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Biomedical subjects

H Walter

Publications and source records attributed to H Walter.

At least 199 records · Page 11Linked to original sources
PubMed1986

Detection of surface differences between two closely related cell populations by partitioning. Erythrocytes from inbred and out-bred rats and rat strains.

We have recently developed a new and powerful method capable of detecting, by purely physical means, surface difference between closely related red (or other) cell populations. The procedure consists of isotopically labeling (with [51Cr]chromate) aliquots of red blood cell populations. Such labeled cells are mixed with an excess of unlabeled red cells to which they are to be compared. The mixtures are subjected to countercurrent distribution in either a charge-sensitive or a non-charge-sensitive dextran-poly(ethylene glycol) aqueous phase system. The distribution curves are analyzed for total cells (in terms of hemoglobin absorbance) and labeled cells (in terms of cpm). Changes in the relative specific activities through the distribution curves are indicative of subtle differences in surface properties between such cell populations. Using this method we have found that erythrocytes from arbitrarily chosen (presumably hematologically normal) individuals differ. In the current work we have examined the surface properties of erythrocytes from Sprague-Dawley and from Lewis rats. This was done with a view to determining whether (a) differences of the type found between different humans can also be detected in other species and (b), if such differences do exist, to examine, by study of the highly inbred Lewis rat strain, whether the differences appear to have a genetic or an acquired basis. It was found that the surface properties of erythrocytes from Lewis and Sprague-Dawley rats differ as do erythrocytes among rats of the Sprague-Dawley strain. No difference was found between red blood cells from different rats of the inbred Lewis strain. These results indicate that the surface differences between red blood cells from different rats detected by partitioning have a genetic rather than acquired origin.

Animals↗
PubMed1986

Gene differentiation among ten endogamous groups of West Bengal, India.

Ten endogamous populations of West Bengal, India have been surveyed for genetic variation in 12 systems. These populations encompass all social ranks in the caste hierarchy and cover almost the entire geographic area of the state. Gene diversity analysis suggests that these groups exhibit significant allele frequency variation at all but three loci. The overall genetic difference is not, however, in accord with the classification based on caste. Two low-ranking scheduled caste groups are, in fact, in close proximity with the high-caste ones, suggesting evidence of past generations of gene flow among them. Three different clusters of groups emerge from the present data, providing support for the anthropologic assertion that in Bengal Proto-Australoid, Caucasoid, and Mongoloid racial elements generally coexist. However, these three components are not uniformly present in all groups. Geographic separation of the groups is a strong determinant of the gene differentiation that exists among these populations.

Alleles↗
PubMed1986

Effect of biologically active light and partial sleep deprivation on sleep, awakening and circadian rhythms in normals.

The effects of biologically active light (BL) on subjective and objective quality of sleep and awakening, as well as circadian rhythms in cortisol, temperature and well-being were studied in 10 hospitalized normal female volunteers as compared with partial sleep deprivation (PSD). After 2 adaption days, three 24-hour periods were recorded before (baseline), during (intervention) and after (recovery) treatment with BL (exposure between 5.00-9.00 p.m. and 6.00-9.00 a.m.; light sensitivity: 2,800 lx at eye level) and PSD (1.30-6.00 a.m.). Somnopolygraphic investigations demonstrated a significant improvement in sleep maintenance both after BL and PSD, while sleep induction improved only after PSD. Subjectively experienced sleep quality increased after both treatments. However, subjective and objective awakening quality (objectivated by means of psychometric test battery) was improved by BL only, while PSD produced no changes or even a deterioration. Cortisol levels tended to be lowered by BL, while the troughs increased after PSD; there was also an earlier rise in cortisol levels after PSD than BL. No significant differences were found in regard to temperature. Subjectively experienced well-being tended to improve after both interventions. Our findings concerning the beneficial effect of BL on objective and subjective quality of sleep and awakening in normals encourages us to initiate a single-dose study with BL in depressed patients.

Adult↗
PubMed1986

Genetic markers and malaria. Observations in Gujarat, India.

189 healthy controls and 175 patients suffering from malaria vivax have been investigated with regard to associations between this disease and 22 genetic polymorphisms of the blood (ABO, MN, Ss, Rh, Kell, P, Lutheran, Kidd, Duffy, Diego, Xg; ABH-Secretor; Hp, Gc, Gm, Km; aP, AK, PGM1, 6-PGD, EsD; Hb variants) Significant associations could be demonstrated only for P and Hp systems, though in accordance with other investigations it cannot be excluded that the ABO system plays also a role in this connection.

Blood Group Antigens↗
PubMed1986

On the variability of Gc subtypes in Italy.

909 individuals from different places of Italy were analyzed for the distribution of Gc subtypes. The observed heterogeneity in the distribution of the allele frequencies was found to be statistically significant. Comparing our results with those reported by other authors it is seen that within Italy a considerable regional variation in the frequencies of the Gc subtype alleles is present. However, there are no indications for any particular distribution patterns or gradients. In one of our samples (Bari district), one case of Gc 1S-1C3 was found.

Alleles↗
PubMed1986

Genetic markers among Meiteis and Brahmins of Manipur, India.

Genetic polymorphism of 16 red-cell antigens, enzymes, serum proteins and Hb variants was investigated in 214 male and female individuals belonging to the Meiteis and a Brahmin caste group living in Imphal (Manipur, Northeast India). Ethnohistorical records suggest that the Meiteis are of Mongoloid origin, while the original Brahmin settlers represent the easternmost part of the so-called Caucasoids. The markers studied are: A1A2BO, MNSs, Rh-system, Duffy, Diego; Gm, Km, Gc, Hp, Tf, Cp; Hb; aP, AK, EsD and LDH. The comparison between the two groups on the basis of the markers studied showed that the Meiteis and Brahmins are very close to each other with respect to most of the loci except Gm, EsD and Hb, where significant statistical differences were found.

Blood Group Antigens↗
PubMed1986

Investigations on the variability of haptoglobin, transferrin and Gc polymorphisms in Assam, India.

Ten different population groups of Assam - Brahmins, Kalitas, Kaibartas, Rajbanshis, Muslims, Ahoms, Chutias, Kacharis, Karbis and Sandwals - have been typed for haptoglobin and for transferrin (Tf) and Gc subtype polymorphisms. Tf and Gc allele subtype frequencies show a considerable inter-population heterogeneity. From genetic distance analysis it appears that the populations under study form some distinct clusters, which can be explained by the historical and ethnic affiliations of these populations. Especially the distribution of Gc subtype alleles reveals some Mongoloid admixture among Assamese populations, which is reflected by the presence of Gc1A8 alleles in them.

Gene Frequency↗
PubMed1986

Alcohol and depression.

The relationship of alcohol and depression has always been a subject of clinical and scientific interest. Though many studies have been carried out to clarify the mode of this relationship it still remains in its complexity an area for further research. The two basic ideas of a possible connection are on one hand symptomatic alcoholism with a preexisting depression and on the other hand alcoholism leading to a symptomatic depression. There is in literature a great variability of results with regard to this problem which will be discussed in view of the results of an own study on 444 chronic alcoholic patients.

Alcoholism↗
PubMed1986

Partitioning of erythrocytes from spontaneously hypertensive and Wistar-Kyoto rats.

The charge-associated and non-charge-associated (probably lipid-related) surface properties of erythrocytes from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY), from which SHR were originally derived, were studied by cell partitioning in dextran-polyethylene glycol aqueous phase systems. A major difference was found in the surface charge-associated and lipid-related properties of red blood cells from SHR and WKY: the cells from WKY had the higher partition ratio in both charge-sensitive and non-charge-sensitive phases. No difference in partitioning could be found between any two SHR nor between any two WKY. The SHR and WKY erythrocytes showed the same difference when compared with one another even when rats had the same blood pressure. When red blood cells from SHR with different blood pressure were compared, there still was no difference in their surface properties. These results suggest that the differences in both charge-associated and lipid-related surface properties of erythrocytes from SHR and WKY are strain-specific (i.e., genetic) but that there is no correlation, reflected by partitioning, between red blood cell surface properties and the degree of the rats' hypertension.

Animals↗
PubMed1986

Subfractionation of human peripheral blood lymphocytes by partitioning in two-polymer aqueous phase systems. Characteristics of a small subpopulation of cells with high partition coefficient.

Mixtures of aqueous solutions of dextran and poly(ethylene glycol) form immiscible 2-phase systems that are suitable for the separation of viable, functionally-competent cells on the basis of their surface properties. With the appropriate choice of ionic composition, these systems will separate cells on the basis of charge-related surface characteristics. We have previously shown that in charge-sensitive phase systems, human B lymphocytes have a low partition coefficient (K) and T cells have an intermediate K. The cell subpopulation with the highest K values contains large null lymphocytes that have most of the antibody-dependent and natural killer activities. The present study further characterizes this latter cell subpopulation. 8-33% of peripheral blood lymphocytes in normal persons had high K values. About 50% of these cells had typical Giemsa-staining granules characteristic of killer cells and one third had Fc receptors, but lacked complement receptors. Although 15-30% of the cells with high K values formed rosettes with sheep erythrocytes, there was virtually no response to T-cell mitogens such as PHA and Con A. Mixing cells having high K values with mitogen-responsive T cells from intermediate cell fractions revealed no evidence of suppressor-cell activity to explain the poor mitogen response. The studies indicate that a heterogeneous population of cells share charge-related surface properties resulting in a high partition coefficient. These cells comprise a significant proportion of human peripheral blood lymphocytes and include virtually all of the large granular lymphocytes as well as a large population without this morphology that shares the feature of unresponsiveness to T-cell mitogens.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1986

[Distribution of major histocompatibility complex antigens in the Bremen area].

320 blood donors from Bremen have been typed for HLA-A-, B- and C-antigens. Phenotype and gene frequencies were calculated and compared with data from Kiel, Hamburg, Essen, Frankfurt/M., Mainz, Mannheim, Freiburg/Br., Munich and Vienna. The Bremen data do not differ significantly from these samples. This is also true for the HLA-ABC linkage disequilibrium.

Austria↗
PubMed1986

Genetic studies of Pangwalas, Transhumant and Settled Gaddis. 4. Colour blindness, mid-phalangeal hair, ear lobe attachment and behavioural traits.

Frequency distributions of colour blindness, midphalangeal hair, ear lobe attachment, hand clasping, arm folding, leg folding and handedness are reported for different population groups from Himachal Pradesh, North India, namely Pangwalas, Transhumant Gaddis (Brahmans, Rajputs and Scheduled Castes) and Settled Gaddis (Brahmans, Rajputs and Schedules Castes). An attempt has been made to compare the results of the present study within and between these groups as well as with the results of other reports from different population groups of India and Asia.

Color Vision Defects↗
PubMed1986

Anthropological studies in Assam, India. 4. Observations on the Kalitas.

Five regional groups of the Kalitas, an Assamese caste group, have been investigated for the distribution of anthropometric and dermatoglyphic traits as well as for the distribution of ABO blood groups and PTC taste sensitivity. The intergroup variability is to some extent considerable. The possible reasons for that are discussed.

ABO Blood-Group System↗
PubMed1986

Anthropological studies in Assam, India.

Four Assamese caste groups--Jogis, Hiras, Kumars and Kaibartas--have been analysed for the distribution of anthropometric and dermatoglyphic traits as well as for the distribution of ABO blood groups and PTC taste sensitivity. The differences among these four caste groups are statistically mostly significant, which can be connected with the history of these groups and their genetic isolation from each other.

ABO Blood-Group System↗