Ultrastructural and seasonal aspects of the kidney lymphatic system of hibernating animals

The kidney lymphatic system of bat, dormouse and marmot consists of intraparenchymal (interlobar, arcuate, interlobular) and extraparenchymal (capsular) vessels sharing common ultrastructural aspects. We did not observe medullary lymphatics. The qualitative and quantitative seasonal changes in the ultrastructure of the lymphatic endothelium represent not only a species-linked feature but also (and mainly) an evident seasonal fluctuation in lymph formation. Furthermore, these ultrastructural changes emphasize the important role played by the different mechanisms involved in the translymphatic movement of proteins and interstitial fluid with particular regard to the 'vesicular route' and intraendothelial channels.     

Ultrastructural and seasonal aspects of the kidney lymphatic system of hibernating animals

Summary The kidney lymphatic system of bat, dormouse and marmot consists of intraparenchymal (interlobar, arcuate, interlobular) and extraparenchymal (capsular) vessels sharing common ultrastructural aspects. We did not observe medullary lymphatics. The qualitative and quantitative seasonal changes in the ultrastructure of the lymphatic endothelium represent not only a species-linked feature but also (and mainly) an evident seasonal fluctuation in lymph formation. Furthermore, these ultrastructural changes emphasize the important role played by the different mechanisms involved in the translymphatic movement of proteins and interstitial fluid with particular regard to the vesicular route and intraendothelial channels.     

The fine structure of the conical-headed sperm of the crinoidAntedon bifida

Summary Scanning- and transmission electron microscopy show that the sperm head ofAntedon bifida is conical and thus different from the spherical sperm head that is typical of crinoids. The head consists of the acrosome and the nucleus. The posterior fibrogranular component of the acrosome is housed in a tubular, axial invagination running from the anterior pole almost to the posterior pole of the nucleus. The middle piece includes a mitochondrion and a pair of centrioles. One of the centrioles is a basal body, which gives rise to the tail flagellum.     

Origin and course of an afferent component of the facial nerve within the central nervous system

Summary The mesencephalic nucleus of trigeminal gives rise to an afferent component of the facial nerve. This nucleus contains large unipolar afferent cell bodies which give rise to an axon which courses caudally through the brainstem and exits via the facial nerve to terminate distal to the stylomastoid foramen.This work was supported by National Aeronautics and Space Administration Grant No. NAS 9-15213.     

Cellular changes of adrenal under the acute stress of O-chlorobenzylidene malononitrile (CS).

This investigation describes histological and cytometrical changes of cortical and medullary tissue of adrenal in rats under the acute stress of O-chlorobenzylidene malononitrile (10 mg/kg and 20 mg/kg). It has been observed that after injection of CS, the adrenal gland showed histological changes both in the cortical and medullary region.     

Antioxidant effects on prostaglandin synthesis in rabbit kidney medulla slices

Summary Sodium diethyldithiocarbamate, 2,6-di-tert-butylphenol and N,N-diphenyl-p-phenylenediamine inhibited the generation of medullary prostaglandin E, but 1,2-dimethoxyethane (OH scavenger) and 2,5-dimethylfuran (¹O₂ scavenger) stimulated basal prostaglandin E production 1.2–1.3-fold. These results suggest that the balance between formation and removal of cellular lipid peroxides sets a peroxide level that can regulate the rate of prostaglandin formation in cells.     

The nucleolar chromosome in embryos of Rana pipiens

Summary Karyotype analyses of prometaphases from medullary plate cells derived from mid-neurulae of Rana pipiens have led to the identification of the nucleolar chromosome and nucleolar organizing region, which is located on the longer arm of a small sub-metacentric chromosome (No. 10).Supported in part by research grant GB19631X from the Natioal Science Foundation. This study constituted a portion of a dissertation submitted by G. R. N. to the Medical College of Pennsylvania in partial fulfillment of requirements for a Ph. D. degree.Supported by NDEA and subsequently NSF predoctoral traineeships.To whom reprint requests should be sent.     

基于主成分分析法的面源污染对李子口小流域水环境影响评价

以四川省南部县李子口小流域为研究对象,采用主成分分析方法,通过SPSS15．0软件对水质进行了定量评价,并结合综合污染损害指数对水质作出定性评价。结果表明：该流域水质污染高峰主要集中在6～10月份,11月份开始出现下降趋势,次年4月份开始出现升高状态,结合第一、二、三主分所反映的信息量,7月份主要为磷污染,5、7、8月份主要是有机物污染,而氮污染则集中在10月份。最后根据评价结果分析农业面源污染的影响。     

Cellular changes of adrenal under the acute stress of O-chlorobenzylidene malononitrile (CS)

Summary This investigation describes histological and cytometrical changes of cortical and medullary tissue of adrenal in rats under the acute stress of O-chlorobenzylidene malononitrile (10 mg/kg and 20 mg/kg). It has been observed that after injection of CS, the adrenal gland showed histological changes both in the cortical and medullary region.The authors are thankful to Dr. P.K. Ramachandran, Director, Defence Research and Development Establishment, Gwalior, for his sustained interest and critical suggestions in the course of this study.     

Reaching-related potentials in caudate nucleus and cerebellum of rats

Summary Electrical correlates of the lateralized reaching reaction were studied in rats with implanted electrodes. Averaged event-related potentials (ERPs) in the cerebellar dentate nucleus consisted of a negative wave coinciding with reach onset and followed 70 msec later by a positive deflection. The most prominent component of the more variable caudate ERPs was a negative wave culminating 60–120 msec after reach onset. The positive and negative ERP deflections corresponded to inhibitory and excitatory reactions respectively, at the single neuron level.     

Aminergic innervation of the hypothalamo-hypophyseal system in Gambusia sp. (Teleost, Poecilidae) studied by two fluorescence techniques]

Using fluorescence techniques (Falck-Hillarp, de La Torre and Surgeon) 2 paired groups of perikarya were observed in the hypothalamus of Gambusia, one in the nucleus recessus lateralis (NRL) and the other in the nucleus recessus posterioris (NRP). No fluorescent neuron could be detected in the nucleus recessus preopticus (NRPO) nor in the nucleus lateralis tuberis (NLT). Fluorescent aminergic fibers demonstrated in the rostral neurohypophysis and in the neurointermediate lobe might originate from the NRL. These two techniques are complementary, but the last one, more rapidly performed, appears promising.     

Der Einfluss von Giften auf die zur Meiose führenden Stoffwechselvorgänge beiSabellaria spinulosa

Summary The metabolic processes leading to meiosis inSabellaria spinulosa were investigated with cytochemical methods (PAS-reaction for polysaccharides, and basic dyes in combination with ribonuclease applied for the detection of ribonucleic acid) and the use of specific inhibitors. Before the beginning of meiotic prophase, polysaccharides and later ribonucleic acid appear in the nuclear sap and become incorporated into the spindle. 2,4-dinitrophenol and NaN₃, which inhibit the formation of energy-rich phosphates, prevent the accumulation of polysaccharides and RNA in the nucleus and the formation of the meiotic spindle. KCN and mono-iodoacetic acid are without influence on polysaccharide and RNA metabolism of the nucleus. The first and second meiotic division are normal, but cleavage is completely suppressed. From these results the following conclusions may be drawn: (1) the division of the nucleus is dependant on the presence of energy-rich phosphate, (2) the division occurs without respiration, and (3) respiration is important for cell division only in so far as it provides the synthesis of energy-rich phosphates.     

Release of calcitonin gene-related peptide from a human medullary carcinoma of the thyroid in vitro

The secretion of human calcitonin gene-related peptide was examined in perifusates of medullary carcinoma of the thyroid with a sensitive radioreceptor assay. Calcitonin gene-related peptide was released after the addition of calcium (25-100 mM), in a dose-dependent manner. The results indicate that human medullary carcinomas of the thyroid secrete the calcitonin gene-related peptide as well as calcitonin.     

Formation of the B cell synapse: retention or recruitment?

Interaction of B cells with membrane antigen results in the formation of the B cell synapse: the B cell receptor (BCR) and antigen concentrate in the contact zone while CD45/B220 and the phosphatase SHP-1 are excluded. This study shows that, unlike in T cells, synapse formation does not require active transport processes (while subsequent antigen extraction and IgM downregulation do). The synapse architecture depends on the available protein ligands in the contact zone. Thus Syk, IgM and Fc receptor accumulation require the presence of ITAM-bearing BCRs, membrane antigen and membrane (IgG-containing) immune complexes, respectively. Remarkably, non-bound proteins are frequently not only homogeneously distributed but excluded from the contact zone. These results suggest that proteins mainly reach the contact zone by undirected diffusion, and in order not to be expelled by molecular crowding they require capture by and fixation to a binding protein.Received 25 August 2004; received after revision 2 November 2004; accepted 17 November 2004     

Release of calcitonin gene-related peptide from a human medullary carcinoma of the thyroid in vitro

Summary The secretion of human calcitonin gene-related peptide was examined in perifusates of medullary carcinoma of the thyroid with a sensitive radioreceptor assay. Calcitonin gene-related peptide was released after the addition of calcium (25–100 mM), in a dose-dependent manner. The results indicate that human medullary carcinomas of the thyroid secrete the calcitonin gene-related peptide as well as calcitonin.     

The ATP synthase (F0-F1) complex in oxidative phosphorylation.

The transmembrane electrochemical proton gradient generated by the redox systems of the respiratory chain in mitochondria and aerobic bacteria is utilized by proton translocating ATP synthases to catalyze the synthesis of ATP from ADP and P(i). The bacterial and mitochondrial H(+)-ATP synthases both consist of a membranous sector, F0, which forms a H(+)-channel, and an extramembranous sector, F1, which is responsible for catalysis. When detached from the membrane, the purified F1 sector functions mainly as an ATPase. In chloroplasts, the synthesis of ATP is also driven by a proton motive force, and the enzyme complex responsible for this synthesis is similar to the mitochondrial and bacterial ATP synthases. The synthesis of ATP by H(+)-ATP synthases proceeds without the formation of a phosphorylated enzyme intermediate, and involves co-operative interactions between the catalytic subunits.     

The corticotropin-releasing factor (CRF) family of peptides as local modulators of adrenal function

Corticotropin-releasing factor (CRF), also termed corticotropin-releasing hormone (CRH) or corticoliberin, is the major regulator of the adaptive response to internal or external stresses. An essential component of the adaptation mechanism is the adrenal gland. CRF regulates adrenal function indirectly through the central nervous system (CNS) via the hypothalamic-pituitary-adrenal (HPA) axis and via the autonomic nervous system by way of locus coeruleus (LC) in the brain stem. Accumulating evidence suggests that CRF and its related peptides also affect the adrenals directly, i.e. not through the CNS but from within the adrenal gland where they form paracrine regulatory loops. Indeed, CRF and its related peptides, the urocortins (UCNs: UCN1, UCN2 and UCN3), their receptors CRF type 1 (CRF₁) and 2 (CRF₂) as well as the endogenous pseudo-receptor CRF-binding protein (CRF-BP) are all expressed in adrenal cortical, medullary chromaffin and resident immune cells. The intra-adrenal CRF-based regulatory system is complex and depends on the balance between the local concentration of CRF ligands and the availability of their receptors. Received 19 December 2006; received after revision 20 February 2007; accepted 26 March 2007     

Effect of repeated electroconvulsive shock on plasma noradrenaline and adrenaline in man

Summary The concentration of noradrenaline (NA) and of adrenaline (A) in plasma was measured before and 3, 30 and 60 min after single and repeated electroconvulsive shocks (ECS). Single ECS resulted in an activation of the sympathoadrenal medullary system; however, after the treatment had been repeated 4 times there was evidence of a diminished response of the peripheral sympathetic nervous system in comparison to the response to the first ECS.     

Elektronenmikroskopische Untersuchung der phäochromen (chromaffinen) Granula in den Markzellen der Nebenniere

Summary The catechol-containing granules in the adrenal medullary cells (mouse, guinea pig, cat) are true cell organells, clearly distinguished from mitochondria; their size varies over a fairly wide range, the mean diameter being calculated at about 175 mµ in the mouse (osmium-tetroxide-fixation). They have a surrounding membrane of 100 Å thickness; their internal structure is finely granular. On the thin sections, many granules are surrounded by spaces which appear empty under the electron microscope and which are limited by double-membranes; it is most likely thatintra vitam these spaces contain lipids.

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