Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| studies on the activity of the ciba geigy compounds cgp 6140, 20376, 20309 and 21833 against third and fourth stage larvae of onchocerca volvulus. | the effect of four new antifilarial compounds, (cgp 6140, 20376, 20309 and 21833, ciba geigy ltd. basle) on the viability of third and fourth stage larvae of onchocerca volvulus was tested in vitro and in vivo. the motility of the larval stages and the moulting process from the third to the fourth stage were used as parameters for the drug activity in vitro. all four compounds showed good effects in vitro on the moulting rates compared to the controls after incubation at different concentrations ... | 1989 | 2740728 |
| 19s and 7s antibody response of mastomys natalensis in experimental filarial (litomosoides carinii, acanthocheilonema viteae, brugia malayi, b. pahangi) infections. | specific total antibody (ab), 19s and 7s ab levels in the serum of m. natalensis were investigated after infection with l. carinii, a. viteae, b. malayi and b. pahangi for period of about 500 days p.i., using elisa (homologous adult antigen) and indirect immunofluorescence tests (iift: homologous adult and microfilariae antigen). total ab levels in l. carinii infected animals rose moderately during prepatency maximum levels occurred during patency. the response during prepatency was stronger in ... | 1989 | 2781895 |
| gamma-glutamyl-transpeptidase in lymphatic tissues of mastomys natalensis during an infection with acanthocheilonema viteae. | during acanthocheilonema viteae infection, the specific activity of gamma-glutamyltranspeptidase (gamma-gt) increased in peritoneal exudate cells and bone marrow and decreased in lymph nodes of mastomys natalensis throughout the course of infection. however, though there was an increase in specific activity of gamma-gt in thymus and spleen during the prepatent phase of a. viteae infection, the level either returned to normal or decreased during the latent phase of infection. a close correlation ... | 1990 | 1973658 |
| antifilarial activities of benzazole derivatives. 3. effects of benzothiazoles on third stage larvae and preadult worms of acanthocheilonema viteae, brugia malayi and b. pahangi in mastomys natalensis. | ten structurally defined benzothiazoles (5-methyl and the analogous 5-methoxy derivatives) with known macrofilaricidal and microfilaricidal activities were tested for efficacy against third stage larvae and preadult worms in acanthocheilonema viteae, brugia malayi, and b. pahangi infected mastomys natalensis. drugs were administered in single oral doses of maximally 100 mg/kg. the benzothiazoles were active against the two stages of the three species. generally the 5-methoxy derivatives displaye ... | 1990 | 2075385 |
| absence of papillomavirus in skin tumors induced in sencar mice by a two-stage carcinogenesis protocol. | sencar mice are unusually sensitive to induction of papillomas and squamous cell carcinomas by initiation with 7,12-dimethylbenzanthracene (dmba) and promotion by 12-o-tetradecanoylphorbol-13-acetate (tpa). tumors induced by this protocol were tested for the presence of papillomavirus by immunohistochemistry, southern blot, reverse southern blot and dot blot hybridization techniques. papillomavirus antigens were not detected in any of 235 tumors or 142 non-tumor-bearing skin samples analyzed. so ... | 1990 | 2154340 |
| evaluation of hepatoprotective activity of picroliv (from picrorhiza kurroa) in mastomys natalensis infected with plasmodium berghei. | administration of picroliv, a standardized fraction of alcoholic extent of picrorhiza kurroa (3-12 mg/kg/day for two weeks) simultaneously with p. berghei infection showed significant protection against hepatic damage in mastomys natalensis. the increased levels of serum glutamate oxaloacetate transaminase (got), glutamate pyruvate transaminase (gpt), alkaline phosphatase, lipoprotein-x (lp-x) and bilirubin in the infected animals were marked reduced by different doses of picroliv. in the liver, ... | 1990 | 2189829 |
| igg response of rats to the excretory-secretory products of litomosoides carinii. | the nature of antibody responses to the excretory-secretory (es) products of adult worms and microfilariae (mf) of litomosoides carinii in albino rats and their possible role in protection have been studied. rats were immunized with es products derived from in vitro incubation of adults or mf. the sera from these rats promoted neutrophil-mediated killing of mf in vitro. the antibody responsible for the cytocidal activity was identified as igg isotype. indirect fluorescent antibody test showed th ... | 1990 | 2191288 |
| hepatic superoxide dismutase, catalase and lipid peroxidation products in mastomys natalensis infected with plasmodium berghei. | p. berghei infection in m. natalensis caused a significant reduction in the hepatic sod and catalase activities. cu-zn sod was more susceptible to infection than mn sod. the inhibition of enzyme activities was associated with marked increase in the levels of lipid peroxides, lipid hydroperoxides and conjugated dienes in infected m. natalensis. the alterations in the hepatic sod, catalase and lipid peroxides are related with the severity of infection. | 1990 | 2196223 |
| acute and chronic bacterial prostatitis due to e. coli. description of an animal model. | inoculation of escherichia coli (serotype o:6) into the bladder of male and female mastomys (praomys) natalensis produced severe prostatitis. in this rodent both male and female animals possess a well developed prostatic gland. the histologic and microbiologic course of the prostatic infection resembled strongly the human disease. acute bacterial prostatitis was followed by the development of chronic bacterial or nonbacterial prostatitis. the infection persisted in some animals for up to six mon ... | 1990 | 2204173 |
| susceptibility of mastomys natalensis to brugia malayi following pretreatment with antifilarials. | mastomys natalensis pretreated with diethylcarbamazine (dec), levamisole or centperazine were exposed to the standard inoculum of infective larvae of brugia malayi. percentage 'take' of infection, duration of prepatent period, course of microfilaraemia and number of adult worms recovered were compared with those of untreated infected mastomys (control). dec and centperazine did not alter the 'take' (dec/centperazine: 100%; control: 88.24%) and the average prepatent period (dec: 105.44 days; cent ... | 1990 | 2227711 |
| antioxidant enzymes in acanthocheilonema viteae and effect of antifilarial agents. | adult worms of acanthocheilonema viteae were found to be susceptible to the reactive oxygen intermediates (roi) generated by the xanthine-xanthine oxidase (x-xo) system. the damage caused by this system was completely abolished by superoxide dismutase (sod) and catalase but not by mannitol. the results, therefore, suggest that superoxide anions (o2-) and hydrogen peroxide (h2o2) alone or in combination might be toxic to the filariid. a. viteae exhibited the presence of an active enzyme system to ... | 1990 | 2244937 |
| a comparative study of the infectivity of t.b. rhodesiense isolates from man to 3 species of small laboratory rodents. | to confirm an earlier observation, that some t.b. rhodesiense isolates from sleeping sickness cases had failed to infect normally susceptible wistar rats, blood samples, freshly drawn from 21 patently parasitaemic ss patients, were each inoculated simultaneously into 3 swiss t.o. white mice, 3 young wistar rats and 3 mastomys natalensis. with the sole exception of one mastomys, which failed to become infected, the 21 stocks infected all the inoculated rodents. levels and durations of parasitaemi ... | 1990 | 2279470 |
| [the dynamic activity of lymphocyte succinate dehydrogenase and its correlations in experimental malaria]. | succinic dehydrogenase (sdh) activity in peripheral blood lymphocytes has been studied in progressing experimental malaria on a p. yoelii model, the strain 265 by; the multinipple rats mastomys natalensis. cytochemical method employing n-nitrotetrazolium violet was used. comparative analysis of changes in sdg activity in peripheral blood lymphocytes and changes in the level of parasitemia has demonstrated that day 10 was a critical period when there was an evident inverse correlation between the ... | 1990 | 2290392 |
| immune response to acanthocheilonema viteae infection in multimammate rats (mastomys natalensis). | the multimammate rat mastomys natalensis, when infected with the filarial parasite acanthocheilonema viteae, develops amicrofilaraemia. worm recovery and the duration and intensity of microfilaraemia were analysed and related to the humoral and cellular immune responses of the host by using an antibody-dependent cell-mediated cytotoxicity (adcc) assay towards microfilariae (mf). mf were detected in the peripheral blood at 7 weeks post-infection (p.i.), reaching maximum levels by 20 weeks p.i., a ... | 1990 | 2318510 |
| intra-ocular transplantation of carcinoid tumours from mastomys and humans. | carcinoid tumours from man and mastomys (praomys) natalensis produce a variety of peptide hormones. the study of these peptide-secreting tumours has been difficult because of the small amount of tissue available and because of limitations with present cell culture systems. the aim of this study was to establish an experimental model where carcinoid tumours could be maintained and their hormone secretion studied. the intra-ocular transplantation technique was chosen for its simplicity and high ra ... | 1990 | 2358971 |
| effect of ivermectin on filariae of mastomys natalensis. | the efficacy of ivermectin (iv) was evaluated against four species of filariae, litomosoides carinii, acanthocheilonema viteae, brugia pahangi and brugia malayi in mastomys natalensis. animals with patent infections, induced with l3 larvae, by intravenous (iv) infusion of the respective microfilariae (mf) (5 x 10(4) mf per animal) or by intraperitoneal (ip) route (2 x 10(4) mf per animal) were used in this study. a single dose of iv (100 micrograms.kg-1) given subcutaneously (sc) to mastomys inf ... | 1990 | 2381895 |
| mastomys natalensis or mastomys coucha. correct species designation in animal experiments. | haemoglobin electrophoresis and chromosome analysis indicate that the widely used multimammate rat (chamois coloured) as experimental animal belongs to the species mastomys coucha (smith, 1836) and not, as commonly assumed, to mastomys natalensis (smith, 1834). | 1990 | 2382103 |
| immunoprophylaxis against filarial parasite, dipetalonema viteae in multimammate rat mastomys natalensis: immunisation with adult worm antigens. | 1990 | 2401531 | |
| significance of gastric endocrine tumor and age-related gut peptide alterations in mastomys. | the mastomys (praomys natalensis) species are a unique natural model in which the bioactivity of gastric carcinoids may be studied. several investigators have previously demonstrated that these tumors contain large amounts of histamine. in this study we investigated the presence of peptides associated with the neoplasm. the levels and location of gastrin, gastric inhibitory peptide (gip), neurotensin, peptide yy (pyy), pancreatic polypeptide (pp), glucagon, bombesin, vasoactive intestinal peptid ... | 1990 | 2326498 |
| cell renewal in non-specific duodenitis, ulcer-related duodenitis and duodenal ulcer. experiments in mastomys (praomys natalensis). | cell renewal in the duodenal mucosa of mastomys was studied by autoradiography 1 and 24 h after intraperitoneal injection of tritiated thymidine. non-specific duodenitis and duodenal ulceration were produced with a continuous infusion of histamine. mucosal renewal in the duodenum of 30 control mastomys was compared with 30 which received histamine dihydrochloride for 5 days. no abnormality developed in the controls, but 11 of the experimental group developed non-specific duodenitis and 12 duoden ... | 1990 | 2351240 |
| activation of latent papillomavirus genomes by chronic mechanical irritation. | the skin of animals of a laboratory strain of mastomys natalensis carrying endogenous, latent papillomavirus genomes was irritated by scratching with glasspaper. hyperproliferation of the epidermis and amplification of viral dna followed this treatment, and in approximately 27% of the animals virus-producing papillomas were induced. | 1991 | 1658206 |
| ultrastructure of the submandibular gland in the african multimammate rodent, praomys natalensis. | praomys natalensis, an african rodent that is phenotypically and cytogenetically intermediate to rats and mice, possesses a submandibular gland that is histologically similar to that in both of these near relatives, but is ultrastructurally unique. acinar cells, which are seromucous in nature, contain secretory granules that often contain a perfect "bull's eye" inclusion (or some variant of this configuration) suspended in a dense matrix. the golgi apparatus in these cells has an unusual structu ... | 1991 | 2012308 |
| immune responses of two mastomys sibling species to yersinia pestis. | this study assessed the in vitro cell-mediated immune responses of mastomys natalensis, with a diploid chromosome number of 2n = 32, and mastomys coucha, with a diploid chromosome number of 2n = 36, to yersinia pestis. splenic mononuclear (mn) cells of uninfected m. natalensis proliferated in response to crude fraction 1 of y. pestis and two subfractions derived from fraction 1 in vitro. proliferation was dose dependent and followed the time kinetics of other well-known mitogens. further charact ... | 1991 | 2037358 |
| ultrastructure of the sublingual gland in the african multimammate rodent. | the sublingual gland of praomys natalensis, an african rodent that is phenotypically and cytogenetically intermediate to mice and rats, is a mixed gland, consisting of mucous acini that are capped by serous demilunes, of intercalated ducts, and of some short striated ducts that quickly become excretory ducts. the mucous cells are typical in appearance, with lucent granules that contain an assortment of scattered vermiform or particulate densities. the serous cells display an array of secretory g ... | 1991 | 2048752 |
| receptors for gastrin on gastric carcinoid tumor membrane of mastomys natalensis. | specific binding sites for human gastrin i (gastrin) were identified in a crude membrane preparation from the gastric carcinoid tumor of mastomys (praomys) natalensis. the binding of 125i-gastrin to the carcinoid tumor membrane was saturable, and scatchard analysis of the data revealed a single class of binding site with a dissociation constant of 139.2 pm and a maximal binding capacity of 23.5 fmol/mg protein. gastrin and cck8 equipotently and dose-dependently displaced the binding of 125i-gast ... | 1991 | 2049096 |
| humoral immune response to infective larval antigen in brugia malayi infected mastomys natalensis. | the sequential changes in the humoral immune response against infective larval antigens during the course of brugia malayi infection in mastomys natalensis have been studied using enzyme linked immunosorbent assay. igm antibody against b. malayi infective larval excretory secretory (es) antigen was detected in the peripheral circulation within a week of infection, whereas igm antibody against b. malayi infective larval somatic antigen and igg antibody against both somatic and es antigens were de ... | 1991 | 1674404 |
| the ngf complex from the african rat mastomys natalensis. | the 7s ngf complex from the male mouse submaxillary gland consists of the alpha, gamma, and beta subunits in the ratio alpha 2 gamma 2 beta. the beta (ngf) subunit contains all the known biolocial activity of 7s ngf. the alpha and gamma subunits are both members of glandular kallikrein gene family, yet only gamma subunit has protease activity. the gamma subunit plays a role in the processing of preprongf to its mature form, while the role of the alpha subunit is not yet understood. despite the f ... | 1991 | 1791910 |
| impact of surface modifications of acanthocheilonema viteae microfilariae on cell adhesion. | exposure of a. viteae microfilariae to various lectins reduced their capacity to react with the peritoneal exudate cells of the host, mastomys natalensis. sugars corresponding to these lectins with the exception of n-acetyl glucosamine, did not affect the adhesion per se. they however, protected the parasite against the adverse effect of lectins. neuraminidase and chitinase also suppressed adhesion capacity of the microfilariae. except sodium dodecylsulphate which enhanced cell attachment, other ... | 1991 | 1814837 |
| cyclic amp level in red blood cells of plasmodium berghei-infected mastomys natalensis. | the present report describes the changes in cyclic amp level which occur upon parasitization of red cells by plasmodium berghei. parasitized erythrocytes were separated from the non-parasitized population by percoll density-gradient centrifugation. an increase in the cyclic amp content of both non-parasitized and parasitized erythrocytes of infected animals compared with that of uninfected animals was observed. the patterns of physiological response to isoproterenol in normal, parasitized and no ... | 1991 | 1849086 |
| on the pathogenesis of anaemia and leukopenia in filarial (litomosoides carinii) infection of mastomys natalensis. | mastomys natalensis infected with the filarial parasite litomosoides carinii show anaemia and leukopenia. alterations start with the onset of microfilaraemia. anaemia is temporally macrocytic (up to 80 days after infection), subsequently normocytic and hypochromic, accompanied by reticulocytosis. increased intravascular haemolysis (i) and functional disorders of the haemopoetic system (ii) are involved in the pathogenesis. i: circulating erythrocytes showed increased osmofragility. hypoglycaemia ... | 1991 | 1853669 |
| role of free radicals in plasmodium berghei infected mastomys natalensis brain. | lipid peroxide, lipid hydroperoxide, reduced glutathione, oxidised glutathione, lipofuscin contents and the activity of the enzyme superoxide dismutase were assessed in p. berghei infected m. natalensis brain. the results showed significant increase in the levels of lipid peroxides, lipid hydroperoxides and lipofuscin in brain subcellular fractions of p. berghei infected m. natalensis. furthermore, a depressed superoxide dismutase activity was observed along with regulation in glutathione conten ... | 1992 | 1294484 |
| studies on the infectivity of gametocytes of plasmodium berghei (nk 65) in anopheles stephensi. | the infectivity of gametocytes of plasmodium berghei (nk 65) has been studied in laboratory bred anopheles stephensi. mosquitoes were fed daily on infected male and female mastomys natalensis and subsequent development of the oocysts was monitored in the midguts. maximum number of oocysts were found in mosquitoes which were fed on infected female mastomys on d8 and in male mastomys on d7 post-inoculation. during the next peak of gametocytaemia, very few oocysts developed. these findings suggest ... | 1992 | 1296945 |
| primary structure of the e6 protein of micromys minutus papillomavirus and mastomys natalensis papillomavirus. | 1992 | 1319576 | |
| a decade of plague epidemiology and control in the western usambara mountains, north-east tanzania. | outbreaks of human plague have been occurring in the western usambara mountains since 1980, involving many cases and deaths. epidemiological surveys and control activities were carried out from june 1980 to may 1990. rodents were trapped live, identified and serologically tested for plague, using the passive haemagglutination and passive haemagglutination inhibition tests. rodent fleas were collected, processed, identified and counted. house fleas were caught with light traps and similarly treat ... | 1992 | 1356303 |
| plague in lushoto district, tanzania, 1980-1988. | rodents were live-trapped in selected plague-inflicted villages from june 1980 to march 1988. flea infestation rates were determined and the animals were serologically tested for plague. clinically suspected and clinically healthy people in the affected areas were similarly tested for plague antibodies. of 1596 rodent sera tested, 91 (5.7%) were positive for plague. these were mostly from rattus rattus, mastomys natalensis, otomys spp. and pelomys fallax. a total of 1772 fleas, of which dinopsyl ... | 1992 | 1440831 |
| effect of picroliv on glutathione metabolism in liver and brain of mastomys natalensis infected with plasmodium berghei. | administration of picroliv, the active principle from picrorhiza kurrooa, at a dose of 6 mg/kg, po for two weeks showed significant protection against changes in liver and brain glutathione metabolism of plasmodium berghei infected mastomys natalensis. the depletion of reduced glutathione level and inhibition of glutathione-s-transferase, glutathione reductase and glutathione peroxidase activities due to p. berghei infection were markedly recovered by picroliv. the increased levels of lipid pero ... | 1992 | 1459651 |
| identification of circulating parasite acetylcholinesterase in human and rodent filariasis. | in the present study, the enzyme acetylcholinesterase (ache) from filarial parasites was identified in sera from humans infected with onchocerca volvulus as well as in mastomys natalensis infected with brugia pahangi. the enzyme was present in immune complexes precipitated with cold 4% polyethylene glycol. the infected sera showed 3-4 times more ache activity than did normal sera, and enzyme activity could be demonstrated in 5% polyacrylamide gels by specific staining. the enzyme from infected s ... | 1992 | 1480604 |
| effect of 2,2'-dicarbomethoxylamino-5,5'-dibenzimidazolyl ketone on antioxidant defenses of acanthocheilonema viteae and its laboratory host mastomys natalensis. | the effect of the macrofilaricidal agent of 2,2'-dicarbomethoxylamino-5,5'-dibenzimidazolyl ketone (c.d.r.i. compound 82/437), on the metabolism of reactive oxygen species (ros) in acanthocheilonema viteae and mastomys natalensis was measured following intraperitoneal administration at therapeutic doses. the recovered worms possessed substantially reduced levels of catalase and glutathione peroxidase (gpx), and thus were less able to detoxify h2o2. nonetheless, the subcutaneous and adjoining mus ... | 1992 | 1510719 |
| cloning and characterization of gastrin receptor from ecl carcinoid tumor of mastomys natalensis. | we report here the cdna cloning of a putative gastrin receptor from enterochromaffin-like (ecl) carcinoid tumor of mastomys natalensis. for this study, we used the polymerase chain reaction technique to amplify transmembrane domain sequences related to rat pancreatic cholecystokinin (cck)-a receptor from the ecl tumor cdna library. the amino acid sequence deduced from the cloned cdna showed 85.7% and 49.0% identity to canine parietal cell gastrin receptor and rat pancreatic cck-a receptor, respe ... | 1992 | 1530611 |
| brugia malayi in mastomys natalensis: efficacy of mebendazole in combination with freund's complete adjuvant. | the chemotherapeutic efficacy of mebendazole given in combination with freund's complete adjuvant (fca) against brugia malayi in multimammate rat was evaluated. animals treated with mebendazole, orally at 200 mg/kg x 5 consecutive days along with fca given subcutaneously (s.c.) on day -10, day 0 and day +15 of the drug treatment killed 48.51% of the adult worms. this drug given alone at the same regimen and by the same route showed only 18.7% mortality rate on adults. mebendazole given intraperi ... | 1992 | 1644349 |
| gastrin/cck-b receptors on brain, gastric parietal cells and ecl carcinoid tumor of mastomys natalensis. | cholecystokinin (cck)-8 and human gastrin i (gastrin) were found to be almost equipotent in displacing the specific binding of not only 125i-cck-8 but also 125i-gastrin to both ecl carcinoid tumor and parietal cell membranes of mastomys natalensis. these binding specificities of the native gastrin receptors for cck-8 and gastrin were identical to that of the cloned gastrin receptor from the ecl carcinoid tumor expressed on cho-k1 cells. in contrast, cck-8 was approximately 10-20 times as potent ... | 1993 | 8182917 |
| immunoreactive proteins of acanthocheilonema viteae (nematoda: filarioidea) adults: solubilization in various detergents. | for optimal solubilization of immunoreactive proteins of filarial parasites, adult worms of acanthocheilonema viteae were extracted in different detergents including anionic, cationic, nonionic and zwitterionic agents under varying incubation periods. each preparation was then analysed by sds-page and immunoblotting using pooled sera from mastomys natalensis infected with a. viteae. amongst the detergents used, maximum immunoreactive proteins were exposed by sodium dodecylsulphate (sds), closely ... | 1993 | 8314178 |
| characterization of gastrin/cck receptors on gastric carcinoid tumor membrane of mastomys natalensis. | recently, we identified the specific binding site for gastrin on the gastric carcinoid tumor of mastomys (praomys) natalensis. in this study, precise characterization of the gastrin binding site on these tumors was performed. both 125i-human gastrin i (gastrin) and 125i-cck-8 bound specifically to the cell membrane, and scatchard analysis revealed a high affinity binding site for each ligand with similar kd and bmax values. the specific binding of both 125i-gastrin and 125i-cck-8 was displaced i ... | 1993 | 8441820 |
| rapid induction of enterochromaffinlike cell tumors by histamine2-receptor blockade. | the effect of acid inhibition on gastric endocrine cells was investigated in praomys (mastomys) natalensis. long-term treatment (1 to 32 weeks) with an irreversible histamine 2-receptor blocker (loxtidine) caused a sustained increase in plasma gastrin levels, which was accompanied by a gradual increase in histamine and histidine decarboxylase activity of the gastric oxyntic mucosa. the density of endocrine cells in the oxyntic mucosa increased gradually, doubled by 8 weeks, and was three times t ... | 1993 | 8097370 |
| 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 | |
| distribution of mrna for cck-b receptor in the brain of mastomys natalensis: abundant expression in telencephalic neurons. | the distribution of cholecystokinin b (cck-b) receptors in the mastomys brain was studied using northern blot analysis and in situ hybridization technique. by northern blot analysis using 32p-labeled cdna probe, the cortex had the highest hybridization signal of cck-b receptor mrna in the brain. the olfactory bulb and hippocampus showed a moderate level of signals. in situ hybridization using 35s-labeled crna probes revealed a wide and region-specific distribution of cck-b receptor mrna in the t ... | 1994 | 8004467 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| immunofluorescence studies on the association between a c-type oncornavirus and renal glomerulopathy in praomys (mastomys) natalensis. | 1995 | 177237 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |