Showing papers by "University of Marburg published in 1979"

Radioimmunoassay for type III procollagen peptide and its application to human liver disease.

Abstract: . A sensitive and specific radioimmunoassay was developed for the precursor-specific peptide segment located at the amino end of bovine type III procollagen. Human material showed high cross-reactivity in this assay. Two forms of human procollagen peptides were detected in body fluids. The larger peptide (45K) was found in serum and ascites, and resembled the whole precursor-specific segment which is presumably released from human type III procollagen by a single enzymatic cleavage. The smaller peptide (10K) was found mainly in urine indicating that further degradation of circulating procollagen peptides is required prior to their passage through the kidney. Compared to peptide concentrations in normal human serum, two to twenty-fold increases were observed in all patients with alcoholic liver disease, in fifteen of seventeen patients with acute hepatitis, and in ten of fourteen patients with chronic active hepatitis. Much higher levels were detected in ascites fluid. Patients with rheumatoid arthritis and other diseases showed far smaller elevations of the serum peptide. In alcoholic liver disease peptide levels correlated well with inflammation and necrosis observed in liver biopsies, but not with other laboratory parameters.

Nickel, cobalt, and molybdenum requirement for growth of Methanobacterium thermoautotrophicum.

Abstract: Growth of Methanobacterium thermoautotrophicum on H2 and CO2 as sole energy and carbon sources was found to be dependent on Ni, Co, and Mo. At low concentrations of Ni (<100 nM), Co (<10 nM) and Mo (<10 nM) the amount of cells formed was roughly proportional to the amount of transition metal added to the medium; for the formation of 1 g cells (dry weight) approximately 150 nmol NiCl2, 20 nmol CoCl2 and 20 nmol Na2MoO4 were required. A dependence of growth on Cu, Mn, Zn, Ca, Al, and B could not be demonstrated. Conditions are described under which the bacterium grew exponentially with a doubling time of 1.8 h up to a cell density of 2 g cells (dry weight)/1.

Experimental coronary artery occlusion. I. Measurement of infarct size.

Abstract: We studied the size of infarcts in 25 dogs 48 hrs after proximal occlusion of the left anterior descending coronary artery. In one group of animals infarct size was measured by histologic criteria, in another group the infarct was measured macrohistochemically using p-NBT and malate to incubate unfixed slices of myocardium. In both groups infarct size was expressed as percentage of the area of perfusion of the occluded artery. Infarct size was 72% of the area-at-risk in the group studied by histology and 74.5% in the macrohistochemical group. The satisfactory agreement of both methods favors the p-NBT technique because of its ease and speed. It is suggested that the expression of infarct size as percentage of the perfusion area is a good definition and should be used in experiments designed to manipulate infarct size. In this way differences in the size of occluded arteries and their respective perfusion areas have no or only a negligible influence on infarct size.

Apolipoprotein A‐IV: a Protein Occurring in Human Mesenteric Lymph Chylomicrons and Free in Plasma

Abstract: 1. Human mesenteric lymph chylomicrons were isolated from chylous ascites fluid by ultra-centrifugation and agarose/gel chromatography and their apoprotein composition was analysed by dodecylsulfate/polyacrylamide gel electrophoresis, analytical isoelectric focusing and immuno-chemically. Major components of mesenteric lymph chylomicrons were apoprotein A-I, proteins of Mr less than 15 000 including the C-group apoproteins and a protein of Mr 46 000. Minor components were apoprotein E and a protein of Mr approximately equal to 200 000 (B-like protein). This apoprotein composition was qualitatively identical with that of chylomicrons from intestinal lymph of the rat, but was distinctly different from plasma chylomicrons of humans with fasting chylomicronaemia. 2. The protein of Mr approximately equal to 46 000 has been isolated by preparative dodecylsulfate/polyacrylamide gel electrophoresis from human and rat lymph chylomicrons and was compared to a protein of identical Mr present in rat high-density lipoproteins (apoplipoprotein A-IV) and in the rho less than 1.006 g/ml serum lipoprotein fraction of individual humans with alimentary hypertriglyceridaemia. In both species the 46 000-Mr proteins isolated from lymph and serum were identical according to amino acid composition and isoelectric point in 6 M urea. The human proteins from both sources were also immunologically identical. The similarities in the molecular properties of the human apolipoprotein and rat apolipoprotein A-IV indicate that these proteins are homologous. 3. Plasma levels of human apolipoprotein A-IV determined by electroimmunodiffusion were 14.15 +/- 3.66 mg/100 ml (n = 59), but greater than 90% of the protein was unassociated with the major lipoprotein fractions. It is concluded, that apolipoprotein A-IV is a main protein component of human lymph chylomicrons, that is removed from the particles in the plasma compartment.

Course and spontaneous regression of acute pancreatitis in the rat.

Abstract: Rat exocrine pancreatic function was studied structurally and biochemically after the in vivo production of acute interstitial pancreatitis by supramaximal stimulation with caerulein. Two major phases in the reaction of the gland were observed: During the first two days after cessation of the supramaximal stimulation a progressive infiltration of the interstitium and the pancreatic tissue with polymorphonuclear leucocytes, lymphocytes and macrophages occurred which led to further destruction of the gland and to decreased functional response. From two days after the cessation of the treatment, hypertrophy of centro-acinar cells and an increased rate of mitotic activity indicated regeneration of the pancreas. This was combined with an accelerated in vitro discharge of newly synthesized proteins over a period of four days. Between days three and six after the initial treatment mitotic activity was also observed in fully differentiated exocrine cells. Total structural and functional recovery of the pancreas was achieved nine to twelve days after the cessation of the supramaximal stimulation.

An Apolipoprotein Homolog of Rat Apolipoprotein A-IV in Human Plasma

Abstract: A protein with properties similar to apoprotein A-IV of Rat high-density lipoproteins has been isolated from the lipoprotein fraction (δ < 1.006 g/ml) of individual non-fasting hypertriglyceridaemic subjects. The Mr of human apolipoprotein A-IV determined by polyacrylamide-gel electrophoresis in sodium dodecylsulfate and by column chromatography in 6 M guanidine hydrochloride is 46000. The amino acid composition is significantly different from any previously characterised human apolipoprotein but resembles that of rat apolipoprotein A-IV. The N-terminal amino acid of human and rat apolipoprotein A-IV is glutamate or glutamine. The pI of the major human A-IV band in 6 M urea is ∼ 5.15. Immunochemically apolipoprotein A-IV is not identical with any of the well known human apolipoproteins. Human apolipoprotein A-IV is present in all fractions of δ < 1.006 g/ml isolated by a single ultracentrifugal spin from non-fasting subjects, but is lost from lipoproteins of δ < 1.006 g/ml upon recentrifugation. Immunoelectrophoretic studies show that most of human apolipoprotein A-IV is present in the fraction of δ > 1.21 g/ml and is unassociated with the major lipoprotein fractions in serum. Charge-shift electrophoresis however clearly demonstrates the hydrophobic character of human apolipoprotein A-IV. There is evidence that apolipoprotein A-IV is a constituent of chylomicrons that is removed from the particle surface when chylomicrons enter the plasma compartment.

Electron spin resonance and hopping conductivity of a-SiOx

Abstract: Amorphous SiOx-layers with O < x < 2 have been prepared by evaporation of Si at oxygen pressures of 10−6 … 10−3 mbar. The composition of the samples was determined by proton backscattering. The band gap, derived from optical measurements, increases with rising oxygen content relatively little at first and the main enhancement occurs above x = 1.5. The ESR spectrum consists of two structures: (1) a relatively broad line A with g-value and linewidth depending considerably on composition, particularly after irradiation with He+-ions of 250 keV energy, and (2) a narrow line B with g ≈ 2.0001 which corresponds to the E′-center in SiO2 and increases in intensity with rising oxygen content. The properties of the broad line A can be described by a superposition of 3 lines with different g-values and linewidths. The hopping conductivity after He+-irradiation decreases strongly with increasing oxygen content indicating that the E′-center does not contribute to the hopping transport.

A hopping model for activated charge transport in amorphous silicon

Abstract: A variable-range hopping model is examined for transport in a band tail. For an exponential density of states the difference of the activation energies of conductivity and thermoelectric power, ΔE, is essentially determined by the steepness of the tail. ΔE varies slowly with tempera ture and depends little on the localization length α of the wave functions and on the magnitude of the density of states. From comparison of the results with experimental data it is suggested that this model applies to activated transport in n-type amorphous silicon. Mit Hilfe eines „variable-range-hopping”-Modells wird der Transport in Bandauslaufern untersucht. Der Unterschied ΔE der Aktivierungsenergien von Leitfahigkeit und Thermokraft wird hauptsachlich vom Abfallparameter α der exponentiellen Zustandsdichte bestimmt. ΔE variiert schwach mit der Temperatur. Die Grose der Zustandsdichte und die Lokalisierungslange haben einen kleinen Einflus auf ΔE. Der Vergleich mit experimentellen Daten legt die Anwendbarkeit dieses Modells auf amorphes Silizium nahe.

Carbon isotope fractionation by Methanobacterium thermoautotrophicum

Abstract: The fractionation of carbon isotopes by Methanobacterium thermoautotrophicum was studied during growth of the bacterium on H2 plus CO2 as sole carbon and energy sources. A 80% H2/20% CO2 gas mixture was continuously bubbled through the culture. At high gassing rates, in the absence of a “closed system effect”, cells and methane were found to be depleted in 13C relative to CO2 in the gas mixture by 2.4% and 3.4%, respectively. At low gassing rates, when more than 90% of the CO2 was converted to methane, the cells were enriched in 13C by 1.3% and methane was depleted in 13C by 0.5%; residual CO2 was enriched in 13C by 3.4%. The magnitude of isotope fractionation suggests that CO2 rather than bicarbonate is the active species of CO2 mainly utilized in both CO2 assimilation and CO2 reduction to methane. The apparent positive 13C-discrimination in cell carbon synthesis, which was observed at low gassing rates, indicates that most of the CO2 assimilated into cell material is not incorporated via reactions involved in CO2 reduction to methane.

Nickel requirement for carbon monoxide dehydrogenase formation in Clostridium pasteurianum

Abstract: Formation of carbon monoxide dehydrogenase in growing Clostridium pasteurianum was found to be dependent on trace nickel present as contaminant in the growth medium. The evidence is: i) Synthesis of the enzyme was increased, when NiCl2 (0.1 μM) was added to the medium; ii) Synthesis of the enzyme was almost completely inhibited when the cells were grown in the presence of nitrilotriacetate (0.1 mM) or of other chelating agents, which inhibited the uptake of trace nickel from the medium; iii) Inhibition of enzyme synthesis by the chelators could be specifically overcome by supplementing the medium with nickel (1μM).

Photomovement of motile microorganisms

Abstract: Introduction Photoreception (a) Photomovement coupled with photosynthesis (b) Blue light responses (c) Other photoreceptor systems Sensory transduction (a) Chemical transmitters (b) Sensory transduction by electrical potential changes (c) Sensory transduction in phototaxis of flagellates Motor responses (a) Bacteria (b) Blue-green algae (c) Diatoms (d) Red algae (e) Desmids (0 Flagellates (8) Slime molds ElTects of internal and external factors References

Magnetic susceptibility of metallic and nonmetallic expanded fluid cesium

Abstract: In this paper the first magnetic-susceptibility results for a fluid metal are reported, which cover a wide range of expansion between the normal melting point and conditions near the critical point. Measurements have been performed for fluid Cs at saturation conditions up to 1680\ifmmode^\circ\else\textdegree\fi{}C and 98 bar, that is 70\ifmmode^\circ\else\textdegree\fi{}C below the critical temperature. In the expanded liquid state, the mass susceptibility first decreases slightly, followed by a strong rise with increasing expansion by almost a factor of 5. A pronounced paramagnetic maximum is observed near 1600\ifmmode^\circ\else\textdegree\fi{}C, corresponding to about double the critical density and a dc conductivity of about ${10}^{3}$ ${\ensuremath{\Omega}}^{\ensuremath{-}1}$ ${\mathrm{cm}}^{\ensuremath{-}1}$ This susceptibility enhancement indicates that the metal-nonmetal transition in fluid Cs might be of the Mott-Hubbard type. In the nonmetallic-dense-vapor phase, the susceptibility data give direct evidence for the existence of a high amount of diamagnetic molecular associations, like ${\mathrm{Cs}}_{2}$ molecules.

Electrical properties of unusual ionic melts

Abstract: The paper reviews the advances that have been made in recent years in the understanding of electrical transport in fully ionized molten salts, partly dissociated molecular liquids and liquid ionic stoichiometric alloys like CsAu. Special emphasis is placed on the recently observed temperature and pressure induced gradual transition between the limiting cases of molecular insulators and ionic melts. At supercritical temperatures salts undergo a continuous transition from an insulating vapour to a highly conducting ionic fluid if the density is increased sufficiently. This transition is due to a shift of the ionization equilibrium between molecules and ions, in favour of the ions, with increasing density. Poorly conducting molten salts and polar substances like water and ammonia also become more ionic, and consequently better conductors, at very high pressures. Recent thermodynamic, magnetic and electrical measurements on liquid alloys which are composed of two metallic elements and which are non-m...

Acetate and carbon dioxide assimilation by Desulfovibrio vulgaris (Marburg), growing on hydrogen and sulfate as sole energy source

Abstract: Desulfovibrio vulgaris (Marburg) was grown on hydrogen plus sulfate as sole energy source and acetate plus CO2 as the sole carbon sources. The incorporation of U-14C acetate into alanine, aspartate, glutamate, and ribose was studied. The labelling data show that alanine is synthesized from one acetate (C-2 + C-3) and one CO2 (C-1), aspartate from one acetate (C-2 + C-3) and two CO2 (C-1 + C-4), glutamate from two acetate (C-1−C-4) and one CO2 (C-5), and ribose from 1.8 acetate and 1.4 CO2. These findings indicate that in Desulfovibrio vulgaris (Marburg) pyruvate is formed via reductive carboxylation of acetyl-CoA, oxaloacetate via carboxylation of pyruvate or phosphoenol pyruvate, and α-ketoglutarate from oxaloacetate plus acetyl-CoA via citrate and isocitrate. Since C-5 of glutamate is derived from CO2, citrate must have been formed via a (R)-citrate synthase rather than a(S)-citrate synthase. The synthesis of ribose from 1.8 mol of acetate and 1.4 mol of CO2 excludes the operation of the Calvin cycle in this chemolithotrophically growing bacterium.

Sialic-acid content of low-density lipoproteins controls their binding and uptake by cultured cells.

Abstract: The (high-affinity receptor)-mediated uptake of homologous low-density (low-rho) lipoproteins by cultured human arterial smooth muscle cells or human skin fibroblasts is controlled by the sialic acid content of low-rho lipoprotein particles This conclusion is derived from the following results 1 Gangliosides incubated with native low-rho lipoproteins associate with low-rho lipoprotein particles Low-rho lipoproteins modified by associated GLac1, GGtet1, and GGtet2b + GGtet3 gangliosides are internalized by arterial smooth muscle cells at a rate up to 80% lower than native low-rho lipoproteins or those preincubated with desialized gangliosides 2 The inhibitory effect of gangliosides is specific for high affinity uptake and not detectable on skin fibroblasts deficient in low-rho-lipoprotein receptor 3 Desialyzed low-rho lipoproteins are internalized by smooth muscle cells up to 100% faster than native low-rho lipoproteins, the enhancement of uptake corresponding to the degree of desialization

Investigations with bioactivated polymethylmethacrylates.

Abstract: Compound bone cement on a PMMA base with an additive of bioactive glass ceramic particles in different portions and different particle sizes are tested in animal experiments. The tissue reactions to extracorporal polymerized specimens and to in situ polymerized specimens are observed. The experiments with an implantation period up to six months demonstrate a tight bonding between the newly formed osseous tissue and the glass ceramic particles at the interface. The inflammatory reactions in the vicinity of the implant are small. It is the objective of the investigations to improve the adherance of the bone cement at the interface to achieve a more durable anchorage of bone cement in the tissue.

Echolocation and obstacle avoidance in the hipposiderid batAsellia tridens

Abstract: The echolocation sounds of the hipposiderid batAsellia tridens consist of a constant frequency (cf) component followed by a frequency modulated (fm) terminal downward sweep of 19–21 kHz. The cf-part constitutes about 7/10 of the entire signal. In individual roosting animals the frequencies of the cf-part of consecutive sounds (resting frequency) is kept very constant but varies from bat to bat. In 18Asellia tridens resting frequencies between 111–124 kHz have been measured.

Electrical and thermodynamic properties of mercury in the metal-semiconductor transition range

Abstract: The paper presents accurate experimental results for the electrical conductivity σ, the equation of state and its derivatives such as isothermal compressibility, thermal expansion coefficient and thermal pressure coefficient, as a function of pressure and temperature to 2500 bar and 1580°C, respectively. Special consideration is given to the range of densities d smaller than 9 g cm−3. The results give considerable evidence, that a temperature-dependent mobility gap (E c − E f) occurs for d < 9 g cm−3. The variation of (E c − E f) with d and T, which is determined from a logarithmic plot of σ versus 1/T and the thermoelectric power S, suggests that (E c − E f) vanishes at d about 8.8 g cm−3. The value of σ0 is about 140–200 ohm−1 cm−1 and in excellent agreement with the prediction of Mott (1971). An attempt is made to analyse the equation-of-state data in terms of a rigid-sphere model. The results indicate the first evidence for a change from metallic cohesion to another interatomic force law in t...

Transport in lithium-doped amorphous siliconf

Abstract: Conductivity (σ) and thermopower (S) data are presented for an amorphous Si film prepared by the glow-discharge technique and doped step-by-step by implantation of 20 keV Li ions. The results are similar to those obtained by doping with phosphorus from the gas phase. By an analysis of In σ+ [eS/k] it is shown that for all doping steps the transport mechanism does not change with temperature. Thus, there is no indication of two-channel transport via localized and extended states. The mobility is found to be activated with an activation energy varying from 0.1 to 0.2 eV depending on the doping rate, while the prefactor of the conductivity is rather insensitive to doping. It is shown that the statistical shift of the Fermi level must be quite large at medium and high doping levels in order to account for the experimental data.

Manifolds of equivalent path integral solutions of the Fokker-Planck equation

Abstract: Path integral solutions of the multi-dimensional Fokker-Planck equation with variable dependent diffusion coefficients are deduced in a simple and exact manner. We show that the Onsager-Machlup function is not defined uniquely but is definable only together with the discretization prescription and the measure in the functional space. We present wide classes of mathematical equivalent path integral representations characterized by nonlinear variable transformationsv(q′, q) and the coefficientsαK of a linear combination, all giving exactly the same solution of the Fokker-Planck equation.

Ecdysteroids in the adult male blowflyCalliphora vicina

Abstract: Male adult blowflies contain ecdysteroids. A considerable amount of ecdysteroid is concentrated in the testes and gives rise to a high local concentration. Analysis by high performance liquid chromatography and thin-layer chromatography indicate that ecdysterone is the most prominent ecdysteroid in male flies. The results can explain several hormone-dependant processes.

Myogenic tumours of the larynx.

Abstract: The pathology and clinical course of the very rare tumours of the smooth and striated muscles of the larynx are described. The literature is reviewed and personal cases of angioleiomyoma, leiomyosarcomas, rhabdomyoma, and rhabdomyosarcoma are reported.

NADPH-Dependent Thioredoxin Reductase and a New Thioredoxin from Wheat

Abstract: Abstract An album in fraction extracted from wheat flour contains thioredoxin reductase (Mr = 65,000) and a heat-stable thioredoxin (Mr = 15,000) which are separated on DEAE cellulose and further purified by gel filtration. W heat thioredoxin stimulates E. coli ribonucleotide reductase but not chloroplast fructose-bis-phosphatase. The enzyme is NADPH -dependent (Km = 3.2 X 10-6 ᴍ) . In presence of the thioredoxin it slowly reduces other proteins like insulin or ribonuclease. Therefore it is most likely identical with a protein disulfide reductase (of unknown specificity) previously described in wheat. This new thioredoxin system is a counterpart of the ferredoxin-dependent system found in photosynthetic plant cells, suggesting different, specific mechanisms for regeneration of reduced thioredoxins in germinating seeds and green plants.

Adaptive liver growth induced by xenobiotic compounds: its nature and mechanism.

Abstract: Several drugs and environmental pollutants which are known to stimulate hepatic drug-metabolizing enzyme activity, liver growth, and multiplication of the endoplasmic reticulum, have recently been found to produce liver tumors in rodents. These “xenobiotic” agents include phenobarbitone, steroid hormones such as cyproterone acetate (CPA) or norethisterone, and organochlorine compounds such as DDT, hexachlorocyclohexane (HCH, lindane), hexachloroben-zene etc. Available evidence suggests that the prolonged induction of growth is responsible for the tumorigenic activity of these agents. Therefore it seems useful to consider some findings relevant to an understanding of the nature and mechanism of the induced growth.

Optical spectra of glow-discharge-deposited silicon

Abstract: The reflectance and the imaginary part e2 of the dielectric function of glowdischarge-deposited silicon (g-Si) have been investigated in the energy range between 1 and 10 eV. The spectra depend strongly on the deposition temperature but do not change much after annealing. The e2 peak, which is considerably larger in g-Si than in evaporated films, occurs also at higher energy, namely 3·55 eV. We assume that this results from an improvement of the covalent network by the incorporation of hydrogen. Decreasing deposition temperature reduces the oscillator strength of the optical transitions, particularly at high energy and this is interpreted as due to an increasing localization of the deeper-lying valence states.