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Biomedical subjects

P Propping

Publications and source records attributed to P Propping.

At least 253 records · Page 14Linked to original sources
PubMed1977

Psychophysiologic test performance in normal twins and in a pair of identical twins with essential tremor that is suppressed by alcohol.

In a sample of 52 adults male twin pairs (26 MZ, 26DZ) performance in a series of psychophysiologic tests was measured. The intraindividual variability was determined by repetitive tests in the same subjects. In a number of cases the measured parameters proved relatively stable within the same peron; identical twins, however, were no more similar to one another than fraternal twins. In a pair of identical twins with autosomal-dominant essential tremor the degree of the tremor could be effectively reduced by alcohol application.

Adult↗
PubMed1977

Genetic control of ethanol action on the central nervous system. An EEG study in twins.

The purpose of the investigation is to claify the genetic contribution to the interindividual variability of ethanol action on the central nervous system. The 52 adult male healthy twin pairs (26 MZ, 26 DZ) got 1.2 ml/kg ethanol p.o. under standardized conditions; furthermore, 13 non-twin subjects were repeatedly subjected to the same procedure in order to test the intraindividual variability. The EEG was recorded before and 60, 120, 180, and 240 min after alcohol intake. The EEGs were off-line analyzed by means of a computer program for time domain analysis. As was already known, on the average alcohol led to a better synchronisation of the EEG, i.e., the number of beta-waves decreased whereas the number of alpha- and theta-waves increased. The extent of the alcohol effect on the EEG varied enormously between individuals; however, the EEGs of MZ twins proved to react indentically to alcohol loading, whereas the EEGs of DZ twins became mor dissimilar during the course of the experiment. The low-voltage EEG presumably is resistant to alchohol; furthermore, it is supposed that there exists a special beta-prone EEG-type which is also genetic in origin. The identical EEG reaction of MZ twins to alcohol loading could not be attributed to more similar blood alcohol concentrations. It is hypothesized that the differences in the extent of the alcohol effect on the EEG between individuals might reflect differences in the sensitivity of the ascending reticular activating system. In the literature it has frequently been reported that alcoholics have preferentially brain wave patterns which are poorly synchronized. These findings are discussed in the light of the present results.

Adult↗
PubMed1977

[Genetic control of the ethanol effect on the human EEG].

26 identical and 26 fraternal twin pairs were subjected to 1,2 ml/kg alcohol loading under standardized conditions; furthermore, 13 non-twin persons were repeatedly subjected to the same procedure in order to test the intraindividual variability. The alcohol effect was pursued by repeated EEG recordings. The EEGs of identical twins proved to react identically to alcohol loading, whereas the EEGs of fraternal twins became more dissimilar during the course of the experiment. The identical reaction of the brain wave pattern in monozygotic twins cannot be attributed to more similar blood alcohol concentrations; instead, this finding is a pharmacogenetic phenomenon of the central nervous system.

Adult↗
PubMed1977

The kinetics of ethanol absorption and elimination in twins and supplementary repetitive experiments in singleton subjects.

The influence of genetic and environmental factors on the metabolism of a single oral dose of ethanol 1.2 ml per kg body weight was analysed in 19 identical and 21 fraternal healthy, adult, un-selected male twin pairs. The heritability values of the rates of absorption, degradation and elimination of ethanol were 0.57, 0.41 and 0.46 respectively. Environmental factors, such as daily alcohol intake and smoking, increased the rate of elimination of blood alcohol. Intrasubject variation in ethanol metabolism was studied by repeated tests in 11 male volunteers at intervals of at least 2 months, under the same conditions as in the twins; the coefficients of variation for parameters of metabolism was about 8%. The results demonstrate both genetic control of ethanol absorption, degradation and elimination and the appreciable influence of environmental factors. The almost total genetic control of ethanol metabolism postulated by Vesell et al. (1971) could not be confirmed.

Adult↗
PubMed1976

[Decrease in twin births in the german federal republic (author's transl)].

The decrease in the frequency of twin births depends solely on the decrease of dizygotic twins (ZZ). Examination of birth registration forms in Baden-Würtemberg from 1955 to 1972 showed that the decrease of ZZ births is only partially due to changes in maternal age and parity. On the other hand one can assume that the proportion of women with genetically determined increased fertility, to whom ZZ mothers largely belong, is reduced among mothers due to widespread contraceptive practice so that ZZ births are also rarer. In addition, the possibility that ovulation inhibitors may have a negative influence on the numbers of double ovulations must also be considered.

Age Factors↗
PubMed1976

Twinning frequencies in Baden-Wurttemberg according to maternal age and parity from 1955 to 1972.

The decline of the twinning rate in Germany since 1900 is exclusively due to a fall of the DZ rate. The analysis of the birth data in Baden-Württemberg from 1955 to 1972 shows that the decline of the DZ twinning rate can be explained only to a small extent by the shift of the maternal age-parity distribution towards younger mothers and lower parities. It appears reasonable that the greater part of this decline is caused by the lessening prevalence of the more fecundable, DZ twin-prone women due to the growing influence of family planning. Furthermore, it is imaginable that the probability for multiple ovulation is decreased after cessation of hormonal contraception.

Contraceptives, Oral↗
PubMedDate not supplied

A novel missense mutation in the DNA mismatch repair gene hMLH1 present among East Asians but not among Europeans.

In a search for germline mutations in the DNA mismatch repair genes hMSH2 and hMLH1 in Chinese patients with colorectal cancer we identified a novel missense mutation (V384D) in exon 12 of the hMLH1 gene in 4 out of 26 individuals. This mutation had not been observed in any of 109 German patients who either fulfill the clinical criteria of hereditary nonpolyposis colorectal cancer or had developed colorectal cancer at an early age. In a second series of experiments, DNA samples of 80 healthy. Japanese and 100 healthy Germans were examined for the presence of the V384D mutation. It was observed in 4 Japanese, but in none of the German individuals. Thus, the V384D mutation seems to be confined to the East-Asian population. Since this missense mutation occurs at a less conserved region of the hMLH1 gene, it may represent a nonfunctional polymorphism. However, a role in the pathogenesis of colorectal cancer cannot be ruled out from the present study.

Adaptor Proteins, Signal Transducing↗