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11.
Aspirin and acetaminophen use by pregnant women and subsequent child IQ and attention decrements 总被引:1,自引:0,他引:1
A P Streissguth R P Treder H M Barr T H Shepard W A Bleyer P D Sampson D C Martin 《Teratology》1987,35(2):211-219
In a longitudinal prospective study of 1,529 women pregnant in 1974-1975, aspirin and acetaminophen were the two medications most frequently taken during the first half of pregnancy (46 and 41%, respectively). In a selected cohort of 421 offspring of these women, examined at 4 years of age, maternal aspirin use during the first half of pregnancy was significantly related to IQ and attention decrements in the exposed children. Multiple regression analyses were used to statistically adjust for a variety of potentially confounding factors including demographic characteristics, child characteristics, other exposures, and lifestyle/environmental variables. Continuous dose-response and step-function parameterizations of aspirin exposure were both statistically significant and not clearly distinguishable from each other. The estimated aspirin effect is significantly greater for girls than boys. Aspirin effects on offspring function were found in the absence of effects on physical size both at birth and at 4 years. Maternal acetaminophen use was not significantly related to child IQ or attention. As this exploratory research originated from observations of a data set gathered for other purposes, it would be desirable to have these findings replicated in other studies. Further follow-up of the children at a later age is planned. 相似文献
12.
Major histocompatibility (B) complex and sex effects on the phytohaemagglutinin wattle response 总被引:2,自引:0,他引:2
The influence of the major histocompatibility (B) complex and sex on the phytohaemagglutinin (PHA) wattle response was studied in 136 segregants (B2/B2, B2/B5 and B5/B5) of a fourth generation cross between inbred lines 6(1) and 15(1). At 6 weeks of age, chickens were injected with 100 micrograms purified PHA-P. Wattle thickness measurements were taken 4, 24, 48, 72 and 96 h after injection. Analysis of variance showed that 4 h after injection, males had a significantly higher response than females but the sex-genotype interaction was also significant. Females had higher responses than males 24 and 48 h after injection as a consequence of more rapid development and earlier resolution of the reaction in males. B2/B2 chickens had significantly lower responses than B5/B5 chickens 72 and 96 h after injection, signifying a faster late resolution phase in the B2/B2 genotype. The developmental and early resolution phases of the PHA wattle response were influenced by sex while the late resolution phase was influenced by B genotype. 相似文献
13.
Allometric Root/Shoot Relationships and Predicted Water Uptake for Desert Succulents 总被引:3,自引:0,他引:3
Root morphology, shoot morphology, and water uptake for Agavedeserti and Ferocactus acanthodes of various sizes were studiedusing allometric relationships (y = axb) and a previously developedwater uptake model. Shoot surface area increased with shootvolume with an exponent b of 0.75 for both species. Root lengthand the ground area explored by the roots increased with shootsurface area with b's of 0.72 for A. deserti and 0.92 for F.acanthodes. Various sized individuals had about the same ratioof root length to explored ground area, with higher values occurringfor A. deserti. Predicted water uptake averaged over the exploredground area was approximately constant over a 104-fold rangein shoot surface area, suggesting that shoot size confers nointraspecific competitive advantage for water uptake. For theroot lengths per explored ground area observed in the field,water uptake was predicted to be 85 per cent of maximal; wateruptake could be increased by the production of more rain roots.When differences in shoot volume were accounted for by allometry,small plants had relatively less shoot surface area and relativelymore root length per shoot volume than did large plants, whichmay be important for the water relations of seedling establishment. Agave deserti, Ferocactus acanthodes, allometry, desert succulents, root distribution, root length, seedling growth, seedling establishment, shoot surface area, shoot volume, water uptake 相似文献
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Human immunodeficiency virus reverse transcriptase expressed in transformed yeast cells. Biochemical properties and interactions with bovine tRNALys 总被引:11,自引:0,他引:11
16.
Radiometric assay for carboxypeptidase H (EC 3.4.17.10) and other carboxypeptidase B-like enzymes 总被引:2,自引:0,他引:2
Carboxypeptidase H, EC 3.4.17.10, also known as enkephalin convertase, carboxypeptidase E, and crino carboxypeptidase B, is an important enzyme involved in the biosynthesis of bioactive peptides. To assay the enzyme, tissues are homogenized in at least 20 vol (ml/g) of 0.025 M Tris-HCl buffer, pH 8, with 5 mg/ml of bovine serum albumin. After centrifugation, the supernatant is brought to pH 5.6 and centrifuged again. Following a 20-min preincubation in 2 mM CoCl2, the supernatant is incubated with 0.1 mM (final concentration) of the radioactive substrate [3H]benzoyl-Phe-Ala-Arg. The 100-microliters assay is stopped by the addition of 680 microliters of acetonitrile/0.25 M HCl (0.7/1). The 1.5-ml tube is transferred into a scintillation vial and is flushed with 4 ml of Econofluor, a water-immiscible scintillation fluid. The product, [3H]benzoyl-Phe-Ala, recovered in the organic phase, is counted directly with no interference from the substrate remaining in the aqueous phase. The blank is below 1%. Expressed in nanomoles per minute per milligram of tissue, the activity of the soluble enzyme in rat is 0.34 for striatum, 21.0 for pancreatic islet, 16.6 for anterior pituitary, 46.0 for intermediate pituitary, and 10.9 for neural pituitary. In every case 25 microM guanidinoethylmercaptosuccinic acid, an active site-directed inhibitor of carboxypeptidase H, completely inhibits the activity. 相似文献
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18.
H S Kwang P J Barr E A Sabin S Sujipto P A Marx M D Power I C Bathurst N C Pedersen 《Journal of virology》1988,62(5):1774-1780
The gp70 and transmembrane gp20 envelope proteins of simian retrovirus-D serotype 1 (SRV-1) were expressed in Saccharomyces cerevisiae as fusion proteins with human superoxide dismutase (SOD). Expression of the SOD-gp70 and SOD-gp20 sequences yielded fusion proteins of 52 and 29 kilodaltons, respectively. The yeast-expressed SRV-1 envelope proteins were used in an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies in the sera of rhesus macaques that recovered from SRV-1. Sera from 47 of 49 such monkeys tested positive for antibodies to the SOD-gp70 fusion protein, while 45 of 49 reacted positively to SOD-gp20. None of 26 SRV-1-nonexposed monkeys tested positive in either ELISA. Monkeys immunized with the recombinant SRV-1 gp20 and gp70 proteins made good ELISA and Western blot (immunoblot) antibodies to whole SRV-1. This antibody was not neutralizing in vitro, however. 相似文献
19.
NADH oxidation by plasma membrane vesicles purified from hypocotyls of etiolated soybean seedlings by two-phase partition was stimulated 2- to 3-fold by auxins, indole-3-acetic acid, 2,4-dichlorophenoxy acetic acid (2,4-D), and α-naphthaleneacetic acid. The stimulation was concentration dependent in the presence or absence of detergent with a maximum for 2,4-D at 1 micromolar. The NADH oxidation activity was solubilized with the zwitterionic detergent CHAPS and purified by ion exchange chromatography and gel filtration approximately 2000-fold over the total homogenate. Both the partially purified fraction and an active band from nondenaturing gel electrophoresis revealed the same three bands when analyzed by denaturing gel electrophoresis. When obtained from plasma membrane vesicles from the region of rapid cell elongation, the NADH oxidase complex retained auxin responsiveness throughout purification (3- to 5-fold stimulation by 1 micromolar 2,4-D). 相似文献
20.