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Sample records for rat fleas xenopsylla

  1. Genetic structure and gene flow of the flea Xenopsylla cheopis in Madagascar and Mayotte.

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    Harimalala, Mireille; Telfer, Sandra; Delatte, Hélène; Watts, Phillip C; Miarinjara, Adélaïde; Ramihangihajason, Tojo Rindra; Rahelinirina, Soanandrasana; Rajerison, Minoarisoa; Boyer, Sébastien

    2017-07-20

    The flea Xenopsylla cheopis (Siphonaptera: Pulicidae) is a vector of plague. Despite this insect's medical importance, especially in Madagascar where plague is endemic, little is known about the organization of its natural populations. We undertook population genetic analyses (i) to determine the spatial genetic structure of X. cheopis in Madagascar and (ii) to determine the potential risk of plague introduction in the neighboring island of Mayotte. We genotyped 205 fleas from 12 sites using nine microsatellite markers. Madagascan populations of X. cheopis differed, with the mean number of alleles per locus per population ranging from 1.78 to 4.44 and with moderate to high levels of genetic differentiation between populations. Three distinct genetic clusters were identified, with different geographical distributions but with some apparent gene flow between both islands and within Malagasy regions. The approximate Bayesian computation (ABC) used to test the predominant direction of flea dispersal implied a recent population introduction from Mayotte to Madagascar, which was estimated to have occurred between 1993 and 2012. The impact of this flea introduction in terms of plague transmission in Madagascar is unclear, but the low level of flea exchange between the two islands seems to keep Mayotte free of plague for now. This study highlights the occurrence of genetic structure among populations of the flea vector of plague, X. cheopis, in Madagascar and suggests that a flea population from Mayotte has been introduced to Madagascar recently. As plague has not been reported in Mayotte, this introduction is unlikely to present a major concern for plague transmission. Nonetheless, evidence of connectivity among flea populations in the two islands indicates a possibility for dispersal by fleas in the opposite direction and thus a risk of plague introduction to Mayotte.

  2. Effects of temperature on the transmission of Yersinia Pestis by the flea, Xenopsylla Cheopis, in the late phase period.

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    Schotthoefer, Anna M; Bearden, Scott W; Holmes, Jennifer L; Vetter, Sara M; Montenieri, John A; Williams, Shanna K; Graham, Christine B; Woods, Michael E; Eisen, Rebecca J; Gage, Kenneth L

    2011-09-29

    Traditionally, efficient flea-borne transmission of Yersinia pestis, the causative agent of plague, was thought to be dependent on a process referred to as blockage in which biofilm-mediated growth of the bacteria physically blocks the flea gut, leading to the regurgitation of contaminated blood into the host. This process was previously shown to be temperature-regulated, with blockage failing at temperatures approaching 30°C; however, the abilities of fleas to transmit infections at different temperatures had not been adequately assessed. We infected colony-reared fleas of Xenopsylla cheopis with a wild type strain of Y. pestis and maintained them at 10, 23, 27, or 30°C. Naïve mice were exposed to groups of infected fleas beginning on day 7 post-infection (p.i.), and every 3-4 days thereafter until day 14 p.i. for fleas held at 10°C, or 28 days p.i. for fleas held at 23-30°C. Transmission was confirmed using Y. pestis-specific antigen or antibody detection assays on mouse tissues. Although no statistically significant differences in per flea transmission efficiencies were detected between 23 and 30°C, efficiencies were highest for fleas maintained at 23°C and they began to decline at 27 and 30°C by day 21 p.i. These declines coincided with declining median bacterial loads in fleas at 27 and 30°C. Survival and feeding rates of fleas also varied by temperature to suggest fleas at 27 and 30°C would be less likely to sustain transmission than fleas maintained at 23°C. Fleas held at 10°C transmitted Y. pestis infections, although flea survival was significantly reduced compared to that of uninfected fleas at this temperature. Median bacterial loads were significantly higher at 10°C than at the other temperatures. Our results suggest that temperature does not significantly effect the per flea efficiency of Y. pestis transmission by X. cheopis, but that temperature is likely to influence the dynamics of Y. pestis flea-borne transmission, perhaps by affecting

  3. Comparative Ability of Oropsylla montana and Xenopsylla cheopis Fleas to Transmit Yersinia pestis by Two Different Mechanisms.

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    B Joseph Hinnebusch

    2017-01-01

    Full Text Available Transmission of Yersinia pestis by flea bite can occur by two mechanisms. After taking a blood meal from a bacteremic mammal, fleas have the potential to transmit the very next time they feed. This early-phase transmission resembles mechanical transmission in some respects, but the mechanism is unknown. Thereafter, transmission occurs after Yersinia pestis forms a biofilm in the proventricular valve in the flea foregut. The biofilm can impede and sometimes completely block the ingestion of blood, resulting in regurgitative transmission of bacteria into the bite site. In this study, we compared the relative efficiency of the two modes of transmission for Xenopsylla cheopis, a flea known to become completely blocked at a high rate, and Oropsylla montana, a flea that has been considered to rarely develop proventricular blockage.Fleas that took an infectious blood meal containing Y. pestis were maintained and monitored for four weeks for infection and proventricular blockage. The number of Y. pestis transmitted by groups of fleas by the two modes of transmission was also determined. O. montana readily developed complete proventricular blockage, and large numbers of Y. pestis were transmitted by that mechanism both by it and by X. cheopis, a flea known to block at a high rate. In contrast, few bacteria were transmitted in the early phase by either species.A model system incorporating standardized experimental conditions and viability controls was developed to more reliably compare the infection, proventricular blockage and transmission dynamics of different flea vectors, and was used to resolve a long-standing uncertainty concerning the vector competence of O. montana. Both X. cheopis and O. montana are fully capable of transmitting Y. pestis by the proventricular biofilm-dependent mechanism.

  4. Transmission efficiency of the plague pathogen (Y. pestis) by the flea, Xenopsylla skrjabini, to mice and great gerbils.

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    Zhang, Yujiang; Dai, Xiang; Wang, Qiguo; Chen, Hongjian; Meng, Weiwei; Wu, Kemei; Luo, Tao; Wang, Xinhui; Rehemu, Azhati; Guo, Rong; Yu, Xiaotao; Yang, Ruifu; Cao, Hanli; Song, Yajun

    2015-05-01

    Plague, a zoonotic disease caused by Yersinia pestis, is characterized by its ability to persist in the plague natural foci. Junggar Basin plague focus was recently identified in China, with Rhombomys opimus (great gerbils) and Xenopsylla skrjabini as the main reservoir and vector for plague. No transmission efficiency data of X. skrjabini for Y. pestis is available till now. In this study, we estimated the median infectious dose (ID50) and the blockage rates of X. skrjabini with Y. pestis, by using artificial feeders. We then evaluated the flea transmission ability of Y. pestis to the mice and great gerbils via artificial bloodmeal feeding. Finally, we investigated the transmission of Y. pestis to mice with fleas fed by infected great gerbils. ID50 of Y. pestis to X. skrjabini was estimated as 2.04 × 10(5) CFU (95% CI, 1.45 × 10(5) - 3.18 × 10(5) CFU), around 40 times higher than that of X. cheopis. Although fleas fed by higher bacteremia bloodmeal had higher infection rates for Y. pestis, they lived significantly shorter than their counterparts. X. skrjabini could get fully blocked as early as day 3 post of infection (7.1%, 3/42 fleas), and the overall blockage rate of X. cheopis was estimated as 14.9% (82/550 fleas) during the 14 days of investigation. For the fleas infected by artificial feeders, they seemed to transmit plague more efficiently to great gerbils than mice. Our single flea transmission experiments also revealed that, the transmission capacity of naturally infected fleas (fed by infected great gerbils) was significantly higher than that of artificially infected ones (fed by artificial feeders). Our results indicated that ID50 of Y. pestis to X. skrjabini was higher than other fleas like X. cheopis, and its transmission efficiency to mice might be lower than other flea vectors in the artificial feeding modes. We also found different transmission potentials in the artificially infected fleas and the naturally infected ones. Further studies are

  5. Effect of temperature and relative humidity on the development times and survival of Synopsyllus fonquerniei and Xenopsylla cheopis, the flea vectors of plague in Madagascar.

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    Kreppel, Katharina S; Telfer, Sandra; Rajerison, Minoarisoa; Morse, Andy; Baylis, Matthew

    2016-02-11

    Plague, a zoonosis caused by Yersinia pestis, is found in Asia, the Americas but mainly in Africa, with the island of Madagascar reporting almost one third of human cases worldwide. In the highlands of Madagascar, plague is transmitted predominantly by two flea species which coexist on the island, but differ in their distribution. The endemic flea, Synopsyllus fonquerniei, dominates flea communities on rats caught outdoors, while the cosmopolitan flea, Xenopsylla cheopis, is found mostly on rats caught in houses. Additionally S. fonquerniei seems restricted to areas above 800 m. Climatic constraints on the development of the two main vectors of plague could explain the differences in their distribution and the seasonal changes in their abundance. Here we present the first study on effects of temperature and relative humidity on the immature stages of both vector species. We examined the two species' temperature and humidity requirements under experimental conditions at five different temperatures and two relative humidities. By employing multivariate and survival analysis we established the impact of temperature and relative humidity on development times and survival for both species. Using degree-day analysis we then predicted the average developmental threshold for larvae to reach pupation and for pupae to complete development under each treatment. This analysis was undertaken separately for the two relative humidities and for the two species. Development times and time to death differed significantly, with the endemic S. fonquerniei taking on average 1.79 times longer to complete development and having a shorter time to death than X. cheopis under adverse conditions with high temperature and low humidity. Temperature had a significant effect on the development times of flea larvae and pupae. While humidity did not affect the development times of either species, it did influence the time of death of S. fonquerniei. Using degree-day analysis we estimated an

  6. Fleas

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    ... small insects that feed on the blood of humans, dogs, cats, and other warm-blooded animals. ... Fleas prefer to live on dogs and cats. They may also be found on ... not be bothered by fleas until their pet has been gone for a ...

  7. EKTOPARASIT (FLEAS PADA RESERVOIR DI DAERAH FOKUS PEST DI KABUPATEN BOYOLALI PROVINSI JAWA TENGAH

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    Tri Ramadhani

    2016-09-01

    Full Text Available ABSTRACTRat is a rodent (rodensia which cannot be separated from parasitic organism attacks the ectoparasites(fleas. In the presence of fleas plague focus areas need to watch out, for no increase in cases of plague(outbreak. Pest is a zoonosis in rat that can be transmitted to humans through the bite of fleas Xenopsyllacheopsis containing Yersinia pestis. Boyolali District is one of the plague focus areas in Central Java. Thisstudy aims to identify the species of rats and fleas, trap succes, flea infestation in rats and flea index as anindicator of vulnerability to transmission of plague. The study is a descriptive survey with cross sectionaldesign. The population is all the rats and fleas in Boyolali district. Samples are rats and fleas that werecaught using live trap with coconut roasted and salted fish is placed inside and outside the home (each 2trap. Rat combed for fleas. The results showed the number of mouses caught were 245. There are 4 speciesrats and small mammals found in R. tanezumi, R. tiomanicus, R. exulans, N. fulvescens and S.murinus withsucces trap at 5.71%. Only 3 species and S.murinus of infected fleas. Species of flea is X. cheopis and S.cognatus. Specific flea index: Xenopsylla cheopis by 1.67; flea index cognatus Stavilus common flea indexof 0.88 and 2.55. Based on the warning system indicator about the bubonic plague spreading,which isspecific flea index of X.cheopis >1 and fleas index >2, Selo sub distric should be aware to the spreading ofbubonic plague in its area, so that it is important to carry out the controlling of rat and flea population.Keyword: ectoparasite, reservoir, fleas, plague. ABSTRAK Tikus adalah hewan mengerat (rodensiayang tidak lepas dari serangan organisme parasit yaitu ektoparasit (pinjal.Pada daerah fokus pestt keberadaan pinjal perlu diwaspadai,agar tidak terjadi peningkatan kasus pestt (KLB. Pest merupakan zoonosispada tikusyang dapat ditularkan kepada manusia melalui gigitan pinjal Xenopsylla

  8. Feeding Behavior Modulates Biofilm-Mediated Transmission of Yersinia pestis by the Cat Flea, Ctenocephalides felis.

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    David M Bland

    2016-02-01

    Full Text Available The cat flea, Ctenocephalides felis, is prevalent worldwide, will parasitize animal reservoirs of plague, and is associated with human habitations in known plague foci. Despite its pervasiveness, limited information is available about the cat flea's competence as a vector for Yersinia pestis. It is generally considered to be a poor vector, based on studies examining early-phase transmission during the first week after infection, but transmission potential by the biofilm-dependent proventricular-blocking mechanism has never been systematically evaluated. In this study, we assessed the vector competence of cat fleas by both mechanisms. Because the feeding behavior of cat fleas differs markedly from important rat flea vectors, we also examined the influence of feeding behavior on transmission dynamics.Groups of cat fleas were infected with Y. pestis and subsequently provided access to sterile blood meals twice-weekly, 5 times per week, or daily for 4 weeks and monitored for infection, the development of proventricular biofilm and blockage, mortality, and the ability to transmit. In cat fleas allowed prolonged, daily access to blood meals, mimicking their natural feeding behavior, Y. pestis did not efficiently colonize the digestive tract and could only be transmitted during the first week after infection. In contrast, cat fleas that were fed intermittently, mimicking the feeding behavior of the efficient vector Xenopsylla cheopis, could become blocked and regularly transmitted Y. pestis for 3-4 weeks by the biofilm-mediated mechanism, but early-phase transmission was not detected.The normal feeding behavior of C. felis, more than an intrinsic resistance to infection or blockage by Y. pestis, limits its vector competence. Rapid turnover of midgut contents results in bacterial clearance and disruption of biofilm accumulation in the proventriculus. Anatomical features of the cat flea foregut may also restrict transmission by both early-phase and

  9. Feeding Behavior Modulates Biofilm-Mediated Transmission of Yersinia pestis by the Cat Flea, Ctenocephalides felis.

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    Bland, David M; Hinnebusch, B Joseph

    2016-02-01

    The cat flea, Ctenocephalides felis, is prevalent worldwide, will parasitize animal reservoirs of plague, and is associated with human habitations in known plague foci. Despite its pervasiveness, limited information is available about the cat flea's competence as a vector for Yersinia pestis. It is generally considered to be a poor vector, based on studies examining early-phase transmission during the first week after infection, but transmission potential by the biofilm-dependent proventricular-blocking mechanism has never been systematically evaluated. In this study, we assessed the vector competence of cat fleas by both mechanisms. Because the feeding behavior of cat fleas differs markedly from important rat flea vectors, we also examined the influence of feeding behavior on transmission dynamics. Groups of cat fleas were infected with Y. pestis and subsequently provided access to sterile blood meals twice-weekly, 5 times per week, or daily for 4 weeks and monitored for infection, the development of proventricular biofilm and blockage, mortality, and the ability to transmit. In cat fleas allowed prolonged, daily access to blood meals, mimicking their natural feeding behavior, Y. pestis did not efficiently colonize the digestive tract and could only be transmitted during the first week after infection. In contrast, cat fleas that were fed intermittently, mimicking the feeding behavior of the efficient vector Xenopsylla cheopis, could become blocked and regularly transmitted Y. pestis for 3-4 weeks by the biofilm-mediated mechanism, but early-phase transmission was not detected. The normal feeding behavior of C. felis, more than an intrinsic resistance to infection or blockage by Y. pestis, limits its vector competence. Rapid turnover of midgut contents results in bacterial clearance and disruption of biofilm accumulation in the proventriculus. Anatomical features of the cat flea foregut may also restrict transmission by both early-phase and proventricular biofilm

  10. Feeding Behavior Modulates Biofilm-Mediated Transmission of Yersinia pestis by the Cat Flea, Ctenocephalides felis

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    Bland, David M.; Hinnebusch, B. Joseph

    2016-01-01

    Background The cat flea, Ctenocephalides felis, is prevalent worldwide, will parasitize animal reservoirs of plague, and is associated with human habitations in known plague foci. Despite its pervasiveness, limited information is available about the cat flea’s competence as a vector for Yersinia pestis. It is generally considered to be a poor vector, based on studies examining early-phase transmission during the first week after infection, but transmission potential by the biofilm-dependent proventricular-blocking mechanism has never been systematically evaluated. In this study, we assessed the vector competence of cat fleas by both mechanisms. Because the feeding behavior of cat fleas differs markedly from important rat flea vectors, we also examined the influence of feeding behavior on transmission dynamics. Methodology/Principal Findings Groups of cat fleas were infected with Y. pestis and subsequently provided access to sterile blood meals twice-weekly, 5 times per week, or daily for 4 weeks and monitored for infection, the development of proventricular biofilm and blockage, mortality, and the ability to transmit. In cat fleas allowed prolonged, daily access to blood meals, mimicking their natural feeding behavior, Y. pestis did not efficiently colonize the digestive tract and could only be transmitted during the first week after infection. In contrast, cat fleas that were fed intermittently, mimicking the feeding behavior of the efficient vector Xenopsylla cheopis, could become blocked and regularly transmitted Y. pestis for 3–4 weeks by the biofilm-mediated mechanism, but early-phase transmission was not detected. Conclusions The normal feeding behavior of C. felis, more than an intrinsic resistance to infection or blockage by Y. pestis, limits its vector competence. Rapid turnover of midgut contents results in bacterial clearance and disruption of biofilm accumulation in the proventriculus. Anatomical features of the cat flea foregut may also restrict

  11. Xenopsylla cheopis (Siphonaptera: Pulicidae susceptibility to Deltamethrin in Madagascar.

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    Sebastien Boyer

    Full Text Available The incidence of bubonic plague in Madagascar is high. This study reports the susceptibility of 32 different populations of a vector, the flea Xenopsylla cheopis (Siphonaptera: Pulicidae, to the insecticide Deltamethrin. Despite the use of Deltamethrin against fleas, plague epidemics have re-emerged in Madagascar. The majority of the study sites were located in the Malagasy highlands where most plague cases have occurred over the last 10 years. X. cheopis fleas were tested for susceptibility to Deltamethrin (0.05%: only two populations were susceptible to Deltamethrin, four populations were tolerant and 26 populations were resistant. KD50 (50% Knock-Down and KD90 (90% Knock-Down times were determined, and differed substantially from 9.4 to 592.4 minutes for KD50 and 10.4 min to 854.3 minutes for KD90. Susceptibility was correlated with latitude, but not with longitude, history of insecticide use nor date of sampling. Combined with the number of bubonic plague cases, our results suggest that an immediate switch to an insecticide other than Deltamethrin is required for plague vector control in Madagascar.

  12. High prevalence of Rickettsia typhi and Bartonella species in rats and fleas, Kisangani, Democratic Republic of the Congo

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    Laudisoit, A.; Falay, D.; Amundala, N.; de Bellock, J.G.; van Houtte, N.; Breno, M.; Verheven, E.; Wilschut, Liesbeth; Parola, P.; Raoult, D.; C., Socolovschi

    2014-01-01

    The prevalence and identity of Rickettsia and Bartonella in urban rat and flea populations were evaluated in Kisangani, Democratic Republic of the Congo (DRC) by molecular tools. An overall prevalence of 17% Bartonella species and 13% Rickettsia typhi, the agent of murine typhus, was found in the

  13. Xenopsylla spp. (Siphonaptera: Pulicidae) in murid rodents from the Canary Islands: an update.

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    Sánchez, S; Gómez, M S

    2012-11-01

    The geographical and host distributions of Xenopsylla fleas parasitizing murid rodents on the Canary Islands have been reported. Three Xenopsylla species, X. cheopis, X. brasiliensis and X. guancha, have been detected on two rodents species, Mus musculus and Rattus rattus. X. guancha has been the most prevalent species detected, specifically on M. musculus, the most abundant rodent, but it has been detected only on three eastern islands, where the species is endemic. X. cheopis has been shown to be the most widely distributed species throughout the archipelago and the species most frequently found on R. rattus. X. brasiliensis has been shown to be the least prevalent Xenopsylla species, with the lowest geographical distribution on the Canary Islands and focused only on R. rattus. The detection of both X. cheopis and X. brasiliensis on the island of Lanzarote, and of X. guancha on the island of Fuerteventura and the islet of La Graciosa represents the first report of these species on those particular Canary Islands.

  14. Xenopsylla spp. (Siphonaptera: Pulicidae in murid rodents from the Canary Islands: An update

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    Sánchez S.

    2012-11-01

    Full Text Available The geographical and host distributions of Xenopsylla fleas parasitizing murid rodents on the Canary Islands have been reported. Three Xenopsylla species, X. cheopis, X. brasiliensis and X. guancha, have been detected on two rodents species, Mus musculus and Rattus rattus. X. guancha has been the most prevalent species detected, specifically on M. musculus, the most abundant rodent, but it has been detected only on three eastern islands, where the species is endemic. X. cheopis has been shown to be the most widely distributed species throughout the archipelago and the species most frequently found on R. rattus. X. brasiliensis has been shown to be the least prevalent Xenopsylla species, with the lowest geographical distribution on the Canary Islands and focused only on R. rattus. The detection of both X. cheopis and X. brasiliensis on the island of Lanzarote, and of X. guancha on the island of Fuerteventura and the islet of La Graciosa represents the first report of these species on those particular Canary Islands.

  15. Fleas and flea control

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    Dautović Živomir

    2002-01-01

    Full Text Available Fleas as hemeatophagous arthropodes take part in the spreading of certain diseases such as bubonic plague, murine typhus, tick-borne typhus tularaemia, or can be transitory hosts for certain species of cestodes for dogs and cats. Depending on the type of host on which fleas persist and the habitat, measures that can be taken to control them can be only sanitary-hygiene, individual, or treatment of the habitat. Sanitary-hygiene measures mostly consist of regular cleaning. Individual protection implies the use of insecticides for re-impregnating clothing, spraying clothing and the use of repellents. Treatment of habitats comprises the use of insecticides of the group of organophosphates, metyl-carbamates, pyrethroids and organo-chlorine compounds, instruments for dusting and spraying. In addition to these compounds, preparations based on imidaclopride, fipronyl and inhibitors of insect growth (IGRs and development (IDIs are also used. Flea control in household pets is implemented using measures of individual protection and treatment of their habitats.

  16. Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides.

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    Miarinjara, Adélaïde; Boyer, Sébastien

    2016-02-01

    Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines). Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur). Only one insecticide (dieldrin) was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin) to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar.

  17. Detection of Rickettsia Species in Fleas Collected from Cats in Regions Endemic and Nonendemic for Flea-Borne Rickettsioses in California.

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    Billeter, Sarah A; Diniz, Pedro Paulo Vissotto de Paiva; Jett, Lindsey A; Wournell, Andrea L; Kjemtrup, Anne M; Padgett, Kerry A; Yoshimizu, Melissa Hardstone; Metzger, Marco E; Barr, Margaret C

    2016-03-01

    Rickettsia typhi, transmitted by rat fleas, causes most human flea-borne rickettsioses worldwide. Another rickettsia, Rickettsia felis, found in cat fleas, Ctenocephalides felis, has also been implicated as a potential human pathogen. In the continental United States, human cases of flea-borne rickettsioses are reported primarily from the southern regions of Texas and California where the cat flea is considered the principal vector. In California, more than 90% of locally acquired human cases are reported from suburban communities within Los Angeles and Orange counties despite the almost ubiquitous presence of cat fleas and their hosts throughout the state. The objective of this study is to assess the presence and infection rate of Rickettsia species in cat fleas from selected endemic and nonendemic regions of California. Cat fleas were collected from cats in Los Angeles County (endemic region) and Sacramento and Contra Costa counties (nonendemic region). Sequencing of 17 amplicons confirmed the presence of R. felis in both the endemic and non-endemic regions with a calculated maximum likelihood estimation of 131 and 234 per 1000 fleas, respectively. R. typhi was not detected in any flea pools. Two R. felis-like genotypes were also detected in fleas from Los Angeles County; Genotype 1 was detected in 1 flea pool and Genotype 2 was found in 10 flea pools. Genotype 1 was also detected in a single flea pool from Sacramento County. Results from this study show that R. felis is widespread in cat flea populations in both flea-borne rickettsioses endemic and nonendemic regions of California, suggesting that a high prevalence of this bacterium in cat fleas does not predispose to increased risk of human infection. Further studies are needed to elucidate the role of R. felis and the two R. felis-like organisms as etiologic agents of human flea-borne rickettsioses in California.

  18. Evidence of Yersinia pestis DNA from fleas in an endemic plague area of Zambia

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    Hang'ombe Bernard M

    2012-01-01

    Full Text Available Abstract Background Yersinia pestis is a bacterium that causes plague which infects a variety of mammals throughout the world. The disease is usually transmitted among wild rodents through a flea vector. The sources and routes of transmission of plague are poorly researched in Africa, yet remains a concern in several sub-Saharan countries. In Zambia, the disease has been reported on annual basis with up to 20 cases per year, without investigating animal reservoirs or vectors that may be responsible in the maintenance and propagation of the bacterium. In this study, we undertook plague surveillance by using PCR amplification of the plasminogen activator gene in fleas. Findings Xenopsylla species of fleas were collected from 83 rodents trapped in a plague endemic area of Zambia. Of these rodents 5 had fleas positive (6.02% for Y. pestis plasminogen activator gene. All the Y. pestis positive rodents were gerbils. Conclusions We conclude that fleas may be responsible in the transmission of Y. pestis and that PCR may provide means of plague surveillance in the endemic areas of Zambia.

  19. Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia pestis in Fleas (Siphonaptera) from Africa.

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    Leulmi, Hamza; Socolovschi, Cristina; Laudisoit, Anne; Houemenou, Gualbert; Davoust, Bernard; Bitam, Idir; Raoult, Didier; Parola, Philippe

    2014-10-01

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia pestis in domestic and urban flea populations in tropical and subtropical African countries. Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high.

  20. Monitoring laundry for fleas

    International Nuclear Information System (INIS)

    Cooper, T.L.; Goldin, E.M.; Warnock, R.V.

    1987-01-01

    The San Onofre Unit 3 nuclear plant experienced fuel cladding failures during its first fuel cycle. When primary systems were opened for maintenance and refueling, areas on site were contaminated with fleas - tiny, highly radioactive fuel fragments. While highly mobile, these fragments demonstrated an affinity to attach to some surfaces and clothing. This paper discusses the problems encountered in detecting fleas in the presence of residual activation and fission product contamination on laundered protective clothing. A novel approach to overcome those inherent problems is presented and a home-built laundry monitor utilizing off-the-shelf components is described

  1. Transit through the flea vector induces a pretransmission innate immunity resistance phenotype in Yersinia pestis.

    Directory of Open Access Journals (Sweden)

    Viveka Vadyvaloo

    2010-02-01

    Full Text Available Yersinia pestis, the agent of plague, is transmitted to mammals by infected fleas. Y. pestis exhibits a distinct life stage in the flea, where it grows in the form of a cohesive biofilm that promotes transmission. After transmission, the temperature shift to 37 degrees C induces many known virulence factors of Y. pestis that confer resistance to innate immunity. These factors are not produced in the low-temperature environment of the flea, however, suggesting that Y. pestis is vulnerable to the initial encounter with innate immune cells at the flea bite site. In this study, we used whole-genome microarrays to compare the Y. pestis in vivo transcriptome in infective fleas to in vitro transcriptomes in temperature-matched biofilm and planktonic cultures, and to the previously characterized in vivo gene expression profile in the rat bubo. In addition to genes involved in metabolic adaptation to the flea gut and biofilm formation, several genes with known or predicted roles in resistance to innate immunity and pathogenicity in the mammal were upregulated in the flea. Y. pestis from infected fleas were more resistant to phagocytosis by macrophages than in vitro-grown bacteria, in part attributable to a cluster of insecticidal-like toxin genes that were highly expressed only in the flea. Our results suggest that transit through the flea vector induces a phenotype that enhances survival and dissemination of Y. pestis after transmission to the mammalian host.

  2. Molecular detection of Rickettsia typhi in cats and fleas.

    Directory of Open Access Journals (Sweden)

    Maria Mercedes Nogueras

    Full Text Available BACKGROUND: Rickettsiatyphi is the etiological agent of murine typhus (MT, a disease transmitted by two cycles: rat-flea-rat, and peridomestic cycle. Murine typhus is often misdiagnosed and underreported. A correct diagnosis is important because MT can cause severe illness and death. Our previous seroprevalence results pointed to presence of human R. typhi infection in our region; however, no clinical case has been reported. Although cats have been related to MT, no naturally infected cat has been described. The aim of the study is to confirm the existence of R. typhi in our location analyzing its presence in cats and fleas. METHODOLOGY/PRINCIPAL FINDINGS: 221 cats and 80 fleas were collected from Veterinary clinics, shelters, and the street (2001-2009. Variables surveyed were: date of collection, age, sex, municipality, living place, outdoor activities, demographic area, healthy status, contact with animals, and ectoparasite infestation. IgG against R. typhi were evaluated by indirect immunofluorescence assay. Molecular detection in cats and fleas was performed by real-time PCR. Cultures were performed in those cats with positive molecular detection. Statistical analysis was carried out using SPSS. A p < 0.05 was considered significant. Thirty-five (15.8% cats were seropositive. There were no significant associations among seropositivity and any variables. R. typhi was detected in 5 blood and 2 cultures. High titres and molecular detection were observed in stray cats and pets, as well as in spring and winter. All fleas were Ctenocephalides felis. R. typhi was detected in 44 fleas (55%, from shelters and pets. Co-infection with R. felis was observed. CONCLUSIONS: Although no clinical case has been described in this area, the presence of R. typhi in cats and fleas is demonstrated. Moreover, a considerable percentage of those animals lived in households. To our knowledge, this is the first time R. typhi is detected in naturally infected cats.

  3. Effects of parasitism on host reproductive investment in a rodent-flea system: host litter size matters.

    Science.gov (United States)

    Warburton, Elizabeth M; Khokhlova, Irina S; Dlugosz, Elizabeth M; Der Mescht, Luther Van; Krasnov, Boris R

    2017-02-01

    Parents may alter offspring phenotype depending on the type of environment they encounter. Parasitism is a common stressor; therefore, maternal reproductive investment could change in response to parasitic infection. However, few experiments have investigated the relationship between parasitism and maternal investment, whereas earlier field studies provided contradictory evidence. We investigated number, sex ratio, and growth of offspring in two rodent species, solitary altricial Meriones crassus and social precocial Acomys cahirinus, exposed to parasitism by fleas Xenopsylla ramesis and Parapulex chephrenis. No effect of treatment on litter size or sex ratio of a litter was found in either rodent species. Flea parasitism was found to affect pre-weaning body mass gain in M. crassus, but not in A. cahirinus pups. Furthermore, it appeared that female M. crassus invested resources into their offspring differently in dependence of litter size. In small litters (1-3 offspring), pups from infested females gained more body mass before weaning than pups from uninfested mothers. However, this trend was reversed in females with large litters indicating that parasitized females have a finite amount of resources with which to provision their young. Thus, M. crassus mothers parasitized by fleas seemed to receive some sort of external cues (e.g., stress caused by infestation) that prompted them to alter offspring provisioning, depending on species-specific possibilities and constraints. Therefore, parasites could be a mediator of environmentally induced maternal effects and offspring provisioning may have adaptive value against parasitism.

  4. Ectoparasitos de roedores da região urbana de Belo Horizonte, MG: III. Indices pulicidianos, anoplurianos e acarianos em Rattus Norvegicus norvegicus Ectoparasites in rodents of the urban region of Belo Horizonte, MG: III. Fleas, anoplura and acari indices in Rattus norvegicus norvegicus

    Directory of Open Access Journals (Sweden)

    Pedro Marcos Linardi

    1985-09-01

    Full Text Available Indices pulicidianos, anoplurianos e acarianos, globais e específicos foram determinados para os ectoparasitos de Rattus norvegicus norvegicus capturados em zona urbana de Belo Horizonte, Minas Gerais, Brasil, no período de junho de 1980 a setembro de 1982. Tendo-se em vista os valores limites ou críticos atribuídos aos índices pulicidianos, sobretudo ao índice "cheopis" e propostos por diversos autores como medida complementar de vigilância epidemiológica para peste bubônica, a comunidade de Belo Horizonte poderia ter estado exposta a esta infecção, uma vez que os índices globais anuais de 0,3 a 2,4 e a pulga prevalente foi Xenopsylla cheopis (99,2%, com os maiores índices coincidindo com o final da estação seca-fria. Em duas ocasiões, a comunidade poderia ter permanecido altamente exposta à infecção, já que os índices-limites tolerados foram suplantados: 8,8 (outubro 1980 e 6,2 (setembro 1982. Sugere-se que medidas profiláticas como anti-ratização e desinsetização sejam eficazmente aplicadas ao final da estação seca-fria, ou anteriormente à chegada das chuvas, sendo sucedidas pela desratização. Informações sobre índices anoplurianos e acarianos são importantes para que se possa, no exclusivas de roedoresThe total and specific indices of fleas, lice and mites were determined for ectoparasites on Rattus norvegicus norvegicus capture in urban areas of Belo Horizonte, Minas state, Brazil, from June 1980 to September 1982. In view of the limiting or critical values attributed to flea indices above all the [quot ]cheopis[quot ] index, proposed by several authors as a complementary measure for bubonic plague surveillance, the community of Belo Horizonte would have been exposed to this infection. The annual total indices ranged from 0.3 to 2.4 and the prevalent flea was Xenopsylla cheopis (99.2%, with the highest indices coinciding with the late dry-cool season. On two occasions, in this period, the community would

  5. [The fleas of mammals from the Ucayali River basin (the Peruvian Amazonia)].

    Science.gov (United States)

    Darskaia, N F; Malygin, V M

    1996-01-01

    The material collected from 57 specimens of 9 mammalian species in two localities of the Peruvian Amazonia includes 212 specimens of fleas belonging to four species (Polygenis klagesi, Ropalopsyllus lugubris, Rh. australis and Rothschildopsylla noctilionis). This is the first record of fleas in the Ucayali River basin. The majority of flea specimens were collected form three morphologically similar but karyotypically and electrophoretically distinct species of spiny rats of the genus Proechimys. These fleas belong to the species P. klagesi. The subspecies P. k. samuelis was collected from 32-chromosome spiny rats nearby Pucallpa (8 degrees 22' S, 74 degrees 43' W), whereas in the locality nearby the village Jenaro Errera (4 degrees 52' S, 73 degrees 39' W) only the nominative subspecies P. k. klagesi were collected from all three species of spiny rats. Other species of fleas have relatively less abundance. Six fleas Rh. l. lugubris were found on one specimen of Cuniculus paca; a single Rh. australis--on one specimen of Myoprocta pratti; and a single R. noctilionis--on one specimen of Eptesicus brasiliensis.

  6. Detection of flea-borne Rickettsia species in the Western Himalayan region of India

    Directory of Open Access Journals (Sweden)

    R Chahota

    2015-01-01

    Full Text Available Human infections by various rickettsial species are frequently reported globally. We investigated a flea-borne rickettsial outbreak infecting 300 people in Western Himalayan region of India. Arthropod vectors (ticks and fleas and animal and human blood samples from affected households were analysed by gltA and ompB genes based polymerase chain reaction (PCR. Rat flea (Ceratophyllus fasciatus samples were found harbouring a Rickettsia sp. Phylogenetic analysis based on gltA gene using PHYLIP revealed that the detected Rickettsia sp. has 100% identity with SE313 and RF2125 strains of Rickettsia sp. of flea origin from Egypt and Thai-Myanmar border, respectively and cf1 and 5 strains from fleas and lice from the USA. But, the nucleotide sequence of genetically variable gene ompB of R14 strain was found closely related to cf9 strain, reported from Ctenocephalides felis fleas. These results highlight the public health importance of such newly discovered or less recognised Rickettsia species/strains, harboured by arthropod vectors like fleas.

  7. Plague and the Human Flea, Tanzania

    DEFF Research Database (Denmark)

    Laudisoit, Anne; Leirs, Herwig; Makundi, Rhodes H

    2007-01-01

    Domestic fleas were collected in 12 villages in the western Usambara Mountains in Tanzania. Of these, 7 are considered villages with high plague frequency, where human plague was recorded during at least 6 of the 17 plague seasons between 1986 and 2004. In the remaining 5 villages with low plague...... frequency, plague was either rare or unrecorded. Pulex irritans, known as the human flea, was the predominant flea species (72.4%) in houses. The density of P. irritans, but not of other domestic fleas, was significantly higher in villages with a higher plague frequency or incidence. Moreover, the P....... irritans index was strongly positively correlated with plague frequency and with the logarithmically transformed plague incidence. These observations suggest that in Lushoto District human fleas may play a role in plague epidemiology. These findings are of immediate public health relevance because...

  8. Parasite spread at the domestic animal - wildlife interface: anthropogenic habitat use, phylogeny and body mass drive risk of cat and dog flea (Ctenocephalides spp.) infestation in wild mammals.

    Science.gov (United States)

    Clark, Nicholas J; Seddon, Jennifer M; Šlapeta, Jan; Wells, Konstans

    2018-01-08

    Spillover of parasites at the domestic animal - wildlife interface is a pervasive threat to animal health. Cat and dog fleas (Ctenocephalides felis and C. canis) are among the world's most invasive and economically important ectoparasites. Although both species are presumed to infest a diversity of host species across the globe, knowledge on their distributions in wildlife is poor. We built a global dataset of wild mammal host associations for cat and dog fleas, and used Bayesian hierarchical models to identify traits that predict wildlife infestation probability. We complemented this by calculating functional-phylogenetic host specificity to assess whether fleas are restricted to hosts with similar evolutionary histories, diet or habitat niches. Over 130 wildlife species have been found to harbour cat fleas, representing nearly 20% of all mammal species sampled for fleas. Phylogenetic models indicate cat fleas are capable of infesting a broad diversity of wild mammal species through ecological fitting. Those that use anthropogenic habitats are at highest risk. Dog fleas, by contrast, have been recorded in 31 mammal species that are primarily restricted to certain phylogenetic clades, including canids, felids and murids. Both flea species are commonly reported infesting mammals that are feral (free-roaming cats and dogs) or introduced (red foxes, black rats and brown rats), suggesting the breakdown of barriers between wildlife and invasive reservoir species will increase spillover at the domestic animal - wildlife interface. Our empirical evidence shows that cat fleas are incredibly host-generalist, likely exhibiting a host range that is among the broadest of all ectoparasites. Reducing wild species' contact rates with domestic animals across natural and anthropogenic habitats, together with mitigating impacts of invasive reservoir hosts, will be crucial for reducing invasive flea infestations in wild mammals.

  9. Non-equilibrium dog-flea model

    Science.gov (United States)

    Ackerson, Bruce J.

    2017-11-01

    We develop the open dog-flea model to serve as a check of proposed non-equilibrium theories of statistical mechanics. The model is developed in detail. Then it is applied to four recent models for non-equilibrium statistical mechanics. Comparison of the dog-flea solution with these different models allows checking claims and giving a concrete example of the theoretical models.

  10. Dipylidium (Dog and Cat Flea Tapeworm) FAQs

    Science.gov (United States)

    ... the most common kind of tapeworm dogs and cats get? The most common tapeworm of dogs and cats in the United States is called Dipylidium caninum . ... infected with a tapeworm larvae. A dog or cat may swallow a flea while self-grooming. Once ...

  11. Evaluation of systemic insecticides mixed in rodenticide baits for plague vector control

    DEFF Research Database (Denmark)

    Larsen, Kim Søholt; Lodal, Jens

    1997-01-01

    Rodenticide baits containing systemic insecticides were evaluated in the laboratory for their palatability to the house rat Rattus rattus and for their toxicity against the oriental rat flea Xenopsylla cheopis - both animals are important Vectors of plague in Africa. The test bait and a non...

  12. Human infestation by pigeon fleas (Ceratophyllus columbae) from feral pigeons.

    OpenAIRE

    Haag-Wackernagel, D; Spiewak, R.W.

    2004-01-01

    The report concerns a married couple who were repeatedly invaded by pigeon fleas (Ceratophyllus columbae) over a period of 2 months. The source of the fleas was a pair of breeding feral pigeons (Columba livia). The birds' nest was located in the attic immediately above the couple's apartment, and the fleas found their way along an unsealed heating pipe. The people encountered up to 40 bites per night. With invasions repeated almost every night, the man gradually developed an allergic urticari...

  13. Fleas and Flea-Associated Bartonella Species in Dogs and Cats from Peru.

    Science.gov (United States)

    Rizzo, M F; Billeter, S A; Osikowicz, L; Luna-Caipo, D V; Cáceres, A G; Kosoy, M

    2015-11-01

    In the present study, we investigated 238 fleas collected from cats and dogs in three regions of Peru (Ancash, Cajamarca, and Lima) for the presence of Bartonella DNA. Bartonella spp. were detected by amplification of the citrate synthase gene (16.4%) and the 16S-23S intergenic spacer region (20.6%). Bartonella rochalimae was the most common species detected followed by Bartonella clarridgeiae and Bartonella henselae. Our results demonstrate that dogs and cats in Peru are infested with fleas harboring zoonotic Bartonella spp. and these infected fleas could pose a disease risk for humans. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

  14. Human infestation by pigeon fleas (Ceratophyllus columbae) from feral pigeons.

    NARCIS (Netherlands)

    Haag-Wackernagel, D; Spiewak, R.W.

    2004-01-01

    The report concerns a married couple who were repeatedly invaded by pigeon fleas (Ceratophyllus columbae) over a period of 2 months. The source of the fleas was a pair of breeding feral pigeons (Columba livia). The birds' nest was located in the attic immediately above the couple's apartment, and

  15. Factors associated with flea infestation among the different rodent ...

    African Journals Online (AJOL)

    Flea infection with the bacterium, Yersinia pestis is acquired from reservoirs which include several rodents and other small mammals. In areas that are endemic of plague, reservoirs of Y. pestis and various flea vectors are responsible for perpetuating existence of the disease. The objective of this cross sectional study was to ...

  16. A review of plague persistence with special emphasis on fleas

    Science.gov (United States)

    Wimsatt, Jeffrey; Biggins, Dean E.

    2009-01-01

    Sylvatic plague is highly prevalent during infrequent epizootics that ravage the landscape of western North America. During these periods, plague dissemination is very efficient. Epizootics end when rodent and flea populations are decimated and vectored transmission declines. A second phase (enzootic plague) ensues when plague is difficult to detect from fleas, hosts or the environment, and presents less of a threat to public health.

  17. Rickettsia species in fleas collected from small mammals in Slovakia.

    Science.gov (United States)

    Špitalská, Eva; Boldiš, Vojtech; Mošanský, Ladislav; Sparagano, Olivier; Stanko, Michal

    2015-11-01

    Epidemiological and epizootiological studies of Rickettsia felis and other Rickettsia spp. are very important, because their natural cycle has not yet been established completely. In total, 315 fleas (Siphonaptera) of 11 species of Ceratophyllidae, Hystrichopsyllidae and Leptopsyllidae families were tested for the presence of Rickettsia species and Coxiella burnetii with conventional and specific quantitative real-time PCR assays. Fleas were collected from five rodent hosts (Myodes glareolus, Apodemus flavicollis, Apodemus agrarius, Microtus subterraneus, Microtus arvalis) and three shrew species (Sorex araneus, Neomys fodiens, Crocidura suaveolens) captured in Eastern and Southern Slovakia. Overall, Rickettsia spp. was found in 10.8% (34/315) of the tested fleas of Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus uncinatus and Nosopsyllus fasciatus species. Infected fleas were coming from A. flavicollis, A. agrarius, and M. glareolus captured in Eastern Slovakia. C. burnetii was not found in any fleas. R. felis, Rickettsia helvetica, unidentified Rickettsia, and rickettsial endosymbionts were identified in fleas infesting small mammals in the Košice region, Eastern Slovakia. This study is the first report of R. felis infection in C. solutus male flea collected from A. agrarius in Slovakia.

  18. Human infestation by pigeon fleas (Ceratophyllus columbae) from feral pigeons.

    Science.gov (United States)

    Haag-Wackernagel, Daniel; Spiewak, Radosław

    2004-01-01

    The report concerns a married couple who were repeatedly invaded by pigeon fleas (Ceratophyllus columbae) over a period of 2 months. The source of the fleas was a pair of breeding feral pigeons (Columba livia). The birds' nest was located in the attic immediately above the couple's apartment, and the fleas found their way along an unsealed heating pipe. The people encountered up to 40 bites per night. With invasions repeated almost every night, the man gradually developed an allergic urticarial reaction. The most traumatic experience for the couple, however, was to learn that they were invaded by fleas (initially, they had presumed they were bothered by mosquitoes). This information resulted in severe psychological distress with phobic reactions and insomnia. Despite the successful removal of the fleas and the pigeons that were source of the pest, parasitophobia of the man persisted over the following 4 months. This case is discussed from the broader aspect of health risks related to feral pigeons and animal fleas. Also summarised are previous observations on people invaded by pigeon fleas.

  19. Rickettsia felis in fleas from Catalonia (Northeast Spain).

    Science.gov (United States)

    Nogueras, María-Mercedes; Pons, Immaculada; Ortuño, Anna; Lario, Sergio; Segura, Ferran

    2011-05-01

    Rickettsia felis produces a syndrome indistinguishable from murine typhus, which has been described in Spain. R. felis is transmitted to humans by fleas. Although no clinical case has been described so far, serologic evidence of infections in humans, cats, and dogs has been obtained in our area. However, no study has been conducted regarding its presence in vectors. Recognition of routes of transmission is of great importance to prevent infection in humans. Taking into account these results, R. felis seems to be present in animals that are in contact with humans. The aim of this study was to determine the presence of R. felis in the fleas of cats and dogs from Northeast Spain, to show the presence of peridomestic cycle in our area. Between May 2006 and July 2008, 78 fleas were collected. Sixty-three fleas were recovered from kennels. Most of them were collected from cages and a few of them on dogs and cats living in kennels. Fifteen fleas were collected from dogs and cats attended at a veterinary clinic. Fleas were rinsed with ethanol, dried, identified, and stored at 4°C. DNA was extracted from each flea individually. Rickettsial DNA was determined by quantitative real-time polymerase chain reaction. OmpB-specific primers and molecular beacon probes targeting specifically R. felis were used. All 78 fleas were identified as Ctenocephalides felis. R. felis was detected in 34 (43.6%) fleas. No nucleic acids were amplified from negative controls and expected results were obtained from positive controls. Eight positive samples were also confirmed by sequencing. R. felis was found in a high percentage of Ct. felis from cats and dogs. It seems that there is a peridomestic cycle in Northeast Spain, which would allow contact of R. felis with humans.

  20. Flea (Pulex simulans) infestation in captive giant anteaters (Myrmecophaga tridactyla).

    Science.gov (United States)

    Mutlow, Adrian G; Dryden, Michael W; Payne, Patricia A

    2006-09-01

    A pair of captive adult giant anteaters (Myrmecophaga tridactyla) presented heavily infested with a flea species (Pulex simulans) commonly found on Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor) in the central United States. In this case, the flea was demonstrated to have completed its entire life cycle with the anteaters as the host. A single treatment of topical imidacloprid, coupled with removal and replacement of infested bedding, was rapidly effective at controlling the infestation and no adverse effects of the drug were noted. Control of the anteater infestation also removed the flea infestation of aardvarks in the same building.

  1. Seasonal and habitat dependence of fleas parasitic on small mammals in Tanzania

    DEFF Research Database (Denmark)

    Laudisoit, Anne; Leirs, Herwig; Makundi, Rhodes

    2009-01-01

    in both host and flea species composition varied seasonally. Despite the relatively rich mammal and flea fauna of the study region, the major contribution to variation in species composition between seasons and among habitats was due to a few species only. Flea assemblages on Lophuromys kilonzoi Verheyen...

  2. Two Pathogens and One Disease: Detection and Identification of Flea-Borne Rickettsiae in Areas Endemic for Murine Typhus in California

    Science.gov (United States)

    EREMEEVA, MARINA E.; KARPATHY, SANDOR E.; KRUEGER, LAURA; HAYES, ERICA K.; WILLIAMS, ASHLEY M.; ZALDIVAR, YAMITZEL; BENNETT, STEPHEN; CUMMINGS, ROBERT; TILZER, ART; VELTEN, ROBERT K.; KERR, NELSON; DASCH, GREGORY A.; HU, RENJIE

    2018-01-01

    Results of an environmental assessment conducted in a newly emergent focus of murine typhus in southern California are described. Opossums, Didelphis virginiana Kerr, infested with cat fleas, Ctenocephalides felis Buché, in the suburban area were abundant. Animal and flea specimens were tested for the DNA of two flea-borne rickettsiae, Rickettsia typhi and Rickettsia felis. R. felis was commonly detected in fleas collected throughout this area while R. typhi was found at a much lower prevalence in the vicinity of just 7 of 14 case-patient homes identified. DNA of R. felis, but not R. typhi, was detected in renal, hepatic, and pulmonary tissues of opossums. In contrast, there were no hematologic polymerase chain reaction findings of R. felis or R. typhi in opossums, rats, and cats within the endemic area studied. Our data suggest a significant probability of human exposure to R. felis in the area studied; however, disease caused by this agent is not recognized by the medical community and may be misdiagnosed as murine typhus using nondiscriminatory serologic methods. PMID:23270180

  3. Factors that affect parasitism of black-tailed prairie dogs by fleas

    Science.gov (United States)

    Eads, David A.; Hoogland, John L.

    2016-01-01

    Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that feed on vertebrate hosts. Fleas can reduce the fitness of hosts by interfering with immune responses, disrupting adaptive behaviors, and transmitting pathogens. The negative effects of fleas on hosts are usually most pronounced when fleas attain high densities. In lab studies, fleas desiccate and die under dry conditions, suggesting that populations of fleas will tend to decline when precipitation is scarce under natural conditions. To test this hypothesis, we compared precipitation vs. parasitism of black-tailed prairie dogs (Cynomys ludovicianus) by fleas at a single colony during May and June of 13 consecutive years (1976–1988) at Wind Cave National Park, South Dakota, USA. The number of fleas on prairie dogs decreased with increasing precipitation during both the prior growing season (April through August of the prior year) and the just-completed winter–spring (January through April of current year). Due to the reduction in available moisture and palatable forage in dry years, herbivorous prairie dogs might have been food-limited, with weakened behavioral and immunological defenses against fleas. In support of this hypothesis, adult prairie dogs of low mass harbored more fleas than heavier adults. Our results have implications for the spread of plague, an introduced bacterial disease, transmitted by fleas, that devastates prairie dog colonies and, in doing so, can transform grassland ecosystems.

  4. A 2015 outbreak of flea-borne rickettsiosis in San Gabriel Valley, Los Angeles County, California.

    Directory of Open Access Journals (Sweden)

    Kimberly Nelson

    2018-04-01

    Full Text Available Although flea-borne rickettsiosis is endemic in Los Angeles County, outbreaks are rare. In the spring of 2015 three human cases of flea-borne rickettsiosis among residents of a mobile home community (MHC prompted an investigation. Fleas were ubiquitous in common areas due to presence of flea-infested opossums and overabundant outdoor cats and dogs. The MHC was summarily abated in June 2015, and within five months, flea control and removal of animals significantly reduced the flea population. Two additional epidemiologically-linked human cases of flea-borne rickettsiosis detected at the MHC were suspected to have occurred before control efforts began. Molecular testing of 106 individual and 85 pooled cat fleas, blood and ear tissue samples from three opossums and thirteen feral cats using PCR amplification and DNA sequencing detected rickettsial DNA in 18.8% of the fleas. Seventeen percent of these cat fleas tested positive for R. felis-specific DNA compared to under two (<2 percent for Candidatus R. senegalensis-specific DNA. In addition, serological testing of 13 cats using a group-specific IgG-ELISA detected antibodies against typhus group rickettsiae and spotted fever group rickettsiae in six (46.2% and one (7.7% cat, respectively. These results indicate that cats and their fleas may have played an active role in the epidemiology of the typhus group and/or spotted fever group rickettsial disease(s in this outbreak.

  5. Fleas and lice of mammals in New Mexico

    Science.gov (United States)

    Paulette L. Ford; Richard A. Fagerlund; Donald W. Duszynski; Paul J. Polechla

    2004-01-01

    All available records are compiled for three orders of ectoparasites of mammals in New Mexico: fleas (Siphonaptera), sucking lice (Anoplura), and chewing lice (Mallophaga). We have drawn from records at the University of New Mexico's Museum of Southwestern Biology, the Vector Control Program of the New Mexico Environment Department, the Environmental Health...

  6. Ticks and Fleas Infestation on East Hedgehogs (Erinaceus concolor in Van Province, Eastern Region of Turkey

    Directory of Open Access Journals (Sweden)

    Yaşar Goz

    2015-10-01

    Full Text Available Background: Ixodid ticks (Acari: İxodidae and fleas (Siphonaptera are the major vectors of pathogens threatening animals and human healths. The aim of our study was to detect the infestation rates of East Hedgehogs (Erinaceus concolor with ticks and fleas in Van Province, eastern region of Turkey.Methods: We examined fleas and ticks infestation patterns in 21 hedgehogs, collected from three suburbs with the greater of number gardens. In order to estimate flea and tick infestation of hedgehogs, we immobilized the ectoparasites by treatment the body with a insecticide trichlorphon (Neguvon®-Bayer.Results: On the hedgehogs, 60 ixodid ticks and 125 fleas were detected. All of the ixodid ticks were Rhipicephalus turanicus and all of the fleas were Archaeopsylla erinacei. Infestation rate for ticks and fleas was detected 66.66 % and 100 %, respectively.Conclusion: We detected ticks (R. turanicus and fleas (A. erinacei in hedgehogs at fairly high rates. Since many ticks and fleas species may harbor on hedgehogs and transmit some tick-borne and flea-borne patogens, this results are the important in terms of veterinary and public health. 

  7. Diversity of Flea (Siphonaptera) Parasites on Red Foxes (Vulpes vulpes) in Romania.

    Science.gov (United States)

    Foley, P; Foley, J; Sándor, A D; Ionica, A M; Matei, I A; D'Amico, G; Gherman, C M; Dom A, C; Mihalca, A D

    2017-09-01

    Red foxes (Vulpes vulpes (L.)) are widespread across Europe, tolerant of synanthropic ecosystems, and susceptible to diseases potentially shared with humans and other animals. We describe flea fauna on red foxes in Romania, a large, ecologically diverse country, in part because fleas may serve as an indicator of the risk of spillover of vector-borne disease. We found 912 individual fleas of seven species on the 305 foxes assessed, for an infestation prevalence of 49.5%. Mean flea load per fox was 5.8 (range 0-44 fleas), and flea detections were most abundant in fall and early spring. Fleas included generalists (Ctenocephalides canis (Curtis), 32.6% of all fleas), Ct. felis (Bouché, 0.1%), and Pulex irritans L. (29.9%), the fox specialist Chaetopsylla globiceps (Taschenberg, 32.5%), mesocarnivore fleas Paraceras melis Walker (3.2%) and Ch. trichosa Kohaut (1.5%), and the small mammal flea Ctenophthalmus assimilis (Taschenberg, 0.1%), which is rarely or never reported from carnivores. There were significantly more female than male Ch. globiceps, Ct. canis, and Pu. irritans, and these three species were the most broadly distributed geographically. Diversity indices suggested reduced diversity in mountainous areas above 700 m. When compared to other flea studies on foxes in Europe, Romania had flea diversity near the median of reports, which was unexpected given Romania's high ecological diversity. Notably absent prey specialists, compared to other studies, include Archaeopsylla erinacei (Bouché) and Spilopsyllus cuniculi (Dale). Further studies of possible disease agents in fox fleas could help elucidate possible risks of vector-borne disease in foxes, domestic animals, and humans as well. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. [Fleas on small mammals in the surrounding area of Erhai Lake].

    Science.gov (United States)

    Dong, Wen-Ge; Guo, Xian-Guo; Men, Xing-Yuan; Gong, Zheng-Da; Wu, Dian; Zhang, Zheng-Kun; Zhang, Li-Yun

    2009-12-01

    To investigate the distribution pattern, species diversity and community structure of fleas on small mammals in the surrounding area of Erhai Lake, and the relationship between fleas and their hosts. Different geographical areas surrounding the Erhai Lake in Yunnan were selected as investigated spots. Small mammals were captured with baited cages. The cage-traps were examined and re-baited each morning. All fleas on the hosts were collected and identified. The richness (S), evenness (J'), diversity index (H'), dominance index (C'), total ectoparasite infestation rate (Rpt), total ectoparasite infestation index (Ipt), and constituent ratio (Cr) were used to measure the community structure. Altogether, 3,303 small mammals and 3,243 fleas were collected. From the 21 species of small mammal hosts, 13 species of fleas were identified. In southern area of the Lake, the species richness (21 species of small mammals & 12 species of fleas) was highest among the three selected areas. Seventeen species of small mammals and 8 species of fleas were found in eastern area, and only 13 species of small mammals and 7 species of fleas found in the west. This implied the probable influences of ecological environments on the fleas and their corresponding hosts. The community structure of fleas on small mammals was complex. The species diversity, species composition, community structure and distribution pattern of fleas were simultaneously influenced by the hosts' body surface microenvironment and the macroenvironment (habitat). The fleas are commonly distributed in small mammals in the areas and their communities are related to host species and the habitats.

  9. Feeding Behavior Modulates Biofilm-Mediated Transmission of Yersinia pestis by the Cat Flea, Ctenocephalides felis

    OpenAIRE

    Bland, David M.; Hinnebusch, B. Joseph

    2016-01-01

    Background The cat flea, Ctenocephalides felis, is prevalent worldwide, will parasitize animal reservoirs of plague, and is associated with human habitations in known plague foci. Despite its pervasiveness, limited information is available about the cat flea?s competence as a vector for Yersinia pestis. It is generally considered to be a poor vector, based on studies examining early-phase transmission during the first week after infection, but transmission potential by the biofilm-dependent p...

  10. Evidence of an aggregation pheromone in the flea beetle,Phyllotreta Cruciferae (Goeze) (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Peng, C; Weiss, M J

    1992-06-01

    Laboratory olfactometer bioassays and field trapping experiments showed that the flea beetle,Phyllotreta cruciferae (Goeze), was highly attracted by oilseed rape(Brassica napus L.) when flea beetles were on the plant. This attraction was mediated by a flea beetle-produced aggregation pheromone based upon: (1) Oilseed rape damaged mechanically, or byP. cruciferae, or by diamondback moth,Plutella xylostella (L.), did not attractP. cruciferae. (2) Contact with the plants or feeding was required for the production of aggregation pheromone because oilseed rape alone was not attractive when separated from flea beetles by a screen. (3) Equal numbers of males and females were attracted.

  11. FLEAS OF BLACK-FOOTED FERRETS (MUSTELA NIGRIPES) AND THEIR POTENTIAL ROLE IN THE MOVEMENT OF PLAGUE.

    Science.gov (United States)

    Mize, Erica L; Grassel, Shaun M; Britten, Hugh B

    2017-07-01

    Sylvatic plague is one of the major impediments to the recovery of the black-footed ferret ( Mustela nigripes ) because it decimates their primary prey species, prairie dogs ( Cynomys spp.), and directly causes mortality in ferrets. Fleas are the primary vector of Yersinia pestis , the causative agent of sylvatic plague. The goal of this research was to better understand the flea fauna of ferrets and the factors that might influence flea abundance on ferrets. Fleas from ferrets were tested for Y. pestis in a post hoc assessment to investigate the plausibility that some ferrets could act as incidental transporter hosts of fleas infected with Y. pestis . Fleas were collected from ferrets captured on the Lower Brule Indian Reservation in central South Dakota, US from 2009 to 2012. A total of 528 fleas collected from 67 individual ferrets were identified and tested for the presence of Y. pestis with a nested PCR assay. The predominant flea recovered from ferrets was Oropsylla hirsuta , a species that comprises 70-100% of the fleas recovered from prairie dogs and their burrows in the study area. Yersinia pestis was detected at low levels in fleas collected from ferrets with prevalence ranging from 0% to 2.9%; male ferrets harbored significantly more fleas than female ferrets. Six of 67 ferrets vaccinated against plague carried fleas that tested positive for Y. pestis , which suggests ferrets vaccinated against plague could inadvertently act as incidental transporter hosts of Y. pestis -positive fleas.

  12. A molecular survey of Rickettsia felis in fleas from cats and dogs in Sicily (Southern Italy.

    Directory of Open Access Journals (Sweden)

    Elisabetta Giudice

    Full Text Available Rickettsia felis, the agent of flea-borne spotted fever, has a cosmopolitan distribution. Its pathogenic role in humans has been demonstrated through molecular and serologic tests in several cases. The cat flea (Ctenocephalides felis is considered the main reservoir and the biological vector. The aim of this study was to assess the presence and occurrence of R. felis in fleas collected from dogs and cats in various sites of Palermo (Sicily. Between August and October 2012, 134 fleas were collected from 42 animals: 37 fleas from 13 dogs and 97 fleas from 29 cats. Two species of fleas were identified: 132 Ctenocephalides felis (98.51% collected on all animals and only two C. canis (1.49% on one dog. Out of 132 C. felis, 34 (25.76%, 12 from dogs (32.43% and 22 (22.68% from cats, were positive for R. felis DNA by a polymerase chain reaction (PCR, confirmed by sequencing. The only two C. canis fleas were negative. About half of examined animals (47.62%, 20/42 were infested with at least one infected flea; in particular 46.15% of dogs (6/13 and 48.28% of cats (14/29. It seems that in the Palermo district there is a peri-domestic cycle, with a relatively high prevalence of R. felis infection in the cat flea, an insect widely diffused in home environments and which can frequently bite humans. The results also suggest that R. felis should be considered in the human differential diagnosis of any spotted-like fever or febrile illness without a clear source of infection in Sicily, especially if the patient is known to have been exposed to flea bites.

  13. Rickettsia felis in cat fleas, Ctenocephalides felis parasitizing opossums, San Bernardino County, California.

    Science.gov (United States)

    Abramowicz, K F; Wekesa, J W; Nwadike, C N; Zambrano, M L; Karpathy, S E; Cecil, D; Burns, J; Hu, R; Eremeeva, M E

    2012-12-01

    Los Angeles and Orange Counties are known endemic areas for murine typhus in California; however, no recent reports of flea-borne rickettsioses are known from adjacent San Bernardino County. Sixty-five opossums (Didelphis virginiana) were trapped in the suburban residential and industrial zones of the southwestern part of San Bernardino County in 2007. Sixty out of 65 opossums were infested with fleas, primarily cat fleas, Ctenocephalides felis (Bouché, 1835). The flea minimum infection rate with Rickettsia felis was 13.3% in pooled samples and the prevalence was 23.7% in single fleas, with two gltA genotypes detected. In spite of historic records of murine typhus in this area, no evidence for circulation of R. typhi in fleas was found during the present study. Factors contributing to the absence of R. typhi in these cat fleas in contrast to its presence in cat fleas from Orange and Los Angeles Counties are unknown and need to be investigated further in San Bernardino County. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  14. Myxomatosis: some observations on breeding the European rabbit flea Spilopsyllus cuniculi (Dale) in an animal house

    Science.gov (United States)

    Sobey, W. R.; Menzies, W.; Conolly, Dorothy

    1974-01-01

    Rabbit fleas for use in Myxomatosis investigations have been successfully bred on rabbits in an animal house. The timing of emergence appeared to be governed by a biological timing control interacting with different forms of disturbance. Yield was found to be related to litter size, the time the doe and her kittens were removed from the nest, the number of fleas put onto a doe before littering and the mean ambient temperature to which the doe was exposed in the week pre-partum. The survival rate of fleas in storage was affected by temperature, the degree of crowding, moisture content of the containers, whether fleas were fed or unfed and the source of fleas in terms of emergence times. PMID:4526409

  15. Dermal neutrophil, macrophage and dendritic cell responses to Yersinia pestis transmitted by fleas.

    Directory of Open Access Journals (Sweden)

    Jeffrey G Shannon

    2015-03-01

    Full Text Available Yersinia pestis, the causative agent of plague, is typically transmitted by the bite of an infected flea. Many aspects of mammalian innate immune response early after Y. pestis infection remain poorly understood. A previous study by our lab showed that neutrophils are the most prominent cell type recruited to the injection site after intradermal needle inoculation of Y. pestis, suggesting that neutrophil interactions with Y. pestis may be important in bubonic plague pathogenesis. In the present study, we developed new tools allowing for intravital microscopy of Y. pestis in the dermis of an infected mouse after transmission by its natural route of infection, the bite of an infected flea. We found that uninfected flea bites typically induced minimal neutrophil recruitment. The magnitude of neutrophil response to flea-transmitted Y. pestis varied considerably and appeared to correspond to the number of bacteria deposited at the bite site. Macrophages migrated towards flea bite sites and interacted with small numbers of flea-transmitted bacteria. Consistent with a previous study, we observed minimal interaction between Y. pestis and dendritic cells; however, dendritic cells did consistently migrate towards flea bite sites containing Y. pestis. Interestingly, we often recovered viable Y. pestis from the draining lymph node (dLN 1 h after flea feeding, indicating that the migration of bacteria from the dermis to the dLN may be more rapid than previously reported. Overall, the innate cellular host responses to flea-transmitted Y. pestis differed from and were more variable than responses to needle-inoculated bacteria. This work highlights the importance of studying the interactions between fleas, Y. pestis and the mammalian host to gain a better understanding of the early events in plague pathogenesis.

  16. Dipylidium caninum infection in dogs infested with fleas.

    Science.gov (United States)

    Wani, Z A; Allaie, I M; Shah, B M; Raies, A; Athar, H; Junaid, S

    2015-03-01

    The present study pertains to the Dipylidium caninum infection in dogs infested with fleas. Twenty dogs were presented to the Divison of Surgery, SKUAST-K for different surgical procedures. Majority of the dogs had a history of pruritus, loss of weight as well as rubbing their perineal region against the wall. On external examination dogs were found infested with Ctenocephalides canis. When dogs were anesthetized, motile segments were seen coming out of their anus, which were then identified as mature segments of D. caninum.

  17. The Biology and Ecology of Cat Fleas and Advancements in Their Pest Management: A Review

    Directory of Open Access Journals (Sweden)

    Michael K. Rust

    2017-10-01

    Full Text Available The cat flea Ctenocephalides felis felis (Bouché is the most important ectoparasite of domestic cats and dogs worldwide. It has been two decades since the last comprehensive review concerning the biology and ecology of C. f. felis and its management. Since then there have been major advances in our understanding of the diseases associated with C. f. felis and their implications for humans and their pets. Two rickettsial diseases, flea-borne spotted fever and murine typhus, have been identified in domestic animal populations and cat fleas. Cat fleas are the primary vector of Bartonella henselae (cat scratch fever with the spread of the bacteria when flea feces are scratched in to bites or wounds. Flea allergic dermatitis (FAD common in dogs and cats has been successfully treated and tapeworm infestations prevented with a number of new products being used to control fleas. There has been a continuous development of new products with novel chemistries that have focused on increased convenience and the control of fleas and other arthropod ectoparasites. The possibility of feral animals serving as potential reservoirs for flea infestations has taken on additional importance because of the lack of effective environmental controls in recent years. Physiological insecticide resistance in C. f. felis continues to be of concern, especially because pyrethroid resistance now appears to be more widespread. In spite of their broad use since 1994, there is little evidence that resistance has developed to many of the on-animal or oral treatments such as fipronil, imidacloprid or lufenuron. Reports of the perceived lack of performance of some of the new on-animal therapies have been attributed to compliance issues and their misuse. Consequentially, there is a continuing need for consumer awareness of products registered for cats and dogs and their safety.

  18. Precipitation, Climate Change, and Parasitism of Prairie Dogs by Fleas that Transmit Plague.

    Science.gov (United States)

    Eads, David A; Hoogland, John L

    2017-08-01

    Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that can reduce the fitness of vertebrate hosts. Laboratory populations of fleas decline under dry conditions, implying that populations of fleas will also decline when precipitation is scarce under natural conditions. If precipitation and hence vegetative production are reduced, however, then herbivorous hosts might suffer declines in body condition and have weakened defenses against fleas, so that fleas will increase in abundance. We tested these competing hypotheses using information from 23 yr of research on 3 species of colonial prairie dogs in the western United States: Gunnison's prairie dog (Cynomys gunnisoni, 1989-1994), Utah prairie dog (Cynomys parvidens, 1996-2005), and white-tailed prairie dog (Cynomys leucurus, 2006-2012). For all 3 species, flea-counts per individual varied inversely with the number of days in the prior growing season with >10 mm of precipitation, an index of the number of precipitation events that might have caused a substantial, prolonged increase in soil moisture and vegetative production. Flea-counts per Utah prairie dog also varied inversely with cumulative precipitation of the prior growing season. Furthermore, flea-counts per Gunnison's and white-tailed prairie dog varied inversely with cumulative precipitation of the just-completed January and February. These results complement research on black-tailed prairie dog (Cynomys ludovicianus) and might have important ramifications for plague, a bacterial disease transmitted by fleas that devastates populations of prairie dogs. In particular, our results might help to explain why, at some colonies, epizootics of plague, which can kill >95% of prairie dogs, are more likely to occur during or shortly after periods of reduced precipitation. Climate change is projected to increase the frequency of droughts in the grasslands of western North America. If so, then climate change might affect the occurrence of plague epizootics

  19. The Biology and Ecology of Cat Fleas and Advancements in Their Pest Management: A Review

    Science.gov (United States)

    2017-01-01

    The cat flea Ctenocephalides felis felis (Bouché) is the most important ectoparasite of domestic cats and dogs worldwide. It has been two decades since the last comprehensive review concerning the biology and ecology of C. f. felis and its management. Since then there have been major advances in our understanding of the diseases associated with C. f. felis and their implications for humans and their pets. Two rickettsial diseases, flea-borne spotted fever and murine typhus, have been identified in domestic animal populations and cat fleas. Cat fleas are the primary vector of Bartonella henselae (cat scratch fever) with the spread of the bacteria when flea feces are scratched in to bites or wounds. Flea allergic dermatitis (FAD) common in dogs and cats has been successfully treated and tapeworm infestations prevented with a number of new products being used to control fleas. There has been a continuous development of new products with novel chemistries that have focused on increased convenience and the control of fleas and other arthropod ectoparasites. The possibility of feral animals serving as potential reservoirs for flea infestations has taken on additional importance because of the lack of effective environmental controls in recent years. Physiological insecticide resistance in C. f. felis continues to be of concern, especially because pyrethroid resistance now appears to be more widespread. In spite of their broad use since 1994, there is little evidence that resistance has developed to many of the on-animal or oral treatments such as fipronil, imidacloprid or lufenuron. Reports of the perceived lack of performance of some of the new on-animal therapies have been attributed to compliance issues and their misuse. Consequentially, there is a continuing need for consumer awareness of products registered for cats and dogs and their safety. PMID:29077073

  20. [Fleas community in introduced Siberian chipmunks (Tamias sibiricus Laxmann) in Forest of Sénart, France].

    Science.gov (United States)

    Pisanu, B; Marmet, J; Beaucournu, J C; Chapuis, J L

    2008-03-01

    We examined the fleas community in an introduced population of Siberian chipmunks, Tamias sibiricus, between 2005 and 2007, in the Forest of Sénart (Essonne, France). We collected and identified 383 fleas on 463 chipmunks (total: 1,891 captures on 471 chipmunks). In 2005, 120 fleas were also collected on 65 bank voles, Clethrionomys glareolus, and on 25 wood mice, Apodemus sylvaticus, trapped within the same area. Ceratophyllus sciurorum sciurorum formed 73.6% of the chipmunks' flea community, with an annual prevalence (P) ranging between 8 and 13% and a mean intensity (I) ranging between 1.1 and 1.6 fleas per individual. Among the six other species infecting this Sciurid, Ctenophthalmus agyrtes impavidus constituted 17.2% (P: 1.6-2.2%; I: 1.1-2.6), and Megabothris turbidus 8.1% (P: 0.8-1.9%; I: 1.0-1.4) of the flea community, respectively. These last two species represented respectively 60.8% and 36.6% of the flea community on the bank vole and the wood mouse. Originated from Asia, chipmunks did not import any flea species to Sénart, probably because they were used as pets before their release in the wild. Abundance in C. s. sciurorum increased with adult chipmunk density and with juvenile density in summer. On adult chipmunks C. s. sciurorum tented to decrease with increasing abundance of red squirrels (Sciurus vulgaris]. Moreover, the two other flea species mainly infected young chipmunks during the fall, and their number was not related to chipmunk density. However, the distribution of species within the flea community became more balanced with increase juvenile chipmunk density. Overall, these results indicate that the close phyletic relationship between chipmunks and red squirrels contributed in the acquisition and the spread of fleas by chipmunks. Primary and secondary hosts densities, their habitat use, and more specifically burrowing activities and tree canopy use, also played a role in the spread of fleas on chipmunks.

  1. Molecular Detection of Rickettsia felis in Humans, Cats, and Cat Fleas in Bangladesh, 2013-2014.

    Science.gov (United States)

    Ahmed, Rajib; Paul, Shyamal Kumar; Hossain, Muhammad Akram; Ahmed, Salma; Mahmud, Muhammad Chand; Nasreen, Syeda Anjuman; Ferdouse, Faria; Sharmi, Rumana Hasan; Ahamed, Farid; Ghosh, Souvik; Urushibara, Noriko; Aung, Meiji Soe; Kobayashi, Nobumichi

    2016-05-01

    High prevalence of Rickettsia felis in patients with fever of unknown origin was revealed in the north-central Bangladesh from 2012 to 2013. Subsequently, in this study, prevalence of R. felis in cats and cat fleas (Ctenocephalides felis), together with febrile patients, was studied by PCR detection of 17 kDa antigen gene and DNA sequencing. R. felis was detected in 28% (28/100) and 21% (14/68) of cat blood and cat flea samples, respectively, whereas 42% (21/50) of patients were positive for R. felis. R. felis-positive cat fleas were detected at significantly higher rate on R. felis-positive cats. The results suggested a potential role of cats and cat fleas for transmission of R. felis to humans in Bangladesh.

  2. Fleas (Siphonaptera) in the Nests of Dormice (Gliridae: Rodentia) in Lithuania.

    Science.gov (United States)

    Lipatova, I; Stanko, M; Paulauskas, A; Spakovaite, S; Gedminas, V

    2015-05-01

    Negative effects of flea (Siphonaptera) parasitism on the host may be expressed in different ways. The aim of this study was to assess distribution of the flea fauna in nests of dormice in Lithuania. Nests of Glis glis (L.), Dryomys nitedula (Pallas), and Muscardinus avellanarius (L.) were collected from nest boxes in 2012 and 2013. Fleas were collected from nests in the laboratory and put into plastic tubes with 70% ethanol. Flea species were identified using morphological keys. From 400 nest boxes, 112 nests of dormice were collected from eight sites from mixed forests of central Lithuania. Twenty-three nests of G. glis were collected from nest boxes, with 16 of them containing 286 fleas belonging to four species: Ceratophyllus sciurorum (Schrank) (259), C. gallinae (Schrank) (23), Hystrichopsylla talpae (Curtis) (3), and Megabothris turbidus (Rothschild) (1). Fourteen nests of M. avellanarius were collected from nest boxes, 4 of which contained 224 fleas belonging to two species: C. sciurorum (221) and C. gallinae (3). Twenty-four nests of D. nitedula were collected from nest boxes, including 17 containing 207 fleas belonging to two species: C. sciurorum (205) and C. gallinae (2). Fifty-one nests of undetermined dormice species also were collected from nest boxes, 12 of them contained 395 fleas belonging to three species: C. sciurorum (374), Ctenophthalmus agyrtes (Heller) (19), and Ctenophthalmus assimilis (Taschenberg) (2). C. sciurorum was a predominant species in the nests of dormice. The occurrence of C. gallinae was documented in Lithuania for the first time. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Cat fleas (Ctenocephalides felis) carrying Rickettsia felis and Bartonella species in Hong Kong.

    Science.gov (United States)

    Šlapeta, Jan; Lawrence, Andrea; Reichel, Michael P

    2018-04-01

    Fleas are commonly recorded on stray as well as domestic dogs and cats in Hong Kong. Fleas can be a major cause of pruritus in dogs and cats and also vectors of potentially zoonotic bacteria in the genera Rickettsia and Bartonella. Morphological examination of 174 fleas from dogs and cats living in Hong Kong revealed only cat fleas (Ctenocephalides felis). Cytochrome c oxidase subunit 1 gene (cox1) genotyping of 20 randomly selected specimens, revealed three cox1 haplotypes (HK-h1 to HK-h3). The most common haplotype was HK-h1 with 17 specimens (17/20, 85%). HK-h1 was identical to cox1 sequences of fleas in Thailand and Fiji. HK-h1 and HK-h2 form a distinct cat flea cox1 clade previously recognized as the Clade 3. HK-h3 forms a new Clade 6. A multiplex Bartonella and Rickettsia real-time PCR of DNA from 20 C. felis found Bartonella and Rickettsia DNA in three (15%) and ten (50%) C. felis, respectively. DNA sequencing confirmed the presence of R. felis, B. clarridgeiae and Bartonella henselae. This is the first reported study of that kind in Hong Kong, and further work is required to expand the survey of companion animals in the geographical region. The sampling of fleas on domestic cats and dogs in Hong Kong revealed them to be exclusively infested by the cat flea and to be harbouring pathogens of zoonotic potential. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Does hair coat length affect flea infestation in naturally infested dogs?

    Science.gov (United States)

    Silva, Guilherme Araujo Collares da; Lins, Luciana Araujo; Irala, Márcio Josué Costa; Cárcamo, Marcial Corrêa; Ribeiro, Paulo Bretanha

    2016-01-01

    The Siphonaptera are parasitic insects of endothermic animals and Ctenocephalides felis and Pulex irritans are important parasites of dogs. This study evaluated the effect of hair coat length and time of year on the population size of C. felis and P. irritans in naturally infested dogs. Fleas were collected from 14 dogs on a monthly basis for a year (February 2015 to January 2016) at a rural property in Bagé, Rio Grande do Sul, Brazil. The dogs were divided into two groups based on hair coat length: short coat (coat length coat (coat length > 5.0 cm, n= 7). In total, 2057 fleas were collected, 1541 of which were C. felis (74.91%) and 516 were P. irritans (25.08%). The number of C. felis and P. irritans individuals was significantly affected by hair coat length and time of year. The variation in flea numbers over the study months was higher in long-coated than in short-coated dogs for the two flea species and flea numbers increased with increasing mean monthly temperatures. The results provide a better understanding of behavioral aspects of flea communities in dogs and may help develop control strategies targeting these parasites.

  5. Flea diversity as an element for persistence of plague bacteria in an East African plague focus.

    Directory of Open Access Journals (Sweden)

    Rebecca J Eisen

    Full Text Available Plague is a flea-borne rodent-associated zoonotic disease that is caused by Yersinia pestis and characterized by long quiescent periods punctuated by rapidly spreading epidemics and epizootics. How plague bacteria persist during inter-epizootic periods is poorly understood, yet is important for predicting when and where epizootics are likely to occur and for designing interventions aimed at local elimination of the pathogen. Existing hypotheses of how Y. pestis is maintained within plague foci typically center on host abundance or diversity, but little attention has been paid to the importance of flea diversity in enzootic maintenance. Our study compares host and flea abundance and diversity along an elevation gradient that spans from low elevation sites outside of a plague focus in the West Nile region of Uganda (~725-1160 m to higher elevation sites within the focus (~1380-1630 m. Based on a year of sampling, we showed that host abundance and diversity, as well as total flea abundance on hosts was similar between sites inside compared with outside the plague focus. By contrast, flea diversity was significantly higher inside the focus than outside. Our study highlights the importance of considering flea diversity in models of Y. pestis persistence.

  6. Five-month comparative efficacy evaluation of three ectoparasiticides against adult cat fleas (Ctenocephalides felis), flea egg hatch and emergence, and adult brown dog ticks (Rhipicephalus sanguineus sensu lato) on dogs housed outdoors.

    Science.gov (United States)

    Varloud, Marie; Hodgkins, Elizabeth

    2015-03-01

    This study was designed to compare the efficacy of three topical combinations on dogs in outdoor conditions against adult cat fleas (Ctenocephalides felis), flea egg hatch and emergence, and against adult brown dog ticks (Rhipicephalus sanguineus sensu lato). Treatment was performed on day 0 with a placebo; dinotefuran, pyriproxifen and permethrin (DPP); fipronil and (S)-methoprene (FM) or imidacloprid and permethrin (IP). Dogs (n = 32), housed outdoors for 7 months, were treated monthly for four consecutive months (on days 0, 30, 60 and 90) and infested with ~100 unfed adult fleas on days 14, 55, 74, 115 and 150 and with ~50 unfed adult ticks on days 28, 44, 88 and 104. Adult fleas were counted and removed 24 h after infestation. Immediately after flea removal, dogs were reinfested with ~100 new adult fleas 72 h prior to egg collection for up to 48 h. Flea eggs were incubated for 32 days, and newly emerged adults were counted. Ticks were counted and removed 48 h after each infestation. FM had >90 % efficacy against fleas at each time point and variable efficacy against ticks (38.0-99.6 %). Efficacy of IP was 60 days after the last treatment. Despite challenging weather conditions, DPP was highly effective, providing >90 % efficacy against adult ticks as well as adult and immature fleas at every time point of the study.

  7. Description of Medwayella independencia (Siphonaptera, Stivaliidae, a new species of flea from Mindanao Island, the Philippines and their phoretic mites, and miscellaneous flea records from the Malay Archipelago

    Directory of Open Access Journals (Sweden)

    Michael Hastriter

    2014-05-01

    Full Text Available Medwayella independencia, a new species of flea, is described from the tupaiid host Urogale everetti (Thomas from Mindanao Island, Philippines. Several other species of fleas are also recorded from the Philippines including a single male of Lentistivalius philippinensis Hastriter & Bush, 2013 (previously known only from two males, the bat fleas Thaumapsylla breviceps orientalis Smit and Thaumapsylla longiforceps Traub, a single unidentified female species of Macrostylophora Ewing collected from the murid Bullimus bagobos Mearns, and a pair of Medwayella robinsoni ssp. from Sundasciurus hoogstraali (Sanborn from Busuanga Island, Philippines. Representatives of Medwayella Traub, 1972 and Macrostylophora have not previously been recorded from the Philippines. A key to the male sex of Medwayella is provided. Phoretic mites of the genus Psylloglyphus (family Winterschmidtiidae were present under the abdominal sclerites of several male and female specimens of M. independencia. This is the second report of a phoretic mite on a species of Medwayella Traub. The co-evolutionary implications between phoretic mites and fleas are discussed.

  8. Characterization of Hop-and-Sink Locomotion of Water Fleas

    Science.gov (United States)

    Skipper, A. N.; Murphy, D. W.; Webster, D. R.

    2017-11-01

    The freshwater crustacean Daphnia magna is a widely studied zooplankton in relation to food webs, predator-prey interactions, and other biological/ecological considerations; however, their locomotion is poorly quantified and understood. These water fleas utilize a hop-and-sink mechanism that consists of making quick, impulsive jumps by beating their antennae to propel themselves forward (roughly 1 body length). The animals then sink for a period, during which they stretch out their antennae to increase drag and thereby reduce their sinking velocity. Time-resolved three-dimensional flow fields surrounding the animals were quantified with a unique infrared tomographic particle image velocimetry (tomo-PIV) system. Three-dimensional kinematics data were also extracted from the image sequences. In the current work, we compared body kinematics and flow disturbance among organisms of size in the range of 1.3 to 2.8 mm. The stroke cycle averaged 150 +/- 20 ms, with each stroke cycle split nearly evenly between power and recovery strokes. The kinematics data collapsed onto a self-similar curve when properly nondimensionalized, and a general trend was shown to exist between the nondimensionalized peak body speed and body length. The fluid flow induced by each antennae consisted of a viscous vortex ring that demonstrated a slow decay in the wake. The viscous dissipation showed no clear dependence on body size, whereas the volume of fluid exceeding 5 mm/s (the speed near the sinking speed of the animal) decayed more slowly with increasing body size.

  9. Preventive efficacy of NexGard Spectra® against Dipylidium caninum infection in dogs using a natural flea (Ctenocephalides felis) infestation model

    OpenAIRE

    Beugnet Frédéric; Meyer Leon; Fourie Josephus; Larsen Diane

    2017-01-01

    The efficacy of a monthly oral endectocide product, NexGard Spectra? (Merial), a combination of afoxolaner and milbemycin oxime, was evaluated in a flea (Ctenocephalides felis) challenge model for the prevention of Dipylidium caninum tapeworm infection in dogs. The efficacy of treatment with NexGard Spectra? was assessed in 10 dogs following weekly flea infestation with metacestode naturally infected fleas and compared with that in 10 untreated control dogs. The 100 fleas deposited weekly on ...

  10. Phylogenetic Analysis of Entomoparasitic Nematodes, Potential Control Agents of Flea Populations in Natural Foci of Plague

    Science.gov (United States)

    Koshel, E. I.; Aleshin, V. V.; Eroshenko, G. A.; Kutyrev, V. V.

    2014-01-01

    Entomoparasitic nematodes are natural control agents for many insect pests, including fleas that transmit Yersinia pestis, a causative agent of plague, in the natural foci of this extremely dangerous zoonosis. We examined the flea samples from the Volga-Ural natural focus of plague for their infestation with nematodes. Among the six flea species feeding on different rodent hosts (Citellus pygmaeus, Microtus socialis, and Allactaga major), the rate of infestation varied from 0 to 21%. The propagation rate of parasitic nematodes in the haemocoel of infected fleas was very high; in some cases, we observed up to 1,000 juveniles per flea specimen. Our study of morphology, life cycle, and rDNA sequences of these parasites revealed that they belong to three distinct species differing in the host specificity. On SSU and LSU rRNA phylogenies, these species representing three genera (Rubzovinema, Psyllotylenchus, and Spilotylenchus), constitute a monophyletic group close to Allantonema and Parasitylenchus, the type genera of the families Allantonematidae and Parasitylenchidae (Nematoda: Tylenchida). We discuss the SSU-ITS1-5.8S-LSU rDNA phylogeny of the Tylenchida with a special emphasis on the suborder Hexatylina. PMID:24804197

  11. Market Hydraulics and Subjectivities in the "Wild": Circulations of the Flea Market

    Directory of Open Access Journals (Sweden)

    Niklas Hansson

    2015-03-01

    Full Text Available Since consumer researchers started paying attention to flea markets they represent common consumer and market research objects. Arguably, in the "natural laboratory" of the flea market, researchers can observe and theorize market and consumer processes "in the wild", as forms of direct marketing and consumption. We build on existing flea market research through adopting a circulatory approach, inspired by actor-network theory (ANT. Rather than presenting a theory of (flea markets, ANT is useful for studying markets from the perspective of grounded market-making processes. Consumption is understood as the interplay of consumers, marketers, retailers, and a wide array of artifacts and market mediators like products, economic theories and ideas, packaging, market space (in the physical sense and furniture, etc. Our results point out that not only does such an approach enable analysis of features commonly studied within consumer research such as calculative action and social interaction, but also issues more rarely in focus in such research, such as cognitive patterns of consumer curiosity, emotions, senses, and affect. Furthermore, even though flea markets foremost are places of commerce and exchange of second hand goods, there is a large variety of other forms of flows or circulations going on "backstage" that enable the surface phenomena of second hand consumption to come into being. Many of these circulations, we argue, are material rather than immaterial Vendor and buyer subjectivities are thus understood as outcomes of circulatory dynamism that involves a range of material and immaterial flows.

  12. Potential role for dog fleas in the cycle of Leishmania spp.

    Science.gov (United States)

    Ferreira, Marilia Gabriele Prado Albuquerque; Fattori, Karina Reinaldo; Souza, Fausto; Lima, Valéria Marçal Felix

    2009-10-28

    Several species of Leishmania spp. cause diseases in humans that range from self-healing cutaneous lesions to fatal visceral leishmaniosis. It has been observed that besides being transmitted by sand flies, Leishmania spp. may also be transmitted by arthropods such as ticks and fleas. To investigate the possible role of dog fleas in the transmission of Leishmania spp., Ctenocefalides felis were removed from 22 dogs which were positive according to ELISA and rK-39 tests. A C. felis sample from each of the 22 dogs was used to infect a hamster. The 22 hamsters were euthanized 4 months after infection with the fleas and the blood was subjected to ELISA to detect antibody anti-Leishmania spp., and the spleen samples were submitted to PCR for detection of Leishmania spp. DNA. PCR and ELISA were both positive in 18.1% (4/22), with PCR alone being positive in 45% (10/22) and ELISA alone in only 9% (2/22). These results suggest the participation of dog fleas in the Leishmania spp. cycle. Confirmation that C. felis indeed transmit leishmaniosis to dogs requires new strategies against leishmaniosis to be enforced by public health authorities and which focus on better ways to keep dogs free of fleas.

  13. Fleas, hosts and habitat: What can we predict about the spread of vector-borne zoonotic diseases?

    Science.gov (United States)

    Megan M. Friggens

    2010-01-01

    Vector-borne diseases of humans and wildlife are experiencing resurgence across the globe. I examine the dynamics of flea borne diseases through a comparative analysis of flea literature and analyses of field data collected from three sites in New Mexico: The Sevilleta National Wildlife Refuge, the Sandia Mountains and the Valles Caldera National Preserve (VCNP). My...

  14. Droughts may increase susceptibility of prairie dogs to fleas: Incongruity with hypothesized mechanisms of plague cycles in rodents

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.; Long, Dustin H.; Gage, Kenneth L.; Antolin, Michael F.

    2016-01-01

    Plague is a reemerging, rodent-associated zoonosis caused by the flea-borne bacterium Yersinia pestis. As a vector-borne disease, rates of plague transmission may increase when fleas are abundant. Fleas are highly susceptible to desiccation under hot-dry conditions; we posited that their densities decline during droughts. We evaluated this hypothesis with black-tailed prairie dogs (Cynomys ludovicianus) in New Mexico, June–August 2010–2012. Precipitation was relatively plentiful during 2010 and 2012 but scarce during 2011, the driest spring–summer on record for the northeastern grasslands of New Mexico. Unexpectedly, fleas were 200% more abundant in 2011 than in 2010 and 2012. Prairie dogs were in 27% better condition during 2010 and 2012, and they devoted 287% more time to grooming in 2012 than in 2011. During 2012, prairie dogs provided with supplemental food and water were in 23% better condition and carried 40% fewer fleas. Collectively, these results suggest that during dry years, prairie dogs are limited by food and water, and they exhibit weakened defenses against fleas. Long-term data are needed to evaluate the generality of whether droughts increase flea densities and how changes in flea abundance during sequences of dry and wet years might affect plague cycles in mammalian hosts.

  15. Systemic activity of the avermectins against the cat flea (Siphonaptera: Pulicidae).

    Science.gov (United States)

    Zakson-Aiken, M; Gregory, L M; Meinke, P T; Shoop, W L

    2001-07-01

    Ivermectin has potent systemic activity against numerous species of nematodes and arthropods, but there are some important species in these two groups, such as the cat flea, Ctenocephalides felis (Bouché), that appear to be refractory to it. In an effort to determine if the lack of systemic activity against C. felis is specific to ivermectin, or if it is a class-wide phenomenon, 20 avermectin derivatives were tested in an artificial membrane flea feeding system at concentrations of 20, 10, and 1 microg/ml. Results showed that ivermectin had LC90 and LC50 values against fleas of 19.1 and 9.9 microg/ml, respectively. Only four of the other 19 compounds evaluated possessed both LC90 and LC50 values more potent than ivermectin and even then the advantage was modest. Among those four compounds was a two-fold increase in potency relative to ivermectin when the LC90 values were considered (range, 9.2-10.3 microg/ml) and a two- to eight-fold increase when the LC50 values were examined (range, 1.23-5.26 microg/ml). Neither the possession nor the number of oleandrosyl sugars on the macrocyclic backbone were relevant for additional flea activity because among these four compounds were two disaccharides, a monosaccharide and an aglycone. Also, bond disposition between C-22 and 23 did not contribute to increase in activity because these molecules comprise members with either single or double bonds. One of these avermectin analogs was scaled-up and tested subcutaneously in a dog at >100 times the commercial ivermectin dosage and zero efficacy was observed against the flea. We conclude that even the best in vitro avermectin does not have the in vivo potential to become a commercial oral or subcutaneous flea treatment for companion animals.

  16. First detection of Candidatus Rickettsia barbariae in the flea Vermipsylla alakurt from north-western China.

    Science.gov (United States)

    Zhao, Shan-Shan; Li, Hong-Yu; Yin, Xiao-Ping; Liu, Zhi-Qiang; Chen, Chuang-Fu; Wang, Yuan-Zhi

    2016-06-07

    Vermipsylla is a genus of the family Vermipsyllidae within the order Siphonaptera of fleas. Vermipsylla alakurt is mainly distributed in alpine pastoral areas of Kazakhstan, Mongolia, China and Nepal, and infests sheep, yaks and horses, causing irritation, poor condition, anaemia and even death. However, to date, no rickettsial agents have been reported in V. alakurt. A total of 133 fleas were collected directly from the tails of three sheep flocks (n = 335) in Minfeng County, Xinjiang Uygur Autonomous Region, north-western China. Of these, 55 fleas were identified by morphological examination and molecular analysis of four loci (the ribosomal 18S and 28S rDNA genes and the mitochondrial genes cytochrome  c oxidase subunit II and elongation factor 1-alpha). Eight Rickettsia-specific gene fragments originated from seven genes: the 17-kilodalton antigen gene (17-kDa), citrate synthase gene (gltA), 16S rRNA gene (rrs), outer membrane protein A gene (ompA), surface cell antigen 1 gene (sca1), PS120 protein gene (gene D), and outer membrane protein B gene (ompB, two fragments), were used to identify the species of Rickettsia in 53 fleas. The amplified products were sequenced and included in a phylogenetic analysis to verify the taxonomic identification of the rickettsial agents. Based on morphological and molecular evidence, the flea was identified as Vermipsylla alakurt. Nine samples were positive (16.98 %, 9/53) for Rickettsia spp. The phylogenetic tree revealed that the rickettsial agents found in V. alakurt cluster with Candidatus Rickettsia barbariae. Our study suggests that: (i) V. alakurt may serve as a carrier for Candidatus R. barbariae; and (ii) Candidatus R. barbariae, previously reported in Israel, is the eighth newly discovered validated Rickettsia species in China. This finding extends our knowledge of the distribution of Candidatus R. barbariae and the profile of carriers, which not only comprise ticks but also fleas.

  17. New record of a phoretic flea associated with earwigs (Dermaptera, Arixeniidae) and a redescription of the bat flea Lagaropsylla signata (Siphonaptera, Ischnopsyllidae)

    OpenAIRE

    Hastriter,Michael; Miller,Kelly; Svenson,Gavin; Whiting,Michael F.; Whiting,Michael

    2017-01-01

    Abstract Lagaropsylla signata (Wahlgren, 1903), previously known only from the Island of Java, Indonesia is redescribed and reported for the first time in Deer Cave, Gunung Mulu National Park, Sarawak, Malaysia (west coast of Borneo). Many were found clinging to the earwig Arixenia esau Jordan, 1909. A similar account of a phoretic flea ( Lagaropsylla turba Smit, 1958) on the same species of cave-dwelling earwig has been reported in peninsular Malaysia in a well-documented association with th...

  18. Control of immature stages of the flea Ctenocephalides felis(Bouché in carpets exposed to cats treated with imidacloprid

    Directory of Open Access Journals (Sweden)

    L.J. Fourie

    2000-07-01

    Full Text Available Fleas cause allergic dermatitis in cats and dogs and therefore warrant control. It has been demonstrated previously that there is marked inhibition of the development of the immature stages of the cat flea Ctenocephalides felis on fleece blankets exposed to cats treated with imidacloprid. This study reports on the efficacy of imidacloprid in suppressing adult flea emergence in carpet exposed to treated cats. Circular discs of carpet pre-seeded with flea eggs and larvae were exposed to 6 untreated control and 6 topically treated (imidacloprid 10 % m/v cats 1 to 2 days after treatment and subsequently fortnightly for 6 weeks. Exposure times on alternate days were either 1 or 6 hours. Adult flea yield from carpets was determined 35 days after exposure. Differences between flea yield on control carpets and those exposed for 1 hour were significant only for days +1 and +14. For the 6-hour exposure, differences were significant at all times except on Day +43. The ability of imidacloprid to suppress the yield of adult fleas on carpets (6-hour exposure steadily declined from 82 % (Day +2 to 12 %(Day +43. For the 1-hour exposure it varied inconsistently between 0 and 83 % over the 6-week study period.

  19. Contribution of land use to rodent flea load distribution in the plague ...

    African Journals Online (AJOL)

    These findings suggest that land use factors have a major influence on rodent flea abundance which can be taken as a proxy for plague infection risk. The results further point to the need for a comprehensive package that includes land tillage and crop type considerations on one hand and the associated human activities on ...

  20. Laboratory and field tests of Carbaryl 5% against fleas in Lushoto ...

    African Journals Online (AJOL)

    Background and Objective: Lushoto district in north-eastern Tanzania has been an active focus of plague disease since 1980 and many pesticides were used to control rodents and fleas from 1980 to 2003 when outbreaks occurred yearly. For over seven years ago commercial Carbaryl 5% powder has been used for ...

  1. Assessing plague risk and presence through surveys of small mammal flea communities

    Science.gov (United States)

    M. M. Friggens; P. L. Ford; R. R. Parmenter; M. Boyden; K. Gage

    2011-01-01

    Plague, caused by the bacterium Yersinia pestis, remains a threat to human and wildlife populations in the Western United States (Gage and Kosoy 2005). Several rodent species have been implicated as important maintenance hosts in the U.S., including Peromyscus maniculatus and Dipodomys spp. Fleas are a critical component of plague foci (Gage and Kosoy 2005)....

  2. Prevalence of fleas and gastrointestinal parasites in free-roaming cats in central Mexico.

    Directory of Open Access Journals (Sweden)

    Germinal J Cantó

    Full Text Available The prevalence of fleas and gastrointestinal parasites in free-roaming and domestic cats in central Mexico was evaluated. Three hundred and fifty eight cats captured in the street or brought in by owners to the Animal Control Center Unit, a unit of State Government, from June 2010 to May 2011, were included in the study. All cats were examined for the presence of fleas and gastrointestinal worms. One-hundred and ninety (53% cats were infested with at least one flea species. Single infestations were observed in 106 (30% cats and mixed infestations in 84 (23% cats. Four species of fleas were recovered: Ctenocephalides felis in 53% of the cats, C. canis in 18%, Echidnophaga gallinacea in 7% and Pulex irritans in 1%. One-hundred and sixty three (45% cats were infected with one or more species of gastrointestinal parasites: 48 (13% with nematodes, 145 (40% with cestodes, and one animal presented Moniliformis moniliformis. Prevalences and mean intensity of infection were: Physaloptera praeputialis 7 and 18; T. cati 3 and 2; Ancylostoma tubaeforme 2.5 and 2; Toxascaris leonina 0.5 and 2; Dipylidium caninum 36 and 32; Taenia taeniformis 4 and 3 and Moniliformis moniliformis 0.3 and 106, respectively. There was significant association (P0.05. The correlation between the total number of ectoparasites and endoparasites was not significant (r = 0.089, P = 0.094.

  3. Prevalence of Fleas and Gastrointestinal Parasites in Free-Roaming Cats in Central Mexico

    Science.gov (United States)

    Cantó, Germinal J.; Guerrero, Roberto I.; Olvera-Ramírez, Andrea M.; Milián, Feliciano; Mosqueda, Juan; Aguilar-Tipacamú, Gabriela

    2013-01-01

    The prevalence of fleas and gastrointestinal parasites in free-roaming and domestic cats in central Mexico was evaluated. Three hundred and fifty eight cats captured in the street or brought in by owners to the Animal Control Center Unit, a unit of State Government, from June 2010 to May 2011, were included in the study. All cats were examined for the presence of fleas and gastrointestinal worms. One-hundred and ninety (53%) cats were infested with at least one flea species. Single infestations were observed in 106 (30%) cats and mixed infestations in 84 (23%) cats. Four species of fleas were recovered: Ctenocephalides felis in 53% of the cats, C. canis in 18%, Echidnophaga gallinacea in 7% and Pulex irritans in 1%. One-hundred and sixty three (45%) cats were infected with one or more species of gastrointestinal parasites: 48 (13%) with nematodes, 145 (40%) with cestodes, and one animal presented Moniliformis moniliformis. Prevalences and mean intensity of infection were: Physaloptera praeputialis 7 and 18; T. cati 3 and 2; Ancylostoma tubaeforme 2.5 and 2; Toxascaris leonina 0.5 and 2; Dipylidium caninum 36 and 32; Taenia taeniformis 4 and 3 and Moniliformis moniliformis 0.3 and 106, respectively. There was significant association (P0.05). The correlation between the total number of ectoparasites and endoparasites was not significant (r = 0.089, P = 0.094). PMID:23573282

  4. Flea Bite Dermatitis in a Herd of Dairy Calves in Vom Nigeria ...

    African Journals Online (AJOL)

    They have piercing and sucking mouth parts which are specially designed for injecting into a host and sucking blood. They feed on the blood of cats, dogs and other animals, including humans (Lyon, 1997; Kramer and Mencke, 2001). Flea infestation in cattle and other ruminants is rare; it has been more commonly reported ...

  5. Coexistence of Bartonella henselae and B. clarridgeiae in populations of cats and their fleas in Guatemala.

    Science.gov (United States)

    Bai, Ying; Rizzo, Maria Fernanda; Alvarez, Danilo; Moran, David; Peruski, Leonard F; Kosoy, Michael

    2015-12-01

    Cats and their fleas collected in Guatemala were investigated for the presence of Bartonella infections. Bartonella bacteria were cultured from 8.2% (13/159) of cats, and all cultures were identified as B. henselae. Molecular analysis allowed detection of Bartonella DNA in 33.8% (48/142) of cats and in 22.4% (34/152) of cat fleas using gltA, nuoG, and 16S-23S internal transcribed spacer targets. Two Bartonella species, B. henselae and B. clarridgeiae, were identified in cats and cat fleas by molecular analysis, with B. henselae being more common than B. clarridgeiae in the cats (68.1%; 32/47 vs 31.9%; 15/47). The nuoG was found to be less sensitive for detecting B. clarridgeiae compared with other molecular targets and could detect only two of the 15 B. clarridgeiae-infected cats. No significant differences were observed for prevalence between male and female cats and between different age groups. No evident association was observed between the presence of Bartonella species in cats and in their fleas. © 2015 The Society for Vector Ecology.

  6. Retracing the evolutionary path that led to flea-borne transmission of Yersinia pestis.

    Science.gov (United States)

    Sun, Yi-Cheng; Jarrett, Clayton O; Bosio, Christopher F; Hinnebusch, B Joseph

    2014-05-14

    Yersinia pestis is an arthropod-borne bacterial pathogen that evolved recently from Yersinia pseudotuberculosis, an enteric pathogen transmitted via the fecal-oral route. This radical ecological transition can be attributed to a few discrete genetic changes from a still-extant recent ancestor, thus providing a tractable case study in pathogen evolution and emergence. Here, we determined the genetic and mechanistic basis of the evolutionary adaptation of Y. pestis to flea-borne transmission. Remarkably, only four minor changes in the bacterial progenitor, representing one gene gain and three gene losses, enabled transmission by flea vectors. All three loss-of-function mutations enhanced cyclic-di-GMP-mediated bacterial biofilm formation in the flea foregut, which greatly increased transmissibility. Our results suggest a step-wise evolutionary model in which Y. pestis emerged as a flea-borne clone, with each genetic change incrementally reinforcing the transmission cycle. The model conforms well to the ecological theory of adaptive radiation. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. A survey of cats and dogs for fleas: with particular reference to their role as intermediate hosts of Dipylidium caninum.

    Science.gov (United States)

    Guzman, R F

    1984-05-01

    Three species of fleas, viz. Ctenocephalides felis, Ctenocephalides canis, and Pulex irritans were found in an examination of 81 cats and 48 dogs in Wellington. C. felis was the most prevalent flea in cats, and C. canis predominated in dogs. It is speculated that C. felis, and its primary host the cat, may assume greater medical and veterinary significance than C. canis. In an examination of 1578 fleas for cysticercoids of the dog tapeworm, Dipylidium caninum, all were found negative. These results do not necessarily reflect the availability of cysticercoids in the environment, and the reasons for this are discussed.

  8. Detection of Rickettsia in Rhipicephalus sanguineus Ticks and Ctenocephalides felis Fleas from Southeastern Tunisia by Reverse Line Blot Assay

    Science.gov (United States)

    Khrouf, Fatma; M'Ghirbi, Youmna; Znazen, Abir; Ben Jemaa, Mounir; Hammami, Adnene

    2014-01-01

    Ticks (n = 663) and fleas (n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected Rickettsia felis in fleas, Rickettsia massiliae Bar 29 and the Rickettsia conorii Israeli spotted fever strain in ticks, and Rickettsia conorii subsp. conorii and Rickettsia spp. in both arthropods. The sensitivity of the adopted technique allowed the identification of a new association between fleas and R. conorii subsp. conorii species. The presence of these vector-borne Rickettsia infections should be considered when diagnosing this disease in humans in Tunisia. PMID:24226919

  9. Role of the Yersinia pestis yersiniabactin iron acquisition system in the incidence of flea-borne plague.

    Directory of Open Access Journals (Sweden)

    Florent Sebbane

    2010-12-01

    Full Text Available Plague is a flea-borne zoonosis caused by the bacterium Yersinia pestis. Y. pestis mutants lacking the yersiniabactin (Ybt siderophore-based iron transport system are avirulent when inoculated intradermally but fully virulent when inoculated intravenously in mice. Presumably, Ybt is required to provide sufficient iron at the peripheral injection site, suggesting that Ybt would be an essential virulence factor for flea-borne plague. Here, using a flea-to-mouse transmission model, we show that a Y. pestis strain lacking the Ybt system causes fatal plague at low incidence when transmitted by fleas. Bacteriology and histology analyses revealed that a Ybt-negative strain caused only primary septicemic plague and atypical bubonic plague instead of the typical bubonic form of disease. The results provide new evidence that primary septicemic plague is a distinct clinical entity and suggest that unusual forms of plague may be caused by atypical Y. pestis strains.

  10. Contribution of land use to rodent flea load distribution in the plague endemic area of Lushoto District, Tanzania.

    Science.gov (United States)

    Hieronimo, Proches; Kihupi, Nganga I; Kimaro, Didas N; Gulinck, Hubert; Mulungu, Loth S; Msanya, Balthazar M; Leirs, Herwig; Deckers, Jozef A

    2014-07-01

    Fleas associated with different rodent species are considered as the major vectors of bubonic plague, which is still rampant in different parts of the world. The objective of this study was to investigate the contribution of land use to rodent flea load distribution at fine scale in the plague endemic area of north-eastern Tanzania. Data was collected in three case areas namely, Shume, Lukozi and Mwangoi, differing in plague incidence levels. Data collection was carried out during both wet and dry seasons of 2012. Analysis of Variance and Boosted Regression Tree (BRT) statistical methods were used to clarify the relationships between fleas and specific land use characteristics. There was a significant variation (P ≤ 0.05) of flea indices in different land use types. Fallow and natural forest had higher flea indices whereas plantation forest mono-crop and mixed annual crops had the lowest flea indices among the aggregated land use types. The influence of individual land use types on flea indices was variable with fallow having a positive effect and land tillage showing a negative effect. The results also demonstrated a seasonal effect, part of which can be attributed to different land use practices such as application of pesticides, or the presence of grass strips around fields. These findings suggest that land use factors have a major influence on rodent flea abundance which can be taken as a proxy for plague infection risk. The results further point to the need for a comprehensive package that includes land tillage and crop type considerations on one hand and the associated human activities on the other, in planning and implementation of plague control interventions.

  11. Using occupancy models to investigate the prevalence of ectoparasitic vectors on hosts: an example with fleas on prairie dogs

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.; Doherty, Paul F.; Gage, Kenneth L.; Huyvaert, Kathryn P.; Long, Dustin H.; Antolin, Michael F.

    2013-01-01

    Ectoparasites are often difficult to detect in the field. We developed a method that can be used with occupancy models to estimate the prevalence of ectoparasites on hosts, and to investigate factors that influence rates of ectoparasite occupancy while accounting for imperfect detection. We describe the approach using a study of fleas (Siphonaptera) on black-tailed prairie dogs (Cynomys ludovicianus). During each primary occasion (monthly trapping events), we combed a prairie dog three consecutive times to detect fleas (15 s/combing). We used robust design occupancy modeling to evaluate hypotheses for factors that might correlate with the occurrence of fleas on prairie dogs, and factors that might influence the rate at which prairie dogs are colonized by fleas. Our combing method was highly effective; dislodged fleas fell into a tub of water and could not escape, and there was an estimated 99.3% probability of detecting a flea on an occupied host when using three combings. While overall detection was high, the probability of detection was always dogs, flea occupancy was heightened in old/natural colonies of prairie dogs, and on hosts that were in poor condition. Occupancy was initially low in plots with high densities of prairie dogs, but, as the study progressed, the rate of flea colonization increased in plots with high densities of prairie dogs in particular. Our methodology can be used to improve studies of ectoparasites, especially when the probability of detection is low. Moreover, the method can be modified to investigate the co-occurrence of ectoparasite species, and community level factors such as species richness and interspecific interactions.

  12. Effect of Rickettsia felis Strain Variation on Infection, Transmission, and Fitness in the Cat Flea (Siphonaptera: Pulicidae).

    Science.gov (United States)

    Healy, Sean P; Brown, Lisa D; Hagstrom, Melena R; Foil, Lane D; Macaluso, Kevin R

    2017-07-01

    Rickettsia felis is a human pathogen transmitted by the cat flea, Ctenocephalides felis (Bouché) (str. LSU), as well as an obligate symbiont of the parthenogenic booklouse Liposcelis bostrychophila (Badonnel) (str. LSU-Lb). The influence of genetic variability in these two strains of R. felis on host specialization and fitness and possible resulting differences on infection and transmission kinetics in C. felis is unknown. Utilizing an artificial host system, cat fleas were exposed to a R. felis str. LSU-Lb-infected bloodmeal and monitored for infection at 7-d intervals for 28 d. Quantitative real-time PCR was used to determine rickettsial load and infection density in newly exposed cat fleas, and transmission frequency between cat fleas. The effect of persistent R. felis infection on cat flea F1 progeny was also assessed. At 7 d postexposure 76.7% of the cat fleas successfully acquired R. felis str. LSU-Lb. In R. felis str. LSU-Lb-exposed cat fleas, the mean infection load (6.15 × 106), infection density (0.76), and infection prevalence (91/114) were significantly greater than R. felis str. LSU infection load (3.09 × 106), infection density (0.68), and infection prevalence (76/113). A persistent R. felis str. LSU-Lb infection was detected for 28 d in adult cat fleas but neither female:male ratio distortion nor vertical transmission was observed in F1 progeny. While infection kinetics differed, with higher intensity associated with R. felis str. LSU-Lb, no distinct phenotype was observed in the F1 progeny. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  13. Efficacy of fluralaner flavored chews (Bravecto) administered to dogs against the adult cat flea, Ctenocephalides felis felis and egg production.

    Science.gov (United States)

    Dryden, Michael W; Smith, Vicki; Bennett, Tashina; Math, Lisa; Kallman, James; Heaney, Kathleen; Sun, Fangshi

    2015-07-11

    Fluralaner is a potent insecticide and acaricide with rapid and persistent efficacy. This study measured the efficacy of fluralaner flavored chews (Bravecto®, Merck Animal Health) administered to dogs against adult Ctenocephalides felis felis and egg production. Twelve purpose-bred dogs were randomly allocated to two groups of six dogs each. Dogs in treatment group 1 were administered a single fluralaner flavored chew to achieve a minimum dose of at least 25 mg/kg while treatment group 2 served as untreated controls. On Days -2, 28, 56, 84, 91, 98, 105, 112, and 120 post-treatment, each dog was infested with approximately 200 unfed cat fleas, C. felis felis (KS1 strain). Forty-eight hours after treatment and 48 h after each infestation, eggs were collected over a 3-h period, counted and viability determined. Dogs were combed to remove any remaining fleas. Treatment of dogs with oral fluralaner provided a 100% reduction in flea counts 48 h after treatment and within 48 h of every post-treatment infestation through Day122. Egg production from fluralaner treated dogs was reduced by 99.9% (two eggs from one dog) within 48 h after treatment and not a single egg (100% efficacy) was thereafter collected from treated dogs. Adult flea counts and egg production from the fluralaner-treated dogs were significantly lower than for non-treated controls at all post-treatment evaluations (P dog 48 h after treatment did not produce any adult fleas. As no additional eggs were collected from treated dogs, no viability assessment was performed. A single oral dose of fluralaner flavored chews provided 100% efficacy against repeated flea infestations on dogs for 4 months. Fluralaner reduced egg production of activity reproducing female fleas by 99.9% and then killed every single female flea before any eggs could be produced following each subsequent re-infestation for the entire 122-day evaluation period.

  14. Parasites of domestic and wild animals in South Africa. XLIV. Fleas (Insecta : Siphonaptera : Pulicidae collected from 15 carnivore species

    Directory of Open Access Journals (Sweden)

    I.G. Horak

    2004-11-01

    Full Text Available Fleas were collected from 61 wild carnivores belonging to 13 species in various nature reserves and on farms, two feral domestic cats in a nature reserve and a domestic dog in the city of Johannesburg. Eleven flea species, including two subspecies of one of these, belonging to six genera were recovered. Amongst these only Ctenocephalides felis felis and Ctenocephalides felis strongylus are considered specific parasites of carnivores. The remaining ten species normally infest the prey animals of the various carnivores.

  15. Rickettsial Infections among Ctenocephalides felis and Host Animals during a Flea-Borne Rickettsioses Outbreak in Orange County, California

    Science.gov (United States)

    Fogarty, Carrie; Krueger, Laura; Macaluso, Kevin R.; Odhiambo, Antony; Nguyen, Kiet; Farris, Christina M.; Luce-Fedrow, Alison; Bennett, Stephen; Jiang, Ju; Sun, Sokanary; Cummings, Robert F.; Richards, Allen L.

    2016-01-01

    Due to a resurgence of flea-borne rickettsioses in Orange County, California, we investigated the etiologies of rickettsial infections of Ctenocephalides felis, the predominant fleas species obtained from opossums (Didelphis virginiana) and domestic cats (Felis catus), collected from case exposure sites and other areas in Orange County. In addition, we assessed the prevalence of IgG antibodies against spotted fever group (SFGR) and typhus group (TGR) rickettsiae in opossum sera. Of the 597 flea specimens collected from opossums and cats, 37.2% tested positive for Rickettsia. PCR and sequencing of rickettsial genes obtained from C. felis flea DNA preparations revealed the presence of R. typhi (1.3%), R. felis (28.0%) and R. felis-like organisms (7.5%). Sera from opossums contained TGR-specific (40.84%), but not SFGR-specific antibodies. The detection of R. felis and R. typhi in the C. felis fleas in Orange County highlights the potential risk for human infection with either of these pathogens, and underscores the need for further investigations incorporating specimens from humans, animal hosts, and invertebrate vectors in endemic areas. Such studies will be essential for establishing a link in the ongoing flea-borne rickettsioses outbreaks. PMID:27537367

  16. Assessing Cat Flea Microbiomes in Northern and Southern California by 16S rRNA Next-Generation Sequencing.

    Science.gov (United States)

    Vasconcelos, Elton J R; Billeter, Sarah A; Jett, Lindsey A; Meinersmann, Richard J; Barr, Margaret C; Diniz, Pedro P V P; Oakley, Brian B

    2018-06-12

    Flea-borne diseases (FBDs) impact both human and animal health worldwide. Because adult fleas are obligately hematophagous and can harbor potential pathogens, fleas act as ectoparasites of vertebrates, as well as zoonotic disease vectors. Cat fleas (Ctenocephalides felis) are important vectors of two zoonotic bacterial genera listed as priority pathogens by the National Institute of Allergy and Infectious Diseases (NIAID-USA): Bartonella spp. and Rickettsia spp., causative agents of bartonelloses and rickettsioses, respectively. In this study, we introduce the first microbiome analysis of C. felis samples from California, determining the presence and abundance of relevant pathogenic genera by characterizing the cat flea microbiome through 16S rRNA next-generation sequencing (16S-NGS). Samples from both northern (NoCal) and southern (SoCal) California were assessed to expand current knowledge regarding FBDs in the state. We identified Rickettsia and Bartonella, as well as the endosymbiont Wolbachia, as the most abundant genera, followed by less abundant taxa. In comparison to our previous study screening Californian cat fleas for rickettsiae using PCR/digestion/sequencing of the ompB gene, the 16S-NGS approach applied herein showed a 95% level of agreement in detecting Rickettsia spp. There was no overall difference in microbiome diversity between NoCal and SoCal samples. Bacterial taxa identified by 16S-NGS in this study may help to improve epidemiological investigations, pathogen surveillance efforts, and clinical diagnostics of FBDs in California and elsewhere.

  17. Modelling the current distribution and predicted spread of the flea species Ctenocephalides felis infesting outdoor dogs in Spain.

    Science.gov (United States)

    Gálvez, Rosa; Musella, Vicenzo; Descalzo, Miguel A; Montoya, Ana; Checa, Rocío; Marino, Valentina; Martín, Oihane; Cringoli, Giuseppe; Rinaldi, Laura; Miró, Guadalupe

    2017-09-19

    The cat flea, Ctenocephalides felis, is the most prevalent flea species detected on dogs and cats in Europe and other world regions. The status of flea infestation today is an evident public health concern because of their cosmopolitan distribution and the flea-borne diseases transmission. This study determines the spatial distribution of the cat flea C. felis infesting dogs in Spain. Using geospatial tools, models were constructed based on entomological data collected from dogs during the period 2013-2015. Bioclimatic zones, covering broad climate and vegetation ranges, were surveyed in relation to their size. The models builded were obtained by negative binomial regression of several environmental variables to show impacts on C. felis infestation prevalence: land cover, bioclimatic zone, mean summer and autumn temperature, mean summer rainfall, distance to urban settlement and normalized difference vegetation index. In the face of climate change, we also simulated the future distributions of C. felis for the global climate model (GCM) "GFDL-CM3" and for the representative concentration pathway RCP45, which predicts their spread in the country. Predictive models for current climate conditions indicated the widespread distribution of C. felis throughout Spain, mainly across the central northernmost zone of the mainland. Under predicted conditions of climate change, the risk of spread was slightly greater, especially in the north and central peninsula, than for the current situation. The data provided will be useful for local veterinarians to design effective strategies against flea infestation and the pathogens transmitted by these arthropods.

  18. Effects on the development of Dipylidium caninum and on the host reaction to this parasite in the adult flea (Ctenocephalides felis felis).

    Science.gov (United States)

    Pugh, R E

    1987-01-01

    Temperature was found to be a major factor affecting the development of Dipylidium caninum and the presence of a host reaction of adult Ctenocephalides felis felis to D. caninum. Adult fleas reared at 30-32 degrees C contained fully developed metacestodes when they emerged from their cocoons. However at lower temperatures, D. caninum could not complete development until the flea hosts had spent some time on their mammalian hosts. It was the surface temperature of the mammals (31-36 degrees C) and not the fleas' blood meals which resulted in the metacestodes completing their development. This development of D. caninum was therefore independent of the flea development. At 20 degrees C, a larger and more prolonged host reaction was mounted than at higher temperatures. The larval flea diet had a small effect on the subsequent cestode development and the adult fleas' reaction to it.

  19. Seasonal fluctuations of small mammal and flea communities in a Ugandan plague focus: evidence to implicate Arvicanthis niloticus and Crocidura spp. as key hosts in Yersinia pestis transmission.

    Science.gov (United States)

    Moore, Sean M; Monaghan, Andrew; Borchert, Jeff N; Mpanga, Joseph T; Atiku, Linda A; Boegler, Karen A; Montenieri, John; MacMillan, Katherine; Gage, Kenneth L; Eisen, Rebecca J

    2015-01-08

    The distribution of human plague risk is strongly associated with rainfall in the tropical plague foci of East Africa, but little is known about how the plague bacterium is maintained during periods between outbreaks or whether environmental drivers trigger these outbreaks. We collected small mammals and fleas over a two year period in the West Nile region of Uganda to examine how the ecological community varies seasonally in a region with areas of both high and low risk of human plague cases. Seasonal changes in the small mammal and flea communities were examined along an elevation gradient to determine whether small mammal and flea populations exhibit differences in their response to seasonal fluctuations in precipitation, temperature, and crop harvests in areas within (above 1300 m) and outside (below 1300 m) of a model-defined plague focus. The abundance of two potential enzootic host species (Arvicanthis niloticus and Crocidura spp.) increased during the plague season within the plague focus, but did not show the same increase at lower elevations outside this focus. In contrast, the abundance of the domestic rat population (Rattus rattus) did not show significant seasonal fluctuations regardless of locality. Arvicanthis niloticus abundance was negatively associated with monthly precipitation at a six month lag and positively associated with current monthly temperatures, and Crocidura spp. abundance was positively associated with precipitation at a three month lag and negatively associated with current monthly temperatures. The abundance of A. niloticus and Crocidura spp. were both positively correlated with the harvest of millet and maize. The association between the abundance of several small mammal species and rainfall is consistent with previous models of the timing of human plague cases in relation to precipitation in the West Nile region. The seasonal increase in the abundance of key potential host species within the plague focus, but not outside of

  20. Preventive efficacy of NexGard Spectra® against Dipylidium caninum infection in dogs using a natural flea (Ctenocephalides felis infestation model

    Directory of Open Access Journals (Sweden)

    Beugnet Frédéric

    2017-01-01

    Full Text Available The efficacy of a monthly oral endectocide product, NexGard Spectra® (Merial, a combination of afoxolaner and milbemycin oxime, was evaluated in a flea (Ctenocephalides felis challenge model for the prevention of Dipylidium caninum tapeworm infection in dogs. The efficacy of treatment with NexGard Spectra® was assessed in 10 dogs following weekly flea infestation with metacestode naturally infected fleas and compared with that in 10 untreated control dogs. The 100 fleas deposited weekly on each dog were not removed until Day 35, allowing enough time for their ingestion. The microscopical analysis of 30 fleas from the flea batches before each weekly challenge demonstrated that 10–33% of the fleas were infected by D. caninum cysticercoid larvae. The arithmetic mean flea count recorded was 47.7 for the 10 untreated dogs and 0 for the 10 treated dogs at Day 35. Based on the daily collection of expelled D. caninum proglottids by dogs during the 70 days of the study, 70% (7/10 of the control dogs and 0% (0/10 of the treated dogs were infected with D. caninum (p < 0.0031. Through its efficacy against fleas, NexGard Spectra® treatment provided indirect prevention of D. caninum infestation. No treatment-related adverse events were observed in dogs during this study.

  1. An update on the distribution and nomenclature of fleas (Order Siphonaptera of bats (Order Chiroptera and rodents (Order Rodentia from La Rioja Province, Argentina

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    M. Fernanda López Berrizbeitia

    2017-06-01

    Full Text Available The mammalian and flea fauna of La Rioja Province is one of the least known from northwestern Argentina. In this study, the distribution and nomenclature of 13 species of fleas of bats and rodents from La Rioja Province are updated. Four species of fleas are recorded for the first time in La Rioja Province including a new record for northwestern Argentina, and two new flea-host associations. An identification key and distribution map are included for all known species of Siphonaptera of bats and rodents from La Rioja Province, Argentina.

  2. First report of a Rickettsia asembonensis related infecting fleas in Brazil.

    Science.gov (United States)

    Silva, Arannadia Barbosa; Vizzoni, Vinicius Figueiredo; Costa, Andréa Pereira; Costa, Francisco Borges; Moraes-Filho, Jonas; Labruna, Marcelo Bahia; Gazêta, Gilberto Salles; de Maria Seabra Nogueira, Rita

    2017-08-01

    The present study was performed in a non-endemic area for spotted fever (SF) in Imperatriz microregion, state of Maranhão, Brazil. Blood samples and ectoparasites were collected from 300 dogs of the Imperatriz microregion. Canine serum samples were tested individually by indirect immunofluorescence assay (IFA), using five Rickettsia isolates from Brazil. Antibodies reactive to at least one of the five species of Rickettsia were detected in 1.6% of the dogs (5/300). These sera were considered reactive to Rickettsia rickettsii and Rickettsia amblyommatis or very closely related species. The ticks (Acari: Ixodidae), identified as Rhipicephalus sanguineus sensu lato (Latreille), and the fleas, identified as Ctenocephalides felis, were tested by polymerase chain reaction (PCR) for detection of rickettsial DNA. More than 78% (83/106) of the C. felis fleas were found to be infected with Rickettsia species using gltA as rickettsial PCR targets, whereas no evidence of Rickettsia spp. was found in R. sanguineus s. l. Genetic analysis based on genes gltA, htrA and ompB showed that the detected strain, is most closely related to Rickettsia asembonensis (formerly Candidatus Rickettsia asemboensis). The present study is the first report of a R. asembonensis related infecting C. felis fleas in Brazil. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. High Prevalence of Rickettsia spp. in Dog Fleas (Siphonaptera: Pulicidae) in Rural Uganda.

    Science.gov (United States)

    Palomar, Ana M; Cevidanes, Aitor; Portillo, Aránzazu; Kalema-Zikusoka, Gladis; Chirife, Andrea D; Romero, Lourdes; Muro, Jesús; Mugisha, Lawrence; Oteo, José A; Millán, Javier

    2017-07-01

    Fleas are known vectors of zoonotic agents. Thirty-five fleas, including 28 Ctenocephalides felis (Bouché), four Pulex irritans (L.), and three Echidnophaga gallinacea (Westwood) from 19 rural dogs from southwestern Uganda were analyzed for the presence of Rickettsia spp. (ompB, gltA, and 17 kDa fragment genes) and Bartonella spp. (rpoB and ITS genes) by PCR. Rickettsial DNA was detected in 27 out of 28 of Ct. felis and in two out of four P. irritans. None of the E. gallinacea specimens harbored Rickettsia DNA. Rickettsia felis was confirmed in 12 Ct. felis and in the two P. irritans specimens with positive PCR-results. In addition, the presence of Candidatus Rickettsia asemboensis was evidenced in 15 Ct. felis. Bartonella spp. was not amplified in any sample. Our survey indicates that R. felis, the agent of the flea-borne spotted fever, is present in the study area. Besides, this is the first description of Ca. R. asemboensis in Uganda. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Predicting small mammal and flea abundance using landform and soil properties in a plague endemic area in Lushoto District, Tanzania.

    Science.gov (United States)

    Meliyo, Joel L; Kimaro, Didas N; Msanya, Balthazar M; Mulungu, Loth S; Hieronimo, Proches; Kihupi, Nganga I; Gulinck, Hubert; Deckers, Jozef A

    2014-07-01

    Small mammals particularly rodents, are considered the primary natural hosts of plague. Literature suggests that plague persistence in natural foci has a root cause in soils. The objective of this study was to investigate the relationship between on the one hand landforms and associated soil properties, and on the other hand small mammals and fleas in West Usambara Mountains in Tanzania, a plague endemic area. Standard field survey methods coupled with Geographical Information System (GIS) technique were used to examine landform and soils characteristics. Soil samples were analysed in the laboratory for physico-chemical properties. Small mammals were trapped on pre-established landform positions and identified to genus/species level. Fleas were removed from the trapped small mammals and counted. Exploration of landform and soil data was done using ArcGIS Toolbox functions and descriptive statistical analysis. The relationships between landforms, soils, small mammals and fleas were established by generalised linear regression model (GLM) operated in R statistics software. Results show that landforms and soils influence the abundance of small mammals and fleas and their spatial distribution. The abundance of small mammals and fleas increased with increase in elevation. Small mammal species richness also increases with elevation. A landform-soil model shows that available phosphorus, slope aspect and elevation were statistically significant predictors explaining richness and abundance of small mammals. Fleas' abundance and spatial distribution were influenced by hill-shade, available phosphorus and base saturation. The study suggests that landforms and soils have a strong influence on the richness and evenness of small mammals and their fleas' abundance hence could be used to explain plague dynamics in the area.

  5. Identification, cloning, and characterization of a major cat flea salivary allergen (Cte f 1).

    Science.gov (United States)

    McDermott, M J; Weber, E; Hunter, S; Stedman, K E; Best, E; Frank, G R; Wang, R; Escudero, J; Kuner, J; McCall, C

    2000-05-01

    An 18 kDa protein isolated from saliva of the cat flea, Ctenocephalides felis, elicits a positive intradermal skin test (IDST) in 100 and 80% of experimental and clinical flea allergic dogs, respectively. Using solid-phase enzyme-linked immuno assay (ELISA), this protein detected IgE in 100 and 80% of experimental and clinical flea allergic dogs, respectively. A cDNA (pFSI) encoding a full-length Cte f 1 protein was isolated from a C. felis salivary gland cDNA library, using a combination of PCR and hybridization screening. This cDNA is 658 bp in length, and contains an open reading frame of 528 bp. The open reading frame encodes a protein of 176 amino acids, consisting of an 18 amino acid signal sequence and a 158 amino acid mature protein. The calculated molecular weight and pI of the mature protein are 18106 Da and 9.3, respectively. The protein, named Cte f 1, is the first novel major allergen described for canine flea allergy. Recombinant Cte f 1 (rCte f 1) was expressed in Escherichia coli, Pichia pastoris and baculovirus infected Trichoplusia ni cells. Approximately, 90% of the rCte f 1 expressed in E. coli accumulated in insoluble inclusion bodies, which could be refolded to a soluble mixture of disulfide isomers with partial IgE binding activity. Small quantities of an apparently correctly refolded form of rCte f 1, which had IgE binding activity equal to the native antigen, was isolated from the soluble fraction of E. coli cells. However, P. pastoris and baculovirus infected insect cells expressed and secreted a fully processed, correctly refolded and fully active form of rCte f 1. Mass spectrometry analysis of the active forms of rCte f 1confirmed that eight intact disulfide bonds were present, matching the number observed in the native allergen. The relative ability of rCte f 1 to bind IgE in the serum of flea allergic animals, produced in these three expression systems, matched that of the native allergen. Competition ELISA demonstrated that

  6. Real-time PCR of the mammalian hydroxymethylbilane synthase (HMBS gene for analysis of flea (Ctenocephalides felis feeding patterns on dogs

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    Wang Chengming

    2012-01-01

    Full Text Available Abstract Background Precise data on quantitative kinetics of blood feeding of fleas, particularly immediately after contact with the host, are essential for understanding dynamics of flea-borne disease transmission and for evaluating flea control strategies. Standard methods used are inadequate for studies that simulate early events after real-life flea access to the host. Methods Here, we developed a novel quantitative polymerase chain reaction targeting mammalian DNA within fleas to quantify blood consumption with high sensitivity and specificity. We used primers and fluorescent probes that amplify the hydroxymethylbilane synthase (HMBS gene, an evolutionary divergent gene that is unlikely to be detected in insects by mammalian-specific primers and probes. To validate this assay, fleas were placed on dogs, allowed to distribute in the hair, and removed at specific time points with single-use combs. Fleas were then immediately homogenized by vigorous shaking with ceramic beads in guanidinium-based DNA preservation buffer for DNA extraction. Results The specificity of this assay was ascertained by amplification of canine, feline and equine blood with differential product melting temperatures (Tm, and lack of amplification of bovine and porcine blood and of adult fleas reared from larvae fed with bovine blood. Sensitivity of the assay was established by limiting dilution and detection of single copies of HMBS DNA equivalent to 0.043 nL blood. Application of the assay indicated that after 15 minutes on a dog, male and female fleas had ingested low, but similar amounts of approximately 1.1. nL blood. Saturation uptake of 118 and 100 nL blood per flea was found at 30 and 60 min on the dog, respectively. Conclusions The HMBS PCR method developed here offers the advantages of both exquisite sensitivity and specificity that make it superior to other approaches for quantification of blood ingested by fleas. The capability to detect minute quantities of

  7. Occurrence of Dipylidium caninum in fleas from client-owned cats and dogs in Europe using a new PCR detection assay.

    Science.gov (United States)

    Beugnet, Frédéric; Labuschagne, Michel; Fourie, Josephus; Jacques, Guillot; Farkas, Robert; Cozma, Vasile; Halos, Lénaïg; Hellmann, Klaus; Knaus, Martin; Rehbein, Steffen

    2014-09-15

    Ctenocephalides fleas are not only the most prevalent ectoparasites of dogs and cats but also the intermediate host of the cestode Dipylidium caninum. Due to the poor sensitivity of coproscopy to diagnose cat and dog infestation by Dipylidium, few epidemiological data are available on its prevalence among pet populations. A new PCR method was developed to specifically identify D. caninum rDNA inside single fleas. The PCR test was then applied to 5529 fleas of Ctenocephalides genus, 2701 Ctenocephalides felis fleas (1969 collected on 435 cats and 732 on 178 dogs) and 2828 Ctenocephalides canis fleas collected from 396 dogs. Precisely, 4.37% of cats were infested by a flea population infected with D. caninum. Out of the 1969 C. felis from cats, 2.23% were found to be infected with Dipylidium. From the 396 dogs infested with C. canis, 9.1%% were infested with the Dipylidium infected fleas, which is significantly higher than the observation made in cats (p=0.03). Moreover, 3.1% of the C. canis fleas were found to be infected with Dipylidium, which is not significantly different than in C. felis. Looking at the number of infected fleas in the positive samples (at least one PCR positive flea in a sample), the infestation rate in samples was varied from 3 to 100% with an average of 19.7% which is in favour of easy and regular Dipylidium reinfestations of both cats and dogs in households. For the first time, the spread of D. caninum between fleas and dogs and cats is confirmed throughout Europe. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Ectoparasites in urban stray cats in Jerusalem, Israel: differences in infestation patterns of fleas, ticks and permanent ectoparasites.

    Science.gov (United States)

    Salant, H; Mumcuoglu, K Y; Baneth, G

    2014-09-01

    In a period cross-sectional study performed to examine ectoparasites on 340 stray cats in Jerusalem, Israel, 186 (54.7%) were infested with the cat flea, Ctenocephalides felis (Siphonaptera: Pulicidae), 49 (14.4%) with the cat louse, Felicola subrostratus (Phthiraptera: Trichodectidae), 41 (12.0%) with the ear mite, Otodectes cynotis (Astigmata: Psoroptidae), three (0.9%) with the fur mite, Cheyletiella blakei (Trobidiformes: Cheyletidae), two (0.6%) with the itch mite Notoedres cati (Astigmata: Sarcoptidae), and 25 (7.3%) with ticks of the species Rhipicephalus sanguineus sensu lato (Ixodida: Ixodidae), Rhipicephalus turanicus or Haemaphysalis adleri (Ixodida: Ixodidae). A higher number of flea infestations was observed in apparently sick cats (P < 0.05) and in cats aged < 6 months (P < 0.05). The proportion of flea-infested cats (P < 0.01), as well as the number of fleas per infested cat (P < 0.01), was higher in autumn than in other seasons. By contrast with findings in cats with flea infestations, rates of infestation with ticks were higher amongst cats with clinical signs (P < 0.01) and cats aged ≥ 6 months (P < 0.05). The high rates of ectoparasite infestation in the cats studied constitute a risk for the spread of vector-borne infections of zoonotic and veterinary importance. © 2013 The Royal Entomological Society.

  9. Identification of the Rdl mutation in laboratory and field strains of the cat flea, Ctenocephalides felis (Siphonaptera: Pulicidae).

    Science.gov (United States)

    Bass, Chris; Schroeder, Iris; Turberg, Andreas; Field, Linda M; Williamson, Martin S

    2004-12-01

    In many insect species, resistance to cyclodiene insecticides is caused by amino acid substitutions at a single residue (A302) within the M2 transmembrane region of the gamma-aminobutyric acid (GABA) receptor sub-unit termed Rdl (resistance to dieldrin). These mutations (A302S and A302G) have also been shown to confer varying levels of cross-resistance to fipronil, a phenylpyrazole insecticide with a similar mode of action to cyclodienes. To investigate the possible occurrence of these mutations in the cat flea, Ctenocephalides felis (Bouché), a 176-bp fragment of the cat flea Rdl gene, encompassing the mutation site, was PCR amplified and sequenced from nine laboratory flea strains. The A302S mutation was found in eight of the nine strains analysed, although the relative frequency of the mutant allele varied between strains. Only one strain (R6) was found to be homozygous for the S302 allele in all the individuals tested, and this correlated with previous reports of low-level fipronil resistance in this strain. A PCR-based diagnostic assay, capable of screening individual fleas for this mutation, was developed and used to survey a range of fleas collected at random from veterinary clinics in the UK and USA. The A302S mutation was present at a high frequency in these domestic pet populations. 2004 Society of Chemical Industry.

  10. Preventive efficacy of NexGard Spectra® against Dipylidium caninum infection in dogs using a natural flea (Ctenocephalides felis) infestation model.

    Science.gov (United States)

    Beugnet, Frédéric; Meyer, Leon; Fourie, Josephus; Larsen, Diane

    2017-01-01

    The efficacy of a monthly oral endectocide product, NexGard Spectra ® (Merial), a combination of afoxolaner and milbemycin oxime, was evaluated in a flea (Ctenocephalides felis) challenge model for the prevention of Dipylidium caninum tapeworm infection in dogs. The efficacy of treatment with NexGard Spectra ® was assessed in 10 dogs following weekly flea infestation with metacestode naturally infected fleas and compared with that in 10 untreated control dogs. The 100 fleas deposited weekly on each dog were not removed until Day 35, allowing enough time for their ingestion. The microscopical analysis of 30 fleas from the flea batches before each weekly challenge demonstrated that 10-33% of the fleas were infected by D. caninum cysticercoid larvae. The arithmetic mean flea count recorded was 47.7 for the 10 untreated dogs and 0 for the 10 treated dogs at Day 35. Based on the daily collection of expelled D. caninum proglottids by dogs during the 70 days of the study, 70% (7/10) of the control dogs and 0% (0/10) of the treated dogs were infected with D. caninum (p caninum infestation. No treatment-related adverse events were observed in dogs during this study. © F. Beugnet et al., published by EDP Sciences, 2017.

  11. Flea abundance, diversity, and plague in Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in northern New Mexico

    Science.gov (United States)

    Megan M. Friggens; Robert R. Parmenter; Michael Boyden; Paulette L. Ford; Kenneth Gage; Paul Keim

    2010-01-01

    Plague, a flea-transmitted infectious disease caused by the bacterium Yersinia pestis, is a primary threat to the persistence of prairie dog populations (Cynomys spp.). We conducted a 3-yr survey (2004-2006) of fleas from Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in Valles Caldera National Preserve in New Mexico. Our...

  12. Absence of zoonotic Bartonella species in questing ticks: First detection of Bartonella clarridgeiae and Rickettsia felis in cat fleas in the Netherlands

    NARCIS (Netherlands)

    Tijsse-Klasen, E.; Fonville, M.; Gassner, F.; Nijhof, A.M.; Hovius, E.K.E.; Jongejan, F.; Takken, W.; Reimerink, J.R.; Overgaauw, P.A.M.; Sprong, H.

    2011-01-01

    Background: Awareness for flea-and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising. Bartonella henselae, the causative agent of Cat Scratch Disease, and other Bartonella species have been reported in fleas and ticks. The

  13. Absence of zoonotic Bartonella species in questing ticks: First detection of Bartonella clarridgeiae and Rickettsia felis in cat fleas in the Netherlands

    NARCIS (Netherlands)

    Tijsse-Klasen, E.; Fonville, M.; Gassner, F.; Nijhof, A.M.; Hovius, E.K.; Jongejan, F.; Takken, F.; Reimerink, J.R.; Overgaauw, P.A.M.; Sprong, H.

    2011-01-01

    BACKGROUND: Awareness for flea- and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising. Bartonella henselae, the causative agent of Cat Scratch Disease, and other Bartonella species have been reported in fleas and ticks. The

  14. Small todents fleas from the bubonic plague focus located in the Serra dos Órgãos Mountain Range, State of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Raimundo Wilson de Carvalho

    2001-07-01

    Full Text Available Eleven species of fleas were collected from 601 small rodents, from November 1995 to October 1997, in areas of natural focus of bubonic plague, including the municipalities of Nova Friburgo, Sumidouro and Teresópolis, State of Rio de Janeiro, Brazil. Among 924 fleas collected, Polygenis (Polygenis rimatus (Rhopalopsyllidae was the predominant species regarding the frequency, representing 41.3% (N:382, followed by P. (Neopolygenis pradoi, representing 20% (N:185 and Craneopsylla minervaminerva (Stephanocircidae, representing 18.9% (N:175. The host Akodon cursor harbored 47.9% of these fleas. Other six host species were infested by 52.1% of the remaining fleas. Fleas were found on hosts and in places within the focus not previously reported by the literature.

  15. Impact of planting dates and insecticide strategies for managing crucifer flea beetles (Coleoptera: Chrysomelidae) in spring-planted canola.

    Science.gov (United States)

    Knodel, Janet J; Olson, Denise L; Hanson, Bryan K; Henson, Robert A

    2008-06-01

    Integration of cultural practices, such as planting date with insecticide-based strategies, was investigated to determine best management strategy for flea beetles (Phyllotreta spp.) (Coleoptera: Chrysomelidae) in canola (Brassica napus L.). We studied the effect of two spring planting dates of B. napus and different insecticide-based management strategies on the feeding injury caused by fleabeetles in North Dakota during 2002-2003. Adult beetle peak emergence usually coincided with the emergence of the early planted canola, and this resulted in greater feeding injury in the early planted canola than later planted canola. Use of late-planted canola may have limited potential for cultural control of flea beetle, because late-planted canola is at risk for yield loss due to heat stress during flowering. Flea beetle injury ratings declined when 1) the high rate of insecticide seed treatment plus a foliar insecticide applied 21 d after planting was used, 2) the high rate of insecticide seed treatment only was used, or 3) two foliar insecticide sprays were applied. These insecticide strategies provided better protection than the low rates of insecticide seed treatments or a single foliar spray, especially in areas with moderate-to-high flea beetle populations. The foliar spray on top of the seed treatment controlled later-emerging flea beetles as the seed treatment residual was diminishing and the crop became vulnerable to feeding injury. The best insecticide strategy for management of flea beetle was the high rate of insecticide seed treatment plus a foliar insecticide applied at 21 d after planting, regardless of planting date.

  16. Tick-, Flea-, and Louse-Borne Diseases of Public Health and Veterinary Significance in Nigeria

    Directory of Open Access Journals (Sweden)

    Oluwaseun Oguntomole

    2018-01-01

    Full Text Available Mosquito-borne diseases are common high-impact diseases in tropical and subtropical areas. However, other non-mosquito vector-borne pathogens (VBPs may share their geographic distribution, seasonality, and clinical manifestations, thereby contributing their share to the morbidity and mortality caused by febrile illnesses in these regions. The purpose of this work was to collect and review existing information and identify knowledge gaps about tick, flea-, and louse-borne diseases of veterinary and public health significance in Nigeria. Full-length articles about VBPs were reviewed and relevant information about the vectors, their hosts, geographic distribution, seasonality, and association(s with human or veterinary diseases was extracted. Specific laboratory tools used for detection and identification of VBPs in Nigeria were also identified. A total of 62 original publications were examined. Substantial information about the prevalence and impacts of ticks and fleas on pet and service dogs (18 articles, and livestock animals (23 articles were available; however, information about their association with and potential for causing human illnesses was largely absent despite the zoonotic nature of many of these peri-domestic veterinary diseases. Recent publications that employed molecular methods of detection demonstrated the occurrence of several classic (Ehrlichia canis, Rickettsia africae, Bartonella sp. and emerging human pathogens (R. aeschlimannii, Neoehrlichia mikurensis in ticks and fleas. However, information about other pathogens often found in association with ticks (R. conorii and fleas (R. typhi, R. felis across the African continent was lacking. Records of louse-borne epidemic typhus in Nigeria date to 1947; however, its current status is not known. This review provides an essential baseline summary of the current knowledge in Nigeria of non-mosquito VBPs, and should stimulate improvements in the surveillance of the veterinary and

  17. Characterization of Spotted Fever Group Rickettsiae in Flea and Tick Specimens From Northern Peru

    Science.gov (United States)

    2004-11-01

    boliviensis 3 (18.7) 1 (6.2) Ixodes pararicinus 2 (12.5) 0 Flea speciesb Adoratopsilla intermedia 2 (3.4) 0 Ctenocephalides felis 33 (55.9) 2 (3.4...analysis of a genus-common rickettsial antigen gene. J. Bacteriol. 171:5199–5201. 3. Azad, A. F., S. Radulovic, J. A. Higgins , B. H. Noden, and J. M...Y. Acad. Sci. 990:57–61. 21. Hackstadt, T. 1996. The biology of rickettsiae. Infect. Agents Dis. 5:127–143. 22. Higgins , J. A., S. Radulovic, M. E

  18. Prophylactic treatment of flea-infested cats with an imidacloprid/flumethrin collar to forestall infection with Dipylidium caninum.

    Science.gov (United States)

    Fourie, Josephus J; Crafford, Dionne; Horak, Ivan G; Stanneck, Dorothee

    2012-07-27

    The objective of the study was to determine the sustained effectiveness of 10% imidacloprid (w/w) and 4.5% flumethrin (w/w) incorporated in a slow-release matrix collar in preventing Dipylidium caninum infection in cats following repeated laboratory-infestations with fleas infected with metacestodes. Efficacy against infection with D. caninum was evaluated by infesting 16 cats with the flea Ctenocephalides felis felis infected with metacestodes of the tapeworm. Medicated collars were fitted to 8 of the cats and infestation of each cat with 200 fleas from a suitably infected batch commenced 7 days later and continued at weekly intervals until Day 28. Efficacy against fleas was evaluated 24 h after each infestation. Infection of the cats with D. caninum was verified by daily examination of the cats' faeces and immediate surroundings for proglottids from Day 21 to Day 60. Calculation of the prophylactic effectiveness of the collars in preventing infection of the cats with D. caninum was based on the difference in the geometric mean number of scoleces recovered from the gastrointestinal tracts of collared compared to untreated cats at necropsy on Day 61. Efficacy of the collars against infestation of the cats with fleas was 99.9% on Day 7 and 100% at each subsequent weekly assessment. Infection of the fleas with metacestodes was ≥40% in 7 to 13 day old fleas, but progressively decreased thereafter. At necropsy all the control cats were infected with D. caninum and harboured between 19 and 346 scoleces with a geometric mean of 58.3. A single treated cat was infected and harboured 2 scoleces. Effective prevention of infection with D. caninum, based on a comparison of the geometric mean numbers of scoleces recovered from control and treated cats, was 99.7%. The insecticidal components of the medicated collars are capable of rapidly eliminating newly-acquired infestations of fleas that are infected with the metacestodes of D. caninum, thus preventing infection with the

  19. Prophylactic treatment of flea-infested cats with an imidacloprid/flumethrin collar to forestall infection with Dipylidium caninum

    Directory of Open Access Journals (Sweden)

    Fourie Josephus J

    2012-07-01

    Full Text Available Abstract Background The objective of the study was to determine the sustained effectiveness of 10% imidacloprid (w/w and 4.5% flumethrin (w/w incorporated in a slow-release matrix collar in preventing Dipylidium caninum infection in cats following repeated laboratory-infestations with fleas infected with metacestodes. Methods Efficacy against infection with D. caninum was evaluated by infesting 16 cats with the flea Ctenocephalides felis felis infected with metacestodes of the tapeworm. Medicated collars were fitted to 8 of the cats and infestation of each cat with 200 fleas from a suitably infected batch commenced 7 days later and continued at weekly intervals until Day 28. Efficacy against fleas was evaluated 24 h after each infestation. Infection of the cats with D. caninum was verified by daily examination of the cats’ faeces and immediate surroundings for proglottids from Day 21 to Day 60. Calculation of the prophylactic effectiveness of the collars in preventing infection of the cats with D. caninum was based on the difference in the geometric mean number of scoleces recovered from the gastrointestinal tracts of collared compared to untreated cats at necropsy on Day 61. Results Efficacy of the collars against infestation of the cats with fleas was 99.9% on Day 7 and 100% at each subsequent weekly assessment. Infection of the fleas with metacestodes was ≥40% in 7 to 13 day old fleas, but progressively decreased thereafter. At necropsy all the control cats were infected with D. caninum and harboured between 19 and 346 scoleces with a geometric mean of 58.3. A single treated cat was infected and harboured 2 scoleces. Effective prevention of infection with D. caninum, based on a comparison of the geometric mean numbers of scoleces recovered from control and treated cats, was 99.7%. Conclusion The insecticidal components of the medicated collars are capable of rapidly eliminating newly-acquired infestations of fleas that are infected

  20. SURVEILLANCE OF SEAPORT RODENTS AND ITS FLEA-INDICES IN CILACAP, CENTRAL JAVA AND PANJANG, SUMATERA, INDONESIA

    Directory of Open Access Journals (Sweden)

    K. C. Megawe

    2012-09-01

    Full Text Available Suatu survai terhadap tikus dan pinjal telah diselenggarakan di daerah pelabuhan Cilacap dan Panjang, pada November 1985 sampai Maret 1986. Dalam survai itu diidentifikasi empat spesies tikus, yaitu Rattus r. diardii, R. norregicus, Bandicota indica, dan Mus musculus, serta seekor insektivora, Suncus murinus. Kepadatan polusi binatang-binatang ini rendah di dalam pelabuhan dan sedang di perkampungan sekitarnya. R.r. diardii terbukti merupakan tikus yang terbanyak dijumpai baik di pelabuhan maupun di perkampungan sekitar. Kepadatan Xenopsylla cheopis ternyata rendah baik pada tikus-tikus maupun insektivora di kedua daerah pelabuhan. Indeks pinjal spesifik tertinggi didapatkan pada R.r. diardii. Tes kerentanan X. cheopis terhadap insektisida dengan menggunakan DDT 4%, melathion 0,5% dan fenit rothion 1% menunjukkan bahwa pinjal itu lebih sensitif terhadap melathion dan fenitrothion dibanding terhadap DDT, di kedua daerah pelabuhan.

  1. Evaluation of sarolaner and spinosad oral treatments to eliminate fleas, reduce dermatologic lesions and minimize pruritus in naturally infested dogs in west Central Florida, USA.

    Science.gov (United States)

    Dryden, Michael W; Canfield, Michael S; Niedfeldt, Emily; Kinnon, Amanda; Kalosy, Kimberly; Smith, Amber; Foley, Kaitlin M; Smith, Vicki; Bress, Todd S; Smith, Nicole; Endrizzi, Mike; Login, Joyce

    2017-08-17

    An in-home investigation of naturally flea infested dogs was conducted in West Central Florida, USA to evaluate and compare the effectiveness of two different oral flea adulticides to control flea infestations, minimize dermatologic lesions and reduce pruritus over an 8-week period. Twenty-nine dogs living in 19 homes and another 26 dogs residing in 16 different homes were orally administered either a sarolaner or spinosad chewable, respectively on day 0 and once between days 28-30. Products were administered by study personnel according to label directions. Flea populations on dogs were estimated using visual area counts and flea infestations in the indoor premises were assessed using intermittent-light flea traps on days 0, 7, 14, 21 and once between days 28-30, 40-45, and 56-60. Assessments of dermatologic lesions were conducted monthly during the study and severity of pruritus was evaluated throughout the study on the same schedule as flea counts were conducted. Concurrent treatments for existing skin disease were not allowed. The administration of sarolaner or spinosad reduced flea populations on dogs by 99.0% and 97.3%, respectively within 7 days. Flea infestations on the sarolaner- and spinosad-treated dogs were reduced by > 99% at every counting period from day 14 post-treatment through the end of the 8-week study. At the end of the study 96.4 and 92.0% of the dogs treated with sarolaner and spinosad, respectively were flea-free. Flea populations in the indoor premises were also markedly reduced the end of the study, with 100 and 99.8% reductions in flea trap counts in the sarolaner and spinosad treatment groups, respectively. FAD lesion scores, atopic dermatitis lesions scores (CADESI-4) and pruritus severity scores were also markedly improved with both formulations. An in-home clinical field study conducted during the summer of 2016 in subtropical Florida demonstrated that two-monthly administrations of either sarolaner or spinosad chewables almost

  2. Evaluation of the speed of kill, effects on reproduction, and effectiveness in a simulated infested-home environment of sarolaner (Simparica™) against fleas on dogs.

    Science.gov (United States)

    Six, Robert H; Becskei, Csilla; Carter, Lori; Gale, Boyd; Young, David R; Mahabir, Sean P; Chapin, Sara; Myers, Melanie R

    2016-05-30

    Four studies were conducted to evaluate the speed of kill, effect on egg production, and efficacy in a simulated infested-home environment of a novel isoxazoline, sarolaner (Simparica™, Zoetis), against fleas on dogs. Individually identified and housed, purpose-bred Beagles were used in each study and were allocated randomly to groups based on pretreatment parasite counts. In two speed of kill studies, groups of dogs infested with 100 fleas prior to treatment were treated orally with placebo or sarolaner tablets providing the minimum dose of 2mg/kg and then re-infested with fleas weekly for five weeks post-treatment. Comb counts were conducted to determine the numbers of viable fleas at one to three, four, eight and 12h after treatment and each subsequent infestation. In the egg production study, sarolaner- and placebo-treated dogs were similarly challenged with fleas and at 48h after each infestation the dogs were housed for 20h in cages allowing the collection and counting of all flea eggs produced during this period. Collected eggs were incubated to evaluate hatch and development to adults. The last study used dogs housed in a flea-infested simulated-home environment. Dogs were allocated to treatment with either placebo or sarolaner tablets providing a dose of 2mg/kg once a month for three treatments. Flea infestations were assessed by comb counts (fleas were replaced on the dogs) on Days 14, 30, 44, 60, 74 and 90. The speed of kill studies demonstrated that a single 2mg/kg oral dose of sarolaner started killing fleas within three to four hours after treatment or subsequent re-infestations for up to a month, and achieved ≥98% control of fleas by eight hours after treatment or re-infestation for 28 days. In the study to assess effects on flea reproduction, a single oral treatment of sarolaner resulted in the complete cessation of egg-laying for 35 days. This rapid kill of fleas and inhibition of reproduction were confirmed in a simulated-home environment

  3. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  4. Stevesaltica, a new genus of moss and leaf-litter inhabiting flea beetles from Bolivia (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

    Science.gov (United States)

    A new genus (Stevesaltica) with two new species (S. normi and S. perdita) from Bolivia is described and illustrated. It is similar to Exoceras Jacoby. An identification key for all flea beetle genera known to occur in mosses in the Western Hemisphere is provided....

  5. SEASON OF DELTAMETHRIN APPLICATION AFFECTS FLEA AND PLAGUE CONTROL IN WHITE-TAILED PRAIRIE DOG (CYNOMYS LEUCURUS) COLONIES, COLORADO, USA.

    Science.gov (United States)

    Tripp, Daniel W; Streich, Sean P; Sack, Danielle A; Martin, Daniel J; Griffin, Karen A; Miller, Michael W

    2016-07-01

    In 2008 and 2009, we evaluated the duration of prophylactic deltamethrin treatments in white-tailed prairie dog ( Cynomys leucurus ) colonies and compared effects of autumn or spring dust application in suppressing flea numbers and plague. Plague occurred before and during our experiment. Overall, flea abundance tended to increase from May or June to September, but it was affected by deltamethrin treatment and plague dynamics. Success in trapping prairie dogs (animals caught/trap days) declined between June and September at all study sites. However, by September trap success on dusted sites (19%; 95% confidence interval [CI] 16-22%) was about 15-fold greater than on undusted control sites (1%; CI 0.3-4%; P≤0.0001). Applying deltamethrin dust as early as 12 mo prior seemed to afford some protection to prairie dogs. Our data showed that dusting even a portion of a prairie dog colony can prolong its persistence despite epizootic plague. Autumn dusting may offer advantages over spring in suppressing overwinter or early-spring flea activity, but timing should be adjusted to precede the annual decline in aboveground activity for hibernating prairie dog species. Large colony complexes or collections of occupied but fragmented habitat may benefit from dusting some sites in spring and others in autumn to maximize flea suppression in a portion of the complex or habitat year-round.

  6. Invertebrates of The H.J. Andrews Experimental Forest, Western Cascades, Oregon: I. An annotated checklist of fleas.

    Science.gov (United States)

    Robert E. Lewis; Chris Maser

    1981-01-01

    During a trapping survey of small mammals (approximately 3,000 individuals), species of fleas (1,632 specimens) were collected in the H.J. Andrews Experimental Forest, Western Cascades, Oregon. Host mammals were represented by 15 species—6 insectivores and 9 rodents captured from June through September. The collections extend our knowledge of the fauna of Oregon.

  7. Integrated control of ticks and fleas on dogs with particular reference to the prevention of vector-borne diseases

    NARCIS (Netherlands)

    Fourie, J.J.

    2015-01-01

    Because dogs are such loved companion animals, their health and wellbeing is of great importance to their human companions. Moreover, controlling ticks and fleas on dogs is also important in respect of the zoonotic risk that some of these parasites pose to their human companions. Numerous products

  8. AFLP markers for the R-gene in the flea beetle, Phyllotreta nemorum, conferring resistance to defenses in Barbarea vulgaris

    NARCIS (Netherlands)

    Breuker, C.J.; Victoir, K.; Jong, de P.W.; Meijden, van der E.; Brakefield, P.M.; Vrieling, K.

    2005-01-01

    A so-called R-gene renders the yellow-striped flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) resistant to the defenses of the yellow rocket Barbarea vulgaris R.Br. (Brassicacea) and enables it to use it as a host plant in Denmark. In this study, genetic markers for an

  9. Survival of cabbage stem flea beetle larvae, Psylliodes chrysocephala, exposed to low temperatures

    DEFF Research Database (Denmark)

    Mathiasen, Helle; Bligaard, J.; Esbjerg, Peter

    2015-01-01

    The cabbage stem flea beetle, Psylliodes chrysocephala (L.) (Coleoptera: Chrysomelidae), is a major pest of winter oilseed rape. The larvae live throughout winter in leaf petioles and stems. Winter temperatures might play an important role in survival during winter and hence population dynamics, ...

  10. Effect of temperature on reproduction and embryonic development of the cabbage stem flea beetle, Psylliodes chrysocephala L., (Coleoptera: Chrysomelidae)

    DEFF Research Database (Denmark)

    Mathiasen, Helle; Sørensen, Helle; Bligaard, J.

    2015-01-01

    The cabbage stem flea beetle, Psylliodes chrysocephala (L.) (Coleoptera: Chrysomelidae), is a major pest of winter oilseed rape. Despite the importance of this pest, detailed information on reproduction to predict risk of crop damage is lacking. This study investigates the effect of temperature...

  11. PREDICTORS OF TRYPANOSOMA LEWISI IN RATTUS NORVEGICUS FROM DURBAN, SOUTH AFRICA.

    Science.gov (United States)

    Archer, Colleen Edith; Schoeman, M Corrie; Appleton, Christopher Charles; Mukaratirwa, Samson; Hope, Karen J; Matthews, Glenda Beverly

    2018-03-16

    This study investigated associations between Trypanosoma lewisi; Xenopsylla cheopis, a common cyclical vector of T. lewisi; Polyplax spinulosa, a reported mechanical vector; and Laelaps ecidnina and L. lamborni, two rodent mites of Rattus norvegicus in Durban. Three hundred and seventy nine R. norvegicus were live-trapped at 48 sites in 4 locality types of Durban during a one year period. Rats were euthanized, cardiac blood was taken to check for hemoparasites and ectoparasites were removed for identification. Parasite species richness was higher in pups (2.11) and juveniles (1.02) than adults (0.87). Most rats in the study harbored 1 or 2 of the 5 parasites examined. Rats with trypanosomes and fleas were more prevalent in the city center and harbor, and juveniles were most affected. Rats with lice were more prevalent in informal settlements and urban/peri-urban areas and pups had the highest infestations. There was a significant positive association between rats with fleas and trypanosomes and a negative association between rats with lice and trypanosomes. Location and rat age were significant predictors of T. lewisi, X. cheopis and P. spinulosa. Mites showed no strong associations with trypanosomes. Ectoparasite associations are possibly habitat and life-cycle related. We conclude that Durban's city center, which offers rats harborage, an unsanitary environment and availability of food, is a high transmission area for fleas and trypanosomes, and consequently, a potential public health risk.

  12. Efficacy and safety of sarolaner (Simparica™) against fleas on dogs presented as veterinary patients in the United States.

    Science.gov (United States)

    Cherni, Judith A; Mahabir, Sean P; Six, Robert H

    2016-05-30

    The efficacy and safety of a novel isoxazoline parasiticide, sarolaner (Simparica™), for the control of fleas on dogs was evaluated in a randomized, controlled clinical study conducted in 19 general veterinary practices throughout the United States. Four hundred and seventy nine (479) dogs from 293 households were enrolled. Each household was randomly assigned to treatment with either sarolaner oral tablets (Simparica™, Zoetis) at the proposed label dose or an approved comparator product at the label dose (spinosad, Comfortis(®), Elanco). Dogs were dosed by their owners at home on Day 0 and on approximately Days 30 and 60. Dogs were examined at the clinics for general health, flea and tick infestation, and clinical signs of flea allergy dermatitis (FAD) at the initial visit and Days 14, 30, 60 and 90. Blood was collected for clinical pathology at screening and Day 90. Sarolaner was well-accepted by dogs with the majority of flavored chewable tablets (91.5%) accepted free choice, by hand or in food. Geometric mean live flea counts were reduced by >99% at the first time measured (14 days) after initiation of treatment and continued to reduce through the study. Treatment success (proportion of dogs with ≥90% reduction in fleas) for the sarolaner-treated dogs was superior to that for spinosad-treated dogs at Days 14 and 30 and non-inferior on Days 60 and 90 (P≤0.025) The rapid reduction in flea infestations resulted in a similar rapid resolution of the clinical signs associated with FAD. Sarolaner chewable tablets were well tolerated with no treatment related adverse reactions. Most of the clinical signs reported were consistent with allergies and dermatitis or sporadic occurrences of conditions commonly observed in the general dog population. A wide variety of concomitant medications, including many commercially available heartworm preventatives and other anthelmintic drugs, were administered to study dogs and all were well tolerated. Sarolaner administered

  13. SPESIES TIKUS, CECURUT DAN PINJAL YANG DITEMUKAN DI PASAR KOTA BANJARNEGARA, KABUPATEN BANJARNEGARA TAHUN 2013

    Directory of Open Access Journals (Sweden)

    Dina Supriyati

    2014-01-01

    Full Text Available ABSTRACTRats harm to human life, both in terms of economics and health. Rats transmitted disease, ectoparasites andendoparasites. Many potential sites where rat found in high enough quantities, one of those sites is a traditionalmarket. The purpose of this study was to know the presence of rats and fleas in the market town Banjarnegara,Banjarnegara District. This research is a descriptive study using survey methods. Research design using crosssectionalapproach. Rats data obtained by trapping rats using a live trap. Population was rats living in marketsBanjarnegara, Banjarnegara. The sample was rats that were caught using bait traps roasted coconut andcucumber. The collected data were analyzed descriptively. Result showed that 33 rats had been caught during thestudy. The most abundant species was Rattus tanezumi (84.85%, while the least is Rattus norvegicus (3.03%. Asmuch 20 (60.61% were male higger than female rat as much as 13 rats (39.39%. Rats in the market stalls(77,42% greater than the outside market stall (22,58%. The trap succes were 8.25% with the successful captureof the highest rats on day 2 (4.5%. While the success of trapping rats (trap success based on the location of thearrest shows that in the market stalls (6.5% greater than the outside market stall (1.75%. Number of fleas thatinfest species caught as many as 67 tails. Species of fleas that infest rats identified as Xenopsylla cheopis. Commonflea index as much 2,03 upper than standard. Control of rats and fleas (Xenopsylla cheopis was needed.Key words: trap success, rats, fleasABSTRAKTikus merugikan bagi kehidupan manusia, baik dari sisi ekonomi maupun kesehatan. Tikus membawa kumanpenyakit, ektoparasit dan endoparasit. Pasar tradisional merupakan tempat potensial ditemukan tikus dalamjumlah cukup tinggi. Tujuan penelitian untuk mengetahui keberadaan tikus, cecurut dan ektoparasit pinjal diPasar Kota Banjarnegara, Kabupaten Banjarnegara. Penelitian deskriptif dengan metode survei

  14. Repellency Effect of Essential Oils of Some Native Plants and Synthetic Repellents against Human Flea, Pulex irritans (Siphonaptera: Pulicidae

    Directory of Open Access Journals (Sweden)

    Mohammad Bagher Ghavami

    2017-04-01

    Full Text Available Background: Fleas are important vectors of human and animal disease, and control measures for protection against their bites and flea-borne diseases are necessary.Methods: The essential oils (EOs of four native medicinal plants, Ziziphora tenuiore, Myrtus communis, Achillea wilhelmsii and Mentha piperita were isolated by hydrodistillation technique and analyzed by GC-MC. The repellent activity of EOs and synthetic compounds, DEET and permethrin, were assayed on human subjects against field col­lected fleas. The effective doses of 50% and 90% of EOs and synthetic compounds were estimated by probit analysis of dose and response regression line.Results: Analysis of EOs revealed about 19 major components. All oils were found to be more repellent (ED50 range= 208–955µg cm-2 than DEET and permethrin (ED50 range= 27–182 x 103 µg cm-2. Thyme and myrtle oils showed high repellent activities and among the total detected terpenes, thymol (36.26% and α- pinene (32.5% were the major components of those oils respectively.Conclusion: Low repellent potency of DEET and permethrin against fleas might be related to flea olfactory system and further molecular and electrophysiological studies are required to conceive new ideas for the discovery and de­velopment of the next generation of repellents. Based on high repellent activity of thyme and myrtle essential oils against Pulex irritans further studies should be staged to develop their appropriate effective formulations. Likewise, field trials should be carried out to evaluate the operational feasibility and dermal toxicity over a long period.

  15. Grooming behaviors of black-tailed prairie dogs are influenced by flea parasitism, conspecifics, and proximity to refuge

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.; Eads, Samantha L.

    2017-01-01

    Grooming is a common animal behavior that aids in ectoparasite defense. Ectoparasites can stimulate grooming, and natural selection can also favor endogenous mechanisms that evoke periodic bouts of “programmed” grooming to dislodge or kill ectoparasites before they bite or feed. Moreover, grooming can function as a displacement or communication behavior. We compared the grooming behaviors of adult female black-tailed prairie dogs (Cynomys ludovicianus) on colonies with or without flea control via pulicide dust. Roughly 91% of the prairie dogs sampled on the non-dusted colony carried at least one flea, whereas we did not find fleas on two dusted colonies. During focal observations, prairie dogs on the non-dusted colony groomed at higher frequencies and for longer durations than prairie dogs on the dusted colonies, lending support to the hypothesis that fleas stimulated grooming. However, the reduced amount of time spent grooming on the dusted colonies suggested that approximately 25% of grooming might be attributed to factors other than direct stimulation from ectoparasites. Non-dusted colony prairie dogs rarely autogroomed when near each other. Dusted colony prairie dogs autogroomed for shorter durations when far from a burrow opening (refuge), suggesting a trade-off between self-grooming and antipredator defense. Allogrooming was detected only on the non-dusted colony and was limited to adult females grooming young pups. Grooming appears to serve an antiparasitic function in C. ludovicianus. Antiparasitic grooming might aid in defense against fleas that transmit the plague bacterium Yersinia pestis. Plague was introduced to North America ca. 1900 and now has a strong influence on most prairie dog populations, suggesting a magnified effect of grooming on prairie dog fitness.

  16. Myxomatosis: passive immunity in the offspring of immune rabbits (Oryctolagus cuniculus) infested with fleas (Spilopsyllus cuniculi Dale) and exposed to myxoma virus.

    Science.gov (United States)

    Sobey, W R; Conolly, D

    1975-02-01

    Kittens with maternal antibodies to myxoma virus, the offspring of rabbits which had recovered from myxomatosis, were exposed to fleas contaminated with myxoma virus and/or contact with infected rabbits from birth. All kittens died or became infected before 8 weeks of age. When compared with adult animals similarly infected the kittens showed no advantage in terms of survival time or recovery rate attributable to maternal antibodies. Flea transmission of virus was found more effective than contact transmissions.

  17. A LysR-Type Transcriptional Regulator, RovM, Senses Nutritional Cues Suggesting that It Is Involved in Metabolic Adaptation of Yersinia pestis to the Flea Gut.

    Directory of Open Access Journals (Sweden)

    Viveka Vadyvaloo

    Full Text Available Yersinia pestis has evolved as a clonal variant of Yersinia pseudotuberculosis to cause flea-borne biofilm-mediated transmission of the bubonic plague. The LysR-type transcriptional regulator, RovM, is highly induced only during Y. pestis infection of the flea host. RovM homologs in other pathogens regulate biofilm formation, nutrient sensing, and virulence; including in Y. pseudotuberculosis, where RovM represses the major virulence factor, RovA. Here the role that RovM plays during flea infection was investigated using a Y. pestis KIM6+ strain deleted of rovM, ΔrovM. The ΔrovM mutant strain was not affected in characteristic biofilm gut blockage, growth, or survival during single infection of fleas. Nonetheless, during a co-infection of fleas, the ΔrovM mutant exhibited a significant competitive fitness defect relative to the wild type strain. This competitive fitness defect was restored as a fitness advantage relative to the wild type in a ΔrovM mutant complemented in trans to over-express rovM. Consistent with this, Y. pestis strains, producing elevated transcriptional levels of rovM, displayed higher growth rates, and differential ability to form biofilm in response to specific nutrients in comparison to the wild type. In addition, we demonstrated that rovA was not repressed by RovM in fleas, but that elevated transcriptional levels of rovM in vitro correlated with repression of rovA under specific nutritional conditions. Collectively, these findings suggest that RovM likely senses specific nutrient cues in the flea gut environment, and accordingly directs metabolic adaptation to enhance flea gut colonization by Y. pestis.

  18. Absence of zoonotic Bartonella species in questing ticks: First detection of Bartonella clarridgeiae and Rickettsia felis in cat fleas in the Netherlands

    Directory of Open Access Journals (Sweden)

    Reimerink Johan R

    2011-04-01

    Full Text Available Abstract Background Awareness for flea- and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising. Bartonella henselae, the causative agent of Cat Scratch Disease, and other Bartonella species have been reported in fleas and ticks. The role of Ixodes ricinus ticks in the natural cycle of Bartonella spp. and the transmission of these bacteria to humans is unclear. Rickettsia spp. have also been reported from as well ticks as also from fleas. However, to date no flea-borne Rickettsia spp. were reported from the Netherlands. Here, the presence of Bartonellaceae and Rickettsiae in ectoparasites was investigated using molecular detection and identification on part of the gltA- and 16S rRNA-genes. Results The zoonotic Bartonella clarridgeiae and Rickettsia felis were detected for the first time in Dutch cat fleas. B. henselae was found in cat fleas and B. schoenbuchensis in ticks and keds feeding on deer. Two Bartonella species, previously identified in rodents, were found in wild mice and their fleas. However, none of these microorganisms were found in 1719 questing Ixodes ricinus ticks. Notably, the gltA gene amplified from DNA lysates of approximately 10% of the questing nymph and adult ticks was similar to that of an uncultured Bartonella-related species found in other hard tick species. The gltA gene of this Bartonella-related species was also detected in questing larvae for which a 16S rRNA gene PCR also tested positive for "Candidatus Midichloria mitochondrii". The gltA-gene of the Bartonella-related species found in I. ricinus may therefore be from this endosymbiont. Conclusions We conclude that the risk of acquiring Cat Scratch Disease or a related bartonellosis from questing ticks in the Netherlands is negligible. On the other hand fleas and deer keds are probable vectors for associated Bartonella species between animals and might also transmit Bartonella spp. to humans.

  19. ectoparasites of the bush cep.a.pi, in the transvaal (rodentia: sciuridae)

    African Journals Online (AJOL)

    plague in Mrica and in some places it is probably the main vector. An additional record of the flea,. Xenopsylla sp., was also recorded from Naboom- spruit (July). The cat flea, CtenocepluJlidesfelis, is widespread over Mrica on Canidae, Felidae, Viver- ridae, Hyaenidae and Leporidae as well as on domestic animals and ...

  20. Flea (Ctenocephalides felis) control efficacy of topical indoxacarb on dogs subsequently bathed with a chlorhexidine-ketoconazole shampoo.

    Science.gov (United States)

    Armstrong, R D; Liebenberg, J E; Heaney, K; Guerino, F

    2015-08-01

    An evaluation of the effect of chlorhexidine/ketoconazole shampoo baths on the flea control efficacy of indoxacarb applied topically to dogs. We randomly allocated 18 healthy mixed-breed dogs to 3 groups: shampoo only; indoxacarb treated and medicated shampoo; and indoxacarb treated but not shampooed. Indoxacarb was administered on day 0 and dogs were shampooed on days 9 and 23. Dogs were infested with 100 adult Ctenocephalides felis initially 2 days before treatment and then weekly from days 7 to 28. Fleas were removed and counted 48 h post-infestation. Medicated shampoo use did not significantly reduce indoxacarb efficacy against C. felis. © 2015 MSD Animal Health. Australian Veterinary Journal published by Wiley Publishing Asia Pty Ltd on behalf of Australian Veterinary Association.

  1. Flea (Ctenocephalides felis) control efficacy of topical indoxacarb on dogs subsequently bathed with a chlorhexidine–ketoconazole shampoo

    Science.gov (United States)

    Liebenberg, JE; Heaney, K; Guerino, F

    2015-01-01

    Objective An evaluation of the effect of chlorhexidine/ketoconazole shampoo baths on the flea control efficacy of indoxacarb applied topically to dogs. Methods and Results We randomly allocated 18 healthy mixed‐breed dogs to 3 groups: shampoo only; indoxacarb treated and medicated shampoo; and indoxacarb treated but not shampooed. Indoxacarb was administered on day 0 and dogs were shampooed on days 9 and 23. Dogs were infested with 100 adult Ctenocephalides felis initially 2 days before treatment and then weekly from days 7 to 28. Fleas were removed and counted 48 h post‐infestation. Conclusion Medicated shampoo use did not significantly reduce indoxacarb efficacy against C. felis. PMID:26220323

  2. Viral haemorrhagic septicaemia virus (VHSV) remains viable for several days but at low levels in the water flea Moina macrocopa

    DEFF Research Database (Denmark)

    Ito, Takafumi; Olesen, Niels Jørgen

    2017-01-01

    in the water flea Moina macrocopa. VHSV was re-isolated from replicate groups of M. macrocopa that had been immersed with 108.0, 107.0, and 105.0 TCID50 ml-1 of VHSV (DK-3592B, Genotype Ia). Furthermore, 40 M. macrocopa that had been immersed with 108.0 TCID50 ml-1 of VHSV for 72 h had VHSV titers of 102...

  3. Prophylactic treatment of flea-infested dogs with an imidacloprid / flumethrin collar (Seresto®, Bayer) to preempt infection with Dipylidium caninum.

    Science.gov (United States)

    Fourie, Josephus J; Crafford, Dionne; Horak, Ivan G; Stanneck, Dorothee

    2013-08-01

    The objective of the study was to determine the sustained effectiveness of 10 % imidacloprid and 4.5 % flumethrin, incorporated in a slow-release matrix collar, in preventing Dipylidium caninum infection in dogs after repeated laboratory infestations with fleas infected with metacestodes of this tapeworm. Efficacy against infection with D. caninum was evaluated by infesting 16 dogs with cat fleas (Ctenocephalides felis) on study days 7, 14, 21, 28, 35 and 42, from batches suitably infected with D. caninum metacestodes. Prior to each post-treatment infestation the D. caninum infection rate for the fleas was determined by microscopically examining 100 fleas for D. caninum metacestodes. The D. caninum prevalence in the fleas used for infestations ranged from 23 % to 52 %. Medicated collars were fitted to 8 of the dogs on study day 0. The weight of the IVP collars varied between 35.48 g and 38.48 g (average 37.16 g), whilst animal weight varied between 12.20 kg and 17.98 kg (treated group, n = 8, average 14.79 kg). Seven days later infestation of each of the 16 dogs with 250 fleas commenced. Infestations continued at weekly intervals until Day 42 with efficacy against fleas evaluated 24 hours after each infestation. From Days 21 to 74, infection of the dogs with D. caninum was verified (daily examination of faeces and cages for the presence of expelled proglottids). Calculation of prophylactic effectiveness of the collars in preventing infection with D. caninum was based on the difference in geometric mean numbers of scoleces between groups at necropsy on Day 75. Effective prevention of infection with D. caninum was found to be 96.6 %. Efficacy of the collars against fleas was ≥ 99.9 % for the duration of the assessment period. Newly acquired infestations of fleas are rapidly eliminated by the insecticidal components of the medicated collars over a period of several months. In the event of fleas being infected with metacestodes, with D. caninum can be prevented in

  4. Preventive efficacy of Frontline® Combo and Certifect® against Dipylidium caninum infestation of cats and dogs using a natural flea (Ctenocephalides felis infestation model

    Directory of Open Access Journals (Sweden)

    Beugnet Frederic

    2013-01-01

    Full Text Available Two studies were performed to evaluate the effectiveness of two monthly topical anti-flea products for the prevention of Dipylidium caninum infestations in cats and dogs. A single treatment with Frontline® Combo spot-on for cats (fipronil-(S-methoprene and two successive monthly treatments of Certifect® for dogs (fipronil-amitraz-(S-methoprene were assessed for the prevention of D. caninum infestations following weekly challenges of treated cats or dogs with metacestode naturally-infected fleas. The rate of infestations using the model in cats versus dogs explains the choice of a 1-month trial in cats and a 2-month trial in dogs. The experimental flea-infection model resulted in a range of 22–53% of the fleas being infected by Dipylidium cysticercoids. The arithmetic mean flea counts recorded for the untreated cats ranged from 51.2 to 68. The geometric mean flea counts recorded for the Frontline Combo treated cats differed significantly (p < 0.05 from those of the untreated control cats on all assessment days. The arithmetic mean flea counts recorded for the untreated dogs ranged from 166.6 to 238.6. The geometric mean flea counts recorded for the Certifect treated dogs differed significantly (p < 0.001 from those of the untreated group on all assessment days. Frontline Combo treatment on cats provided ≥99.8% persistent anti-flea efficacy throughout the 30-day treatment period. In the dog study, the two Certifect treatments provided ≥97% persistent efficacy throughout the 60-day study. Based on the collection of expelled D. caninum proglottids by cats, 100% (6/6 of the control cats and 0% (0/6 of Frontline Combo treated cats were infested with D. caninum. Frontline Combo spot-on for cats was therefore 100% effective in preventing infection with D. caninum. In dogs, 7 out of the 8 control group dogs (87.5% produced proglottids following infestation of infected fleas, whereas 0 out of 8 dogs (0% in the treated group were infected. The

  5. Silencing urease: a key evolutionary step that facilitated the adaptation of Yersinia pestis to the flea-borne transmission route.

    Science.gov (United States)

    Chouikha, Iman; Hinnebusch, B Joseph

    2014-12-30

    The arthropod-borne transmission route of Yersinia pestis, the bacterial agent of plague, is a recent evolutionary adaptation. Yersinia pseudotuberculosis, the closely related food-and water-borne enteric species from which Y. pestis diverged less than 6,400 y ago, exhibits significant oral toxicity to the flea vectors of plague, whereas Y. pestis does not. In this study, we identify the Yersinia urease enzyme as the responsible oral toxin. All Y. pestis strains, including those phylogenetically closest to the Y. pseudotuberculosis progenitor, contain a mutated ureD allele that eliminated urease activity. Restoration of a functional ureD was sufficient to make Y. pestis orally toxic to fleas. Conversely, deletion of the urease operon in Y. pseudotuberculosis rendered it nontoxic. Enzymatic activity was required for toxicity. Because urease-related mortality eliminates 30-40% of infective flea vectors, ureD mutation early in the evolution of Y. pestis was likely subject to strong positive selection because it significantly increased transmission potential.

  6. Silencing urease: A key evolutionary step that facilitated the adaptation of Yersinia pestis to the flea-borne transmission route

    Science.gov (United States)

    Chouikha, Iman; Hinnebusch, B. Joseph

    2014-01-01

    The arthropod-borne transmission route of Yersinia pestis, the bacterial agent of plague, is a recent evolutionary adaptation. Yersinia pseudotuberculosis, the closely related food-and water-borne enteric species from which Y. pestis diverged less than 6,400 y ago, exhibits significant oral toxicity to the flea vectors of plague, whereas Y. pestis does not. In this study, we identify the Yersinia urease enzyme as the responsible oral toxin. All Y. pestis strains, including those phylogenetically closest to the Y. pseudotuberculosis progenitor, contain a mutated ureD allele that eliminated urease activity. Restoration of a functional ureD was sufficient to make Y. pestis orally toxic to fleas. Conversely, deletion of the urease operon in Y. pseudotuberculosis rendered it nontoxic. Enzymatic activity was required for toxicity. Because urease-related mortality eliminates 30–40% of infective flea vectors, ureD mutation early in the evolution of Y. pestis was likely subject to strong positive selection because it significantly increased transmission potential. PMID:25453069

  7. Preventive efficacy of Frontline® Combo and Certifect® against Dipylidium caninum infestation of cats and dogs using a natural flea (Ctenocephalides felis) infestation model.

    Science.gov (United States)

    Beugnet, Frederic; Delport, Peet; Luus, Hermann; Crafford, Dione; Fourie, Josephus

    2013-01-01

    Two studies were performed to evaluate the effectiveness of two monthly topical anti-flea products for the prevention of Dipylidium caninum infestations in cats and dogs. A single treatment with Frontline(®) Combo spot-on for cats (fipronil-(S)-methoprene) and two successive monthly treatments of Certifect(®) for dogs (fipronil-amitraz-(S)-methoprene) were assessed for the prevention of D. caninum infestations following weekly challenges of treated cats or dogs with metacestode naturally-infected fleas. The rate of infestations using the model in cats versus dogs explains the choice of a 1-month trial in cats and a 2-month trial in dogs. The experimental flea-infection model resulted in a range of 22-53% of the fleas being infected by Dipylidium cysticercoids. The arithmetic mean flea counts recorded for the untreated cats ranged from 51.2 to 68. The geometric mean flea counts recorded for the Frontline Combo treated cats differed significantly (p caninum proglottids by cats, 100% (6/6) of the control cats and 0% (0/6) of Frontline Combo treated cats were infested with D. caninum. Frontline Combo spot-on for cats was therefore 100% effective in preventing infection with D. caninum. In dogs, 7 out of the 8 control group dogs (87.5%) produced proglottids following infestation of infected fleas, whereas 0 out of 8 dogs (0%) in the treated group were infected. The infection rates of the two groups were significantly different. The percent effectiveness for the Certifect treatment group for the prevention of D. caninum infection was 100% during this 2-month trial. No treatment-related adverse events were observed in either cats or dogs during these studies. © F. Beugnet et al., Published by EDP Sciences 2013.

  8. Efficacy of imidacloprid + moxidectin and selamectin topical solutions against the KS1 Ctenocephalides felis flea strain infesting cats

    Directory of Open Access Journals (Sweden)

    Dryden Michael W

    2011-09-01

    Full Text Available Abstract Background Two studies were conducted to evaluate and compare the efficacy of imidacloprid + moxidectin and selamectin topical solutions against the KS1 flea strain infesting cats. In both studies the treatment groups were comprised of non-treated controls, 6% w/v selamectin (Revolution®; Pfizer Animal Health topical solution and 10% w/v imidacloprid + 1% w/v moxidectin (Advantage Multi® for Cats, Bayer Animal Health topical solution. All cats were infested with 100 fleas on Days -2, 7, 14, 21, and 28. The difference in the studies was that in study #1 efficacy evaluations were conducted at 24 and 48 hours post-treatment or post-infestation, and in study #2 evaluations were conducted at 12 and 24 hours. Results In study #1 imidacloprid + moxidectin and the selamectin formulation provided 99.8% and 99.0% efficacy at 24 hours post-treatment. On day 28, the 24 hour efficacy of the selamectin formulation dropped to 87.1%, whereas the imidacloprid + moxidectin formulation provided 98.9% efficacy. At the 48 hour assessments following the 28 day infestations, efficacy of the imidacloprid + moxidectin and selamectin formulations was 96.8% and 98.3% respectively. In study # 2 the efficacy of the imidacloprid + moxidectin and selamectin formulations 12 hours after treatment was 100% and 69.4%, respectively. On day 28, efficacy of the imidacloprid + moxidectin and selamectin formulations 12 hours after infestation was 90.2% and 57.3%, respectively. In study #2 both formulations provided high levels of efficacy at the 24 hour post-infestation assessments, with selamectin and imidacloprid + moxidectin providing 95.3% and 97.5% efficacy, following infestations on day 28. Conclusions At the 24 and 48 hour residual efficacy assessments, the imidacloprid + moxidectin and selamectin formulations were similarly highly efficacious. However, the imidacloprid + moxidectin formulation provided a significantly higher rate of flea kill against the KS1 flea

  9. Detection of Bartonellaspp. and Rickettsiaspp. in fleas, ticks and lice collected in rural areas of Peru

    Directory of Open Access Journals (Sweden)

    Abraham G. Cáceres

    2013-12-01

    Full Text Available Bartonellosis and rickettsiosis are commonly reported in Peru. In order to detect Bartonella sp. and Rickettsiasp. in fleas, ticks and lice, specimens from five distinct locations in Peru (Marizagua, Cajaruro, Jamalca, Lonya Grande and El Milagro were collected and screened for the presence of these bacteria using PCR and later confirmation by DNA sequencing. The specimens collected were distributed in 102 pools (76 Ctenocephalides felis, 2 Ctenocephalides canis, 16 Pulex irritans, 5 Pediculus humanus, 2 Rhiphicephalus sanguineus, and 1 Boophilus spp., where Bartonellawas detected in 17 pools (6 of C. felis, 9 of P. irritans, 1 of C. canis, and 1 P. humanus. Also, Rickettsiawas detected in 76 pools (62 C. felis, 10 P. irritans, 2 P. humanus, and 2 C. canis. Bartonella clarridgeiaewas detected in C. felis, C. canisand P. irritanspools at 5.3%, 50% and 12.5%, respectively.Bartonella rochalimaewas detected in one C. felisand two P. irritanspools at 1.3% and 12.5%, respectively. Furthermore, B. henselaewas detected in one C. felispool and one P. humanuspool corresponding to 1.3% and 20%, respectively; and Bartonella spp.was also found in 5 pools of P. irritansat 31.3%. Additionally, R. feliswas detected in C. felis, C. canisand P. irritanspools at 76.3%, 100% and 37.5%, respectively; and Rickettsia spp. was detected in C. felis, P. irritansand P. humanuspools at 5.3%, 25% and 40%, respectively. These results demonstrate the circulation of these bacteria in Peru.

  10. Prevalence of Yersinia pestis in rodents and fleas associated with black-tailed prairie dogs (Cynomys ludovicianus) at Thunder Basin National Grassland, Wyoming

    Science.gov (United States)

    Thiagarajan, Bala; Bai, Ying; Gage, Kenneth L.; Cully, Jack F.

    2008-01-01

    Rodents (and their fleas) that are associated with prairie dogs are considered important for the maintenance and transmission of the bacterium (Yersinia pestis) that causes plague. Our goal was to identify rodent and flea species that were potentially involved in a plague epizootic in black-tailed prairie dogs at Thunder Basin National Grassland. We collected blood samples and ectoparasites from rodents trapped at off- and on-colony grids at Thunder Basin National Grassland between 2002 and 2004. Blood samples were tested for antibodies to Y. pestis F-1 antigen by a passive hemagglutination assay, and fleas were tested by a multiplex polymerase chain reaction, for the presence of the plague bacterium. Only one of 1,421 fleas, an Oropsylla hirsuta collected in 2002 from a deer mouse, Peromyscus maniculatus, tested positive for Y. pestis. Blood samples collected in summer 2004 from two northern grasshopper mice, Onychomys leucogaster, tested positive for Y. pestis antibodies. All three positive samples were collected from on-colony grids shortly after a plague epizootic occurred. This study confirms that plague is difficult to detect in rodents and fleas associated with prairie dog colonies, unless samples are collected immediately after a prairie dog die-off.

  11. FAUNA BINATANG MENGERAT DAN PARASITNYA DI BEBERAPA DAERAH TRANSMIGRASI DI INDONESIA, SERTA HUBUNGANNYA DENGAN PENYAKIT RICKETTSIOSIS YANG DITULARKAN OLEH VEKTOR

    Directory of Open Access Journals (Sweden)

    Tuti R. Hadi

    2012-09-01

    Full Text Available Surveys on small mammal parasites conducted in several transmigration schemes in South Sulawesi, Central Sulawesi and East Kalimantan, Indonesia revealed 10 species of murid rodents. Rattus exulans and some forest rats were predominant in newly opened schemes, whereas Rattus rattus was predomi­nant in older schemes. Six species of rats collected in all areas surveyed were found infested with a chigger species Lepto trombodium (L. deliensis, a known vector of scrub typhus. Xenopsylla cheopis, a flea vector of murine typhus, was not found during the survey. Serological studies revealed that 22.7% of the rats collected in an area planned for a transmigration scheme in Central Sulawesi, have antibodies against scrub typhus and 12,5% against murine typhus. The risk of transmission of scrub typhus and murine typhus to human is discussed.

  12. A study of ectoparasites in wild rodents of the Jaz Murian area in the southeast of Iran

    Directory of Open Access Journals (Sweden)

    Asghar Khajeh

    2017-07-01

    Full Text Available Objective: To detect wild rodents ectoparasites in the southeast of Iran. Methods: In this survey, the wild rodents were trapped from 2014 to 2015. The captured rodents were checked for any ectoparasites. Results: In this study, 681 ectoparasites belonged to 6 species of flea, 2 species of lice, 1 species of mite and 2 species of hard tick were collected. The flea species were including, Xenopsylla gerbilli, Xenopsylla cheopis, Xenopsylla buxtoni, Xenopsylla conformis, Nosopsyllus medus and Amphipysylla spp., the lice species were including Hoplopleura spp. and Polyplax spp., the mite species was Ornithonyssus bacoti and tick species were Rhipicephalus spp. and Hyalomma spp. Conclusions: Among all ectoparasites, Hoplopleura spp. and Amphipysylla spp. had the high and low frequency infestation in rodents, respectively. Also among captured rodents, the highest ectoparasites infestation was found in Tatera indica and no ectoparasites in Apodemus witherbyi, Cricetelus migratorius, and Microtus mystacinus kermanesis.

  13. Efficacy of orally administered powdered aloe juice (Aloe ferox against ticks on cattle and ticks and fleas on dogs

    Directory of Open Access Journals (Sweden)

    J.J. Fourie

    2005-06-01

    Full Text Available The efficacy of orally administered powdered aloe juice (Aloe ferox was evaluated against ticks on cattle and against ticks and fleas on dogs. Twelve calves were each infested over a 25-day period with approximately 4000 larvae of Rhipicephalus (Boophilus decoloratus and allocated to 3 groups of 4 calves each. Three days after the last larval infestation and daily for 22 days thereafter, the calves in 1 group were fed 5 mg / kg body weight and those in another 25 mg / kg body weight of powdered aloe juice incorporated in game maintenance pellets, while the animals in the 3rd group received only pellets. Detached female ticks were collected daily and counted and the weights and the fertility of groups of 50 engorged female ticks collected from the animals were ascertained. The powdered aloe juice in the game maintenance pellets had no effect on the tick burdens of the calves or on the fertility of the ticks. Six dogs, in each of 2 groups, were treated daily for 15 consecutive days, commencing on Day -5 before the 1st tick infestation, with either 0.39 g or 0.74 g of powdered aloe juice, administered orally in gelatin capsules, while a 3rd group of 6 dogs served as untreated controls. All the dogs were challenged with Haemaphysalis leachi on Days 0 and +7, and with Ctenocephalides felis on Days+1and +8, and efficacy assessments were made 1 day after flea and 2 days after tick challenge, respectively. Treatment was not effective against ticks or fleas on the dogs.

  14. Adverse reactions from essential oil-containing natural flea products exempted from Environmental Protection Agency regulations in dogs and cats.

    Science.gov (United States)

    Genovese, Allison G; McLean, Mary Kay; Khan, Safdar A

    2012-08-01

    To describe adverse effects in dogs and cats exposed to Environmental Protection Agency exempted plant-derived flea preventatives containing mixtures of essential oils. Retrospective study from 2006 to 2008. Records of dog and cat cases were reviewed from the American Society for the Prevention of Cruelty to Animals, Animal Poison Control Center database. Thirty-nine cats and 9 dogs with history of exposure to natural flea preventatives. The following information was retrieved from each incident: number of animals, species involved, frequency, types, onset time, duration of clinical signs, exposure appropriateness, final outcome, and treatment information. Ninety-two percent of animals (n = 44) showed presence of one or more adverse effects. The frequency of adverse effects in dogs (n = 8; 89%) and cats (n = 36; 92%) was similar. Onset time of adverse effects in 39 of 44 animals occurred within 24 hours. The duration of signs in 24 animals ranged from 30 minutes to 149 hours. The products were used as per label in 77% animals (n = 37). Of 28 animals with known outcome, 50% (n = 14) recovered with bathing alone while others received intravenous fluids, muscle relaxants, and anticonvulsive medications. Death (1 cat; n = 1/28; 4%) or euthanasia (1 cat and 1 dog; n = 2/28; 7%) was reported in 3 animals. Dogs and cats can experience significant adverse effects when exposed to plant-derived flea preventatives even when used according to label directions. The number of reports of exposure in cats was higher than dogs, but the frequency of reported adverse effects was similar between the 2 species. Agitation and hypersalivation were common in cats, whereas lethargy and vomiting were common in dogs. © Veterinary Emergency and Critical Care Society 2012.

  15. Identification of Hepatozoon erhardovae Krampitz, 1964 from bank voles (Myodes glareolus) and fleas in Southern Hungary.

    Science.gov (United States)

    Rigó, Krisztina; Majoros, Gábor; Szekeres, Sándor; Molnár, Imola; Jablonszky, Mónika; Majláthová, Viktória; Majláth, Igor; Földvári, Gábor

    2016-06-01

    In order to investigate the prevalence and life cycle of apicomplexan parasites, small mammals were live-trapped with modified Sherman traps in Southern Hungary between 2010 and 2012. Altogether, 528 rodents (Apodemus flavicollis Melchior, 1834, Apodemus agrarius Pallas, 1771, Myodes glareolus Schreber, 1780, Microtus agrestis Linnaeus, 1761, Mus musculus Linnaeus, 1758 and Micromys minutus Pallas, 1771) were collected and four shrews (Sorex spp.) were by-catched. Captured animals belonging to non-protected species were euthanized, and spleen samples were preserved for histological and molecular analyses. During the examination of spleen smears, Hepatozoon parasites were observed in eight out of 48 bank voles (M. glareolus). DNA was isolated from altogether 221 spleen samples, and 18S rDNA was amplified using two different PCR protocols. The eight bank vole samples were positive with PCR, but none of the other M. glareolus spleen samples or any of the tissue samples from other species were found to be infected. Sequenced amplicons were very similar to Hepatozoon spp. detected in M. glareolus in Spain and Poland. Ectoparasites were collected from the small mammal carcasses and from the vegetation. Hepatozoon DNA was not found in the 181 ticks removed from the small mammals or in the 162 ticks collected with flagging, but was detected in all three flea species (4/43 Megabothris turbidus Rothschild, 1909, 3/10 Ctenophthalmus assimilis Taschenberg, 1880 and 7/78 Ctenophthalmus agyrtes Heller, 1896). Based on gamont morphology, vertebrate and arthropod host species and DNA sequences, the parasites in our study can be identified as Hepatozoon erhardovae.

  16. Gene expression profiling of three different stressors in the water flea Daphnia magna.

    Science.gov (United States)

    Jansen, Mieke; Vergauwen, Lucia; Vandenbrouck, Tine; Knapen, Dries; Dom, Nathalie; Spanier, Katina I; Cielen, Anke; De Meester, Luc

    2013-07-01

    Microarrays are an ideal tool to screen for differences in gene expression of thousands of genes simultaneously. However, often commercial arrays are not available. In this study, we performed microarray analyses to evaluate patterns of gene transcription following exposure to two natural and one anthropogenic stressor. cDNA microarrays compiled of three life stage specific and three stressor-specific EST libraries, yielding 1734 different EST sequences, were used. We exposed juveniles of the water flea Daphnia magna for 48, 96 and 144 h to three stressors known to exert strong selection in natural populations of this species i.e. a sublethal concentration of the pesticide carbaryl, infective spores of the endoparasite Pasteuria ramosa, and fish predation risk mimicked by exposure to fish kairomones. A total of 148 gene fragments were differentially expressed compared to the control. Based on a PCA, the exposure treatments were separated into two main groups based on the extent of the transcriptional response: a low and a high (144 h of fish or carbaryl exposure and 96 h of parasite exposure) stress group. Firstly, we observed a general stress-related transcriptional expression profile independent of the treatment characterized by repression of transcripts involved in transcription, translation, signal transduction and energy metabolism. Secondly, we observed treatment-specific responses including signs of migration to deeper water layers in response to fish predation, structural challenge of the cuticle in response to carbaryl exposure, and disturbance of the ATP production in parasite exposure. A third important conclusion is that transcription expression patterns exhibit stress-specific changes over time. Parasite exposure shows the most differentially expressed gene fragments after 96 h. The peak of differentially expressed transcripts came only after 144 h of fish exposure, while carbaryl exposure induced a more stable number of differently expressed gene

  17. Propulsion of the Water Flea, Daphnia magna: Experiments, Scaling, and Modelling

    Science.gov (United States)

    Skipper, A. N.; Murphy, D.; Webster, D. R.; Yen, J.

    2016-02-01

    The freshwater crustacean Daphnia magna is a widely studied zooplankton in relation to food webs, predator-prey interactions, and other biological/ecological considerations; however, their locomotion is poorly quantified and understood. These water fleas utilize a hop-and-sink mechanism that consists of making quick, impulsive jumps by beating their antennae to propel themselves forward ( 1 body length). The animals then sink for a period, during which they stretch out their antennae to increase drag and thereby reduce their sinking velocity. Time-resolved three-dimensional flow fields surrounding the animals were quantified with a unique infrared tomographic particle image velocity (tomo-PIV) system. Three-dimensional kinematics data were also extracted from the image sequences. In the current work, we compared body kinematics and flow disturbance among organisms of size in the range of 1.3 to 2.8 mm. The stroke cycle averaged 150 ms in duration, ranging from 100 to 180 ms; this period is generally evenly split between the power and recovery strokes. The range of peak hop velocity was 27.2 to 32.5 mm/s, and peak acceleration was in the range of 0.68 to 1.8 m/s2. The results showed a distinct relationship between peak hop speed (Vmax 14 BL/s) and body size; these data collapsed onto a single time-record curve during the power stroke when properly non-dimensionalized. The fluid flow induced by each antennae consisted of a viscous vortex ring that demonstrated a slow decay in the wake. The strength, size, and decay of the induced viscous vortex rings were compared as a function of organism size. Finally, the viscous vortex rings were analyzed in the context of a double Stokeslet model that consisted of two impulsively applied point forces separated by the animal width.

  18. Yersinia pestis insecticidal-like toxin complex (Tc family proteins: characterization of expression, subcellular localization, and potential role in infection of the flea vector

    Directory of Open Access Journals (Sweden)

    Spinner Justin L

    2012-12-01

    Full Text Available Abstract Background Toxin complex (Tc family proteins were first identified as insecticidal toxins in Photorhabdus luminescens and have since been found in a wide range of bacteria. The genome of Yersinia pestis, the causative agent of bubonic plague, contains a locus that encodes the Tc protein homologues YitA, YitB, YitC, and YipA and YipB. Previous microarray data indicate that the Tc genes are highly upregulated by Y. pestis while in the flea vector; however, their role in the infection of fleas and pathogenesis in the mammalian host is unclear. Results We show that the Tc proteins YitA and YipA are highly produced by Y. pestis while in the flea but not during growth in brain heart infusion (BHI broth at the same temperature. Over-production of the LysR-type regulator YitR from an exogenous plasmid increased YitA and YipA synthesis in broth culture. The increase in production of YitA and YipA correlated with the yitR copy number and was temperature-dependent. Although highly synthesized in fleas, deletion of the Tc proteins did not alter survival of Y. pestis in the flea or prevent blockage of the proventriculus. Furthermore, YipA was found to undergo post-translational processing and YipA and YitA are localized to the outer membrane of Y. pestis. YitA was also detected by immunofluorescence microscopy on the surface of Y. pestis. Both YitA and YipA are produced maximally at low temperature but persist for several hours after transfer to 37°C. Conclusions Y. pestis Tc proteins are highly expressed in the flea but are not essential for Y. pestis to stably infect or produce a transmissible infection in the flea. However, YitA and YipA localize to the outer membrane and YitA is exposed on the surface, indicating that at least YitA is present on the surface when Y. pestis is transmitted into the mammalian host from the flea.

  19. Knock-down and speed of kill of a combination of fipronil and permethrin for the prevention of Ctenocephalides felis flea infestation in dogs.

    Science.gov (United States)

    Halos, Lénaïg; Fourie, Josephus J; Fankhauser, Becky; Beugnet, Frederic

    2016-02-02

    A topical combination of fipronil + permethrin (Frontline Tri-Act/Frontect, Merial) has recently been developed to control fleas, ticks, mosquitoes, sandflies and stable flies on dogs. Two studies were conducted to assess its speed of kill and knock-down effect on Ctenocephalides felis fleas. The combination was compared to either fipronil alone or to a combination of permethrin, dinotefuran, and pyriproxyfen, In each study, 18 dogs were randomly allocated to one of three groups: (Group 1: untreated dog; Group 2: treated once on D0 with the combination of fipronil and permethrin; Group 3: treated once on D0 either with fipronil alone (study 1) or with a combination of permethrin, dinetofuran and pyriproxyfen (study 2)). Each dog was infested with 100 unfed adult C. felis fleas on Days 2 (study 2), 7, 14, 21 and 28. Fleas were collected from dogs at 1 h and 12 h post- infestations (PI) (study 1) or at 2 h and 6 h PI (study 2) to assess efficacy and from collection pans underneath cages 1 h (study 1) or 5 min (study 2) PI to assess knock-down effect. All treated dogs had significantly (p ≤ 0.01) lower flea counts than untreated dogs at every time point in both studies. For a whole month, a significant knock-down effect against infesting fleas is obtained in five minutes PI with the combination of permethrin and fipronil. Complete efficacy (>95%) was achieved in 1 h (study 1) or 2 h (study 2) PI for 14 days and by 6 h PI for all challenges conducted throughout the month. Efficacy remains >85% at 2 h PI for the whole month. A significantly higher efficacy of the fipronil + permethrin combination compared to other treatments was demonstrated at the earliest time points for the month (1 h knock-down effect and insecticidal efficacy compared to fipronil alone; 5 min knock-down effect compared to the combination of permethrin + dinetofuran + pyriproxyfen). The rapid flea knock-down effect and speed of kill demonstrated by the spot on combination of

  20. Ectoparasites and endoparasites of peridomestic house-rats in ile-ife, Nigeria and implication on human health.

    Directory of Open Access Journals (Sweden)

    Titus Ogunniyi

    2014-03-01

    Full Text Available There has never been a single case report of any parasitic zoonosis in Ile-Ife while just a case of human Acanthocephalan infection in Nigeria is available.Fifty (house-rats Rattus rattus (Linnaeus, 1758 were caught in houses and raw food sellers' stalls in a market in Ile-Ife. A caught rat was removed from the cage and sacrificed by cervical jerking. A rat was weighed, measured, quickly following which thick and thin blood films on microscope slides were made from blood collected from the tail vein. The rat was examined for ectoparasites then dissected to check for endoparasites.Two ectoparasites (Xenopsylla cheopis and Laelaptid mite were recovered from 19 (38.0% of the rats. Five genera of helminthes (Moniliformis, Hymenolepis, Taenia, Trichuris and Trichinella were recovered from 29 (58.0% of the rats while seven genera of protozoa organisms (Amoeba, Dientamoeba, Entamoeba, Retortamonas, Trichomonas, Chilomastix and Trypanosoma were recovered from 48 (96.0% of them. There was no correlation (Spearman's correlation coefficient = -0.111 between the weight of the individual rat and the total number of alimentary canal acquired parasites.In relation to human health, implications of the rats serving as reservoir hosts for the different pathogens are highlighted. In view of the possibility of unexpected zoonosis arising from the parasites found in the peridomestic rats in this investigation and others not found, and in view of the difficulties that may be associated with diagnosing such ailment, especially by a clinician who trained locally, this report should be like raising awareness to these salient facts.

  1. Comparative analysis of storage conditions and homogenization methods for tick and flea species for identification by MALDI-TOF MS.

    Science.gov (United States)

    Nebbak, A; El Hamzaoui, B; Berenger, J-M; Bitam, I; Raoult, D; Almeras, L; Parola, P

    2017-12-01

    Ticks and fleas are vectors for numerous human and animal pathogens. Controlling them, which is important in combating such diseases, requires accurate identification, to distinguish between vector and non-vector species. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was applied to the rapid identification of arthropods. The growth of this promising tool, however, requires guidelines to be established. To this end, standardization protocols were applied to species of Rhipicephalus sanguineus (Ixodida: Ixodidae) Latreille and Ctenocephalides felis felis (Siphonaptera: Pulicidae) Bouché, including the automation of sample homogenization using two homogenizer devices, and varied sample preservation modes for a period of 1-6 months. The MS spectra were then compared with those obtained from manual pestle grinding, the standard homogenization method. Both automated methods generated intense, reproducible MS spectra from fresh specimens. Frozen storage methods appeared to represent the best preservation mode, for up to 6 months, while storage in ethanol is also possible, with some caveats for tick specimens. Carnoy's buffer, however, was shown to be less compatible with MS analysis for the purpose of identifying ticks or fleas. These standard protocols for MALDI-TOF MS arthropod identification should be complemented by additional MS spectrum quality controls, to generalize their use in monitoring arthropods of medical interest. © 2017 The Royal Entomological Society.

  2. Comparative efficacy on dogs of a single topical treatment with fipronil/(S-methoprene or weekly physiological hygiene shampoos against Ctenocephalides felis in a simulated flea-infested environment

    Directory of Open Access Journals (Sweden)

    Beugnet F.

    2012-05-01

    Full Text Available Flea infestations of pets continue to persist due to the lack of knowledge of flea biology and ecology. It is not unusual that pet owners believe regular hygiene, such as shampooing their dogs can replace regular insecticidal treatment. The objective of this study was to compare in a flea simulated environment, modelling exposure similar to that found in a home, that the use of regular physiological shampoo does not control fleas adequately when compared to a long acting topical formulation. Three groups of six dogs were formed: one untreated control group, one group treated monthly with the topical formulation of fipronil/(S-methoprene, and a third group treated weekly with a hygiene shampoo. All dogs were infested with adult unfed Ctenocephalides felis fleas (200 ± 5 on Days -28 and -21. Each animal’s sleeping box was fitted with a plastic cup mounted to the inside roof of the box. The sleeping bench of each animal was covered with a carpet to accommodate flea development. The dogs were maintained in their kennels throughout the study. In order to maintain the environmental flea challenge, C. felis pupae (100 ± 5 were placed in the plastic cup in each animal’s sleeping box on Days -14, -7, 0, 7, 14, 21, 28, 35 and 42. The dogs were combed and fleas counted weekly on Days -1, 3, 10, 17, 24, 31, 38, 45, and 51. The fleas were placed immediately back on the dogs. On Day 60, fleas were counted and removed. Flea infestations in the untreated control group at each count averaged between 46.2 and 74.2 fleas throughout the study. The average number of fleas infesting dogs was significantly different (p < 0.05 between the untreated and the two treatment groups and between the two treatment groups at all counts throughout the two months study (Days 3, 10, 17, 24, 31, 38, 45, 51 and 60. The efficacy was never below 99.1% in the fipronil/(S-methoprene group, and efficacy in the shampoo group was never above 79.2%. Weekly shampooing in treatment

  3. New contributions to the knowledge of Chinese flea beetle fauna (I); Gansuapteris new genus and Primulavorus new genus (Coleoptera; Chrysomelidae; Galerucinae)

    Science.gov (United States)

    Two new genera and species of flea beetles (Gansuapteris gen. nov., Primulavorus gen. nov., Gansuapteris fulvus sp. nov. and Primulavorus maculata sp. nov.) from South-west China are described and illustrated. The morphological differences of new genera and their allies are discussed....

  4. New contributions to the knowledge of Chinese flea beetle fauna (III): Revision of Meishania Chen & Wang with description of five new species (Coleoptera: Chrysomelidae: Galerucinae)

    Science.gov (United States)

    The flea beetle genus Meishania Chen & Wang is revised and five new species - M. cangshanensis sp. nov., M. flavipennis sp. nov., M. fulvotigera sp. nov., and M. sichuanica sp. nov. from China and M. bhutanensis sp. nov. from Bhutan - are described. All species of Meishania are illustrated and a key...

  5. Efficacy of fipronil, amitraz and (S)-methoprene combination spot-on for dogs against adult dog fleas (Ctenocephalides canis, Curtis, 1826).

    Science.gov (United States)

    Bouhsira, Emilie; Yoon, Stephen S; Roques, Martine; Manavella, Coralie; Vermot, Solange; Cramer, Luiz G; Ollagnier, Catherine; Franc, Michel

    2011-07-15

    A novel spot-on formulation combining fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) was evaluated in adult Beagle dogs in a study to determine its adulticidal efficacy against the dog flea (Ctenocephalides canis, Curtis, 1826). Sixteen dogs were randomly allocated to treatment groups: 8 dogs served as untreated controls, and 8 dogs were treated once. Treatment consisted of applying a new combination formulation to deliver at least 6.7mg fipronil/kg body weight (bw), 8.0mg amitraz/kg bw, and 6.0mg (S)-methoprene/kg bw. The combination was designed to enhance the efficacy against ticks of the original fipronil/(S)-methoprene combination. Each dog was infested with 100 adult unfed dog fleas within 24h prior to treatment and then at weekly intervals for 8 weeks after treatment. At 24h after treatment or after each subsequent infestation, each dog was combed thoroughly to remove live fleas to be counted. A single treatment with CERTIFECT provided excellent knock-down of fleas within 24h after treatment and controlled re-infestations for up to 7 weeks (efficacy ≥96.5%, p<0.05). Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Development of a loop-mediated isothermal amplification (LAMP) assay for rapid screening of ticks and fleas for spotted fever group rickettsia.

    Science.gov (United States)

    Noden, Bruce H; Martin, Jaclyn; Carrillo, Yisel; Talley, Justin L; Ochoa-Corona, Francisco M

    2018-01-01

    The importance of tick and flea-borne rickettsia infections is increasingly recognized worldwide. While increased focus has shifted in recent years to the development of point-of-care diagnostics for various vector-borne diseases in humans and animals, little research effort has been devoted to their integration into vector surveillance and control programs, particularly in resource-challenged countries. One technology which may be helpful for large scale vector surveillance initiatives is loop-mediated isothermal amplification (LAMP). The aim of this study was to develop a LAMP assay to detect spotted fever group (SFG) rickettsia DNA from field-collected ticks and fleas and compare with published end-point PCR results. A Spotted Fever Group rickettsia-specific loop-mediated isothermal amplification (SFGR-LAMP) assay was developed using primers based on a region of the R. rickettsii 17kDa protein gene. The sensitivity, specificity, and reproducibility of the assay were evaluated. The assay was then compared with the results of end-point PCR assays for pooled tick and flea samples obtained from field-based surveillance studies. The sensitivity of the SFGR-LAMP assay was 0.00001 ng/μl (25μl volume) which was 10 times more sensitive than the 17kDa protein gene end-point PCR used as the reference method. The assay only recognized gDNA from SFG and transitional group (TRG) rickettsia species tested but did not detect gDNA from typhus group (TG) rickettsia species or closely or distantly related bacterial species. The SFGR-LAMP assay detected the same positives from a set of pooled tick and flea samples detected by end-point PCR in addition to two pooled flea samples not detected by end-point PCR. To our knowledge, this is the first study to develop a functional LAMP assay to initially screen for SFG and TRG rickettsia pathogens in field-collected ticks and fleas. With a high sensitivity and specificity, the results indicate the potential use as a field

  7. Toxicity and transfer of polyvinylpyrrolidone-coated silver nanowires in an aquatic food chain consisting of algae, water fleas, and zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Yooeun; An, Youn-Joo, E-mail: anyjoo@konkuk.ac.kr

    2016-04-15

    Highlights: • Trophic transfer of silver nanowires (AgNWs) was studied in an aquatic food chain. • The transfer of AgNWs from algae to fish via water fleas was observed. • Toxicity of long AgNWs on aquatic organisms is higher than that of short ones. • AgNWs damage the gut of water fleas and may cause undernourishment. • Quantity of lipid droplets increased with increasing exposure concentration. - Abstract: Nanomaterials of various shapes and dimensions are widely used in the medical, chemical, and electronic industries. Multiple studies have reported the ecotoxicological effects of nanaoparticles when released in aquatic and terrestrial ecosystems; however, information on the toxicity of silver nanowires (AgNWs) to freshwater organisms and their transfer through the food webs is limited. In the present study, we aimed to evaluate the toxicity of 10- and 20-μm-long AgNWs to the alga Chlamydomonas reinhardtii, the water flea Daphnia magna, and the zebrafish and study their movement through this three-species food chain using a variety of qualitative and quantitative methods as well as optical techniques. We found that AgNWs directly inhibited the growth of algae and destroyed the digestive organs of water fleas. The results showed that longer AgNWs (20 μm) were more toxic than shorter ones (10 μm) to both algae and water fleas, but shorter AgNWs were accumulated more than longer ones in the body of the fish. Overall, this study suggests that AgNWs are transferred through food chains, and that they affect organisms at higher trophic levels, potentially including humans. Therefore, further studies that take into account environmental factors, food web complexity, and differences between nanomaterials are required to gain better understanding of the impact of nanomaterials on natural communities and human health.

  8. Toxicity and transfer of polyvinylpyrrolidone-coated silver nanowires in an aquatic food chain consisting of algae, water fleas, and zebrafish

    International Nuclear Information System (INIS)

    Chae, Yooeun; An, Youn-Joo

    2016-01-01

    Highlights: • Trophic transfer of silver nanowires (AgNWs) was studied in an aquatic food chain. • The transfer of AgNWs from algae to fish via water fleas was observed. • Toxicity of long AgNWs on aquatic organisms is higher than that of short ones. • AgNWs damage the gut of water fleas and may cause undernourishment. • Quantity of lipid droplets increased with increasing exposure concentration. - Abstract: Nanomaterials of various shapes and dimensions are widely used in the medical, chemical, and electronic industries. Multiple studies have reported the ecotoxicological effects of nanaoparticles when released in aquatic and terrestrial ecosystems; however, information on the toxicity of silver nanowires (AgNWs) to freshwater organisms and their transfer through the food webs is limited. In the present study, we aimed to evaluate the toxicity of 10- and 20-μm-long AgNWs to the alga Chlamydomonas reinhardtii, the water flea Daphnia magna, and the zebrafish and study their movement through this three-species food chain using a variety of qualitative and quantitative methods as well as optical techniques. We found that AgNWs directly inhibited the growth of algae and destroyed the digestive organs of water fleas. The results showed that longer AgNWs (20 μm) were more toxic than shorter ones (10 μm) to both algae and water fleas, but shorter AgNWs were accumulated more than longer ones in the body of the fish. Overall, this study suggests that AgNWs are transferred through food chains, and that they affect organisms at higher trophic levels, potentially including humans. Therefore, further studies that take into account environmental factors, food web complexity, and differences between nanomaterials are required to gain better understanding of the impact of nanomaterials on natural communities and human health.

  9. Differential control of Yersinia pestis biofilm formation in vitro and in the flea vector by two c-di-GMP diguanylate cyclases.

    Directory of Open Access Journals (Sweden)

    Yi-Cheng Sun

    2011-04-01

    Full Text Available Yersinia pestis forms a biofilm in the foregut of its flea vector that promotes transmission by flea bite. As in many bacteria, biofilm formation in Y. pestis is controlled by intracellular levels of the bacterial second messenger c-di-GMP. Two Y. pestis diguanylate cyclase (DGC enzymes, encoded by hmsT and y3730, and one phosphodiesterase (PDE, encoded by hmsP, have been shown to control biofilm production in vitro via their opposing c-di-GMP synthesis and degradation activities, respectively. In this study, we provide further evidence that hmsT, hmsP, and y3730 are the only three genes involved in c-di-GMP metabolism in Y. pestis and evaluated the two DGCs for their comparative roles in biofilm formation in vitro and in the flea vector. As with HmsT, the DGC activity of Y3730 depended on a catalytic GGDEF domain, but the relative contribution of the two enzymes to the biofilm phenotype was influenced strongly by the environmental niche. Deletion of y3730 had a very minor effect on in vitro biofilm formation, but resulted in greatly reduced biofilm formation in the flea. In contrast, the predominant effect of hmsT was on in vitro biofilm formation. DGC activity was also required for the Hms-independent autoaggregation phenotype of Y. pestis, but was not required for virulence in a mouse model of bubonic plague. Our results confirm that only one PDE (HmsP and two DGCs (HmsT and Y3730 control c-di-GMP levels in Y. pestis, indicate that hmsT and y3730 are regulated post-transcriptionally to differentially control biofilm formation in vitro and in the flea vector, and identify a second c-di-GMP-regulated phenotype in Y. pestis.

  10. Isolation and characterization of a novel Rickettsia species (Rickettsia asembonensis sp. nov.) obtained from cat fleas (Ctenocephalides felis).

    Science.gov (United States)

    Maina, Alice N; Luce-Fedrow, Alison; Omulo, Sylvia; Hang, Jun; Chan, Teik-Chye; Ade, Fredrick; Jima, Dereje D; Ogola, Eric; Ge, Hong; Breiman, Robert F; Njenga, Moses K; Richards, Allen L

    2016-11-01

    A novel rickettsial agent, 'Candidatus Rickettsia asembonensis' strain NMRCiiT, was isolated from cat fleas, Ctenocephalides felis, from Kenya. Genotypic characterization of the new isolate based on sequence analysis of five rickettsial genes, rrs, gltA, ompA, ompB and sca4, indicated that this isolate clustered with Rickettsia felis URRWXCal2. The degree of nucleotide similarity demonstrated that isolate NMRCiiT belongs within the genus Rickettsia and fulfils the criteria for classification as a representative of a novel species. The name Rickettsia asembonensis sp. nov. is proposed, with NMRCiiT (=DSM 100172T=CDC CRIRC RAS001T=ATCC VR-1827T) as the type strain.

  11. Evaluation of the effectiveness of a novel oral formulation of sarolaner (Simparica™) for the treatment and control of fleas on dogs.

    Science.gov (United States)

    Six, Robert H; Geurden, Thomas; Packianathan, Raj; Colgan, Sally; Everett, William R; Grace, Sarah; Hodge, Andrew; Mahabir, Sean P; Myers, Melanie R; Slootmans, Nathalie; Davis, Kylie

    2016-05-30

    The efficacy of a single oral dose of a novel isoxazoline, sarolaner (Simparica™, Zoetis), for the treatment and control of flea infestations on dogs was confirmed in five laboratory studies. The studies were conducted using adult purpose-bred Beagles and/or mixed breed dogs. All animals were individually identified and housed, and were allocated randomly to treatment with either placebo or sarolaner (eight to 10 per group) based on pretreatment parasite counts. Three studies used cat flea (Ctenocephalides felis felis) strains recently isolated from the field from the US, EU, or Australia; in the fourth study a laboratory strain (KS1) with documented tolerance to a number of insecticides such as fipronil, imidacloprid, and permethrin was used. In the fifth study, dogs were infested with dog fleas, Ctenocephalides canis. Dogs were treated orally on Day 0 with a placebo or a sarolaner tablet providing a minimum dose of 2mg/kg. Dogs were infested with approximately 100 unfed, adult fleas prior to treatment and at weekly intervals post-treatment. Comb counts were conducted to determine the numbers of viable fleas at 24h after treatment and after each subsequent infestation. Efficacy against C. felis and C. canis was 99.8-100% from treatment through Day 35. In all five studies, elimination of existing infestations was achieved within 24h after dosing, with only a single live C. felis found on one dog on Day 1. Similarly, control of flea challenges was achieved within 24h after infestation throughout the 35day study periods, with only single live C. felis found on two dogs on Day 28 in one study, and on a single dog on Day 35 in another study. There were no adverse reactions to treatment with sarolaner. These studies confirmed that a single oral dose of sarolaner at 2mg/kg provided highly effective treatment of existing C. felis infestations and persistent control of C. felis on dogs for 35days after treatment. Efficacy equivalent to that seen with C. felis was

  12. Myxomatosis: changes in the epidemiology of myxomatosis coincident with the establishment of the European rabbit flea Spilopsyllus cuniculi (Dale) in the Mallee region of Victoria.

    Science.gov (United States)

    Shepherd, R C; Edmonds, J W

    1978-12-01

    Outbreaks of myxomatosis during the winter or spring have coincided with the establishment of the European rabbit flea in the Mallee region. The severity of these outbreaks has varied from causing complete suppression of the normal spring increase in rabbit numbers to being completely ineffective in a year in which late spring rains allowed rabbit breeding to extend into the early summer.In 1973 and 1974 effective spring myxomatosis caused heavy mortality in kittens before they emerged from the warrens. The age of the population increased as the result of few young rabbits coming into the population and of the lessened stress on old rabbits in a low summer-autumn population. This effect was reversed in the late-breeding year, 1976, when flea numbers were apparently too low to maintain a spring outbreak and rabbit numbers increased rapidly.

  13. Rickettsia typhi in rodents and R. felis in fleas in Yucatán as a possible causal agent of undefined febrile cases.

    Science.gov (United States)

    Peniche-Lara, Gaspar; Dzul-Rosado, Karla; Pérez-Osorio, Carlos; Zavala-Castro, Jorge

    2015-01-01

    Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study's results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

  14. [Present Status of Displaying Pharmaceutical Products for Sale on Flea Market Applications for Smartphones and the Responses to Illicit Selling by Service Providers].

    Science.gov (United States)

    Kishimoto, Keiko; Takeuchi, Tomoe; Fukushima, Noriko

    2017-12-01

     In Japan, a pharmacy or drug store license is required for selling pharmaceutical products. However, civilians without a pharmacy or drug store license are displaying pharmaceutical products for sale on a flea market application, which is illegal dealing. This study discussed the modality for implementing countermeasures for the illicit selling of pharmaceutical products. We extracted pharmaceutical products displayed for sale on three flea market applications (Mercari, Rakuma, Fril) on one day. One hundred and eighty-one pharmaceutical products were displayed (49 on Mercari, 86 on Rakuma, and 46 on Fril). There were 6.1% (11/181) domestically prescribed drugs, 69.1% (125/181) domestic OTC drugs, 23.8% (43/181) foreign-made prescribed drugs, and 1.1% (2/181) foreign-made OTC drugs. The seller could display the product for sale without confirming whether it is prohibited. We alerted the service providers of this illicit selling at flea markets at three different instances. The pharmaceutical product displays were deleted by the service providers at a rate of 55.1% (27/49) for Mercari and 51.2% (44/86) for Rakuma. The average number of drugs that were displayed for sale by each seller was 1.4 and the average number of total products that were displayed for sale by each seller was 100. The seller could have unintentionally displayed the pharmaceutical products for sale, without the knowledge that it is illegal. The service providers of flea market applications should create mechanisms to alert the sellers that displaying pharmaceutical products for sale is an illicit act and regulate these violations.

  15. Extract of the seeds of the plant Vitex agnus castus proven to be highly efficacious as a repellent against ticks, fleas, mosquitoes and biting flies.

    Science.gov (United States)

    Mehlhorn, Heinz; Schmahl, Günter; Schmidt, Jürgen

    2005-03-01

    About 70 plant extracts were tested for their ability to repel the attacks of blood-sucking arthropods. It was found that a CO2 extract of the seeds of the Mediterranean plant Vitex agnus castus (monk's pepper) can be used as a spray to keep away especially Ixodes ricinus and Rhipicephalus sanguineus ticks from animals and humans for at least 6 h. In addition mosquitoes, biting flies and fleas are also repelled for about 6 h.

  16. Deltamethrin flea-control preserves genetic variability of black-tailed prairie dogs during a plague outbreak

    Science.gov (United States)

    Jones, P.H.; Biggins, D.E.; Eads, D.A.; Eads, S.L.; Britten, H.B.

    2012-01-01

    Genetic variability and structure of nine black-tailed prairie dog (BTPD, Cynomys ludovicianus) colonies were estimated with 15 unlinked microsatellite markers. A plague epizootic occurred between the first and second years of sampling and our study colonies were nearly extirpated with the exception of three colonies in which prairie dog burrows were previously dusted with an insecticide, deltamethrin, used to control fleas (vectors of the causative agent of plague, Yersinia pestis). This situation provided context to compare genetic variability and structure among dusted and non-dusted colonies pre-epizootic, and among the three dusted colonies pre- and post-epizootic. We found no statistical difference in population genetic structures between dusted and non-dusted colonies pre-epizootic. On dusted colonies, gene flow and recent migration rates increased from the first (pre-epizootic) year to the second (post-epizootic) year which suggested dusted colonies were acting as refugia for prairie dogs from surrounding colonies impacted by plague. Indeed, in the dusted colonies, estimated densities of adult prairie dogs (including dispersers), but not juveniles (non-dispersers), increased from the first year to the second year. In addition to preserving BTPDs and many species that depend on them, protecting colonies with deltamethrin or a plague vaccine could be an effective method to preserve genetic variability of prairie dogs. ?? 2011 Springer Science+Business Media B.V.

  17. Letterman Army Institute of Research Annual Research Progress Report, FY 1981.

    Science.gov (United States)

    1981-10-01

    five species of mosquitoes. These compounds were tested against sand flies ( Lutzomyia longipalpis), fleas (Xenopsylla cheopis ) and bugs (Rhodnius...BUESCHER, M.D., L.C. RUTLEDGE, R.A. WIRTZ, K.B. GLACKIN, and M.A. MOUSSA. Laboratory tests of repellents against Lutzomyia longipalpis (Diptera

  18. Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species

    Directory of Open Access Journals (Sweden)

    Gaasenbeek Cor

    2009-09-01

    Full Text Available Abstract Background Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus, the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variability of rickettsiae infections of the different tick stages were determined for 9 years. Results The DNA of the human pathogen R. conorii as well as R. helvetica, R. sp. IRS and R. bellii-like were found. Unexpectedly, the DNA of the highly pathogenic R. typhi and R. prowazekii and 4 other uncharacterized Rickettsia spp. related to the typhus group were also detected in I. ricinus. The presence of R. helvetica in fleas isolated from small rodents supported our hypothesis that cross-infection can occur under natural conditions, since R. typhi/prowazekii and R. helvetica as well as their vectors share rodents as reservoir hosts. In one biotope, the infection rate with R. helvetica was ~66% for 9 years, and was comparable between larvae, nymphs, and adults. Larvae caught by flagging generally have not yet taken a blood meal from a vertebrate host. The simplest explanation for the comparable prevalence of R. helvetica between the defined tick stages is, that R. helvetica is vertically transmitted through the next generation with high efficiency. The DNA of R. helvetica was also present in whole blood from mice, deer and wild boar. Conclusion Besides R. helvetica, unexpected rickettsiae are found in I. ricinus ticks. We propose that I. ricinus is a major reservoir host for R. helvetica, and that vertebrate hosts play important roles in the further geographical dispersion of rickettsiae.

  19. Evaluation and comparison of a flumethrin-imidacloprid collar and repeated monthly treatments of fipronil/(s)-methoprene to control flea, Ctenocephalides f. felis, infestations on cats for eight months.

    Science.gov (United States)

    Dryden, Michael W; Smith, Vicki; Davis, Wendell L; Settje, Terry; Hostetler, Joe

    2016-05-17

    This controlled laboratory study was designed to evaluate the efficacy of the 10 % imidacloprid/4.5 % flumethrin collar (Seresto®, Bayer Animal Health) against fleas (Ctenocephalides f. felis) on cats, when compared to fipronil (9.8 %w/w)/(s)-methoprene (11.8 % w/w) topical spot-on formulation (Frontline® Plus for Cats and Kittens, Merial). Thirty cats were randomized into three groups of ten animals based on pre-treatment flea counts: Group 1: imidacloprid/flumethrin collar; Group 2: fipronil/(s)-methoprene topical spot-on and Group 3: non-treated controls. The imidacloprid/flumethrin collars were applied one time on Day 0, while the fipronil/(s)-methoprene spot-on was administered every 30 days from Day 0 through Day 210. Cats were infested with 100 fleas on study days 0, 7, 14, 29, 59, 89, 119, 149, 179, 209 and 239. All flea counts were conducted by combing to remove fleas on post-treatment days 2, 8, 15, 30, 60, 90, 120, 150, 180, 210 and 240. The efficacy of the imidacloprid/flumethrin collar ranged from 98.2 to 100 % for eight months. The efficacy of fipronil/(s)-methoprene spot-on ranged from 68.2 to 99.9 %. Efficacy was imidacloprid/flumethrin collar group when compared to the fipronil/(s)-methoprene group on Days 90, 150 and 210 (P imidacloprid/flumethrin collar (Seresto®, Bayer Animal Health) maintained excellent ( > 98.2 %) efficacy against fleas on cats for the entire 8 month study. Monthly applications of fipronil/(s)-methoprene (Frontline® Plus for Cats and Kittens, Merial) generally had high, but variable (68.2 to 99.9 %) efficacy over the course of the eight month study. Based on the very high residual efficacy achieved by the imidacloprid/flumethrin collar in this study, veterinarians should expect that this collar will control and eliminate existing flea infestations on cats and in their in-home premises as long as every flea infested host is treated.

  20. Revision of fleas of the genus Plocopsylla belonging to the 'angusticeps-lewisi' complex in the Andean biogeographic region, with the description of a new species.

    Science.gov (United States)

    Sanchez, J; Beaucournu, J-C; Lareschi, M

    2015-06-01

    In Argentina, the Andean biogeographic region accommodates the most diverse population of fleas in the country. The Craneopsyllinae (Siphonaptera: Stephanocircidae) represent one of the most commonly found subfamilies in this region and show some endemism and high diversity. Plocopsylla is the most diverse genus of Craneopsyllinae; it includes 10 species mainly distributed in the Patagonian subregion, which parasitize sigmodontine rodents (Rodentia: Cricetidae). We describe and illustrate the morphology of the aedeagus in species of Plocopsylla that belong to the 'angusticeps-lewisi' complex. This character is of diagnostic value in differentiating among species. A new species of this complex, Plocopsylla (Plocopsylla) linardii sp. n., is described and identified by the shape and chaetotaxy of the distal arm of sternite IX, as well as by the shape of the median dorsal lobe of the aedeagus. New host associations for this complex and range extensions for most of its species are reported. Plocopsylla (P.) silewi is recorded for the first time in Argentina. The southern limits of the distributions of Plocopsylla (P.) lewisi and Plocopsylla (P.) wilesi are extended to Santa Cruz Province. The angusticeps-lewisi complex is found for the first time in San Juan Province. The information may be useful in epidemiological studies of flea-borne diseases. © 2015 The Royal Entomological Society.

  1. Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

    Directory of Open Access Journals (Sweden)

    Gaspar PENICHE-LARA

    2015-04-01

    Full Text Available Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

  2. Uninvited guests: traditional insect repellents in Estonia used against the clothes moth Tineola bisselliella, human flea Pulex irritons and bedbug Cimex lectularius.

    Science.gov (United States)

    Sõukand, Renata; Kalle, Raivo; Svanberg, Ingvar

    2010-01-01

    Extensive folklore records from pre-modern Estonia give us an excellent opportunity to study a variety of local plant knowledge and plant use among the peasantry in various parts of the country. One important biocultural domain where plant knowledge has been crucial was in the various methods of combating different ectoparasites that cohabited and coexisted with humans and their domestic animals. Some of these methods were widely known (world-wide, Eurasia, Europe, Baltic Rim), while others were more local. Here we discuss ways of reducing clothes moths Tineola bisselliella (Hummel) (Lepidoptera: Tineidae), human fleas Pulex irritons L. (Siphonaptera: Pulicidae) and bedbugs Cimex lectularius L. (Hemiptera: Cimicidae) with the help of plants. Various taxa used as traditional repellents have been identified. The use of plants as repellents and their toxic principles are also discussed from a comparative perspective.

  3. Flea beetles (Coleoptera: Chrysomelidae: Alticinae collected by malaise trap method in Gölcük Natural Park (Isparta, Turkey, with a new record for Turkish fauna

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    Aslan Gül E.

    2012-01-01

    Full Text Available This study is based on Alticinae (Coleoptera: Chrysomelidae material collected by Malaise trapping which is different from other standardized collecting methods. A total of 19 flea beetle species belonging to 6 genera were collected from Gölcük Natural Park, Isparta (Turkey during 2009. The species are listed in a table together with distributional data in Turkey. Among them, Longitarsus curtus (Allard, 1860 is recorded for the first time in Turkey. L. monticola Kutschera, 1863 and L. curtus are recently separated synonyms and thus all data referring to the distribution of both species are currently important. Hence, the zoogeographical distribution of the new record is reviewed with some remarks; habitus and genitalia are illustrated.

  4. Occurrence of ectoparasitic arthropods associated with rodents in Hail region northern Saudi Arabia.

    Science.gov (United States)

    Asiry, Khalid A; Fetoh, Badr El-Sabah A

    2014-09-01

    Ectoparasitic arthropods are a diverse element of the Saudi fauna. Due to this, a survey of ectoparasites associated with rodents was conducted as a preliminary study in five districts of Hail region of northern Saudi Arabia for the first time. Ectoparasites extracted from 750 rodents were sampled and identified by recording their frequency of appearance. Results revealed that 1,287 ectoparasites infested 316 of the captured rodent hosts. These ectoparasites parasitized on four species of rodents including three species of rats Rattus rattus rattus, Rattus rattus frugivorus, and Rattus rattus alexandrinus and one species of mouse Acomys dimidiatus (Rodentia: Muridae). The ectoparasites belong to four different groups: ticks, fleas, lice, and mites. Ticks were the highest in the number, while fleas were the lowest among all the extracted ectoparasite groups. The collected ectoparasitic arthropods consisted of seven species. Ticks were of two species: Rhipicephalus turanicus and Rhipicephalus sanguineus (Acari: Ixodidae), fleas were of two species: Xenopsylla cheopis and Xenopsyllus conformis mycerini (Siphonaptera: Pulicidae), lice was a single species: Polyplax serrata (Anoplura: Hoplopleuridae), and mites were of two species: Laelaps nuttali and Laelaps echidninus (Mesostigmata: Laelapidae). The findings of the study showed that the intensity of infestation was varied between rodent host sexes, wherein females had the highest rate of parasitic infestation, and the parasitic index of appearance was very high for one group of parasites (i.e., ticks). The parasitic prevalence was 42.13 % on rodents, and mites were the most prevalent parasite species. Overall, this study was carried out to establish baseline data for ectoparasite-infested rodents in Hail region, Saudi Arabia, and may help for appropriate planning to control zoonotic diseases in this area.

  5. The Asian house shrew Suncus murinus as a reservoir and source of human outbreaks of plague in Madagascar.

    Science.gov (United States)

    Rahelinirina, Soanandrasana; Rajerison, Minoarisoa; Telfer, Sandra; Savin, Cyril; Carniel, Elisabeth; Duplantier, Jean-Marc

    2017-11-01

    Identifying key reservoirs for zoonoses is crucial for understanding variation in incidence. Plague re-emerged in Mahajanga, Madagascar in the 1990s but there has been no confirmed case since 1999. Here we combine ecological and genetic data, from during and after the epidemics, with experimental infections to examine the role of the shrew Suncus murinus in the plague epidemiological cycle. The predominance of S. murinus captures during the epidemics, their carriage of the flea vector and their infection with Yersinia pestis suggest they played an important role in the maintenance and transmission of plague. S. murinus exhibit a high but variable resistance to experimental Y. pestis infections, providing evidence of its ability to act as a maintenance host. Genetic analyses of the strains isolated from various hosts were consistent with two partially-linked transmission cycles, with plague persisting within the S. murinus population, occasionally spilling over into the rat and human populations. The recent isolation from a rat in Mahajanga of a Y. pestis strain genetically close to shrew strains obtained during the epidemics reinforces this hypothesis and suggests circulation of plague continues. The observed decline in S. murinus and Xenopsylla cheopis since the epidemics appears to have decreased the frequency of spillover events to the more susceptible rats, which act as a source of infection for humans. Although this may explain the lack of confirmed human cases in recent years, the current circulation of plague within the city highlights the continuing health threat.

  6. The Asian house shrew Suncus murinus as a reservoir and source of human outbreaks of plague in Madagascar.

    Directory of Open Access Journals (Sweden)

    Soanandrasana Rahelinirina

    2017-11-01

    Full Text Available Identifying key reservoirs for zoonoses is crucial for understanding variation in incidence. Plague re-emerged in Mahajanga, Madagascar in the 1990s but there has been no confirmed case since 1999. Here we combine ecological and genetic data, from during and after the epidemics, with experimental infections to examine the role of the shrew Suncus murinus in the plague epidemiological cycle. The predominance of S. murinus captures during the epidemics, their carriage of the flea vector and their infection with Yersinia pestis suggest they played an important role in the maintenance and transmission of plague. S. murinus exhibit a high but variable resistance to experimental Y. pestis infections, providing evidence of its ability to act as a maintenance host. Genetic analyses of the strains isolated from various hosts were consistent with two partially-linked transmission cycles, with plague persisting within the S. murinus population, occasionally spilling over into the rat and human populations. The recent isolation from a rat in Mahajanga of a Y. pestis strain genetically close to shrew strains obtained during the epidemics reinforces this hypothesis and suggests circulation of plague continues. The observed decline in S. murinus and Xenopsylla cheopis since the epidemics appears to have decreased the frequency of spillover events to the more susceptible rats, which act as a source of infection for humans. Although this may explain the lack of confirmed human cases in recent years, the current circulation of plague within the city highlights the continuing health threat.

  7. Comparative ecotoxicity of potential biofuels to water flea (Daphnia magna), zebrafish (Danio rerio) and Chinese hamster (Cricetulus griseus) V79 cells.

    Science.gov (United States)

    Heger, Sebastian; Du, Miaomiao; Bauer, Kevin; Schäffer, Andreas; Hollert, Henner

    2018-08-01

    The ecotoxicity of two biofuel candidates (1‑octanol and 2‑butanone) was investigated by an integrative test strategy using three bioassays: the acute immobilisation test with water flea (D. magna), the fish embryo acute toxicity test with zebrafish (Danio rerio) and the in vitro micronucleus assay with Chinese hamster (Cricetulus griseus) V79 cells. The median effective concentration (EC 50 ) values were 14.9±0.66mgL -1 for 1‑octanol, and 2152.1±44.6mgL -1 for 2‑butanone in the D. magna test. Both 1‑octanol and 2‑butanone caused teratogenic and lethal effects on zebrafish embryos, while exposure to 1‑octanol significantly induced these effects at concentrations ≥2.0mgL -1 . These results indicate that 1‑octanol exert much higher ecotoxicity than 2‑butanone to D. magna and zebrafish embryos. Moreover, both 1‑octanol and 2‑butanone did not cause significant genotoxic effects, while their metabolites significantly induced micronuclei in V79 cells. The present study proposed an integrative test approach to evaluate the potential ecotoxicity of biofuels using simple, quick and inexpensive bioassays. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Comparative Global Gene Expression Profiles of Wild-Type Yersinia pestis CO92 and Its Braun Lipoprotein Mutant at Flea and Human Body Temperatures

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    Cristi L. Galindo

    2010-01-01

    Full Text Available Braun/murein lipoprotein (Lpp is involved in inflammatory responses and septic shock. We previously characterized a Δlpp mutant of Yersinia pestis CO92 and found that this mutant was defective in surviving in macrophages and was attenuated in a mouse inhalation model of plague when compared to the highly virulent wild-type (WT bacterium. We performed global transcriptional profiling of WT Y. pestis and its Δlpp mutant using microarrays. The organisms were cultured at 26 and 37 degrees Celsius to simulate the flea vector and mammalian host environments, respectively. Our data revealed vastly different effects of lpp mutation on the transcriptomes of Y. pestis grown at 37 versus 26C. While the absence of Lpp resulted mainly in the downregulation of metabolic genes at 26C, the Y. pestis Δlpp mutant cultured at 37C exhibited profound alterations in stress response and virulence genes, compared to WT bacteria. We investigated one of the stress-related genes (htrA downregulated in the Δlpp mutant relative to WT Y. pestis. Indeed, complementation of the Δlpp mutant with the htrA gene restored intracellular survival of the Y. pestis Δlpp mutant. Our results support a role for Lpp in Y. pestis adaptation to the host environment, possibly via transcriptional activation of htrA.

  9. Invertebrate vectors, parasites, and rickettsial agents in Guam

    Directory of Open Access Journals (Sweden)

    Johnson, J.

    2012-12-01

    Full Text Available We conducted a 3-week field study of ectoparasites of humans and domestic animals throughout Guam. Thirteen species of ectoparasitic arthropods were collected. Ectoparasites of medical or veterinary significance included the ticks Rhipicephalus sanguineus and Rhipicephalus microplus, fleas Ctenocephalides felis and Xenopsylla cheopsis, and the head louse Pediculus humanus capitis. Polymerase chain reaction based screening for rickettsial and protozoan pathogens detected pathogens in eight arthropods. These included Anaplasma platys, Coxiella burnetii, Babesia canis vogeli, and Hepatozoon canis.

  10. Ectoparasitos de roedores da região urbana de Belo Horizonte, MG. I. Interação entre ectoparasitos e hospedeiros Ectoparasites of rodents of the urban region of Belo Horizonte MG I. Interaction between ectoparasites and hosts

    Directory of Open Access Journals (Sweden)

    Pedro Marcos Linardi

    1984-06-01

    Full Text Available Um levantamento de ectoparasitos de roedores domesticos da região urbana de Belo Horizonte, Minas Gerais, Brasil, foi realizado no período de junho de 1980 a setembro de 1982. As espécies de ectoparasitos capturadas de 950 Rattus norvegicus foram: Xenopsylla cheopis, Ctenocephalides felis felis, Polyplax spinulosa, Laelaps nuttalli, Eschinolaelaps echidninus e Atricholaelaps glasgowi, esta ultima apenas representada por três exemplares intercambiados com roedores silvestres. As espécies P. spinulosa e L. nuttalli, embora cosmopolitas, sao registradas pela primeira vez no Estado de Minas Gerais. A relação entre os sexos dos ectoparasitos bem como a prevalência de pulgas, ácaros e piolho por sexos separados de roedores são apresentadas. 66,9% dos roedores estavam infestados por ácaros, quase duas vezes mais do que as infestações por pulgas e piolho conjuntamente (39%. L. nuttalli foi a espécie mais numerosa e a que apresentou o maior índice de infestação: 55,1%. As infestações simples e associadas se equivaleram numericamente. P. spinulosa, ao contrário de L. nuttalli, raramente ocorreu em infestações simples. Dados sobre a distribuição dos ectoparasitos nos roedores sao também assinalados. A infestação observada em Belo Horizonte e confrontada com aquelas obtidas por outros autores em algumas cidades do mundo.A rodent ectoparasite survey was made in the city of Belo Horizonte, Minas Gerais, Brazil, from June 1980 to September 1982. The species of ectoparasites captured from 950 Rattus norvegicus norvegicus were: Xenopsylla cheopis, Ctenocephalides felis felis, Polyplax spinulosa, Laelaps nuttalli, Echinolaelaps echidninus and Atricholaelaps glasgowi, the last species only represented by three specimens interchanged with wild rodent. P. spinulosa and L. nuttalli, although cosmopolitan, are recorded for the first time in State of Minas Gerais. The sex ratio of the ectoparasites, as well as the prevalence of fleas, mites

  11. Distributional data and taxonomic notes on the flea Strepsylla (Siphonaptera: Ctenophthalmidae: Neopsyllinae: Phalacropsyllini Datos de distribución y notas taxonómicas de las especies de Strepsylla (Siphonaptera: Ctenophthalmidae: Neopsyllinae: Phalacropsyllini

    Directory of Open Access Journals (Sweden)

    Roxana Acosta

    2011-12-01

    Full Text Available Strepsylla Traub, 1950 is considered a New World flea genus, parasitizing, in most cases, species of Muridae, particularly peromyscines. Thirteen species of Strepsylla are addressed with respect to their taxonomic characters, host preferences and geographic distribution. A detailed list of material is included.Strepsylla Traub, 1950 es considerado un género de pulgas del nuevo mundo, que en la mayoría de los casos parasitan múridos, particularmente peromisinos. Se comentan algunos de los caracteres taxonómicos, preferencia de huéspedes, distribución geográfica y el material examinado de las 13 especies del género.

  12. Evaluation of the long-term efficacy and safety of an imidacloprid 10%/flumethrin 4.5% polymer matrix collar (Seresto® in dogs and cats naturally infested with fleas and/or ticks in multicentre clinical field studies in Europe

    Directory of Open Access Journals (Sweden)

    Stanneck Dorothee

    2012-03-01

    Full Text Available Abstract Background The objective of these two GCP multicentre European clinical field studies was to evaluate the long-term efficacy and safety of a new imidacloprid/flumethrin collar (Seresto®, Bayer AnimalHealth, Investigational Veterinary Product(IVP in dogs and cats naturally infested with fleas and/or ticks in comparison to a dimpylat collar ("Ungezieferband fuer Hunde/fuer Katzen", Beaphar, Control Product (CP. Methods 232 (IVP and 81 (CP cats and 271(IVP and 129 (CP dogs were treated with either product according to label claims and formed the safety population. Flea and tick counts were conducted in monthly intervals for up to 8 months in the efficacy subpopulation consisting of 118 (IVP + 47 (CP cats and 197 (IVP + 94 (CP dogs. Efficacy was calculated as reduction of infestation rate within the same treatment group and statistically compared between the two treatment groups. Results Preventive efficacy against fleas in cats/dogs varied in the IVP group between 97.4%/94.1% and 100%/100% (overall mean: 98.3%/96.7% throughout the 8 month period and in the CP group between 57.1%/28.2% and 96.1%/67.8% (overall mean: 79.3%/57.9%. Preventive efficacy against ticks in cats/dogs varied in the IVP group between 94.0%/91.2% and 100%/100% (overall mean: 98.4%/94.7% throughout the 8 month period and in the CP group between 90.7%/79.9% and 100%/88.0% (overall mean: 96.9%/85.6%. The IVP group was statistically non-inferior to the CP group, and on various assessment days, statistical superiority was proven for flea and tick count reduction in dogs and cats. Both treatments proved to be safe in dogs and cats with mainly minor local observations at the application site. There was moreover, no incidence of any mechanical problem with the collar in dogs and cats during the entire study period. Conclusions The imidacloprid/flumethrin collar proved to reduce tick counts by at least 90% and flea counts by at least 95% for a period of at least 7-8 months in

  13. Evaluation of the long-term efficacy and safety of an imidacloprid 10%/flumethrin 4.5% polymer matrix collar (Seresto®) in dogs and cats naturally infested with fleas and/or ticks in multicentre clinical field studies in Europe

    Science.gov (United States)

    2012-01-01

    Background The objective of these two GCP multicentre European clinical field studies was to evaluate the long-term efficacy and safety of a new imidacloprid/flumethrin collar (Seresto®, Bayer AnimalHealth, Investigational Veterinary Product(IVP)) in dogs and cats naturally infested with fleas and/or ticks in comparison to a dimpylat collar ("Ungezieferband fuer Hunde/fuer Katzen", Beaphar, Control Product (CP)). Methods 232 (IVP) and 81 (CP) cats and 271(IVP) and 129 (CP) dogs were treated with either product according to label claims and formed the safety population. Flea and tick counts were conducted in monthly intervals for up to 8 months in the efficacy subpopulation consisting of 118 (IVP) + 47 (CP) cats and 197 (IVP) + 94 (CP) dogs. Efficacy was calculated as reduction of infestation rate within the same treatment group and statistically compared between the two treatment groups. Results Preventive efficacy against fleas in cats/dogs varied in the IVP group between 97.4%/94.1% and 100%/100% (overall mean: 98.3%/96.7%) throughout the 8 month period and in the CP group between 57.1%/28.2% and 96.1%/67.8% (overall mean: 79.3%/57.9%). Preventive efficacy against ticks in cats/dogs varied in the IVP group between 94.0%/91.2% and 100%/100% (overall mean: 98.4%/94.7%) throughout the 8 month period and in the CP group between 90.7%/79.9% and 100%/88.0% (overall mean: 96.9%/85.6%). The IVP group was statistically non-inferior to the CP group, and on various assessment days, statistical superiority was proven for flea and tick count reduction in dogs and cats. Both treatments proved to be safe in dogs and cats with mainly minor local observations at the application site. There was moreover, no incidence of any mechanical problem with the collar in dogs and cats during the entire study period. Conclusions The imidacloprid/flumethrin collar proved to reduce tick counts by at least 90% and flea counts by at least 95% for a period of at least 7-8 months in cats and dogs

  14. treated rats

    African Journals Online (AJOL)

    aghomotsegin

    2014-01-08

    Jan 8, 2014 ... nucleus, bizarre segmentation; (I) shows hypersegmentation, bizarre segmentation of neutrophils in the shape of ring nucleus with polychromatophilic RBCs. 1998; Muller and Tobin, 1980). The current study shows that rats administered C. edulis hydro-ethanol extract, orally for 28 days, developed anemia, ...

  15. RatMap--rat genome tools and data.

    Science.gov (United States)

    Petersen, Greta; Johnson, Per; Andersson, Lars; Klinga-Levan, Karin; Gómez-Fabre, Pedro M; Ståhl, Fredrik

    2005-01-01

    The rat genome database RatMap (http://ratmap.org or http://ratmap.gen.gu.se) has been one of the main resources for rat genome information since 1994. The database is maintained by CMB-Genetics at Goteborg University in Sweden and provides information on rat genes, polymorphic rat DNA-markers and rat quantitative trait loci (QTLs), all curated at RatMap. The database is under the supervision of the Rat Gene and Nomenclature Committee (RGNC); thus much attention is paid to rat gene nomenclature. RatMap presents information on rat idiograms, karyotypes and provides a unified presentation of the rat genome sequence and integrated rat linkage maps. A set of tools is also available to facilitate the identification and characterization of rat QTLs, as well as the estimation of exon/intron number and sizes in individual rat genes. Furthermore, comparative gene maps of rat in regard to mouse and human are provided.

  16. Rat Genome Database (RGD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Rat Genome Database (RGD) is a collaborative effort between leading research institutions involved in rat genetic and genomic research to collect, consolidate,...

  17. Immunology taught by rats

    OpenAIRE

    Klenerman, P; Barnes, EJ

    2017-01-01

    Immunology may be best taught by viruses, and possibly by humans, but the rats of New York City surprisingly also have plenty to offer. A survey published in 2014 of the pathogens carried by rats trapped in houses and parks in Manhattan identified a huge burden of infectious agents in these animals, including several novel viruses. Among these are Norway rat hepaciviruses (NrHVs), which belong to the same family as hepatitis C virus (HCV). NrHVs were found in rat livers, raising the possibili...

  18. RatMap—rat genome tools and data

    Science.gov (United States)

    Petersen, Greta; Johnson, Per; Andersson, Lars; Klinga-Levan, Karin; Gómez-Fabre, Pedro M.; Ståhl, Fredrik

    2005-01-01

    The rat genome database RatMap (http://ratmap.org or http://ratmap.gen.gu.se) has been one of the main resources for rat genome information since 1994. The database is maintained by CMB–Genetics at Göteborg University in Sweden and provides information on rat genes, polymorphic rat DNA-markers and rat quantitative trait loci (QTLs), all curated at RatMap. The database is under the supervision of the Rat Gene and Nomenclature Committee (RGNC); thus much attention is paid to rat gene nomenclature. RatMap presents information on rat idiograms, karyotypes and provides a unified presentation of the rat genome sequence and integrated rat linkage maps. A set of tools is also available to facilitate the identification and characterization of rat QTLs, as well as the estimation of exon/intron number and sizes in individual rat genes. Furthermore, comparative gene maps of rat in regard to mouse and human are provided. PMID:15608244

  19. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Petersen, L. B.

    This report presents the results from the design analyses made for the clustered suction caisson used as foundation for a Riser Access Tower (RAT). The RAT is intended built next to the K15-FA-1 Platform in the Dutch Sector of the North Sea....

  20. Colon of the rat

    International Nuclear Information System (INIS)

    Lindstroem, C.G.; Rosengren, J.-E.; Fork, F.-T.

    1979-01-01

    The anatomy and radiologic appearance of the colon in rats are described on the basis of 300 animals treated with carcinogenic agents and 40 normal rats. The macroscopic and microscopic appearance of the mucosa varies in the different parts of the colon. Lymphoid plaques are normal structures. The results justify a new anatomic nomenclature. (Auth.)

  1. Cethromycin-mediated protection against the plague pathogen Yersinia pestis in a rat model of infection and comparison with levofloxacin.

    Science.gov (United States)

    Rosenzweig, Jason A; Brackman, Sheri M; Kirtley, Michelle L; Sha, Jian; Erova, Tatiana E; Yeager, Linsey A; Peterson, Johnny W; Xu, Ze-Qi; Chopra, Ashok K

    2011-11-01

    The Gram-negative plague bacterium, Yersinia pestis, has historically been regarded as one of the deadliest pathogens known to mankind, having caused three major pandemics. After being transmitted by the bite of an infected flea arthropod vector, Y. pestis can cause three forms of human plague: bubonic, septicemic, and pneumonic, with the latter two having very high mortality rates. With increased threats of bioterrorism, it is likely that a multidrug-resistant Y. pestis strain would be employed, and, as such, conventional antibiotics typically used to treat Y. pestis (e.g., streptomycin, tetracycline, and gentamicin) would be ineffective. In this study, cethromycin (a ketolide antibiotic which inhibits bacterial protein synthesis and is currently in clinical trials for respiratory tract infections) was evaluated for antiplague activity in a rat model of pneumonic infection and compared with levofloxacin, which operates via inhibition of bacterial topoisomerase and DNA gyrase. Following a respiratory challenge of 24 to 30 times the 50% lethal dose of the highly virulent Y. pestis CO92 strain, 70 mg of cethromycin per kg of body weight (orally administered twice daily 24 h postinfection for a period of 7 days) provided complete protection to animals against mortality without any toxic effects. Further, no detectable plague bacilli were cultured from infected animals' blood and spleens following cethromycin treatment. The antibiotic was most effective when administered to rats 24 h postinfection, as the animals succumbed to infection if treatment was further delayed. All cethromycin-treated survivors tolerated 2 subsequent exposures to even higher lethal Y. pestis doses without further antibiotic treatment, which was related, in part, to the development of specific antibodies to the capsular and low-calcium-response V antigens of Y. pestis. These data demonstrate that cethromycin is a potent antiplague drug that can be used to treat pneumonic plague.

  2. Fleas on wild birds in Costa Rica

    Czech Academy of Sciences Publication Activity Database

    Acosta, R.; Literák, I.; Sychra, O.; Čapek, Miroslav

    2013-01-01

    Roč. 115, č. 1 (2013), s. 1-8 ISSN 0013-8797 R&D Projects: GA AV ČR IAA601690901 Institutional support: RVO:68081766 Keywords : Ceratophyllus * Dasypsyllus * Plusaetis * Siphonaptera Subject RIV: EG - Zoology Impact factor: 0.479, year: 2013

  3. Individually reared rats

    International Nuclear Information System (INIS)

    Kraeuchi, K.; Gentsch, C.; Feer, H.

    1981-01-01

    The influence of social isolation in rats on postsynaptic alpha 1 - and beta-adrenergic receptors, on the cAMP generating system and on the presynaptic uptake mechanism in the central noradrenergic system was examined in different brain regions. Rearing rats in isolation from the 19th day of life for 12 weeks leads in all regions to a general tendency for a reduction in 3 H-DHA binding, to an enhanced 3 H-WB4101 binding and to a decreased responsiveness of the noradrenaline sensitive cAMP generating system. These changes reach significance only in the pons-medulla-thallamusregion. Isolated rats showed an increased synaptosomal uptake of noradrenaline, most pronounced and significant in the hypothalamus. Our data provide further support for a disturbance in central noradrenergic function in isolated rats. (author)

  4. Structure of the vitreoretinal border region in spontaneously hypertensive rats (SHR rats)

    DEFF Research Database (Denmark)

    Heegaard, Steffen

    1993-01-01

    Øjenpatologi, vitreoretinal border region, inner limiting membrane of the retina, spontaneously hypertensive rats, SHR rats, ultrastructure......Øjenpatologi, vitreoretinal border region, inner limiting membrane of the retina, spontaneously hypertensive rats, SHR rats, ultrastructure...

  5. Rat bite fever.

    NARCIS (Netherlands)

    Gaastra, W.; Boot, R.G.A.; Ho, H.; Lipman, L.J.A.

    2009-01-01

    Rat bite fever (RBF) is a bacterial zoonosis for which two causal bacterial species have been identified: Streptobacillis moniliformis and Spirillum minus. Haverhill fever (HF) is a form of S. moniliformis infection believed to develop after ingestion of contaminated food or water. Here the

  6. Laughing rats are optimistic.

    Directory of Open Access Journals (Sweden)

    Rafal Rygula

    Full Text Available Emotions can bias human decisions- for example depressed or anxious people tend to make pessimistic judgements while those in positive affective states are often more optimistic. Several studies have reported that affect contingent judgement biases can also be produced in animals. The animals, however, cannot self-report; therefore, the valence of their emotions, to date, could only be assumed. Here we present the results of an experiment where the affect-contingent judgement bias has been produced by objectively measured positive emotions. We trained rats in operant Skinner boxes to press one lever in response to one tone to receive a food reward and to press another lever in response to a different tone to avoid punishment by electric foot shock. After attaining a stable level of discrimination performance, the animals were subjected to either handling or playful, experimenter-administered manual stimulation - tickling. This procedure has been confirmed to induce a positive affective state in rats, and the 50-kHz ultrasonic vocalisations (rat laughter emitted by animals in response to tickling have been postulated to index positive emotions akin to human joy. During the tickling and handling sessions, the numbers of emitted high-frequency 50-kHz calls were scored. Immediately after tickling or handling, the animals were tested for their responses to a tone of intermediate frequency, and the pattern of their responses to this ambiguous cue was taken as an indicator of the animals' optimism. Our findings indicate that tickling induced positive emotions which are directly indexed in rats by laughter, can make animals more optimistic. We demonstrate for the first time a link between the directly measured positive affective state and decision making under uncertainty in an animal model. We also introduce innovative tandem-approach for studying emotional-cognitive interplay in animals, which may be of great value for understanding the emotional

  7. Tubuloglomerular feedback in Dahl rats

    DEFF Research Database (Denmark)

    Karlsen, F M; Leyssac, P P; Holstein-Rathlou, N H

    1998-01-01

    in both Dahl-S and salt-resistant Dahl rats on high- and low-salt diets. TGF was investigated in the closed-loop mode with a videometric technique, in which the response in late proximal flow rate to perturbations in Henle flow rate was measured. All Dahl rats showed a similar compensatory response...

  8. Neutron radiography of osteopetrotic rat

    International Nuclear Information System (INIS)

    Graf, B.; Renard, G.; Le Gall, J.; Laporte, A.

    1983-01-01

    The osteopetrotic disease is characterized by bone and cartilage tissue coexistence in the medullary space of long bones. The authors have studied ''congenital osteopetrosis'' of ''op'' rats. Comparing radiography, neutrography and histology, the evolution of the ''osteopetrotic disease'' and the healing of the ill rats by a single injection of bone marrow from normal animals is shown. (Auth.)

  9. The three-kidney rat

    International Nuclear Information System (INIS)

    Provoost, A.P.; Van Aken, M.

    1984-01-01

    In contrast to the numerous research into the adaption of renal function when nephons are lost, much less attention has been paid to the effects of an extra kidney. Through the availability of inbred rat strains, techniques to transplant rat kidneys, and methods to measure total and individual kidney function repeatedly in the same animal, it became possible to study the renal function in rats with three kidneys. Adult male rats of a highly inbred Wistar strain were used. Nine recipients of a third kidney (3-K) were compared with 5 sham operated control (2-K) rats. The total GFR, as measured by the plasma clearance of Cr-5l EDTA, was taken 1,3,6,9, and 15 weeks after operation. The contribution of each kidney to the total renal function was determined by a Tc-99m DTPA scan performed at weeks 10 and 16. After transplantation the total GFR of 3-K rats was, in general, not different from the value before transplantation or from that of 2-K rats. The lack of increase of the GFR of 3-K rats was not the result of a non-functioning graft

  10. Do rats have orgasms?

    Science.gov (United States)

    Pfaus, James G.; Scardochio, Tina; Parada, Mayte; Gerson, Christine; Quintana, Gonzalo R.; Coria-Avila, Genaro A.

    2016-01-01

    Background Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Method Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs) in other species: 1) physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2) short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3) long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Results Both male and female rats display behavioral patterns consistent with OLRs. Conclusions The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research. PMID:27799081

  11. Do rats have orgasms?

    Directory of Open Access Journals (Sweden)

    James G. Pfaus

    2016-10-01

    Full Text Available Background: Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Method: Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs in other species: 1 physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2 short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3 long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Results: Both male and female rats display behavioral patterns consistent with OLRs. Conclusions: The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research.

  12. The academic rat race

    DEFF Research Database (Denmark)

    Landes, Xavier; Andersen, Martin Marchman; Nielsen, Morten Ebbe Juul

    2012-01-01

    : an increased pressure to produce articles (in peer-reviewed journals) has created an unbalanced emphasis on the research criterion at the expense of the latter two. More fatally, this pressure has turned academia into a rat race, leading to a deep change in the fundamental structure of academic behaviour......, and entailing a self-defeating and hence counter-productive pattern, where more publications is always better and where it becomes increasingly difficult for researchers to keep up with the new research in their field. The article identifies the pressure to publish as a problem of collective action. It ends up...

  13. Observations on the endemicity of plague in Karatu and Ngorongoro, northern Tanzania.

    Science.gov (United States)

    Kilonzo, B S; Mbise, T J; Mwalimu, D C; Kindamba, L

    2006-01-01

    Commensal and field rodents and wild small carnivores were live-trapped in five villages of Karatu district and one settlement in the Ngorongoro Conservation Area in Ngorongoro district in Tanzania. Blood samples were taken and serologically tested for plague, using the Blocking ELISA technique. Some domestic dogs and cats in the Karatu villages were aseptically bled and similarly tested for plague. Fleas were collected from the examined animals and from randomly selected residential houses. A total of 241 rodents, 1 Crocidura spp, 43 dogs, 12 cats and 4 slender mongooses were involved in the survey. Of the rodents, 14.5% were infested with fleas, which comprised of Xenopsylla brasiliensis (45.8%) and Dinopsyllus lypusus (54.2%), with an overall population density of 0.2 fleas/animal. Thirty one (72.1%) of the dogs were infested with fleas, all of which were Ctenocephalides spp. Thirty five (63.3%) houses were infested with fleas whose population was composed of Ctenocephalides spp, Pulex irritans, Tunga penetrans and Echinophaga gallinacea. Infected rodents were found in all the villages while the infected dog was found at Rhotia-Kati. Nineteen (11%) of the rodents and one (2%) dog harboured specific plague antibodies. It was broadly concluded that sylvatic plague was endemic in Karatu district and Ngorongoro Conservation Area and that outbreaks of the disease can occur in the area any time if and when relevant conditions become favourable. Prompt application of appropriate preventive and control measures and survey for substantiating the status in the Lake Manyara National Park, which is adjacent to some of the infected villages, are recommended.

  14. The Rat Race

    CERN Multimedia

    Stephen Haywood

    Dear Muriel, Being an animal, you are probably more familiar with rats than most of us. Yet it seems to me that our Community (not just ATLAS) is stuck in a huge "rat race". I am somewhat mystified as to how we have got ourselves into this and I wonder whether you or your readers could explain this - I give my own observations below. In HEP and ATLAS specifically, we are all working long hours and we are all becoming exhausted. There are people at Point 1 who are working day and night, every day of the week; there are people writing software who send emails round the clock, including weekends. It is one thing to have bursts of activity which require us to put in some longer hours, but in ATLAS, the bursts last months or years. I have been on ATLAS 14 years and it has felt like one endless rush. Why do we do this? We are all highly motivated, we love our work and want to succeed individually and collectively. We are parts of various teams, and we do not want to let the side down. We worked hard at school an...

  15. Serotonin metabolism in rat brain

    International Nuclear Information System (INIS)

    Schutte, H.H.

    1976-01-01

    The metabolism of serotonin in rat brain was studied by measuring specific activities of tryptophan in plasma and of serotonin, 5-hydroxyindole acetic acid and tryptophan in the brain after intravenous injection of tritiated tryptophan. For a detailed analysis of the specific activities, a computer simulation technique was used. It was found that only a minor part of serotonin in rat brain is synthesized from tryptophan rapidly transported from the blood. It is suggested that the brain tryptophan originates from brain proteins. It was also found that the serotonin in rat brain is divided into more than one metabolic compartment

  16. Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

    International Nuclear Information System (INIS)

    Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

    1986-01-01

    Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-β endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I 125 h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables

  17. Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

    1986-01-20

    Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-..beta.. endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I/sup 125/ h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables.

  18. Wild Rodent Ectoparasites Collected from Northwestern Iran

    Directory of Open Access Journals (Sweden)

    Zabihollah Zarei

    2017-04-01

    Full Text Available Background: Rodents play an important role as reservoir of some pathogens, and the host of some ectoparasites as well. These ectoparasites can transmit rodents’ pathogens to human or animals. The aim of this study was to assess the distribution and infestation load of ectoparasites on rodents in Meshkin-Shahr District, northwestern Iran.Method: Rodents were captured using baited live traps in spring 2014 from Meshkin-Shahr District and were trans­ferred to the laboratory for identification to the species level. Their ectoparasites were collected, mounted and identi­fied.Results: Three rodent species including Meriones persicus (74%, Mus musculus (16.9% and Cricetulus migrato­rius (9% were identified. Among all rodents, 185 specimens (90.69% were infested with a total of 521 ectopara­sites. Overall, 10 arthropods species were collected, including fleas (97.6%, one mite (1.6% and one louse species (0.6% as follows: Xenopsylla nubica, X. astia, X. buxtoni, X. cheopis, Nosopsyllus fasciatus, N. iranus, Cten­ocephalides felis, Ctenophthalmus rettigismiti, Ornithonyssus sp and one species of genus Polyplax. The most prev­alent ectoparasites species was X. nubica (89%.Conclusion: Nearly all rodent species were infested with Xenopsylla species. Monitoring of ectoparasites on infested rodents is very important for awareness and early warning towards control of arthropod-borne diseases.

  19. Intramitochondrial autonomy in rat tissues

    International Nuclear Information System (INIS)

    Subramanian, M.; Rajwade, M.S.; Satav, J.G.; Katyare, S.S.; Fatterpaker, P.; Sreenivasan, A.

    1974-01-01

    The biogenesis of mitochondria in rat liver and their protein turnover has been investigated using 1- 14 C leucine. The results indicate that intramitochondrial autonomy exists both with respect to their genesis and turnover. (M.G.B.)

  20. Autoshaping in micrencephalic rats

    International Nuclear Information System (INIS)

    Goldstein, L.H.; Oakley, D.A.

    1989-01-01

    An autoshaping procedure in which the illumination of a lever was predictive of food reinforcement was used to compare learning in rats with micrencephaly induced by irradiation on the 16th day of gestation and in sham-irradiated controls. Both groups showed equivalent levels of lever-directed activity, and the micrencephalic animals differentiated as well as the control animals between the predictive lever and a nonpredictive lever. The micrencephalic animals were able to redistribute their lever-directed activity when the significance of the levers was reversed and did so more readily than the control animals. Results support the claim that association learning survives either traumatic or developmental neocortical damage and have implications for remedial procedures following both head injury and developmental cerebral pathology in humans

  1. Autoshaping in micrencephalic rats.

    Science.gov (United States)

    Goldstein, L H; Oakley, D A

    1989-06-01

    An autoshaping procedure in which the illumination of a lever was predictive of food reinforcement was used to compare learning in rats with micrencephaly induced by irradiation on the 16th day of gestation and in sham-irradiated controls. Both groups showed equivalent levels of lever-directed activity, and the micrencephalic animals differentiated as well as the control animals between the predictive lever and a nonpredictive lever. The micrencephalic animals were able to redistribute their lever-directed activity when the significance of the levers was reversed and did so more readily than the control animals. Results support the claim that association learning survives either traumatic or developmental neocortical damage and have implications for remedial procedures following both head injury and developmental cerebral pathology in humans.

  2. Biokinetics of radiotellurium in rats

    International Nuclear Information System (INIS)

    Nishimura, Y.; Sahoo, S.K.; Kim, S.; Homma-Takeda, S.; Watanabe, Y.; Inaba, J.

    2003-01-01

    Radiotellurium is present in the environment primarily due to its release during nuclear reactor accidents. Little is known of tellurium metabolism in juveniles, although the element is relatively abundant and has a number of industrial uses. A biokinetic study of radiotellurium in rats was done using gamma-ray counting. Wistar strain rats were used to determine the uptake of H 2 123 Te m O 3 by the whole-body retention of juvenile rats and the conceptus in relation to its gestational stages, by measurements in the placenta, fetal membranes, fetal fluid, and fetus. The whole-body retention of 123 Te m in juvenile rats was higher than that of adult rats. The relative concentration in the placenta and fetal membranes was higher than in the fetus. No activity was observed in the fetal fluid. These results indicate that the placenta and fetal membranes play significant roles as barriers to the transfer of 123 Te m into the fetus. The ratio, relative concentration in fetus/relative concentration in mother (C F /C M ), was calculated. The C F /C M ratio was dependent on the stage of gestation and ranged from 0.2 to 0.5. A little 123 Te m was transferred to the suckling rats through the mother's milk when the isotope was administered intravenously to the mother. (author)

  3. Tryptophan depletion affects compulsive behaviour in rats

    DEFF Research Database (Denmark)

    Merchán, A; Navarro, S V; Klein, A B

    2017-01-01

    investigated whether 5-HT manipulation, through a tryptophan (TRP) depletion by diet in Wistar and Lister Hooded rats, modulates compulsive drinking in schedule-induced polydipsia (SIP) and locomotor activity in the open-field test. The levels of dopamine, noradrenaline, serotonin and its metabolite were......-depleted HD Wistar rats, while the LD Wistar and the Lister Hooded rats did not exhibit differences in SIP. In contrast, the TRP-depleted Lister Hooded rats increased locomotor activity compared to the non-depleted rats, while no differences were found in the Wistar rats. Serotonin 2A receptor binding...

  4. Population Structure of Rat-Derived Pneumocystis carinii in Danish Wild Rats

    DEFF Research Database (Denmark)

    Palmer, Robert J.; Settnes, Osvald P.; Lodal, Jens

    2000-01-01

    The rat model of Pneumocystis carinii pneumonia is frequently used to study human P. carinii infection, but there are many differences between the rat and human infections. We studied naturally acquired P. carinii in wild rats to examine the relevance of the rat model for human infection. P. cari...

  5. DOPA, norepinephrine, and dopamine in rat tissues

    DEFF Research Database (Denmark)

    Eldrup, E; Richter, Erik; Christensen, N J

    1989-01-01

    We studied the effect of unilateral sympathectomy on rat quadriceps and gastrocnemius muscle concentrations of endogenous dihydroxyphenylalanine (DOPA), dopamine (DA), and norepinephrine (NE) and assessed the relationships between these catecholamines in several rat tissues. Catecholamines were...

  6. False Context Fear Memory in Rats

    Science.gov (United States)

    Bae, Sarah; Holmes, Nathan M.; Westbrook, R. Frederick

    2015-01-01

    Four experiments used rats to study false context fear memories. In Experiment 1, rats were pre-exposed to a distinctive chamber (context A) or to a control environment (context C), shocked after a delay in a second chamber (context B) and tested either in B or A. Rats pre-exposed to A froze just as much as control rats in B but more than control…

  7. EFFECT OF ETHANOL ON HEPATOBILIARY TRANSPORT OF CATIONIC DRUGS - A STUDY IN THE ISOLATED-PERFUSED RAT-LIVER, RAT HEPATOCYTES AND RAT MITOCHONDRIA

    NARCIS (Netherlands)

    STEEN, H; MEIJER, DKF; Merema, M.T.

    The effect of ethanol on the hepatic uptake of various cationic drugs was studied in isolated perfused rat livers, isolated rat hepatocytes and isolated rat liver mitochondria. In isolated rat hepatocytes and in isolated perfused rat livers, the uptake of the model organic cation

  8. The serotonin transporter knockout rat : A review

    NARCIS (Netherlands)

    Olivier, Jocelien; Cools, Alexander; Ellenbroek, Bart A.; Cuppen, E.; Homberg, Judith; Kalueff, Allan V.; LaPorte, Justin L.

    2010-01-01

    This chapter dicusses the most recent data on the serotonin transporter knock-out rat, a unique rat model that has been generated by target-selected N-ethyl-N-nitrosourea (ENU) driven mutagenesis. The knock-out rat is the result of a premature stopcodon in the serotonin transporter gene, and the

  9. Tuberculosis Detection by Giant African Pouched Rats

    Science.gov (United States)

    Poling, Alan; Weetjens, Bart; Cox, Christophe; Beyene, Negussie; Durgin, Amy; Mahoney, Amanda

    2011-01-01

    In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

  10. Teratology studies in the rat.

    Science.gov (United States)

    Leroy, Mariline; Allais, Linda

    2013-01-01

    The rat is the rodent species of choice for the regulatory safety testing of xenobiotics, such as medicinal products, food additives, and other chemicals. Many decades of experience and extensive data have accumulated for both general and developmental toxicology investigations in this species. The high fertility and large litter size of the rat are advantages for teratogenicity testing. The study designs are well defined in the regulatory guidelines and are relatively standardized between testing laboratories across the world. Teratology studies address maternal- and embryo-toxicity following exposure during the period of organogenesis. This chapter describes the design and conduct of a teratology study in the rat in compliance with the regulatory guidelines. The procedures for the handling and housing of the pregnant animals, the caesarean examinations and the sampling of fetuses for morphological examinations are described. The utility and design of preliminary studies and the inclusion of satellite animals in the main study for toxicokinetic sampling are discussed.

  11. Voluntary Sleep Loss in Rats

    Science.gov (United States)

    Oonk, Marcella; Krueger, James M.; Davis, Christopher J.

    2016-01-01

    Study Objectives: Animal sleep deprivation (SDEP), in contrast to human SDEP, is involuntary and involves repeated exposure to aversive stimuli including the inability of the animal to control the waking stimulus. Therefore, we explored intracranial self-stimulation (ICSS), an operant behavior, as a method for voluntary SDEP in rodents. Methods: Male Sprague-Dawley rats were implanted with electroencephalography/electromyography (EEG/EMG) recording electrodes and a unilateral bipolar electrode into the lateral hypothalamus. Rats were allowed to self-stimulate, or underwent gentle handling-induced SDEP (GH-SDEP), during the first 6 h of the light phase, after which they were allowed to sleep. Other rats performed the 6 h ICSS and 1 w later were subjected to 6 h of noncontingent stimulation (NCS). During NCS the individual stimulation patterns recorded during ICSS were replayed. Results: After GH-SDEP, ICSS, or NCS, time in nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep increased. Further, in the 24 h after SDEP, rats recovered all of the REM sleep lost during SDEP, but only 75% to 80% of the NREM sleep lost, regardless of the SDEP method. The magnitude of EEG slow wave responses occurring during NREM sleep also increased after SDEP treatments. However, NREM sleep EEG slow wave activity (SWA) responses were attenuated following ICSS, compared to GH-SDEP and NCS. Conclusions: We conclude that ICSS and NCS can be used to sleep deprive rats. Changes in rebound NREM sleep EEG SWA occurring after ICSS, NCS, and GH-SDEP suggest that nonspecific effects of the SDEP procedure differentially affect recovery sleep phenotypes. Citation: Oonk M, Krueger JM, Davis CJ. Voluntary sleep loss in rats. SLEEP 2016;39(7):1467–1479. PMID:27166236

  12. Rat bite fever without fever.

    Science.gov (United States)

    Stehle, P; Dubuis, O; So, A; Dudler, J

    2003-09-01

    Rat bite fever is a rarely reported acute febrile bacterial illness caused by Streptobacillus moniliformis or Spirillum minus following a rat bite. It is classically characterised by abrupt onset of fever with rigors, myalgias, headache, and the appearance of a generalised maculopapular petechial skin rash. Polyarthritis complicates the course of the disease in up to 50% of infected patients, and numerous hurdles can make the diagnosis particularly difficult in the absence of fever or rash, as in the present case. A high degree of awareness is necessary to make the correct diagnosis in such cases. Diagnosis has important prognostic implications as the disease is potentially lethal, but easily treatable.

  13. Treatment of diabetic rats with encapsulated islets.

    Science.gov (United States)

    Sweet, Ian R; Yanay, Ofer; Waldron, Lanaya; Gilbert, Merle; Fuller, Jessica M; Tupling, Terry; Lernmark, Ake; Osborne, William R A

    2008-12-01

    Immunoprotection of islets using bioisolator systems permits introduction of allogeneic cells to diabetic patients without the need for immunosuppression. Using TheraCyte immunoisolation devices, we investigated two rat models of type 1 diabetes mellitus (T1DM), BB rats and rats made diabetic by streptozotocin (STZ) treatment. We chose to implant islets after the onset of diabetes to mimic the probable treatment of children with T1DM as they are usually diagnosed after disease onset. We encapsulated 1000 rat islets and implanted them subcutaneously (SQ) into diabetic biobreeding (BB) rats and STZ-induced diabetic rats, defined as two or more consecutive days of blood glucose>350 mg/dl. Rats were monitored for weight and blood glucose. Untreated BB rats rapidly lost weight and were euthanized at >20% weight loss that occurred between 4 and 10 days from implantation. For period of 30-40 days following islet implantation weights of treated rats remained steady or increased. Rapid weight loss occurred after surgical removal of devices that contained insulin positive islets. STZ-treated rats that received encapsulated islets showed steady weight gain for up to 130 days, whereas untreated control rats showed steady weight loss that achieved >20% at around 55 days. Although islet implants did not normalize blood glucose, treated rats were apparently healthy and groomed normally. Autologous or allogeneic islets were equally effective in providing treatment. TheraCyte devices can sustain islets, protect allogeneic cells from immune attack and provide treatment for diabetic-mediated weight loss in both BB rats and STZ-induced diabetic rats.

  14. Induced Chronic Prostatitis in Rats

    African Journals Online (AJOL)

    Similarly, compared with reference group (176.1 ± 12.1 pg/ml), IL-1β level of prostate tissues of high-dose PCS ..... Fig 1: Effect of PCS extract on the histomorphology of prostate tissues in rats. ... involved with cellular recruitment, fever, acute.

  15. Isolating Lysosomes from Rat Liver.

    Science.gov (United States)

    Pryor, Paul R

    2016-04-01

    This protocol describes the generation of a fraction enriched in lysosomes from rat liver. The lysosomes are rapidly isolated using density-gradient centrifugation with gradient media that retain the osmolarity of the lysosomes such that they are functional and can be used in in vitro assays. © 2016 Cold Spring Harbor Laboratory Press.

  16. CCl4 cirrhosis in rats

    DEFF Research Database (Denmark)

    Fischer-Nielsen, A; Poulsen, H E; Hansen, B A

    1991-01-01

    Cirrhosis of the rat liver was induced by a 12 week individualized CCl4/phenobarbital treatment. After treatment, all surviving animals (81%) showed cirrhosis of the liver. The cirrhosis induced was irreversible when evaluated 24 weeks after cessation of treatment. Quantitative liver function...

  17. Whiskers aid anemotaxis in rats.

    Science.gov (United States)

    Yu, Yan S W; Graff, Matthew M; Bresee, Chris S; Man, Yan B; Hartmann, Mitra J Z

    2016-08-01

    Observation of terrestrial mammals suggests that they can follow the wind (anemotaxis), but the sensory cues underlying this ability have not been studied. We identify a significant contribution to anemotaxis mediated by whiskers (vibrissae), a modality previously studied only in the context of direct tactile contact. Five rats trained on a five-alternative forced-choice airflow localization task exhibited significant performance decrements after vibrissal removal. In contrast, vibrissal removal did not disrupt the performance of control animals trained to localize a light source. The performance decrement of individual rats was related to their airspeed threshold for successful localization: animals that found the task more challenging relied more on the vibrissae for localization cues. Following vibrissal removal, the rats deviated more from the straight-line path to the air source, choosing sources farther from the correct location. Our results indicate that rats can perform anemotaxis and that whiskers greatly facilitate this ability. Because air currents carry information about both odor content and location, these findings are discussed in terms of the adaptive significance of the interaction between sniffing and whisking in rodents.

  18. Acute renal failure in rats

    International Nuclear Information System (INIS)

    Cederholm, C.; Almen, T.; Bergquist, D.; Golman, K.; Takolander, R.; Malmoe Allmaenna Sjukhus

    1989-01-01

    It was demonstrated in rats that renal injury which follows transient renal hypoxia is potentiated by the contrast media metrizoate, ioxaglate, iopamidol and iohexol. Intravenous injection of 1 g I/kg of all four media alone to 82 rats caused no significant increase in serum urea 1, 3 and 7 days later. The percentage increase of serum urea is given in median values and interquartile range (in parentheses). Bilateral renal arterial occlusion alone for 40 minutes in 42 rats increased serum urea one day later by 40% (20-130). Intravenous injection of the media followed in one hour by bilateral renal arterial occlusion for 40 minutes in 104 rats caused serum urea to increase one day later by 130% (70-350) after metrizoate, by 220% (50-380) after ioxaglate, by 290 % (60-420) after iopamidol and by 160% (50-330) after iohexol. There were no significant differences between the potentiating effects of the various media on ischemic renal failure. (orig.)

  19. August rats are more resistant to arrhythmogenic effect of myocardial ischemia and reperfusion than Wistar rats.

    Science.gov (United States)

    Belkina, L M; Kirillina, T N; Pshennikova, M G; Arkhipenko, Yu V

    2002-06-01

    As differentiated from Wistar rats, myocardial ischemia and reperfusion produce no ventricular fibrillation in August rats. Pretreatment with nitric oxide synthase inhibitor Nw-nitro-L-arginine increased mortality rate in August rats with acute myocardial infarction from 20 to 40%. Under these conditions mortality rate in Wistar rats increased from 50 to 71%. Interstrain differences in the resistance of these animals to the arrhythmogenic effect of ischemia are probably associated with higher activity of the nitric oxide system in August rats compared to Wistar rats.

  20. Diminished hormonal responses to exercise in trained rats

    DEFF Research Database (Denmark)

    Galbo, H; Richter, Erik; Holst, J J

    1977-01-01

    Male rats (120 g) either were subjected to a 12-wk physical training program (T rats) or were sedentary controls (C rats). Subsequently the rats were killed at rest or after a 45- or 90-min forced swim. At rest, T rats had higher liver and muscle glycogen concentrations but lower plasma insulin...

  1. Dithiobiuret toxicity in the rat

    International Nuclear Information System (INIS)

    Williams, K.D.

    1985-01-01

    Raising the daily dose of dithiobiuret (DTB) in male rats from 0.5 to 1 to 5 mg/kg shortened the latency to the onset of flaccid muscle tone and associated diminished performance in a treadmill test from 7 to 5 to 3 days, respectively. Concomitant with the development of flaccid muscle tone gastrocnemius muscle contractions elicited by high frequency motor nerve stimulation were lower in peak tension and tended to fade more rapidly in DTB-treated rats than in control rats. Remarkably, rats treated with highly daily doses (10-16 mg/kg) of DTB were resistant to the expected development of DTB-induced flaccid muscle tone, and tetanic contractile abnormalities but a corresponding refractoriness to body weight loss, decreased fed and water intake, diuresis, and depression in water balance was not present. This nonselectivity of the refractory responses supported the results of a histopathological study indicating that DTB-induced neuromuscular toxicity was unlikely to be secondary to effect on other organ systems. It is not known whether the ultimate neurotoxin is DTB or a metabolite. In this regard, two pathways for the metabolism of DTB were proposed based on the results of thin-layer chromatography of urine samples from rats treated with either 14 C- or 35 S-DTB. One pathway involved the reversible oxidation of DTB to the disulfide-containing compound thiuret, and the other involved the replacement of a sulfur atom with oxygen to form monothiobiuret. Thiuret, but not monothiobiuret, possessed comparable toxicity to STB. This further suggested that redox cycling between DTB and thiuret could be an important contributing factor to the toxicity of DTB

  2. Sexual dimorphism in hybrids rats.

    Science.gov (United States)

    Garcia-Falgueras, Alicia; Pinos, Helena; Fernández, Rosa; Collado, Paloma; Pasaro, Eduardo; Segovia, Santiago; Guillamon, Antonio

    2006-12-06

    Laboratory rat strains descend from Wistar rats as a consequence of artificial selection. Previously we reported that the medial posterior division of the bed nucleus of the stria terminalis (BSTMP) was sexually dimorphic in Wistar and Long-Evans strains while the medial anterior division (BSTMA) and the locus coeruleus (LC) only showed sex differences in the ancestor Wistar strain. The lateral posterior division (BSTLP) was isomorphic in both strains. The present work studies the number of neurons in the BSTMP, BSTMA, BSTLP and LC of male and female Wistar and Long-Evans rats (F(0)) and their hybrid F(1) and F(2) generations. The BSTMP is sexually dimorphic in the F(0), F(1) and F(2) generations while sex differences in the LC are only seen in F(0) Wistar rats but not in the F(0) Long-Evans or the F(1) and F(2) hybrid generations. Sex differences in the BSTMA are seen in F(0) Wistar but not in F(0) Long-Evans rats and completely disappear in the F(2) generations. The number of neurons in the LC of both males and females decreased in heterozygotic individuals (F(1)) but increased in homozygotic (F(2)). However, the number of neurons in the BSTMP changes significantly over the generations, although the ratio of neurons (female/male) is stable and unaffected in homo- or heterozygosis. Thus, the mechanism that regulates the neuronal female/male ratio would be different from the one that controls the number of neurons. The facts that sex differences in the BSTMP are not affected by homo- or heterozygosis and that they are seen in several mammalian orders suggest the existence of a "fixed" type of brain sex differences in the Mammalia Class.

  3. Effects of heroin on rat prosocial behavior.

    Science.gov (United States)

    Tomek, Seven E; Stegmann, Gabriela M; Olive, M Foster

    2018-05-04

    Opioid use disorders are characterized in part by impairments in social functioning. Previous research indicates that laboratory rats, which are frequently used as animal models of addiction-related behaviors, are capable of prosocial behavior. For example, under normal conditions, when a 'free' rat is placed in the vicinity of rat trapped in a plastic restrainer, the rat will release or 'rescue' the other rat from confinement. The present study was conducted to determine the effects of heroin on prosocial behavior in rats. For 2 weeks, rats were given the opportunity to rescue their cagemate from confinement, and the occurrence of and latency to free the confined rat was recorded. After baseline rescuing behavior was established, rats were randomly selected to self-administer heroin (0.06 mg/kg/infusion i.v.) or sucrose pellets (orally) for 14 days. Next, rats were retested for rescuing behavior once daily for 3 days, during which they were provided with a choice between freeing the trapped cagemate and continuing to self-administer their respective reinforcer. Our results indicate that rats self-administering sucrose continued to rescue their cagemate, whereas heroin rats chose to self-administer heroin and not rescue their cagemate. These findings suggest that rats with a history of heroin self-administration show deficits in prosocial behavior, consistent with specific diagnostic criteria for opioid use disorder. Behavioral paradigms providing a choice between engaging in prosocial behavior and continuing drug use may be useful in modeling and investigating the neural basis of social functioning deficits in opioid addiction. © 2018 Society for the Study of Addiction.

  4. Genome Editing in Rats Using TALE Nucleases.

    Science.gov (United States)

    Tesson, Laurent; Remy, Séverine; Ménoret, Séverine; Usal, Claire; Thinard, Reynald; Savignard, Chloé; De Cian, Anne; Giovannangeli, Carine; Concordet, Jean-Paul; Anegon, Ignacio

    2016-01-01

    The rat is an important animal model to understand gene function and model human diseases. Since recent years, the development of gene-specific nucleases has become important for generating new rat models of human diseases, to analyze the role of genes and to generate human antibodies. Transcription activator-like (TALE) nucleases efficiently create gene-specific knockout rats and lead to the possibility of gene targeting by homology-directed recombination (HDR) and generating knock-in rats. We describe a detailed protocol for generating knockout and knock-in rats via microinjection of TALE nucleases into fertilized eggs. This technology is an efficient, cost- and time-effective method for creating new rat models.

  5. Cerveau isolé and pretrigeminal rats.

    Science.gov (United States)

    Zernicki, B; Gandolfo, G; Glin, L; Gottesmann, C

    1984-01-01

    Cortical and hippocampal EEG activity was analysed in 14 cerveau isole and 8 pretrigerninal rats. In the acute stage, waking EEG patterns were absent in the cerveau isole, whereas sleep EEG patterns were absent in the pretrigeminal preparations. However, already on the second day the EEG waking-sleep cycle recovered in the majority of rats. Paradoxically, stimuli directed to the caudal part of preparations evoked stronger cortical and hippocampal EEG arousal than olfactory and visual stimuli. The behavior of the caudal part was observed in 25 preparations. Although in abortive form, the rats did show some locomotor and grooming behavior, and could be fed orally. The peripheral events of paradoxical sleep appeared only on the fourth or fifth day of survival of the cerveau isole rats. It is concluded that the activity of the isolated cerebrum of the rat is similar to that of cat preparations, but that functions of the caudal neuraxis are superior in rats.

  6. Pubertal neurocranium growth in thymectomized rats.

    Science.gov (United States)

    Rino, W; Teixeira, D

    1979-01-01

    Differences in neurocranium growth at puberty were studied in rats of both sexes thymectomized and sham-thymectomized at 2, 4, 6, 8, 10, 12 and 14 days of age and in controls of matched age and sex; skull length, width and height, and skull base length and face length were measured. The neurocranium of the thymectomized rats was significantly smaller than that of the sham-thymectomized and control rats of both sexes and in all age-groups.

  7. Treatment of diabetic rats with encapsulated islets

    OpenAIRE

    Sweet, Ian R; Yanay, Ofer; Waldron, Lanaya; Gilbert, Merle; Fuller, Jessica M; Tupling, Terry; Lernmark, Ake; Osborne, William R A

    2008-01-01

    Immunoprotection of islets using bioisolator systems permits introduction of allogeneic cells to diabetic patients without the need for immunosuppression. Using TheraCyte? immunoisolation devices, we investigated two rat models of type 1 diabetes mellitus (T1DM), BB rats and rats made diabetic by streptozotocin (STZ) treatment. We chose to implant islets after the onset of diabetes to mimic the probable treatment of children with T1DM as they are usually diagnosed after disease onset. We enca...

  8. Rat bite fever in a pet lover.

    Science.gov (United States)

    Cunningham, B B; Paller, A S; Katz, B Z

    1998-02-01

    Rat-bite fever is an uncommon bacterial illness resulting from infection with Streptobacillus moniliformis that is often transmitted by the bite of a rat. The cutaneous findings in rat-bite fever are nonspecific but have been described as maculopapular or petechial. We describe a 9-year-old girl with acrally distributed hemorrhagic pustules, fever, and arthralgias. Diagnosis was delayed because of difficulty in identifying the pathologic organism. She was successfully treated with 10 days of ceftriaxone.

  9. Phosphodiesterases in the rat ovary

    DEFF Research Database (Denmark)

    Petersen, Tonny Studsgaard; Stahlhut, Martin; Andersen, Claus Yding

    2015-01-01

    that augmented cAMP levels stimulate primordial follicle growth. The present study examined the gene expression, enzyme activity and immunolocalization of the different cAMP hydrolysing PDEs families in the rat ovary. Further, the effect of PDE4 inhibition on primordial follicle activation in cultured neonatal......Phosphodiesterases (PDEs) are important regulators of the intracellular cAMP concentration, which is a central second messenger that affects a multitude of intracellular functions. In the ovaries, cAMP exerts diverse functions, including regulation of ovulation and it has been suggested...... rat ovaries was also evaluated. We found varied expression of all eight families in the ovary with Pde7b and Pde8a having the highest expression each accounting for more than 20% of the total PDE mRNA. PDE4 accounted for 15-26% of the total PDE activity. Immunoreactive PDE11A was found in the oocytes...

  10. Isolation of rat adrenocortical mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Solinas, Paola [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Fujioka, Hisashi [Electron Microscopy Facility, Department of Pharmacology, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Tandler, Bernard [Department of Biological Sciences, School of Dental Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Hoppel, Charles L., E-mail: charles.hoppel@case.edu [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer A method for isolation of adrenocortical mitochondria from the adrenal gland of rats is described. Black-Right-Pointing-Pointer The purified isolated mitochondria show excellent morphological integrity. Black-Right-Pointing-Pointer The properties of oxidative phosphorylation are excellent. Black-Right-Pointing-Pointer The method increases the opportunity of direct analysis of adrenal mitochondria from small animals. -- Abstract: This report describes a relatively simple and reliable method for isolating adrenocortical mitochondria from rats in good, reasonably pure yield. These organelles, which heretofore have been unobtainable in isolated form from small laboratory animals, are now readily accessible. A high degree of mitochondrial purity is shown by the electron micrographs, as well as the structural integrity of each mitochondrion. That these organelles have retained their functional integrity is shown by their high respiratory control ratios. In general, the biochemical performance of these adrenal cortical mitochondria closely mirrors that of typical hepatic or cardiac mitochondria.

  11. Renal function in streptozotocin-diabetic rats

    DEFF Research Database (Denmark)

    Jensen, P K; Christiansen, J S; Steven, K

    1981-01-01

    to the rise in kidney glomerular filtration rate (diabetic rats: 37.0 nl/min; control rats: 27.9 nl/min). Likewise renal plasma flow was significantly higher in the diabetic rats (4.1 ml/min) than in the control group (3.0 ml/min). Glomerular capillary pressure was identical in both groups (56.0 and 56.0 mm......-1mmHg-1). Kidney weight was significantly higher in the diabetic rats (1.15 g; control rats: 0.96 g) while body weight was similar in both groups (diabetic rats: 232 g; control rats: 238 g). Calculations indicate that the increases in transglomerular hydraulic pressure, renal plasma flow......Renal function was examined with micropuncture methods in the insulin-treated streptozotocin-diabetic rat. Kidney glomerular filtration rate was significantly higher in the diabetic rats (1.21 ml/min) than in the control group (0.84 ml/min) Nephron glomerular filtration rate increased in proportion...

  12. X-ray lethality in diabetic rats

    International Nuclear Information System (INIS)

    Cember, H.; Thorson, T.M. Jr.

    1978-01-01

    Rats were made diabetic with streptozotocin and were irradiated with X-rays at various exposure levels in order to determine the LD-50/30 day dose. Non-diabetic control rats were exposed in a similar manner. The LD-50 exposures for the diabetic rats and the control rats were 436 R, and 617 R respectively. In view of the high prevalence of diabetes among the adult population, this finding may have important implications for diabetic workers who may be exposed accidentally to high levels of ionizing radiation

  13. Automatic Training of Rat Cyborgs for Navigation.

    Science.gov (United States)

    Yu, Yipeng; Wu, Zhaohui; Xu, Kedi; Gong, Yongyue; Zheng, Nenggan; Zheng, Xiaoxiang; Pan, Gang

    2016-01-01

    A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat's behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs.

  14. Toxicity and repellency to rats of actidione

    Science.gov (United States)

    Traub, R.; DeWitt, J.B.; Welch, J.F.; Newman, D.

    1950-01-01

    The antibiotic actidione was found to be highly repellent to laboratory rats and to significantly reduce gnawing attacks upon treated paperboards. Rats refused to accept food or water containing this material even under conditions of acute starvation and died of starvation and thirst,rather than accept water containing l.0 mg. of actidione per liter. The compound is highly toxic to .rats with the minimum .lethal dose by oral administration being approximately l.0 mg./Kg body weight. Paperboard treated with the compound resisted gnawing attacks by specially trained and motivated rats for periods of two hundred hours, although similar .untreated boards were pierced within thirty-to sixty minutes.

  15. [Pharmacokinetics of crocetin in rats].

    Science.gov (United States)

    Liu, Tong-zheng; Qian, Zhi-yu

    2002-05-01

    To develop an HPLC method for the determination of crocetin in rat plasma and study the pharmacokinetics in rats. Hypersil C18 column (5 microns, 4.6 mm x 200 mm) was used at column temperature 30 degrees C. The mobile phase consisted of methanol-water-acetic acid (75:24.5:0.5) at the flow rate of 1.0 mL.min-1. The UV detection wave length was 423 nm. The calibration curve was linear (gamma = 0.9996) in the range from 0.49 microgram.mL-1 to 7.87 micrograms.mL-1 for crocetin. The mean recovery was 105.2%. The lowest detectable concentration of crocetin was 0.14 microgram.mL-1 (S/N = 3). The RSDs of within-day and between-day were all less than 5%. The plasma crocetin was steady. The HPLC method of determination of crocetin in the plasma was established. After single dose of 50 mg.kg-1 ig in 10 rats, the main pharmacokinetic parameters were estimated as follows: T1/2 alpha (30 +/- 6) min, Tmax(65 +/- 16) min, Cmax(5.0 +/- 1.0) microgram.mL-1, AUC0-T(845 +/- 109) microgram.min.mL-1, Vd(5.0 +/- 0.8) L.kg-1. Crocetin was shown to be absorbed into the blood through the gastrointestinal tract. This method is quick, precise and reliable. Crocetin was shown to be quickly absorbed in rats.

  16. Stevia preferences in Wistar rats.

    Science.gov (United States)

    Núñez Martínez, Paula; Argüelles Luis, Juan; Perillán Méndez, Carmen

    2016-11-01

    The Stevia rebaudiana plant is likely to become a major source of high-potency sweetener for the growing natural-food market. S. rebaudiana is the source of a number of sweet diterpenoid glycosides, but the major sweet constituents are rebaudioside A and stevioside. These two constituents have similar pharmacokinetic and metabolic profiles in rats and humans, and thus, studies carried out with either steviol glycoside are relevant to both. Other studies illustrate the diversity of voluntary sweet intake in mammals. This study was done using a series of two-bottle tests that compared a wide range of sweetener concentrations versus saccharin concentrations and versus water. Wistar rats displayed preferences for stevia extract and pure rebaudioside A solutions over water at a range of concentrations (0.001% to 0.3%), and their intake peak occurred at 0.1% concentration. They also preferred solutions prepared with a commercial rebaudioside A plus erythritol mixture to water, and their peak was at 2% concentration. The present study provides new information about the responses of Wistar rats to stevia compounds and commercial stevia products such as Truvia. These results could help with the appropriate dosage selection for focused behavioral and physiological studies on stevia.

  17. Predicting small mammal and flea abundance using landform and ...

    African Journals Online (AJOL)

    Small mammals particularly rodents, are considered the primary natural hosts of plague. Literature suggests that plague persistence in natural foci has a root cause in soils. The objective of this study was to investigate the relationship between on the one hand landforms and associated soil properties, and on the other hand ...

  18. Spatiotemporal variations of the incidence of the fleas (Siphonaptera ...

    African Journals Online (AJOL)

    SARAH

    2014-08-31

    Aug 31, 2014 ... Therefore, awareness of the authorities on the zoonotic risk of small ... Human Health in Benin must sensitize the populations at high risk of the rodent transmitted diseases. ..... Preventive. Veterinary Medicine 60: 227-235.

  19. Water fleas require microbiota for survival, growth and reproduction.

    Science.gov (United States)

    Sison-Mangus, Marilou P; Mushegian, Alexandra A; Ebert, Dieter

    2015-01-01

    Microbiota have diverse roles in the functioning of their hosts; experiments using model organisms have enabled investigations into these functions. In the model crustacean Daphnia, little knowledge exists about the effect of microbiota on host well being. We assessed the effect of microbiota on Daphnia magna by experimentally depriving animals of their microbiota and comparing their growth, survival and fecundity to that of their bacteria-bearing counterparts. We tested Daphnia coming from both lab-reared parthenogenetic eggs of a single genotype and from genetically diverse field-collected resting eggs. We showed that bacteria-free hosts are smaller, less fecund and have higher mortality than those with microbiota. We also manipulated the association by exposing bacteria-free Daphnia to a single bacterial strain of Aeromonas sp., and to laboratory environmental bacteria. These experiments further demonstrated that the Daphnia-microbiota system is amenable to manipulation under various experimental conditions. The results of this study have implications for studies of D. magna in ecotoxicology, ecology and environmental genomics.

  20. flea beetle populations and economic yield of okra as influenced

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Aussi, il n'yavait pas eu de difference significative en terme d'interaction .... The study was carried out at the Teaching and ..... metabolic pathways especially when applied .... Journal of Plant Nutrition ... Annals of Botany 105 (2):333-339.

  1. Illnesses on the Rise From Mosquito, Tick, and Flea Bites

    Science.gov (United States)

    ... Done The Federal government is Funding states, territories, industry, university, and international groups to detect and respond ... and tents, with permethrin or buy permethrin-treated clothing and gear. Take steps to control ticks and ...

  2. 1 Predicting small mammal and flea abundance using landform and ...

    African Journals Online (AJOL)

    Particle size distribution. pH. (H2O). OC. (%). CEC .... (Intercept). 20.889. 12.493. 1.67. 0.1075. Elevation (m). 0.0097. 0.005. 1.82. 0.0821 ... convergence and divergence of water flows, soil water content and soil water retention characteristics.

  3. Determination of rat vertebral bone compressive fatigue properties in untreated intact rats and zoledronic-acid-treated, ovariectomized rats

    NARCIS (Netherlands)

    Brouwers, J.E.M.; Ruchselman, M.; Rietbergen, van B.; Bouxsein, M.L.

    2009-01-01

    Summary Compressive fatigue properties of whole vertebrae, which may be clinically relevant for osteoporotic vertebral fractures, were determined in untreated, intact rats and zoledronic-acid-treated, ovariectomized rats. Typical fatigue behavior was found and was similar to that seen in other

  4. Modulation of rat behaviour by using a rat-like robot

    International Nuclear Information System (INIS)

    Shi, Qing; Ishii, Hiroyuki; Kinoshita, Shinichi; Takanishi, Atsuo; Okabayashi, Satoshi; Iida, Naritoshi; Kimura, Hiroshi; Shibata, Shigenobu

    2013-01-01

    In this paper, we study the response of a rat to a rat-like robot capable of generating different types of behaviour (stressful, friendly, neutral). Experiments are conducted in an open-field where a rat-like robot called WR-4 is put together with live rats. The activity level of each rat subject is evaluated by scoring its locomotor activity and frequencies of performing rearing (rising up on its hind limbs) and body grooming (body cuddling and head curling) actions, whereas the degree of preference of that is indicated by the robot–rat distance and the frequency of contacting WR-4. The moving speed and behaviour of WR-4 are controlled in real-time based on the feedback from rat motion. The activity level and degree of preference of rats for each experimental condition are analysed and compared to understand the influence of robot behaviour. The results of this study show that the activity level and degree of preference of the rat decrease when exposed to a stressful robot, and increase when the robot exhibit friendly behaviour, suggesting that a rat-like robot can modulate rat behaviour in a controllable, predictable way. (paper)

  5. Use of novel compounds for pest control: insecticidal and acaricidal activity of essential oil components from heartwood of Alaska yellow cedar.

    Science.gov (United States)

    Panella, Nicholas A; Dolan, Marc C; Karchesy, Joseph J; Xiong, Yeping; Peralta-Cruz, Javier; Khasawneh, Mohammad; Montenieri, John A; Maupin, Gary O

    2005-05-01

    Laboratory bioassays were conducted to determine the activity of 15 natural products isolated from essential oil components extracted from the heartwood of Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don) Spach., against Ixodes scapularis Say nymphs, Xenopsylla cheopis (Rothchild), and Aedes aegypti (L.) adults. Four of the compounds from the essential oil have been identified as monoterpenes, five as eremophilane sesquiterpenes, five as eremophilane sesquiterpene derivatives from valencene and nootkatone, and one as a sesquiterpene outside the eremophilane parent group. Carvacrol was the only monoterpene that demonstrated biocidal activity against ticks, fleas, and mosquitoes with LC50 values after 24 h of 0.0068, 0.0059, and 0.0051% (wt:vol), respectively. Nootkatone from Alaska yellow cedar was the most effective of the eremophilane sesquiterpenes against ticks (LC50 = 0.0029%), whereas the nootkatone grapefruit extract exhibited the greatest biocidal activity against fleas (LC50 = 0.0029%). Mosquitoes were most susceptible to one of the derivatives of valencene, valencene-13-aldehyde (LC50 = 0.0024%), after 24 h. Bioassays to determine residual activity of the most effective products were conducted at 1, 2, 4, and 6 wk after initial treatment. Residual LC50 values for nootkatone did not differ significantly at 4 wk posttreatment from the observations made at the initial 24-h treatment. The ability of these natural products to kill arthropods at relatively low concentrations represents an alternative to the use of synthetic pesticides for control of disease vectors.

  6. Use it or lose it: reproductive implications of ecological specialization in a haematophagous ectoparasite.

    Science.gov (United States)

    Arbiv, A; Khokhlova, I S; Ovadia, O; Novoplansky, A; Krasnov, B R

    2012-06-01

    Using experimentally induced disruptive selection, we tested two hypotheses regarding the evolution of specialization in parasites. The 'trade-off' hypothesis suggests that adaptation to a specific host may come at the expense of a reduced performance when exploiting another host. The alternative 'relaxed selection' hypothesis suggests that the ability to exploit a given host would deteriorate when becoming obsolete. Three replicate populations of a flea Xenopsylla ramesis were maintained on each of two rodent hosts, Meriones crassus and Dipodillus dasyurus, for nine generations. Fleas maintained on a specific host species for a few generations substantially decreased their reproductive performance when transferred to an alternative host species, whereas they generally did not increase their performance on their maintenance host. The results support the 'relaxed selection' hypothesis of the evolution of ecological specialization in haematophagous ectoparasites, while suggesting that trade-offs are unlikely drivers of specialization. Further work is needed to study the extent by which the observed specializations are based on epigenetic or genetic modifications. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  7. Grooming behavior of spontaneously hypertensive rats

    NARCIS (Netherlands)

    Buuse, M. van den; Jong, Wybren de

    1987-01-01

    In an open field spontaneously hypertensive rats (SHR) exhibited lower scores for grooming when compared to their normotensive controls, the Wistar Kyoto rats (WKY). After i.c.v. injection of 1 μg ACTH1–24 cumulative 50-min grooming scores were lower in SHR. Analysis of subscores indicated that the

  8. Morphological and neurohistological changes in adolescent rats ...

    African Journals Online (AJOL)

    Pregnancy was confirmed and the pregnant rats were divided into 3 groups based on the 3 trimesters (A, B, C), with each group having a control and a treated subgroup. The Control Groups (A1, B1, ... offspring of tobacco smokers. Keywords: Cortex, Histology, Prenatal nicotine, Adolescent rats, Neurological abnormalities ...

  9. Target-selected mutagenesis of the rat

    NARCIS (Netherlands)

    Smits, B.M.; Mudde, J.B.; Plasterk, R.; Cuppen, E.

    2004-01-01

    The rat is one of the most extensively studied model organisms, and with its genome being sequenced, tools to manipulate gene function in vivo have become increasingly important. We here report proof of principle for target-selected mutagenesis as a reverse genetic or knockout approach for the rat.

  10. Optical coherence tomography of the rat cochlea

    NARCIS (Netherlands)

    Wong, B. J. F.; de Boer, JF; Park, B.H.; Chen, ZP; Nelson, JS

    2000-01-01

    Optical coherence tomography (OCT) was used to image the internal structure of a rat cochlea (ex vivo). Immediately following sacrifice, the temporal bone of a Sprague-Dawley rat was harvested. Axial OCT cross sectional images lover regions of interest, 1x1 mm-2x8 mm) were obtained with a spatial

  11. Same-Different Categorization in Rats

    Science.gov (United States)

    Wasserman, Edward A.; Castro, Leyre; Freeman, John H.

    2012-01-01

    Same-different categorization is a fundamental feat of human cognition. Although birds and nonhuman primates readily learn same-different discriminations and successfully transfer them to novel stimuli, no such demonstration exists for rats. Using a spatial discrimination learning task, we show that rats can both learn to discriminate arrays of…

  12. in Alloxan-induced Diabetic Rats

    African Journals Online (AJOL)

    HP

    Group 4: Diabetic rats that were administered. 500 mg/kg body weight extracts. Group 5: Diabetic rats that were administered. 300 mg/kg body weight of metformin. The drug and extracts treatment was done for a period of 21 days using orogastric tube. Collection of blood samples. Following 21 days of extract administration, ...

  13. ischemic brain injury in neonatal rats

    African Journals Online (AJOL)

    Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, ... Methods: Forty-eight rats (P7-pups) were randomly assigned to one of four groups: ... Keywords: Hypoxic–ischemic brain injury, α-Lipoic acid, Cerebral infarct area, Edema, Antioxidants, .... Of the 48 rats initially used in the current study, 5.

  14. Bromsulphalein (BSP) clearance in ageing rats

    NARCIS (Netherlands)

    Hollander, C.F.; Leeuw-Israel, F.R. de; Arp-Neefjes, J.M.

    1968-01-01

    Liver function in ageing rats was studied, using the bromsulphalein (BSP) clearance test. The test was done on ultramicro scale. This made it possible to repeat the test several times in the same animal and to start a longitudinal study. In 3-month-old rats the BSP retentions, measured 15, 30 and 45

  15. Adrenergic blockade in diabetic and uninephrectomized rats

    DEFF Research Database (Denmark)

    Thulesen, J; Poulsen, Steen Seier; Jørgensen, P E

    1999-01-01

    The present study reports on the effects of adrenergic blocking agents on the renal growth and on the renal content and urinary excretion of epidermal growth factor (EGF) in streptozotocin-induced diabetic or uninephrectomized rats. Diabetic and uninephrectomized rats were allocated to groups...... treated with either saline or adrenergic antagonists and compared to controls and sham-operated controls, respectively. 24-hour urine samples were obtained on days 7, 14, and 21 and renal tissue samples on day 21. The 24-hour urinary excretion of EGF from controls and saline-treated diabetic rats...... was comparable. In adrenergic antagonist treated diabetic rats, it was reduced by at least 40% throughout the study period. Uninephrectomy caused a 50% reduction in the urinary excretion of EGF. This was not influenced by treatment with an adrenergic antagonist. After 3 weeks, saline-treated diabetic rats had...

  16. Transfer RNA methylases in rat placenta

    International Nuclear Information System (INIS)

    Jagtiani, S.K.; Narurkar, L.M.; Narurkar, M.V.

    1977-01-01

    Presence of tRNA methylases (5-adenosylmethionine : tRNA methyltransferases) was demonstrated at various stages of gestation in rat placenta, the enzyme being 50-100% higher than that of adult rat liver during early gestation. Placental tRNA methylases were shown to differ from those of liver in the extent of methylation. Glycine methyltransferase (S-adenosylmethionine : glycine methyltransferase), a regulatory enzyme in adult rat liver, was absent in placenta throughout gestation. The placental tRNA methylases could be inhibited in vitro by semipurified glycine methyltransferase from adult rat liver. The high placental tRNA methylase activity was comparable with the inhibitor-free enzyme activity of the adult rat liver. S-adenosyl-[Me- 14 C]-methionine was used in the investigation. (author)

  17. Development of ELISA kit for rat albumin

    International Nuclear Information System (INIS)

    Yuan Zhigang; Han Shiquan; Liu Yibing; Xu Wenge; Jia Juanjuan

    2009-01-01

    The Anti-rat albumin serum was prepared by immunized the sheep with rat albumin. A ELISA method was established for rat albumin. The measurement range of the assay was 1-50 mg/L, sensitivity of the assay was 0.42 mg/L, recovery rate was 85.0%-106.0%. Intra-and inter-assay variation coefficients were <8.9% and <12.8% respectively. The correlation coefficients between measured and expected values were 0.999 after serial dilution of the urine samples with high concentrations of rat albumin. A good correlation was observed between the ELISA and RIA methods, and the kit for rat albumin might provide a convenience in exploitation of renal drugs and experimental injury of the kidney. (authors)

  18. Metabolism of methylphenidate in dog and rat

    International Nuclear Information System (INIS)

    Egger, H.; Bartlett, F.; Dreyfuss, R.; Karliner, J.

    1981-01-01

    The urinary metabolites of methylphenidate in the dog and rat were investigated. After oral administration of 14C-labeled methylphenidate, approximately 86% and 63% of the dose was recovered in the urine of the dog and rat, respectively. Less than 1% of the dose was excreted as unchanged drug. Metabolism involved oxidation, hydrolysis, and conjugation processes. The primary hydrolytic product was alpha-phenyl-2-piperidineacetic acid (24%, dog; 35-40%, rat). The primary metabolites of oxidation were methyl 6-oxo-alpha-phenyl-2-piperidineacetate (3%, dog; 1.5%, rat) and the glucuronide of alpha-(p-hydroxyphenyl)-2-piperidineacetic acid (10%, rat). The former also underwent extensive biotransformation, including: 1) hydrolysis to the lactam acid (27%, dog; 7-10%, rat) and subsequent carboxylic acid O-glucuronidation (15%, dog); or 2) hydroxylation at the 5-position (1%, dog; 2%, rat) and subsequent hydrolysis (4%, dog; 15-17%, rat); or 3) 5-O-glucuronidation (12%, dog). Additional minor metabolites from methyl-6-oxo-alpha-phenyl-2-piperidineacetate were the phenolic O-glucuronide of methyl alpha-(p-hydroxyphenyl)-6-oxo-2-piperidineacetate (1%, dog), and the 4-O-glucuronide of methyl 4-hydroxy-6-oxo-alpha-phenyl-2-piperidineacetate (1%, dog), and the taurine amide conjugate of alpha-(p-hydroxyphenyl)-6-oxo-2-piperidineacetic acid (1%, dog). Additional products from methylphenidate conjugation included methyl 1-carbamoyl-alpha-phenyl-2-piperidineacetate (1%, dog or rat) and its carboxylic acid hydrolysis product (1%, rat). The chirality of the major metabolites isolated from dog urine showed that metabolism was partially stereoselective in all investigated cases, except in the formation of alpha-phenyl-2-piperidineacetic acid

  19. Genetic susceptibility to mammary carcinogenesis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Kenji; Nitta, Yumiko [Hiroshima Univ. (Japan). Research Inst. for Radiation Biology and Medicine

    1999-06-01

    The Copenhagen (COP) rat strain has previously been shown to be genetically resistant to chemical induction of breast cancer, while Wistar/Furth (WF) and Fischer 344 (F344) animals are relatively susceptible. We have compared the carcinogenic response of these three strains of rats to N-methyl-N-nitrosourea (MNU) with that to {sup 60}Co gamma rays. High incidences of mammary carcinomas were induced by MNU in the F344 and WF rats (100%), whereas the COP strain proved resistant (11.8%). In contrast, radiation-induced mammary carcinomas in COP rats developed in a similar incidence (37.0%) to those in the F344 (22.6%) and WF (26.9%) strains. The low incidence of papillary carcinomas in MNU-treated COP rats appeared to be directly related to the COP genetic resistance controlled by the Mcs genes. Ionizing radiation did, however, induce papillary carcinomas in all the three strains of rats. These carcinomas were more differentiated than MNU-induced cancers with regard to the two mammary differentiation markers, rat milk fat globule membrane (R-MFGM) and {alpha}-smooth muscle actin ({alpha}-SMA). Furthermore, ionizing radiation but not MNU induced mammary adenomas in all three strains, especially in COP rats. Such adenomas had differentiation marker profiles similar to these of carcinomas induced by {sup 60}Co gamma rays. When transplanted into syngenic hosts, growth of adenomas was 17 {beta}-estradiol (E{sub 2})-dependent and they progressed to carcinomas. Furthermore, one microcarcinoma was observed to develop from adenoma tissue in a radiation-exposed COP rat. The findings suggest that radiation and chemical carcinogens are likely to induce mammary cancers through different pathways or from different cell populations. The induction of relatively high incidences of mammary carcinomas and adenomas by radiation in COP rats may correlate with the genetically modulated and highly differentiated physiological status of their mammary glands. (author)

  20. Social exclusion intensifies anxiety-like behavior in adolescent rats.

    Science.gov (United States)

    Lee, Hyunchan; Noh, Jihyun

    2015-05-01

    Social connection reduces the physiological reactivity to stressors, while social exclusion causes emotional distress. Stressful experiences in rats result in the facilitation of aversive memory and induction of anxiety. To determine the effect of social interaction, such as social connection, social exclusion and equality or inequality, on emotional change in adolescent distressed rats, the emotional alteration induced by restraint stress in individual rats following exposure to various social interaction circumstances was examined. Rats were assigned to one of the following groups: all freely moving rats, all rats restrained, rats restrained in the presence of freely moving rats and freely moving rats with a restrained rat. No significant difference in fear-memory and sucrose consumption between all groups was found. Change in body weight significantly increased in freely moving rats with a restrained rat, suggesting that those rats seems to share the stressful experience of the restrained rat. Interestingly, examination of the anxiety-like behavior revealed only rats restrained in the presence of freely moving rats to have a significant increase, suggesting that emotional distress intensifies in positions of social exclusion. These results demonstrate that unequally excluded social interaction circumstances could cause the amplification of distressed status and anxiety-related emotional alteration. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Oxidative stress of crystalline lens in rat menopausal model

    OpenAIRE

    Acer, Semra; Pekel, Gökhan; Küçükatay, Vural; Karabulut, Aysun; Yağcı, Ramazan; Çetin, Ebru Nevin; Akyer, Şahika Pınar; Şahin, Barbaros

    2016-01-01

    ABSTRACT Purpose: To evaluate lenticular oxidative stress in rat menopausal models. Methods: Forty Wistar female albino rats were included in this study. A total of thirty rats underwent oophorectomy to generate a menopausal model. Ten rats that did not undergo oophorectomy formed the control group (Group 1). From the rats that underwent oophorectomy, 10 formed the menopause control group (Group 2), 10 were administered a daily injection of methylprednisolone until the end of the study (Gro...

  2. Dithiobiuret metabolism in the rat

    International Nuclear Information System (INIS)

    Williams, K.D.; Porter, W.R.; Peterson, R.E.

    1982-01-01

    Our main objective was to describe the metabolism of dithiobiuret (DTB) in the adult, male rat. Based on the thin-layer chromatographic analysis of urine from animals treated with [ 14 C] or [ 35 S] labeled DTB, two pathways for metabolism are proposed. One pathway is reversible and involves the oxidation of DTB to thiuret and the reduction of thiuret back to DTB. The other pathway consists of the desulfurization of DTB to monothiobiuret. The liver appears to desulfurate DTB because DTB-derived [35S] was eliminated from the liver more rapidly than [ 14 C]. The liver was the only tissue where the elimination kinetics of [ 35 S] and [ 14 C] DTB were different. DTB-derived radioactivity in urine that co-chromatographed with DTB, monothiobiuret, thiuret and sulfate was quantitated along with that of three uncharacterized metabolites. The presence of these unknown metabolites suggests that DTB metabolism is complex. The present study is the first description of the metabolic fate of DTB in the rat and serves as a starting point for determining whether DTB neurotoxicity is caused by the parent compound or a metabolite

  3. Lessons From Experiments in Rats

    Directory of Open Access Journals (Sweden)

    Albert Gramsbergen

    2001-01-01

    Full Text Available In this essay a few relevant aspects of the neural and behavioral development of the brain in the human and in the rat are reviewed and related to the consequences of lesions in the central and peripheral nervous system at early and later age. Movements initially are generated by local circuits in the spinal cord and without the involvement of descending projections. After birth, both in humans and in rats it seems that the devlopment of postural control is the limiting factor for several motor behaviors to mature. Strong indications exist that the cerebellum is significantly involved in this control. Lesions in the CNS at early stages interfere with fundamental processes of neural development, such as the establishment of fiber connections and cell death patterns. Consequently, the functional effects are strongly dependent on the stage of development. The young and undisturbed CNS, on the other hand, has a much greater capacity than the adult nervous system for compensating abnormal reinnervation in the peripheral nervous system. Animal experiments indicated that the cerebellar cortex might play an important part in this compensation. This possibility should be investigated further as it might offer important perspectives for treatment in the human.

  4. Autoprotection in acetaminophen intoxication in rats

    DEFF Research Database (Denmark)

    Dalhoff, K; Laursen, H; Bangert, K

    2001-01-01

    and liver tissue were collected before and 12, 24, 36, and 48 hr after the toxic dose and were analysed for hepatic glutathione and cysteine contents, hepatic glutathione-S-transferase and blood alanine aminotransferase activity, as well as acetaminophen concentration in plasma. Steady-state mRNA levels......Autoprotection by acetaminophen, i.e. increased resistance to toxic effects caused by pretreatment, is a well-known phenomenon. The purpose of the present work was to identify mechanisms for increased acetaminophen tolerance induced by pretreatment of rats. One group of female Wistar rats...... (pretreated rats) received acetaminophen orally in increasing doses (1 to 4.3 g/kg) twice a week for 3 weeks, one group (naïve rats) received the vehicle. At time zero pretreated rats received a toxic dose of 7.5 g/kg (100% lethal in naïve rats), and naïve rats received a toxic dose of 4.3 g/kg. Blood...

  5. Cerebral ammonia metabolism in hyperammonemic rats

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, A J; Mora, S N; Cruz, N F; Gelbard, A S

    1985-06-01

    The short-term metabolic fate of blood-borne (/sup 13/N)ammonia was determined in the brains of chronically (8- or 14-week portacaval-shunted rats) or acutely (urease-treated) hyperammonemic rats. Using a freeze-blowing technique it was shown that the overwhelming route for metabolism of blood-borne (/sup 13/N)ammonia in normal, chronically hyperammonemic and acutely hyperammonemic rat brain was incorporation into glutamine (amide). However, the rate of turnover of (/sup 13/N)ammonia to L-(amide-/sup 13/N)glutamine was slower in the hyperammonemic rat brain than in the normal rat brain. The activities of several enzymes involved in cerebral ammonia and glutamate metabolism were also measured in the brains of 14-week portacaval-shunted rats. The rat brain appears to have little capacity to adapt to chronic hyperammonemia because there were no differences in activity compared with those of weight-matched controls for the following brain enzymes involved in glutamate/ammonia metabolism: glutamine synthetase, glutamate dehydrogenase, aspartate aminotransferase, glutamine transaminase, glutaminase, and glutamate decarboxylase. The present findings are discussed in the context of the known deleterious effects on the CNS of high ammonia levels in a variety of diseases.

  6. Abstract numerical discrimination learning in rats.

    Science.gov (United States)

    Taniuchi, Tohru; Sugihara, Junko; Wakashima, Mariko; Kamijo, Makiko

    2016-06-01

    In this study, we examined rats' discrimination learning of the numerical ordering positions of objects. In Experiments 1 and 2, five out of seven rats successfully learned to respond to the third of six identical objects in a row and showed reliable transfer of this discrimination to novel stimuli after being trained with three different training stimuli. In Experiment 3, the three rats from Experiment 2 continued to be trained to respond to the third object in an object array, which included an odd object that needed to be excluded when identifying the target third object. All three rats acquired this selective-counting task of specific stimuli, and two rats showed reliable transfer of this selective-counting performance to test sets of novel stimuli. In Experiment 4, the three rats from Experiment 3 quickly learned to respond to the third stimulus in object rows consisting of either six identical or six different objects. These results offer strong evidence for abstract numerical discrimination learning in rats.

  7. Total parenteral nutrition in diabetic rats

    International Nuclear Information System (INIS)

    Norcross, E.D.; Stein, T.P.

    1986-01-01

    Parenteral Nutrition with hypertonic glucose is frequently given to diabetic patients. Large amounts of insulin can be required. The purpose of this investigation was to develop a totally parenterally nourished diabetic rat model. 200 g Female Sprague Dawley rats were made diabetic by i.v. injection of streptozotocin (50 mg/kg). Rats were then allowed to recover for at least 1 week before undergoing surgical insertion of a central venous catheter for parenteral feeding. TPN was begun 3 days after surgery. Prior to this they were allowed unlimited access to food and water. Control (non-streptozotocin treated) rats were run at the same time. Protein turnover was investigated by using 15 N glycine. Preliminary results: diabetic rats given mostly fat as a calorie source survived well in the absence of exogenous insulin whereas those that were given glucose only as their non-protein calorie source showed poor survival even with exogenous insulin. N balance and protein turnover in the lipid treated diabetic rats were comparable to the non-diabetic control rats

  8. Embryogenesis-promoting factors in rat serum.

    Science.gov (United States)

    Katoh, M; Kimura, R; Shoji, R

    1998-06-15

    Regarding whole rat embryo cultures in vitro, rat serum as a culture medium is known to support the normal growth of rat embryos in the organogenesis phase. The purpose of the present study was to isolate the embryogenesis-promoting factors from rat serum as a first step in the development of a defined serum-free medium for a whole embryo culture system. Pooled rat serum after heat inactivation was fractionated into three major peaks (frA, containing a region of void volume, frB, and frC) by gel filtration. The 9.5-day rat embryos that were cultivated for 48 hr in essential salt medium containing frB (with a molecular size range of 100-500 kDa) revealed normal growth. Three proteins (27 kDa, 76 kDa, and 190 kDa) that had the embryogenesis-promoting effects were isolated from 3-hr delayed centrifuged rat serum by the ion exchange chromatography. The 76-kDa protein was found to be rat transferrin by immunoblotting. The 27-kDa protein was identified as apo-AI (the major apoprotein of high-density lipoprotein) by immunoblotting. High-density lipoprotein obtained from pooled rat serum by a NaBr density gradient ultracentrifugation was found to have a positive effect on embryogenesis. The 10-kDa protein was also identified as alpha 1-inhibitor 3 by immunoblotting. In addition, the embryogenesis-promoting effect of the fraction containing 27-kDa and 190-kDa proteins declined within a short period of storage at -20 degrees C. This decrease was countered by supplementing its fraction (D-2) with albumin isolated from rat serum. These results in the present study suggest that transferrin, high-density lipoprotein, and alpha 1-inhibitor 3 in rat serum may be embryogenesis-promoting factors, and that albumin appeared to play a role in the embryogenesis of rat embryos in whole embryo cultures.

  9. Establishment of a novel dwarf rat strain: cartilage calcification insufficient (CCI) rats.

    Science.gov (United States)

    Tanaka, Masami; Watanabe, Minoru; Yokomi, Izuru; Matsumoto, Naoki; Sudo, Katsuko; Satoh, Hitoshi; Igarashi, Tsuneo; Seki, Azusa; Amano, Hitoshi; Ohura, Kiyoshi; Ryu, Kakei; Shibata, Shunichi; Nagayama, Motohiko; Tanuma, Jun-ichi

    2015-01-01

    Rats with dwarfism accompanied by skeletal abnormalities, such as shortness of the limbs, tail, and body (dwarf rats), emerged in a Jcl-derived Sprague-Dawley rat colony maintained at the Institute for Animal Experimentation, St. Marianna University Graduate School of Medicine. Since the dwarfism was assumed to be due to a genetic mutation based on its frequency, we bred the dwarf rats and investigated their characteristics in order to identify the causative factors of their phenotypes and whether they could be used as a human disease model. One male and female that produced dwarf progeny were selected, and reproduction was initiated by mating the pair. The incidence of dwarfism was 25.8% among the resultant litter, and dwarfism occurred in both genders, suggesting that it was inherited in an autosomal recessive manner. At 12 weeks of age, the body weights of the male and female dwarf rats were 40% and 57% of those of the normal rats, respectively. In soft X-ray radiographic and histological examinations, shortening and hypoplasia of the long bones, such as the tibia and femur, were observed, which were suggestive of endochondral ossification abnormalities. An immunohistochemical examination detected an aggrecan synthesis disorder, which might have led to delayed calcification and increased growth plate thickening in the dwarf rats. We hypothesized that the principal characteristics of the dwarf rats were systemically induced by insufficient cartilage calcification in their long bones; thus, we named them cartilage calcification insufficient (CCI) rats.

  10. Establishment of a novel dwarf rat strain: cartilage calcification insufficient (CCI) rats

    Science.gov (United States)

    TANAKA, Masami; WATANABE, Minoru; YOKOMI, Izuru; MATSUMOTO, Naoki; SUDO, Katsuko; SATOH, Hitoshi; IGARASHI, Tsuneo; SEKI, Azusa; AMANO, Hitoshi; OHURA, Kiyoshi; RYU, Kakei; SHIBATA, Shunichi; NAGAYAMA, Motohiko; TANUMA, Jun-ichi

    2014-01-01

    Rats with dwarfism accompanied by skeletal abnormalities, such as shortness of the limbs, tail, and body (dwarf rats), emerged in a Jcl-derived Sprague-Dawley rat colony maintained at the Institute for Animal Experimentation, St. Marianna University Graduate School of Medicine. Since the dwarfism was assumed to be due to a genetic mutation based on its frequency, we bred the dwarf rats and investigated their characteristics in order to identify the causative factors of their phenotypes and whether they could be used as a human disease model. One male and female that produced dwarf progeny were selected, and reproduction was initiated by mating the pair. The incidence of dwarfism was 25.8% among the resultant litter, and dwarfism occurred in both genders, suggesting that it was inherited in an autosomal recessive manner. At 12 weeks of age, the body weights of the male and female dwarf rats were 40% and 57% of those of the normal rats, respectively. In soft X-ray radiographic and histological examinations, shortening and hypoplasia of the long bones, such as the tibia and femur, were observed, which were suggestive of endochondral ossification abnormalities. An immunohistochemical examination detected an aggrecan synthesis disorder, which might have led to delayed calcification and increased growth plate thickening in the dwarf rats. We hypothesized that the principal characteristics of the dwarf rats were systemically induced by insufficient cartilage calcification in their long bones; thus, we named them cartilage calcification insufficient (CCI) rats. PMID:25736479

  11. Ontogenic changes in selenite metabolism in rats

    International Nuclear Information System (INIS)

    Ostadalova, I.; Babicky, A.; Kopoldova, J.

    1982-01-01

    Radioselenium concentration and excretion was studied after administration of 75 Se-labelled selenite to male rats during ontogeny. The concentration of radioselenium in individual organs decreases with increasing age. The largest differences between young and adults were in the quantity and quality of excreted substances. During 2 h after the administration of 20 μmol selenite/kg young rats excreted 2.4% of the dose, essentially in the urine only, whilst adults excreted a total of 11%, distributed equally in breath and urine. The part excreted as methylated metabolites was 0.1% of the administered dose in young and 6.3% in adult rats. These results support the hypothesis that the differences in the sensitivity to the toxic action of selenite between young and adult rats can be due to ontogenic differences in selenium metabolism. (orig.)

  12. Tissue disposition of bifenthrin in the rat

    Data.gov (United States)

    U.S. Environmental Protection Agency — Tissue disposition of bifenthrin in the rat and oral and intravenous administration. This dataset is associated with the following publication: Hughes , M., D. Ross...

  13. Dietary GABA and food selection by rats.

    Science.gov (United States)

    Tews, J K; Repa, J J; Harper, A E

    1986-01-01

    To obtain further information pertaining to amino acid-induced alterations in feeding behavior, studies were performed to examine the food choices made by rats fed low protein diets made more or less aversive by the addition of various amino acids. When rats were allowed to choose between two diets, they preferred a low protein control, threonine-imbalanced or nonprotein diet to one containing 2.5% gamma-aminobutyric acid (GABA). Acceptance increased when GABA content was lowered to 1.5%; rats preferred this diet when the alternative diet was made sufficiently aversive. There were large individual differences among rats selecting from pairs of unacceptable diets. Avoidance of, or preference for, a given diet is clearly affected by the relative aversive qualities of the offered pair of diets.

  14. Experimental Salmonella typhimurium infections in rats. I

    DEFF Research Database (Denmark)

    Hougen, H P; Jensen, E T; Klausen, B

    1989-01-01

    The course of experimentally induced Salmonella typhimurium infection was studied in three groups of inbred LEW rats: homozygous +/+, athymic rnu/rnu and isogeneic thymus-grafted rnu/rnu rats. In the first experiment the animals were inoculated intraperitoneally with 10(8) bacteria and all animals...... became severely septicemic and died within a week of inoculation, irrespective of presence or absence of thymus. In the second experiment the animals were inoculated with 10(6) bacteria, and both euthymic and thymus-grafted animals responded with high titres of anti bacterial antibodies while these were...... very low in the athymic nude animals. Polyclonal antibody production was only observed in the euthymic animals and only regarding IgG. Athymic rats were not able to clear the infection, while the thymus-grafted animals reacted like euthymic rats: Very few animals housed the bacteria four weeks after...

  15. Black ginseng extract ameliorates hypercholesterolemia in rats

    Directory of Open Access Journals (Sweden)

    Evelyn Saba

    2016-04-01

    Conclusion: Administration of BG extracts to Sprague Dawley rats fed with high-cholesterol diet ameliorated hypercholesterolemia, which was mediated via modulation of cholesterol-metabolizing marker genes. This data throw a light on BG's cardioprotective effects.

  16. Reactive Protein Synthesis in Pregnant Rats

    African Journals Online (AJOL)

    olayemitoyin

    Department of Physiology, College of Medicine, University of Lagos, Nigeria. Summary: Genistein ... Oral exposure of pregnant rats to genistein precipitated hypothyroidism, altered some metabolic hormones with a ... consumption. Exposure to ...

  17. Tritium metabolism in rat tissues

    International Nuclear Information System (INIS)

    Takeda, H.

    1982-01-01

    As part of a series of studies designed to evaluate the relative radiotoxicity of various tritiated compounds, metabolism of tritium in rat tissues was studied after administration of tritiated water, leucine, thymidine, and glucose. The distribution and retention of tritium varied widely, depending on the chemical compound administered. Tritium introduced as tritiated water behaved essentially as body water and became uniformly distributed among the tissues. However, tritium administered as organic compounds resulted in relatively high incorporation into tissue constituents other than water, and its distribution differed among the various tissues. Moreover, the excretion rate of tritium from tissues was slower for tritiated organic compounds than for tritiated water. Administrationof tritiated organic compounds results in higher radiation doses to the tissues than does administration of tritiated water. Among the tritiated compounds examined, for equal radioactivity administered, leucine gave the highest radiation dose, followed in turn by thymidine, glucose, and water. (author)

  18. How rats combine temporal cues.

    Science.gov (United States)

    Guilhardi, Paulo; Keen, Richard; MacInnis, Mika L M; Church, Russell M

    2005-05-31

    The procedures for classical and operant conditioning, and for many timing procedures, involve the delivery of reinforcers that may be related to the time of previous reinforcers and responses, and to the time of onsets and terminations of stimuli. The behavior resulting from such procedures can be described as bouts of responding that occur in some pattern at some rate. A packet theory of timing and conditioning is described that accounts for such behavior under a wide range of procedures. Applications include the food searching by rats in Skinner boxes under conditions of fixed and random reinforcement, brief and sustained stimuli, and several response-food contingencies. The approach is used to describe how multiple cues from reinforcers and stimuli combine to determine the rate and pattern of response bouts.

  19. [Risk assessments and control strategies of plague in five key surveillance counties, Zhejiang province].

    Science.gov (United States)

    Shi, Guoxiang; Ju, Cheng; Zhang, Rong; Zhang, Zheng; Sun, Jimin; Wang, Miaoruo; Zhang, Xiaohe; Ye, Xianming; Zhu, Zhihong; Xing, Jianguang; Liao, Xiaowei; Chen, Zhiping

    2015-10-01

    To analyze the epidemiology data on plague in five counties in Zhejiang province and to evaluate the risk of plague in theses areas. We selected five monitoring stations as a risk assessment (Qingyuan county, Longquan city, Yiwu city, Wencheng county, and Ruian city) in Zhejiang province where the plague epidemic more serious in the history. At least one constant site and 1-4 variable sites where plague occurred in history were selected for monitoring. We collected the five counties (cities) surveillance data of indoor rat density, indoor Rattus flavipectus density, the Xenopsylla cheopis index of rat, the Xenopsylla cheopis index of Rattus flavipectus in 1995-2014. Isolation of Yersinia pestis was conducted among 171,201 liver samples and F1 antibody were detected among 228,775 serum samples. Risk matrix, Borda count method, and Delphi approach were conducted to assess risk of the plague of five counties (cities) in Zhejiang province. Indoor rat density in Qingyuan county, Longquan city, Yiwu city, Wencheng county, Ruian city was 1.58%-5.50%, 1.13%-9.76%, 0.56%-3.67%, 2.83%-16.08%, 7.16%-15.96%, respectively; Indoor Rattus flavipectus density of five counties (cities) was 0.08%-2.23%, 0-2.02%, 0-0.54%, 0.71%-5.58%, 0.55%-4.92%, respectively. The Xenopsylla cheopis index of rat in Qingyuan county and Wencheng county was 0.011-0.500 and 0.015-0.227, respectively; The Xenopsylla cheopis index of Rattus flavipectus of Qingyuan county and Wencheng county was 0.119-3.412 and 0.100-1.430, respectively; Ruian City and Yiwu city cannot collected Xenopsylla cheopis, Long quan city only collected the Xenopsylla cheopis index of rat in the five years. Yersinia pestis were not isolated in five counties (cities).There were 3 Apodemus agrarius samples positive of plague F1 antibody test, in Longquan city and Yiwu city in 2005. Borda count method to assess the Longquan city, Yiwu (Borda point were both 321) plague risk was higher than three other regions; Delphi approach to

  20. Epidermal growth factor in the rat prostate

    DEFF Research Database (Denmark)

    Tørring, Niels; Jørgensen, P E; Poulsen, Steen Seier

    1998-01-01

    Epidermal growth factor (EGF) induces proliferation in prostate epithelial and stromal cells in primary culture. This investigation was set up to characterize the time and spatial expression of EGF in the rat prostate.......Epidermal growth factor (EGF) induces proliferation in prostate epithelial and stromal cells in primary culture. This investigation was set up to characterize the time and spatial expression of EGF in the rat prostate....

  1. Epidermal growth factor reactivity in rat milk

    DEFF Research Database (Denmark)

    Raaberg, Lasse; Nexø, Ebba; Tollund, L

    1990-01-01

    whey elutes as a broad peak corresponding to a Stokes radius of 4.0 nm (an approximate molecular weight of 80 kDa). Almost no 6 kDa EGF is present. Judged by gel filtration of whey pre-incubated with 125I-EGF (6 kDa), no binding protein for EGF is present in rat whey. When rat milk is incubated...

  2. Genetically determined differences in the resistance to myocardial infarction in Wistar and August rats.

    Science.gov (United States)

    Belkina, L M; Saltykova, V A; Pshennikova, M G

    2001-06-01

    In intact August rats, the cardiac contractile function at rest was by 76% higher than in Wistar rats, while their hearts, both intact and after acute myocardial infarction, were more resistant to isometric load than the hearts of Wistar rats. Postinfarction mortality in August rats was 18% vs. 70% in Wistar rats. Adrenoreactivity of the myocardium in August rats was decreased compared to that in Wistar rats. These peculiarities can determine high resistance of August rats to myocardial infarction.

  3. Factors influencing zinc bioavailability in rats

    International Nuclear Information System (INIS)

    Mahalko, J.R.; Johnson, P.E.; Swan, P.B.

    1986-01-01

    The amount of Zn fed, its source, and the Zn status of experimental animals may affect Zn bioavailability. To test this, rats were fed doses of Zn from ZnCl 2 or from various foods labeled extrinsically. Three weeks before and after the test meal, rats were fed an AIN diet modified in Zn content. Absorption was calculated by monitoring whole body retention and extrapolating to zero time. In rats fed 12 ppm Zn and test doses of 6 to 275 μg, absorption decreased from 80 to 50%, and the amount absorbed increased quadratically (r 2 = 0.998), but turnover was unaffected. Rats fed 38 or 77 ppm Zn absorbed less of test doses of 290, 613, or 1700 μg Zn than did those fed 12 ppm, and their Zn turnover rate was higher. In two 2 x 7 factorial experiments, rats fed 12 or 38 ppm Zn were given 16 or 98 μg Zn from 7 Zn sources. Bioavailability from some foods was higher than from ZnCl 2 except in rats eating only 12 ppm Zn and receiving the small dose. There were greater differences in bioavailability among foods when tested at the higher Zn status or dose. This may explain inconsistencies seen in comparing Zn bioavailability by traditional growth assay with that seen in 65 Zn tracer studies. The authors conclude that Zn status of the experimental animal, as well as the amount of Zn and its source, will affect Zn bioavailability

  4. Modifying factors in rat mammary gland carcinogenesis

    International Nuclear Information System (INIS)

    Shellabarger, C.J.

    1975-01-01

    The spontaneous incidence of mammary adenocarcinomas and mammary fibroadenomas in rats was found to be related to the strain of rat studied. Strains of rats that are sensitive to chemical carcinogens in regard to induced mammary neoplasia tend to be the same strains of rats that are sensitive to radiation. Methylcholantrene (MCA) and x-rays appeared to act in an additive fashion on the induction of mammary adenocarcinomas when they were given together. Lactating and older rats lose responsiveness to chemical carcinogens but do not lose responsiveness to radiation. Radiation appears to act in a scopal fashion in the induction of mammary neoplasia. Mammary neoplasia induction was not changed when low LET radiation was split into 2 equal fractions and high LET radiation was more effective than low LET radiation in inducing mammary neoplasia. It is suggested that DMBA can act as an initiator for the induction of mammary adenocarcinomas, that phorbol can act as a promotor, and that viruses may induce mammary neoplasia. Diethylstilbestrol (DES) and radiation appeared to act synergistically in the induction of mammary adenocarcinomas in one strain of rat but not in another strain. (U.S.)

  5. Diuron-induced rat bladder epithelial cytotoxicity.

    Science.gov (United States)

    Da Rocha, Mitscheli S; Arnold, Lora L; Pennington, Karen L; Muirhead, David; Dodmane, Puttappa R; Anwar, Muhammad M; Battalora, Michael; De Camargo, João Lauro V; Cohen, Samuel M

    2012-12-01

    Diuron, a substituted urea herbicide, is carcinogenic to the rat urinary bladder at high dietary levels (2500 ppm). To further elucidate the mode of action, this study aimed to determine the time course and sequence of bladder cytotoxic and proliferative changes induced by diuron treatment of male Wistar rats. Rats were randomized into two groups (control and 2500 ppm diuron) and treated for 28 days. Ten rats from each group were terminated on each of study days 1, 3, 7, or 28. Scanning electron micro scopy (SEM) showed urothelial cell swelling beginning on day 1, and by day 28, showed extensive necrosis, exfoliation and piling up of cells suggestive of hyperplasia. No difference in the bromo deoxyuridine labeling index was detected. In a second experiment, rats were randomized into control and diuron-treated groups and treated for 7 days or 8 weeks. After 7 days, transmission electron microscopy showed cell degenerative changes and distention of the cytoplasm, organelles, and nuclei characteristic of cytolysis. This resulted in protrusion of the superficial cells into the lumen, corresponding to the cell swelling observed previously by SEM. After 8 weeks, bladders in the diuron-treated group showed an increased incidence of simple hyperplasia by light microscopy (6/10, p diuron exposure in rats.

  6. Radiation nephropathy in young and adult rats

    International Nuclear Information System (INIS)

    Jongejan, H.T.; van der Kogel, A.J.; Provoost, A.P.; Molenaar, J.C.

    1987-01-01

    The effects of bilateral kidney irradiation were compared in young and adult rats. During a 1 year period after a single dose of 0, 7.5, 10, 12.5, or 15 Gy on both kidneys, renal function (glomerular filtration rate and effective renal plasma flow), urine composition, and systolic blood pressure were measured periodically. The first changes after irradiation were observed in the glomerular filtration rate and urine osmolality. One month after 10, 12.5, and 15 Gy, glomerular filtration rate (GFR) and urine osmolality had declined below control values in the young rats. After this initial decline, renal function increased at control rate or even more during the third and fourth month after irradiation but decreased progressively thereafter. In the adult rats, GFR and urine osmolality started to decrease 3 months after 10, 12.5, and 15 Gy. A rise in systolic blood pressure and proteinuria started 2-3 months after 12.5 and 15 Gy in both age groups. Early changes in the glomerular filtration rate with a drop in urine osmolality in young rats, occurring during a period of rapid renal development indicated an irradiation-induced inhibition of glomerular and tubular development. Although renal function deteriorated at a later time in adult rats, dose-response relationships obtained in young and adult rats did not show significant differences

  7. Reproductive toxicity of Samanea tubulosa on rats

    Directory of Open Access Journals (Sweden)

    Maria Rafaella Luz de Araújo

    2015-12-01

    Full Text Available Samanea tubulosa is a plant used for medicinal and feeding purposes. However, ingestion of S. tubulosa pods has been associated with bovine abortion. Thus, the aim of this work was to investigate the effects of diet containing 5% of S. tubulosa pod meal on male and female Wistar rats. Diet was administered to male rats (n = 10 for 60 days before mating. Female rats (n = 10 received the treatment for 30 days, during cohabitation and from gestational day (GD 0 to GD20. Treated animals were mated with untreated rats. In male rats, plant consumption caused decreased food consumption and 20% fertility index reduction. Litters from treated males presented lower body weight and crown–rump length. Female rats treated with the plant increased water and food intake and body weight. Decreases in fertility, fecundity and gestation indices and increase of placenta weight and mean number of corpora lutea were found. Thus, owing to the possible general and reproductive toxic effects, long-term consumption of S. tubulosa is not recommended for phytotherapic or food purposes.

  8. Regulation of brain aromatase activity in rats

    International Nuclear Information System (INIS)

    Roselli, C.E.; Ellinwood, W.E.; Resko, J.A.

    1984-01-01

    The distribution and regulation of aromatase activity in the adult rat brain with a sensitive in vitro assay that measures the amount of 3 H 2 O formed during the conversion of [1 beta- 3 H]androstenedione to estrone. The rate of aromatase activity in the hypothalamus-preoptic area (HPOA) was linear with time up to 1 h, and with tissue concentrations up to 5 mgeq/200 microliters incubation mixture. The enzyme demonstrated a pH optimum of 7.4 and an apparent Michaelis-Menten constant (Km) of 0.04 microns. The greatest amount of aromatase activity was found in amygdala and HPOA from intact male rats. The hippocampus, midbrain tegmentum, cerebral cortex, cerebellum, and anterior pituitary all contained negligible enzymatic activity. Castration produced a significant decrease in aromatase activity in the HPOA, but not in the amygdala or cerebral cortex. The HPOAs of male rats contained significantly greater aromatase activity than the HPOAs of female rats. In females, this enzyme activity did not change during the estrous cycle or after ovariectomy. Administration of testosterone to gonadectomized male and female rats significantly enhanced HPOA aromatase activities to levels approximating those found in HPOA from intact males. Therefore, the results suggest that testosterone, or one of its metabolites, is a major steroidal regulator of HPOA aromatase activity in rats

  9. Radio protective effects of selenium on rats

    International Nuclear Information System (INIS)

    Bakir, A.; Alya, G

    2005-11-01

    Potential radio-protective effects of different selenium supplement concentrations of 4, 8, 15 and 30 ppm were evaluated in rats. Four groups of rats were administered different concentrations of selenium in drinking water for 30 days before irradiation starting from the ablactation which considered as day 0. The results showed that the sodium selenite of 4 ppm and 8 ppm enhance the 30-day survival of irradiated rats at 7 Gy ( sup 6 sup 0 Co source, whole body irradiation dose rate of 1 Gy x min sup - sup 1) compared to the control group. The mean cumulated probability of survival of rats was 69%+-6 (mean+-S.E.) and 77%+-6 in 4 and 8 ppm groups, respectively, versus 42%+-9 for control group (P<0.001). It was also indicated that sodium selenite with concentrations of 15 and 30 ppm had no significant reduction in mortality. The mean cumulated probability of survival of rats was 50%+-12 (P=0.39) and 49%+-14 (P=0.04), respectively. The toxic effects of selenium were observed at 15 ppm and 30 ppm, survivals after 30 days of selenium intake were 76% and 46%, respectively. It was concluded that 4 and 8 ppm sodium selenite have a radio-protective effect. 15 and 30 ppm sodium selenite had no radio-protective effects in rats, this may be due to a synergism of toxicity and radiation effects. (author)

  10. [Preventive effects of pueraria on presbycusis in rats].

    Science.gov (United States)

    Chen, Wangyan; Yao, Qi; Liu, Weihong; Zhang, Bibo; Wang, Ying; Liu, Bo

    2009-08-01

    To investigate the preventive effects of Pueraria on presbycusis in rats. Thirty-two 24-26 month old Wistar rats were randomly divided into four groups, and were treated with different dosages of Pueraria (1, 2, 4, 0 g x kg(-1) x d(-1)) separately for 4 weeks. Auditory brainstem response (ABR) was used to detect the change of hearing threshold of rats. Hemorheological items of rats were checked in each group. Compared with control group, the hearing threshold and hemorheological items of rats was significantly improved after treated with Pueraria (Ppresbycusis of rats.

  11. Fish oil versus arachis oil food supplementation in relation to pregnancy duration in rats

    DEFF Research Database (Denmark)

    Olsen, S.F.; Hansen, Harald S.; Jensen, B.

    1990-01-01

    Throughout pregnancy, Lewis rats were fed standard rat chow supplemented with 15% (w/w) of either MaxEPA fish oil (FO) or arachis oil (AO); a third group was fed standard rat chow only (St) (n = 15, 15, and 16 rats, respectively). Compared to AO-rats, FO-rats had substantially higher levels of n-3...

  12. Increased radiosensitivity of cerebral capillaries in neonatal Gunn rats as compared to Sprague-Dawley rats

    International Nuclear Information System (INIS)

    Landolt, R.; Arn, D.

    1979-01-01

    The extent of petechial haemorrhages of the cerebral cortex examined between 14 hours and 4 days after X-irradiation to the head was compared in Sprague-Dawley and homozygous Gunn rats with congenital hyperbilirubinaemia. Animals 1 to 2 days old received single doses of either 250, 500 or 750 rad. By means of a special scoring scale the degree of the damage to the micro vasculature was semi-quantitatively estimated. In both strains a significant difference in effect was obtained between 250 and 500 rad, but not between 500 and 750 rad. The shape of the dose-effect curve in Gunn rats was similar to that of Sprague-Dawley rats, but displaced upwards. In Gunn rats the effect of 250 rad was greater that that of 750 rad in Sprague-Dawley rats. Possible radiosensitizing mechanisms are discussed with reference to the literature and these results. (author)

  13. Social structure predicts genital morphology in African mole-rats.

    Directory of Open Access Journals (Sweden)

    Marianne L Seney

    2009-10-01

    Full Text Available African mole-rats (Bathyergidae, Rodentia exhibit a wide range of social structures, from solitary to eusocial. We previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. This was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals examined. We hypothesized that the lack of sex differences in naked mole-rats might be related to their unusual social structure.We compared the genitalia and perineal muscles in three African mole-rat species: the naked mole-rat, the solitary silvery mole-rat, and the Damaraland mole-rat, a species considered to be eusocial, but with less reproductive skew than naked mole-rats. Our findings support a relationship between social structure, mating system, and sexual differentiation. Naked mole-rats lack sex differences in genitalia and perineal morphology, silvery mole-rats exhibit sex differences, and Damaraland mole-rats are intermediate.The lack of sex differences in naked mole-rats is not an attribute of all African mole-rats, but appears to have evolved in relation to their unusual social structure and reproductive biology.

  14. Social structure predicts genital morphology in African mole-rats.

    Science.gov (United States)

    Seney, Marianne L; Kelly, Diane A; Goldman, Bruce D; Sumbera, Radim; Forger, Nancy G

    2009-10-15

    African mole-rats (Bathyergidae, Rodentia) exhibit a wide range of social structures, from solitary to eusocial. We previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. This was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals examined. We hypothesized that the lack of sex differences in naked mole-rats might be related to their unusual social structure. We compared the genitalia and perineal muscles in three African mole-rat species: the naked mole-rat, the solitary silvery mole-rat, and the Damaraland mole-rat, a species considered to be eusocial, but with less reproductive skew than naked mole-rats. Our findings support a relationship between social structure, mating system, and sexual differentiation. Naked mole-rats lack sex differences in genitalia and perineal morphology, silvery mole-rats exhibit sex differences, and Damaraland mole-rats are intermediate. The lack of sex differences in naked mole-rats is not an attribute of all African mole-rats, but appears to have evolved in relation to their unusual social structure and reproductive biology.

  15. Automated registration of tail bleeding in rats.

    Science.gov (United States)

    Johansen, Peter B; Henriksen, Lars; Andresen, Per R; Lauritzen, Brian; Jensen, Kåre L; Juhl, Trine N; Tranholm, Mikael

    2008-05-01

    An automated system for registration of tail bleeding in rats using a camera and a user-designed PC-based software program has been developed. The live and processed images are displayed on the screen and are exported together with a text file for later statistical processing of the data allowing calculation of e.g. number of bleeding episodes, bleeding times and bleeding areas. Proof-of-principle was achieved when the camera captured the blood stream after infusion of rat whole blood into saline. Suitability was assessed by recording of bleeding profiles in heparin-treated rats, demonstrating that the system was able to capture on/off bleedings and that the data transfer and analysis were conducted successfully. Then, bleeding profiles were visually recorded by two independent observers simultaneously with the automated recordings after tail transection in untreated rats. Linear relationships were found in the number of bleedings, demonstrating, however, a statistically significant difference in the recording of bleeding episodes between observers. Also, the bleeding time was longer for visual compared to automated recording. No correlation was found between blood loss and bleeding time in untreated rats, but in heparinized rats a correlation was suggested. Finally, the blood loss correlated with the automated recording of bleeding area. In conclusion, the automated system has proven suitable for replacing visual recordings of tail bleedings in rats. Inter-observer differences can be eliminated, monotonous repetitive work avoided, and a higher through-put of animals in less time achieved. The automated system will lead to an increased understanding of the nature of bleeding following tail transection in different rodent models.

  16. Effect of radiation on rat skin collagen

    International Nuclear Information System (INIS)

    Nogami, Akira

    1980-01-01

    I. Albino male rats were exposed for 16 weeks to ultraviolet light (UVL) which has principle emission at 305 nm. There were no significant changes between control and UVL-exposed skins in the total hydroxyproline content. However, a little increase of citrate-soluble collagen, a little decrease of insoluble collagen and a decrease of aldehyde content in soluble collagen were observed with UVL exposure. Total acid glycosaminoglycan in skin increased 30% or more from control. These results show that the effect of UVL on rat skin in vivo was merely inflammation phenomenon and that the 'aging' process of skin was not caused in our experimental conditions. II. The effects of radiation on the solubility of rat skin collagen were examined under various conditions. 1) When intact rats were exposed to a single dose of radiation from 43 kVp X-ray source, the solubility in skin collagen did not change at 4,000 R dosage, while in irradiation of 40,000 R a decreased solubility in collagen was observed. When rats were given 400 R a week for 12 weeks, there was no changes in the solubility of collagen during experimental period. 2) In vitro exposure to skins, an irradiation of 40,000 R from 43 kVp X-ray source caused a decrease in the solubility of collagen. While an irradiation of 40,000 R of dosage from 200 kVp X-ray source resulted in the increase in soluble collagen and the decrease in insoluble collagen. 3) When intact rats were given a single dose of 40,000 R from 60 Co- gamma -ray, insoluble collagen decreased in both young and adult rats. Similar changes in collagen solubility were observed in vitro gamma -irradiation. (author)

  17. [Pinealectomy and early castration in the female Wistar rat].

    Science.gov (United States)

    Slama-Scemama, A

    1976-05-17

    Pinealectomy does not significantly modify the level of pituitary and plasma gonadotropins in intact and in castrated female Rats from brith to 75 days of age. Only the weight of the thyroid gland is higher in pinealectomized rats.

  18. Patterns of blood pressure variability in normotensive and hypertensive rats

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; He, J; Wagner, A J

    1995-01-01

    We sought patterns in mean arterial pressure of normotensive rats and alterations in chronic hypertension. Pressure was recorded for 4-6 days by telemetry from conscious, unrestrained rats and sampled digitally at 3 Hz, using normotensive Sprague-Dawley rats, spontaneously hypertensive rats (SHR)...... the day; less pronounced in 2K,1C; and not detectable in SHR. There are regular patterns of blood pressure fluctuations and specific modifications to the patterns by different forms of hypertension.......We sought patterns in mean arterial pressure of normotensive rats and alterations in chronic hypertension. Pressure was recorded for 4-6 days by telemetry from conscious, unrestrained rats and sampled digitally at 3 Hz, using normotensive Sprague-Dawley rats, spontaneously hypertensive rats (SHR...

  19. Classical clinical signs in rats experimemtally infected with Trypanosoma brucei

    Directory of Open Access Journals (Sweden)

    Nwoha Rosemary Ijeoma Ogechi

    2015-02-01

    Full Text Available Objective: To investigate clinical signs in Trypanosoma brucei infection in albino rats. Methods: Fourteen rats grouped into 2 with 7 rats in each group were used to determine classical clinical manifestation of Trypanosoma brucei infection in rats. Group A rats were uninfected control and Group B rats were infected with Trypanosoma brucei. Results: Parasitaemia was recorded in Group B by (3.86±0.34 d and the peak of parasitaemia was observed at Day 5 post infection. Classical signs observed included squint eyes, raised whiskers, lethargy, no weight loss, pyrexia, isolation from the other rats, and starry hair coat. Conclusions: These signs could be diagnostic or aid in diagnosis of Trypanosoma brucei infection in rats.

  20. [Pituitary function of dysgenesic femal rats. Studies with grafting method].

    Science.gov (United States)

    Vanhems, E; Busquet, J

    1975-01-01

    Misulban administered to pregnant rats on the 15th day of gestation provoked gonadal dysgenesia in the offspring. Study of the pituitary function of dysgenesic female rats, realized by grafting method, showed gonadotrophic hypersecretion.

  1. Water metabolism and modification of tritium excretion in the rat

    International Nuclear Information System (INIS)

    Ichimasa, Y.; Akita, Y.

    1982-01-01

    1. The intake and excretion of tritium were studied in rats exposed to tritiated water vapor. The metabolism of tritium was also investigated in rats given single administrations of tritiated water and in rats given daily administrations (per os or i.p.). The results were essentially in accord with those reported previously. 2. Amounts of drinking water consumed and urine excreted by rats drinking water with 0.15% saccharin were 1.5 to 2 times higher than in rats drinking tap water. The tritium activity in various tissues of rats drinking water with 0.15% saccharin decreased to about half of that of rats drinking tap water. A similar tendency was observed also in rats drinking beer. The diuretic agent sodium acetazolamide also enhanced the urinary excretion of tritium. (author)

  2. Uptake of trace elements in adult and suckling rat lenses

    International Nuclear Information System (INIS)

    Nabekura, Tomohiro; Ito, Yoshimasa; Minami, Takeshi; Hirunuma, Rieko; Enomoto, Shuichi

    2001-01-01

    The uptake of trace elements in the lens was compared in adult and suckling rat lenses. Multitracers, including 15 trace elements, As, Be, Co, Fe, Mn, Rb, Rh, Ru, Sc, Se, Sr, Y, V, Zn, and Zr, were incubated with the lenses for 4 hr and their concentrations in the lens were measured. A high uptake rate of Zn was observed in the lenses of both adult and suckling rats in comparison with those of the other elements, and the Zn concentration in the lens of suckling rats was higher than that of adult rats. The uptake rate of Sr was higher in adult rats than in suckling rats. On the other contrary, Rb and Se concentrations in the lens were higher in suckling rats than in adult rats. The present study suggests that the different mechanisms depending on development serve to transport trace elements into the lens. (author)

  3. Absorption of plutonium in the iron-deficient rat

    International Nuclear Information System (INIS)

    Ragan, H.A.

    1977-01-01

    Iron deficiency did not enhance absorption of plutonium following intragastric gavage of rats. Absorption of plutonium citrate in both control and iron-deficient rats was about 0.03% of the administered dose

  4. (Urginea Altissima), Against the Field Rat, Arvicanthis Abyssinicus

    African Journals Online (AJOL)

    Bernt Lindtjorn

    the field rat, Arvicanthis abyssincus with the aim of developing locally based ... inhabited by humans and is commonly found in open ... rat, A. abyssinicus in a choice and non-choice tests. ..... sowing control of house mice (Mus domesticus):.

  5. Biochemical and Haematological Indices of Weanly Albino Rats Fed ...

    African Journals Online (AJOL)

    acer

    ABSTRACT: Malnutrition is a public health problem in Nigeria accounting for more than 50% of ... weanly albino rats using nutritional, biochemical ... groundnut (16%), soy beans (16%), crayfish ... consumption was observed in rats on PC and.

  6. Ulinastatin Reduces T Cell Apoptosis in Rats with Severe Acute ...

    African Journals Online (AJOL)

    in rats with severe acute pancreatitis (SAP) and to elucidate its underlying molecular mechanism. Methods: Thirty .... on T lymphocytes apoptosis in SAP rat model and elucidated ..... oxygen radicals, the exhaustion of adenine nucleotide and ...

  7. Healing effect of Shaoshang Yuhe yihao on burns in rats

    African Journals Online (AJOL)

    tissue expressions of transforming growth factor-beta (TGF-β) were determined along with skin histopathology. ... Polygonum cuspidatum Sieb. et Zucc., Aloe vera var. chinensis ... anesthetizing the rats after the rat hair was shaved. The top of ...

  8. Biological effects of 137Cs, incorporated into organism of rats

    International Nuclear Information System (INIS)

    Monakhov, A.S.; Strekalov, S.A.; Sokolov, A.V.; Aver'yanova, T.K.

    1987-01-01

    Results of investigating mutagenous and hemotoxic effects of 137 Cs on blood lymphocytes of rats are presented. 137 Cs was orally administrated into organism of rats as 270 kBq/g chloride solution. 137 Cs mutagenous effect was studied on metaphase plates of rat blood lymphocytes in course of rats lifetime experiment. It is stated that 137 Cs inducing severe disturbances of genetic material in a great quantity of blood lymphocytes, causes their total killing

  9. Tumorigenicity of sodium ascorbate in male rats.

    Science.gov (United States)

    Cohen, S M; Anderson, T A; de Oliveira, L M; Arnold, L L

    1998-06-15

    Sodium ascorbate, like other sodium salts such as saccharin, glutamate, and bicarbonate, produces urinary alterations when fed at high doses to rats, which results in mild superficial urothelial cytotoxicity and regeneration but not tumors in a standard 2-year bioassay. Sodium saccharin was shown to produce a low incidence of bladder tumors in rats if administered in a two-generation bioassay. In the present study, we evaluated sodium ascorbate in a two-generation bioassay that involved feeding to the male and female parental F344 rats for 4 weeks before mating, feeding the dams during gestation and lactation, and then feeding the weaned (at 28 days of age) male F1 generation rats for the remainder of their lifetime (up to 128 weeks of the experiment). Dietary levels of 1.0, 5.0, and 7.0% sodium ascorbate were tested. At 5.0 and 7.0% sodium ascorbate, there was an increase in urinary bladder urothelial papillary and nodular hyperplasia and the induction of a few papillomas and carcinomas. There was a dose-responsive increase in renal pelvic calcification and hyperplasia and inhibition of the aging nephropathy of rats even at the level of 1% sodium ascorbate. Because the short-term urothelial effects of sodium ascorbate in rats are inhibited by treatments producing urinary acidification to pH sodium ascorbate to evaluate the long-term effects. The combination of 7.0% sodium ascorbate plus 2.78% NH4Cl in the diet was toxic, and the group was terminated early during the course of the experiment. The group fed 5.0% sodium ascorbate plus 2.04% NH4Cl showed complete inhibition of the urothelial effects of sodium ascorbate and significant inhibition of its renal effects. We also demonstrated the presence of a calcium phosphate-containing urinary precipitate in rats fed sodium ascorbate at all doses, in a dose-responsive manner. The formation of the precipitate was inhibited by coadministration with NH4Cl. The proliferative effects of sodium ascorbate on the male rat

  10. From engineering to editing the rat genome.

    Science.gov (United States)

    Meek, Stephen; Mashimo, Tomoji; Burdon, Tom

    2017-08-01

    Since its domestication over 100 years ago, the laboratory rat has been the preferred experimental animal in many areas of biomedical research (Lindsey and Baker The laboratory rat. Academic, New York, pp 1-52, 2006). Its physiology, size, genetics, reproductive cycle, cognitive and behavioural characteristics have made it a particularly useful animal model for studying many human disorders and diseases. Indeed, through selective breeding programmes numerous strains have been derived that are now the mainstay of research on hypertension, obesity and neurobiology (Okamoto and Aoki Jpn Circ J 27:282-293, 1963; Zucker and Zucker J Hered 52(6):275-278, 1961). Despite this wealth of genetic and phenotypic diversity, the ability to manipulate and interrogate the genetic basis of existing phenotypes in rat strains and the methodology to generate new rat models has lagged significantly behind the advances made with its close cousin, the laboratory mouse. However, recent technical developments in stem cell biology and genetic engineering have again brought the rat to the forefront of biomedical studies and enabled researchers to exploit the increasingly accessible wealth of genome sequence information. In this review, we will describe how a breakthrough in understanding the molecular basis of self-renewal of the pluripotent founder cells of the mammalian embryo, embryonic stem (ES) cells, enabled the derivation of rat ES cells and their application in transgenesis. We will also describe the remarkable progress that has been made in the development of gene editing enzymes that enable the generation of transgenic rats directly through targeted genetic modifications in the genomes of zygotes. The simplicity, efficiency and cost-effectiveness of the CRISPR/Cas gene editing system, in particular, mean that the ability to engineer the rat genome is no longer a limiting factor. The selection of suitable targets and gene modifications will now become a priority: a challenge where

  11. Opiates and cerebral functional activity in rats

    International Nuclear Information System (INIS)

    Trusk, T.C.

    1986-01-01

    Cerebral activity was measured using the free-fatty acid [1- 14 C] octanoate as a fast functional tracer in conscious, unrestrained rats 5 minutes after intravenous injection of heroin, cocaine or saline vehicle. Regional changes of octanoate labeling density in the autoradiograms relative to saline-injected animals were used to determine the functional activity effects of each drug. Heroin and cocaine each produced a distinctive pattern of activity increases and suppression throughout the rat brain. Similar regional changes induced by both drugs were found in limbic brain regions implicated in drug reinforcement. Labeled octanoate autoradiography was used to measure the cerebral functional response to a tone that had previously been paired to heroin injections. Rats were trained in groups of three consisting of one heroin self-administration animal, and two animals receiving yoked infusion of heroin or saline. A tone was paired with each infusion during training. Behavioral experiments in similarly trained rats demonstrated that these training conditions impart secondary reinforcing properties to the tone in animals previously self-administering heroin, while the tone remains behaviorally neutral in yoked-infusion rats. Cerebral functional activity was measured during presentation of the tone without drug infusion. Octanoate labeling density changed in fifteen brain areas in response to the tone previously paired to heroin without response contingency. Labeling density was significantly modified in sixteen regions as a result of previously pairing the tone to response-contingent heroin infusions

  12. Working Memory Systems in the Rat.

    Science.gov (United States)

    Bratch, Alexander; Kann, Spencer; Cain, Joshua A; Wu, Jie-En; Rivera-Reyes, Nilda; Dalecki, Stefan; Arman, Diana; Dunn, Austin; Cooper, Shiloh; Corbin, Hannah E; Doyle, Amanda R; Pizzo, Matthew J; Smith, Alexandra E; Crystal, Jonathon D

    2016-02-08

    A fundamental feature of memory in humans is the ability to simultaneously work with multiple types of information using independent memory systems. Working memory is conceptualized as two independent memory systems under executive control [1, 2]. Although there is a long history of using the term "working memory" to describe short-term memory in animals, it is not known whether multiple, independent memory systems exist in nonhumans. Here, we used two established short-term memory approaches to test the hypothesis that spatial and olfactory memory operate as independent working memory resources in the rat. In the olfactory memory task, rats chose a novel odor from a gradually incrementing set of old odors [3]. In the spatial memory task, rats searched for a depleting food source at multiple locations [4]. We presented rats with information to hold in memory in one domain (e.g., olfactory) while adding a memory load in the other domain (e.g., spatial). Control conditions equated the retention interval delay without adding a second memory load. In a further experiment, we used proactive interference [5-7] in the spatial domain to compromise spatial memory and evaluated the impact of adding an olfactory memory load. Olfactory and spatial memory are resistant to interference from the addition of a memory load in the other domain. Our data suggest that olfactory and spatial memory draw on independent working memory systems in the rat. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Gastric secretion elicited by conditioning in rats.

    Science.gov (United States)

    Caboclo, José Liberato Ferreira; Cury, Francico de Assis; Borin, Aldenis Albanese; Caboclo, Luís Otávio Sales Ferreira; Ribeiro, Maria Fernanda Sales Caboclo; de Freitas, Pedro José; Andersson, Sven

    2009-01-01

    To investigate whether interdigestive gastric acid secretion can be controlled by a possible memory-related cortical mechanism. To evaluate gastric secretion in rats, we used a methodology that allows gastric juice collection in rats in their habitual conditions (without any restraining) by pairing sound as the conditioning stimulus (CS) and food as the unconditioning stimulus (US). The levels of gastric acid secretion under basal conditions and under sound stimulation were recorded and the circulating gastrin levels determined. When the gastric juice was collected in the course of the conditioning procedure, the results showed that under noise stimulation a significant increase in gastric acid secretion occurred after 10 days of conditioning (p<0.01). The significance was definitively demonstrated after 13 days of conditioning (p<0.001). Basal secretions of the conditioned rats reached a significant level after 16 days of conditioning. The levels of noise-stimulated gastric acid secretion were the highest so far described in physiological experiments carried out in rats and there were no significant increases in the circulating gastrin levels. The results point to the important role played by cortical structures in the control of interdigestive gastric acid secretion in rats. If this mechanism is also present in humans, it may be involved in diseases caused by inappropriate gastric acid secretion during the interprandial periods.

  14. Opiates and cerebral functional activity in rats

    Energy Technology Data Exchange (ETDEWEB)

    Trusk, T.C.

    1986-01-01

    Cerebral activity was measured using the free-fatty acid (1-/sup 14/C) octanoate as a fast functional tracer in conscious, unrestrained rats 5 minutes after intravenous injection of heroin, cocaine or saline vehicle. Regional changes of octanoate labeling density in the autoradiograms relative to saline-injected animals were used to determine the functional activity effects of each drug. Heroin and cocaine each produced a distinctive pattern of activity increases and suppression throughout the rat brain. Similar regional changes induced by both drugs were found in limbic brain regions implicated in drug reinforcement. Labeled octanoate autoradiography was used to measure the cerebral functional response to a tone that had previously been paired to heroin injections. Rats were trained in groups of three consisting of one heroin self-administration animal, and two animals receiving yoked infusion of heroin or saline. A tone was paired with each infusion during training. Behavioral experiments in similarly trained rats demonstrated that these training conditions impart secondary reinforcing properties to the tone in animals previously self-administering heroin, while the tone remains behaviorally neutral in yoked-infusion rats. Cerebral functional activity was measured during presentation of the tone without drug infusion. Octanoate labeling density changed in fifteen brain areas in response to the tone previously paired to heroin without response contingency. Labeling density was significantly modified in sixteen regions as a result of previously pairing the tone to response-contingent heroin infusions.

  15. Hematological changes in opium addicted diabetic rats.

    Science.gov (United States)

    Asadikaram, Gholamreza; Sirati-Sabet, Majid; Asiabanha, Majid; Shahrokhi, Nader; Jafarzadeh, Abdollah; Khaksari, Mohammad

    2013-01-01

    Chronic opioid treatment in animal models has shown to alter hematological parameters. The aim of this study was to evaluate the biological effects of opium on the number of peripheral blood cells and red blood cells (RBCs) indices in diabetic rats. Peripheral blood samples were collected from diabetic, opium-addicted, diabetic opium-addicted and normal male and female rats and hematological parameters were measured. The mean number of white blood cells (WBCs) was significantly higher in diabetic opium-addict females compared to diabetic non-addict female group. In both male and female, the mean number of neutrophils was significantly higher and the mean number of lymphocytes was lower in diabetic opium-addicted rats than those observed in diabetic non-addicted group. In diabetic opium-addicted male group the mean counts of RBC significantly increased as compared with diabetic male group. However, in diabetic addicted female, the mean number of RBCs was significantly lower than diabetic non-addicted female group. In both males and females, the mean number of platelets was significantly lower in diabetic addict rats compared to diabetic non-addict group. Generally, the results indicated that opium addiction has different effects on male and female rats according to the number of WBC, RBC and RBC indices. It could also be concluded that in the opium-addicts the risk of infection is enhanced due to the weakness of immune system as a result of the imbalance effect of opium on the immune cells.

  16. Cardiopulmonary Changes with Moderate Decompression in Rats

    Science.gov (United States)

    Robinson, R.; Little, T.; Doursout, M.-F.; Butler, B. D.; Chelly, J. E.

    1996-01-01

    Sprague-Dawley rats were compressed to 616 kPa for 120 min then decompressed at 38 kPa/min to assess the cardiovascular and pulmonary responses to moderate decompression stress. In one series of experiments the rats were chronically instrumented with Doppler ultrasonic probes for simultaneous measurement of blood pressure, cardiac output, heart rate, left and right ventricular wall thickening fraction, and venous bubble detection. Data were collected at base-line, throughout the compression/decompression protocol, and for 120 min post decompression. In a second series of experiments the pulmonary responses to the decompression protocol were evaluated in non-instrumented rats. Analyses included blood gases, pleural and bronchoalveolar lavage (BAL) protein and hemoglobin concentration, pulmonary edema, BAL and lung tissue phospholipids, lung compliance, and cell counts. Venous bubbles were directly observed in 90% of the rats where immediate post-decompression autopsy was performed and in 37% using implanted Doppler monitors. Cardiac output, stroke volume, and right ventricular wall thickening fractions were significantly decreased post decompression, whereas systemic vascular resistance was increased suggesting a decrease in venous return. BAL Hb and total protein levels were increased 0 and 60 min post decompression, pleural and plasma levels were unchanged. BAL white blood cells and neutrophil percentages were increased 0 and 60 min post decompression and pulmonary edema was detected. Venous bubbles produced with moderate decompression profiles give detectable cardiovascular and pulmonary responses in the rat.

  17. Somatostatin ontogenesis in the gastrointestinal and pancreatic tract: study in normal rats and during a induced diabetes in neonates rats

    International Nuclear Information System (INIS)

    Cunha, M.C.

    1980-01-01

    The ontogenic studies of somatostatin of pancreas, ileum and duodenum of Wistar rats and the rats with induced diabetes were done. The radioimmunologic method to dose the somatostatin was used. (L.M.J.)

  18. Phenotypic Characterization of LEA Rat: A New Rat Model of Nonobese Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Tadashi Okamura

    2013-01-01

    Full Text Available Animal models have provided important information for the genetics and pathophysiology of diabetes. Here we have established a novel, nonobese rat strain with spontaneous diabetes, Long-Evans Agouti (LEA rat derived from Long-Evans (LE strain. The incidence of diabetes in the males was 10% at 6 months of age and 86% at 14 months, while none of the females developed diabetes. The blood glucose level in LEA male rats was between 200 and 300 mg/dl at 120 min according to OGTT. The glucose intolerance in correspondence with the impairment of insulin secretion was observed in male rats, which was the main cause of diabetes in LEA rats. Histological examination revealed that the reduction of β-cell mass was caused by progressive fibrosis in pancreatic islets in age-dependent manner. The intracytoplasmic hyaline droplet accumulation and the disappearance of tubular epithelial cell layer associated with thickening of basement membrane were evident in renal proximal tubules. The body mass index and glycaemic response to exogenous insulin were comparable to those of control rats. The unique characteristics of LEA rat are a great advantage not only to analyze the progression of diabetes, but also to disclose the genes involved in type 2 diabetes mellitus.

  19. Effect of Yushen zhuyun decoction on rats with diminished ovarian ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of Yushen zhuyun decoction (YSZYF) on rats with diminished ovarian reserve (DOR). Methods: High-performance liquid chromatography (HPLC) was used to determine the major phytochemical constituents of YSZYF. Rats with DOR (DOR rats) were prepared by administration of ...

  20. Haematological and Serum Biochemical Variables in rats Treated ...

    African Journals Online (AJOL)

    The haematology and serum biochemical effects of oral administration of the ethanolic extract of the root of Moringa oleifera at 50, 100 and 150 mg/kg were investigated in 30 mated female Wistar rats. The rats were assigned into five groups of six rats each. Group A was given 50mg/kg of the extract; group B, 100mg/kg; ...

  1. Activation of peripheral leukocytes in rat pregnancy and experimental preeclampsia

    NARCIS (Netherlands)

    Faas, MM; Schuiling, GA; Linton, EA; Sargent, IL; Redman, CWG

    OBJECTIVE: The aim of this study was to search for activation markers of peripheral leukocytes in experimental preeclampsia in the rat. STUDY DESIGN: Experimental preeclampsia was induced in 14-day-pregnant rats by infusion of endotoxin (1.0 mu g/kg body weight). For comparison, rats with normal

  2. Effects of Culling on Leptospira interrogans Carriage by Rats

    Science.gov (United States)

    Byers, Kaylee A.; Donovan, Christina M.; Bidulka, Julie J.; Stephen, Craig; Patrick, David M.; Himsworth, Chelsea G.

    2018-01-01

    We found that lethal, urban rat control is associated with a significant increase in the odds that surviving rats carry Leptospira interrogans. Our results suggest that human interventions have the potential to affect and even increase the prevalence of zoonotic pathogens within rat populations. PMID:29350160

  3. ( Cola Nitida Rubra ) on Reproductive Hormones in Rats

    African Journals Online (AJOL)

    Our previous study suggests that aqueous extract of kola nut had effect on reproductive hormones in male rats. This study evaluates the effects of kola nut extract on plasma level of testosterone and luteinizing hormones in male rats. 30 adult male rats were used. These were divided into three groups: group A served as ...

  4. Effect of thiabendazole on some rat hepatic xenobiotic metabolising enzymes

    NARCIS (Netherlands)

    Price, R.J.; Scott, M.P.; Walters, D.G.; Stierum, R.H.; Groten, J.P.; Meredith, C.; Lake, B.G.

    2004-01-01

    The effect of thiabendazole (TB) on some rat hepatic xenobiotic metabolising enzymes has been investigated. Male Sprague-Dawley rats were fed control diet or diets containing 102-5188 ppm TB for 28 days. As a positive control for induction of hepatic xenobiotic metabolism, rats were also fed diets

  5. Immature rats show ovulatory defects similar to those in adult rats lacking prostaglandin and progesterone actions

    Directory of Open Access Journals (Sweden)

    Sanchez-Criado Jose E

    2004-09-01

    Full Text Available Abstract Gonadotropin-primed immature rats (GPIR constitute a widely used model for the study of ovulation. Although the equivalence between the ovulatory process in immature and adult rats is generally assumed, the morphological and functional characteristics of ovulation in immature rats have been scarcely considered. We describe herein the morphological aspects of the ovulatory process in GPIR and their response to classical ovulation inhibitors, such as the inhibitor of prostaglandin (PG synthesis indomethacin (INDO and a progesterone (P receptor (PR antagonist (RU486. Immature Wistar rats were primed with equine chorionic gonadotropin (eCG at 21, 23 or 25 days of age, injected with human chorionic gonadotropin (hCG 48 h later, and sacrificed 16 h after hCG treatment, to assess follicle rupture and ovulation. Surprisingly, GPIR showed age-related ovulatory defects close similar to those in adult rats lacking P and PG actions. Rats primed with eCG at 21 or 23 days of age showed abnormally ruptured corpora lutea in which the cumulus-oocyte complex (COC was trapped or had been released to the ovarian interstitum, invading the ovarian stroma and blood and lymphatic vessels. Supplementation of immature rats with exogenous P and/or PG of the E series did not significantly inhibit abnormal follicle rupture. Otherwise, ovulatory defects were practically absent in rats primed with eCG at 25 days of age. GPIR treated with INDO showed the same ovulatory alterations than vehicle-treated ones, although affecting to a higher proportion of follicles. Blocking P actions with RU486 increased the number of COC trapped inside corpora lutea and decreased ovulation. The presence of ovulatory defects in GPIR, suggests that the capacity of the immature ovary to undergo the coordinate changes leading to effective ovulation is not fully established in Wistar rats primed with eCG before 25 days of age.

  6. Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells

    International Nuclear Information System (INIS)

    Eissa, Laila A.; Smith, Sylvia B.; El-sherbeny, Amira A.

    2006-01-01

    Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

  7. Threonine phosphorylation of rat liver glycogen synthase

    International Nuclear Information System (INIS)

    Arino, J.; Arro, M.; Guinovart, J.J.

    1985-01-01

    32 P-labeled glycogen synthase specifically immunoprecipitated from 32 P-phosphate incubated rat hepatocytes contains, in addition to [ 32 P] phosphoserine, significant levels of [ 32 P] phosphothreonine. When the 32 P-immunoprecipitate was cleaved with CNBr, the [ 32 P] phosphothreonine was recovered in the large CNBr fragment (CB-2, Mapp 28 Kd). Homogeneous rat liver glycogen synthase was phosphorylated by all the protein kinases able to phosphorylate CB-2 in vitro. After analysis of the immunoprecipitated enzyme for phosphoaminoacids, it was observed that only casein kinase II was able to phosphorylate on threonine and 32 P-phosphate was only found in CB-2. These results demonstrate that rat liver glycogen synthase is phosphorylated at threonine site(s) contained in CB-2 and strongly indicate that casein kinase II may play a role in the ''in vivo'' phosphorylation of liver glycogen synthase. This is the first protein kinase reported to phosphorylate threonine residues in liver glycogen synthase

  8. Iron appetite and latent learning in rats.

    Science.gov (United States)

    Woods, S C; Vasselli, J R; Milam, K M

    1977-11-01

    Two experiments are reported which show that rats are capable of forming an association between the presence of iron in a solution when it is not specifically needed and a subsequent state of iron deficiency. Specifically, rats were trained to lever press for water while thirsty. One group received ferrous ions in addition to the water. When these rats were subsequently rendered iron deficient, they lever pressed more under extinction conditions as a graded function of lower hemoglobin levels. Controls that either did not receive ferrous ions during training or received solutions other than ferrous solutions during training did not respond this way under extinction conditions. This is therefore a type of latent learning previously demonstrated only for sodium appetite.

  9. Metabolic neural mapping in neonatal rats

    International Nuclear Information System (INIS)

    DiRocco, R.J.; Hall, W.G.

    1981-01-01

    Functional neural mapping by 14 C-deoxyglucose autoradiography in adult rats has shown that increases in neural metabolic rate that are coupled to increased neurophysiological activity are more evident in axon terminals and dendrites than neuron cell bodies. Regions containing architectonically well-defined concentrations of terminals and dendrites (neuropil) have high metabolic rates when the neuropil is physiologically active. In neonatal rats, however, we find that regions containing well-defined groupings of neuron cell bodies have high metabolic rates in 14 C-deoxyglucose autoradiograms. The striking difference between the morphological appearance of 14 C-deoxyglucose autoradiograms obtained from neonatal and adult rats is probably related to developmental changes in morphometric features of differentiating neurons, as well as associated changes in type and locus of neural work performed

  10. Helminth parasites in black rats (Rattus rattus) and brown rats (Rattus norvegicus) from different environments in the Netherlands

    NARCIS (Netherlands)

    Franssen, Frits; Swart, Arno; van Knapen, Frans|info:eu-repo/dai/nl/070114749; van der Giessen, Joke

    2016-01-01

    BACKGROUND: Rattus norvegicus (brown rat) and Rattus rattus (black rat) are known carriers of bacteria, viruses, and parasites of zoonotic and veterinary importance. Moreover, rats may play a role in the transmission of muscle larvae of the zoonotic nematode Trichinella spiralis to farm animals. We

  11. Neutron irradiation of rat embryos in utero

    International Nuclear Information System (INIS)

    Vogel, H.H. Jr.

    1978-01-01

    In the rat radiation is most effective in producing congenital anomalies during the organ-forming period (days 9 to 13), which is approximately equivalent to the 14th to 50th days of human pregnancy. We have exposed female Sprague--Dawley rats on the 18th day of pregnancy to single whole-body doses of fission neutrons (20 to 150 rads). After 20 rads there was a small decrease in body weight which lasted from birth to weaning. During this period 9% of the irradiated rats died compared with 4% of the controls. After 50 rads, 65/275 (23.6%) of the rats died between birth and weaning, and the body-weight loss of the survivors was increased. After 100 rads, 62/133 (47%) died at birth or day 1 and 103/133 (77.4%) died before weaning. A large and significant decrease in body weight persisted in the survivors. After 150 rads of fission neutrons, all 95 rats died within 48 hr of birth. From cross-fostering experiments, we believe this is a direct effect of radiation on the embryos and not an indirect action through the mother or her milk. The LD 50 for the period from birth to weaning is approximately 75 rads of fission neutrons. Studies of organ weight were conducted daily for the first week after birth in an attempt to find the cause of radiation mortality. Body weight of the irradiated animals averaged only about one-half that of the controls. The liver, kidney, brain, and testes of the neutron-irradiated rats weighed significantly less than those of the controls. The weights of the spleen, lungs, duodenum, and stomach were decreased but not significantly. The bone marrow appeared depleted in the irradiated long bones, but the spleen maintained active hematopoiesis 1 to 2 months after neutron exposure

  12. Oxidative stress in normal and diabetic rats.

    Science.gov (United States)

    Torres, M D; Canal, J R; Pérez, C

    1999-01-01

    Parameters related to oxidative stress were studied in a group of 10 Wistar diabetic rats and 10 control rats. The levels of total erythrocyte catalase activity in the diabetic animals were significantly (pC18:2) ratios. Greater vitaminE/triglyceride (TG) ratio, however, appeared in the control group. The corresponding vitamin A ratios (vitaminA/TG, vitaminA/PUFA, vitaminA/C 18:2) were higher in the control group. Our work corroborates the findings that fatty acid metabolism presents alterations in the diabetes syndrome and that the antioxidant status is affected.

  13. Renal alterations in prediabetic rats with periodontitis

    DEFF Research Database (Denmark)

    Andersen, Carla Cruvinel Pontes; Holmstrup, Palle; Buschard, Karsten

    2008-01-01

    BACKGROUND: Periodontitis was shown to have an impact on glucose levels in prediabetic and diabetic rats. The Zucker fatty rat (ZFR) is a well-characterized model of prediabetes presenting with impaired glucose tolerance, hyperinsulinemia, dyslipidemia, and moderate hypertension. The aim...... IValpha1, fibronectin, and nephrin. Urinary albumin excretion and creatinine clearance were also evaluated. RESULTS: In prediabetic ZFRs, periodontitis was associated with kidney hypertrophy (P = 0.03) and a tendency for increased glomerular volume (P = 0.06). In lean littermates, elevated fibronectin m...

  14. Immunity to Fasciola hepatica in the rat

    International Nuclear Information System (INIS)

    Armour, J.; Dargie, J.D.

    1974-01-01

    Experiments were carried out which demonstrated an acquired immunity to Fasciola hapatica in the rat. It was shown that this immunity could be transferred to recipients using either lymphoid cells or serum from infected donor rats. The extent of the protection obtained by cells appeared to be related to the quantity and persistence of the antigenic stimulus in the donor. Likewise, the degree of immunity conferred by immune serum was dependent upon the volume transferred. The significance of these results in relation to the mechanism of immunity to fascioliasis is discussed

  15. Characterization of rat lung ICAM-1

    DEFF Research Database (Denmark)

    Beck-Schimmer, B; Schimmer, R C; Schmal, H

    1998-01-01

    studies, rat pulmonary artery endothelial cells (RPAEC), rat alveolar macrophages and aortic rings were stimulated (as described below) and evaluated for ICAM-1 expression. TREATMENT: RPAEC and macrophages were stimulated with lipopolysaccharide (LPS) and recombinant murine tumour necrosis factor alpha...... peaked at 4 h, while lung ICAM- I protein peaked at 6 h. CONCLUSIONS: Quantitation of ICAM-1 expression in vitro and in vivo suggests that ICAM-1 plays a central role in two lung inflammatory models. Furthermore, lung ICAM-1 upregulation involves at least two cell types: vascular endothelial cells...

  16. Absorption of pentacaine from ulcerous rat stomach

    International Nuclear Information System (INIS)

    Tomcikova, O.; Babulova, A.; Durisova, M.; Trnovec, T.; Benes, L.

    1985-01-01

    Pentacaine is a local anaesthetic which exhibited positive effects on healing of model ulcers in the rat stomach. The in situ disappearance of pentacaine from the ulcerous and intact rat stomach was studied. Gastric ulcers were produced by oral administration of phenylbutazone (200 mg/kg) 3.5 h before absorption experiment. Pentacaine exhibited a biexponential decrease from the lumen of the stomach, the rate of which was essentially the same in both groups. The total amount of pentacaine absorbed was small because of extremly low absorption rate. (author)

  17. Fenbendazole treatment and litter size in rats.

    Science.gov (United States)

    Johnston, Nancy A; Bieszczak, Jeremiah R; Verhulst, Steven; Disney, Kimberly E; Montgomery, Kyle E; Toth, Linda A

    2006-11-01

    Fenbendazole is commonly used in laboratory animal medicine as an anthelmintic for elimination of pinworms. It is generally regarded as a safe drug with minimal side effects. In our facility, 2 breeding colonies of rats were treated with fenbendazole to eliminate pinworms. Analysis of the breeding records revealed that feeding Sprague-Dawley rats a diet containing fenbendazole on a continuous basis for 7 consecutive weeks was associated with a significant reduction in litter size. Although the mechanism underlying this effect is unknown, the finding prompts caution when using fenbendazole to treat valuable breeding colonies or strains that are poor breeders.

  18. The oncogenic action of ionizing radiation on rat skin

    International Nuclear Information System (INIS)

    Burns, F.J.

    1991-01-01

    Progress has occurred in several areas corresponding to the specific aims of the proposal: (1) Progression and multiple events in radiation carcinogenesis of rat skin as a function of LET; (2) cell cycle kinetics of irradiated rat epidermis as determined by double labeling and double emulsion autoradiography; (3) oncogene activation detected by in situ hybridization in radiation-induced rat skin tumors; (4) amplification of the c-myc oncogene in radiation-induced rat skin tumors as a function of LET; and (5) transformation of rat skin keratinocytes by ionizing radiation in combination with c-Ki-ras and c-myc oncogenes. 111 refs., 13 figs., 12 tabs

  19. Rats demonstrate helping behavior toward a soaked conspecific.

    Science.gov (United States)

    Sato, Nobuya; Tan, Ling; Tate, Kazushi; Okada, Maya

    2015-09-01

    Helping behavior is a prosocial behavior whereby an individual helps another irrespective of disadvantages to him or herself. In the present study, we examined whether rats would help distressed, conspecific rats that had been soaked with water. In Experiment 1, rats quickly learned to liberate a soaked cagemate from the water area by opening the door to allow the trapped rat into a safe area. Additional tests showed that the presentation of a distressed cagemate was necessary to induce rapid door-opening behavior. In addition, it was shown that rats dislike soaking and that rats that had previously experienced a soaking were quicker to learn how to help a cagemate than those that had never been soaked. In Experiment 2, the results indicated that rats did not open the door to a cagemate that was not distressed. In Experiment 3, we tested behavior when rats were forced to choose between opening the door to help a distressed cagemate and opening a different door to obtain a food reward. Irrespective of how they learned to open the door, in most test trials, rats chose to help the cagemate before obtaining a food reward, suggesting that the relative value of helping others is greater than the value of a food reward. These results suggest that rats can behave prosocially and that helper rats may be motivated by empathy-like feelings toward their distressed cagemate.

  20. [Subcutaneous transplants of juvenile rat testicular tissues continue to develop and secret androgen in adult rats].

    Science.gov (United States)

    Yu, Zhou; Wang, Tong; Cui, Jiangbo; Song, Yajuan; Ma, Xianjie; Su, Yingjun; Peng, Pai

    2017-12-01

    Objective To explore the effects of subcutaneous microenvironment of adult rats on survival, development and androgen secretion of Leydig cells of transplanted juvenile rat testis. Methods Healthy adult SD rats were randomly divided into control group, sham group, castrated group and non-castrated group. Rats in the control group were kept intact, no testis was transplanted subcutaneously after adult recipients were castrated in the sham group; 5-7-day juvenile rat testes were transplanted subcutaneously in the castrated group, with one testis per side; Testes resected from juvenile rats were directly transplanted subcutaneously on both sides of the recipients in the non-castrated group. The grafts were obtained and weighed 4 weeks later. Then the histological features of the grafts were examined by HE staining; the expression and distribution of hydroxysteroid 17-beta dehydrogenase 1 (HSD-17β1) were investigated by immunohistochemistry; and the serum androgen level was determined by ELISA. Results The average mass of grafts obtained from the castrated group was significantly higher than that of the non-castrated group. Immunohistochemistry indicated that Leydig cells were visible in the tissues from both the castrated and non-castrated groups, but the number of HSD-17β1-posotive cells in the castrated group was larger than that in the non-castrated group. ELISA results showed that the serum androgen level was higher in the control group and non-castrated group than in the sham group and castrated group, and compared with the sham group, the serum androgen level in the castrated group was significantly higher. Conclusion The juvenile rat testis subcutaneously transplanted could further develop under the adult recipient rat skin, and the Leydig cells of grafts harbored the ability to produce and secret androgen.

  1. Effect of x-irradiation in rats bearing walker-256-carcinosarcoma and normal rats

    International Nuclear Information System (INIS)

    Ehara, Kazuhiko

    1978-01-01

    Serum protein fractions and total proteins were studied with bloods obtained from the rats exposed each to the partial-, whole-bodies and the transplanted tumors (Walker-256-carcinosarcoma transplanted in the right hind leg). The electrophoretic variation induced in the sera of tumor-bearing rats (Group II), and the content of total proteins decreased. Early irradiation to the tumor part of rats less induced the variations of the electrophoretic pattern and the decrease of the amount of serum total proteins. When the distant metastasis appeared during irradiation treatment, the electrophoretic patterns and content of total proteins changed proportionally to the variation in sera of Group II. On the other hand, the γ-globulin (G) fraction increased in the long-term survival rat. The separation of the rat serum β-G into two peaks of β 1 - and β 2 -G was shown only in Group IV (late irradiation to the right hind leg). This finding supposed that some factors involve in the sera of rats with transplanted primary tumor grown up to a fixed size and guessed the appearance of the distant metastasis during x-irradiation. The percentages of the albumin and γ-G decreased slightly and those of the α 1 -, α 2 - and β-G increased slightly in the rats with 300 rad partial-body (the right hind leg) x-irradiation daily for 20 days. The remarkable decrease of the albumin and γ-G, the increase of the α 1 - and β-G, the marked increase of the α 2 -G and the decrease of serum total proteins were demonstrated for the sera of rats with 1,000 rad whole-body x-irradiation at a time. These phenomena seem to be related to the destructive and reticuloendothelial injury by the exposure. (auth.)

  2. Palmitoylated PrRP analog decreases body weight in DIO rats but not in ZDF rats

    Czech Academy of Sciences Publication Activity Database

    Holubová, Martina; Zemenová, Jana; Mikulášková, Barbora; Panajotová, V.; Stöhr, J.; Haluzík, M.; Kuneš, Jaroslav; Železná, Blanka; Maletínská, Lenka

    2016-01-01

    Roč. 229, č. 2 (2016), s. 85-96 ISSN 0022-0795 R&D Projects: GA ČR(CZ) GA15-08679S; GA TA ČR(CZ) TE01020028 Institutional support: RVO:61388963 Keywords : prolactin-releasing peptide * lipidization * diet-induced obesity * ZDF rats * food intake * rat Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 4.706, year: 2016

  3. Palmitoylated PrRP analog decreases body weight in DIO rats but not in ZDF rats

    Czech Academy of Sciences Publication Activity Database

    Holubová, M.; Zemenová, J.; Mikulášková, Barbora; Panajotová, V.; Stöhr, J.; Haluzík, M.; Kuneš, Jaroslav; Železná, B.; Maletínská, L.

    2016-01-01

    Roč. 229, č. 2 (2016), s. 85-96 ISSN 0022-0795 R&D Projects: GA TA ČR(CZ) TE01020028; GA ČR(CZ) GA15-08679S Institutional support: RVO:67985823 Keywords : prolactin-releasing peptide * lipidization * diet-induced obesity * ZDF rats * food intake rat Subject RIV: ED - Physiology Impact factor: 4.706, year: 2016

  4. Efficacy and Safety of Gwakhyangjeonggi-San Retention Enema in Normal Rats and Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Eunyoung Song

    2013-01-01

    Full Text Available The purpose of this study is to establish a protocol of retention-enema experiments and evaluate the antihypertensive effect and the safety of Gwakhyangjeonggi-san retention enema. Normal and spontaneously hypertensive rats (SHRs were divided into treatment and control groups, respectively. We applied the Gwakhyangjeonggi-san extract by decoction and 0.9% NaCl in each group, estimated the blood pressure and body weight, and performed HPLC analysis. ALT, AST, BUN, and creatinine were examined. The systolic blood pressure within each group in normal rats differed significantly in time effect, and so did the diastolic blood pressure in the treatment group of normal rats. The systolic, diastolic, and mean blood pressure showed significant differences in group effect in the treatment group of the SHRs. The time effect of the body weight in both groups of normal rats differed significantly, so did group × time and time effects in both groups of SHRs. AST, ALT, BUN, and creatinine showed no significant difference between groups. We concluded that the Gwakhyangjeonggi-san retention enema has a hypotensive effect in normal rats within the regular range of blood pressure, but an antihypertensive effect in SHRs. Also, the intervention is safe and does not affect the liver and kidney functions in normal rats.

  5. Rats do not eat alone in public: Food-deprived rats socialize rather than competing for baits.

    Directory of Open Access Journals (Sweden)

    Omri Weiss

    Full Text Available Limited resources result in competition among social animals. Nevertheless, social animals also have innate preferences for cooperative behavior. In the present study, 12 dyads of food-deprived rats were tested in four successive trials, and then re-tested as eight triads of food-deprived rats that were unfamiliar to each other. We found that the food-deprived dyads or triads of rats did not compete for the food available to them at regular spatially-marked locations that they had previously learnt. Rather, these rats traveled together to collect the baits. One rat, or two rats in some triads, lead (ran ahead to collect most of the baits, but "leaders" differed across trials so that, on average, each rat ultimately collected similar amounts of baits. Regardless of which rat collected the baits, the rats traveled together with no substantial difference among them in terms of their total activity. We suggest that rats, which are a social species that has been found to display reciprocity, have evolved to travel and forage together and to share limited resources. Consequently, they displayed a sort of 'peace economy' that on average resulted in equal access to the baits across trials. For social animals, this type of dynamics is more relaxed, tolerant, and effective in the management of conflicts. Rather than competing for the limited available food, the food-deprived rats socialized and coexisted peacefully.

  6. Juvenile female rats, but not male rats, show renewal, reinstatement, and spontaneous recovery following extinction of conditioned fear.

    Science.gov (United States)

    Park, Chun Hui J; Ganella, Despina E; Kim, Jee Hyun

    2017-12-01

    Anxiety disorders emerge early, and girls are significantly more likely to develop anxiety compared to boys. However, sex differences in fear during development are poorly understood. Therefore, we investigated juvenile male and female rats in the relapse behaviors following extinction of conditioned fear. In all experiments, 18-d-old rats first received three white-noise-footshock pairings on day 1. On day 2, extinction involved 60 white-noise alone trials. In experiment 1, we examined renewal by testing the rats in either the same or different context as extinction on day 3. Male rats did not show renewal, however, female rats showed renewal. Experiment 2 investigated reinstatement by giving rats either a mild reminder footshock or context exposure on day 3. When tested the next day, male rats did not show reinstatement, whereas female rats showed reinstatement. Experiment 3 investigated spontaneous recovery by testing the rats either 1 or 5 d following extinction. Male rats did not show any spontaneous recovery whereas female rats did. Taken together, fear regulation appear to be different in males versus females from early in development, which may explain why girls are more prone to suffer from anxiety disorders compared to boys. © 2017 Park et al.; Published by Cold Spring Harbor Laboratory Press.

  7. Extracellular ATP induces albuminuria in pregnant rats

    NARCIS (Netherlands)

    Faas, M.M.; van der Schaaf, G.; Borghuis, T.; Jongman, R.M.; van Pampus, Maria; de Vos, P.; van Goor, Harry; Bakker, W.W.

    BACKGROUND: As circulating plasma ATP concentrations are increased in pre-eclampsia, we tested whether increased plasma ATP is able to induce albuminuria during pregnancy. METHODS: Pregnant (day 14) and non-pregnant rats were infused with ATP (3000 microg/kg bw) via a permanent jugular vein cannula.

  8. Gastric emptying of oils in the rat

    International Nuclear Information System (INIS)

    Palin, K.J.; Whalley, D.R.; Wilson, C.G.; Phillips, A.J.; Davis, S.S.

    1982-01-01

    Sulphur colloid, labelled with technetium 99 and emulsified with arachis oil, miglyol 812 or liquid paraffin, was administered orally to male rats. A gamma camera, linked to a computer was used for imaging for 108 mins. after administration. The efficiency of the oils to aid stomach emptying was compared and arachis oil found to be the most effective. (U.K.)

  9. Spatial Memory in Spontaneously Hypertensive Rats (SHR)

    NARCIS (Netherlands)

    Sontag, Thomas-A.; Fuermaier, Anselm B. M.; Hauser, Joachim; Kaunzinger, Ivo; Tucha, Oliver; Lange, Klaus W.

    2013-01-01

    The spontaneously hypertensive rat (SHR) is an established animal model of ADHD. It has been suggested that ADHD symptoms arise from deficits in executive functions such as working memory, attentional control and decision making. Both ADHD patients and SHRs show deficits in spatial working memory.

  10. Developmental neurotoxicity of Propylthiouracil in rats

    DEFF Research Database (Denmark)

    Petersen, Marta Axelstad; Hansen, P.; Christiansen, S.

    2007-01-01

    early in pregnancy may cause adverse effects on the offspring. This has led to increased concern about thyroid hormone disrupting chemicals (TDCs) in our environment. We have studied how developmental exposure to the known antithyroid agent propylthiouracil (PTU) affects the development of rat pups...... behaviour and hearing function. This supports that exposure to TDC's in general may cause long-lasting developmental neurotoxicity....

  11. Estrogen induces glomerulosclerosis in analbuminemic rats

    NARCIS (Netherlands)

    Joles, JA; van Goor, H; Koomans, HA

    Progression of chronic renal disease: is usually more rapid in males, both In humans and in experimental animals. Estrogen-replacement studies indicate that this may be related to the beneficial effects of estrogen on the lipoprotein profile. However, in hyperlipidemic analbuminemic rats (NAR),

  12. DNA isolation from rat tail or ear

    NARCIS (Netherlands)

    Cuppen, E.

    2010-01-01

    This protocol describes a rapid procedure for isolating DNA from rat tail or ear punches. The simplest version of the protocol can be scaled for use in 96-well (deep-well) plates. The quality of the DNA is sufficient for any polymerase chain reaction (PCR)-based genotyping approach.

  13. Gastrointestinal absorption of Np in rats

    International Nuclear Information System (INIS)

    Wirth, R.; Volf, V.

    1985-01-01

    The effect of Np mass and the acidity of the administered Np solutions as well as the age, sex and nutritional status of the animals injected or gavaged with 239Np or 237Np were determined. The latter factor proved to be dominant for absorption of Np from the gut. Thus in fasting weanling and young adult male rats, the absorption of 239Np was sixfold higher (0.18% and 0.12%, respectively) than in fed ones (0.03% and 0.02%, respectively). Absorption by fasted adult females was 0.05% of the administered 239Np, about half of that of adult males. Raising the Np-mass gavaged to fasted female rats to 1 and 10 mg 237Np/kg resulted in an absorption of 0.23% and 0.26%, respectively. Thus, an increased absorption of Np in adult rats seems to be expected only if a large mass is ingested. No dependence of the absorption of Np on nitric acid concentration was found. The data obtained after oral administration of 238Pu and 239Np to adult rats suggest that the f1 factor recommended by the ICRP for fractional absorption of soluble Np compounds from the gut should be decreased, whereas the f1 factor for soluble Pu compounds should be raised

  14. Rat Lungworm Expands into North America

    Centers for Disease Control (CDC) Podcasts

    2016-01-21

    Emily York, integrated pest management specialist at the Sam Noble Museum of Natural History, discusses the rat lungworm expansion in North America.  Created: 1/21/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 1/21/2016.

  15. Sequential causal learning in humans and rats

    NARCIS (Netherlands)

    Lu, H.; Rojas, R.R.; Beckers, T.; Yuille, A.; Love, B.C.; McRae, K.; Sloutsky, V.M.

    2008-01-01

    Recent experiments (Beckers, De Houwer, Pineño, & Miller, 2005;Beckers, Miller, De Houwer, & Urushihara, 2006) have shown that pretraining with unrelated cues can dramatically influence the performance of humans in a causal learning paradigm and rats in a standard Pavlovian conditioning paradigm.

  16. Episodic-like memory in the rat.

    Science.gov (United States)

    Babb, Stephanie J; Crystal, Jonathon D

    2006-07-11

    A fundamental question in comparative cognition is whether animals remember unique, personal past experiences. It has long been argued that memories for specific events (referred to as episodic memory) are unique to humans. Recently, considerable evidence has accumulated to show that food-storing birds possess critical behavioral elements of episodic memory, referred to as episodic-like memory in acknowledgment of the fact that behavioral criteria do not assess subjective experiences. Here we show that rats have a detailed representation of remembered events and meet behavioral criteria for episodic-like memory. We provided rats with access to locations baited with distinctive (e.g., grape and raspberry) or nondistinctive (regular chow) flavors. Locations with a distinctive flavor replenished after a long but not a short delay, and locations with the nondistinctive flavor never replenished. One distinctive flavor was devalued after encoding its location by prefeeding that flavor (satiation) or by pairing it with lithium chloride (acquired taste aversion), while the other distinctive flavor was not devalued. The rats selectively decreased revisits to the devalued distinctive flavor but not to the nondevalued distinctive flavor. The present studies demonstrate that rats selectively encode the content of episodic-like memories.

  17. A microculture technique for rat lymphocyte transformation.

    Science.gov (United States)

    Lindsay, V J; Allardyce, R A

    1979-01-01

    We report the development of an economical microculture technique suitable for measuring rat lymphocyte response to mitogens and in mixed lymphocyte reactions. The effects of varying culture conditions, i.e. source of serum, addition and concentration of 2-mercaptoethanol, mitogen concentrations, culture incubation times, absorption of serum, lymphocyte numbers and microtitre plate well shape are described.

  18. In Utero Hepatocellular Transplantation in Rats

    Directory of Open Access Journals (Sweden)

    Emma Muñoz-Sáez

    2013-01-01

    Full Text Available This work represents a step forward in the experimental design of an in utero hepatocellular transplantation model in rats. We focused on the enrichment optimization of isolated fetal hepatocytes suspension, arranging the surgery methodology of in utero transplantation, monitoring the biodistribution of the transplanted hepatocytes, and assessing the success of the transplants. Rat fetuses have been transplanted at the 17th embryonic day (ED17 with fetal hepatocytes isolated from rats at the end of pregnancy (ED21. We assessed possible differences between lymphocyte population, CD4 positive, CD8 positive, double-positive T-cells, and anti-inflammatory cytokines interleukins 4 and 10 (IL4 and IL10 as well. Cellular viability reached the rates of 90–95%. Transplanted groups had a limited success. Transplanted hepatocytes were not able to pass through the hematoplacental barrier. The hepatocytes injected were primarily located in the liver. There was an upward trend in the whole amount of T CD4 and T CD8 cells. There was an increased IL4 in the transplanted groups observed in the pregnant rats. The possibility to induce tolerance in fetuses with a hepatocyte transplant in utero could be a key point to avoid the immunosuppression treatments which must be undergone by transplanted patients.

  19. Transfer of memory retrieval cues in rats.

    Science.gov (United States)

    Briggs, James F; Fitz, Kelly I; Riccio, David C

    2007-06-01

    Two experiments using rats were conducted to determine whether the retrieval of a memory could be brought under the control of new contextual cues that had not been present at the time of training. In Experiment 1, rats were trained in one context and then exposed to different contextual cues immediately, 60 min, or 120 min after training. When tested in the shifted context, rats that had been exposed shortly after training treated the shifted context as if it were the original context. The control that the previously neutral context had over retrieval disappeared with longer posttraining delays, suggesting the importance of an active memory representation during exposure. Experiment 2 replicated the basic finding and demonstrated that the transfer of retrieval cues was specific to the contextual cues present during exposure. These findings with rats are consistent with findings from infant research (see, e.g., Boller & Rovee-Collier, 1992) that have shown that a neutral context can come to serve as a retrieval cue for an episode experienced elsewhere.

  20. Oxytocin biotransformation in the rat limbic brain

    NARCIS (Netherlands)

    Burbach, J.P.H.; Schotman, P.; Kloet, E.R. de

    2006-01-01

    Two peptide fragments of oxytocin were isolated by high-pressure liquid chromatography from digests of oxytocin obtained after exposure to a SPM preparation of the rat limbic brain. The structures of these peptides, being Gln-Asn-Cys(O)x-Pro-Leu-GlyNH2 and Gln-Asn-Cys(-S-S-Cys)-Pro-Leu-GlyNH2, were

  1. Taurine content of tissues of irradiated rats

    International Nuclear Information System (INIS)

    Akhalaya, M.Ya.; Bogatyrev, G.P.; Kudryashov, Yu.B.; Yartsev, E.I.

    1976-01-01

    The taurine content of tissues (liver, stomach, small intestine and spleen) of rats irradiated with doses of 700 and 450 rads has been studied. Phase changes have been found in the taurine content of radiosensitive tissues in the course of radiation injury development

  2. Serum testosterone concentration in chloroquine- treated rats ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... The effects of ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) were studied on serum testosterone ... chloroquine are probably mediated via the generation of free radicals. ... Effects of ascorbic acid and alpha-tocopherol on serum testosterone concentration in chloroquine-treated rats. Groups.

  3. Morphological and neurohistological changes in adolescent rats ...

    African Journals Online (AJOL)

    olayemitoyin

    Pregnancy was confirmed and the pregnant rats were divided into 3 groups based on the 3 trimesters ... form of attention deficit hyperactive disorder characterised by ..... Yoshinaga K., Rice C., Krenn J., Pilot R.L. (1979). Effects of nicotine on ...

  4. Toluene depresses plasma corticosterone in pregnant rats

    DEFF Research Database (Denmark)

    Hougaard, K. S.; Hansen, A. M.; Hass, Ulla

    2003-01-01

    of corticosteroids from the maternal to the foetal compartment. Pregnant rats were subjected to either 1500 ppm toluene 6 hr/day and/or a schedule of "Chronic mild stress" during the last two weeks of gestation. Exposure to toluene was associated with reduced birth weight and lower maternal weight gain, the latter...

  5. METABOLISM AND DOSIMETRY OF VINCLOZOLIN IN RAT

    Science.gov (United States)

    Vinclozolin (V) is an agricultural fungicide. V administered to rats is hydrolyzed to 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1) and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2). V, M1and M2 are antiandrogenic by interacting with the androgen r...

  6. Prenatal Caffeine Exposure Impairs Pregnancy in Rats

    Directory of Open Access Journals (Sweden)

    Maryam Yadegari

    2016-12-01

    Full Text Available Background: In recent years, concerns have been raised about human reproductive disorders. Caffeine consumption is increasing by the world’s population and there is a relationship between caffeine intake and adverse reproductive outcomes. The aim of this study was to evaluate the effects of caffeine on implantation sites, number of live births, birth weight, crown-rump length (CRL and abnormality in pregnant rats. Materials and Methods: In this experimental study, 40 female albino rats (170-190 g were randomly divided into two experimental and two control groups (n=10/each group. In both experimental groups, animals received caffeine intraperitoneally (IP: 150 mg/kg/day on days 1-5 of pregnancy. In experimental group 1, treated animals were euthanized on day 7of pregnancy and the number of implantation sites was counted. In experimental group 2, treated animals maintained pregnant and after delivery, the number of live births, birth weight, CRL and abnormality of neonates were investigated. In control group, animals received IP injections of distilled water. Data were analyzed by independent t test. Results: Results showed that administration of caffeine significantly decreased the number of implantation sites, number of live births and CRL as compared with control group (P<0.05. There were no significant differences regarding birth weight and abnormality of neonate rats between experimental and control groups. Conclusion: These results suggest that caffeine caused anti-fertility effect and significantly decreased CRL in neonate rats.

  7. The rat incisor in toxicologic pathology

    NARCIS (Netherlands)

    Kuijpers, M.H.M.; Kooij, A.J. van de; Slootweg, P.J.

    1996-01-01

    Microscopic examination of the incisors of rats and mice may reveal toxicologically significant changes. First, the incisor morphology reflects the nutritional status of the animal: fluctuations of mineral metabolism and vitamin availability are disclosed by the rodent incisors, because the incisors

  8. Behavioral effects of etiracetam in rats

    NARCIS (Netherlands)

    Wolthuis, O.L.

    1981-01-01

    The effects of etiracetam, a structural analogue or piracetam, were investigated in rats on Y-maze discrimination acquisition, on open field behavior, on one-trial passive avoidance learning and on shuttlebox acquisition and extinction. The results indicate that this drug significantly enhances

  9. Following Exhaustive Exercise in Male Rats

    Directory of Open Access Journals (Sweden)

    reza Badalzadeh

    2014-12-01

    Conclusion: Long-term treatment of rats with cinnamon and regular training improved cardiac hemodynamic through an additive effect. The positive effects of cinnamon and regular training on cardiac function were associated with a reduced serum MDA level and an improved blood lipid profile.

  10. Cytoarchitecture in cultured rat neocortex explants

    NARCIS (Netherlands)

    de Jong, B. M.; Ruijter, J. M.; Romijn, H. J.

    1988-01-01

    Neocortex explants obtained from 6-day-old rat pups and cultured in a serum-free medium from 5 hr to 13 days in vitro (DIV) show preservation of cytoarchitectural characteristics. Major changes in the size of the explants and their layers occur during the first 2 DIV. A radial arrangement of neurons

  11. Swelling of rat hepatocytes stimulates glycogen synthesis

    NARCIS (Netherlands)

    Baquet, A.; Hue, L.; Meijer, A. J.; van Woerkom, G. M.; Plomp, P. J.

    1990-01-01

    In hepatocytes from fasted rats, several amino acids are known to stimulate glycogen synthesis via activation of glycogen synthase. The hypothesis that an increase in cell volume resulting from amino acid uptake may be involved in the stimulation of glycogen synthesis is supported by the following

  12. Disposition of hexobarbital enantiomers in the rat

    NARCIS (Netherlands)

    van der Graaff, M; Vermeulen, N P; Joeres, R P; Breimer, D D

    1983-01-01

    The enantiomers of hexobarbital (HB), designated as (+)-HB and (-)-HB, were administered orally to separate groups of rats. Blood concentration-time curves of the parent compounds and the metabolites 3'-hydroxyhexobarbital (OH-HB) and 3'-ketohexobarbital (K-HB) were determined, as well as the

  13. seed on haematological parameters of albino rats

    African Journals Online (AJOL)

    Dr Ejere

    2015-06-23

    Jun 23, 2015 ... and its indices (haemoglobin content, pack cell volume, mean corpuscular volume, mean corpuscular haemoglobin ... demands in plant-based proteins for humans and livestock, ... hypogea) and animal based proteins (Siddhuraju et al.,. 1995 ..... difference in the packed cell volume (PCV) of albino rats.

  14. Muscle fragments on a scaffold in rats

    DEFF Research Database (Denmark)

    Jangö, Hanna; Gräs, Søren; Christensen, Lise

    2015-01-01

    -PLGA scaffolds seeded with autologous MFF affected some histological and biomechanical properties of native tissue repair in an abdominal wall defect model in rats. The method thus appears to be a simple tissue engineering concept with potential relevance for native tissue repair of POP....

  15. Lipogenesis in maintenance cultures of rat hepatocytes

    NARCIS (Netherlands)

    Geelen, Math J.H.; Gibson, David M.

    1975-01-01

    Induction of the several enzymes in the liver cytosol catalyzing de novo synthesis of fatty acids from glucose has been demonstrated in intact animals. When carbohydrate is provided to previously starved rats the metabolism of liver switches from a gluconeogenic-ketogenic economy to a

  16. Curcumin inhibits amygdaloid kindled seizures in rats.

    Science.gov (United States)

    DU, Peng; Li, Xin; Lin, Hao-Jie; Peng, Wei-Feng; Liu, Jian-Ying; Ma, Yu; Fan, Wei; Wang, Xin

    2009-06-20

    Curcumin can reduce the severity of seizures induced by kainate acid (KA), but the role of curcumin in amygdaloid kindled models is still unknown. This study aimed to explore the effect of curcumin on the development of kindling in amygdaloid kindled rats. With an amygdaloid kindled Sprague-Dawley (SD) rat model and an electrophysiological method, different doses of curcumin (10 mgxkg(-1)xd(-1) and 30 mgxkg(-1)xd(-1) as low dose groups, 100 mgxkg(-1)xd(-1) and 300 mgxkg(-1)xd(-1) as high dose groups) were administrated intraperitoneally during the whole kindling days, by comparison with the course of kindling, afterdischarge (AD) thresholds and the number of ADs to reach the stages of class I to V seizures in the rats between control and experimental groups. One-way or two-way ANOVA and Fisher's least significant difference post hoc test were used for statistical analyses. Curcumin (both 100 mgxkg(-1)xd(-1) and 300 mgxkg(-1)xd(-1)) significantly inhibited the behavioral seizure development in the (19.80 +/- 2.25) and (21.70 +/- 2.21) stimulations respectively required to reach the kindled state. Rats treated with 100 mgxkg(-1)xd(-1) curcumin 30 minutes before kindling stimulation showed an obvious increase in the stimulation current intensity required to evoke AD from (703.3 +/- 85.9) microA to (960.0 +/- 116.5) microA during the progression to class V seizures. Rats treated with 300 mgxkg(-1)xd(-1) curcumin showed a significant increase in the stimulation current intensity required to evoke AD from (735.0 +/- 65.2) microA to (867.0 +/- 93.4) microA during the progression to class V seizures. Rats treated with 300 mgxkg(-1)xd(-1) curcumin required much more evoked ADs to reach the stage of class both IV (as (199.83 +/- 12.47) seconds) and V seizures (as (210.66 +/- 10.68) seconds). Rats treated with 100 mgxkg(-1)xd(-1) curcumin required much more evoked ADs to reach the stage of class V seizures (as (219.56 +/- 18.24) seconds). Our study suggests that curcumin has

  17. Effect of dietary soy isoflavones on bone loss in ovariectomized rats ...

    African Journals Online (AJOL)

    Purpose: To determine the effect of dietary soy isoflavone supplementation on bone loss in ovariectomized (OVX) rats. Methods: Forty-eight rats were assigned randomly to groups of OVX rats receiving soy isoflavones (20, 30, or 40 mg/kg of body weight daily), untreated OVX rats, or untreated intact rats. After 8 weeks, bone ...

  18. Protein synthesis in the growing rat lung

    International Nuclear Information System (INIS)

    Kelley, J.; Chrin, L.

    1986-01-01

    Developmental control of protein synthesis in the postnatal growth of the lung has not been systematically studied. In male Fischer 344 rats, lung growth continues linearly as a function of body weight (from 75 to 450 g body weight). To study total protein synthesis in lungs of growing rats, we used the technique of constant intravenous infusion of tritiated leucine, an essential amino acid. Lungs of sacrificed animals were used to determine the leucine incorporation rate into newly synthesized protein. The specific radioactivity of the leucine associated with tRNA extracted from the same lungs served as an absolute index of the precursor leucine pool used for lung protein synthesis. On the basis of these measurements, we were able to calculate the fractional synthesis rate (the proportion of total protein destroyed and replaced each day) of pulmonary proteins for each rat. Under the conditions of isotope infusion, leucyl-tRNA very rapidly equilibrates with free leucine of the plasma and of the extracellular space of the lung. Infusions lasting 30 minutes or less yielded linear rates of protein synthesis without evidence of contamination of lung proteins by newly labeled intravascular albumin. The fractional synthesis rate is considerably higher in juvenile animals (55% per day) than in adult rats (20% per day). After approximately 12 weeks of age, the fractional synthesis rate remains extremely constant in spite of continued slow growth of the lung. It is apparent from these data that in both young and adult rats the bulk of total protein synthesis is devoted to rapidly turning over proteins and that less than 4 percent of newly made protein is committed to tissue growth

  19. Hypercholesterolemia downregulates autophagy in the rat heart.

    Science.gov (United States)

    Giricz, Zoltán; Koncsos, Gábor; Rajtík, Tomáš; Varga, Zoltán V; Baranyai, Tamás; Csonka, Csaba; Szobi, Adrián; Adameová, Adriana; Gottlieb, Roberta A; Ferdinandy, Péter

    2017-03-23

    We have previously shown that efficiency of ischemic conditioning is diminished in hypercholesterolemia and that autophagy is necessary for cardioprotection. However, it is unknown whether isolated hypercholesterolemia disturbs autophagy or the mammalian target of rapamycin (mTOR) pathways. Therefore, we investigated whether isolated hypercholesterolemia modulates cardiac autophagy-related pathways or programmed cell death mechanisms such as apoptosis and necroptosis in rat heart. Male Wistar rats were fed either normal chow (NORM; n = 9) or with 2% cholesterol and 0.25% cholic acid-enriched diet (CHOL; n = 9) for 12 weeks. CHOL rats exhibited a 41% increase in plasma total cholesterol level over that of NORM rats (4.09 mmol/L vs. 2.89 mmol/L) at the end of diet period. Animals were sacrificed, hearts were excised and briefly washed out. Left ventricles were snap-frozen for determination of markers of autophagy, mTOR pathway, apoptosis, and necroptosis by Western blot. Isolated hypercholesterolemia was associated with a significant reduction in expression of cardiac autophagy markers such as LC3-II, Beclin-1, Rubicon and RAB7 as compared to controls. Phosphorylation of ribosomal S6, a surrogate marker for mTOR activity, was increased in CHOL samples. Cleaved caspase-3, a marker of apoptosis, increased in CHOL hearts, while no difference in the expression of necroptotic marker RIP1, RIP3 and MLKL was detected between treatments. This is the first comprehensive analysis of autophagy and programmed cell death pathways of apoptosis and necroptosis in hearts of hypercholesterolemic rats. Our data show that isolated hypercholesterolemia suppresses basal cardiac autophagy and that the decrease in autophagy may be a result of an activated mTOR pathway. Reduced autophagy was accompanied by increased apoptosis, while cardiac necroptosis was not modulated by isolated hypercholesterolemia. Decreased basal autophagy and elevated apoptosis may be responsible for the

  20. Telmisartan attenuates diabetes induced depression in rats.

    Science.gov (United States)

    Aswar, Urmila; Chepurwar, Shilpa; Shintre, Sumit; Aswar, Manoj

    2017-04-01

    Role of brain renin angiotensin system (RAS) is well understood and various clinical studies have proposed neuroprotective effects of ARB's. It is also assumed that diabetic depression is associated with activation of brain RAS, HPA axis dysregulation and brain inflammatory events. Therefore, the present study was designed to investigate the antidepressant effect of low dose telmisartan (TMS) in diabetes induced depression (DID) in rats. Diabetes was induced by injecting streptozotocin. After 21days of treatment the rats were subjected to forced swim test (FST). The rats, with increased immobility time, were considered depressed and were treated with vehicle or TMS (0.05mg/kg, po) or metformin (200mg/kg, po) or fluoxetine (20mg/kg, po). A separate group was also maintained to study the combination of metformin and TMS. At the end of 21days of treatments, FST, open field test (OFT) and elevated plus maze (EPM) paradigm were performed. Blood was drawn to estimate serum cortisol, nitric oxide (NO), interleukin-6 (IL-6) and interleukin-1β (IL-1β). Persistent hyperglycemia resulted in depression and anxiety in rats as observed by increased immobility, reduced latency for immobility, reduced open arm entries and time spent. The depressed rats showed a significant rise in serum cortisol, NO, IL-6 and IL-1β (pdepression and anxiety. It also significantly attenuated serum cortisol, NO, IL-6 and IL-1β (pdepressive mood, reduces pro-inflammatory mediators and ameliorates the HPA axis function; thereby providing beneficial effects in DID. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

  1. Ontogeny of the rat hepatic adrenoceptors

    International Nuclear Information System (INIS)

    McMillian, M.K.

    1985-01-01

    Hepatic alpha-1, alpha-2, and beta-2 adrenoceptors were characterized during development of the rat through Scatchard analysis of ( 3 H)-prazosin, ( 3 H)-rauwolscine and ( 125 I)-pindolol binding to washed particle membrane preparations. Major changes in adrenoceptor number occur shortly before birth and at weaning. The fetal rat liver is characterized by a large number of alpha-2 adrenoceptors which falls 10-20 fold at birth. The number of hepatic beta adrenoceptors decreases 30-50% during the third week after birth increases slightly at weaning, then decreases gradually in the adult. Hepatic alpha-1 adrenoceptor number increases 3-5 fold at weaning to become the predominant adrenoceptor in the adult rat liver. The basis for the fall in alpha-2 number at birth remains unclear. The fall in beta receptor number at the end of the second week post-natally appears dependent on increased insulin and corticosterone secretion as well as increased NE release form nerve terminals. The basis for the increase in beta number at weaning and the sex-dependent loss of beta function but not receptor number in the adult rat remains unknown. The dramatic increases in alpha-1 number and function at weaning are dependent on increased adrenocortical secretion, adrenalectomy prevents the normal. This effect of adrenocorticoids might be mediated through glycogen, as glycogen depletion during fasting decreases alpha-1 receptor number and function at weaning are dependent on increased adrenocortical secretion, adrenalectomy prevents the normal. This effect of adrenocorticoids might be mediated through glycogen, as glycogen depletion during fasting decreases alpha-1 receptor number and function. These findings suggest that hepatic adrenoceptor number adapts from the low carbohydrate diet of the suckling rat to the high carbohydrate diet of the adult at weaning

  2. Thallium kinetics in rat cardiac transplant rejection

    International Nuclear Information System (INIS)

    Barak, J.H.; LaRaia, P.J.; Boucher, C.A.; Fallon, J.T.; Buckley, M.J.

    1988-01-01

    Cardiac transplant rejection is a very complex process involving both cellular and vascular injury. Recently, thallium imaging has been used to assess acute transplant rejection. It has been suggested that changes in thallium kinetics might be a sensitive indicator of transplant rejection. Accordingly, thallium kinetics were assessed in vivo in acute untreated rat heterotopic (cervical) transplant rejection. Male Lewis rats weighing 225-250 g received heterotopic heart transplants from syngeneic Lewis rats (group A; n = 13), or allogeneic Brown Norway rats (group B; n = 11). Rats were imaged serially on the 2nd and the 7th postoperative days. Serial cardiac thallium content was determined utilizing data collected every 150 sec for 2 hr. The data were fit to a monoexponential curve and the decay rate constant (/sec) derived. By day 7 all group B hearts had histological evidence of severe acute rejection, and demonstrated decreased global contraction. Group A hearts showed normal histology and contractility. However, thallium uptakes and washout of the two groups were the same. Peak thallium uptake of group B was +/- 3758 1166 counts compared with 3553 +/- 950 counts in the control group A (P = 0.6395); The 2-hr percentage of washout was 12.1 +/- 1.04 compared with 12.1 +/- 9.3 (P = 1.0000); and the decay constant was -0.00002065 +/- 0.00001799 compared with -0.00002202 +/- 0.00001508 (P = 0.8409). These data indicate that in vivo global thallium kinetics are preserved during mild-to-severe acute transplant rejection. These findings suggest that the complex cellular and extracellular processes of acute rejection limit the usefulness of thallium kinetics in the detection of acute transplant rejection

  3. Cerebral microbleeds in a neonatal rat model.

    Directory of Open Access Journals (Sweden)

    Brianna Carusillo Theriault

    Full Text Available In adult humans, cerebral microbleeds play important roles in neurodegenerative diseases but in neonates, the consequences of cerebral microbleeds are unknown. In rats, a single pro-angiogenic stimulus in utero predisposes to cerebral microbleeds after birth at term, a time when late oligodendrocyte progenitors (pre-oligodendrocytes dominate in the rat brain. We hypothesized that two independent pro-angiogenic stimuli in utero would be associated with a high likelihood of perinatal microbleeds that would be severely damaging to white matter.Pregnant Wistar rats were subjected to intrauterine ischemia (IUI and low-dose maternal lipopolysaccharide (mLPS at embryonic day (E 19. Pups were born vaginally or abdominally at E21-22. Brains were evaluated for angiogenic markers, microhemorrhages, myelination and axonal development. Neurological function was assessed out to 6 weeks.mRNA (Vegf, Cd31, Mmp2, Mmp9, Timp1, Timp2 and protein (CD31, MMP2, MMP9 for angiogenic markers, in situ proteolytic activity, and collagen IV immunoreactivity were altered, consistent with an angiogenic response. Vaginally delivered pups exposed to prenatal IUI+mLPS had spontaneous cerebral microbleeds, abnormal neurological function, and dysmorphic, hypomyelinated white matter and axonopathy. Pups exposed to the same pro-angiogenic stimuli in utero but delivered abdominally had minimal cerebral microbleeds, preserved myelination and axonal development, and neurological function similar to naïve controls.In rats, pro-angiogenic stimuli in utero can predispose to vascular fragility and lead to cerebral microbleeds. The study of microbleeds in the neonatal rat brain at full gestation may give insights into the consequences of microbleeds in human preterm infants during critical periods of white matter development.

  4. NMR characteristics of rat mammary tumors

    International Nuclear Information System (INIS)

    Osbakken, M.; Kreider, J.; Taczanowsky, P.

    1984-01-01

    12 rats were injected intradermally with 13762A rat mammary adenocarcinoma (1 x 10/sup 6/ cells). 3 rats died before completion of the study and 2 rat had tumor regression; the first 3 were excluded from data analysis. NMR imaging with a 1.5K gauss resistive magnet at 2, 3, 4, and 5 weeks after injection demonstrated increasing tumor mass. Saturation recovery (SR), inversion recovery (IR), and spin echo (SE) pulse sequence images and T/sub 1/ calculation were done for tumor characterization. (Tumor size was too small to identify at 2 weeks.) 3 rats were sacrificed after the last 3 imaging periods for histological studies, done to distinguish solid tumor mass from necrosis. Planimetry of tumor areas showed that as tumors grew in size, the ratio of necrotic area to area of solid tumor increased (week 3 = .3 +- .11; week 4 = .45 +- .07; week 5 = .51 +- 05); simultaneous calculated T/sub 1/ values also increased (week 3 = .35 +- .15; week 4 = .45 +- .06; week 5 = .42 +- 03). Qualitative NMR image T/sub 1/ values also increased as evidenced by progression of SR and IR tumor image intensity from very bright compared to the rest of the body at week 3 to less intense than other structures at week 5. These findings indicate that change in T/sub 1/ may be secondary to the pathophysiological change in the tumor (the increasing in necrosis, associated with increased free water). Thus, the range of T/sub 1/ values obtained in tumors in this study (and in previous studies) may be due to change in tumor physiology and anatomy. Careful correlation of histological with NMR data may allow ultimate use of NMR relaxation characteristics for determination of the physiological state of tumors

  5. Rats socially-reared and full fed learned an autoshaping task, showing less levels of fear-like behaviour than fasted or singly-reared rats.

    Science.gov (United States)

    Molina-Hernández, Miguel; Téllez-Alcántara, N Patricia

    2004-07-01

    During the learning of instrumental tasks, rats are usually fasted to increase reinforced learning. However, fasting produces several undesirable side effects. The aim of this study was to test the hypothesis that control rats, i.e. full-fed and group-reared rats, will learn an autoshaping task to the same level as fasted or singly-reared rats. The interaction between fasting and single-rearing of rats was also tested. Results showed that control rats and fasted rats acquired the autoshaping task similarly, independently of rearing condition or gender. However, fasted or singly-reared rats produced fear-like behaviour, since male rats group-reared and fasted (85% body/wt, P autoshaping task to the same level as fasted or singly-reared rats. However, fasting or single-rearing produced fear-like behaviour. Thus, the training of control rats in autoshaping tasks may be an option that improves animal welfare.

  6. Sex differences in the stress response in SD rats.

    Science.gov (United States)

    Lu, Jing; Wu, Xue-Yan; Zhu, Qiong-Bin; Li, Jia; Shi, Li-Gen; Wu, Juan-Li; Zhang, Qi-Jun; Huang, Man-Li; Bao, Ai-Min

    2015-05-01

    Sex differences play an important role in depression, the basis of which is an excessive stress response. We aimed at revealing the neurobiological sex differences in the same study in acute- and chronically-stressed rats. Female Sprague-Dawley (SD) rats were randomly divided into 6 groups: chronic unpredictable mild stress (CUMS), acute foot shock (FS) and controls, animals in all 3 groups were sacrificed in proestrus or diestrus. Male SD rats were randomly divided into 3 groups: CUMS, FS and controls. Comparisons were made of behavioral changes in CUMS and control rats, plasma levels of corticosterone (CORT), testosterone (T) and estradiol (E2), and of the hypothalamic mRNA-expression of stress-related molecules, i.e. estrogen receptor α and β, androgen receptor, aromatase, mineralocorticoid receptor, glucocorticoid receptor, corticotropin-releasing hormone, arginine vasopressin and oxytocin. CUMS resulted in disordered estrus cycles, more behavioral and hypothalamic stress-related molecules changes and a stronger CORT response in female rats compared with male rats. Female rats also showed decreased E2 and T levels after FS and CUMS, while male FS rats showed increased E2 and male CUMS rats showed decreased T levels. Stress affects the behavioral, endocrine and the molecular response of the stress systems in the hypothalamus of SD rats in a clear sexual dimorphic way, which has parallels in human data on stress and depression. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Alcohol and acute pancreatitis. An experimental study in the rat.

    Science.gov (United States)

    Jalovaara, P; Apaja, M

    1978-01-01

    The effect of chronic alcohol pretreatment and various pancreatobiliary secretions on the severity of experimental pancreatitis was studied in the rat. 95 rats were pretreated with ethanol (20% w/v, 1.1 ml/100 g body weight) five times weekly for 10 to 12 weeks by gastric intubation. 88 rats served as controls. Pancreatic lesions were produced by retograde injection of different pancreatobiliary secretions into the pancreatic ducts. The secretions were collected from both normal and chronically alcohol-fed rats, and each was used for induction of experimental pancreatitis in the control and alcohol pretreated rats. Bile obtained from normal rats was no more toxic to the pancreas than 0.9% saline solution, while bile obtained from the chronically alcohol-fed rats caused significantly more serious lesions to the pancreas than did normal rat bile. Bile-pancreatic juice (mixture of secretions at papilla of Vater) of normal and chronically alcohol-fed rats was as toxic as the bile of the alcohol-fed rats. Alcohol pretreatment had no significant effect on the severity of pancreatitis when control and alcohol-fed groups separately or the whole material according to pretreatment was examined. These results suggest that the metabolic effects of ethanol on the pancreas as such do not sensitize the pancreas to acute pancreatitis. An exogenous mechanism is required. The reflux of toxic alcoholic bile into the pancreas might act as an induction factor in acute alcohol pancreatitis.

  8. Methionine metabolism after portacaval shunt in the rat

    International Nuclear Information System (INIS)

    Benjamin, L.E.; Steele, R.D.

    1985-01-01

    The effect of portacaval shunt (PCS) on methionine metabolism in the rat was investigated. Male Sprague-Dawley rats were subjected to PCS and maintained on an 18% casein diet. Growth curves of operated rats were similar to controls. PCS rats excreted more urinary 35 SO 4 and less [ 35 S]taurine than controls after intraperitoneal injection of 0.3 mmol/100 g [ 35 S]methionine or [ 35 S]cysteine. Total urinary taurine excretion was similar in PCS and control rats after a methionine or cysteine load; however, under basal conditions PCS rats had higher urinary taurine levels than controls, indicating that PCS may cause the taurine pool to be expanded. Hepatic methionine, S-adenosylmethionine, and cysteine pools were significantly decreased in PCS rats, while S-adenosylhomocysteine levels were unchanged. Relative rates of transsulfuration in PCS and control rats were studied by following the decrease in the 3 H-to- 35 S ratio in liver protein after injection of [methyl-3H]methionine and [ 35 S]methionine, and no difference in flux of 35 S from [ 35 S]methionine to [ 35 S]cysteine was found. Similarly, total hepatic activities of methionine adenosyltransferase, cystathionine synthase, and cystathionine gamma-lyase were unchanged in PCS rats. These results indicate that altered methionine metabolism in PCS rats is not explained by changes in conversion of methionine to cysteine via the transsulfuration pathway

  9. Influence of age and magnesium on calcium metabolism in rats

    International Nuclear Information System (INIS)

    McElroy, S.T.; Link, J.E.; Dowdy, R.P.; Zinn, K.R.; Ellersieck, M.R.

    1991-01-01

    This study evaluates the effect of dietary magnesium concentration on calcium metabolism in rats of differing ages. Young (3 wk) and old (18 mo) Fischer 344 rats were fed the AIN-76A diet modified to contain either low (218 mg/kg) or adequate (419 mg/kg) Mg for 4 wk. Some rats subsequently underwent a metabolic balance study (12 d duration). Other rats were gavaged with approximately 220 KBq (6 microCi) of 47 Ca; daily fecal and urine collections were made and periodic whole body radioactivity determined. Femurs were removed and analyzed. Calcium retention and balance were not affected by Mg in young rats. In old rats low Mg intake increased apparent Ca balance. Young rats retained about 3.25 times more of the original dose of 47 Ca than did old rats. Young rats retained more 47 Ca in the femur than did old rats; Mg intake had little effect. Aging accelerated Ca turnover rate, and whole body retention data suggest that adequate Mg does not significantly reduce Ca turnover

  10. [Establishment of rat model of psychical erectile dysfunction].

    Science.gov (United States)

    Wang, Qiu-lin; Wang, Shu-ren; Duan, Jin

    2006-01-01

    To set up a method of establishing the animal model of psychical erectile dysfunction with emotional stress. All thirty-six male rats with normal sexual function were divided into three groups, i. e. normal group, model group and demasculinized group randomly according to their weights. The rats in the model group were suspended upside down in midair over the water and irritated repeatedly. Two weeks later, the sexual abilities of all rats, i. e. the times of mounting and intromitting the estrus female rats, the latent period of mounting, intromission and ejaculation, were recorded, and the number of rats that had sexual activities was also counted. And the hemorheology indices of the rats were measured. Compared with the normal rats, the latency of mounting [(152.5 +/- 24.6) s vs (42.4 +/- 9.6) s] and intromission [(437.0 +/- 67.7) s vs (130.8 +/- 39.1) s] of the model rats were longer (P 0.05). The hemorheology indices, e. g. blood viscosity, hematocrit (Hct) and red cell aggregation (RCA), of the model rats was significant higher than that of the normal and demasculinized rats (P erectile dysfunction can be made ideally with psychical stress.

  11. Functional adaptation in female rats: the role of estrogen signaling.

    Directory of Open Access Journals (Sweden)

    Susannah J Sample

    Full Text Available Sex steroids have direct effects on the skeleton. Estrogen acts on the skeleton via the classical genomic estrogen receptors alpha and beta (ERα and ERβ, a membrane ER, and the non-genomic G-protein coupled estrogen receptor (GPER. GPER is distributed throughout the nervous system, but little is known about its effects on bone. In male rats, adaptation to loading is neuronally regulated, but this has not been studied in females.We used the rat ulna end-loading model to induce an adaptive modeling response in ovariectomized (OVX female Sprague-Dawley rats. Rats were treated with a placebo, estrogen (17β-estradiol, or G-1, a GPER-specific agonist. Fourteen days after OVX, rats underwent unilateral cyclic loading of the right ulna; half of the rats in each group had brachial plexus anesthesia (BPA of the loaded limb before loading. Ten days after loading, serum estrogen concentrations, dorsal root ganglion (DRG gene expression of ERα, ERβ, GPER, CGRPα, TRPV1, TRPV4 and TRPA1, and load-induced skeletal responses were quantified. We hypothesized that estrogen and G-1 treatment would influence skeletal responses to cyclic loading through a neuronal mechanism. We found that estrogen suppresses periosteal bone formation in female rats. This physiological effect is not GPER-mediated. We also found that absolute mechanosensitivity in female rats was decreased, when compared with male rats. Blocking of adaptive bone formation by BPA in Placebo OVX females was reduced.Estrogen acts to decrease periosteal bone formation in female rats in vivo. This effect is not GPER-mediated. Gender differences in absolute bone mechanosensitivity exist in young Sprague-Dawley rats with reduced mechanosensitivity in females, although underlying bone formation rate associated with growth likely influences this observation. In contrast to female and male rats, central neuronal signals had a diminished effect on adaptive bone formation in estrogen-deficient female rats.

  12. Origins of albino and hooded rats: implications from molecular genetic analysis across modern laboratory rat strains.

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    Takashi Kuramoto

    Full Text Available Albino and hooded (or piebald rats are one of the most frequently used laboratory animals for the past 150 years. Despite this fact, the origin of the albino mutation as well as the genetic basis of the hooded phenotype remained unclear. Recently, the albino mutation has been identified as the Arg299His missense mutation in the Tyrosinase gene and the hooded (H locus has been mapped to the ∼460-kb region in which only the Kit gene exists. Here, we surveyed 172 laboratory rat strains for the albino mutation and the hooded (h mutation that we identified by positional cloning approach to investigate possible genetic roots and relationships of albino and hooded rats. All of 117 existing laboratory albino rats shared the same albino missense mutation, indicating they had only one single ancestor. Genetic fine mapping followed by de novo sequencing of BAC inserts covering the H locus revealed that an endogenous retrovirus (ERV element was inserted into the first intron of the Kit gene where the hooded allele maps. A solitary long terminal repeat (LTR was found at the same position to the ERV insertion in another allele of the H locus, which causes the so called Irish (h(i phenotype. The ERV and the solitary LTR insertions were completely associated with the hooded and Irish coat patterns, respectively, across all colored rat strains examined. Interestingly, all 117 albino rat strains shared the ERV insertion without any exception, which strongly suggests that the albino mutation had originally occurred in hooded rats.

  13. Generation and characterization of rat liver stem cell lines and their engraftment in a rat model of liver failure

    Science.gov (United States)

    Kuijk, Ewart W.; Rasmussen, Shauna; Blokzijl, Francis; Huch, Meritxell; Gehart, Helmuth; Toonen, Pim; Begthel, Harry; Clevers, Hans; Geurts, Aron M.; Cuppen, Edwin

    2016-01-01

    The rat is an important model for liver regeneration. However, there is no in vitro culture system that can capture the massive proliferation that can be observed after partial hepatectomy in rats. We here describe the generation of rat liver stem cell lines. Rat liver stem cells, which grow as cystic organoids, were characterized by high expression of the stem cell marker Lgr5, by the expression of liver progenitor and duct markers, and by low expression of hepatocyte markers, oval cell markers, and stellate cell markers. Prolonged cultures of rat liver organoids depended on high levels of WNT-signalling and the inhibition of BMP-signaling. Upon transplantation of clonal lines to a Fah−/− Il2rg−/− rat model of liver failure, the rat liver stem cells engrafted into the host liver where they differentiated into areas with FAH and Albumin positive hepatocytes. Rat liver stem cell lines hold potential as consistent reliable cell sources for pharmacological, toxicological or metabolic studies. In addition, rat liver stem cell lines may contribute to the development of regenerative medicine in liver disease. To our knowledge, the here described liver stem cell lines represent the first organoid culture system in the rat. PMID:26915950

  14. Identification of rat Rosa26 locus enables generation of knock-in rat lines ubiquitously expressing tdTomato.

    Science.gov (United States)

    Kobayashi, Toshihiro; Kato-Itoh, Megumi; Yamaguchi, Tomoyuki; Tamura, Chihiro; Sanbo, Makoto; Hirabayashi, Masumi; Nakauchi, Hiromitsu

    2012-11-01

    Recent discovery of a method for derivation and culture of germline-competent rat pluripotent stem cells (PSCs) enables generation of transgenic rats or knock-out rats via genetic modification of such PSCs. This opens the way to use rats, as is routine in mice, for analyses of gene functions or physiological features. In mouse or human, one widely used technique to express a gene of interest stably and ubiquitously is to insert that gene into the Rosa26 locus via gene targeting of PSCs. Rosa26 knock-in mice conditionally expressing a reporter or a toxin gene have contributed to tracing or ablation of specific cell lineages. We successfully identified a rat orthologue of the mouse Rosa26 locus. Insertion of tdTomato, a variant of red fluorescent protein, into the Rosa26 locus of PSCs of various rat strains allows ubiquitous expression of tdTomato. Through germline transmission of one Rosa26-tdTomato knock-in embryonic stem cell line, we also obtained tdTomato knock-in rats. These expressed tdTomato ubiquitously throughout their bodies, which indicates that the rat Rosa26 locus conserves functions of its orthologues in mouse and human. The new tools described here (targeting vectors, knock-in PSCs, and rats) should be useful for a variety of research using rats.

  15. Xenotransplantation of uterine leiomyoma in Wistar rats: a pilot study.

    Science.gov (United States)

    Sousa, Willane Bandeira de; Garcia, João Batista Santos; Nogueira Neto, João; Furtado, Pablo Gustavo Ribeiro; Anjos, Jonhnathan Adriano Araújo dos

    2015-07-01

    To evaluate whether xenografts derived from hysterectomized patients would implant successfully and lead to uterine leiomyoma in Wistar rats. This experimental study examined six female Wistar rats implanted with uterine leiomyoma obtained from patients who underwent hysterectomies at the gynecological surgery service of the HUUFMA. The rats were divided into two groups. Group I consisted of three rats in which the uterine leiomyoma had been implanted in the parietal peritoneum, and group II consisted of three rats in which the uterine leiomyoma was implanted in the subcutaneous tissue. The immunosuppressant mycophenolate mofetil (MMF) was administered orally by gavage (at a dose of 40 mg/kg of body weight) to prevent transplant rejection starting 15 days before the transplant and continuing throughout the entire experiment. After four weeks, necrosis and neovascularization were evaluated histologically in both groups and were classified as either absent or present. Lymphocytic inflammatory infiltration was also examined and classified as mild, moderate or intense (by hematoxylin and eosin staining), and fibrosis was classified as grade I-III (by Masson's trichrome staining). Necrosis was absent from all three rats in group I and was observed in only one rat from group II. Neovascularization was present in two rats from group I and in only one rat from group II. The lymphocytic inflammatory infiltrate was mild in two rats and moderate in one rat from group I, and it was moderate in two rats and intense in one rat from group II. Two rats from group 1 exhibited grade III fibrosis, and one rat presented grade I fibrosis. In group II, two rats presented grade I fibrosis and one rat had grade II fibrosis. When necrosis and neovascularization were evaluated as variables, group I demonstrated greater evidence of successful implantation when compared to group II, indicating that the peritoneal implantation technique produces better results than the subcutaneous approach (p

  16. The local effect of octreotide on mechanical pain sensitivity is more sensitive in DA rats than DA.1U rats.

    Science.gov (United States)

    Yao, Fan-Rong; Wang, Hui-Sheng; Guo, Yuan; Zhao, Yan

    2016-02-01

    A recent study by the authors indicated that major histocompatibility complex (MHC) genes are associated with the differences in basal pain sensitivity and in formalin model between Dark-Agouti (DA) and novel congenic DA.1U rats, which have the same genetic background as DA rats except for the u alleles of MHC. The objective of the present study is to investigate whether there is a difference in the pristane-induced arthritis (PIA) model and local analgesic effect of octreotide (OCT) between DA and DA.1U rats. The hindpaw mechanical withdrawal threshold (MWT) and heat withdrawal latency (HWL) were observed. The C unit firings of the tibial nerve evoked by non-noxious and noxious toe movements were recorded by electrophysiological methods in normal and PIA models in DA and DA.1U rats before and after local OCT administration. The expression of somatostatin receptor 2A (SSTR2A) was observed by immunohistochemistry. The results demonstrate that DA rats have a higher mechanical sensitivity than DA.1U rats after PIA. Local OCT administration significantly elevated MWT in DA rats under normal and PIA sate, but not in DA.1U rats. The electrophysiological experiments showed OCT significantly attenuated the firings of C units evoked by non-noxious and noxious stimulation in DA rats more than those in DA.1U rats both in normal and PIA states. In addition, the expression of SSTR2A in the dorsal horn of the spinal cord was significantly higher in DA than in DA.1U rats. All of the findings suggest a higher local analgesic effect of OCT in DA rats than DA.1U rats, which might be associated with the MHC genes. © 2016 John Wiley & Sons Australia, Ltd.

  17. The petit rat (pet/pet), a new semilethal mutant dwarf rat with thymic and testicular anomalies.

    Science.gov (United States)

    Chiba, Junko; Suzuki, Katsushi; Suzuki, Hiroetsu

    2008-12-01

    The petit rat (pet/pet) is a recently discovered semilethal mutant dwarf. The neonatal pet/pet rats had a low body weight and small thymus and testis. During the first 3 d after birth, 50% of the male and 80% of the female pet/pet pups were lost or found dead. Surviving pet/pet rats showed marked retardation of postnatal growth, and their body weights were 41% (female rats) and 32% (male rats) of those of normal rats at the adult stage. The pet/pet rats exhibited proportional dwarfism, and their longitudinal bones were shorter than those of controls without skeletal malformations. Most organs of male pet/pet rats, especially the thymus, testis, adipose tissue surrounding the kidney, and accessory sex organs, weighed markedly less at 140 d of age than did those of their normal counterparts. The thymus of pet/pet rats was small with abnormal thymic follicles. Testes from pet/pet rats exhibited 2 patterns of abnormal histology. Spermatogenesis was present in testes that were only slightly anomalous, but the seminiferous tubules were reduced in diameter. In severely affected testes, most of the seminiferous tubules showed degeneration, and interstitial tissue was increased. Plasma growth hormone concentrations did not differ between pet/pet and normal male rats. The dwarf phenotype of pet/pet rats was inherited as an autosomal recessive trait. These results indicate that the pet/pet rat has a semilethal growth-hormone-independent dwarf phenotype that is accompanied by thymic and testicular anomalies and low birth weight.

  18. 5α-reductase activity in rat adipose tissue

    International Nuclear Information System (INIS)

    Zyirek, M.; Flood, C.; Longcope, C.

    1987-01-01

    We measured the 5 α-reductase activity in isolated cell preparations of rat adipose tissue using the formation of [ 3 H] dihydrotestosterone from [ 3 H] testosterone as an endpoint. Stromal cells were prepared from the epididymal fat pad, perinephric fat, and subcutaneous fat of male rats and from perinephric fat of female rats. Adipocytes were prepared from the epididymal fat pad and perinephric fat of male rats. Stromal cells from the epididymal fat pad and perinephric fat contained greater 5α-reductase activity than did the adipocytes from these depots. Stromal cells from the epididymal fat pad contained greater activity than those from perinephric and subcutaneous depots. Perinephric stromal cells from female rats were slightly more active than those from male rats. Estradiol (10 -8 M), when added to the medium, caused a 90% decrease in 5α-reductase activity. Aromatase activity was minimal, several orders of magnitude less than 5α-reductase activity in each tissue studied

  19. Secretion of hepatic triglycerides into plasma of rats fed retinol

    International Nuclear Information System (INIS)

    Ahuja, H.C.; Misra, U.K.

    1975-01-01

    The effect of feeding 33 mg of retinol daily for two days on liver and plasma lipids of rats has been studied. The secretion of liver TG into plasma of retinol fed rats has been measured by the use of palmitic acid-1- 14 C and of Triton WR 1339. Liver and plasma lipids, TG, phospholipids and PC were significantly higher in retinol fed rats as compared to control rats. The incorporation of palmitic acid-1- 14 C into liver TG, PC and PE was significantly higher in retinol fed rats. The labelling pattern with time of liver and plasma TG and PC shows that the secretion of liver TG and PC into plasma was impaired in retinol fed rats. (auth.)

  20. Sulfur amino acids metabolism in magnesium deficient rats

    Energy Technology Data Exchange (ETDEWEB)

    Tojo, H.; Kosokawa, Y.; Yamaguchi, K.

    1984-01-01

    Effect of magnesium (Mg) deficiency on sulfur amino acid metabolism was investigated in rats. Young male rats were fed on the diet containing either 2.26 (deficient rats) or 63.18 mg Mg/100g diet (control and low protein rats) for 2 weeks. A remarkable decrease of body weight gain, serum Mg contents and a slight decreases in the hematological parameters such as Hb, Ht and RBC was observed, while the hepatic Mg and Ca was not significantly changed. Erythema and cramps were observed 5 days after feeding on the Mg-depleted diet. The hepatic glutathione and cysteine contents increased in Mg-deficient rats. However, no significant change of cysteine dioxygenase (CDO) activity and taurine content in Mg-deficient rat liver was observed. These results suggest that Mg deficiency affects the utilization and biosynthesis of hepatic glutathione but not the cysteine catabolism.

  1. Taurine in the osmoregulation of the Brattleboro rat

    International Nuclear Information System (INIS)

    Nieminen, M.J.; Tuomisto, L.; Solatunturi, E.; Eriksson, L.; Paasonen, M.K.

    1988-01-01

    The function of taurine in mammalian osmoregulation was studied in the Brattleboro rat with hereditary hypothalamic diabetes insipidus (DI). DI rats are chronically dehydrated because of their inability to synthesize vasopressin. One day of water deprivation did not affect the water balance in rats with normal vasopressin synthesis, whereas DI rats were markedly dehydrated and lost considerably body weight. Taurine content and 3 H-taurine accumulation by platelets were significantly higher in DI rats, with a further increase after one day of water deprivation. In DI rats, water deprivation also evoked a clear taurine increase in skeletal muscle and in the brain. These findings indicate that taurine has an osmoregulatory function in mammals

  2. Influence of Dietary Avocado on Gut Health in Rats.

    Science.gov (United States)

    Paturi, Gunaranjan; Butts, Christine A; Bentley-Hewitt, Kerry L

    2017-09-01

    This study investigated the impact of diets containing various levels of avocado (5, 10 and 15%) on gut health in rats fed for six weeks. Avocado-fed rats had significantly higher food intakes while their body weights remained similar to the control diet-fed rats. No significant changes in intestinal bacterial populations (ileum, cecum and colon) were found in rats fed avocado diets compared to the control diet. Ileum and colon tissues of rats fed avocado diets showed significantly higher expression of genes (β-defensin 1, mucin 3 or mucin 4) and a greater number of mucin-producing goblet cells in the colon. The percentage of avocado in the diet had varying effects in altering the biomarkers, whereby diet containing 15% avocado was the more effective diet. This study delivers new knowledge on the role of avocado on gut health in rats.

  3. Development of rat telencephalic neurons after prenatal x-irradiation

    International Nuclear Information System (INIS)

    Norton, S.

    1979-01-01

    Telencephalic neurons of rats, irradiated at day 15 of gestation with 125 R, develop synaptic connections on dendrites during maturation which appear to be normal spines in Golgi-stained light microscope preparations. At six weeks of postnatal age both control and irradiated rats have spiny dendritic processes on cortical pyramidal cells and caudate Golgi type II neurons. However, when the rats are 6 months old the irradiated rats have more neurons with beaded dendritic processes that lack spines or neurons and are likely to be degenerating neurons. The apparently normal development of the neurons followed by degeneration in the irradiated rat has a parallel in previous reports of the delayed hyperactivity which develops in rats irradiated on the fifteenth gestational day

  4. City rats: insight from rat spatial behavior into human cognition in urban environments.

    Science.gov (United States)

    Yaski, Osnat; Portugali, Juval; Eilam, David

    2011-09-01

    The structure and shape of the urban environment influence our ability to find our way about in the city. Understanding how the physical properties of the environment affect spatial behavior and cognition is therefore a necessity. However, there are inherent difficulties in empirically studying complex and large-scale urban environments. These include the need to isolate the impact of specific urban features and to acquire data on the physical activity of individuals. In the present study, we attempted to overcome the above obstacles and examine the relation between urban environments and spatial cognition by testing the spatial behavior of rats. This idea originated from the resemblance in the operative brain functions and in the mechanisms and strategies employed by humans and other animals when acquiring spatial information and establishing an internal representation, as revealed in past studies. Accordingly, we tested rats in arenas that simulated a grid urban layout (e.g. Manhattan streets) and an irregular urban layout (e.g. Jerusalem streets). We found that in the grid layout, rat movement was more structured and extended over a greater area compared with their restricted movement in the irregular layout. These movement patterns recall those of humans in respective urban environments, illustrating that the structure and shape of the environment affect spatial behavior similarly in humans and rats. Overall, testing rats in environments that simulate facets of urban environments can provide new insights into human spatial cognition in urban environments.

  5. Beta Adrenergic Regulation of Intrapulmonary Arteriovenous Anastomoses in Intact Rat and Isolated Rat Lungs

    Directory of Open Access Journals (Sweden)

    Melissa L. Bates

    2017-04-01

    Full Text Available Intrapulmonary arteriovenous anastomoses (IPAVA allow large diameter particles of venous origin to bypass the pulmonary capillary bed and embolize the systemic arterial circulation. IPAVA have been routinely observed in healthy humans with exercise, hypoxia, and catecholamine infusion, but the mechanism by which they are recruited is not well-defined. We hypothesized that beta-adrenergic receptor stimulation recruits IPAVA and that receptor blockade would limit hypoxia-induced IPAVA recruitment. To test our hypothesis, we evaluated the transpulmonary passage of microspheres in intact rats and isolated rats lung infused with the beta-adrenergic receptor agonist isoproterenol. We also evaluated IPAVA recruitment in intact rats with hypoxia and the beta-adrenergic receptor blocker propranolol. We found that IPAVA are recruited in the intact rat by isoproterenol and their recruitment by hypoxia can be minimized by propranolol, suggesting a role for the adrenergic system in the recruitment of IPAVA by hypoxia. IPAVA recruitment is completely abolished by ventilation with 100% oxygen. Isoproterenol also recruits IPAVA in isolated rat lungs. The fact that isoproterenol can recruit IPAVA in isolated lungs, without increased pulmonary flow, suggests that elevated cardiac output is not required for IPAVA recruitment.

  6. Effect of high dietary calcium on weight management in rats

    International Nuclear Information System (INIS)

    Mohamad, M.T.

    2012-01-01

    The present study was undertaken to find out a suitable dietary regime to maintain a lower prevalence of overweight or obesity by adjusting the diet components. Therefore, male Swiss albino rats were selected according to their ages and divided into two main groups, i.e., premature and mature groups. Each rat group was divided into 4 subgroups and each subgroup was fed on a diet of varied composition. Serum levels of lipids, calcium, phosphorous and testosterone were determined in addition to body weight measurement. The results indicate non-significant decrease of percentage of body weight gain in premature rats fed on high-calcium diets while significant decrease of percentage of body weight gain in mature rats fed on the same diet composition. The levels of serum HDL-C, LDL-C, triglycerides and testosterone were significantly decreased in premature rats fed high- calcium diets. In premature rats, only rat subgroup fed on high calcium from milk, showed a significant decrease in serum cholesterol levels. Calcium and phosphorus levels exhibited non- significant change between premature rats. In mature rats, LDL-C data demonstrate nonsignificant changes while cholesterol and triglyceride levels were significantly decreased in rats fed high -calcium diet compared to control. HDL-C level revealed a significant decrease in sera of mature rats fed on high calcium from milk. Serum testosterone levels were significantly decreased in mature rats fed low- fat diets or low fat diets supplemented with high- calcium level. In general, one would suggest to consume low fat diet (4%) supplemented with high calcium from dry skimmed milk fortified with hydroxyapatite as suitable dietary program to avoid overweight or obesity.

  7. The Metabolism of Tetralin in Fischer 344 Rats

    Science.gov (United States)

    1986-04-01

    would die from the disease . The relevance of nephropathy observed in male rats exposed to various hydrocarbons to the occurrence of renal neoplasia in man...34 often obscure pathologic evaluations. "Old-rat nephropathy" is a common degenerative kidney disease predominantly seen in the male rat. By careful...studies have been performed with n-hexane and n-heptane to characterize their metabolism and role in neurotoxicity (Perbellini et al., 1982; Bahima et

  8. Striatal grafts in a rat model of Huntington's disease

    DEFF Research Database (Denmark)

    Guzman, R; Meyer, M; Lövblad, K O

    1999-01-01

    Survival and integration into the host brain of grafted tissue are crucial factors in neurotransplantation approaches. The present study explored the feasibility of using a clinical MR scanner to study striatal graft development in a rat model of Huntington's disease. Rat fetal lateral ganglionic...... time-points graft location could not be further verified. Measures for graft size and ventricle size obtained from MR images highly correlated with measures obtained from histologically processed sections (R = 0.8, P fetal rat lateral ganglionic...

  9. Tobacco Induced Priapism in Wister Rat: A Case Report | Ugbor ...

    African Journals Online (AJOL)

    In an eight-week study on the effect of potash-tobacco dust ingestion on rats, a persistent penile erection for days was observed amongst some of the rats under study. This study involved a total of 42 Wister rats of weights ranging between 150-300g and grouped into four groups (A, B, C and D). Group A served as control, ...

  10. The oncogenic action of ionizing radiation on rat skin

    International Nuclear Information System (INIS)

    Burns, F.J.; Garte, S.J.

    1990-01-01

    An extensive experiment involving approximately 400 rats exposed to the neon ion beam at the Bevalac in Berkeley, CA and to electrons is nearing completion. Progress is described in three areas corresponding to the specific aims of the proposal: (1) carcinogenesis and DNA strand breaks in rat skin following exposure by the neon ions or electrons; (2) oncogene activation in radiation-induced rat skin cancers; (3) DNA strand breaks in the epidermis as a function of radiation penetration. 59 refs., 4 tabs

  11. Energy intake of rats fed a cafeteria diet.

    Science.gov (United States)

    Prats, E; Monfar, M; Castellà, J; Iglesias, R; Alemany, M

    1989-02-01

    The proportion of lipid, carbohydrate and protein energy self-selected by male and female rats from a cafeteria diet has been studied for a 48-day period (36-day in female rats). The diet consisted in 12 different items and was offered daily, in excess and under otherwise standard conditions, to rats--caged in groups of three--from weaning to adulthood. Groups of control animals were studied in parallel and compared with the cafeteria groups. Cafeteria diet fed groups of rats ingested more energy and lowered their metabolic efficiency with age. Male rats ate more than females and increased their body weight even after female practically stopped growing. There was a wide variation in the aliments consumed each day by the cafeteria-fed rats. However, the proportion of lipid, protein and carbohydrate the rats ate remained constant. Male rats ingested more lipid than females. Carbohydrate consumption was constant in control and cafeteria fed groups of rats independently of sex. Protein consumption was higher in cafeteria rats than in controls, but the differences were not so important as with liquid. Fiber content of the cafeteria diet was lower than that of the control diet. The cafeteria diet selected by the rats was, thus, hypercaloric and hyperlipidic, with practically the same amount of carbohydrate than the control diet, slightly hyperproteic and, nevertheless, remarkably constant in its composition with respect to time. Cafeteria rats had a higher water intake than controls. All these trends were maintained despite the observed changes in the animals' tastes and their differential consumption of the ailments of the diet.

  12. Mutagenicity of comfrey (Symphytum Officinale) in rat liver

    OpenAIRE

    Mei, N; Guo, L; Fu, P P; Heflich, R H; Chen, T

    2005-01-01

    Comfrey is a rat liver toxin and carcinogen that has been used as a vegetable and herbal remedy by humans. In order to evaluate the mechanisms underlying its carcinogenicity, we examined the mutagenicity of comfrey in the transgenic Big Blue rat model. Our results indicate that comfrey is mutagenic in rat liver and the types of mutations induced by comfrey suggest that its tumorigenicity results from the genotoxicity of pyrrolizidine alkaloids in the plant.

  13. Mutagenicity of comfrey (Symphytum Officinale) in rat liver.

    Science.gov (United States)

    Mei, N; Guo, L; Fu, P P; Heflich, R H; Chen, T

    2005-03-14

    Comfrey is a rat liver toxin and carcinogen that has been used as a vegetable and herbal remedy by humans. In order to evaluate the mechanisms underlying its carcinogenicity, we examined the mutagenicity of comfrey in the transgenic Big Blue rat model. Our results indicate that comfrey is mutagenic in rat liver and the types of mutations induced by comfrey suggest that its tumorigenicity results from the genotoxicity of pyrrolizidine alkaloids in the plant.

  14. Coenzyme metabolism in rat liver transketolase

    International Nuclear Information System (INIS)

    Gorbach, Z.V.; Kubyshin, V.L.; Maglysh, S.S.; Zabrodskaya, S.V.

    1987-01-01

    On the basis of the results of kinetic investigations, two binding sites for hydroxythiamine diphosphate were determined in apotransketolase, with sharply differing values of K/sub i/: (7-22) x 10 -9 and (13.0-19.7) x 10 -8 M. A study was made of the turnover rate of thiamine diphosphate in holotransketolase in rat liver tissue by a radioisotope method, using [ 14 C] thiamine as the labeled precursor. The half-substitution time and rate constant of degradation of the coenzyme in transketolase are close in absolute values to the analogous indices for the protein portion of the enzyme and constitute 153 h and 0.108 day -1 , respectively. Rat liver transketolase exists in vivo in the form of a substituted α-carbanion. Replacement of thiamine diphosphate by hydroxythiamine diphosphate in the holoenzyme has no effect on the formation of the intermediate α-carbanion form of the enzyme

  15. Pharmacokinetics of vinyl chloride in the rat

    International Nuclear Information System (INIS)

    Bolt, H.M.; Laib, R.J.; Kappus, H.; Buchter, A.

    1977-01-01

    When rats are exposed to [ 14 C]vinyl chloride in a closed system, the vinyl chloride present in the atmosphere equilibrates with the animals' organism within 15 min. The course of equilibration could be determined using rats which had been given 6-nitro-1,2,3-benzothiadiazole. This compound completely blocks metabolism of vinyl chloride. The enzymes responsible for metabolism of vinyl chloride are saturated at an atmospheric concentration of vinyl chloride of 250 ppm. Pharmacokinetic analysis shows that no significant cumulation of vinyl chloride or its major metabolites is to be expected on repeated administration of vinyl chlorides. This may be consistent with the theory that a reactive, shortly living metabolite which occurs in low concentration only, may be responsible for the toxic effects of vinyl chloride

  16. Neurodevelopmental Reflex Testing in Neonatal Rat Pups.

    Science.gov (United States)

    Nguyen, Antoinette T; Armstrong, Edward A; Yager, Jerome Y

    2017-04-24

    Neurodevelopmental reflex testing is commonly used in clinical practice to assess the maturation of the nervous system. Neurodevelopmental reflexes are also referred to as primitive reflexes. They are sensitive and consistent with later outcomes. Abnormal reflexes are described as an absence, persistence, reappearance, or latency of reflexes, which are predictive indices of infants that are at high risk for neurodevelopmental disorders. Animal models of neurodevelopmental disabilities, such as cerebral palsy, often display aberrant developmental reflexes, as would be observed in human infants. The techniques described assess a variety of neurodevelopmental reflexes in neonatal rats. Neurodevelopmental reflex testing offers the investigator a testing method that is not otherwise available in such young animals. The methodology presented here aims to assist investigators in examining developmental milestones in neonatal rats as a method of detecting early-onset brain injury and/or determining the effectiveness of therapeutic interventions. The methodology presented here aims to provide a general guideline for investigators.

  17. Radiation-induced mesotheliomas in rats

    International Nuclear Information System (INIS)

    Hahn, F.F.; Haley, P.J.; Hubbs, A.F.; Hoover, M.D.; Lundgren, D.L.

    1990-01-01

    Mesotheliomas have been reported in rats that inhaled plutonium, but these tumors have not been extensively studied. To investigate a possible role for inhaled radionuclides in the induction of mesotheliomas, four life-span studies conducted at the Inhalation Toxicology Research Institute are reviewed. A total of 3076 F344 rats were exposed by inhalation to aerosols of 239 PuO 2 , mixed uranium-plutonium oxide, or 144 CeO 2 . Results showed that a low incidence of pleural mesotheliomas was induced by either alpha- or beta-emitting radionuclides deposited and retained in the lung. Chronic alpha irradiation was more effective per unit dose in producing mesotheliomas than chronic beta irradiation of the lung by a factor of 15. 7 refs., 1 tab., 7 figs

  18. Radiation-induced mesotheliomas in rats

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, F.F.; Haley, P.J.; Hubbs, A.F.; Hoover, M.D.; Lundgren, D.L.

    1990-01-01

    Mesotheliomas have been reported in rats that inhaled plutonium, but these tumors have not been extensively studied. To investigate a possible role for inhaled radionuclides in the induction of mesotheliomas, four life-span studies conducted at the Inhalation Toxicology Research Institute are reviewed. A total of 3076 F344 rats were exposed by inhalation to aerosols of {sup 239}PuO{sub 2}, mixed uranium-plutonium oxide, or {sup 144}CeO{sub 2}. Results showed that a low incidence of pleural mesotheliomas was induced by either alpha- or beta-emitting radionuclides deposited and retained in the lung. Chronic alpha irradiation was more effective per unit dose in producing mesotheliomas than chronic beta irradiation of the lung by a factor of 15. 7 refs., 1 tab., 7 figs. (MHB)

  19. Gluconeogenesis in lethally X-irradiated rats

    International Nuclear Information System (INIS)

    Paulikova, E.; Ahlers, I.; Praslicka, M.

    1983-01-01

    The in vivo incorporation of U- 14 C-alanine into blood glucose and liver glycogen was measured in rats irradiated with a single whole body lethal dose of X-rays. Changes in gluconeogenic enzyme activities were studied in the liver. Increased incorporation of 14 C-alanine into blood glucose and liver glycogen were found after irradiation. Liver phosphoenolpyruvate carboxykinase and glycogenic activity underwent almost parallel changes and were significantly elevated from the 6th to the 48th hour, with resultant accumulation of glycogen. Glucose-6-phosphatase activity was depressed and there was a negative correlation between it and liver glycogen concentration. Maximum fructose-1,6-diphosphatase activity was found at 48 hours. The results show that glycogen accumulation in the liver and the raised blood glucose level in X-irradiated rats are based on raised gluconeogenesis. (author)

  20. Gluconeogenesis in lethally X-irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Paulikova, E.; Ahlers, I.; Praslicka, M. (Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie)

    1983-02-01

    The in vivo incorporation of U-/sup 14/C-alanine into blood glucose and liver glycogen was measured in rats irradiated with a single whole body lethal dose of X-rays. Changes in gluconeogenic enzyme activities were studied in the liver. Increased incorporation of /sup 14/C-alanine into blood glucose and liver glycogen were found after irradiation. Liver phosphoenolpyruvate carboxykinase and glycogenic activity underwent almost parallel changes and were significantly elevated from the 6th to the 48th hour, with resultant accumulation of glycogen. Glucose-6-phosphatase activity was depressed and there was a negative correlation between it and liver glycogen concentration. Maximum fructose-1,6-diphosphatase activity was found at 48 hours. The results show that glycogen accumulation in the liver and the raised blood glucose level in X-irradiated rats are based on raised gluconeogenesis.

  1. Proteome analysis of the hypercholestrolemic rat, RICO

    International Nuclear Information System (INIS)

    Cho, S.Y.; Park, K.-S.; Paik, Y.-K.; Seong, J.-K.

    2001-01-01

    In an attempt to develop novel markers for hypercholesterolemia, hepatic tissues and serum prepared from hypeicholesterolemic rat (i e RICO) were analyzed by two-dimensional electrophoresis (2DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-ToF). Results were compared to those of paired inbreed rat (WKY). Comparative analysis of the respective spot patterns in 2DE revealed that the numbers of differential expression proteins were identified in serum and liver tissues of RICO. Some of the representative proteins annotated in 2DE were apolipoprotein family and numerous lipid metabolism related proteins. Especially, we found that protein disulfide isomerase subunits (ER-60) in 2DE have differential post-translational modification pattern by MALDI-ToF analysis. Our results suggest that the proteomic analysis of these proteins might be a novel approach to identify the molecular events in detail during lipid disorder such atherosclerosis

  2. Microarray Analysis of the Developing Rat Mandible

    Institute of Scientific and Technical Information of China (English)

    Hideo KABURAGI; Naoyuki SUGANO; Maiko OSHIKAWA; Ryosuke KOSHI; Naoki SENDA; Kazuhiro KAWAMOTO; Koichi ITO

    2007-01-01

    To analyze the molecular events that occur in the developing mandible, we examined the expression of 8803 genes from samples taken at different time points during rat postnatal mandible development.Total RNA was extracted from the mandibles of 1-day-old, 1-week-old, and 2-week-old rats. Complementary RNA (cRNA) was synthesized from cDNA and biotinylated. Fragmented cRNA was hybridized to RGU34A GeneChip arrays. Among the 8803 genes tested, 4344 were detectable. We identified 148 genes with significantly increased expression, and 19 genes with significantly decreased expression. A comprehensive analysis appears to be an effective method of studying the complex process of development.

  3. Pinocytosis in the rat visceral yolk sac

    International Nuclear Information System (INIS)

    Duncan, R.; Lloyd, J.B.

    1978-01-01

    Low temperature, 2,4-dinitrophenol and moniodoacetate could each completely abolish the pinocytic uptake of 125 I-labelled polyvinylpyrrolidone, 125 I-labelled bovine serum albumin or colloidal 198 Au by 17.5-day rat visceral yolk sac cultured in vitro. Cytochalasin B and colchicine caused a partial and dose-dependent inhibition. It is concluded that the mechanism of pinocytic uptake of these substrates is not micropinocytosis as conventionally defined. Removal of extracellular calcium or the presence of theophylline inhibited liquid-phase pinocytosis by the rat yolk sac, whereas addition of ouabain caused a biphasic response: a slight stimulation of pinosome formation at a low concentration, and an inhibitory effect at a higher concentration. (Auth.)

  4. Concussion: comparison of humans and rats.

    Science.gov (United States)

    Parkinson, D; West, M; Pathiraja, T

    1978-01-01

    Concussion is the most primitive and probably the most simple central nervous system response to an outside agent. Although millions of neurons undergo a very rapid reversal with loss and restoration of function, many physicians argue that every knockout blow leaves some residual damage, i.e., some or all of these neurons stop short of recovery. Clinical experience shows a wide discrepancy in the appearance or persistence of certain signs and symptoms after all types of head injury, but particularly after concussing blows, when third party or grievance cases are involved. Using slow motion filmstrips of boxing ring knockouts, we established a grading system for concussion and duplicated these grades in nonanesthetized rats. When we compared the performance, learning, and memory of concussed rats with their preconcussion performance and with the performance of nonconcussed controls, we were unable to find any differences.

  5. Rat1p maintains RNA polymerase II CTD phosphorylation balance

    DEFF Research Database (Denmark)

    Jimeno-González, Silvia; Schmid, Manfred; Malagon, Francisco

    2014-01-01

    . Here we describe a function of Rat1p in regulating phosphorylation levels of the C-terminal domain (CTD) of the largest RNAPII subunit, Rpb1p, during transcription elongation. The rat1-1 mutant exhibits highly elevated levels of CTD phosphorylation as well as RNAPII distribution and transcription...... termination defects. These phenotypes are all rescued by overexpression of the CTD phosphatase Fcp1p, suggesting a functional relationship between the absence of Rat1p activity, elevated CTD phosphorylation, and transcription defects. We also demonstrate that rat1-1 cells display increased RNAPII...

  6. High prevalence of Leptospira spp. in sewer rats (Rattus norvegicus)

    DEFF Research Database (Denmark)

    Krøjgaard, L H; Villumsen, S; Markussen, M D K

    2009-01-01

    Earlier studies on the ecology of leptospirosis in temperate regions focused mainly on free-ranging rats in rural areas. Here we report on the occurrence of Leptospira spp. in Rattus norvegicus living in sewers in a suburban area in Copenhagen, Denmark. In 2006-2007, about 30 rats were captured...... in sewers at each of six different locations. Rat kidneys were screened by PCR for pathogenic Leptospira spp. In one location no infected rats were found, whereas the prevalence in the remaining five locations ranged between 48% and 89%. Micro-agglutination tests showed that serogroup Pomona, Sejroe...

  7. ENU mutagenesis to generate genetically modified rat models.

    Science.gov (United States)

    van Boxtel, Ruben; Gould, Michael N; Cuppen, Edwin; Smits, Bart M G

    2010-01-01

    The rat is one of the most preferred model organisms in biomedical research and has been extremely useful for linking physiology and pathology to the genome. However, approaches to genetically modify specific genes in the rat germ line remain relatively scarce. To date, the most efficient approach for generating genetically modified rats has been the target-selected N-ethyl-N-nitrosourea (ENU) mutagenesis-based technology. Here, we describe the detailed protocols for ENU mutagenesis and mutant retrieval in the rat model organism.

  8. Tonic immobility and factors influencing its duration in rats.

    Science.gov (United States)

    Tikal, K

    1991-01-01

    The author developed a method for inducing tonic immobility (paroxysmal inhibition) in rats and mice. By means of a plexiglass plate and plexiglass box the rat is immobilised, rotated at 180 degrees and subjected to constant pressure corresponding to the weight of the plexiglass plate. This way it is possible to prolong substantially tonic immobility in rats without using foregoing time consuming and interfering, so called sensitizing procedures. The duration of TI can be influenced by pharmacologic and nonpharmacological interventions. A longer duration of TI appeared to be typical for rats tending to react in other situations with anxiety, motor inhibition and submission.

  9. Spreading depression analysis of contact behaviour of rats.

    Science.gov (United States)

    Tikal, K

    1977-08-01

    Social contact behaviour induced by spreading cortical depression was studied in rats. The controls looked for and remained in contact, whereas between the rats with spreading cortical depression and their other partners there was no contact. This phenomenon is due mainly to the absence of an active urge for contact. The contact behaviour of rats is evidently controlled by the cerebral cortex or by subcortical areas of the brain which are inhibited after the elicitation of spreading depression. The experiments show that the contact behaviour of rats has at least two components - an active urge for contact and passive tolerance of contact.

  10. Database of Physiological Parameters for Early Life Rats and Mice

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Database of Physiological Parameters for Early Life Rats and Mice provides information based on scientific literature about physiological parameters. Modelers...

  11. Influence of Samarium on Learning and Memory Function of Rats

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Sixty-four Spraque-Dawley(SD)big rats with weaning weight of (195±15) g were randomly divided into 4 groups with 8 males and 8 females each group. One group drunk with de-ionized water served as control and was also used for analysis of the background. The other three groups rats were raised by de-ionized water containing low, middle and high concentrations of Sm for four months, then learning and memory tests were carried out in Y-electric maze. Compared with the control rats, the learning and memory of rats in low and middle groups shows a deterioration trend, exhibiting the function degradation of rats' brain. It may results from the rare earth elements through blood-brain barrier affecting the normal physiological functions of rats' brain. In addition, the activity of superoxide dismutase (SOD) in rats' brain decreases, while the content of malondialdehyde (MDA) concentration increases. The decreased SOD activity and the increased MDA mean the degeneration the ability of anti-oxidation in rats' brain, which are accordance with the degradation of learning and memory function of rats in low and middle Sm groups.

  12. Effect of moderate exercise on peritoneal neutrophils from juvenile rats.

    Science.gov (United States)

    Braz, Glauber Ruda; Ferreira, Diorginis Soares; Pedroza, Anderson Apolonio; da Silva, Aline Isabel; Sousa, Shirley Maria; Pithon-Curi, Tania Cristina; Lagranha, Claudia

    2015-09-01

    Previous studies showed that moderate exercise in adult rats enhances neutrophil function, although no studies were performed in juvenile rats. We evaluated the effects of moderate exercise on the neutrophil function in juvenile rats. Viability and neutrophils function were evaluated. Moderate exercise did not impair the viability and mitochondrial transmembrane potential of neutrophils, whereas there was greater reactive oxygen species production (164%; p < 0.001) and phagocytic capacity (29%; p < 0.05). Our results suggest that moderate exercise in juvenile rats improves neutrophil function, similar to adults.

  13. Suppressed serum prolactin in sinoaortic-denervated rats

    International Nuclear Information System (INIS)

    Alexander, N.; Melmed, S.; Morris, M.

    1987-01-01

    The authors investigated the effect of arterial baroreceptor deafferentation on serum and pituitary prolactin (PRL) and on catecholamines in median eminence (ME) and anterior and posterior pituitaries. Male Wistar rats were sinoaortic denervated (SAD) or sham operated (SO). Three days after surgery serum prolactin, measured by radioimmunoassay, was suppressed in SAD rats, and dopamine (DA) and norepinephrine (NE) concentrations, measured by radioenzymatic or high-performance liquid chromatography electron capture methods, were significantly reduced in ME of SAD rats. Simultaneously, anterior pituitary of SAD rats had significant increases in both catecholamines, whereas posterior pituitary showed no changes. Four hours after surgery serum PRL was also reduced in SAD rats, but no changes in ME catecholamines were found. Mean arterial pressure (MAP) and heart rate were measured before and after injection of bromocriptine in SAD and SO rats 3 days after surgery. Bromocriptine markedly suppressed serum PRL in both groups and reduced MAP from 144 +/- 10 to 84 +/- 5 and from 116 +/- 2 to 99 +/- 3 in SAD and SO rats, respectively; heart rate was reduced in SAD rats. They conclude that the SAD rat is a model of hypertension with suppressed serum PRL and that interruption of arterial baroreceptor nerves suppresses PRL secretion probably by modulating tuberoinfundibular turnover of catecholamines

  14. Thrombolytic and anticoagulation treatment in a rat embolic stroke model

    DEFF Research Database (Denmark)

    Rasmussen, Rune Skovgaard; Overgaard, K; Meden, P

    2003-01-01

    OBJECTIVES: The effects of pentasaccharide (PENTA), given alone or combined with thrombolysis using recombinant tissue plasminogen activator (rt-PA), on infarct size and clinical outcome were evaluated in a rat embolic stroke model. MATERIALS AND METHODS: Ninety-two rats were embolized unilateral...... alone or combined with rt-PA did not significantly increase mortality or tendency for hemorrhage.......OBJECTIVES: The effects of pentasaccharide (PENTA), given alone or combined with thrombolysis using recombinant tissue plasminogen activator (rt-PA), on infarct size and clinical outcome were evaluated in a rat embolic stroke model. MATERIALS AND METHODS: Ninety-two rats were embolized unilaterally...

  15. Exenatide Induces Impairment of Autophagy Flux to Damage Rat Pancreas.

    Science.gov (United States)

    Li, Zhiqiang; Huang, Lihua; Yu, Xiao; Yu, Can; Zhu, Hongwei; Li, Xia; Han, Duo; Huang, Hui

    2017-01-01

    The study aimed to explore the alteration of autophagy in rat pancreas treated with exenatide. Normal Sprague-Dawley rats and diabetes-model rats induced by 2-month high-sugar and high-fat diet and streptozotocin injection were subcutaneously injected with exenatide, respectively, for 10 weeks, with homologous rats treated with saline as control. Meanwhile, AR42J cells, pancreatic acinar cell line, were cultured with exenatide at doses of 5 pM for 3 days. The pancreas was disposed, and several sections were stained with hematoxylin-eosin. Immunohistochemistry was used to measure the expressions of glucagon-like peptide 1 receptor (GLP-1R) and cysteine-aspartic acid protease-3 in rat pancreas, and Western blot was used to test the expressions of GLP-1R, light chain 3B-I and -II, and p62 in rat pancreas and AR42J cells. The data were expressed as mean (standard deviation) and analyzed by unpaired Student's t-test. Exenatide can induce pathological changes in rat pancreas. The GLP-1R, p62, light chain 3B-II, and cysteine-aspartic acid protease-3 in rat pancreas and AR42J cells treated with exenatide were significantly overexpressed. Exenatide can activate and upregulate its receptor, GLP-1R, then impair autophagy flux and activate apoptosis in the pancreatic acinar cell, thus damaging rat pancreas.

  16. Characterizing a Rat Brca2 Knockout Model

    Science.gov (United States)

    2007-05-01

    Brca2 was tested in various tumor inducing experimental settings [49,52] * activated form Hs = Homo sapiens ; Rn = Rattus norvegicus; MMTV...sequencing gDNA from a wild-type 2 SD rat over a region of intron 21 that contains the splicing branch site 2 (underlined). ( el The same sequence from the...from the El pups at 1 week of age for macromolecule isolation. We also visually checked all Fk pups for gross abnormalities in physi- cal

  17. Proteomic profiling of the rat hypothalamus

    Directory of Open Access Journals (Sweden)

    Pedroso Amanda P

    2012-04-01

    Full Text Available Abstract Background The hypothalamus plays a pivotal role in numerous mechanisms highly relevant to the maintenance of body homeostasis, such as the control of food intake and energy expenditure. Impairment of these mechanisms has been associated with the metabolic disturbances involved in the pathogenesis of obesity. Since rodent species constitute important models for metabolism studies and the rat hypothalamus is poorly characterized by proteomic strategies, we performed experiments aimed at constructing a two-dimensional gel electrophoresis (2-DE profile of rat hypothalamus proteins. Results As a first step, we established the best conditions for tissue collection and protein extraction, quantification and separation. The extraction buffer composition selected for proteome characterization of rat hypothalamus was urea 7 M, thiourea 2 M, CHAPS 4%, Triton X-100 0.5%, followed by a precipitation step with chloroform/methanol. Two-dimensional (2-D gels of hypothalamic extracts from four-month-old rats were analyzed; the protein spots were digested and identified by using tandem mass spectrometry and database query using the protein search engine MASCOT. Eighty-six hypothalamic proteins were identified, the majority of which were classified as participating in metabolic processes, consistent with the finding of a large number of proteins with catalytic activity. Genes encoding proteins identified in this study have been related to obesity development. Conclusion The present results indicate that the 2-DE technique will be useful for nutritional studies focusing on hypothalamic proteins. The data presented herein will serve as a reference database for studies testing the effects of dietary manipulations on hypothalamic proteome. We trust that these experiments will lead to important knowledge on protein targets of nutritional variables potentially able to affect the complex central nervous system control of energy homeostasis.

  18. Oxalic acid decreases calcium absorption in rats

    International Nuclear Information System (INIS)

    Weaver, C.M.; Martin, B.R.; Ebner, J.S.; Krueger, C.A.

    1987-01-01

    Calcium absorption from salts and foods intrinsically labeled with 45 Ca was determined in the rat model. Calcium bioavailability was nearly 10 times greater for low oxalate kale, CaCO 3 and CaCl 2 than from CaC 2 O 4 (calcium oxalate) and spinach (high in oxalates). Extrinsic and intrinsic labeling techniques gave a similar assessment of calcium bioavailability from kale but not from spinach

  19. Validation of a radioimmunoassay for rat insulin

    International Nuclear Information System (INIS)

    Delattre, E.; Boschero, A.C.

    1984-01-01

    A methodological approach that permits, in a radioimmunoassay, the evaluation of rat insulin by using bovine insulin as reference is presented. As in general the technics for radioimmunoassay of different substances follow the same principles (competitive inhibition), we believe that the methodology presented here could be used for evaluation of other hormones when the adequated referential, of know biological activity, is not available. (Author) [pt

  20. Radial oxygen gradients over rat cortex arterioles

    OpenAIRE

    Galler, Michael

    2011-01-01

    Purpose: We present the results of the visualisation of radial oxygen gradients in rats’ cortices and their use in neurocritical management. Methods: PO2 maps of the cortex of 10 wistar rats were obtained with a camera (SensiMOD, PCO, Kehlheim, Germany). Those pictures were analyzed and edited by a custom-made software. We chose a vessel for examination. A matrix, designed to evaluate the cortical O2 partial pressure, was placed vertically to the artery and afterwards multiple regio...

  1. Neurosteroids exhibit anticonvulsant action in immature rats

    Czech Academy of Sciences Publication Activity Database

    Mareš, Pavel

    2005-01-01

    Roč. 46, č. S8 (2005), s. 115-116 ISSN 0013-9580. [Joint Annual Meeting of the American Epilepsy Society and American Clinical Neurophysiology Society. 02.12.2005-06.12.2005, Washington, DC] R&D Projects: GA AV ČR(CZ) IBS5011007 Institutional research plan: CEZ:AV0Z50110509 Keywords : neurosteroids * anticonvulsants * immature rats Subject RIV: ED - Physiology

  2. Occurrence of riboflavinyl glucoside in rat urine

    International Nuclear Information System (INIS)

    Ohkawa, Hiroshi; Ohishi, Nobuko; Yagi, Kunio

    1983-01-01

    To investigate the metabolism of riboflavin, [2- 14 C]-riboflavin was administered orally to a rat. The urine pooled for 24 h after administration was fractionated by paper and silica gel thin layer chromatographies using various solvent systems. Among the radioactive metabolites, riboflavinyl glucoside was found along with 7-carboxy lumichrome and 8-carboxy lumichrome. The radioactivity of riboflavinyl glucoside comprised about 6 % of the total radioactivity excreted in the urine during 24 h. (author)

  3. Urinary metabolites of tetrahydronorharman in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Greiner, B.; Rommelspacher, H.

    1982-01-01

    The metabolism of THN in the rat was studied in vivo by use of /sup 14/C-radiolabelled compound. Structures of major urinary metabolites were determined by exact spectral data. Their concentrations were measured by liquid scintillation counting. It was found that THN is submitted to endogenous transformation, and that the excreted derivatives form three groups of similar concentration: unchanged substance, hydroxylated/conjugated compounds, and aromatic metabolites. Structures and proposed pathways are summed in diagram.

  4. Urinary metabolites of tetrahydronorharman in the rat

    International Nuclear Information System (INIS)

    Greiner, B.; Rommelspacher, H.

    1982-01-01

    The metabolism of THN in the rat was studied in vivo by use of 14 C-radiolabelled compound. Structures of major urinary metabolites were determined by exact spectral data. Their concentrations were measured by liquid scintillation counting. It was found that THN is submitted to endogenous transformation, and that the excreted derivatives form three groups of similar concentration: unchanged substance, hydroxylated/conjugated compounds, and aromatic metabolites. Structures and proposed pathways are summed in diagram

  5. Chemical Renal Denervation in the Rat

    Energy Technology Data Exchange (ETDEWEB)

    Consigny, Paul M., E-mail: paul.consigny@av.abbott.com; Davalian, Dariush, E-mail: dariush.davalian@av.abbott.com [Abbott Vascular, Innovation Incubator (United States); Donn, Rosy, E-mail: rosy.donn@av.abbott.com; Hu, Jie, E-mail: jie.hu@av.abbott.com [Abbott Vascular, Bioanalytical and Material Characterization (United States); Rieser, Matthew, E-mail: matthew.j.rieser@abbvie.com; Stolarik, DeAnne, E-mail: deanne.f.stolarik@abbvie.com [Abbvie, Analytical Pharmacology (United States)

    2013-12-03

    Introduction: The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Methods: Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose–response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography–mass spectrometry. Results: Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10{sup −5} M through 10{sup −2} M paclitaxel. Conclusion: We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

  6. Rabbiteye blueberry prevents osteoporosis in ovariectomized rats.

    Science.gov (United States)

    Li, Tao; Wu, Shou-Mian; Xu, Zhi-Yuan; Ou-Yang, Sheng

    2014-08-08

    It has been forecasted that the rabbiteye blueberry could inhibit osteoporosis. However, the inhibition and prevention of osteoporosis via rabbiteye blueberry are still elusive. This study was aim to evaluate the anti-osteoporosis effects of rabbiteye blueberry in ovariectomized rats. Thirty rats were randomly divided into three groups of ten rats each as follows: sham-operated group (SG), ovariectomized model control group (OMG), and ovariectomized rabbiteye blueberry treatment group (OBG). The blood mineral levels, the alkaline phosphatase (ALP) activity, and osteoprotegerin (OPG) level were determined. The expression analyses of type I collagen, integrin-β1, and focal adhesion kinase (FAK) were performed. Besides, the bone mineral density (BMD) and bone histomorphometry (BH) were measured. The ALP activity in SG and OBG was significantly lower than that in OMG. For the OPG level, the significant increase of OPG level in OBG was indicated compared with the other groups. The mRNA expression levels of type I collagen, integrin-β1, and FAK in OMG were significantly lower than those in other groups. The BMD in OMG were all significantly lower than those in SG and OBG. For BH, blueberry significantly improved the trabecular bone volume fraction, trabecular thickness, mean trabecular bone number, and bone formation rate, and decreased the trabecular separation, the percent of bone resorption perimeter, and mean osteoclast number in OBG compared with OMG. The rabbiteye blueberries had an effective inhibition in bone resorption, bone loss, and reduction of bone strength of ovariectomized rats and could improve the BMD, osteogenic activity, and trabecular bone structure.

  7. Social opportunity and ethanol drinking in rats.

    Science.gov (United States)

    Tomie, Arthur; Burger, Kelly M; Di Poce, Jason; Pohorecky, Larissa A

    2004-11-01

    Two experiments were designed to evaluate the effects of pairings of ethanol sipper conditioned stimulus (CS) with social opportunity unconditioned stimulus (US) on ethanol sipper CS-directed drinking in rats. In both experiments, rats were deprived of neither food nor water, and initiation of drinking of unsweetened 3% ethanol was evaluated, as were the effects of increasing the concentration of unsweetened ethanol (3-10%) across sessions. In Experiment 1, Group Paired (n=8) received 35 trials per session wherein the ethanol sipper CS was presented for 10 s immediately prior to 15 s of social opportunity US. All rats initiated sipper CS-directed drinking of 3% ethanol. Increasing the concentration of ethanol in the sipper CS [(3%, 4%, 6%, 8%, 10% (vol./vol.)] across sessions induced escalation of daily g/kg ethanol intake. To evaluate the hypothesis that the drinking in Group Paired was due to autoshaping, Experiment 2 included a pseudoconditioning control that received sipper CS and social opportunity US randomly with respect to one another. All rats in Group Paired (n=6) and in Group Random (n=6) initiated sipper CS-directed drinking of 3% ethanol and daily mean g/kg ethanol intake in the two groups was comparable. Also comparable was daily g/kg ethanol intake, which increased for both groups with the availability of higher concentrations of ethanol in the sipper CS, up to a maximum of approximately 0.8 g/kg ethanol intake of 10% ethanol. Results indicate that random presentations of ethanol sipper CS and social opportunity US induced reliable initiation and escalation of ethanol intake, and close temporally contiguous presentations of CS and US did not induce still additional ethanol intake. This may indicate that autoshaping CR performance is not induced by these procedures, or that high levels of ethanol intake induced by factors related to pseudoconditioning produces a ceiling effect. Implications for ethanol drinking in humans are discussed.

  8. Chemical Renal Denervation in the Rat

    International Nuclear Information System (INIS)

    Consigny, Paul M.; Davalian, Dariush; Donn, Rosy; Hu, Jie; Rieser, Matthew; Stolarik, DeAnne

    2014-01-01

    Introduction: The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Methods: Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose–response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography–mass spectrometry. Results: Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10 −5  M through 10 −2  M paclitaxel. Conclusion: We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel

  9. Chemical renal denervation in the rat.

    Science.gov (United States)

    Consigny, Paul M; Davalian, Dariush; Donn, Rosy; Hu, Jie; Rieser, Matthew; Stolarik, Deanne

    2014-02-01

    The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose-response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography-mass spectrometry. Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10(-5) M through 10(-2) M paclitaxel. We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

  10. D-RATS 2011: RAFT Protocol Overview

    Science.gov (United States)

    Utz, Hans

    2011-01-01

    A brief overview presentation on the protocol used during the D-RATS2011 field test for file transfer from the field-test robots at Black Point Lava Flow AZ to Johnson Space Center, Houston TX over a simulated time-delay. The file transfer actually uses a commercial implementation of an open communications standard. The focus of the work lies on how to make the state of the distributed system observable.

  11. Vitamin K requirement in Danish anticoagulant-resistant Norway rats (Rattus norvegicus)

    DEFF Research Database (Denmark)

    Markussen, Mette D.; Heiberg, Ann-Charlotte; Nielsen, Robert

    2003-01-01

    Norway rats, Rattus norvegicus, Denmark, anticoagulant rodenticide resistance, vitamin K requirement......Norway rats, Rattus norvegicus, Denmark, anticoagulant rodenticide resistance, vitamin K requirement...

  12. Adaptation of the cardiovascular system to postinfarction cardiosclerosis in rats with congenital adrenoreactivity of the myocardium.

    Science.gov (United States)

    Usacheva, M A; Popkova, E V; Smirnova, E A; Saltykova, V A; Belkina, L M

    2007-12-01

    Three months after myocardial infarction the severity of heart failure and size of postinfarction scars in August rats with inherently reduced adrenoreactivity of the myocardium were similar to those in Wistar rats. The mortality rate in August rats was 2.5-fold lower than in Wistar rats. During the postinfarction period, myocardial adrenoreactivity in August rats remained lower, while the efficiency of cardiac function was 62% higher than in Wistar rats. The incidence of epinephrine-induced arrhythmias in August rats was much lower than in Wistar rats.

  13. Antihypertensive action of non-natriuretic doses of furosemide in Dahl salt-sensitive rats

    DEFF Research Database (Denmark)

    Haugan, Ketil; Petersen, Jørgen Søberg; Spannow, Jesper

    1997-01-01

    Farmakologi, blood pressure, Dahl rats, furosemide, sodium balance, total body sodium, non-natriuretic......Farmakologi, blood pressure, Dahl rats, furosemide, sodium balance, total body sodium, non-natriuretic...

  14. Long-term BPA infusions. Evaluation in the rat brain tumor and rat spinal cord models

    International Nuclear Information System (INIS)

    Coderre, J.A.; Micca, P.L.; Nawrocky, M.M.; Joel, D.D.; Morris, G.M.

    2000-01-01

    In the BPA-based dose escalation clinical trial, the observations of tumor recurrence in areas of extremely high calculated tumor doses suggest that the BPA distribution is non-uniform. Longer (6-hour) i.v. infusions of BPA are evaluated in the rat brain tumor and spinal cord models to address the questions of whether long-term infusions are more effective against the tumor and whether long-term infusions are detrimental in the central nervous system. In the rat spinal cord, the 50% effective doses (ED 50 ) for myeloparesis were not significantly different after a single i.p. injection of BPA-fructose or a 6 hour i.v. infusion. In the rat 9L gliosarcoma brain tumor model, BNCT following 2-hr or 6-hr infusions of BPA-F produced similar levels of long term survival. (author)

  15. Fetal rat pancreas transplantation in BB rats: immunohistochemical and functional evaluation

    DEFF Research Database (Denmark)

    Yderstræde, Knud Bonnet; Starklint, Henrik; Steinbrüchel, Daniel Andreas

    1993-01-01

    Spontaneously diabetic BB/Wor rats received either a syngeneic fetal pancreas transplant or adult islets. In the former, 4-8 fetal pancreases were transplanted, and in the latter, 3-5000 islets. Transplantation was performed by transferring a blood clot containing the pancreases or islets...... to the renal subcapsular space. Insulin therapy was undertaken postoperatively, except in one experiment with adult islets. Of the fetal pancreas transplanted BB rats, 52% became normoglycaemic, and 21% remained so throughout an observation period of 10 months. Nephrectomy caused a prompt return of diabetes...... that recurrent diabetes is not inevitable following syngeneic fetal pancreas transplantation to spontaneously diabetic BB rats. Recurrent diabetes was only occasionally associated with mononuclear cell infiltration. Transplanted tissue was well-preserved and vascularized; mega-islets were a constant finding....

  16. Progesterone impairs social recognition in male rats.

    Science.gov (United States)

    Bychowski, Meaghan E; Auger, Catherine J

    2012-04-01

    The influence of progesterone in the brain and on the behavior of females is fairly well understood. However, less is known about the effect of progesterone in the male system. In male rats, receptors for progesterone are present in virtually all vasopressin (AVP) immunoreactive cells in the bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA). This colocalization functions to regulate AVP expression, as progesterone and/or progestin receptors (PR)s suppress AVP expression in these same extrahypothalamic regions in the brain. These data suggest that progesterone may influence AVP-dependent behavior. While AVP is implicated in numerous behavioral and physiological functions in rodents, AVP appears essential for social recognition of conspecifics. Therefore, we examined the effects of progesterone on social recognition. We report that progesterone plays an important role in modulating social recognition in the male brain, as progesterone treatment leads to a significant impairment of social recognition in male rats. Moreover, progesterone appears to act on PRs to impair social recognition, as progesterone impairment of social recognition is blocked by a PR antagonist, RU-486. Social recognition is also impaired by a specific progestin agonist, R5020. Interestingly, we show that progesterone does not interfere with either general memory or olfactory processes, suggesting that progesterone seems critically important to social recognition memory. These data provide strong evidence that physiological levels of progesterone can have an important impact on social behavior in male rats. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Growth hormone aggregates in the rat adenohypophysis

    Science.gov (United States)

    Farrington, M.; Hymer, W. C.

    1990-01-01

    Although it has been known for some time that GH aggregates are contained within the rat anterior pituitary gland, the role that they might play in pituitary function is unknown. The present study examines this issue using the technique of Western blotting, which permitted visualization of 11 GH variants with apparent mol wt ranging from 14-88K. Electroelution of the higher mol wt variants from gels followed by their chemical reduction with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. With the blot procedure we found 1) that GH aggregates greater than 44K were associated with a 40,000 x g sedimentable fraction; 2) that GH aggregates were not present in glands from thyroidectomized rats, but were in glands from the thyroidectomized rats injected with T4; 3) that GH aggregates were uniquely associated with a heavily granulated somatotroph subpopulation isolated by density gradient centrifugation; and 4) that high mol wt GH forms were released from the dense somatotrophs in culture, since treatment of the culture medium with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. Taken together, the results show that high mol wt GH aggregates are contained in secretory granules of certain somatotrophs and are also released in aggregate form from these cells in vitro.

  18. Aluminum neurotoxicity in the rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Yumoto, S [Tokyo Univ. (Japan). Faculty of Medicine; Ohashi, H; Nagai, H; Kakimi, S; Ogawa, Y; Iwata, Y; Ishii, K

    1993-12-31

    To investigate the etiology of Alzheimer`s disease, we administered aluminum to healthy rats and examined the aluminum uptake in the brain and isolated brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Ten days after the last injection, Al was detected in the rat brain and in isolated brain cell nuclei by PIXE analysis. Al was also demonstrated in the brain after 15 months of oral aluminum administration. Moreover, Al was detected in the brain and isolated brain cell nuclei from the patients with Alzheimer`s disease. Silver impregnation studies revealed that spines attached to the dendritic processes of cortical nerve cells decreased remarkably after aluminum administration. Electron microscopy revealed characteristic inclusion bodies in the hippocampal nerve cells 75 days after the injection. These morphological changes in the rat brain after the aluminum administration were similar to those reportedly observed in the brain of Alzheimer`s disease patients. Our results indicate that Alzheimer`s disease is caused by irreversible accumulation of aluminum in the brain, as well as in the nuclei of brain cells. (author).

  19. Visual Categorization of Natural Movies by Rats

    Science.gov (United States)

    Vinken, Kasper; Vermaercke, Ben

    2014-01-01

    Visual categorization of complex, natural stimuli has been studied for some time in human and nonhuman primates. Recent interest in the rodent as a model for visual perception, including higher-level functional specialization, leads to the question of how rodents would perform on a categorization task using natural stimuli. To answer this question, rats were trained in a two-alternative forced choice task to discriminate movies containing rats from movies containing other objects and from scrambled movies (ordinate-level categorization). Subsequently, transfer to novel, previously unseen stimuli was tested, followed by a series of control probes. The results show that the animals are capable of acquiring a decision rule by abstracting common features from natural movies to generalize categorization to new stimuli. Control probes demonstrate that they did not use single low-level features, such as motion energy or (local) luminance. Significant generalization was even present with stationary snapshots from untrained movies. The variability within and between training and test stimuli, the complexity of natural movies, and the control experiments and analyses all suggest that a more high-level rule based on more complex stimulus features than local luminance-based cues was used to classify the novel stimuli. In conclusion, natural stimuli can be used to probe ordinate-level categorization in rats. PMID:25100598

  20. Visual categorization of natural movies by rats.

    Science.gov (United States)

    Vinken, Kasper; Vermaercke, Ben; Op de Beeck, Hans P

    2014-08-06

    Visual categorization of complex, natural stimuli has been studied for some time in human and nonhuman primates. Recent interest in the rodent as a model for visual perception, including higher-level functional specialization, leads to the question of how rodents would perform on a categorization task using natural stimuli. To answer this question, rats were trained in a two-alternative forced choice task to discriminate movies containing rats from movies containing other objects and from scrambled movies (ordinate-level categorization). Subsequently, transfer to novel, previously unseen stimuli was tested, followed by a series of control probes. The results show that the animals are capable of acquiring a decision rule by abstracting common features from natural movies to generalize categorization to new stimuli. Control probes demonstrate that they did not use single low-level features, such as motion energy or (local) luminance. Significant generalization was even present with stationary snapshots from untrained movies. The variability within and between training and test stimuli, the complexity of natural movies, and the control experiments and analyses all suggest that a more high-level rule based on more complex stimulus features than local luminance-based cues was used to classify the novel stimuli. In conclusion, natural stimuli can be used to probe ordinate-level categorization in rats. Copyright © 2014 the authors 0270-6474/14/3410645-14$15.00/0.

  1. Aluminum neurotoxicity in the rat brain

    International Nuclear Information System (INIS)

    Yumoto, S.; Ohashi, H.; Nagai, H.; Kakimi, S.; Ogawa, Y.; Iwata, Y.; Ishii, K.

    1992-01-01

    To investigate the etiology of Alzheimer's disease, we administered aluminum to healthy rats and examined the aluminum uptake in the brain and isolated brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Ten days after the last injection, Al was detected in the rat brain and in isolated brain cell nuclei by PIXE analysis. Al was also demonstrated in the brain after 15 months of oral aluminum administration. Moreover, Al was detected in the brain and isolated brain cell nuclei from the patients with Alzheimer's disease. Silver impregnation studies revealed that spines attached to the dendritic processes of cortical nerve cells decreased remarkably after aluminum administration. Electron microscopy revealed characteristic inclusion bodies in the hippocampal nerve cells 75 days after the injection. These morphological changes in the rat brain after the aluminum administration were similar to those reportedly observed in the brain of Alzheimer's disease patients. Our results indicate that Alzheimer's disease is caused by irreversible accumulation of aluminum in the brain, as well as in the nuclei of brain cells. (author)

  2. Metabolism and pharmacokinetics of rhynchophylline in rats.

    Science.gov (United States)

    Wang, Wei; Ma, Chao-Mei; Hattori, Masao

    2010-01-01

    The alkaloid, rhynchophylline (RHY), from the stems and hooks of Uncaria rhynchophylla was revealed in recent years to have protective effect on neuronal damage. The present research was carried out to investigate the in vivo metabolism of this bioactive alkaloid. After administering RHY to rats, LC-MS detected RHY in plasma, bile, brain, urine and feces, the glucuronides, 11-hydroxyrhynchophylline 11-O-beta-D-glucuronide (M1) and 10-hydroxyrhynchophylline 10-O-beta-D-glucuronide (M2) in bile, and 11-hydroxyrhynchophylline (M3) and 10-hydroxyrhynchophylline (M4) in urine and feces. Within 24 h, 78.0% of RHY was excreted into the feces and 12.6% into the urine of rats after oral administration of 37.5 mg/kg. Monitoring by LC-MS showed that 9.4% of RHY was metabolized to M3 and M4 in a ratio of about 1 : 1. RHY was also detected in the brain (0.650 ng/g) at 3 h after oral administration of the same dose. Cytochrome P450 (CYP) in rat liver microsomes played a key role in RHY hydroxylation. Specific inhibition of CYP isozymes indicated that CYP2D, CYP1A1/2 and CYP2C participated in RHY hydroxylation, but not CYP3A.

  3. Toxicological evaluation of dimethoate in male rats

    International Nuclear Information System (INIS)

    Tawfik, S.M.F.

    2004-01-01

    The present study was conducted to investigate the harmful effects and biochemical changes caused by dimethoate, an organophosphorus insecticide, at two different doses which represents 1/50 of LD 5 0 (4.3 mg/kg body weight/day) or 1/10 of LD 5 0 (21.5 mg/kg body weight/day). After thirty days of daily oral administrations to male rats, serum total lipids, triglycerides, cholesterol and high density lipoprotein levels were estimated. Also, its toxic effects on serum total protein, albumin, globulin and glucose levels were studied. The glucose level at the early periods after the treatment with dimethoate using D-(U-I4C) glucose was studied. The results showed significant increases in serum total lipids, triglycerides, y-globulin and glucose levels. On the other hand, cholesterol, HDL, total protein and albumin levels in serum of rats were decreased after dimethoate treatment. In conclusion, the data obtained in the present study indicated that dimethoate has harmful effects on the parameters under investigation after thirty days of daily treatments and also on glucose level after few hours of its administration compared to control rats

  4. Trace element distribution in the rat cerebellum

    International Nuclear Information System (INIS)

    Kwiatek, W.M.; Long, G.J.; Pounds, J.G.; Reuhl, K.R.; Hanson, A.L.; Jones, K.W.

    1989-10-01

    Spatial distributions and concentrations of trace elements (TE) in the brain are important because TE perform catalytic structural functions in enzymes which regulate brain function and development. We have investigated the distributions of TE in rat cerebellum. Structures were sectioned and analyzed by the Synchrotron Radiation Induced X-ray Emission (SRIXE) method using the NSLS X-26 white-light microprobe facility. Advantages important for TE analysis of biological specimens with x-ray microscopy include short time of measurement, high brightness and flux, good spatial resolution, multielemental detection, good sensitivity, and non-destructive irradiation. Trace elements were measured in thin rat brain sections of 20-micrometers thickness. The analyses were performed on sample volumes as small as 0.2 nl with Minimum Detectable Limits (MDL) of 50 ppb wet weight for Fe, 100 ppb wet weight for Cu, and Zn, and 1 ppM wet weight for Pb. The distribution of TE in the molecular cell layer, granule cell layer and fiber tract of rat cerebella was investigated. Both point analyses and two-dimensional semi-quantitative mapping of the TE distribution in a section were used

  5. Obesity-resistant S5B rats showed great cocaine conditioned place preference than the obesity-prone OM rats

    Energy Technology Data Exchange (ETDEWEB)

    Thanos, P.K.; Wang, G.; Thanos, P.K..; Kim, R.; Cho, J.; Michaelides, M.; Anderson, B.J.; Primeaux, S.D.; Bray, G.A.; Wang, G.-J.; Robinson, J.K.; Volkow, N.D.

    2010-12-01

    Dopamine (DA) and the DA D2 receptor (D2R) are involved in the rewarding and conditioned responses to food and drug rewards. Osborne-Mendel (OM) rats are genetically prone and S5B/P rats are genetically resistant to obesity when fed a high-fat diet. We hypothesized that the differential sensitivity of these two rat strains to natural rewards may also be reflected in sensitivity to drugs of abuse. Therefore, we tested whether OM and S5B/P rats showed a differential preference to cocaine using conditioned place preference (CPP). To also evaluate whether there is specific involvement of the D2R in this differential conditioning sensitivity, we then tested whether the D2R agonist bromocriptine (BC) would differentially affect the effects of cocaine in the two strains. OM and S5B/P rats were conditioned with cocaine (5 or 10 mg/kg) in one chamber and saline in another for 8 days. Rats were then tested for cocaine preference. The effects of BC (0.5, 1, 5, 10, 20 mg/kg) on cocaine preference were then assessed in subsequent test sessions. OM rats did not show a significant preference for the cocaine-paired chamber on test day. Only the S5B/P rats showed cocaine CPP. Later treatment with only the highest dose of BC resulted in reduced cocaine CPP in S5B/P rats when treated with 5 mg/kg cocaine and in OM rats treated with 10 mg/kg cocaine. Our results indicated that obesity-resistant S5B rats showed greater cocaine CPP than the obesity-prone OM rats. These findings do not support a theory of common vulnerability for reinforcer preferences (food and cocaine). However, they show that BC reduced cocaine conditioning effects supporting at least a partial regulatory role of D2R in conditioned responses to drugs.

  6. Acoustic noise improves motor learning in spontaneously hypertensive rats, a rat model of attention deficit hyperactivity disorder.

    Science.gov (United States)

    Söderlund, Göran B W; Eckernäs, Daniel; Holmblad, Olof; Bergquist, Filip

    2015-03-01

    The spontaneously hypertensive (SH) rat model of ADHD displays impaired motor learning. We used this characteristic to study if the recently described acoustic noise benefit in learning in children with ADHD is also observed in the SH rat model. SH rats and a Wistar control strain were trained in skilled reach and rotarod running under either ambient noise or in 75 dBA white noise. In other animals the effect of methylphenidate (MPH) on motor learning was assessed with the same paradigms. To determine if acoustic noise influenced spontaneous motor activity, the effect of acoustic noise was also determined in the open field activity paradigm. We confirm impaired motor learning in the SH rat compared to Wistar SCA controls. Acoustic noise restored motor learning in SH rats learning the Montoya reach test and the rotarod test, but had no influence on learning in Wistar rats. Noise had no effect on open field activity in SH rats, but increased corner time in Wistar. MPH completely restored rotarod learning and performance but did not improve skilled reach in the SH rat. It is suggested that the acoustic noise benefit previously reported in children with ADHD is shared by the SH rat model of ADHD, and the effect is in the same range as that of stimulant treatment. Acoustic noise may be useful as a non-pharmacological alternative to stimulant medication in the treatment of ADHD. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Genetic profiling of two phenotypically distinct outbred rats derived from a colony of the Zucker fatty rats maintained at Tokyo Medical University

    Science.gov (United States)

    Nakanishi, Satoshi; Kuramoto, Takashi; Kashiwazaki, Naomi; Yokoi, Norihide

    2016-01-01

    The Zucker fatty (ZF) rat is an outbred rat and a well-known model of obesity without diabetes, harboring a missense mutation (fatty, abbreviated as fa) in the leptin receptor gene (Lepr). Slc:Zucker (Slc:ZF) outbred rats exhibit obesity while Hos:ZFDM-Leprfa (Hos:ZFDM) outbred rats exhibit obesity and type 2 diabetes. Both outbred rats have been derived from an outbred ZF rat colony maintained at Tokyo Medical University. So far, genetic profiles of these outbred rats remain unknown. Here, we applied a simple genotyping method using Ampdirect reagents and FTA cards (Amp-FTA) in combination with simple sequence length polymorphisms (SSLP) markers to determine genetic profiles of Slc:ZF and Hos:ZFDM rats. Among 27 SSLP marker loci, 24 loci (89%) were fixed for specific allele at each locus in Slc:ZF rats and 26 loci (96%) were fixed in Hos:ZFDM rats, respectively. This indicates the low genetic heterogeneity in both colonies of outbred rats. Nine loci (33%) showed different alleles between the two outbred rats, suggesting considerably different genetic profiles between the two outbred rats in spite of the same origin. Additional analysis using 72 SSLP markers further supported these results and clarified the profiles in detail. This study revealed that genetic profiles of the Slc:ZF and Hos:ZFDM outbred rats are different for about 30% of the SSLP marker loci, which is the underlying basis for the phenotypic difference between the two outbred rats. PMID:27795491

  8. SWIMMING ENHANCES BONE MASS ACQUISITION IN GROWING FEMALE RATS

    Directory of Open Access Journals (Sweden)

    Joanne McVeigh

    2010-12-01

    Full Text Available Growing bones are most responsive to mechanical loading. We investigated bone mass acquisition patterns following a swimming or running exercise intervention of equal duration, in growing rats. We compared changes in bone mineral properties in female Sprague Dawley rats that were divided into three groups: sedentary controls (n = 10, runners (n = 8 and swimmers (n = 11. Runners and swimmers underwent a six week intervention, exercising five days per week, 30min per day. Running rats ran on an inclined treadmill at 0.33 m.s-1, while swimming rats swam in 25oC water. Dual energy X-ray absorptiometry scans measuring bone mineral content (BMC, bone mineral density (BMD and bone area at the femur, lumbar spine and whole body were recorded for all rats before and after the six week intervention. Bone and serum calcium and plasma parathyroid hormone (PTH concentrations were measured at the end of the 6 weeks. Swimming rats had greater BMC and bone area changes at the femur and lumbar spine (p < 0.05 than the running rats and a greater whole body BMC and bone area to that of control rats (p < 0.05. There were no differences in bone gain between running and sedentary control rats. There was no significant difference in serum or bone calcium or PTH concentrations between the groups of rats. A swimming intervention is able to produce greater beneficial effects on the rat skeleton than no exercise at all, suggesting that the strains associated with swimming may engender a unique mechanical load on the bone

  9. Impaired NaCl taste thresholds in Zn deprived rats

    International Nuclear Information System (INIS)

    Brosvic, G.M.; Slotnick, B.M.; Nelson, N.; Henkin, R.I.

    1986-01-01

    Zn deficiency is a relatively common cause of loss of taste acuity in humans. In some patients replacement with exogenous Zn results in rapid reversal of the loss whereas in others prolonged treatment is needed to restore normal taste function. To study this 300 gm outbred Sprague Dawley rats were given Zn deficient diet (< 1 ppm Zn) supplemented with Zn in drinking water (0.1 gm Zn/100 gm body weight). Rats were trained in an automated operant conditions procedure and NaCl taste thresholds determined. During an initial training period and over two replications mean thresholds were 0.006% and mean plasma Zn was 90 +/- 2 μg/dl (M +/- SEM) determined by flame atomic absorption spectrophotometry. Rats were then divided into two groups; in one (3 rats) Zn supplement was removed, in the other (4 rats), pair-fed with the former group, Zn supplement was continued. In 10 days NaCl thresholds in Zn deprived rats increased significantly (0.07%, p < 0.01) and in 17 days increased 13 fold (0.08%) but thresholds for pair fed, supplemented rats remained constant (0.006%). There was no overlap in response between any rat in the two groups. Plasma Zn at 17 days in Zn-deprived rats was significantly below pair-fed rats (52 +/- 13 vs 89 +/- 6 μg/dl, respectively, P < 0.01). At this time Zn-deprived rats were supplemented with Zn for 27 days without any reduction in taste thresholds. These preliminary results are consistent with previous observations in Zn deficient patients

  10. Structure of the vitreoretinal border region in spontaneously diabetic BB rats

    DEFF Research Database (Denmark)

    Heegaard, S

    1993-01-01

    The morphology of the vitreoretinal border region, also termed the inner limiting membrane, was examined in spontaneously diabetic rats (BB rats), in non-diabetes-prone rats (WB rats) and in Buffalo rats (BUF rats) by scanning electron microscopy (SEM) and transmission electron microscopy (TEM......). This was performed in order to visualize a possible increase in thickness of the lamina densa or in the whole vitreoretinal border region complex with duration of diabetes. The median thickness of the lamina densa in the three groups varied between 34 and 68 nm. In BB rats the thickness decreased with age...... and duration of diabetes. In WB rats the lamina densa thickened up to the 9th month and then decreased to the level of the young rats. In BUF rats the lamina densa decreased in thickness with age. The median thickness of the whole vitreoretinal border region varied between: BB rats: 84 and 126 nm (SEM) and 68...

  11. Development of acute hydrocephalus does not change brain tissue mechanical properties in adult rats, but in juvenile rats.

    Science.gov (United States)

    Pong, Alice C; Jugé, Lauriane; Bilston, Lynne E; Cheng, Shaokoon

    2017-01-01

    Regional changes in brain stiffness were previously demonstrated in an experimental obstructive hydrocephalus juvenile rat model. The open cranial sutures in the juvenile rats have influenced brain compression and mechanical properties during hydrocephalus development and the extent by which closed cranial sutures in adult hydrocephalic rat models affect brain stiffness in-vivo remains unclear. The aims of this study were to determine changes in brain tissue mechanical properties and brain structure size during hydrocephalus development in adult rat with fixed cranial volume and how these changes were related to brain tissue deformation. Hydrocephalus was induced in 9 female ten weeks old Sprague-Dawley rats by injecting 60 μL of a kaolin suspension (25%) into the cisterna magna under anaesthesia. 6 sham-injected age-matched female SD rats were used as controls. MR imaging (9.4T, Bruker) was performed 1 day before and then at 3 days post injection. T2-weighted anatomical MR images were collected to quantify ventricle and brain tissue cross-sectional areas. MR elastography (800 Hz) was used to measure the brain stiffness (G*, shear modulus). Brain tissue in the adult hydrocephalic rats was more compressed than the juvenile hydrocephalic rats because the skulls of the adult hydrocephalic rats were unable to expand like the juvenile rats. In the adult hydrocephalic rats, the cortical gray matter thickness and the caudate-putamen cross-sectional area decreased (Spearman, P hydrocephalus is complex and is not solely dependent on brain tissue deformation. Further studies on the interactions between brain tissue stiffness, deformation, tissue oedema and neural damage are necessary before MRE can be used as a tool to track changes in brain biomechanics in hydrocephalus.

  12. Isoproterenol effects evaluated in heart slices of human and rat in comparison to rat heart in vivo

    International Nuclear Information System (INIS)

    Herrmann, Julia E.; Heale, Jason; Bieraugel, Mike; Ramos, Meg; Fisher, Robyn L.; Vickers, Alison E.M.

    2014-01-01

    Human response to isoproterenol induced cardiac injury was evaluated by gene and protein pathway changes in human heart slices, and compared to rat heart slices and rat heart in vivo. Isoproterenol (10 and 100 μM) altered human and rat heart slice markers of oxidative stress (ATP and GSH) at 24 h. In this in vivo rat study (0.5 mg/kg), serum troponin concentrations increased with lesion severity, minimal to mild necrosis at 24 and 48 h. In the rat and the human heart, isoproterenol altered pathways for apoptosis/necrosis, stress/energy, inflammation, and remodeling/fibrosis. The rat and human heart slices were in an apoptotic phase, while the in vivo rat heart exhibited necrosis histologically and further progression of tissue remodeling. In human heart slices genes for several heat shock 70 kD members were altered, indicative of stress to mitigate apoptosis. The stress response included alterations in energy utilization, fatty acid processing, and the up-regulation of inducible nitric oxide synthase, a marker of increased oxidative stress in both species. Inflammation markers linked with remodeling included IL-1α, Il-1β, IL-6 and TNFα in both species. Tissue remodeling changes in both species included increases in the TIMP proteins, inhibitors of matrix degradation, the gene/protein of IL-4 linked with cardiac fibrosis, and the gene Ccl7 a chemokine that induces collagen synthesis, and Reg3b a growth factor for cardiac repair. This study demonstrates that the initial human heart slice response to isoproterenol cardiac injury results in apoptosis, stress/energy status, inflammation and tissue remodeling at concentrations similar to that in rat heart slices. - Highlights: • Human response to isoproterenol induced cardiac injury evaluated in heart slices. • Isoproterenol altered apoptosis, energy, inflammation and remodeling pathways. • Human model verified by comparison to rat heart slices and rat heart in vivo. • Human and rat respond to isoproterenol

  13. Effect of irradiation on glycosaminoglycans connect in rat tissue

    Energy Technology Data Exchange (ETDEWEB)

    Drozdz, M; Kucharz, E; Glowacki, A; Zylka, J

    1981-01-01

    Glycosaminoglycan (GAGs) fractions were determined in tissues (skin, liver, lungs, aortic wall) and blood serum of rats irradiated with a single dose of 500 R. An increase of total GAGs as well as changes in the fractions were found in the tissues and urine of exposed rats.

  14. Gastrointestinal helminths and external parasites of domestic rats ...

    African Journals Online (AJOL)

    A survey of domestic rats was conducted to investigate the prevalence of gastrointestinal helminths and external parasites in Maiduguri municipal between February and June 2015. Rats were randomly collected from residential sites within Maiduguri metropolis by trapping using mechanical and glue board traps. Trapped ...

  15. Day-to-day reliability of gait characteristics in rats

    DEFF Research Database (Denmark)

    Raffalt, Peter Christian; Nielsen, Louise R; Madsen, Stefan

    2018-01-01

    day-to-day reliability of the gait pattern parameters observed in rats during treadmill walking. The results of the present study may serve as a reference material that can help future intervention studies on rat gait characteristics both with respect to the selection of outcome measures...

  16. Rat macrophages: membrane glycoproteins in differentiation and function

    NARCIS (Netherlands)

    van den Berg, T. K.; Döpp, E. A.; Dijkstra, C. D.

    2001-01-01

    Macrophages (mphi) play a crucial role in the immune system. The rat offers unique advantages for studying the biology of mphi. Firstly, monoclonal antibodies (mAb) against many rat mphi surface glycoproteins have become available. These have not only demonstrated a considerable heterogeneity among

  17. Pharmacokinetic Interaction between Magnolol and Piperine in Rats ...

    African Journals Online (AJOL)

    Purpose: To investigate the pharmacokinetic mechanism of interaction between magnolol and piperine when co-administered to rats. Methods: The rats were divided into five groups as follows: magnolol group (625 mg/kg); low dose of piperine group (20 mg/kg); high dose of piperine group (40 mg/kg); low dose of piperine ...

  18. Chronic Tea Consumption Lowers Blood Pressure in Rats: Some ...

    African Journals Online (AJOL)

    Chronic Tea Consumption Lowers Blood Pressure in Rats: Some Associated Mechanisms. ... Nigerian Journal of Health and Biomedical Sciences ... In experiment 5, group 9 (kept on NF and indomethacin solution) also had similar BP as group 10 (kept on ... KEY WORDS: Blood pressure (BP), heart rate (HR), rats, tea.

  19. Intelligence-Augmented Rat Cyborgs in Maze Solving.

    Directory of Open Access Journals (Sweden)

    Yipeng Yu

    Full Text Available Cyborg intelligence is an emerging kind of intelligence paradigm. It aims to deeply integrate machine intelligence with biological intelligence by connecting machines and living beings via neural interfaces, enhancing strength by combining the biological cognition capability with the machine computational capability. Cyborg intelligence is considered to be a new way to augment living beings with machine intelligence. In this paper, we build rat cyborgs to demonstrate how they can expedite the maze escape task with integration of machine intelligence. We compare the performance of maze solving by computer, by individual rats, and by computer-aided rats (i.e. rat cyborgs. They were asked to find their way from a constant entrance to a constant exit in fourteen diverse mazes. Performance of maze solving was measured by steps, coverage rates, and time spent. The experimental results with six rats and their intelligence-augmented rat cyborgs show that rat cyborgs have the best performance in escaping from mazes. These results provide a proof-of-principle demonstration for cyborg intelligence. In addition, our novel cyborg intelligent system (rat cyborg has great potential in various applications, such as search and rescue in complex terrains.

  20. Intelligence-Augmented Rat Cyborgs in Maze Solving.

    Science.gov (United States)

    Yu, Yipeng; Pan, Gang; Gong, Yongyue; Xu, Kedi; Zheng, Nenggan; Hua, Weidong; Zheng, Xiaoxiang; Wu, Zhaohui

    2016-01-01

    Cyborg intelligence is an emerging kind of intelligence paradigm. It aims to deeply integrate machine intelligence with biological intelligence by connecting machines and living beings via neural interfaces, enhancing strength by combining the biological cognition capability with the machine computational capability. Cyborg intelligence is considered to be a new way to augment living beings with machine intelligence. In this paper, we build rat cyborgs to demonstrate how they can expedite the maze escape task with integration of machine intelligence. We compare the performance of maze solving by computer, by individual rats, and by computer-aided rats (i.e. rat cyborgs). They were asked to find their way from a constant entrance to a constant exit in fourteen diverse mazes. Performance of maze solving was measured by steps, coverage rates, and time spent. The experimental results with six rats and their intelligence-augmented rat cyborgs show that rat cyborgs have the best performance in escaping from mazes. These results provide a proof-of-principle demonstration for cyborg intelligence. In addition, our novel cyborg intelligent system (rat cyborg) has great potential in various applications, such as search and rescue in complex terrains.