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21.
Selenium,zinc, and thyroid hormones in healthy subjects 总被引:3,自引:0,他引:3
Oliviero Olivieri Domenico Girelli Anna Maria Stanzial Luigi Rossi Antonella Bassi Roberto Corrocher 《Biological trace element research》1996,51(1):31-41
Iodothyronine 5′ deiodinase, which is mainly responsible for peripheral T3 production, has recently been demonstrated to be a selenium (Se)-containing enzyme. The structure of nuclear thyroid hormone
receptors contains Zinc (Zn) ions, crucial for the functional properties of the protein. In the elderly, reduced peripheral
conversion of T4 to T3 with a lower T3/T4 ratio and overt hypothyroidism are frequently observed. We measured serum Se and RBC GSH-Px (as indices of Se status), circulating
and RBC Zinc (as indices of Zn status), thyroid hormones and TSH in 109 healthy euthyroid subjects (52 women, 57 men), carefully
selected to avoid abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects
were subdivided into three age groups. To avoid under- or malnutrition conditions, dietary records were obtained for a sample
of 24 subjects, randomly selected and representative of the whole population for age and sex. Low T3/T4 ratios and reduced Se and RBC GSH-Px activity were observed only in the older group. A highly significant linear correlation
between the T3/T4 ratio and indices of Se status was observed in the older group of subjects (r=0.54;p<0.002, for Se;r=0.50;p<0.002, for RBC GSH-Px). Indices of Zn status did not correlate with thyroid hormones, but RBC Zn was decreased in older as
compared with younger subjects. We concluded that reduced peripheral T4 conversion is related to impaired Se status in the elderly. 相似文献
22.
Robust variance-components approach for assessing genetic linkage in pedigrees. 总被引:45,自引:16,他引:29
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C. I. Amos 《American journal of human genetics》1994,54(3):535-543
To assess evidence for genetic linkage from pedigrees, I developed a limited variance-components approach. In this method, variability among trait observations from individuals within pedigrees is expressed in terms of fixed effects from covariates and effects due to an unobservable trait-affecting major locus, random polygenic effects, and residual nongenetic variance. The effect attributable to a locus linked to a marker is a function of the additive and dominance components of variance of the locus, the recombination fraction, and the proportion of genes identical by descent at the marker locus for each pair of sibs. For unlinked loci, the polygenic variance component depends only on the relationship between the relative pair. Parameters can be estimated by either maximum-likelihood methods or quasi-likelihood methods. The forms of quasi-likelihood estimators are provided. Hypothesis tests derived from the maximum-likelihood approach are constructed by appeal to asymptotic theory. A simulation study showed that the size of likelihood-ratio tests was appropriate but that the monogenic component of variance was generally underestimated by the likelihood approach. 相似文献
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A denitrifying consortium capable of transforming carbon tetrachloride (CCl(4)) was cultured from aquifer sediment from the U.S. Department of Energy's Hanford Site in southeastern Washington State. To understand the kinetics of the biological destruction of CCl(4) by these microbes, a set of experiments, the conditions of which were chosen according to a fractional factorial experimental design, were completed. This article reports on the experimental design along with the results for CCl(4), biomass, acetate, nitrate, and nitrite concentrations. These data indicate that growth is inhibited by high nitrite concentrations, whereas CCl(4) degradation is slowed by the presence of nitrate and/or nitrite. (c) 1994 John Wiley & Sons, Inc. 相似文献
25.
Mang C. Yu Amos G. Gona Ophelia Gona Suad Al-Rabiai Stanley Von Hagen Edwin Cohen 《Bioelectromagnetics》1993,14(5):449-458
This study was undertaken to determine the effects of extremely low frequency (ELF; 60 Hz) electromagnetic (EM) fields on somatic growth and cortical development, as well as biochemical and morphological maturation, of the rat neopallium. On the fifth day of pregnancy, female rats were put in pairs into plastic cages that were housed in a specially constructed apparatus for irradiation under three separate sets of combination and intensity: 1) 1 kV/m and 10 gauss; 2) 100 kV/m and 1 gauss; and 3) 100 kV/m and 10 gauss. The dams were exposed for 23 h daily, from days 5 through 19 postconception after which they were returned to cages outside the exposure apparatus until they littered. The neonates were culled to eight pups per litter. At 0 (birth), 5, 12, and 19 days postnatally, they were killed for biochemical and morphological studies. Another group of pregnant rats was sham-exposed in an identical apparatus, which was not energized, and the pups were used as controls. The irradiated rats exhibited no physical abnormalities, nor did they show brain deformities such as swelling or herniation following exposure to ELF-EM fields. There was no difference in somatic growth between control and exposed rats, but a small reduction in cortical weight was observed in rats exposed at 1 kV/m and 10 gauss, and 100 kV/m and 1 gauss, respectively. Biochemical measurements of DNA. RNA, protein, and cerebroside concentrations indicated that among the three separate exposures, only the neopallium of rats exposed at 1 kV/m and 10 gauss showed a small reduction in DNA level, as well as small reductions in RNA and protein levels. No changes were noticed in cerebroside levels in any exposed animals, and there were no differences in protein/DNA and cerebroside/DNA ratios between control and exposed rats. Morphological observations did not reveal any detectable alterations in the irradiated rats. These results indicate that exposure to ELF-EM fields caused minimal or no changes in somatic growth and cerebral development of the rat. © 1993 Wiley-Liss, Inc. 相似文献
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27.
Parietochloris incisa comb. nov. (Trebouxiophyceae, Chlorophyta) 总被引:3,自引:0,他引:3
Shin Watanabe Seishiro Hirabayashi Sammy Boussiba Zvi Cohen Avigad Vonshak Amos Richmond 《Phycological Research》1996,44(2):107-108
A coccoid green alga, Myrmecia incisa Reisigl, was isolated from the soil of Mt Tateyama, Japan. Electronmicroscopy revealed that the organism has pyrenoids sparsely covered with starch segments and traversed by many parallel thylakoid membranes, and zoo-spores with counterclockwise basal body orientation. Due to the presence of these features, we have proposed a reclassification of M. incisa into the genus Parietochloris, Trebouxiophyceae. 相似文献
28.
29.
Intratracheal instillation of a novel NO/nucleophile adduct selectively reduces pulmonary hypertension 总被引:1,自引:0,他引:1
Brilli Richard J.; Krafte-Jacobs Brian; Smith Daniel J.; Roselle Dominick; Passerini Daniel; Vromen Amos; Moore Lori; Szabo Csaba; Salzman Andrew L. 《Journal of applied physiology》1997,83(6):1968-1975
Brilli, Richard J., Brian Krafte-Jacobs, Daniel J. Smith,Dominick Roselle, Daniel Passerini, Amos Vromen, Lori Moore, CsabaSzabó, and Andrew L. Salzman. Intratracheal instillation ofa novel NO/nucleophile adduct selectively reduces pulmonary hypertension. J. Appl. Physiol. 83(6):1968-1975, 1997.We examined the pulmonary and systemichemodynamic effects of administering soluble nitric oxide (NO) donorcompounds (NO/nucleophile adducts, i.e., NONOates) directly into thetrachea of animals with experimentally induced pulmonary hypertension.Steady-state pulmonary hypertension was created by using thethromboxane agonist U-46619. Yorkshire pigs were randomly assigned toone of four groups: group 1,intratracheal saline (control; n = 8);group 2, intratracheal sodiumnitroprusside (n = 6);group 3, intratracheal ethylputreanineNONOate (n = 6); andgroup 4, intratracheal2-(dimethylamino)-ethylputreanine NONOate (DMAEP/NO;n = 6). Pulmonary and systemichemodynamics were monitored after drug instillation.Group 4 had significant reductions in pulmonary vascular resistance index (PVRI) at all time points comparedwith steady state and compared with group1 (P < 0.05), whereas systemic vascular resistance index did not change. The meanchange in mean pulmonary arterial pressure in group4 was 33.1 ± 1.2% compared with +6.4 ± 1.3% in group 1 (P < 0.001), and the mean change inmean arterial pressure was 9.3 ± 0.7% compared with acontrol value of 0.9 ± 0.5%(P < 0.05). Groups 2 and 3 hadsignificant decreases in both PVRI and systemic vascular resistanceindex compared with steady state and with group1. In conclusion, intratracheal instillation of apolar-charged tertiary amine NONOate DMAEP/NO results in the selectivereduction of PVRI. Intermittent intratracheal instillation of selectiveNONOates may be an alternative to continuously inhaled NO in thetreatment of pulmonary hypertension. 相似文献
30.
Nonsyndromic cleft lip with or without cleft palate: evidence of linkage to BCL3 in 17 multigenerational families. 总被引:11,自引:6,他引:5
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J Stein J B Mulliken S Stal D L Gasser S Malcolm R Winter S H Blanton C Amos E Seemanova J T Hecht 《American journal of human genetics》1995,57(2):257-272
Nonsyndromic cleft lip with or without cleft palate (CL/P) is a common craniofacial developmental defect. Recent segregation analyses have suggested that major genes play a role in the etiology of CL/P. Linkage to 22 candidate genes was tested in 11 multigenerational families with CL/P, and 21 of these candidates were excluded. APOC2, 19q13.1, which is linked to the proto-oncogene BCL3, gave suggestive evidence for linkage to CL/P. The study was expanded to include a total of 39 multigenerational CL/P families. Linkage was tested in all families, using an anonymous marker, D19S178, and intragenic markers in BCL3 and APOC2. Linkage was tested under two models, autosomal dominant with reduced penetrance and affecteds only. Homogeneity testing on the two-point data gave evidence of heterogeneity at APOC2 under the affecteds-only model. Both models showed evidence of heterogeneity, with 43% of families linked at zero recombination to BCL3 when marker data from BCL3 and APOC2 were included. A maximum multipoint LOD score of 7.00 at BCL3 was found among the 17 families that had posterior probabilities > = 50% in favor of linkage. The transmission disequilibrium test provided additional evidence for linkage with the 3 allele of BCL3 more often transmitted to affected children. These results suggest that BCL3, or a nearby gene, plays a role in the etiology of CL/P in some families. 相似文献