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At least 523 records · Page 29Linked to original sources
PubMed1988

Neutrophil lactoferrin content: variation among mammals.

Lactoferrin (Lf) in blood and/or marrow neutrophils was semiquantified using indirect immunofluorescence technique in nine mammalian species. Neutrophil iron-binding reactivity (NFeBR), which corresponds primarily to Lf, was also visualized and semiquantified using functional cytochemical (FeNTA-AF) technique at the light microscopic level in these nine and in an additional fifteen mammalian species, and in selected species at the ultrastructural level. Neutrophil immunoreactive Lf was positively correlated with total cellular and granule content of NFeBR among these nine species, and with previously reported concentrations of neutrophil Lf quantified by radioimmunoassay. Relative levels of Lf in neutrophil extracts from rat, hamster, and human were confirmed using SDS-polyacrylamide gel electrophoresis and immunoblotting. Relatively high levels of immunoreactive neutrophil Lf and/or NFeBR were observed in carnivores (ten species) and primates (six species). Among rodents (five species), the levels were variable, and the artiodactyls (four species) studied had low levels. These results demonstrate that neutrophil Lf levels vary widely among mammalian species. In addition, FeNTA-AF technique provides a rapid means of evaluating animals for relative quantities of neutrophil Lf.

Animals↗
PubMed1990

Development of the giraffe horn and its blood supply.

The giraffe horn is an unusual cranial exostosis that lacks clear delineation and categorization as either horn or antler. The distinction between the two is made by contrasting their methods of development and basic composition. This process of development has not been detailed in the giraffe, a factor contributing to the difficulty in distinguishing the classification of these horns. In a chronological series of giraffe horns from prenatal and postnatal animals, we have observed unique morphologies that define their proper location on the skull, the blood supply to them, and the transitions involved in their histological development. While our observations have facilitated the classification of the giraffe horn, our interpretations were not always in accord with previous reports.

Animals↗
PubMed1991

Sympathetic innervation of the hindlimb arterial system in the giraffe (Giraffa camelopardalis).

We report the distribution of sympathetic nerves in the hindlimb arterial system of the giraffe based on the histochemical demonstration of monoamines by the sucrose-potassium phosphate-glyoxylic acid method. It is noted that the hindlimb arterial system shows regional variations in its sympathetic innervation with regard to the density and the penetration of the nerves into the tunica media not hitherto described. The femoral and popliteal arteries showed a paucity of sympathetic innervation. Distally the dorsal pedal and great metatarsal arteries showed sparse sympathetic innervation characterized by a tendency toward exclusion of the nerves toward the outer layers of the tunica media. In contrast, the anterior (cranial) tibial artery in the leg revealed a relatively rich pattern of sympathetic innervation and a greater penetration of the nerves into the tunica media. The latter part of the arterial system showed a marked thickening of the tunica media and luminal narrowing, thus suggesting a "sphincteric" function. It is conceivable that this sphincter subserves a dual function, namely, to modulate blood flow to the distal parts of the limbs, and secondly to channel blood to the thigh and crural musculature. Pertinent to this is the fact that the presumptive sphincter occurs immediately after the crural muscular branches are given off.

Animals↗
PubMed1991

The structural organization and adrenergic innervation of the carotid arterial system of the giraffe (Giraffa camelopardalis).

The sympathetic innervation of the giraffe (Giraffa camelopardalis) carotid arterial system is described in this study using the sucrose-potassium phosphate-glyoxylic acid (SPG) method. The brachiocephalic and bicarotid trunks showed a paucity of sympathetic innervation. Smooth muscle nests observed in the outer layers of the tunica media in these arteries revealed a rich network of sympathetic nerve fibres. The common carotid artery showed numerous sympathetic nerve fibres particularly in the outer muscular zone of the tunica media. The internal maxillary, ramus anastomoticus, and arteria anastomotica also revealed a rich sympathetic innervation and a deep penetration of the nerve fibres into the tunica media. It is suggested that the rich sympathetic innervation of the giraffe carotid arteries maintains a basal tonic state in the smooth muscle in the tunica media. This, in turn, may enable the animal to maintain a relatively high rate of blood flow in the carotid arteries in diastole despite the pressure run-off. It is further suggested that the muscular structure and dense sympathetic innervation of the internal maxillary and its branches to the carotid rete mirabile provide the animal with an array of mechanisms to modulate its cranial circulation particularly when it bends its head to drink.

Adrenergic Fibers↗
PubMed2005

Morphomolecular neuronal phenotypes in the neocortex reflect phylogenetic relationships among certain mammalian orders.

The cytoarchitecture of the cerebral cortex in mammals has been traditionally investigated using Nissl, Golgi, or myelin stains and there are few comparative studies on the relationships between neuronal morphology and neurochemical specialization. Most available studies on neuronal subtypes identified by their molecular and morphologic characteristics have been performed in species commonly used in laboratory research such as the rat, mouse, cat, and macaque monkey, as well as in autopsic human brain specimens. A number of cellular markers, such as neurotransmitters, structural proteins, and calcium-buffering proteins, display a highly specific distribution in distinct classes of neocortical neurons in a large number of mammalian species. In this article, we present an overview of the morphologic characteristics and distribution of three calcium-binding proteins, parvalbumin, calbindin, and calretinin, and of a component of the neuronal cytoskeleton, nonphosphorylated neurofilament protein in the neocortex of various species, representative of the major subdivisions of mammals. The distribution of these neurochemical markers defined several species- and order-specific patterns that permit assessment of the degree to which neuronal morphomolecular specialization, as well as the regional and laminar distribution of distinct cell types in the neocortex, represents derived or ancestral features. In spite of the remarkable diversity in morphologic and cellular organization that occurred during mammalian neocortical evolution, such patterns identified several associations among taxa that closely match their phylogenetic relationships.

Animals↗
PubMed1992

Visual factors in sound localization in mammals.

The ability of mammals to localize sound varies widely among species. During the past decade, evidence has accumulated that this variation cannot be accounted for simply on the basis of the availability of the physical cues for locus. Evidence is presented that a major factor in sound localization is the need to direct the field of best vision to a sound source for further scrutiny. Thus, species with broad fields of best vision (such as visual streaks) require less accurate information regarding the location of a sound source than do species with very narrow fields of best vision (such as foveae). To support this suggestion, data are reported for the width of the field of best vision in the form of retinal ganglion cell isodensity contours for thirteen species of mammals. The possible contribution of other factors including binocular fields, visual acuity, and the degree to which a species is predatory in lifestyle, is also examined.

Animals↗
PubMed1975

Binding of (T,G)-A--L by normal sera.

The synthetic polypeptide poly-L-(Tyr, Glu)-poly-DL-Ala--poly-L-Lys [(T,G)-A--L] was found to be bound not only by mouse immune serum, but also by nonimmune sera from several species. A combination of immunoelectrophoresis and autoradiography showed that albumin, beta-globulins and immunoglobulins in these sera may bind the antigen. This binding pattern is different, however, for the various species investigated.

Animals↗
PubMed1988

Immediate response to repeated capture and handling of wild impala.

The composition of blood from veld and boma (enclosure)-kept impala, obtained immediately after the animals were manually restrained, was compared to control values. Statistically significant differences existed between the values for hematocrit, lactate, glucose, and osmolarity of veld and boma-kept animals compared to control data. Cortisol values were significantly greater (P less than .05) in boma-kept animals (93 +/- 21 nmol/liter) but not in veld impala (11 +/- 3 nmol/liter). It is suggested that the high cortisol and other values measured in boma-kept impala were due to an anticipatory conditioned response in these animals which occurred prior to them actually being caught. Repeated capture and handling, over a period of several months, of boma-kept impala resulted in statistically insignificant decreases in the mean values of several variables. Although this is indicative of adaptation it is doubtful whether the animals would ever fully adapt to the procedures involved.

Adaptation, Physiological↗
PubMed2001

Transverse masticatory movements, occlusal orientation, and symphyseal fusion in selenodont artiodactyls.

Based on extensive experimental work on primates, two masticatory loading regimes have emerged as the likely determinants of mandibular symphyseal fusion-dorsoventral shear and lateral transverse bending (wishboning) (Ravosa and Hylander, 1994; Hylander et al., 1998, 2000). Recently, however, it has been argued that, rather than functioning to strengthen the symphysis during mastication, fusion serves to stiffen the symphyseal joint so as to facilitate increased transverse jaw movements during occlusion (Lieberman and Crompton, 2000). As part of this transverse stiffness model, it has been suggested that taxa with fused symphyses should also exhibit more horizontally oriented occlusal wear facets. Using a series of univariate and bivariate analyses, we test predictions of these three models in a sample of 44 species of selenodont artiodactyls. Consistent with the wishboning and transverse stiffness models, taxa with fused symphyses (camelids) have more horizontally oriented M(2) and M(2) occlusal wear facets, anteroposteriorly (AP) elongate symphyses, and relatively wider corpora. Contrary to the dorsoventral shear model, camelids do not have relatively deeper corpora (due to greater parasagittal bending). While taxa with ossified symphyses have relatively larger symphysis cross-sectional areas, this appears to be the byproduct of an increase in AP symphysis length due to greater lateral transverse bending of the mandible. Theoretical consideration of the biomechanics of mastication further suggests that strength, not stiffness, is the critical factor in determining symphyseal ossification. Thus, like anthropoid primates, fusion in selenodont artiodactyls appears to function in resisting increased wishboning stresses arising from an emphasis on transverse occlusal/mandibular movements and loads.

Animals↗
PubMed1983

Comparative and functional morphology of the stomach in the adult and newborn pigmy hippopotamus (Choeropsis liberiensis).

Examination of the topographical anatomy of the stomach complex and intestinal tract of an adult male and a newborn female pigmy hippopotamus (Choeropsis liberiensis) shows that the stomach consists of four chambers, the first three constituting the proventriculus and the fourth the glandular stomach. The proventriculus is made up of a visceral and parietal blind sac opening into a connecting chamber, which in turn opens into the glandular compartment. The walls of the proventricular chambers are covered with villi and non-glandular mucous membrane. The significant difference between the animals is that whereas the connecting chamber of the adult stomach lies transversely deep in the cranial part of the abdomen and connects with the glandular chamber on the right side, that of the newborn lies almost vertically and connects ventrally with the glandular compartment situated on the floor of the abdomen. A groove which in the adult runs more or less horizontally from the cardia through the visceral sac and connecting chambers is aligned almost vertically in the newborn. In the adult the connecting chamber is the largest compartment, but in the neonate the visceral blind sac and the glandular compartment are proportionally larger. Functional aspects of these anatomical differences are discussed in relation to suckling behavior.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗