Showing papers by "University of Göttingen published in 1981"

Subharmonic Route to Chaos Observed in Acoustics

Abstract: A subharmonic route to chaos including period-doubling bifurcations up to $\frac{f}{8}$ has been observed in experiments on acoustical turbulence (acoustic cavitation noise). The system also shows signs of reverse bifurcation with increasing control parameter (acoustic driving pressure amplitude). In view of the large variety of phenomena observed and yet to be expected the system investigated may well serve as a further experimental paradigm of nonlinear dynamical systems besides Rayleigh-B\'enard and circular couette flow.

Clostridium aceticum (Wieringa), a microorganism producing acetic acid from molecular hydrogen and carbon dioxide

Abstract: Spores of Clostridium aceticum (Wieringa) from 1947 have been revived, and a study for a redescription of this microorganism has been carried out. C. aceticum was Gram negative. The cells were rodshaped and peritrichously flagellated. Round spores were formed in terminal position. The DNA contained 33 mol % guanine plus cytosine. The organism was obligately anaerobic and grew either chemolithotrophically with H2 + CO2 or chemoorganotrophically with compounds such as fructose, L-glutamate, L-malate or pyruvate. H2 and CO2 were converted to acetic acid according to the following equation: 2CO2 + 4H2 leads to CH3COOH + 2H2O The optimal temperature for growth was 30 degrees C. The optimal pH for chemolithotrophic growth was 8.3. The doubling times for chemolithotrophic and chemoorganotrophic growth were 25 and 8 h, respectively.

Ökologische Gruppierung von Böden nach ihrem chemischen Bodenzustand

Abstract: Auf Grund der Loslichkeit von Kohlensaure, Calciumcarbonat sowie der oxidischen Al- und Fe-Verbindungen im Boden werden folgende Pufferbereiche definiert und durch pH-Werte in der Bodenlosung voneinander abgegrenzt: Kohlensaure/Carbonat-Pufferbereich (pH 6,2 bis 8,6), Kohlensaure/Silikat-Pufferbereich (pH 5,0 bis 6,2), Austauscher-Pufferbereich (pH 4,2 bis 5,0), Aluminium-Pufferbereich (pH 2,8 bis 4,2), Eisen-Pufferbereich (pH 2,4 bis 3,8). Es werden die Pufferkapazitaten berechnet und Literaturhinweise auf Pufferraten zusammengestellt. An einem Bodenkollektiv wird der fur jeden Pufferbereich charakteristische chemische Bodenzustand demonstriert. Mit zunehmender Bodenversauerung nimmt das Ca/Al-Molverhaltnis in Feinwurzeln von Werten > 1 auf Werte um 0,3 ab; hieraus wird auf eine Zunahme der Disposition fur Al-Toxicitat geschlossen. Es wird vorgeschlagen, die Zuordnung von Bodenhorizonten zu Pufferbereichen auf Grund von pH(H2O)-Messungen an feldfrischen Proben vorzunehmen. Die pH(Salz)-Messung wird als Mas fur die Schwingungsbreite des chemischen Bodenzustands bei H-Ionen- und Salzbelastung interpretiert. Ecological grouping of soils according to their chemical soil state On the base of the solubility of carbonic acid, calcium carbonate, as well as the oxidic compounds of Al and Fe existing in soils, the following buffer ranges are defined and separated from each other by pH values in the soil solution: Carbonic acid/Carbonate buffer range (pH 6.2 to 8.6), Carbonic acid/Silicate buffer range (pH 5.0 to 6.2), Exchanger buffer range (pH 4.2 to 5.0), Aluminium buffer range (pH 2.8 to 4.2), Iron buffer range (pH 2.4 to 3.8). The buffer capacities are calculated and literature indications regarding buffer rates are compiled. The characteristical chemical soil state is demonstrated for the various buffer ranges with aid of a soil collection. With increasing soil acidification the Ca/Al mole ratio in fine roots decreases from values > 1 to values around 0.3; this is taken as evidence for increasing disposition for Al-toxicity. It is suggested to attach soil horizons to buffer ranges on the base of pH(H2O) measurements made on field fresh samples. The measurement of pH in salt solution is taken as measure for the amplitude of the chemical soil state in case of H-ion or salt stress.

Clostridium thermoautotrophicum species novum, a thermophile producing acetate from molecular hydrogen and carbon dioxide

Abstract: Fourteen strains of a thermophilic, rod-shaped, peritrichously flagellatedClostridium species were isolated from various mud and soil samples. Round to slightly oval spores were formed in terminal position. The isolates were obligate anaerobes and grew chemolithotrophically with H2 plus CO2 as well as chemoorganotrophically with fructose, glucose, glycerate, or methanol. Under both conditions, acetate was the only organic fermentation product formed in significant amounts. The pH optimum for growth was 5.7; the marginal temperatures for growth wereT min, 36°C;T opt, 56–60°C; andT max, 69/70°C. The DNA contained 53–55 mol% guanine plus cytosine. the isolated strains form a new clostridial species; the nameClostridium thermoautotrophicum is proposed.

Assembly of Cytochrome c. Apocytochrome c Is Bound to Specific Sites on Mitochondria before Its Conversion to Holocytochrome c

Abstract: Transport of apocytochrome c across the outer mitochondrial membrane and conversion to holocytochrome c were studied in vitro. Apocytochrome c was synthesized in a cell-free homogenate from Neurospora crassa. Transfer in vitro was accomplished in a reconstituted system consisting of the postribosomal supernatant of the cell-free homogenate and of isolated and purified mitochondria from Neurospora. The reconstituted system has the following characteristics: * 1. Apocytochrome c is rapidly cleared from the supernatant and holocytochrome c appears in the mitochondria with the same kinetics. More than 80% of the apocytochrome c employed is converted to holocytochrome c. No transient accumulation of apocytochrome c is found in mitochondria. * 2. The heme group becomes covalently linked to apocytochrome c in the reconstituted system as demonstrated by analysis of tryptic peptide maps of the apoprotein and holoprotein. * 3. Deuterohemin added to the reconstituted system but not deuteroporphyrin inhibits the formation of holocytochrome c. This inhibition is reversed by protohemin. * 4. In the presence of deuterohemin about half of the apocytochrome c remains in the supernatant; the other half becomes associated with the mitochondria. The latter portion is tightly bound and is specifically released upon incubation of the mitochondria with excess apocytochrome c. It is converted to holocytochrome c after addition of protohemin. We conclude from these observations that apocytochrome c is transported across the outer mitochondrial membrane via receptor sites. In the presence of the heme analogue deuterohemin, binding to the receptor sites on the cytoplasmic surface of the outer mitochondrial membrane still takes place but translocation does not. The latter step is apparently coupled to the covalent linkage of the heme group. We suggest that the formation of the thioether bonds between apoprotein and heme is catalysed by an enzyme in the intermembrane space and that deuterohemin can compete with protohemin for binding to the enzyme. Finally, the data indicate that it is the heme group and not the porphyrin group which is coupled to the apoprotein.

Acetogenium kivui, a new thermophilic hydrogen-oxidizing acetogenic bacterium

Abstract: Hydrogen-oxidizing acetogenic bacteria in pure culture are presently represented by the two mesophilic species, Acetobacterium woodii and Clostridium aceticum. From Lake Kivu we have isolated a Gram negative, chemolithotrophic, thermophilic anaerobe (LKT-1) that oxidizes hydrogen and reduces carbon dioxide to acetic acid. It is a non-motile, non-sporeforming rod, about 0.7μm in width and 2–7.5μm in length, often occuring in pairs or chains. The cell wall has a banded appearance; the surface layer contains a regular array of particles with six-fold rotational symmetry. No outer membrane is present. The temperature optimum for growth is 66°C, and the pH optimum is 6.4. Organic growth substrates include glucose, mannose, fructose, pyruvate, and formate; acetate is the principal product. The doubling time for growth on hydrogen and carbon dioxide is about 2h. Vitamins are neither required nor stimulatory. Yeast extract and Trypticase enhance the final yield but do not affect the growth rate. Cysteine or sulfide are required and cannot be replaced by thioglycolate or dithiothreitol. LKT-1 was mass cultured on hydrogen and carbon dioxide in a 24.1 fermentor with a yield of 34g (wet weight) of cells. The DNA base composition as determined by buoyant density is 38 mol % guanine plus cytosine. LKT-1 appears only distantly related to physiologically similar bacteria. A new genus Acetogenium is proposed, and the species is Acetogenium kivui.

A critical look at currently used indirect indices of myocardial oxygen consumption

Abstract: Myocardial oxygen consumption indices that are frequently applied to man such as tension-time index (TTI), pressure-rate product (P·HR) and triple product (TP) have not been fully validated so far. These easily obtainable indices and a modified TTI\((\overline P \cdot \sqrt {HR} )\), therefore, were examined in 10 closed-chest dogs with very broad variations of hemodynamics and oxygen consumption (3–36 ml/min·100 g) analyzing 162 steady states. Myocardial blood flow was directly measured by a differential pressure coronary sinus catheter.\(M\dot VO_2 \) was varied by administration of catecholamines and other inotropic drugs, atropine, beta-blocking agents and hypo- and hypervolemia. Over a wide range of hemodynamic states, correlations with directly measured\(M\dot VO_2 \) of TTI (r=0.63), P·HR (r=0.87), TP (r=0.65) and\(\overline P \cdot \sqrt {HR} \) (r=0.80) are not satisfactory due to neglect of contractility and cardiac volumes by these terms. Better correlations are obtained when relating these indices to\(M\dot VO_2 \) under different inotropic states. At normal and moderately increased contractility, correlations with\(M\dot VO_2 \) rose as follows: TTI (r=0.96), P·HR (r=0.91), TP (r=0.96) and\(\overline P \cdot \sqrt {HR} \) (r=0.94). Significant rises in correlation are due to the close relationship between peak pressure and dP/dtmax at only moderately increased contraction velocity. Correlation differences within this inotropic range must be related to incorporation or neglect of ejection time as a partial determinant of\(M\dot VO_2 \). At markedly increased contractility, results for these indices, however, are in part very poor: TTI (r=0.40), P·HR (r=0.81), TP (r=0.38) and\(\overline P \cdot \sqrt {HR} \) (r=0.76). Within this inotropic state neglect of dP/dtmax as a major determinant of\(M\dot VO_2 \) and the inverse relationship between ejection time and dP/dtmax mainly account for these correlation shifts. It is concluded that non-invasively obtainable indices, currently in use, are no reliable predictors of actual overall\(M\dot VO_2 \) of the left ventricle if the contractile state of the myocardium is not checked invasively before. The broad variability of the relation of the energy demand of velocity of tension development to maintenance of systolic wall tension is not sufficiently considered by these terms. Appropriate caution, therefore, is necessary when applying those indirect indices of\(M\dot VO_2 \) to humans.

High abundance of small zoobenthos around biogenic structures in tidal sediments of the Wadden Sea

Abstract: On the tidal flats of the island of Sylt (eastern part of the North Sea) the quantity of micro- and meiofauna associated with shoots of seagrass(Zostera noltii), with infaunal bivalves(Macoma balthica), and with tubes and burrows of polychaetes(Pygospio elegans, Pectinaria koreni, Nereis diversicolor, Nereis virens, Arenicola marina) was found to add up to 5 to 33 % of the overall abundance. These structures, taken together, account for 10 to 50 % of the faunal abundance on an average tidal flat at Sylt. The quantitative effect of biogenic structures at the sediment surface (casts and funnels) is small compared to that of tubes and burrows penetrating the anaerobic subsurface layer. In providing stable oxic microenvironments these elite structures frequently bring together more individuals than occur in the entire reducing sediment below surface. Faunal composition of irrigated dwellings of large infauna is different from that of the oxic surface sediment. The common denominator of all elite structures of the subsurface is an oxic halo. Burrows without such a halo are unattractive. There is no evidence that owners of burrows prey on their smaller inmates.

Fatty acids of cuphea (lythraceae) seed lipids and their systematic significance

Abstract: Fatty acid analyses of seed lipids in 46 species of Cuphea are presented, representing the first major survey of a molecular nature for the family. A remarkable diversity in composition is found, with seeds containing high amounts of several medium chain fatty acids. Lauric acid (12:0) predominates in 43% of the species studied, constituting 50-74% of the total fatty acid content. Capric acid (10:0) is the dominant fatty acid in 32% of the species, comprising as much as 87% of the total acid content. Caprylic acid (8:0) predominates in one section of the genus. The emphasis on production of fatty acids with carbon chain lengths of 12, ten, and eight carbon atoms is unique among plant genera studied to date. Among seven of the nine sections studied, one pattern of fatty acid composition predominates. Two sections have no characteristic pattern, supporting other evidence of their polyphyletic origin. The most significant systematic contribution is made by comparison of the predominate fatty acid components in the seed lipids. When used in conjunction with floral morphology, pollen studies, and chromosome number, it provides an important new basis on which to draw inferences of evolution and clarify present relationships within the genus. Additionally, a trend from the longer-chained, unsaturated linoleic acid (18:2) as a major lipid component to shorter-chained saturated capric and caprylic acids is correlated with increasing floral specialization. It is suggested that mutations in regulatory genes have occurred which cause fatty acid production in seeds to cease at progressively earlier stages, resulting in accumulation of large amounts of single fatty acids of progressively shorter carbon chain lengths. THE VALUE of fatty acid patterns in deducing systematic relationships among plants is becoming increasingly apparent. Examples are particularly plentiful in bacterial taxonomy (e.g., MacKenzie, Lapp and Child, 1979; Durham and Kloos, 1978; Minnikin, Collins and Goodfellow, 1979). Fatty acids also have contributed to the assessment of taxonomic schemes in algae (Nichols, 1970; Attavian, Floyd and Fairbrothers, 1977) and fungi (Kroppenstedt and Kutzner, 1978). The fatty acids in a few genera of Bryophyta and ferns have been identified, but information here is still too meager to draw valid taxonomic or phylogenetic conclusions. Investigations of lipids of higher plants show that leaves most commonly contain only small quantities of linoleic acid (18:2) as the major constituent.3 Fatty acid composition in lipids of fruit coats is also simple, generally consist' Received for publication 16 June 1980; revision accepted 16 September 1980. This study was supported by grants from Henkel Cie., Dusseldorf, Federal Republic, Germany. 3The first number in the formula refers to the number of carbon atoms composing the fatty acid chain. It is followed by the number of unsaturated bonds in the chain. Both common and scientific names are available for fatty acids but common names are employed here in keeping with typical usage in other references. ing of palmitic and oleic acids (14:0, 18:1). Neither leaf or fruit coat lipids presently show promise of taxonomic application (Shorland, 1963). Lipids of higher plant seeds have received relatively more attention because of the large quantities produced and the economic value of some of the oils. Recent seed analyses in which taxonomy or phylogenetic aspects are considered in relation to fatty acid composition suggest fatty acids have taxonomic significance and evolutionary implications for higher plant classification and can be used to differentiate or relate taxa at several hierarchial levels (Opute, 1978; Hohn and Meinschein, 1976; Patudin, Yusupova and Voloshina, 1976; Tetenyi, 1974; Rogers, 1972; Vickery, 1971; Stone, Adrouny and Flake, 1969). Most analyses of seed lipids have been directed toward discovery of new sources of industrial, pharmaceutical, or food oils, with sampling spanning a wide array of plant families (Barclay and Earle, 1974; summaries in Hilditch and Williams, 1964, and Shorland, 1963). In an extensive survey of angiosperm seed oils by the U.S. Department of Agriculture, a species of the American tropical and subtropical genus Cuphea (C. llavea Lex.) was found to contain unusually high amounts of capric acid (83% of total seed lipid) (Wilson,

Different Transport Pathways of Individual Precursor Proteins in Mitochondria

Abstract: Transport of mitochondrial precursor proteins into mitochondria of Neurospora crassa was studied in a cell-free reconstituted system. Precursors were synthesized in a reticulocyte lysate programmed with Neurospora mRNA and transported into isolated mitochondria in the absence of protein synthesis. Uptake of the following precursors was investigated: apocytochrome c, ADP/ATP carrier and subunit 9 of the oligomycin-sensitive ATPase. Addition of high concentrations of unlabelled chemically prepared apocytochrome c (1-10 microM) inhibited the appearance in the mitochondrial of labelled cytochrome c synthesized in vitro because the unlabelled protein dilutes the labelled one and because the translocation system has a limited capacity [apparent V is 1-3 pmol X min-1 X (mg mitochondrial protein)-1]. Concentrations of added apocytochrome c exceeding the concentrations of precursor proteins synthesized in vitro by a factor of about 10(4) did not inhibit the transfer of ADP/ATP carrier or ATPase subunit 9 into mitochondria. Carbonylcyanide m-chlorophenylhydrazone, an uncoupler of oxidate phosphorylation, inhibited transfer in vitro of ADP/ATP carrier and of ATPase subunit 9, but not of cytochrome c. These findings suggest that cytochrome c and the other two proteins have different import pathways into mitochondria. It can be inferred from the data presented that different 'receptors' on the mitochondria. It can be inferred from the data presented that different 'receptors' on the mitochondrial surface mediate the specific recognition of precursor proteins by mitochondria by mitochondria as a first step in the transport process.

Patterns of parallel signal transmission between multiple alpha efferents and multiple Ia afferents in the cat semitendinosus muscle.

Abstract: 1. Certain features of signal transmission from multiple α-axons to multiple Ia fibres via extrafusal muscle tissue were studied by stimulating three ventral root filaments separately and simultaneously and by recording spike trains from three dorsal root filaments. 2. Post-stimulus time histograms (PSTH) revealed widely graded influences of single motor unit contractions on different muscle spindles, thus confirming results of Binder et al. (1976, 1980a). 3. In most instances, the signal transmission from a single motor unit to a single Ia fibre was disturbed to varying degrees by concomitant activity from other motor units. 4. This deterioration of signal transmission can probably be compensated for, at least in part, by correlations between discharge patterns of two or more Ia fibres induced by the “common input” of motor unit activity. 5. These correlations showed a topographical pattern such that a peak in the cross-correlogram (CCH) occurred at zero time for pairs of spindles located virtually in parallel to each other, and was shifted away from zero time as a function of the serial distance between spindles in the longitudinal muscle fibre direction. 6. Fusimotor innervation had complex effects on correlations between Ia fibre discharge patterns. It might de-correlate the latter as well as favour new correlations. 7. The possible role of topographical correlation patterns in the afferent reflex limb for tremor suppression is discussed.

Theoretische Betrachtung des Ionenkreislaufs in Waldökosystemen

Abstract: Aus dem Gesetz der Erhaltung der Materie und dem Elektroneutralitatsprinzip wird fur den stationaren Zustand von Waldokosystemen abgeleitet, das Protonen-Produktion oder -Konsumtion bei der Ionenaufnahme jeweils durch entgegengesetzte Protonenumsatze bei der Mineralisierung kompensiert werden. Am Beispiel eines Buchenwald-Okosystems im Solling wird gezeigt, das den Umsetzungen des Stickstoffs hierbei eine Schlusselrolle zukommt. Zeitliche und raumliche Entkoppelungen des Ionenkreislaufs fuhren zur Ausbildung von Versauerungsschuben und Entsauerungsphasen. Es werden witterungsgesteuerte saisonale Versauerungsschube und klimagesteuerte klimatische Versauerungsschube unterschieden. Starke nachhaltige Reduktionen der Phytomasseproduktion, sei es durch Klimasturze oder menschliche Eingriffe, konnen zu instationaren Zustanden fuhren. Es werden zwei aufeinander folgende instationare Zustande unterschieden, die mit Bodenversauerung verknupft sind: Humus-Disintegration und Podsolierung. Es wird geschlossen, das in Laubwaldern und alteren Nadelholzbestanden auftretende akute Podsoligkeit keine okosysteminternen Ursachen haben kann, sondern auf den Eintrag von Saure mit dem Sauren Niederschlag zuruckzufuhren ist. Theoretical consideration of the ion cycle in forest ecosystems From the law of mass conservation and the principle of electrical neutrality it is deduced for forest ecosystems being in steady state that proton production or -consumption during ion uptake is balanced by opposite proton turnover during mineralization. With a beech (Fagus silvatica) forest ecosystem in the Solling as an example it is shown that the turnover of nitrogen plays a key role in this respect. Temporal and spatial discoupling of the ion cycle cause acidification pushes and deacidification phases. It is distinguished between seasonal acidification pushes, which are regulated by weather conditions, and climatic acidification pushes, which are regulated by climate fluctuations. Strong long lasting reductions of the phytomass production, as caused by strong changes in climate or by human interaction, can lead to instationary states. It is distinguished between two consecutive instationary states, which are connected with soil acidification: humus-disintegration and podzolization. It is concluded that an acute podzolization in its beginning stage, which appears at present in deciduous forest and older stands of spruce and pine, cannot be caused by ecosystem internal reasons, but is the consequence of acid precipitation.

Eine ökosystemare Hypothese über die Ursachen des Tannensterbens (Abies alba Mill.)

Abstract: Es wird folgende Hypothese uber das Tannensterben aufgestell: In kuhl-feuchten Jahren haufen sich im Wurzelraum N-reiche, leicht mineralisierbare Ruckstande aus der Wurzelzersetzung an. Werden diese Vorrate in warm-trockenen Jahren mineralisiert, so losen sie einen Versauerungsschub aus. Fuhrt die Versauerung zum Auftreten von Al-Ionen in der Bodenlosung, so kann es durch Al-Toxicitat zu Wurzelschaden kommen. Der ab 1950 grosraumig auftretende Saure Niederschlag hat die Bodenversauerung so weit fortschreiten lassen, das Wurzelschaden immer haufiger auftreten. Die geschadigten Wurzeln stellen die Eingangspforten fur die den Naskern auslosenden Bakterien dar. Der Naskern fuhrt uber Verringerung der Transpiration zur Kronentrocknis. Einmalige bodenchemische Untersuchungen an Schadflachen fuhren zu Hypothesen uber die vom Zustand des Okosystems abhangige Prozeskette, die zum Tannensterben fuhrt.

Modulation of the Glucagon‐Dependent Induction of Phosphoenolpyruvate Carboxykinase and Tyrosine Aminotransferase by Arterial and Venous Oxygen Concentrations in Hepatocyte Cultures

Abstract: Periportal and perivenous hepatocytes are heterogeneous as to their outfit with enzymes and subcellular structures. The influence of different physiological oxygen concentrations on gene expression was studied in primary cultures of adult rat hepatocytes. 1 In 24-cultures the activities of phosphoenolpyruvate carboxykinase andtyrosine aminotransferase, which are predominantly located in periportal cells, were increased by glucagons(0.1 μmol/1)within 4 h to higher levels under 13%(v/v)oxygen in the gas atmosphere (mimicking arterial oxygen concentrations)than under 6%(v/v)oxygen (mimicking venous oxygen concentrations). The increase was due to enzyme induction as indicated by its prevention with cycloheximide or actinomycin D and by direct immunochemical titration. 2 Half-maximal induction of phosphoenolpyruvate carboxykinase and tyrosine aminotransferase was obtained under high and low oxygen tensions with glucagons concentrations around 0.5 nmol/1. 3 The induction of phosphoenolpyruvate carboxykinase and tyrosine aminotransferase by glucagons showed a sigmoidal rather than a linear dependence on oxygen tension; the range of highest sensitivity was found to be between 8% and 11% oxygen(v/v). 4 The oxygen dependence of the induction of phosphoenolpyruvate carboxykinase and tyrosine aminotransferase was probably specific and did not reflect a general impairment of energy metabolism. In the hapatocytes cultured under 13% and 6% oxygen (v/v) a)the adenine nucleotide levels were essentially the same the energy charge being 0.89;(b)the oxygen consumption was similar, 2.42±0.10 and 2.27±0.26μmol min −1wet weight −1; and (c)incorporation of [14] leucine into cellular protein as a measure of general protein synthesis amounted to 6.9 ±0.38 and 6.0 ± 0.4. nmol min −1mg DNA−1. The present results demonstrate that different physiological oxygen tensions can modulate the induction of liver enzymes and can thus contribute to the heterogeneity of hapatocytes.

The distribution of keratin type intermediate filaments in human breast cancer. An immunohistological study.

Abstract: Antibodies to different intermediate filament proteins can be used to distinguish cells of epithelial, mesenchymal, muscle, glial and neuronal origin. Antibodies to prekeratin which characterize cells of epithelial origin, and antibodies to vimentin which recognize cells of mesenchymal origin have been used to study twenty cases of breast carcinoma (sixteen infiltrating ductal carcinomas and four infiltrating intraductal carcinomas), two cases of cystic breast disease, two fibroadenomas and one case of benign cystosarcoma phylloides. The prekeratin and vimentin were detected using specific antibodies to these proteins by immunofluorescence microscopy using alcohol fixed paraffin-embedded tissues. In eighteen out of the twenty carcinomas the tumor cells were strongly and specifically stained by antibodies to prekeratin. Different tumors gave different patterns of prekeratin staining. In contrast, when the same specimens were tested with the vimentin antibody, the tumor cells were unstained, and instead only the usual strong staining to fibroblasts and blood vessels in the stroma was observed. In cystic breast disease, fibroadenomas, and benign cystosarcoma phylloides, cells of epithelial origin were strongly stained by the prekeratin but not by the vimentin antibody.

Effect of molecular hydrogen and carbon dioxide on chemo-organotrophic growth of Acetobacterium woodii and Clostridium aceticum.

Abstract: During growth of Acetobacterium woodii on fructose, glucose or lactate in a medium containing less than 0.04% bicarbonate, molecular hydrogen was evolved up to 0.1 mol per mol of substrate. Under an H2-atmosphere growth of A. woodii with organic substrates was completely inhibited whereas under an H2/CO2-atmosphere rapid growth occurred. Under these conditions H2+CO2 and the organic substrate were utilized simultaneously indicating that A. woodii was able to grow mixotrophically. Clostridium aceticum differed from A. woodii in that H2 was only evolved in the stationary phase, that the inhibition by H2 was observed at pH 8.5 but not at pH 7.5, anf that in the presence of fructose and H2+CO2 only fructose was utilized. The hydrogenase activity of fructose-grown cells of C. aceticum amounted to only 12% of that of H2+CO2-grown cells. With A. woodii a corresponding decrease of the activity of this enzyme was not observed.

Frequency response characteristics of a multi-loop representation of the segmental muscle stretch reflex

Abstract: This paper continues the investigation of a three-loop representation of the segmental muscle stretch reflex system introduced in a preceding communication. Frequency response characteristics were computed for open-loop conditions, control and disturbance signal inputs under a variety of conditions: (i) "in parallel" and "in series" peripheral arrangements of muscle compartments, (ii) various patterns of central connectivity, (iii) various recruitment levels of motor units, (iv) various overall reflex gains, (v) absence or presence of muscle spindle accleration sensitivity. These computations disclosed a number of mechanisms by which the nervous system might improve system stability and behaviour. These mechanisms are discussed with regard to physiological data.

The dup(3q) syndrome: report of eight cases and review of the literature.

Abstract: Clinical and cytogenetic examinations were performed on eight unrelated infants with duplication of part of the long arm of chromosome 3. A review of published cases shows a clinical syndrome characterized by statomotoric retardation, shortened life span, and a multiple congenital anomalies (MCA) syndrome of abnormal head configuration, hypertrichosis, hypertelorism, ocular anomalies, anteverted nostrils, long philtrum, maxillary prognathia, down-turned corners of the mouth, highly arched or cleft plate, micrognathia, malformed auricles, short, webbed neck, clinodactyly, simian crease, talipes, and congenital heart disease. The dup(3q) syndrome is a clinically easily recognizable entity.

Catabolism of Naphthalenesulfonic Acids by Pseudomonas sp. A3 and Pseudomonas sp. C22.

Abstract: Naphthalene and two naphthalenesulfonic acids were degraded by Pseudomonas sp. A3 and Pseudomonas sp. C22 by the same enzymes. Gentisate is a major metabolite. Catabolic activities for naphthalene, 1-naphthalenesulfonic acid, and 2-naphthalenesulfonic acid are induced by growth with naphthalene, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, methylnaphthalene, or salicylate. Gentisate is also an inducer in strain A3. Inhibition kinetics show that naphthalene and substituted naphthalenes are hydroxylated by the same naphthalene dioxygenase. Substrates with nondissociable substituents such as CH(3), OCH(3), Cl, or NO(2) are hydroxylated in the 7,8-position, and 4-substituted salicylates are accumulated. If CO(2)H, CH(2)CO(2)H, or SO(3)H are substituents, hydroxylation occurs with high regioselectivity in the 1,2-position. Thus, 1,2-dihydroxy-1,2-dihydronaphthalene-2-carboxylic acids are formed quantitatively from the corresponding naphthalenecarboxylic acids. Utilization of naphthalenesulfonic acids proceeds by the same regioselective 1,2-dioxygenation which labilizes the C-SO(3) bond and eliminates sulfite.

Sporulation and further nutritional characteristics of Desulfotomaculum acetoxidans

Abstract: Acetate-oxidizing sulfate-reducing bacteria of the Desulfotomaculum acetoxidans type have been enriched from animal manure, rumen content and dung contaminated freshwater habitats, indicating that they are primarily intestinal bacteria. Sporulation was observed only when acetate was the organic substrate; with butyrate, which allowed faster growth than acetate, spore formation never occurred. The cone-shaped highly refractile areas adjacent to the spores in spore-forming mother cells were shown to be gas vacuoles. Biotin was the only growth factor required by Desulfotomaculum acetoxidans strain 5575 in minimal media with sulfate and acetate or other organic substrates.

The influence of soil aeration on the efficiency of vesicular‐arbuscular mycorrhizas

Abstract: SUMMARY Oxygen concentrations in the soil atmosphere greatly influenced the growth and mineral uptake of Eupatorium odoratum inoculated with Glomus macrocarpus. Shoot and root dry weights and length of mycorrhizal plants increased with O2 concentration up to 16%. Mycorrhizal plants at 21% O2 or non-aerated controls were smaller than those at 12 and 16% O2. Non-mycorrhizal plants had lower shoot and root dry wts than mycorrhizal plants at all O2 levels except at 0%. Phosphorus concentration in mycorrhizal and non-mycorrhizal plants differed significantly but did not increase with increasing O2. Mycorrhizal plants contained higher quantities of N, K, Ca and Mg than non-mycorrhizal and showed positive response in nutrient uptake to increase in soil O2. Inoculation and increased soil O2 resulted in higher concentrations of K and Mg but not of N and Ca. The development of Glomus macrocarpus exhibited quantitative and qualitative response to different soil O2 levels.

Effect of GABA-administration on murine neuroblastoma cells in culture. I. Increased membrane dynamics and formation of specialized contacts

Abstract: (Gamma aminobutyric acid) GABA was applied to cultures of mouse neuroblastoma cells of different ages at concentrations ranging from 10-4 to 10-6 M. The cultures were exposed to GABA either in short term experiments for 2 h to 2 days or for longer periods by adding the substance twice within 10 days at 5-day intervals. The following effects were observed: (1) There was a strong proliferation of coated vesicles, appearing to derive from the Golgi complex and the rough endoplasmic reticulum (RER), and also showing all intermediate stages of fusion and pinching off from the plasma membranes. (2) In numerous areas, electron-dense material aggregated at the inner aspect of the plasma membrane and around small invaginations of the plasmalemma. (3) The number and area of specialized contacts increased between cells and their processes. (4) Similar to cultures free of GABA, varicosities and terminal swellings of the cells and their processes were filled with small round vesicles, 40–60 nm in diameter, or with smooth, very large, empty-appearing vesicular inclusions, or with flat pleiomorphic vesicles. In addition, mitochondria and some formations of the smooth endoplasmic reticulum (SER) appeared, and primitive contacts (symmetrical densities) were formed. (5) Dense-cored vesicles were found peripherally and linearly arranged, surrounded by an electron-dense substance. (6) Electron-dense material of unknown origin was seen between cells or their processes near the peripherally arranged dense-cored vesicles. Exogenous GABA may play a specific role in the early stages of synaptogenesis, since it showed a positive effect on the neuroblastoma cells, which in the absence of GABA are only capable of forming primitive or immature presynaptic elements. The significance of the peripheral accumulation of dense-cored vesicles, accompanied by an amorphous, electron-dense substance occurring both intra- and extracellularly is discussed.

Eccrine sweat glands are not innervated in hereditary sensory neuropathy type IV. An electron-microscopic study.

Abstract: The ultrastructural study of a skin biopsy in a patient afflicted with hereditary sensory neuropathy type IV (congenital insensitivity to pain with anhidrosis) did not reveal any unmyelinated axons or axonal terminals around eccrine sweat glands but only proccsses, partially covered by a basement membrane and therefore resembling Schwann cell processes. The absence of such unmyelinated axons in close proximity to eccrine sweat glands where they normally occur appears to be the morphological equivalent to the anhidrosis and also corresponds to the deficiency of unmyelinated axons in the sural nerve of the same patient, as previously reported.