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PubMed1996

[Morphological study of laryngeal ganglions and associated nerve cells in humans and five mammals].

The arrangement and numbers of intralaryngeal ganglia and associated neurons in humans and four mammals (dogs, rabbits, guinea pigs and rats) were investigated morphologically and compared with the results obtained in the cat which have been reported previously. Intralaryngeal ganglia were mostly distributed in branches of the internal branch of superior laryngeal nerve in all species, dorsal and/or dorsolateral to the posterior cricoarytenoid muscle in humans, dogs and cats and around the inferior laryngeal nerve in humans, dogs, cats, guinea pigs and rats. The total number of laryngeal ganglionic neurons was 2,000 to 2,400 in humans, 300-450 in dogs, 600-800 in cats, 250-320 in rats, and 100-150 in rabbits and guinea pigs. More than 80 percent of ganglionic neurons were present in the supraglottis in all species, except the rat, in which about 60 percent were in the subglottis. Each ganglion in all species existed within the nerve bundle, and was chiefly encapsulated with fibrous tissue, many ganglionic cells, glial cells, Schwann cells, vessels and connective tissue. The present morphological study of intralaryngeal ganglia in humans and four mammals suggests that the laryngeal ganglionic neurons have the same arrangement as in cats.

Adult↗
PubMed1997

Patterns of association with host and habitat: antibody reactive with Sin Nombre virus in small mammals in the major biotic communities of the southwestern United States.

The distribution and prevalence of antibody reactive with Sin Nombre virus were determined in mammals in biotic communities of the southwestern United States. Small mammals (n = 3,069) of 69 species were trapped in nine communities from lower Sonoran desert to alpine tundra. Antibody was found in rodents from all communities (overall prevalence = 6.3%); prevalence was lowest at the altitudinal and climatic extremes (0.4% in desert and 2.0% in alpine tundra). Antibody occurred in 11% of 928 deer mice, 20% of 355 brush mice, 23% of 35 western harvest mice, and 12% of 24 Mexican voles. No infected deer mice were found in desert habitat; prevalence varied from 4% in chaparral to 17% in pinyon-juniper. Brush mice were frequently infected in chaparral and montane forest (25%). Seropositivity was higher in males and in heavier animals, suggesting horizontal transmission among adult males. Decreasing prevalence with age among the youngest deer mice suggests that infected dams confer passive immunity to pups.

Altitude↗
PubMed1996

Auditory quality cues are more effective than auditory location cues in a R--no R (go--no go) differentiation: the extension of the rule to primitive mammals (American opossum, Didelphis virginiana).

Discrimination learning of instrumental responses to auditory compound stimuli was investigated in opossums using the R-no R (go-no go) differentiation. Each compound stimulus consisted of two factors: quality and location. Each correct response performed to the conditioned positive, or "safe" stimulus, was rewarded by food and never punished. Each incorrect response performed to the conditioned negative, or "warning" stimulus, was punished by an electric shock. In subsequent testing, each opossum proved to use only the quality cues to solve the task even though later testing showed them capable of using the location cues. Thus, the rule discovered in higher mammals, that the efficacy of auditory stimuli in differentiation depends on the perceptual ability of the animal as well as the type of the behavioral response with which the animal is confronted, may be extended to neurologically primitive mammals and also to a joint conditioned approach-avoidance method.

Acoustic Stimulation↗
PubMed1979

Causes of death in marine mammals stranded along the Oregon coast.

Sixty-eight marine mammals stranded on the Oregon beaches were examined at necropsy. Gunshot was the primary cause of death in 30% of the pinnipeds examined. Bacterial infections (27%) and parasitism (27%) were also of major importance in the death and debilitation of Oregon marine mammals. Traumatic death or debilitation other than gunshot was observed in 11 animals (16%). Predation, starvation due to neonatal abandonment, viral encephalitis (presumptive diagnosis), dystocia and neoplasia were diagnosed as primary or contributory causes of stranding.

Animals↗
PubMed1980

Small mammals and white-tailed deer as possible reservoir hosts of Brucella abortus in Texas.

Four hundred sixty-eight wild mammals were collected from four ranches in Texas where Brucella-infected cattle herds are maintained, and examined as possible reservoir hosts for Brucella abortus. Seventy-one serums from five species were tested for Brucella antibodies. Liver and spleen from 453 mammals (14 species) were cultured for B. abortus. Results of the serologic and bacteriologic examination of rodents, opossums (Didelphis virginiana), raccoons (Procyon lotor) and white-tailed deer (Odocoileus virginianus) did not provide evidence of an extrabovine reservoir of B. abortus.

Animals↗
PubMed1981

The efficacy of UV irradiation in the microbial disinfection of marine mammal water.

A study was made on the efficacy of a commercial ultraviolet (UV) sterilizer in reducing the number of bacteria and yeasts ina saline, closed-system marine mammal complex. UV irradiation was effective in lowering bacterial counts in the effluent of the unit (greater than 75% reduction), but bacteria in more remote parts of the water system reached levels equal to or greater than pre-UV counts. Yeast reduction was considerably less, and a trend similar to that of the bacteria was observed in remote sections of the water system. It is concluded that UV irradiation is of limited value in the disinfection of marine mammal water. Factors contributing to the poor performance of the sterilizer were the long recycle time of the water and lack of a residual effect.

Animals↗
PubMed1997

Serologic survey for phocid herpesvirus-1 and -2 in marine mammals from Alaska and Russia.

Blood samples were collected from 1,042 marine mammals off the coast of Alaska (USA) and Russia during the period 1978 to 1994. Eight species of pinnipeds were represented. Sera were tested for presence of neutralizing antibodies to both the PB84 isolate of phocid herpesvirus-1 (PhHV-1) and the 7848/Han90 strain of phocid herpesvirus-2 (PhHV-2). Species-specific antibody prevalences ranged from 22% to 77% for PhHV-1 and 11% to 50% for PhHV-2. Species-specific antibody prevalences for PhHV-1 were greater than or equal to prevalences for PhHV-2. For both viruses and each host species, differences in antibody prevalences were not related to: (1) sex, (2) location of capture, or (3) year of collection. Antibody prevalence of PhHV-1 in walruses (Odobenus rosmarus) could be quantitatively predicted as a function of age. These two viruses have distinct biological properties and based on current data the epizootiology of the two viruses is different, as well. No evidence of herpesvirus-induced mortality has been detected in areas included in this survey. Based on results of this survey, neither PhHV-1 nor PhHV-2 are considered significant mortality factors in mammals which inhabit the marine environment off the coast of Alaska or Russia.

Age Factors↗
PubMed2003

Characterization and clinical manifestations of Arcanobacterium phocae infections in marine mammals stranded along the central California coast.

Between 1994 and 2000, 141 Arcanobacterium phocae isolates were recovered from marine mammals that stranded along the central California coast (USA). Arcanobacterium phocae was cultured from tissue sites with abnormal discharge or evidence of inflammation in 66 California sea lions (Zalophus californianus), 50 Pacific harbor seals (Phoca vitulina richardii), 19 northern elephant seals (Mirounga angustirostris), five southern sea otters (Enhydra lutris nereis), and one common dolphin (Delphinus delphis). The overall prevalence of A. phocae among cultured stranded marine mammals was 8%. This is the first report of A. phocae in animals from the Pacific Ocean. Sequence analysis of a portion of the 16S ribosomal RNA gene confirmed recent isolates as A. phocae. Prior to phylogenetic testing and the routine use of the esculin hydrolysis and motility tests, A. phocae isolates may have been misidentified as Listeria ivanovii. Arcanobacterium phocae was commonly isolated from superficial abscesses, was often present in mixed infections, and was susceptible to all antimicrobial agents tested.

Abscess↗
PubMedDate not supplied

[Characteristics of distribution of fleas from small mammals and birds in the southern taiga of Priirtysh'ie].

The analysis of the landscape distribution of fleas from small mammals and birds in the southern taiga of Priirtishje is given. According to their abundance and faunistic composition the population of fleas from small mammals can be arranged into four groups: fleas of forest floodland landscape, those of forest-meadow floodland landscape, fleas of settlements and bogs.

Animals↗
PubMedDate not supplied

On the presence of ganglion cells in the intracranial portion of the accessory nerve (XI cranial nerve) in some mammals.

The intracranial tract of the accessory nerve (XI cranial nerve) was studied in some mammals (equines, domestic and wild ruminants, pig, carnivores, rabbit, nutria, guinea pig, hamster, hedgehog). The specimens were embedded in paraffin or paraplast, the sections were stained with cresyl violet, haematoxylin and eosin, or submitted to argentic impregnation. Pseudounipolar ganglion cells were found in all the mammals examined, with the exception of the cat. The number of cells and their variability in the different species and subjects were related. The topography and morphology of the cells were described. This comparative study has demonstrated that the accessory nerve is not a entirely motor nerve, but it is a mixed, motor and sensitive, nerve. Nevertheless, we think further studies are necessary in order to establish the peripheral distribution, the central pathway and the functional role of the pseudounipolar neurons found in the intracranial tract of the accessory nerve.

Accessory Nerve↗
PubMed2000

Cortisol and prolactin concentrations during repeated blood sample collection from freely moving, mouse-sized mammals (Phodopus spp.).

BACKGROUND AND PURPOSE: Validation of a method for obtaining blood samples that does not change cortisol or prolactin concentrations yet allows serial blood samples to be collected from animals under anesthesia, without prior handling, from freely interacting social groups of small mammals. METHODS: Results from five experiments are reported. Male dwarf hamsters (Phodopus spp.) were housed in modified home cages under continuous flow of compressed air that could be switched to isoflurane in O2 vehicle without approaching the cages. RESULTS: Dwarf hamsters respond to manual restraint with behavioral distress and increase in the concentration of the dominant glucocorticoid, cortisol, and decrease in prolactin concentration. Both effects are evident within one minute. In contrast, when this new method was used, neither cortisol nor prolactin changed in response to repeated sample collection (up to 8 successive samples at 2 hour intervals), prolonged isoflurane exposure, or substantial blood volume reduction (30%). Prolactin concentration was suppressed and cortisol concentration was increased in response to stimuli from other hamsters tested without anesthesia. Suppression of prolactin concentration was graded in response to the degree of stress and equaled the pharmacologic reduction caused by bromocryptine mesylate (50 microg of CB154 x 3 days). CONCLUSIONS: The technique is superior to alternatives for studies of behavioral endocrinology of freely interacting small mammals.

Administration, Inhalation↗
PubMed1976

Comparative anatomy of cerebellar catecholamine innervation from teleosts to mammals.

The cerebellar innervation of the catecholamine (CA) neurons was experimentally investigated with histofluorescence method in the brains of the vertebrates from teleosts to mammals. In the teleosts the source for the cerebellar CA are composed of three CA neuron groups. Hypothalamic CA neuron group contributes mainly to innervation in the valvula cerebelli whose development is dependent on the high degree of the development of the lateral-line organ. CA neurons in the medulla oblongata might innervate the vestibulo-lateral lobe and corpus cerebelli. These two CA neuron groups appear to constitute the main source for the cerebellar CA, though it is certain that rhombencephalic CA neurons also send their axons to innervate the cerebellum. In the tailless amphibian which is devoid of the lateral-line nerves, cerebellar CA especially in the corpus cerebelli is supplied mainly by the rhombencephalic CA neurons which still remain in less developed stage in phylogenetic scale. In the bird, ascending CA neuron system is maintained by long axons and the anlage of locus coeruleus (LC) appear first in this class. A large number of CA nerve terminals in the cerebellum of the bird are supplied by both CA neurons of the dorsal part of the tegmentum and CA neurons disseminated in the tegmental reticular formation. In the mammals showing the highest development of the cerebellar and cerebral cortices, LC is well developed and cerebellar CA is supplied mainly by LC, though cerebellum is innervated by other CA neurons besides LC. Possible significance of the CA neurons on the development of the cerebellum in phylogeny was discussed.

Animals↗
PubMed1984

Muscularity as a function of species, sex and age in small mammals.

The size of individual skeletal muscles in mammals is well known to change with the degree of mechanical loading imposed on the muscle. Less clear has been the effect of changes in loading of the whole organism on size of the total skeletal musculature. Pitts and coworkers have provided valuable insights by dissection and weighing of the skeletal musculature of animals subjected to various chronic centrifugation, exercise and dietary regimens, and their recent findings are reported at this meeting. However, questions remain. Independently, our laboratory several years ago embarked on a systematic definition of body composition and energy metabolism changes as a function of sex and age in 5 species of small laboratory mammals, the mouse, hamster, rat, guinea pig and rabbit. Six animals of each sex were examined in 8 age cohorts ranging from 1 to 24 months for each of the 5 species.

Aging↗
PubMedDate not supplied

[The evolution of the structure of the neocortex in mammals: a new theory of cytoarchitecture].

INTRODUCTION: The evolution of the structural organization of the mammalian neocortex can only be appreciated studying its ontogenetic development. DEVELOPMENT: We studied its evolution in embryos of different mammals (hamster, mouse, rat, cat and man) using the Golgi method. Development of the neocortex starts with the establishment of a primordial plexiform layer (PPL) in the telencephalus. This PPL represents a primitive cortical organization which is shared by amphibians, reptiles and mammals. From the PPL derived: the layer 1 with its elements including: the Cajal Retzius cells (CR) and primitive afferent fibres of a possibly origin in mesencephalic nuclei and the elements the interstitial cells and afferent fibres of the subplaca. The formation of the PPL is a prerequisite for the subsequent formation of the cortical plate (CP) from which the remaining layers of the neocortex derived. The ascending neuronal migration, the morphology of pyramidal neurons and the inside outside arrangement of neurons within the CP are evolutionary processes controlled by the CR cells. These neurons secrete a glycoprotein reelin which attracts the migrating neurons toward the first layer. All migrating neuroblasts, guided by the radial glia, must reach layer 1, establish contacts with the CR cells, develop an apical dendrite and become pyramidal cells. Without losing either their original contact with layer 1 or their cortical level, each neuron has to elongate its apical dendrite to accommodate the arrival of subsequent neurons, such that all develop a common initial pyramidal morphology. Older neurons have longer apical dendrites and deeper cortical level than the newer ones. The subsequent morphological and functional maturation of the CP neurons also follows an ascending progression and is under thalamic control. Two basic types of neurons develop in the neocortex following its ascending stratification. Some neurons maintain their original contact with the first layer to become the pyramidal cells. Others lose their original contact with layer 1 and become stellate interneurons. These neurons are free to develop specific size, spatial morphology and synaptic endings. The CP is a mammalian innovation and represents a biologically open and stratified nucleus which adds, during mammalian evolution, new pyramidal cell strata to those already present. CONCLUSIONS: Based on the above observations, we propose a new cytoarchitectural theory and nomenclature for the structural evolution of the mammalian neocortex. The theory emphasizes the ascending structural and functional stratification of the mammalian neocortex and the increase in the number of pyramidal cell strata reflecting the motor needs of each species.

Animals↗
PubMedDate not supplied

[Determination of clotting factor VIII activity in mammals using the one-stage clotting and the chromogenic methods].

Two different laboratory assays exist for the determination of clotting factor VIII activities in human plasma. One method is based on the one-stage clotting principle, the other one on the chromogenic principle. To evaluate the suitability for veterinary medicine human plasma and plasma of ten mammalian species (pig, cattle, dog, cat, zebra, llama, snow leopard, greater kudu, horse-like antelope, mink) were examined with each method. Factor VIII activities in human plasma determined using both assays were in a good agreement. Results of factor VIII activities in plasma of mammals obtained with both methods were similar, if a species-specific reference plasma was used. The practicability of the chromogenic method was reduced. However, the factor VIII activities differed nonsystematically up to 500% between both methods, if a human plasma was used as a reference plasma. Determination of factor VIII activities in plasma of mammals using the chromogenic assay cannot be recommended.

Animals↗
PubMed2002

Urinary proteins and pheromonal communication in mammals.

Urinary proteins play a significant role as pheromones and pheromone-binders in mammalian reproduction and social behaviour. The present study was carried out to quantify the urinary proteins in five different mammalian species viz mouse, rat, rabbit, bovine and human. The results revealed that the male rodents excrete large amounts of urinary protein as compared to that of other mammals. In addition, the male mammals excrete a higher quantity of protein than do the females., suggesting the role of androgens in excretion of protein. The presence of higher concentration of urinary proteins in rodents suggests that the rodents depend more on urinary proteins for olfactory/social communication.

Androgens↗
PubMed1975

Myosin from fast and slow skeletal and cardiac muscles of mammals of different size.

The ATPase activity of myosin and contraction time in extensor digitorum longus muscle, soleus muscle and cardiac muscle was compared in mammals differing in size. It was shown that the myosin ATPase activity of homologous muscles decreases and contraction time increases with increasing size of animals. The rate of tryptic digestion of myosin, the electrophoretic pattern of light chains of myosin and the effect of p-chloromercuribenzoate on ATPase activity of myosin were also studied. All these three myosin properties are very characteristic when the myosin from a fast muscle is compared with the myosin from a slow muscle of the same animal, but no relationship between these three myosin properties and ATPase activity of myosin was found, when homologous muscles of various mammals were compared.

Adenosine Triphosphatases↗
PubMed2003

Nicastrin is required for assembly of presenilin/gamma-secretase complexes to mediate Notch signaling and for processing and trafficking of beta-amyloid precursor protein in mammals.

Recent studies indicate that nicastrin (NCT) and presenilins form functional components of a multimeric gamma-secretase complex required for the regulated intramembraneous proteolysis of Notch and beta-amyloid (Abeta) precursor protein (APP). To determine whether nicastrin is required for proteolytic processing of Notch and APP in mammals and the role of nicastrin in presenilin/gamma-secretase complex assembly, we generated nicastrin-deficient (NCT-/-) mice and derived fibroblasts from NCT-/- embryos. Nicastrin-null embryos died by embryonic day 10.5 and exhibited several patterning defects, including abnormal somite segmentation, phenotypes that are reminiscent of embryos lacking Notch1 or both presenilins. Importantly, secretion of Abeta peptides is abolished in NCT-/- fibroblasts, whereas it is reduced by approximately 50% in NCT+/- cells; the failure to generate Abeta peptides in NCT-/- cells is accompanied by destabilization of the presenilin/gamma-secretase complex and accumulation of APP-C-terminal fragments. Moreover, APP trafficking analysis in NCT-/- fibroblasts revealed a significant delay in the rate of APP reinternalization compared with that of control cells. Together, these results establish that nicastrin is an essential component of the multimeric gamma-secretase complex in mammals required for both gamma-secretase activity and APP trafficking and suggest that nicastrin may be a valuable therapeutic target for Alzheimer's disease.

Abnormalities, Multiple↗