The functional brain state of hibernators and nonhibernators at different animals temperatures

Literature and our own data on structural and functional state of neocortex and hippocampus during both entrance in hibernation of ground squirrel (Spermophilus undulates) and Wistar rats in hypothermia were generalized. During hibernation when body temperature is about 2-4 degrees C the suppression of both bioelectrical and protein-synthesizing activity, the decrease of neuronal cell bodies and the branching of dendrites, retraction of dendritic spines, and a decrease of postsynaptic active zones of synapses were observed. Similar changes in those parameters were triggered for rats during hypoxia-hypercapnia at body temperature 17-19 degrees C. Hypoxia-hypercapnia facilitates the entrance in torpid state for hole animals. Nonhibernating animals during cooling and hypoxia-hypercapnia trigger functioning some mechanisms similar hibernators during entrance in hibernation. Similar morphological and functional changes for both hibernators and nonhibernators at low temperature state show similarity of mechanisms which induce a low level of brain activity of different animals.     

Principle of spiral arrangement of the skeletal muscles of humans and animals

It has been stated long ago, that smooth muscle elements in the vascular walls and other tubular systems in the human being and in the animals demonstrate spiral arrangement. The authors decided to show that there is a spiral formation of the skeletal musculature in the human being and in vertebrata at the level of the whole organism, its parts and separate muscles. By means of successive joining certain muscles, their parts and even separate groups of muscular fasciculi by tendons, aponeuroses, fascia and intermuscular septa, ligaments and bones kinematic chains of muscles have been revealed, those chains that have spiral direction regarding the longitudinal axes of the body and its parts. Two examples of left- and right-hand-screw types of spirals are presented and it is stressed that the spiral principle reflects biological symmetry of structural oppositions--enantiomorphism. A conclusion is made that the spiral form of the skeletal musculature is a universal regularity for the human being and for all vertebrata. The cylindric form of the vertebral body serves as a predestinated moment for this. The spiral twisting of the muscles is the most optimal for ensuring variability of movements and performing adaptive survival of the human being and animals in the Earth gravitational field.     

Ultrasound-guided cannulation of the caudal vena cava in the bovine for selective sampling of ovarian effluent

The accuracy of real-time, B-mode ultrasonography was assessed in the visualization and placement of the cannula tip, cranial to the entrance of the ovarian veins as they enter the caudal vena cava of the bovine. A cannula containing a wire guide was introduced into the coccygeal vein via a 14-gauge needle, and was then directed cranially into the caudal vena cava. Once the caudal vena cava was successfully cannulated (7 of 14 cows), ultrasonography allowed for the visualization of the cannula in 7 out of 7 cows. The tip of the cannula was successfully placed cranial to the entrance of the ovarian effuent into the vena cava in 6 of these 7 animals using ultrasound guidance. This was confirmed using progesterone or prostaglandin F(2alpha) radioimmunoassay (RIA). The primary limitation to this technique was the initial catherization of the coccygeal vein which was not achieved in 7 of 14 cows attempted in this study. Successful cannulation was limited to large framed Holstein cows that had at least one calf. Results from this study indicate that real-time, B-mode, ultrasonography is an effective tool for the visualization and accurate placement of the cannula tip within the caudal vena cava. This finding could have implications for research in ovarian hormonal physiology in the cyclic, postpartum or anestrous cow.     

Acquired antigenicity of DNA after modification with peroxynitrite

There are many contaminants affecting human beings, the most important being the metabolites of gases in air around us or certain deleterious by products from metabolic activity. They are reactive species of nitrogen, oxygen and their derivatives. Nitrogen is taken into body as nitrates, nitrites, peptides, proteins, etc. and its metabolites include higher oxides of nitrogen and peroxynitrite. Although NO is a free radical, it is probably insufficiently reactive to attack DNA directly. By contrast its derivatives N2O3, HNO2, ONOO- can nitrate, deaminate, cause strand breaks in DNA leading to serious consequences including mutations. The study exploits this property of ONOO-, such that on modification DNA which in its native form is non-immunogenic acquires the ability to elicit immune response in experimental animals. The extent of modifications, characterization of induced antibodies along with antigen-antibody interactions are studied and analyzed through different techniques.     

Recombinant human insulin-like growth factor I (IGF-I): risks and benefits of normalizing blood IGF-I concentrations

Recombinant human (rh) insulin-like growth factor I (IGF-I) is being developed as a therapy for short stature caused by IGF deficiency (IGFD) and also for diabetes mellitus. To complement the human efficacy and safety data, a large amount of information is available regarding the pharmacology and toxicology of rhIGF-I in animals. This review summarizes the risks and benefits of normalizing blood IGF-I concentrations in IGFD, especially with regard to carcinogenicity, and compares and contrasts safety data for rhIGF-I, recombinant human growth hormone (rhGH), and insulin. A major difference between rhIGF-I and rhGH is that rhIGF-I (like insulin) has hypoglycaemic activity, whereas rhGH opposes insulin action and is diabetogenic. In most of their actions, GH and IGF-I are similar. IGF-I mediates most of the actions of GH, so the safety of rhGH and that of rhIGF-I also share many common features. In animals, the transgenic expression of hGH has been shown to act directly, by activating the prolactin receptor, to increase the incidence of mammary and prostate tumours. In comparison, the over-expression of IGF-I in animals or the administration of rhIGF-I does not have a carcinogenic effect. In formal toxicology and carcinogenicity studies, rhIGF-I has similar effects to insulin in that it can increase food intake, body size, and the growth rate of existing tumours. In animals and humans, IGFD has many long-term detrimental effects besides short stature: it increases the risk of diabetes, cardiovascular disease, and low bone mineral density. Therefore, a case can be made for replacement therapy with rhIGF-I to normalize blood IGF-I levels and reverse the detrimental effects of IGFD.     

Dosimetry methods used in the studies of the effects of protons on primates: a review.

In a program to determine the acute and long-term effects of the space radiation environment, a series of primate irradiations was conducted from 1964 through 1969 by the USAF School of Aerospace Medicine. The animals were exposed total-body to protons, electrons, and X rays. The doses assigned were either body midline or body entrance geometrically averaged across the exposure field depending on the degree of penetration (total or partial body) of the radiation used. A 10-cm-diameter unit-density cylinder was used as an appropriate model for the animal in the determination of the body doses. The physical dosimetry methods used at the time of the irradiations are reviewed.     

Non-climatic thermal adaptation: implications for species' responses to climate warming

There is considerable interest in understanding how ectothermic animals may physiologically and behaviourally buffer the effects of climate warming. Much less consideration is being given to how organisms might adapt to non-climatic heat sources in ways that could confound predictions for responses of species and communities to climate warming. Although adaptation to non-climatic heat sources (solar and geothermal) seems likely in some marine species, climate warming predictions for marine ectotherms are largely based on adaptation to climatically relevant heat sources (air or surface sea water temperature). Here, we show that non-climatic solar heating underlies thermal resistance adaptation in a rocky–eulittoral-fringe snail. Comparisons of the maximum temperatures of the air, the snail''s body and the rock substratum with solar irradiance and physiological performance show that the highest body temperature is primarily controlled by solar heating and re-radiation, and that the snail''s upper lethal temperature exceeds the highest climatically relevant regional air temperature by approximately 22°C. Non-climatic thermal adaptation probably features widely among marine and terrestrial ectotherms and because it could enable species to tolerate climatic rises in air temperature, it deserves more consideration in general and for inclusion into climate warming models.     

Axial stretch: A novel mechanism of the lower esophageal sphincter relaxation

Swallow and esophageal distension-induced relaxations of the lower esophageal sphincter (LES) are associated with an orad movement of the LES because of a concurrent esophageal longitudinal muscle contraction. We hypothesized that the esophageal longitudinal muscle contraction induces a cranially directed mechanical stretch on the LES and therefore studied the effects of a mechanical stretch on the LES pressure. In adult opossums, a silicon tube was placed via mouth into the esophagus and laparotomy was performed. Two needles with silk sutures were passed, 90 degrees apart, through the esophageal walls and silicon tube, 2 cm above the LES. The tube was withdrawn, and one end of each of the four sutures was anchored to the esophageal wall and the other end exited through the mouth to exert graded cranially directed stretch on the LES by using pulley and weights. A cranially directed stretch caused LES relaxation, and with the cessation of stretch there was recovery of the LES pressure. The degree an d duration of LES relaxation increased with the weight and the duration of stretch, respectively. The mean LES relaxation in all animals was 77.7 +/- 4.7%. The required weight to induce maximal LES relaxation differed in animals (714 +/- 348 g). N(G)-nitro-L-arginine, a nitric oxide inhibitor, blocked the axial stretch-induced LES relaxation almost completely (from 78 to 19%). Our data support the presence of an axial stretch-activated inhibitory mechanism in the LES. The role of axial stretch in the LES relaxation induced by swallow and esophageal distension requires further investigation.     

The penis of elephant shrews (Mammalia: Macroscelididae)

The penis of elephant shrews is very long, extending cranially to near the sternum where it emerges from a small caudally-pointing prepuce. The distal half of the penis lies free in a sheath and is termed the glans. In most species the corpus cavernosum is the main vascular body and extends to the tip of the penis while the corpus spongiosum around the urethra becomes much reduced distally, but in Rhynchocyon all vascular bodies are small and most of the penis consists of connective tissue. The distal tip of the penis is elaborated into various shapes, characteristic for each genus as currently defined. These penile features have more similarities with soricids and paenungulates than with archontans and lagomorphs but they are likely to be primitive characters and so should be interpreted cautiously.     

Predicting risk of decompression sickness in humans from outcomes in sheep.

In animals, the response to decompression scales as a power of species body mass. Consequently, decompression sickness (DCS) risk in humans should be well predicted from an animal model with a body mass comparable to humans. No-stop decompression outcomes in compressed air and nitrogen-oxygen dives with sheep (n = 394 dives, 14.5% DCS) and humans (n = 463 dives, 4.5% DCS) were used with linear-exponential, probabilistic modeling to test this hypothesis. Scaling the response parameters of this model between species (without accounting for body mass), while estimating tissue-compartment kinetic parameters from combined human and sheep data, predicts combined risk better, based on log likelihood, than do separate sheep and human models, a combined model without scaling, and a kinetic-scaled model. These findings provide a practical tool for estimating DCS risk in humans from outcomes in sheep, especially in decompression profiles too risky to test with humans. This model supports the hypothesis that species of similar body mass have similar DCS risk.     

Infants' knowledge of their own species

Recognition of individuals at first sight is important for social species and can be achieved by attending to facial or body information. Previous research suggests that infants possess a perceptual template for evolutionarily relevant stimuli, which may include humans, dangerous animals (e.g. snakes), but not non-dangerous animals. To be effective, such a mechanism should result in a systematic preference for attending to humans over non-dangerous animals. Using a preferential looking paradigm, the present studies investigated the nature of infants' early representation of humans. We show that 3.5- and six-month-old infants attend more to human beings than non-human primates (a gorilla or monkey) which are examplars of non-dangerous animals. This occurred when infants were presented with head or body information in isolation, as well as when both are presented simultaneously. This early preference for humans by 3.5 months of age suggests that there is a basic representation for humans, which includes both head and/or body information. However, neonates demonstrated a preference only for human faces over non-human primate faces, not for humans over non-human primates when the stimuli were presented with both head and body simultaneously. The results show that although neonates display a preference for human faces over others, preference for the human body only develops later, in the first few months of life. This suggests that infants have acquired some knowledge about the human body at 3.5 months of age that may have developed from their privileged experience with other humans in the first few months of life, rather than an innate ability to detect humans in their entirety.     

The ovaries and reproduction in Pontoporia blainvillei (Cetacea: Platanistidae)

The ovaries of 113 Pontoporia blainvillei (Franciscana dolphin) were examined and their characteristics related to season, body length of the animals and, in some individuals, foetal length. The following conclusions were drawn from the results: most females attain sexual maturity when they reach 136–146 cm body length; most conceptions occur in the period December to February, with a peak in the first half of January; usually only one ovulation occurs, and no animal ovulated more than twice, in a season; postpartum ovulation may occur, and evidence is presented that this is probably followed by conception and that animals may breed once a year but most females breed every other year; body length at birth is greater than 70 cm and less than 85 cm, and probably nearer the smaller figure; the gestation period is 10.5–12 months (depending on what is the actual figure for length at birth, but probably less than 11 months); lactation lasts at least nine months; the corpus luteum contains two morphologically distinct, but apparently functional cell types; there is no apparent morphological difference between corpora lutea which are not associated with pregnancy, and corpora lutea of pregnancy; corpora albicantia may persist for a maximum of four years before being reabsorbed completely.     

Flow-through respirometry applied to chamber systems: pros and cons, hints and tips

Flow-through respirometry is a powerful, accurate methodology for metabolic measurement that is applicable to organisms spanning a body mass range of many orders of magnitude. Concentrating on flow-through respirometry that utilizes a chamber to contain the experimental animals, we describe the most common flow measurement and control methodologies (push, pull and stop-flow) and their associated advantages and disadvantages. Objective methods for calculating air flow rates through the chamber, based on the body mass and taxon of the experimental organism, are presented. Techniques for removing the effect of water vapor dilution, including the direct measurement of water vapor pressure and mathematical compensation for its presence, are described and evaluated, as are issues surrounding the analysis of one or both of the respiratory gases (oxygen and carbon dioxide), and issues related to the mathematical correction of wash-out phenomena (response correction). Two important biomedical applications of flow-through respirometry (metabolic phenotyping and room calorimetry) are discussed in detail, and we conclude with a list of suggestions aimed primarily at investigators starting out in applying flow-through respirometry.     

Mating Behavior in Halictine Bees (Hymenoptera: Halictidae)

Studied two types of mate-orientation behavior in ♂♂ of the sweat bee, Lasioglossum rohweri: microterritoriality and patrolling. Observations were made in both the laboratory and the field. These ♂♂ behave uniquely for Hymenoptera in that 2–5 of them establish microterritories immediately around the same nest entrance. Some ♂♂ are exclusively patrollers, flying about flowers and nest sites. Rendezvous places (locations where animals are likely to find mates) in bees are: flowers, nesting sites, vegetative parts of plants, nest entrances, air, and nests. Territoriality in male bees may have arisen independently in 7 of the 9 families of bees.     

金黄色葡萄球菌引起食物中毒的作用机制与其耐药性的研究进展

葡萄球菌广泛分布于自然界中,如空气、土壤、水以及物体的表面,在人和动物的皮肤表面部、鼻咽、肠道也常可发现葡萄球菌.大部分葡萄球菌是非致病菌,少数可引起人或动物致病,金黄色葡萄球菌(Staphylococcus aureus,金葡菌)即为最主要的致病性葡萄球菌.金葡菌是一种革兰氏阳性球菌,是医院感染常见的病原体之一,同时也是引起食品污染和细菌性食物中毒的一种重要细菌,其产生的毒素可使人中毒,带来非常严重的公共卫生负担.本文拟对金葡菌的病原与病理学特性,金葡菌与食物中毒,抗生素滥用与金葡菌耐药性等方面做简要综述.     

Body temperature and resistance to evaporative water loss in tropical Australian frogs

Although the skin of most amphibians measured to date offers no resistance to evaporative water loss (EWL), some species, primarily arboreal frogs, produce skin secretions that increase resistance to EWL. At high air temperatures, it may be advantageous for amphibians to increase EWL as a means to decrease body temperature. In Australian hylid frogs, most species do not decrease their resistance at high air temperature, but some species with moderate resistance (at moderate air temperatures) gradually decrease resistance with increasing air temperature, and some species with high resistance (at moderate air temperatures) abruptly decrease resistance at high air temperatures. Lower skin resistance at high air temperatures decreases the time to desiccation, but the lower body temperatures allow the species to avoid their critical thermal maximum (CT(Max)) body temperatures. The body temperatures of species with low to moderate resistances to EWL that do not adjust resistance at high air temperatures do not warm to their CT(Max), although for some species, this is because they have high CT(Max) values. As has been reported previously for resistance to EWL generally, the response pattern of change of EWL at high air temperatures has apparently evolved independently among Australian hylids. The mechanisms involved in causing resistance and changes in resistance are unknown.     

Body temperature and resistance to evaporative water loss in tropical Australian frogs.

Although the skin of most amphibians measured to date offers no resistance to evaporative water loss (EWL), some species, primarily arboreal frogs, produce skin secretions that increase resistance to EWL. At high air temperatures, it may be advantageous for amphibians to increase EWL as a means to decrease body temperature. In Australian hylid frogs, most species do not decrease their resistance at high air temperature, but some species with moderate resistance (at moderate air temperatures) gradually decrease resistance with increasing air temperature, and some species with high resistance (at moderate air temperatures) abruptly decrease resistance at high air temperatures. Lower skin resistance at high air temperatures decreases the time to desiccation, but the lower body temperatures allow the species to avoid their critical thermal maximum (CT(Max)) body temperatures. The body temperatures of species with low to moderate resistances to EWL that do not adjust resistance at high air temperatures do not warm to their CT(Max), although for some species, this is because they have high CT(Max) values. As has been reported previously for resistance to EWL generally, the response pattern of change of EWL at high air temperatures has apparently evolved independently among Australian hylids. The mechanisms involved in causing resistance and changes in resistance are unknown.     

Comparative mapping in farm animals.

This paper summarises the current status of comparative mapping in farm animals. For most of the major farm animal species, a wide range of genomic tools are now available to create high-resolution genetic and physical maps of the genome. For many farm animals, the use of radiation hybrid panels and sequence data from expressed sequence tag (EST) projects has accelerated the development of high-resolution comparative maps, with human--the model species for farm animals. These tools and comparative maps are being used to map and identify the genes at the loci for simple and complex traits. The development of detailed physical maps in farm animals based on radiation hybrid panels and bacterial artificial chromosome (BAC) contigs provides a direct link between the 'information-poor' maps of farm animals and the 'information-rich' genomes of human and other model organisms.     

Metabolism and thermoregulation during fasting in king penguins, Aptenodytes patagonicus, in air and water

We measured oxygen consumption rate (Vo(2)) and body temperatures in 10 king penguins in air and water. Vo(2) was measured during rest and at submaximal and maximal exercise before (fed) and after (fasted) an average fasting duration of 14.4 +/- 2.3 days (mean +/- 1 SD, range 10-19 days) in air and water. Concurrently, we measured subcutaneous temperature and temperature of the upper (heart and liver), middle (stomach) and lower (intestine) abdomen. The mean body mass (M(b)) was 13.8 +/- 1.2 kg in fed and 11.0 +/- 0.6 kg in fasted birds. After fasting, resting Vo(2) was 93% higher in water than in air (air: 86.9 +/- 8.8 ml/min; water: 167.3 +/- 36.7 ml/min, P < 0.01), while there was no difference in resting Vo(2) between air and water in fed animals (air: 117.1 +/- 20.0 ml O(2)/min; water: 114.8 +/- 32.7 ml O(2)/min, P > 0.6). In air, Vo(2) decreased with M(b), while it increased with M(b) in water. Body temperature did not change with fasting in air, whereas in water, there were complex changes in the peripheral body temperatures. These latter changes may, therefore, be indicative of a loss in body insulation and of variations in peripheral perfusion. Four animals were given a single meal after fasting and the temperature changes were partly reversed 24 h after refeeding in all body regions except the subcutaneous, indicating a rapid reversal to a prefasting state where body heat loss is minimal. The data emphasize the importance in considering nutritional status when studying king penguins and that the fasting-related physiological changes diverge in air and water.     

Observations on the use of grottos by Mediterranean Monk seals (Monachus monachus)

A group of six Monk seals ( Monachus monachus ) was discovered to lie up inside a grotto on the shores of a lake reached via an underwater passage. Nearly 1200 hours of observation on the movement of the seals showed that the greatest use of the grotto was made during the winter months and when the wind was towards the grotto entrance. Entry and exit times were not significantly affected by sea state, dark or light, nor were they significantly correlated with sunrise and sunset times or sea and air temperature. These variables did not significantly affect the length of stay in the grotto. Entry occurred most frequently in the early morning and exist at night.
Discussion is given of the possible reasons why grottos are used by Monk seals. This appears to be a recent adaptation which may be related to the effects of human disturbance.