Short- and long-term effects of ACTH on the adrenal zona glomerulosa of the rat

Summary Short-term ACTH treatment provoked a decrease in volume of the lipid-droplet compartment in rat zona glomerulosa cells, and a rise in plasma and intracellular concentrations of corticosterone and aldosterone. It enhanced activities of 3-hydroxysteroid dehydrogenase (3HSD), 11-hydroxylase (11OH) and 18-hydroxylase (18OH). Long-term ACTH administration produced a hypertrophy of the zona glomerulosa and its parenchymal cells, a result of the increase in volume of the smooth endoplasmic reticulum and the mitochondrial compartment. The surface area per cell of mitochondrial inner membranes increased; the tubular cristae were transformed into a homogeneous population of vesicles. The plasma and intracellular concentrations of corticosterone further increased, whereas those of aldosterone fell below basal levels (the aldosterone-escape phenomenon). The activities of 3HSD and 11OH were enhanced, that of 180H decreased. Therefore, ACTH stimulates zona glomerulosa growth and transforms parenchymal elements into zona fasciculata celltypes. Cyanoketone nullified acute ACTH effects on plasma and intracellular concentrations of corticosterone and aldosterone, but did not affect the activities of 11OH and 18OH. Chronic ACTH treatment produced similar results, although 18OH activity was not suppressed. The mechanism underlying the aldosterone-escape phenomenon may thus involve a rise in the intracellular concentration of corticosterone, caused by the enhanced synthesis and activation of 3HSD and 11OH.     

Contextualizing Images in Dreams and Daydreams

A contextualizing image (CI) is a powerful central image of a dream which appears to contextualize (provide a picture-context for) the dreamer's emotion. For instance, dreamers who have experienced any serious traumatic event sometimes dream, I was overwhelmed by a tidal wave. This appears to picture their feeling of terror and/or vulnerability.A scoring system for CIs is examined here and is applied to dreams and daydreams supplied by 40 students. Two raters scoring dreams on a blind basis showed good inter-rater reliability. Recent dreams were shown to have more as well as more intense CIs than recent daydreams; likewise, dreams that stand out had more intense CIs than daydreams that stand out. Students with thin boundaries had more and more intense CIs than students with thick boundaries in their recent dreams and nightmare, but not so clearly in dreams and nightmares that stand out. The emotions judged as contextualized by the powerful images tended towards fear/terror and helplessness/vulnerability in dreams (especially in dreams that stand out) whereas emotions contextualized by images in daydreams showed a wide range with no clusters.     

The influence of externally applied organic substances on phloem translocation in detached maize leaves

Summary Solutions of organic substances show differing influences on the direction of phloem transport of ¹⁴C-labeled assimilates in predarkened maize leaf strips, when externally applied to one end of the strip. One group of substances pushes the assimilates away from the site of application. Examples of this group are 75 mM solutions of sucrose, trehalose, maltose, D-glucose, D-fructose, glucose-6-phosphate, raffinose and galactose. There is strong evidence that pushing substances are taken up from the apoplast and loaded into the phloem. Another group of substances attracts the assimilates, it seems to pull the assimilates in direction to the site of application. Examples of this second group are 75 mM solutions of arabinose, melibiose, myo-inositol, D-mannitol, polyethylene glycol 2000, and Na₂-EDTA (ethylene-diaminetetraacetate). The pulling substances obviously are not taken up into living cells. It is assumed that they accumulate in the apoplast and build up a water stress (water potential), which is counteracted by an increase of solute concentration in the parenchyma, thus creating a sink for assimilates. A third group of substances shows inert behaviour, having no perceptible influence on phloem transport, at least not, when applied as 75 mM solutions. At concentrations of more than 300 mM, inert substances tend to attract assimilates like those of the second group. Inert substances are xylose, sorbose, 2-deoxy-D-glucose, mannose and sorbitol.abbreviation EDTA ethylenediaminetetraacetate Supported by Deutsche Forschungsgemeinschaft     

Charles Darwin's theory of evolution: A review of our present understanding

The paper characterizes Darwin's theory, providing a synthesis of recent historical investigations in this area. Darwin's reading of Malthus led him to appreciate the importance of population pressures, and subsequently of natural selection, with the help of the wedge metaphor. But, in itself, natural selection did not furnish an adequate account of the origin of species, for which a principle of divergence was needed. Initially, Darwin attributed this to geographical isolation, but later, following his work on barnacles which underscored the significance of variation, and arising from his work on botanical arithmetic, he supposed that diversity allowed more places to be occupied in a given region. So isolation was not regarded as essential. Large regions with intense competition, and with ample variation spread by blending, would facilitate speciation. The notion of place was different from niche, and it is questioned whether Darwin's views on ecology were as modern as is commonly supposed. Two notions of struggle are found in Darwin's theory; and three notions of variation. Criticisms of his theory led him to emphasize the importance of variation over a range of forms. Hence the theory was populational rather than typological. The theory required a Lamarckian notion of inheritable changes initiated by the environment as a source of variation. Also, Darwin deployed a use/habit theory; and the notion of sexual selection. Selection normally acted at the level of the individual, though kin selection was possible. Group selection was hinted at for man. Darwin's thinking (and also the exposition of his theory) was generally guided by the domestic-organism analogy, which satisfied his methodological requirement of a vera causa principle.     

Polymorphism of the HLA DR1 haplotype in the Israeli population investigated at the serological,cellular, and genomic levels

In the present report, we used serological, cellular, and restriction fragment length polymorphism (RFLP) to investigate the DR1 haplotype in the Israeli population. We describe an Israeli homozygous typing cell (HTC), HLA-DwLVA, which defines a new lymphocyte-activating determinant associated with Bw65, DR1 and distinct from Dwl. The parents of this donor, non-Ashkenazi Algerian Jews, are first cousins and share HLA-Cw8, Bw65, BfS, DR1, DQw1, DPw4. No specificity could be assigned to HLA-DwLVA using the 91 Ninth Workshop HTCs. Two families and forty unrelated DR1 individuals were studied with DwLVA and a panel of DR1/Dw1 HTCs. HLA-DwLVA showed segregation as a single determinant within families. This new specificity was present in 24 out of 40 (60%) unrelated DR1 individuals, indicating that in the Israeli population DwLVA is the main lymphocyte-defined determinant associated with the serologically defined DRI specificity, in contrast to non-Jewish Caucasoids where DR1 is significantly associated with Dw1. The vast majority of DwLVA-positive carriers were also Bw65 carriers, indicating that Bw65, DR1, DwLVA may represent a typical allele combination in the Israeli population. The RFLP analysis established the correlation of certain RFLPs with Dw1 and DwLVA. In addition, we describe a cluster of RFLPs that may correspond to a new Dw subtype associated with DR1, for which no serological and cellular reagents have been described so far.     

Age-related accumulation of lysosomes and other cytological features in active thyroid follicles of the CBA mouse

Summary This study attempts to elucidate the mechanism through which lysosomal accumulation occurs with age in the epithelial cells of the thyroid gland and especially in the active follicles of the aging mouse thyroid. Thyroid morphology and function in old CBA (at least 24 months of age) male mice were compared with those in young (2 months of age) animals. The effects of different intake of iodine were tested and compared in both cohorts, each of which was divided into three groups: (i) low iodine group, (ii) moderate iodine group, and (iii) high iodine group. As expected, the present work confirmed the well-known accumulation with age of cold follicles coexisting with active follicles in the old mouse thyroid. Attention has been focused on the active follicles whose follicular cells contained in their cytoplasm a large number of pleomorphic dense bodies. The lysosomal nature of these bodies, referred to as secondary lysosomes, was confirmed by histochemistry; however, they displayed variability in acid phosphatase staining. In old animals, regardless of the type of iodine regimen, the ratio between relative follicular volume and relative colloid volume as determined by morphometry remained unchanged. Ultrastructurally, the relative volume occupied by secondary lysosomes in active follicles was always higher than in the young groups. Autoradiographic studies with ¹²⁵I revealed that a large part of the radioactivity was located in secondary lysosomes of thyroid cells in active follicels of old mice when radioiodine was injected 3 weeks before death. Two different types of vacuoles were present in a non-negligible number of thyrocytes of the active follicles in aged cohorts. The first type was made up of grossly dilated rough endoplasmic cisternae, the second corresponded to intracytoplasmic microfollicular vacuoles. Both aspects have been described in conditions of chronic stimulation. It is concluded (1) that different intake of iodine for 6 weeks does not modulate the thyroid morphology in old mice; (2) that in the thyrocytes of the active follicles in old mice accumulation of secondary lysosomes occurs due to a slowdown of turnover; and (3) that the follicular cells of active follicles feature morphological aspects suggesting a hyperactive state compensating the lack of hormone production in the cold follicles.     

Primary structure of the hemoglobin beta-chain of rose-ringed parakeet (Psittacula krameri)

The primary structure of Rose-ringed Parakeet hemoglobin -chain was established, completing the analysis of this hemoglobin. Comparisons with other avian -chains show variations smaller than those for the corresponding -chains. There are 11 amino acid exchanges in relationship to the only other characterized psittaciform -chain, and a total of 35 positions are affected by differences among all avian -chains analyzed (versus 61 for the -chains). At three positions, the Psittacula -chain has residues unique to this species. Three ₁₁ contacts are modified, by substitutions at positions 51, 116, and 125.     

Excitatoren und paarungsverhalten mitteleuropäischer malachiiden (Coleopt., Malacodermata)

Ohne ZusammenfassungAlphabetisches Verzeichnis der im Text gebranchten Abkürzungen AK Anbieten der Kopfgrube () - AR-seitig außenrandseitig (auf Elytre bezogen) - EO Elytralorgan (EO-Arten = Arten mit Elytralorganen im männlichen Geschlecht) - f Flucht () - F Flucht () - FA, fa frontale Auseinandersetzung (, ) - FS, fs Fühlertrillern bzw. Frontalspiel (, ) - gk Grubenknabbern () - IR-seitig innenrandseitig (auf Elytre bezogen) - K Kopulation - KG Kopfgrube (KG-Arten = Arten mit Kopfgrube im männlichen Geschlecht) - KI Abdomenkitzeln () - KV Kopulationsversuch () - LP-Feld den weiblichen Labialpalpen korreliertes Drüsenporenfeld - MP-Feld den weiblichen Maxillarpalpen korreliertes Drüsenporenfeld - 180 Drehung des um 180° - ob Organbeißen () - ok Organknabbern () - OZ Organzuwendung () - P Prüfung der Kopulationsbereitschaft durch - RB rückwärtige Berührung durch - SLV Seitwärtslauf nach vorn () - SLH Seitwärtslauf nach hinten () - U Umrundung () - vl Vorwärtslauf () - 180 Drehung des um 180° Habilitationsschrift.     

Aflatoxin influences on seed germination and root elongation by two cultivars of Glycine max and uptake of 65 Zn-ZnCl2 by the cultivars

Maximum inhibition of Glycine max, cv. Essex seed germination occurred at 10 g/ml following 72 hr imbibition in constant light. Seeds imbided 108 hr in constant darkness at this concentration showed a 20% rise in germination over that of the control. Imbibition of G. max, cv. Williams seeds in either light or dark for 96 hr did not suppress germination. Imbibition of Essex seeds in either light or dark at 2.5 through 10 g/ml stimulated root elongation except for 10 g/ml at 96 hr (light). Maximum inhibition of Williams root elongation under constant light was at 48 and 72 hr with 10 g/ml. Statistically significant differences in cotyledon, leaf and stem lengths between non-treated (NT) and treated (T) seedlings were not found except for Williams stem length at 2.5 / ml. Root elongation was stimulated 1.2- and 1.1-folds, respectively, at 5.0 (Essex) and 2.5 (Williams) g/ml. Toxin at 2.5 through 10.0 g/ml did not markedly alter either cotyledon or leaf widths with the exception of Williams leaf width at 2.5 g/ml. Medium supplementation with 2.5 through 10.0 g/ml resulted in cotyledon, leaf and root weight enhancements for Essex seedlings. Stem weight was not markedly affected. An 18% rise in Williams cotyledon weight above that of the control was seen at 2.5 g/ml. Williams leaf weights were increased 1.75- and 1.25-folds, respectively, at 2.5 and 10.0 g/ml. Aflatoxin B₁, at 2.5 g/ml promoted Williams stem and root elongation 1.20- and 1.09-folds, respectively. Most of the radioactivity from ⁶⁵Zn-ZnCl₂ recovered within organs was found within Essex roots for both T and NT seedlings. A higher amount of radioactivity was recovered within roots at each toxin concentration than was without toxin. However, this was not statistically significant. Significant differences in the distribution of radioactivity within roots between NT and T Williams seedlings were not observed. Generally, AFB₁ failed to affect significantly these two varieties of soybeans based on the tests relating to germination, growth and radiolabel uptake.     

In vitro meristem cloning of Eucalyptus tereticornis Sm.

Rapid multiplication of axillary meristems and direct shoot development occurred from nodal explants of mature Eucalyptus tereticornis Sm. with 5.3 M NAA, 1.1 M IAA and 4.4 M BA in Murashige-Skoog medium. Repeated subcultures of the second generation shoot cultures into low cytokinin-auxin containing media (0.44–0.88 M BA+0.1 M NAA) yielded axillary microshoots in large numbers. Half-strength MS liquid medium with 4.9 M IBA, 5.5 M IAA and 5.3 M NAA for four days, half-strength semi-solid hormonefree MS medium with charcoal, and MS liquid medium without charcoal and hormones, in sequence, induced rooting of shoots in the dark. This system is suitable for the mass propagation of this difficult-to-root eucalypt.Abbreviations BA 6-benzyladenine - IAA indole-3-acetic acid - IBA -indole-3-butyric acid - 2-iP isopentyl adenine - Kn kinetin - MS Murashige-Skoog - NAA -naphthalene acetic acid - PVP polyvinylpyrrolidone     

Line source models for active fibers

It is shown that the utility of usual circular line source models is highly questionable. A line source model related to arbitrary cross-sections is given and essential differences between the source strength of the circular and non-circular model are found in the case of fairly flat elliptic fibers.     

Cluster Maintenance in Mobile Ad-hoc Networks

The main contribution of this paper is to propose a new cluster maintenance algorithm and a companion cluster initialization algorithm based on a number of interesting and novel properties of diameter-2 graphs. The initialization algorithm naturally blends into cluster maintenance, showing the unity between these two operations. We refer to our algorithms as tree-based since they depend on a spanning tree maintained at various nodes. Unlike the vast majority of published clustering algorithms, our algorithms are cluster-centric, as opposed to node-centric, and work in the presence of node mobility. Extensive simulation results have shown the effectiveness of our algorithms when compared to other clustering schemes proposed in the literature.Lan Wang received his B.S. and M.S. degrees in computer science from Harbin Engineering University, China in 1992 and 1995, respectively. From 1995 to 1999, he worked as a software engineer at the System Engineering Research Institute of CSSC, Beijing, China. He is currently a PhD student at the Computer Science Department of Old Dominion University.Stephan Olariu received the M.Sc. and Ph.D. degrees in computer science from McGill University, Montreal, Canada in 1983 and 1986, respectively. In 1986 he joined the Computer Science Department at Old Dominion University where he is now a full professor. He has published extensively in various journals, book chapters, and conference proceedings. His research interests include wireless networks and mobile computing, parallel and distributed systems, performance evaluation, and medical image processing. Prof. Olariu serves on the editorial board of several archival journals including IEEE Transactions on Parallel and Distributed Systems, Journal of Parallel and Distributed Computing, International Journal of Foundations of Computer Science, Journal of Supercomputing, International Journal of Computer Mathematics, VLSI Design, and Parallel Algorithms and Applications.     

Die Intravitale Karyorrhexis Der Exokrinen Pankreaszelle im Elektronenmikroskopischen Bild

Zusammenfassung Die intravitale Karyorrhexig wird am exokrinen Pankreas der Maus nach Osmium- und Formalinfixierung licht- und elektronenmikroskopisch untersucht. Im Verlaufe der Karyorrhexis kommt es zu einer Trennung des Karyoplasmas in 'Chromatin und 'Karyolymphe (Interchromatin-Substanz). In fortgeschrittenen Stadien ist das Bild solcher Zellkerne — im Gegensatz zu normalen Intermitosekernen — nach beiden Fixierungsmethoden fast identisch. Das Chromatin ist in dichten, membranständigen Kappen konzentriert. Der übrige Kernraum wird — abgesehen vom Nukleolus — von der hellen Karyolymphe ausgefüllt. In ihrem Bereich treten die sog. Interchromatingranula (200–250 Å), einzeln oder in dichten Haufen, meist deutlich hervor. Der Nukleolus, dessen Feinstruktur nicht auffallend verändert ist, liegt entweder frei oder den Chromatinkappen unmittelbar an. Die Kernhülle ist bei fortgeschrittener Karyoplasmaentmischung unversehrt oder über kürzere oder längere Strecken geschwunden. Im Endstadium der Karyorrhexis sind mehrere, von Kernmembranfragmenten unvollständig begrenzte Chromatinbrocken wahllos im Zelleib verstreut. Die cytoplasmatischen Strukturen können auch bei ausgeprägten Kernveränderungen noch weitgehend normal aussehen.Die karyorrhektischen Kernveränderungen werden als Folge einer 'Entmischung des Karyoplasmas gedeutet, für die eine Dehydratation der DNS-tragenden Chromosomenstrukturen verantwortlich gemacht wird. Auch das Sichtbarwerden und das Verklumpen der 'Interchromatingranula wird auf eine Dehydratation zurückgeführt.

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Summary The intravital caryorrhexis in the exocrine pancreas of the mouse was studied by means of light- and electron microscopy after fixation with osmium and formaldehyde. During caryorrhexis the caryoplasm segregates into chromatin and caryolymphe (interchromatinic substance). In contrast to normal intermitotic nuclei both fixations result in a very similar picture of the typical caryorrhectic nuclei. The chromatin is concentrated in dense caps associated with the nuclear envelope. Except those dense caps and apart from the nucleolus the whole nucleus is occupied by the light caryolymphe. In this area the so-called interchromatinic granules (200–250 Å) become clearly visible, isolated or in dense clumps. The nucleolus, the fine structure of which has not remarkably changed, can be found either isolated or in touch with the chromatin caps. During advanced segregation of the caryoplasm the nuclear envelope was found to be either unimpaired or had disappeared for variable lenghths. In the final stage of caryorrhexis several chromatin clumps — partly confined by fragments of the nuclear envelope — are distributed irregularly within the cell. Even in the case of pronounced nuclear changes the cytoplasmic structures may appear almost unaffected.It is assumed that the nuclear changes during caryorrhexis are due to a segregation of the caryoplasm, caused by dehydration of the DNA-carrying chromosome fibrils. Also dehydration is made responsible for the appearance and clumping of the interchromatinic granules.

     

Protein synthesis in tissues cultured from the bovine hoof

Salmon gonadotropin (GTH II) is a heterodimeric glycoprotein hormone ( and II subunits), serving as a maturational GTH, and is produced in a specific gonadotropic cell-type (GTH II-cells) containing small granules and large globules. In trout GTH II-cells, double immunolabeling for the - and II-subunits shows that colocalization of the - and II-immunolabeling is confined to the small granules, indicating storage of functional GTH II. On the other hand, -immunolabeling is absent in the large globules, even though II labeling is abundant throughout the period of seasonal gametogenesis. The -specific antiserum recognizes the intact -subunit as well as the reduced and deglycosylated -subunits by immunoblotting. These results indicate that an accumulation of the II-subunit is specifically generated in the large globules of these cells. In fact, with sexual maturity, the quantity of II-subunits becomes elevated in the trout pituitary due to a marked increase in GTH II-cells containing many large globules. However, the derivation and function of the large globules and the fate of their contained II-subunits remains unknown.     

Kinetics of growth and lactic acid production in continuous and batch culture

Summary In a lactic acid fermentation by Streptococcus faecalis, the specific consumption rate of glucose (v) and the specific production rate of lactic acid () were represented by the following simple equations as functions of the specific growth rate (): 1/=(1/) + 1/ = (1/) + By use of data from a batch culture, these two equations were derived from enzyme kinetics of the product inhibition. These equations were successfully applied to the results of batch culture and chemostat culture. In addition, calculation of ATP yield by these equations agreed with the experimental results better than the conventional Leudeking-Piret type equation, which includes two terms associated with growth and not with growth. Correspondence to: H. Ohara     

Modulation of natural killer activity by thymosin alpha 1 and interferon

Summary A single injection of -interferon (-IFN) (30 000 units/mouse), a major biological modifier of natural killer (NK) cytolytic activity, strongly stimulated NK activity in normal mice, as expected, while the same treatment did not statistically alter the NK response in cyclophosphamide (CY)-suppressed animals.We investigated the possibility of thymosin ₁ cooperating with -IFN in boosting NK activity in CY-suppressed animals.The results show that treatment with thymosin ₁ (200 g/kg) for 4 days, followed by a single injection of -IFN 24 h before testing, strongly restored NK activity in CY-suppressed mice. Thymosin ₁ was, moreover, able to accelerate the recovery rate of NK activity in bone marrow reconstituted murine chimeras.Taken together the data support the concept that the synergic effect between thymosin ₁ and -IFN could be the result of effects on differentiation of the NK lineage at different levels.     

An algorithm for feature classification and structural memorization

Given a finite set of strings of elements (e.g. words or syllables written in terms of letters, which may be true alphabetic symbols, or markers for features which put together form the word describing an object), the problem is posed of memorizing the strings not in lexicographic order, but by grouping them into classes, each of which can be taken as an entry into a multilayered, fast-access memory; this is equivalent to memorizing, rather than the strings, the structural rules which characterize them. This problem is solved by means of a heuristic algorithm, which gives results that stay invariant under arbitrary permutations of the elements; heuristics may affect optimality, not exactness of the solution, and provides considerable gains in computing costs. The exposition, for convenience of the reader, is self-contained, although this work is part of a more general program on form and language analysis.     

On the heterogeneity of the slow reassociating (“unique”) DNA

Summary The slow reassociating fraction of mouse DNA (unique DNA), when allowed to reassociate in 0.14 m sodium phosphate buffer at 50 °C showed a biphasic melting curve with a transition at 78–80 °C. On the basis of this feature, the slow reassociating DNA was separated preparatively into two fractions: unique DNA I and II. Their duplexes showed differences with respect to thermal stability, S1 nuclease resistance and rate of reassociation. About one third of the sequences in each fraction were fraction-specific. The conclusion was drawn that for unique DNA I these should be the low repetitive or single copy related sequences (multigene families) and for unique DNA II—the unrelated single copy sequences or recent families of low repetitive not yet diverged sequences.     

Long Range Force between Pre-Replication Complexes (Pre-RC) in DNA Controls Replication and Cell Cycle Progression

A nonstationary interaction, that controls DNA replication and the cell cycle, is derived from a manybody physics model in a chemically open T cell. The model predicts a long range force F()=-(/2) (1-)(2-) between the pre-replication complexes (pre-RCs) bound by DNA, =/N being the relative displacement of preRCs, the number of pre-RCs, N the threshold for initiation, and the compressibility modulus in thelattice of pre-RCs which behaves like an elastically braced string. Initiation of DNA replication is induced by a switch of sign of F(), from attraction (-)and assembly in the G ₁ phase (0 < < N), to repulsion (+) and partialdisassembly in the S phase (N < < 2N), with release of licensing factors from the pre-RCs, thus explaining prevention of re-replication. Replication is terminated by a switch of sign of F at = 2N, when all primed replicons are duplicated once, and F(0)=0 corresponds to a resting cell in absence of driving force at = 0. The switch of sign of force at = N also explains the dynamic instability in growing microtubules (MTs), as well as switch in the interleukin-2 (IL2) interaction with its receptor in late G ₁, at the restriction point. Shape, slope and scale of the response curves derived agree well with experimental data from dividing T cells and polymerizing MTs, the variable length of which is due to anonlinear dependence of the growth amplitude on the initial concentrations of tubulin dimers and guanosine-tri-phosphate (GTP).