Reproduction in the slow loris (Nycticebus coucang)

The reproductive biology of the slow loris (Nycticebus coucang) is poorly documented because of infrequent captive breeding success and the absence of field studies of this species. Reproductive data were collected from a breeding colony of slow lorises held at the Duke University Primate Center for the past 10 years. Nineteen infants were born, with a sex ratio of 1:1 and a neonatal mortality rate of 15.8%. In all cases, litter size was one. Females born in the colony copulated for the first time between 18 and 24 months of age. A male that reached sexual maturity in the colony sired his first offspring at the age of 17 months. Estrous cycles ranged in duration from 29–45 days, with copulations usually occurring for 1 day of estrus. Gestation length averaged 192.2 days. Although a postpartum estrus was observed in three cases of infant death, no conceptions resulted. Lactation lasted approximately 6 months. A clear birth peak was observed, with 12 out of 19 births occurring in March, April, and May. The comparatively low basal metabolic rate of this species may account for the unusually low reproductive rate of the slow loris in comparison with other prosimian primates.     

某些内科系统疾病患者血浆游离氨基酸的变化及意义

为了解某些内科系统疾病的血氨基酸代谢特点。测定１７０例９种内科系统急慢性疾病患者血浆游离氨基酸浓度,并分别与５８例健康人血浆氨基酸浓度作对比分析。９种疾病的血浆胱氨基酸浓度不同程度升高,以尿毒症病人最为显著,炎症性病人血浆苯丙、蛋、赖氨酸和苯丙／酪比值显著升高,丙、组、精、脯氨酸和支／芳比值显著降低;糖尿病和甲亢病人血浆总游离氨基酸、谷、丙、酪、赖和支链氨酸显著升高;糠尿病病人支／芳比值显著升高,表明不同疾病的血氨基酸浓度有特征性变化,炎症是导致血氨基酸代谢紊乱的重要因素     

Selected aspects of Lemur variegatus reproductive biology

Results from data collected during the 1978–1979 breeding season on the reproduction of Lemur variegatus at the San Diego Zoo provide information which generally supports previously published reports on this species. Comparison of selected results from these data to a larger data base of which they are a part makes it possible to resolve some of the discrepancies between reports. Certain aspects of the reproductive biology of this species may then be generally characterized with confidence: The onset of seasonal breeding as evidenced by estrous behavior begins as early as mid-December in the northern hemisphere and may continue through March; genital changes associated with estrus in females last 9.85 ± 1.67 days (± SD); female receptivity occurs 7.0 ± 1.53 days after the onset of these genital changes and lasts 12-24 hours, during which breeding occurs; gestation averages 99.47 ± 4.19 days; the peak birth season is April–May; litters normally contain two to three offspring, with full-term neonates weighing an average of 104.63 ± 19.10 grams. In addition, L variegatus appears to be highly resistant to the impact of captivity on both its reproductive physiology and behavior, as indicated by the 100% breeding success of the diversely reared and managed groups of study animals.     

健康学龄前儿童血浆氨基酸与血红蛋白含量

本文采用丹酰氯聚酰胺薄层分析法研究了６５名３—７岁健康儿童的血浆游离氨基酸和血红蛋白浓度。结果表明：（１）赖氨酸促进蛋白质合成不仅供机体生长需要,同样也供合成血红蛋白;（２）贫血前期已有血浆游离氨基酸的变化,继而出现贫血,提示儿童时期生长旺盛,应注重补充某些氨基酸消耗和补充维生素、叶酸、铁元素等造血原料。     

Analysis of the oviductal glycoprotein 1 polymorphisms and their effects on components of litter size in rabbits

The objective of this work was to study the effect of the oviductal glycoprotein 1 ( OVGP1 ) genotype and mRNA expression on litter size and other fertility measures, as OVGP1 has positive effects on fertilization and early embryo development. We have analysed an F₂ cross of two lines of rabbits divergently selected for uterine capacity. The OVGP1 mRNA expression was analysed in both lines, but no differences were observed between them. The promoter region and mRNA were sequenced in the F₀ generation, and 17 polymorphic sites were found to co-segregate in three haplotypes (A, B and C). An association study was performed between several reproductive traits and a triallelic microsatellite identified in the promoter region as well as a non-synonymous SNP located in exon 11 [g.12944C>G (p.Arg468Gly)]. The alleles g.12944G and g.325(GT)₁₄T(G)₅ of the B haplotype have a positive effect on the total number of kits born, number born alive, number of implanted embryos and foetal and prenatal embryo survival.     

烧伤狗浆血游离氨基酸的动态变化

烧伤狗浆血游离氨基酸的动态变化黎君友,周幼勤,赖业馥,赵有,伊少杰ＳｅｑｕｅｎｔｉａｌＣｈａｎｇｅｓｉｎＰｌａｓｍａＦｒｅｅＡｍｉｎｏＡｃｉｄＣｏｎｃｅｎｔｒａｔｉｏｎｉｎＢｕｒｎｅｄＤｏｇｓ￥Ｌｉｊｕｎｙｏｎ;Ｚｈｏｕｙｏｕｑｉｎ;Ｌａｉｙｅｆｕ;...     

脑卒中患者血浆中含硫氨基酸的测定

本文建立了测定血浆中胱氨酸、蛋氨酸的方法,探讨了胱氨酸、蛋氨酸与脑卒中的关系,旨在对脑卒中的发病机理,临床诊断,以及防治对策提供有益效果。     

Experimental litter size reduction reveals costs of gestation and delayed effects on offspring in a viviparous lizard

Experimental studies have often been employed to study costs of reproduction, but rarely to study costs of gestation. Disentangling the relative importance of each stage of the reproductive cycle should help to assess the costs and benefits of different reproductive strategies. To that end, we experimentally reduced litter size during gestation in a viviparous lizard. We measured physiological and behavioural parameters during gestation and shortly after parturition, as well as survival and growth of females and their offspring. This study showed four major results. First, the experimental litter size reduction did not significantly affect the cellular immune response, the metabolism and the survival of adult females. Second, females with reduced litter size decreased their basking time. Third, these females also had an increased postpartum body condition. As postpartum body condition is positively related to future reproduction, this result indicates a gestation cost. Fourth, even though offspring from experimentally reduced litters had similar weight and size at birth as other offspring, their growth rate after birth was significantly increased. This shows the existence of a maternal effect during gestation with delayed consequences. This experimental study demonstrates that there are some costs to gestation, but it also suggests that some classical trade-offs associated with reproduction may not be explained by gestation costs.     

Influence of branched-chain amino acid composition of culture media on the synthesis of plasma proteins by serum-free cultured rat hepatocytes

Summary Supplementation of Ham's F12 culture medium with essential amino acids (EAA) up to the rat plasma levels increased the rates of synthesis of albumin and transferrin by cultured rat hepatocytes by 1.3 and 1.7, respectively. Fifty percent of this increase could be attributed to three of the EAA: the branched-chain amino acids (BCAA: Leu Ile and Val). Non-branched-chain essential amino acids (non-BC-EAA) stimulated only 25% of the increase produced by the whole EAA mixture. When each EAA was tested individually, none of them caused an appreciable increase in albumin and transferrin in culture medium. When the concentrations of all EAA were raised to rat postprandial portal levels, albumin and transferrin synthesis rates reached a maximum, increasing by 3.2 and 3.5, respectively. Supplementation with BCAA at postprandial portal concentrations increased albumin and transferrin synthesis rates by 2.2 and 2.0, respectively, and had no noteworthy effect on the synthesis of cellular proteins. Non-BC-EAA at their postprandial portal concentrations increased albumin and transferrin synthesis rates by 1.7 and 1.9, respectively. Supplementation with alanine to reach a nitrogen content equal to that of the modified EAA-enriched medium had no stimulatory effect. Our results show that EAA have a specific effect on the synthesis of plasma proteins by cultured hepatocytes, and that BCAA at physiologic concentrations account for the major part of this stimulatory effect. Consequently, EAA and particularly BCAA concentration should be elevated in serum-free nutrient media to sustain maximum plasma protein synthesis.     

Regulation of the plasma amino acid profile by leucine via the system L amino acid transporter

Plasma concentrations of amino acids reflect the intracellular amino acid pool in mammals. However, the regulatory mechanism requires clarification. In this study, we examined the effect of leucine administration on plasma amino acid profiles in mice with and without the treatment of 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) or rapamycin as an inhibitor of system L or mammalian target of rapamycin complex 1, respectively. The elevation of plasma leucine concentration after leucine administration was associated with a significant decrease in the plasma concentrations of isoleucine, valine, methionine, phenylalanine, and tyrosine; BCH treatment almost completely blocked the leucine-induced decrease in plasma amino acid concentrations. Rapamycin treatment had much less effects on the actions of leucine than BCH treatment. These results suggest that leucine regulates the plasma concentrations of branched-chain amino acids, methionine, phenylalanine, and tyrosine, and that system L amino acid transporters are involved in the leucine action.     

Studies on the mechanism of induction of hypercholesterolemia in rabbits by high dietary levels of amino acids

Increasing the proportion of an amino acid mixture corresponding to casein in a low-fat, cholesterol-free, semipurified diet fed to rabbits causes a progressive increase in serum total and low density lipoprotein cholesterol, and the effect appears to be due primarily to the essential amino acids in the mixture. Our recent studies have also shown that the variations in serum cholesterol in response to different levels of the amino acid mixture are not associated with any changes in fecal excretion of cholesterol or bile acids. Further attempts to understand the mechanism of action of dietary amino acids on serum cholesterol levels have shown the following: (1) no correlation with levels of plasma amino acids, either in the fasting or postprandial state: (2) no correlation with serum levels of thyroid hormones: (3) no relationship to activity of hepatic or intestinal microsomal hydroxymethylglutaryl coenzyme A reductase: (4) no corresponding effects on the activities of cholesterol esterifying enzymes of intestinal mucosa: and (5) no correlation with the degree of esterification of cholesterol in very low or low density lipoproteins. Further studies are required to identify the specific amino acids responsible for the hypercholesterolemic effects and to determine the mechanisms involved.     

Plasma and Cerebrospinal Fluid Amino Acids in Epileptic Patients

Altered plasma and cerebrospinal fluid amino acid levels may be associated with human epilepsy. We studied three groups of patients, those with a generalized epileptic syndrome, juvenile myoclonic epilepsy, patients with refractory localization-related epilepsies, and patients with acute seizures (within 24 h). Plasma levels of amino acids were studied in all patient groups, as were those in the cerebrospinal fluid (CSF) of patients with acute seizures. After acute seizures, the amino acid changes in the CSF were limited to a reduction in the level of taurine, whereas the levels of most amino acids in plasma were decreased. On the other hand, levels of the excitatory amino acids glutamate and aspartate were increased. The most notable finding in the juvenile myoclonic epilepsy patients was an increase in glutamate level in the plasma. Our study supports the conception of an altered metabolism of glutamate in generalized epilepsies.