Similarities and differences in the growth of the heart in situ and in transplants

Growth and ploidy of rat ventricular myocytes were studied during development in situ and in grafts (1 day old rat ventricle transplanted under kidney capsule of syngenic adult animals). Both in situ and in the transplants polyploidization occurred on days 4-14 of postnatal life, and the modal group of myocytes was represented by binucleate diploid (2c x 2) cells. Minor quantities of 4c, 4c x 2, 8c and 2c x 4 myocytes were detected as well. In ventricles of 14 and 28 days old rats and in the transplants of the corresponding age the portion of polyploid myocytes was 90-96% and 32-63% respectively. The intensity of postmitotic myocyte transplants was decreased as compared with in situ development, and cells that exit proliferation cycle did not grow until day 14. The data on thymidine label dilution suggest that diploid myocytes of the transplant can divide two or three times but the majority of labeled diploids divided only once. Labeled 2c x 2 myocytes originated from the first, and less frequently, the second cell generation or resulted from initial acytokinetic mitosis. Mononucleate tetraploids 4c originated from 2c x 2 and mostly from 2c cells. Octaploids were formed after 3d or 4th labeled mitosis. The conclusion about cardiac myocyte polyploidization as an intrinsic developmental program is supported, implying the programming of onset, mode, duration and termination of polyploidization and its prolongation during early postnatal life.(ABSTRACT TRUNCATED AT 250 WORDS)     

国际植物基因组组织与计划概况及我国的应对策略

本文简要介绍了植物基因组领域主要的组织和计划,简单分析了国际植物基因组计划的特点和我国存在的问题,并初步提出我国的应对策略。     

Variants in the CNR1 and the FAAH Genes and Adiposity Traits in the Community

Pharmacologic blockade of the endocannabinoid receptor 1 leads to weight loss and an improved metabolic risk profile in overweight and obese individuals. We hypothesize that common genetic variants in the CNR1 (encoding endocannabinoid receptor 1) and FAAH genes (encoding fatty acid amide hydrolase, a key enzyme hydrolyzing endocannabinoids) are associated with adiposity traits. We genotyped 18 single‐nucleotide polymorphisms (SNPs) in the CNR1 gene and 9 SNPs in the FAAH gene in 2,415 Framingham Offspring Study participants (mean age 61 ± 10 years; 52.6% women; mean BMI 28.2 ± 5.4 kg/m²; 30.3% obese) and studied them for association with cross‐sectional and longitudinal measures of adiposity (BMI, waist circumference, change over time in BMI and waist circumference, visceral and subcutaneous adipose tissue) using linear mixed‐effect models. The selected SNPs captured 85% (r² = 0.8) of the common variation (minor allele frequency >5%) at the CNR1 locus and 96% (r² = 0.8) of the common variation at the FAAH locus (defined as the genomic segment containing the gene +20 kb upstream and +10 kb downstream). After correction for multiple testing, none of the SNPs in the CNR1 gene or in the FAAH gene displayed statistical evidence for association with BMI, waist circumference, and visceral adipose tissue or subcutaneous adipose tissue (all P > 0.18). Despite comprehensive SNP mapping across the genes and their regulatory regions in a large unselected sample, we failed to find evidence for an association of common variants in the CNR1 and FAAH genes with measures of adiposity in our community‐based sample.     

Mitochondria and ischemic reperfusion damage in the adult and in the developing brain

The developing and the adult brain respond in similar ways to ischemia, but also display clear differences. For example, the relative contributions of necrosis and apoptosis to neuronal death may be different, such that apoptotic mechanisms would be more prevalent in the developing brain. During normal development, more than half of the neurons in some brain regions are removed through apoptosis, and effectors like caspase-3 are highly upregulated in the immature brain. Mitochondria are pivotal regulators of cell death through their role in energy production and calcium homeostasis, their capacity to release apoptogenic proteins and to produce reactive oxygen species. This review will summarize some of the current studies dealing with mitochondria-related mechanisms of ischemic brain damage, with special reference to developmental aspects.     

Dysmorphology in the Bible and the Talmud

This article enumerates the congenital anomalies mentioned in the Bible and the Talmud, the two holiest and oldest texts in Judaism. Most of these conditions were described to regulate attributes that would disqualify a Priest from performing religious rituals in the Temple in Jerusalem. However, the cultural atmosphere in Biblical and Talmudical times was one in which physical deformity did not necessarily evoke a negative aesthetic reaction, an assumption of ill health, or the expectation of economic dependence.     

Fertilization and the cytoskeleton in the mouse

The behaviour and roles of the microtubule network and the microfilaments following fertilization in the mouse oocyte are described. The microtubule network is organized by multiple microtubule organizing centres (MTOCs) and these play a major role in establishing spindle structure and pronuclear movement following fertilization; in contrast to sea urchin and frog eggs, the sperm centriole plays little part in organization of the post-fertilization spindle. The microfilaments are required for spindle rotation, polar body formation, certain changes in the egg cortex, and also for pronuclear movement. Influences of the chromosomes on microtubule and microfilament organisation are also discussed.     

Neural induction and patterning in the mouse in the absence of the node and its derivatives

The signals which induce vertebrate neural tissue and pattern it along the anterior-posterior (A-P) axis have been proposed to emanate from Spemann's organizer, which in mammals is a structure termed the node. However, mouse embryos mutant for HNF3 beta lack a morphological node and node derivatives yet undergo neural induction. Gene expression domains occur at their normal A-P axial positions along the mutant neural tubes in an apparently normal temporal manner, including the most anterior and posterior markers. This neural patterning occurs in the absence of expression of known organizer genes, including the neural inducers chordin and noggin. Other potential signaling centers in gastrulating mutant embryos appear to express their normal constellation of putative secreted factors, consistent with the possibility that neural-inducing and -patterning signals emanate from elsewhere or at an earlier time. Nevertheless, we find that the node and the anterior primitive streak, from which the node derives, are direct sources of neural-inducing signals, as judged by expression of the early midbrain marker Engrailed, in explant-recombination experiments. Similar experiments showed the neural-inducing activity in HNF3 beta mutants to be diffusely distributed. Our results indicate that the mammalian organizer is capable of neural induction and patterning of the neural plate, but that maintenance of an organizer-like signaling center is not necessary for either process.     

Infrastructure and the environment in the Anthropocene

For centuries, man‐made infrastructure has been viewed as separate from natural systems. Yet in the past few centuries, as the scale and scope of human activities have dramatically increased, there is accumulating evidence that natural systems are becoming increasingly, and in some cases entirely, managed by humans. The dichotomy between infrastructure and the environment is narrowing, and natural systems are increasingly becoming human design spaces. This is already apparent with the management of hydrologic systems for urban water supply, wildlife, agriculture, forests, and even the atmosphere, and we can expect management of the environment to become more so as human activities grow. Yet our infrastructure largely remains obdurate. They are designed to last for long times even as changes in the environment and technology accelerate. As such, our current infrastructure paradigms fail at the level of the complex, integrated systems and behaviors that characterize the Anthropogenic Earth. Infrastructure in the future will need to be designed for adaptive capacity and the complexities associated with techno‐environmental systems.     

Bathing before sleep in the young and in the elderly

In this study we investigated the effects of bathing on the quality of sleep in 30 elderly people (ages 65-83 years) and in 30 young people (ages 17-22 years) in their homes. Room temperature did not vary significantly during the nights that data were acquired, ranging from 8 to 12 degrees C. After bathing and at the beginning of sleep, the mean (SE) rectal temperatures of the young and the elderly were 37.8 (0.08) and 37.5 (0.07) degrees C, respectively, and were higher by 0.7 (0.13) and 0.6 (0.07) degrees C, respectively, than when the subjects had not bathed. At the beginning of the sleep after bathing in the young subjects, skin temperature was 32.5 (0.24) and 1.5 (0.34) degrees C higher than when those subjects had not bathed. In the elderly, however, there were no significant differences in skin temperature with and without prior bathing because they used electric blankets during sleep. After bathing, the young people reported "warmth" in their hands and/or legs, while the elderly more often reported "good sleep" or "quickness of falling asleep". During the first 3 h of sleep, body movements were less frequent after bathing for both the young and the elderly subjects. The results suggest that a bath before sleep enhances the quality of sleep, particularly in the elderly.     

Endothelium-microenvironment interactions in the developing embryo and in the adult

The vascular endothelium is best known for its role in oxygen and nutrient delivery to the various tissues. Growing evidence supports a far more complex role in tissue homeostasis. In particular, reciprocal interactions between endothelial cells and the local microenvironment may regulate organ development and pattern formation. Such interactions appear to be important also in the adult, in normal and pathological conditions.     

Ethnicity in the USSR and the CIS

After the USSR: Ethnicity, Nationalism, and Politics in the Commonwealth of Independent States. Anatoly M. Khazanov. Madison: University of Wisconsin Press, 1995. 311pp.
Who Gets the Past? Competition for Ancestors among Non-Russian Intellectuals in Russia. Victor A. Shnirelman. Washington, DC: Woodrow Wilson Center Press; Baltimore, MD: Johns Hopkins University Press, 1966. 98 pp.
In the Soviet House of Culture:. Century of Perestroikas. Bruce Grant. Princeton, NJ: Princeton University Press, 1995. 225 pp.     

Tremor characteristics in the norm and in the diagnosis and treatment of parkinsonism

With the aid of tensotremorography, a voluntary effort was recorded and characteristics of involuntary and voluntary components of the hands' isometrically recorded efforts were studied. The revealed frequency ranges of the oscillations spectral density's changes corroborate existence of two suprasegmental systems of movements control, the systems being related to voluntary control and a current control of the efforts maintaining or preserving a posture. Results of cross-correlation analysis of the hands' efforts maintained under conditions of a visual feedback are demonstrated in norm and in central disorders of the movement control system.     

Differences in the concentration of erythrocytes and the hematocrit value in the blood in relation to the location of the vessels and the intensity of the blood flow

The experiments in adult rabbits revealed that in the blood flowing in cerebral veins the red cell concentration and hematocrit are much greater than in the veins of hind legs of the same animals. In blood samples taken from the heart these values are higher than in those taken from the hind leg, but usually lower than in blood samples taken from the brain. Under conditions of reduced cerebral blood flow (ischemia) the red cell concentration and hematocrit in the brain vessels decrease significantly as compared to the control conditions. Thus, the red cell distribution in arterial branching sequence is irregular, depending both on the localization of the vascular bed and the blood flow rate in it.     

Olfactory sensitivity in the black-billed magpie and in the pigeon

• 1.1. Changes in respiration frequency were used to evaluate the olfactory sensitivity of the black-billed magpie and the pigeon to ethanethiol, butanethiol, menthol and putrid meat odorants.
• 2.2. The threshold concentrations of ethanethiol and butanethiol, but not menthol, were lower in the magpies than in the pigeons. Only the magpies responded to the putrid meat odorant.
• 3.3. The greater responsiveness of the magpies to ethanethiol, butanethiol and putrid meat odorants is attributed to the biological relevance which these odors have for them.

     

Seed size and shape and persistence in the soil in the New Zealand flora

Seed size and shape predict seed persistence in the soil for British and Argentinian herbaceous plant species. Those species with small, rounded seeds tend to have persistent seeds while those with larger, more elongate or flattened seeds usually lack persistence. It has been suggested that the mechanism underlying this pattern may be ease of burial, as small, rounded seeds are incorporated into the soil more easily than large, elongate or flattened seeds and are therefore less likely to be eaten by seed predators. We tested whether seed size and shape were related to persistence in the soil for 47 species native to New Zealand forests. There was a tendency for species with persistent seeds to have smaller seeds than species with transient seeds. However, species with large and/or elongate or flattened persistent seeds were relatively common. This indicates that seed size and shape are not related to persistence in New Zealand in the same way as in Britain and Argentina. A similar negative result has been found in Australia. The underlying cause of the patterns observed is unlikely to be ease of burial, since incorporation of seeds into the soil is likely to operate in all countries in a similar manner on seeds without specialised seed burial mechanisms. Data from all four floras studied to date also suggest that species with small, rounded seeds that do not germinate immediately must have the ability to survive periods of burial.     

Thermal comfort conditions in the morning and in the evening

Eight females and eight males participated each in 4 comfort experiments on 4 different days. Two experiments took place in the morning and two in the evening. In each experiment (21/2 hours) the preferred ambient temperature was determined for each subject by adjusting the ambient temperature according to his wishes. The subjects were sedentary. Skin temperatures, rectal temperature and evaporative weight loss were measured. Although the rectal temperature and the mean skin temperature were slightly higher in the evening than in the morning the subjects did not prefer an ambient temperature which was different from that in the morning. This indicates that the same thermal comfort conditions can be used from morning to evening.     

Interactions in the Metabolism of Glutamate and the Branched-Chain Amino Acids and Ketoacids in the CNS

Glutamatergic neurotransmission entails a tonic loss of glutamate from nerve endings into the synapse. Replacement of neuronal glutamate is essential in order to avoid depletion of the internal pool. In brain this occurs primarily via the glutamate-glutamine cycle, which invokes astrocytic synthesis of glutamine and hydrolysis of this amino acid via neuronal phosphate-dependent glutaminase. This cycle maintains constancy of internal pools, but it does not provide a mechanism for inevitable losses of glutamate N from brain. Import of glutamine or glutamate from blood does not occur to any appreciable extent. However, the branched-chain amino acids (BCAA) cross the blood–brain barrier swiftly. The brain possesses abundant branched-chain amino acid transaminase activity which replenishes brain glutamate and also generates branched-chain ketoacids. It seems probable that the branched-chain amino acids and ketoacids participate in a “glutamate-BCAA cycle” which involves shuttling of branched-chain amino acids and ketoacids between astrocytes and neurons. This mechanism not only supports the synthesis of glutamate, it also may constitute a mechanism by which high (and potentially toxic) concentrations of glutamate can be avoided by the re-amination of branched-chain ketoacids.     

pRb and the cdks in apoptosis and the cell cycle

Apoptosis is a fundamental biological process present in metazoan cells. Linking apoptosis to the cell cycle machinery provides a mechanism to maintain proper control of cell proliferation in a multicellular organism. pRb and the cyclin-dependent kinases may have dual roles as integral components of the cell cycle and regulators of apoptosis. In many instances manipulation of the cell cycle through these molecules can induce or inhibit apoptosis. Recent studies also identify pRb as a substrate for an apoptotic protease; however, other cell cycle components are not known substrates. While it is clear that many common molecules can affect cell proliferation and cell death, the universality of any one cell cycle molecule in apoptosis has yet to be determined.     

Metamorphosis in the Cirripedia Rhizocephala and the homology of the kentrogon and trichogon

The Rhizocephala are considered to be monophyletic due to several synapomorphies in the ontogeny of the cndoparasitic phase. The various types of metamorphosis described in the Rhizocephala are discussed and compared to metamorphosis in the Cirripedia Thoracica and Acrothoracica. In males and females of the suborder Kentrogonida. the cyprid settles and metamorphoses into a new instar, in males the trichogen and in females the infective kentrogon. The kentrogon goes through yet another. incomplete moult associated with the development of the stylet. Within the three kentrogonidan families. the Iernaeodiscid-peltogastrid type of kentrogon differs from the sacculinid type in the mode of attachment to the host. in the complexity of internal anatomy. in the position and penetration of the stylet, and in whether or not the cyprid carapace must be shed prior to penetration of the stylet. In the Akentrogonida metamorphosis never results in a new instar. Where observed (Clistosaccidae and Thompsoniidae). both male and female cyprids settle and penetrate into their substrate (female parasite or new host) with one of the antennules. Using the antennule as a syringe. male cyprids inject spermatogonia while female cyprids injects embryonic cells developing into an endoparasite. By comparison with metamorphosis in the Cirripedia Thoracica and Acrothoracica it is concluded that the presence of a metamorphic moult leading to a post-cyprid instar is plesiomorphic and that the trichogon and kentrogon are homologous with the first metamorphosed juvenile in these outgroups. The abbreviated ontogeny in the Akentrogonida without metamorphic moult and post-cyprid larval instars is considered apomorphic. This contradicts the long-held supposition that the Akentrogonida are the most‘primitive’Rhizocephala and dovetails with new information that this suborder contains many advanced traits. Within the Kentrogonida. the lernacodiseid-peltogastrid type of kentrogon is considered more plesiomorphic than the sacculinid type, which resembles the clistosaccidthompsoniid type in having the antennules involved in the penetration process. The homologization of the kentrogon with a juvenile barnacle indicates that presence of a kentrogon is plesiomorphic within the Rhizocephala and that the Kentrogonida is paraphyletic.     

Change in the cholesterol and triglyceride content in the blood in self-stimulation and avoidance reactions]

The changes in the blood serum cholesterol and triglyceride content were studied or rabbits of both sexes during reactions of self-stimulation and avoidance. Self-stimulation was accompanied by a significant decrease in the blood serum cholesterol and triglyceride content. During the reaction of avoidance the character of the cholesterol changes varied. The reaction of avoidance of the "agression" type was accompanied by elevated blood serum cholesterol content, whereas the reaction of the "fear" type was associated with a decrease in its content. The maximal changes in the cholesterol and triglyceride content as compared to the initial level were observed in all types of the reactions 15--30 minutes following stimulation.