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Biomedical subjects

E M Banks

Publications and source records attributed to E M Banks.

At least 19 recordsLinked to original sources

Epithelial lymphocyte and macrophage distribution in the adult and fetal equine lung.

Leucocytes in the lung epithelium play an important role in the ability of an animal to respond appropriately to inhaled pathogens. The distribution of lymphoid and myeloid cells associated with the lung epithelium was examined immunohistochemically throughout the respiratory tract of four horses, comprising two adults from an abattoir, one pregnant mare, and her fetus (in the final stage of gestation). Cross and tangential cryosections were labelled with monoclonal antibodies against T-cell, B-cell, macrophage/dendritic myeloid cell, and major histocompatibility Class (MHC) II surface antigens. Cell numbers were determined by microscopy. In the three adult horses, epithelial CD3+ T-cell numbers decreased progressively from the upper to the lower respiratory tract, but in the fetus there were low numbers of T cells (at most, 10% of those seen in the adult airways) and little variation in different parts of the respiratory tract. MHC Class II was expressed on the airway epithelium of the two abattoir horses, but not that of the mare and her fetus. In these two animals occasional large, mostly irregularly-shaped, Class II-positive cells were seen. Very few epithelium-associated cells in any animal were labelled by anti-CD21 antibody, which identifies B cells, or anti-myeloid cell antibodies; an anti-rat macrophage antibody (ED2) was shown, for the first time, to identify mature equine alveolar macrophages. Despite the small number of animals, the results suggest that in normal adult horses the greatest numbers of epithelial T cells are found where there is greatest contact with airborne antigens, and that there is constitutive epithelial MHC Class II expression. The low level of MHC Class II expression in the fetus, together with the reduced numbers of T cells, was consistent with the suggestion that the fetal immune system requires exposure to airborne stimuli for full development. The low level of MHC Class II expression in the mare may have reflected the immunosuppression that accompanies pregnancy.

Animals↗

Nitric oxide inhibits IgE-mediated degranulation of mast cells and is the principal intermediate in IFN-gamma-induced suppression of exocytosis.

IFN-gamma regulates various aspects of rodent peritoneal mast cell function, including mediator release, cell growth, TNF-alpha-mediated cytotoxicity, and MHC class II expression. We investigated whether the suppressive action of IFN-gamma on IgE/Ag-mediated degranulation of mast cells is mediated via synthesis of nitric oxide. Incubation of mouse peritoneal cells with L-NMMA, an inhibitor of nitric oxide synthase, or in medium lacking the nitric oxide precursor L-arginine reversed the inhibitory effect of IFN-gamma on Ag-induced serotonin release. Furthermore, the nitric oxide donors sodium nitroprusside and S-nitrosoglutathione inhibited degranulation, and this effect was direct, since it was seen equally on purified and unfractionated mast cells and occurred independently of IFN-gammaR expression. Additional experiments revealed that accessory cells in peritoneal cell populations were the principal target for the action of IFN-gamma and the main source of nitric oxide; the cytokine was more potent on unfractionated compared with purified mast cells, and IFN-gamma induced detectable nitrite production in mixed peritoneal cells, but not in purified mast cells. These studies show that IFN-gamma induces nitric oxide production in peritoneal cell populations, and that synthesized nitric oxide directly inhibits the IgE-mediated secretory function of mast cells. The activation of nitric oxide-producing cells in the tissue microenvironment may be important in the control of mast cell-dependent allergic reactions.

Animals↗

A comparative study of peritoneal mast cells from mutant IL-4 deficient and normal mice: evidence that IL-4 is not essential for mast cell development but enhances secretion via control of IgE binding and passive sensitization.

IL-4 enhances the growth and secretory function of mouse connective tissue type mast cells in vitro. To examine further the mast cell regulatory role of IL-4 we compared certain phenotypic and functional characteristics of peritoneal mast cells from mutant IL-4 deficient (IL-4(-/-)) or normal wildtype (IL-4(+/+)) mice. No differences were seen between mast cells from the two types of mouse in terms of numbers, histamine content, cell size, ultrastructure and number and size of granules. Mast cells from IL-4 deficient or wildtype mice responded equally to specific IgE/antigen and IL-4. However, Fc epsilon RI of IL-4(-/-) (in contrast to wildtype) mast cells were not pre-loaded with IgE, which would be expected to facilitate passive sensitization. Moreover, the in vitro total IgE binding capacity of mutant mast cells was significantly less than that of wildtype. Further in vitro experiments showed that IL-4 selectively enhanced IgE/antigen- rather than anti-IgE-induced degranulation from normal mast cells, and this effect was accompanied by an IL-4 induced increase in IgE binding capacity. In conclusion, IL-4 is not essential for peritoneal mast cell growth and exocytosis but regulates secretion via control of IgE binding and sensitization.

Animals↗

Interactions of IFN-gamma with IL-3 and IL-4 in the regulation of serotonin and arachidonate release from mouse peritoneal mast cells.

We have examined the interactions between interferon-gamma (IFN-gamma), interleukin-3 (IL-3) and interleukin-4 (IL-4) in the regulation of IgE/antigen-induced secretory responses of mouse peritoneal mast cells. The cytokines were added either alone or in various combinations to cultured mast cells sensitized passively with IgE antibody. In experiments with unfractionated peritoneal cells (containing approx. 1% mast cells), IL-3 and IL-4 enhanced in an additive manner antigen-induced release of serotonin (5-HT), while IFN-gamma inhibited release regardless of whether IL-3 and/or IL-4 were present. In experiments employing mast cells purified to > 90%, IL-3 and IL-4 retained their enhancing activities whereas the inhibitory effect of IFN-gamma was considerably diminished. Nevertheless, IFN-gamma still inhibited significantly IL-4-enhanced secretion. The effects of IL-3 and IL-4 +/- IFN-gamma on arachidonate release were identical to those seen for 5-HT release, indicating that the secretion of both preformed mediators and newly synthesized eicosanoids is regulated in a similar way by these cytokines.

Animals↗

Evidence for aggression-modulating pheromones in prepuberal pigs.

A series of behavioral bioassays were conducted to determine the aggression-influencing properties of urine and other fluids. Subjects were prepuberal castrated male and female domestic pigs from commercial stocks. In the behavior assay, pigs were painted with a test fluid and grouped for a videotaped 90 min observation period. Experiment 1 validated use of videotape recording by showing that duration of aggressive behavior registered live was correlated with that obtained from video records (R = .98). In experiment 2, urine and plasma collected from actively aggressive pigs reduced the durations of aggressive behavior of test pigs compared with the effects of urine and plasma collected from socially stable, handled pigs. In Experiment 3, a new set of test pigs confirmed that urine from fighting pigs reduced the duration of attack by test pigs compared with urine from nonfighting, handled pigs. In addition, the suggested reproductive pheromone, 5 alpha-androst-16-en-3-one, substantially reduced the duration of attack. The effects of gender and aggressive state of urine-donor pigs on test pigs was determined in Experiment 4. Again, urine from castrated male and female aggressive pigs reduced attack by test pigs compared with the level of attack shown by test pigs coated with urine from handled castrated males and females. Urine from fighting and nonfighting intact males had similar effects on test pig aggression. In Experiment 5, urine was obtained from nonhandled, socially stable pigs in their home pens and again from the same pigs after they had been regrouped (aggressive). These urine types had no significant influence on test pigs' aggression over the entire 90-min observation. However, during the first 30 min nonhandled, nonfighting pigs' urine induced less aggression in test pigs than did urine from fighting pigs. Results indicate that urine and blood plasma from aggressive pigs reduces aggression by test pigs compared with the effects of urine from handled pigs. Handling may increase the aggression-promoting properties of urine, and aggression may inhibit this aggression-promoting property.

Aggression↗

Effects of pre- and postpubertal social experience on sexual and social behavior in male and female brown lemmings (Lemmus sibiricus).

The effects of prepubertal social contact and postpubertal mating experience on sexual behavior were examined in male and female brown lemmings (Lemmus sibiricus). Subjects of both sexes were either isolated at weaning (18 days) or then housed with siblings for another 10 days before being isolated. Before testing for sexual behavior at the age of 75 days, half of each group of males received a series of exposures to estrous females and half of each group of females was housed with a stud male. The results of mating tests indicated that whereas prior sexual experience facilitated subsequent copulatory behavior in both sexes, prepubertal interactions subsequently facilitated contact social and sexual behavior in males but did not increase the behavioral scores of females, which engaged in high levels of sexual behavior regardless of prepubertal experience. The effect of prior copulatory activity on male sexual performance could not be attributed to increasing age (i.e., maturational processes) because the behavior of males tested once but at different ages did not differ appreciably. Prepubertal social interaction appeared to predispose males to benefit from sexual experience later in life.

Age Factors↗

Warder Clyde Allee and the Chicago School of Animal Behavior.

Warder Clyde Allee, (1885-1955) was a pioneer American scientist in the fields of ecology and animal behavior. His contributions to the development of a general animal sociology are discussed, with particular attention to his concept of animal cooperation and his research in the area of dominance hierarchies.

Animals↗

Social olfaction in male brown lemmings (Lemmus sibiricus = trimucronatus) and collared lemmings (Dicrostonyx groenlandicus): I. Discrimination of species, sex, and estrous condition.

When tested in a Y-maze olfactometer, sexually experienced and sexually naive brown and collared lemmings (Lemmus sibiricus = trimucronatus and Dicrostonyx groenlandicus) preferred the odor of conspecific females to the odor of females of another species. Both experienced and naive males also preferred the odor of conspecific females to that of conspecific males. Only sexually experienced males showed a significant preference for estrous over nonestrous conspecific females. Sexually experienced males also discriminated between estrous and nonestrous heterospecific females of a familiar (lemming) and unfamiliar (meadow vole, Microtus pennsylvanicus) species. In conjunction with the results of earlier studies of the development of species-specific olfactory preferences, these findings suggest that two olfactory cues mediate a male's attraction to receptive females: a species-specific odor that is learned during early development and a sexual attractant whose saliency is established as a result of adult experience with a receptive female.

Animals↗

Social olfaction in male brown lemmings (Lemmus sibiricus = trimucronatus) and collared lemmings (Dicrostonyx groenlandicus): II. Discrimination of mated and unmated females.

When tested in a Y-maze olfactometer, male brown and collared lemmings (Lemmus sibiricus = trimucronatus and Dicrostonyx groenlandicus) preferred the odor of unmated receptive females to the odor of females with which they had just copulated. Similarly, sexually satiated males preferred the odor of an unmated receptive female to that of a strange female that had recently copulated with another male. Sexually experienced males without recent copulatory experience also demonstrated this preference, but sexually naive males did not. Sexually satiated collared lemmings preferred the odor of bedding from a novel estrous female to bedding from the female with which they had just copulated even when the bedding was collected before mating occurred. These results suggest that discrimination between prior mates and unmated females may be based on individual recognition as well as recognition of subclasses of females (i.e., mated vs. unmated, familiar vs. unfamiliar).

Animals↗

Effects of olfactory cues on sexual behavior in the brown lemming, Lemmus trimucronatus.

Three groups of female lemmings were tested to determine the effects of odor familiarity on measures of reproductive behavior. A familiar odor (FO) group was exposed to the bedding of a particular male for 1 wk, then tested with that male. A second female group (unfamiliar odor; UO) was exposed to the bedding of a male for 1 wk, then tested with a different male. A third group (control; CO) was not exposed to male bedding prior to being tested with a male. The FO females engaged in higher frequencies of contact social behaviors than did UO and CO females. Males with FO females ejaculated more frequently than did the males with UO and CO females. Latencies to first display of sexual behaviors (female: lordosis; male: mount, thrust, and ejaculation) were lower for FO pairs. These results suggest that previous exposure of females to the odor of a given male facilitates sexual behaviors when such females are later paired with that male.

Animals↗

Ultrasounds in neonatal rats: novel, predator and conspecific odor cues.

Neonatal rat ultrasound repetition rates were monitored in response to 6 odor cues, including 1 novel, 2 predator, and 3 conspecific olfactory stimuli. Contrary to predictions of previous studies, predator odor did not elicit consistently low call rates. A significant difference was detected between litters tested with the same odor cue for the foreign and predator odor treatments. Odor was the only significant effect to explain differences in neonatal ultrasonic responses to conspecific odor treatments. Call rates recorded for the novel lactating female odor were significantly greater than those for the home bedding and adult male odors. Odors associated with the home cage or with an adult male elicited low call rates.

Animals↗

Behavioral research to answer questions about animal welfare.

A research strategy designed to develop systematically the behavioral catalogues (ethograms) of domestic production animals is presented. Measurement scales, observational techniques and recording methods are discussed. Suggestions about how these behavioral measures may be used to resolve animal welfare problems are presented. The need for trained applied ethologists and for the allocation of research funds to increase our understanding of animal behavior, in general, and to use this knowledge to enhance the quality of life of production animals is emphasized.

Animal Husbandry↗