黄河三角洲土壤运行多样性初步调查研究

1995－1996年对黄河三角洲9个代表性样区,进行了土壤运动定性,定量调查,并对古代,近代,现代黄河三角洲3个代表性样区开展了土壤动物周年调查,研究了土壤动物的种类组成,分布和节季变化,以及土壤动物多样性,调查研究结果,黄河三角洲共鉴定出土壤运动38种,土壤运动种类组成和数量分布因三个三角洲成土年龄不同而存在差异,土壤运动多样性以夏季为丰富,黄河三角洲土壤运动多样性]与均匀度表现为正相关关系,与单纯度呈负相关趋势。     

Are there physiological and biochemical adaptations of metabolism in deep-sea animals?

From the earliest observations of deep-sea animals, it was obvious that they differed in many ways from shallower-living relatives. Over the years, there has been speculation that deep-sea animals have unusually low rates of biological activity; numerous adaptive scenarios explaining this have ben offered. However, these speculations and scenarios have rarely been tested due to the difficulty of data collection and the inevitable confounding of a number of major variables which covary with depth. In recent years, study of the metabolic properties of animals of several phyla from widely differing deep-sea habitats, including the hydrthermal vents, has made it possible, using comparative approaches, to test hypotheses concerning the metabolic adaptations of deep-sea animals.     

Diabetes-induced rat hyposensitivity to compound 48/80

Rat mortality and contractile responses of isolated tracheas to compound 48/80 from rats made diabetic 4 days before by a single intravenous injection of alloxan and from diabetic rats that had been treated with insulin 6 h before were compared with control animals. Diabetic animals and tracheal segments from diabetic rats were significantly less responsive to compound 48/80 than control and insulin-treated diabetic animals. On the other hand, diabetic animals have a lower quantity of peritoneal mast cells than control rats, and insulin restored the normal quantity of cells in diabetic animals. These data indicate that diabetes elicits an hyposensitivity to compound 48/80, possibly related to a diabetes-induced decrease in the mast cell count.     

Role of motor activity in the development of hypothyroid rat pups

Studies have been made on the role of the thyroid in the development of rats. In the first group of experiments, newborn rat received within a month mercazolyl which inhibits the activity of the thyroid; in animals of the second group, mercazolyl injections were combined with cold exposures which stimulated motor activity in animals. It was found that hypothyroid rats in both groups exhibit retardation of growth as compared to normal animals. However, retardation is less significant in animals of the second group, as it is indicated by smaller changes in the protein content and total mass of skeletal muscles.     

Population dynamics of microfilarial production and eosinophilic levels in slow lorises infected with Breinlia sergenti. Petter (Filarioidea: Dipetalonematidae)

Population dynamics of microfilarial production and eosinophilic levels in slow lorises infected with Breinlia sergenti, Petter (Filarioidea: Dipetalonematidae). International Journal for Parsitology 4: 383388. Observations have been made on microfilarial and eosinophilic levels in slow lorises infected with Breinlia sergenti. Animals given a single inoculation of 100-150 infective larvae exhibited three different patterns of microfilaraemia while superinfected animals showed enhanced microfilarial levels. It appeared that the number of inoculations as well as the interval between inocula are important factors in enhancing microfilarial levels. Two different types of incubation periods were seen, one at 100-120 days and the other at 200 days. The eosinophilic levels were investigated in some of the animals and an attempt was made to correlate these levels with the microfilaraemia. Cortisone injection appeared to promote a vigorous eosinophilia in some of the infected animals tested.     

The application of transgenic techniques for the improvement of domestic animal productivity

The application of transgenesis techniques to domestic animals has now been achieved in all the major species of domestic animals. In this review, the progress towards genuine practical applications of the technique is examined. Areas which appear to have made progress during the past several years include the evaluation of animals with elevated growth hormone levels, the introduction of novel metabolic pathways, the expression of transgenes in the mammary glands of pigs and sheep, and the real possibility that functional immunoglobulin genes might be used to confer genetically-inherited disease resistance to commercially-valuable animal breeds.     

国外动物生物技术研究和产业化趋势分析

生物技术在全世界范围取得了飞速的进展,与此同时其应用和产业化在各国政府、科研机构和生物技术公司的大力参与和激烈竞争中也逐步加快,预计它将成为许多国家经济的重要支柱产业之一。一些重大生物研究项目如人类基因组计划、克隆技术等开始引起公众的广泛注意。综述了２０世纪９０ 来动物生物技术的发展状况,对基因组研究、转基因动物、克隆技术和细胞培养等重要研究方向作了介绍和分析。     

Role of thyroid hormones in the modification of diet-induced thermogenesis by propranolol

The effect of thyroid hormones on the reduction in resting metabolic rate by the beta-blocker propranolol has been investigated in young pigs. Oxygen consumption was measured 12 to 20 hr after the last meal in euthyroid and hypothyroid animals on a high or low level of energy intake. The increase in resting metabolic rate in animals on the high energy intake was reduced by propranolol in the euthyroid controls but not in those animals made hypothyroid by methimazole. Thus at least part of the action of propranolol to decrease diet-induced thermogenesis depends on its interaction with thyroid hormones.     

转基因动物应用的研究现状与发展前景

转基因动物的迅速发展使医药、农业、环保、生物材料等领域发生了巨大变革。综述了国际和国内转基因动物在这些领域中的研究历史、现状和产业化进展,同时也预测了转基因动物应用的发展前景以及给社会带来的深远影响。     

Safety and sensitizing properties of a polyvalent corpuscular Pseudomonas aeruginosa vaccine and its effect on hematological indices

The acute and chronic toxicity, influence on hematological characteristics and sensitizing properties of P. aeruginosa polyvalent corpuscular vaccine have been studied in experiments on 3 species of animals. The acute experiment has shown that the LD50 of the preparation contains not less than 7800 million cells, which is almost 160 times higher than the recommended immunizing dose (500 million cells). The safety of the preparation is confirmed by the data obtained in the histological and histochemical investigations of the tissues and organs of animals subjected to multiple immunizations with the vaccine. These investigations have revealed no pathological changes in the animals. During the study of the chronic toxicity of the preparation the hematological characteristics of the animals have been found to remain within normal limits. The vaccine has been shown to possess low sensitizing activity, which is manifested by the absence of severe reactions to allergic skin tests with different bacterial allergens (specific allergens obtained from P. aeruginosa and allergens obtained from other bacterial species), made on completion of the course of immunization with the vaccine.     

Changes in the biochemical composition of Balanus balanoides (L.) under experimental conditions: The effect of a starch diet

A comparison has been made of the changes in biochemical composition of experimental and natural populations of Balanus balanoides (L.). The ‘bodies’ and the ovary were separately analysed. The lipid components have been investigated in some detail; lipid classes were separated and the component fatty acids of the major components (triglycerides + diglycerides and phospholipids) determined.Animals fed on brine shrimp increased in weight more than the natural population, that of the starved animals was less, and that of animals fed on starch only, even less. The starch-fed animals continued to produce faecal pellets and it is suggested that the greater energy expenditure in feeding (cirral) activity with little gain of useful metabolic substrate was responsible for this decrease in body weight. These differences extend to the component lipid classes. Even so, these starch-fed animals produced ovarian tissue as, indeed, did starved animals, presumably by transfer of body material; the low level or absence of nutrients did not interfere with the hormonal stimulation of reproduction.     

Cytogenetic studies of 1-29 translocation carrying cows and their embryos

An examination has been made of embryos from infertile 1-29 translocation carrying heifers. Cytogenetic measurements of C-banded chromosomes from these cattle, together with those from fertile 1-29 cows, have been made and compared with those from normal karyotypes. There are relative differences between normal animals and translocation carriers in the ratios of total to C-banded material throughout the karyotypes: their possible effects on mitosis and meiosis are discussed. Of the embryos recovered from the infertile heifers, one did not survive transplantation and others had various indications of inviability.     

Changes in unsaturated fatty acids in serum lipids of hamsters infected with schistosomes (S. mansoni)

Measurements have been made of the fatty-acid composition of lipids in normal hamster sera compared with sera of hamsters infected with Schistosoma mansoni. The results show a consistent decrease of linoleic and eicosapentaenoic acids, and an increase in arachidonic acid in the phosphatidylcholine and lysophosphatidylcholine of the infected animals. Arachidonic acid was also increased in cholesterol ester, and docosahexaenoic acid was raised in free fatty acid and in phosphatidylcholine in sera from infected animals.     

Sarcocystosis

Sarcocystis infections of animals are commonplace and of worldwide distribution. Some species can be severely pathogenic to farm animals, causing anorexia, weight-loss, abortion and even death. But perhaps because sarcocysts are so common they have frequently been regarded as innocuous. Even in the USA and UK, many cases of abortion in farm animals go undiagnosed, and it is only now that sarcocystosis is being implicated as potentially of economic importance to the farm industry. In many cases however, the major effect is likely to be subclinical, seen in farm animals only as a reduction in liveweight gain. As this review shows, the history of research on Sarcocystis has been marked by confusion and neglect, although enormous progress has been made in the last decade. But until their economic importance is fully recognized, these widespread infections seem likely to continue unchallenged.     

Veterinary significance of verocytotoxin-producing Escherichia coli O157

Verocytotoxin-producing Escherichia coli O157 is a serious pathogen in man that is carried by ruminants and has been isolated from some other animal species. Except in the very young of certain species and in greyhounds, the organism is not associated with disease in animals. Humans may be infected by ingestion of the organism through direct animal contact, from contaminated food or water or from the environment. Great efforts have been made to improve hygienic food production and handling, to protect water supplies and to give adequate advice to people handling animals. It is also essential to try to reduce the numbers of organisms shed by animals and, to do this, a clear understanding of the ecology of the organism is required. This revised version was published online in November 2006 with corrections to the Cover Date.     

The ex-vivo effects of thyroid status and extracellular calcium concentration on rat atrial and ventricular electrophysiology

The purpose of this study was to explore the relationship between the thyroid status and both ventricular and atrial electrophysiology in the rat. The study was extended to consider the effects of altering the extracellular calcium concentration. The work was performed in two sections. First, hypothyroid animals were compared with euthyroid (untreated animals); second, hypothyroid animals were compared with hyperthyroid animals. Rats were rendered hypothyroid by pretreatment with the goitrogen methimazole and hyperthyroid by additional treatment with triiodothyronine. Action potential recordings were obtained using standard microelectrode techniques. Action potential measurements were made initially in a Krebs solution to which had been added 2.55 mM calcium (higher Ca Krebs solution) and at the end of each experiment after stabilization with Krebs solution to which had been added 1.28 mM calcium (lower Ca Krebs solution). Assessment of the change in action potential duration on transition from higher to lower Ca Krebs solution revealed that the euthyroid preparations demonstrated less prolongation of action potential duration than the hypothyroid group, and the hyperthyroid group showed hardly any response to reduction in calcium concentration.     

Transgenic animals in inflammatory disease models

Inflammatory diseases affect a significant portion of the population worldwide and have been intensely studied for several decades. The advent of transgenic technology has allowed researchers to study individual gene contributions to the pathogenesis of these diseases. This has been done using standard inflammatory disease models in transgenic animals and by identifying novel models through the spontaneous generation of disease in the transgenic animal. Recent advances have been made in the understanding of rheumatoid arthritis, pulmonary inflammation, multiple sclerosis and inflammatory bowel disease through the use of transgenic animals in models of human inflammatory disease.     

Development in ontogeny of the effect of ACTH fragment 4-7 on rat learning

Studies have been made of the effect of ACTH fragment 4-7 on learning in rats in early postnatal ontogenesis, as well as of the possibility of preservation of early learning during administration of this peptide to adult animals. It was shown that conditioned reaction of active avoidance practically cannot be formed in normal 13-15-day animals; however, administration of ACTH 4-7 increases the number of animals exhibiting adequate reactions. Weak effect of ACTH 4-7 in 12-15-day animals, in older ones (20-24 days) is changed by a significant stimulating effect.     

Statistical variation of selected clinical pathological and biochemical measurements in rodents

The variability in clinical pathological and biochemical measurements among replicates is often greater than the effects under study. To minimize the effects of this variability, it is recommended that replicated concurrent analyses (randomized blocks) of groups of animals be used. That is, some samples from each of the groups of animals to be compared are analyzed at the same time. This process is replicated until a sufficient number of animals are sampled. If replicated concurrent analyses are not conducted and clinical measurements are made at different times for different groups of animals, the biases may be large. Clinical data were examined from several experiments to illustrate that the problems of clinical measurements are not confined to a particular endpoint, species, or sex. In one case, four times as many animals would have been required using nonconcurrent analyses to achieve the same precision as for concurrent analyses. Permutation analyses of two of the data sets indicate that statistical conclusions concerning the comparison of average clinical levels in different groups of animals would have been incorrect, falsely indicating higher or lower levels in a group over one-half of the time with nonconcurrent analyses.     

Molecular evolution study in China: progress and future promise

China has a large land area with highly diverse topography, climate and vegetation, and animal resources and is ranked eighth in the world and first in the Northern Hemisphere on richness of biodiversity. Even though little work on molecular evolution had been reported a decade ago, studies on both the evolution of macromolecules and the molecular phylogeny have become active in China in recent years. This review highlights some of the interesting and important developments in molecular evolution study in China. Chinese scientists have made significant contribution on the methods inferring phylogeny and biogeography of animals and plants in East Asia using molecular data. Studies on population and conservation genetics of animals and plants, such as Golden monkey and Chinese sturgeon, provided useful information for conserving the endangered species. East and South Asia has been demonstrated to be one of the centres of domestication. Origin and evolution of genes and gene families have been explored, which shed new insight on the genetic mechanism of adaptation. In the genomic era, Chinese researchers also made a transition from single-gene to a genomic investigation approach. Considering the fact that amazing progress has been made in the past few years, and more and more talented young scientists are entering field, the future of molecular evolution study in China holds much promise.