| effect of synthetic hormones on reproduction in mastomys natalensis. | rodent pest management traditionally relies on some form of lethal control. developing effective fertility control for pest rodent species could be a major breakthrough particularly in the context of managing rodent population outbreaks. this laboratory-based study is the first to report on the effects of using fertility compounds on an outbreaking rodent pest species found throughout sub-saharan africa. mastomys natalensis were fed bait containing the synthetic steroid hormones quinestrol and l ... | 2018 | 29367841 |
| the shape of the contact-density function matters when modelling parasite transmission in fluctuating populations. | models of disease transmission in a population with changing densities must assume a relation between infectious contacts and density. typically, a choice is made between a constant (frequency-dependence) and a linear (density-dependence) contact-density function, but it is becoming increasingly clear that intermediate, nonlinear functions are more realistic. it is currently not clear, however, what the exact consequences would be of different contact-density functions in fluctuating populations ... | 2017 | 29291115 |
| comparative non-metric and morphometric analyses of rats at residential halls of the university of benin campus, nigeria. | in mammals and across rat species, the variation in conformation is markedly observed in the head and the variation in the shape of the head is mostly determined by the shape of the skull. hence comparative topographic analysis and morphometry is a veritable tool in precise categorization of peri-domestic rats and species identification. | 2017 | 28967498 |
| diagnosis and genetic analysis of the worldwide distributed rattus-borne trypanosoma (herpetosoma) lewisi and its allied species in blood and fleas of rodents. | trypanosoma (herpetosoma) lewisi is a cosmopolitan parasite of rodents strongly linked to the human dispersal of rattus spp. from asia to the rest of the world. this species is highly phylogenetically related to trypanosomes from other rodents (t. lewisi-like), and sporadically infects other mammals. t. lewisi may opportunistically infect humans, and has been considered an emergent rat-borne zoonosis associated to poverty. we developed the thecatl-pcr based on cathepsin l (catl) sequences to spe ... | 2017 | 28882517 |
| understanding the cryptic nature of lassa fever in west africa. | lassa fever (lf) is increasingly recognized by global health institutions as an important rodent-borne disease with severe impacts on some of west africa's poorest communities. however, our knowledge of lf ecology, epidemiology and distribution is limited, which presents barriers to both short-term disease forecasting and prediction of long-term impacts of environmental change on lassa virus (lasv) zoonotic transmission dynamics. here, we synthesize current knowledge to show that extrapolations ... | 2017 | 28875769 |
| genetic distinction between contiguous urban and rural multimammate mice in tanzania despite gene flow. | special conditions are required for genetic differentiation to arise at a local geographical scale in the face of gene flow. the natal multimammate mouse, mastomys natalensis, is the most widely distributed and abundant rodent in sub-saharan africa. a notorious agricultural pest and a natural host for many zoonotic diseases, it can live in close proximity to humans and appears to compete with other rodents for the synanthropic niche. we surveyed its population genetic structure across a 180-km t ... | 2016 | 27306876 |
| host evolution in mastomys natalensis (rodentia: muridae): an integrative approach using geometric morphometrics and genetics. | the commensal rodent mastomys natalensis is the natural reservoir of lassa arenavirus (lasv), which causes hemorrhagic fever in west africa. to study a possible effect of the virus on phenotypic and genotypic variation of its persistently infected host, we compared lasv-positive and non-infected wild-caught m. natalensis. the lasv effects on the phenotypic variation were explored using standard external morphometric measurements, geometric morphometric analyses of the cranial size and shape, and ... | 2015 | 26331855 |
| polymorphism in vkorc1 gene of natal multimammate mice, mastomys natalensis, in tanzania. | resistance of rodents to anticoagulant rodenticides has emerged in several areas across the world. single nucleotide mutations in the vkorc1 gene have been shown to elicit various levels of anticoagulant resistance, and these mutations are prevalent in several rattus and mus musculus populations. in sub-saharan africa, the natal multimammate mouse, mastomys natalensis, is one of the most damaging pests to crops, and anticoagulant poisons such as bromadiolone are frequently used to control these ... | 2016 | 26223233 |
| spatial segregation between invasive and native commensal rodents in an urban environment: a case study in niamey, niger. | invasive rodents have been responsible for the diffusion worldwide of many zoonotic agents, thus representing major threats for public health. cities are important hubs for people and goods exchange and are thus expected to play a pivotal role in invasive commensal rodent dissemination. yet, data about urban rodents' ecology, especially invasive vs. native species interactions, are dramatically scarce. here, we provide results of an extensive survey of urban rodents conducted in niamey, niger, d ... | 2014 | 25379785 |
| anthropogenic soils and land use patterns in relation to small mammal and flea abundance in plague endemic area of western usambara mountains, tanzania. | heterogeneity in the landscapes of west usambara mountains on land use and human activities has been reported. however, the interface of land use patterns and human modified soils with small mammal and flea abundance for possible explanation of plague has not been explored. this study was carried out to determine the link between anthropogenic soils and land use patterns on small mammal and flea abundance and the occurrence of reported plague in the western usambara mountains in tanzania. standa ... | 2014 | 26867282 |
| vegetation habitats and small mammals in a plague endemic area in western usambara mountains, tanzania. | human plague still exists in different parts of the world, including some landscapes in north-eastern tanzania. wherever the hotspot of plague, small mammals seem to play a key role as host. the objective of this study was to investigate the relationship between vegetation habitats types and small mammals in a plague endemic area of lushoto district in tanzania. a combination of field survey and landsat images was used to identify the vegetation habitats. small mammals were trapped in the mapped ... | 2014 | 26867279 |
| small mammal distribution and diversity in a plague endemic area in west usambara mountains, tanzania. | small mammals play a role in plague transmission as hosts in all plague endemic areas. information on distribution and diversity of small mammals is therefore important for plague surveillance and control in such areas. the objective of this study was to investigate small mammals' diversity and their distribution in plague endemic area in the west usambara mountains in north-eastern tanzania. landsat images and field surveys were used to select trapping locations in different landscapes. three l ... | 2014 | 26867277 |
| the effects of unilateral truncal vagotomy on gastric carcinogenesis in hypergastrinemic japanese female cotton rats. | the stomach is innervated by the vagal nerve. several studies have demonstrated that the vagal nerve has a trophic effect on the rat oxyntic mucosa and that the trophic effect of hypergastrinemia is dependent on intact vagal innervation. the effect of vagal denervation on gastric carcinogenesis has been examined in mastomys natalensis and hypergastrinemic transgenic ins-gas mice, with no effect of unilateral vagotomy in mastomys but an anti-carcinogenic effect in ins-gas mice. a proportion of fe ... | 2013 | 23499800 |
| population dynamics and breeding patterns of multimammate mouse, mastomys natalensis (smith 1834), in irrigated rice fields in eastern tanzania. | multimammate mice are the most important vertebrate pests in sub-saharan africa and are also reservoirs of many zoonotic diseases, including sylvan plague. this study investigated the population dynamics and breeding patterns of this mouse in irrigated rice cropping systems in eastern tanzania. | 2013 | 22718470 |
| 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 |
| 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 |
| 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 |
| the role of endogenous gastrin in the development of enterochromaffin-like cell carcinoid tumors in mastomys natalensis: a study with the specific gastrin receptor antagonist ag-041r. | we examined the effects of a newly synthesized gastrin receptor antagonist, ag-041r, on the growth of enterochromaffin-like (ecl) carcinoid tumors in mastomys natalensis both in vitro and in vivo. ag-041r was as potent as the well known gastrin antagonist l365,260 in inhibiting not only the gastrin-induced release of histamine from but also histidine decarboxylase (hdc) gene expression in the ecl carcinoid tumor cells. ag-041r also inhibited gastrin-induced dna synthesis and c-fos gene expressio ... | 2016 | 10461356 |
| histamine metabolism of gastric carcinoids in mastomys natalensis. | pharmacological inhibition of gastric acid secretion and subsequent hypergastrinemia in mastomys natalensis is an experimental model well suited for the study of gastric carcinoid formation. the genetic susceptibility of mastomys to develop such tumors is a feature reminiscent of the situation in patients with the men-1 zollinger ellison syndrome, in whom tumor-induced hypergastrinemia, promotes the development of gastric carcinoids. chronic hypergastrinemia, induced by the irreversible h2-recep ... | 2014 | 10461353 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| analysis of histamine receptors in the central thermoregulatory mechanism of mastomys natalensis. | 1 the effect of intracerebroventricular (i.c.v.) injection of histamine on the rectal temperature of mastomys natalensis at ambient temperatures of 10, 24 and 33 degrees c has been studied. 2 low doses (0.1-1.0 microgram) of histamine produced hypothermia while larger doses (5-20 micrograms) produced dose-dependent hyperthermia. the hypothermic effect was significantly antagonized by mepyramine while the hyperthermia was blocked by cimetidine. 3 histamine h1-receptor agonists, 2-methyl-histamine ... | 1982 | 7074279 |
| effects of melatonin on heat production and enzymatic activity in diurnal and in nocturnal rodents. | 1. heat production by means of oxygen consumption (vo2), and enzymatic activity of malate dehydrogenase (mdh), lactate dehydrogenase (ldh), and glucose-6-phosphate dehydrogenase (g6pdh) were studied in diurnal (rhabdomys pumilio) as well as nocturnal (praomys natalensis) murids, as a response to melatonin treatment. 2. a significant (p less than 0.001) increase in vo2 was noticed in melatonin treated mice of both species at ambient temperatures of ta = 6 degrees c, 25 degrees c, 30 degrees c and ... | 1982 | 6120787 |
| novel flushing provoked by volatile anesthetics in mastomys natalensis bearing a transplantable substrain of gastric carcinoid that predominantly secretes serotonin. | a tumor substrain secreting a large amount of serotonin [5-hydroxytryptamine (5-ht); cas: 50-67-9; 3-(2-amino-ethyl)indol-5-ol] and a minute amount of histamine (cas: 51-45-6) has been isolated from the previously established strain of transplantable gastric carcinoid of mastomys (praomys) natalensis secreting both histamine and 5-ht. mastomys bearing a large growing transplant and excreting a large amount of 5-hydroxy-indoleacetic acid [(5-hiaa) cas: 54-16-0] were associated often with reddenin ... | 1984 | 6202924 |
| morphological and histochemical study of the submandibular gland in praomys (mastomys) natalensis. | the submandibular gland in female and male praomys (mastomys) natalensis (a south african multimammate rodent) was studied using light microscopy and techniques for the demonstration of carbohydrates. hematoxylin and eosin stain revealed the presence of a single secreting component that gave a strongly positive pas reaction. limiting elements of the granular tubules gave a weakly positive pas reaction. acidic glycoproteins were evidenced only in granules of the acinar component. | 1985 | 3976344 |
| the baseline susceptibility levels of chunya praomys natalensis, the commonest plague reservoir and crop pest in tanzania, to warfarin. | p. natalensis were live-trapped at kibwawa (chunya district) in november 1977 and november 1979. an f3 generation was raised from animals which tolerated 0.025% a.i. warfarin. all three populations were tested using the who standard method (who/vbc/75.595), with 0.025% warfarin. the populations tested were fully susceptible to the rodenticide, and the latter was well acceptable to the rodents. in this area, warfarin can be successfully used for controlling p. natalensis. failure to obtain 100% m ... | 1985 | 4096714 |
| tumor induction in praomys (mastomys) natalensis by n,n'-2,7-fluorenylenebisacetamide. | feeding n,n'-2,7-fluorenylenebisacetamide (cas:304-28-9) at 0.025% to 15 male and 15 female mastomys considerably shortened their life-span. at death every treated mastomys had several primary tumors; untreated animals at comparable ages had none. several mastomys with hepatoblastomas and 1 with giant cell hepatitis and a metastasizing pancreatic carcinoma are first reported here. the tumor load per animal averaged 4.0 for treated females, 2.6 for treated males, 1.5 for untreated females, and 0. ... | 1985 | 3857384 |
| marked inhibition of histamine formation in transplantable histamine-producing gastric carcinoid of mastomys natalensis by (s)-alpha-fluoromethylhistidine and its potent antiulcer effect on tumor-bearing hosts. | | 1985 | 4074392 |
| histochemical determination of carbohydrates in the prostate of male and female praomys (mastomys) natalensis. | the ventral lobes of the prostate in the female and male praomys (mastomys) natalensis were studied using light microscopic techniques for the demonstration and localization of carbohydrates. a weakly pas-positive material appeared in the secretory product and secretory granules in epithelial cells of both female and male ventral lobes. this reaction is unaffected by diastase and is completely blocked by acetylation. alcian blue, toluidine blue and methylene blue stains demonstrate metachromatic ... | 1986 | 2431673 |
| prenatal development of the prostate in male praomys (mastomys) natalensis. | | 2004 | 3778083 |
| light and electron microscopic study of the postnatal prostate in male praomys (mastomys) natalensis. | the postnatal development of the prostate was studied in male praomys (mastomys) natalensis using both light and electron microscopy. at birth, the ventral and dorsal lobes consist of cords of cells that previously budded from the urogenital epithelium into condensed pads of stroma. the ventral cords have developed small lumina, whereas lumina do not develop in the dorsal lobe until two days after birth. the cords and tubules lengthen, branch, and coil so that by six days, the tubules of the ven ... | 1986 | 3959153 |
| ontogenic studies on brain biogenic amines in mastomys natalensis. | | 1986 | 3781597 |
| ontogenic studies on biogenic amines in heart, lung and adrenal glands of mastomys natalensis. | | 1986 | 3596628 |
| histochemical and proliferative changes preceding the onset of spontaneous gastric adenocarcinoma in mastomys natalensis. | the histochemical and proliferative changes preceding spontaneously developing gastric adenocarcinoma were examined in mastomys natalensis. the stomachs of 86 inbred animals from the dwz strain were examined between 1 and 24 months of age. two thirds of the animals had a small solitary ulcer in the middle of the lesser curvature which was observed by the first month of age. with increasing age, more and more dysplastic glands invading the submucosa were seen around the ulcer and eventually adeno ... | 1987 | 3113067 |
| comparative morphology of the prostate in adult male and female praomys (mastomys) natalensis studied with electron microscopy. | comparative study at the cellular and subcellular levels of the adult male and female prostates of a unique species of rodent--praomys (mastomys) natalensis--was made. the female possesses a well-developed prostate throughout life that may be considered homologous to the ventral prostatic lobe in the male praomys. histologically, only small differences exist to indicate that the female prostate is somewhat less active than the male (less secretion and the presence of fewer supranuclear light are ... | 1987 | 3560297 |
| angiostrongylus sandarsae alicata, 1968 (nematoda: metastrongyloidea) from praomys natalensis in kenya. | | 1988 | 3373927 |
| cytochemical demonstration of enzymatic activities of the parotid, submandibular, and sublingual glands of praomys (mastomys) natalensis. | histochemical techniques were applied to salivary glands removed from adult multimmate rodents (praomys) of either sex to detect and localize the following enzymatic activities: acid and alkaline phosphatase, arylsulphatase, ali-esterases, beta-glucuronidase, n-acetyl-betaglucosaminidase, and l-leucyl-aminopeptidase. no reaction was observed for alkaline phosphatase and glucuronidase. the glands reacted differently to the other enzymatic activities. alkaline phosphatase and glucosaminidase were ... | 1988 | 3415628 |
| intracisternal a particle gene related sequences are present in multiple copies in normal tissues and tumors of mastomys natalensis (muridae). | | 1988 | 3340555 |
| blood leucocytes in mastomys natalensis with filarial infections. | | 1988 | 3229786 |
| characterization of histamine receptors in tracheal smooth muscle of mastomys natalensis. | the tracheal smooth muscle of mastomys natalensis contracted with carbachol administration while histamine (h) caused concentration-dependent relaxation. the specific h2-receptor agonists 4-methyl histamine, dimaprit, impromidine and a high concentration of 2-methyl histamine (h1-agonist) caused relaxation similar to h which was selectively blocked by cimetidine. low concentrations (10(-5)-10(-4) mol/l) of 2-methyl histamine and of h (10(-8)-10(-7) mol/l) occasionally produced small contractions ... | 1989 | 2816396 |
| mammary gland growth and response to hormones in mastomys compared with mice. | mammary gland growth with or without hormone manipulation was examined in virgin mastomys (praomys (mastomys) natalensis) and compared with c3h/he mice having a low mammary tumor incidence. mammary glands of mastomys consisted mostly of duct systems even at 720 days of age, whereas conspicuous formation of normal end-buds and preneoplastic hyperplastic alveolar nodules were seen in the glands of mice after 180 days of age. mammary glands of mastomys showed a higher response to estrogen or proges ... | 1989 | 2761236 |
| 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 |
| the effect of intracerebroventricular administration of catecholamines and their antagonists on rectal temperature of mastomys natalensis. | noradrenaline (na), adrenaline (adr), isoprenaline (iso) and dopamine (da) were given through a chronically implanted cannula in the lateral cerebral ventricle of mastomys natalensis. low doses of na (0.05-0.25 microgram) reduced rectal temperature while larger doses (0.35 microgram upwards) produced dose-dependent hyperthermia. the hypothermic effect was antagonised by alpha-adrenoceptor and the hyperthermia by beta-adrenoceptor antagonists. alpha-methyl noradrenaline produced less hyperthermia ... | 1981 | 6120469 |
| association of autoantibodies and pathological changes in aged praomys (mastomys) natalensis. | | 1982 | 6125285 |
| polysomal polyadenylated rna and albumin messenger rna in mastomys liver and in a chemically induced hepatocellular carcinoma. | a hepatocellular carcinoma line (h78) was established from a primary liver tumor induced in mastomys natalensis by a single administration of dimethylnitrosamine. six to 8 months after transplantation (passages 5 to 7), well-differentiated tumors, still containing glucogen-storing cells, were isolated and used for the preparation of rna. polysomal polyadenylated rnas from mastomys liver and from h78 tumor line were then compared by hybridization kinetics. total kinetic complexities were 6.6 x 10 ... | 1982 | 6175401 |
| spontaneous autoimmune thyroiditis in praomys (mastomys) natalensis. | | 1982 | 7166012 |
| morphological and histochemical studies on the parotid gland of praomys (mastomys) natalensis. | the parotid gland of praomys (mastomys) natalensis follows the same anatomical pattern of rodentia since no peculiar morphological and histochemical features were found in the present study that differentiate it from homologous glands in other rodents. it consists of serous secreting components and intralobular ducts that demonstrate no sexual dimorphism. histochemical studies reveal that the glandular cells of the praomys' parotid gland contain no acid mucosubstance, but that material of a neut ... | 1984 | 6083776 |
| production of serotonin by a transplantable strain of histamine-producing primary gastric carcinoid of mastomys natalensis. | two biochemically distinguishable transplantable tumor strains (a and b) were established from a primary gastric carcinoid of mastomys secreting histamine alone. strain a in the third generation acquired a new ability to produce serotonin [5-hydroxytryptamine (5-ht)] and retained endocrine activities to produce both histamine and 5-ht through the following subpassages, whereas strain b (like the primary tumor) continued to produce histamine alone. the findings were further supported by the immun ... | 1984 | 6199546 |
| the submaxillary salivary glands of the african rodent praomys (mastomys) natalensis as the richest available source of the nerve growth factor. | | 1981 | 7238613 |
| morphology of experimentally induced so-called keratoacanthomas and squamous cell carcinomas in 2 inbred-lines of mastomys natalensis. | | 1981 | 7343569 |
| gastric ulcer disease: gastric ulcer induced by mucosal anaphylaxis in ovalbumin-sensitized praomys (mastomys) natalensis. | | 1981 | 7193420 |
| [electron microscopic studies of spontaneous and experimentally induced neoplasms and of normal skin of mastomys natalensis (gra giessen and wsa giessen strains)]. | | 1981 | 6794250 |
| [neoplasms of the skin in a wild-colored inbred strain of mastomys natalensis (wsa giessen)]. | | 1980 | 7404971 |
| the efficacy of amoscanate (c9333-go/cgp 4540) on filarial infections of mastomys natalensis. | | 1980 | 6106365 |
| measurement of glycoprotein content and cell kinetics in preulcerous gastric mucosa. | in an attempt to evaluate the role of gastric mucosal defense factors in ulcerogenesis, we measured the levels of glycoproteins in the mucosa as well as mucosal cell turnover in the preulcerous phase and compared these parameters to the normal mucosa in the same animal. ovalbumin-presensitized praomys (mastomys) natalensis were challenged in the gastric wall with ovalbumin and a gastric ulcer developed at the challenge site 3 days later as a result of a mucosal anaphylactic reaction. this model ... | 1979 | 487921 |
| animal model: carcinoids and adenocarcinoma of the glandular stomach of praomys (mastomys) natalensis. | | 1979 | 464025 |
| [induction of epidermal tumor growth in the skin of mastomys natalensis by transfer of virus-containing tumor tissue from a squamous cell carcinoma]. | | 1976 | 1266439 |
| electron microscope study on endocrine cells and tumor cells in the glandular stomach of praomys (mastomys) natalensis. | endocrine cells in the normal glandular stomach and gastric carcinoids of mastomys were observed by electron microscopy and at least five types of endocrine cells, ec, g, d-like, r (round-granule) and ecl cells were identified. of these, four types excepting g cells were recognized in the fundic mucosa. characteristic in mastomys was a scarcity of endocrine cells in the fundic mucosa, where ecl and r cells were predominant types. silver impregnation methods including sevier-munger's argyrophil r ... | 1975 | 1203028 |
| [occupationally induced sensitization of respiratory airways by animal-hair and animal-dust]. | an occupational sensitization of the respiratory tract caused by hair and dust of laboratory animals (mastomys natalensis) was reported in 3 persons. intracutaneous tests confirmed the relationship between the professional activity and the clinical symptoms of an inhalation allergy. the very pronounced reaction to different dust extracts and the special conditions of exposure suggest an occupational sensitization to the dust of laboratory animals. | 1975 | 1200957 |
| prostatic hyperplasia and neoplasia in female praomys (mastomys) natalensis. | | 1970 | 4098904 |
| histamine production by transplantable argyrophilic gastric carcinoid of praomys (mastomys) natalensis. | a transplantable argyrophilic gastric carcinoid of praomys (mastomys) natalensis contained appreciable amounts of histamine. dialyzed, microsome-free supernatant of tumor tissue produced definite amounts of histamine in the presence of l-histidine and pyridoxal phosphate. these findings may relate to hypersecretion of gastric acid and formation of multiple ulcers in the stomach and duodenum of mastomys bearing carcinoids. | 1970 | 5460070 |
| response of adult mastomys (praomys natalensis) to subcutaneous injection of n-nitrosodimethylamine. | | 1970 | 4320041 |
| histological and immunohistochemical studies on spontaneous renal lesions of praomys (mastomys) natalensis. | | 1970 | 4928077 |
| malignant argyrophilic gastric carcinoids of praomys (mastomys) natalensis. | cells of carcinoid tumors which arise in the glandular stomach of old male and female praomys (mastomys) natalensis contain argyrophil granules when tissues fixed in formalin are colored with solutions of silver salts. the carcinoids metastasize in about 25 percent of cases, and are transplantable to other mastomys. tumor-bearing animals may show gastric and duodenal ulcers and multiple endocrine adenomas. | 1969 | 5303997 |
| concerning the incidence of "spontaneous" stomach cancer in praomys (mastomys) natalensis. | | 1968 | 5673570 |
| thymomas and thymic hyperplasia in praomys (mastomys) natalensis. concomitant myositis, myocarditis, and sialodacryoadenitis. | | 1968 | 5660267 |
| pathological analysis of spontaneous carcinogenesis in glandular stomach of praomys (mastomys) natalensis. | | 1968 | 5666251 |
| neoplastic and non-neoplastic renal disease in praomys (mastomys) natalensis. | | 1967 | 6030033 |
| production of tumours in rattus (mastomys) natalensis by polyoma virus. | | 1960 | 14435664 |
| androgen concentrations in prostate and serum of the male and female praomys (mastomys) natalensis. | the levels of androgens in the male prostate, seminal vesicles, and serum, as well as in the female prostate and serum, were measured in the rodent praomys (mastomys) natalensis. measurements were made in different age groups of both males and females using a sensitive radioimmunoassay. the results showed that the values for serum testosterone were 10 times greater in the male than the female. the concentration of serum dihydrotestosterone in the male was approximately one-tenth of the concentra ... | 1977 | 591266 |
| effects of various diets on growth, longevity and incidence of spontaneous tumors of praomys (mastomys) natalensis. | | 1977 | 929163 |
| identification of an androgen receptor in the cytosol of the female mastomys prostate. | an in vivo and in vitro study was carried out on the prostate from the female praomys (mastomys) natalensis to identify and characterize the binding of androgens within the cytoplasm. the labelled cytosol was prepared and subjected to gel exclusion chromatography and density gradient centrifugation. a macromolecular protein associated with the radioactivity was isolated on sephadex g-200. subsequent analysis of the steroid receptor complex showed that the major part of the radioactive steroid (6 ... | 1977 | 562799 |
| spontaneous tumors and atypical proliferation of pancreatic acinar cells in mastomys (praomys) natalensis. | in 17 of 90 untreated 2-year-old mastomys (praomys) natalensis, an acinar cell tumor was observed, and atypical acinar proliferation was noted in 30. the lesions, either neoplastic or proliferative, consisted of large polygonal cells with prominent nucleili in the enlarged hyperchromatic nuclei. the cytopalsms of these cells were polychromatic and were characterized by a central eosinophilic granular area and a peripheral basophilic fibrillar zone around an eccentric nucleus. the differntiated c ... | 1976 | 1003562 |
| an electrophoretic polymorphism in the serum transferrins of praomys (mastomys) natalensis. | three serum transferrin phenotypes of praomys (mastomys) natalensis, and african rodent having a high incidence of many varieties of spontaneous neoplasms, were detected by electrophoresis and autoradiography. on electrophoresis, transferrin of trf-k was found to be a protein that migrates slowly toward the cathode, whereas that of trf-m migrates rapidly. trf-km is a heterozygous phenotype of the above two. progeny testing demonstrated that these three serum transferrin phenotypes in mastomys ar ... | 1976 | 1008800 |
| [pathological anatomy and histology of spontaneous, epithelial skin tumors in mastomys natalensis]. | | 1976 | 822652 |
| histidine decarboxylase in the transplantable argyrophilic gastric carcinoid of praomys (mastomys) natalensis. | | 1971 | 4329805 |
| [comparison of the influence of mixed grain food and food pellets on reproduction and growth of mastomys natalensis (smith, 1834)]. | | 1971 | 5096329 |
| carcinomas of the glandular stomach and hepatomas in rattus (mastomys) natalensis infected with bilharzia mansoni. | | 1959 | 13649450 |
| identification of a prostate in female praomys (mastomys) natalensis using 3-h steroids. | the female of the species praomys (mastomys) natalensis has a ventral prostate similar both in position and in histological appearance to the ventral lobe of the male prostate. the hormonal uptake of this female prostate has been investigated using (3-h) testosterone and (3-h) oestradiol. the results showed that the uptake of these steroid hormones by the prostate was identically to our findings in the male prostate. the potential value of a female prostate in prostatic research is discussed. | 1975 | 1131500 |
| patterns of neoplastic and nonneoplastic diseases of praomys (mastomys) natalensis. | | 1975 | 796913 |
| histamine formation in spontaneous gastric carcinoids of praomys (mastomys) natalensis. | | 1974 | 4852273 |
| a renal tumour of the nephroblastoma type in praomys (mastomys) natalensis. | | 1974 | 4366011 |
| seroprevalence of toxoplasma gondii in commensal rodents sampled across senegal, west africa. | risks related to toxoplasma gondii infection in humans remain poorly known in senegal. although rodent surveys could help to assess the circulation of t. gondii, they have seldom been set up in sub-saharan africa. the aim of this study was to examine toxoplasma seroprevalence in rodents from villages and towns across senegal. rodents were sampled in 40 localities using a standardised trapping protocol. detection of t. gondii antibodies was performed on 1205 rodents, using a modified agglutinatio ... | 2018 | 30016257 |
| fluorescence and electron microscopic histochemistry of endocrine-like cells in gastric mucosa and argyrophil tumor of praomys (mastomys) natalensis. analysis of 5-hydroxytryptamine, histamine, histidine decarboxylase, and aromatic amino acid decarboxylase. | | 1973 | 4770333 |
| ultrastructure of endocrine cells and argyrophil carcinoids of the stomach of praomys (mastomys) natalensis. | | 1973 | 4736894 |
| [infectious keratoacanthomas of the epidermis in praomys (mastomys) natalensis]. | | 1973 | 4709365 |
| tumors of the testes and seminal vesicles in praomys (mastomys) natalensis. | | 1972 | 4650201 |
| [cellular composition of the bone marrow of mastomys natalensis]. | | 1972 | 5021992 |
| the development of ultrastructural glomerular alterations in praomys (mastomys) natalensis. an electron microscopic study. | | 1972 | 4336536 |
| [normal values of various enzymes in the serum of mastomys natalensis (smith 1834)]. | | 1972 | 5036387 |