Copper distribution in the normal human brain

Copper concentration was determined in samples from 38 areas of 7 normal human brains. The grey matter contained higher concentrations of copper than the white matter. Identical areas of the grey and white matter of the cerebral cortex showed significant differences between individuals. In the caudate nucleus the highest concentrations of copper were found in the tail followed by the body and the head, respectively. A negative linear regression between age and brain copper levels was demonstrated.     

Distribution of ABO blood groups and other genetic markers in mothers of infants with congenital malformations

The distribution of ABO and Rh (antigen D) blood groups and of serum albumin, haptoglobin and transferrin variants, in a group of mothers of malformed newborns was investigated. In the first phase of the study, the results showed borderline statistical differences in the distribution of the transferrin types between the study group and a suitable control population. The second phase of the research, where only transferrin phenotypes were studied, showed the same trend as in the first one, but the results were not statistically significant. We conclude that probably there are no true distribution differences, but that it would be desirable to study this problem in a different ethnic group.     

Conformational properties of streptokinase--secondary structure and localization of aromatic amino acids.

The conformational properties of streptokinase (Sk) have been assessed by several spectroscopic techniques. A solvent accessibility of about 70% of the 22 Tyr residues was found by u.v. perturbation spectroscopy. Fluorescence spectroscopy indicates also the surface localization of the single Trp 6 residue. Circular dichroism (c.d.), infrared (i.r.), and Raman spectra were analysed in order to estimate the contents of secondary structure elements of Sk. Values in the range of 14-23% alpha-helices, 38-46% beta-structures, 10-30% turns and 12-23% residual structures were found. The characteristics of the c.d. spectrum support the classification of Sk as an alpha + beta protein. Effects of temperature, pH, and denaturants were studied by c.d. spectroscopy, and on spin-labelled Sk, by e.p.r. spectroscopy. Structural effects were induced at temperatures above 40 degrees C, pH values below 3.0 and urea concentrations above 2 M. At temperatures above 70 degrees C, at pH 2.1, and at urea and Gu.HCl concentrations of 7 M and 5 M, respectively, no further structural changes are revealed in the spectra. At temperatures around 50 degrees C, at pH 3.0, and denaturant concentrations of about 1 M Gu.HCl and 1 M to 2 M urea, c.d. effects were observed in the near-u.v. region indicating an increase in the asymmetry for aromatic amino acids in comparison with the structure of Sk in low ionic strength buffers at neutral pH, 20 degrees C and in the absence of denaturants. These effects were most pronounced for the temperature dependence of the c.d. spectra. E.p.r. spectroscopy has shown that loosening of the protein surrounding of the spin label already begins at 1 M urea and that the mobility of the spin label points to a structural change in Sk at 46 degrees C.     

Quantitative and qualitative finger dermatoglyphics in the Basque Valley of Urola, Spain

Digital dermatoglyphics of an indigenous sample of 87 males and 101 females from the Urola Valley in the Spanish Basque Country are compared with those from the nine other Basque valleys previously analyzed. In both sexes of the Urola Valley, there is a very high frequency of radial loops; the mean found in this valley extends the range of variation for South European-Mediterranean populations, and it is in the superior limit of all Caucasian populations. There are bimanual and sex differences in the frequencies of whorls and loops. Contrary to what occurs normally in populations, in the Urola Valley the frequency of whorls is higher in females and the quantitative value of digital patterns is lower in males. The results of this study show the existence of heterogeneity among valleys for digital trait frequencies and for finger ridge count, and this heterogeneity is more marked in females.     

Host Susceptibility to endogenous viruses: defective, glycoprotein-expressing proviruses interfere with infections.

Three defective endogenous avian leukosis viruses, ev3, ev6 and ev9, interfered with subgroup E virus infections, ev3, ev6, and ev9 expressed high levels of subgroup E envelope glycoproteins. These glycoproteins reduced the activity of cellular receptors for subgroup E viruses. ev3 and ev6 protected chickens and cultured cells from subgroup E virus infections.     

State of hepatitis B viral DNA in a human hepatoma cell line.

PLC/PRF/5, a tissue culture cell line isolated from a human hepatocellular carcinoma and producing hepatitis B surface antigen, was studied for the presence of hepatitis B virus (HBV)-specific DNA and RNA. PLC/PRF/5 cell DNA accelerated the rate of reassociation of HBV [32P]DNA, and quantitative experiments indicated that the cells contained approximately four copies of viral DNA per haploid, mammalian cell DNA equivalent. PLC/PRF/5 DNA accelerated the rate of reassociation of all individual restriction endonucleases HincII and HaeIII fragments of HBV [32P]DNA, indicating that DNA from all regions of the viral genome is present in the cells. This suggests that these cells contain at least most, and possibly all, of the viral genome. Digestion of PLC/PRF/5 cell DNA with restriction endonuclease HindIII (an enzyme found not to cleave the DNA of any HBV isolate so far examined) yielded only three fragments, all larger than virion DNA, which contained HBV DNA base sequences, suggesting that HBV DNA is integrated in high-molecular-weight DNA at three different sites in these cells and that there is no viral DNA in an episomal form. PLC/PRF/5 cell [32P]RNA was found to hybridize with all restriction fragments of HBV DNA adequately tested, indicating that at least most, and possibly all, of the viral DNA in these cells is transcribed.     

Three triterpenes and other terpenoids from Catha cassinoides

The investigation of stems and leaves of Catha cassinoides afforded, in addition to sitosterol, β-amyrin, ursolic acid, lup-20(29)-en-3β,30-diol and friedelin, three new pentacyclic triterpenes: 30-hydroxyfriedelan-3-one, 29-hydroxyfriedelan-3-one and 3-oxo-friedelan-29-oic acid. The structures ofthese were determined by spectral studies and correlations, and were confirmed by X-ray analysis of 29-hydroxyfriedelan-3-one acetate.     

Ataxin1L Is a Regulator of HSC Function Highlighting the Utility of Cross-Tissue Comparisons for Gene Discovery

Hematopoietic stem cells (HSCs) are rare quiescent cells that continuously replenish the cellular components of the peripheral blood. Observing that the ataxia-associated gene Ataxin-1-like (Atxn1L) was highly expressed in HSCs, we examined its role in HSC function through in vitro and in vivo assays. Mice lacking Atxn1L had greater numbers of HSCs that regenerated the blood more quickly than their wild-type counterparts. Molecular analyses indicated Atxn1L null HSCs had gene expression changes that regulate a program consistent with their higher level of proliferation, suggesting that Atxn1L is a novel regulator of HSC quiescence. To determine if additional brain-associated genes were candidates for hematologic regulation, we examined genes encoding proteins from autism- and ataxia-associated protein–protein interaction networks for their representation in hematopoietic cell populations. The interactomes were found to be highly enriched for proteins encoded by genes specifically expressed in HSCs relative to their differentiated progeny. Our data suggest a heretofore unappreciated similarity between regulatory modules in the brain and HSCs, offering a new strategy for novel gene discovery in both systems.     

Patterns of variation in desiccation resistance in a set of recombinant inbred lines in Drosophila melanogaster

Desiccation, resulting from extremely dry environmental conditions, is a serious obstacle to the survival of organisms. Water is vital for the maintenance of intracellular structure and prevents the irreversible formation of aggregates, an occurrence leading to loss of cellular function. To characterize genetic variation in desiccation stress resistance (DSR) in Drosophila melanogaster Meigen, an intercontinental set of recombinant inbred lines (RIL) is used. Flies are exposed to a low humidity environment (<10% relative humidity) at a constant temperature of 25 °C. Desiccation stress resistance is higher in RIL derived from a backcross to the parental stock sensitive to heat stress (from Denmark) than in RIL derived from the reciprocal backcross to the heat‐stress resistant stock (from Australia). Composite interval mapping reveals significant quantitative trail loci (QTL) for DSR in the set of RIL. Both major and minor effects QTL are detected, suggesting a complex genetic architecture. When compared with a previous investigation performed on the same set of RIL, the present study indicates that not all traits of resistance to environmental stressors are affected in the same direction by segregating co‐localized QTL.