Chemical analysis of powder and set forms of Portland cement, gray ProRoot MTA, white ProRoot MTA, and gray MTA-Angelus.

OBJECTIVE: To evaluate the chemical composition and crystalline structures of Portland cement, gray ProRoot MTA (gray MTA), white ProRoot MTA (white MTA), and gray MTA-Angelus. STUDY DESIGN: X-ray diffraction analysis was used to identify and characterize crystalline phases, and energy dispersive x-ray spectrometer was used to determine the chemical composition of the test materials. Both powder form and set form were examined. RESULTS: The crystalline structure and chemical composition of gray and white MTA were similar except for the presence of iron in gray MTA. Both were composed mainly of bismuth oxide and calcium silicate oxide. Portland cement was composed mainly of calcium silicate oxide and did not contain bismuth oxide. Gray MTA-Angelus had a lower content of bismuth oxide than ProRoot MTA. There were no noticeable differences in the chemical composition and crystalline structures between the powder and set forms of any of the material tested. CONCLUSION: Portland cement differed from the MTA by the absence of bismuth ions and presence of potassium ions. Gray MTA contained a significant amount of iron when compared with white MTA. In addition, gray MTA-Angelus had a lower content of bismuth oxide than ProRoot MTA.     

自体腹白线片修补十二指肠溃疡穿孔(附13例报告)

目的探讨用游离自体腹白线片修补急性十二指肠溃疡穿孔的应用价值。方法从2006年1月至2006年7月对13例用自体腹白线片修补急性十二指肠溃疡穿孔的病人的临床资料和随访情况进行回顾性分析,其中2例穿孔大于2cm2,平均手术时间60分钟,平均失血量20ml,平均住院天数9±1天。结果游离自体腹白线片修补急性十二指肠溃疡穿孔13例均痊愈出院。随访15天至6个月,无手术并发症。结论本方法操作较简单、安全、效果好,其适应症广,是一种可行的新方法。     

A binding site peptide fragment of the nicotinic acetylcholine receptor. Sequence-specific assignment of 1H-NMR resonances in the dodecamer alpha 185-196

The total sequence-specific 1H assignment for the alpha 185-peptide was accomplished by analysis of COSY spectra along with spin-decoupling and confirmatory NOE difference experiments. Some ambiguities in the assignments were successfully addressed utilizing additional peptides with selective amino acid substitutions. The chemical shifts of several of the C alpha H resonances, along with evidence for a slowly exchanging amide at Thr-191 suggest that the alpha 185-peptide may contain a certain amount of non-random coil structure. The role of any such ordered structure in the mechanism of binding to alpha-bungarotoxin remains to be determined. The assignment of the peptide 1H resonances will facilitate the analysis and identification of chemical shift perturbations observed upon formation of the complex between alpha-bungarotoxin and the alpha 185-peptide [7].     

白细胞介素—2新的功能位点及其中枢镇痛作用

白细胞介素－２（ＩＬ－２）不仅是重要的免疫调节因子，而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标，发现侧脑室注射ＩＬ—２能显著提高动物痛阈，并能被纳洛酮所阻断，表示ＩＬ－２的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性ＩＬ－２实查体仍具有中枢镇痛作用，表明ＩＬ—２分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断ＩＬ—２的中枢镇痛作用，而不能影响ＩＬ—２增殖ＣＴＬＬ－２细胞的作用，提示ＩＬ－２发挥镇痛和免疫调节作用可能通过不同的受体途径。ＩＬ－２分子中第４５位Ｔｙｒ残基突变为Ｖａｌ后，虽仍保留了免疫活性，但丧失了镇痛功能，表示４５位Ｔｙｒ残基是ＩＬ—２发挥中枢镇痛功能的关键残基之一。我们推测ＩＬ—２的镇痛功能位点可能在ＩＬ—２分子中第４５位Ｔｙｒ残基附近区域。     

Long-term follow-up of hypothalamic-pituitary function in patients with transsphenoidal pituitary herniation and midfacial anomalies.

OBJECTIVE: We wished to determine whether patients with transsphenoidal pituitary herniation were at risk of developing pituitary failure. DESIGN: We followed up hypothalamic-pituitary function annually in patients with midfacial anomalies and pituitary herniation. PATIENTS: Two patients who had transsphenoidal pituitary herniation and midfacial anomalies were included and the literature was reviewed. RESULTS: Both patients became gonadotrophin, TSH and growth hormone-deficient despite neurosurgical repair. CONCLUSION: We conclude that the early diagnosis and neurosurgical repair of transsphenoidal pituitary herniation may prevent central nervous system infection and rhinorrhoea. Surgical repair may not prevent pituitary failure as was evident in both of our cases. Periodic evaluation of the hypothalamic-pituitary axis is essential to determine whether early hormonal replacement therapy is necessary.     

Endovascular stent implantation in patients with stenotic aortoarteriopathies: early and medium-term results.

Data regarding stent implantation for stenotic aortoarteriopathy (SAA) are incomplete. We report on nine patients with this rare syndrome who underwent arterial stent implantation. Indications, results, and complications for patients with SAA were reviewed. Nine patients underwent 11 procedures. Twenty-two stents were implanted in the aorta or brachiocephalic vessels. Five patients had diffuse stenoses, three patients had middle aortic syndrome, and one patient had thoracic and abdominal coarctation. Associated diagnoses included Williams syndrome (2), neurofibromatosis (2), Takayasu's (1), and congenital rubella (1). Median gradient was 60 mm Hg (20-140 mm Hg). Poststent gradient was 15 mm Hg (0-60 mm Hg; P < 0.001). Additional stents were implanted in two patients and five underwent stent redilation. Two patients (22%) were found to have aneurysm formation. Stent implantation effectively provides gradient relief in SAA. Gradient reduction persists or is amenable to redilation. Importantly, however, uncomplicated stent implantation does not preclude aneurysm formation and may be more common than in traditional patient groups.     

京剧器乐的听力损伤（附55例调查报告）

本文对从事京剧打击乐的55人（110耳）进行了听力调查及动态观察。利用图表进行对比分析，发现110耳中高频听力损伤89耳，占81％；语频听力损伤32耳，占29.1%；其中伴有高频耳鸣78耳，占70．9％。动态观察30人（60耳），均为永久性听阈阈移。高频听力损伤最早出现的频率是4kHz，并见典型“V”谷，符合噪声性聋的诊断。     

恒猴精索内注射长效局麻药后对睾丸和附睾的影响

在13只恒河猴精索内注射长效局麻药后,睾丸发生明显变化;而且给药剂量不同,睾丸曲精小管改变的程度和恢复正常的时间亦不同。睾丸间质细胞无明显变化;睾酮分泌不减少,无毒性反应。对临床男性节育应用及生殖生理研究均具有意义。