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At least 1,675 records · Page 93Linked to original sources
PubMed1975

[Blood parasites of small wild mammals in Czechoslovakia].

The author investigated 4,853 specimens of wild living small mammals (43 species: Insectivora, Chiroptera, Lagomorpha, Rodentia, Carnivora) from Czechoslovakia for blood parasites. Trypanosomes were found in Talpa europaea, Sorex alpinus, Crocidura suaveolens, Myotis myotis, Apodemus sylvaticus, Apodemus flavicollis, Mus musculus, Rattus norvegicus, Clethrionomys glareolus and Microtus agrestis. Babesia was detected in Myotis emarginatus, Myotis myotis, Clethrionomys glareolus, Microtus arvalis and Microtus agrestis. Grahaemella was found in Talpa europaea, Sorex araneus, Neomys fodiens, Neomys anomalus, Myotis emarginatus, Myotis myotis, Apodemus sylvaticus, Apodemus flavicollis, Apodemus microps, Apodemus agrarius, Mus musculus, Clethrionomys glareolus, Arvicola terrestris, Pitymys subterraneus, Microtus arvalis, Microtus agrestis, and Microtus oeconomus. Spontaneous Bartonella-infection was ascertained in one Microtus arvalis and, in erythrocytes of one Sorex araneus, parasitic organisms very similar to Bartonella were found.

Animals↗
PubMed1975

Leptospirosis in selected wild mammals of the Florida panhandle and southwestern Georgia.

A group of 144 wild mammals, including white-tailed deer, cottontail rabbits, fox squirrels, gray squirrels, raccoons, opossums, a bobcat, and various small rodents was examined for cultural or serologic evidence of leptospiral infection. Leptospires were isolated from 1 of 25 rabbits, 1 of 27 fox squirrels, 1 of 26 gray squirrels, 4 of 18 mice and rats, 8 of 21 raccoons, 7 of 17 opossums, and a bobcat. Isolations were not made from 6 deer examined. Serotypes isolated were Leptospira interrogans, serotype grippotyphosa and L interrogans, serotype ballum. New host-serotype relationships were noticed in the following instances: bobcat: grippotyphosa, and gray squirrel: ballum. These studies further confirm the occurrence of grippotyphosa in the fox squirrel. Serologic response in these animals did not necessarily correlate with isolations, although some relationship was noticed in raccoons and opossums.

Animals↗
PubMedDate not supplied

[Retrospective estimate of the individual history of life in population studies on mammals].

Analysis of the recording structures in mammals, such as dentine, cementum, or bone tissue, makes it possible to estimate the parameters of individual history of life: age at the moment of death, seasons of death and birth, growth rate, age of sexual maturation, etc. Using the reindeer (Rangifer tarandus) as an example, it has been shown what specific life features essential for population studies may be estimated when only mandibles with teeth are available.

Age Factors↗
PubMed2001

Distribution of tissue kallikrein in the integumental blood vessel system of wild mammals.

The study demonstrates tissue kallikrein with the help of a very sensitive immunohistochemical B-SA method in smooth muscle cells and myocytes / pericytes of the wall of subepidermal arterioles and capillaries of 17 mammalian species from 6 different orders. Positive immunoreactions could also be detected in the wall of blood vessels near to and between hair follicles and skin glands. The reaction staining in subepidermal blood vessels was particularly distinct in animals with a vital epidermis that was significantly thicker than 20 microm. The results obtained are discussed with special regard to the general skin biology of the wild mammals studied, considering comparative hair coat density and normal hazards to the integument.

Animals↗
PubMed1975

[Comparative study of respiratory exchanging surfaces in birds and mammals].

Anatomical studies of the respiratory apparatus of birds show evidences for a gas exchanging tubular system (parabronchi and air capillaries); these exchanging structures are entirely dissociated from the ventilatory drive acting on the air sacs. A "cross-current" gas exchanging system (perpendicular disposition of air and blood capillaries) allow a good wash-out of carbon dioxide (PaCO2 lower than PECO2). The great efficiency of this lung is allowed by its very large diffusive surface (ASa) and by the high values of lung specific oxygen diffusing capacity (DO2/ASa) and of O2 extraction coefficient in inspired air. The ventilatory pattern of birds is characterized by a greater tidal volume and a smaller respiratory frequency than in mammals of same weight. Respiratory centers of birds receive afferences from lung stretch receptors, CO2-sensitive lung receptors and arterial chemoreceptors.

Animals↗
PubMedDate not supplied

[The role of chloride channels and chloride ions in steroidogenesis regulation in the gonads of amphibians, birds and mammals].

The paper represents the first review of data on the involvement of chloride channels (their inhibitors and media, in which chloride ions are substituted for anions that poorly penetrate in the cell) in the regulation of basal and gonadotropin-stimulated steroidogenesis in the gonads of amphibians, birds, and mammals. Possible causes are considered for different reactions of the gonad steroidogenic cells in representatives of different vertebrate classes to a decreased medium concentration of chloride and the involvement of chloride channels and/or chloride ions in the regulation of steroidogenesis is discussed.

Amphibians↗
PubMed1975

[Comparative anatomy of the arterial and venous vascularization of the septomarginal trabecula in man and mammals].

By means of naked-eyed dissections and microscopic examinations of the right ventricle in 71 mammals, the authors explained the contents of the trabecula septomarginalis. Besides the right branch of the atrioventricular bundle, they always observed a long artery running deeply from the left coronary artery to the anterior papillar muscle where it joins some right coronary vessels. A few various venous capillaries may be observed going to the anterior interventricular vein or mouthing into the right ventricular chamber (Thebesian veins).

Animals↗
PubMed1976

[Morphofunctional characteristics of the lipids in the early embryogeny of placental mammals].

The comparative cytological study of lipids points to species specific character of lipid metabolism in early embryogenesis of placentate mammals. The general level of lipid metabolism is genetically determined in oogenesis being expressed by different loading of the ooplasm with substances of lipoid nature. At the cleavage stage lipids play a plastic role. Their significance as functionally active complexes is manifested in the period of the blastocyst formation, which is dependent on morphological differentiation and the beginning of the trophoblast functioning as an early metabolic organ.

Animals↗
PubMedDate not supplied

History of the anatomy of the funiculus umbilicalis in mammals.

The authors, based on a bibliographic search, present a brief survey of the history of the anatomical aspects of the funiculus in mammals, including the evolution of their interpretation and their relationship with the evolution of scientific and technological approaches to their study.

Animals↗
PubMed1992

[The chemosensory support of feeding behavior in precocial and altricial mammals during ontogeny].

The development of the structure and function of chemosensory apparatus of the tongue of mature and immature mammals was studied by scanning electron microscopy and in behavioral tests. Heterochronic development of receptors structures of dorsal surface of the tongue was established. At birth the chemoreceptors of body and root of the tongue were relatively mature in morphological aspects (the number of taste buds with pore). Taste pores in buds of anterior part of the tongue were found immediately at birth in mature and at the third week of postnatal period in immature animals. Behavioral tests found functional immaturity of chemosensory structures. Immature pups were able to recognize flavoured solutions only on the 7-10 day of age, and preference-aversion reactions of mature pups appeared to the third day of age. The data obtained are discussed in the respect of different ways of adaptation to food contacts with environment of the pups of mature and immature animals.

Aging↗
PubMedDate not supplied

A census of mammal populations in Punta Leona Private Wildlife Refuge, Costa Rica.

Population sizes of six mammal species were estimated using the King method during the late dry season (March) of 1996 in the Punta Leona Private Wildlife Refuge, Costa Rica. The white-faced monkey (Cebus capucinus), coati (Nasua narica) and nine-banded armadillo (Dasypus novemcinctus) with 148, 46, and 8 sighted individuals, respectively, demonstrated the largest populations in the refuge. The Central American spider monkey (Ateles geoffroyi), tamandua anteater (Tamandua mexicana), and variegated squirrel (Sciurus variegatoides) were also included in the census. Population densities are calculated, habitat types are described, and habitat use and activity periods are discussed.

Animals↗
PubMed1992

[The biological indication of the radiation load in forest communities of small mammals].

The content of cesium-137 in the organisms of different species of small mammals in forests of Bryansk Province five years later the Chernobyl accident varies to a great extent within some modal value n.10(-6)-n.10(-7) Cu/kg. Gamma-radiation is about 200 mcR/h. The revealed radiation level results in increased mortality during embryonal and postnatal periods, as during these periods a very intensive process of radiocesium accumulation in the animal organism takes place. Statistically valid differences of young and old animals ratio with the asymmetrical deviation towards old age groups have been found on the polluted territory at the end of summer season.

Accidents↗
PubMed1976

[Motricity of the female genital apparatus in mammals. Hormonal correlations].

The motility and the pharmacological reactivity of the uterine tract of mammals are linked with the ovarian cycle and the gestation. In the birds, the study of general scheme of the hormonal mechanism and the uterine motility involued in the ovulation, the egg formation and the uterine dilatation can be used as an experimental model of the mammalian gestation.

Animals↗
PubMed2003

[Morphology and structure of the nictitating membrane cartilage in mammals].

In 30 species of Mammals of varying body size (from rat to elephant), the form, dimensions and structure of the cartilage of the third eyelid were studied. The cartilage is a thin lamina concave in its corneal side, usually elongated in the oro-aboral direction. In the most species studied the outline of the cartilage may be inscribed in a triangle with a oral base, a dorsal margin, a ventral margin and an aboral apex. A study of stained sections revealed, in more than half of species, the presence of elastic fibres in the aboral part of cartilage; these fibres are particularly numerous, but non uniformly distributed, in the Equidae, lion and Suidae.

Animals↗
PubMedDate not supplied

Longevity of mammals in captivity--an update.

The life span of the various mammalian species differs and is an important parameter in comparative oncology; it should always be expressed as a percentage in relation to the potential life span of each species investigated. Mammals are a highly heterogenous class of animals. This heterogeneity is also reflected in a random variation of their life span by species.

Animals↗
PubMedDate not supplied

[Molecular markers and modern phylogenetics of mammals].

Application of modern molecular techniques such as molecular cloning, sequences and polymerase chain reaction of DNA resulted in the increasing of resolution of the phylogenetic analysis and enhanced the role of molecular markers in the evolutionary and taxonomic studies. However, certain properties of the molecular markers are to be taken into consideration when results of the molecular phylogenetic analyses are discussed. This survey reviews the advantages and shortages of different molecular markers (mtDNA and nDNA genes, satellite sequences, long and short retroposons) at the various taxonomic levels. The most part of new phylogenetic reconstructions are established on the results of mtDNA analysis and must be interpreted cautiously because of non-mendelian inheritance of mitochondrial genome. The extremely rapid rate of nucleotide change in mtDNA as compared with nDNA reinforces the saturation in nucleotide sequence and screens the phylogenetic signal. The analysis of nuclear genomes in constrained by that only truly orthologous genes are suitable for the phylogeny reconstruction. So there is a problem to distinguish genes from pseudogenes. Besides, there are some general problems of gene reconstruction such as nucleotide and amino acid compositional shift, long branch attraction and the choice of outgroup. Short interspersed nuclear elements (SINEs) may provide the most valuable phylogenetic information. The markers of multilocus DNA analysis (RAPD-PCR, IS-PCR, RELP, ISSR-PCR), their advantages and shortages are also discussed. A brief survey of the recent studies of molecular phylogeny of mammals for the period of about ten years is presented. The results based on the combined analysis of the mitochondrial and nuclear genes reject the reliability of some previously recognized supraordinal Eutherian taxa in favour of independent range of four main super-order clades: Afrotheria, Xenarthra, Euarchontoglires, and Laurasiatheria. Within these clades, monophyly of some of traditionally recognized orders was proved by molecular data. The recent advances of molecular phylogenetics are very encouraging. However, its future developments are full off serious difficulties. The problem of accumulation of the data turns into the problem of their correct analysis that is more difficult from the methodological point of view. The careful analysis of the conformities and contradictions between different data sets and looking for congruent conclusions deduced from different characters are the most fruitful way of further phylogenetic development.

Animals↗
PubMed2004

Genomic imprinting in mammals.

In contrast to the biallelic expression of most genes, expression of imprinted genes is monoallelic and depends on the sex of the transmitting parents. In humans it has been implicated in some developmental failures, neurodevelopmental and neurobehavioral disorders (such as Prader-Willi/Angelman, Silver-Russel or Beckwith-Wiedemann syndromes). The aim of this review is to present the phenomenon of parental imprinting as well as its molecular mechanism in various mammals. Several maternal and paternal imprinted genes and gene clusters are described.

Animals↗
PubMedDate not supplied

[A model for the age-dependent dynamics of growth of terrestrial mammals].

Two hypothetical biological mechanisms were proposed that largely determine the dynamics of growth of overland mammals. The first mechanism is the maintenance of a spatial similarity of the anatomy of the organism during its growth, and the second is the maintenance of the stability of the internal environment of the organism. On the basis of the advanced hypothesis, a model of age-dependent dynamics of growth was constructed, and a differential equation describing the changes in the body mass with time was derived. According to this model, the dynamics of growth and the mass of an adult individual are determined by two energy constants that characterize the mechanism of food assimilation and the energy expenditures for the movement of the individual in space. The deviation between the solution obtained and the experimental data on age-dependent changes in the mass of the human body was on the average 6%. These insignificant deviations were explained in the framework of the proposed hypothesis, which indicates its validity.

Age Factors↗