Feng Fengyi , Zhang Pin , He Youjian 1, Li Yuhong1 , Zhou Meizhen2 , Chen Gang2 and Li Lin2 The Cancer Hospital of the CAMS & PUMC, Beijing 1000211 The Cancer Hospital of Sun Yat Sen University of Medical Science...Feng Fengyi , Zhang Pin , He Youjian 1, Li Yuhong1 , Zhou Meizhen2 , Chen Gang2 and Li Lin2 The Cancer Hospital of the CAMS & PUMC, Beijing 1000211 The Cancer Hospital of Sun Yat Sen University of Medical Sciences, Guangzhou 5100602Beijing Hospital of the Ministry of Health, Beijing 100730展开更多
We tested mutation accumulation hypothesis for the evolution of senescence using short-lived and long-lived populations of the seed-feeding beetle, Acanthoscelides obtectus （Say）, obtained by selection on early- and...We tested mutation accumulation hypothesis for the evolution of senescence using short-lived and long-lived populations of the seed-feeding beetle, Acanthoscelides obtectus （Say）, obtained by selection on early- and late-life for many generations. The expected consequence of the mutation accumulation hypothesis is that in short-lived pop- ulations, where the force of natural selection is the strongest early in life, the late-life fitness traits should decline due to genetic drift which increases the frequency of mutations with deleterious effects in later adult stages. Since it is unlikely that identical deleterious mutations will increase in several independent populations, hybrid vigor for late-life fit- ness is expected in offspring obtained in crosses among populations selected for early-life fitness traits. We tested longevity of both sexes, female fecundity and male reproductive behavior for hybrid vigor by comparing hybrid and nonhybrid short-lived populations. Hybrid vigor was confirmed for male virility, mating speed and copulation duration, and longevity of both sexes at late ages. In contrast to males, the results on female fecundity in short-lived populations did not support mutation accumulation as a genetic mechanism for the evolution of this trait. Contrary to the prediction of this hypothesis, male mating ability indices and female fecundity in long-lived populations exhibited hybrid vigor at all assayed age classes. We demonstrate that nonhybrid long-lived populations diverged randomly regarding female and male reproductive fitness, indicating that sexually antag- onistic selection, when accompanied with genetic drift for female fecundity and male virility, might be responsible for overriding natural selection in the independently evolving long-lived populations.展开更多
Studies in several songbird species have shown that treating females with the androgenic steroid hormone testoste- rone （T） can negatively affect female reproductive behaviors and breeding success. As the effects of...Studies in several songbird species have shown that treating females with the androgenic steroid hormone testoste- rone （T） can negatively affect female reproductive behaviors and breeding success. As the effects of T on females appear to be species-specific, it is not clear if similar effects of high T occur in non-songbird species. Here, we studied the effects of T supplementation on female reproductive behavior and oviposition in the budgerigar, Melopsittacus undulatus, a small monogamous parrot species with distinct sex differences in parental behavior. We experimentally increased T concentrations to male-like levels in T-treated females compared to controls and we allowed females to breed. We found no significant effects of treatment on the latency to enter the nestbox but T treatment significantly interfered with oviposition. Our results show that T-treated females were seven times less likely to produce a clutch than control females. As we found that T treatment had a strong inhibitory effect on oviposition, our results indicate that female budgerigars suffer fitness costs from male-like plasma T levels. Therefore, it may be possible that, also in non-songbird species, selection for higher T levels in males is constrained by a correlated response to selection which imposes fitness costs on females in terms of reproduction. Evaluating whether or not this is indeed the case requires further work combining different approaches to the study of the evolution of male and female testosterone levels [Current Zoology 61 （4）： 586-595, 2015].展开更多
Background Tamsulosin hydrochloride can significantly improve benign prostatic hyperplasia （BPH） symptoms after the first dose and achieve long-term efficacy in European and American populations; however, the coresp...Background Tamsulosin hydrochloride can significantly improve benign prostatic hyperplasia （BPH） symptoms after the first dose and achieve long-term efficacy in European and American populations; however, the coresponding studies from China are rarely seen. The purpose of this study was to evaluate the long-term efficacy and safety of tamsulosin hydrochloride 0.2 mg once daily in patients with lower urinary tract symptoms （LUTS） suggestive of BPH in China. Methods Chinese patients with LUTS suggestive of BPH were enrolled in a 4-week placebo run-in period and subsequent 60-week open-label study. Tamsulosin hydrochloride 0.2 mg was administered daily during the period of the study. The efficacy and safety parameters were evaluated at the end of treatment period I （0-12 weeks） and period II （13-60 weeks）. The BPH patients were divided into tamsulosin monotherapy group and combination therapy group which received concomitant medication of finasteride 5 mg once daily after the evaluation at the end of treatment period I. Results A total of 113 patients were recruited to the study. Eighty-two patients received tamsulosin monotherapy and twenty-nine received combination therapy during the treatment period I1. Tamsulosin hydrochloride produced a great improvement in mean maximum urinary flow rate （Qmax） （1.7 ml/s, 3 ml/s） and a significant decrease in mean international prostate symptom score （IPSS） （4.1,6.4） after 12-week and 60-week treatments, respectively. At the end of treatment period II, there were significant improvement in IPSS, quality of life （QOL） score, Qmax and average flow rate （eave） for combination therapy group compared with the treatment period I （all P 〈0.05）. No serious adverse events （SAE） were recorded during the study. Conclusion Long-term tamsulosin hydrochloride therapy is a safe, effective and well-tolerated method for the treatment for LUTS suggestive of BPH in China.展开更多
Objective To explore the role of endothelin (ET) in the pathogenesis of exercise induced asthma (EIA), we investigated the effects of ET B receptor antagonists, ET 1 11 21 fragment and N cis 2,6 dimethylp...Objective To explore the role of endothelin (ET) in the pathogenesis of exercise induced asthma (EIA), we investigated the effects of ET B receptor antagonists, ET 1 11 21 fragment and N cis 2,6 dimethylpi^peridinocardonyl L γ methylleucyl D 1 methoxycarbonyl tryptophanyl D norleucine (BQ788) on broncho^constriction elicited by isocapnic hyperpnea in guinea pigs Methods Eighteen pathogen free Hartley guinea pigs were randomly divided into three groups A: normal saline (NS) inhalation control group (n=6), B: BQ788 group (n=6), and C: ET 1 11 21 fragment group (n=6) Guinea pigs were anesthetized with pentobarbital sodium After measuring the basal value of lung resistance (R L) and dynamic compliance of the respiratory system (Cdyn), NS (0 96?ml), BQ788 (9?nmol) and ET 1 11 21 fragment (9?nmol) were inhaled A rodent respirator with a dry 5%CO 2-95%O 2 mixture at room temperature provided mechanical ventilation (V T 8?ml/animal, 100 breaths/min) for 5?min R L and Cdyn of the 3 groups were measured again after isocapnic hyperpnea challenge Results In the control group, isocapnic hyperpnea of dry gas elicited a marked increase in R L and decrease in Cdyn R L and Cdyn of the guinea pigs from BQ788 group and ET 1 11 21 fragment group did not change significantly Conclusion It was demonstrated that selective ET B receptor antagonists, ET 1 11 21 fragment and BQ788, inhibited the bronchoconstriction induced by isocapnic hyperpnea in guinea pigs The data showed that ETs are potent constrictors of guinea pig airway smooth muscle via a direct effect on ET receptors It was suggested that ET receptor antagonists, especially ET B receptor antagonist, might be beneficial in preventing EIA展开更多
文摘Feng Fengyi , Zhang Pin , He Youjian 1, Li Yuhong1 , Zhou Meizhen2 , Chen Gang2 and Li Lin2 The Cancer Hospital of the CAMS & PUMC, Beijing 1000211 The Cancer Hospital of Sun Yat Sen University of Medical Sciences, Guangzhou 5100602Beijing Hospital of the Ministry of Health, Beijing 100730
文摘We tested mutation accumulation hypothesis for the evolution of senescence using short-lived and long-lived populations of the seed-feeding beetle, Acanthoscelides obtectus （Say）, obtained by selection on early- and late-life for many generations. The expected consequence of the mutation accumulation hypothesis is that in short-lived pop- ulations, where the force of natural selection is the strongest early in life, the late-life fitness traits should decline due to genetic drift which increases the frequency of mutations with deleterious effects in later adult stages. Since it is unlikely that identical deleterious mutations will increase in several independent populations, hybrid vigor for late-life fit- ness is expected in offspring obtained in crosses among populations selected for early-life fitness traits. We tested longevity of both sexes, female fecundity and male reproductive behavior for hybrid vigor by comparing hybrid and nonhybrid short-lived populations. Hybrid vigor was confirmed for male virility, mating speed and copulation duration, and longevity of both sexes at late ages. In contrast to males, the results on female fecundity in short-lived populations did not support mutation accumulation as a genetic mechanism for the evolution of this trait. Contrary to the prediction of this hypothesis, male mating ability indices and female fecundity in long-lived populations exhibited hybrid vigor at all assayed age classes. We demonstrate that nonhybrid long-lived populations diverged randomly regarding female and male reproductive fitness, indicating that sexually antag- onistic selection, when accompanied with genetic drift for female fecundity and male virility, might be responsible for overriding natural selection in the independently evolving long-lived populations.
文摘Studies in several songbird species have shown that treating females with the androgenic steroid hormone testoste- rone （T） can negatively affect female reproductive behaviors and breeding success. As the effects of T on females appear to be species-specific, it is not clear if similar effects of high T occur in non-songbird species. Here, we studied the effects of T supplementation on female reproductive behavior and oviposition in the budgerigar, Melopsittacus undulatus, a small monogamous parrot species with distinct sex differences in parental behavior. We experimentally increased T concentrations to male-like levels in T-treated females compared to controls and we allowed females to breed. We found no significant effects of treatment on the latency to enter the nestbox but T treatment significantly interfered with oviposition. Our results show that T-treated females were seven times less likely to produce a clutch than control females. As we found that T treatment had a strong inhibitory effect on oviposition, our results indicate that female budgerigars suffer fitness costs from male-like plasma T levels. Therefore, it may be possible that, also in non-songbird species, selection for higher T levels in males is constrained by a correlated response to selection which imposes fitness costs on females in terms of reproduction. Evaluating whether or not this is indeed the case requires further work combining different approaches to the study of the evolution of male and female testosterone levels [Current Zoology 61 （4）： 586-595, 2015].
文摘Background Tamsulosin hydrochloride can significantly improve benign prostatic hyperplasia （BPH） symptoms after the first dose and achieve long-term efficacy in European and American populations; however, the coresponding studies from China are rarely seen. The purpose of this study was to evaluate the long-term efficacy and safety of tamsulosin hydrochloride 0.2 mg once daily in patients with lower urinary tract symptoms （LUTS） suggestive of BPH in China. Methods Chinese patients with LUTS suggestive of BPH were enrolled in a 4-week placebo run-in period and subsequent 60-week open-label study. Tamsulosin hydrochloride 0.2 mg was administered daily during the period of the study. The efficacy and safety parameters were evaluated at the end of treatment period I （0-12 weeks） and period II （13-60 weeks）. The BPH patients were divided into tamsulosin monotherapy group and combination therapy group which received concomitant medication of finasteride 5 mg once daily after the evaluation at the end of treatment period I. Results A total of 113 patients were recruited to the study. Eighty-two patients received tamsulosin monotherapy and twenty-nine received combination therapy during the treatment period I1. Tamsulosin hydrochloride produced a great improvement in mean maximum urinary flow rate （Qmax） （1.7 ml/s, 3 ml/s） and a significant decrease in mean international prostate symptom score （IPSS） （4.1,6.4） after 12-week and 60-week treatments, respectively. At the end of treatment period II, there were significant improvement in IPSS, quality of life （QOL） score, Qmax and average flow rate （eave） for combination therapy group compared with the treatment period I （all P 〈0.05）. No serious adverse events （SAE） were recorded during the study. Conclusion Long-term tamsulosin hydrochloride therapy is a safe, effective and well-tolerated method for the treatment for LUTS suggestive of BPH in China.
文摘Objective To explore the role of endothelin (ET) in the pathogenesis of exercise induced asthma (EIA), we investigated the effects of ET B receptor antagonists, ET 1 11 21 fragment and N cis 2,6 dimethylpi^peridinocardonyl L γ methylleucyl D 1 methoxycarbonyl tryptophanyl D norleucine (BQ788) on broncho^constriction elicited by isocapnic hyperpnea in guinea pigs Methods Eighteen pathogen free Hartley guinea pigs were randomly divided into three groups A: normal saline (NS) inhalation control group (n=6), B: BQ788 group (n=6), and C: ET 1 11 21 fragment group (n=6) Guinea pigs were anesthetized with pentobarbital sodium After measuring the basal value of lung resistance (R L) and dynamic compliance of the respiratory system (Cdyn), NS (0 96?ml), BQ788 (9?nmol) and ET 1 11 21 fragment (9?nmol) were inhaled A rodent respirator with a dry 5%CO 2-95%O 2 mixture at room temperature provided mechanical ventilation (V T 8?ml/animal, 100 breaths/min) for 5?min R L and Cdyn of the 3 groups were measured again after isocapnic hyperpnea challenge Results In the control group, isocapnic hyperpnea of dry gas elicited a marked increase in R L and decrease in Cdyn R L and Cdyn of the guinea pigs from BQ788 group and ET 1 11 21 fragment group did not change significantly Conclusion It was demonstrated that selective ET B receptor antagonists, ET 1 11 21 fragment and BQ788, inhibited the bronchoconstriction induced by isocapnic hyperpnea in guinea pigs The data showed that ETs are potent constrictors of guinea pig airway smooth muscle via a direct effect on ET receptors It was suggested that ET receptor antagonists, especially ET B receptor antagonist, might be beneficial in preventing EIA
