Increase in neuronal nitric oxide synthase content of the gastroduodenal tract of diabetic rats

This study examined the changes occurring in the pattern of distribution and expression of neuronal nitric oxide synthase (nNOS)-positive nerves in the gastroduodenal tract of streptozotocin-induced diabetic rats. The ganglion cells of the myenteric plexus of the gastric antrum of normal rats contain nNOS. We also observed nNOS-positive neurons and fibres in the myenteric plexus of the duodenum of normal rats. After the onset of diabetes, the number and intensity of staining of nNOS-positive nerve profiles in the gastric antrum and duodenum did not change significantly. However, Western blotting showed a significant increase in the expression of nNOS after the onset of diabetes. In conclusion, diabetes of 4 and 32 weeks duration induced an increase in the tissue content of nNOS in the gastroduodenum of rat. The increase in the level of nNOS in the gastroduodenum of diabetic rats may explain why impaired gastric emptying is common in patients with diabetes.     

Sex differences in human circadian rhythms: Intrinsic periods and sleep fractions

Summary The period of freerunning circadian rhythms is significantly shorter and the fraction of sleep is significantly larger in human females than in males, as long as the rhythms run internally synchronized. The sex difference in the period could be a property either of the whole circadian system or of only one of the oscillators in a multi-oscillator system. The sex difference in the sleep fraction could be a fixed property of the sleep-wake rhythm or could depend on interactions in the multi-oscillator system. To investigate these questions, a sample of 33 long-term experiments, in which the rhythms ran internally synchronized in one section and internally desynchronized in another section, were analyzed. The periods of rhythms in rectal temperature were different in females and males during internal synchronization, but became identical during internal desynchronization. In contrast, sex differences in sleep-wake periods were more pronounced when the rhythms were desynchronized than when they were internally synchronized. This result provides evidence that the sex difference in periodicity is a property only of the sleep-wake rhythm; the intrinsic periods of temperature rhythms are identical in females and males, whereas those of sleep-wake rhythms are distinctly shorter in females than in males. In the state of internal synchronization, the joint period is a compromise between the intrinsic periods of the rhythms involved, and therefore it shows a small but significant sex difference. Moreover, the transition from internally synchronized to desynchronized rhythms is combined with a highly significant reduction in the sleep fraction, which is considerably greater in females than in males. These results suggest that the occurrence of internal desynchronization strongly affects the sleep-wake rhythm, and that the influence of rhythm disorders is considerably greater in females than in males.     

氮同位素示踪技术在研究地下水硝酸盐污染中的应用

氮是重要的生源要素之一,地下水中硝酸盐污染问题不容忽视;由于不同氮污染源的同位素组成不同,所以氮同位素示踪技术应用于地下水硝酸盐污染研究具有重要意义。本文重点介绍了氮同位素示踪的基本原理及其测定方法,并归纳总结了氮同位素示踪技术在地下水中硝酸盐污染研究中的应用现状,指出了今后研究工作中值得重视的有关问题。     

高校产学研一体化发展的实践与前瞻

本文探讨我国高校产学研一体化发展的必要性、可行性及其前景。从人类社会发展的历史特点入手，并借鉴了美国硅谷发展的经验和我国改革开放推进社会主义市场发展的需求，对高校产学研一体化发展的道路作了论述。针对目前高校产学研一体化中存在的问题，作者提出了加速高校产学研一体化发展的四条建议：1，高校产学研一体化发展必须转变观念，积极参与社会大循环；2，推进高校产学研一体化要有过硬的产品和准确的市场定位；3，高校产学研一体化发展要依托高科技园区，切实解决经费投入问题；4，高校产学研一体化发展要突出以人为本的思想，努力造就发明家和企业家。     

Involvement of D-amino acid oxidase in elimination of D-serine in mouse brain

The physiological role of D-amino acid oxidase (EC 1. 4. 3. 3) in mouse brain is described. The presence of D-enantiomers of neutral common amino acids was surveyed in the brain. D-serine was shown to be present at high concentration only in regions where the enzyme activity was low. In normal mice whose D-amino acid oxidase activity was much higher in the cerebellum than in the cerebrum, free D-serine content was apparently lower in the cerebellum than in the cerebrum. In mice of a mutant strain lacking D-amino acid-oxidase activity, the free D-serine level was remarkably high both in the cerebrum and cerebellum. The results suggest that the enzyme is involved in the elimination of free D-serine in the cerebellum.     

Development of dopaminergic neurons in the mammalian brain

Dopaminergic neurons in the mammalian brain have received substantial attention in the past given their fundamental role in several body functions and behaviours. The largest dopaminergic population is found in two nuclei of the ventral midbrain. Cells of the substantia nigra pars compacta are involved in the control of voluntary movements and postural reflexes, and their degeneration in the adult brain leads to Parkinson’s disease. Cells of the ventral tegmental area modulate rewarding and cognitive behaviours, and their dysfunction is involved in the pathogenesis of addictive disorders and schizophrenia. Because of their clinical relevance, the embryonic development and maintenance of the midbrain dopaminergic cell groups in the adult have been intensively studied in recent years. In the present review, we provide an overview of the mechanisms and factors involved in the development of dopaminergic neurons in the mammalian brain, with a special emphasis on the midbrain dopaminergic population. Received 17 August 2005; received after revision 28 September 2005; accepted 21 October 2005     

Chemistry,microscopy and smell: bloodstains and nineteenth-century legal medicine

This paper analyses the development of three methods for detecting bloodstains during the first half of the nineteenth-century in France. After dealing with the main problems in detecting bloodstains, the paper describes the chemical tests introduced in the mid-1820s. Then the first uses of the microscope in the detection of bloodstains around 1827 are discussed. The most controversial method is then examined, the smell test introduced by Jean-Pierre Barruel in 1829, and the debates which took place in French academies and learned societies during ensuing years are surveyed. Moving to the courtrooms a review is conducted of how the different methods were employed in criminal trials. By reviewing these cases, the main arguments against Barruel's test during the 1830s are explored as well as the changes making possible the return of the microscope to legal medicine around 1840. By reconstructing the history of these three methods, the paper reveals how the senses of smell and vision (colours and microscopic images) were employed in order to produce convincing evidence in both academies and courts. The paper questions two linear master narratives that are organized in terms of progress and decline: the development of forensic science as a result of continued technological progress; and the supposed decline of smell in the history of the senses, particularly in the realm of chemistry and medicine.     

Aristotle's biological works as scientific literature

This contribution deals with the question of where and why in his biological writings Aristotle uses dialogical elements, examining which dialogical structures can be found and what the meaning of the dialogical structures is in respect of the argumentative strategies used in literature. This discursive style has to be seen in relation to the importance of the dialectical method which was practiced in the Platonic Academy and on which Aristotle reflected in his Topics. For Aristotle the dialectical method also becomes the method of the investigator researching for himself. But more than that one can see the reason for the dialogical structures in Aristotle's writings in his attempt to combine the way of acquiring knowledge with the way of presenting knowledge. It can thus be said that at the moment in which the dialectical procedure is translated into the medium of writing, a fact-oriented presentation is also an addressee-oriented representation. Nowadays we are more accustomed to a technical literature which, after completing the first step of the deduction of knowledge, presents the results in a systematic and hierarchical way in its literary representation; in such technical literature, normally an individual's thought process is not set out in writing. Admittedly, with the application of the dialectical method and with the attempt to set down one's own thought process in the medium of writing, other elements also come in.     

The emerging roles for the chromatin structure regulators CTCF and cohesin in neurodevelopment and behavior

Recent genetic and technological advances have determined a role for chromatin structure in neurodevelopment. In particular, compounding evidence has established roles for CTCF and cohesin, two elements that are central in the establishment of chromatin structure, in proper neurodevelopment and in regulation of behavior. Genetic aberrations in CTCF, and in subunits of the cohesin complex, have been associated with neurodevelopmental disorders in human genetic studies, and subsequent animal studies have established definitive, although sometime opposing roles, for these factors in neurodevelopment and behavior. Considering the centrality of these factors in cellular processes in general, the mechanisms through which dysregulation of CTCF and cohesin leads specifically to neurological phenotypes is intriguing, although poorly understood. The connection between CTCF, cohesin, chromatin structure, and behavior is likely to be one of the next frontiers in our understanding of the development of behavior in general, and neurodevelopmental disorders in particular.     

Age-related differences in the effect of in vivo administration of indomethacin on hemopoietic cell lineages of the spleen and bone marrow of mice

During 21 days of indomethacin treatment, erythroid cells in the spleens of both young adult and older mice, and in the bone marrow of young adult mice, were increased significantly early, in treatment, relative to age-matched control organs, and remained high throughout treatment. During drug exposure, the numbers of myeloid cells in young adult bone marrow, but not spleen, were reduced, but in older mice these cells were elevated in both organs. Lymphoid cells in the young adult and older mouse spleens decreased and increased, respectively, during treatment, but were unchanged and decreased, respectively, in the bone marrow of young adult and older mice. Monocytemacrophage cells in the spleen were elevated but unchanged in the bone marrow of both age groups. During 14 days of indomethacin treatment of houng adult mice, the proportions of precursor cells in DNA synthesis of only the splenic erythroid lineage were increased. Thus, the major hemopoietic lineages in both the bone marrow and spleen are affected by exposure to indomethacin in a time-dependent and age-dependent manner. For all lineages studied, those of the bone marrow were least disturbed, and/or were first to recover, even during continued drug exposure.     

The rule of law: Natural,human, and divine

In this paper we compare two different contexts—the legal and the scientific—in which the concept of law is prominent. We argue that the acute philosophical awareness, in the early modern period, of the difficulties surrounding the law concept in the scientific context, and the various responses to these difficulties, are rooted in an earlier tradition of jurisprudential concerns over the concept of natural law in its legal sense. We seek to show, further, that each one of the various philosophical accounts of the concept of natural law (in both of its senses) is embedded in a metaphysical and theological context, so that different visions of God yield different accounts of the meaning of the natural law idiom in science as well as legal theory.     

Involvement of D-amino acid oxidase in elimination of D-serine in mouse brain.

The physiological role of D-amino acid oxidase (EC 1. 4. 3. 3) in mouse brain is described. The presence of D-enantiomers of neutral common amino acids was surveyed in the brain. D-serine was shown to be present at high concentration only in regions where the enzyme activity was low. In normal mice whose D-amino acid oxidase activity was much higher in the cerebellum than in the cerebrum, free D-serine content was apparently lower in the cerebellum than in the cerebrum. In mice of a mutant strain lacking D-amino acid-oxidase activity, the free D-serine level was remarkably high both in the cerebrum and cerebellum. The results suggest that the enzyme is involved in the elimination of free D-serine in the cerebellum.     

Defective phosphoinositide metabolism in primary hypertension

An increase in free cytosolic calcium content has been reported in essential hypertension. Since within the membrane, the phosphoinositides participate in the control of cell calcium homeostasis, we investigated whether impaired phosphoinositide metabolism could account for the calcium handling abnormality observed in hypertensives. In erythrocyte membranes of hypertensives the activity of kinases involved in polyphosphoinositide formation appears to be impaired and could be related to the alteration in calcium handling binding capacity and ATP-dependent calcium transport. In platelets of hypertensives, the hyperactivity of phospholipase C (observed even in the absence of calcium in the external medium) is likely to be responsible for the hypersensitivity of cells to various agonists. These observations are consistent with the hypothesis that in cells from hypertensives, a membrane defect linked to phosphoinositide metabolism is involved in the overall calcium handling defect.     

Die Verteilung von Noradrenalin und Adrenalin im Herzen der Katze,des Kaninchens und der Ratte

Summary The concentration of noradrenaline in different parts of the heart was estimated in cats, rabbits, and rats. In each heart, the concentration of noradrenaline was much higher in the right atrium than in the left atrium and higher in the right ventricle than in the left one.     

Evidence for no relationship of the pineal activity with the neonatal shrinkage of Leydig cells in the rat

Summary The collective volume of Leydig cells in prenatally pinealectomized newborn rats declined as sharply as in intact newborn rats. Also, the collective volume in pups born in the dark declined in a fashion similar to that in pups born in the light. The results indicate that neither the pineal gland nor the light is responsible for the neonatal shrinkage of Leydig cells.This study was supported in part by a Grant-in Aid for Scientific Research (No. 548067) from the Ministry of Education, Science and Culture of Japan.     

Expression of the genes of interferons and other cytokines in normal and diseased tissues of man

Specific interferon genes are transcribed at low levels in the spleen, liver, and peripheral blood leukocytes of normal individuals in the apparent absence of virus infection while other interferon genes remain unexpressed in the same tissues. In contrast, the genes of cytokines such as IL-1, IL-6 and TNF are expressed at relatively high levels in the organs of normal individuals. The level of expression of the IL-1, IL-6 and TNF genes is markedly reduced in the livers of patients with autoimmune liver disease compared to the level of expression in the liver of normal individuals, whereas the expression of interferon genes is similar in both normal and diseased liver, suggesting that a defect in the expression of specific cytokines is associated with severe liver disease.     

AMP deaminase, 5'-nucleotidase and adenosine deaminase in rat myocardial tissue in myocardial infarction and hypothermia

AMP deaminase, 5'-nucleotidase and adenosine deaminase have been estimated in skeletal muscle and myocardial tissue in normal rats and in rats subjected to experimental myocardial infarction or hypothermia. A difference in the enzyme distribution was found between the right and left ventricles in the normal rat. A decrease in the activity of 5'-nucleotidase and an increase in the activity of adenosine deaminase were observed in infarcted myocardial tissue. The activity of all 3 enzymes was found to be depressed in the myocardium in rats subjected to hypothermia. These results are discussed in relation to adenosine production and its beneficial effects.     

Histochemical localization of lactate dehydrogenase in the trout embryo (Salmo irideus, Gibb) during early organogenesis of the cord and the neural tube]

The histochemical study of the LDH in the Trout embryo during the early organogenesis shows a specific localization in notochord cells, in mesodermic cells of the terminal knob and in some prosencephalic neuroblasts. The role of the LDH in the metabolism of NAD as well as in the energetic metabolism of embryonic cells is discussed.     

Sexual dimorphism of mouse fetal brain lesions after X-irradiation prior to gonadal differentiation

Fractionated X-irradiation of gestational days 11-13 in the mouse, with doses between 3 x 1.05 and 3 x 1.33 Gy resulted in rosette-like clusters of primitive ependym-resembling cells dispersed within the cortex walls. Quantification of these abnormalities showed a general prevalence in the female fetuses, especially due to the larger number of rosettes in the females than in the males. It was concluded that X-irradiation acts on sex-specific differentiation steps, which are fully developed at the beginning of the fetal period. As it was recently speculated that these are linked to an early divergence of gene expression between the sexes, we suggest that X-chromosome damage may be involved in the pathogenesis of the dimorphic lesion pattern. While, in principle, this will valid for any fetal tissue, it only becames evident in the forebrain because of the outstanding relationship between cell necrosis and rosette development in this specific organ.