Cytological studies on the developing vitreous as related to the hyaloid vessel system

The embryonic development of the cell population of the mammalian vitreous has been traced to two sources: the undifferentiated mesenchymal cells of the eye primordium and the primitive reticular cells of the bone marrow. Undifferentiated mesenchymal cells invade the future vitreous space in two ways: through the annular opening between the rim of the optic cup and the lens primordium, and through the open embryonic fissure. They differentiate into prevascular cells, hemangioblasts, and fibrocytes located in the area of the optic nerve head. From the very beginning of fetal development, another ameboid-type cell of mesenchymal origin makes its entrance into the vitreous through the hyaloid vessels; these monocyte-like cells differentiate into hyalocytes and populate a well-defined area of the cortical vitreous close to the retina and to the ora serrata. Gamma-irradiation (600 rads) of newly born rabbits and cats decreases the number of migrating amebocytes in their vitreous; 24 h later, however, they are replaced by monocytes from the hyaloid vessels.     

The activity of digestive enzymes in the digestive and nondigestive organs during stress exposures

The effects of fasting and immobilization manifests itself in changes of the enzymes activity in the stomach, duodenum, jejunum, ileum, colon as well as in the liver, spleen, kidneys. In these conditions, the protective function is primarily fulfilled by the enzyme systems of the non-digestive organs whereas the enzymatic intestinal barrier is less obvious.     

Innervation of developing human taste buds. An immunohistochemical study

1. Vinorelbine produced a dominant metabolite (M1) after incubation with rat liver microsomes. 2. Several major metabolites other than M1 were identified by HPLC in bile and faeces of rat after intravenous administration. 3. The structures of the major metabolites were identified as 15,16-epoxyvinorelbine (M1), 11'-hydroxyvinorelbine (M2), 19'-hydroxyvinorelbine (M3a), 15,16-epoxy-10'-hydroxyvinorelbine (M3b) and 10'-hydroxyvinorelbine (M4) by comparison of HPLC retention times and by extensive analyses of two-dimensional NMR and hybrid MS/MS spectra.     

Comparative biochemical and immunohistochemical studies on the cathepsin D content of human breast cancer

Cathepsin D (CD) has been introduced as a predictor of prognosis in patients with breast cancer due to its mitogenic effect and its role in tumour metastasis. Commonly, the CD content of tumours is examined by means of a biochemical method based upon the use of monoclonal antibodies, and immunohistochemical visualization of CD has not been used extensively. The present study compares the biochemical and immunohistochemical findings in 216 cases of human breast cancer. CD may occur in tumour cells and/or macrophages. Correlation of immunohistochemically determined CD content and biochemical CD content is better in tumour cells than in macrophages. The possible causes of this observation are briefly discussed. Although a statistical correlation between the biochemical and the immunohistochemical CD findings exists, the results in individual cases vary within a wide range. Hence, the results of biochemical and immunohistochemical CD assay in an individual tumour cannot be compared directly.     

The effect of glypondin on glycogen and protein accumulation in rat organs

Rats were treated for 21 days with 20, 30 and 40 mg/kg Glypondin dissolved in the drinking water. The weight-increasing effect of Glypondin was studied in rat organs. In the liver a significant rise in the concentration of TCA-soluble glycogen was demonstrated. In the myocardium and m. gastrocnemius the concentration of both the labile and glycogen was unchanged. In the m. gastrocnemius of rats treated with Glypondin a significant rise in the concentration of noncollagenous protein was demonstrated.     

Measurement of digestive disorders in the piglet at weaning and related risk factors

Inputs from the amygdaloid and extraamygdaloid areas terminate in various divisions of the central nucleus. To elucidate the interconnections between the different regions of the central nucleus and its connectivity with the other amygdaloid areas, we injected the anterograde tracer, Phaseolus vulgaris-leucoagglutinin (PHA-L) into the capsular, lateral, intermediate, and medial divisions of the central nucleus in rat. There were a number of labeled terminals near the injection site within each division. The intrinsic connections between the various divisions of the central nucleus were organized topographically and originated primarily in the lateral division, which projected to the capsular and medial divisions. Most of the connections were unidirectional, except in the capsular division, which received a light reciprocal projection from its efferent target, the medial division. The intermediate division did not project to any of the other divisions of the central nucleus. Extrinsic projections from the central nucleus to the other amygdaloid nuclei were meager. Light projections were observed in the parvicellular division of the basal nucleus, the anterior cortical nucleus, the amygdalohippocampal area, and the anterior amygdaloid area. No projections to the contralateral amygdala were found. These data show that the central nucleus has a dense network of topographically organized intradivisional and interdivisional connections that may integrate the intraamygdaloid and extraamygdaloid information entering the different regions of the central nucleus. The sparse reciprocal connections to the other amygdaloid nuclei suggest that the central nucleus does not regulate the other amygdaloid regions but, rather, executes the responses evoked by the other amygdaloid nuclei that innervate the central nucleus.     

Comparative studies on acid phosphatase isozymes of developing human placenta and fetal liver

Acid phosphatases from human placenta and fetal liver during ontogenic development have been studied by electrophoresis on polyacrylamide gels. Three isozymes have been detected in liver as well as in early and term placenta, and one more in placenta at mid-gestation. These isozymes behaved differentially towards heat and a number of inhibitors at different weeks of gestation. Quantitative determination of each isozyme also showed stage-specific variation.     

Fundamental studies related to the development of the smelting reduction of iron oxide and carbon-constant volume studies

Abstract

Today, most of the iron-making capacity of the world is still dependent upon the blast furnace process, although the production of sponge iron by direct reduction processes is gaining acceptance in many areas. Another method of making iron, known as smelting reduction, is receiving attention, and pilot-plant scale operations are being developed in Europe and possibly elsewhere. In this method, iron oxide is reduced with carbon (coal) by a fast reaction such that liquid iron is the product, heat being provided to the reaction by the exothermic oxidation of carbon monoxide by oxygen within the reaction vessel.

In the present investigation, an attempt has been made to study the behaviour of composite pellets of wüstite and carbon in the region of 1500°C in various gas atmospheres at constant volume. Reaction rates were followed within the constant-volume system by measuring the increase in pressure with time using a pressure transducer. Composite pellets containing slightly more than the stoichiometrically required amount of carbon were reacted to form liquid iron in an argon atmosphere; to achieve melting, good mixing of the pellets was a critical requirement. Melting conditions were also obtained in carbon monoxide-carbon dioxide mixtures between 100 per cent CO and 100 per cent CO₂ When composite pellets, surrounded by a protective layer of carbon, were introduced into an atmosphere containing free oxygen, it was again possible to obtain melting and reduction to liquid iron. The activation energy for the reaction was approximately 15 kcal/mole. Possible reaction mechanisms are discussed.

Résumé

De nos jours, la réduction des oxydes de fer s'accomplit en grande partie au haut foumeau. On note toutefois une implantation graduelle des procédés de réduction directe des oxydes en fer éponge. Une autre méthode de production du fer, connue sous Ie nom de smeltage réducteur, est actuellement à l'étude. Des essais à l'échelle de l'usine pilote se font actuellement en Europe et possiblement ailleurs. La méthode consiste à produire du fer liquide en réduisant rapidement l'oxyde de fer par du carbone. L'énergie requise pour la réaction vient de l'oxydation exothermique du monoxyde de carbone par l'oxygène présént dans l'enceinte réactionnelle.

Les auteurs ont étudié le comportement de boulet1es composées de wüstite et de carbone en présence de diverses atmosphères gazeuses dans une enceinte fermée à 1,500°C. Les vitesses de réaction ont été détérminées en mesurant l'augmentation de la pression dans l'enceinte au moyen d'un transducteur de pression. Des boule1tes composées comportant un peu plus que la quantité stoechiométrique de carbone ont été réduites en fer liquide dans une atmosphère d'argon. La fusion n'avait lieu que si les constituants des boulet1es étaient intimement mélangés. La fusion de boulet1es a été réalisée dans des atmosphères constituées de melanges CO-CO₂, les proportions variant entre 100% CO et 100% CO₂. Le fer liquide a aussi été obtenu en faisant réagir des boulettes d'oxyde et de carbone entourées d'une couche protectrice de carbone, dans une atmosphère contenant de l'oxygène libre. L' énergie d'activation de la réaction était d'environ 15 kcal/mole. En fin, les auteurs discutent des mécanismes de la réaction.     

The role of glucose 6-phosphate in the control of glycogen synthase

Elevated blood glucose concentrations result in increased intracellular levels of glucose 6-phosphate in liver, skeletal muscle, and adipose tissue. In liver, blood glucose concentrations are the main factor in control of the synthesis of glycogen; insulin has only a potentiating effect. In skeletal muscle and adipocytes, glucose alone has little effect on the activity of glycogen synthase, the limiting enzyme in glycogen synthesis. However, insulin released as a result of elevated blood glucose stimulates the translocation of specific glucose transporters to the cell membrane, increases the uptake of glucose, and causes the covalent, dephosphorylation-mediated activation of glycogen synthase. We present evidence that elevated intracellular contents of glucose 6-phosphate provoke the activation of glycogen synthase in liver, muscle, and adipose tissue. In addition, glucose 6-phosphate may inhibit the phosphorylation of glycogen synthase by cyclic AMP-stimulated protein kinase. We show that the stimulated glucose uptake and phosphorylation appear to play a major role in the control by insulin of the enzymes involved in glycogen synthesis.     

Functional change of NMDA receptors related to enhancement of susceptibility to neurotoxicity in the developing pontine nucleus

The developing neurons have been reported to be extremely susceptible to toxicity of NMDA during a restricted developmental period. Pontosubicular neuronal necrosis is a typical type of perinatal human brain lesion and often coexists with other forms of cerebral hypoxic and ischemic injuries. To determine whether functional changes of NMDA receptors related to the susceptibility to NMDA toxicity are involved in developing neurons in the pontine nucleus, we have examined the lesion produced by in vivo direct injection of NMDA into the pontine nucleus of rats at postnatal days 1-30, recorded NMDA-induced whole-cell currents from neurons in the pontine nucleus in the developing rat brainstem slices, and performed in situ hybridization for NMDA receptor subunit mRNAs in the pontine nucleus. The susceptibility to NMDA neurotoxicity peaked near postnatal day 15, and the NMDA-induced currents showed prominent reduction of the voltage-dependent block by Mg2+ near postnatal day 15. The pontine nucleus near postnatal day 15 showed distinct expression of the NMDA receptor subunit NR2C mRNA. These results suggest that the susceptibility to NMDA neurotoxicity that is enhanced in the rat pontine nucleus near postnatal day 15 is mediated by the NMDA receptor channels that are relatively insensitive to Mg2+ and that the reduction in the sensitivity of NMDA receptors to Mg2+ correlates with the expression of the NR2C. We present the possibility that functional changes in the NMDA receptor channels play a crucial role in the occurrence of developmentally specific neuronal injury.     

Trigeminal nuclear complex of the ferret: anatomical and immunohistochemical studies

In order to establish the ferret as an animal model for studies of trigeminal pain, we describe the cytoarchitecture and neurochemistry of the trigeminal nuclear complex in the ferret and compare them to those of the cat and rat. The complex was divided as previously described, but the ferret differed in the extent of the nuclear boundaries. The neuroanatomical istribution of substance P-, calcitonin gene-related peptide-, galanin-, enkephalin-, serotonin-, somatostatin-, neuropeptide Y-, and neurotensin-immunoreactivity was determined throughout the rostrocaudal extent of the complex. In subnucleus caudalis, substance P-, calcitonin gene-related peptide-, enkephalin-, serotonin-, somatostatin-, neuropeptide Y-, and galanin-immunoreactivity was densest in laminae I and II. In subnucleus interpolaris, immunoreactivity for all the above neurochemicals was most dense along the lateral border and the ventral third of the caudal part of the subnucleus. Enkephalin-immunoreactive cell bodies were present in subnucleus caudalis and interpolaris. In subnucleus oralis, labelling for substance P, calcitonin gene-related peptide, galanin, enkephalin, and serotonin was most prominent in the dorsomedial part of the subnucleus. Somatostatin-immunoreactive cell bodies were distributed throughout the spinal nucleus. Labelling of serotonin, substance P, calcitonin gene-related peptide, galanin, enkephalin, and somatostatin was present in the main sensory nucleus. The motor nucleus contained fibers immunoreactive for substance P, enkephalin, serotonin and neuropeptide Y, and cell bodies immunoreactive for calcitonin gene-related peptide. The majority of neurotensin-immunoreactivity was found at the level of subnucleus caudalis, where it was densest in the trigeminal extension of the lateral cervical nucleus. The distribution of peptides in this species throughout the spinal nucleus is consistent with the notion that all the subnuclei may be involved in the processing of nociceptive inputs.     

Scanning electron microscopic and immunohistochemical studies of pelvic endometriosis

The pathogenesis of pelvic endometriosis has been studied by using scanning electron and light microscopy, observing the surface structure of bluish lesions obtained from 26 patients during laparotomy. Paraffin sections included another 17 tissue samples of endometriosis, based on immunohistochemical responses to epithelial membrane antigen, keratin and vimentin. Ultrastructurally, the surface epithelial cells could not be detected in 13 out of 17 pelvic peritoneal endometriosis samples. In one case in which the surface peritoneal cells were seen histologically to dip into the subperitoneal stroma, many surface peritoneal infoldings were observed, and ciliated cells were detected at the edge of these infoldings. Ovarian endometriosis was composed of three types of cells, none of which had any cilia. These findings were observed in continuity with adjacent normal mesothelial cells. No characteristic structure of the endometrial surface was observed for the bluish lesion, but the gland surface of endometriosis located in the subperitoneal stroma initially had ciliated cells. The immunoreactions in both the columnar mesothelial cells with surface peritoneal infoldings and the glands of endometriotic tissues were similar to those of normal endometrial glands, but different from those of normal mesothelial cells. Pelvic endometriosis might originate by a process of metaplasia from the pelvic peritoneum.     

Fields and currents in the organs of the human body when exposed to power lines and VLF transmitters

A study is made of the electric fields and currents induced in the organs of the human body when exposed to high-voltage 50-60-Hz transmission lines and 10-30-kHz high-power transmitters. Relevant analyses previously carried out are summarized and supplemented with detailed investigations that complete the picture. Incomplete, misleading, and incorrect statements and methods in the related literature are pointed out, completed, and corrected. The major contribution is to provide quantitatively accurate, relatively simple analytic formulas that relate the incident electric field to the induced field in the organs of the body. The formulation and solution of the underlying integral equation are carried out in the Appendix.     

Australia's role in HIV prevention in the developing world

A scientist with the National Centre in HIV Epidemiology and Clinical Research at the University of New South Wales in Sydney, Australia, addresses the fact that Australians working in the area of HIV infection have been very successful in prevention, treatment, and care. In the early 1980s, a bipartisan political decision was made to foster an effective partnership between HIV-infected communities, health care providers, and governments. HIV-infected communities included sex workers, prisoners, Aboriginal people, and high profile gay community activists. These three different groups succeeded in forming such a partnership, as reflected in the fact that the annual number of new HIV cases is down to 500 from a peak of 3000 in 1984. A key method used to contain HIV infection was needle-and-syringe exchange programs and continuing access to needles to prevent HIV transmission in the injecting drug community. Even though Australia has all this experience and success, it had a backseat role in ushering in the UNAIDS program because Australia did not contribute a significant share of the agency's relatively small budget (US$100 million/year). If Australia were to give just 10%, it would acquire a front row seat along with the Netherlands, Sweden, Belgium, France, and the UK. These nations have the greatest say as to where UNAIDS funds go. The Australian international aid organization has recently received an increase in funds, $110 million for 4 years to spend on four areas, one of which is HIV/AIDS. Australia has just allocated $25 million for a 5-year program for HIV/STD (sexually transmitted disease) prevention in Indonesia. This money would have been able to buy Australia a leading role in UNAIDS. Australians need to reassess their priorities. Australians can help their neighbors in the Asia-Pacific region move away from their denial of HIV to HIV prevention and care. They can conduct clinical trials of shorter and more user-friendly regimens of antiviral drugs that may lead to reduced perinatal transmission and research on microbicides. They can prevent tuberculosis and introduce manageable methods of securing safe blood supplies and mass screening.     

Essential role of mouse telomerase in highly proliferative organs

We have investigated the role of the enzyme telomerase in highly proliferative organs in successive generations of mice lacking telomerase RNA. Late-generation animals exhibited defective spermatogenesis, with increased programmed cell death (apoptosis) and decreased proliferation in the testis. The proliferative capacity of haematopoietic cells in the bone marrow and spleen was also compromised. These progressively adverse effects coincided with substantial erosion of telomeres (the termini of eukaryotic chromosomes) and fusion and loss of chromosomes. These findings indicate an essential role for telomerase, and hence telomeres, in the maintenance of genomic integrity and in the long-term viability of high-renewal organ systems.