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Biomedical subjects

H Berndt

Publications and source records attributed to H Berndt.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Prevalence of cholelithiasis. Results of an epidemiologic study using sonography in East Germany].

In two middle-sized towns in the northern part of the German Democratic Republic, a random sample of the population and unselected subjects, respectively, were examined for gallbladder stones (GS) by ultrasound. The prevalence of cholelithiasis (sum of GS detected by ultrasound and history of cholecystectomy for GS) ist higher than in other European populations screened by similar methods. It is suggested that dietary habits are responsible for this finding. About one third of subjects with GS had complications of GS and about one third gave a history of cholecystectomy for GS. The frequency of nonspecific dyspeptic complaints was the same in persons with GS as in persons without GS.

Adolescent↗
PubMed1988

Isolation and characterization of high-molecular mass DNA from hair shafts.

Experiments to identify species by DNA analysis of their hair failed so far because no DNA could be isolated from hair shafts. In this work the preparation of DNA from human--as well as from animal hair shafts (alpaca, angora-rabbit, cashmere, cashgora, mohair, merino and yak) is described for the first time. In general the isolated DNA shows a length of more than 20 kbp. The species of the hair shaft samples could be exactly identified by DNA hybridization experiments. The isolated DNA from hair shafts allow new possibilities to identify species and individuals employing techniques from molecular biology.

Animals↗
PubMed1987

Enantiomeric resolution of amino acid derivatives on chiral stationary phases by high-performance liquid chromatography.

Chiral stationary phases (CSPs) containing urethane-blocked alpha-arylglycines as chiral groups were synthesized and found to have good enantioselectivity for several N alpha-acylamino acid esters. Depending on the derivatization pattern of the amino acids, two different mechanisms of adsorption, generating opposite elution orders, could be observed. The best results were obtained utilizing amino acids as their N alpha-3,5-dinitrobenzoylamino acid esters. The high resolution makes this method suitable for racemization studies in peptide and protein chemistry, as was demonstrated in some examples. The mechanism of enantiomeric adsorption of N alpha-3,5-dinitrobenzoylamino acid esters on such CSPs could be elucidated by a new method based on energy calculations for the reversible diastereomeric complexes. The calculated structures of the adsorption complexes agreed well with the observed elution orders of the amino acid derivatives.

Amino Acids↗
PubMed1987

[The cancer register and notification responsibility].

Changes of the age-specific and age-standardized incidence of malignant neoplasms in the GDR between 1962 and 1980 are investigated. A series of cancer localisation has increased in which case improved diagnostics and increased risk are discussed as causes (cancer of colon and rectum, of the pancreas, the breast and the testicle). The epidemics of bronchial cancer has apparently reached its climax, the admission rates stagnate. Cancer of the stomach and recently also cancer of the gallbladder and the extrahepatic bile ducts decrease in their frequency.

Cross-Sectional Studies↗
PubMed1987

Effect of noise on auditory evoked responses in awake guinea pigs.

Changes in the auditory nerve action potential (AP), evoked responses from the inferior colliculus (IC-ER) and auditory cortex (AC-ER) were assessed after exposure to white noise of 120 dB SPL for 1 h in awake guinea pigs. Auditory thresholds were estimated with the aid of averaged AP, IC-ER and AC-ER, besides the threshold shifts also the changes in amplitude-intensity functions were evaluated. Auditory thresholds for tone pips and clicks increased by 20-30 dB 1 h after exposure and were similar in all the three investigated structures. The maximum threshold shifts for tone pips were observed at 8 kHz and were 33.2 +/- 12.9 dB for AP, 30.4 +/- 12.7 dB for IC-ER and 30.8 +/- 13.0 dB for AC-ER (n = 20). The thresholds recovered to preexposure levels within one week. Reduction in AP and IC-ER amplitudes 1 h after exposure was similar, the amplitude-intensity functions were shifted by 20-40 dB. In contrast, the amplitude-intensity functions in the auditory cortex 1 h after exposure were steeper than before exposure and this amplitude enhancement was present for 24 h after exposure. The enhancement of the AC-ER which resembles recruitment and which may be a sign of hypersensitivity of the animal to auditory stimuli was present only when the animals exposed to noise were awake. The noise exposure in animals anaesthetized with urethane reduced the amplitude-intensity functions of all three recorded potentials.

Anesthesia↗