Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MAMMALS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,765 records · Page 98Linked to original sources
PubMed1993

[Piroplasmosis transmission in mammals. Epidemiological and prophylactic consequences].

The author analyses the nosological complex "piroplasmosis" and emphasizes the differences between the two sub-orders and families of "piroplasms". He studies the life-cycle of these parasites in mammals and in their vectors, acari belonging to the super-family Ixodoidea. He lays out the mechanisms of piroplasmosis transmission to animals and, sometimes, to man and draws from these data the epidemiological features and means of control.

Animals↗
PubMed1993

The gastric groove, a specific adaptation to nutritional ontogeny in eutherian mammals.

In this paper grooves or groove-like structures along the lesser gastric curvature in 19 eutherian mammal species are classified according to their muscular architecture and according to mucosal differentiations. It is shown that the differentiations along the lesser curvature represent morphological and functional links between the length of lactation and weaning times, on the one hand, and the types of digestion applied by the adult animal, on the other.

Adaptation, Physiological↗
PubMed1993

[Molecular systems in cellular interactions. II: Embryonal implantation in mammals].

In the present paper we consider the molecular mechanisms for cell recognition and cell adhesion on embryo implantation in mammals. In mammalian embryo implantation, the cellular interactions are complex, because several kinds of cells are involved: embryo trophoblast cells interact with several uterine cells and their respective extracellular matrices, participating lactosaminoglycans, integrins, cadherins and galactosyl transferases.

Animals↗
PubMedDate not supplied

Comparative study of sensitive and vegetative innervation of external and internal anal sphincter muscles in different mammals.

Proprioceptive innervation of the external anal sphincter muscle and the organization of the vegetative and sensitive nerve components of the internal and sphincter muscle have been studied in different mammals. The findings of typical muscle spindles in the external anal sphincter muscle were constant in the pig, frequent in the goat and cow, rare in the sheep and horse and absent in the roe and rabbit. In the pig, muscle spindles were observed in the entire extension of the muscle, while in the sheep, goat, cow and horse, the receptors were found only in the cranial portion of the muscle. In all the species studied, the internal anal sphincter muscle had numerous ganglion cells, isolated or grouped, and rare Pacinian, Pacinian-like, and Golgi-Mazzoni corpuscles. Their functional role has been hypothesized.

Anal Canal↗
PubMedDate not supplied

[Fertilization in mammals].

The mechanisms involved in gamete recognition and gamete fusion are identical to those allowing the fixation of somatic cells to a basal lamina and cell or viral fusion. Therefore specificity of the fertilization process only derives from the cytological originality of both gametes : acrosomal reaction and egg activation are two typical examples. Mitochondria, ARNs, proteins and metabolic reserves are brought by the oocyte. Sperm contributions to zygote development are essentially an oscillatory calcium protein, oscilline, and, the sperm proximal centrosome. In mammals, once the pronuclei are formed, paternal and maternal genomes never mix. A better knowledge of the female genital tract milieu, allowing long or very long sperm survival, is primordial to improve in vitro fertilization procedure.

Animals↗
PubMed1977

Excretion in mammals: role of the renal pelvis in the modification of the urinary concentration and composition.

The mammalian renal pelvis has previously been regarded as having no physiological function other than that of a receptacle for the urine before it moves through the ureter. It has long been known that the renal pelvis in mammals shows elaborate extensions that bring the urine in intimate contact with outer and inner medullary tissue. The epithelium covering these areas is of a type that indicates that transport of solutes and water can take place across it. Physiological studies have shown that urea and water readily move across the renal papillary epithelium. The pronounced ability of ruminants to conserve urea when placed on a low protein diet coincides with a highly developed renal pelvis with specialized fornices and secondary pouches. It is suggested that urea conservation in low protein animals takes place partly in the renal pelvic extensions where urea is returned to the blood. A hypothesis is also proposed for the concentrating mechanism in which recycling of urea from the pelvic urine across the papillary epithelium plays an important role.

Animals↗
PubMedDate not supplied

[The harderian gland in mammals: The biochemical and physiological aspects].

This review continues analysis of the published data on the Harderian gland in mammals (the first part described the structural properties). Here, biochemical and physiological aspects are considered, including the effect of photoperiod and sex hormones on the Harderian gland. The relationship between the Harderian and pineal glands as well as their production of biologically active indolamines and porphyrins are discussed.

Animals↗
PubMed1997

A computer-assisted method for the determination of hair cuticula patterns in mammals.

The study describes a rather simple, computer-assisted method for the determination of different mammalian species or groups with the aid of the cuticula pattern of guard hairs (primary hairs) following SEM presentation. The method is based on an image analysis program developed for metallographic investigations, and includes the evaluation of five parameters (scale area, scale perimeter, number of scales per mm2, ratio of scale width and height, scale index). The scale index as a combination of scale numbers per square unit and the width/height ratio proved to be most useful for a relevant species or group identification of mammals according to the hair cuticula pattern.

Animals↗
PubMed1997

[The morphofunctional organization of the accessory olfactory organ in mammals].

The study was performed in 180 fetuses of albino rat aged 12-21 d, cat--5-120 mm parietococcygeal length and man--4-70 mm parietococcygeal length, divided into histological slices. Vomeronasal organ of mammals, human included was found to be closely connected with nasal cavity, being its derivative. Within the period of primary palate formation in animals vomeronasal organ opens up into primary choanae, being linked both with oral and nasal cavities in similar extent. In following stages of development the period of secondary palate formation vomeronasal organ displays specific features of its structure.

Animals↗
PubMed1997

[Gradualism or punctualism: data on genetic differentiationof small mammals from the Holarctic region].

Genetic differentiation of taxa from three Holarctic and three originally Afrotropical phyla of small mammals was analyzed. Its extrapolation to the time scale revealed the following trends: (1) Distributions of fixed gene differences along the scale are relatively independent. (2) Extrapolation of these distributions to the time scale shows that the speciation process is discontinuous. It consists of relatively stable periods interrupted by speciation bursts. (3) Periods of speciation activity in different phyla coincide. In general, these results are consistent with the concept of punctuated equilibria and suggest that the speciation process is temporally discontinuous.

Animals↗
PubMed1996

Contribution to the knowledge of helminthofauna of wild mammals of Somalia.

Within a survey of parasitic infections in wild mammals of Somalia, during the first semester of 1983 and the second of 1984, endoparasites were collected from 11 host species: Gazella soemmeringi, Gazella spekei, Madoqua saltiana, Phacochoerus aethiopicus, Xerus rutilus, Lepus sp., Genetta genetta, Herpestes (Galerella) sanguineus, Felis sylvestris libyca, Felis caracal, Canis mesomelas. A total of 22 species of helminths (20 nematode and 2 metacestode species) were identified. Lepus sp. is a new host for Heteroxinema (P.) proboscidiphora and Herpestes sanguineus for Oxinema sp. Teladorsagia hamata had not been previously reported in G. spekei; the genital cone and the corresponding supporting apparatus of this nematode are described. Two metacestodes were collected from the mesenteric membranes of a P. aethiopicus. The shape, number and length of their rostellar hooks, the size of the larvocysts, the occurrence of pseudostrobilum, are similar to those of the Taenia regis metacestode: but the size and shape of the hooks of the Somalian warthog larvocysts are slightly different and they have not been recovered from the musculature as previously reported in the intermediate hosts of T. regis.

Animals↗
PubMed1996

Contribution to the knowledge of Ixodidae ticks of wild mammals of Somalia.

This study was based on material collected in 1983-1984 from wild mammals of the Middle Scebeli. Low Scebeli and Bay Regions of Somalia. A total of 292 specimens (156 males, 65 females, 70 nymphase, 1 larva) from 13 host species were examined. The following species of ixodidae were identified. Amblyomma variegatum (Fabricius, 1794); Haemaphysalis calcarata Neumann, 1902; Haemaphysalis spinulosa Neumann, 1906; Rhipicephalus armatus Pocock, 1900; Rhipicephalus pravus Donitz, 1910; Rhipicephalus pulchellus Gerastcker, 1873; Rhipicephalus sanguineus (Latreille, 1806); Rhipicephalus simus Koch, 1844. H. spinulosa was found throughout the majority of host species (10 mammalian species).

Animals↗
PubMed1997

[Theoretical rationale for structure-genotoxicity relationships in the series of halogenated short-chain aliphatic compounds for mammals and bacteria].

Structure-genotoxicity relationships for mammals and structure-mutagenic activity relationships for bacterial were derived in the series of halogenated short-chain hydrocarbons and alcohols, by using the calculated quantum chemical parameters, namely the energy differences of frontier molecular orbitals and the electronic characteristics of the probable metabolites.

Alcohols↗
PubMed1996

Comparative neurobiology of the optokinetic reflex in mammals.

Mammals have developed almost perfect functional adaptations of their eyes, central visual system and oculomotor system for high resolution and stable vision. This performance is subserved by stabilizing reflexes like the optokinetic and the vestibular ocular reflex. Visual information about retinal image slip is relayed through the nucleus of the optic tract in the pretectum and the terminal nuclei of the accessory optic system to the visual motor system. Retinal and more importantly cortical information is integrated in these nuclei to optimize visual control of gaze stabilization during ego-motion.

Anatomy, Comparative↗
PubMedDate not supplied

[Helminths in the small mammals of Zakarpats'ka Province (the eastern Carpathians, Ukraine)].

935 specimens of small mammals (21 species) from the Transcarpathian Province of Ukraine were examined to check a helminth infection. 666 animals (71.2%) were infected with 44 parasite species belonging to 22 families of 4 classes: Trematoda (7 species), Cestoda (18), Nematoda (18) and Acanthocephala (1). A carried out analysis of the distribution of parasite species among their host took in account a host biology and their landscape zone.

Animals↗
PubMed1976

[Comparative study of tracheal epithelium of different mammals].

Tracheal epithelia of ten different mammals were investigated with the light and the electron microscope. Characteristic differences were found concerning the thickness of the epithelia, the length of the cilia, the density of the cells in the epithelia, the numerical distribution of the different cells and their ultrastructure. Special attention was paid to the morphology of the kinetosomes. Brush cells and chromaffin cells, which are sparsely distributed in the different tracheal epithelia, were discussed.

Anatomy, Comparative↗
PubMed1997

[Caenorhabditis elegans and neuronal death in mammals].

The development of the nervous system implies not only the generation of neurons, but also their death. This neuronal death can occur through several mechanisms, one of them being apoptosis. This type of cell death seems to be also implicated in some neurodegenerative diseases. This study of the nematode Caenorhabditis elegans has led to the discovery of several genes controlling apoptosis in neurons. Two of them, the pro-apoptotic ced3 and the anti-apoptotic ced9, have mammalian homologs. The mammalian homologs to Ced9 form the Bcl-2 family and can be either pro-apoptotic or anti-apoptotic. Some of them, Bcl-x, and Bax have been shown to be involved in neuronal death during development in some pathological situations. The first mammalian homolog of Ced3 to be described was the Interleukin-1b Converting Enzymes (ICE). Since then, many other homologs of the proteases Ced3 and ICE have been discovered constituting the Caspases family. These Cysteinyl Aspartate Specific Proteases are pro-apoptotic in many different systems. Several studies using viral or peptidic inhibitors of the Caspases have demonstrated their role in neuronal death in vitro. In vivo, CPP32, a member of the Caspases family, has been shown to be clearly involved in the development of the nervous system. Finally, the analysis of apoptosis in Caenorhabditis elegans has led to the discovery of two families of genes involved in the cascade of events inducing neuronal death in mammals. Indeed, the Caspases seem to be controlled by the Bcl-2 family, as Ced3 is by Ced9.

Animals↗