Showing papers by "University of Marburg published in 1984"

Characterization of DNA sequences through which cadmium and glucocorticoid hormones induce human metallothionein-IIA gene.

Abstract: Deletion experiments have defined two stretches of DNA (genetic elements), lying close to the promoter for a human gene for metallothionein, that separately mediate the induction of the gene by heavy metal ions, particularly cadmium, and by glucocorticoid hormones. The element responsible for induction by cadmium is duplicated, yet a single copy is fully functional; the element responsible for induction by glucocorticoid hormones is coincident with the DNA-binding site for the glucocorticoid hormone receptor.

Controlled death (apoptosis) of normal and putative preneoplastic cells in rat liver following withdrawal of tumor promoters.

Abstract: Numerous drugs, hormones and environmental pollutants induce liver growth by hypertrophy and/or hyperplasia, and promote preferential growth of putative preneoplastic foci in the liver. In the present study the regression of hyperplasia after cessation of inducer/promoter treatment was studied in normal liver and in liver foci. High doses of cyproterone acetate (CPA), a synthetic sex steroid, were administered to rats and produced a doubling of liver size; after cessation of treatment liver size declined, and 27% of the total liver DNA disappeared within 6 days. In histological sections from the involuting liver no necroses, but numerous apoptotic bodies (ABs) were found; retreatment with CPA interrupted the formation of ABs. These findings suggest that elimination of excess liver DNA after cessation of CPA treatment is due to controlled cell death by apoptosis. In a further series of experiments putative preneoplastic foci were produced by a single dose of N-nitrosomorpholine and subsequently stimulated to grow by 10 or 28 weeks of phenobarbital (PB) treatment. After withdrawal of PB numerous ABs were present in normal liver and in the foci; in both, retreatment with PB decreased the appearance of ABs. It appears that inhibition of cell death by PB may contribute to tumour promotion. Under all conditions tested more ABs were found in the foci than in non-focal parts of the liver, suggesting an enhanced cell turnover in foci. The apparent sensitivity of foci to mechanisms controlling cell death might eventually provide a means for elimination of preneoplastic lesions.

Apolipoprotein E phenotypes and hyperlipidemia.

Abstract: Apolipoprotein E phenotypes were determined in 361 patients with hyperlipidemia and in controls. The E2 isoform was significantly more frequent in the group of hyperlipidemics (P P>0.005), ii) that isoform E4 was significantly more frequent in patients with hypercholesterolemia (0.01>P>0.005) and iii) that isoforms E2 (P>0.005) and E4 (0.05>P>0.025) were both more frequent in patients with mixed hyperlipidemia. Roughly 20% of patients with mixed hyperlipidemia had one of the rare phenotypes E-4/4,-4/2 or-2/2. We conclude that alleles e2 and e4 both contribute to the susceptibility for, and/or phenotypic expression of hyperlipidemia. Whereas the gene e2 seems to exert its influence on plasma lipoproteins by an abnormal gene product (E2) that has reduced binding activity to lipoprotein receptors, the mechanism underlying the association of the e4 gene with hyperlipidemia is presently unclear.

Radiobiological advanced biostack experiment

Abstract: The radiobiological properties of the heavy ions of cosmic radiation were investigated on Spacelab 1 by use of biostacks, monolayers of biological test organisms sandwiched between thin foils of different types of nuclear track detectors. Biostacks were exposed to cosmic radiation at several locations with different shielding environments in the module and on the pallet. Evaluations of the physical and biological components of the experiment to date indicate that in general they survived the spaceflight in good condition. Dosimetric data are presented for the different shielding environments.

Physiology and Pathophysiology of Neutral Proteinases of Human Granulocytes

Abstract: The occurence of proteolytic enzymes in polymorphonuclear granulocytes was first demonstrated in 1888 by the famous clinician and biochemist Friedrich von Muller1 who showed that a glycerine extract of fresh pus digests fibrin or coagulated protein at a neutral or weakly alkaline pH. Later on at the end of the last and the beginning of this century further characterization of the enzymes including their serum antiproteases was achieved by German and American scientists2,3,4. However, the neutral proteases then became largely forgotten as the result of the attention paid to the acid-cathepsins of the rabbit leukocyte, a convenient but somewhat misleading cell.

Charge transport in molecularly doped polymers

Abstract: This paper re-examines literature data on the charge-carrier mobility in tri-phenyl methane/polycarbonate, triphenyl amine/lexan and PVK: TNF composite systems. In all cases the dependence of μ on both temperature T and electric field E, as well as its absolute magnitude, can be interpreted consistently in terms of hopping across a Gaussian density-of-states distribution of width σ. The exponential dependence of μ on T −2 and E predicted by computer simulation and analytic theory for transport in the long-time limit are recovered. The essential parameters that control μ are μ0= lim μ(T) which is the mobility of the hypothetical crystalline counterpart structure, and σ. The latter quantity increases with increasing polarity of the constituent molecules and is responsible for the variation of μ upon chemical substitution reported for the triphenyl methane polycarbonate system.

The Defect Correction Approach

Abstract: This is an introductory survey of the defect correction approach which may serve as a unifying frame of reference for the subsequent papers on special subjects.

Thermal sensibility changes during ischemie nerve block

Abstract: Changes in perception of pure thermal stimuli delivered to the hand at threshold intensity were observed during ischemic nerve block in 27 healthy subjects in order to study the significance of unmyelinated cutaneous cold receptors for thermal sensibility. Paresthesias and an increasing feeling of numbness were followed by a sudden change in cold sensation which developed a clearly dysesthetic quality. When complete motor block was reached and no myelinated axon functions were left, cold stimuli were still clearly but abnormally perceived. Warm sensation was little affected during the whole course of nerve block. The results indicate that the information from unmyelinated low threshold cold receptors alone leads to a dysesthetic cold sensation which normally is suppressed by the activity of myelinated cold afferents. Obviously these receptors are not needed for the discrimination of minor cold stimuli but they seem to be essential for the perception of the first burning cold pain.

Foraging in male bumblebees ( Bombus lucorum L.): maximizing energy or minimizing water load?

Abstract: The O2, CO2, and H2O exchange of single flying male bumblebees (Bombus lucorum and B. terrestris) were measured simultaneously. A respiratory quotient RQ=1 was found for all activities investigated (torpor-flight). The dependence of respiratory CO2 production in flight on body-weight was measured: for a 220-mg male bumblebee it amounts to 24.5 mg CO2/h (=56.4 ml O2/g·h). The corresponding evaporative water loss amounts to 6 mg H2O/h. Males tranferred to a climatic test chamber and conditioned to artificial flower feeders started to fly, after a few days of acclimatization, in typical scent-marked flight-paths. The daily pattern of flight activity was recorded: the mean total time in flight amounts to 244 min, and the corresponding daily flight length is about 17 km. At 20°C and 50% relative humidity (RH) a daily uptake of 180 μl (≙ 220mg) of 50% sugar solution was measured, equal to the mean body weight of the male bumblebees. Since the body weight remains constant on consecutive days a 24-h energy- and water-budget could be calculated. The energy-budget is balanced; the activities observed can be fuelled with the sugar available. About 70% of the energy is used for the 4 h of flight activity. With the daily nectar volume 110 mg of water is ingested; in the oxidation of 110 mg sugar, 66 mg of metabolic water is produced and 40 mg water is dissipated by the evaporative water-loss. Thus, to have a balanced water-budget, 136 mg of water must be voided in 24 h, which equals the total body-water of the bumblebees. Nectar is a nutrient of high water content which not only provides the sugar necessary for activity but also, in most circumstances, an excess of water. The effect of this high water load in limiting daily activity is discussed and compared with the water- and osmoregulation of hummingbirds. The strategy of maximizing energy for a male bumblebee must be one of minimizing water load.

Effect of an extract of Ginkgo biloba on rat brain energy metabolism in hypoxia.

Abstract: The purpose of the present investigation was to determine brain energy metabolism under hypoxic conditions as influenced by an extract of Ginkgo biloba (EGB). Male Sprague-Dawley rats treated with EGB were exposed to hypobaric or hypoxic hypoxia, and at various time points during or after hypoxia the levels of high-energy phosphates and some substrates of glycolysis were measured in brain cortical tissue. Rats treated with EGB (100 mg/kg, intraperitoneally) survived hypobaric hypoxia for a much longer period than controls (e.g. controls: 3.9±1.8 min, EGB-treated: 23.6±10.5 min). The brain glucose level was elevated by EGB in most experimental series, and the lactate concentration was slightly lower than in control brains. The lowering of lactate/pyruvate ratio was due to the decreased level of lactate and to the enhanced concentration of pyruvate as well. When hypoxia was sufficiently severe the breakdown of high-energy phosphates was less pronounced in EGB-treated animals. After oral application of EGB for 14 days the rats survived hypobaric hypoxia for 25.7± 2.5 min whereas controls survived for 11.5±5.1 min. However, brain energy metabolism was not significantly influenced by this oral treatment. It is suggested that changes in brain energy metabolism and blood flow may contribute to the protective effect of EGB against hypoxia.

Catalysis of an isotopic exchange between CO2 and the carboxyl group of acetate by Methanosarcina barkeri grown on acetate

Abstract: Cell suspensions of Methanosarcina barkeri (strain Fusaro) grown on acetate were found to catalyze the formation of methane and CO2 from acetate (30–40 nmol/min·mg protein) and an isotopic exchange between the carboxyl group of acetate and 14CO2 (30–40 nmol/min·mg protein). An isotopic exchange between [14C]-formate and acetate was not observed. Cells grown on methanol mediated neither methane formation from acetate nor the exchange reactions. The data indicate that the isotopic exchange between CO2 and the carboxyl group of acetate is a partial reaction of methanogenesis from acetate. Both reactions were completely inhibited by low concentrations of cyanide (20 μM) or of hydrogen (0.5% in the gas phase). Methane formation from acetate was also completely inhibited by low concentrations of carbon monoxide (0.2% in the gas phase) whereas only significantly higher concentrations of CO had an effect on the exchange reaction. In the concentration range tested KCN, H2 and CO had no effect on methane formation from methanol or from H2 and CO2; however, cyanide (20 μM) also affected methane formation from CO. The results are discussed with respect to proposed mechanisms of methane and CO2 formation from acetate.

Photopolymerization of diacetylenes

Abstract: This article reviews the current state of art of photopolymerization of crystalline diacetylenes, although complementary information on thermal and γ-polymerization is also included whenever felt appropriate. Priority is given to an outline of recent achievements regarding reaction kinetics and energetics as well as to model considerations for both initiation and propagation of the polymer chain. It will be shown that at least for diacetylene-bis(p-toluenesulfonate) (TS) existing experimental data allow establishing a consistent picture of the polymerization process. After discussing recent works on photopolymerization in Langmuir-Blodgett-multilayer assemblies, including sensitization and self-sensitization effects, potential applications of the unusual optical, electrical, and reaction properties of diacetylenes are outlined.

A Fast Correlation Method for Scale-and Translation-Invariant Pattern Recognition

Abstract: A size- and position-invariant description of an image function can be obtained via the absolute value of the Mellin transform of its Fourier amplitude spectrum. If the transform is implemented on a digital computer via a discrete Fourier-Mellin transform, these exact invariances are not preserved due to sampling-and border-effects. In this paper these effects are discussed, and an alternative correlation method is proposed. The method consists of calculating the normalized absolute magnitude of the discrete Fourier transform (DFT) of the image function (which gives invariance to translation and multiplicative amplitude changes) and a subsequent logarithmic distortion in x- and y- direction, which converts scaling to translation. Two such transforms are compared by calculating the normalized Euclidean distances between both for all possible relative shifts along the main diagonal. If, for some shift, the distance has a minimum below a similarity threshold, the underlying image functions will probably differ only by translation and scaling. The magnitude of this shift is related to the scale factor between the objects. Good separation between similar and nonsimilar objects is possible if two size criteria imposed by the DFT are met: the total object size must not exceed N/4 (N is the number of image points in each dimension), and object details have to be larger than about 4 image points. As a consequence, N increases with object complexity and desired scale range.

Zur Kenntnis des Faktors F430 aus methanogenen Bakterien: Struktur des proteinfreien Faktors

Abstract: Factor F430 from Methanogenic Bacteria: Structure of the Protein-free Factor Factor F430, the porphinoid nickel-containing coenzyme of the methylcoenzyme-M reductase of metanogenic bacteria is shown to be the 33,83,122,133,182-pentaacid derivative of the pentamethylester F430M, the structure of which had been determined previously (see structural formulae 1 and 2). The structure assignment rests on chromatographic, UV/VIS-, CD-, IR-, and 13C-NMR-spectroscopic as well as FAB-mass spectral comparision of F430 with F430M and the pentaacid prepared by acid-catalyzed hydrolysis of F430M. In the cells of Methanobacterium thermoautotrophicum, factor F430 is present in a ‘bound’ and also, depending on the growth conditions, in ‘free’ form, the latter being defined as the part of total F430 that can be extracted from the cells under extremely mild conditions (80% EtOH at 0–4°). From the (protein)-‘bound’ form, F430 is extracted by subsequently treating the cells at 0–4° with 80% EtOH containing (e.g.), 2m LiCi. From both sources, the extracted factor is the same pentaacid, and there is no indication for the existence of a protein-free F430 species that would contain additional (covalently bound) structural elements.

Growth yields and saturation constant of Desulfovibrio vulgaris in chemostat culture

Abstract: Desulfovibrio vulgaris (strain Marburg) was grown on H2 and sulfate as sole energy source in a chemostat limited by the sulfate supply. The biomass concentration and the sulfate concentration in the culture were determined as a function of the dilution rate. From the data a K S (saturation constant) for sulfate of 10 μM, a μmax of 0.23 h−1, and a $${\text{Y}}_{{\text{SO}}_{\text{4}} ^{2 - } }^{{\text{max}}}$$ of 13 g/mol were calculated. The organism was also grown in chemostat culture on H2 and sulfite, H2 and thiosulfate, and pyruvate (without sulfate). $${\text{Y}}_{{\text{SO}}_3 ^{2 - } }^{{\text{max}}}$$ was found to be 35 g/mol, $${\text{Y}}_{{\text{S}}_{\text{2}} {\text{O}}_{\text{3}} ^{2 - } }^{{\text{max}}}$$ 36 g/mol, and Y pyr max 10 g/mol. The growth yields are discussed with respect to ATP gains in dissimilatory sulfate reduction.

A model for size- and rotation-invariant pattern processing in the visual system

Abstract: The mapping of retinal space onto the striate cortex of some mammals can be approximated by a log-polar function. It has been proposed that this mapping is of functional importance for scale- and rotation-invariant pattern recognition in the visual system. An exact log-polar transform converts centered scaling and rotation into translations. A subsequent translation-invariant transform, such as the absolute value of the Fourier transform, thus generates overall size- and rotation-invariance. In our model, the translation-invariance is realized via the R-transform. This transform can be executed by simple neural networks, and it does not require the complex computations of the Fourier transform, used in Mellin-transform size-invariance models. The logarithmic space distortion and differentiation in the first processing stage of the model is realized via "Mexican hat" filters whose diameter increases linearly with eccentricity, similar to the characteristics of the receptive fields of retinal ganglion cells. Except for some special cases, the model can explain object recognition independent of size, orientation and position. Some general problems of Mellin-type size-invariance models-that also apply to our model-are discussed.

Chemotactic, magnetotactic and tactile behaviour in a magnetic spirillum

Abstract: Cells of a magnetic spirillum exhibited a chemotactic (aerotactic) response when suspended in a solution of 2-mercaptoethanesulfonate, mercaptoethanol, or thioglycolate. In a slide preparation masses of cells formed bands. Cells in a band reversed their direction of motility along the applied magnetic lines of force without turning; the tactile response of cells occurred in a similar manner. It is proposed that in nature possession of an intracellular magnet allows the microaerophilic cell to pursue the most efficient aerotactic behaviour; orientation in the geomagnetic lines of force eliminates the need for twiddling, long runs and short runs.

Self-injurious behavior in institutionalized, severely/profoundly retarded adults—Prevalence data and staff agreement

Abstract: Staff agreement on the identification of 18 different types of self-injurious behavior (SIB) and the prevalence of SIB were assessed in a population of 91 severely and profoundly retarded residents in a large facility for mentally retarded people in West Germany (FRG). The survey included 27 direct care staff; groups of three to five rated the behavior of 8 to 27 residents from their own wards. Agreement was calculated with two different formulas for multiple raters. The data suggest that the standard definition of SIB [Tate, B. G.,& Baroff, G. S. (1966).Behavior Research and Therapy, 4, 281–287], together with a list of the most common SIB topographies, yields variable and generally low staff agreement. The data for the prevalence statistics were derived from cases in which at least 50% of the staff had indicated the occurrence of an SIB topography in a resident. Sixty of the 91 residents exhibited some form of SIB; of these, 15 demonstrated only one type, 12 two, and 33 three or more SIB topographies. The data corroborate the notion of the two taxonomic classes of “social and “nonsocial” SIB. Contrary to other classifications the data indicate that “ruminative vomiting” belongs to the social SIB class.

Isolation, characterisation and crystallization of deoxyribonuclease I from bovine and rat parotid gland and its interaction with rabbit skeletal muscle actin

Abstract: A purification procedure is described yielding DNase I from bovine and rat parotid glands of high homogeneity. The apparent molecular masses of the DNases I isolated have been found by sodium dodecyl sulfate/polyacrylamide gel electrophoresis to be 34 and 32 kDa for bovine and rat parotid DNase I, respectively, and thus differ from the enzyme isolated from bovine pancreas (31 kDa). By a number of different criteria concerning their enzymic behaviour, the isolated enzymes could be clearly classified as DNases I, i.e. endonucleolytic activity preferentially on native double-stranded DNA yielding 5′-oligonucleotides, a pH optimum at about 8.0, the dependence of their enzymic activity on divalent metal ions, their inhibition by 2-nitro-5-thiocyanobenzoic acid and by skeletal muscle actin. Comparison of their primary structure by analysis of their amino acid composition and also two-dimensional fingerprints and isoelectric focusing indicate gross similarities between the enzymes isolated from bovine pancreas and parotid, but distinct species differences, i.e. between the enzymes isolated from bovine and rat parotid. All the DNases I are glycoproteins. From bovine parotid DNase I crystals suitable for X-ray structure analysis could be obtained. The DNases I from both parotid sources specifically interact with monomeric actin forming 1:1 stoichiometric complexes. Their binding constants to monomeric actin differ, being 2 × 108 M−1 and 5.5 × 106 M−1 for bovine and rat parotid DNase I, respectively. Only the enzyme isolated from bovine sources is able to depolymerize filamentous actin.

Apolipoprotein A‐IGiessen (Pro143→Arg)

Abstract: Apolipoprotein A-IGiessen is a variant form of apo A-I that is displaced from the corresponding normal A-I isoforms on isoelectric focusing gels by a single charge unit towards the cathode [Utermann et al. (1982) J. Biol. Chem. 257, 501–507]. Three subjects heterozygous for the variant were detected in one family. The percentage of the total A-I in plasma represented by the A-IGiessen in these subjects ranged over 25–30%. The variant and normal major A-I isoforms from the proband (Y.J.) were purified by preparative isoelectric focusing and cleaved with CNBr. Analytical focusing of CNBr fragments demonstrated a charge difference between CB3Giessen and normal CB3. Sequence analysis of CB3Giessen revealed that a proline existing in normal A-I was replaced by an arginine in the variant A-I at residue 143. The ability of the mutant A-I to activate purified lecithin:cholesterol acyltransferase was determined in vitro. The cofactor activity of [Arg143]apolipoprotein A-I was about 60–70% of that demonstrated by control A-I. Residue 143 is in a putative β-turn between two of the repeating amphiphilic helices in apolipoprotein A-I and may be a critical determinant of the protein's structure and function.

Acetate synthesis from 2 CO2 in acetogenic bacteria: is carbon monoxide an intermediate?

Abstract: Cultures of Acetobacterium woodii and Clostridium thermoaceticum growing on fructose or glucose, respectively, were found to produce small, but significant amounts of carbon monoxide. In the gas phase of the cultures up to 53 ppm CO were determined. The carbon monoxide production was completely inhibited by 1 mM cyanide. Cultures and cell suspensions of both acetogens incorporated 14CO specifically into the carboxyl group of acetate. This CO fixation into C1 of acetate was unaffected by cyanide (1 mM). The findings are taken to indicate that CO (in a bound form) is the physiological precursor of the C1 of acetate in acetate synthesis from CO2. The cyanide inhibition experiments support the hypothesis that the cyanide-sensitive carbon monoxide dehydrogenase may serve to reduce CO2 to CO rather than to incorporate the carbonyl into C1 of acetate.

Intraoperative angiography in cerebral aneurysm and AV-malformation.

Abstract: The device is constructed for intra-operative angiographic studies. The main features of the unit are: semi-automatic positioning of the tube into preset coordinates, TV camera serving as receptor, reproduction of the videosignal with twice the number of lines compared with that used normally, retrieval technique permitting one to study the flow of the contrast medium in slow motion at the required speed. Further advantages: Intra-operative control of the correct operative technique. No need for postoperative anaesthesia and cerebral angiography.

Stilbene Synthase and Chalcone Synthase Two Different Constitutive Enzymes in Cultured Cells of Picea excelsa

Abstract: Cultured cells of Picea excelsa capable of forming stilbenes and flavanoids have been established. Unlike needles of intact plants containing piceatannol (3,3',4',5-tetrahydroxystilbene) and stilbene glycosides the cultured cells converted phenylalanine and p-coumaric acid primarily into resveratrol monomethyl ether (3,4'-dihydroxy-5-methoxystilbene) and naringenin. Partially purified enzyme preparations were assayed for chalcone synthase as well as for stilbene synthase activity converting malonyl-CoA plus p-coumaroyl-CoA into 3,4',5-trihydroxystilbene (resveratrol).Although stilbene synthase and chalcone synthase use the same substrates and exhibit similar molecular properties, i.e. molecular weight and subunit molecular weight, they are two different proteins. This difference was demonstrated by gel electrophoresis and by means of monospecific antibodies.

Histamine content, diamine oxidase activity and histamine methyltransferase activity in human tissues: fact or fictions?

Abstract: To understand the role of histamine in the aetiology and pathogenesis of human diseases reliable data are urgently needed for the histamine content and for the activities of histamine-forming and-inactivating enzymes in human tissues. In order to make a substantial progress toward this aim a tissue-sampling programme during surgical interventions was carefully conceived and conducted. From March 1982 until January 1983 106 tissue specimens were taken from 56 patients who underwent surgery. Only healthy tissues, not injured or oedematous, and without adherent structures were taken by only one surgeon who was interested in this research and experienced in tissue preparation procedures in biochemistry. The times of ‘warm’ ischaemia during the operative procedures were visually estimated, the times between resection of the organs or specimens and deep-freezing of the tissues were precisely recorded.