Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| histochemical localization of prostaglandin-synthetase in the salivary glands of praomys (mastomys) natalensis. | the cellular distribution of prostaglandin-synthetase was studied in the salivary glands of praomys (mastomys) natalensis. only the epithelial cells of the ducts showed discrete prostaglandin-synthetase activity, whereas the acini and the stroma gave completely negative results in all three salivary glands of both sexes. the presence of exogenous substrates was not required for the reaction, since identical results are observed following incubation with and without arachidonic acid. the localiza ... | 2011 | 3147652 |
| isolation of trypanosoma brucei gambiense from cured and relapsed sleeping sickness patients and adaptation to laboratory mice. | sleeping sickness due to trypanosoma brucei (t.b.) gambiense is still a major public health problem in some central african countries. historically, relapse rates around 5% have been observed for treatment with melarsoprol, widely used to treat second stage patients. later, relapse rates of up to 50% have been recorded in some isolated foci in angola, sudan, uganda and democratic republic of the congo (drc). previous investigations are not conclusive on whether decreased sensitivity to melarsopr ... | 2011 | 21526217 |
| novel arenavirus sequences in hylomyscus sp. and mus (nannomys) setulosus from c+¦te d'ivoire: implications for evolution of arenaviruses in africa. | this study aimed to identify new arenaviruses and gather insights in the evolution of arenaviruses in africa. during 2003 through 2005, 1,228 small mammals representing 14 different genera were trapped in 9 villages in south, east, and middle west of c+¦te d'ivoire. specimens were screened by pan-old world arenavirus rt-pcrs targeting s and l rna segments as well as immunofluorescence assay. sequences of two novel tentative species of the family arenaviridae, menekre and gbagroube virus, were de ... | 2011 | 21695269 |
| novel arenavirus, zambia. | to investigate arenavirus in zambia, we characterized virus from the kidneys of 5 arenavirus rna-positive rodents (mastomys natalensis) among 263 captured. full-genome sequences of the viruses suggested that they were new strains similar to lassa virus-related arenaviruses. analyzing samples from additional rodents and other species can elucidate epizootiologic aspects of arenaviruses. | 2011 | 22000372 |
| comparative population genetics of a parasitic nematode and its host community: the trichostrongylid neoheligmonella granjoni and mastomys rodents in southeastern senegal. | contrasting host and parasite population genetic structures can provide information about the population ecology of each species and the potential for local adaptation. here, we examined the population genetic structure of the nematode neoheligmonella granjoni at a regional scale in southeastern senegal, using 11 microsatellite markers. using the results previously obtained for the two main rodent species of the host community, mastomys natalensis and mastomys erythroleucus, we tested the hypoth ... | 2011 | 21924271 |
| serological markers for papillomavirus infection and skin tumour development in the rodent model mastomys coucha. | this study used the rodent mastomys coucha latently infected with mastomys natalensis papillomavirus (mnpv) and mastomys coucha pv2 (mcpv2), which induce skin papillomas and anogenital condylomas, respectively, to investigate pv antibody responses as serological markers during pathogenesis. in a case-control study (137 animals), virus and tumour prevalence correlated with the seroresponse against the early e2 and late l1 viral proteins. a prospective study (53 animals) revealed for the first tim ... | 2011 | 20965987 |
| a capture elisa for monitoring papillomavirus-induced antibodies in mastomys coucha. | the present report describes the development of an enzyme-linked immunosorbent assay (elisa), whereby the first insights have been obtained into the humoral immune response to papillomavirus (pv) infections of the rodent mastomys coucha, a natural model for papillomavirus-induced skin carcinogenesis. the established glutathione s-transferase (gst)-capture elisa is based on a one-step purification of bacterially expressed antigens and was designed to detect serum antibodies against l1 capsid prot ... | 2010 | 19800367 |
| sympatric occurrence of 3 arenaviruses, tanzania. | to determine the specificity of morogoro virus for its reservoir host, we studied its host range and genetic diversity in tanzania. we found that 2 rodent species other than mastomys natalensis mice carry arenaviruses. analysis of 340 nt of the viral rna polymerase gene showed sympatric occurrence of 3 distinct arenaviruses. | 2010 | 20350390 |
| rodent host cell/lassa virus interactions: evolution and expression of α-dystroglycan, large-1 and large-2 genes, with special emphasis on the mastomys genus. | arenaviruses are usually rodent-borne viruses that constitute a major threat for human health. among them, lassa fever virus (lfv) occurs in western africa where it infects hundreds of thousands of people annually. according to the most recent surveys, lfv is hosted by one of the multimammate rats, mastomys natalensis, but has never been detected in its sibling and sometimes sympatric species mastomys erythroleucus. this pattern suggests that intrinsic, i.e. genetic properties underlie such a dr ... | 2010 | 20674789 |
| presence of mopeia virus, an african arenavirus, related to biotope and individual rodent host characteristics: implications for virus transmission. | abstract the east african mopeia virus (mopv) is an arenavirus closely related to the highly pathogenic west african lassa virus, even sharing the same reservoir rodent host mastomys natalensis. because mopv is not known to cause human disease, it offers a unique alternative for studying lassa virus transmission. we investigated how habitat, population density, and host characteristics are related to mopv occurrence in m. natalensis populations in morogoro, tanzania. in 3 contrasting habitats, 5 ... | 2010 | 21142956 |
| seasonal abundance of plague vector xenopsylla brasiliensis from rodents captured in three habitat types of periurban suburbs of harare, zimbabwe. | abstract the study was aimed at determining the seasonal abundance of xenopsylla brasiliensis, an important vector of plague in zimbabwe, from rodent hosts captured in selected habitat types of two periurban suburbs of harare, zimbabwe. the removal-trapping method was used to capture the rodents, from which fleas were collected and identified. percentage incidence index (pii) and specific flea index (sfi) were calculated for x. brasiliensis in relation to rodent species host. mastomys natalensis ... | 2010 | 21142965 |
| polymorphism and signatures of selection in the multimammate rat dqb gene. | in order to test if dqb is a good candidate marker to investigate the relationship between major histocompatibility complex genes and pathogens in natural populations of mastomys natalensis, we assessed the polymorphism and evolutionary history of this gene. twenty-four individuals were genotyped for exon 2 of dqb using capillary electrophoresis single-strand conformation polymorphism, cloning, and sequencing. we found 21 different alleles. four individuals show three alleles implying a duplicat ... | 2010 | 19953242 |
| praomys (mastomys) natalensis: a model for gastric carcinoid formation. | the gastric carcinoid tumors of praomys (mastomys) natalensis have been reviewed with respect to histogenesis, development, biochemistry, and morphological properties. multicentric gastric carcinoids frequently develop in the oxyntic mucosa of aging mastomys. the development of these tumors can be significantly enhanced by drug-induced hypergastrinemia, e.g., histamine2-receptor blockade. spontaneous and drug-induced gastric carcinoids are endocrine in nature, as evidenced by their argyrophilic ... | 2010 | 1341076 |
| mopeia virus-related arenavirus in natal multimammate mice, morogoro, tanzania. | a serosurvey involving 2,520 small mammals from tanzania identified a hot spot of arenavirus circulation in morogoro. molecular screening detected a new arenavirus in natal multimammate mice (mastomys natalensis), morogoro virus, related to mopeia virus. only a small percentage of mice carry morogoro virus, although a large proportion shows specific antibodies. | 2009 | 19961688 |
| parasites of the nile rat in rural and urban regions of sudan. | in this investigation on endoparasites (helminths) and ectoparasites of the nile rat (arvicanthis niloticus desmarest, 1822), a total of 220 nile rats were trapped from different regions of sudan during the period january 2003-january 2006. examination of different tissues, identification of parasites, effect of these parasites on the organs, the prevalence and intensity of infestation of the parasites and their relation to the habitat of the host, and sex-related infestations were considered. r ... | 2009 | 21392288 |
| risk maps of lassa fever in west africa. | lassa fever is caused by a viral haemorrhagic arenavirus that affects two to three million people in west africa, causing a mortality of between 5,000 and 10,000 each year. the natural reservoir of lassa virus is the multi-mammate rat mastomys natalensis, which lives in houses and surrounding fields. with the aim of gaining more information to control this disease, we here carry out a spatial analysis of lassa fever data from human cases and infected rodent hosts covering the period 1965-2007. i ... | 2009 | 19255625 |
| schistosoma kisumuensis n. sp. (digenea: schistosomatidae) from murid rodents in the lake victoria basin, kenya and its phylogenetic position within the s. haematobium species group. | schistosoma kisumuensis n. sp. is described based on 6 adult males and 2 adult females collected from the circulatory system of 3 murid rodent species, pelomys isseli, mastomys natalensis, and dasymys incomtus. specimens were collected from a single location, nyabera swamp, in kisumu, kenya in the lake victoria basin. this new species is morphologically similar to members of the s. haematobium group, currently represented by 8 species parasitizing artiodactyls and primates, including humans. sch ... | 2009 | 19573258 |
| complementary dna sequences encoding the multimammate rat mhc class ii dq alpha and beta chains and cross-species sequence comparison in rodents. | sequences of the complete open reading frame (orf) for rodents major histocompatibility complex (mhc) class ii genes are rare. multimammate rat (mastomys natalensis) complementary dna (cdna) encoding the alpha and beta chains of mhc class ii dq gene was cloned from a rapid amplifications of cdna emds (race) cdna library. the orfs consist of 801 and 771 bp encoding 266 and 256 amino acid residues for dqb and dqa, respectively. the genomic structure of mana-dq genes is globally analogous to that d ... | 2009 | 19691639 |
| prevalence and risk factors of lassa seropositivity in inhabitants of the forest region of guinea: a cross-sectional study. | lassa fever is a viral hemorrhagic fever endemic in west africa. the reservoir host of the virus is a multimammate rat, mastomys natalensis. prevalence estimates of lassa virus antibodies in humans vary greatly between studies, and the main modes of transmission of the virus from rodents to humans remain unclear. we aimed to (i) estimate the prevalence of lassa virus-specific igg antibodies (lv igg) in the human population of a rural area of guinea, and (ii) identify risk factors for positive lv ... | 2009 | 19924222 |
| seasonal and habitat dependence of fleas parasitic on small mammals in tanzania. | we investigated host and flea species composition across different habitats during dry and rainy seasons in the western usambara mountains in tanzania. during both seasons, similarity in flea species composition increased with an increase in the similarity in host species composition. nevertheless, between-season within-habitat as well as within-season between-habitat similarity in host species composition was higher than similarity in flea species composition. ordination of habitats according t ... | 2009 | 21392290 |
| first detection of mycobacteria in african rodents and insectivores, using stratified pool screening. | with the rising number of patients with human immunodeficiency virus (hiv)/aids in developing countries, the control of mycobacteria is of growing importance. previous studies have shown that rodents and insectivores are carriers of mycobacteria. however, it is not clear how widespread mycobacteria are in these animals and what their role is in spreading them. therefore, the prevalence of mycobacteria in rodents and insectivores was studied in and around morogoro, tanzania. live rodents were tra ... | 2008 | 18065608 |
| cryptosporidia: epicellular parasites embraced by the host cell membrane. | the ultrastructure of two gastric cryptosporidia, cryptosporidium muris from experimentally infected rodents (mastomys natalensis) and cryptosporidium sp. 'toad' from naturally infected toads (duttaphrynus melanostictus), was studied using electron microscopy. observations presented herein allowed us to map ultrastructural aspects of the cryptosporidian invasion process and the origin of a parasitophorous sac. invading parasites attach to the host cell, followed by gradual envelopment, with the ... | 2008 | 18158154 |
| reproductive characteristics of mastomys natalensis and lassa virus prevalence in guinea, west africa. | we recently reported increased prevalence of lassa virus (lasv) infection in mastomys natalensis during the rainy season in guinea, west africa. here, the association of lasv prevalence with fecundity, fertility, and the age structure of the rodent population was analyzed using data from the previous study. the animals reproduced throughout the year, but highest fecundity was observed during the rainy season. accordingly, the rodent population was aged at the beginning and young at the end of th ... | 2008 | 18237265 |
| dispersal in mastomys natalensis mice: use of fine-scale genetic analyses for pest management. | mastomys natalensis is the major pest rodent in sub-saharan africa. in this study, population genetic techniques were used to gain new insights into its dispersal behaviour, a critical parameter in pest management. using 11 microsatellites, 272 individuals from a 300 ha area in tanzania were genotyped. genetic diversity was high, with no isolation by distance and little differentiation between field plots far apart, indicating a large effective population size and high dispersal rates in agreeme ... | 2008 | 19200138 |
| soil type limits population abundance of rodents in crop fields: case study of the multimammate rat mastomys natalensis smith, 1834 in tanzania. | studies of populations of the multimammate rat mastomys natalensis in morogoro, tanzania, show that soil texture appears to influence the population abundance and distribution of these rats in agricultural fields. the lowest rodent population abundance was found on sandy clay soils (f((2, 5)) = 8.42; p= 0.025). the population abundances of m. natalensis on sandy clay loam and sandy loam soils did not differ significantly (p≤ 0.05), possibly because these soils have a very similar texture. the re ... | 2008 | 21396048 |
| understanding and managing sanitary risks due to rodent zoonoses in an african city: beyond the boston model. | the boston model describes a successful rodent management plan that succeeded in a first-world city in the usa. in third-world cities, which often contain informal shack settlements, it is debatable whether the boston model would apply. in durban, a major harbor city of three million people on the east coast of south africa, we investigated the sanitary risks due to rodents in both formal (residential and commercial) and informal (shacks) sectors, and we evaluated the relative merits of differen ... | 2008 | 21396050 |
| reproduction and population dynamics of mastomys natalensis smith, 1834 in an agricultural landscape in the western usambara mountains, tanzania. | the multimammate rat, mastomys natalensis smith 1834, is a dominant species in agro-ecosystems in sub-saharan africa, but adapts quickly to changes in non-agricultural landscape, particularly woodlands and forests. in this study we report on reproduction and population dynamics of m. natalensis in deforested high elevation localities in the usambara mountains, north-east tanzania. we conducted capture-mark-recapture studies in 2002-2004, and established that reproduction of m. natalensis takes p ... | 2007 | 21396040 |
| multimammate rat (mastomys natalensis), tristram's jird (meriones tristrami) and wagner's gerbil (gerbillus dasyurus) as laboratory models of acute neosporosis. | to test the different sensitivity of rodents of the subfamily murinae and gerbillinae, wagner's gerbils (gerbillus dasyurus), tristram's jirds (meriones tristrami) and multimammate rats (mastomys natalensis) were inoculated with neospora caninum tachyzoites. clinical signs of neosporosis appeared in all inoculated animals. histopathological examination confirmed the presence of tachyzoites in brains, lungs, skeletal muscle, myocardium, liver, in serosa of stomach and intestines, and in vesicular ... | 2007 | 17134728 |
| isolation and propagation of trypanosoma brucei gambiense from sleeping sickness patients in south sudan. | this study aimed at isolating trypanosoma brucei gambiense from human african trypanosomiasis (hat) patients from south sudan. fifty hat patients identified during active screening surveys were recruited, most of whom (49/50) were in second-stage disease. blood and cerebrospinal fluid samples collected from the patients were cryopreserved using triladyl as the cryomedium. the samples were stored at -150 degrees c in liquid nitrogen vapour in a dry shipper. eighteen patient stabilates could be pr ... | 2007 | 17275053 |
| host habitat patchiness and the distance decay of similarity among gastro-intestinal nematode communities in two species of mastomys (southeastern senegal). | beta-diversity, or how species composition changes with geographical distance, has seldom been studied for different habitats. we present here quantitative estimates of the relationship between geographic distance and similarity of parasitic nematode communities in two closely related rodent host species that live in habitats with very different spatial configurations. in southeastern senegal mastomys natalensis lives exclusively inside human villages whereas m. erythroleucus is continuously dis ... | 2007 | 17351796 |
| lassa fever in west african sub-region: an overview. | lassa fever is an acute viral zoonotic illness caused by lassa virus, an arenavirus known to be responsible for a severe haemorrhagic fever characterised by fever, muscle aches, sore throat, nausea, vomiting and, chest and abdominal pain. the virus exhibits persistent, asymptomatic infection with profuse urinary virus excretion in the ubiquitous rodent vector, mastomys natalensis. lassa fever is endemic in west africa and has been reported from sierra leone, guinea, liberia, and nigeria. some st ... | 2007 | 17378212 |
| population genetic structure of two ecologically distinct multimammate rats: the commensal mastomys natalensis and the wild mastomys erythroleucus in southeastern senegal. | using the same set of microsatellite markers, we compared the population genetic structure of two mastomys species, one being exclusively commensal in southeastern senegal, and the other being continuously distributed outside villages in this region. both species were sampled in the same landscape context and at the same spatial scale. according to the expectations based on the degree of habitat patchiness (which is higher for commensal populations in this rural area), genetic diversity was lowe ... | 2007 | 17614912 |
| poor housing quality increases risk of rodent infestation and lassa fever in refugee camps of sierra leone. | lassa fever, a viral hemorrhagic fever endemic in parts of west africa, is a severe febrile illness transmitted to humans by the rodent mastomys natalensis. to determine risk of lassa fever in households in sierra leonean refugee camps, we analyzed the spatial relationships between households with a lassa case and focal locations of potential rodent habitats. quality and hygiene factors of households were assessed to determine possible risk factors for household rodent infestation and occurrence ... | 2007 | 17620650 |
| fluctuation of abundance and lassa virus prevalence in mastomys natalensis in guinea, west africa. | based on empiric surveillance data, the incidence of human lassa fever (lf) cases in guinea and other west african countries has been reported to increase during the dry season compared to the rainy season. to investigate possible links with the ecology of the rodent reservoir of the virus, we conducted a 2-year longitudinal survey of mastomys natalensis in a region of high human lassa virus (lasv) seropositivity in guinea. standardized rodent trapping with similar trapping efforts between seaso ... | 2007 | 17627428 |
| persistence of mastomys natalensis papillomavirus in multiple organs identifies novel targets for infection. | the high incidence of multiple wart formation and skin cancer in organ-transplant recipients, as well as the question of an involvement of papillomaviruses in a variety of human cancers, require a model system for papillomavirus infections in immunocompetent animals. such an in vivo model is represented by the multimammate rat mastomys coucha, which is infected with mastomys natalensis papillomavirus (mnpv). mnpv primarily induces benign skin tumours, such as papillomas and keratoacanthomas. her ... | 2007 | 17872518 |
| description of a new species of heligmonina baylis, 1928 (nematoda: heligmonellidae) a parasite of mastomys natalensis (rodentia: muridae) from swaziland and new data on the synlophe of heligmonina chabaudi (desset, 1966). | a new species of heligmosomoid nematode belonging to the subfamily nippostrongylinae durette-desset, 1970 is described: heligmonina wakelini n. sp., a parasite from the small intestine of the commensal rodent mastomys natalensis (smith, 1834) from swaziland. it differs from the most closely related species h. boomkeri durette-desset & digiani, 2005 by the number of the cuticular ridges in the female synlophe (10 vs 12), the width of the left ala, larger than the body diameter in the male, and th ... | 2007 | 18225415 |
| survival and maturation rates of the african rodent, mastomys natalensis: density-dependence and rainfall. | survival and maturation rates of female mastomys natalensis were analysed based on a ten-year monthly capture-recapture data set. we investigated whether direct and delayed density dependent and independent (rainfall) variables accounted for the considerable variation in demographic traits. it was estimated that seasonal and annual covariates accounted for respectively 29 and 26% of the total variation in maturation rates and respectively 17 and 11% of the variation in survival rates. explaining ... | 2007 | 21396039 |
| mastomys natalensis and lassa fever, west africa. | pcr screening of 1,482 murid rodents from 13 genera caught in 18 different localities of guinea, west africa, showed lassa virus infection only in molecularly typed mastomys natalensis. distribution of this rodent and relative abundance compared with m. erythroleucus correlates geographically with lassa virus seroprevalence in humans. | 2006 | 17326956 |
| [the mammals of guinea as reservoirs and carriers of arboviruses]. | a great body of data on the fauna and ecology of wild mammals and their participation in the circulation of arboviruses were collected when the ecology of the latter of the republic of guinea was studied in 1978 to 1989. a hundred and eighteen species belonging to 10 orders were identified. over 2,000 biological specimens were virologically and serologically examined. six arboviruses were isolated. these included dugbe virus (from the hussar monkey cercopithecus (erythrocebus patas) and 5 viruse ... | 2006 | 16562748 |
| cryopreservation of trypanosoma brucei gambiense in a commercial cryomedium developed for bull semen. | there have been major advances in the formulation of cryomedia for spermatozoa owing to their economic importance. in this study, the suitability of the commercial cryomedium triladyl developed for bull semen was evaluated for the cryopreservation of trypanosoma brucei gambiense. cryopreservation efficacy was determined by direct counting of motile trypanosomes and by viability assessment using in vitro and in vivo methods. culture medium containing 10% glycerol was used as the control. trypanos ... | 2006 | 16806029 |
| effects of predation and dispersal on mastomys natalensis population dynamics in tanzanian maize fields. | 1. we investigate the effects of different levels of predation pressure and rodent dispersal on the population dynamics of the african pest rodent mastomys natalensis in maize fields in tanzania. 2. three levels of predation risk were used in an experimental set-up: natural level (control), excluding predators by nets and attracting avian predators by nest boxes and perch poles. because dispersal of the rodents could mask the predation pressure treatment effects, control and predator exclusion t ... | 2006 | 16903058 |
| a model of leptospirosis infection in an african rodent to determine risk to humans: seasonal fluctuations and the impact of rodent control. | human leptospirosis (leptospira spp. infection) is a worldwide public health problem that is of greatest concern for humid tropical and subtropical regions. the magnitude of the problem in these areas is larger because of the climatic and environmental conditions the bacterium face outside their hosts but also because of the frequency of contacts between people and sources of infection. rodents are thought to play the most important role in the transmission of human leptospirosis. we here model ... | 2006 | 16996018 |
| lassa virus: seroepidemiological survey of rodents caught in ekpoma and environs. | of the 876 rodents caught in different parts of ekpoma, nigeria, and environs, 218 were mastomys natalensis, while 658 were other rodents. of the 218 m. natalensis caught, 102 (46.79%) were positive for complement fixing antibody to lassa virus. | 2005 | 15712534 |
| susceptibility of grammomys surdaster thicket rats to trypanosoma brucei gambiense infection. | human african trypanosomiasis is caused by trypanosoma brucei gambiense and t. b. rhodesiense. historically, a treatment relapse rate of about 5% is observed in patients treated with melarsoprol, an arsenical derivative used for treatment of both gambiense and rhodesiense second stage sleeping sickness. more recently, relapse rates up to 30% are noted in gambiense sleeping sickness foci in angola, sudan and uganda. therefore, who established a network on treatment failure and drug resistance in ... | 2005 | 16135191 |
| small mammals as hosts of immature ixodid ticks. | two hundred and twenty-five small mammals belonging to 16 species were examined for ticks in free state, mpumalanga and limpopo provinces, south africa, and 18 ixodid tick species, of which two could only be identified to genus level, were recovered. scrub hares, lepus saxatilis, and cape hares, lepus capensis, harboured the largest number of tick species. in free state province namaqua rock mice, aethomys namaquensis, and four-striped grass mice, rhabdomys pumilio, were good hosts of the immatu ... | 2005 | 16300195 |
| renal physiology of two southern african mastomys species (rodentia: muridae): a salt-loading experiment to assess concentrating ability. | aspects of renal physiology were examined to test the hypothesis that two cryptic species of the genus mastomys (mastomys natalensis and mastomys coucha) are geographically separated by differences in aridity tolerance. laboratory-bred females of each species were subjected to different levels of salinity in their water source (distilled water, 0.9% nacl, and 1.5% nacl; 10 conspecifics in each group) from weaning until sexual maturity. individuals of the two species exhibited similar rates of wa ... | 2004 | 15596389 |
| diet quality differentially affects breeding effort of mastomys coucha and m. natalensis: implications for rodent pests. | in this study we compare the reproductive ability of mastomys natalensis, an agricultural rodent pest and that of the closely related species m. coucha, which has not been ascribed as a pest. we suggest that the ability of m. natalensis to plague, as well as dominate, resource-limited habitats, may in part be related to its differential breeding response to variation in diet quality. thus, we examined the reproductive response of m. coucha and m. natalensis mothers to variation in dietary protei ... | 2004 | 14695692 |
| prenatal development of the prostate in male praomys (mastomys) natalensis. | 2004 | 3778083 | |
| increased incidence of squamous cell carcinomas in mastomys natalensis papillomavirus e6 transgenic mice during two-stage skin carcinogenesis. | papillomaviruses cause certain forms of human cancers, most notably carcinomas of the uterine cervix. in contrast to the well-established involvement of papillomavirus infection in the etiology of cervical carcinomas and in carcinomas of a rare hereditary condition, epidermodysplasia verruciformis, a causative role for cutaneous human papillomavirus types in the development of nonmelanoma skin cancer has not been proven. in order to better understand the functions of individual genes of cutaneou ... | 2004 | 15078961 |
| imported lassa fever--new jersey, 2004. | lassa fever is an acute viral illness caused by lassa virus, which is hosted by rodents in the mastomys natalensis species complex and rarely imported to countries outside of those areas in africa where the disease is endemic. lassa fever is characterized by fever, muscle aches, sore throat, nausea, vomiting, and chest and abdominal pain. approximately 15%-20% of patients hospitalized for lassa fever die from the illness; however, approximately 80% of human infections with lassa virus are mild o ... | 2004 | 15457145 |
| global expression analysis of ecl cells in mastomys natalensis gastric mucosa identifies alterations in the ap-1 pathway induced by gastrin-mediated transformation. | enterochromaffin-like (ecl) cell hyperplasia and then irreversible neoplasia can be generated in the african rodent mastomys natalensis using the h2 receptor blocker, loxtidine, for 8-16 wk. we used a genechip approach complemented by standard technologies to identify gene expression alterations in the gastric mucosa during gastrin-mediated ecl cell transformation. gastric mucosa (mucosal scrapping) and ecl cell-enriched fractions were obtained from untreated mastomys (controls) and from animals ... | 2004 | 15602048 |
| effects of gastrin on the histamine-secretory and proliferative activity of cultured carcinoid cells derived from the stomach of the rodent mastomys natalensis. | the effects of gastrin on the synthesis and release of histamine and on cellular proliferation were investigated in a homotransplantable carcinoid tumor implanted in the rodent mastomys natalensis and in cultured cells derived from the tumor. the homotransplanted tumor was immunopositive for histamine, synaptophysin and protein gene product 9.5, and its cells contained numerous secretory granules that were visualized by electron microscopy. when carcinoid cells were cultured in a medium with a h ... | 2003 | 9088027 |
| population dynamics of small mammals in semi-arid regions: a comparative study of demographic variability in two rodent species. | the seasonally determined demographic structure of two semi-arid rodents, both agricultural pest species (the leaf-eared mouse (phyllotis darwini) in chile and the multimammate mouse (mastomys natalensis) in tanzania), is analysed using capture-mark-recapture (cmr) statistical models and measures for elasticity (the relative change in the growth rate due to a relative unit change in the parameter of concern) derived from projection linear matrix models. we demonstrate that reproduction and survi ... | 2003 | 14561287 |
| preferential transcription of a gene for alpha amylase in the carcinoid tumor of african rodent mastomys natalensis. | the carcinoid tumor in mastomys natalensis provides a useful animal model of tumorigenesis. we investigated preferentially transcribed genes in this carcinoid tumor by differential hybridization. fourteen clones corresponding to high levels of transcription were isolated from a cdna library. sequencing analysis and a homology search revealed that the clones corresponded to genes for chromogranin and alpha-amylase. high-level transcription of a gene for alpha-amylase gene in mastomys carcinoid tu ... | 2002 | 12071519 |
| the effect of colonisation by helicobacter pylori in praomys (mastomys) natalensis on the incidence of carcinoids. | an animal model of experimental gastric helicobacter pylori infection has been developed in the z strain of praomys (mastomys) natalensis; this animal has been reported to develop gastric carcinoids and adenocarcinoma spontaneously. in the present study, male and female mastomys were killed at 1, 2, 4, 8 and 16 weeks after h. pylori inoculation. colonisation of h. pylori was maintained in the stomachs of all animals for up to 16 weeks. h. pylori were mainly found in the antrum. lymphoid infiltra ... | 2002 | 12358069 |
| the egyptian mongoose, herpestes ichneumon, is a possible reservoir host of visceral leishmaniasis in eastern sudan. | investigations were made on possible reservoir hosts of leishmania donovani in 2 zoonotic foci of visceral leishmaniasis (vl) in dinder national park (dnp) and the peri-domestic habitats of adjacent villages of eastern sudan. animals were captured, in november 1997-1998 and april-may 1999 and examined for l. donovani infection using light microscopy and 2 sensitive polymerase chain reaction (pcr) systems. microscopy and pcr investigations were also used to determine the infection rates of l. don ... | 2001 | 11393826 |
| hosts of the immature stages of the rhinoceros tick, dermacentor rhinocerinus (acari, ixodidae). | the collection of the immature stages of dermacentor rhinocerinus from host animals is described for the first time. these are the bushveld gerbil (tatera leucogaster, from which larvae and nymphs were collected, the red veld rat (aethomys crysophilus), from which a larva was collected, and the natal multimammate rat (mastomys natalensis), from which a nymph was collected. the rodents were examined in a nature reserve in which there are white rhinoceroses (ceratotherium simum). | 2001 | 11403434 |
| transplantable argyrophilic gastric carcinoid of mastomys natalensis secreting both histamine and serotonin. | a transplantable strain of gastric carcinoids of mastomys (praomys) natalensis secreted not only histamine but also serotonin [5-hydroxytryptamine (5-ht)]. mastomys bearing growing transplants excreted 11.3 times more histamine and 4.4 times more 5-hydroxyindole-3-acetic acid (5-hiaa) in the urine than did mastomys in which transplanted tumors did not grow. mastomys that developed primary gastric carcinoids also excreted 3.9 times more histamine than did those free from primary tumors, but the d ... | 2001 | 92588 |
| molecular phylogeny of myomys/stenocephalemys complex and its relationships with related african genera. | partial 16s rrna mitochondrial gene sequences were used to infer the phylogenetic relationships among stenocephalemys albocaudata, s. griseicauda and myomys albipes, three closely related ethiopian endemic murines and a selection of related species (myomys daltoni, praomys delectorum, mastomys natalensis, hylomyscus kaimosae, and colomys goslingi) from other african regions. the obtained phylogeny confirms the close relationship between m. albipes and the two stenocephalemys species, but it also ... | 2001 | 11336808 |
| pdz-dependent activation of nitric-oxide synthases by the serotonin 2b receptor. | taking advantage of three cellular systems, we established that 5-ht(2b) receptors are coupled with no signaling pathways. in the 1c11 serotonergic cell line and mastomys natalensis carcinoid cells, which naturally express the 5-ht(2b) receptor, as well as in transfected lmtk(-) fibroblasts, stimulation of the 5-ht(2b) receptor triggers intracellular cgmp production through dual activation of constitutive nitric-oxide synthase (cnos) and inducible nos (inos). the group i pdz motif at the c termi ... | 2000 | 10734074 |
| altered influence of cck-b/gastrin receptors on hdc expression in ecl cells after neoplastic transformation. | gastrin is one of the main factors controlling enterochromaffin-like (ecl) cell endocrine function and growth. long-standing hypergastrinemia may give rise to ecl cell carcinoids in the gastric corpus in man and in experimental models. we have analysed the expression and function of cck-b/gastrin receptors in normal ecl cells and in ecl cell tumours (gastric carcinoids) of the african rodent mastomys natalensis. hypergastrinemia induced by short-term (5 days) histamine2-receptor blockade (loxtid ... | 1999 | 10651065 |
| interspecies polymorphisms confer constitutive activity to the mastomys cholecystokinin-b/gastrin receptor. | the enteroendocrine hormone, gastrin, exerts trophic effects on the gastric mucosa through the cck-b/gastrin receptor (cck-br). to varying degrees in different species, excess circulating gastrin leads to proliferation of enterochromaffin-like cells and to the development of gastric carcinoid tumors. the african rodent, mastomys natalensis, is distinguished from other mammals by its propensity toward cck-br-mediated growth even in the absence of hypergastrinemia. here, we report that the mastomy ... | 1998 | 9786876 |
| comparison of the signal transduction pathways activated by gastrin in enterochromaffin-like and parietal cells. | gastrin stimulates acid secretion from parietal cells and histamine release from enterochromaffin-like (ecl) cells through identical gastrin receptors. however, gastrin has been shown to have a trophic effect only on ecl cells. the aim of this study was to compare gastrin-induced signal transduction pathways in the ecl and parietal cells of mastomys natalensis, an african rodent. | 1998 | 9649463 |
| the sheaths of brugia microfilariae: isolation and composition. | burgia malayi and b. pahangi microfilariae were isolated from the blood of infected mastomys natalensis, and were exsheathed by freezing, thawing and agitation. pure sheaths were obtained by a filtration procedure. the sheaths were found to contain about 95 mol% of amino acids, with proline, glutamic acid/glutamine, alanine, cysteine/cystine and glycine being the major components, and 5 mol% of carbohydrates, notably (n-acetyl)galactosamine, but no (n-acetyl)glucosamine. | 1997 | 1891453 |
| 1h nmr spectroscopic and histopathological studies on propyleneimine-induced renal papillary necrosis in the rat and the multimammate desert mouse (mastomys natalensis). | the renal papillary toxin, propyleneimine (pi), was administered at 20 or 30 microliters/kg i.p. to male sprague dawley (sd) rats (n = 5), fischer 344 (f344) rats (n = 4), and to multimammate desert mice (mastomys natalensis, n = 4). urine was collected at time points up to 4 days p.d. and the toxicological response of the different animal models to pi compared using 1h nmr spectroscopy of urine, renal histopathology, and urinary assays for alkaline phosphatase (alp), lactate dehydrogenase (ldh) ... | 1997 | 9134698 |
| cyclo (his-pro) modulation of body temperature at hot ambient temperature in the desert rat (mastomys natalensis). | cyclo(his-pro) (chp) has been shown to facilitate cold-induced hypothermia in the desert rat mastomys natalensis. in the present study, we examined the role of endogenous chp in hyperthermia induced by hot ambient temperature (40 degrees c) in the above rodent species. the results of these studies show that housing rodents at 40 degrees c resulted in a altered distribution of chp in the brain, with a rise in hypothalamic content accompanied by an increase in rectal temperature. while administrat ... | 1997 | 9213362 |
| innocuity studies of sag-2 oral rabies vaccine in various zimbabwean wild non-target species. | the sag-2 modified live rabies vaccine was tested for innocuity when administered by the oral route in several potential wild non-target bait-consuming species, as follows: ten chacma baboons (papio ursinus), six african civets (civettictis civetta), six slender mongooses (galerella sanguinea), six honey badgers (mellivora capensis), six large-spotted genets (genetta tigrina), 39 multi-mammate mice (mastomys natalensis), 26 bushveld gerbils (tatera leucogaster) and six pied crows (corvus albus). ... | 1997 | 9261938 |
| stochastic seasonality and nonlinear density-dependent factors regulate population size in an african rodent. | ecology has long been troubled by the controversy over how populations are regulated. some ecologists focus on the role of environmental effects, whereas others argue that density-dependent feedback mechanisms are central. the relative importance of both processes is still hotly debated, but clear examples of both processes acting in the same population are rare. key-factor analysis (regression of population changes on possible causal factors) and time-series analysis are often used to investiga ... | 1997 | 9296494 |
| polyamine metabolism in various tissues during pathogenesis of chloroquine-susceptible and resistant malaria. | the pathophysiological impact of infections with chloroquine-susceptible (cqs) and chloroquine-resistant (cqr) strains of plasmodium berghei in mastomys natalensis was studied with respect to changes in polyamine profiles in various tissues. both cqs and cqr infections produced similar changes in polyamine profiles of various tissues. maximum increase was recorded in spleen followed by liver and lungs. renal, cardiac and cerebral tissues did not register significant changes. an increase in sperm ... | 1997 | 9415968 |
| fate of infective larvae of brugia malayi in the peritoneal cavity of mastomys natalensis and meriones unguiculatus. | the fate of intraperitoneally inoculated infective third-stage larvae (l3) of the nematode brugia malayi lichtenstein and the status of the peritoneal macrophage function were investigated in the susceptible rodent hosts mastomys natalensis roberts and meriones unguiculatus milne-edwards (jird). jirds and m. natalensis were inoculated intraperitoneally with 125 and 250 l3 and the worm burden and peritoneal macrophage function in the two species were compared at different days post-inoculation (d ... | 1997 | 9437845 |
| susceptibility of laboratory-bred rodents to the experimental infection with dengue virus type 2. | various strains of laboratory-bred rodents viz. mice [swiss, c57bl/6, c3h/hej, dba/2, balb/c, nmri (nu/nu) and bl6 (nu/nu) and their heterozygous siblings (nu/+)], mastomys natalensis, wistar rat, golden hamster and indian desert gerbil were inoculated intracerebrally (ic) with mouse-adapted dengue virus type 2 (dv-2). the inoculated animals were observed daily for dullness, anorexia, occult blood in faeces, patechial haemorrhages, lacrymation, paralysis, cachexia, death. necropsied animals were ... | 1996 | 8891094 |
| role of calcium influx & energy metabolism in histamine release by filarial antigen in mastomys natalensis experimentally infected with brugia malayi. | the present work was undertaken to study the biochemical pathways involved in terms of role of calcium influx and status of energy metabolism in the activation of mast cells obtained from mastomys natalensis infected with brugia malayi when challenged in vitro with a potentially allergenic antigen (60 kda) of brugia malayi. it was observed that histamine release from sensitized lung and peritoneal mast cells was associated with intracellular influx of radioactive ca2+, thus establishing the role ... | 1996 | 8935742 |
| ras involvement in signal transduction by the serotonin 5-ht2b receptor. | the family of serotonin 5-ht2 receptors stimulates the phospholipase c second messenger pathway via the alpha subunit of the gq gtp-binding protein. here, we show that agonist stimulation of the 5-ht2b receptor subtype stably expressed in the mouse fibroblast lmtk- cell line causes a rapid and transient activation of the proto-oncogene product p21ras as measured by an increase in gtp-bound ras in response to serotonin. furthermore, 5-ht2b receptor stimulation activates p42mapk/p44mapk (erk2/erk1 ... | 1996 | 8621713 |
| animal reservoirs of leishmaniasis in marigat, baringo district, kenya. | a total of 1128 rodents belonging to seven genera were examined for leishmanial parasites over a period of sixteen months. parasites were isolated from 36 (12.5%) tatera robusta, 3 (0.5%) arvicanthis niloticus, and 2 (0.8%) mastomys natalensis. all isolates were characterised by isoenzyme analysis using nine enzymes. the enzymes examined were: malate dehydrogenase (mdh), phosphoglucomutase (pgm), glucose phosphate isomerase (gpi), isocitrate dehydrogenase (icd), nucleoside hydrolase (nh), glucos ... | 1996 | 8625862 |
| comparative biochemical effects of low doses of mercury ii chloride in the f344 rat and the multimammate mouse (mastomys natalensis). | the biochemical effects and comparative nephroxicity of mercury ii chloride (hgcl2) dosed at 0.75 mg/kg i.p. was investigated in the fisher 344 rat (f344) and mastomys natalensis using high resolution 1h nuclear magnetic resonance (nmr) spectroscopy of urine, histopathology and clinical chemical techniques. the effects of hgcl2 treatment were followed for up to 4 days post-dosing (p.d.). in f344 rats there was extensive proximal tubular damage and renal cortical necrosis together with elevated l ... | 1996 | 8689530 |
| the effect of vagotomy on enterochromaffin-like cells in mastomys natalensis. | the effect of vagotomy on the development of ecl cell tumours was analyzed during drug-induced hypergastrinemia in mastomys natalensis, a rodent prone to develop ecl cell tumours. untreated animals were compared with animals receiving the histamine2-receptor blocker loxtidine (lox) and with animals subjected to unilateral subdiaphragmatic vagotomy prior to loxtidine treatment (vag+lox). loxtidine (2g/l) was administered in drinking water for 48 weeks to allow multiple ecl cell carcinoids to deve ... | 1996 | 8832519 |
| histidine decarboxylase expression and histamine metabolism in gastric oxyntic mucosa during hypergastrinemia and carcinoid tumor formation. | histamine is an important stimulator of gastric acid secretion. in experimental animals, inhibition of acid secretion by long term histamine2 receptor blockade causes hypergastrinemia, proliferation of enterochromaffin-like (ecl) cells, and formation of histamine-producing gastric carcinoids. the aim of this study was to examine the role of gastrin in histamine synthesis and metabolism of the oxyntic mucosa of normal, hyperplastic, and carcinoid-bearing mastomys natalensis. administration of exo ... | 1996 | 8828505 |
| copresence of prostaglandin ep2 and ep3 receptors on gastric enterochromaffin-like cell carcinoid in african rodents. | prostaglandins (pgs) have important roles in the regulation of gastric acid secretion. the aim of this study was to examine the possible presence of pg receptors on the gastric enterochromaffin-like (ecl) carcinoid of mastomys natalensis, which might be a useful model of normal ecl cells. | 1995 | 7542217 |
| are enterochromaffinlike cell tumours reversible? an experimental study on gastric carcinoids induced in mastomys by histamine2-receptor blockade. | a rapid induction of enterochromaffinlike (ecl) cell tumours has been shown in praomys (mastomys) natalensis subjected to histamine2-receptor blockade. in the present study the reversibility of ecl cell proliferation induced by acid inhibition was investigated. short-term treatment (8 weeks) with the histamine2-receptor antagonist loxtidine caused a moderate hypergastrinemia, accompanied by a minor increase in histamine contents and a 2-fold increased volume density of the endocrine cells in gas ... | 1995 | 7770630 |
| immunofluorescence studies on the association between a c-type oncornavirus and renal glomerulopathy in praomys (mastomys) natalensis. | 1995 | 177237 | |
| a report on the demonstration of microfilariae of brugia malayi in the brain of an experimental animal host, mastomys natalensis. | the brain tissues of microfilaraemic animals, mastomys natalensis, which were earlier inoculated (s.c.) with brugia malayi infective larvae (100 each) were examined for the occurrence of mf. this was done by staining squash preparations of the brain tissues which were cleared off from the vascular piamater. animals with blood mf count of 50 >/per 20 cu. mm were found to harbour mf in the brain tissues. the mf count in the brain varied from 5-86/81 cu. mm (sum of mf detected in 3 tissue pieces, e ... | 1995 | 8847173 |
| comparative studies on the nephrotoxicity of 2-bromoethanamine hydrobromide in the fischer 344 rat and the multimammate desert mouse (mastomys natalensis). | renal papillary necrosis (rpn) was induced in fischer 344 (f344) rats (n = 4) using 2-bromoethanamine hydrobromide (bea) dosed at 150 mg/kg, and in multimammate desert mice (mastomys natalensis) at 150 and 250 mg/kg (n = 4 per group). control rats and mastomys were dosed with 0.9% saline (n = 4 per group). urine was collected at regular intervals for up to 4 days post-dosing and analysed for low mw metabolites using high resolution 1h nmr spectroscopy. the urinary activity of lactate dehydrogena ... | 1995 | 8773180 |
| the effect(s) of carbaryl-treated seed on body maintenance and survival of the multi-mammate mouse, mastomys natalensis (sensu lato). | maintenance, expressed as change in daily body mass, and survival rates of mastomys natalensis (sensu lato) were recorded from may to september 1994 in laboratory feeding trials, to investigate the short-term effects of a carbaryl insecticide on these variables. individuals were subjected to seeds treated with carbaryl insecticide in three different treatments (5, 10, and 20 g of carbaryl/kg of seeds). carbaryl did not have short-term adverse effects on growth and survival of this species when t ... | 1995 | 8668321 |
| analysis of genomic sequences of 95 papillomavirus types: uniting typing, phylogeny, and taxonomy. | our aim was to study the phylogenetic relationships of all known papillomaviruses (pvs) and the possibility of establishing a supratype taxonomic classification based on this information. of the many detectably homologous segments present in pv genomes, a 291-bp segment of the l1 gene is notable because it is flanked by the my09 and my11 consensus primers and contains highly conserved amino acid residues which simplify sequence alignment. we determined the my09-my11 sequences of human pv type 20 ... | 1995 | 7707535 |
| mastomys natalensis and tatera gambiana as probable reservoirs of human cutaneous leishmaniasis in nigeria. | leishmania sp. was isolated from the livers and spleens of 4 of 56 mastomys natalensis and one of 21 tatera gambiana in keana district, nigeria; none of the rodents had cutaneous lesions. parasites were not found in 42 rattus rattus. experimentally infected mice developed cutaneous lesions characteristic of l. major infection. the organisms could not be cultivated in vitro. | 1995 | 7747299 |
| isolation and characterization of flagellates from rodents and canids in masinga, machakos district, kenya. | a total of 728 animals comprising of 633 rodents and 95 canids were examined for leishmanial parasites. flagellates were isolated from 67 out of 111 (60.4%) acomys subspinosus (spiny mouse), 12 out of 143 (8.4% ) mastomys natalensis (multimammate rat), 2 out of 50 (4.0%) lemniscomys striatus (striped mouse), 2 out of 6 (33.3%) herpestes sanguineus (slender mongoose), 1 of 1 helogale parvula (dwarf mongoose) and 1 out of 84 canis familiaris (domestic dog). all isolates were characterized by isoen ... | 1995 | 12160424 |
| immunoprophylactic potential of a 120 kda brugia malayi adult antigen fraction, bma-2, in lymphatic filariasis. | a 120 kda antigen containing sds-page fraction bma-2 isolated from brugia malayi adult parasite was highly reactive with normal sera from filarial endemic area. bma-2 was analysed for its prophylactic potential in in vitro and in vivo. sera collected from bma-2 immunized jirds induced a significant level (80 to 90%) of protection against infective larvae and microfilariae in in vitro adcc assay as well as in in situ micropore chamber implantation studies. mastomys natalensis immunized with bma-2 ... | 1995 | 7494640 |
| polyamine uptake by a rodent filariid, acanthocheilonema viteae (nematoda: filarioidea). | helminth parasites lack the capacity to synthesize polyamines de novo. with the view to characterise alternative pools for the replenishment of polyamines, uptake of spermidine and spermine, were studied in acanthocheilonema viteae, a parasite known to infect rodents. motile worms recovered from the subcutaneous tissues of experimentally infected mastomys natalensis were incubated in vitro with radiolabelled polyamines for the uptake assays. a time-dependent, temperature-sensitive, energy-requir ... | 1995 | 7584620 |
| status of hepatic glutathione-s-transferase(s) during plasmodium berghei infection and chloroquine treatment in mastomys natalensis. | plasmodium berghei infection in mastomys natalensis impaired the hepatic mitochondrial, microsomal and cytosolic glutathione-s-transferase(s) activity with 1-chloro-2,4-dinitrobenzene as substrate. the enzyme activity was concomitantly decreased with rise in parasitaemia. the decreased enzyme activity due to infection was almost normalized with oral treatment of 16 mg (kg body wt)-1 of chloroquine for 4 days. | 1995 | 7622326 |
| gastric carcinoid tumors: the biology and therapy of an enigmatic and controversial lesion. | gastric carcinoid tumors were previously believed to be rare lesions, representing less than 2% of all carcinoid tumors and less than 1% of all stomach neoplasms. more recent studies have demonstrated that they may constitute as much as 10-30% of carcinoid tumors. patients with conditions associated with hypergastrinemia, such as chronic atrophic gastritis, zollinger-ellison syndrome with multiple endocrine neoplasia type 1 (zes-men-1), and pernicious anemia, display a markedly elevated incidenc ... | 1995 | 7872269 |
| picroliv affects gamma-glutamyl cycle in liver and brain of mastomys natalensis infected with plasmodium berghei. | picroliv, the standardized preparation of iridoid glycosides from picrorhiza kurrooa, at the dose of 6 mg/kg, po for two weeks provided significant protection against depletion of reduced glutathione levels in liver and brain of plasmodium berghei infected mastomys natalensis. the activation of gamma-glutamyl transpeptidase enzyme and decreased levels of cysteine, sulphydryl groups as well as glutathione synthesis in both tissues due to p. berghei infection were reversed by picroliv. enzymatic a ... | 1994 | 7927525 |
| antiparasitic activity of diallyl trisulfide (dasuansu) on human and animal pathogenic protozoa (trypanosoma sp., entamoeba histolytica and giardia lamblia) in vitro. | garlic (allium sativum l.) and one of its major components, allicin, have been known to have antibacterial and antifungal activity for a long time. diallyl trisulfide is a chemically stable final transformation product of allicin which was synthesized in 1981 in china and used for treatment of bacterial, fungal and parasitic infections in man. the activity of diallyl trisulfide was investigated in several important protozoan parasites in vitro. the ic50 (concentration which inhibits metabolism o ... | 1994 | 8024350 |
| brugia malayi in mastomys natalensis: influence of immunostimulators on exertion of antifilarial activity of diethylcarbamazine. | the effect of immunopotentiators (freund's complete adjuvant and cdri compound no. 84/201) has been evaluated on exertion of antifilarial activity of diethylcarbamazine (dec) at different dose levels in mastomys natalensis experimentally infected with brugia malayi. dec alone exhibited dose dependent micro- as well as macrofilarial action. in combination with immunomodulators, activity of dec was significantly enhanced even at a lower dose level (12.5 mg/kg). however at higher dose level (> 25 m ... | 1994 | 8066377 |
| canine oral papillomavirus genomic sequence: a unique 1.5-kb intervening sequence between the e2 and l2 open reading frames. | the canine oral papillomavirus (copv) is associated with oropharyngeal papillomatosis in dogs, coyotes, and wolves. we have determined the complete nucleotide sequence of copv, the largest of all known pv genomes (8607 bp). the genomic architecture of the copv genome is similar to that of other pvs except for a unique and large noncoding region of 1.5 kb between the end of the early region (e2) and the beginning of the late region (l2) and a small (345 bp) upstream regulatory region between the ... | 1994 | 8091677 |
| the testis-determining gene, sry, exists in multiple copies in old world rodents. | sry is a unique gene on the y chromosome in most mammalian species including the laboratory mouse, mus musculus, and the closely related european wild mouse species m. spicilegus, m. macedonicus, and m. spretus. in contrast, sry is present in 2-6 copies in the more distantly related asian mouse species m. caroli, m. cervicolor, and m. cookii and in 2-13 copies in the related murid species pyromys saxicola, coelomys pahari, nannomys minutoides, mastomys natalensis, and rattus norvegicus. copy num ... | 1994 | 7698639 |
| role of endogenous cyclo(his-pro) in cold-induced hypothermia in the desert rat (mastomys natalensis). | central administration of exogenous cyclo(his-pro) (chp) is known to produce hypothermia in rodents. in the present study, we examined the role of endogenous chp in cold-induced hypothermia in the desert rat, mastomys natalensis. the results of these studies show that a rise in hypothalamic chp content accompanied a decrease in rectal temperature during cold exposure. immunoneutralization of endogenous chp resulted in a significant decline in cold-induced hypothermia. in addition, central admini ... | 1994 | 7700849 |
| the mastomys natalensis papillomavirus: nucleotide sequence, genome organization, and phylogenetic relationship of a rodent papillomavirus involved in tumorigenesis of cutaneous epithelia. | mastomys natalensis is a rodent of african origin afflicted with a very high incidence of skin tumors (keratoacanthomas and squamous carcinomas), which are associated with a papillomavirus, m. natalensis papillomavirus (mnpv). we have determined the genomic sequence of mnpv, which has a size of 7687 bp. the genomic organization is similar to that of other papillomaviruses, with open reading frames e6, e7, e1, e2, and e4 in the early and l2 and l1 in the late region. due to an unusually large hin ... | 1994 | 8291235 |
| [the host-opportunistic protozoa system. the dissemination of leishmania infantum infection in naturally susceptible laboratory animals subjected to drug-induced immunosuppression]. | the possibility to awake the disseminated infection of leishmania infantum in golden hamsters mesocricetus auratus, hispid cotton rats sigmodon hispidus, soft furred rats mastomys natalensis by means of different immunodepressants has been examined. on the background of the immunosuppression caused by corticosteroids of short time activity (metipred, hydrocortison) leishmaniae were revealed both in the target organs (spleen, liver, marrow) and in lungs, in cases of using the corticosteroid of pr ... | 1994 | 7816511 |
| gastrin receptor genes are expressed in gastric parietal and enterochromaffin-like cells of mastomys natalensis. | although gastric enterochromaffin-like (ecl) carcinoid tumors are known to develop in patients with long-standing hypergastrinemia, the expression of the gastrin receptor gene in ecl cells has not yet been demonstrated. therefore, this study was designed to examine gastrin receptor gene expression in ecl cells. mastomys gastric mucosal cells isolated by enzyme dispersion were separated into 10 fractions (f1-10) by centrifugal elutriation. each fraction was examined histologically to determine wh ... | 1994 | 7924734 |
| expression of cck-a and cck-b/gastrin receptors in enterochromaffin-like cell carcinoids of mastomys natalensis. | 1994 | 7910444 |