Ultrastructural changes in the uropygial gland of the male Japanese quail,Coturnix coturnix,after testosterone treatment

Summary The ultrastructure of the uropygial gland of the male quail was compared to that of the sebaceous gland of the male rat after castration and testosterone treatment of both species. In intact animals, the differentiating cells of these glands displayed almost the same pattern as regards their smooth endoplasmic reticulum, an organelle involved in lipogenesis in both cases. Castration reduced the volume of this organelle, while testosterone administration restored cell morphology to a normal or supranormal level. Finally, this study showed that at ultrastructural level, there is a close functional analogy between the uropygial gland of quail and the sebaceous glands of rats as regards their androgen dependency. Consequently, the uropygial gland might be an attractive model for study of action of androgens on sebaceous-like glands.     

Comparative ultrastructural studies on the prolactin cells in the pituitary of nine-spined sticklebacks,Pungitius pungitius L., with and without adenohypophyseal cysts

Summary The ultrastructure of the prolactin cells in nine-spined sticklebacks (Pungitius pungitius L.) with and without large pituitary cysts was compared. Prolactin cells from animals with cysts were less active as regards hormone synthesis and release than those from animals without cysts. Rough endoplasmic reticulum, mitochondria, Golgi apparatus and exocytotic figures were all more prominent in animals without cysts. Lysosomes and mature secretory granules were more plentiful in animals with cysts. The correlation between inactive prolactin cells and pituitary cysts argues against the hypothesis that cysts store prolactin released by holocrine secretion. It is more likely that the origin of cysts from degenerating cells signals extreme inactivity in the rostral pars distalis.     

Effect of glucose, fructose, sorbitol and amino acid solutions employed in clinical medicine on the development of liver regeneration after partial hepatectomy

The authors studied the effect of glucose (G), fructose (F), sorbitol (So), 4% Nutramin S Spofa (NuS) and Nutramin C Spofa (NuC) on development of liver regeneration. NuS is used clinically to improve a negative nitrogen balance, while the amino acid composition of NuC has a beneficial effect on the ornithine cycle and thus helps to normalize the NH3 level in patients with liver failure. Glucose seems to be the best substance for an optimal onset of liver regeneration. Its onset in rats given NuC was slower than in animals given NuS, but 48 h after partial hepatectomy there was no difference between NuC and NuS as regards the total DNA content and 96 h after the operation there was no difference as regards either the number of mitoses or the number of liver cells. In addition to reducing the plasma ammonia level, therefore, NuC also has a favourable effect on the development on liver regeneration.     

Herders' Perceptions, Practice, and Problems of Night Grazing in the Sahel: Case Studies from Niger

A survey was conducted from February to June of 1997 among livestock herders in two villages of Niger, Kodey and Toukounous, on their perceptions, practice, and problems of night grazing. Cattle and sheep were the species that were taken out for night grazing by the herders. Small herd size and labor constraints were mentioned as the principal reasons for not practicing night grazing. Major benefits of night grazing included good body condition, herd growth, increased milk production, prevention of diseases, and reduction in herd mortality. Insecurity, difficulty in staying awake at night, labor constraints, and damage to crops by animals were given as problems of night grazing. According to the herders, grazing time (duration) during the day and night was shorter in the wet season than in the dry season. In the wet season animals were herded (followed and closely supervised by herders), whereas in the dry season, animals were mostly left to range freely in both villages. In general, children herded the animals during the day, while adults were responsible for night-time herding. Herders' perceptions on night grazing as regards animal production parameters such as weight development, water consumption, fecal output and feeding behavior are consistent with available experimental results. Therefore, future technical research needs to recognize the constraints faced by herders and determine how to overcome them to improve technical and economic efficiency.     

Studies on the Endocrine Pancreas of Amphibians and Reptiles

At this time, it can be said that the available data obtainedfrom amphibians and reptiles as regards the endocrine pancreasis consistent with the much more extensive data known for themetabolic effects of insuilin and glucagon in mammals. Thereremain, however, many unexplored facets of the specific responsesof the pancreas and the target tissues in lower animals.     

Electrical stability of mitochondrial membranes: the role of thyroid hormones and the fat component of the diet

Electric stability of the membranes of the mitochondria and liposomes formed from mitochondrial lipids was studied. The mitochondria were isolated from the liver of euthyroid or hyperthyroid rats kept on the diets with varying degree of food fat unsaturation. In the first group animals, butter was used as a fatty component of the diet whereas the second group animals received sunflower oil. The electric stability of the membranes of the mitochondria and respective liposomes appeared lower in the first group animals as compared with those in the second group animals. Hyperthyrosis was accompanied by the increased electrical stability of mitochondrial lipids in both the groups. At the same time the liposomal membranes were similar as regards the electric stability, whereas the electric stability of the mitochondrial membranes in the first group hyperthyroid and euthyroid rats was lower than in the organelles of the second group animals. It is thus assumed that the electric stability of the mitochondria is determined not only by the chemical composition of lipids but also by other factors.     

Attitudes,knowledge and wild animals as pets in Costa Rica

Abstract

A nationwide survey in Costa Rica, using Kellert's conceptual framework (Kellert, S. R. 1996. The Value of Life. Washington D.C., Island Press), revealed at least five attitude dimensions toward animals. Overall, Costa Rican adults have a strong sentimental attitude toward animals, an expression of feelings of affection toward animals. In contrast, the materialistic attitude, which regards animals as resources and praises acts of control over them, is weak. This reflects a prevailing opposition to the act of hunting per se, rather than to its potentially detrimental effect on natural populations. There is a strong inquisitive attitude, corresponding to a widespread interest in learning about the biology of animals and their habitats. High scores on the ethical attitude indicate concern for the ethical treatment of animals and nature. The schematic attitude emphasizes the role of aesthetic appearance in the preferences for certain animals and acknowledges feelings of aversion, dislike or fear of some animals. Scores for this attitude were weakly positive. The attitude profile of Costa Ricans is probably incomplete, given the small battery of questions used in this study and differences between this and Kellert's study in the assignment of questions to particular attitudes resulting from the factor analysis. Aesthetic appeal of the animals, compassion, affection and a desire to please and stimulate the children are important motives for the acquisition of wild animals as pets. These positive feelings and a misguided empathy for animals backfire by condemning these pets to an alien environment and inadequate care. The current study also showed that adults who keep wildlife have better biological knowledge than those who never kept wildlife as pets. In addition, Costa Ricans ranked highest in the percentage of correct answers to five questions about animals, in comparison to Kellert's data for US and Japanese citizens (Kellert S.R. 1993. Journal of Social Issues 49: 53–69). Such knowledge of natural history and an animal protection profile, however, do not translate into more animal friendly practices, as seen by the keeping of wildlife as pets under conditions of concern. Rather than changing the attitudes of Costa Ricans toward animals, the challenge is to increase the awareness about the animals' needs and thereby trigger the ethical concern for their well-being.     

Rumen-protected conjugated linoleic acid supplementation to dairy cows in late pregnancy and early lactation: effects on milk composition,milk yield,blood metabolites and gene expression in liver

After 27 years with no detected cases, an outbreak of anthrax occurred in a beef cattle herd in the south of Sweden. The outbreak was unusual as it occurred in winter, in animals not exposed to meat-and-bone meal, in a non-endemic country. The affected herd consisted of 90 animals, including calves and young stock. The animals were kept in a barn on deep straw bedding and fed only roughage. Seven animals died during 10 days, with no typical previous clinical signs except fever. The carcasses were reportedly normal in appearance, particularly as regards rigor mortis, bleeding and coagulation of the blood. Subsequently, three more animals died and anthrax was suspected at necropsy and confirmed by culture and PCR on blood samples. The isolated strain was susceptible to tetracycline, ciprofloxacin and ampicillin. Subtyping by MLVA showed the strain to cluster with isolates in the A lineage of Bacillus anthracis. Environmental samples from the holding were all negative except for two soil samples taken from a spot where infected carcasses had been kept until they were picked up for transport. The most likely source of the infection was concluded to be contaminated roughage, although this could not be substantiated by laboratory analysis. The suspected feed was mixed with soil and dust and originated from fields where flooding occurred the previous year, followed by a dry summer with a very low water level in the river allowing for the harvesting on soil usually not exposed. In the early 1900s, animal carcasses are said to have been dumped in this river during anthrax outbreaks and it is most likely that some anthrax spores could remain in the area. The case indicates that untypical cases in non-endemic areas may be missed to a larger extent than previously thought. Field tests allowing a preliminary risk assessment of animal carcasses would be helpful for increased sensitivity of detection and prevention of further exposure to the causative agent.     

Consequences a long terme de la vasectomie: Revue de la litterature

Since 20 years, many contradictory data have been reported about vasectomy in animals and in humans, as regards its efficacy and safety. We have examined the main experimental and clinical reports, published these last 20 years. In particular experimental conditions, in animals subject to hypercholesterolemic diets, vasectomy would cause negative effects, particularly an increased atheroma risk. But, none of the large epidemiologic inquiries performed until now in several developed and on developing countries, showed an increased vascular and infarction risk in vasectomized males.     

Tyrosine hydroxylase activity in the brains of rats with different levels of initial alcoholic motivation

Activity and KM of hypothalamic tyrosine hydroxylase (TH) were studied in rats preliminarily tested for predisposition to high ethanol consumption. It was shown that as regards cofactor of DMPH4 enzymatic reaction, KM of hypothalamic TH of animals with an initially high alcoholic motivation is lower than that from the brain of animals rejecting alcohol, being 0.34 +/- 0.3 mM and 0.46+/- 0.10 mM, respectively. A conclusion is made that the catecholaminergic system is involved into the realization of the rewarding effects of ethanol.     

Damage to the hemato-encephalic barrier during one-time immobilization stress

Intravenous injection of trypan blue followed by treatment of the brain according to the Falc-Hillarp was used for morphological study of the blood-brain barrier in control rats and in animals exposed to the 6.5-hour stress. The density of the blood-brain barrier as regards the macromolecules in control animals was found to be liable to noticeable areal variations. The zones of primary increased barrier permeability were found near the basal surface of the brain. Prolonged single immobilization stress gave rise to destructive changes in the blood-brain barrier in the reticular formations of the midbrain and medulla oblongata. Besides, in control animals, there was a slight increase in permeability of the brain areas marked by the reduced barrier density.     

New perspectives of nanoneuroprotection, nanoneuropharmacology and nanoneurotoxicity: modulatory role of amino acid neurotransmitters, stress, trauma, and co-morbidity factors in nanomedicine

Recent advancement in nanomedicine suggests that nanodrug delivery using nanoformulation of drugs or use of nanoparticles for neurodiagnostic and/or neurotherapeutic purposes results in superior effects than the conventional drugs or parent compounds. This indicates a bright future for nanomedicine in treating neurological diseases in clinics. However, the effects of nanoparticles per se in inducing neurotoxicology by altering amino acid neurotransmitters, if any, are still being largely ignored. The main aim of nanomedicine is to enhance the drug availability within the central nervous system (CNS) for greater therapeutic successes. However, once the drug together with nanoparticles enters into the CNS compartments, the fate of nanomaterial within the brain microenvironment is largely remained unknown. Thus, to achieve greater success in nanomedicine, our knowledge in understanding nanoneurotoxicology in detail is utmost important. In addition, how co-morbidity factors associated with neurological disease, e.g., stress, trauma, hypertension or diabetes, may influence the neurotherapeutic potentials of nanomedicine are also necessary to explore the details. Recent research in our laboratory demonstrated that engineered nanoparticles from metals or titanium nanowires used for nanodrug delivery in laboratory animals markedly influenced the CNS functions and alter amino acid neurotransmitters in healthy animals. These adverse reactions of nanoparticles within the CNS are further aggravated in animals with different co-morbidity factors viz., stress, diabetes, trauma or hypertension. This effect, however, depends on the composition and dose of the nanomaterials used. On the other hand, nanodrug delivery by TiO₂ nanowires enhanced the neurotherapeutic potential of the parent compounds in CNS injuries in healthy animals and do not alter amino acids balance. However, in animals with any of the above co-morbidity factors, high dose of nanodrug delivery is needed to achieve some neuroprotection. Taken together, it appears that while exploring new nanodrug formulations for neurotherapeutic purposes, co-morbidly factors and composition of nanoparticles require more attention. Furthermore, neurotoxicity caused by nanoparticles per se following nanodrug delivery may be examined in greater detail with special regards to changes in amino acid balance in the CNS.     

Unit activity in the posterior sigmoid and proreal gyri of the cat cortex during bemegride administration

Unit activity was studied in the posterior sigmoid and proreal gyri of the cat cortex in response to photic, acoustic, and somatic stimulation. The animals were first anesthetized with pentobarbital and, after recovery, were given intravenous injections of bemegride (β-ethyl-β-methylglutarimide) and immobilized with diplacin [1, 3-di(β-platyneciniumethoxy)-benzene hydrochloride]. The state of the preparation used was similar to the state of waking animals as regards the characteristics of its unit activity. Unit responses of the proreal gyrus were chiefly modally nonspecific and consisted of brief suppression of spontaneous activity for 100–200 msec. Neurons of the posterior sigmoid gyrus were characterized by much greater modal specificity and variety of types of responses to stimuli of different modalities. Comparison of the characteristics of unit activity in these parts of the neocortex suggests that the frontal cortex in cats is still a highly unspecialized structure.     

亚热带气候环境下西藏小型猪部分血液生理生化指标的比较

目的比较研究西藏小型猪在亚热带气候环境下的部分血液生理生化指标。方法常规方法测定原代和F1代西藏小型猪血液的9项生理和9项生化指标,比较两代之间以及雌、雄之间的不同,并与其他实验动物及人类的同类指标进行对比分析。结果在生化指标中,原代雌雄之间AST差异显著;F1代雌雄之间TG、ALB有差异,BUN、CHOL有显著性差异。在生理指标中,原代雌、雄间无差异,F1代雌雄间MONO有显著性差异。结论西藏小型猪已经基本适应亚热带地区的环境。与其他实验动物相比西藏小型猪许多生理生化指标更接近人类,非常适合替代犬、猴用于生物医学研究。     

Evaluation of rage isoforms, ligands, and signaling in the brain

Since the identification of the receptor for advanced glycosylation end products (RAGE) in 1992, there have been tremendous strides made in our understanding of the role RAGE receptors play in a variety of physiological and pathological processes. Despite such progress, several fundamental aspects of RAGE expression and RAGE function remain largely unanswered. In particular, while multiple forms of the RAGE receptor are known to exist, little is known with regards to how these different isoforms of the RAGE receptor work together to mediate RAGE signaling. For example, some forms of the RAGE receptor may promote deleterious feed-forward pathways, while others may serve to inhibit deleterious activation of the RAGE receptor. Additionally, important questions remain with regards to the intracellular domain of the full-length RAGE receptor, and the specifics surrounding how intracellular signaling pathways become activated via the RAGE family of receptors. The focus of this review is to address each of these important issues, as well as other key aspects of RAGE biology, and discuss how they are important for both our understanding of the physiological and pathological roles of RAGE signaling within the brain.     

Chronic hyperglycemia in experimental diabetes mellitus of short duration does not contribute to muscle capillary basement membrane thickening

The effect of chronic hyperglycemia on the relationship of nonenzymatic glycation and capillary basement membrane thickness in muscle was studied in streptozotocin-induced diabetic rats early in the course of diabetes mellitus. Diabetic animals were placed on either standard (24%) or restricted (8%) protein diet. The animals on 8% protein diet had elevated glycated hemoglobin levels (p less than 0.01) and increased levels of nonenzymatic glycation of basement membrane (p less than 0.01) as compared to insulin-treated diabetic (euglycemic), age-matched control, and streptozotocin-injected nondiabetic animals also on 8% protein diet. In contrast, diabetic animals on restricted (8%) protein diet and those on standard (24%) protein diet showed no statistical differences between them with regards to the above parameters. Moreover, there were no statistical differences among diabetic and control animals on either 8 or 24% protein diet with respect to muscle capillary membrane thickness. Even though the peripheral muscle biopsy study of capillary basement membrane is less invasive than kidney biopsy, the results of this study suggest that neither nonenzymatic glycation nor basement membrane thickness can be utilized as predictors of renal dysfunction during early onset of diabetes mellitus.     

Untersuchung zum Einfluß des Erkundungs- und Spielverhaltens auf das Lernen bei Iltisfrettchen (Mustela putorius X M. furo)

This paper investigates the dependence of learning performance on previous exploration and playing with objects. The subjects are polecats (Mustela putorius X M. furo). Behaviour of social animals, who are offered changing tube systems in certain periods, is described and analysed. A maze-test shows that subjects with tube training are superior to subjects without tube training as regards acquisition and reversal learning. The learning performance in pattern recognition tests is the same in all tests with the different groups, however.     

Statistical analysis of variations in total cholesterol, HDL, HDL2, HDL3, LDL-cholesterol, VLDL-triglycerides, apo-A and apo-B lipoproteins in dyslipidemias during antilipemic therapy

In our study, bezafibrate in short-acting formula and long-acting formula, administered to hyperlipidaemic patients, resulted in a significant lowering of atherogenic lipids and lipoproteins (chol.-T, LDL and VLDL-chol., apolipoprotein B and VDLD-TR), and a marked increase in the levels of HDL, HDL2, HDL3-chol. and apolipoprotein A with a protective action as regards vascular atherosclerotic damage. The long-acting formula showed a greater effectiveness.     

(−)-Linalool, a naturally occurring monoterpene compound, impairs memory acquisition in the object recognition task, inhibitory avoidance test and habituation to a novel environment in rats

It is known that (−)-linalool is a competitive antagonist of NMDA receptors, which play a key role in the learning and memory processes; however, only a few studies have reported a possible interference of (−)-linalool in memory. The purpose of this study was to investigate the (−)-linalool effects on acquisition of short- and long-term memories through the objects recognition task, inhibitory avoidance test and habituation to a novel environment. Furthermore, the open field test was used to investigate the interference of (−)-linalool in motivation, locomotion and exploration by animals. Wistar male adult rats received an intraperitoneal injection (i.p.) of saline (NaCl 0.9%), tween 5% or (−)-linalool (50 or 100 mg/kg) before training in the tasks; MK-801 (0.1 mg/kg), a glutamate antagonist, was used as positive control. Short-term (STM) and long-term (LTM) memories were tested 1.5 and 24 h after training, respectively, in the inhibitory avoidance and recognition objects. The results suggested that (−)-linalool (as 50- and 100-mg/kg doses) impaired LTM acquisition, but not STM acquisition, in the object recognition task. In the inhibitory avoidance test, animals receiving linalool (both doses) showed impairment in acquisition of both memories measured. In the open field test, the animals that received (−)-linalool showed no significant difference in the crossings and latency to start the locomotion in any of the doses tested, although (−)-linalool 100 mg/kg reduced rearing behavior. When re-exposed to open field 24 h after training, the rats that received (−)-linalool 100 mg/kg showed no habituation. Taken together, these data suggested that (−)-linalool was able to impair the acquisition of memory in rats, which can be associated to (−)-linalool antagonist capacity as regards NMDA glutamatergic receptors, since other glutamate antagonists also seem to affect memory.     

MicroRNAs as mediators of insect host–pathogen interactions and immunity

Insects are the most successful group of animals on earth, owing this partly to their very effective immune responses to microbial invasion. These responses mainly include cellular and humoral responses as well as RNA interference (RNAi). Small non-coding RNAs (snRNAs) produced through RNAi are important molecules in the regulation of gene expression in almost all living organisms; contributing to important processes such as development, differentiation, immunity as well as host–microorganism interactions. The main snRNAs produced by the RNAi response include short interfering RNAs, microRNAs and piwi-interacting RNAs. In addition to the host snRNAs, some microorganisms encode snRNAs that affect the dynamics of host–pathogen interactions. In this review, we will discuss the latest developments in regards to the role of microRNA in insect host–pathogen interactions and provide some insights into this rapidly developing area of research.