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At least 1,135 records · Page 63Linked to original sources
PubMed2000

Role of mother-young interactions in the survival of offspring in domestic mammals.

The defining characteristic of mammals is that females nurse and care for their young; without this, the neonate has no chance to survive. Studies on wild and domestic species show that the neonatal period is the most critical step in the lifetime of a mammal. This review compares three well-studied species (the rabbit, pig and sheep) that differ in their parental strategies and in the problems that neonates have to overcome. As a general trend, mother-young interactions vary according to the maturity of the newborn, and the size of the litter. Neonatal survival relies to a great extent on an environment that is ecologically appropriate for the developmental stage of the neonate, and on optimum interactions with the mother. Adaptive maternal care supposes that the mother provides the basic needs of the neonate: warmth (in pigs and rabbits) or shelter, food, water and immunological protection (via colostrum) and, in some instances, protection from predators and other conspecifics. A major risk facing all neonates, other than the birth process itself, is inadequate colostrum intake owing to delayed suckling or competition with siblings, which leads to starvation, hypothermia or even crushing, as has been observed in pigs.

Animals↗
PubMed2005

Fowlpox virus as a recombinant vaccine vector for use in mammals and poultry.

Live vaccines against fowlpox virus, which causes moderate pathology in poultry and is the type species of the Avipoxvirus genus, were developed in the 1920s. Development of recombinant fowlpox virus vector vaccines began in the 1980s, for use not only in poultry, but also in mammals including humans. In common with other avipoxviruses, such as canarypox virus, fowlpox virus enters mammalian cells and expresses proteins, but replicates abortively. The use of fowlpox virus as a safe vehicle for expression of foreign antigens and host immunomodulators, is being evaluated in numerous clinical trials of vaccines against cancer, malaria, tuberculosis and AIDS, notably in heterologous prime-boost regimens. In this article, technical approaches to, and issues surrounding, the use of fowlpox virus as a recombinant vaccine vector in poultry and mammals are reviewed.

Animals↗
PubMed2005

Differential trappability of small mammals in three habitats of Southeastern Brazil.

We compared the trappability of marked and unmarked individuals in species of marsupials and rodents of three tropical assemblages of small mammals in Brazil. Two studies used trapping grids, one in cerrado and the other in an Atlantic forest reserve, whereas the study in a rural area used transects. In the two studies using trapping grids, marked animals were frequently more trappable than unmarked ones, but in some species this difference was not significant. In the rural area, marked and unmarked animals did not differ significantly. The number of recaptures per resident animal was higher in the two studies using trapping grids than in the rural area where transects were used. Differences in trappability between the three studies might have been caused by differences not only in trapping design (grids vs. transects), but also in the type of trap used, bait, and habitat. Although differential trappability tends to be considered the rule in small mammals, these results suggest that trappability of marked and unmarked animals may be specific for the particular combination of sampling design, field methods, and habitat under study.

Animals↗
PubMed1981

A comparative histochemical study on alkaline phosphatase of the anterior pituitary gland in various mammals.

Alkaline phosphatase was histochemically studied in the anterior pituitary gland of mammals. By the azo dye method, the enzymatic activity was observed on the cell membrane, and in the cytoplasm and Golgi apparatus of the glandular cells in the swine, dog and guinea pig, while it was found on the cell membrane and in the cytoplasm of the glandular cells in the cattle, sheep and rabbit but only in the cytoplasm of the glandular cells in the hamster, rat and mouse. By the lead citrate method, the enzymatic activity in the glandular cells decreased in all the mammals examined, and was hardly found in the hamster, rat and mouse. It was shown that the localization of alkaline phosphatase activity by the lead citrate method is finer than that by the azo dye method in the anterior pituitary gland. In the swine and dog, the cells with the enzymatic activity were found throughout the gland though they mainly concentrated in the zona tuberalis. In the castrated males, the enzymatic activity was stronger than that in the males and females, and the cells with the activity increased in number. From these results, these cells in the two species studied were regarded as gonadotrophs. Furthermore, it was suggested that the alkaline phosphatase in the glandular cells of the gland displays a high activity in active stage of the synthesis and/or release of gonadotrophic hormone, and have some connection with the regulatory mechanism of membrane permeability.

Alkaline Phosphatase↗
PubMed2003

Evidence of Brucella sp. infection in marine mammals stranded along the coast of southern New England.

After recent isolations of Brucella sp. from pinnipeds and cetaceans, a survey was initiated to investigate the prevalence of Brucella sp. infections and serologic evidence of exposure in marine mammals stranded along the coasts of Connecticut and Rhode Island. One hundred and nineteen serum samples from four species of cetaceans and four species of pinnipeds were collected from 1985 to 2000 and tested for antibodies to Brucella sp. using the brucellosis card test, buffered acidified plate antigen test, and rivanol test. In addition, 20 of these were necropsied between 1998 and 2000, with lymphoid and visceral tissues cultured for Brucella sp. Three of 21 (14%) harbor seals (Phoca vitulina) and four of 53 (8%) harp seals (Phoca groenlandica) were seropositive. Brucella sp. was isolated from two of four (50%) harbor seals and three of nine (33%) harp seals. Of the five animals with positive cultures, two were seropositive and three seronegative. Brucella sp. was most frequently cultured from the lung and axillary, inguinal, and prescapular lymph nodes. Tissues from which Brucella sp. was isolated showed no gross or histopathologic changes. These results indicate that marine mammals stranded along the coast of southern New England can be exposed to and infected with Brucella sp.

Animals↗
PubMed2001

Helminths from introduced small mammals on Kerguelen, Crozet, and Amsterdam Islands (southern Indian Ocean).

Four monoxenous nematodes and 1 heteroxenous cestode were found in 4 species of introduced small mammals on isolated sub-Antarctic islands of the Indian Ocean. In the Kerguelen Archipelago, Syphacia obvelata, Passalurus ambiguus (Nematoda: Oxyuridae), and Rodentolepis straminea (Cestoda: Cyclophyllidae) were respectively found in the house mouse Mus musculus, the rabbit Oryctolagus cuniculus, and the black rat Rattus rattus. One accidental nematode, Trichostrongylus sp. (Nematoda: Trichostrongylidae), was also found in a black rat on Kerguelen. On Possession Island (Crozet Archipelago), R. straminea was present in the black rat. On Amsterdam Island, the brown rat R. norvegicus harbored 2 species, R. straminea and Nippostrongylus brasiliensis (Nematoda: Heligmonellidae). The small number of founder hosts and the depauperate terrestrial communities on these remote islands explain the low diversity in the helminth communities of these introduced mammals compared with continental populations.

Animals↗
PubMed2002

Ecology and host specificity of laelapine mites (Acari: Laelapidae) of small mammals in an Atlantic forest area of Brazil.

Mesostigmatic mites of the Laelapinae Berlese, 1892 (Acari: Laelapidae) are nidicolous arthropods that commonly occur in the fur of Neotropical small mammmals. In this 2-yr study, the laelapine acarofauna associated with the small mammal community in an area of Atlantic forest on Ilha Grande, Rio de Janeiro State, was examined, including observations on patterns of host specificity, mite dispersal, ecology, and food habits. A total of 1,347 laelapines was sampled from the pelage of 6 species of small mammals (Marmosops incanus, Nectomys squamipes, Oryzomys russatus, Rhipidomys n. sp., Oxymycterus dasytrichus, and Trinomys dimidiatus), all of which occurred exclusively in monoxenous associations with their hosts. No evidence of a blood meal was observed in the gut of the mites. With the exception of the 2 species of Tur, mite populations on hosts were entirely or nearly restricted to adult females. These results, together with some morphological characteristics of laelapines, reinforce the hypotheses that Neotropical laelapine mites are not ectoparasitic, and that females disperse by phoresy.

Animals↗
PubMed2005

Molecular phylogenetics and diagnosis of Anisakis, Pseudoterranova, and Contracaecum from northern Pacific marine mammals.

Individual specimens of Anisakis, Pseudoterranova, and Contracaecum collected from marine mammals inhabiting northern Pacific waters were used for comparative diagnostic and molecular phylogenetic analyses. Forty-eight new sequences were obtained for this study of 14 Anisakis taxa, 8 Pseudoterranova taxa, 4 Contracaecum taxa, and 4 outgroup species. Partial 28S (LSU) and complete internal transcribed spacer (ITS-1, 5.8S, ITS-2) ribosomal DNA was amplified by the polymerase chain reaction and sequenced. Sequences of ITS indicated that Pseudoterranova specimens from Zalophus californianus (California sea lion), Mirounga angustirostris (northern elephant seal), Phoca vitulina (harbor seal), Enhydra lutris (sea otter), and Eumetopias jubatus (Steller's sea lion) exactly matched P. decipiens s. str., extending the host and geographic range of this species. Anisakis from northern Pacific marine mammals were most closely related to members of the A. simplex species complex. Comparison of Anisakis ITS sequences diagnosed the presence of A. simplex C in 2 M. angustirostris hosts, which is a new host record. Anisakis specimens from Phocoena phocoena (harbor porpoise), Lissodelphis borealis (Pacific rightwhale porpoise), and E. jubatus included 3 ITS sequences that did not match any known species. Contracaecum adults obtained from Z. californianus were most closely related to C. ogmorhini s.l. and C. rudolphii, but ITS sequences of these Contracaecum specimens did not match C. ogmorhini s. str. or C. margolisi. These novel Anisakis and Contracaecum ITS sequences may represent previously uncharacterized species. Phylogenetic analysis of LSU sequences revealed strong support for the monophyly of Anisakinae, Contracaecum plus Phocascaris, Pseudoterranova, and Anisakis. Phylogenetic trees inferred from ITS sequences yielded robustly supported relationships for Pseudoterranova and Anisakis species that are primarily consistent with previously published phenograms based on multilocus electrophoretic data.

Animals↗
PubMed2005

Prevalence of Cryptosporidium spp. and Giardia spp. in five marine mammal species.

Cryptosporidium spp. and Giardia spp. are protozoan parasites that are often associated with severe diarrheal disease in a variety of mammals. Although these parasites have been extensively studied in terrestrial ecosystems, little is known about either parasite in the marine environment. Therefore, the objective of this study was to determine the prevalence of both Cryptosporidium spp. and Giardia spp. in 5 marine mammal species. Fecal samples were collected from 39 bowhead whales (Balaena mysticetus), 49 North Atlantic right whales (Eubalaena glacialis), 31 ringed seals (Phoca hispida), 22 bearded seals (Erignathus barbatus), and 18 beluga whales (Delphinapterus leucas) between 1998 and 2003. Using an immunofluorescent assay, parasites were detected in the feces of bowhead whales, right whales, and ringed seals, while neither parasite was detected in samples from bearded seals or beluga whales. Overall, prevalences were highest in ringed seals (Cryptosporidium spp., 22.6%; Giardia spp., 64.5%) and right whales (Cryptosporidium spp., 24.5%; Giardia spp., 71.4%) and lowest in bowhead whales (Cryptosporidium spp., 5.1%; Giardia spp., 33.3%). To our knowledge, this is the first report of Cryptosporidium spp. and Giardia spp. in either whale species and of Cryptosporidium spp. in the ringed seal.

Age Distribution↗
PubMed2006

Migration of Neodiplostomum leei (Digenea: Neodiplostomidae) neodiplostomula to the livers of various mammals.

Of morphologically indistinguishable small-sized neodiplostomula in the grass snake Rhabdophis tigrina in the Republic of Korea, some, such as Neodiplostomum seoulense, mature into adults in the intestines of rodents, whereas others, such as Neodiplostomum leei, migrate to rodent livers and mature in the intestines of chicks. In the present study, we aimed to observe in more detail the extraintestinal migration and development of N. leei by using various animal models, i.e., mice, rats, hamsters, rabbits, cats, and chicks. In mammals, small-sized neodiplostomula (N. leei) inoculated orally penetrated the intestinal wall, entered the peritoneal cavity, and oriented to the liver without passing through any other organ. In rodent livers, the neodiplostomula were surrounded by host inflammatory cells and fibrotic tissues from day 10 postinfection (PI); the worms were found dead by day 56 PI. When neodiplostomula from rodent livers were transferred orally to mammals, they reoriented to the liver, although they were able to develop into adults in the chick intestine by day 6-7 PI. The possibility of human infections, i.e., liver migration, by N. leei neodiplostomula, among snake consumers, warrants investigation.

Animals↗
PubMed1976

Blood corticosteroids in Australian marsupial and placental mammals and one monotreme.

Peripheral blood corticosteroid levels were determined in nine species of Australian marsupial (Eastern grey kangaroo, black-tailed, Bennett's and pademelon wallabies, quokka, wombat, koala and Western native and tiger cats), one species of monotreme (echidna) and one placental Australian mammal (dingo). Animals were obtained or bled with minimal disturbance and came from areas considered to have adequate sodium content of the vegetation. Aldosterone, corticosterone, cortisol, 11-deoxycorticosterone and 11-deoxycortisol were measured and levels found to be similar to five introduced eutherian species (sheep, cow, dog, fox and man) with the exception of the koala and the wombat. Cortisol was the predominant corticosteroid, except in the koala, which produced corticosterone in relatively the greatest quantity, and the wombat which produced more 11-deoxycortisol. Steroid levels were generally low in the wombat. ACTH administered to the koala changed its pattern of corticosteroid secretion from predominantly corticosterone to cortisol. In the dingo, administration of ACTH caused rises in corticosteroid levels similar to those seen in most other eutherian mammals.

Adrenal Cortex Hormones↗
PubMed2006

A comparison of the effects of single and repeated exposure to an organophosphate insecticide on acetylcholinesterase activity in mammals.

Exposure to organophosphate (OP) pesticides can occur in free-living mammals in treated areas. Risk to nontarget animals from OPs usually is assessed with acute exposure data, but exposure of wild animals is likely to be intermittent and chronic. We compared the effects of single or repeated (hourly and daily) exposure to dimethoate on acetylcholinesterase (AChE) activity in laboratory mice to assess the suitability of standard laboratory tests for assessing risk. Mice were exposed either to a single dose (10 or 30 mg/kg) or to short-term repeated (three hourly doses of 10 mg/kg) intraperitoneal doses of dimethoate, and brain and serum AChE activity were measured. No significant difference was found in the degree of inhibition of AChE activity following acute and short-term repeated exposure. In a second experiment, mice were given three daily doses of 10 or 20 mg/kg of dimethoate, and both AChE activity and hepatic cytochrome P450 enzyme activity were measured. Daily exposure resulted in a dose-dependent decline in brain and serum AChE activity, and inhibition increased progressively with successively repeated exposures. However, this effect was relatively small compared to the effect of dose. Cytochrome P450 enzyme activity (CYP2B) was inhibited in the dimethoate-dosed mice. Our results indicate that acute dose-response toxicity studies are suitable models for predicting the likely occurrence of adverse effects from either short- or longer-term exposure of wild mammals to anticholinesterase compounds. Likely differences in exposure pattern between the laboratory and the natural environment are unlikely to bias the predictive power of these studies significantly.

Acetylcholinesterase↗
PubMed2006

Cloning of putative uncoupling protein 1 cDNA in a cold-intolerant mammal, the house musk shrew (Suncus murinus).

The house musk shrew (Suncus murinus), or suncus, is a unique experimental animal. We recently showed that this mammal is cold intolerant and hypothesized that its sensitivity to cold is caused by low thermogenic activity in brown adipose tissue (BAT). Thermogenesis in BAT is performed by a unique mitochondrial protein, uncoupling protein 1 (UCP1). Interestingly, only eutherians possess UCP1, and some traits in the suncus resemble those in the Ucp1-ablated mouse, including cold intolerance, histology of BAT, and obesity resistance. In a previous study, we hypothesized that UCP1 may not be present in BAT of the suncus or may be dysfunctional. Therefore, we performed cDNA cloning of suncus Ucp1 and compared it to homologs from other species. The deduced amino acid sequence showed high similarity to other mammalian UCP1. Northern blot analysis revealed mRNA in BAT, as in other mammals. However, a difference in an amino acid residue was observed in an important residue for thermogenesis. Genomic sequence analysis showed that this difference existed in our two genetically distant laboratory colonies. These results suggest that cold intolerance in the suncus is derived from low thermogenic activity of UCP1 and may exist in wild house musk shrews.

Amino Acid Sequence↗
PubMed2002

Phagocytosis of apoptotic cells in mammals, caenorhabditis elegans and Drosophila melanogaster: molecular mechanisms and physiological consequences.

Phagocytosis is the necessary corollary of apoptosis. It leads to the clearance of apoptotic cells by phagocytes, which can be 'professional' or 'amateur'. I review the known molecular aspects of phagocytosis of apoptotic corpses in mammals, Caenorhabditis elegans and Drosophila melanogaster from the point of view of the phagocyte and the apoptotic corpse. I highlight recent advances made in the field and discuss the physiological outcomes and consequences of this process. Indeed, phagocytosis of apoptotic cells is important in shaping or remodeling tissues to maintain their integrity and specialized functions during development and wound healing. It also contributes to the development of inflammation and/or its resolution after an injury or infection. This perhaps explains why the molecular mechanisms of phagocytosis of apoptotic cells are redundant and complex in mammals and suggests why they appear to have been mostly conserved through evolution. Caenorhabditis elegans has already proven to be useful in genetically dissecting the molecular mechanisms underlying phagocytosis of apoptotic corpses by 'amateur' neighboring cells. Drosophila melanogaster will become the model of choice in genetically dissecting the molecular mechanisms underlying phagocytosis of apoptotic cells by 'professional' phagocytes such as macrophages.

Animals↗
PubMed1997

Comparative study of sound localization and its anatomical correlates in mammals.

One of the fundamental features of hearing is the ability to localize the sources of sounds, particularly brief sounds, which may warn of nearby animals. Yet not all mammals localize sound equally well with threshold acuity ranging from about 1 degree for elephants and humans to more than 25 degrees for gerbils and horses and a near absence of localization in some subterranean species. During the past decade evidence has accumulated that this variation cannot be accounted for simply by the availability of the physical cues for locus. Nor does it appear to be a function of an animal's lifestyle. Rather sound-localization acuity in mammals appears to be a function of the precision required of the visual orienting response to sound. Thus the neural integration of hearing and vision in cortex, as well as in multimodal subcortical structures, is a reflection of their behavioral integration and evolutionary coupling.

Animals↗
PubMed2003

Human neurobrucellosis with intracerebral granuloma caused by a marine mammal Brucella spp.

We present the first report of community-acquired human infections with marine mammal-associated Brucella spp. and describe the identification of these strains in two patients with neurobrucellosis and intracerebral granulomas. The identification of these isolates as marine mammal strains was based on omp2a sequence and amplification of the region flanking bp26.

Adolescent↗
PubMed1973

Fleas (Siphonaptera) Infesting Small Mammals From The Western Oriental Region.

Nine species of fleas representing 4 families were collected in 1972 form 14 species of small mammals: 2 hedgehogs, 1 shrew, 2 bats, 8 rodents and 1 mongoose. Most specimens were from 7 localities in Karachi District. Xenopsylla astis accounted for 78% of the 404 fleas collected. Collection data, especially flea-mammal associations and locality records, are presented and discussed.

Journal Article↗
PubMed1999

Karyotypes of Pneumocystis carinii derived from several mammals.

Pneumocystis carinii is the most important opportunistic pathogen of humans in the world. Pneumocystis carinii is experimentally detected in the lungs of rats, mice, rabbits, and monkeys, however, the organisms from different mammals are identical in microscopic morphology. The present study tried to find out more mammalian hosts of P. carinii and also to differentiate the organisms from different mammals by karyotyping. Rats, mice, hamsters, rabbits, cats, and dogs were successfully infected by P. carinii, but guinea pigs and pigs were not. Karyotype of P. carinii from rabbits showed similar size range of chromosomes with that of the prototype, but in different pattern. The patterns from cats and dogs were also different from that of rats. The present study confirms that cats and dogs are infected by P. carinii and at least total three karyotype strains of P. carinii are proven in Korea.

Animals↗