牙冠延长术在残根残冠修复中的临床疗效

目的评价牙冠延长术在牙体缺损达龈下的残根残冠修复中的临床疗效。方法自2004年5月至2005年6月,对32例患者的36颗牙体缺损达龈下的患牙,术前按断端位于龈下最深距离分为A组(20颗患牙,距离<3.0mm)和B组(16颗患牙,3.0mm≤距离≤4.0mm),均采用牙冠延长术暴露龈下牙体断面,术后6周行桩冠修复。分别记录和比较手术前、后牙周探诊深度(PD)、菌斑指数(PLI)、龈沟出血指数(SBI)和牙齿松动度,以观察临床疗效。结果术后随访患者6个月,两组病例术后6周牙体断端均暴露较好、龈缘颜色正常,术后修复效果有效率为100%,满意率为77.78%。A组术后无松动,修复效果满意;B组术后50.00%出现Ⅰ度松动,修复效果欠佳,两组修复效果比较差异有显著意义(P<0.05)。术后各阶段两组的PD、PLI、SBI均明显优于术前(P<0.05),但两组术后牙周指数比较差异无显著意义(P>0.05)。结论牙冠延长术有利于残根残冠的保存和修复,但要注意适应证的选择。     

Prevention of Bone Loss by Clodronate in Early Postmenopausal Women with Vertebral Osteopenia: A Dose-Finding Study

This double-masked, placebo-controlled study was undertaken to determine the efficacy and safety of oral clodronate in the prevention of bone loss in early postmenopausal women with vertebral osteopenia. Altogether 610 women with a mean age of 53 years were recruited for the study. They were 1–5 years postmenopausal and their lumbar spine bone mineral density (BMD) was at least 1 standard deviation below the mean of premenopausal women (T-score ≤−1). The subjects were randomized into five study groups to receive either placebo, clodronate 65 mg, 400 mg or 800 mg daily, or intermittent clodronate in 3 month cycles with 400 mg daily for 15 days followed with no treatment for 75 days for 3 years. One hundred and eighty-seven of 509 women who completed the primary study continued in the extension study of 2 years in which previous placebo users were switched to clodronate 800 mg daily, while previous users of 400 mg or 800 mg of clodronate used either placebo or 800 mg of clodronate daily. In the primary study clodronate was administered in the evening, and in the extension 1 h before breakfast on an empty stomach. In the primary study mean changes in lumbar spine BMD were −3.4% in the placebo group and +0.4% in 800 mg clodronate group [difference between groups at 3 years 3.8% (95% CI 2.7% to 4.9%, p<0.0001)], and in the trochanter area BMD −1.1% in the placebo group, and + 0.4% in the 800 mg clodronate group [difference between groups at 3 years 1.5% (95% CI 0.05% to 2.9%)]. During the extension study mean changes in lumbar spine BMD were +1.5% in the clodronate group and −0.2 % in the placebo group [difference between groups 1.7% (CI 0.4% to 3.0%, p = 0.010)] and in trochanter BMD were +2.5% in the clodronate group and no change in the placebo group [difference between groups 2.1% (CI 0.3% to 3.9%, p = 0.007)]. No statistically significant differences between the placebo and 800 mg clodronate groups were found in the femoral neck BMD. In the primary study the urinary excretion of type I collagen aminoterminal telopeptide (NTX) decreased by 44% (p<0.0001 compared with placebo) and that of deoxypyridinoline by 18% (p<0.0001) in the clodronate 800 mg group. In the extension study urinary NTX decreased by 51% (p<0.0001) in those who were switched to 800 mg of clodronate and increased by 67% (p<0.0001) in those who stopped using that dose. There was no difference in the frequency of gastrointestinal complaints between clodronate- and placebo-treated patients in the primary study, but they were more common among women who received clodronate in the extension phase. Clodronate in daily doses of 400–800 mg caused a slight elevation of aminotransferase levels, usually within the reference range. In bone biopsies no defect in mineralization was found. In conclusion, clodronate in a daily dose of 800 mg prevents early postmenopausal bone loss at the sites of the skeleton in which cancellous bone predominates. It effectively reduces bone resorption and bone turnover rate. Antifracture efficacy of clodronate remains to be established by prospective, placebo-controlled trials. Received: 4 March 2002 / Accepted: 9 July 2002     

The value of MCA, CA 15-3, CEA and CA-125 for discrimination between metastatic breast cancer and adenocarcinoma of other primary sites

MCA, CA 15-3, CEA and CA 125 were determined in the serum of 49 patients with metastatic breast cancer and 38 patients with metastatic adenocarcinoma of other primary sites. By using the 99th percentile of the normal value distribution as the cut-off point, the positive predictive value (PV+) was found to be 85% (95% CI 76-94) for MCA, and 71% (95% CI 61-81) for CA 15-3. When receiver-operating-characteristic (ROC) curves were constructed, the PV+ for CA 15-3 was increased to 82% (95% CI 72-92), using 60 U ml-1 as the cut-off point. With the exception of two patients who had a slightly elevated MCA, MCA and CA 15-3 identified the same patients with breast cancer. By combining a positive MCA or CA 15-3 with a negative CEA and CA 125, further improvement of the PV+ could be achieved; 100% (95% CI 91-100). We conclude that MCA and CA 15-3 may play a useful role in discrimination between patients with metastatic breast cancer and those with adenocarcinoma of other primary sites.     

BILIARY HYPERPRESSURE IN RAT EXTRAHEPATIC CHOLESTASIS ALTERS HORSERADISH PEROXIDASE BILIARY EXCRETION

1. The authors investigated the effect of two extrahepatic cholestasis models (one by bile duct ligation and the other by choledocho-jugular fistula) on the hepatic clearance of horseradish peroxidase in male Sprague-Dawley rats divided into four groups. 2. In groups A (n = 5 rats) and B (n = 5), bile duct ligation was performed, while a choledocho-jugular fistula was created in groups C (n = 5) and D (n= 7). A 10 mg intravenous bolus of horseradish peroxidase was injected after 24 h (groups A and C), 48 h (groups B and D) or 1 h (Group E; five sham-operated rats). Serum and bile samples were then serially collected for 2 h. 3. In all groups, serum horseradish peroxidase levels increased soon after injection and then rapidly decreased, the curves being similar. Biliary excretion increased for 30 min and then slowly decreased. The highest horseradish peroxidase biliary concentrations and outputs were found in Group B followed by Group A; both groups had significantly higher levels than Group E. No difference was found between horseradish peroxidase biliary excretion of groups C and D and that of sham-operated rats. 4. When each group was considered separately, sampling times correlated with the corresponding ratios of bile/ plasma HRP. Significant differences were found between the relative slopes of groups A, B and E, but not between those of groups C, D and E. 5. In conclusion, bile duct obstruction greatly affects the plasma-bile transfer of fluid phase markers, such as horseradish peroxidase, while single retention, caused by choledocho-jugular fistula, has no influence. The increased biliary hyperpressure related to the duration of cholestasis may account for the degree of horseradish peroxidase transfer which, in turn, probably depends on an enhanced paracellular passage.     

Effects of smoking and drinking on excretion of hippuric acid among toluene-exposed workers

Summary In order to investigate possible effects of smoking and drinking on the metabolism of toluence in occupational settings, 206 toluene-exposed men (mean age: 31.4 years) in shoemaking, painting, or surface-coating workshops together with 246 nonexposed control men (36.8 years) were studied for the time-weighted average intensities of exposure to toluene, hippuric acid concentration in shift-end urine samples, and the two social habits of smoking and drinking. The mean daily consumptions of cigarettes and ethanol were about 20 pieces and 10 g among smokers and drinkers, respectively. The geometric mean toluene concentration among the exposed subjects was about 20 ppm, with a maximum of 521 ppm. Regression analysis after classification of the subjects by smoking and drinking clearly demonstrated that the two social habits, when combined, markedly reduce the hippuric acid level in the urine of workers exposed to was a significant association between smoking and drinking habits, which hindered separate evaluation of the effects of the two habits on toluene metabolism. Comparison of the present results with the findings reported in the literature, however, suggested that the observed effects may be attributable to smoking rather than to drinking habits.     

~(125)碘-绒毛膜促性腺激素的电泳纯化及分析

标记抗原在贮存过程中,由于受幅射分解和脱碘影响而使免疫活性和生物活性降低。我们对自制的~(125)碘-绒毛膜促性腺激素进行了实验观察。结果显示:贮存1月后,其免疫活性和生物活性分别降低了33.1％和44.0％;经电泳纯化后的标记物的免疫活性和生物活性明显提高,分别达到了最初的90.5％和95.3％。     

云南金铁锁的生物学特性及其保护的初步研究

对金铁锁的生物学特征、适应性及其机理进行探讨。结果表明：金铁锁具有旱生植物的结构和特征，耐旱、耐贫瘠能力较细。同时提出了相应的保护措施。为合理的开发、利用和保护金铁锁提供了依据。     

Detection of proteinous toxins using the Bio-Threat Alert system, part 3: effects of heat pretreatment and interfering substances

We previously reported that the Guardian Bio-Threat Alert (BTA) system could detect (detection limit: about 0.1 μg/ml) staphylococcal enterotoxin B (SEB), botulinum toxins (BTX) A and B, and ricin, with no interference by white-powdered materials or colored matrices. In this study, the capability of the BTA system was further assessed. With 10 min of preheating at 60°C, all toxins could be detected, but with preheating at 80°C, BTX A and B and ricin became undetectable. About 20% SEB could be detected after heating at 80°C, but this detection ability was completely removed after heating at 100°C. The effects of chemicals usually used for decontamination, such as sodium hypochlorite, hydrogen peroxide, formaldehyde, and sodium nitrite, on the detectability of SEB, BTX A, or ricin in the BTA system were also tested. The concentrations giving 50% line intensity for SEB, BTX A, and ricin were 3.1, 11, and 15 μM for sodium hypochlorite and 88, 210, and 60 mM for formaldehyde, respectively. The addition of hydrogen peroxide or sodium nitrite did not decrease the detectability even when used at high concentrations.