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Biomedical subjects

G Jung

Publications and source records attributed to G Jung.

At least 523 records · Page 29Linked to original sources
PubMed1980

The value of the thromboelastogram as means of monitoring the sub-cutaneous preventive action of calcium heparinate.

The index of the thrombodynamic potential (I.T.P.) as one of the biological means of controlling the prophylactic effect of sub-cutaneous injections of Calcium Heparinate has been studied in 34 spinal cord injuries during the acute phase. Individual tolerance variations, some of them important, have been noted as well as the necessity of adjusting the doses, according to the time after injury. A biological hypercoagulability has been noted within the first and third month after injury. The interest and the cost of such a method are discussed and further comparative biological investigations, using other methods, have started.

Female↗
PubMed1980

Herbicolins--New peptide antibiotics from Erwinia herbicola.

Erwinia herbicols (strain A 111) produces two acylated peptide antibiotics herbicolins A and B. Isolation of herbicolins was performed by adsorption on a polystryrol adsorbent followed by elution with methanol. Further purification was achieved by gel filtration on Sephadex LH-20, counter-current distribution or by TLC. Herbicolin A was chemically characterized, containing 2 glycines, 1 L-threonine, 1 D-allo-threonine, 1 D-glutamic acid, 1 D-leucine, 1 L-agrinine and beta-hydroxy myristic acid. Herbicolins A and B are inactive against bacteria, but highly active against yeasts and filamentous fungi.

Anti-Bacterial Agents↗
PubMed1978

The 1H-nmr spectra of mixed valence complexes of copper with derivatives of 1-amino-2,2-dimethyl-2-mercaptoethane.

Paramagnetic cluster ions of the type Cu(II)6Cu(I)8L12ClZ, where Z Is charge and L a derivative of 1-amino-2,2-dimethyl-2-mercaptoethane, have been shown to produce detectable 1H-nmr absorptions. Linewidths are narrow enough to permit the use of high resolution instruments. Downfield shifting of all detectable resonances is indicative of S leads to Cu2+ charge transfer, which results in a positive spin density at sulfur. Exchange measurements with 67Cu indicate relatively static structures.

Chemical Phenomena↗
PubMed1978

[Clinical and histological studies on the effect of a surfactant containing toothpaste on the gingiva].

A clinical double blind trial on 98 volunteers was undertaken with the aid of the SB Index to show the effects on the gum of a tooth paste containing detergents. It resulted in a significant increase of the SBI after 6 weeks of a tooth paste with a high content of surface active substances. With the light microscope changes are demonstrable in the Stratum spinosum which could be identified electron-microscopically as a strong increase of bundles of filament in the cytoplasm. The contradiction between clinical and morphological findings is explained by the assumption that the greatincrease in filament bundles leads to a lowering of the adaptability of the epithelium and consequently to increased tendency to bleed, especially in response to mechanical irritation.

Adult↗
PubMed1978

[Incidence of iron deficiency in a sample-population of Frankfurt children (author's transl)].

Using customary hematological and biochemical criteria, peripheral iron deficiency was observed, depending on age, in 12-51% and anemia in up to 6%, in a sample of 337 children (age: 4 4 months to 10 years). The majority of children were well nourished. Since iron deficiency occurs even in these children, it appears to be important to study this situation in underpriviledged German children as well. Even after peripheral iron deficiency was excluded, hemoglobin concentration varied significantly with age. This has to be considered in order to avoid unnecessary iron medication, that, according to recent findings, could cause adverse effects. The data presented here, do not as yet justify a general iron fortification program for all infants in Germany. Iron research should be directed toward the relationship of iron nutrition and iron-related blood chemistry of children on the one hand, and general criteria of functional capacity, morbidity, and longivity on the other. It will only be possible to give rational definitions of what are normal iron and hemoglobin concentrations in childhood, when we know more about these relationships.

Age Factors↗
PubMed1978

Enzyme-coupled measurement of ethanol in whole blood and plasma with a centrifugal analyzer.

We describe an automated enzymic method for ethanol determination with a centrifugal analyzer (the GEMSAEC) by measuring the rate of the reaction catalyzed by alcohol dehydrogenase and coupled to aldehyde dehydrogenase. The detection limits, reproducibility, and accuracy of the method have been evaluated. It can be applied to whole blood or plasma, with or without previous deproteinization. Our results, compared with those by an automated alcohol dehydrogenase method in the presence of semicarbazide, show an improved linearity, sensitivity, and rapidity of determination.

Alcohol Oxidoreductases↗
PubMed1977

[Enzymatic determination of blood ethanol with centrifugal analyser].

An automated method for ethanol determination on Gemsaec centrifugal fast analyser is described. The measurements have been done by a non linear two-point kinetic method during 10 minutes. The suitability of the proposed method has been evaluated by determination of the detection limit and the recovery. The method is applicated to whole blood and to plasma with and without initial perchloric acid deproteinization. Similar results are obtained for the different samples.

Alcohol Oxidoreductases↗
PubMed1977

[Determination of lactate with centrifugal analyser (Gemsaec) by lactate dehydrogenase in the presence of alanine aminotransferase].

An automated method for lactat determination on centrifugal analyser is described. The measurements have been done by end-point method during 300 seconds. A reagent blank is introduced in each run and its absorbance is deduced from those of the tests. The suitability of the method is assessed, particularly the sensitivity (detection limit) and the accuracy by checking the recovery. The results obtained by the automated and the manual method are well correlated.

Alanine Transaminase↗
PubMed1976

pH dependence of 13C-15N coupling constants of highly 14N-enriched amino acids isolated from mass cultivation of algae.

The alga Ankistrodesmus braunii was grown with [14N]nitrate under optimized conditions of a large-scale mass cultivation. 19.7% of the dried algae were isolated as a mixture of amino acids. The 15N-labelled amino acids (15N content up to 98%) were separated by ion exchange chromatography using pyridine acetate gradients. The 15N cotent of the analytically pure amino acid was determined by combined gas-liquid chromatography-mass spectrometry of the trifluoroacetylated methylesters and by emission spectroscopy in the 15N analysator. Using pulse Fourier transform 13C nuclear magnetic resonance, the pH dependence of the 13C-15N coupling constants of Asp, Pro, Ser, Glu, Gly, Ala, Val, Ile and Leu was determined in aqueous solutions. Increasing coupling constants were found with pH and decreasing electron density, respectively. The relation of Binsch et al. (Binsch, G., Lambert, J.B., Roberts, B.W. and Roberts, J.D. (1964) J.Am. Chem. Soc. 86,5564-5570) between the coupling constant and the product of the S-part of the 13C and 15N hybridization SC - SN = 80 - J (13C-45X) fits best in acidic medium. The magnitude of coupling constants correlates well with the electron densities calculated by Del Re et al. (Del Re, G., Pullman, B. and Yonezawa, T. (1963) Biochim. Biophys. Acta 75, 153-182). The recording of 13C nuclear magnetic resonance spectra over the entire pH range revealed no change in the sign of the 13C-15N coupling constants of the amino acids.

Amino Acids↗
PubMed1976

On the transport of tripeptide antibiotics in bacteria.

The two tripeptide antibiotics L-2-amino-4-methylphosphinobutyryl-alanyl-alanyl-alanine (L-phosphinothricyl-alanyl-alanine) and L-(N5-phosphono)methionine-S-sulfoximinyl-alanyl-alanine, both inhibitors of the glutamine synthetase, are transported into the cell of Escherichia coli K 12 via the oligopeptide transport system. The uptake by this system is proved first of all by cross-resistance with tri-L-ornithine using oligopeptide-transport-deficient mutants, and secondly by antagonism tests demonstrating competitive reversal of the action of the antibiotic by several peptides which have been shown to be transported via the oligopeptide transport system, e.g. tri-L-alanine, tetra-L-alanine, tri-L-lysine, tri-L-serine, tri-glycine, glycyl-glycyl-L-alanine and the synthetic tripeptide L-azadenyl-aminohexanoyl-alanyl-alanine. On the other hand, there is no effect on the action of the antibiotic in antagonism tests with compounds which use different transport systems, such as L-alanyl-alanine, L-lysyl-lysine, glutathione and the synthetic amino acid azaadenylaminohexanoic acid, i.e. 2-amino-6-(7-amino-3H-v-triazolo-[4,5-d]-pyrimidin-3-yl)hexanoic acid. Another inhibitor of the glutamine synthetase, L-methionine-S-dioxide (methioninesulfone) could be converted into a tripeptide form by linkage to L-alanyl-alanine analogously to the tripeptide antibiotics described above. Whereas the free L-methionine-S-dioxide seems to be transported via the methionine transport system, the tripeptide form is transported via the oligopeptide transport system. Thus, this glutamine synthetase inhibitor can be taken up by the cell via two different transport mechanisms. Our results indicate that this could provide a synergistic effect. The syntheses of the new tripeptides L-azaadenylaminohexanoyl-alanyl-alanine and L-methionine-S-dioxidyl-alanyl-alanine were performed by dicyclohexylcarbodiimide couplings of the unusual N-protected L-alpha-amino acids azaadenylaminohexanoic acid and L-methionine-S-dioxide to L-alanyl-alanine-tert-butyl ester followed by common deprotection steps. Tri-L-ornithine was synthesized without carboxyl protection via two successive couplings of hydroxybenzotriazol esters of Nalpha-butoxycarbonyl-Ndelta-benzyloxycarbonyl-L-ornithine.

Anti-Bacterial Agents↗
PubMed1976

[Circular dichroism of heterodetic cyclic cystinyl tripeptides (author's transl)].

The circular dichroism of two series of heterodetic cyclic tripeptides, t-butoxycarbonyl-L-cysteinyl-X-cysteine disulfide methyl esters [X=Ala, Val, Leu, Phe, Glu(OBut), Lys(Z)] and L-cysteinyl-X-cysteine disulfide methyl ester formates, and a corresponding series of t-butoxycarbonyl-L-cysteinyl-(glycyl)n-cysteine disulfide methyl esters (n=1-5) was investigated. The interaction between the disulfide group and the amide bonds results in a long-wavelength Cotton effect at 300 nm, which exhibits a strong solvent dependence. In contrast to the long-wavelength disulfide band and to the n-pi amide Cotton effect a bathochromic shift is observed from less polar to strongly polar solvents. Within the series of N-terminal protected tripeptide esters the influence of the central chiral amino acid X is small, but it increases in the non-protected peptide esters. The circular dichroism is dominated by the influence of the conformation of the disulfide ring, which is essentially the same in both series. Due to interactions of the disulfide group with the amide chromophores, the sign of the long-wavelength disulfide Cotton effect cannot be used for the determination of the helicity of the CSSC group. Infrared spectra of the protected compounds indicate trans-peptide bonds in the solid state, which may also be true for the solutions. A pronounced time-dependence is observed for the circular dichroism of t-butoxycarbonyl-L-cysteinyl-glycyl-cysteine disulfide methyl ester after dissolving in ethanol. This is due to a uniform conformational change of the ring structure as shown by spectroscopic analysis using extinction and ellipticity diagrams. In the series of the cyclic cystinyl peptides containing glycyl residues a strong electronic disulfide-amide interaction is observed is observed for the tripeptide, being still observable for the tetra-peptide. The comparison of the glycyl tripeptide with the tripeptides containing chiral central amino acids reveals a negative contribution to the circular dichroism at 260 nm due to these L-residues.

Circular Dichroism↗
PubMed1976

Structural and membrane modifying properties of suzukacillin, a peptide antibiotic related to alamethicin. Part A. Sequence and conformation.

The primary structure and conformation of the polypeptide antibiotic suzukacillin A are investigated. Suzukacillin A is isolated from the Trichoderma viride strain 1037 and exhibits membrane modifying and lysing properties similar to those of alamethicin. A combined gas chromatographic mass spectrometric analysis of the trifluoroacetylated peptide methyl esters of partial hydrolysates revealed a tentative sequence of 23 residues including 10 2-methylalanines and one phenylalaninol, which shows many fragments known from alamethicin: Ac-Aib-Pro-Val-Aib-Val-Ala-Aib-Ala-Aib-Aib-Gln-Aib-Leu-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-Glu(Pheol)-Gln-OH. All chiral amino acids and phenylalainol have L-configuration. Ultraviolet and infrared spectroscopy, circular dichroism in various solvents and in particular 13C nuclear magnetic resonance have been used for a comparative study of suzukacillin with alamethicin. Suzukacillin has a partially alpha-helical structure and the helix content increases largely from polar to lipophilic solvents. Suzukacillin aggregates more strongly than alamethicin in aqueous medis due to a longer alpha-helical part and higher number of aliphatic residues. A part of the alpha-helix is exceptionally stabilized due to 2-methylalanine residues shielding the peptide bonds from interactions with polar solvents. In lipophilic solvents and lecithin vesicles particularly large temperature induced reductions of the high alpha-helix content are found for alamethicin. Suzukacillin shows similar temperature coefficients in lipophilic media, however, in contrast to alamethicin a more linear change in intensity of the Cotton effects is observed.

Alamethicin↗
PubMed1976

Structural and membrane modifying porperties of suzukacillin, a peptide antibiotic related to alamethicin. Part B. Pore formation in black lipid films.

Suzukacillin, a polypeptide consisting of presumably 23 amino acids and 1 phenylalaninol, is produced by a Trichoderma viride strain No. 1037 and it can be isolated from the culture medium. It shows membrane-modifying properties similar to those of alamethicin. Discrete condustance fluctuations indicate the formation of oligomer pores of varying diameter. On the basis of voltage jump relaxation experiments evidence is given that the dimer is the nucleation state from which pore formation starts and the oligomer disappears. According to the voltage-current characteristics, voltage-dependent and voltage-independent conductances are observed. A slow process is involved, which can be interpreted as a change in the equilibrium distribution between different conformations of the suzukacillin monomer at the membrane interphase. This change results from its interaction with the lipid matrix. Differences in experimental observations between suzukacillin and alamethicin are attributed to the relatively larger alpha-helix and higher number of aliphatic side chains of the suzukacillin monomer and to a more intense interaction with the lipid membrane. This leads to a higher probability of forming dimers from monomers and to the occurrence of "inactivation".

Alamethicin↗