K sensitive and was not a component of the lipopolysaccharide, which, although [3H]palmitate labeled, was resistant to proteinase K digestion. The most probable explanation is that the 16-kDa antigen is a membrane-associated, surface-exposed, immunodominant lipoprotein.

Trichomonas vaginalis - an indicator for other sexually transmitted infecting agents

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Agrawal B

1998-01-01

Full Text Available The present study is based on 350 women having sexually transmitted diseases and 68 men counterparts. Trichomonas vaginalis was a significant contributor in 216 (61.7% out of 350 female SID cases′ and in 56 (82.3% out of 68 male counterparts. Further, out of 216 cases of T.vaginalis, 41 cases (32.5% were associated with infection with Candida species; 29 (23% with Neisseria gonorrhoea. 18 cases (14.3% with Haemophilus ducreyi and 11 cases (8.7%, Chlamydia trachomatis. Treponema pallidum was observed in 8 cases (6.3% which constituted a low percentage. Present study highlighted the importance of T. vaginalis by showing positivity in two-third cases which suggested that it can be an important indicator for other etiological STD agents in women.

Syphilitic lymphadenitis clinically and histologically mimicking lymphogranuloma venereum.

Science.gov (United States)

Wessels, Annesu; Bamford, Colleen; Lewis, David; Martini, Markus; Wainwright, Helen

2016-04-19

An inguinal lymph node was discovered incidentally during surgery for a suspected strangulated inguinal hernia. The patient had recently been treated for candidal balanoposthitis and was known to have a paraphimosis. A new foreskin ulcer was discovered when he was admitted for the hernia surgery. The lymph node histology showed stellate abscesses suggestive of lymphogranuloma venereum (LGV). Chlamydial serologic tests were negative. As the histological appearance and clinical details provided were thought to suggest LGV, tissue was also sent for a real-time quadriplex polymerase chain reaction assay. This was used to screen for Chlamydia trachomatis in conjunction with other genital ulcer-related pathogens. The assay was negative for C. trachomatis, but positive for Treponema pallidum. Further histochemical staining of the histological specimen confirmed the presence of spirochaetes.

Molecular Typing and Macrolide Resistance of Syphilis Cases in Manitoba, Canada, From 2012 to 2016.

Science.gov (United States)

Shuel, Michelle; Hayden, Kristy; Kadkhoda, Kamran; Tsang, Raymond S W

2018-04-01

The province of Manitoba, Canada, with a population of approximately 1.3 million, has been experiencing increased incidence of syphilis cases since 2015. In this study, we examined the detection of Treponema pallidum DNA in 354 clinical samples from 2012 to 2016, and determined molecular types and mutations conferring resistance to azithromycin in the polymerase chain reaction (PCR)-positive samples. T. pallidum DNA detection was done by PCR amplification of tpp47, bmp, and polA genes. Syphilis serology results were reviewed for the PCR-positive cases. Molecular typing of syphilis strains was done by analysis of the T, pallidum arp, tpr, and tp0548 gene targets as well as partial sequencing of the 23S rRNA gene for azithromycin resistance. Of the 354 samples tested, 74 individual cases were PCR positive. A result from the treponemal antibody chemiluminescent microparticle immunoassay test was positive in 72 of these cases and that from the Venereal Disease Research Laboratory testing was positive in 66. Mutations conferring resistance to azithromycin were found in all 74 PCR-positive samples. Molecular typing was completed on 57 PCR-positive samples, and 12 molecular types were identified with 14d/g found in 63.2%. Increased strain diversity was observed with 8 molecular types detected in 2016, whereas only 2 to 3 types were found in 2012 to 2014. A patient with 2 episodes of infection 9 months apart caused by different molecular strain types was also identified. The finding of an increase in genetic diversity in the strains in this study and an increase in macrolide resistance compared with previous Canadian reports highlighted the need for continued surveillance including strain characterization.

Control of mother-to-child transmission of infectious diseases in Brazil: progress in HIV/AIDS and failure in congenital syphilis Controle da transmissão vertical de doenças infecciosas no Brasil: avanços na infecção pelo HIV/AIDS e descompasso na sífilis congênita

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Alberto Novaes Ramos Jr.

2007-01-01

Full Text Available In Brazil, syphilis and HIV infection are considered serious public health problems. However, in practice, epidemiological surveillance, prevention measures, and prenatal care seem to be more effective in the control of mother-to-child transmission of the HIV than in the control of transmission of the Treponema pallidum. Here we discuss the differences in surveillance, prenatal care, and care of the newborn. Important differences were identified. It is concluded that there is an urgent need to establish prevention of mother-to-child transmission of syphilis as a public health priority, using an integrated approach including women's health, children's health, primary health care, and STD/AIDS programs on all governmental levels. These issues also need to be discussed with all stakeholders involved. Important aspects related to the problem are the training of public health professionals, as well as the participation of the community. The elimination of congenital syphilis does not require expensive drugs, and diagnostic tools, but a long-term sustainable approach.No Brasil, a infecção pelo Treponema pallidum e pelo vírus da imunodeficiência humana são eventos considerados prioritários. No entanto, apesar das políticas públicas, a resposta em termos das ações de vigilância e prevenção, assistência pré-natal e ao recém-nascido, é diferenciada, parecendo ser mais bem estruturada para a redução da transmissão vertical do HIV do que para a do T. pallidum. No presente artigo, potenciais diferenças são analisadas quanto ao desenvolvimento das ações. Identificou-se que as desigualdades existentes na atenção aos dois problemas apresentam dimensões diferenciadas nas regiões do país. Reconheceu-se a necessária e urgente priorização da sífilis na gravidez, envolvendo áreas técnicas como atenção básica, saúde da mulher, saúde da criança e controle de doenças sexualmente transmissíveis, em todas as esferas de governo

Performance evaluation of the Elecsys syphilis assay for the detection of total antibodies to Treponema pallidum.

Science.gov (United States)

Enders, Martin; Hunjet, Andrea; Gleich, Michael; Imdahl, Roland; Mühlbacher, Annelies; Schennach, Harald; Chaiwong, Kriangsak; Sakuldamrongpanich, Tasanee; Turhan, Ajda; Sertöz, Rüchan; Wolf, Eva; Mayer, Wolfgang; Tao, Chuanmin; Wang, Lan Lan; Semprini, Simona; Sambri, Vittorio

2015-01-01

Syphilis is a health problem of increasing incidence in recent years that may have severe complications if not diagnosed and treated at an early stage. There are many diagnostic tests available for syphilis, but there is no gold standard, and diagnosis therefore usually relies upon a combination of tests. In this multicenter study, we evaluated the treponemal Elecsys syphilis assay for use in the diagnosis of syphilis in routine samples, i.e., when syphilis is suspected or during antenatal or blood donation screening. The sensitivity and specificity of the Elecsys syphilis assay were compared head to head with those of other treponemal assays used in routine clinical practice and were assessed in potentially cross-reactive samples from patients with Epstein-Barr virus, HIV, and Lyme disease. In a total of 8,063 syphilis-negative samples collected from routine diagnostic requests and blood donations, the Elecsys syphilis assay had a specificity of 99.88%. In 928 samples previously identified as syphilis positive, the sensitivity was 99.57 to 100% (the result is presented as a range depending on whether four initially indeterminate samples are included in the assessment). The specificity of the Elecsys syphilis assay in patients with other infections was 100%; no false-positive samples were identified. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Performance Evaluation of the Elecsys Syphilis Assay for the Detection of Total Antibodies to Treponema pallidum

Science.gov (United States)

Enders, Martin; Hunjet, Andrea; Gleich, Michael; Imdahl, Roland; Mühlbacher, Annelies; Schennach, Harald; Chaiwong, Kriangsak; Sakuldamrongpanich, Tasanee; Turhan, Ajda; Sertöz, Rüchan; Wolf, Eva; Mayer, Wolfgang; Tao, Chuanmin; Wang, Lan Lan; Semprini, Simona

2014-01-01

Syphilis is a health problem of increasing incidence in recent years that may have severe complications if not diagnosed and treated at an early stage. There are many diagnostic tests available for syphilis, but there is no gold standard, and diagnosis therefore usually relies upon a combination of tests. In this multicenter study, we evaluated the treponemal Elecsys syphilis assay for use in the diagnosis of syphilis in routine samples, i.e., when syphilis is suspected or during antenatal or blood donation screening. The sensitivity and specificity of the Elecsys syphilis assay were compared head to head with those of other treponemal assays used in routine clinical practice and were assessed in potentially cross-reactive samples from patients with Epstein-Barr virus, HIV, and Lyme disease. In a total of 8,063 syphilis-negative samples collected from routine diagnostic requests and blood donations, the Elecsys syphilis assay had a specificity of 99.88%. In 928 samples previously identified as syphilis positive, the sensitivity was 99.57 to 100% (the result is presented as a range depending on whether four initially indeterminate samples are included in the assessment). The specificity of the Elecsys syphilis assay in patients with other infections was 100%; no false-positive samples were identified. PMID:25355799

Antibodies to a common outer envelope antigen of Treponema hyodysenteriae with antibacterial activity.

Science.gov (United States)

Sellwood, R; Kent, K A; Burrows, M R; Lysons, R J; Bland, A P

1989-08-01

Outer envelopes of Treponema hyodysenteriae strains P18A and VS1 were prepared and characterized by SDS-PAGE. In Western blot analysis of eleven strains of T. hyodysenteriae and two intestinal non-pathogenic spirochaetes, polyclonal antiserum raised to the outer envelopes of strain P18A contained antibodies primarily to two polypeptides. A 45 kDa polypeptide was present in only two strains of T. hyodysenteriae, P18A and MC52/80, whereas another antigen of 16 kDa was common to all eleven strains of T. hyodysenteriae but was not present in the two nonpathogens. Immunogold labelling of whole organisms suggested that the 16 kDa antigen was present on the surface of the spirochaetes. In in vitro tests the serum agglutinated and inhibited growth of only the T. hyodysenteriae strains, suggesting that antibodies to the 16 kDa antigen were responsible for these activities. Serum from a gnotobiotic pig infected with T. hyodysenteriae strain P18A had antibodies to the 16 kDa antigen alone and also possessed agglutinating and growth-inhibitory activities.

Recombinant Programming

OpenAIRE

Pawlak , Renaud; Cuesta , Carlos; Younessi , Houman

2004-01-01

This research report presents a promising new approach to computation called Recombinant Programming. The novelty of our approach is that it separates the program into two layers of computation: the recombination and the interpretation layer. The recombination layer takes sequences as inputs and allows the programmer to recombine these sequences through the definition of cohesive code units called extensions. The output of such recombination is a mesh that can be used by the interpretation la...

Recombiner

International Nuclear Information System (INIS)

Kikuchi, Nobuo.

1983-01-01

Purpose: To shorten the pre-heating time for a recombiner and obtain a uniform temperature distribution for the charged catalyst layer in a BWR type reactor. Constitution: A pre-heating heater is disposed to the outer periphery of a vessel for a recombiner packed with catalysts for recombining hydrogen and oxygen in gases flowing through a radioactive gaseous wastes processing system. Heat pipes for transmitting the heat applied to said container to the catalyst are disposed vertically and horizontally within the container. Different length of the heat pipes are combined. In this way, pre-heating time for the recombiner before the operation start and before the system switching can be shortened and the uniform pre-heating for the inside of the recombiner is also made possible. Further, heater control in the pre-heating can be carried out effectively and with ease. (Moriyama, K.)

Confirmation of high specificity of an automated enzyme immunoassay test for serological diagnosis of syphilis: retrospective evaluation versus results after implementation.

Science.gov (United States)

van Dommelen, Laura; Hoebe, Christian J P A; van Tiel, Frank H; Thijs, Carel; Goossens, Valère J; Bruggeman, Cathrien A; van Loo, Inge H M

2015-03-01

The optimal algorithm for serological syphilis screening is still a matter of debate. We have previously evaluated the performance of the Bioelisa Syphilis 3.0, using a selection of archived sera, and in this study compare these results with the Bioelisa results after clinical implementation. All Bioelisa Syphilis 3.0 results obtained since clinical implementation were analyzed. Bioelisa-positive or borderline samples were retested using Treponema pallidum particle agglutination, rapid plasma reagin test, fluorescent treponemal antibody-absorption test, and/or immunoblot. On sera sent in together with cerebrospinal fluid, occasionally both the T. pallidum particle agglutination and Bioelisa were performed. The Bioelisa was performed on 14,622 sera. Bioelisa-positive samples, which were not retested by the previously described assays, were withdrawn from the database (n = 36). In 1.3% of the samples (187/14,586), the Bioelisa was positive or borderline and, ultimately, 115 sera were considered true positive (prevalence 0.8%). The specificity of the Bioelisa was 99.5%. Based on the results of all performed diagnostic assays, the specificity of the Bioelisa of 99.5% is very consistent with that found in the initial study (100%; 95% confidence interval was 98.0%-100%). Interpreting (positive) test results is difficult in the absence of a gold standard, especially when the disease prevalence is low. Results should be viewed in the light of the patients' characteristics.

Significance of isolated reactive treponemal chemiluminescence immunoassay results.

Science.gov (United States)

Hunter, Michael G; Robertson, Peter W; Post, Jeffrey J

2013-05-01

Isolated reactive serum treponemal chemiluminescence immunoassay (CIA) specimens cause clinical uncertainty. Sera were screened by CIA, and reactive samples underwent reflex testing with rapid plasma reagin (RPR), Treponema pallidum particle agglutination (TPPA), and fluorescent treponemal antibody absorption (FTA Abs) assays. Samples reactive only on the CIA were deemed "isolated" reactive CIA samples. We undertook detailed review of a subset of subjects with isolated reactive CIA specimens. Of 28 261 specimens, 1171 (4.1%) were reactive on CIA, of which 133 (11.3%) had isolated CIA reactivity. Most subjects (66 of 82 [80.5%]) with isolated reactive CIA specimens were from high-prevalence populations. We found evidence of CIA, TPPA, and FTA Abs seroreversion. The median chemiluminescent signal-to-cutoff ratio was similar for isolated reactive CIA sera and sera that were reactive on either FTA Abs or TPPA assays (2.19 vs 2.32; P = .15) but lower than for sera reactive on both FTA Abs and TPPA assays (12.37; P < .001) or for sera reactive on RPR assays (25.53; P < .001). A total of 11 of 20 patients (55%) with an isolated reactive CIA specimen who underwent medical record review had previous or subsequent evidence of syphilis infection. Isolated reactive CIA specimens may represent true T. pallidum infection and may be found after seroreversion of traditional treponemal assays.

Acute syphilitic chorioretinitis after a missed primary diagnosis: a case report

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Handtrack Claudia

2008-02-01

Full Text Available Abstract Introduction Syphilis is well known as an infectious disease which can present with a large variety of symptoms. Clinical diagnosis can be difficult and may be complicated in modern medicine by immunosuppressive treatment and possible side effects of medication. Case presentation We describe a rare case of placoid chorioretinitis due to Treponema pallidum which developed after the primary symptom of proteinuria was not recognized as a rare manifestation of syphilis. Diagnosis of syphilitic chorioretinitis and/or endophthalmitis was made by broad range amplification of the bacterial 16S ribosomal RNA gene obtained from vitreous after diagnostic vitrectomy. Conclusion This case shows that clinicians should be alert in patients with proteinuria and chorioretinitis as they can represent rare manifestations of syphilis. Syphilis should be in the differential diagnosis of any unknown symptom and in the presumed side effects of medication.

Syphilis and HIV co-infection (PhD-afhandling)

DEFF Research Database (Denmark)

Salado-Rasmussen, Kirsten

2015-01-01

The studies included in this PhD thesis examined the interactions of syphilis, which is caused by Treponema pallidum, and HIV. Syphilis reemerged worldwide in the late 1990s and hereafter increasing rates of early syphilis were also reported in Denmark. The proportion of patients with concurrent...... HIV has been substantial, ranging from one third to almost two thirds of patients diagnosed with syphilis some years. Given that syphilis facilitates transmission and acquisition of HIV the two sexually transmitted diseases are of major public health concern. Further, syphilis has a negative impact...... on HIV infection, resulting in increasing viral loads and decreasing CD4 cell counts during syphilis infection. Likewise, HIV has an impact on the clinical course of syphilis; patients with concurrent HIV are thought to be at increased risk of neurological complications and treatment failure. Almost ten...

An investigation of genital ulcers in Jackson, Mississippi, with use of a multiplex polymerase chain reaction assay: high prevalence of chancroid and human immunodeficiency virus infection.

Science.gov (United States)

Mertz, K J; Weiss, J B; Webb, R M; Levine, W C; Lewis, J S; Orle, K A; Totten, P A; Overbaugh, J; Morse, S A; Currier, M M; Fishbein, M; St Louis, M E

1998-10-01

In 1994, an apparent outbreak of atypical genital ulcers was noted by clinicians at the sexually transmitted disease clinic in Jackson, Mississippi. Of 143 patients with ulcers tested with a multiplex polymerase chain reaction (PCR) assay, 56 (39%) were positive for Haemophilus ducreyi, 44 (31%) for herpes simplex virus, and 27 (19%) for Treponema pallidum; 12 (8%) were positive for > 1 organism. Of 136 patients tested for human immunodeficiency virus (HIV) by serology, 14 (10%) were HIV-seropositive, compared with none of 200 patients without ulcers (P chancroid were significantly more likely than male patients without ulcers to report sex with a crack cocaine user, exchange of money or drugs for sex, and multiple sex partners. The strong association between genital ulcers and HIV infection in this population highlights the urgency of preventing genital ulcers in the southern United States.

Undetectable hepatitis C virus RNA during syphilis infection in two HIV/HCV-co-infected patients

DEFF Research Database (Denmark)

Salado-Rasmussen, Kirsten; Knudsen, Andreas; Krarup, Henrik Bygum

2014-01-01

BACKGROUND: Treponema pallidum, the causative agent of syphilis, elicits a vigorous immune response in the infected host. This study sought to describe the impact of syphilis infection on hepatitis C virus (HCV) RNA levels in patients with HIV and chronic HCV infection. METHODS: Patients......-α), interferon gamma (IFN-γ), and IFN-γ-inducible protein 10 kDa (IP-10). RESULTS: Undetectable HCV RNA at the time of early latent syphilis infection was observed in 2 patients with HIV and chronic HCV infection. After treatment of the syphilis infection, HCV RNA levels increased again in patient 1, whereas...... patient 2 initiated HCV therapy and remained HCV RNA-negative. Available plasma samples obtained before and after the episode with undetectable HCV RNA were phylogenetically identical, making the possibility of spontaneous clearance and HCV reinfection less likely. The IL-10, TNF-α, and IP-10 levels...

Evaluation of Elecsys Syphilis Assay for Routine and Blood Screening and Detection of Early Infection.

Science.gov (United States)

Kremastinou, J; Polymerou, V; Lavranos, D; Aranda Arrufat, A; Harwood, J; Martínez Lorenzo, M J; Ng, K P; Queiros, L; Vereb, I; Cusini, M

2016-09-01

Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T. pallidum The performance of this assay was investigated previously in a multicenter study. The current study expands on that evaluation in a variety of diagnostic settings and patient populations, at seven independent laboratories. The samples included routine diagnostic samples, blood donation samples, samples from patients with confirmed HIV infections, samples from living organ or bone marrow donors, and banked samples, including samples previously confirmed as syphilis positive. This study also investigated the seroconversion sensitivity of the assay. With a total of 1,965 syphilis-negative routine diagnostic samples and 5,792 syphilis-negative samples collected from blood donations, the Elecsys Syphilis assay had specificity values of 99.85% and 99.86%, respectively. With 333 samples previously identified as syphilis positive, the sensitivity was 100% regardless of disease stage. The assay also showed 100% sensitivity and specificity with samples from 69 patients coinfected with HIV. The Elecsys Syphilis assay detected infection in the same bleed or earlier, compared with comparator assays, in a set of sequential samples from a patient with primary syphilis. In archived serial blood samples collected from 14 patients with direct diagnoses of primary syphilis, the Elecsys Syphilis assay detected T. pallidum antibodies for 3 patients for whom antibodies were not detected with the Architect Syphilis TP assay, indicating a trend for earlier detection of infection, which may have the potential to shorten the time between infection and reactive screening test results. Copyright © 2016 Kremastinou et al.

Evaluation of Elecsys Syphilis Assay for Routine and Blood Screening and Detection of Early Infection

Science.gov (United States)

Kremastinou, J.; Polymerou, V.; Lavranos, D.; Aranda Arrufat, A.; Harwood, J.; Martínez Lorenzo, M. J.; Ng, K. P.; Queiros, L.; Vereb, I.

2016-01-01

Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T. pallidum. The performance of this assay was investigated previously in a multicenter study. The current study expands on that evaluation in a variety of diagnostic settings and patient populations, at seven independent laboratories. The samples included routine diagnostic samples, blood donation samples, samples from patients with confirmed HIV infections, samples from living organ or bone marrow donors, and banked samples, including samples previously confirmed as syphilis positive. This study also investigated the seroconversion sensitivity of the assay. With a total of 1,965 syphilis-negative routine diagnostic samples and 5,792 syphilis-negative samples collected from blood donations, the Elecsys Syphilis assay had specificity values of 99.85% and 99.86%, respectively. With 333 samples previously identified as syphilis positive, the sensitivity was 100% regardless of disease stage. The assay also showed 100% sensitivity and specificity with samples from 69 patients coinfected with HIV. The Elecsys Syphilis assay detected infection in the same bleed or earlier, compared with comparator assays, in a set of sequential samples from a patient with primary syphilis. In archived serial blood samples collected from 14 patients with direct diagnoses of primary syphilis, the Elecsys Syphilis assay detected T. pallidum antibodies for 3 patients for whom antibodies were not detected with the Architect Syphilis TP assay, indicating a trend for earlier detection of infection, which may have the potential to shorten the time between infection and reactive screening test results. PMID:27358468

Porphyromonas gingivalis Outer Membrane Vesicles Mediate Coaggregation and Piggybacking of Treponema denticola and Lachnoanaerobaculum saburreum

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Daniel Grenier

2013-01-01

Full Text Available Porphyromonas gingivalis sheds outer membrane vesicles that contain several virulence factors, including adhesins. In this study, we investigated the ability of P. gingivalis outer membrane vesicles to mediate the coaggregation and piggybacking of Treponema denticola and Lachnoanaerobaculum saburreum. Marked coaggregation between T. denticola and L. saburreum occurred in the presence of P. gingivalis outer membrane vesicles. Sucrose was an effective chemoattractant for the motile species T. denticola. The addition of outer membrane vesicles to a mixture of T. denticola and L. saburreum significantly increased the number of nonmotile bacteria that migrated into a sucrose-filled capillary tube immersed in the bacterial mixture. Under optimal conditions, the number of nonmotile L. saburreum in the capillary tube increased approximately 5-fold, whereas no increase occurred when boiled vesicles were used. This study showed that P. gingivalis outer membrane vesicles mediate coaggregation between T. denticola and L. saburreum and that nonmotile bacteria can be translocated by piggybacking on spirochetes.

Photoionization and Recombination

Science.gov (United States)

Nahar, Sultana N.

2000-01-01

Theoretically self-consistent calculations for photoionization and (e + ion) recombination are described. The same eigenfunction expansion for the ion is employed in coupled channel calculations for both processes, thus ensuring consistency between cross sections and rates. The theoretical treatment of (e + ion) recombination subsumes both the non-resonant recombination ("radiative recombination"), and the resonant recombination ("di-electronic recombination") processes in a unified scheme. In addition to the total, unified recombination rates, level-specific recombination rates and photoionization cross sections are obtained for a large number of atomic levels. Both relativistic Breit-Pauli, and non-relativistic LS coupling, calculations are carried out in the close coupling approximation using the R-matrix method. Although the calculations are computationally intensive, they yield nearly all photoionization and recombination parameters needed for astrophysical photoionization models with higher precision than hitherto possible, estimated at about 10-20% from comparison with experimentally available data (including experimentally derived DR rates). Results are electronically available for over 40 atoms and ions. Photoionization and recombination of He-, and Li-like C and Fe are described for X-ray modeling. The unified method yields total and complete (e+ion) recombination rate coefficients, that can not otherwise be obtained theoretically or experimentally.

Results of Multiplex Polymerase Chain Reaction Assay to Identify Urethritis Pathogens

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Mehmet Sarıer

2017-03-01

Full Text Available Objective: The purpose of this study was to evaluate the results of multiplex polymerase chain reaction (PCR test applied to identify the pathogens in male patients who attended our urology clinic with a pre-diagnosis of urethritis related with sexual intercourse. Materials and Methods: In this study, we included a total of 91 male patients, who sought medical advice in our clinic between August 2015 and October 2016 due to complaints of urethral discharge, dysuria and urethral itching, having a visible urethral discharge during the physical examination or a positive leukocyte esterase test (Combur-Test®-Roche in the first urine sample. In the urethral swab samples of these patients, urethritis pathogens were searched with a multiplex PCR test. The multiplex PCR kit, which is able to identify nine pathogens and produced by PathoFinder® (Holland, was used in the process. The pathogens that could be detected by the kit were Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, Gardnerella vaginalis, Trichomonas vaginalis, Treponema pallidum, and Candida albicans. Results: The average age of the subjects was 35.1 (19-57 years. Sixty one out of 91 patients (67% were found to have a pathogen in the urethral swab sample. In 45 patients (49.4%, only one pathogen, in 12 (13.1% - two different pathogens and in 4 (4.3% patients, 3 different pathogens were detected. The pathogens found were as follows: Ureaplasma urealyticum in 22 patients (27.1%, Gardnerella vaginalis in 15 (18.6%, Neisseria gonorrhoeae in 13 (16.1%, Mycoplasma genitalium (10 patients; 12.3%, Mycoplasma hominis (8 patients; 9.9%, Chlamydia trachomatis (8 patients; 9.9%, Trichomonas vaginalis (3 patients; 3.8%, and Candida albicans (2 patients; 2.4%. None of the patients were identified with Treponema pallidum. None of the pathogens were identified in 30 patients (32.9% whose samples were examined by PCR method. Conclusion

Cocaine Dysregulates Opioid Gating of GABA Neurotransmission in the Ventral Pallidum

Science.gov (United States)

Scofield, Michael D.; Rice, Kenner C.; Cheng, Kejun; Roques, Bernard P.

2014-01-01

The ventral pallidum (VP) is a target of dense nucleus accumbens projections. Many of these projections coexpress GABA and the neuropeptide enkephalin, a δ and μ opioid receptor (MOR) ligand. Of these two, the MOR in the VP is known to be involved in reward-related behaviors, such as hedonic responses to palatable food, alcohol intake, and reinstatement of cocaine seeking. Stimulating MORs in the VP decreases extracellular GABA, indicating that the effects of MORs in the VP on cocaine seeking are via modulating GABA neurotransmission. Here, we use whole-cell patch-clamp on a rat model of withdrawal from cocaine self-administration to test the hypothesis that MORs presynaptically regulate GABA transmission in the VP and that cocaine withdrawal changes the interaction between MORs and GABA. We found that in cocaine-extinguished rats pharmacological activation of MORs no longer presynaptically inhibited GABA release, whereas blocking the MORs disinhibited GABA release. Moreover, MOR-dependent long-term depression of GABA neurotransmission in the VP was lost in cocaine-extinguished rats. Last, GABA neurotransmission was found to be tonically suppressed in cocaine-extinguished rats. These substantial synaptic changes indicated that cocaine was increasing tone on MOR receptors. Accordingly, increasing endogenous tone by blocking the enzymatic degradation of enkephalin inhibited GABA neurotransmission in yoked saline rats but not in cocaine-extinguished rats. In conclusion, our results indicate that following withdrawal from cocaine self-administration enkephalin levels in the VP are elevated and the opioid modulation of GABA neurotransmission is impaired. This may contribute to the difficulties withdrawn addicts experience when trying to resist relapse. PMID:24431463

Activation of murine macrophages by lipoprotein and lipooligosaccharide of Treponema denticola.

Science.gov (United States)

Rosen, G; Sela, M N; Naor, R; Halabi, A; Barak, V; Shapira, L

1999-03-01

We have recently demonstrated that the periodontopathogenic oral spirochete Treponema denticola possesses membrane-associated lipoproteins in addition to lipooligosaccharide (LOS). The aim of the present study was to test the potential of these oral spirochetal components to induce the production of inflammatory mediators by human macrophages, which in turn may stimulate tissue breakdown as observed in periodontal diseases. An enriched lipoprotein fraction (dLPP) from T. denticola ATCC 35404 obtained upon extraction of the treponemes with Triton X-114 was found to stimulate the production of nitric oxide (NO), tumor necrosis factor alpha (TNF-alpha), and interleukin-1 (IL-1) by mouse macrophages in a dose-dependent manner. Induction of NO by dLPP was at 25% of the levels obtained by Salmonella typhosa lipopolysaccharide (LPS) at similar concentrations, while IL-1 was produced at similar levels by both inducers. dLPP-mediated macrophage activation was unaffected by amounts of polymyxin B that neutralized the induction produced by S. typhosa LPS. dLPP also induced NO and TNF-alpha secretion from macrophages isolated from endotoxin-unresponsive C3H/HeJ mice to an extent similar to the stimulation produced in endotoxin-responsive mice. Purified T. denticola LOS also produced a concentration-dependent activation of NO and TNF-alpha in LPS-responsive and -nonresponsive mouse macrophages. However, macrophage activation by LOS was inhibited by polymyxin B. These results suggest that T. denticola lipoproteins and LOS may play a role in the inflammatory processes that characterize periodontal diseases.

Intracellular localization of Treponema denticola chymotrypsin-like proteinase in chronic periodontitis

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Emilia Marttila

2014-07-01

Full Text Available Treponema denticola is an important periodontal pathogen capable of tissue invasion. Its chymotrypsin-like proteinase (CTLP can degrade a number of basement membrane components in vitro, thus suggesting a contribution to tissue invasion by the spirochete. The aim of this study was to analyze the localization of CTLP in chronic periodontitis tissues ex vivo. A polyclonal antibody specific to T. denticola cell-bound CTLP was used to detect the spirochetes in the gingival tissues of patients with moderate to severe chronic periodontitis (n=25 by immunohistochemistry and periodic acid-Schiff staining (PAS. The presence of T. denticola in the periodontal tissue samples was analyzed by PCR. Periodontal tissue samples of 12 of the 25 patients were found to be positive for T. denticola by PCR. Moreover, CTLP could be detected in the periodontal tissues of all these patients by immunohistochemistry. In the epithelium, the CTLP was mostly intracellular. Typically, the positive staining could be seen throughout the whole depth of the epithelium. When detected extracellularly, CTLP was localized mainly as granular deposits. The connective tissue stained diffusely positive in four cases. The positive staining co-localized with the PAS stain in nine cases. T. denticola and its CTLP could be detected in diseased human periodontium both intra- and extracellularly. The granular staining pattern was suggestive of the presence of T. denticola bacteria, whereas the more diffused staining pattern was indicative of the recent presence of the bacterium and shedding of the cell-bound proteinase.

Chlamydial Proctitis in a Young Man Who Has Sex with Men: Misdiagnosed as Inflammatory Bowel Disease.

Science.gov (United States)

Lee, Kyung Jin; Kim, Jaeyeon; Shin, Dong Hwan; Jung, Jun Oh; Koh, Seokyoung; Kim, Ka Young; Lee, Jae Min

2015-12-01

We report the case of a 20-year-old man with a 2-month history of anal pain and bloody rectal discharge. He was referred to our clinic of gastroenterology for suspected inflammatory bowel disease (IBD). The colonoscopy showed mucosal nodularities on the rectum and an anal tag. Because the colonoscopic findings were not consistent with the typical manifestations of IBD, we took an additional sexual history and performed studies for infectious proctitis, including serologic tests for Chlamydia trachomatis, Neisseria gonorrhoeae, and Treponema pallidum. He had homosexual experience, and the serologic tests and PCR of a rectal swab were positive for C. trachomatis infection. Finally he was diagnosed as having chlamydial proctitis and was treated with intramuscular ceftriaxone 250 mg in a single dose and doxycycline 100 mg orally twice daily for 7 days. After 2 months, he had no lower abdominal symptoms and his endoscopic findings were improved.

Sífilis secundaria en un paciente viviendo con VIH

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Mauricio La Rosa

2007-07-01

Full Text Available Se presenta el caso de un paciente varón de 31 años, con diagnóstico de infección por el virus de inmunodeficiencia humana (VIH sin tratamiento antirretroviral, presentó lesiones ulcerativas en la región genital que luego progresaron por todo el cuerpo, se le diagnosticó sífilis secundaria. Fue tratado con penicilina benzatínica, con lo cual las lesiones desaparecieron. Se discute las pruebas diagnósticas realizadas y la terapéutica empleada. La coinfección por Treponema pallidum y por el VIH está presente en la población general y en especial en poblaciones de riesgo, como los hombres que tienen sexo con hombres y clientes de trabajadoras sexuales, esta situación puede afectar la presentación inicial así como el curso de la enfermedad.

A comparative study of single-dose treatment of chancroid using thiamphenicol versus Azithromycin.

Science.gov (United States)

Belda, Walter; Di Chiacchio, Nilton G; Di Chiacchio, Nilton; Romiti, Ricardo; Criado, Paulo R; Velho, Paulo Eduardo N Ferreira

2009-06-01

A study was conducted in São Paulo, Brazil, to compare azithromycin with thiamphenicol for the single-dose treatment of chancroid. In all, 54 men with chancroid were tested. The etiology was determined by clinical characterization and direct bacterioscopy with Gram staining. None of the patients had positive serology or dark-field examination indicating active infection with Treponema pallidum. Genital infections due to Neisseria gonorrhoeae and herpes simplex virus were excluded by polymerase chain reaction testing. For 54 patients with chancroid, cure rates with single-dose treatment were 73% with azithromycin and 89% with thiamphenicol. HIV seropositivity was found to be associated with treatment failure (p=0.001). The treatment failed in all HIV positive patients treated with azithromycin (p=0.002) and this drug should be avoided in these co-infected patients. In the view of the authors, thiamphenicol is the most indicated single-dose regimen for chancroid treatment.

Cytokine expression during syphilis infection in HIV-1-infected individuals

DEFF Research Database (Denmark)

Knudsen, Andreas; Benfield, Thomas; Kofoed, Kristian

2009-01-01

BACKGROUND: Little is known about cytokine responses to syphilis infection in HIV-1-infected individuals. METHODS: We retrospectively identified patients with HIV-1 and Treponema pallidum coinfection. Plasma samples from before, during, and after coinfection were analyzed for interleukin (IL)-2, IL......-4, IL-6, IL-8, IL-10, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha. RESULTS: Thirty-six patients were included. IL-10 levels increased significantly in patients with primary or secondary stage syphilis from a median of 12.8 pg/mL [interquartile range (IQR), 11.0-27.8] before...... infection to 46.7 pg/mL (IQR, 28.4-78.9) at the time of diagnosis (P = 0.027) and decreased to 13.0 pg/mL (IQR, 6.2-19.4) after treatment of syphilis (P syphilis in patients with primary or secondary stage syphilis (median 3.9 pg...

Recombiner

International Nuclear Information System (INIS)

Osumi, Morimichi.

1979-01-01

Purpose: To provide a recombiner which is capable of converting hydrogen gas into water by use of high-frequency heating at comparatively low temperatures and is safe and cheap in cost. Constitution: Hydrogen gas is introduced from an outer pipeline to the main structure of a recombiner, and when it passes through the vicinity of the central part of the recombiner, it is reacted with copper oxide (CuO 2 ) heated to a temperature more than 300 0 C by a high-frequency heater, and converted gently into water by reduction operation (2H 2 + CuO 2 → Cu + 2H 2 O). The thus prepared water is exhausted through the outer pipeline to a suppression pool. A part of hydrogen gas which has not been converted completely into water by the reaction and is remaining as hydrogen is recovered through exhaust nozzles and again introduced into the main structure of the recombiner. (Yoshino, Y.)

Porphyromonas gingivalis and Treponema denticola Mixed Microbial Infection in a Rat Model of Periodontal Disease

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Raj K. Verma

2010-01-01

Full Text Available Porphyromonas gingivalis and Treponema denticola are periodontal pathogens that express virulence factors associated with the pathogenesis of periodontitis. In this paper we tested the hypothesis that P. gingivalis and T. denticola are synergistic in terms of virulence; using a model of mixed microbial infection in rats. Groups of rats were orally infected with either P. gingivalis or T. denticola or mixed microbial infections for 7 and 12 weeks. P. gingivalis genomic DNA was detected more frequently by PCR than T. denticola. Both bacteria induced significantly high IgG, IgG2b, IgG1, IgG2a antibody levels indicating a stimulation of Th1 and Th2 immune response. Radiographic and morphometric measurements demonstrated that rats infected with the mixed infection exhibited significantly more alveolar bone loss than shaminfected control rats. Histology revealed apical migration of junctional epithelium, rete ridge elongation, and crestal alveolar bone resorption; resembling periodontal disease lesion. These results showed that P. gingivalis and T. denticola exhibit no synergistic virulence in a rat model of periodontal disease.

Ceftriaxone treatment for two neurosyphilis cases presenting with cognitive and psychiatric symptoms

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Melek Kandemir

2011-06-01

Full Text Available Syphilis is a disease caused by the spirochetal bacterium Treponema Pallidum subspecies pallidum. The route of transmission of syphilis is almost always through sexual contact. The incidence of syphilis decreased significantly with the introduction of penicilin in the 1940s but rose sharply again with the advent of HIV infection in the 1980s. Tertiary or late syphilis develops years after the initial infection and can involve any organ system. Neurologic involvement occurs in up to 10 percent of patients with untreated syphilis. General paresis, the clinical form of neurosyphilis most associated with psychiatric symptoms, occurs with parenchymatous disease and involves neuronal loss as opposed to the vascular lesions or inflammatory changes characteristic of most other forms of neurosyphilis. In the classic description, after early psychiatric manifestations such as mood changes, psychosis, or cognitive changes, demantia becomes prominent. Penicillin is the only drug that has proved effective in the treatment of neurosyphilis. Ceftriaxone is used as an alternative treatment in patients with penicilin allergy. This article reports two cases of neurosyphilis one of whom is presented with dementia and the other with psychiatric symptoms. Both of them are treated with ceftriaxone. Our purpose is to reveal the fact that ceftriaxone is a succesful alternative treatment for the cases with penicilin allergy and to emphasize the importance of neurosyphilis in the differential diagnosis for the psychiatric cases that are resistant to treatment

Kiła układu nerwowego jako trudny problem w codziennej praktyce klinicznej – opis przypadku

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Karolina Mędrek

2011-07-01

Full Text Available Introduction. Syphilis still represents an important clinical problem.Involvement of the nervous system is one of the major features of latesyphilis, but may also occur in early syphilis.Objective. To present a case of neurosyphilis in relation to the currentproblems of diagnostics and therapy of Treponema pallidum infection.Case report. We present a 31-year-old woman with neurosyphilis. Atthe beginning the patient was treated with erythromycin, and twelvemonths later, because of insufficient decrease of titre of syphilis tests inthe serum, with doxycycline. Despite the second therapy the titres ofsyphilis tests remained high and therefore after another nine monthsthe patient was referred to our department for further diagnostics andtreatment. Because of the long course of the disease, high titres ofsyphilis tests in the serum and abnormalities in neurological examination(hypoaesthesia below the Th8 level, foot clonus and hyporeflexiain lower extremities T. pallidum neuroinfection was suspected andcerebrospinal fluid was collected. The serological examination of cerebrospinalfluid revealed positive treponemal tests (FTA 1 : 10, TPHA++, while VDRL was negative. Based on the whole clinical presentationand laboratory abnormalities, neurosyphilis was diagnosed andtherapy with crystalline penicillin followed by procaine penicillin wasperformed.Conclusions. Neurosyphilis is characterized by rich symptomatologyand its diagnosis based only on clinical manifestation can be very difficult;particularly subtle symptoms may be easily overlooked. Therefore,evaluation of cerebrospinal fluid is necessary in all questionablepatients in order to establish a correct diagnosis.

Activation of Murine Macrophages by Lipoprotein and Lipooligosaccharide of Treponema denticola

Science.gov (United States)

Rosen, Graciela; Sela, Michael N.; Naor, Ronit; Halabi, Amal; Barak, Vivian; Shapira, Lior

1999-01-01

We have recently demonstrated that the periodontopathogenic oral spirochete Treponema denticola possesses membrane-associated lipoproteins in addition to lipooligosaccharide (LOS). The aim of the present study was to test the potential of these oral spirochetal components to induce the production of inflammatory mediators by human macrophages, which in turn may stimulate tissue breakdown as observed in periodontal diseases. An enriched lipoprotein fraction (dLPP) from T. denticola ATCC 35404 obtained upon extraction of the treponemes with Triton X-114 was found to stimulate the production of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and interleukin-1 (IL-1) by mouse macrophages in a dose-dependent manner. Induction of NO by dLPP was at 25% of the levels obtained by Salmonella typhosa lipopolysaccharide (LPS) at similar concentrations, while IL-1 was produced at similar levels by both inducers. dLPP-mediated macrophage activation was unaffected by amounts of polymyxin B that neutralized the induction produced by S. typhosa LPS. dLPP also induced NO and TNF-α secretion from macrophages isolated from endotoxin-unresponsive C3H/HeJ mice to an extent similar to the stimulation produced in endotoxin-responsive mice. Purified T. denticola LOS also produced a concentration-dependent activation of NO and TNF-α in LPS-responsive and -nonresponsive mouse macrophages. However, macrophage activation by LOS was inhibited by polymyxin B. These results suggest that T. denticola lipoproteins and LOS may play a role in the inflammatory processes that characterize periodontal diseases. PMID:10024558

Genome-wide recombination rate variation in a recombination map of cotton.

Science.gov (United States)

Shen, Chao; Li, Ximei; Zhang, Ruiting; Lin, Zhongxu

2017-01-01

Recombination is crucial for genetic evolution, which not only provides new allele combinations but also influences the biological evolution and efficacy of natural selection. However, recombination variation is not well understood outside of the complex species' genomes, and it is particularly unclear in Gossypium. Cotton is the most important natural fibre crop and the second largest oil-seed crop. Here, we found that the genetic and physical maps distances did not have a simple linear relationship. Recombination rates were unevenly distributed throughout the cotton genome, which showed marked changes along the chromosome lengths and recombination was completely suppressed in the centromeric regions. Recombination rates significantly varied between A-subgenome (At) (range = 1.60 to 3.26 centimorgan/megabase [cM/Mb]) and D-subgenome (Dt) (range = 2.17 to 4.97 cM/Mb), which explained why the genetic maps of At and Dt are similar but the physical map of Dt is only half that of At. The translocation regions between A02 and A03 and between A04 and A05, and the inversion regions on A10, D10, A07 and D07 indicated relatively high recombination rates in the distal regions of the chromosomes. Recombination rates were positively correlated with the densities of genes, markers and the distance from the centromere, and negatively correlated with transposable elements (TEs). The gene ontology (GO) categories showed that genes in high recombination regions may tend to response to environmental stimuli, and genes in low recombination regions are related to mitosis and meiosis, which suggested that they may provide the primary driving force in adaptive evolution and assure the stability of basic cell cycle in a rapidly changing environment. Global knowledge of recombination rates will facilitate genetics and breeding in cotton.

Fine-Scale Recombination Maps of Fungal Plant Pathogens Reveal Dynamic Recombination Landscapes and Intragenic Hotspots.

Science.gov (United States)

Stukenbrock, Eva H; Dutheil, Julien Y

2018-03-01

Meiotic recombination is an important driver of evolution. Variability in the intensity of recombination across chromosomes can affect sequence composition, nucleotide variation, and rates of adaptation. In many organisms, recombination events are concentrated within short segments termed recombination hotspots. The variation in recombination rate and positions of recombination hotspot can be studied using population genomics data and statistical methods. In this study, we conducted population genomics analyses to address the evolution of recombination in two closely related fungal plant pathogens: the prominent wheat pathogen Zymoseptoria tritici and a sister species infecting wild grasses Z. ardabiliae We specifically addressed whether recombination landscapes, including hotspot positions, are conserved in the two recently diverged species and if recombination contributes to rapid evolution of pathogenicity traits. We conducted a detailed simulation analysis to assess the performance of methods of recombination rate estimation based on patterns of linkage disequilibrium, in particular in the context of high nucleotide diversity. Our analyses reveal overall high recombination rates, a lack of suppressed recombination in centromeres, and significantly lower recombination rates on chromosomes that are known to be accessory. The comparison of the recombination landscapes of the two species reveals a strong correlation of recombination rate at the megabase scale, but little correlation at smaller scales. The recombination landscapes in both pathogen species are dominated by frequent recombination hotspots across the genome including coding regions, suggesting a strong impact of recombination on gene evolution. A significant but small fraction of these hotspots colocalize between the two species, suggesting that hotspot dynamics contribute to the overall pattern of fast evolving recombination in these species. Copyright © 2018 Stukenbrock and Dutheil.

Transcriptional responses of Treponema denticola to other oral bacterial species.

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Juni Sarkar

Full Text Available The classic organization by Socransky and coworkers categorized the oral bacteria of the subgingival plaque into different complexes. Treponema denticola, Porphyromonas gingivalis and Tannerella forsythia are grouped into the red complex that is highly correlated with periodontal disease. Socransky's work closely associates red with orange complex species such as Fusobacterium nucleatum and Prevotella intermedia but not with members of the other complexes. While the relationship between species contained by these complexes is in part supported by their ability to physically attach to each other, the physiological consequences of these interactions and associations are less clear. In this study, we employed T. denticola as a model organism to analyze contact-dependent responses to interactions with species belonging to the same complex (P. gingivalis and T. forsythia, the closely associated orange complex (using F. nucleatum and P. intermedia as representatives and the unconnected yellow complex (using Streptococcus sanguinis and S. gordonii as representatives. RNA was extracted from T. denticola alone as well as after pairwise co-incubation for 5 hrs with representatives of the different complexes, and the respective gene expression profiles were determined using microarrays. Numerous genes related to motility, metabolism, transport, outer membrane and hypothetical proteins were differentially regulated in T. denticola in the presence of the tested partner species. Further analysis revealed a significant overlap in the affected genes and we identified a general response to the presence of other species, those specific to two of the three complexes as well as individual complexes. Most interestingly, many predicted major antigens (e.g. flagella, Msp, CTLP were suppressed in responses that included red complex species indicating that the presence of the most closely associated species induces immune-evasive strategies. In summary, the data

Assessment of reactivity of three treponemal tests in non-treponemal non-reactive cases from sexually transmitted diseases clinic, antenatal clinic, integrated counselling and testing centre, other different outdoor patient departments/indoor patients of a tertiary care centre and peripheral health clinic attendees

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M Bala

2013-01-01

Full Text Available In India, many state reference centres for sexually transmitted infections perform only a single screening assay for syphilis diagnosis. In this study, Treponema pallidum haemagglutination (TPHA was performed on 1115 Venereal Disease Research Laboratory (VDRL/rapid plasma regain (RPR non-reactive and 107 reactive sera out of 10,489 tested by VDRL/RPR according to the National AIDS Control Organisation syphilis testing protocol. A total of 47 Specimens reactive in TPHA and non-reactive with VDRL test were subjected to fluorescent treponemal antibody absorption and enzyme-immunoassay. Seroprevalence considering both VDRL and TPHA positivity was highest (4.4% in sexually transmitted diseases clinic attendees than in other subject groups. Positivity by two treponemal tests in 24 (2.2% cases non-reactive by VDRL/RPR was representative of the fully treated patients or latent or late syphilis cases. The findings highlight that a suitable treponemal confirmatory test should be performed in all the diagnostic laboratories.

Neurosyphilis in Anglo-American Composers and Jazz Musicians.

Science.gov (United States)

Breitenfeld, Darko; Kust, Davor; Breitenfeld, Tomislav; Prpić, Marin; Lucijanić, Marko; Zibar, Davor; Hostić, Vedran; Franceschi, Maja; Bolanča, Ante

2017-09-01

Syphilis is a sexually transmitted, systemic disease caused by the spirochete bacterium Treponema pallidum. The most common mechanism of transmission is sexual intercourse. Although there are several hypotheses, the exact origin of the disease remains unknown. Newly published evidence suggests that the hypothesis supporting the theory of the American origin of the disease is the valid one. Among 1500 analyzed pathographies of composers and musicians, data on ten Anglo-American composers and jazz musicians having suffered from neurosyphilis (tertiary stage of the disease) were extracted for this report. In this group of Anglo-American composers and musicians, most of them died from progressive paralysis while still in the creative phase of life. Additionally, diagnoses of eleven other famous neurosyphilitic composers, as well as basic biographic data on ten less known composers that died from neurosyphilis-progressive paralysis are also briefly mentioned. In conclusion, neurosyphilis can cause serious neurological damage, as well as permanent disability or death, preventing further work and skill improvement.

Carrion's disease (Bartonellosis bacilliformis) confirmed by histopathology in the High Forest of Peru.

Science.gov (United States)

Maco, Vicente; Maguiña, Ciro; Tirado, Antonio; Maco, Vicente; Vidal, José E

2004-01-01

Bartonellosis or Carrion's disease is endemic in some regions of Peru, classically found in the inter-Andean valleys located between 500 and 3200 meters above sea level. We report the case of a 43 year-old male patient, farmer, who was born in the Pichanaki district (Chanchamayo, Junin), located in the High Forest of Peru. He presented with disseminated, raised, erythematous cutaneous lesions, some of which bled. The distribution of these lesions included the nasal mucosa and penile region. Additionally subcutaneous nodules were distributed over the trunk and extremities. Hematologic exams showed a moderate anemia. Serologic studies for HIV and Treponema pallidum were negative. The histopathologic results of two biopsies were compatible with Peruvian wart. Oral treatment with ciprofloxacin (500 mg BID) was begun. Over 10 days, the patient showed clinical improvement. This is the first report of a confirmed case of bartonellosis in the eruptive phase originating from the Peruvian High Forest, showing the geographical expansion of the Carrion's disease.

Chancroid, primary syphilis, genital herpes, and lymphogranuloma venereum in Antananarivo, Madagascar.

Science.gov (United States)

Behets, F M; Andriamiadana, J; Randrianasolo, D; Randriamanga, R; Rasamilalao, D; Chen, C Y; Weiss, J B; Morse, S A; Dallabetta, G; Cohen, M S

1999-10-01

Ulcer material from consecutive patients attending clinics in Antananarivo, Madagascar, was tested using multiplex polymerase chain reaction (M-PCR) to detect Treponema pallidum, Haemophilus ducreyi, and herpes simplex virus. Sera were tested for syphilis and for IgG and IgM antibodies to Chlamydia trachomatis by microimmunofluorescence testing (MIF). By M-PCR, 33% of 196 patients had chancroid, 29% had syphilitic ulcers, and 10% had genital herpes; 32% of the ulcer specimens were M-PCR negative. Compared with M-PCR, syphilis serology was 72% sensitive and 83% specific. The sensitivity of clinical diagnosis of syphilis, chancroid, and genital herpes was 93%, 53%, and 0% and specificity was 20%, 52%, and 99%, respectively. Less schooling was associated with increased prevalence of syphilitic ulcers (P=.001). Sixteen patients (8%) were clinically diagnosed with lymphogranuloma venereum (LGV); 1 plausible case of LGV was found by MIF. In Madagascar, primary care of genital ulcers should include syndromic treatment for syphilis and chancroid.

A comparative study of single-dose treatment of chancroid using thiamphenicol versus Azithromycin

Directory of Open Access Journals (Sweden)

Walter B. Junior

Full Text Available A study was conducted in São Paulo, Brazil, to compare azithromycin with thiamphenicol for the single-dose treatment of chancroid. In all, 54 men with chancroid were tested. The etiology was determined by clinical characterization and direct bacterioscopy with Gram staining. None of the patients had positive serology or dark-field examination indicating active infection with Treponema pallidum. Genital infections due to Neisseria gonorrhoeae and herpes simplex virus were excluded by polymerase chain reaction testing. For 54 patients with chancroid, cure rates with single-dose treatment were 73% with azithromycin and 89% with thiamphenicol. HIV seropositivity was found to be associated with treatment failure (p=0.001. The treatment failed in all HIV positive patients treated with azithromycin (p=0.002 and this drug should be avoided in these co-infected patients. In the view of the authors, thiamphenicol is the most indicated single-dose regimen for chancroid treatment.

Canadian Laboratory Standards for Sexually Transmitted Infections: Best Practice Guidelines

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Max A Chernesky

2005-01-01

Full Text Available Sexually transmitted infections (STI continue to spread, and show no international boundaries. Diseases such as gonorrhea and syphilis, which we thought were under control in Canadian populations, have increased in incidence. Sexually transmitted or associated syndromes such as cervicitis, enteric infections, epididymitis, genital ulcers, sexually related hepatitis, ophthalmia neonatorum, pelvic inflammatory disease, prostatitis and vulvovaginitis present a challenge for the physician to identify the microbial cause, treat the patient and manage contacts. During the past 10 years, new technologies developed for the diagnosis of STIs have provided a clearer understanding of the real accuracy of traditional tests for the diagnosis of infections caused by Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, herpes simplex viruses, hepatitis B virus, human papillomaviruses, HIV, Haemophilus ducreyi, Trichomonas vaginalis and mycoplasmas. This has presented a major challenge to the diagnostic laboratory, namely, selecting the most sensitive and specific test matched with the most appropriate specimens to provide meaningful and timely results to facilitate optimal patient care.

Genetic Recombination

Science.gov (United States)

Whitehouse, H. L. K.

1973-01-01

Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

Morphological alterations in the caudate, putamen, pallidum and thalamus in Parkinson’s disease.

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Amanmeet eGarg

2015-03-01

Full Text Available Like many neurodegenerative diseases, the clinical symptoms of Parkinson’s disease (PD do not manifest until significant progression of the disease has already taken place, motivating the need for sensitive biomarkers of the disease. While structural imaging is a potentially attractive method due to its widespread availability and non-invasive nature, global morphometric measures (e.g. volume have proven insensitive to subtle disease change. Here we use individual surface displacements from deformations of an average surface model to capture disease related changes in shape of the subcortical structures in Parkinson’s disease. Data were obtained from both the University of British Columbia (UBC (n=54 healthy controls (HC & n=55 Parkinson’s disease (PD patients and the publicly available Parkinson’s Progression Marker’s Initiative (PPMI(n=137(HC & n=189 (PD database. A high dimensional non-rigid registration algorithm was used to register target segmentation labels (caudate, putamen, pallidum and thalamus to a set of segmentation labels defined on the average-template. The vertex-wise surface displacements were significantly different between PD and HC in thalamic and caudate structures. However overall displacements did not correlate with disease severity, as assessed by the Unified Parkinson's Disease Rating Scale (UPDRS. The results from this study suggest disease-relevant shape abnormalities can be robustly detected in subcortical structures in Parkinson’s disease. Future studies will be required to determine if shape changes in subcortical structures are seen in the prodromal phases of the disease.

Prevalencia y factores de riesgo asociados a sífilis en mujeres Prevalence and risk factors associated with syphilis in women

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Carlos A. Hernández-Girón

1998-12-01

Full Text Available INTRODUCCIÓN: Se ha demostrado que la sífilis, debido a la ulceración genital que produce, es un cofactor asociado para adquirir otras enfermedades de transmisión sexual (ETS, principalmente de origen viral como herpes tipo-2, hepatitis B, y el VIH. Aunque las mujeres trabajadoras del sexo comercial (MTSC han adquirido mejores conocimientos para prevenir las ETS, constituyen un grupo que por su heterogenicidad en términos de condición socioeconómica, estado de salud, ambiente y sitio de trabajo, manifiestan diferentes actitudes y conocimientos que hacen latente la posibilidad de adquirir y transmitir ETS incluyendo sífilis, por lo que lo estudio hace un acercamiento hacia los factores asociados a infección por Treponema pallidum en este grupo de mujeres. MÉTODO: Basado en un marco muestral, que identifica sitios donde se practica el comercio sexual femenino en la ciudad de México, se seleccionó una muestra de 807 MTSC, a quienes previo consentimiento informado, se entrevistó para que respondieran un cuestionario estructurado. Se obtuvo una muestra sanguínea para la identificación de diversos marcadores serológicos de ETS de acuerdo al manual de procedimientos para el diagnóstico de ETS. Para el diagnóstico de Treponema pallidum se utilizó una prueba de tamizaje de RPR (Bigaux Diagnóstica, y prueba confirmatoria de FTA-ABS (Pasteur Diagnostics. RESULTADOS: Las prevalencias de sífilis en la muestra de MTSC fue de 6,4% (52/807, siendo mayor en quienes trabajaban en sitios de calle comparadas con aquellas de estéticas. La edad de las mujeres entrevistadas osciló entre 17 y 58 años con una media de 29,2 años (d.s. 7,3 años. La prevalencia de sífilis fue mayor en los grupos etáreos mayores de 30 anos. La edad de inicio de relaciones sexuales varió desde 11 hasta 30 anos con una media de 16 años (d.s. 3,1 años. Los factores predictores de infección por T. pallidum, determinados mediante regresión logística ajustada

Discovery of Bovine Digital Dermatitis-Associated Treponema spp. in the Dairy Herd Environment by a Targeted Deep-Sequencing Approach

DEFF Research Database (Denmark)

Schou, Kirstine Klitgaard; Weiss Nielsen, Martin; Ingerslev, Hans-Christian

2014-01-01

The bacteria associated with the infectious claw disease bovine digital dermatitis (DD) are spirochetes of the genus Treponema; however, their environmental reservoir remains unknown. To our knowledge, the current study is the first report of the discovery and phylogenetic characterization of r...... of this disease among cows within a herd as well as between herds. To address the issue of DD infection reservoirs, we searched for evidence of DD-associated treponemes in fresh feces, in slurry, and in hoof lesions by deep sequencing of the V3 and V4 hypervariable regions of the 16S rRNA gene coupled...... with identification at the operational-taxonomic-unit level. Using treponeme-specific primers in this high-throughput approach, we identified small amounts of DNA (on average 0.6% of the total amount of sequence reads) from DD-associated treponemes in 43 of 64 samples from slurry and cow feces collected from six...

The tradition algorithm approach underestimates the prevalence of serodiagnosis of syphilis in HIV-infected individuals.

Science.gov (United States)

Chen, Bin; Peng, Xiuming; Xie, Tiansheng; Jin, Changzhong; Liu, Fumin; Wu, Nanping

2017-07-01

Currently, there are three algorithms for screening of syphilis: traditional algorithm, reverse algorithm and European Centre for Disease Prevention and Control (ECDC) algorithm. To date, there is not a generally recognized diagnostic algorithm. When syphilis meets HIV, the situation is even more complex. To evaluate their screening performance and impact on the seroprevalence of syphilis in HIV-infected individuals, we conducted a cross-sectional study included 865 serum samples from HIV-infected patients in a tertiary hospital. Every sample (one per patient) was tested with toluidine red unheated serum test (TRUST), T. pallidum particle agglutination assay (TPPA), and Treponema pallidum enzyme immunoassay (TP-EIA) according to the manufacturer's instructions. The results of syphilis serological testing were interpreted following different algorithms respectively. We directly compared the traditional syphilis screening algorithm with the reverse syphilis screening algorithm in this unique population. The reverse algorithm achieved remarkable higher seroprevalence of syphilis than the traditional algorithm (24.9% vs. 14.2%, p algorithm, the traditional algorithm also had a missed serodiagnosis rate of 42.8%. The total percentages of agreement and corresponding kappa values of tradition and ECDC algorithm compared with those of reverse algorithm were as follows: 89.4%,0.668; 99.8%, 0.994. There was a very good strength of agreement between the reverse and the ECDC algorithm. Our results supported the reverse (or ECDC) algorithm in screening of syphilis in HIV-infected populations. In addition, our study demonstrated that screening of HIV-populations using different algorithms may result in a statistically different seroprevalence of syphilis.

Evaluation of a new serological test for syphilis based on chemiluminescence assay in a tertiary care hospital.

Science.gov (United States)

Tiwari, Aseem K; Pandey, Prashant K; Dara, Ravi C; Rawat, Ganesh S; Raina, Vimarsh; Bhargava, Richa

2015-01-01

Syphilis is a transfusion transmissible infections and it is mandatory to do serological test for syphilis (STS) on all donor blood samples. STS is usually based on detection of antibodies against the cardiolipin-lecithin antigen or against the Treponema-specific antigen. STS with good sensitivity and specificity helps enhance blood safety and consolidation of STS along with other transfusion transmittable infections such as human immunodeficiency virus, hepatitis-C virus, and hepatitis-B virus helps in reducing the errors and enhances efficiency. This study was designed to evaluate the performance of newly introduced VITROS(®) syphilis Treponema pallidum agglutination (TPA) assay based on enhanced chemiluminescence principle for its analytical performance for use as a STS on donor blood samples at a tertiary care health center in National Capital Region, India. A total of 108 random blood units collected from the donors (both voluntary and replacement donors) and 28 known syphilis sero-reactive samples stored at -20°C, were used to evaluate the performance of VITROS(®) syphilis TPA assay based on enhanced chemiluminescence assay on VITROS(®) ECiQ immunodiagnostics system along with its analytical performance in terms of its sensitivity, precision, cross-reactivity and interference studies. VITROS(®) syphilis TPA showed 100% sensitivity and specificity with precision (20 days study) of endogenous interfering substances like free hemoglobin or fats. Performance of the VITROS(®) syphilis TPA assay meets the requirements for its use as STS in blood bank, thus allowing consolidation with other transfusion transmittable infections screening assay on chemiluminescence platform, which is highly valuable for optimizing workflow and efficiency.

Sífilis: diagnóstico, tratamento e controle Syphilis: diagnosis, treatment and control

Directory of Open Access Journals (Sweden)

João Carlos Regazzi Avelleira

2006-03-01

Full Text Available A sífilis é doença infecto-contagiosa, transmitida pela via sexual e verticalmente durante a gestação. Caracteriza-se por períodos de atividade e latência; pelo acometimento sistêmico disseminado e pela evolução para complicações graves em parte dos pacientes que não trataram ou que foram tratados inadequadamente. É conhecida desde o século XV, e seu estudo ocupou todas as especialidades médicas e, de modo especial, a dermatologia. Seu agente etiológico, o Treponema pallidum, nunca foi cultivado e, apesar de descrito há mais de 100 anos e sendo tratado desde 1943 pela penicilina, sua droga mais eficaz, continua como um problema de saúde importante em países desenvolvidos ou subdesenvolvidos. Dadas as características da forma de transmissão, a doença acompanhou as mudanças comportamentais da sociedade e nos últimos anos tornou-se mais importante ainda devido à possibilidade de aumentar o risco de transmissão da síndrome de imunodeficiência adquirida. Novos testes laboratoriais e medidas de controle principalmente voltadas para o tratamento adequado do paciente e parceiro, uso de preservativo, informação à população fazem parte das medidas adotadas para controle da sífilis pelos responsáveis por programas de saúde.Syphilis is an infectious disease transmitted through sex or vertically during pregnancy. It is characterized by periods of activity and latency, disseminated systemic involvement, and progression to acute complications in patients that remain untreated or have been inadequately treated. Syphilis is known since the 15th century and studied by all medical specialties, particularly by Dermatology. The etiologic agent Treponema pallidum has never been cultured and was described over 100 years ago. The disease has been effectively treated with penicillin since 1943, but it remains an important health problem in developed and developing countries. Given its transmission characteristics, the condition has

Sífilis secundaria en cavidad oral: Reporte de dos casos Oral secondary syphilis: Two cases report

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M G Díaz

2008-12-01

Full Text Available La sífilis es una enfermedad infecciosa humana causada por una bacteria: el Treponema pallidum. La enfermedad es transmitida por contacto directo a través de lesiones durante el estadio primario y secundario, por vía transplacentaria intrauterina o a través del canal uterino; puede afectar cualquier órgano de la economía causando un número infinito de presentaciones clínicas. La sífilis secundaria cursa con manifestaciones mucocutáneas características y eventual sintomatología general. La presentación clínica de nuestros dos pacientes es singular ya que solo poseían lesiones en la cavidad oral. La respuesta al tratamiento instaurado fue buena.Syphilis is a human infectious disease caused by the bacterium Treponema pallidum. The disease is transmitted by direct contact with a lesion during the primary or secondary stages, in utero by the transplacental route, or during delivery as the baby passes through an infected canal. The bacterium may infect any organ, causing an infinite number of clinical presentations. Secondary syphilis is characterized by mucocutaneous lesions, a flulike syndrome, and generalized adenopathy. Hepatosplenomegaly may be present. The oral mucosa is the second most frequent site of luetic lesions; the genital areas are the most frequent. In the oral cavity, the most characteristic lesion is a whitish mucosal patch, normally located on the lips, tongue, or palate, which is extremely contagious. The differential diagnosis of this lesion may include oral squamous carcinoma, leukoplakia, candidosis, lichen planus, and hairy oral leukoplakia. Definitive diagnosis is based on clinical information and completed by laboratory examinations even the biopsy can help us. With the diagnosis of secondary syphilis treatment with penicillin G benzathine must be started. We present two cases of secondary syphilis with oral lesions only; the first one, a man with macule covered with a whitish membrane on palate mucosa and a

[Factors associated with syphilis/HIV infection among men who have sex with men in Shenzhen,2011-2016].

Science.gov (United States)

Cai, Y M; Song, Y J; Liu, H; Hong, F C

2017-11-06

Objective: To investigate the factors associated with syphilis/HIV infection among men who have sex with men (MSM) maintaining a single sexual partner in Shenzhen. Methods: Respondent driven sampling and snowball sampling method were used to recruit MSM receiving voluntary counseling and testing in Shenzhen Rainbow clinic from 2011 to 2016. aged 18 years and above; reported having one or more anal sexual partners in the recent 6 months. A total of 3 109 men who have sex with men (MSM) were involved in the study. Questionnaire-based interviews were conducted on a one-on-one basis. Data were collected including socio-demographic information, human immunodeficiency virus (HIV) testing history, history of blood donation and drug abuse in the recent two years, self-identified sexual orientation, role in homosexual behavior, ever being money boys (MB) and clients of MB, female sexual partners in the recent 6 months. 5 ml blood samples were taken after questionnaires. Syphilis was screened using toluidine red unheated serum test for the antibody of treponema pallidum and then confirmed by treponema pallidum particle assay. The enzyme-linked immunosorbent assay (ELISA) was used for screening HIV and western blot was used to confirm the HIV screening results. The difference of condom use among MSM between female sexual partners and male sexual partners were compared. Multivariate unconditional stepwise logistic regression model was used to analyze factors associated with syphilis infection and HIV positive among MSM. Results: A total of 3 109 eligible participants with mean (SD) age of 31.49 (8.64) years were enrolled in this study. Among them, 565 cases were infected with syphilis (18.17%), 330 cases were infected with HIV (10.61%), and 165 cases (5.31%) were syphilis co-infected with HIV. 791 (25.44%) reported maintaining a single sexual partners in the recent 6 months. Compared to MSM with multiple sexual partners, the prevalence of syphilis and HIV infection among MSM

Recombining without Hotspots: A Comprehensive Evolutionary Portrait of Recombination in Two Closely Related Species of Drosophila

Science.gov (United States)

Smukowski Heil, Caiti S.; Ellison, Chris; Dubin, Matthew; Noor, Mohamed A.F.

2015-01-01

Meiotic recombination rate varies across the genome within and between individuals, populations, and species in virtually all taxa studied. In almost every species, this variation takes the form of discrete recombination hotspots, determined in some mammals by a protein called PRDM9. Hotspots and their determinants have a profound effect on the genomic landscape, and share certain features that extend across the tree of life. Drosophila, in contrast, are anomalous in their absence of hotspots, PRDM9, and other species-specific differences in the determination of recombination. To better understand the evolution of meiosis and general patterns of recombination across diverse taxa, we present a truly comprehensive portrait of recombination across time, combining recently published cross-based contemporary recombination estimates from each of two sister species with newly obtained linkage-disequilibrium-based historic estimates of recombination from both of these species. Using Drosophila pseudoobscura and Drosophila miranda as a model system, we compare recombination rate between species at multiple scales, and we suggest that Drosophila replicate the pattern seen in human–chimpanzee in which recombination rate is conserved at broad scales. We also find evidence of a species-wide recombination modifier(s), resulting in both a present and historic genome-wide elevation of recombination rates in D. miranda, and identify broad scale effects on recombination from the presence of an inversion. Finally, we reveal an unprecedented view of the distribution of recombination in D. pseudoobscura, illustrating patterns of linked selection and where recombination is taking place. Overall, by combining these estimation approaches, we highlight key similarities and differences in recombination between Drosophila and other organisms. PMID:26430062

Laser-induced electron--ion recombination used to study enhanced spontaneous recombination during electron cooling

International Nuclear Information System (INIS)

Schramm, U.; Wolf, A.; Schuess ler, T.; Habs, D.; Schwalm, D.; Uwira, O.; Linkemann, J.; Mueller, A.

1997-01-01

Spontaneous recombination of highly charged ions with free electrons in merged velocity matched electron and ion beams has been observed in earlier experiments to occur at rates significantly higher than predicted by theoretical estimates. To study this enhanced spontaneous recombination, laser induced recombination spectra were measured both in velocity matched beams and in beams with well defined relative velocities, corresponding to relative electron-ion detuning energies ranging from 1 meV up to 6.5 meV where the spontaneous recombination enhancement was found to be strongly reduced. Based on a comparison with simplified calculations, the development of the recombination spectra for decreasing detuning energies indicates additional contributions at matched velocities which could be related to the energy distribution of electrons causing the spontaneous recombination rate enhancement

Effects of nuclear mutations for recombination and repair functions and of caffeine on mitochondrial recombination

International Nuclear Information System (INIS)

Fraenkel, A.H.M.

1974-01-01

Studies of both prokaryotic and eukaryotic organisms indicate that pathways governing repair of damage to nuclear DNA caused by x-ray or ultraviolet irradiation overlap with those controlling recombination. Fourteen nuclear mutants of Saccharomyces cerevisiae were tested in order to determine whether these mutant genes affected mitochondrial recombination. None of the mutations studied significantly affected mitochondrial recombination. The nuclear recombination and repair pathways studied do not overlap with the nuclear pathway which controls recombination of mitochondrial DNA. A second set of experiments was designed to test the effect of caffeine on both nuclear and mitochondrial recombination in Saccharomyces cerevisiae. (U.S.)

Metagenomic analysis reveals presence of Treponema denticola in a tissue biopsy of the Iceman.

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Frank Maixner

Full Text Available Ancient hominoid genome studies can be regarded by definition as metagenomic analyses since they represent a mixture of both hominoid and microbial sequences in an environment. Here, we report the molecular detection of the oral spirochete Treponema denticola in ancient human tissue biopsies of the Iceman, a 5,300-year-old Copper Age natural ice mummy. Initially, the metagenomic data of the Iceman's genomic survey was screened for bacterial ribosomal RNA (rRNA specific reads. Through ranking the reads by abundance a relatively high number of rRNA reads most similar to T. denticola was detected. Mapping of the metagenome sequences against the T. denticola genome revealed additional reads most similar to this opportunistic pathogen. The DNA damage pattern of specifically mapped reads suggests an ancient origin of these sequences. The haematogenous spread of bacteria of the oral microbiome often reported in the recent literature could already explain the presence of metagenomic reads specific for T. denticola in the Iceman's bone biopsy. We extended, however, our survey to an Iceman gingival tissue sample and a mouth swab sample and could thereby detect T. denticola and Porphyrimonas gingivalis, another important member of the human commensal oral microflora. Taken together, this study clearly underlines the opportunity to detect disease-associated microorganisms when applying metagenomics-enabled approaches on datasets of ancient human remains.

Recombining without Hotspots: A Comprehensive Evolutionary Portrait of Recombination in Two Closely Related Species of Drosophila.

Science.gov (United States)

Smukowski Heil, Caiti S; Ellison, Chris; Dubin, Matthew; Noor, Mohamed A F

2015-10-01

Meiotic recombination rate varies across the genome within and between individuals, populations, and species in virtually all taxa studied. In almost every species, this variation takes the form of discrete recombination hotspots, determined in some mammals by a protein called PRDM9. Hotspots and their determinants have a profound effect on the genomic landscape, and share certain features that extend across the tree of life. Drosophila, in contrast, are anomalous in their absence of hotspots, PRDM9, and other species-specific differences in the determination of recombination. To better understand the evolution of meiosis and general patterns of recombination across diverse taxa, we present a truly comprehensive portrait of recombination across time, combining recently published cross-based contemporary recombination estimates from each of two sister species with newly obtained linkage-disequilibrium-based historic estimates of recombination from both of these species. Using Drosophila pseudoobscura and Drosophila miranda as a model system, we compare recombination rate between species at multiple scales, and we suggest that Drosophila replicate the pattern seen in human-chimpanzee in which recombination rate is conserved at broad scales. We also find evidence of a species-wide recombination modifier(s), resulting in both a present and historic genome-wide elevation of recombination rates in D. miranda, and identify broad scale effects on recombination from the presence of an inversion. Finally, we reveal an unprecedented view of the distribution of recombination in D. pseudoobscura, illustrating patterns of linked selection and where recombination is taking place. Overall, by combining these estimation approaches, we highlight key similarities and differences in recombination between Drosophila and other organisms. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Therapeutic Recombinant Monoclonal Antibodies

Science.gov (United States)

Bakhtiar, Ray

2012-01-01

During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

Genomic and Metagenomic Analysis of Diversity-Generating Retroelements Associated with Treponema denticola

Directory of Open Access Journals (Sweden)

Sutichot eNimkulrat

2016-06-01

Full Text Available Diversity-generating retroelements (DGRs are genetic cassettes that can produce massive protein sequence variation in prokaryotes. Presumably DGRs confer selective advantages to their hosts (bacteria or viruses by generating variants of target genes—typically resulting in target proteins with altered ligand-binding specificity—through a specialized error-prone reverse transcription process. The only extensively studied DGR system is from the Bordetella phage BPP-1, although DGRs are predicted to exist in other species. Using bioinformatics analysis, we discovered that the DGR system associated with the Treponema denticola species (a human oral-associated periopathogen is dynamic (with gains/losses of the system found in the isolates and diverse (with multiple types found in isolated genomes and the human microbiota. The T. denticola DGR is found in only nine of the 17 sequenced T. denticola strains. Analysis of the DGR-associated template regions and reverse transcriptase gene sequences revealed two types of DGR systems in T. denticola: the ATCC35405-type shared by seven isolates including ATCC35405; and the SP32-type shared by two isolates (SP32 and SP33, suggesting multiple DGR acquisitions. We detected additional variants of the T. denticola DGR systems in the human microbiomes, and found that the SP32-type DGR is more abundant than the ATCC35405-type in the healthy human oral microbiome, although the latter is found in more sequenced isolates. This is the first comprehensive study to characterize the DGRs associated with T. denticola in individual genomes as well as human microbiomes, demonstrating the importance of utilizing both individual genomes and metagenomes for characterizing the elements, and for analyzing their diversity and distribution in human populations.

Recombination every day: abundant recombination in a virus during a single multi-cellular host infection.

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Remy Froissart

2005-03-01

Full Text Available Viral recombination can dramatically impact evolution and epidemiology. In viruses, the recombination rate depends on the frequency of genetic exchange between different viral genomes within an infected host cell and on the frequency at which such co-infections occur. While the recombination rate has been recently evaluated in experimentally co-infected cell cultures for several viruses, direct quantification at the most biologically significant level, that of a host infection, is still lacking. This study fills this gap using the cauliflower mosaic virus as a model. We distributed four neutral markers along the viral genome, and co-inoculated host plants with marker-containing and wild-type viruses. The frequency of recombinant genomes was evaluated 21 d post-inoculation. On average, over 50% of viral genomes recovered after a single host infection were recombinants, clearly indicating that recombination is very frequent in this virus. Estimates of the recombination rate show that all regions of the genome are equally affected by this process. Assuming that ten viral replication cycles occurred during our experiment-based on data on the timing of coat protein detection-the per base and replication cycle recombination rate was on the order of 2 x 10(-5 to 4 x 10(-5. This first determination of a virus recombination rate during a single multi-cellular host infection indicates that recombination is very frequent in the everyday life of this virus.

Regulation of Meiotic Recombination

Energy Technology Data Exchange (ETDEWEB)

Gregory p. Copenhaver

2011-11-09

Meiotic recombination results in the heritable rearrangement of DNA, primarily through reciprocal exchange between homologous chromosome or gene conversion. In plants these events are critical for ensuring proper chromosome segregation, facilitating DNA repair and providing a basis for genetic diversity. Understanding this fundamental biological mechanism will directly facilitate trait mapping, conventional plant breeding, and development of genetic engineering techniques that will help support the responsible production and conversion of renewable resources for fuels, chemicals, and the conservation of energy (1-3). Substantial progress has been made in understanding the basal recombination machinery, much of which is conserved in organisms as diverse as yeast, plants and mammals (4, 5). Significantly less is known about the factors that regulate how often and where that basal machinery acts on higher eukaryotic chromosomes. One important mechanism for regulating the frequency and distribution of meiotic recombination is crossover interference - or the ability of one recombination event to influence nearby events. The MUS81 gene is thought to play an important role in regulating the influence of interference on crossing over. The immediate goals of this project are to use reverse genetics to identify mutants in two putative MUS81 homologs in the model plant Arabidopsis thaliana, characterize those mutants and initiate a novel forward genetic screen for additional regulators of meiotic recombination. The long-term goal of the project is to understand how meiotic recombination is regulated in higher eukaryotes with an emphasis on the molecular basis of crossover interference. The ability to monitor recombination in all four meiotic products (tetrad analysis) has been a powerful tool in the arsenal of yeast geneticists. Previously, the qrt mutant of Arabidopsis, which causes the four pollen products of male meiosis to remain attached, was developed as a facile system

Recombination of cluster ions

Science.gov (United States)

Johnsen, Rainer

1993-01-01

Some of our recent work on molecular band emissions from recombination of molecular dimer ions (N4(+) and CO(+) CO) is discussed. Much of the experimental work was done by Y. S. Cao; the results on N4(+) recombination have been published. A brief progress report is given on our ongoing measurements of neutral products of recombination using the flowing-afterglow Langmuir-probe technique in conjunction with laser-induced fluorescence.

In vivo production of recombinant proteins using occluded recombinant AcMNPV-derived baculovirus vectors.

Science.gov (United States)

Guijarro-Pardo, Eva; Gómez-Sebastián, Silvia; Escribano, José M

2017-12-01

Trichoplusia ni insect larvae infected with vectors derived from the Autographa californica multiple nucleopolyhedrovirus (AcMNPV), are an excellent alternative to insect cells cultured in conventional bioreactors to produce recombinant proteins because productivity and cost-efficiency reasons. However, there is still a lot of work to do to reduce the manual procedures commonly required in this production platform that limit its scalability. To increase the scalability of this platform technology, a current bottleneck to be circumvented in the future is the need of injection for the inoculation of larvae with polyhedrin negative baculovirus vectors (Polh-) because of the lack of oral infectivity of these viruses, which are commonly used for production in insect cell cultures. In this work we have developed a straightforward alternative to obtain orally infective vectors derived from AcMNPV and expressing recombinant proteins that can be administered to the insect larvae (Trichoplusia ni) by feeding, formulated in the insect diet. The approach developed was based on the use of a recombinant polyhedrin protein expressed by a recombinant vector (Polh+), able to co-occlude any recombinant Polh- baculovirus vector expressing a recombinant protein. A second alternative was developed by the generation of a dual vector co-expressing the recombinant polyhedrin protein and the foreign gene of interest to obtain the occluded viruses. Additionally, by the incorporation of a reporter gene into the helper Polh+ vector, it was possible the follow-up visualization of the co-occluded viruses infection in insect larvae and will help to homogenize infection conditions. By using these methodologies, the production of recombinant proteins in per os infected larvae, without manual infection procedures, was very similar in yield to that obtained by manual injection of recombinant Polh- AcMNPV-based vectors expressing the same proteins. However, further analyses will be required for a

Lateral hypothalamus, nucleus accumbens, and ventral pallidum roles in eating and hunger: interactions between homeostatic and reward circuitry

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Daniel Charles Castro

2015-06-01

Full Text Available The study of the neural bases of eating behavior, hunger, and reward has consistently implicated the lateral hypothalamus (LH and its interactions with mesocorticolimbic circuitry, such as mesolimbic dopamine projections to nucleus accumbens (NAc and ventral pallidum (VP, in controlling motivation to eat. The NAc and VP play special roles in mediating the hedonic impact (‘liking’ and motivational incentive salience (‘wanting’ of food rewards, and their interactions with LH help permit regulatory hunger/satiety modulation of food motivation and reward. Here, we review some progress that has been made regarding this circuitry and its functions: the identification of localized anatomical hedonic hotspots within NAc and VP for enhancing hedonic impact; interactions of NAc/VP hedonic hotspots with specific LH signals such as orexin; an anterior-posterior gradient of sites in NAc shell for producing intense appetitive eating versus intense fearful reactions; and anatomically distributed appetitive functions of dopamine and mu opioid signals in NAc shell and related structures. Such findings help improve our understanding of NAc, VP, and LH interactions in mediating affective and motivation functions, including ‘liking’ and ‘wanting’ for food rewards.

Recombination pattern reanalysis of some HIV-1 circulating recombination forms suggest the necessity and difficulty of revision.

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Lei Jia

Full Text Available Recombination is one of the major mechanisms underlying the generation of HIV-1 variability. Currently 61 circulating recombinant forms of HIV-1 have been identified. With the development of recombination detection techniques and accumulation of HIV-1 reference stains, more accurate mosaic structures of circulating recombinant forms (CRFs, like CRF04 and CRF06, have undergone repeated analysis and upgrades. Such revisions may also be necessary for other CRFs. Unlike previous studies, whose results are based primarily on a single recombination detection program, the current study was based on multiple recombination analysis, which may have produced more impartial results.Representative references of 3 categories of intersubtype recombinants were selected, including BC recombinants (CRF07 and CRF08, BG recombinants (CRF23 and CRF24, and BF recombinants (CRF38 and CRF44. They were reanalyzed in detail using both the jumping profile hidden Markov model and RDP3.The results indicate that revisions and upgrades are very necessary and the entire re-analysis suggested 2 types of revision: (i length of inserted fragments; and (ii number of inserted fragments. The reanalysis also indicated that determination of small regions of about 200 bases or fewer should be performed with more caution.Results indicated that the involvement of multiple recombination detection programs is very necessary. Additionally, results suggested two major challenges, one involving the difficulty of accurately determining the locations of breakpoints and the second involving identification of small regions of about 200 bases or fewer with greater caution. Both indicate the complexity of HIV-1 recombination. The resolution would depend critically on development of a recombination analysis algorithm, accumulation of HIV-1 stains, and a higher sequencing quality. With the changes in recombination pattern, phylogenetic relationships of some CRFs may also change. All these results may

Electron-ion recombination in merged beams

International Nuclear Information System (INIS)

Wolf, A.; Habs, D.; Lampert, A.; Neumann, R.; Schramm, U.; Schuessler, T.; Schwalm, D.

1993-01-01

Detailed studies of recombination processes between electrons and highly charged ions have become possible by recent improvements of merged-beams experiments. We discuss in particular measurements with stored cooled ion beams at the Test Storage Ring (TSR) in Heidelberg. The cross section of dielectronic recombination was measured with high energy resolution for few-electron systems up to the nuclear charge of Cu at a relative energy up to 2.6 keV. At low energy (∼0.1 eV) total recombination rates of several ions were measured and compared with calculated radiative recombination rates. Laser-stimulated recombination of protons and of C 6+ ions was investigated as a function of the photon energy using visible radiation. Both the total recombination rates and the stimulated recombination spectra indicate that in spite of the short interaction time in merged beams, also collisional capture of electrons into weakly bound levels (related to three-body recombination) could be important

Multiple barriers to recombination between divergent HIV-1 variants revealed by a dual-marker recombination assay

DEFF Research Database (Denmark)

Nikolaitchik, Olga A; Galli, Andrea; Moore, Michael D

2011-01-01

Recombination is a major force for generating human immunodeficiency virus type 1 (HIV-1) diversity and produces numerous recombinants circulating in the human population. We previously established a cell-based system using green fluorescent protein gene (gfp) as a reporter to study the mechanisms...... of HIV-1 recombination. We now report an improved system capable of detecting recombination using authentic viral sequences. Frameshift mutations were introduced into the gag gene so that parental viruses do not express full-length Gag; however, recombination can generate a progeny virus that expresses...

Oxygen-hydrogen recombination system

International Nuclear Information System (INIS)

Sato, Shuichiro; Takejima, Masaki.

1981-01-01

Purpose: To avoid reduction in the performance of catalyst used for an oxygen-hydrogen recombiner in the off gas processing system of a nuclear reactor. Constitution: A thermometer is provided for the detection of temperature in an oxygen-hydrogen recombiner. A cooling pipe is provided in the recombiner and cooling medium is introduced externally. The cooling medium may be water or air. In accordance with the detection value from the thermometer, ON-OFF control is carried out for a valve to control the flow rate of the cooling medium thereby rendering the temperature in the recombiner to a predetermined value. This can prevent the catalyst from being exposed to high temperature and avoid the reduction in the performance of the catalyst. (Ikeda, J.)

[Autopsy case of Lissauer's general paresis with rapidly progressive left hemiparesis].

Science.gov (United States)

Kato, Hiroko; Yoshida, Mari; Ando, Tetsuo; Sugiura, Makoto; Hashizume, Yoshio

2009-06-01

A 48-years-old man presented with slowly progressive bradykinesia, personality change and rapidly progressive left hemiparesis. On admission, he presented dementia, poor judgment, left hemiparesis. MRI revealed a widespread high intensity area in right hemisphere and MRA was almost normal. Serological tests of serum and CSF demonstrated high titers of antibodies to Treponema pallidum. He was treated for syphilis with daily penicillin injections without improvement. He died of sepsis eight months after admission. At autopsy, the brain weighed 1,100 g and the right cerebral hemisphere was atrophic, especially in frontal base, temporal, parietal, angular, and posterior regions covered by thickened, fibrotic leptomeninges. Microscopically, chronic meningoencephalitis was observed. Severe neuronal loss with gliosis was seen in the right cerebral cortices. Scattered rod-shaped microglia and inflammatory cell infiltration were visible in the cerebral parenchyma. The dorsal column of the spinal cord was not involved and meningovascular syphilis was unclear. The distribution of the encephalitic lesions was well correlated with the clinical and neuroradiological findings. This was a rare autopsy case presenting Lissauer's general paresis, clinically manifesting as rapidly progressive stroke-like episode.

Dizziness and progressively poor memory for one year, combined with epilepsy, mental and behavior disorder for 19 days

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Kun JIANG

2015-04-01

Full Text Available It is well known that neurosyphilis has various brain MRI manifestations. In this report, we present a rare case with DWI lace-like high signal in cerebral cortex, which is usually seen in Creutzfeldt-Jakob disease (CJD. A 50-year-old male developed dizziness, poor memory, seizures, mental and behavioral disorders, and was admitted to our Emergency Department, where he experienced sudden left hemiplegia. Rapid plasma regain (RPR and treponema pallidum particle agglutination assay (TPPA was positive in blood and cerebrospinal fluid (CSF. CSF: 14-3-3 protein (+. Brain MRI showed high FLAIR signals in the right frontal lobe, temporal lobe, insular lobe, occipital lobe and thalamus before the treatment. As for this patient, it was difficult to differentiate CJD from neurosyphilis at first. He was given penicillin treatment and responded well. Those lesions in brain MRI decreased after treatment. This case was reported to raise the awareness of early treatment of neruosyphilis and showed a special DWI lace-like image of this disease. DOI: 10.3969/j.issn.1672-6731.2015.04.016

Association of human papillomavirus and Chlamydia trachomatis with intraepithelial alterations in cervix samples

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Denise Wohlmeister

2016-02-01

Full Text Available The influence of different infectious agents and their association with human papillomavirus (HPV in cervical carcinogenesis have not been completely elucidated. This study describes the association between cytological changes in cervical epithelium and the detection of the most relevant aetiological agents of sexually transmitted diseases. Samples collected from 169 patients were evaluated by conventional cytology followed by molecular analysis to detect HPV DNA, Chlamydia trachomatis, herpes simplex virus 1 and 2,Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, andTreponema pallidum, besides genotyping for most common high-risk HPV. An association between cytological lesions and different behavioural habits such as smoking and sedentariness was observed. Intraepithelial lesions were also associated with HPV and C. trachomatis detection. An association was also found between both simple and multiple genotype infection and cytological changes. The investigation of HPV and C. trachomatisproved its importance and may be considered in the future for including in screening programs, since these factors are linked to the early diagnosis of patients with precursor lesions of cervical cancer.

Evaluation of the rapid plasma reagin "teardrop" card test for screening of syphilis in field conditions.

Science.gov (United States)

Van Dyck, E; Van de Velden, L; Ndoye, I; Piot, P; Meheus, A

1993-01-01

The availability of simple diagnostic methods may contribute to more efficient control of sexually transmitted diseases (STDs) in developing countries. For the detection of syphilis, a simple rapid plasma reagin (RPR) "teardrop" assay for finger-prick blood samples was developed in 1962. The reliability of this test is compared with RPR, Treponema pallidum hemagglutination assay (TPHA), and fluorescent treponemal antibody absorption (FTA-Abs) assays performed on venous blood samples. To evaluate the potential usefulness of the finger-stick RPR teardrop assay for diagnosis of syphilis in settings with poor medical resources. Pregnant women evaluated at two health centers in Pikine, Senegal were tested for STDs. The RPR teardrop assay was performed on plasma from blood samples obtained by finger prick, and standard RPR, TPHA, and FTA-Abs procedures were performed on serum obtained by vein puncture. The sensitivity and specificity of the finger-prick RPR teardrop assay were 69.7% and 96.5%, respectively, and its reactivity was correlated with RPR serum antibody titer. The finger-prick RPR teardrop assay is not a reliable alternative to the classic serum RPR test.

The management of isolated positive syphilis enzyme immunoassay results in HIV-negative patients attending a sexual health clinic.

Science.gov (United States)

Thorley, Nicola; Adebayo, Michael; Smit, Erasmus; Radcliffe, Keith

2016-08-01

An unconfirmed positive treponemal enzyme immunoassay (enzyme immunoassay positive, Treponema pallidum particle agglutination negative and rapid plasma reagin negative) presents a clinical challenge to distinguish early syphilis infection from false-positive results. These cases are referred for syphilis line assay (INNO-LIA) and recalled for repeat syphilis serology. We performed a retrospective audit to establish the proportion of HIV-negative cases with unconfirmed positive enzyme immunoassay results, the proportion of these cases that received an INNO-LIA test and repeat syphilis serology testing and reviewed the clinical outcomes; 0.35% (80/22687) cases had an unconfirmed positive treponemal enzyme immunoassay result. Repeat syphilis serology was performed in 80% (64/80) cases, but no additional cases of syphilis were identified. Eighty-eight per cent (70/80) received an INNO-LIA test; 14% (5/37) unconfirmed enzyme immunoassay-positive cases with no prior history of syphilis were confirmed on INNO-LIA assay, supporting a diagnosis of latent syphilis. As a confirmatory treponemal test, the INNO-LIA assay may be more useful than repeat syphilis serological testing. © The Author(s) 2016.

Oral and dental infections with anaerobic bacteria: clinical features, predominant pathogens, and treatment.

Science.gov (United States)

Tanner, A; Stillman, N

1993-06-01

Microbial populations colonizing the teeth are a major source of pathogens responsible for oral and dental infections, including periodontal diseases, gingivitis, pericoronitis, endodontitis, peri-implantitis, and postextraction infections. Each entity has distinct clinical and microbial features. Bacterial species associated with oral infections include Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Campylobacter rectus, Eubacterium species, Fusobacterium nucleatum, Eikenella corrodens, and Peptostreptococcus micros. Treponema pallidum-related spirochetes have been associated with acute necrotizing ulcerative gingivitis. Porphyromonas endodontalis appears to be specifically related to endodontic infections. Oral infections in medically compromised patients, including those with AIDS, are associated with similar species and are usually complicated by superinfection with enteric and Candida species. Isolation of species causing oral infections requires the collection of appropriate samples and the use of strictly anaerobic techniques. Rapid selective culture, immunofluorescence, and DNA probe methods have been developed for the identification of these oral species. The varied measures required in the management of oral and dental infections may include antimicrobial therapy. Accurate microbiological diagnosis, including antibiotic susceptibility testing, is indicated for cases that do not respond to therapy.

[Serological diagnosis of congenital infections and algorithms to improve diagnostic efficacy].

Science.gov (United States)

García-Bermejo, Isabel; de Ory-Manchón, Fernando

2015-07-01

Congenital infection is those transmitted by the mother to the fetus before delivery. It can occur transplacentally or by direct contact with the pathogen during birth or in the immediate postnatal period. Congenital infection can be due to viruses (rubella, cytomegalovirus, herpes simplex, varicella-zoster, hepatitis B and C virus, human inunodeficiencia, erythrovirus B19) as bacteria (Treponema pallidum) and parasites (Toxoplasma gondii and Trypanosoma cruzi). Serological diagnosis of congenital infection is based on both the knowledge of infectious serology in the mother, including the systematic serological screening and diagnostic aspects of the determination of IgM and confirmatory methods, IgG avidity tests, establishment of antibody profiles, and in the diagnosis the neonate. Serological diagnosis of congenital infection in the newborn is mainly based on the detection of specific IgM usually by immunoenzymatic assays or immunochemiluminescence techniques. In some instances it is important to perform the serological follow up of the newborn to confirm the congenital infection. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

The tradition algorithm approach underestimates the prevalence of serodiagnosis of syphilis in HIV-infected individuals.

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Bin Chen

2017-07-01

Full Text Available Currently, there are three algorithms for screening of syphilis: traditional algorithm, reverse algorithm and European Centre for Disease Prevention and Control (ECDC algorithm. To date, there is not a generally recognized diagnostic algorithm. When syphilis meets HIV, the situation is even more complex. To evaluate their screening performance and impact on the seroprevalence of syphilis in HIV-infected individuals, we conducted a cross-sectional study included 865 serum samples from HIV-infected patients in a tertiary hospital. Every sample (one per patient was tested with toluidine red unheated serum test (TRUST, T. pallidum particle agglutination assay (TPPA, and Treponema pallidum enzyme immunoassay (TP-EIA according to the manufacturer's instructions. The results of syphilis serological testing were interpreted following different algorithms respectively. We directly compared the traditional syphilis screening algorithm with the reverse syphilis screening algorithm in this unique population. The reverse algorithm achieved remarkable higher seroprevalence of syphilis than the traditional algorithm (24.9% vs. 14.2%, p < 0.0001. Compared to the reverse algorithm, the traditional algorithm also had a missed serodiagnosis rate of 42.8%. The total percentages of agreement and corresponding kappa values of tradition and ECDC algorithm compared with those of reverse algorithm were as follows: 89.4%,0.668; 99.8%, 0.994. There was a very good strength of agreement between the reverse and the ECDC algorithm. Our results supported the reverse (or ECDC algorithm in screening of syphilis in HIV-infected populations. In addition, our study demonstrated that screening of HIV-populations using different algorithms may result in a statistically different seroprevalence of syphilis.

The big imitator strikes again: a case report of neurosyphilis in a patient with newly diagnosed HIV.

Science.gov (United States)

de Bruijn, Sévérine; Kenyon, Chris; Léonard, Nicolas; Vlieghe, Erika

2017-10-01

Neurosyphilis is the result of an infection of the central nervous system caused by the spirochete Treponema pallidum. Its clinical presentation includes meningovascular syphilis, tabes dorsalis, and dementia paralytica, resulting in a wide range of symptoms such as psychosis, Parkinsonism, and depression. A 49-year-old male was admitted to a psychiatric hospital because of social withdrawal and self-neglect, indicative of a major depression. A routine HIV-test was positive and resulted in an admission to the Antwerp University Hospital. Clinical examination showed Argyll Robertson pupils, a wide-based gait, absence of vibration sense in the lower limbs, and a MMSE-score of 25/30. Blood analysis revealed a CD4+ count of 99 cells/μL and a HIV viral load of 2,13 × 10 5 copies/mL plasma. A serum TPHA (T. pallidum hemagglutination assay) titre of 1/20480 and RPR (rapid plasma reagin) titre of 1/128 were detected. TPHA and RPR titre in the cerebrospinal fluid were, respectively, 1/10240 and 1/4. A brain MRI showed diffuse cortical atrophy and lesions in the white matter compatible with HIV-encephalopathy. The diagnoses of advanced HIV-infection and late neurosyphilis were made. HAART (highly active antiretroviral therapy) and high-dose IV penicillin G were started. In all patients with new-onset dementia or untreatable psychosis, neurosyphilis should always be considered. Argyll Robertson pupils are regarded as pathognomonic of neurosyphilis. The management of neurosyphilis includes high-dose IV benzyl penicillin for 10 to 14 days. Close follow-up including a lumbar puncture after 6 months is warranted to ensure treatment recovery.

Hydrogen recombiner development at AECL

International Nuclear Information System (INIS)

Dewit, W.A.; Koroll, G.W.; Loesel Sitar, J.; Graham, W.R.C.

1997-01-01

Catalytic recombiners have been developed at AECL for the purpose of hydrogen removal in post-accident nuclear containment buildings. The recombiners are based on a particular catalyst designed by AECL which has extraordinary resistance to fouling from water and water vapour and a large thermodynamic range of operation. The catalysts were developed, originally, for the purpose of heavy water manufacturing by way of a catalytic exchange process. Application of these catalyst materials in recombiners for containment applications began in the late 1980's. The first application was a passive recombiner, qualified for use in control of radiolytic hydrogen in the headspace of a pool-type experimental reactor of AECL design in 1988. The passive, or natural convection recombiner concept has continued development to commercial stage for application in power reactor containments. This paper reviews the AECL recombiner development, describes the current model and shows results from tests of full-scale recombiners in the Large Scale Vented Combustion Test Facility at AECL-WL. The AECL recombiner is designed for compactness and ease of engineering into containment. The design is a simple, open-ended rectangular enclosure with catalyst elements arranged inside to promote optimum convective flow driven by heat of recombination at the catalyst surface. Self start, as evidenced by catalyst heating and initiation of flow, is achieved in less than 1% hydrogen, with available oxygen, at room temperature and 100% relative humidity. This low temperature start-up in condensing atmospheres is viewed as the most challenging condition for wet-proofing effectiveness. Cold start-up is a vital performance requirement in containments, such as CANDU, where engineered air-cooling systems are operating and where long-term hydrogen control is required, after containment atmospheres have cooled. Once started, the removal capacity scales linearly with the inlet cross-section area and the partial

On the relict recombination lines

International Nuclear Information System (INIS)

Bershtejn, I.N.; Bernshtejn, D.N.; Dubrovich, V.K.

1977-01-01

Accurate numerical calculation of intensities and profiles of hydrogen recombination lines of cosmological origin is made. Relie radiation distortions stipulated by recombination quantum release at the irrevocable recombination are investigated. Mean number calculation is given for guantums educing for one irrevocably-lost electron. The account is taken of the educed quantums interraction with matter. The main quantum-matter interrraction mechanisms are considered: electronic blow broadening; free-free, free-bound, bound-bound absorptions Recombination dynamics is investigated depending on hydrogen density and total density of all the matter kinds in the Universe

Late replicating domains are highly recombining in females but have low male recombination rates: implications for isochore evolution.

Directory of Open Access Journals (Sweden)

Catherine J Pink

Full Text Available In mammals sequences that are either late replicating or highly recombining have high rates of evolution at putatively neutral sites. As early replicating domains and highly recombining domains both tend to be GC rich we a priori expect these two variables to covary. If so, the relative contribution of either of these variables to the local neutral substitution rate might have been wrongly estimated owing to covariance with the other. Against our expectations, we find that sex-averaged recombination rates show little or no correlation with replication timing, suggesting that they are independent determinants of substitution rates. However, this result masks significant sex-specific complexity: late replicating domains tend to have high recombination rates in females but low recombination rates in males. That these trends are antagonistic explains why sex-averaged recombination is not correlated with replication timing. This unexpected result has several important implications. First, although both male and female recombination rates covary significantly with intronic substitution rates, the magnitude of this correlation is moderately underestimated for male recombination and slightly overestimated for female recombination, owing to covariance with replicating timing. Second, the result could explain why male recombination is strongly correlated with GC content but female recombination is not. If to explain the correlation between GC content and replication timing we suppose that late replication forces reduced GC content, then GC promotion by biased gene conversion during female recombination is partly countered by the antagonistic effect of later replicating sequence tending increase AT content. Indeed, the strength of the correlation between female recombination rate and local GC content is more than doubled by control for replication timing. Our results underpin the need to consider sex-specific recombination rates and potential covariates in

Prevalencia y factores de riesgo asociados a sífilis en mujeres

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Carlos A. Hernández-Girón

1998-12-01

Full Text Available INTRODUCCIÓN: Se ha demostrado que la sífilis, debido a la ulceración genital que produce, es un cofactor asociado para adquirir otras enfermedades de transmisión sexual (ETS, principalmente de origen viral como herpes tipo-2, hepatitis B, y el VIH. Aunque las mujeres trabajadoras del sexo comercial (MTSC han adquirido mejores conocimientos para prevenir las ETS, constituyen un grupo que por su heterogenicidad en términos de condición socioeconómica, estado de salud, ambiente y sitio de trabajo, manifiestan diferentes actitudes y conocimientos que hacen latente la posibilidad de adquirir y transmitir ETS incluyendo sífilis, por lo que lo estudio hace un acercamiento hacia los factores asociados a infección por Treponema pallidum en este grupo de mujeres. MÉTODO: Basado en un marco muestral, que identifica sitios donde se practica el comercio sexual femenino en la ciudad de México, se seleccionó una muestra de 807 MTSC, a quienes previo consentimiento informado, se entrevistó para que respondieran un cuestionario estructurado. Se obtuvo una muestra sanguínea para la identificación de diversos marcadores serológicos de ETS de acuerdo al manual de procedimientos para el diagnóstico de ETS. Para el diagnóstico de Treponema pallidum se utilizó una prueba de tamizaje de RPR (Bigaux Diagnóstica, y prueba confirmatoria de FTA-ABS (Pasteur Diagnostics. RESULTADOS: Las prevalencias de sífilis en la muestra de MTSC fue de 6,4% (52/807, siendo mayor en quienes trabajaban en sitios de calle comparadas con aquellas de estéticas. La edad de las mujeres entrevistadas osciló entre 17 y 58 años con una media de 29,2 años (d.s. 7,3 años. La prevalencia de sífilis fue mayor en los grupos etáreos mayores de 30 anos. La edad de inicio de relaciones sexuales varió desde 11 hasta 30 anos con una media de 16 años (d.s. 3,1 años. Los factores predictores de infección por T. pallidum, determinados mediante regresión logística ajustada

Prevalencia y factores de riesgo asociados a sífilis en mujeres

Directory of Open Access Journals (Sweden)

Hernández-Girón Carlos A.

1998-01-01

Full Text Available INTRODUCCIÓN: Se ha demostrado que la sífilis, debido a la ulceración genital que produce, es un cofactor asociado para adquirir otras enfermedades de transmisión sexual (ETS, principalmente de origen viral como herpes tipo-2, hepatitis B, y el VIH. Aunque las mujeres trabajadoras del sexo comercial (MTSC han adquirido mejores conocimientos para prevenir las ETS, constituyen un grupo que por su heterogenicidad en términos de condición socioeconómica, estado de salud, ambiente y sitio de trabajo, manifiestan diferentes actitudes y conocimientos que hacen latente la posibilidad de adquirir y transmitir ETS incluyendo sífilis, por lo que lo estudio hace un acercamiento hacia los factores asociados a infección por Treponema pallidum en este grupo de mujeres. MÉTODO: Basado en un marco muestral, que identifica sitios donde se practica el comercio sexual femenino en la ciudad de México, se seleccionó una muestra de 807 MTSC, a quienes previo consentimiento informado, se entrevistó para que respondieran un cuestionario estructurado. Se obtuvo una muestra sanguínea para la identificación de diversos marcadores serológicos de ETS de acuerdo al manual de procedimientos para el diagnóstico de ETS. Para el diagnóstico de Treponema pallidum se utilizó una prueba de tamizaje de RPR (Bigaux Diagnóstica, y prueba confirmatoria de FTA-ABS (Pasteur Diagnostics. RESULTADOS: Las prevalencias de sífilis en la muestra de MTSC fue de 6,4% (52/807, siendo mayor en quienes trabajaban en sitios de calle comparadas con aquellas de estéticas. La edad de las mujeres entrevistadas osciló entre 17 y 58 años con una media de 29,2 años (d.s. 7,3 años. La prevalencia de sífilis fue mayor en los grupos etáreos mayores de 30 anos. La edad de inicio de relaciones sexuales varió desde 11 hasta 30 anos con una media de 16 años (d.s. 3,1 años. Los factores predictores de infección por T. pallidum, determinados mediante regresión logística ajustada

Auger recombination in sodium iodide

Science.gov (United States)

McAllister, Andrew; Kioupakis, Emmanouil; Åberg, Daniel; Schleife, André

2014-03-01

Scintillators are an important tool used to detect high energy radiation - both in the interest of national security and in medicine. However, scintillator detectors currently suffer from lower energy resolutions than expected from basic counting statistics. This has been attributed to non-proportional light yield compared to incoming radiation, but the specific mechanism for this non-proportionality has not been identified. Auger recombination is a non-radiative process that could be contributing to the non-proportionality of scintillating materials. Auger recombination comes in two types - direct and phonon-assisted. We have used first-principles calculations to study Auger recombination in sodium iodide, a well characterized scintillating material. Our findings indicate that phonon-assisted Auger recombination is stronger in sodium iodide than direct Auger recombination. Computational resources provided by LLNL and NERSC. Funding provided by NA-22.

Regulation of homologous recombination in eukaryotes

OpenAIRE

Heyer, Wolf-Dietrich; Ehmsen, Kirk T.; Liu, Jie

2010-01-01

Homologous recombination is required for accurate chromosome segregation during the first meiotic division and constitutes a key repair and tolerance pathway for complex DNA damage including DNA double-stranded breaks, interstrand crosslinks, and DNA gaps. In addition, recombination and replication are inextricably linked, as recombination recovers stalled and broken replication forks enabling the evolution of larger genomes/replicons. Defects in recombination lead to genomic instability and ...

Variability of Actinobacteria, a minor component of rumen microflora.

Science.gov (United States)

Suľák, M; Sikorová, L; Jankuvová, J; Javorský, P; Pristaš, P

2012-07-01

Actinobacteria (Actinomycetes) are a significant and interesting group of gram-positive bacteria. They are regular, though infrequent, members of the microbial life in the rumen and represent up to 3 % of total rumen bacteria; there is considerable lack of information about ecology and biology of rumen actinobacteria. During the characterization of variability of rumen treponemas using non-cultivation approach, we also noted the variability of rumen actinobacteria. By using Treponema-specific primers a specific 16S rRNA gene library was prepared from cow and sheep rumen total DNA. About 10 % of recombinant clones contained actinobacteria-like sequences. Phylogenetic analyses of 11 clones obtained showed the high variability of actinobacteria in the ruminant digestive system. While some sequences are nearly identical to known sequences of actinobacteria, we detected completely new clusters of actinobacteria-like sequences, representing probably new, as yet undiscovered, group of rumen Actinobacteria. Further research will be necessary for understanding their nature and functions in the rumen.

Recombination coefficients in extrinsic n-InSb

International Nuclear Information System (INIS)

Schneider, W.; Groh, H.; Huebner, K.

1976-01-01

The bulk recombination coefficients for linear recombination via recombination centers as well as for direct recombination have been determined measuring the conductivity decay after two-photon absorption with a CO 2 laser. The Suhl effect was applied to measure the surface recombination velocity. The corresponding literature is discussed and compared with our results. We conclude that two different kinds of recombination centers are possible in n-InSb, with energy levels (0.1-0.12)eV above the valence band, or (0.14-0.2)eV respectively. (orig.) [de

Electron-ion recombination rates for merged-beams experiments

International Nuclear Information System (INIS)

Pajek, M.

1994-01-01

Energy dependence of the electron-ion recombination rates are studied for different recombination processes (radiative recombination, three-body recombination, dissociative recombination) for Maxwellian relative velocity distribution of arbitrary asymmetry. The results are discussed in context of the electron-ion merged beams experiments in cooling ion storage rings. The question of indication of a possible contribution of the three-body recombination to the measured recombination rates versus relative energy is particularly addressed. Its influence on the electron beam temperature derived from the energy dependence of recombination rate is discussed

Electron-ion recombination at low energy

International Nuclear Information System (INIS)

Andersen, L.H.

1993-01-01

The work is based on results obtained with a merged-beams experiment. A beam of electronics with a well characterized density and energy distribution was merged with a fast, monoenergetic ion beam. Results have been obtained for radiative recombination and dielectronic recombination at low relative energies (0 to ∼70eV). The obtained energy resolution was improved by about a factor of 30. High vacuum technology was used to suppress interactions with electrons from the environments. The velocity distribution of the electron beam was determined. State-selective dielectronic-recombination measurements were performable. Recombination processes were studied. The theoretical background for radiative recombination and Kramers' theory are reviewed. The quantum mechanical result and its relation to the semiclassical theory is discussed. Radiative recombination was also measured with several different non-bare ions, and the applicability of the semiclassical theory to non-bare ions was investigated. The use of an effective charge is discussed. For dielectronic recombination, the standard theoretical approach in the isolated resonance and independent-processes approximation is debated. The applicability of this method was tested. The theory was able to reproduce most of the experimental data except when the recombination process was sensitive to couplings between different electronic configurations. The influence of external perturbing electrostatic fields is discussed. (AB) (31 refs.)

Recombinant Innovation and Endogenous Transitions

OpenAIRE

Koen Frenken; Luis R. Izquierdo; Paolo Zeppini

2012-01-01

We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create “short-cuts” which reduce switching costs allowing agents to escape a technological lock-in. As a result, recombinant innovations speed up technological progress allowing transitions that are impossible with only branching ...

Interface recombination influence on carrier transport

International Nuclear Information System (INIS)

Konin, A

2013-01-01

A theory of interface recombination in the semiconductor–semiconductor junction is developed. The interface recombination rate dependence on the nonequilibrium carrier densities is derived on the basis of a model in which the interface recombination occurs through the mechanism of trapping. The general relation between the interface recombination parameters at small carrier density deviation from the equilibrium ones is obtained. The validity of this relation is proved considering the generation of the Hall electric field in the extrinsic semiconductor sample. The anomalous Hall electromotive force in a weak magnetic field was investigated and interpreted by means of a new interface recombination model. The experimental data corroborate the developed theory. (paper)

Caenorhabditis briggsae recombinant inbred line genotypes reveal inter-strain incompatibility and the evolution of recombination.

Directory of Open Access Journals (Sweden)

Joseph A Ross

2011-07-01

Full Text Available The nematode Caenorhabditis briggsae is an emerging model organism that allows evolutionary comparisons with C. elegans and exploration of its own unique biological attributes. To produce a high-resolution C. briggsae recombination map, recombinant inbred lines were generated from reciprocal crosses between two strains and genotyped at over 1,000 loci. A second set of recombinant inbred lines involving a third strain was also genotyped at lower resolution. The resulting recombination maps exhibit discrete domains of high and low recombination, as in C. elegans, indicating these are a general feature of Caenorhabditis species. The proportion of a chromosome's physical size occupied by the central, low-recombination domain is highly correlated between species. However, the C. briggsae intra-species comparison reveals striking variation in the distribution of recombination between domains. Hybrid lines made with the more divergent pair of strains also exhibit pervasive marker transmission ratio distortion, evidence of selection acting on hybrid genotypes. The strongest effect, on chromosome III, is explained by a developmental delay phenotype exhibited by some hybrid F2 animals. In addition, on chromosomes IV and V, cross direction-specific biases towards one parental genotype suggest the existence of cytonuclear epistatic interactions. These interactions are discussed in relation to surprising mitochondrial genome polymorphism in C. briggsae, evidence that the two strains diverged in allopatry, the potential for local adaptation, and the evolution of Dobzhansky-Muller incompatibilities. The genetic and genomic resources resulting from this work will support future efforts to understand inter-strain divergence as well as facilitate studies of gene function, natural variation, and the evolution of recombination in Caenorhabditis nematodes.

Molecular requirements for radiation-activated recombination

International Nuclear Information System (INIS)

Stevens, Craig W.; Zeng Ming; Stamato, Thomas; Cerniglia, George

1997-01-01

Purpose/Objective: The major stumbling block to successful gene therapy today is poor gene transfer. We hypothesized that ionizing radiation might activate cellular recombination, and so improve stable gene transfer. We further hypothesized that known DNA-damage-repair proteins might also be important in radiation-activated recombination. Materials and Methods: The effect of irradiation on stable gene transfer efficiency was determined in human (A549 and 39F) and rodent (NIH/3T3) cell lines. Continuous low dose rate and multiple radiation fractions were also tested. Nuclear extracts were made and the effect of irradiation on inter-plasmid recombination/ligation determined. Multiple DNA damage-repair deficient cell lines were tested for radiation-activated recombination. Results: A significant radiation dose-dependent improvement in stable plasmid transfection (by as much as 1300 fold) is demonstrated in neoplastic and primary cells. An improvement in transient plasmid transfection is also seen, with as much as 85% of cells transiently expressing b-galactosidase (20-50 fold improvement). Stable transfection is only improved for linearized or nicked plasmids. Cells have improved gene transfer for at least 96 hours after irradiation. Both fractionated and continuous low dose rate irradiation are effective at improving stable gene transfer in mammalian cells, thus making relatively high radiation dose delivery clinically feasible. Inter-plasmid recombination is radiation dose dependent in nuclear extract assays, and the type of overhang (3', 5' or blunt end) significantly affects recombination efficiency and the type of product. The most common end-joining activity involves filling-in of the overhang followed by blunt end ligation. Adenovirus is a linear, double stranded DNA virus. We demonstrate that adenoviral infection efficiency is increased by irradiation. The duration of transgene expression is lengthened because the virus integrates with high efficiency (∼10

Recombinant pinoresinol/lariciresinol reductase, recombinant dirigent protein, and methods of use

Science.gov (United States)

Lewis, Norman G.; Davin, Laurence B.; Dinkova-Kostova, Albena T.; Fujita, Masayuki; Gang, David R.; Sarkanen, Simo; Ford, Joshua D.

2001-04-03

Dirigent proteins and pinoresinol/lariciresinol reductases have been isolated, together with cDNAs encoding dirigent proteins and pinoresinol/lariciresinol reductases. Accordingly, isolated DNA sequences are provided which code for the expression of dirigent proteins and pinoresinol/lariciresinol reductases. In other aspects, replicable recombinant cloning vehicles are provided which code for dirigent proteins or pinoresinol/lariciresinol reductases or for a base sequence sufficiently complementary to at least a portion of dirigent protein or pinoresinol/lariciresinol reductase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding dirigent protein or pinoresinol/lariciresinol reductase. Thus, systems and methods are provided for the recombinant expression of dirigent proteins and/or pinoresinol/lariciresinol reductases.

Population inversion in recombining hydrogen plasma

International Nuclear Information System (INIS)

Furukane, Utaro; Yokota, Toshiaki; Oda, Toshiatsu.

1978-11-01

The collisional-radiative model is applied to a recombining hydrogen plasma in order to investigate the plasma condition in which the population inversion between the energy levels of hydrogen can be generated. The population inversion is expected in a plasma where the three body recombination has a large contribution to the recombining processes and the effective recombination rate is beyond a certain value for a given electron density and temperature. Calculated results are presented in figures and tables. (author)

Consequences of recombination on traditional phylogenetic analysis

DEFF Research Database (Denmark)

Schierup, M H; Hein, J

2000-01-01

We investigate the shape of a phylogenetic tree reconstructed from sequences evolving under the coalescent with recombination. The motivation is that evolutionary inferences are often made from phylogenetic trees reconstructed from population data even though recombination may well occur (mt......DNA or viral sequences) or does occur (nuclear sequences). We investigate the size and direction of biases when a single tree is reconstructed ignoring recombination. Standard software (PHYLIP) was used to construct the best phylogenetic tree from sequences simulated under the coalescent with recombination....... With recombination present, the length of terminal branches and the total branch length are larger, and the time to the most recent common ancestor smaller, than for a tree reconstructed from sequences evolving with no recombination. The effects are pronounced even for small levels of recombination that may...

Density dependence of dielectronic recombination in selenium

International Nuclear Information System (INIS)

Hagelstein, P.L.; Rosen, M.D.; Jacobs, V.L.

1986-01-01

Dielectronic recombination has been found to be the dominant recombination process in the determination of the ionization balance of selenium near the Ne-like sequence under conditions relevant to the exploding-foil EUV laser plasmas. The dielectronic recombination process tends to populate excited levels, and these levels in turn are more susceptible to subsequent excitation and ionization than are the ground-state ions. If one defines an effective recombination rate which includes, in addition to the primary recombination, the subsequent excitation and ionization of the additional excited-state population due to the primary recombination, then this effective recombination rate can be density-sensitive at relatively low electron density. We present results for this effective dielectronic recombination rate at an electron density of 3 x 10/sup 20/ electrons/cm 3 for recombination from Ne-like to Na-like selenium and from F-like to Ne-like selenium. In the former case, the effective recombination rate coefficient is found to be 1.8 x 10/sup -11/ cm 3 /sec at 1.0 keV, which is to be compared with the zero-density value of 2.8 x 10/sup -11/ cm 3 /sec. In the latter case (F-like to Ne-like), the effective recombination rate coefficient is found to be 1.3 x 10/sup -11/ cm 3 /sec, which is substantially reduced from the zero-density result of 3.3 x 10/sup -11/ cm 3 /sec. We have examined the effects of dielectronic recombination on the laser gain of the dominant Ne-like 3p-3s transitions and have compared our results with those presented by Whitten et al. [Phys. Rev. A 33, 2171 (1986)

SequenceLDhot: detecting recombination hotspots.

Science.gov (United States)

Fearnhead, Paul

2006-12-15

There is much local variation in recombination rates across the human genome--with the majority of recombination occurring in recombination hotspots--short regions of around approximately 2 kb in length that have much higher recombination rates than neighbouring regions. Knowledge of this local variation is important, e.g. in the design and analysis of association studies for disease genes. Population genetic data, such as that generated by the HapMap project, can be used to infer the location of these hotspots. We present a new, efficient and powerful method for detecting recombination hotspots from population data. We compare our method with four current methods for detecting hotspots. It is orders of magnitude quicker, and has greater power, than two related approaches. It appears to be more powerful than HotspotFisher, though less accurate at inferring the precise positions of the hotspot. It was also more powerful than LDhot in some situations: particularly for weaker hotspots (10-40 times the background rate) when SNP density is lower (maths.lancs.ac.uk/~fearnhea/Hotspot.

Experimental evolution across different thermal regimes yields genetic divergence in recombination fraction but no divergence in temperature associated plastic recombination.

Science.gov (United States)

Kohl, Kathryn P; Singh, Nadia D

2018-04-01

Phenotypic plasticity is pervasive in nature. One mechanism underlying the evolution and maintenance of such plasticity is environmental heterogeneity. Indeed, theory indicates that both spatial and temporal variation in the environment should favor the evolution of phenotypic plasticity under a variety of conditions. Cyclical environmental conditions have also been shown to yield evolved increases in recombination frequency. Here, we use a panel of replicated experimental evolution populations of D. melanogaster to test whether variable environments favor enhanced plasticity in recombination rate and/or increased recombination rate in response to temperature. In contrast to expectation, we find no evidence for either enhanced plasticity in recombination or increased rates of recombination in the variable environment lines. Our data confirm a role of temperature in mediating recombination fraction in D. melanogaster, and indicate that recombination is genetically and plastically depressed under lower temperatures. Our data further suggest that the genetic architectures underlying plastic recombination and population-level variation in recombination rate are likely to be distinct. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

The extent and importance of intragenic recombination

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de Silva Eric

2004-11-01

Full Text Available Abstract We have studied the recombination rate behaviour of a set of 140 genes which were investigated for their potential importance in inflammatory disease. Each gene was extensively sequenced in 24 individuals of African descent and 23 individuals of European descent, and the recombination process was studied separately in the two population samples. The results obtained from the two populations were highly correlated, suggesting that demographic bias does not affect our population genetic estimation procedure. We found evidence that levels of recombination correlate with levels of nucleotide diversity. High marker density allowed us to study recombination rate variation on a very fine spatial scale. We found that about 40 per cent of genes showed evidence of uniform recombination, while approximately 12 per cent of genes carried distinct signatures of recombination hotspots. On studying the locations of these hotspots, we found that they are not always confined to introns but can also stretch across exons. An investigation of the protein products of these genes suggested that recombination hotspots can sometimes separate exons belonging to different protein domains; however, this occurs much less frequently than might be expected based on evolutionary studies into the origins of recombination. This suggests that evolutionary analysis of the recombination process is greatly aided by considering nucleotide sequences and protein products jointly.

Recombination epoch revisited

International Nuclear Information System (INIS)

Krolik, J.H.

1989-01-01

Previous studies of cosmological recombination have shown that this process produces as a by-product a highly superthermal population of Ly-alpha photons which retard completion of recombination. Cosmological redshifting was thought to determine the frequency distribution of the photons, while two-photon decay of hydrogen's 2s state was thought to control their numbers. It is shown here that frequency diffusion due to photon scattering dominate the cosmological redshift in the frequency range near line center which fixes the ratio of ground state to excited state population, while incoherent scattering into the far-red damping wing effectively destroys Ly-alpha photons as a rate which is competitive with two-photon decay. The former effect tends to hold back recombination, while the latter tends to accelerate it; the net results depends on cosmological parameters, particularly the combination Omega(b) h/sq rt (2q0), where Omega(b) is the fraction of the critical density provided by baryons. 18 references

Recombination of Globally Circulating Varicella-Zoster Virus

Science.gov (United States)

Depledge, Daniel P.; Kundu, Samit; Atkinson, Claire; Brown, Julianne; Haque, Tanzina; Hussaini, Yusuf; MacMahon, Eithne; Molyneaux, Pamela; Papaevangelou, Vassiliki; Sengupta, Nitu; Koay, Evelyn S. C.; Tang, Julian W.; Underhill, Gillian S.; Grahn, Anna; Studahl, Marie; Breuer, Judith; Bergström, Tomas

2015-01-01

ABSTRACT Varicella-zoster virus (VZV) is a human herpesvirus, which during primary infection typically causes varicella (chicken pox) and establishes lifelong latency in sensory and autonomic ganglia. Later in life, the virus may reactivate to cause herpes zoster (HZ; also known as shingles). To prevent these diseases, a live-attenuated heterogeneous vaccine preparation, vOka, is used routinely in many countries worldwide. Recent studies of another alphaherpesvirus, infectious laryngotracheitis virus, demonstrate that live-attenuated vaccine strains can recombine in vivo, creating virulent progeny. These findings raised concerns about using attenuated herpesvirus vaccines under conditions that favor recombination. To investigate whether VZV may undergo recombination, which is a prerequisite for VZV vaccination to create such conditions, we here analyzed 115 complete VZV genomes. Our results demonstrate that recombination occurs frequently for VZV. It thus seems that VZV is fully capable of recombination if given the opportunity, which may have important implications for continued VZV vaccination. Although no interclade vaccine-wild-type recombinant strains were found, intraclade recombinants were frequently detected in clade 2, which harbors the vaccine strains, suggesting that the vaccine strains have already been involved in recombination events, either in vivo or in vitro during passages in cell culture. Finally, previous partial and complete genomic studies have described strains that do not cluster phylogenetically to any of the five established clades. The additional VZV strains sequenced here, in combination with those previously published, have enabled us to formally define a novel sixth VZV clade. IMPORTANCE Although genetic recombination has been demonstrated to frequently occur for other human alphaherpesviruses, herpes simplex viruses 1 and 2, only a few ancient and isolated recent recombination events have hitherto been demonstrated for VZV. In the

BIOTECHNOLOGY OF RECOMBINANT HORMONES IN DOPING

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Biljana Vitošević

2011-09-01

Full Text Available Recombinant DNA technology has allowed rapid progress in creating biosynthetic gene products for the treatment of many diseases. In this way it can produce large amounts of hormone, which is intended for the treatment of many pathological conditions. Recombinant hormones that are commonly used are insulin, growth hormone and erythropoietin. Precisely because of the availability of these recombinant hormones, it started their abuse by athletes. Experiments in animal models confirmed the potential effects of some of these hormones in increasing physical abilities, which attracted the attention of athletes who push the limits of their competitive capability by such manipulation. The risks of the use of recombinant hormones in doping include serious consequences for the health of athletes. Methods of detection of endogenous hormones from recombined based on the use of a monoclonal antibodies, capillary zone electrophoresis and protein biomarkers

Delayed recombination and cosmic parameters

International Nuclear Information System (INIS)

Galli, Silvia; Melchiorri, Alessandro; Bean, Rachel; Silk, Joseph

2008-01-01

Current cosmological constraints from cosmic microwave background anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination, altering the cosmic ionization history and the cosmological inferences drawn from the cosmic microwave background data. We show that for recent observations of the cosmic microwave background anisotropy, from the Wilkinson microwave anisotropy probe satellite mission (WMAP) 5-year survey and from the arcminute cosmology bolometer array receiver experiment, additional resonance radiation is nearly degenerate with variations in the spectral index, n s , and has a marked effect on uncertainties in constraints on the Hubble constant, age of the universe, curvature and the upper bound on the neutrino mass. When a modified recombination scheme is considered, the redshift of recombination is constrained to z * =1078±11, with uncertainties in the measurement weaker by 1 order of magnitude than those obtained under the assumption of standard recombination while constraints on the shift parameter are shifted by 1σ to R=1.734±0.028. From the WMAP5 data we obtain the following constraints on the resonance and ionization sources parameters: ε α i <0.058 at 95% c.l.. Although delayed recombination limits the precision of parameter estimation from the WMAP satellite, we demonstrate that this should not be the case for future, smaller angular scales measurements, such as those by the Planck satellite mission.

Evaluation of the BioPlex 2200 syphilis system as a first-line method of reverse-sequence screening for syphilis diagnosis.

Science.gov (United States)

Marangoni, Antonella; Nardini, Paola; Foschi, Claudio; Moroni, Alessandra; D'Antuono, Antonietta; Bacchi Reggiani, Letizia; Cevenini, Roberto

2013-07-01

Despite recent technological advances, the diagnosis of syphilis remains a challenging enterprise. Actually, most high-volume laboratories have adopted the "reverse algorithm" due several factors, including the potential to automate testing. Recently, immunoassays processed on random-access systems have been proposed as screening tests. The purpose of this study was to evaluate diagnostic performances of BioPlex 2200 Syphilis IgG and BioPlex 2200 Syphilis IgM, tests based on Multiplex Flow technology, in comparison with the performance of Architect Syphilis TP, a chemiluminescent immunoassay for the detection of IgG and/or IgM anti-Treponema pallidum antibodies. A retrospective study was performed with a panel of 100 blood donor sera, a panel of 350 clinical and laboratory-characterized syphilitic sera, and 170 samples obtained from subjects with potentially interfering conditions. Moreover, 200 unselected samples submitted to the Microbiology Laboratory of St. Orsola Hospital in Bologna for routine screening for syphilis were evaluated. As confirmatory tests, T. pallidum hemagglutination and Western blot assays were used. Considering the IgG Western blot (WB) assay to be the gold standard method, BioPlex 2200 Syphilis IgG specificity was far higher than Architect Syphilis TP specificity (89.7% versus 78.4%, respectively), whereas the sensitivity was 100% for both automated methods. Compared to the IgM WB assay, BioPlex 2200 Syphilis IgM performed with a specificity of 94.9%, whereas the sensitivity was 84.8%. Considering the excellent ease of use and automation, the high sample throughput and its valuable analytical performances, BioPlex Syphilis 2200 IgG could represent a suitable choice for high-volume laboratories. BioPlex Syphilis 2200 IgM could be considered a good addition to IgG testing for uncovering active infections.

Field evaluation of a dual rapid diagnostic test for HIV infection and syphilis in Lima, Peru.

Science.gov (United States)

Bristow, Claire C; Leon, Segundo R; Huang, Emily; Brown, Brandon J; Ramos, Lourdes B; Vargas, Silver K; Flores, Juan A; Caceres, Carlos F; Klausner, Jeffrey D

2016-05-01

Screening for HIV and syphilis in key populations is recommended by the WHO to reduce the morbidity, mortality and transmission associated with undiagnosed and untreated infections. Rapid point-of-care tests that can detect multiple infections with a single fingerprick whole blood specimen using a single device are gaining popularity. We evaluated the field performance of a rapid dual HIV and syphilis test in people at high risk of HIV and syphilis infections. Participants included men who have sex with men and transgender women recruited in Lima, Peru. Reference standard testing for detection of HIV and syphilis infections, conducted using blood samples from venipuncture, included Treponema pallidum particle agglutination and fourth-generation HIV enzyme immunoassay for which positive results had a confirmation HIV Western blot test. For the evaluation test, SD BIOLINE HIV/Syphilis Duo test (Standard Diagnostics, Korea), a fingerprick blood specimen was used. Sensitivity and specificity were calculated and the exact binomial method was used to determine 95% CIs. A total of 415 participants were recruited for the study. The dual test sensitivity for detection of T. pallidum infection was 89.2% (95% CI 83.5% to 93.5%) and specificity 98.8% (95% CI 96.5% to 99.8%). For detection of HIV infection, the sensitivity of the dual test was 99.1% (95% CI 94.8% to 100%) and specificity 99.4% (95% CI 97.7% to 99.9%). This high performing dual test should be considered for the use in clinical settings to increase uptake of simultaneous testing of HIV and syphilis and accelerate time to treatment for those who need it. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Cerebrospinal fluid abnormalities in HIV-negative patients with secondary and early latent syphilis and serum VDRL ≥ 1:32

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Maciej Pastuszczak

2013-01-01

Full Text Available Background : Syphilis is caused by a spirochete Treponema pallidum. Invasion of the central nervous system (CNS by T. pallidum may appear early during the course of disease. The diagnosis of confirmed neurosyphilis is based on the reactive Venereal Disease Research Laboratory (VDRL in cerebrospinal fluid (CSF. Recent studies indicated that serum RPR ≥ 1:32 are associated with higher risk of reactivity of CSF VDRL. Aims : The main aim of the current study was to assess cerebrospinal fluid serological and biochemical abnormalities in HIV negative subjects with secondary and early latent syphilis and serum VDRL ≥ 1:32. Materials and Methods : Clinical and laboratory data of 33 HIV-negative patients with secondary and early latent syphilis, with the serum VDRL titer ≥ 1:32, who underwent a lumbar puncture and were treated in Department of Dermatology at Jagiellonian University School of Medicine in Cracow, were collected. Results : Clinical examination revealed no symptoms of CNS involvement in all patients. 18% ( n = 6 of patients met the criteria of confirmed neurosyphilis (reactive CSF-VDRL. In 14 (42% patients CSF WBC count ≥ 5/ul was found, and in 13 (39% subjects there was elevated CSF protein concentration (≥ 45 mg/dL. 10 patients had CSF WBC count ≥ 5/ul and/or elevated CSF protein concentration (≥ 45 mg/dL but CSF-VDRL was not reactive. Conclusions : Indications for CSF examination in HIV-negative patients with early syphilis are the subject of discussion. It seems that all patients with syphilis and with CSF abnormalities (reactive serological tests, elevated CSF WBC count, elevated protein concentration should be treated according to protocols for neurosyphilis. But there is a need for identification of biomarkes in order to identify a group of patients with syphilis, in whom risk of such abnormalities is high.

HTLV-1 cosmopolitan and HTLV-2 subtype b among pregnant women of non-endemic areas of Argentina.

Science.gov (United States)

Berini, Carolina A; Delfino, Cecilia; Torres, Oscar; García, Gabriela; Espejo, Rogelio; Pianciola, Luis; Juarez, Mirna; Arribere, Graciela; Nadal, Mónica; Eirin, Maria E; Biglione, Mirna M

2013-06-01

The objective of this study was to estimate the prevalence of human T cell lymphotropic virus (HTLV)-1/2, HIV-1, hepatitis B virus (HBV), Trypanosoma cruzi, Treponema pallidum and Toxoplasma gondii infections and to identify the subtypes/subgroups of HTLV-1/2 among pregnant women (PW) from non-endemic provinces of Argentina. Methods A total of 2403 samples were screened for HTLV-1/2 and confirmed by western blot and PCR. The long terminal repeat (LTR) of HTLV-1 and HTLV-2 were amplified. Phylogenetic analysis was performed by Neighbour Joining by using molecular evolutionary genetics analysis (MEGA) 4.0. Among a total of 2403 PW studied, 6 (0.25%) tested positive for HTLV-1/2 (3 HTLV-1 (0.12%) and 3 HTLV-2 (0.12%)). The total prevalence when distributed by province was 0.3% (3/804) for Buenos Aires (BA), 0.4% (1/241) for BA surroundings, 0.1% (1/707) for Neuquen and 1.0% (1/95) for Ushuaia. In San Juan, no PW were HTLV-1/2 positive. The prevalence was similar when compared with rates among blood donors of the same areas and years. The phylogenetic analysis classified one sequence as HTLV-1 aA and one as HTLV-2b. The prevalence of HIV-1, HBV, T cruzi, T pallidum and T gondii was 0.6%, 0.2%, 1.4%, 1.2% and 20.9%, respectively. One case of HTLV-1/HIV-1 and one of HTLV-2/HIV-1 co-infection were detected. HTLV-1/2, which have been associated with different diseases, are circulating among PW of Argentina, even in non-endemic areas. Therefore, testing should be recommended in women who have risk factors for these infections given that the majority of HTLV-1/2 mother to child transmission can be prevented by the avoidance of breast feeding.

Evaluation of a new serological test for syphilis based on chemiluminescence assay in a tertiary care hospital

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Aseem K Tiwari

2015-01-01

Full Text Available Context: Syphilis is a transfusion transmissible infections and it is mandatory to do serological test for syphilis (STS on all donor blood samples. STS is usually based on detection of antibodies against the cardiolipin-lecithin antigen or against the Treponema-specific antigen. STS with good sensitivity and specificity helps enhance blood safety and consolidation of STS along with other transfusion transmittable infections such as human immunodeficiency virus, hepatitis-C virus, and hepatitis-B virus helps in reducing the errors and enhances efficiency. Aims: This study was designed to evaluate the performance of newly introduced VITROS ® syphilis Treponema pallidum agglutination (TPA assay based on enhanced chemiluminescence principle for its analytical performance for use as a STS on donor blood samples at a tertiary care health center in National Capital Region, India. Materials and Methods: A total of 108 random blood units collected from the donors (both voluntary and replacement donors and 28 known syphilis sero-reactive samples stored at −20°C, were used to evaluate the performance of VITROS ® syphilis TPA assay based on enhanced chemiluminescence assay on VITROS ® ECiQ immunodiagnostics system along with its analytical performance in terms of its sensitivity, precision, cross-reactivity and interference studies. Results: VITROS ® syphilis TPA showed 100% sensitivity and specificity with precision (20 days study of <10% co-efficient of variation. There was no cross-reactivity with other viral and auto-immune antibodies. No interference was observed from endogenous interfering substances like free hemoglobin or fats. Conclusions: Performance of the VITROS ® syphilis TPA assay meets the requirements for its use as STS in blood bank, thus allowing consolidation with other transfusion transmittable infections screening assay on chemiluminescence platform, which is highly valuable for optimizing workflow and efficiency.

Significance of the combined tests application in serum and liquor of patients with suspected neurosyphilis

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Mirković Mihailo

2007-01-01

Full Text Available Background. Tertiary syphilis develops in 8-40% of untreated patients. It is most commonly manifested in the form of neurosyphilis, which can be asymptomatic taking the form of tabes dorsalis or progressive paralyze. Nowadays, in the developed countries, progressive paralyze is a rather rare disease, although the incidence of this disease has been rising within the last decades. Case report. We reported a 74-year-old male with the clinical image of dementia showing psychotic symptoms. On cytobiochemical examination of cerebrospinal liquor, hyperproteinorhacmia of 0.70 g/l with the normal number of cells was revealed. Computed tomography of the brain showed the marked cortical cerebral and cerebellar reduction changes with multiple ischemic lesions. Within a routine examination of patients with demention, we performed serologic reactions to syphilis out of which the Veneral Disease Researc Laboratory (VDRL test in serum and liquor was unreactive, while the Treponema pallidum hemagglutination (TPNA test in serum and liquor was positive. Positivity in serum and liquor was additionally confirmed by the Western blot method and fluoroscent treponema antibody (FTA test. The treatment with benzathine fenylpenicilline 2.4 g once weekly resulted in significant improving the psychotic symptoms of the disease even after two weeks. Conclusion. This case report showed that within the differential diagnostics in patients with demention or psychotic disorder it is obligatory to consider syphilis of the nervous system, as well as to apply a combination of various tests which, besides the typical liquor findings, significantly improve the accuracy of diagnosis. Such approach is especially important regarding the fact that neurosyphilis can remain clinically quite asymptomatic for a long period, which could lead to late therapy, while, on the contrary, an adequate and timely treatment can contribute to a significant recovery of any patients.

Meiotic recombination in human oocytes.

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Edith Y Cheng

2009-09-01

Full Text Available Studies of human trisomies indicate a remarkable relationship between abnormal meiotic recombination and subsequent nondisjunction at maternal meiosis I or II. Specifically, failure to recombine or recombination events located either too near to or too far from the centromere have been linked to the origin of human trisomies. It should be possible to identify these abnormal crossover configurations by using immunofluorescence methodology to directly examine the meiotic recombination process in the human female. Accordingly, we initiated studies of crossover-associated proteins (e.g., MLH1 in human fetal oocytes to analyze their number and distribution on nondisjunction-prone human chromosomes and, more generally, to characterize genome-wide levels of recombination in the human female. Our analyses indicate that the number of MLH1 foci is lower than predicted from genetic linkage analysis, but its localization pattern conforms to that expected for a crossover-associated protein. In studies of individual chromosomes, our observations provide evidence for the presence of "vulnerable" crossover configurations in the fetal oocyte, consistent with the idea that these are subsequently translated into nondisjunctional events in the adult oocyte.

Electron - ion recombination processes - an overview

International Nuclear Information System (INIS)

Hahn, Yukap

1997-01-01

Extensive theoretical and experimental studies have been carried out for the past 20 years on electron - ion recombination processes, as they are applied to the analysis of astrophysical and laboratory plasmas. We review the basic understanding gained through these efforts, with emphasis on some of the more recent progress made in recombination theory as the recombining system is affected by time-dependent electric fields and plasma particles at low temperature. Together with collisional ionization and excitation processes, recombination is important in determining ionization balance and excited-state population in non-equilibrium plasmas. The radiation emitted by plasmas is usually the principal medium with which to study the plasma condition, as it is produced mainly during the recombination and decay of excited states of ions inside the plasma. This is especially true when the plasma under study is not readily accessible by direct probes, as in astrophysical plasmas. Moreover, external probes may sometimes cause undesirable disturbances of the plasma. Electron-ion recombination proceeds in several different modes. The direct modes include three-body recombination (TBR) and one-step radiative recombination (RR), all to the ground- and singly-excited states of the target ions. By contrast, the indirect resonant mode is a two-step dielectronic recombination (DR), which proceeds first with the formation of doubly-excited states by radiationless excitation/capture. The resonant states thus formed may relax by autoionization and/or radiative cascades. For more exotic modes of recombination, we consider off-shell dielectronic recombination (radiative DR = RDR), in which an electron capture is accompanied by simultaneous radiative emission and excitation of the target ion. Some discussion on attachment of electrons to neutral atoms, resulting in the formation of negative ions, is also given. When resonance states involve one or more electrons in high Rydberg states

Controlled Release from Recombinant Polymers

Science.gov (United States)

Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

2014-01-01

Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

Live recombinant BHV/BRSV vaccine

NARCIS (Netherlands)

Keil, G.M.; Rijsewijk, F.A.M.

1998-01-01

The present invention refers to synthetic Bovine Respiratory Syncytium virus genes. Also the invention relates to live attenuated Bovine Herpesvirus recombinants carrying such synthetic genes. Furthermore, the invention relates to vaccines based on these live attenuated recombinants, for the

First-principles study of Frenkel pair recombination in tungsten

International Nuclear Information System (INIS)

Qin, Shi-Yao; Jin, Shuo; Li, Yu-Hao; Zhou, Hong-Bo; Zhang, Ying; Lu, Guang-Hong

2017-01-01

The recombination of one Frenkel pair in tungsten has been investigated through first-principles simulation. Two different recombination types have been identified: instantaneous and thermally activated. The small recombination barriers for thermally activated recombination cases indicate that recombination can occur easily with a slightly increased temperature. For both of the two recombination types, recombination occurs through the self-interstitial atom moving towards the vacancy. The recombination process can be direct or through replacement sequences, depending on the vertical distance between the vacancy and the 〈1 1 1〉 line of self-interstitial atom pair.

Containment air circulation for optimal hydrogen recombination

International Nuclear Information System (INIS)

Spinks, N.; Krause, M.

1997-01-01

An accepted first-line defense for hydrogen mitigation is to design for the hydrogen to be rapidly mixed with the containment atmosphere and diluted to below flammability concentrations. Then, as hydrogen continues to be produced in the longer term, recombiners can be used to remove hydrogen: recombiners can be located in forced-air ducts or passive recombiners can be distributed within containment and the heat of recombination used to promote local air circulation. However, this principle does not eliminate the possibility of high hydrogen concentrations at locations removed from the recombiners. An improvement on this strategy is to arrange for a specific, buoyancy-driven, overall circulation of the containment atmosphere such that the recombiners can be located within the recirculation flow, immediately downstream of the hydrogen source. This would make the mixing process more predictable and solve the mass-transfer problem associated with distributed recombiners. Ideally, the recombiners would be located just above the hydrogen source so that the heat of recombination would assist the overall circulation. In this way, the hydrogen would be removed as close as possible to the source, thereby minimizing the amount of hydrogen immediately downstream of the source and reducing the hydrogen concentration to acceptable levels at other locations. Such a strategy requires the containment volume to be divided into an upflow path, past the hydrogen source and the recombiner, and a downflow path to complete the circuit. The flow could be generated actively using fans or passively using buoyancy forces arising from the difference in density of gases in the upfiow and downflow paths; the gases in the downflow path being cooled at an elevated heat sink. (author)

Recombination properties of dislocations in GaN

Science.gov (United States)

Yakimov, Eugene B.; Polyakov, Alexander Y.; Lee, In-Hwan; Pearton, Stephen J.

2018-04-01

The recombination activity of threading dislocations in n-GaN with different dislocation densities and different doping levels was studied using electron beam induced current (EBIC). The recombination velocity on a dislocation, also known as the dislocation recombination strength, was calculated. The results suggest that dislocations in n-GaN giving contrast in EBIC are charged and surrounded by a space charge region, as evidenced by the observed dependence of dislocation recombination strength on dopant concentration. For moderate (below ˜108 cm-2) dislocation densities, these defects do not primarily determine the average diffusion length of nonequilibrium charge carriers, although locally, dislocations are efficient recombination sites. In general, it is observed that the effect of the growth method [standard metalorganic chemical vapor deposition (MOCVD), epitaxial lateral overgrowth versions of MOCVD, and hydride vapor phase epitaxy] on the recombination activity of dislocations is not very pronounced, although the average diffusion lengths can widely differ for various samples. The glide of basal plane dislocations at room temperature promoted by low energy electron irradiation does not significantly change the recombination properties of dislocations.

Oligonucleotide recombination enabled site-specific mutagenesis in bacteria

Science.gov (United States)

Recombineering refers to a strategy for engineering DNA sequences using a specialized mode of homologous recombination. This technology can be used for rapidly constructing precise changes in bacterial genome sequences in vivo. Oligo recombination is one type of recombineering that uses ssDNA olig...

Recombination: the good, the bad and the variable.

Science.gov (United States)

Stapley, Jessica; Feulner, Philine G D; Johnston, Susan E; Santure, Anna W; Smadja, Carole M

2017-12-19

Recombination, the process by which DNA strands are broken and repaired, producing new combinations of alleles, occurs in nearly all multicellular organisms and has important implications for many evolutionary processes. The effects of recombination can be good , as it can facilitate adaptation, but also bad when it breaks apart beneficial combinations of alleles, and recombination is highly variable between taxa, species, individuals and across the genome. Understanding how and why recombination rate varies is a major challenge in biology. Most theoretical and empirical work has been devoted to understanding the role of recombination in the evolution of sex-comparing between sexual and asexual species or populations. How recombination rate evolves and what impact this has on evolutionary processes within sexually reproducing organisms has received much less attention. This Theme Issue focusses on how and why recombination rate varies in sexual species, and aims to coalesce knowledge of the molecular mechanisms governing recombination with our understanding of the evolutionary processes driving variation in recombination within and between species. By integrating these fields, we can identify important knowledge gaps and areas for future research, and pave the way for a more comprehensive understanding of how and why recombination rate varies. © 2017 The Authors.

Genetic recombination of the hepatitis C virus: clinical implications.

Science.gov (United States)

Morel, V; Fournier, C; François, C; Brochot, E; Helle, F; Duverlie, G; Castelain, S

2011-02-01

Genetic recombination is a well-known feature of RNA viruses that plays a significant role in their evolution. Although recombination is well documented for Flaviviridae family viruses, the first natural recombinant strain of hepatitis C virus (HCV) was identified as recently as 2002. Since then, a few other natural inter-genotypic, intra-genotypic and intra-subtype recombinant HCV strains have been described. However, the frequency of recombination may have been underestimated because not all known HCV recombinants are screened for in routine practice. Furthermore, the choice of treatment regimen and its predictive outcome remain problematic as the therapeutic strategy for HCV infection is genotype dependent. HCV recombination also raises many questions concerning its mechanisms and effects on the epidemiological and physiopathological features of the virus. This review provides an update on recombinant HCV strains, the process that gives rise to recombinants and clinical implications of recombination. © 2010 Blackwell Publishing Ltd.

Cell biology of mitotic recombination

DEFF Research Database (Denmark)

Lisby, Michael; Rothstein, Rodney

2015-01-01

Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules as w...

Test tube systems with cutting/recombination operations

Energy Technology Data Exchange (ETDEWEB)

Freund, R. [Technische Universitaet Wien (Austria); Csuhaj-Varju, E. [Computer and Automation Institute, Budapest (Hungary); Wachtler, F. [Universitaet Wien (Austria)

1996-12-31

We introduce test tube systems based on operations that are closely related to the splicing operations, i.e. we consider the operations of cutting a string at a specific site into two pieces with marking them at the cut ends and of recombining two strings with specifically marked endings. Whereas in the splicing of two strings these strings are cut at specific sites and the cut pieces are recombined immediately in a crosswise way, in CR(cutting/recombination)-schemes cutting can happen independently from recombining the cut pieces. Test tube systems based on these operations of cutting and recombination turn out to have maximal generative power even if only very restricted types of input filters for the test tubes are used for the redistribution of the contents of the test tubes after a period of cuttings and recombinations in the test tubes. 10 refs.

Atomic excitation and recombination in external fields

International Nuclear Information System (INIS)

Nayfeh, M.H.; Clark, C.W.

1985-01-01

This volume offers a timely look at Rydberg states of atoms in external fields and dielectronic recombination. Each topic provides authoritative coverage, presents a fresh account of a flourishing field of current atomic physics and introduces new opportunities for discovery and development. Topics considered include electron-atom scattering in external fields; observations of regular and irregular motion as exemplified by the quadratic zeeman effect and other systems; Rydberg atoms in external fields and the Coulomb geometry; crossed-field effects in the absorption spectrum of lithium in a magnetic field; precise studies of static electric field ionization; widths and shapes of stark resonances in sodium above the saddle point; studies of electric field effects and barium autoionizing resonances; autoionization and dielectronic recombination in plasma electric microfields; dielectronic recombination measurements on multicharged ions; merged beam studies of dielectronic recombination; Rydberg atoms and dielectronic recombination in astrophysics; and observations on dielectronic recombination

Genetic evidence for inducibility of recombination competence in yeast

International Nuclear Information System (INIS)

Fabre, F.; Roman, H.

1977-01-01

Recombination between unirradiated chromosomes was induced by UV or x-ray irradiation of haploids followed by a mating with heteroallelic diploids of Saccharomyces cerevisiae. The selected event of intragenic recombination did not involve the participation of the irradiated chromosome and apparently was not caused by lesions introduced into the unirradiated chromosomes by some indirect process. The results favor the idea that recombination is repressed in the majority of vegetative cells and that one effect of radiation is the release of some factor(s) necessary for recombination. Consequently, the proportion of competent cells (i.e., cells able to recombine) in the population increases. This competent state seems necessary not only for the recombinational repair of radiation-induced lesions but also, since recombinants are produced in the absence of such lesions, for spontaneous recombination. Photoreactivation of the UV-irradiated haploids led to a decrease in the production of recombinants. Hence, lesions in the DNA appear to be responsible for the induction of the recombinational ability

Three-body recombination of cold fermionic atoms

International Nuclear Information System (INIS)

Suno, H; Esry, B D; Greene, Chris H

2003-01-01

Recombination of identical, spin-polarized fermions in cold three-body collisions is investigated. We parametrize the mechanisms for recombination in terms of the 'scattering volume' V p and another length scale r 0 . Model two-body interactions were used within the framework of the adiabatic hyperspherical representation. We examine the recombination rate K 3 as a function of the collision energy E for various values of V p . Not only do we consider the dominant J Π = 1 + case, but also the next-leading order contributions from J Π = 1 - and 3 - . We discuss the behaviour near a two-body resonance and the expected universality of fermionic recombination. Comparisons with boson recombination are considered in detail

Recombination Modulates How Selection Affects Linked Sites in Drosophila

Science.gov (United States)

McGaugh, Suzanne E.; Heil, Caiti S. S.; Manzano-Winkler, Brenda; Loewe, Laurence; Goldstein, Steve; Himmel, Tiffany L.; Noor, Mohamed A. F.

2012-01-01

One of the most influential observations in molecular evolution has been a strong association between local recombination rate and nucleotide polymorphisms across the genome. This is interpreted as evidence for ubiquitous natural selection. The alternative explanation, that recombination is mutagenic, has been rejected by the absence of a similar association between local recombination rate and nucleotide divergence between species. However, many recent studies show that recombination rates are often very different even in closely related species, questioning whether an association between recombination rate and divergence between species has been tested satisfactorily. To circumvent this problem, we directly surveyed recombination across approximately 43% of the D. pseudoobscura physical genome in two separate recombination maps and 31% of the D. miranda physical genome, and we identified both global and local differences in recombination rate between these two closely related species. Using only regions with conserved recombination rates between and within species and accounting for multiple covariates, our data support the conclusion that recombination is positively related to diversity because recombination modulates Hill–Robertson effects in the genome and not because recombination is predominately mutagenic. Finally, we find evidence for dips in diversity around nonsynonymous substitutions. We infer that at least some of this reduction in diversity resulted from selective sweeps and examine these dips in the context of recombination rate. PMID:23152720

Recombinational repair: workshop summary

International Nuclear Information System (INIS)

Howard-Flanders, P.

1983-01-01

Recombinational repair may or may not be synonymous with postreplication repair. Considerable progress has been made in the study of the relevant enzymes, particularly those from bacteria. In this workshop we focus on the recombination enzyme RecA protein. What structural changes take place in the protein and in DNA during repair. How does homologous pairing take place. How is ATP hydrolysis coupled to the stand exchange reaction and the formation of heteroduplx DNA. Turning to another enzyme needed for certain kinds of bacterial recombination, we will ask whether the purified recB protein and recC protein complement each other and are sufficient for exonuclease V activity. In higher cells, we would like to know whether sister exchanges, which occur in bacteria after uv irradiation, are also seen in animal cells

Recombinant vaccines: experimental and applied aspects

DEFF Research Database (Denmark)

Lorenzen, Niels

1999-01-01

Development of vaccines for aquaculture fish represent an important applied functional aspect of fish immunology research. Particularly in the case of recombinant vaccines, where a single antigen is usually expected to induce immunity to a specific pathogen, knowledge of mechanisms involved...... in induction of a protective immune response may become vital. The few recombinant vaccines licensd so far, despite much research during the last decade, illustrate that this is not a straightforward matter. However, as vaccine technology as well as our knowledge of the fish immune system is steadily improved......, these fields will open up a number of interesting research objectives of mutual benefit. Recent aspects of recombinant protein vaccines, live recombinant vaccines and DNA vaccines are discussed....

Mitigating Mitochondrial Genome Erosion Without Recombination.

Science.gov (United States)

Radzvilavicius, Arunas L; Kokko, Hanna; Christie, Joshua R

2017-11-01

Mitochondria are ATP-producing organelles of bacterial ancestry that played a key role in the origin and early evolution of complex eukaryotic cells. Most modern eukaryotes transmit mitochondrial genes uniparentally, often without recombination among genetically divergent organelles. While this asymmetric inheritance maintains the efficacy of purifying selection at the level of the cell, the absence of recombination could also make the genome susceptible to Muller's ratchet. How mitochondria escape this irreversible defect accumulation is a fundamental unsolved question. Occasional paternal leakage could in principle promote recombination, but it would also compromise the purifying selection benefits of uniparental inheritance. We assess this tradeoff using a stochastic population-genetic model. In the absence of recombination, uniparental inheritance of freely-segregating genomes mitigates mutational erosion, while paternal leakage exacerbates the ratchet effect. Mitochondrial fusion-fission cycles ensure independent genome segregation, improving purifying selection. Paternal leakage provides opportunity for recombination to slow down the mutation accumulation, but always at a cost of increased steady-state mutation load. Our findings indicate that random segregation of mitochondrial genomes under uniparental inheritance can effectively combat the mutational meltdown, and that homologous recombination under paternal leakage might not be needed. Copyright © 2017 by the Genetics Society of America.

The effect of a single recombination event

DEFF Research Database (Denmark)

Schierup, Mikkel Heide; Jensen, Thomas Mailund; Wiuf, Carsten

We investigate the variance in how visible a single recombination event is in a SNP data set as a function of the type of recombination event and its age. Data is simulated under the coalescent with recombination and inference is by the popular composite likelihood methods. The major determinant...

Recombination rate plasticity: revealing mechanisms by design

Science.gov (United States)

Sefick, Stephen; Rushton, Chase

2017-01-01

For over a century, scientists have known that meiotic recombination rates can vary considerably among individuals, and that environmental conditions can modify recombination rates relative to the background. A variety of external and intrinsic factors such as temperature, age, sex and starvation can elicit ‘plastic’ responses in recombination rate. The influence of recombination rate plasticity on genetic diversity of the next generation has interesting and important implications for how populations evolve. Further, many questions remain regarding the mechanisms and molecular processes that contribute to recombination rate plasticity. Here, we review 100 years of experimental work on recombination rate plasticity conducted in Drosophila melanogaster. We categorize this work into four major classes of experimental designs, which we describe via classic studies in D. melanogaster. Based on these studies, we highlight molecular mechanisms that are supported by experimental results and relate these findings to studies in other systems. We synthesize lessons learned from this model system into experimental guidelines for using recent advances in genotyping technologies, to study recombination rate plasticity in non-model organisms. Specifically, we recommend (1) using fine-scale genome-wide markers, (2) collecting time-course data, (3) including crossover distribution measurements, and (4) using mixed effects models to analyse results. To illustrate this approach, we present an application adhering to these guidelines from empirical work we conducted in Drosophila pseudoobscura. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109222

The Great Impostor: Transaminitis Masking the Coinfection of Syphilis and Human Immunodeficiency Virus

Directory of Open Access Journals (Sweden)

Sunit Tolia

2017-01-01

Full Text Available Introduction. The incidence of syphilis continues to rise in the United States over the past 15 years. This disease process is classified into stages and may present with a coinfection of Human Immunodeficiency Virus (HIV. Case Report. We present a case of a 32-year-old African American male who presented with cutaneous manifestations of secondary syphilis and transaminitis. A workup revealed that the transaminitis was secondary to underlying syphilitic hepatitis in the presence of HIV coinfection. The patient had a reactive rapid plasma reagin (RPR of 1 : 64 TU and reactive Treponema pallidum particle agglutination assay (TPPA. Lab findings showed alkaline phosphate (ALP of 648 unit/L, aspartate aminotransferase (AST of 251 unit/L, and alanine aminotransferase (ALT of 409 unit/L. Conclusion. Syphilitic hepatitis is a recognized entity in the medical literature. It is a manifestation of secondary syphilis and it is more commonly seen in coinfected patients with both syphilis and HIV. Therefore, primary care physicians should keep infectious etiologies (e.g., syphilis and HIV in the differential diagnosis of patients who present with unexplained liver dysfunction in a cholestatic pattern.

CRITERIA FOR LABORATORY DIAGNOSIS OF VARIOUS FORMS EARLY CONGENITAL SYPHILIS

Directory of Open Access Journals (Sweden)

G. P. Martynova

2014-01-01

Full Text Available The results of clinical and laboratory (blood count and serological monitoring of 156 children with various forms of early congenital syphilis in the initial period and the dynamics on the background of specific therapy. Violations in haemogram characterized hypochromic anemia, thrombocytopenia, leukocytosis, neytrofillezom stab shift with a sharP increase in ESR, which prevailed among the most children with the disease over polisimptomnym and significantly exceeded the level of the norm even after specific therapy. For serological examination in 84.62 % cases registered positive results in microprecipitation reaction (RMR to 56.52% — IgM, and 97.83% — IgG reaction Enzymeimmuno assay (EIA and 100 % — Treponema pallidum hemagglutination assay (ТРHА. On the background of specific therapy indicated positive results in the growth of bladder cancer (85.19 %, in the formulation of IgM EIA (72.22 % and IgG (100%, thus, recorded a decline titer positivity serological RMR 2 times , IgM EIA reaction 12 times with simultaneous increase IgG positivity 4 times and 2 times in the ТРHА in the formulation of these reactions in the dynamics.

Syphilis screening among 27,150 pregnant women in South Chinese rural areas using point-of-care tests.

Directory of Open Access Journals (Sweden)

Li-Gang Yang

Full Text Available To determine the prevalence and correlates of syphilis among pregnant women in rural areas of South China.Point-of-care syphilis testing was provided at 71 health facilities in less developed, rural areas of Guangdong Province. Positive samples were confirmed at a local referral center by toluidine red unheated serum tests (TRUST and Treponema pallidum particle agglutination (TPPA tests.Altogether 27,150 pregnant women in rural Guangdong were screened for syphilis. 106 (0.39% syphilis cases were diagnosed, of which 78 (73.6% received treatment for syphilis. Multivariate analysis revealed that older pregnant women (31-35 years old, aOR 2.7, 95% CI 0.99-7.32; older than 35 years old, aOR 5.9, 95% CI 2.13-16.34 and those with a history of adverse pregnant outcomes (aOR 3.64, 95% CI 2.30-5.76 were more likely to be infected with syphilis.A high prevalence of syphilis exists among pregnant women living in rural areas of South China. Enhanced integration of syphilis screening with other routine women's health services (OB GYN, family planning may be useful for controlling China's syphilis epidemic.

Recombination analysis based on the complete genome of bocavirus

Directory of Open Access Journals (Sweden)

Chen Shengxia

2011-04-01

Full Text Available Abstract Bocavirus include bovine parvovirus, minute virus of canine, porcine bocavirus, gorilla bocavirus, and Human bocaviruses 1-4 (HBoVs. Although recent reports showed that recombination happened in bocavirus, no systematical study investigated the recombination of bocavirus. The present study performed the phylogenetic and recombination analysis of bocavirus over the complete genomes available in GenBank. Results confirmed that recombination existed among bocavirus, including the likely inter-genotype recombination between HBoV1 and HBoV4, and intra-genotype recombination among HBoV2 variants. Moreover, it is the first report revealing the recombination that occurred between minute viruses of canine.

FASEB Summer Research Conference. Genetic Recombination and Chromosome Rearrangements

Energy Technology Data Exchange (ETDEWEB)

Jinks-Robertson, Sue

2002-02-01

The 2001 meeting entitled ''Genetic Recombination and Genome Rearrangements'' was held July 21-26 in Snowmass, Colorado. The goal of the meeting was to bring together scientists using diverse approaches to study all aspects of genetic recombination. This goal was achieved by integrating talks covering the genetics, biochemistry and structural biology of homologous recombination, site-specific recombination, and nonhomologous recombination. The format of the meeting consisted of a keynote address on the opening evening, two formal plenary sessions on each of the four full meeting days, a single afternoon workshop consisting of short talks chosen from among submitted abstracts, and afternoon poster sessions on each of the four full meeting days. The eight plenary session were entitled: (1) Recombination Mechanisms, (2) Prokaryotic Recombination, (3) Repair and Recombination, (4) Site-specific Recombination and Transposition, (5) Eukaryotic Recombination I, (6) Genome Rearrangements, (7) Meiosis, and (8) Eukaryotic Recombination II. Each session included a mix of genetic, biochemical and structural talks; talks were limited to 20 minutes, followed by 10 minutes of very lively, general discussion. Much of the data presented in the plenary sessions was unpublished, thus providing attendees with the most up-to-date knowledge of this rapidly-moving field.

Hadron Correlations and Parton Recombination

Energy Technology Data Exchange (ETDEWEB)

Fries, R.J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)]. E-mail: rjfries@comp.tamu.edu

2007-02-15

Parton recombination has been found to be an extremely useful model to understand hadron production at the Relativistic Heavy Ion Collider. It is particularly important to explore its connections with hard processes. This article reviews some of the aspects of the quark recombination model and places particular emphasis on hadron correlations.

Exceptionally high levels of recombination across the honey bee genome.

Science.gov (United States)

Beye, Martin; Gattermeier, Irene; Hasselmann, Martin; Gempe, Tanja; Schioett, Morten; Baines, John F; Schlipalius, David; Mougel, Florence; Emore, Christine; Rueppell, Olav; Sirviö, Anu; Guzmán-Novoa, Ernesto; Hunt, Greg; Solignac, Michel; Page, Robert E

2006-11-01

The first draft of the honey bee genome sequence and improved genetic maps are utilized to analyze a genome displaying 10 times higher levels of recombination (19 cM/Mb) than previously analyzed genomes of higher eukaryotes. The exceptionally high recombination rate is distributed genome-wide, but varies by two orders of magnitude. Analysis of chromosome, sequence, and gene parameters with respect to recombination showed that local recombination rate is associated with distance to the telomere, GC content, and the number of simple repeats as described for low-recombining genomes. Recombination rate does not decrease with chromosome size. On average 5.7 recombination events per chromosome pair per meiosis are found in the honey bee genome. This contrasts with a wide range of taxa that have a uniform recombination frequency of about 1.6 per chromosome pair. The excess of recombination activity does not support a mechanistic role of recombination in stabilizing pairs of homologous chromosome during chromosome pairing. Recombination rate is associated with gene size, suggesting that introns are larger in regions of low recombination and may improve the efficacy of selection in these regions. Very few transposons and no retrotransposons are present in the high-recombining genome. We propose evolutionary explanations for the exceptionally high genome-wide recombination rate.

Three-particle recombination at low temperature: QED approach

International Nuclear Information System (INIS)

Bhattacharyya, S.; Roy, A.

2001-01-01

A theoretical study of three-body recombination of proton in presence of a spectator electron with electronic beam at near-zero temperature is presented using field theory and invariant Lorentz gauge. Contributions from the Feynman diagrams of different orders give an insight into the physics of the phenomena. Recombination rate coefficient is obtained for low lying principal quantum number n = 1 to 10. At a fixed ion beam temperature (300 K) recombination rate coefficient is found to increase in general with n, having a flat and a sharp peak at quantum states 3 to 5, respectively. In absence of any theoretical and experimental results for low temperature formation of H-atom by three-body recombination at low lying quantum states, we have presented the theoretical results of Stevefelt and group for three-body recombination of deuteron with electron along with the present results. Three-body recombination of antihydrogen in antiproton-positron plasma is expected to yield similar result as that for three-body recombination of hydrogen formation in proton-electron plasma. The necessity for experimental investigation of low temperature three-body recombination at low quantum states is stressed. (author)

Activated recombinant adenovirus proteinases

Science.gov (United States)

Anderson, Carl W.; Mangel, Walter F.

1999-08-10

This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying said peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described.

Hadron correlations from recombination

Energy Technology Data Exchange (ETDEWEB)

Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

2005-01-01

Quark recombination is a successful model to describe the hadronization of a deconfined quark gluon plasma. Jet-like dihadron correlations measured at RHIC provide a challenge for this picture. We discuss how correlations between hadrons can arise from correlations between partons before hadronization. An enhancement of correlations through the recombination process, similar to the enhancement of elliptic flow is found. Hot spots from completely or partially quenched jets are a likely source of such parton correlations.

X-ray- and TEM-induced mitotic recombination in Drosophila melanogaster: Unequal and sister-strand recombination

International Nuclear Information System (INIS)

Becker, H.J.

1975-01-01

Twin mosaic spots of dark-apricot and light-apricot ommatidia were found in the eyes of wsup(a)/wsup(a) females, of wsup(a) males, of females homozygous for In(1)sc 4 , wsup(a) and of attached-X females homozygous for wsup(a). The flies were raised from larvae which had been treated with 1,630 R of X-rays at the age of 48-52 hours. An additional group of wsup(a)/wsup(a) females and wsup(a) males came from larvae that had been fed with triethylene melamine (TEM) at the age of 22-24 hours. The twin spots apparently were the result of induced unequal mitotic recombination, i.e. from unequal sister-strand recombination in the males and from unequal sister-strand recombination as well as, possibly, unequal recombination between homologous strands in the females. That is, a duplication resulted in wsup(a)Dpwsup(a)/wsup(a) dark-apricto ommatidia and the corresponding deficiency in an adjacent area of wsup(a)/Dfwsup(a) light-apricot ommatidia. In an additional experiment sister-strand mitotic recombination in the ring-X chromosome of ring-X/rod-X females heterozygous for w and wsup(co) is believed to be the cause for X-ray induced single mosaic spots that show the phenotype of the rod-X marker. (orig.) [de

Two novel porcine epidemic diarrhea virus (PEDV) recombinants from a natural recombinant and distinct subtypes of PEDV variants.

Science.gov (United States)

Chen, Nanhua; Li, Shuangjie; Zhou, Rongyun; Zhu, Meiqin; He, Shan; Ye, Mengxue; Huang, Yucheng; Li, Shuai; Zhu, Cong; Xia, Pengpeng; Zhu, Jianzhong

2017-10-15

Porcine epidemic diarrhea virus (PEDV) causes devastating impact on global pig-breeding industry and current vaccines have become not effective against the circulating PEDV variants since 2011. During the up-to-date investigation of PEDV prevalence in Fujian China 2016, PEDV was identified in vaccinated pig farms suffering severe diarrhea while other common diarrhea-associated pathogens were not detected. Complete genomes of two PEDV representatives (XM1-2 and XM2-4) were determined. Genomic comparison showed that these two viruses share the highest nucleotide identities (99.10% and 98.79%) with the 2011 ZMDZY strain, but only 96.65% and 96.50% nucleotide identities with the attenuated CV777 strain. Amino acid alignment of spike (S) proteins indicated that they have the similar mutation, insertion and deletion pattern as other Chinese PEDV variants but also contain several unique substitutions. Phylogenetic analysis showed that 2016 PEDV variants belong to the cluster of recombination strains but form a new branch. Recombination detection suggested that both XM1-2 and XM2-4 are inter-subgroup recombinants with breakpoints within ORF1b. Remarkably, the natural recombinant HNQX-3 isolate serves as a parental virus for both natural recombinants identified in this study. This up-to-date investigation provides the direct evidence that natural recombinants may serve as parental viruses to generate recombined PEDV progenies that are probably associated with the vaccination failure. Copyright © 2017. Published by Elsevier B.V.

Rapid generation of markerless recombinant MVA vaccines by en passant recombineering of a self-excising bacterial artificial chromosome.

Science.gov (United States)

Cottingham, Matthew G; Gilbert, Sarah C

2010-09-01

The non-replicating poxviral vector modified vaccinia virus Ankara (MVA) is currently a leading candidate for development of novel recombinant vaccines against globally important diseases. The 1980s technology for making recombinant MVA (and other poxviruses) is powerful and robust, but relies on rare recombination events in poxviral-infected cells. In the 21st century, it has become possible to apply bacterial artificial chromosome (BAC) technology to poxviruses, as first demonstrated by B. Moss' lab in 2002 for vaccinia virus. A similar BAC clone of MVA was subsequently derived, but while recombination-mediated genetic engineering for rapid production was used of deletion mutants, an alternative method was required for efficient insertion of transgenes. Furthermore "markerless" viruses, which carry no trace of the selectable marker used for their isolation, are increasingly required for clinical trials, and the viruses derived via the new method contained the BAC sequence in their genomic DNA. Two methods are adapted to MVA-BAC to provide more rapid generation of markerless recombinants in weeks rather than months. "En passant" recombineering is applied to the insertion of a transgene expression cassette and the removal of the selectable marker in bacteria; and a self-excising variant of MVA-BAC is constructed, in which the BAC cassette region is rapidly and efficiently lost from the viral genome following rescue of the BAC into infectious virus. These methods greatly facilitate and accelerate production of recombinant MVA, including markerless constructs. Copyright 2010 Elsevier B.V. All rights reserved.

Mechanisms and factors that influence high frequency retroviral recombination

DEFF Research Database (Denmark)

Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga

2011-01-01

With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse...... transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity...... of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment...

Induction of homologous recombination in Saccharomyces cerevisiae.

Science.gov (United States)

Simon, J R; Moore, P D

1988-09-01

We have investigated the effects of UV irradiation of Saccharomyces cerevisiae in order to distinguish whether UV-induced recombination results from the induction of enzymes required for homologous recombination, or the production of substrate sites for recombination containing regions of DNA damage. We utilized split-dose experiments to investigate the induction of proteins required for survival, gene conversion, and mutation in a diploid strain of S. cerevisiae. We demonstrate that inducing doses of UV irradiation followed by a 6 h period of incubation render the cells resistant to challenge doses of UV irradiation. The effects of inducing and challenge doses of UV irradiation upon interchromosomal gene conversion and mutation are strictly additive. Using the yeast URA3 gene cloned in non-replicating single- and double-stranded plasmid vectors that integrate into chromosomal genes upon transformation, we show that UV irradiation of haploid yeast cells and homologous plasmid DNA sequences each stimulate homologous recombination approximately two-fold, and that these effects are additive. Non-specific DNA damage has little effect on the stimulation of homologous recombination, as shown by studies in which UV-irradiated heterologous DNA was included in transformation/recombination experiments. We further demonstrate that the effect of competing single- and double-stranded heterologous DNA sequences differs in UV-irradiated and unirradiated cells, suggesting an induction of recombinational machinery in UV-irradiated S. cerevisiae cells.

Spectrum Recombination.

Science.gov (United States)

Greenslade, Thomas B., Jr.

1984-01-01

Describes several methods of executing lecture demonstrations involving the recombination of the spectrum. Groups the techniques into two general classes: bringing selected portions of the spectrum together using lenses or mirrors and blurring the colors by rapid movement or foreshortening. (JM)

Genetic analysis of variation in human meiotic recombination.

Directory of Open Access Journals (Sweden)

Reshmi Chowdhury

2009-09-01

Full Text Available The number of recombination events per meiosis varies extensively among individuals. This recombination phenotype differs between female and male, and also among individuals of each gender. In this study, we used high-density SNP genotypes of over 2,300 individuals and their offspring in two datasets to characterize recombination landscape and to map the genetic variants that contribute to variation in recombination phenotypes. We found six genetic loci that are associated with recombination phenotypes. Two of these (RNF212 and an inversion on chromosome 17q21.31 were previously reported in the Icelandic population, and this is the first replication in any other population. Of the four newly identified loci (KIAA1462, PDZK1, UGCG, NUB1, results from expression studies provide support for their roles in meiosis. Each of the variants that we identified explains only a small fraction of the individual variation in recombination. Notably, we found different sequence variants associated with female and male recombination phenotypes, suggesting that they are regulated by different genes. Characterization of genetic variants that influence natural variation in meiotic recombination will lead to a better understanding of normal meiotic events as well as of non-disjunction, the primary cause of pregnancy loss.

Recombination in Avian Gamma-Coronavirus Infectious Bronchitis Virus

Directory of Open Access Journals (Sweden)

Mark W. Jackwood

2011-09-01

Full Text Available Recombination in the family Coronaviridae has been well documented and is thought to be a contributing factor in the emergence and evolution of different coronaviral genotypes as well as different species of coronavirus. However, there are limited data available on the frequency and extent of recombination in coronaviruses in nature and particularly for the avian gamma-coronaviruses where only recently the emergence of a turkey coronavirus has been attributed solely to recombination. In this study, the full-length genomes of eight avian gamma-coronavirus infectious bronchitis virus (IBV isolates were sequenced and along with other full-length IBV genomes available from GenBank were analyzed for recombination. Evidence of recombination was found in every sequence analyzed and was distributed throughout the entire genome. Areas that have the highest occurrence of recombination are located in regions of the genome that code for nonstructural proteins 2, 3 and 16, and the structural spike glycoprotein. The extent of the recombination observed, suggests that this may be one of the principal mechanisms for generating genetic and antigenic diversity within IBV. These data indicate that reticulate evolutionary change due to recombination in IBV, likely plays a major role in the origin and adaptation of the virus leading to new genetic types and strains of the virus.

The unconventional xer recombination machinery of Streptococci/Lactococci

NARCIS (Netherlands)

Le Bourgeois, Pascal; Bugarel, Marie; Campo, Nathalie; Daveran-Mingot, Marie-Line; Labonte, Jessica; Lanfranchi, Daniel; Lautier, Thomas; Pages, Carine; Ritzenthaler, Paul

Homologous recombination between circular sister chromosomes during DNA replication in bacteria can generate chromosome dimers that must be resolved into monomers prior to cell division. In Escherichia coli, dimer resolution is achieved by site-specific recombination, Xer recombination, involving

Graded Recombination Layers for Multijunction Photovoltaics

KAUST Repository

Koleilat, Ghada I.; Wang, Xihua; Sargent, Edward H.

2012-01-01

it to achieve multicolor and spectrally tunable behavior. In series-connected current-matched multijunction devices, the recombination layers must allow the hole current from one cell to recombine, with high efficiency and low voltage loss, with the electron

V(D)J recombination frequency is affected by the sequence interposed between a pair of recombination signals: sequence comparison reveals a putative recombinational enhancer element

DEFF Research Database (Denmark)

Roch, F A; Hobi, R; Berchtold, M W

1997-01-01

respectively, can markedly affect the frequency of V(D)J recombination. We report that the entire Emu, the Emu core as well as its flanking 5' and 3' matrix associated regions (5' and 3' MARs) upregulate V(D)J recombination while the downstream section of the 3' MAR of Emu does not. Also, prokaryotic sequences...

Bio-equivalent doses of recombinent HCG and recombinent LH during ovarian stimulation result in similar oestradiol output

DEFF Research Database (Denmark)

Alsbjerg, Birgit; Elbaek, Helle Olesen; Laursen, Rita Jakubcionyte

2017-01-01

In nature, HCG is secreted by the implanting embryo from peri-implantation and onwards. In contrast, LH is mandatory for steroidogenesis and follicular development during the follicular phase, working in synergy with FSH. Moreover, LH is mandatory for the function of the corpus luteum. Although LH...... and HCG bind to the same receptor, significant molecular, structural and functional differences exist, inducing differences in bioactivity. This randomized controlled study compared the effect of recombinant FSH stimulation combined with daily either micro-dose recombinant HCG or recombinant LH...

Mechanisms and Factors that Influence High Frequency Retroviral Recombination

Science.gov (United States)

Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga; Mens, Helene; Pathak, Vinay K.; Hu, Wei-Shau

2011-01-01

With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment, and vaccine development. PMID:21994801

Recombinant innovation and endogenous technological transitions

NARCIS (Netherlands)

Frenken, K.; Izquierdo, L.R.; Zeppini, P.

2012-01-01

We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create "short-cuts" which reduce

Bimolecular recombination in ambipolar organic field effect transistors

NARCIS (Netherlands)

Charrier, D. S. H.; de Vries, T.; Mathijssen, S. G. J.; Geluk, E. -J.; Smits, E. C. P.; Kemerink, M.; Janssen, R. A. J.

In ambipolar organic field effect transistors (OFET) the shape of the channel potential is intimately related to the recombination zone width W, and hence to the electron-hole recombination strength. Experimentally, the recombination profile can be assessed by scanning Kelvin probe microscopy

Bimolecular recombination in ambipolar organic field effect transistors

NARCIS (Netherlands)

Charrier, D.S.H.; Vries, T. de; Mathijssen, S.G.J.; Geluk, E.-J.; Smits, E.C.P.; Kemerink, M.; Janssen, R.A.J.

2009-01-01

In ambipolar organic field effect transistors (OFET) the shape of the channel potential is intimately related to the recombination zone width W, and hence to the electron–hole recombination strength. Experimentally, the recombination profile can be assessed by scanning Kelvin probe microscopy

Genome-wide variation in recombination rate in Eucalyptus.

Science.gov (United States)

Gion, Jean-Marc; Hudson, Corey J; Lesur, Isabelle; Vaillancourt, René E; Potts, Brad M; Freeman, Jules S

2016-08-09

Meiotic recombination is a fundamental evolutionary process. It not only generates diversity, but influences the efficacy of natural selection and genome evolution. There can be significant heterogeneity in recombination rates within and between species, however this variation is not well understood outside of a few model taxa, particularly in forest trees. Eucalypts are forest trees of global economic importance, and dominate many Australian ecosystems. We studied recombination rate in Eucalyptus globulus using genetic linkage maps constructed in 10 unrelated individuals, and markers anchored to the Eucalyptus reference genome. This experimental design provided the replication to study whether recombination rate varied between individuals and chromosomes, and allowed us to study the genomic attributes and population genetic parameters correlated with this variation. Recombination rate varied significantly between individuals (range = 2.71 to 3.51 centimorgans/megabase [cM/Mb]), but was not significantly influenced by sex or cross type (F1 vs. F2). Significant differences in recombination rate between chromosomes were also evident (range = 1.98 to 3.81 cM/Mb), beyond those which were due to variation in chromosome size. Variation in chromosomal recombination rate was significantly correlated with gene density (r = 0.94), GC content (r = 0.90), and the number of tandem duplicated genes (r = -0.72) per chromosome. Notably, chromosome level recombination rate was also negatively correlated with the average genetic diversity across six species from an independent set of samples (r = -0.75). The correlations with genomic attributes are consistent with findings in other taxa, however, the direction of the correlation between diversity and recombination rate is opposite to that commonly observed. We argue this is likely to reflect the interaction of selection and specific genome architecture of Eucalyptus. Interestingly, the differences amongst

Induction of intrachromosomal homologous recombination in whole plants

International Nuclear Information System (INIS)

Puchta, H.; Swoboda, P.; Hohn, B.

1995-01-01

The influence of different factors on frequencies of intrachromosomal homologous recombination in whole Arabidopsis thaliana and tobacco plants was analyzed using a disrupted β-glucuronidase marker gene. Recombination frequencies were enhanced several fold by DNA damaging agents like UV-light or MMS (methyl methanesulfonate). Applying 3-methoxybenzamide (3-MB), an inhibitor of poly(ADP)ribose polymerase (PARP), an enzyme that is postulated to be involved in DNA repair, enhanced homologous recombination frequencies strongly. These findings indicate that homologous recombination is involved in DNA repair and can (at least partially) compensate for other DNA repair pathways. Indications that recombination in plants can be induced by environmental stress factors that are not likely to be involved in DNA metabolism were also found; Arabidopsis plants growing in a medium containing 0.1 M NaCl exhibited elevated recombination frequencies. The possible general effects of ‘environmental’ challenges on genome flexibility are discussed. (author)

Metal binding proteins, recombinant host cells and methods

Science.gov (United States)

Summers, Anne O.; Caguiat, Jonathan J.

2004-06-15

The present disclosure provides artificial heavy metal binding proteins termed chelons by the inventors. These chelons bind cadmium and/or mercuric ions with relatively high affinity. Also disclosed are coding sequences, recombinant DNA molecules and recombinant host cells comprising those recombinant DNA molecules for expression of the chelon proteins. In the recombinant host cells or transgenic plants, the chelons can be used to bind heavy metals taken up from contaminated soil, groundwater or irrigation water and to concentrate and sequester those ions. Recombinant enteric bacteria can be used within the gastrointestinal tracts of animals or humans exposed to toxic metal ions such as mercury and/or cadmium, where the chelon recombinantly expressed in chosen in accordance with the ion to be rededicated. Alternatively, the chelons can be immobilized to solid supports to bind and concentrate heavy metals from a contaminated aqueous medium including biological fluids.

Electric hydrogen recombiner special tests

International Nuclear Information System (INIS)

Wilson, J.F.

1975-12-01

Westinghouse has produced an electric hydrogen recombiner to control hydrogen levels in reactor containments following a postulated loss-of-coolant accident. The recombiner underwent extensive testing for NRC qualification (see WCAP 7709-L and Supplements 1, 2, 3, 4). As a result, WCAP 7709-L and Supplements 1, 2, 3, and 4 have been accepted by the NRC for reference in applications not committed to IEEE-323-1974. Supplement 5 and the next supplement will demonstrate conformance to IEEE-323-1974. This supplement describes additional tests, beyond those necessary to qualify the system, which will be referenced in supplement 6. Each test has demonstrated a considerable margin of safety over required performance. Concurrently, the test results increased the fund of technical information on the electric hydrogen recombiner

Frequent intra-subtype recombination among HIV-1 circulating in Tanzania.

Directory of Open Access Journals (Sweden)

Ireen E Kiwelu

Full Text Available The study estimated the prevalence of HIV-1 intra-subtype recombinant variants among female bar and hotel workers in Tanzania. While intra-subtype recombination occurs in HIV-1, it is generally underestimated. HIV-1 env gp120 V1-C5 quasispecies from 45 subjects were generated by single-genome amplification and sequencing (median (IQR of 38 (28-50 sequences per subject. Recombination analysis was performed using seven methods implemented within the recombination detection program version 3, RDP3. HIV-1 sequences were considered recombinant if recombination signals were detected by at least three methods with p-values of ≤0.05 after Bonferroni correction for multiple comparisons. HIV-1 in 38 (84% subjects showed evidence for intra-subtype recombination including 22 with HIV-1 subtype A1, 13 with HIV-1 subtype C, and 3 with HIV-1 subtype D. The distribution of intra-patient recombination breakpoints suggested ongoing recombination and showed selective enrichment of recombinant variants in 23 (60% subjects. The number of subjects with evidence of intra-subtype recombination increased from 29 (69% to 36 (82% over one year of follow-up, although the increase did not reach statistical significance. Adjustment for intra-subtype recombination is important for the analysis of multiplicity of HIV infection. This is the first report of high prevalence of intra-subtype recombination in the HIV/AIDS epidemic in Tanzania, a region where multiple HIV-1 subtypes co-circulate. HIV-1 intra-subtype recombination increases viral diversity and presents additional challenges for HIV-1 vaccine design.

Construction and characterization of a recombinant invertebrate iridovirus.

Science.gov (United States)

Ozgen, Arzu; Muratoglu, Hacer; Demirbag, Zihni; Vlak, Just M; van Oers, Monique M; Nalcacioglu, Remziye

2014-08-30

Chilo iridescent virus (CIV), officially named Insect iridescent virus 6 (IIV6), is the type species of the genus Iridovirus (family Iridoviridae). In this paper we constructed a recombinant CIV, encoding the green fluorescent protein (GFP). This recombinant can be used to investigate viral replication dynamics. We showed that homologous recombination is a valid method to make CIV gene knockouts and to insert foreign genes. The CIV 157L gene, putatively encoding a non-functional inhibitor of apoptosis (IAP), was chosen as target for foreign gene insertion. The gfp open reading frame preceded by the viral mcp promoter was inserted into the 157L locus by homologous recombination in Anthonomus grandis BRL-AG-3A cells. Recombinant virus (rCIV-Δ157L-gfp) was purified by successive rounds of plaque purification. All plaques produced by the purified recombinant virus emitted green fluorescence due to the presence of GFP. One-step growth curves for recombinant and wild-type CIV were similar and the recombinant was fully infectious in vivo. Hence, CIV157L can be inactivated without altering the replication kinetics of the virus. Consequently, the CIV 157L locus can be used as a site for insertion of foreign DNA, e.g. to modify viral properties for insect biocontrol. Copyright © 2014 Elsevier B.V. All rights reserved.

Poliovirus Polymerase Leu420 Facilitates RNA Recombination and Ribavirin Resistance

Science.gov (United States)

Kempf, Brian J.; Peersen, Olve B.

2016-01-01

ABSTRACT RNA recombination is important in the formation of picornavirus species groups and the ongoing evolution of viruses within species groups. In this study, we examined the structure and function of poliovirus polymerase, 3Dpol, as it relates to RNA recombination. Recombination occurs when nascent RNA products exchange one viral RNA template for another during RNA replication. Because recombination is a natural aspect of picornavirus replication, we hypothesized that some features of 3Dpol may exist, in part, to facilitate RNA recombination. Furthermore, we reasoned that alanine substitution mutations that disrupt 3Dpol-RNA interactions within the polymerase elongation complex might increase and/or decrease the magnitudes of recombination. We found that an L420A mutation in 3Dpol decreased the frequency of RNA recombination, whereas alanine substitutions at other sites in 3Dpol increased the frequency of recombination. The 3Dpol Leu420 side chain interacts with a ribose in the nascent RNA product 3 nucleotides from the active site of the polymerase. Notably, the L420A mutation that reduced recombination also rendered the virus more susceptible to inhibition by ribavirin, coincident with the accumulation of ribavirin-induced G→A and C→U mutations in viral RNA. We conclude that 3Dpol Leu420 is critically important for RNA recombination and that RNA recombination contributes to ribavirin resistance. IMPORTANCE Recombination contributes to the formation of picornavirus species groups and the emergence of circulating vaccine-derived polioviruses (cVDPVs). The recombinant viruses that arise in nature are occasionally more fit than either parental strain, especially when the two partners in recombination are closely related, i.e., members of characteristic species groups, such as enterovirus species groups A to H or rhinovirus species groups A to C. Our study shows that RNA recombination requires conserved features of the viral polymerase. Furthermore, a

Genome-wide recombination dynamics are associated with phenotypic variation in maize.

Science.gov (United States)

Pan, Qingchun; Li, Lin; Yang, Xiaohong; Tong, Hao; Xu, Shutu; Li, Zhigang; Li, Weiya; Muehlbauer, Gary J; Li, Jiansheng; Yan, Jianbing

2016-05-01

Meiotic recombination is a major driver of genetic diversity, species evolution, and agricultural improvement. Thus, an understanding of the genetic recombination landscape across the maize (Zea mays) genome will provide insight and tools for further study of maize evolution and improvement. Here, we used c. 50 000 single nucleotide polymorphisms to precisely map recombination events in 12 artificial maize segregating populations. We observed substantial variation in the recombination frequency and distribution along the ten maize chromosomes among the 12 populations and identified 143 recombination hot regions. Recombination breakpoints were partitioned into intragenic and intergenic events. Interestingly, an increase in the number of genes containing recombination events was accompanied by a decrease in the number of recombination events per gene. This kept the overall number of intragenic recombination events nearly invariable in a given population, suggesting that the recombination variation observed among populations was largely attributed to intergenic recombination. However, significant associations between intragenic recombination events and variation in gene expression and agronomic traits were observed, suggesting potential roles for intragenic recombination in plant phenotypic diversity. Our results provide a comprehensive view of the maize recombination landscape, and show an association between recombination, gene expression and phenotypic variation, which may enhance crop genetic improvement. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

RNAi and heterochromatin repress centromeric meiotic recombination

DEFF Research Database (Denmark)

Ellermeier, Chad; Higuchi, Emily C; Phadnis, Naina

2010-01-01

During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes, is essen......During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes....... Surprisingly, one mutant derepressed for recombination in the heterochromatic mating-type region during meiosis and several mutants derepressed for centromeric gene expression during mitotic growth are not derepressed for centromeric recombination during meiosis. These results reveal a complex relation between...... types of repression by heterochromatin. Our results also reveal a previously undemonstrated role for RNAi and heterochromatin in the repression of meiotic centromeric recombination and, potentially, in the prevention of birth defects by maintenance of proper chromosome segregation during meiosis....

Effects of UV radiation on genetic recombination

International Nuclear Information System (INIS)

Vlahovic, K.; Zahradka, D.; Petranovic, M.; Petranovic, D.

1996-01-01

We have used the model consisting of Escherichia coli cells and l phage to study the effects of UV radiation on genetic recombination. We found two radiation induced processes that reduce or inhibit genetic recombination. One such process leads to the inability of prophage to excise itself from the irradiated bacterial chromosome by the site-specific recombination. The other process was shown to inhibit a type of general recombination by which the prophage transfers one of its genetic markers to the infecting homologous phage. Loss of the prophage ability to take part in both site-specific and general recombination was shown to develop in recB + but not in recB cells. From this we infer that the loss of prophage recombinogenicity in irradiated cells is a consequence of one process in which RecBCD enzyme (the product of recB, recC and recD genes) plays an essential role. (author)

Temporally-controlled site-specific recombination in zebrafish.

Directory of Open Access Journals (Sweden)

Stefan Hans

Full Text Available Conventional use of the site-specific recombinase Cre is a powerful technology in mouse, but almost absent in other vertebrate model organisms. In zebrafish, Cre-mediated recombination efficiency was previously very low. Here we show that using transposon-mediated transgenesis, Cre is in fact highly efficient in this organism. Furthermore, temporal control of recombination can be achieved by using the ligand-inducible CreER(T2. Site-specific recombination only occurs upon administration of the drug tamoxifen (TAM or its active metabolite, 4-hydroxy-tamoxifen (4-OHT. Cre-mediated recombination is detectable already 4 or 2 hours after administration of TAM or 4-OHT, demonstrating fast recombination kinetics. In addition, low doses of TAM allow mosaic labeling of single cells. Combined, our results show that conditional Cre/lox will be a valuable tool for both, embryonic and adult zebrafish studies. Furthermore, single copy insertion transgenesis of Cre/lox constructs suggest a strategy suitable also for other organisms.

Algae-based oral recombinant vaccines

Science.gov (United States)

Specht, Elizabeth A.; Mayfield, Stephen P.

2014-01-01

Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for “molecular pharming” in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae could be poised to become the next candidate in recombinant subunit vaccine production, as they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and systemic immune reactivity. PMID:24596570

Recombination in hepatitis C virus.

Science.gov (United States)

González-Candelas, Fernando; López-Labrador, F Xavier; Bracho, María Alma

2011-10-01

Hepatitis C virus (HCV) is a Flavivirus with a positive-sense, single-stranded RNA genome of about 9,600 nucleotides. It is a major cause of liver disease, infecting almost 200 million people all over the world. Similarly to most RNA viruses, HCV displays very high levels of genetic diversity which have been used to differentiate six major genotypes and about 80 subtypes. Although the different genotypes and subtypes share basic biological and pathogenic features they differ in clinical outcomes, response to treatment and epidemiology. The first HCV recombinant strain, in which different genome segments derived from parentals of different genotypes, was described in St. Petersburg (Russia) in 2002. Since then, there have been only a few more than a dozen reports including descriptions of HCV recombinants at all levels: between genotypes, between subtypes of the same genotype and even between strains of the same subtype. Here, we review the literature considering the reasons underlying the difficulties for unequivocally establishing recombination in this virus along with the analytical methods necessary to do it. Finally, we analyze the potential consequences, especially in clinical practice, of HCV recombination in light of the coming new therapeutic approaches against this virus.

Algae-based oral recombinant vaccines

Directory of Open Access Journals (Sweden)

Elizabeth A Specht

2014-02-01

Full Text Available Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for molecular pharming in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae are poised to become the next candidate in recombinant subunit vaccine production, and they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally-delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and system immune reactivity.

Enhanced defects recombination in ion irradiated SiC

International Nuclear Information System (INIS)

Izzo, G.; Litrico, G.; Grassia, F.; Calcagno, L.; Foti, G.

2010-01-01

Point defects induced in SiC by ion irradiation show a recombination at temperatures as low as 320 K and this process is enhanced after running current density ranging from 80 to 120 A/cm 2 . Ion irradiation induces in SiC the formation of different defect levels and low-temperature annealing changes their concentration. Some levels (S 0 , S x and S 2 ) show a recombination and simultaneously a new level (S 1 ) is formed. An enhanced recombination of defects is besides observed after running current in the diode at room temperature. The carriers introduction reduces the S 2 trap concentration, while the remaining levels are not modified. The recombination is negligible up to a current density of 50 A/cm 2 and increases at higher current density. The enhanced recombination of the S 2 trap occurs at 300 K, which otherwise requires a 400 K annealing temperature. The process can be related to the electron-hole recombination at the associated defect.

PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

Energy Technology Data Exchange (ETDEWEB)

Moriya, Takashi J., E-mail: takashi.moriya@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8583 (Japan)

2012-05-01

Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

Dissociation of recombinant prion autocatalysis from infectivity.

Science.gov (United States)

Noble, Geoffrey P; Supattapone, Surachai

2015-01-01

Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only hypothesis of prion replication--that autocatalytic PrP conformers should be infectious. To understand this dissociation of autocatalysis from infectivity, we recently performed a structural and functional comparison between a highly infectious and non-infectious pair of autocatalytic recombinant PrP conformers derived from the same initial prion strain. (1) We identified restricted, C-terminal structural differences between these 2 conformers and provided evidence that these relatively subtle differences prevent the non-infectious conformer from templating the conversion of native PrP(C) substrates containing a glycosylphosphatidylinositol (GPI) anchor. (1) In this article we discuss a model, consistent with these findings, in which recombinant PrP, lacking post-translational modifications and associated folding constraints, is capable of adopting a wide variety of autocatalytic conformations. Only a subset of these recombinant conformers can be adopted by post-translationally modified native PrP(C), and this subset represents the recombinant conformers with high specific infectivity. We examine this model's implications for the generation of highly infectious recombinant prions and the protein-only hypothesis of prion replication.

Recombiner

International Nuclear Information System (INIS)

Saalfrank, H.

1985-01-01

Air containing hydrogen can be oxidized by heating in a container called a recombiner, in order to avoid the collection of hydrogen. The container is long and a large number of straight heating bars are arranged in parallel in it and they are flanged to a lid. The heating bars are surrounded by tubes, in order to obtain good heat transfer by a narrow annular gap. (orig.) [de

Anti-proliferative activity of recombinant melittin expressed in ...

African Journals Online (AJOL)

Recombinant melittin was then successfully expressed in Escherichia coli. The activity of affinity-purified recombinant melittin was determined in human leukemic U937 cells. Results show that the recombinant melittin had the same anti-proliferative activity in human leukemic U937 cells in vitro as natural one. This shows the ...

Site directed recombination

Science.gov (United States)

Jurka, Jerzy W.

1997-01-01

Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

Recombination and dissociative recombination of H2+ and H3+ ions on surfaces with application to hydrogen negative ion sources

International Nuclear Information System (INIS)

Hiskes, J.R.; Karo, A.M.

1988-12-01

A four-step model for recombination and dissociative recombination of H 2 + and H 3 + ions on metal surfaces is discussed. Vibrationally excited molecules, H 2 (v''), from H 3 + recombination are produced in a broad spectrum that enhances the excited level distribution. The application of this latter process to hydrogen negative ion discharges is discussed. 5 refs., 3 figs., 1 tab

Recombination rate variation in mice from an isolated island.

Science.gov (United States)

Wang, Richard J; Gray, Melissa M; Parmenter, Michelle D; Broman, Karl W; Payseur, Bret A

2017-01-01

Recombination rate is a heritable trait that varies among individuals. Despite the major impact of recombination rate on patterns of genetic diversity and the efficacy of selection, natural variation in this phenotype remains poorly characterized. We present a comparison of genetic maps, sampling 1212 meioses, from a unique population of wild house mice (Mus musculus domesticus) that recently colonized remote Gough Island. Crosses to a mainland reference strain (WSB/EiJ) reveal pervasive variation in recombination rate among Gough Island mice, including subchromosomal intervals spanning up to 28% of the genome. In spite of this high level of polymorphism, the genomewide recombination rate does not significantly vary. In general, we find that recombination rate varies more when measured in smaller genomic intervals. Using the current standard genetic map of the laboratory mouse to polarize intervals with divergent recombination rates, we infer that the majority of evolutionary change occurred in one of the two tested lines of Gough Island mice. Our results confirm that natural populations harbour a high level of recombination rate polymorphism and highlight the disparities in recombination rate evolution across genomic scales. © 2016 John Wiley & Sons Ltd.

Live recombinant BHV/BRSV vaccine

OpenAIRE

Keil, G.M.; Rijsewijk, F.A.M.

1998-01-01

The present invention refers to synthetic Bovine Respiratory Syncytium virus genes. Also the invention relates to live attenuated Bovine Herpesvirus recombinants carrying such synthetic genes. Furthermore, the invention relates to vaccines based on these live attenuated recombinants, for the protection of cattle against both Bovine herpesvirus infection and against Bovine Respiratory Syncytium virus infection. Also the invention relates to methods for the preparation of such live attenuated r...

Recombinant snake venom prothrombin activators

OpenAIRE

L?vgren, Ann

2012-01-01

Three prothrombin activators; ecarin, which was originally isolated from the venom of the saw-scaled viper Echis carinatus, trocarin from the rough-scaled snake Tropidechis carinatus, and oscutarin from the Taipan snake Oxyuranus scutellatus, were expressed in mammalian cells with the purpose to obtain recombinant prothrombin activators that could be used to convert prothrombin to thrombin. We have previously reported that recombinant ecarin can efficiently generate thrombin without the need ...

Electronic recombination in some physics problems

International Nuclear Information System (INIS)

Guzman, O.

1988-01-01

This work is related to calculations of electronic recombination rates, as a function of electronic density, electronic temperature, and ion nuclear charge. Recombination times can be calculated and compared to cooling time, in cooling processes of ion beans by electrons from storage rings. (A.C.A.S.) [pt

Expression and purification of recombinant hemoglobin in Escherichia coli.

Directory of Open Access Journals (Sweden)

Chandrasekhar Natarajan

Full Text Available Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe a protocol for expressing Hbs with low intrinsic solubilities. Since the α- and β-chain Hbs of different species span a broad range of solubilities, experimental protocols that have been optimized for expressing recombinant human HbA may often prove unsuitable for the recombinant expression of wildtype and mutant Hbs of other species.As a test case for our expression system, we produced recombinant Hbs of the deer mouse (Peromyscus maniculatus, a species that has been the subject of research on mechanisms of Hb adaptation to hypoxia. By experimentally assessing the combined effects of induction temperature, induction time and E. coli expression strain on the solubility of recombinant deer mouse Hbs, we identified combinations of expression conditions that greatly enhanced the yield of recombinant protein and which also increased the efficiency of post-translational modifications.Our protocol should prove useful for the experimental study of recombinant Hbs in many non-human animals. One of the chief advantages of our protocol is that we can express soluble recombinant Hb without co-expressing molecular chaperones, and without the need for additional reconstitution or heme-incorporation steps. Moreover, our plasmid construct contains a combination of unique restriction sites that allows us to produce recombinant Hbs with different α- and β-chain subunit combinations by means of cassette mutagenesis.

Expression and purification of recombinant hemoglobin in Escherichia coli.

Science.gov (United States)

Natarajan, Chandrasekhar; Jiang, Xiaoben; Fago, Angela; Weber, Roy E; Moriyama, Hideaki; Storz, Jay F

2011-01-01

Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb) and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe a protocol for expressing Hbs with low intrinsic solubilities. Since the α- and β-chain Hbs of different species span a broad range of solubilities, experimental protocols that have been optimized for expressing recombinant human HbA may often prove unsuitable for the recombinant expression of wildtype and mutant Hbs of other species. As a test case for our expression system, we produced recombinant Hbs of the deer mouse (Peromyscus maniculatus), a species that has been the subject of research on mechanisms of Hb adaptation to hypoxia. By experimentally assessing the combined effects of induction temperature, induction time and E. coli expression strain on the solubility of recombinant deer mouse Hbs, we identified combinations of expression conditions that greatly enhanced the yield of recombinant protein and which also increased the efficiency of post-translational modifications. Our protocol should prove useful for the experimental study of recombinant Hbs in many non-human animals. One of the chief advantages of our protocol is that we can express soluble recombinant Hb without co-expressing molecular chaperones, and without the need for additional reconstitution or heme-incorporation steps. Moreover, our plasmid construct contains a combination of unique restriction sites that allows us to produce recombinant Hbs with different α- and β-chain subunit combinations by means of cassette mutagenesis.

Expression and purification of recombinant hemoglobin in Escherichia coli

DEFF Research Database (Denmark)

Natarajan, Chandrasekhar; Jiang, Xiaoben; Fago, Angela

2011-01-01

BACKGROUND: Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb) and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe...... a protocol for expressing Hbs with low intrinsic solubilities. Since the alpha- and beta-chain Hbs of different species span a broad range of solubilities, experimental protocols that have been optimized for expressing recombinant human HbA may often prove unsuitable for the recombinant expression......-translational modifications. CONCLUSION/SIGNIFICANCE: Our protocol should prove useful for the experimental study of recombinant Hbs in many non-human animals. One of the chief advantages of our protocol is that we can express soluble recombinant Hb without co-expressing molecular chaperones, and without the need...

Bayesian inference of shared recombination hotspots between humans and chimpanzees.

Science.gov (United States)

Wang, Ying; Rannala, Bruce

2014-12-01

Recombination generates variation and facilitates evolution. Recombination (or lack thereof) also contributes to human genetic disease. Methods for mapping genes influencing complex genetic diseases via association rely on linkage disequilibrium (LD) in human populations, which is influenced by rates of recombination across the genome. Comparative population genomic analyses of recombination using related primate species can identify factors influencing rates of recombination in humans. Such studies can indicate how variable hotspots for recombination may be both among individuals (or populations) and over evolutionary timescales. Previous studies have suggested that locations of recombination hotspots are not conserved between humans and chimpanzees. We made use of the data sets from recent resequencing projects and applied a Bayesian method for identifying hotspots and estimating recombination rates. We also reanalyzed SNP data sets for regions with known hotspots in humans using samples from the human and chimpanzee. The Bayes factors (BF) of shared recombination hotspots between human and chimpanzee across regions were obtained. Based on the analysis of the aligned regions of human chromosome 21, locations where the two species show evidence of shared recombination hotspots (with high BFs) were identified. Interestingly, previous comparative studies of human and chimpanzee that focused on the known human recombination hotspots within the β-globin and HLA regions did not find overlapping of hotspots. Our results show high BFs of shared hotspots at locations within both regions, and the estimated locations of shared hotspots overlap with the locations of human recombination hotspots obtained from sperm-typing studies. Copyright © 2014 by the Genetics Society of America.

Effects of the rad52 gene on recombination in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, S.; Prakash, L.; Burke, W.; Montelone, B.A.

1979-01-01

Effects of the rad52 mutation in Saccharomyces cerevisiae on meiotic, γ-ray-induced, uv-induced, and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNA synthesis; sporulation occurs but inviable spores are produced. Intra- and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the hisl-1/hisl-315 and trp5-2/trp5-48 heteroalleles. Gene-centromere recombination was also not observed in rad52/rad52 diploids. No γ-ray-induced intragenic mitotic recombination is seen in rad52/rad52 diploids and uv-induced intragenic recombination is greatly reduced. However, spontaneous mitotic recombination is not similarly affected. The RAD52 gene thus functions in recombination in meiosis and in γ-ray and uv-induced mitotic recombination but not in spontaneous mitotic recombination

Heterogeneous recombination among Hepatitis B virus genotypes.

Science.gov (United States)

Castelhano, Nadine; Araujo, Natalia M; Arenas, Miguel

2017-10-01

The rapid evolution of Hepatitis B virus (HBV) through both evolutionary forces, mutation and recombination, allows this virus to generate a large variety of adapted variants at both intra and inter-host levels. It can, for instance, generate drug resistance or the diverse viral genotypes that currently exist in the HBV epidemics. Concerning the latter, it is known that recombination played a major role in the emergence and genetic diversification of novel genotypes. In this regard, the quantification of viral recombination in each genotype can provide relevant information to devise expectations about the evolutionary trends of the epidemic. Here we measured the amount of this evolutionary force by estimating global and local recombination rates in >4700 HBV complete genome sequences corresponding to nine (A to I) HBV genotypes. Counterintuitively, we found that genotype E presents extremely high levels of recombination, followed by genotypes B and C. On the other hand, genotype G presents the lowest level, where recombination is almost negligible. We discuss these findings in the light of known characteristics of these genotypes. Additionally, we present a phylogenetic network to depict the evolutionary history of the studied HBV genotypes. This network clearly classified all genotypes into specific groups and indicated that diverse pairs of genotypes are derived from a common ancestor (i.e., C-I, D-E and, F-H) although still the origin of this virus presented large uncertainty. Altogether we conclude that the amount of observed recombination is heterogeneous among HBV genotypes and that this heterogeneity can influence on the future expansion of the epidemic. Copyright © 2017 Elsevier B.V. All rights reserved.

Graded Recombination Layers for Multijunction Photovoltaics

KAUST Repository

Koleilat, Ghada I.

2012-06-13

Multijunction devices consist of a stack of semiconductor junctions having bandgaps tuned across a broad spectrum. In solar cells this concept is used to increase the efficiency of photovoltaic harvesting, while light emitters and detectors use it to achieve multicolor and spectrally tunable behavior. In series-connected current-matched multijunction devices, the recombination layers must allow the hole current from one cell to recombine, with high efficiency and low voltage loss, with the electron current from the next cell. We recently reported a tandem solar cell in which the recombination layer was implemented using a progression of n-type oxides whose doping densities and work functions serve to connect, with negligible resistive loss at solar current densities, the constituent cells. Here we present the generalized conditions for design of efficient graded recombination layer solar devices. We report the number of interlayers and the requirements on work function and doping of each interlayer, to bridge an work function difference as high as 1.6 eV. We also find solutions that minimize the doping required of the interlayers in order to minimize optical absorption due to free carriers in the graded recombination layer (GRL). We demonstrate a family of new GRL designs experimentally and highlight the benefits of the progression of dopings and work functions in the interlayers. © 2012 American Chemical Society.

Review of Parton Recombination Models

International Nuclear Information System (INIS)

Bass, Steffen A

2006-01-01

Parton recombination models have been very successful in explaining data taken at RHIC on hadron spectra and emission patterns in Au+Au collisions at transverse momenta above 2 GeV/c, which have exhibited features which could not be understood in the framework of basic perturbative QCD. In this article I will review the current status on recombination models and outline which future challenges need to be addressed by this class of models

The model of recombination process in TlBr

International Nuclear Information System (INIS)

Grigorjeva, L.; Millers, D.

2002-01-01

The time-resolved luminescence was used as a tool in the study of recombination process in several undoped TlBr crystals. The spectra and decay kinetics observed under electron beam excitation were investigated. Observation of several luminescence bands with different decay rates shows that more than one recombination center is involved and the recombination process is quite complicated. The band at ∼2.5 eV is dominant under 10 ns excitation pulse (electron beam or nitrogen laser pulses). The results of short-lived absorption and luminescence are used for analysis of possible mechanisms of recombination processes in TlBr

Affinity purification of recombinant human plasminogen activator ...

African Journals Online (AJOL)

Affinity purification of recombinant human plasminogen activator from ... Screening antibody was performed using rhPA milk in an ELISA-elution assay. ... useful for purifying other tPA mutants or other novel recombinant milkderived proteins.

Recombinant human bone morphogenetic protein induces bone formation

International Nuclear Information System (INIS)

Wang, E.A.; Rosen, V.; D'Alessandro, J.S.; Bauduy, M.; Cordes, P.; Harada, T.; Israel, D.I.; Hewick, R.M.; Kerns, K.M.; LaPan, P.; Luxenberg, D.P.; McQuaid, D.; Moutsatsos, I.K.; Nove, J.; Wozney, J.M.

1990-01-01

The authors have purified and characterized active recombinant human bone morphogenetic protein (BMP) 2A. Implantation of the recombinant protein in rats showed that a single BMP can induce bone formation in vivo. A dose-response and time-course study using the rat ectopic bone formation assay revealed that implantation of 0.5-115 μg of partially purified recombinant human BMP-2A resulted in cartilage by day 7 and bone formation by day 14. The time at which bone formation occurred was dependent on the amount of BMP-2A implanted; at high doses bone formation could be observed at 5 days. The cartilage- and bone-inductive activity of the recombinant BMP-2A is histologically indistinguishable from that of bone extracts. Thus, recombinant BMP-2A has therapeutic potential to promote de novo bone formation in humans

Inference of Ancestral Recombination Graphs through Topological Data Analysis

Science.gov (United States)

Cámara, Pablo G.; Levine, Arnold J.; Rabadán, Raúl

2016-01-01

The recent explosion of genomic data has underscored the need for interpretable and comprehensive analyses that can capture complex phylogenetic relationships within and across species. Recombination, reassortment and horizontal gene transfer constitute examples of pervasive biological phenomena that cannot be captured by tree-like representations. Starting from hundreds of genomes, we are interested in the reconstruction of potential evolutionary histories leading to the observed data. Ancestral recombination graphs represent potential histories that explicitly accommodate recombination and mutation events across orthologous genomes. However, they are computationally costly to reconstruct, usually being infeasible for more than few tens of genomes. Recently, Topological Data Analysis (TDA) methods have been proposed as robust and scalable methods that can capture the genetic scale and frequency of recombination. We build upon previous TDA developments for detecting and quantifying recombination, and present a novel framework that can be applied to hundreds of genomes and can be interpreted in terms of minimal histories of mutation and recombination events, quantifying the scales and identifying the genomic locations of recombinations. We implement this framework in a software package, called TARGet, and apply it to several examples, including small migration between different populations, human recombination, and horizontal evolution in finches inhabiting the Galápagos Islands. PMID:27532298

Retroviral Vectors for Analysis of Viral Mutagenesis and Recombination

Directory of Open Access Journals (Sweden)

Jonathan M.O. Rawson

2014-09-01

Full Text Available Retrovirus population diversity within infected hosts is commonly high due in part to elevated rates of replication, mutation, and recombination. This high genetic diversity often complicates the development of effective diagnostics, vaccines, and antiviral drugs. This review highlights the diverse vectors and approaches that have been used to examine mutation and recombination in retroviruses. Retroviral vectors for these purposes can broadly be divided into two categories: those that utilize reporter genes as mutation or recombination targets and those that utilize viral genes as targets of mutation or recombination. Reporter gene vectors greatly facilitate the detection, quantification, and characterization of mutants and/or recombinants, but may not fully recapitulate the patterns of mutagenesis or recombination observed in native viral gene sequences. In contrast, the detection of mutations or recombination events directly in viral genes is more biologically relevant but also typically more challenging and inefficient. We will highlight the advantages and disadvantages of the various vectors and approaches used as well as propose ways in which they could be improved.

Hadron production at RHIC: recombination of quarks

Energy Technology Data Exchange (ETDEWEB)

Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

2005-01-01

We discuss quark recombination applied to the hadronization of a quark gluon plasma. It has been shown that the quark recombination model can explain essential features of hadron production measured in high energy heavy ion collisions.

Catalytic hydrogen recombination for nuclear containments

International Nuclear Information System (INIS)

Koroll, G.W.; Lau, D.W.P.; Dewit, W.A.; Graham, W.R.C.

1994-01-01

Catalytic recombiners appear to be a credible option for hydrogen mitigation in nuclear containments. The passive operation, versatility and ease of back fitting are appealing for existing stations and new designs. Recently, a generation of wet-proofed catalyst materials have been developed at AECL which are highly specific to H 2 -O 2 , are active at ambient temperatures and are being evaluated for containment applications. Two types of catalytic recombiners were evaluated for hydrogen removal in containments based on the AECL catalyst. The first is a catalytic combustor for application in existing air streams such as provided by fans or ventilation systems. The second is an autocatalytic recombiner which uses the enthalpy of reaction to produce natural convective flow over the catalyst elements. Intermediate-scale results obtained in 6 m 3 and 10 m 3 spherical and cylindrical vessels are given to demonstrate self-starting limits, operating limits, removal capacity, scaling parameters, flow resistance, mixing behaviour in the vicinity of an operating recombiner and sensitivity to poisoning, fouling and radiation. (author). 13 refs., 10 figs

Recombination Processes and Nonlinear Markov Chains.

Science.gov (United States)

Pirogov, Sergey; Rybko, Alexander; Kalinina, Anastasia; Gelfand, Mikhail

2016-09-01

Bacteria are known to exchange genetic information by horizontal gene transfer. Since the frequency of homologous recombination depends on the similarity between the recombining segments, several studies examined whether this could lead to the emergence of subspecies. Most of them simulated fixed-size Wright-Fisher populations, in which the genetic drift should be taken into account. Here, we use nonlinear Markov processes to describe a bacterial population evolving under mutation and recombination. We consider a population structure as a probability measure on the space of genomes. This approach implies the infinite population size limit, and thus, the genetic drift is not assumed. We prove that under these conditions, the emergence of subspecies is impossible.

[Construction and expression of a recombinant adenovirus with LZP3].

Science.gov (United States)

Chen, Bang-dang; Zhang, Fu-chun; Sun, Mei-yu; Li, Yi-jie; Ma, Zheng-hai

2007-08-01

To explore a new immunocontraceptive vaccine and construct an attenuated recombinant adenoviral vaccine against Lagurus lagurus zona pellucida 3(LZP3). LZP3 gene was subcloned into the shuttle vector pShuttle-CMV, and then a two-step transformation procedure was employed to construct a recombinant adenoviral plasmid with LZP3, which was digested with Pac I and transfected into HEK293 cells to package recombinant adenovirus particles. Finally, HeLa cells were infected by the recombinant adenovirus. LZP3 gene was detected from the recombinant virus by PCR, and its transcription and expression were analyzed by RT-PCR and Western blot. Recombinant adenovirus vector pAd-LZP3 with LZP3 gene was constructed by homologous recombination in E.coli, and a recombinant adenovirus was obtained by transfecting HEK293 cells with pAd-LZP3. PCR test indicated that LZP3 gene was successfully integrated into the adenoviral genome, and the titer of the recombinant adenovirus reached 1.2x10(10) pfu/L. The transcription and expression of LZP3 gene in the infected HeLa cells were confirmed by RT-PCR and Western blot. The recombinant adenovirus RAd-LZP3 can be successfully expressed in the infected HeLa cells, which lays the foundation for further researches into immunizing animals with RAd-LZP3.

Genetic characterization of somatic recombination in Trichoderma pseudokoningii

Directory of Open Access Journals (Sweden)

Barcellos Fernando Gomes

2003-01-01

Full Text Available Crossing experiments via hyphal anastomosis between two strains contrasting for auxotrophic markers of Trichoderma pseudokoningii were conducted to characterize the somatic recombination process in this specie. Four crossings were made and a total of 1052 colonies obtained from conidial suspensions of the heterokaryotic colonies were analyzed. Sixty-eight recombinant colonies, from four growing generations, were analyzed for the auxotrophic markers. Of the 68 colonies analyzed, 58 were stable after four generations and the remainders were unstable, reverting to one of the parentals. Most of the recombinant colonies were unstable through subculture and after four growing generations they showed the leu ino met markers (auxotrophic for leucin, inositol and metionin respectively. The unstable recombinant colonies showed irregular growing borders, sparse sporulation and frequent sector formation. The results suggest the occurrence of recombination mechanisms in the heterokaryon (somatic recombination, different from those described for the parasexual cycle or parameiosis. Therefore, we proposed the ocurrence of nuclei degradation from one parental (non prevalent parental in the heterokaryon and that the resulting chromosomal fragments may be incorporated into whole nuclei of the another parental (prevalent parental. However the parameiosis as originally described cannot be excluded.

Variation in Recombination Rate and Its Genetic Determinism in Sheep Populations.

Science.gov (United States)

Petit, Morgane; Astruc, Jean-Michel; Sarry, Julien; Drouilhet, Laurence; Fabre, Stéphane; Moreno, Carole R; Servin, Bertrand

2017-10-01

Recombination is a complex biological process that results from a cascade of multiple events during meiosis. Understanding the genetic determinism of recombination can help to understand if and how these events are interacting. To tackle this question, we studied the patterns of recombination in sheep, using multiple approaches and data sets. We constructed male recombination maps in a dairy breed from the south of France (the Lacaune breed) at a fine scale by combining meiotic recombination rates from a large pedigree genotyped with a 50K SNP array and historical recombination rates from a sample of unrelated individuals genotyped with a 600K SNP array. This analysis revealed recombination patterns in sheep similar to other mammals but also genome regions that have likely been affected by directional and diversifying selection. We estimated the average recombination rate of Lacaune sheep at 1.5 cM/Mb, identified ∼50,000 crossover hotspots on the genome, and found a high correlation between historical and meiotic recombination rate estimates. A genome-wide association study revealed two major loci affecting interindividual variation in recombination rate in Lacaune, including the RNF212 and HEI10 genes and possibly two other loci of smaller effects including the KCNJ15 and FSHR genes. The comparison of these new results to those obtained previously in a distantly related population of domestic sheep (the Soay) revealed that Soay and Lacaune males have a very similar distribution of recombination along the genome. The two data sets were thus combined to create more precise male meiotic recombination maps in Sheep. However, despite their similar recombination maps, Soay and Lacaune males were found to exhibit different heritabilities and QTL effects for interindividual variation in genome-wide recombination rates. This highlights the robustness of recombination patterns to underlying variation in their genetic determinism. Copyright © 2017 by the Genetics Society

Evolution of recombination in eutherian mammals: insights into mechanisms that affect recombination rates and crossover interference

OpenAIRE

Segura, Joana; Ferretti, Luca; Ramos-Onsins, Sebastián; Capilla, Laia; Farré, Marta; Reis, Fernanda; Oliver-Bonet, Maria; Fernández-Bellón, Hugo; Garcia, Francisca; Garcia-Caldés, Montserrat; Robinson, Terence J.; Ruiz-Herrera, Aurora

2013-01-01

Recombination allows faithful chromosomal segregation during meiosis and contributes to the production of new heritable allelic variants that are essential for the maintenance of genetic diversity. Therefore, an appreciation of how this variation is created and maintained is of critical importance to our understanding of biodiversity and evolutionary change. Here, we analysed the recombination features from species representing the major eutherian taxonomic groups Afrotheria, Rodentia, Primat...

In vitro V(D)J recombination: signal joint formation.

Science.gov (United States)

Cortes, P; Weis-Garcia, F; Misulovin, Z; Nussenzweig, A; Lai, J S; Li, G; Nussenzweig, M C; Baltimore, D

1996-11-26

The first step of V(D)J recombination, specific cleavage at the recombination signal sequence (RSS), can be carried out by the recombination activating proteins RAG1 and RAG2. In vivo, the cleaved coding and signal ends must be rejoined to generate functional antigen receptors and maintain chromosomal integrity. We have investigated signal joint formation using deletion and inversion substrates in a cell free system. RAG1 and RAG2 alone or in combination were unable to generate signal joints. However, RAG1 and RAG2 complemented with nuclear extracts were able to recombine an extrachromosomal substrate and form precise signal joints. The in vitro reaction resembled authentic V(D)J recombination in being Ku-antigen-dependent.

Recombinant DNA production of spider silk proteins.

Science.gov (United States)

Tokareva, Olena; Michalczechen-Lacerda, Valquíria A; Rech, Elíbio L; Kaplan, David L

2013-11-01

Spider dragline silk is considered to be the toughest biopolymer on Earth due to an extraordinary combination of strength and elasticity. Moreover, silks are biocompatible and biodegradable protein-based materials. Recent advances in genetic engineering make it possible to produce recombinant silks in heterologous hosts, opening up opportunities for large-scale production of recombinant silks for various biomedical and material science applications. We review the current strategies to produce recombinant spider silks. © 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Recombination-Driven Genome Evolution and Stability of Bacterial Species.

Science.gov (United States)

Dixit, Purushottam D; Pang, Tin Yau; Maslov, Sergei

2017-09-01

While bacteria divide clonally, horizontal gene transfer followed by homologous recombination is now recognized as an important contributor to their evolution. However, the details of how the competition between clonality and recombination shapes genome diversity remains poorly understood. Using a computational model, we find two principal regimes in bacterial evolution and identify two composite parameters that dictate the evolutionary fate of bacterial species. In the divergent regime, characterized by either a low recombination frequency or strict barriers to recombination, cohesion due to recombination is not sufficient to overcome the mutational drift. As a consequence, the divergence between pairs of genomes in the population steadily increases in the course of their evolution. The species lacks genetic coherence with sexually isolated clonal subpopulations continuously formed and dissolved. In contrast, in the metastable regime, characterized by a high recombination frequency combined with low barriers to recombination, genomes continuously recombine with the rest of the population. The population remains genetically cohesive and temporally stable. Notably, the transition between these two regimes can be affected by relatively small changes in evolutionary parameters. Using the Multi Locus Sequence Typing (MLST) data, we classify a number of bacterial species to be either the divergent or the metastable type. Generalizations of our framework to include selection, ecologically structured populations, and horizontal gene transfer of nonhomologous regions are discussed as well. Copyright © 2017 by the Genetics Society of America.

Genetic recombination of tick-borne flaviviruses among wild-type strains.

Science.gov (United States)

Norberg, Peter; Roth, Anette; Bergström, Tomas

2013-06-05

Genetic recombination has been suggested to occur in mosquito-borne flaviviruses. In contrast, tick-borne flaviviruses have been thought to evolve in a clonal manner, although recent studies suggest that recombination occurs also for these viruses. We re-analyzed the data and found that previous conclusions on wild type recombination were probably falsely drawn due to misalignments of nucleotide sequences, ambiguities in GenBank sequences, or different laboratory culture histories suggestive of recombination events in laboratory. To evaluate if reliable predictions of wild type recombination of tick-borne flaviviruses can be made, we analyzed viral strains sequenced exclusively for this study, and other flavivirus sequences retrieved from GenBank. We detected genetic signals supporting recombination between viruses within the three clades of TBEV-Eu, TBEV-Sib and TBEV-Fe, respectively. Our results suggest that the tick-borne encephalitis viruses may undergo recombination under natural conditions, but that geographic barriers restrict most recombination events to involve only closely genetically related viruses. Copyright © 2013 Elsevier Inc. All rights reserved.

The influence of recombination on human genetic diversity.

Directory of Open Access Journals (Sweden)

Chris C A Spencer

2006-09-01

Full Text Available In humans, the rate of recombination, as measured on the megabase scale, is positively associated with the level of genetic variation, as measured at the genic scale. Despite considerable debate, it is not clear whether these factors are causally linked or, if they are, whether this is driven by the repeated action of adaptive evolution or molecular processes such as double-strand break formation and mismatch repair. We introduce three innovations to the analysis of recombination and diversity: fine-scale genetic maps estimated from genotype experiments that identify recombination hotspots at the kilobase scale, analysis of an entire human chromosome, and the use of wavelet techniques to identify correlations acting at different scales. We show that recombination influences genetic diversity only at the level of recombination hotspots. Hotspots are also associated with local increases in GC content and the relative frequency of GC-increasing mutations but have no effect on substitution rates. Broad-scale association between recombination and diversity is explained through covariance of both factors with base composition. To our knowledge, these results are the first evidence of a direct and local influence of recombination hotspots on genetic variation and the fate of individual mutations. However, that hotspots have no influence on substitution rates suggests that they are too ephemeral on an evolutionary time scale to have a strong influence on broader scale patterns of base composition and long-term molecular evolution.

Triplet formation in the ion recombination in irradiated liquids

International Nuclear Information System (INIS)

Bartczak, W.M.; Tachiya, M.; Hummel, A.

1990-01-01

The formation of singlet and triplet excited stages in the ion recombination in groups of oppositely charged ions (or positive ions and electrons) in nonpolar liquids, as occurs in the tracks of high energy electrons, is considered. Theoretical studies on triplet formation in groups of ion pairs have thus far concentrated on the case where recombination of the negative ions with any of the positive ions in the group is equally probable (random recombination). In this paper the probability for geminate recombination (electron and parent positive ion) vs cross-recombination (an electron with a positive ion other than its parent ion) in multiple ion pair groups is calculated by computer simulation and the effect of the initial spatial configuration of the charged species is investigated. It is also shown explicitly that the probability for singlet formation as a result of cross recombination is equal to 1/4, when spin relaxation by magnetic interaction with the medium and by exchange interaction can be neglected. The effect of the preferential recombination on the singlet formation probability is illustrated and recent experimental results on singlet to triplet ratios are discussed. (author)

Damage-induced ectopic recombination in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Kupiec, M; Steinlauf, R

1997-06-09

Mitotic recombination in the yeast Saccharomyces cerevisiae is induced when cells are irradiated with UV or X-rays, reflecting the efficient repair of damage by recombinational repair mechanisms. We have used multiply marked haploid strains that allow the simultaneous detection of several types of ectopic recombination events. We show that inter-chromosomal ectopic conversion of lys2 heteroalleles and, to a lesser extent, direct repeat recombination (DRR) between non-tandem repeats, are increased by DNA-damaging agents; in contrast, ectopic recombination of the naturally occurring Ty element is not induced. We have tested several hypotheses that could explain the preferential lack of induction of Ty recombination by DNA-damaging agents. We have found that the lack of induction cannot be explained by a cell cycle control or by an effect of the mating-type genes. We also found no role for the flanking long terminal repeats (LTRs) of the Ty in preventing the induction. Ectopic conversion, DRR, and forward mutation of artificial repeats show different kinetics of induction at various positions of the cell cycle, reflecting different mechanisms of recombination. We discuss the mechanistic and evolutionary aspects of these results.

A Glance at Recombination Hotspots in the Domestic Cat.

Directory of Open Access Journals (Sweden)

Hasan Alhaddad

Full Text Available Recombination has essential roles in increasing genetic variability within a population and in ensuring successful meiotic events. The objective of this study is to (i infer the population-scaled recombination rate (ρ, and (ii identify and characterize regions of increased recombination rate for the domestic cat, Felis silvestris catus. SNPs (n = 701 were genotyped in twenty-two East Asian feral cats (random bred. The SNPs covered ten different chromosomal regions (A1, A2, B3, C2, D1, D2, D4, E2, F2, X with an average region size of 850 Kb and an average SNP density of 70 SNPs/region. The Bayesian method in the program inferRho was used to infer regional population recombination rates and hotspots localities. The regions exhibited variable population recombination rates and four decisive recombination hotspots were identified on cat chromosome A2, D1, and E2 regions. As a description of the identified hotspots, no correlation was detected between the GC content and the locality of recombination spots, and the hotspots enclosed L2 LINE elements and MIR and tRNA-Lys SINE elements.

Dielectronic recombination theory

International Nuclear Information System (INIS)

LaGattuta, K.J.

1991-01-01

A theory now in wide use for the calculation of dielectronic recombination cross sections (σ DR ) and rate coefficients (α DR ) was one introduced originally by Feshbach for nuclear physics applications, and then later adapted for atomic scattering problems by Hahn. In the following, we briefly review this theory in a very general form, which allows one to account for the effects of overlapping and interacting resonances, as well as continuum-continuum coupling. An extension of our notation will then also allow for the inclusion of the effects of direct radiative recombination, along with a treatment of the interference between radiative and dielectronic recombination. Other approaches to the calculation of σ DR have been described by Fano and by Seaton. We will not consider those theories here. Calculations of α DR have progressed considerably over the last 25 years, since the early work of Burgess. Advances in the reliability of theoretical predictions have also been promoted recently b a variety of direct laboratory measurements of σ DR . While the measurements of σ DR for δn ≠ 0 excitations have tended to agree very well with calculations, the case of δn = 0 has been much problematic. However, by invoking a mechanism originally proposed by Jacobs, which takes into account the effect of stray electric fields on high Rydberg states (HRS) participating in the DR process, new calculations have improved the agreement between theory and experiment for these cases. Nevertheless, certain discrepancies still remain

Scrambling Eggs: Meiotic Drive and the Evolution of Female Recombination Rates

Science.gov (United States)

Brandvain, Yaniv; Coop, Graham

2012-01-01

Theories to explain the prevalence of sex and recombination have long been a central theme of evolutionary biology. Yet despite decades of attention dedicated to the evolution of sex and recombination, the widespread pattern of sex differences in the recombination rate is not well understood and has received relatively little theoretical attention. Here, we argue that female meiotic drivers—alleles that increase in frequency by exploiting the asymmetric cell division of oogenesis—present a potent selective pressure favoring the modification of the female recombination rate. Because recombination plays a central role in shaping patterns of variation within and among dyads, modifiers of the female recombination rate can function as potent suppressors or enhancers of female meiotic drive. We show that when female recombination modifiers are unlinked to female drivers, recombination modifiers that suppress harmful female drive can spread. By contrast, a recombination modifier tightly linked to a driver can increase in frequency by enhancing female drive. Our results predict that rapidly evolving female recombination rates, particularly around centromeres, should be a common outcome of meiotic drive. We discuss how selection to modify the efficacy of meiotic drive may contribute to commonly observed patterns of sex differences in recombination. PMID:22143919

Recombinant expression systems: the obstacle to helminth vaccines?

Science.gov (United States)

Geldhof, Peter; De Maere, Veerle; Vercruysse, Jozef; Claerebout, Edwin

2007-11-01

The need for alternative ways to control helminth parasites has in recent years led to a boost in vaccination experiments with recombinant antigens. Despite the use of different expression systems, only a few recombinants induced high levels of protection against helminths. This is often attributed to the limitations of the current expression systems. Therefore, the need for new systems that can modify and glycosylate the expressed antigens has been advocated. However, analysis of over 100 published vaccine trials with recombinant helminth antigens indicates that it is often not known whether the native parasite antigen itself can induce protection or, if it does, which epitopes are important. This information is vital for a well-thought-out strategy for recombinant production. So, in addition to testing more expression systems, it should be considered that prior evaluation and characterization of the native antigens might help the development of recombinant vaccines against helminths in the long term.

A study on the hydrogen recombination rates of catalytic recombiners and deliberate ignition

International Nuclear Information System (INIS)

Fineschi, F.; Bazzichi, M.; Carcassi, M.

1994-01-01

A study is being carried out by the Department of Nuclear and Mechanical Constructions (DCMN) at the University of Pisa on catalytic recombiners and on deliberately induced weak deflagration. The recombination rates of different types of catalytic devices were obtained from a thorough analysis of published experimental data. The main parameter that affects the effectiveness of these devices seems to be the molar density of the deficiency reactant rather than its volumetric concentration. The recombination rate of weak deflagrations in vented compartments has been assessed with experimental tests carried out in a small scale glass vessel. Through a computerized system of analysis of video recordings of the deflagrations, the flame surface and the burned gas volume were obtained as functions of time. Although approximations are inevitable, the method adopted to identify the position of the flame during propagation is more reliable than other non-visual methods (thermocouples and ion-probes). It can only easily be applied to vented weak deflagrations, i.e. when the hydrogen concentration is far from stoichiometric conditions and near to flammability limits, because the pressurization has to be limited due to the low mechanical resistance of the glass. The values of flame surface and burned gas volume were used as inputs for a computer code to calculate the recombining rate, the burning velocity and the pressure transient in the experimental test. The code is being validated with a methodology principally based on a comparison of the measurements of pressure with the calculated values. The research gave some very interesting results on a small scale which should in the future be compared with large scale data

Photoionization and electron-ion recombination of Cr I

International Nuclear Information System (INIS)

Nahar, Sultana N.

2009-01-01

Using the unified method, the inverse processes of photoionization and electron-ion recombination are studied in detail for neutral chromium, (CrI+hν↔CrII+e), for the ground and excited states. The unified method based on close-coupling approximation and R-matrix method (i) subsumes both the radiative recombination (RR) and dielectronic recombination (DR) for the total rate and (ii) provides self-consistent sets of photoionization cross sections σ PI and recombination rates α RC . The present results show in total photoionization of the ground and excited states an enhancement in the background at the first excited threshold, 3d 4 4s 5 D state of the core. One prominent phot-excitation-of-core (PEC) resonance due to one dipole allowed transition ( 6 S- 6 P o ) in the core is found in the photoionization cross sections of most of the valence electron excited states. Structures in the total and partial photoionization, for ionization into various excited core states and ground state only, respectively, are demonstrated. Results are presented for the septet and quintet states with n≤10 and l≤9 of Cr I. These states couple to the core ground state 6 S and contribute to the recombination rates. State-specific recombination rates are also presented for these states and their features are illustrated. The total recombination rate shows two DR peaks, one at a relatively low temperature, at 630 K, and the other around 40,000 K. This can explain existence of neutral Cr in interstellar medium. Calculations were carried out in LS coupling using a close-coupling wave function expansion of 40 core states. The results illustrate the features in the radiative processes of Cr I and provide photoionization cross sections and recombination rates with good approximation for this astrophysically important ion.

Workshop on Radio Recombination Lines

CERN Document Server

1980-01-01

Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

Determination of recombination in Mycoplasma hominis

DEFF Research Database (Denmark)

Jacobsen, Iben Søgaard; Boesen, Thomas; Mygind, Tina

2002-01-01

disequilibrium and distance between the segregating sites, by the homoplasy ratio (H ratio), and by compatibility matrices. The gap gene showed well-supported evidence for high levels of recombination, whereas recombination was less frequent and not significant within the other genes. The analysis revealed......B-hitL, excinuclease ABC subunit A (uvrA) and glyceraldehyde-3-phosphate dehydrogenase (gap) genes. The level of variability of these M. hominis genes was low compared with the housekeeping genes from Helicobacter pylori and Neisseria meningitidis, but only few M. hominis isolates had identical sequences in all genes...... intergenic and intragenic recombination in M. hominis and this may explain the high intraspecies variability. The results obtained in the present study may be of importance for future population studies of Mycoplasma species....

Radiative and three-body recombination in the Alcator C-Mod divertor

International Nuclear Information System (INIS)

Lumma, D.; Terry, J.L.; Lipschultz, B.

1997-01-01

Significant recombination of the majority ion species has been observed in the divertor region of Alcator C-Mod [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] under detached conditions. This determination is made by analysis of the visible spectrum from the divertor, in particular the Balmer series line emission and the observed recombination continuum, including an apparent recombination edge at ∼375 nm. The analysis shows that the electron temperature in the recombining plasma is 0.8 endash 1.5 eV. The measured volume recombination rate is comparable to the rate of ion collection at the divertor plates. The dominant recombination mechanism is three-body recombination into excited states (e+e+D + Right-arrow D 0 +e), although radiative recombination (e+D + Right-arrow D 0 +hν) contributes ∼5% to the total rate. Analysis of the Balmer series line intensities (from n upper =3 through 10) shows that the upper levels of these transitions are populated primarily by recombination. Thus the brightnesses of the Balmer series (and Lyman series) are directly related to the recombination rate. copyright 1997 American Institute of Physics

Recombination Promoted by DNA Viruses: Phage λ to Herpes Simplex Virus

Science.gov (United States)

Weller, Sandra K.; Sawitzke, James A.

2015-01-01

The purpose of this review is to explore recombination strategies in DNA viruses. Homologous recombination is a universal genetic process that plays multiple roles in the biology of all organisms, including viruses. Recombination and DNA replication are interconnected, with recombination being essential for repairing DNA damage and supporting replication of the viral genome. Recombination also creates genetic diversity, and viral recombination mechanisms have important implications for understanding viral origins as well as the dynamic nature of viral-host interactions. Both bacteriophage λ and herpes simplex virus (HSV) display high rates of recombination, both utilizing their own proteins and commandeering cellular proteins to promote recombination reactions. We focus primarily on λ and HSV, as they have proven amenable to both genetic and biochemical analysis and have recently been shown to exhibit some surprising similarities that will guide future studies. PMID:25002096

A New Metazoan Recombination Rate Record and Consistently High Recombination Rates in the Honey Bee Genus Apis Accompanied by Frequent Inversions but Not Translocations

Science.gov (United States)

Kuster, Ryan; Miller, Katelyn; Fouks, Bertrand; Rubio Correa, Sara; Collazo, Juan; Phaincharoen, Mananya; Tingek, Salim; Koeniger, Nikolaus

2016-01-01

Abstract Western honey bees (Apis mellifera) far exceed the commonly observed 1–2 meiotic recombination events per chromosome and exhibit the highest Metazoan recombination rate (20 cM/Mb) described thus far. However, the reasons for this exceptional rate of recombination are not sufficiently understood. In a comparative study, we report on the newly constructed genomic linkage maps of Apis florea and Apis dorsata that represent the two honey bee lineages without recombination rate estimates so far. Each linkage map was generated de novo, based on SNP genotypes of haploid male offspring of a single female. The A. florea map spans 4,782 cM with 1,279 markers in 16 linkage groups. The A. dorsata map is 5,762 cM long and contains 1,189 markers in 16 linkage groups. Respectively, these map sizes result in average recombination rate estimates of 20.8 and 25.1 cM/Mb. Synteny analyses indicate that frequent intra-chromosomal rearrangements but no translocations among chromosomes accompany the high rates of recombination during the independent evolution of the three major honey bee lineages. Our results imply a common cause for the evolution of very high recombination rates in Apis. Our findings also suggest that frequent homologous recombination during meiosis might increase ectopic recombination and rearrangements within but not between chromosomes. It remains to be investigated whether the resulting inversions may have been important in the evolutionary differentiation between honey bee species. PMID:28173114

Analysis of chickens for recombination within the MHC (B-complex)

DEFF Research Database (Denmark)

Skjødt, K; Koch, C; Crone, M

1985-01-01

In an attempt to further map the chicken MHC (the B complex), a systematic search for genetic recombinants within the B complex was performed by serotyping the progeny from F2 crosses of chickens by means of specific anti-class I, anti-class II, and anti-class IV alloantisera. Two recombinant B......-haplotypes (B21r and B15r) were found by analysing 2,656 F2 chickens representing 5,312 informative typings. In either case, the B-G (class IV) allele was recombined with both the B-F and B-L alleles of the opposite haplotype. MLC typings, tests for direct compatibility by GVH reactions, and absorption analyses...... confirmed the original serological typing of the two recombinant B haplotypes. No recombination between B-F (class I) and B-L (class II) loci was found. This very low frequency of recombination within the B complex as compared with recombination frequencies found in mammalian MHC's is discussed...

Meiotic recombination hotspots - a comparative view.

Science.gov (United States)

Choi, Kyuha; Henderson, Ian R

2015-07-01

During meiosis homologous chromosomes pair and undergo reciprocal genetic exchange, termed crossover. Meiotic recombination has a profound effect on patterns of genetic variation and is an important tool during crop breeding. Crossovers initiate from programmed DNA double-stranded breaks that are processed to form single-stranded DNA, which can invade a homologous chromosome. Strand invasion events mature into double Holliday junctions that can be resolved as crossovers. Extensive variation in the frequency of meiotic recombination occurs along chromosomes and is typically focused in narrow hotspots, observed both at the level of DNA breaks and final crossovers. We review methodologies to profile hotspots at different steps of the meiotic recombination pathway that have been used in different eukaryote species. We then discuss what these studies have revealed concerning specification of hotspot locations and activity and the contributions of both genetic and epigenetic factors. Understanding hotspots is important for interpreting patterns of genetic variation in populations and how eukaryotic genomes evolve. In addition, manipulation of hotspots will allow us to accelerate crop breeding, where meiotic recombination distributions can be limiting. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Cell biology of homologous recombination in yeast

DEFF Research Database (Denmark)

Eckert-Boulet, Nadine Valerie; Rothstein, Rodney; Lisby, Michael

2011-01-01

Homologous recombination is an important pathway for error-free repair of DNA lesions, such as single- and double-strand breaks, and for rescue of collapsed replication forks. Here, we describe protocols for live cell imaging of single-lesion recombination events in the yeast Saccharomyces...

Recombination Parameters for Antimonide-Based Semiconductors using RF Photoreflection Techniques

International Nuclear Information System (INIS)

Kumar, R.J.; Borrego, J.M.; Dutta, P.S.; Gutmann, R.J.; Wang, C.A.; Martinelli, R.U.; Nichols, G.

2002-01-01

RF photoreflection measurements and PC-1D simulations have been used to evaluate bulk and surface recombination parameters in antimonide-based materials. PC-1D is used to simulate the photoconductivity response of antimonide-based substrates and doubly-capped epitaxial layers and also to determine how to extract the recombination parameters using experimental results. Excellent agreement has been obtained with a first-order model and test structure simulation when Shockley-Reed-Hall (SRH) recombination is the bulk recombination process. When radiative, Auger and surface recombination are included, the simulation results show good agreement with the model. RF photoreflection measurements and simulations using PC-1D are compatible with a radiative recombination coefficient (B) of approximately 5 x 10 -11 cm 3 /s, Auger coefficient (C) ∼ 1.0 x 10 -28 cm 6 /s and surface recombination velocity (SRV) ∼ 600 cm/s for 0.50-0.55 eV doubly-capped InGaAsSb material with GaSb capping layers using the experimentally determined active layer doping of 2 x 10 17 cm -3 . Photon recycling, neglected in the analysis and simulations presented, will affect the extracted recombination parameters to some extent

Effects of the rad52 gene on recombination in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, S.; Prakash, L.; Burke, W.; Montelone, B.A.

1980-01-01

Effects of the rad 52 mutation in Saccharomyces cerevisiae on meiotic, γ-ray-induced, uv-induced and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNA synthesis; sporulation occurs but inviable spores are produced. Both intra and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the his1-1/his1-315 and trp-5-2/trp5-48 heteroalleles. Gene-centromere recombination also was not observed in rad/52/rad52 diploids. No γ-ray- or uv-induced intragenic mitotic recombination is seen in rad52/rad52 diploids. The rate of spontaneous mitotic recombination is lowered five-fold at the his1-1/his1-315 and leu1-c/leu1-12 heteroalleles. Spontaneous reversion rates of both his1-1 and his1-315 were elevated 10 to 20 fold in rad52/rad52 diploids. The RAD52 gene function is required for spontaneous mitotic recombination, uv- and γ-ray-induced mitotic recombination and mitotic recombination

Phylogenetic and recombination analysis of tomato spotted wilt virus.

Directory of Open Access Journals (Sweden)

Sen Lian

Full Text Available Tomato spotted wilt virus (TSWV severely damages and reduces the yield of many economically important plants worldwide. In this study, we determined the whole-genome sequences of 10 TSWV isolates recently identified from various regions and hosts in Korea. Phylogenetic analysis of these 10 isolates as well as the three previously sequenced isolates indicated that the 13 Korean TSWV isolates could be divided into two groups reflecting either two different origins or divergences of Korean TSWV isolates. In addition, the complete nucleotide sequences for the 13 Korean TSWV isolates along with previously sequenced TSWV RNA segments from Korea and other countries were subjected to phylogenetic and recombination analysis. The phylogenetic analysis indicated that both the RNA L and RNA M segments of most Korean isolates might have originated in Western Europe and North America but that the RNA S segments for all Korean isolates might have originated in China and Japan. Recombination analysis identified a total of 12 recombination events among all isolates and segments and five recombination events among the 13 Korea isolates; among the five recombinants from Korea, three contained the whole RNA L segment, suggesting reassortment rather than recombination. Our analyses provide evidence that both recombination and reassortment have contributed to the molecular diversity of TSWV.

Effect of interface roughness on Auger recombination in semiconductor quantum wells

Science.gov (United States)

Tan, Chee-Keong; Sun, Wei; Wierer, Jonathan J.; Tansu, Nelson

2017-03-01

Auger recombination in a semiconductor is a three-carrier process, wherein the energy from the recombination of an electron and hole pair promotes a third carrier to a higher energy state. In semiconductor quantum wells with increased carrier densities, the Auger recombination becomes an appreciable fraction of the total recombination rate and degrades luminescence efficiency. Gaining insight into the variables that influence Auger recombination in semiconductor quantum wells could lead to further advances in optoelectronic and electronic devices. Here we demonstrate the important role that interface roughness has on Auger recombination within quantum wells. Our computational studies find that as the ratio of interface roughness to quantum well thickness is increased, Auger recombination is significantly enhanced. Specifically, when considering a realistic interface roughness for an InGaN quantum well, the enhancement in Auger recombination rate over a quantum well with perfect heterointerfaces can be approximately four orders of magnitude.

Total and partial recombination cross sections for F6+

International Nuclear Information System (INIS)

Mitnik, D.M.; Pindzola, M.S.; Badnell, N.R.

1999-01-01

Total and partial recombination cross sections for F 6+ are calculated using close-coupling and distorted-wave theory. For total cross sections, close-coupling and distorted-wave results, which include interference between the radiative and dielectronic pathways, are found to be in good agreement with distorted-wave results based on a sum of independent processes. Total cross sections near zero energy are dominated by contributions from low-energy dielectronic recombination resonances. For partial cross sections, the close-coupling and distorted-wave theories predict strong interference for recombination into the final recombined ground state 1s 2 2s 21 S 0 of F 5+ , but only weak interference for recombination into the levels of the 1s 2 2s2p configuration. copyright 1999 The American Physical Society

B chromosomes are associated with redistribution of genetic recombination towards lower recombination chromosomal regions in perennial ryegrass.

Science.gov (United States)

Harper, John; Phillips, Dylan; Thomas, Ann; Gasior, Dagmara; Evans, Caron; Powell, Wayne; King, Julie; King, Ian; Jenkins, Glyn; Armstead, Ian

2018-04-09

Supernumerary 'B' chromosomes are non-essential components of the genome present in a range of plant and animal species-including many grasses. Within diploid and polyploid ryegrass and fescue species, including the forage grass perennial ryegrass (Lolium perenne L.), the presence of B chromosomes has been reported as influencing both chromosome pairing and chiasma frequencies. In this study, the effects of the presence/absence of B chromosomes on genetic recombination has been investigated through generating DArT (Diversity Arrays Technology) marker genetic maps for six perennial ryegrass diploid populations, the pollen parents of which contained either two B or zero B chromosomes. Through genetic and cytological analyses of these progeny and their parents, we have identified that, while overall cytological estimates of chiasma frequencies were significantly lower in pollen mother cells with two B chromosomes as compared with zero B chromosomes, the recombination frequencies within some marker intervals were actually increased, particularly for marker intervals in lower recombination regions of chromosomes, namely pericentromeric regions. Thus, in perennial ryegrass, the presence of two B chromosomes redistributed patterns of meiotic recombination in pollen mother cells in ways which could increase the range of allelic variation available to plant breeders.

Analysis of intermolecular RNA-RNA recombination by rubella virus

International Nuclear Information System (INIS)

Adams, Sandra D.; Tzeng, W.-P.; Chen, M.-H.; Frey, Teryl K.

2003-01-01

To investigate whether rubella virus (RUB) undergoes intermolecular RNA-RNA recombination, cells were cotransfected with pairs of in vitro transcripts from genomic cDNA plasmid vectors engineered to contain nonoverlapping deletions: the replicative transcript maintained the 5'-proximal nonstructural (NS) ORF (which contained the replicase, making it RNA replication competent), had a deletion in the 3'-proximal structural protein (SP) ORF, and maintained the 3' end of the genome, including the putative 3' cis-acting elements (CSE), while the nonreplicative transcript consisted of the 3' half of the genome including the SP-ORF and 3' CSE. Cotransfection yielded plaque-forming virus that synthesized the standard genomic and subgenomic RNAs and thus was generated by RNA-RNA recombination. Using transcripts tagged with a 3'-terminal deletion, it was found that recombinants contained the 3' end derived from the replicative strand, indicating a cis-preference for initiation of negative-strand synthesis. In cotransfections in which the replicative transcript lacked the 3' CSE, recombination occurred, albeit at lower efficiency, indicating that initiation in trans from the NS-ORF can occur. The 3' CSE was sufficient as a nonreplicative transcript, showing that it can serve as a promoter for negative-strand RNA synthesis. While deletion mutagenesis showed that the presence of the junction untranslated region (J-UTR) between the ORFs appeared to be necessary on both transcripts for recombination in this region of the genome, analysis with transcripts tagged with restriction sites showed that the J-UTR was not a hot spot for recombination compared to neighboring regions in both ORFs. Sequence analysis of recombinants revealed that both precise (homologous) and imprecise recombination (aberrant, homologous resulting in duplications) occurred; however, imprecise recombination only involved the J-UTR or the 3' end of the NS-ORF and the J-UTR (maintaining the NS-ORF), indicating

Intrinsic and experimental quasiparticle recombination times in superconducting films

International Nuclear Information System (INIS)

Eisenmenger, W.; Lassmann, K.; Trumpp, H.J.; Krauss, R.

1977-01-01

Experimental quasiparticle recombination lifetime data for superconducting Al, Sn, and Pb films are compared with calculations based on a ray acoustic model taking account of the film thickness dependence of the reabsorption of recombination phonons. Information on the true or intrinsic quasiparticle recombination lifetime obtained from these and other data is discussed. (orig.) [de

Diagnostic dilemma of the single screening test used in the diagnosis of syphilis in Nepal.

Science.gov (United States)

Dumre, S P; Shakya, G; Acharya, D; Malla, S; Adhikari, N

2011-12-01

Syphilis screening by the nontreponemal rapid plasma reagin (RPR) test is not usually followed up by specific treponemal tests in most of the resource poor healthcare settings of Nepal. We analyzed serum specimens of 504 suspected syphilis cases at the immunology department of the national reference laboratory in Nepal during 2007-2009 using RPR test and Treponema pallidum hemagglutination assay (TPHA). In overall, 35.7% were positive by both methods (combination) while 13.1% were RPR positive and TPHA negative, 8.7% were positive by TPHA only and 42.5% were negative by both methods. Among the RPR reactive (n = 246), 73.2% were positive by TPHA. Non-specific agglutination in RPR testing was relatively higher (26.8%) compared to TPHA (19.6%). Although TPHA was found more specific than RPR test, either of the single tests produced inaccurate diagnosis. Since the single RPR testing for syphilis may yield false positive results, specific treponemal test should be routinely used as confirmatory test to rule out false RPR positive cases. More attention needs to be paid on formulation of strict policy on the implementation of the existing guidelines throughout the country to prevent misdiagnosis in syphilis with the use of single RPR test.

The cost-effectiveness of 10 antenatal syphilis screening and treatment approaches in Peru, Tanzania, and Zambia.

Science.gov (United States)

Terris-Prestholt, Fern; Vickerman, Peter; Torres-Rueda, Sergio; Santesso, Nancy; Sweeney, Sedona; Mallma, Patricia; Shelley, Katharine D; Garcia, Patricia J; Bronzan, Rachel; Gill, Michelle M; Broutet, Nathalie; Wi, Teodora; Watts, Charlotte; Mabey, David; Peeling, Rosanna W; Newman, Lori

2015-06-01

Rapid plasma reagin (RPR) is frequently used to test women for maternal syphilis. Rapid syphilis immunochromatographic strip tests detecting only Treponema pallidum antibodies (single RSTs) or both treponemal and non-treponemal antibodies (dual RSTs) are now available. This study assessed the cost-effectiveness of algorithms using these tests to screen pregnant women. Observed costs of maternal syphilis screening and treatment using clinic-based RPR and single RSTs in 20 clinics across Peru, Tanzania, and Zambia were used to model the cost-effectiveness of algorithms using combinations of RPR, single, and dual RSTs, and no and mass treatment. Sensitivity analyses determined drivers of key results. Although this analysis found screening using RPR to be relatively cheap, most (>70%) true cases went untreated. Algorithms using single RSTs were the most cost-effective in all observed settings, followed by dual RSTs, which became the most cost-effective if dual RST costs were halved. Single test algorithms dominated most sequential testing algorithms, although sequential algorithms reduced overtreatment. Mass treatment was relatively cheap and effective in the absence of screening supplies, though treated many uninfected women. This analysis highlights the advantages of introducing RSTs in three diverse settings. The results should be applicable to other similar settings. Copyright © 2015 International Federation of Gynecology and Obstetrics. All rights reserved.

Serological diagnosis of syphilis: a comparison of different diagnostic methods.

Science.gov (United States)

Simčič, Saša; Potočnik, Marko

2015-01-01

Serological tests' limitations in syphilis diagnosis as well as numerous test interpretations mean that patients with discordant serology results can present diagnostic and treatment challenges for clinicians. We analyzed three common diagnostic algorithms for detecting suspected syphilis in high-prevalence populations in Slovenia. The prospective study included a total of 437 clinical serum samples from adults throughout Slovenia tested with Rapid Plasma Reagin (RPR), Treponema pallidum hemagglutination (TPHA), and an automated chemiluminescence immunoassay (CIA) according to the manufacturer's instructions. In addition to percent agreement, kappa coefficients were calculated as a secondary measure of agreement between the three algorithms. Overall, of 183 subjects that had seroreactive results, 180 were seroreactive in both the reverse sequence and the European Centre for Disease Prevention and Control (ECDC) algorithm. The traditional algorithm had a missed serodiagnosis rate of 30.0%, the overall percent agreement between the traditional and the reverse algorithm (or the ECDC algorithm) was 87.6%, and the kappa value was 0.733. However, the reverse and ECDC algorithm failed to detect three subjects with positive serodiagnosis determined by additional confirmative treponemal assays. Our results supported the ECDC algorithm in the serodiagnosis of syphilis in high-prevalence populations and the use of nontreponemal serology to monitor the response to treatment.

Optimized Benzalkonium Chloride Gel: A Potential Vaginal Microbicides

Institute of Scientific and Technical Information of China (English)

Xun-cheng DING; Wei-hua LI; Jie-fei LI; Qiang-yi WANG

2007-01-01

Objective To develop an optimized BZK gel with good pharmaceutical effect and less toxicity to vaginal mucosa.Methods Four methods as below were used to research the spermicidal activity of BZK gel: 1)in vitro spermicidal test; 2) in vivo spermicidal test in rabbits; 3) anti-fertility test in rabbits; 4)contraceptive test in rabbits. Mucosal irritation test was used in rats to evaluate the safety of optimized BZK gel. Microbiological assessments were used to research anti-STI pathogens (including treponema pallidum, neisseria gonorrhoeae, trichomona vaginalis, candida albicans,ureaplama urealyticum, herpes simplex virus type-2, chlamydiae trachomatis) effect of optimized BZK gel.Results In vitro spermicidal test, EC50 of BZK gel was 0.029 mg/ml, a little higher than that of N-9 (0.019 mg/ml). The MIC of BZK gel was 0.25 mg/ml, similar to that of N-9 (0.20 mg/ml).The vaginal mucosal irritation test in rats showed that 0.429% BZK gel showed only minimal vaginal irritation, and did not damage the vaginal epithelium or cause local inflammation in rats. Microbiological assessments showed that optimized BZK gel could inhibit or inactivate common STI pathogens even after 3-fold or 5-fold dilution.Conclusion Optimized BZK gel was an effective microbicides.

Neurosyphilis with dementia and bilateral hippocampal atrophy on brain magnetic resonance imaging

International Nuclear Information System (INIS)

Mehrabian, S.; Raycheva, M.; Traykova, M.; Stankova, T.; Penev, L.; Georgieva-Kozarova, G.; Grigorova, O.; Traykov, L.

2012-01-01

Full text: Background: This article reports a rare case of active neurosyphilis in a 33-years-old man with mild to moderate dementia and marked hippocampal atrophy, mimicking early onset Alzheimer's disease. Few number of cases described bilateral hippocampal atrophy mimicking Alzheimer's disease in neurosyphilis. Case presentation: The clinical feature is characterized by a progressive cognitive decline and behavioral changes for the last 18 months. Neuropsychological examination revealed mild to moderate dementia (MMSE=16) with impaired memory, attention and executive dysfunction. Pyramidal, extrapyramidal signs, dysarthria and impairment in coordination were documented. Brain magnetic resonance imaging showed cortical atrophy with marked bilateral hippocampal atrophy. The diagnosis of active neurosyphilis was based on positive results of Venereal Disease Research Laboratory test - Treponema Pallidum. Hemagglutination reactions in blood and cerebrospinal fluid samples. In addition, cerebrospinal fluid analysis showed pleocytosis and elevated protein levels. High dose intravenous penicillin therapy was administered. During the follow up examination at 6 month, the clinical signs, and neuropsychological examinations, and cerebrospinal fluid samples showed improvement. Conclusion: This case underlines the importance of early diagnosis of neurosyphilis. The results suggest that neurosyphilis should be considered when magnetic resonance imaging results indicate mesiotemporal abnormalities and hippocampal atrophy. Neurosyphilis is a treatable condition and needs early aggressive antibiotic therapy

Neurodevelopmental Versus Neurodegenerative Model of Schizophrenia and Bipolar Disorder: Comparison with Physiological Brain Development and Aging.

Science.gov (United States)

Buoli, Massimiliano; Serati, Marta; Caldiroli, Alice; Cremaschi, Laura; Altamura, Alfredo Carlo

2017-03-01

Available data support a contribution of both neurodevelopmental and neurodegenerative factors in the etiology of schizophrenia (SCH) and bipolar disorder (BD). Of note, one of the most important issue of the current psychiatric research is to identify the specific factors that contribute to impaired brain development and neurodegeneration in SCH and BD, and especially how these factors alter normal brain development and physiological aging process. Our hypothesis is that only specific damages, taking place in precise brain development stages, are associated with future SCH /BD onset and that neurodegeneration consists of an acceleration of brain aging after SCH /BD onset. In support of our hypothesis, the results of the present narrative mini-review shows as neurodevelopmental damages generally contribute to neuropsychiatric syndromes (e.g. hypothyroidism or treponema pallidum), but only some of them are specifically associated with adult SCH and BD (e.g. toxoplasma or substance abuse), particularly if they happen in specific stages of brain development. On the other hand, cognitive impairment and brain changes, associated with long duration of SCH /BD, look like what happens during aging: memory, executive domains and prefrontal cortex are implicated both in aging and in SCH /BD progression. Future research will explore possible validity of this etiological model for SCH and BD.

SEROPREVALENCE OF HEPATITIS B, HEPATITIS C, SYPHILIS AND HIV IN PREGNANT WOMEN IN A TERTIARY CARE HOSPITAL, GUJARAT, INDIA

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Swati Dhirajlal Jethava

2017-08-01

Full Text Available BACKGROUND This study was conducted to assess the extent of seropositivity of hepatitis B, hepatitis C, syphilis and HIV in pregnant women at tertiary care hospitals in Gujarat from December 2015 to June 2016 and to re-evaluate the need for routine antenatal care screening for these infections among obstetric patients. MATERIALS AND METHODS Patients were enrolled for study after taking informed consent. All samples were tested to detect HbsAg by Enzyme-Linked Immunosorbent Assay (ELISA, anti-HCV by ELISA, samples were also tested for antibodies to Treponema pallidum by Rapid Plasma Regain (RPR, samples were tested for antibodies to HIV by three different methods as per strategy III of the National AIDS Control Organisation by using different systems of testing to establish a diagnosis of HIV. RESULTS Total 1000 samples were tested. Out of this, seropositivity of hepatitis B was (0.6%, hepatitis C was (0.2%, syphilis was (0.0% and HIV was 0.1%. Out of the 1000 samples, no coinfection was found between hepatitis B, hepatitis C, syphilis or HIV. CONCLUSION This study can help the health professionals to efficiently treat antenatal patients. Early diagnosis of disease in antenatal period is helpful for proper management and initiation of treatment to prevent transmission to newborn.

Tertiary syphilis in the lumbar spine: a case report.

Science.gov (United States)

Bai, Yang; Niu, Feng; Liu, Lidi; Sha, Hui; Wang, Yimei; Zhao, Song

2017-07-24

The incidence of tertiary syphilis involvement in the spinal column with destructive bone lesions is very rare. It is difficult to establish the correct diagnosis from radiographs and histological examination alone. Limited data are available on surgical treatment to tertiary syphilitic spinal lesions. In this article, we report a case of tertiary syphilis in the lumbar spine with osteolytic lesions causing cauda equina compression. A 44-year-old man who suffered with low back pain for 6 months and progressive radiating pain at lower extremity for 1 week. Radiologic findings showed osteolytic lesion and new bone formation in the parts of the bodies of L4 and L5. Serum treponema pallidum hemagglutination (TPHA) test was positive. A surgery of posterior debridement, interbody and posterolateral allograft bone fusion with instrumentation from L3 to S1 was performed. The low back pain and numbness abated after operation. But the follow-up radiographs showed absorption of the bone grafts and failure of instrumentation. A Charcot's arthropathy was formed between L4 and L5. It is challenging to diagnose the tertiary syphilis in the spine. Surgery is a reasonable auxiliary method to antibiotic therapy for patients who suffered with neuropathy. Charcot's arthropathy should be considered as an operative complication.

Generation of Modified Pestiviruses by Targeted Recombination

DEFF Research Database (Denmark)

Rasmussen, Thomas Bruun; Friis, Martin Barfred; Risager, Peter Christian

involves targeted modification of viral cDNA genomes, cloned within BACs, by Red/ET recombination-mediated mutagenesis in E.coli DH10B cells. Using recombination-mediated mutagenesis for the targeted design, the work can be expedited and focused in principal on any sequence within the viral genome...

Polarity of recombination in transformation of Streptococcus pneumoniae.

Science.gov (United States)

Pasta, F; Sicard, M A

1999-03-16

In transformation of Streptococcus pneumoniae DNA enters the cell as single-strand fragments and integrates into the chromosome by homologous recombination. Deletions and insertions of a few hundred base pairs frequently stop the recombination process of a donor strand. In this work we took advantage of such interruptions of recombination to compare the transformation efficiencies of the segments 5'- and 3'-ward from a deletion. The deletion was created in the center of a fragment of the ami locus, and sites around the deletion were labeled by a frameshift generating a restriction site. Heteroduplexes were constructed containing two restriction sites on one strand and two different ones on the complementary strand. ami+ bacteria were transformed with such heteroduplexes. ami- transformants were isolated and individually underwent amplification of the transformed ami region. We have obtained two kinds of amplification products: short when the deletion was integrated, long when recombination stops at the deletion. Each long fragment was tested by the four restriction enzymes to detect which strand and which side of the deletion had recombined. We found that 80% of the cuts were located 5' to the deletion, showing that, in vivo, the 5' side is strongly favored by recombination. Further results suggest that exchanges occurring from 5' to 3' relative to the donor strand are more efficient than in the opposite direction, thus accounting for the 5' preference.

Recombinant activated factor VII in cardiac surgery: single-center experience.

Science.gov (United States)

Singh, Sarvesh Pal; Chauhan, Sandeep; Choudhury, Minati; Malik, Vishwas; Choudhary, Shiv Kumar

2014-02-01

The widespread off-label use of recombinant activated factor VII for the control of refractory postoperative hemorrhage continues despite a warning from the Food and Drug Administration. Although effective in reducing the need for transfusion of blood and blood products, safety concerns still prevail. To compare the dosing and efficacy of recombinant activated factor VII between pediatric and adult patients, and in the operating room and intensive care unit. The records of 69 patients (33 children and 36 adults) who underwent cardiovascular surgery and received recombinant activated factor VII were reviewed retrospectively. The dose of recombinant activated factor VII, mediastinal drainage, use of blood and blood products, incidence of thrombosis, and 28-day mortality were studied. the efficacy of recombinant activated factor VII was comparable in adults and children, despite the lower dose in adults. Prophylactic use of recombinant activated factor VII decreased the incidence of mediastinal exploration and the duration of intensive care unit stay. A 4.3% incidence of thrombotic complications was observed in this study. The efficacious dose of recombinant activated factor VII is much less in adults compared to children. Prophylactic use of recombinant activated factor VII decreases the dose required, the incidence of mediastinal exploration, and intensive care unit stay, with no survival benefit.

HIV, STI prevalence and risk behaviours among women selling sex in Lahore, Pakistan

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Zaman Shakila

2011-05-01

Full Text Available Abstract Background More than 340 million cases of curable sexually transmitted infections (STIs were estimated to have occurred worldwide in 1995. Previous studies have shown that the presence of other concomitant STIs increases the likelihood of HIV transmission. The first national study of STIs conducted in Pakistan in 2004 revealed a high burden of STIs among women selling sex. The HIV epidemic in Pakistan has thus far followed the "Asian epidemic model". Earlier studies among women selling sex have shown a low prevalence of HIV coupled with a low level of knowledge about AIDS. The aim of our study was to estimate the prevalence of HIV and STIs, and assess knowledge and risk behaviours related to HIV/STI, among women selling sex in Lahore, Pakistan. Methods A total of 730 participants were recruited through respondent-driven sampling. The participants were women selling sex in three areas (referred to as "A", "B", and "C" of Lahore. A structured questionnaire addressing demographic information, sexual life history, sexual contacts, and knowledge and practices related to HIV/STI prevention was administered by face-to-face interview. Biological samples were obtained from all participants and tested for HIV, Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis. Pearson's chi-square and multivariable logistic regression analysis were performed to test associations between potential risk factors and specified diagnosed infections. Results The prevalence of HIV infection was 0.7%, T pallidum 4.5%, N gonorrhoeae 7.5%, C trachomatis 7.7% and T vaginalis 5.1%. The participants had been selling sex for a median period of seven years and had a median of three clients per day. Sixty five percent of the participants reported that they "Always use condom". The median fee per sexual contact was Rs. 250 (3 Euro. Compared to Areas A and C, women selling sex in Area B had a significantly higher risk of chlamydial

Prácticas sexuales y seroprevalencia de infección por VIH, HTLV-1 sífilis en meretrices clandestinas de Lima

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Luis Trujillo

1996-10-01

Full Text Available Objetivo: Investigar la prevalencia de prácticas sexuales de riesgo para infección por Enfermedades de Transmisión Sexual (ETS y la seroprevalencia de infección por VIH-1, HTLV-1 y Treponema pallidum en meretrices de los burdeles clandestinos de Lima. Material y métodos: Estudio de diseño transversal, descriptivo y no probabilístico. Se realizó una encuesta anónima por entrevista directa sobre prácticas sexuales y antecedentes de ETS y se tomó una muestra de sangre para análisis serológico de anticuerpos contra VIH-1, HTLV-1 y T. Pallidum de 158 meretrices voluntarias en 15 burdeles clandestinos de Lima Metropolitana entre marzo y junio de 1994. Resultados: Todas las muestras de suero fueron negativas para VIH-1 (IC 95%, 0.0 - 1.8 pero dos resultaron indeterminadas (ELISA positivo y WB banda p24 presente. Seis (3.8% positivas para HTLV-1 (IC 95%, 1.4 - 8.1. Cinco (3.2% fueron VDRL reactivas (IC 95%, 1.0 - 7.3. El uso consistente de condón con los clientes fue 75% (119/158. Sólo 3% (4/137 lo usan con su pareja sexual estable. Las prácticas sexuales de riesgo encontradas fueron: coito anal 7.6%, relaciones sexuales durante la menstruación 37%, felación 93%, relaciones sexuales con clientes portadores de úlceras genitales 19%; pero refirieron un mayor uso del condón en las mismas. El 25% tuvo antecedentes de alguna ETS en los últimos 5 años, siendo gonorrea, la más frecuente (22%. Conclusiones: La población de meretrices de los burdeles clandestinos de Lima tiene un elevado uso consistente del condón con clientes, y la prevalencia de infección retroviral y de sífilis es baja. (Rev Med Hered 1996; 7: 162-171.

[Specificity and sensitivity of immunological diagnosis of congenital neonatal syphilis by the 19S(IgM)-FTA-ABS test (author's transl)].

Science.gov (United States)

Müller, F; Sinzig, G

1982-07-01

Reports on the significance in the demonstration of IgM class antibodies in congenital syphilis are contradictory. The reason for discrepant observations are of technical or biological source. In order to explain the several uncertainties, serum samples from 1031 newborns and infants of syphilitic mothers were investigated quantitatively with the IgM-FTA-ABS, the 19S (IgM)-FTA-ABS and cardiolipin CF test. If serum specimens of the mothers were available they were investigated in the same tests for treponema-specific 19S(IgM) class and antilipoidal antibodies. In the evaluation of the results, the history of infection and treatment of the mothers as well as clinical observations in the infants were considered. In 26 children a congenital acquired syphilis was strongly indicated by demonstration of treponema-specific 19S(IgM) class antibodies by the 19S(IgM)-FTA-ABS-Test and tae good agreement with the history of untreated mothers. In another 1005 infants a congenital infection by T. pallidum could be excluded by the non-reactive 19S(IgM)-FTA-ABS as well as clinical observations. Furthermore, immunological findings of three children who had acquired syphilis after birth are demonstrated before and after specific treatment. It could be shown that the 19S(IgM)-FTA-ABS is much more infaillable than the IgM-FTA-ABS as far as technical and biological uncertainties are concerned. Considering all possible errors and the results of re-investigations of IgM non-reactive infants of syphilitic mothers (up to one year after birth) it is demonstrated that congenital syphilis can be differentiated from passively transmitted 7S(IgG) class antibodies (of the mother) or 19S(IgM) class anti-antibodies (of the child) with a significance of about 99%. It is finally concluded that serological diagnosis of congenital syphilis should be started in the pregnant women. By making the diagnosis in pregnancy followed by adequate treatment, irreversible damages as well as so-called serological

Homologous Recombination as a Replication Fork Escort: Fork-Protection and Recovery

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Audrey Costes

2012-12-01

Full Text Available Homologous recombination is a universal mechanism that allows DNA repair and ensures the efficiency of DNA replication. The substrate initiating the process of homologous recombination is a single-stranded DNA that promotes a strand exchange reaction resulting in a genetic exchange that promotes genetic diversity and DNA repair. The molecular mechanisms by which homologous recombination repairs a double-strand break have been extensively studied and are now well characterized. However, the mechanisms by which homologous recombination contribute to DNA replication in eukaryotes remains poorly understood. Studies in bacteria have identified multiple roles for the machinery of homologous recombination at replication forks. Here, we review our understanding of the molecular pathways involving the homologous recombination machinery to support the robustness of DNA replication. In addition to its role in fork-recovery and in rebuilding a functional replication fork apparatus, homologous recombination may also act as a fork-protection mechanism. We discuss that some of the fork-escort functions of homologous recombination might be achieved by loading of the recombination machinery at inactivated forks without a need for a strand exchange step; as well as the consequence of such a model for the stability of eukaryotic genomes.

Low-temperature radiative recombination of electrons with bare nuclei

International Nuclear Information System (INIS)

Omidvar, K.

1993-01-01

Aside from empirical formulas, the radiative-recombination cross section and coefficient are usually given in tabulated forms instead of analytic formulas. Here, we give analytic expressions in the form of expansions for the recombination cross section as a function of the electron energy E for low E, and for the recombination coefficient as a function of the temperature T for low T. The expansion coefficients are combinations of confluent hypergeometric functions, and are tabulated for a large number of the final principal and angular-momentum quantum numbers n and l. It is shown that the recombination cross section for arbitrary nuclear charge number Z is independent of Z, while the recombination coefficient for T/Z 2 much-lt 1.58x10 5 K increases as Z 2 . Excellent agreement is found with the published tabulated values

PRODUCTION OF RECOMBINANT HIGH pI-BARLEY α-GLUCOSIDASE

DEFF Research Database (Denmark)

Næsted, Henrik; Svensson, Birte

plantlet [1]. Recently, expression and characterization of the recombinant full length, fully functional barley high pI α-glucosidase in Pichia pastoris has been achieved. To enable production of recombinant protein in mg amounts, a transformant harbouring a clone encoding the N-terminally hexa histidine...... tagged recombinant form of the enzyme was propagated using a high cell-density fermentation procedure. This system resulted in successful expression under the highly sensitive methanol utilization phase conducting the fermentation process using a BiostatB 5 L reactor. The recombinant high pI α...... glycosylation of the recombinant α-glucosidase. The enzyme activity was highly stable during the 5 day long fermentation. Characterisation of the enzymatic properties confirmed the specific activity actually to be superior to that of the native enzyme purified from malt [2]. The kinetic parameters Km, Vmax...

High-Resolution Patterns of Meiotic Recombination across the Human Major Histocompatibility Complex

Science.gov (United States)

Cullen, Michael; Perfetto, Stephen P.; Klitz, William; Nelson, George; Carrington, Mary

2002-01-01

Definitive characteristics of meiotic recombination events over large (i.e., >1 Mb) segments of the human genome remain obscure, yet they are essential for establishing the haplotypic structure of the genome and for efficient mapping of complex traits. We present a high-resolution map of recombination at the kilobase level across a 3.3-Mb interval encompassing the major histocompatibility complex (MHC). Genotyping of 20,031 single sperm from 12 individuals resulted in the identification and fine mapping of 325 recombinant chromosomes within genomic intervals as small as 7 kb. Several principal characteristics of recombination in this region were observed: (1) rates of recombination can differ significantly between individuals; (2) intense hot spots of recombination occur at least every 0.8 Mb but are not necessarily evenly spaced; (3) distribution in the location of recombination events can differ significantly among individuals; (4) between hot spots, low levels of recombination occur fairly evenly across 100-kb segments, suggesting the presence of warm spots of recombination; and (5) specific sequence motifs associate significantly with recombination distribution. These data provide a plausible model for recombination patterns of the human genome overall. PMID:12297984

Intermediate bands versus levels in non-radiative recombination

International Nuclear Information System (INIS)

Luque, Antonio; Marti, Antonio; Antolin, Elisa; Tablero, Cesar

2006-01-01

There is a practical interest in developing semiconductors with levels situated within their band gap while preventing the non-radiative recombination that these levels promote. In this paper, the physical causes of this non-radiative recombination are analyzed and the increase in the density of the impurities responsible for the mid-gap levels to the point of forming bands is suggested as the means of suppressing the recombination. Simple models supporting this recommendation and helping in its quantification are presented

Correlation between pairing initiation sites, recombination nodules and meiotic recombination in Sordaria macrospora.

Science.gov (United States)

Zickler, D; Moreau, P J; Huynh, A D; Slezec, A M

1992-09-01

The decrease of meiotic exchanges (crossing over and conversion) in two mutants of Sordaria macrospora correlated strongly with a reduction of chiasmata and of both types of "recombination nodules." Serial section reconstruction electron microscopy was used to compare the synapsis pattern of meiotic prophase I in wild type and mutants. First, synapsis occurred but the number of synaptonemal complex initiation sites was reduced in both mutants. Second, this reduction was accompanied by, or resulted in, modifications of the pattern of synapsis. Genetic and synaptonemal complex maps were compared in three regions along one chromosome arm divided into well marked intervals. Reciprocal exchange frequencies and number of recombination nodules correlated in wild type in the three analyzed intervals, but disparity was found between the location of recombination nodules and exchanges in the mutants. Despite the twofold exchange decrease, sections of the genome such as the short arm of chromosome 2 and telomere regions were sheltered from nodule decrease and from pairing modifications. This indicated a certain amount of diversity in the control of these features and suggested that exchange frequency was dependent not only on the amount of effective pairing but also on the localization of the pairing sites, as revealed by the synaptonemal complex progression in the mutants.

Sequence and recombination analyses of the geminivirus replication

Indian Academy of Sciences (India)

Prakash

2006-09-18

Sep 18, 2006 ... Recombination can provide selective advantage in the evolution of viruses .... Program (v 1.08): Recombination Detection Program (RDP). (Martin and Rybicki ..... Sweet potato leaf curl virus - [US:Louisiana:1994]. AF104036.

Recombinant zoster (shingles) vaccine, RZV - what you need to know

Science.gov (United States)

... year in the United States get shingles. Shingles vaccine (recombinant) Recombinant shingles vaccine was approved by FDA in 2017 for the ... life-threatening allergic reaction after a dose of recombinant shingles vaccine, or has a severe allergy to any component ...

Variation in recombination frequency and distribution across eukaryotes: patterns and processes

Science.gov (United States)

Feulner, Philine G. D.; Johnston, Susan E.; Santure, Anna W.; Smadja, Carole M.

2017-01-01

Recombination, the exchange of DNA between maternal and paternal chromosomes during meiosis, is an essential feature of sexual reproduction in nearly all multicellular organisms. While the role of recombination in the evolution of sex has received theoretical and empirical attention, less is known about how recombination rate itself evolves and what influence this has on evolutionary processes within sexually reproducing organisms. Here, we explore the patterns of, and processes governing recombination in eukaryotes. We summarize patterns of variation, integrating current knowledge with an analysis of linkage map data in 353 organisms. We then discuss proximate and ultimate processes governing recombination rate variation and consider how these influence evolutionary processes. Genome-wide recombination rates (cM/Mb) can vary more than tenfold across eukaryotes, and there is large variation in the distribution of recombination events across closely related taxa, populations and individuals. We discuss how variation in rate and distribution relates to genome architecture, genetic and epigenetic mechanisms, sex, environmental perturbations and variable selective pressures. There has been great progress in determining the molecular mechanisms governing recombination, and with the continued development of new modelling and empirical approaches, there is now also great opportunity to further our understanding of how and why recombination rate varies. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109219

Lineage specific recombination rates and microevolution in Listeria monocytogenes

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Nightingale Kendra K

2008-10-01

Full Text Available Abstract Background The bacterium Listeria monocytogenes is a saprotroph as well as an opportunistic human foodborne pathogen, which has previously been shown to consist of at least two widespread lineages (termed lineages I and II and an uncommon lineage (lineage III. While some L. monocytogenes strains show evidence for considerable diversification by homologous recombination, our understanding of the contribution of recombination to L. monocytogenes evolution is still limited. We therefore used STRUCTURE and ClonalFrame, two programs that model the effect of recombination, to make inferences about the population structure and different aspects of the recombination process in L. monocytogenes. Analyses were performed using sequences for seven loci (including the house-keeping genes gap, prs, purM and ribC, the stress response gene sigB, and the virulence genes actA and inlA for 195 L. monocytogenes isolates. Results Sequence analyses with ClonalFrame and the Sawyer's test showed that recombination is more prevalent in lineage II than lineage I and is most frequent in two house-keeping genes (ribC and purM and the two virulence genes (actA and inlA. The relative occurrence of recombination versus point mutation is about six times higher in lineage II than in lineage I, which causes a higher genetic variability in lineage II. Unlike lineage I, lineage II represents a genetically heterogeneous population with a relatively high proportion (30% average of genetic material imported from external sources. Phylograms, constructed with correcting for recombination, as well as Tajima's D data suggest that both lineages I and II have suffered a population bottleneck. Conclusion Our study shows that evolutionary lineages within a single bacterial species can differ considerably in the relative contributions of recombination to genetic diversification. Accounting for recombination in phylogenetic studies is critical, and new evolutionary models that

Regulation of Homologous Recombination by SUMOylation

DEFF Research Database (Denmark)

Pinela da Silva, Sonia Cristina

factors such as the homologous recombination (HR) machinery. HR constitutes the main DSB repair pathway in Saccharomyces cerevisiae and despite being largely considered an error-free process and essential for genome stability, uncontrolled recombination can lead to loss of heterozygosity, translocations......, deletions, and genome rearrangements that can lead to cell death or cancer in humans. The post-translational modification by SUMO (small ubiquitinlike modifier) has proven to be an important regulator of HR and genome integrity, but the molecular mechanisms responsible for these roles are still unclear....... In this study I present new insights for the role of SUMOylation in regulating HR by dissecting the role of SUMO in the interaction between the central HR-mediator protein Rad52 and its paralogue Rad59 and the outcome of recombination. This data provides evidence for the importance of SUMO in promoting protein...

Study of volume recombination and radiation opacity effects in Alcator C-Mod

International Nuclear Information System (INIS)

Terry, J.L.; Lipschultz, B.; Pigarov, A.Y.; Boswell, C.; Krasheninnikov, S.I.; LaBombard, B.; Pappas, D.A.

1998-01-01

Observations of significant volume recombination within the Alcator C-Mod divertor plasma and in the edge plasma (MARFE) are described. The recombination occurs in regions where T e approx-lt 1 eV and n e approx-gt 1x10 21 m -3 . The determinations of the recombination rates are made by measuring the D 0 Lyman and/or Balmer spectra and by using a collisional radiative model describing the level populations, ionization and recombination of D 0 . In regions of strong recombination the upper levels (n approx-gt 4) populations are close to those determined by Saha-Boltzmann distribution and are independent of the ground state density. Thus the intensities of lines from these levels are related to the recombination rate, and curves determining the number of open-quote recombinations per photon close-quote are calculated. Ly β line emission is shown to be trapped in some cases, meaning that Ly α can be strongly trapped. Since opacity affects the recombination rates, the effects of the trapping of Ly α,β photons on the open-quote recombinations per photon close-quote curves are calculated and considered in the recombination rate determinations. Total recombination rates in the detached divertor plasma and in MARFEs located at the periphery of the main plasma are determined. Recombination can be a significant sink for ions. copyright 1998 American Institute of Physics

Evidence of recombination in intrapatient populations of hepatitis C virus.

Science.gov (United States)

Sentandreu, Vicente; Jiménez-Hernández, Nuria; Torres-Puente, Manuela; Bracho, María Alma; Valero, Ana; Gosalbes, María José; Ortega, Enrique; Moya, Andrés; González-Candelas, Fernando

2008-09-18

Hepatitis C virus (HCV) is a major cause of liver disease worldwide and a potential cause of substantial morbidity and mortality in the future. HCV is characterized by a high level of genetic heterogeneity. Although homologous recombination has been demonstrated in many members of the family Flaviviridae, to which HCV belongs, there are only a few studies reporting recombination on natural populations of HCV, suggesting that these events are rare in vivo. Furthermore, these few studies have focused on recombination between different HCV genotypes/subtypes but there are no reports on the extent of intra-genotype or intra-subtype recombination between viral strains infecting the same patient. Given the important implications of recombination for RNA virus evolution, our aim in this study has been to assess the existence and eventually the frequency of intragenic recombination on HCV. For this, we retrospectively have analyzed two regions of the HCV genome (NS5A and E1-E2) in samples from two different groups: (i) patients infected only with HCV (either treated with interferon plus ribavirin or treatment naïve), and (ii) HCV-HIV co-infected patients (with and without treatment against HIV). The complete data set comprised 17712 sequences from 136 serum samples derived from 111 patients. Recombination analyses were performed using 6 different methods implemented in the program RDP3. Recombination events were considered when detected by at least 3 of the 6 methods used and were identified in 10.7% of the amplified samples, distributed throughout all the groups described and the two genomic regions studied. The resulting recombination events were further verified by detailed phylogenetic analyses. The complete experimental procedure was applied to an artificial mixture of relatively closely viral populations and the ensuing analyses failed to reveal artifactual recombination. From these results we conclude that recombination should be considered as a potentially

Genome-Wide Fine-Scale Recombination Rate Variation in Drosophila melanogaster

Science.gov (United States)

Song, Yun S.

2012-01-01

Estimating fine-scale recombination maps of Drosophila from population genomic data is a challenging problem, in particular because of the high background recombination rate. In this paper, a new computational method is developed to address this challenge. Through an extensive simulation study, it is demonstrated that the method allows more accurate inference, and exhibits greater robustness to the effects of natural selection and noise, compared to a well-used previous method developed for studying fine-scale recombination rate variation in the human genome. As an application, a genome-wide analysis of genetic variation data is performed for two Drosophila melanogaster populations, one from North America (Raleigh, USA) and the other from Africa (Gikongoro, Rwanda). It is shown that fine-scale recombination rate variation is widespread throughout the D. melanogaster genome, across all chromosomes and in both populations. At the fine-scale, a conservative, systematic search for evidence of recombination hotspots suggests the existence of a handful of putative hotspots each with at least a tenfold increase in intensity over the background rate. A wavelet analysis is carried out to compare the estimated recombination maps in the two populations and to quantify the extent to which recombination rates are conserved. In general, similarity is observed at very broad scales, but substantial differences are seen at fine scales. The average recombination rate of the X chromosome appears to be higher than that of the autosomes in both populations, and this pattern is much more pronounced in the African population than the North American population. The correlation between various genomic features—including recombination rates, diversity, divergence, GC content, gene content, and sequence quality—is examined using the wavelet analysis, and it is shown that the most notable difference between D. melanogaster and humans is in the correlation between recombination and

Hadron correlations from recombination and fragmentation

Energy Technology Data Exchange (ETDEWEB)

Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

2005-04-01

We review the formalism of quark recombination applied to the hadronization of a quark-gluon plasma. Evidence in favour of the quark recombination model is outlined. Recent work on parton correlations, leading to detectable correlations between hadrons, is discussed. Hot spots from completely quenched jets are a likely source of such correlations which appear to be jet like. It will be discussed how such a picture compares with measurement of associated hadron yields at RHIC.

Feline immunodeficiency virus (FIV) env recombinants are common in natural infections.

Science.gov (United States)

Bęczkowski, Paweł M; Hughes, Joseph; Biek, Roman; Litster, Annette; Willett, Brian J; Hosie, Margaret J

2014-09-17

Recombination is a common feature of retroviral biology and one of the most important factors responsible for generating viral diversity at both the intra-host and the population levels. However, relatively little is known about rates and molecular processes of recombination for retroviruses other than HIV, including important model viruses such as feline immunodeficiency virus (FIV). We investigated recombination in complete FIV env gene sequences (n = 355) isolated from 43 naturally infected cats. We demonstrated that recombination is abundant in natural FIV infection, with over 41% of the cats being infected with viruses containing recombinant env genes. In addition, we identified shared recombination breakpoints; the most significant hotspot occurred between the leader/signal fragment and the remainder of env. Our results have identified the leader/signal fragment of env as an important site for recombination and highlight potential limitations of the current phylogenetic classification of FIV based on partial env sequences. Furthermore, the presence of abundant recombinant FIV in the USA poses a significant challenge for commercial diagnostic tests and should inform the development of the next generation of FIV vaccines.

Charge-carrier transport and recombination in heteroepitaxial CdTe

International Nuclear Information System (INIS)

Kuciauskas, Darius; Farrell, Stuart; Dippo, Pat; Moseley, John; Moutinho, Helio; Li, Jian V.; Allende Motz, A. M.; Kanevce, Ana; Zaunbrecher, Katherine; Gessert, Timothy A.; Levi, Dean H.; Metzger, Wyatt K.; Colegrove, Eric; Sivananthan, S.

2014-01-01

We analyze charge-carrier dynamics using time-resolved spectroscopy and varying epitaxial CdTe thickness in undoped heteroepitaxial CdTe/ZnTe/Si. By employing one-photon and nonlinear two-photon excitation, we assess surface, interface, and bulk recombination. Two-photon excitation with a focused laser beam enables characterization of recombination velocity at the buried epilayer/substrate interface, 17.5 μm from the sample surface. Measurements with a focused two-photon excitation beam also indicate a fast diffusion component, from which we estimate an electron mobility of 650 cm 2 (Vs) −1 and diffusion coefficient D of 17 cm 2  s −1 . We find limiting recombination at the epitaxial film surface (surface recombination velocity S surface  = (2.8 ± 0.3) × 10 5  cm s −1 ) and at the heteroepitaxial interface (interface recombination velocity S interface  = (4.8 ± 0.5) × 10 5  cm s −1 ). The results demonstrate that reducing surface and interface recombination velocity is critical for photovoltaic solar cells and electronic devices that employ epitaxial CdTe.

Regulation of homologous recombination at telomeres in budding yeast

DEFF Research Database (Denmark)

Eckert-Boulet, Nadine; Lisby, Michael

2010-01-01

Homologous recombination is suppressed at normal length telomere sequences. In contrast, telomere recombination is allowed when telomeres erode in the absence of telomerase activity or as a consequence of nucleolytic degradation or incomplete replication. Here, we review the mechanisms that contr...... that contribute to regulating mitotic homologous recombination at telomeres and the role of these mechanisms in signalling short telomeres in the budding yeast Saccharomyces cerevisiae....

Recombining overlapping BACs into a single larger BAC

Directory of Open Access Journals (Sweden)

Huxley Clare

2004-01-01

Full Text Available Abstract Background BAC clones containing entire mammalian genes including all the transcribed region and long range controlling elements are very useful for functional analysis. Sequenced BACs are available for most of the human and mouse genomes and in many cases these contain intact genes. However, large genes often span more than one BAC, and single BACs covering the entire region of interest are not available. Here we describe a system for linking two or more overlapping BACs into a single clone by homologous recombination. Results The method was used to link a 61-kb insert carrying the final 5 exons of the human CFTR gene onto a 160-kb BAC carrying the first 22 exons. Two rounds of homologous recombination were carried out in the EL350 strain of bacteria which can be induced for the Red genes. In the first round, the inserts of the two overlapping BACs were subcloned into modified BAC vectors using homologous recombination. In the second round, the BAC to be added was linearised with the very rare-cutting enzyme I-PpoI and electroporated into recombination efficient EL350 bacteria carrying the other BAC. Recombined BACs were identified by antibiotic selection and PCR screening and 10% of clones contained the correctly recombined 220-kb BAC. Conclusion The system can be used to link the inserts from any overlapping BAC or PAC clones. The original orientation of the inserts is not important and desired regions of the inserts can be selected. The size limit for the fragments recombined may be larger than the 61 kb used here and multiple BACs in a contig could be combined by alternating use of the two pBACLink vectors. This system should be of use to many investigators wishing to carry out functional analysis on large mammalian genes which are not available in single BAC clones.

Mitochondrial Recombination and Introgression during Speciation by Hybridization.

Science.gov (United States)

Leducq, Jean-Baptiste; Henault, Mathieu; Charron, Guillaume; Nielly-Thibault, Lou; Terrat, Yves; Fiumera, Heather L; Shapiro, B Jesse; Landry, Christian R

2017-08-01

Genome recombination is a major source of genotypic diversity and contributes to adaptation and speciation following interspecies hybridization. The contribution of recombination in these processes has been thought to be largely limited to the nuclear genome because organelles are mostly uniparentally inherited in animals and plants, which prevents recombination. Unicellular eukaryotes such as budding yeasts do, however, transmit mitochondria biparentally, suggesting that during hybridization, both parents could provide alleles that contribute to mitochondrial functions such as respiration and metabolism in hybrid populations or hybrid species. We examined the dynamics of mitochondrial genome transmission and evolution during speciation by hybridization in the natural budding yeast Saccharomyces paradoxus. Using population-scale mitochondrial genome sequencing in two endemic North American incipient species SpB and SpC and their hybrid species SpC*, we found that both parental species contributed to the hybrid mitochondrial genome through recombination. We support our findings by showing that mitochondrial recombination between parental types is frequent in experimental crosses that recreate the early step of this speciation event. In these artificial hybrids, we observed that mitochondrial genome recombination enhances phenotypic variation among diploid hybrids, suggesting that it could play a role in the phenotypic differentiation of hybrid species. Like the nuclear genome, the mitochondrial genome can, therefore, also play a role in hybrid speciation. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Trends in recombinant protein use in animal production.

Science.gov (United States)

Gifre, Laia; Arís, Anna; Bach, Àlex; Garcia-Fruitós, Elena

2017-03-04

Recombinant technologies have made possible the production of a broad catalogue of proteins of interest, including those used for animal production. The most widely studied proteins for the animal sector are those with an important role in reproduction, feed efficiency, and health. Nowadays, mammalian cells and fungi are the preferred choice for recombinant production of hormones for reproductive purposes and fibrolytic enzymes to enhance animal performance, respectively. However, the development of low-cost products is a priority, particularly in livestock. The study of cell factories such as yeast and bacteria has notably increased in the last decades to make the new developed reproductive hormones and fibrolytic enzymes a real alternative to the marketed ones. Important efforts have also been invested to developing new recombinant strategies for prevention and therapy, including passive immunization and modulation of the immune system. This offers the possibility to reduce the use of antibiotics by controlling physiological processes and improve the efficacy of preventing infections. Thus, nowadays different recombinant fibrolytic enzymes, hormones, and therapeutic molecules with optimized properties have been successfully produced through cost-effective processes using microbial cell factories. However, despite the important achievements for reducing protein production expenses, alternative strategies to further reduce these costs are still required. In this context, it is necessary to make a giant leap towards the use of novel strategies, such as nanotechnology, that combined with recombinant technology would make recombinant molecules affordable for animal industry.

Constraints from jet calculus on quark recombination

International Nuclear Information System (INIS)

Jones, L.M.; Lassila, K.E.; Willen, D.

1979-01-01

Within the QCD jet calculus formalism, we deduce an equation describing recombination of quarks and antiquarks into mesons within a quark or gluon jet. This equation relates the recombination function R(x 1 ,x 2 ,x) used in current literature to the fragmentation function for producing that same meson out of the parton initiating the jet. We submit currently used recombination functions to our consistency test, taking as input mainly the u-quark fragmentation data into π + mesons, but also s-quark fragmentation into K - mesons. The constraint is well satisfied at large Q 2 for large moments. Our results depend on one parameter, Q 0 2 , the constraint equation being satisfied for small values of this parameter

Experimental study of para- and ortho-H3+ recombination

International Nuclear Information System (INIS)

Plasil, R; Varju, J; Hejduk, M; Dohnal, P; KotrIk, T; Glosik, J

2011-01-01

Recombination of H 3 + with electrons is a key process for many plasmatic environments. Recent experiments on storage ring devices used ion sources producing H 3 + with enhanced populations of H 3 + ions in the para nuclear spin configuration to shed light on the theoretically predicted faster recombination of para states. Although increased recombination rates were observed, no in situ characterization of recombining ions was performed. We present a state selective recombination study of para- and ortho-H 3 + ions with electrons at 77 K in afterglow plasma in a He/Ar/H 2 gas-mixture. Both spin configurations of H 3 + have been observed in situ with a near infrared cavity ring down spectrometer (NIR-CRDS) using the two lowest energy levels of H 3 + . Using hydrogen with an enhanced population of H 2 molecules in para states allowed us to influence the [para-H 3 + ]/[ortho-H 3 + ] ratio in the discharge and in the afterglow. We observed an increase in the measured effective recombination rate coefficients with the increase of the fraction of para-H 3 + . Measurements with different fractions of para-H 3 + at otherwise identical conditions allowed us to determine the binary recombination rate coefficients for pure para-H 3 + p α bin (77 K) = (2.0±0.4)x10 -7 cm 3 s -1 and pure ortho-H 3 + o α bin (77 K) = (4±3)x10 -8 cm 3 s -1 .

Experimental study of para- and ortho-H3+ recombination

Science.gov (United States)

Plašil, R.; Varju, J.; Hejduk, M.; Dohnal, P.; Kotrík, T.; Glosík, J.

2011-07-01

Recombination of H3+ with electrons is a key process for many plasmatic environments. Recent experiments on storage ring devices used ion sources producing H3+ with enhanced populations of H3+ ions in the para nuclear spin configuration to shed light on the theoretically predicted faster recombination of para states. Although increased recombination rates were observed, no in situ characterization of recombining ions was performed. We present a state selective recombination study of para- and ortho-H3+ ions with electrons at 77 K in afterglow plasma in a He/Ar/H2 gas-mixture. Both spin configurations of H3+ have been observed in situ with a near infrared cavity ring down spectrometer (NIR-CRDS) using the two lowest energy levels of H3+. Using hydrogen with an enhanced population of H2 molecules in para states allowed us to influence the [para-H3+]/[ortho-H3+] ratio in the discharge and in the afterglow. We observed an increase in the measured effective recombination rate coefficients with the increase of the fraction of para-H3+. Measurements with different fractions of para-H3+ at otherwise identical conditions allowed us to determine the binary recombination rate coefficients for pure para-H3+ pαbin(77 K) = (2.0±0.4)×10-7 cm3s-1 and pure ortho-H3+ oαbin(77 K) = (4±3)×10-8 cm3s-1.

Characterization of recombination features and the genetic basis in multiple cattle breeds.

Science.gov (United States)

Shen, Botong; Jiang, Jicai; Seroussi, Eyal; Liu, George E; Ma, Li

2018-04-27

Crossover generated by meiotic recombination is a fundamental event that facilitates meiosis and sexual reproduction. Comparative studies have shown wide variation in recombination rate among species, but the characterization of recombination features between cattle breeds has not yet been performed. Cattle populations in North America count millions, and the dairy industry has genotyped millions of individuals with pedigree information that provide a unique opportunity to study breed-level variations in recombination. Based on large pedigrees of Jersey, Ayrshire and Brown Swiss cattle with genotype data, we identified over 3.4 million maternal and paternal crossover events from 161,309 three-generation families. We constructed six breed- and sex-specific genome-wide recombination maps using 58,982 autosomal SNPs for two sexes in the three dairy cattle breeds. A comparative analysis of the six recombination maps revealed similar global recombination patterns between cattle breeds but with significant differences between sexes. We confirmed that male recombination map is 10% longer than the female map in all three cattle breeds, consistent with previously reported results in Holstein cattle. When comparing recombination hotspot regions between cattle breeds, we found that 30% and 10% of the hotspots were shared between breeds in males and females, respectively, with each breed exhibiting some breed-specific hotspots. Finally, our multiple-breed GWAS found that SNPs in eight loci affected recombination rate and that the PRDM9 gene associated with hotspot usage in multiple cattle breeds, indicating a shared genetic basis for recombination across dairy cattle breeds. Collectively, our results generated breed- and sex-specific recombination maps for multiple cattle breeds, provided a comprehensive characterization and comparison of recombination patterns between breeds, and expanded our understanding of the breed-level variations in recombination features within an

Linkage disequilibrium in HLA cannot be explained by selective recombination.

Science.gov (United States)

Termijtelen, A; D'Amaro, J; van Rood, J J; Schreuder, G M

1995-11-01

Some combinations of HLA-A, -B and -DR antigens occur more frequently than would be expected from their gene frequencies in the population. This phenomenon, referred to as Linkage Disequilibrium (LD) has been the origin of many speculations. One hypothesis to explain LD is that some haplotypes are protected from recombination. A second hypothesis is that these HLA antigens preferentially recombine after cross-over to create an LD haplotype. We tested these 2 hypotheses: from a pool of over 10,000 families typed in our department, we analyzed 126 families in which HLA-A:B or B:DR recombinant offspring was documented. To overcome a possible bias in our material, we used the non-recombined haplotypes from the same 126 families as a control group. Our results show that the number of cross-overs through LD haplotypes is not significantly lower then would be expected if recombination occurred randomly. Also the number of LD haplotypes created upon recombination was not significantly increased.

Branching innovation, recombinant innovation, and endogenous technological transitions

NARCIS (Netherlands)

Frenken, K.; Izquierdo, L.; Zeppini, P.

2012-01-01

We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create "short-cuts" which reduce

Determination of the trap-assisted recombination strength in polymer light emitting diodes

NARCIS (Netherlands)

Kuik, Martijn; Nicolai, Herman T.; Lenes, Martijn; Wetzelaer, Gert-Jan A. H.; Lu, Mingtao; Blom, Paul W. M.

2011-01-01

The recombination processes in poly(p-phenylene vinylene) based polymer light-emitting diodes (PLEDs) are investigated. Photogenerated current measurements on PLED device structures reveal that next to the known Langevin recombination also trap-assisted recombination is an important recombination

Determination of the trap-assisted recombination strength in polymer light emitting diodes

NARCIS (Netherlands)

Kuik, M.; Nicolai, H.T.; Lenes, M.; Wetzelaer, G.-J.A.H.; Lu, M.; Blom, P.W.M.

2011-01-01

The recombination processes in poly(p -phenylene vinylene) based polymer light-emitting diodes (PLEDs) are investigated. Photogenerated current measurements on PLED device structures reveal that next to the known Langevin recombination also trap-assisted recombination is an important recombination

Recombination of a fast expanding plasma

International Nuclear Information System (INIS)

Salvat, M.

1979-05-01

The goal of the following calculations is to determine numerically the recombination of dense plasmas (for instance of laser-produced plasmas). The recombination is computed for plasmas with initial densities of 10 24 27 [m -3 ] and with initial temperatures >= 50 eV. The ionization of the plasma remains essentially constant during the early phase of expansion. The time for which the ionization is 'frozen-in' grows with decreasing initial density and with increasing initial temperature. (orig.) [de

Co-factor activated recombinant adenovirus proteinases

Science.gov (United States)

Anderson, Carl W.; Mangel, Walter F.

1996-08-06

This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying said peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described.

Mitochondrial recombination increases with age in Podospora anserina

NARCIS (Netherlands)

van Diepeningen, Anne D; Goedbloed, Daniël J; Slakhorst, S Marijke; Koopmanschap, A Bertha; Maas, Marc F P M; Hoekstra, Rolf F; Debets, Alfons J M

With uniparental inheritance of mitochondria, there seems little reason for homologous recombination in mitochondria, but the machinery for mitochondrial recombination is quite well-conserved in many eukaryote species. In fungi and yeasts heteroplasmons may be formed when strains fuse and transfer

The Λ0 polarization and the recombination mechanism

International Nuclear Information System (INIS)

Herrera, G.; Montano, L.M.

1997-01-01

We use the recombination and the Thomas Precession Model to obtain a prediction for the Λ 0 polarization in the p+p → Λ 0 + X reaction. We study the effect of the recombination function on the Λ 0 polarization. (author)

Is routine antenatal venereal disease research laboratory test still justified? Nigerian experience

Directory of Open Access Journals (Sweden)

Nwosu BO

2015-01-01

Full Text Available Betrand O Nwosu,1 George U Eleje,1 Amaka L Obi-Nwosu,2 Ita F Ahiarakwem,3 Comfort N Akujobi,4 Chukwudi C Egwuatu,4 Chukwudumebi O Onyiuke5 1Department of Obstetrics and Gynecology, Nnamdi Azikiwe University, Nnewi Campus, Nnewi, Anambra State, Nigeria; 2Department of Family Medicine, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria; 3Department of Medical Microbiology, Imo State University Teaching Hospital, Orlu, Imo State, Nigeria; 4Department of Medical Microbiology, Nnamdi Azikiwe University, Nnewi Campus, Nnewi, Anambra State, Nigeria; 5Department of Medical Microbiology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, NigeriaObjective: To determine the seroreactivity of pregnant women to syphilis in order to justify the need for routine antenatal syphilis screening.Methods: A multicenter retrospective analysis of routine antenatal venereal disease research laboratory (VDRL test results between 1 September 2010 and 31 August 2012 at three specialist care hospitals in south-east Nigeria was done. A reactive VDRL result is subjected for confirmation using Treponema pallidum hemagglutination assay test. Analysis was by Epi Info 2008 version 3.5.1 and Stata/IC version 10.Results: Adequate records were available regarding 2,156 patients and were thus reviewed. The mean age of the women was 27.4 years (±3.34, and mean gestational age was 26.4 weeks (±6.36. Only 15 cases (0.70% were seropositive to VDRL. Confirmatory T. pallidum hemagglutination assay was positive in 4 of the 15 cases, giving an overall prevalence of 0.19% and a false-positive rate of 73.3%. There was no significant difference in the prevalence of syphilis in relation to maternal age and parity (P>0.05.Conclusion: While the prevalence of syphilis is extremely low in the antenatal care population at the three specialist care hospitals in south-east Nigeria, false-positive rate is high and prevalence did not significantly vary with maternal age or

A simple negative selection method to identify adenovirus recombinants using colony PCR

Directory of Open Access Journals (Sweden)

Yongliang Zhao

2014-01-01

Conclusions: The negative selection method to identify AdEasy adenovirus recombinants by colony PCR can identify the recombined colony within a short time-period, and maximally avoid damage to the recombinant plasmid by limiting recombination time, resulting in improved adenovirus packaging.

The potential of shifting recombination hotspots to increase genetic gain in livestock breeding.

Science.gov (United States)

Gonen, Serap; Battagin, Mara; Johnston, Susan E; Gorjanc, Gregor; Hickey, John M

2017-07-04

This study uses simulation to explore and quantify the potential effect of shifting recombination hotspots on genetic gain in livestock breeding programs. We simulated three scenarios that differed in the locations of quantitative trait nucleotides (QTN) and recombination hotspots in the genome. In scenario 1, QTN were randomly distributed along the chromosomes and recombination was restricted to occur within specific genomic regions (i.e. recombination hotspots). In the other two scenarios, both QTN and recombination hotspots were located in specific regions, but differed in whether the QTN occurred outside of (scenario 2) or inside (scenario 3) recombination hotspots. We split each chromosome into 250, 500 or 1000 regions per chromosome of which 10% were recombination hotspots and/or contained QTN. The breeding program was run for 21 generations of selection, after which recombination hotspot regions were kept the same or were shifted to adjacent regions for a further 80 generations of selection. We evaluated the effect of shifting recombination hotspots on genetic gain, genetic variance and genic variance. Our results show that shifting recombination hotspots reduced the decline of genetic and genic variance by releasing standing allelic variation in the form of new allele combinations. This in turn resulted in larger increases in genetic gain. However, the benefit of shifting recombination hotspots for increased genetic gain was only observed when QTN were initially outside recombination hotspots. If QTN were initially inside recombination hotspots then shifting them decreased genetic gain. Shifting recombination hotspots to regions of the genome where recombination had not occurred for 21 generations of selection (i.e. recombination deserts) released more of the standing allelic variation available in each generation and thus increased genetic gain. However, whether and how much increase in genetic gain was achieved by shifting recombination hotspots depended

Polyploidization increases meiotic recombination frequency in Arabidopsis

Directory of Open Access Journals (Sweden)

Rehmsmeier Marc

2011-04-01

Full Text Available Abstract Background Polyploidization is the multiplication of the whole chromosome complement and has occurred frequently in vascular plants. Maintenance of stable polyploid state over generations requires special mechanisms to control pairing and distribution of more than two homologous chromosomes during meiosis. Since a minimal number of crossover events is essential for correct chromosome segregation, we investigated whether polyploidy has an influence on the frequency of meiotic recombination. Results Using two genetically linked transgenes providing seed-specific fluorescence, we compared a high number of progeny from diploid and tetraploid Arabidopsis plants. We show that rates of meiotic recombination in reciprocal crosses of genetically identical diploid and autotetraploid Arabidopsis plants were significantly higher in tetraploids compared to diploids. Although male and female gametogenesis differ substantially in meiotic recombination frequency, both rates were equally increased in tetraploids. To investigate whether multivalent formation in autotetraploids was responsible for the increased recombination rates, we also performed corresponding experiments with allotetraploid plants showing strict bivalent pairing. We found similarly increased rates in auto- and allotetraploids, suggesting that the ploidy effect is independent of chromosome pairing configurations. Conclusions The evolutionary success of polyploid plants in nature and under domestication has been attributed to buffering of mutations and sub- and neo-functionalization of duplicated genes. Should the data described here be representative for polyploid plants, enhanced meiotic recombination, and the resulting rapid creation of genetic diversity, could have also contributed to their prevalence.

Report of recombinant norovirus GII.g/GII.12 in Beijing, China.

Science.gov (United States)

Sang, Shaowei; Zhao, Zhongtang; Suo, Jijiang; Xing, Yubin; Jia, Ning; Gao, Yan; Xie, Lijun; Du, Mingmei; Liu, Bowei; Ren, Shiwang; Liu, Yunxi

2014-01-01

Norovirus (NoV) has been recognized as the most important cause of nonbacterial acute gastroenteritis affecting all age group people in the world. Genetic recombination is a common occurance in RNA viruses and many recombinant NoV strains have been described since it was first reported in 1997. However, the knowledge of recombinant NoV in China is extremely limited. A total of 685 stool specimens were tested for NoV infection from the acute gastroenteritis patients who visited one general hospital in Beijing from April 2009 to November 2011. The virus recombination was identified by constructing phylogenetic trees of two genes, further SimPlot and the maximum chi-square analysis. The overall positive rate was 9.6% (66/685). GII.4 New Orleans 2009 and GII.4 2006b variants were the dominant genotype. Four GII.g/GII.12 and one GII.12/GII.3 recombinant strains were confirmed, and all derived from adult outpatients. The predictive recombination point occurred at the open reading frame (ORF)1/ORF2 overlap. The GII.g ORF1/GII.12ORF2 recombinant has been reported in several countries and it was the first report of this recombinant in China.

Recombinational Cloning Using Gateway and In-Fusion Cloning Schemes

Science.gov (United States)

Throop, Andrea L.; LaBaer, Joshua

2015-01-01

The comprehensive study of protein structure and function, or proteomics, depends on the obtainability of full-length cDNAs in species-specific expression vectors and subsequent functional analysis of the expressed protein. Recombinational cloning is a universal cloning technique based on site-specific recombination that is independent of the insert DNA sequence of interest, which differentiates this method from the classical restriction enzyme-based cloning methods. Recombinational cloning enables rapid and efficient parallel transfer of DNA inserts into multiple expression systems. This unit summarizes strategies for generating expression-ready clones using the most popular recombinational cloning technologies, including the commercially available Gateway® (Life Technologies) and In-Fusion® (Clontech) cloning technologies. PMID:25827088

Productive Homologous and Non-homologous Recombination of Hepatitis C Virus in Cell Culture

Science.gov (United States)

Li, Yi-Ping; Mikkelsen, Lotte S.; Gottwein, Judith M.; Bukh, Jens

2013-01-01

Genetic recombination is an important mechanism for increasing diversity of RNA viruses, and constitutes a viral escape mechanism to host immune responses and to treatment with antiviral compounds. Although rare, epidemiologically important hepatitis C virus (HCV) recombinants have been reported. In addition, recombination is an important regulatory mechanism of cytopathogenicity for the related pestiviruses. Here we describe recombination of HCV RNA in cell culture leading to production of infectious virus. Initially, hepatoma cells were co-transfected with a replicating JFH1ΔE1E2 genome (genotype 2a) lacking functional envelope genes and strain J6 (2a), which has functional envelope genes but does not replicate in culture. After an initial decrease in the number of HCV positive cells, infection spread after 13–36 days. Sequencing of recovered viruses revealed non-homologous recombinants with J6 sequence from the 5′ end to the NS2–NS3 region followed by JFH1 sequence from Core to the 3′ end. These recombinants carried duplicated sequence of up to 2400 nucleotides. HCV replication was not required for recombination, as recombinants were observed in most experiments even when two replication incompetent genomes were co-transfected. Reverse genetic studies verified the viability of representative recombinants. After serial passage, subsequent recombination events reducing or eliminating the duplicated region were observed for some but not all recombinants. Furthermore, we found that inter-genotypic recombination could occur, but at a lower frequency than intra-genotypic recombination. Productive recombination of attenuated HCV genomes depended on expression of all HCV proteins and tolerated duplicated sequence. In general, no strong site specificity was observed. Non-homologous recombination was observed in most cases, while few homologous events were identified. A better understanding of HCV recombination could help identification of natural recombinants

Inhomogeneous bimolecular recombination in partially crystallised tri-methylphenyl diamine glasses

International Nuclear Information System (INIS)

Goldie, D.M.

2013-01-01

The rise and fall dynamics of transient photocurrents induced by exposure to ultraviolet radiation have been analysed for a series of glassy tri-methylphenyl diamine films that have been partially crystallised by ageing under ambient conditions following vapour deposition. An inhomogeneous bimolecular recombination model that uses coupled rate equations is found to provide a consistent fit for the observed photocurrent dynamics provided the recombination rate of holes in the crystallised regions of the films is lower compared to the amorphous regions. Parameters returned by the bimolecular model are investigated as a function of the film age but are observed to be highly sensitive to the initial experimental estimates that are supplied for the effective hole recombination time. The effective hole recombination time generated by the model is found to be relatively independent of film age, however, and has a value of around 0.16 s for a carrier generation rate of 7 × 10 14 cm −3 s −1 . The effective recombination time and steady-state photoconductivity magnitudes are found to be consistent with experimental hole mobility and photo-carrier generation efficiency values that are obtained using complementary time-of-flight and charge collection experiments. - Highlights: ► Transient photocurrents in evaporated diamine films have fast and slow components. ► Transient photocurrents are modelled using inhomogeneous bimolecular recombination. ► Recombination rates differ between crystallised and amorphous film regions. ► Recombination parameters evolve with film age as the films crystallise

Dielectronic recombination of highly ionized iron

International Nuclear Information System (INIS)

Griffin, D.C.; Pindzola, M.S.

1987-01-01

Dielectronic recombination of the iron ions Fe/sup 15+/, Fe/sup 23+/, and Fe/sup 25+/ has been studied in the isolated-resonance, distorted-wave approximation. The cross-section calculations include the dielec- tronic transitions associated with the 3s→3l and 3s→4l excitations in Fe/sup 15+/, the 2s→2p and 2s→3l excitations in Fe/sup 23+/, and the 1s→2l excitations in Fe/sup 25+/. The effects of external electric fields have been included by employing intermediate-coupled, field-mixed eigenvectors for the doubly excited Rydberg states, determined by diagonalizing a Hamiltonian matrix which includes the internal electrostatic and spin-orbit terms, as well as the Stark matrix elements. The field effects are found to be quite large in Fe/sup 15+/, relatively small in Fe/sup 23+/, and negligible in Fe/sup 25+/. The calculations indicate that there are large resonances near threshold in Fe/sup 23+/ that are unaffected by external fields and may be measurable in new experiments currently being designed. In addition, the contributions of radiative recombination and the possible interference between radiative and dielectronic recombination in low-lying resonances are considered. Even though the radiative recombination cross sections may be appreciable near threshold in Fe/sup 15+/ and Fe/sup 23+/, the interference between these processes appears to be completely negligible

Measurements of EEDF in recombination dominated afterglow plasma

Science.gov (United States)

Plasil, R.; Korolov, I.; Kotrik, T.; Varju, J.; Dohnal, P.; Donko, Z.; Bano, G.; Glosik, J.

2009-11-01

Electron energy distribution functions (EEDF) have been measured in decaying plasma in Flowing Afterglow Langmuir Probe (FALP) experiment. The measurements have been carried out in diffusion and recombination governed plasmas used for studies of recombination of KrD+ and H3+ ions.

Measurements of EEDF in recombination dominated afterglow plasma

International Nuclear Information System (INIS)

Plasil, R; Korolov, I; Kotrik, T; Varju, J; Dohnal, P; Glosik, J; Donko, Z; Bano, G

2009-01-01

Electron energy distribution functions (EEDF) have been measured in decaying plasma in Flowing Afterglow Langmuir Probe (FALP) experiment. The measurements have been carried out in diffusion and recombination governed plasmas used for studies of recombination of KrD + and H 3 + ions.

The Genetic Architecture of Natural Variation in Recombination Rate in Drosophila melanogaster.

Science.gov (United States)

Hunter, Chad M; Huang, Wen; Mackay, Trudy F C; Singh, Nadia D

2016-04-01

Meiotic recombination ensures proper chromosome segregation in many sexually reproducing organisms. Despite this crucial function, rates of recombination are highly variable within and between taxa, and the genetic basis of this variation remains poorly understood. Here, we exploit natural variation in the inbred, sequenced lines of the Drosophila melanogaster Genetic Reference Panel (DGRP) to map genetic variants affecting recombination rate. We used a two-step crossing scheme and visible markers to measure rates of recombination in a 33 cM interval on the X chromosome and in a 20.4 cM interval on chromosome 3R for 205 DGRP lines. Though we cannot exclude that some biases exist due to viability effects associated with the visible markers used in this study, we find ~2-fold variation in recombination rate among lines. Interestingly, we further find that recombination rates are uncorrelated between the two chromosomal intervals. We performed a genome-wide association study to identify genetic variants associated with recombination rate in each of the two intervals surveyed. We refined our list of candidate variants and genes associated with recombination rate variation and selected twenty genes for functional assessment. We present strong evidence that five genes are likely to contribute to natural variation in recombination rate in D. melanogaster; these genes lie outside the canonical meiotic recombination pathway. We also find a weak effect of Wolbachia infection on recombination rate and we confirm the interchromosomal effect. Our results highlight the magnitude of population variation in recombination rate present in D. melanogaster and implicate new genetic factors mediating natural variation in this quantitative trait.

Manipulation of GABA in the ventral pallidum, but not the nucleus accumbens, induces intense, preferential, fat consumption in rats.

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Covelo, Ignacio R; Patel, Zaid I; Luviano, Jennifer A; Stratford, Thomas R; Wirtshafter, David

2014-08-15

Injections of the GABAA antagonist bicuculline into the medial ventral pallidum (VPm) induce marked increases in food intake, but nothing is known about the way in which these injections alter the distribution of intake in a macronutrient selection situation. We investigated this topic by adapting rats to a diet containing independent sources of protein, carbohydrate and fat, and then examining the effects of intra-VPm bicuculline on diet selection. Under these conditions, bicuculline produced a massive, preferential increase in fat intake with subjects consuming a mean of 97% of their calories from fat. Furthermore, all treated subjects ate fat before any other macronutrient, suggesting that the animals' behavior was directed selectively toward this dietary component even before consumption had begun. Similar effects were not observed following food deprivation, which exerted its largest effect on carbohydrate intake. To compare the intra-VPm bicuculline response to that seen after activation of GABA receptors in the nucleus accumbens shell (AcbSh), a major source of projections to the VPm, we conducted similar experiments with intra-AcbSh injections of muscimol and baclofen. These injections also enhanced food intake, but did not reproduce the selective preference for fat seen after intra-VPm bicuculline. These experiments provide the first demonstration of preferential enhancement of fat intake following manipulations of a nonpeptide neurotransmitter. Since mean intakes of fat under baseline conditions and after deprivation tended to be lower than those of carbohydrates, it seems unlikely that the effects of intra-VPm bicuculline are related to the intrinsic "rewarding" properties of fat, but might rather reflect the induction of a state of "fat craving." Copyright © 2014 Elsevier B.V. All rights reserved.

Recombination in feline immunodeficiency virus from feral and companion domestic cats

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Rodrigo Allen G

2008-06-01

Full Text Available Abstract Background Recombination is a relatively common phenomenon in retroviruses. We investigated recombination in Feline Immunodeficiency Virus from naturally-infected New Zealand domestic cats (Felis catus by sequencing regions of the gag, pol and env genes. Results The occurrence of intragenic recombination was highest in env, with evidence of recombination in 6.4% (n = 156 of all cats. A further recombinant was identified in each of the gag (n = 48 and pol (n = 91 genes. Comparisons of phylogenetic trees across genes identified cases of incongruence, indicating intergenic recombination. Three (7.7%, n = 39 of these incongruencies were found to be significantly different using the Shimodaira-Hasegawa test. Surprisingly, our phylogenies from the gag and pol genes showed that no New Zealand sequences group with reference subtype C sequences within intrasubtype pairwise distances. Indeed, we find one and two distinct unknown subtype groups in gag and pol, respectively. These observations cause us to speculate that these New Zealand FIV strains have undergone several recombination events between subtype A parent strains and undefined unknown subtype strains, similar to the evolutionary history hypothesised for HIV-1 "subtype E". Endpoint dilution sequencing was used to confirm the consensus sequences of the putative recombinants and unknown subtype groups, providing evidence for the authenticity of these sequences. Endpoint dilution sequencing also resulted in the identification of a dual infection event in the env gene. In addition, an intrahost recombination event between variants of the same subtype in the pol gene was established. This is the first known example of naturally-occurring recombination in a cat with infection of the parent strains. Conclusion Evidence of intragenic recombination in the gag, pol and env regions, and complex intergenic recombination, of FIV from naturally-infected domestic cats in New Zealand was found. Strains

Recombination in feline immunodeficiency virus from feral and companion domestic cats.

Science.gov (United States)

Hayward, Jessica J; Rodrigo, Allen G

2008-06-17

Recombination is a relatively common phenomenon in retroviruses. We investigated recombination in Feline Immunodeficiency Virus from naturally-infected New Zealand domestic cats (Felis catus) by sequencing regions of the gag, pol and env genes. The occurrence of intragenic recombination was highest in env, with evidence of recombination in 6.4% (n = 156) of all cats. A further recombinant was identified in each of the gag (n = 48) and pol (n = 91) genes. Comparisons of phylogenetic trees across genes identified cases of incongruence, indicating intergenic recombination. Three (7.7%, n = 39) of these incongruencies were found to be significantly different using the Shimodaira-Hasegawa test.Surprisingly, our phylogenies from the gag and pol genes showed that no New Zealand sequences group with reference subtype C sequences within intrasubtype pairwise distances. Indeed, we find one and two distinct unknown subtype groups in gag and pol, respectively. These observations cause us to speculate that these New Zealand FIV strains have undergone several recombination events between subtype A parent strains and undefined unknown subtype strains, similar to the evolutionary history hypothesised for HIV-1 "subtype E".Endpoint dilution sequencing was used to confirm the consensus sequences of the putative recombinants and unknown subtype groups, providing evidence for the authenticity of these sequences. Endpoint dilution sequencing also resulted in the identification of a dual infection event in the env gene. In addition, an intrahost recombination event between variants of the same subtype in the pol gene was established. This is the first known example of naturally-occurring recombination in a cat with infection of the parent strains. Evidence of intragenic recombination in the gag, pol and env regions, and complex intergenic recombination, of FIV from naturally-infected domestic cats in New Zealand was found. Strains of unknown subtype were identified in all three gene