Social Monitoring Reflects Dominance Relationships in a Small Captive Group of Brown Capuchin Monkeys (Cebus apella)

In several studies of social monitoring in primates, subordinate animals directed more visual attention toward dominant animals than vice versa. This behavior is thought to enable subordinate animals to avoid conflict. We sought to clarify whether visual attention behavior functions in this manner in a small captive group of brown capuchin monkeys, Cebus apella. We tested the hypothesis that social monitoring is related to dominance status. Dominance status was determined based on the directionality of aggressive behavior, and visual attention was quantified by using focal animal sampling. Subordinate animals directed significantly more visual attention toward others than dominant animals. Subordinate animals also looked more frequently at the animals that attacked them and others the most. The results indicate that social monitoring behavior in this captive group was driven by conflict‐avoidance.     

Antioxidative activity of lipids in mice during aging and administration of an antioxidant with gerontological protective action

Changes in the antioxidative activity (AOA) of the liver were studied during natural aging in noninbred and C3HA mice and during administration of the synthetic anti-oxidant 2-ethyl-6-methyl-3-hydroxypyridine hydroxypyridine hydrochloride to the animals, and the effect of the doses of this compound on the level of AOA in the liver of animals aged 2 months also was investigated. Liver AOA in mice was found to decrease during aging; the decreae in animals with tumors was found to be two or three times slower than in animals without tumors. Administration of the compound after the age of 8 months led to a considerable increase in liver AOA, and this may evidently account for the considerable lengthening of the life of the experimental animals.     

Reduced genetic diversity and significant genetic differentiation after translocation: Comparison of the remnant and translocated populations of bridled nailtail wallabies (Onychogalea fraenata)

Loss of genetic diversity and increased population differentiation from source populations are common problems associated with translocation programmes established from captive-bred stock or a small number of founders. The bridled nailtail wallaby is one of the most endangered macropods in Australia, having been reduced to a single remnant population in the last 100 years. A translocated population of bridled nailtail wallabies was established using animals sourced directly from the remnant population (wild-released) as well as the progeny of animals collected for a captive breeding programme (captive-bred). The aims of this study were to compare genetic diversity among released animals and their wild-born progeny to genetic diversity observed in the remnant population, and to monitor changes in genetic diversity over time as more animals were released into the population. Heterozygosity did not differ between the translocated and remnant population; however, allelic diversity was significantly reduced across all released animals and their wild-born progeny. Animals bred in captivity and their wild-born progeny were also significantly differentiated from the source population after just four generations. Wild-released animals, however, were representative of the source population and several alleles were unique to this group. Both heterozygosity and allelic diversity among translocated animals decreased over time with the additional release of captive-bred animals, as no new genetic stock was added to the population. Captive breeding programmes can provide large numbers of animals for release, but this study highlights the importance of sourcing animals directly from remnant populations in order to maintain genetic diversity and minimise genetic drift.     

Effects of neonatal thymic exposure to high doses of X-irradiation.

The thymic region of neonatal Swiss mice was exposed to doses varying from 1000 R to 2000 R of X-irradiation. The animals did not show any signs of wasting syndrome up to 6 months after irradiation. At this time hyperplasia of the thymus with an associated lymphocytosis was evident in irradiated animals. Antibody production to sheep red blood cells (SRBC) was not affected. However, at 12 months post-irradiation the animals showed signs of wasting disease with a progressive increase in their numbers at 18 and 24 months of age. The percentage incidence of animals with wasting disease was dose dependent. At this stage in the majority of the animals with the disease the thymus showed varying degrees of atrophy along with splenomegaly. There were no significant differences in the number of lymphocytes but the number of granulocytes showed a substantial increase. This was more evident in animals exposed to 2000 R to the thymic region. Though one observed a lowered ability to form antibodies to bovine serum albumin (BSA) with advancing age, the thymic irradiation did not affect the immune response to BSA even in animals manifesting wasting disease. An interesting observation has been the development of a severe loss of muscle power and tone in the hind limbs in a large majority of animals.     

Analgesia in phasic and tonic pain tests in a pharmacological model of autotomy

Self-mutilation or self-injurious behaviour is a well known behavioural disorder in humans. The proposition that this behaviour in animals is a response to chronic pain of peripheral nerve injury has been met with controversy. In the present study a pharmacological model, which produces no sensory or motor loss was used to study how autotomy is related to pain. In a group of rats autotomy was induced by amphetamine in phenoxybenzamine and reserpine treated animals. The pain tests, both phasic and tonic were then performed. The results of this study showed that a total analgesia was produced in both phasic and tonic pain tests, in animals that exhibited autotomy. Injection of naloxone in these animals prevented autotomy. A correlation between autotomy and no pain is suggested in this pharmacological model of autotomy.     

Serum lipids and cholesterol distribution in lipoproteins of exercise-trained female rats fed sucrose

This study was undertaken to evaluate the combined effects of sucrose feeding and exercise training on serum insulin, triglycerides, as well as cholesterol and its distribution into lipoproteins of female Wistar rats. The animals were fed ad libitum either laboratory chow alone, or chow and a 32% aqueous sucrose solution. Half of each dietary group was submitted to an exercise-training program. Both sucrose feeding and exercise training elicited greater energy intake. Sucrose feeding produced a marked elevation in triglyceridemia that was prevented by exercise training. Insulin levels paralleled those of triglycerides. The sucrose-fed animals had higher total cholesterol levels than the animals given chow. Although exercise training did not affect total cholesterol in the chow-fed animals, it partly prevented the sucrose-induced elevation in total cholesterol. Cholesterol in the lipoproteins of lower densities was increased significantly with sucrose feeding, and exercise training totally prevented this augmentation. The amount of cholesterol carried by high-density lipoprotein (HDL) was not affected by exercise training in the chow-fed animals. In contrast, sucrose feeding increased HDL-cholesterol in sedentary animals, whereas exercise training partly prevented this increase. The HDL/total cholesterol ratio was similar in all groups. Changes in insulin concentration underline the importance of this hormone in the regulation of blood lipid levels.     

Development of an immunochromatographic strip for the rapid detection of Toxoplasma gondii circulating antigens

We developed a rapid immunochromatographic strip (ICS) procedure that can detect circulating antigens in the blood of animals during the acute stage of toxoplasmosis. The aim of this study was to evaluate this test using sera from field samples and from experimentally infected animals. The sensitivity and specificity of the ICS were compared with those of an enzyme-linked immunosorbent assay (ELISA). Both assays detected circulating antigens in the sera of animals experimentally infected with the Gansu Jingtai strain of Toxoplasma gondii, and the agreement between the two assays was 100%. In the infected animals, circulating antigens could be detected as early as the second day post-infection (PI) and in all animals by the fourth day. In the 381 field serum samples, the positive rates of the ICS and ELISA were 5.2% and 5.8%, respectively. In addition, there was no cross-reactivity of the antigens with Neospora caninum. The results presented here suggest that the ICS is a feasible, convenient, rapid and effective method to detect infection by T. gondii. This test could be a powerful supplement to the current diagnostic methods. Taken together, the results of this study encourage further research toward the production of commercial diagnostic tests for detecting T. gondii in animals.     

温度和热驯化对胡氏大生熊虫运动行为的影响

对外温脊椎动物体温和运动能力关系的研究表明,外温动物的运动行为对身体温度的变化高度敏感(Bennett,1990)。在许多动物种类中,体温的升高或降低显著影响动物的运动能力(Huey,1982;Miller,1982;Watkins,2000),而运动能力的下降则影响外温动物逃避捕食者(Christian andTracy,19     

Role of glomerular nitric oxide in glycerol-induced acute renal failure

Myoglobinuric acute renal failure remains one of the least understood clinical syndromes and the mediators involved remain obscure. The aim of the present study was to assess the role of nitric oxide in glycerol-induced acute renal failure under normal conditions and after uninephrectomy. Acute renal failure was induced in rats by injection of 50% glycerol (10 mL x kg(-1) body weight). Half of the animals were subjected to uninephrectomy two days before glycerol injection. Two days after the induction of acute renal failure, glomeruli from some animals were isolated and glomerular nitrite production was measured. Another group of animals was used for acute clearance studies. In this case, the effect of infusing either L-NAME or L-arginine was assayed. Glomerular nitrite production was significantly decreased in glycerol-induced acute renal failure. Glomeruli from uninephrectomized animals showed an increase in nitrite production, both in normal conditions and after glycerol injection, as compared with glomeruli from non-nephrectomized animals. L-NAME infusion worsened renal function in all the study groups, but more slowly in animals with glycerol-induced acute renal failure than in control rats. In uninephrectomized animals L-NAME reduced renal function more than in animals with two kidneys. In conclusion, in this model of acute renal failure the decrease in glomerular nitric oxide production plays an important role in the decrease in renal function. After uninephrectomy, an increase in glomerular nitric oxide synthesis plays a protective role against glycerol-induced acute renal failure.     

The Effects of Nisin on the Microbial Flora of the Dental Plaque of Monkeys (Macaca fascicularis)

Nisin was incorporated in a soft diet and fed to eight monkeys for five months. At the end of this period dental plaque was removed from one site in the mouths of these animals and from a similar site in eight control animals. Twelve different selective media were used for the cultivation of the bacteria in the plaque. Streptococci, Haemophilus spp. and Gram negative anaerobes were the organisms most frequently isolated. There was some evidence that streptococci constituted a lesser proportion of the flora in the nisin-fed animals.     

Effects of lovastatin therapy on guinea pig low density lipoprotein composition and metabolism

Lovastatin therapy is known to induce hepatic low density lipoprotein (LDL) receptor mRNA and LDL receptor activity. Yet, in studies in humans and animals it has been difficult to demonstrate an enhancement of the plasma fractional catabolic rate (FCR) of an injected LDL tracer during lovastatin therapy. One explanation may be that the composition of the LDL tracer may also change during therapy, independently affecting LDL clearance. To test this possibility we fed guinea pigs lovastatin, which led to a decrease in their plasma LDL cholesterol levels. Composition studies showed that LDL isolated from lovastatin-treated guinea pigs was slightly cholesterol-depleted and triglyceride-enriched when compared to LDL isolated from control animals. Several independent lines of investigation documented that a substantial increase in hepatic LDL receptor activity occurred in response to the lovastatin treatment. Consistent with this, when a single LDL tracer was injected into control and lovastatin-treated guinea pigs, the FCR was always more rapid in the lovastatin-treated animals. However, when LDL isolated from lovastatin-treated animals (L-LDL) was simultaneously injected intravenously with LDL isolated from control animals (C-LDL) the FCR of the C-LDL was always more rapid than that of the L-LDL. When one compared the FCR of C-LDL determined in control animals with the FCR of L-LDL determined in lovastatin animals there was no difference. Possible explanations for these paradoxical findings are discussed.     

Effect of pregnancy, postnatal growth, and gender on renal sulfate transport.

Serum sulfate concentrations are increased in infants, young children, and pregnant women, compared with adult values. The objective of this investigation was to examine the influences of age, gender, and pregnancy on renal sulfate transport using guinea pigs as an animal model. Membrane vesicles were isolated from the kidney cortex of male animals at four different ages, from male and female adult animals, and from pregnant and nonpregnant female animals. There were no significant differences in marker enzymes for the brush-border membrane (BBM) or basolateral membrane (BLM) among all groups examined. Uptake was determined by a rapid filtration method and membrane fluidity by measuring the steady-state fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene. The Vmax values for Na+ /sulfate co-transport in BBM were significantly increased with decreasing age, whereas the Km for this process was unchanged. The Vmax and Km for Na + /sulfate co-transport in BBM of pregnant animals were significantly higher than the values in the nonpregnant group. Bicarbonate-driven anion exchange of sulfate in BLM was not different among the different age groups. The Vmax for the bicarbonate/sulfate exchange process in BLM was not different between pregnant and nonpregnant groups; however, the Km for this process in BLM of pregnant animals was significantly greater than the value in nonpregnant animals. There were no gender-related differences in sulfate transport in BBM or BLM isolated from adult male and female animals. Renal BBM fluidity was increased with decreasing age and in pregnant animals, suggesting that altered membrane fluidity may represent one possible mechanism to explain the increased sodium/sulfate uptake in young and pregnant animals. The higher Vmax for Na+/sulfate co-transport in young and pregnant animals suggests that there is an increased density of co-transporter protein or an increase in the rate of movement of the carrier protein (i.e., turnover) once loaded with sodium and sulfate. This increased conservation of inorganic sulfate in young and pregnant guinea pigs may be related to the increased demand for sulfated substrates, such as sulfated glycosaminoglycans, during growth and development.     

Strategies for the avoidance of faeces by grazing sheep

Experiments were conducted to investigate which environmental cues were used by sheep when discriminating against patches of pasture contaminated with faeces. The influence of the spatial distribution of contaminated patches and the parasite infection status of sheep on avoidance of contaminated patches and ingestion of parasite larvae was also investigated. In experiment 1, sheep infected with the parasite Ostertagia circumcincta were given the opportunity to graze in uncontaminated or aggregated contaminated patches. Patch contamination comprised of either faeces from sheep infected with O. circumcincta larvae, faeces from uninfected sheep, or O. circumcincta larvae only. Infected sheep discriminated against faeces from parasite-infected animals and faeces from uninfected animals equally. Sheep did not discriminate against patches contaminated with parasite larvae only. In experiment 2, sheep infected with O. circumcincta and uninfected sheep grazed experimental plots with differing spatial patterns of faecal-contaminated patches, allowing animals the opportunity to forage in contaminated or uncontaminated patches of herbage. Plots were also grazed by infected and uninfected animals that were fistulated at the oesophagus to enable the collection of ingested herbage. Sheep spent a greater proportion of their time foraging in uncontaminated patches than in contaminated patches. Where patches were highly aggregated, infected animals spent a greater proportion of total grazing time in uncontaminated patches than did uninfected animals, and grazed uncontaminated patches for longer on each sampling occasion. On grazing plots where all patches were contaminated, the difference between the numbers of larvae isolated from pasture herbage and ingested herbage was greatest for infected animals. In this situation, infected animals avoided parasites most. On grazing plots consisting of both contaminated and uncontaminated patches, the difference between the numbers of larvae isolated from pasture herbage and ingested herbage was greatest for uninfected animals. In this situation, uninfected animals were most effective at parasite avoidance as they consumed fewer parasite larvae relative to what was available on pasture.     

Estimating myostatin gene effect on milk performance traits using estimated gene content for a large number of non-genotyped cows

The objective of this study was to estimate the myostatin (mh) gene's effect on milk, protein and fat yield in a large heterogeneous cow population, of which only a small portion was genotyped. For this purpose, a total of 13 992 889 test-day records derived from 799 778 cows were available. The mh gene effect was estimated via BLUP using a multi-lactation, multi-trait random regression test-day model with an additional fixed regression on mh gene content. As only 1416 animals, (of which 1183 cows had test-day records) were genotyped, more animals of additional breeds with assumed known genotype were added to estimate the genotype (gene content) of the remaining cows more reliably. This was carried out using the conventional pedigree information between genotyped animals and their non-genotyped relatives. Applying this rule, mean estimated gene content over all cows with test-day records was 0.104, showing that most cows were homozygous +/+. In contrast, when gene content estimation was only based on genotyped animals, mean estimated gene content over all cows with test-day records was with 1.349 overestimated. Therefore, the applied method for gene content estimation in large populations needs additional genotype assumptions about additional animals representing genetic diversity when the breed composition in the complete population is heterogeneous and only a few animals from predominantly one breed are genotyped. Concerning allele substitution effects for one copy of the 'mh' gene variant, significant decreases of -76.1 kg milk, -3.6 kg fat and -2.8 kg protein/lactation were obtained on average when gene content estimation was additionally based on animals with assumed known genotype. Based on this result, knowledge of the mh genotypes and their effects has the potential to improve milk performance traits in cattle.     

数据记忆动物游泳测试仪的研制

目的研制一种用于检测动物负载游泳状况及过程的仪器,用于动物疲劳游泳试验。方法采用不同直径的可调换加载钢球、恒温水池、接近传感器信号转换、51系列单片微机控制和记忆信号。结果研制出一台可同时做六路平行实验的动物游泳测试仪,自动记忆动物在加载的情况下抗疲劳游泳的全过程。结论经36例小鼠实验证明,效果良好,该仪器为动物负载游泳实验提供了一种全新的测试方法。     

The biotransformation of MPTP and disposition of MPP+: the effects of aging

The primary objective of this study was to investigate possible biochemical correlates of the enhanced effects of MPTP with aging in C57BL/6 mice. Striatal MPP+ concentrations were found to increase directly with the age of the animals injected (range 6 to 32 weeks). In vitro studies confirmed an enhanced rate of production of MPP+ in striatum, ventral mesencephalon, and frontal cortex in older animals. The rate of clearance of MPP+ from striatum was approximately the same in 6-8 week old mice as in 8 month old mice, but the total exposure of this brain region to MPP+ was approximately three times greater when older animals were compared to younger ones given equivalent doses of MPTP. These results are compatible with increased MPP+ production (i.e., a pharmacokinetic effect) as the explanation for the increased dopamine depletion induced by MPTP in older animals. We suggest that this approach may provide a new avenue of investigation for the study of neurodegenerative phenomena and the aging process.     

Metabolism of apoprotein B in selectively bred baboons with low and high levels of low density lipoproteins

Very low density lipoprotein (VLDL) and low density lipoprotein (LDL) apoprotein (apo)-B turnover rates were measured simultaneously by injecting 131I-labeled VLDL and 125I-labeled LDL into fasting baboons (Papio sp.) selectively bred for high serum cholesterol levels and having either low or high LDL levels. The radioactivities in VLDL, intermediate density lipoprotein (IDL), LDL apoB, and urine were measured at intervals between 5 min and 6 days. Kinetic parameters for apoB were calculated in each baboon fed a chow diet or a high cholesterol, high fat diet (HCHF). VLDL apoB residence times were similar in the two groups of animals fed chow; they were increased by HCHF feeding in high LDL animals, but not in low LDL animals. Production rates of VLDL apoB were decreased by the HCHF diet in both high and low LDL animals. Most of the radioactivity from VLDL apoB was transferred to IDL. However, a greater proportion of radioactivity was removed directly from IDL apoB in low LDL animals than in high LDL animals, and only about one-third appeared in LDL. In high LDL animals, a greater proportion of this radioactivity was converted to LDL (61.4 +/- 7.2% in chow-fed animals and 49.2 +/- 10.9% in animals fed the HCHF diet; mean +/- SEM, n = 5). Production rates for LDL apoB were higher in high LDL animals than those in low LDL animals on both diets. The HCHF diet increased residence times of LDL apoB without changing production rates in both groups. VLDL apoB production was not sufficient to account for LDL apoB production in high LDL animals, a finding that suggested that a large amount of LDL apoB was derived from a source other than VLDL apoB in these animals.     

Kinetic studies of D-glucose transport in renal brush-border membrane vesicles of streptozotocin-induced diabetic rats

Renal brush-border membrane vesicles prepared from streptozotocin-induced 4-day-diabetic rats possessed a Na+-dependent D-glucose transport system that exhibited apparent Kt and Vmax values about 2-fold greater than normal. Apparently, hyperglycemia and probably other stimuli cause the induction and membrane incorporation of a low-affinity transporter in these membranes; this increased sugar-transport capacity is retained for at least 4 weeks so long as the animals maintained or increased their body weight. Membranes prepared from 28-day-diabetic, severely ill ketoacidotic animals lose this enhanced transport ability and the decrease in Vmax was found to correlate directly with the weight loss. Furthermore, the transporter in brush-border membranes prepared from these cachectic animals had an even lower affinity for glucose than those from the acute hyperglycemic animals. That these changes in the diabetic animals represent major alterations in renal brush-border membrane construction is further supported by our observation that the specific activity of the marker enzymes, alkaline phosphatase and neutral alpha-glucosidase, are profoundly increased and decreased, respectively, in this condition.     

Orthotopic transplantation of LH receptor knockout and wild-type ovaries

Luteinizing hormone (LH) receptor knockout animals have an ovarian failure due to an arrest in folliculogenesis at the antral stage. As a result, the animals have an infertility phenotype. The present study was undertaken to determine whether this phenotype could be reversed by orthotopic transplantation of wild-type ovaries. The results revealed that transplanting wild-type ovaries into null animals did not result in resumption of estrus cycles. Although the number of different types of follicles increased, none progressed to ovulation. The serum hormone profiles improved, reflecting the ovarian changes. The wild-type animals with null ovaries also failed to cycle and their ovaries and serum hormone levels were more like null animals with their own ovaries. Although the lack of rescue of null ovaries placed into wild-type animals was predicted, the failure of wild-type ovaries placed in null animals was not, which could be due to chronic exposure of transplanted tissue to high circulating LH levels and also possibly due to altered internal milieu in null animals. These findings may have implications for potential future considerations of grafting normal donor ovaries into women who have an ovarian failure resulting from inactivating LH receptor mutations.     

Applicability of SSCP analysis for MHC genotyping: fingerprinting of Ovar-DRB1 exon 2 alleles from Finnish and Russian breeds

The applicability of single strand conformation polymorphism (SSCP) analysis for major histocompatibility complex (MHC) genotyping in sheep was studied. A panel of Ovar-DRB1 exon 2 'allele fingerprints' was defined. The panel could accelerate DRB1 genotyping of new breeds when already existing sequences are used as references in SSCP analysis. In this study, seven new exon 2 sequences and 19 different alleles in total were detected from 31 animals of Finnish and Russian sheep breeds. Ovar-DRB1 * 0201 was detected in all the six grey Finnsheep animals included in this study, suggesting reduced MHC diversity within these animals.