Biomedical subjects

D Thiele

Publications and source records attributed to D Thiele.

9 recordsLinked to original sources

PubMed1992

Evaluation of the polymerase chain reaction (PCR) for detection of Chlamydia psittaci in abortion material from ewes.

The polymerase chain reaction (PCR) was evaluated as a diagnostic tool for detection of Chlamydia (C.) psittaci in abortion material from 40 ewes. For this purpose, PCR results of 87 samples were compared with direct microscopic identification after chemical staining, cell culture isolation and a commercially available enzyme-linked immunosorbent assay (ELISA). The value for sensitivity as compared to cell culture was 97.7% whereas the specificity-value was calculated to be 84.1%.

Abortion, Veterinary↗

PubMed1992

Immunoblot analysis of IgG subclass antibody response against Coxiella burnetii in Balb/c mice.

Balb/c mice were inoculated with live or inactivated organisms of Coxiella burnetii, strain Nine Mile, phase I. Sera collected after different time intervals were subjected to immunoblot analysis and results compared with ELISA values. Immunoblots were performed with different horseradish peroxidase labelled conjugates (goat anti-mouse IgG1, IgG2a, IgG2b, IgG3) and results monitored and analysed by laser densitometry. ELISA analysis was performed using the same peroxidase labelled goat anti-mouse subclass antibody conjugates. In addition, goat anti-mouse IgG(H+L), IgG(H), IgM, and IgA conjugates were used for ELISA tests.

Animals↗

PubMed1979

Alcohol metabolism in man: effect of intravenous fructose infusion on blood ethanol elimination rate following stimulation by phenobarbital treatment or chronic alcohol consumption.

The effect of phenobarbital (PB) pretreatment and of chronic alcoholism on blood ethanol elimination rate (BEER) was investigated in man. In order to gain additional information concerning the mechanism of possible changes BEER was determined before and during intravenous infusion of fructose, a compound known to increase the NADH-oxidizing capacity of the liver and thereby stimulating alcohol oxidation rate. Following PB-treatment (300 mg/day for 5-6 days, n = 8) a marked increase in unstimulated (U-) BEER was obtained. But the fructose stimulated (FS-) BEER was not significantly changed by PB-treatment. In chronic alcoholics (n = 15) U-BEER values above the upper limit (chi + 2 S D) obtained in healthy controls, were observed only when the time of sobriety was less than one week (n = 6). Values of FS-BEER in chronic alcoholics with increased basal alcohol oxidation rates were in the same range as those of healthy controls. In 5 out of the 6 alcoholics in whom the values were elevated on admission, BEER decreased significantly after withdrawal of alcohol for 2-4 weeks. Since FS-BEER was nearly identical in all conditions tested, the distinct changes in U-BEER are probably independent of changes in the activity of enzymes involved in alcohol oxidation. It is assumed that alcohol metabolism in man is mainly controlled by the rate of NADH reoxidation in the liver.

Adult↗

PubMed1979

Sudden death during doxorubicin administration.

Three patients are described who either died suddenly or had severe, life-threatening arrhythmias during or immediately after doxorubicin administration. Since doxorubicin and daunorubicin administration is known to be associated with acute EKG abnormalities, the acute decompensation in these patients appeared to be caused by the administration of these agents. The importance of careful observation of patients receiving doxorubicin, because of the possibility of acute cardiac arrhythmias, is stressed.

Arrhythmias, Cardiac↗

PubMed1978

Poly(dG).poly(dC) at neutral and alkaline pH: the formation of triple stranded poly(dG).poly(dG).poly(dC).

Alkaline titrations of different samples of poly(dG).poly(dC) and of the constituent homopolymers poly(dG) and poly(dC) have been performed in 0.15 M NaCl and their CD spectra followed. Sample I contained a slight excess of poly(dC) (52% C: 48% G) and showed a single reversible transition (pK = 11.9) due to the dissociation of double stranded poly(dG).poly(dC). Sample II, containing an excess of poly(dG) (43% C: 57% G), showed two transitions (pK1 = 11.4, PK2 = 11.9) the first one being only partially reversible. Examination of the CD spectra along the alkaline titrations indicated the presence of another hydrogen-bonded complex of higher G content. Mixing curves performed at pH 8 have confirmed the presence of a 2G: 1C complex, besides the double stranded complex. It can be formed in amounts up to 30% by mixing the two homopolymers, alkali treatment and heating. The CD spectra of the two complexes have been computed from the CD data of the mixing curves. This permitted the determination of the concentrations of both complexes and homopolymers in all samples. The ratio of triple to double stranded complex is not only dependent on the G/C ratio of the sample, but also a function of the previous physico-chemical conditions. These results explain the variability of many properties of different poly(dG).poly(dC) samples observed by other workers.

Centrifugation, Density Gradient↗

PubMed1978

Protonated polynucleotides structures - 22.CD study of the acid-base titration of poly(dG).poly(dC).

The acid-base titration (pH 8 --> pH 2.5 --> pH 8) of eleven mixing curve samples of the poly(dG) plus poly(dC) system has been performed in 0.15 M NaCl. Upon protonation, poly(dG).poly(dC) gives rise to an acid complex, in various amounts according to the origin of the sample. We have established that the hysteresis of the acid-base titration is due to the non-reversible formation of an acid complex, and the liberation of the homopolymers at the end of the acid titration and during the base titration: the homopolymer mixtures remain stable up to pH 7. A 1G:1C stoichiometry appears to be the most probable for the acid complex, a 1G:2C stoichiometry, as found in poly(C(+)).poly(I).poly(C) or poly(C(+)).poly(G).poly(C), cannot be rejected. In the course of this study, evidence has been found that the structural consequences of protonation could be similar for both double stranded poly(dG).poly(dC) and G-C rich DNA's: 1) protonation starts near pH 6, dissociation of the acid complex of poly(dG).poly(dC) and of protonated DNA take place at pH 3; 2) the CD spectrum computed for the acid polymer complex displays a positive peak at 255 nm as found in the acid spectra of DNA's; 3) double stranded poly(dG).poly(dC) embedded in triple-stranded poly(dG).poly(dG).poly(dC) should be in the A-form and appears to be prevented from the proton induced conformational change. The neutral triple stranded poly(dG).poly(dG).poly(dC) appears therefore responsible, although indirectly, for the complexity and variability of the acid titration of poly(dG).poly(dC) samples.

Circular Dichroism↗

PubMed1978

Protonated polynucleotides structures - 23. The acid-base hysteresis of poly(dG).poly(dC).

The large hysteresis observed during the acid-base titration of poly(dG). poly (dC) was studied by CD and potentiometric scanning curves. Intermediate scanning loops as well as the equilibrium and metastable branches of the hysteresis loop have been determined. The potentiometric titrations showed, however, that the various complexes were not discrete entities, but were linked in "polycomplexes" as had been already suggested. This prevented a thermodynamic study of the system. The acid-base titration was further investigated as a function of ionic strength and temperature. The pK's showed considerably lower ionic strength dependence than observed for polyribonucleotide complexes. The thermal transitions permitted to establish the relative stabilities of the various complexes between pH 2.5 and pH 12.0.

Circular Dichroism↗

PubMed1976

[Influence of prenatal malnutrition on later body-weight gain in guinea pigs].

In prenatally underfed guinea pigs the following data were obtained: 1. On the 1st day of life the mean body weight of 18 underfed animals was significantly reduced as compared to that of 18 control animals. This difference was not compensated by postnatal feeding ad libitum but persisted up to the 36th week of life (day of sacrificing). 2. The mean food intake per day estimated over 10 days during the 5th month of life was also significantly diminished in the prenatally underfed animals. 3. A significant positive correlation was found between the body weight at birth and the adult body weight, adult body length and adult body weight/body length, when the parameters of the experimental plus control animals were evaluated together. These findings suggest that in guinea pigs, which are born in a relatively mature stage, the prenatal nutrition can influence body weight, body length and body weight/body length ratio as well as food intake in adulthood.

Animals↗

PubMed1975

[Inhibition of ethanol exidation on prolonged fasting in man: reversibility on fructose infusion(author's transl)].

Fasting for over 36 hours was found to inhibit ethanol metabolism in healthy volunteers by 43% (P less than 0.01) compared with values obtained after 12 hours' fasting. Ethanol oxidation was not inhibited by prolonged fasting when it was stimulated by intravenous fructose. The explanation for this effect is thought to lie in the inhibition of alcohol oxidation mainly by limiting the rate of NADH-reoxidation in the liver.

Alcohol Oxidoreductases↗