两种后牙根管预备方法的临床效果比较

目的 :评估 2种后牙根管预备方法的临床效果。方法 :采用机用镍钛扩大锉 (ProFile)和手用不锈钢扩大锉 (K file)扩大后牙根管 ,并对 2组病例术后疼痛以及充填情况加以比较。结果 :发现机用镍钛扩大锉扩大后牙根管 ,具有去除根管感染物质彻底 ,根管形态保持良好 ,速度快 ,术后疼痛率较低的优点 ,但易出现断针。而手用不锈钢扩大锉扩大后牙根管速度较慢 ,术后疼痛率略高 ,但不易出现断针 ,操作上容易掌握。结论 :2种后牙根管方法都有优缺点 ,可结合起来使用。     

Consequences of foot binding among older women in Beijing, China.

OBJECTIVES: This study examined the prevalence and consequences of foot binding in older Chinese women. METHODS: Women older than 70 years in Beijing, China, were assessed for bound feet, falls, functional status, and bone density. RESULTS: Thirty-eight percent of women aged 80 years and older and 18% of women aged 70 through 79 years had bound-foot deformities. Women with bound feet were more likely to fall, less able to squat, and less able to stand up from a chair without assistance than women with normal feet. They also had 14.3% less functional reach (a test of balance) and 5.1% lower hip bone density. CONCLUSIONS: Foot binding has caused substantial disability that is still evident in many elderly Chinese women.     

Different effects of intracellular and extracellular TEA on voltage-dependent K currents of acutely isolated hippocampal CA1 neurons.

Tetraethylammonium (TEA) effects on K currents were examined on either side of the membrane of hippocampal CA1 neurons by means of whole-cell voltage-clamp recording and intracellular perfusion. Recording media contained ion channel blockers to allow the selective activation of voltage-dependent K currents which consisted of a rapidly decaying component (A-current) and a delayed component. Voltage protocols were applied to separate the A-current from the delayed component. Results show that 10 mM extracellular TEA suppressed 50 +/- 11% (S.D., n = 4) of the delayed current at different levels of depolarization but had little effect on the A-current. In contrast 10 mM TEA applied by intracellular perfusion suppressed the A-current by 42 +/- 10% (S.D., n = 4) in addition to inhibiting the delayed currently 55 +/- 15% (S.D., n = 4). Both the intracellular and extracellular actions of TEA on K currents showed no voltage- nor time-dependency. The results suggest that voltage-dependent transient current (A-current) is mediated through a separate group of ionic channels distinct from those that sustained the delayed current. Furthermore, the asymmetrical effects of intracellular and extracellular TEA on the transient current are similar to those described for the A-current in molluscan neurons. This observation supports the notion that the structure of the ion channel mediating the A-current is closely conserved across different species.     

A comparative study of pepsinogen (PG) and lactic acid dehydrogenase (LDH) activities and isoenzyme patterns in tissues from human primary gastric cancer, gastric cancer xenografts in nude mice and gastric cancer cell lines]

Tissue and cell homogenates were prepared for PG and LDH study from 20 samples of histologically proven gastric cancer (GC), 6 samples of gastric cancer xenografts (THPGC-1) of different passages (GCXG) and cultured cells of 3 different gastric cancer cell lines (GCCL). Normal gastric mucosa (NGM) was also obtained from the resected stomach far distant from the primary tumor and histologically tumor free. The results indicated that the expression of PG isoenzymes was low or absent and the PG activities were significantly decreased in GC, GCXG and GCCL as compared to NGM. The activity of LDH was also significantly increased in GC, GCXG and GCCL. In addition, there was a change in isoenzyme pattern in GC and GCXG in which isoenzyme type M was observed whereas isoenzyme type H was preponderent in NGM. The results show that the human gastric cancer xenograft, THPGC-1, has biological properties very similar to those of the primary tumor suggesting that THPGC-1 is a reliable model for the study of the molecular biology of human gastric cancer.     

Surgical treatment of primary small cell carcinoma of the esophagus. Clinical analysis of 11 cases]

545 cases of esophageal carcinoma were confirmed histologically and by esophagoscopic biopsy between Jan. 1982 and May 1990. Primary small cell carcinoma was identified in 19 cases. Of 11 patients confirmed operatively, 5 had oat cell carcinoma, 4 combined oat cell carcinoma and 2 intermediate cell carcinoma. The mean overall survival period was 13.9 months. The longest survival period was 27 months. The prognosis of primary small cell carcinoma was poorer than that of squamous carcinoma of the esophagus because of its propensity of spread and metastasis. Once the diagnosis of small cell carcinoma was established, surgery was undertaken as early as possible. For patients who had lymph node metastasis at the time of diagnosis, we recommended surgical treatment plus systemic chemotherapy after operation. To increase the resection rate, it is important to do chest CT scan, bronchiofiberscopy and B-type ultrasonography before operation.     

Acute fatal myeloencephalopathy after combined intrathecal chemotherapy in a child with acute lymphoblastic leukemia

We report a case of a fatal toxic encephalomyelopathy in a 12-year-old girl due to prophylactic intrathecal injection of methotrexate and cytosine arabinoside, with a characteristic progressive symptomatology leading to death after 28 days. The location and type of neuropathological changes support the hypothesis of a direct toxic effect of methotrexate and/or cytosine arabinoside on structures directly exposed to the cerebrospinal fluid.