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In order to ascertain the prevalence of chronic respiratory disease in residents of a rural town and to determine the relative importance of tobacco smoking and air pollution, a survey was conducted of 726 persons living at Chilliwack, British Columbia, in May and June, 1963. Over 95% of a random sample of adults was interviewed and performed simple tests of respiratory function. The sample was selected from a commercial census. An analysis of the demographic characteristics of the sample indicated that the group, aged 25 to 74 years, was reasonably representative for detailed study of chronic respiratory disease. 相似文献
96.
97.
Charles F. Aylsworth James E. Trosko Chia C. Chang K. Benjamin Elizabeth Lockwood 《Cell biology and toxicology》1989,5(1):27-37
The effects of TPA and/or DDT and oleic acid and/or DDT on gap junction-mediated intercellular communication (i.e. metabolic cooperation) between Chinese hamster V79 cells was examined. Addition of TPA, DDT or oleic acid alone to cocultures of 6t-hioguanine-resistant (6-TG
R
) and 6-thioguanine-sensitive (6-TG
S
) V79 cells significantly increased the recovery of 6-TG
R
cells indicating inhibition of metabolic cooperation. In the presence of TPA and DDT or oleic acid and DDT the observed recovery of 6-TG
R
cells was significantly greater than the expected (calculated) additive 6-TG
R
cell recovery. No synergistic increases in 6-TG
R
cell recovery were observed when co-cultures of V79 cells were exposed to dieldrin and DDT. These results indicate that TPA and DDT or oleic acid and DDT can act synergistically to inhibit metabolic cooperation. These data suggest a role for protein kinase C in the regulation of gap junction-mediated intercellular communication.Abbreviations DDT
dichlorodiphenyltrichlorethane
- MC
metabolic cooperation defective
- 6-TG
6thioguanine
- TPA
12-0-tetradecanoylphorbol-13-acetate 相似文献
98.
The primary effect of the Ity locus is on the rate of growth of Salmonella typhimurium that are relatively protected from killing 总被引:14,自引:0,他引:14
W H Benjamin P Hall S J Roberts D E Briles 《Journal of immunology (Baltimore, Md. : 1950)》1990,144(8):3143-3151
The Ity locus affects the net increase in numbers of Salmonella typhimurium in the liver and spleen of infected mice. There has been controversy, however, about whether the effects of this locus are due to differential killing of S. typhimurium or differential growth rates of S. typhimurium in mice. Our studies using S. typhimurium aroA mutants, which do not grow in vivo, demonstrate that growth of the infecting salmonella is necessary for the observation of the Ity phenotype. To examine the effects of the Ity locus on the growth and killing of fully virulent salmonella, we infected Ity-congenic mice i.v. with stationary phase S. typhimurium containing a single copy of the plasmid pHSG422. This plasmid exhibits defective replication at body temperature and is diluted out during salmonella growth in vivo. Thus, the frequency of plasmid-containing salmonella recovered from mice provides a measure of salmonella cell divisions in vivo. Inasmuch as the numbers of plasmid-containing salmonella are only slightly affected by bacterial division, any decline in the numbers of plasmid-containing salmonella is an unbiased measure of killing. By infecting mice with these plasmid-containing salmonella we observed that: 1) during the first four h post infection (during blood clearance of injected salmonella) there is about 3-fold more killing of salmonella in Ityr mice than in Itys mice; 2) from 4 to 44 h postinfection (after blood clearance is completed) there is little if any additional killing in either Itys or Ityr mice; and 3) during the first 48 h postinfection there is about 18-fold more growth of salmonella in Itys mice than in Ityr mice. Thus, the major effect of the Ity locus on resistance to salmonella, is the regulation of growth within a "safe" (relatively nonbactericidal) site in the liver and spleen. 相似文献
99.
Comparison of deuterated leucine, valine, and lysine in the measurement of human apolipoprotein A-I and B-100 kinetics 总被引:3,自引:0,他引:3
A H Lichtenstein J S Cohn D L Hachey J S Millar J M Ordovas E J Schaefer 《Journal of lipid research》1990,31(9):1693-1701
The production rates of apolipoprotein (apo)B-100 in very low density lipoprotein and in low density lipoprotein and apolipoprotein A-I in high density lipoprotein were determined using a primed-constant infusion of [5,5,5,-2H3]leucine, [4,4,4,-2H3]valine, and [6,6-2H2,1,2-13C2]lysine. The three stable isotope-labeled amino acids were administered simultaneously to determine whether absolute production rates calculated using a stochastic model were independent of the tracer species utilized. Three normolipidemic adult males were studied in the constantly fed state over a 15-h period. The absolute production rates of very low density lipoprotein apoB-100 were 11.4 +/- 5.8 (leucine), 11.2 +/- 6.8 (valine), and 11.1 +/- 5.4 (lysine) mg per kg per day (mean +/- SDM). The absolute production rates for low density lipoprotein apoB-100 were 8.0 +/- 4.7 (leucine), 7.5 +/- 3.8 (valine), and 7.5 +/- 4.2 (lysine) mg per kg per day. The absolute production rates for high density lipoprotein apoA-I were 9.7 +/- 0.2 (leucine), 9.4 +/- 1.7 (valine, and 9.1 +/- 1.3 (lysine) mg per kg per day. There were no statistically significant differences in absolute synthetic rates of the three apolipoproteins when the plateau isotopic enrichment values of very low density lipoprotein apoB-100 were used to define the isotopic enrichment of the intracellular precursor pool. Our data indicate that deuterated leucine, valine, or lysine provided similar results when used for the determination of apoA-I and apoB-100 absolute production rates within plasma lipoproteins as part of a primed-constant infusion protocol. 相似文献
100.
In vivo microdialysis has been used to study the acute effects of antipsychotic drugs on the extracellular level of dopamine from the nucleus accumbens, striatum, and prefrontal cortex of the rat. (-)-Sulpiride (20, 50, and 100 mg/kg i.v.) and haloperidol (0.1 and 0.5 mg/kg i.v.) enhanced the outflow of dopamine in the striatum and nucleus accumbens. In the medial prefrontal cortex, (-)-sulpiride at all doses tested did not significantly affect the extracellular level of dopamine. The effect of haloperidol was also attenuated in the medial prefrontal cortex; 0.1 mg/kg did not increase the outflow of dopamine and the effect of 0.5 mg/kg haloperidol was of shorter duration in the prefrontal cortex than that observed in striatum and nucleus accumbens. The atypical antipsychotic drug clozapine (5 and 10 mg/kg) increased the extracellular concentration of dopamine in all three regions. In contrast to the effects of sulpiride and haloperidol, that of clozapine in the medial prefrontal cortex was profound. These data suggest that different classes of antipsychotic drugs may have distinct effects on the release of dopamine from the nigrostriatal, mesolimbic, and mesocortical terminals. 相似文献