AIM　To study the effects of superoxide anion (O.2) on Ca2+ homeostasi and contractility in cultured bovine aortic smooth muscle cell. METHODS　Using Fura-2 fluorescence technique to determine Ca2+ level and collagen gel contraction system to analyze muscle contractility. RESULTS　ATP (10 μmol*L-1 )-induced Ca2+ transient was smaller in xanthine oxidase treated cells(X/XO) than control. The mean peak increment of ［Ca2+］i(△［Ca2+］i peak) and the time integral of the elevated ［Ca2+］i(∫△［Ca2+］i dt) for 5 min were decreased from (206.1±10.2) to (147.4±14.7) nmol·L-1,and from (12.2±0.5) to (9.8±0.8) μmol·L-1·s-1. Δ［Ca2+］i peak induced by thapsigargin（1 μmol·L-1 ）in Ca2+-free solution was not affected by X/XO, but was decreased from (27.3±1.0) nmol·L-1 to (13.5±1.0) nmol·L-1 in Ca2+-containing solution because of the activation of CRAC(△［Ca2+］i CRAC). X/XO accelerated the velocity of thapsigargin-induced Ca2+ leak from (78.7±3.4) s to (64.8±4.40) s. Gel contraction area in X/XO-treated cells induced by ATP or thapsigargin (in Ca2+ free solution and in Krebs solution)was decreased from 23.6%±4.6% to 7.4%±0.2%, from 3.5%±0.6% to -1.0%±0.5%, and from 7.9%±1.4% to -0.5%±0.7%, respectively. CONCLUTION　O.2 attenuats smooth muscle contraction by impairing some of Ca2+ mobilization pathways.

The purpose of this study was to investigate heme oxygenase-1 (HO-1) mRNA expression and bilirubin concentration alteration in humans exposed to acute hypoxia. Fourteen healthy adult males were randomly assigned to a sea level group and a hypoxia group, and then exposed to normoxia (400 m, 20.0 %O₂) and hypoxia (3,000 m, 14.5 %O₂) respectively, in a hypoxic chamber for 3 hours. SpO₂ during hypoxia were significantly lower than those at sea level (P＜0.05). Indirect bilirubin levels after hypoxia were significantly higher than those at sea level (P＜0.05). However, HO-1 mRNA expression was unaltered by hypoxia. In conclusion, our data indicate that an acute exposure to hypoxia at resting state for 3 hours might lead to antioxidative cytoprotective response without any increase in HO-1 gene expression.

AIM To study the effects of superox- ide anion (O ) on Ca2+ homeostasi and contractility in cultured bovine aortic smooth muscle cell. METHODS Using Fura-2 fluorescence technique to determine Ca2+ level and collagen gel contraction system to analyze muscle contractility. RESULTS ATP (10 ?mol? L-1 )-induced Ca2+ transient was smaller in xanthine oxidase treated cells(X/XO) than control. The mean peak increment of [Ca2+ ]i (△[Ca2+ ], peak) and the time integral of the elevated [Ca2+ ], (∫ △[Ca2+ ]i dt) for 5 min were decreased from (206. 1 ? 10.2) to (147.4 ? 14.7) nmol? L-1, and from (12.2 ?0.5) to (9.8 ? 0.8) ?mol?L-1 .s-1. △ [Ca2+ ], peak induced by thapsigargin(1 ?mol. L- 1 ) in Ca2+ -free solution was not affected by X/XO, but was decreased from (27. 3 ? 1 .0) nmol? L－l to (13 .5 ? 1 .0 ) nmol? L- １ in Ca2+ -containing solution be cause of the activation of CRAC(△［Ｃa2+ ], CRAC). X/XO accelerated the velocity of thapsigargin-induced Ca2+ leak from (78.7 ? 3.4) s to (64.8 ? 4.40) s. Gel contraction area in X/XO-treated cells induced by ATP or thapsigargin (in Ca2+ free solution and in Krebs solution) was decreased from 23.6% ? 4.6% to 7.4% ?0.2%, from 3.5% ?0.6% to － l.0% ? 0.5%, and from 7.9% ? l.4% to － 0.5% ? 0.7%, respectively. CONCLUTION O2- attenuats smooth muscle contraction by impairing some of Ca2+ mobilization pathways.

Objective: The purpose of the present study was to clarify the efficacy of alendronate and raloxifene for preventing bone loss in patients with hip fracture by monitoring bone mineral densities (BMDs) and biochemical markers during the 9-month period after fracture. Patients and Methods: Eighty-two female hip fracture patients from 50 to 99 years old (mean ± SD: 81.6 ± 9.5) were randomly divided into two groups; there were 46 patients in the alendronate-treated group (group ALN) and 36 patients in the raloxifene-treated group (group RLX). Drugs were administered to patients six weeks after their operations. Lumbar spine BMD and neck, trochanter, Ward's and total BMDs of the contralateral proximal femur, serum intact osteocalcin (intact OC), bone-specific alkaline phosphatase (BAP) and urinary N-terminal telopeptide of type I collagen (NTX) were measured just before the start of drug administration and at 9 months thereafter. Results: Twenty-two out of 46 patients in group ALN and 23 out of 36 patients in group RLX completed the study. The most common reason for dropping out was the patient's failure to visit the outpatient clinic. Trochanter BMD in group ALN tended to increase by 8.4% compared with the baseline, and total hip BMD in group RLX showed a significant increase (5.7%), although neck BMD in both groups decreased during the 9 months of treatment (–8.7% for group ALN and –4.2% for group RLX compared with the baseline). Spine BMD did not change significantly in eithr group. Serum BAP and urinary NTX decreased significantly in both groups. Serum intact OC did not change significantly. Conclusions: Both alendronate and raloxifene have a favorable effect on trochanter and total BMDs of the contralateral proximal femur in the short period after hip fracture. However, both drugs could not prevent bone loss in the femoral neck during the 9 months of treatment.

Objectives : Many reports have investigated the work environment of physicians and reported the association between work environment, burnout, and the quality of medical care. We aimed to determine the key to improving the work environment by analyzing the results of a Japanese survey for young cardiovascular surgeons. Methods : A survey on work environment was performed among the young members of The Japanese Society for Cardiovascular Surgery (≤40 years of age) to measure their job satisfaction for 9 items : operation, perioperative work, number of hours working or sleeping, board affairs (application or renewal of board certification), motivation, salary, days off, quality of life, and mental status. Univariate and multivariate analyses using 16 factors for the work environment (age, number of years in practice, gender, subspecialty, board certification in surgery, board certification in cardiovascular surgery, primary practice hospital, workdays and nights on duty in a primary practice setting, workdays and nights on duty outside primary practice, total annual income, overtime work hours, overtime entitlement, gap in overtime work and entitlement, and presence of an intensive care unit [ICU] managed by ICU physicians) were performed to identify the risk factors for dissatisfaction. Results : The survey was completed by 327 of 1,304 (25.1% response rate) young members of the Japanese Society for Cardiovascular Surgery. The respondents had an average of 8.5±3.5 years in practice, and 292 (89.3%) respondents were male. Only 14.2% of the responding young surgeons reported no dissatisfaction in any items. In all items, the young surgeons were most satisfied with operation (34.6% of all responders). Age, years in practice, female gender, board certification in surgery, working at a university hospital, workdays in a primary practice setting, and workdays outside a primary practice setting were identified as significant factors for dissatisfaction, while a subspecialty in vascular surgery, total annual income, board certification in cardiovascular surgery, and the presence of an ICU managed by ICU physicians were identified as significant factors against dissatisfaction in the work environment. Conclusions : Our analyses of the survey results identified a number of risk factors for dissatisfaction in the work environment among young cardiovascular surgeons. Regarding the quality of medical care, respondents hoped for a reduced burden on surgeons and the establishment of a work-shift system in the cardiovascular department and an interdisciplinary team including an ICU physician. Multidimensional analyses including job satisfaction, rewards as training, and a quantitative evaluation of the quality of medical care will be necessary to clarify the corresponding relationship between consumers and providers of cardiovascular surgery in the work environment.