Phenotypic and genetic differentiation of human populations with respect to morphologic and psychophysiological traits

Four groups of human characters (mendelian markers, anthropometry, neurodynamics and psychodynamics) were studied in eight human populations characterized by different degrees of isolation and different ethnic backgrounds, and located in different ecological conditions. The populations examined were proved to display phenotypic and genetic differentiation for the studied groups of characters which were compared with linguistic and geographical distances. The role of genetic factors and that of environmental factors was shown to diminish and to increase, respectively, as the degree of complexity of expression of the group of characters under study (from anthropometry to psychodynamics) goes up.     

Heritability of bone mass: a longitudinal study in aging male twins

Midshaft radial bone mass was first measured from 1970 through 1972 by photon absorptiometry in 42 pairs of monozygotic (MZ) and 38 pairs of dizygotic (DZ) male Caucasian twins (age 44-55 years). The MZ intraclass correlation (rMZ) of .70 was significantly larger (P less than .05) than the DZ correlation (rDZ) of .45, providing evidence for genetic influences (Smith et al. 1973). Radial bone mass measurements repeated 16 years later (1986-87) on 25 of the MZ pairs and on 21 of the DZ pairs revealed an rMZ of .61 and an rDZ of .44, but the difference was not significant (P greater than .05). The twins had an average radial mass loss of 0.49%/year between the two examinations. The rMZ (.52) and rDZ (.49) values for the 16-year loss in radial mass were both significantly different from zero, but their similar size indicated that the correlations were due to nongenetic factors. In a search for the source of genetic influences on adult radial mass, heritability was estimated by the formula 2(rMZ - rDZ) for radial width and was found to be .66 and .76 (P less than .05) for examinations 1 and 2, respectively. An index of radial density (mass/width) was calculated, and the differences between rMZ and rDZ were not significant at either examination. The intraclass correlations (rMZ = .35; rDZ = .43) were both significant for the loss of bone density between examinations but provided no evidence for genetic influences, results similar to the findings for the loss of mass.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunocytochemical study of parvalbumin fibers and cell bodies in the rat hipothalamus

The distribution of parvalbumin (PA) cell bodies and fibers in the hypothalamus of the rat was studied using a monoclonal antibody and the avidin-biotin-peroxidase method. The densest clusters of immunoreactive perikarya were observed in the nuclei mamillare medialis, arcuatus and dorsomedialis hypothalami, whereas the corpus mamillare lateralis had the lowest density. The densest network of immunoreactive fibers was observed in the corpus mamillare lateralis and nucleus arcuatus. The corpus mamillare medialis contained a moderate number of PA fibers, whereas the nucleus dorsomedialis hypothalami had the lowest density of immunoreactive fibers. In addition, a large number of immunoreactive fibers was found in the tractus opticus and the tractus mamillo-thalamicus. Essentially, the distribution of PA in the rat hypothalamus after using a monoclonal antibody seems to be broader in comparison with previous studies carried out in the same diencephalic region of the rat. The presence of PA in several nuclei of the rat hypothalamus suggests that this protein could be directly or indirectly involved in neuroendocrine, limbic and visual functions.     

Magnetic separation of pinocytic vesicles of defined age from Entamoeba histolytica

We describe a rapid and simple method to isolate pinocytic vesicles of defined age (residing time within the cell) from Entamoeba histolytica. Amoebas are allowed to pinocytize for greater than 5 min a suspension of superparamagnetic iron oxide particles, washed, and resuspended for predetermined periods (up to 150 min) in iron oxide-free medium. Subsequently, the cells are homogenized and iron oxide-containing vesicles are separated magnetically. Recovery of vesicles (estimated with fluorescein isothiocyanate-dextran as a quantitative marker for pinocytosis) was 20-40%. Contamination with "older" vesicles or with plasma membrane (estimated with fluorescein isothiocyanate-dextran and with fluorescein isothiocyanate-conjugated, succinylated concanavalin A, respectively) was negligible. Using this method we obtained evidence that in E. histolytica, contrary to the situation in animal cells, pinocytic vesicles within 150 min after invagination neither shrunk nor fused with each other to any significant extent. The method should be generally applicable to protozoa for the isolation of pinocytic vesicles and digestive vacuoles.     

Four different b-type cytochromes in the halophilic archaebacterium, Halobacterium halobium

The halophilic archaebacterium, Halobacterium halobium has been found to contain four different b-type cytochromes. The four components were recognized by their potentiometric characteristics in situ in their functional environment in the membrane of H. halobium. Oxidation-reduction midpoint potentials of these four b-type cytochromes were determined to be +261, +160, +30, and -153 mV, respectively. We also demonstrate that the pathway involved in the transport of reducing equivalents from succinate to oxygen proceeds through the b-type cytochromes with oxidation-reduction midpoint potentials of +261 and +161 mV. The cytochrome with oxidation-reduction midpoint potential of -153 mV was not substrate reducible by NADH but was chemically reducible by dithionite. Antimycin inhibits reduction of b-type cytochrome in the succinate pathway, but has no effect on b-type cytochrome reduction when reducing equivalents are provided by NADH. The carbon monoxide difference spectrum of H. halobium membranes shows at least one carbon monoxide-binding b-type cytochrome, indicating a terminal oxidase. A scheme for electron transport in H.halobium involving the b-type cytochromes and terminal oxidase is suggested.     

Selective oxidation of mitochondrial glutathione in cultured rat adrenal cells and its relation to polycyclic aromatic hydrocarbon-induced cytotoxicity

Primary cultures of rat adrenal cells, as well as rat adrenals in vivo, are sensitive to the potent carcinogen 7,12-dimethylbenz[a]anthracene and its liver metabolite 7-hydroxymethyl-12-methylbenz[a]anthracene, whereas unmethylated polycyclic aromatic hydrocarbons like benzo[a]pyrene or benzo[a]anthracene are ineffective. The adrenocorticolytic potencies of the hydrocarbons are affected by adrenocorticotrophic hormone and various steroids, cytochrome P450 inhibitors, and antioxidants. In the present investigation digitonin was used to fractionate cultured rat adrenal cells. It was found that the mitochondria and cytosol of the cells contained 3-5 nmol/10(6) cells (approximately 15%) and 20-30 nmol/10(6) cells (approximately 85%) of the total soluble cellular glutathione equivalents, respectively. After exposing the cells to 7-hydroxymethyl-12-methylbenz[a]anthracene in the culture medium, a time- and concentration-dependent selective oxidation of mitochondrial glutathione was observed, whereas the effect on the cytosolic glutathione was negligible. Under the same conditions, 7,12-dimethylbenz[a]anthracene and benzo[a]pyrene were unable to alter the redox levels of the subcellular pools of glutathione. Omission of adrenocorticotrophic hormone lowered the oxidation of mitochondrial glutathione induced by 7-hydroxymethyl-12-methylbenz[a]anthracene about twofold. The results suggest that rat adrenal cells contain two separate pools of glutathione, one cytosolic and one mitochondrial, of which the latter is selectively influenced by 7-hydroxymethyl-12-methylbenz[a]anthracene. Moreover, it is concluded that rat adrenal cells offer a unique model system for general studies of the effects of a selective oxidation of mitochondrial glutathione on various cell functions. These effects may constitute early changes in cytotoxicity, preceding, e.g., membrane damage and loss of cytosolic components.     

Characterization and quantitation of fatty acids covalently bound to erythrocyte membrane proteins: anion transporter contains 1 mol of fatty acid thiol ester

Human erythrocyte membranes which had been thoroughly extracted with organic solvents contained 20 nmol of fatty acids/mg dry wt. The major fatty acids were palmitic and stearic with their monoethenoic derivatives as minor constituents. No other fatty acids were detected. When solvent-extracted membranes were digested with Pronase about 90% of the original content of fatty acids was retained in the insoluble residue. Fatty acids were linked to membrane proteins through alkali-labile bonds of which 30% were of a thiol ester and the remainder of an O-ester type. This conclusion is based on differential liberation of fatty acids by hydroxylamine at pH 7.0 and pH 11.0. Two extracts of membranes enriched in peripheral proteins (bands 1, 2, 5 and 2.1, 4.1, 4.2, 6) were prepared and extracted with organic solvents but each contained about six times less fatty acids than the parent solvent-extracted membranes. Glycophorin A contains little if any covalently bound fatty acids. Anion transporter (band 3) contains about 1 mol of thiol ester of fatty acid. This accounts for about half of the thiol ester-linked fatty acids in the parent solvent-extracted membranes. Most of the O-ester-linked fatty acids are linked to an undisclosed membrane protein.     

Interaction of ferric complexes with rat liver nuclei to catalyze NADH-and NADPH-Dependent production of oxygen radicals

The production of potent oxygen radicals by microsomal reaction systems has been well characterized. Relatively little attention has been paid to generation of oxygen radicals by liver nuclei, or to the interaction of nuclei with different ferric complexes to catalyze NADH- or NADPH-dependent production of reactive oxygen intermediates. Intact rat liver nuclei were capable of catalyzing an iron-dependent production of .OH as reflected by the oxidation of .OH scavenging agents such as 2-keto-4-thiomethylbutyrate, dimethyl sulfoxide, and t-butyl alcohol. Inhibition of .OH production by catalase implicates H2O2 as the precursor of .OH generated by the nuclei, whereas superoxide dismutase had only a partially inhibitory effect. The production of .OH with either cofactor was striking increased by addition of ferric-EDTA or ferric-diethylenetriamine-pentaacetic acid (DTPA) whereas ferric-ATP and ferric-citrate were not effective catalysts. All these ferric complexes were reduced by the nuclei in the presence of either NADPH or NADH. The pattern of iron chelate effectiveness in catalyzing lipid peroxidation by nuclei was opposite to that of .OH production; with either NADH or NADPH, nuclear lipid peroxidation was increased by the addition of ferric ammonium sulfate, ferric-ATP, or ferric-citrate, but not by ferric-EDTA or ferric-DTPA. NADPH-dependent nuclear lipid peroxidation was insensitive to catalase, superoxide dismutase, or .OH scavengers; the NADH-dependent reaction showed a partial sensitivity (30 to 40%) to these additions. The overall patterns of .OH production and lipid peroxidation by the nuclei are similar to those shown by microsomes, e.g., effect of ferric complexes, sensitivity to antioxidants; however, rates with the nuclei are less than 20% those of microsomes, which reflect the lower activities of NADPH- and NADH-cytochrome c reductase in the nuclei. The potential for nuclei to reduce ferric complexes and catalyze production of .OH-like species may play a role in the susceptibility of the genetic material to oxidative damage under certain conditions since such radicals would be produced site-directed and not exposed to cellular antioxidants.     

Nitrogen metabolism in tumor bearing mice

In experiments with whole animals infested with a highly malignant strain of Ehrlich ascites tumor cells, serial concentrations of amino acids were determined for host plasma, ascitic fluid, and tumor cells, throughout tumor development. Concentration gradients of glutamine, asparagine, valine, leucine, isoleucine, phenylalanine, tyrosine, histidine, tryptophan, arginine, serine, methionine, and taurine from the host plasma toward the ascitic liquid were established; while on the other hand, concentration gradients from the ascitic liquid toward the plasma were established for glutamate, aspartate, glycine, alanine, proline, and threonine. With the exception of aspartate the concentrations of these amino acids were highest inside the cells. Arginine was the only amino acid not detected in tumor cells. In vitro incubations of tumor cells in the presence of glutamine and/or glucose, as the energy and nitrogen sources, confirmed the amino acid fluxes previously deduced from the observed relative concentrations of amino acids in plasma, ascitic liquid, and tumor cells, suggesting that glutamate, alanine, aspartate, glycine, and serine can be produced by tumors. These findings support that changes in amino acid patterns occurring in the host system are related to tumor development.     

The immunogenic capacity of soluble "vaccinia" antigen (fractionated smallpox vaccine) administered simultaneously with inactivated typhoid vaccine and with purified and concentrated tetanus anatoxin

In this study we have investigated the immune humoral response in the associated vaccination with smallpox, tetanus and typhoid fractionated vaccine (trivaccine) administered in two series at 1 month interval, by dermojet, in a group of young people of 18-20 years old. The results were comparatively estimated with those obtained in two groups of young people of the same age (control group), separately immunized with two components of the tri-vaccine: fractionated smallpox vaccine and tetanus toxoid, following-up the humoral response to the two vaccine components. It was find that, at the end of the surveillance period, similar results were obtained for the testing group and control group, the antibody titers (in geometric mean) presenting very close values: 1/1,140,463 for the testing group, and 1/1,053,583 for the control group against vaccinia component, and 1/1,86,880,586 for the testing group and 1/79,900,431 for the control group, against the tetanus component. The results obtained entitle us to propose this vaccination scheme for the vaccination practice.