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Biomedical subjects

P Propping

Publications and source records attributed to P Propping.

At least 235 records · Page 13Linked to original sources
PubMed1982

Is there an increase of reproductive rates in schizophrenics? I. Critical review of the literature.

It is well-known that the fertility of schizophrenic patients, particularly males, is below the population average. The main measures of fertility (reproductivity) are marriage rate, marital fertility, and rate of reproduction. A review of the literature reveals the rate of reproduction of schizophrenic patients to be 30% to 80% of the general population, the reduction being mainly due to reduced probability of marriage. At least one investigation presented evidence for an increase in marriage rate and rate of reproduction in schizophrenic patients relative to the general population in recent time. If this increase were to be confirmed it would undoubtedly have practical as well as theoretical implications. The hypothesis of a compensatory higher fertility of healthy relatives of schizophrenics based on a physiological advantage is empirically unproven. Additionally, the concept of a balanced polymorphism in schizophrenia rests on a superficial analogy with Mendelian traits.

Female↗
PubMed1981

Genetic disposition to alcoholism. An EEG study in alcoholics and their relatives.

Family, twin, and adoption studies have shown that genetic factors are involved in the etiology of alcoholism. Based on earlier EEG findings in alcoholics and on the known genetic determination of the alcohol effect on the EEG, the hypothesis was tested whether the resting EEG reflects a certain disposition to alcoholism. Resting EEGs were examined for 115 alcoholics (78 males, 37 females) and matched controls. In addition, the first-degree relatives of two extreme groups of alcoholics--those with poor and those with particularly good alpha waves--were examined and compared with matched controls. The EEGs were analyzed with an EEG processor. Whereas male alcoholics did not differ from their controls, female patients showed a shift from the alpha and theta to the beta bands of the brain wave pattern. The relatives of the two extreme groups of alcoholics, who did not misuse alcohol, exhibited the same tendency. This is an argument supporting the notion that in females a poorly synchronized EEG pattern reflects a certain disposition to alcoholism. This finding is discussed in light of drinking motivation in males and females. The latter more often belong to the alpha- and gamma-types of alcoholism than do males. Because of comparable findings in schizophrenics it is argued that a genetically determined desynchronized resting EEG pattern is not specific for a certain illness, but reflects basic mechanisms that enhance the risk for different psychiatric disorders.

Adolescent↗
PubMed1981

Platelet monoamine oxidase in healthy subjects: the "biochemical high-risk paradigm" revisited.

Activity of platelet monoamine oxidase (MAO) has repeatedly been reported to be associated with various forms of psychopathology. This investigation was designed to reexamine the "biochemical high-risk paradigm" developed by Buchsbaum et al. (1976). In 383 healthy students (193 males, 190 females) platelet MAO activity was measured. The 35 students with the lowest and 37 with the highest enzyme activities were then examined with three personality tests (16 PF of Cattell, Freiburger Persönlichkeitsinventar, Eysenck Personality Questionnaire). Furthermore, biographic data with respect to psychosocial problems were explored. There were no consistent differences between subjects with low or high MAO. Therefore, we could not confirm any correlation between psychopathology and platelet MAO in this study.

Adult↗
PubMed1981

Intraindividual stability and extent of genetic determination of platelet monoamine oxidase activity.

Intraindividual stability and extent of genetic determination of platelet MAO activity with tryptamine as substrate was evaluated. Repeated determinations on the same days as well as during an interval of 1-30 days show a high intraindividual stability of MAO. Reexamination of subjects who had formerly been selected because of either low or high MAO activity led to a "regression to the mean", thus pointing to a certain influence of environmental factors on the enzyme values. Twin and family studies, however, show a remarkable influence of genetic factors.

Blood Platelets↗
PubMed1981

Platelet MAO activity in patients with affective psychosis and their first-degree relatives.

26 patients with affective psychoses, 11 with the unipolar and 15 with the bipolar form of the disease, 102 first-degree relatives and healthy controls matched for age and sex were examined for their platelet MAO activity. For evaluation of enzyme activity kinetic parameters as well as activities under saturation conditions were determined. The degree of depression was estimated by two standard self-rating depression scales. Intrafamilial correlation of MAO was found. MAO activities of patients did not differ from controls, and there was no consistent difference in MAO between the relatives and their controls. Neither among patients nor among relatives or controls were there indications for a relationship between MAO and the degree of depression. Reduced MAO activity cannot be regarded as a genetic marker of vulnerability to affective psychosis.

Affective Disorders, Psychotic↗
PubMed1981

Low platelet MAO activity and schizophrenia: sex differences.

The authors compared platelet monoamine oxidase activity in schizophrenic patients and normal controls. A significant reduction in the enzyme activity was found in the male schizophrenic patients but not in the females. No differences were detected among the subgroups of schizophrenia. Sources of bias and the possible mechanism for the findings are discussed.

Adult↗
PubMed1980

Further evidence for a correlation between EEG synchronization and plasma DBH activity in normal subjects.

In a former investigation we had got evidence for a relationship between synchronization of the resting EEG and plasma dopamine-beta-hydroxylase (DBH) activity in healthy males. In order to substantiate this finding we now examined a new sample of males and a sample of females, both with either low-voltage or monotonous alpha-EEGs, and relatives of probands with either EEG type. In the new sample of males, the carriers of a low-voltage EEG (n = 15) again had significantly lower plasma DBH activity than the subjects with a monotonous alpha-EEG (n = 16). In females there was no difference. In the families of probands with a monotonous alpha-EEG the relatives carrying the trait significantly exceeded non-trait-carriers in DBH activity. This effect is mainly due to the male subjects, confirming the results in the proband groups. Presumably there are common genetic factors that contribute to the variability of both the EEG and DBH.--Taking into account experimental findings on central catecholaminergic activity and EEG synchronization, a hypothesis on the mechanisms that are responsible for the relationship is proposed.

Brain↗
PubMed1980

Effect of alcohol on genetically determined variants of the normal electroencephalogram.

The effect of a single dose of alcohol on the electroencephalograms (EEGs) of healthy male carriers of extreme variants of the EEG was examined. The EEG variants included: low voltage, borderline alpha, diffuse beta, and monotonous alpha EEG. The EEGs were analyzed on a small processor by means of a program for interval-amplitude analysis. The synchronizing effect of alcohol (increase of alpha activity and decrease of variance of frequency) was most pronounced in the borderline alpha EEG. As the interindividual variability of the resting EEG is known to be genetically determined, it can be concluded that the differential effects of ethanol on the EEG have a genetic basis.

Adult↗
PubMed1979

The electroencephalogram (EEG) as a research tool in human behavior genetics: psychological examinations in healthy males with various inherited EEG variants. I. Rationale of the study. Material. Methods. Heritability of test parameters.

In the first section of this paper, various research designs in human behavior genetics are compared. In this context, the commonly used concept of biometric genetics is critically evaluated from the point of view of science theory. It is contrasted with the Mendelian gene concept, which, in principle, leads to a much deeper theoretical understanding by offering clues for basic mechanisms. To explore this advantage fully, a research strategy is needed that first looks for genetic variability in a physiological parameter of possible importance for human behavior and then tries to explore the influence of this parameter on the function of the human brain and on behavior. If possible, this genetic parameter should be selected in a way that inferences as to the mechanism of its influence on behavior become feasible. Such genetic variability is provided by the hereditary variants of the normal EEG discovered by earlier work (cf. Vogel, 1970). In the following section, a research program on 298 adult healthy males, most of them soldiers, with various inherited EEG variants is described. Apart from controls with inconspicuous EEGs, this material comprises probands with the following EEG variants: low-voltage (N); low-voltage borderline (NG); monotonous alpha-waves (R); occipital fast alpha-variants (BO); fronto-precentral beta-groups (BG), and diffuse beta-waves (BD). In addition to an EEG examination, the probands were examined with various test methods measuring intelligence (IST; LPS; Raven); working speed and concentration (d-2; KLT); personal attitudes (MMPI; 16PF; RKS); and sensory and motor abilities (flicker fusion; tachistoscopy; reaction time to optic, acoustic and combined stimuli; two-hand dexterity; pursuit rotor; tapping). In a supplementary twin study on 52 male adult twin pairs (26 MZ, 26 DZ), heritabilities were determined for the test scores included in the main study. For most test scores, heritabilities are relatively low; the data are compared with those from the literature. We conclude that the test methods utilized in the main study (on EEG variants) are expected to demonstrate at the most a small to moderate correlation of the EEGs with psychological phenotypes as defined by test examinations, even if a major part of the genetic variability underlying these phenotypes would be due to differences in brain physiology that could be revealed by EEG variation.

Adult↗
PubMed1979

Platelet monoamine oxidase activity in first-degree relatives of schizophrenic patients.

Platelet monoamine oxidase (MAO) is under genetic control. A lower MAO activity in chronic schizophrenia has repeatedly been reported, and it has been suggested that reduced activity of this enzyme reflects an increased vulnerability to schizophrenia. To test this hypothesis platelet MAO was determined in 65 first-degree relatives of 22 schizophrenic index patients and in matched healthy controls. No difference in mean activity between the two samples could be detected, suggesting that reduced MAO activity in schizophrenia is more likely to be a phenomenon secondary to the disease. A significant parent-offspring correlation of MAO activities was obtained.

Adolescent↗
PubMed1979

Plasma DBH, platelet MAO and proteins of red blood cell membranes in individuals with variants of the normal EEG.

Plasma DBH, platelet MAO and proteins of red blood cell membranes were examined in healthy male carriers of variants of the normal resting EEG. The variants included low-voltage EEG, badly synchronized alpha-EEG, diffuse beta-EEG and monotonous alpha-EEG. Mean DBH activity of the low-voltage EEG group was only half that of the monotonous alpha-EEG group. No difference between EEG types in platelet MAO activity and in polypeptide pattern of erythrocyte membranes after electrophoresis could be detected.

Adult↗
PubMed1979

Genetic influences on pharmacodynamic properties of psychotropic drugs.

Most of the well-known examples of pharmacogenetics are based on differences of biotransformation and elimination of drugs. Since a drug interacts with a genetically determined biological target, hereditary differences on the pharmacodynamic level are also probable. Especially psychotropics show interindividual variation in their pharmacological effects. The differential effects of psychotropic drugs on the EEG presumably reflect genetic differences of brain function. Lithium transport across the erythrocyte membrane exhibits large interindividual differences that have a genetic basis, and that possibly indicate a link between lithium transport and manic-depressive psychosis.

Animals↗
PubMed1978

A twin study on three enzymes (DBH, COMT, MAO) of catecholamine metabolism. Correlations with MMPI.

Ina a sample of 48 healthy adult male twin pairs (24 MZ, 24 DZ) the activities of DBH (serum), COMT (red blood cells), and MAO (platelets) were determined. The twins had undergone a detailed psychodiagnostic test procedure before. Interindividual variability of enzyme activities is almost exclusively genetically determined. No correlation between enzyme activities within one subject is found. Correlations between enzyme activities and MMPI test scores were calculated. As in a comparable investigation by Murphy et al. (1977), negative correlations between MAO activity and MMPI scores prevailed.

Adult↗
PubMed1978

Pharmacogenetics.

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Acetyltransferases↗