Delayed Administration of the K+ Channel Activator Cromakalim Attenuates Cerebral Vasospasm after Experimental Subarachnoid Hemorrhage

Summary ? Background. Delayed cerebral vasospasm remains an unpredictable and inadequately treated complication of aneurysmal subarachnoid hemorrhage (SAH). Recent evidence indicates that the potassium channel activator cromakalim is capable of limiting cerebral vasospasm in rabbits when administered immediately after experimental SAH (i.e. before spastic constriction has been initiated). However, the ultimate clinical value of cromakalim for treating vasospasm will depend in part on its effectiveness when administered after SAH-induced constriction has already been initiated. The present study examined the effects of cromakalim on vasospasm when treatment was initiated after SAH-induced constriction was underway.  Methods. New Zealand white rabbits were subjected to experimental SAH by injecting autologous blood into the cisterna magna. Cromakalim (0.03, 0.1 or 0.3 mg/kg) or vehicle was injected intravenously at 8 hour intervals beginning 24 hours post-SAH. Animals were killed by perfusion fixation 48 hours after SAH. Basilar arteries were removed and sectioned, and cross-sectional area was measured.  Findings. The average cross sectional areas of basilar arteries were reduced by 64% and 68% in the SAH-only and SAH+vehicle groups, respectively. Treatment with cromakalim dose-dependently attenuated SAH-induced constriction. The groups treated with 0.03, 0.1, and 0.3 mg/kg cromakalim exhibited average decreases in cross-sectional area of 57%, 42%, and 19%, respectively.  Interpretation. These findings indicate that cromakalim dose-dependently attenuates cerebral vasospasm when administered 24 hours after experimental SAH in the rabbit. The results suggest K_ATP channel activators, such as cromakalim, could be of benefit for reversing cerebral vasospasm after aneurysmal SAH.     

Acetabular revision with use of a bilobed component inserted without cement in patients who have acetabular bone-stock deficiency

BACKGROUND: Massive deficiency of acetabular bone stock is a challenging problem in the increasing number of patients who need a revision of a failed hip arthroplasty. The bilobed cup has been presented as one alternative reconstruction technique for hips with extensive acetabular bone loss. The purpose of this study was to assess the results with use of a bilobed acetabular component inserted without cement for revision reconstruction in hips with acetabular bone deficiency in order to clarify the indications for its use and to identify the factors that influence the clinical and radiographic outcome. METHODS: Forty-one hips in thirty-eight patients had an acetabular revision with a bilobed acetabular component inserted without cement between December 1991 and December 1995. These hips were a subset of the 414 hips treated with an acetabular revision during the same period of time. One patient was lost to follow-up, and one died during the study period. Two patients who could not return for radiographic evaluation completed questionnaires. The remaining thirty-four patients (thirty-seven hips) were evaluated radiographically and clinically and were followed for an average of forty-one months (range, twenty-four to sixty-six months). RESULTS: Radiographic analysis demonstrated an improvement in the average vertical displacement of the hip center. At the time of the latest follow-up examination, 76 percent (twenty-eight) of the thirty-seven cups were stable, 8 percent (three) were probably unstable with a change in the screw position but no definite migration of the cup, and 16 percent (six) were unstable. Eight of the nine loose or probably loose components were in patients who had more than two centimeters of superior migration of the component and disruption of Kohler's line on preoperative radiographs. Additionally, implants were more likely to become unstable (demonstrating more than 4 degrees of change in the abduction angle or more than four millimeters of radiographic migration) when the inferior aspect of the component did not extend to or distal to the interteardrop line, which indicated that the component was undersized. CONCLUSIONS: On the basis of our early rate of probable or definite loosening of 24 percent (nine of thirty-seven cups) and the technical difficulties involved, we do not recommend the routine use of this component. We believe that this device is indicated when a patient has an oblong-shaped acetabular defect and the surgeon wants to correct an elevated hip center. However, the medial wall of the acetabulum (Kohler's line) should be intact if the failed component has migrated more than two centimeters. An alternative reconstruction technique, such as use of a structural allograft with or without an acetabular cage, is also an option in this situation.     

Neuroblastoma and hepatocyte coculture conditioned media alter apoptosis

BACKGROUND: Neuroblastoma is a childhood tumor that often displays unusual biological behavior. The tumor may present with widespread metastases that are unresponsive to aggressive treatment. At other times, both the metastases and the primary tumor may spontaneously regress without treatment. Apoptosis, or programmed cell death, is thought to play a role in the dichotomous behavior of neuroblastoma. We hypothesize that neuroblastoma cells will interact with host tissues to release mediators that affect apoptosis. MATERIALS AND METHODS: Human neuroblastoma cells and human Chang hepatocytes are grown in a noncontact, coculture system. After incubation for 4 days, the medium from the coculture system is collected. Neuroblastoma cells and Chang hepatocytes are then plated separately with the conditioned medium and their own standard growth medium as controls. After 4 days, these cells are harvested and cytospins made for immunostaining. Tumor necrosis factor alpha (TNF-alpha), Fas ligand, and Bcl-2, are measured with immunohistochemistry. Apoptosis is detected with the TUNEL method. Immunostaining data are interpreted with computer image analysis and reported as stain index. TUNEL data are reported as percentage apoptotic cells. All data are reported as means +/- SEM. Statistical analysis is performed and P < 0.05 considered significant. RESULTS: Chang hepatocytes grown in the coculture conditioned media have an increase in TNF-alpha and Fas ligand. The neuroblastoma cells have a significant decrease in Fas ligand. There is a significant increase in the number of apoptotic hepatocytes when they are cultured in the conditioned media. In contrast, the neuroblastoma cells grown in the coculture conditioned media show no increase in apoptosis. Finally, Bcl-2 is significantly increased in the neuroblastoma cells cultured in the conditioned media. CONCLUSIONS: Neuroblastoma cells grown in coculture conditioned media show increased expression of Bcl-2 and decreased Fas ligand levels. These changes should diminish apoptosis activity in the tumor cells. In contrast, the conditioned media induce elevated levels of proapoptotic mediators in the Chang hepatocytes. A tumor's ability to successfully metastasize may be dependent on mediators generated in the tumor-host interaction, and may not be just an independent characteristic of the tumor itself.     

微流芯片检测流感病毒多重逆转录聚合酶链反应产物的实验研究

[目的 ]　建立应用微流芯片检测甲 1型、甲 3型、乙型流感病毒多重逆转录聚合酶链反应 (mRT -PCR)产物的方法 ,在mRT -PCR扩增核酸的基础上自动化灵敏的定量检测扩增产物 ,快速检测甲亚型、乙型流感病毒 ,帮助临床快速诊断和鉴别诊断其他呼吸道病毒感染 ,以及明确流感病毒在人群中感染、流行情况。　 [方法 ]　采用经MDCK细胞分离培养的甲 1型、甲 3型、乙型流感病毒毒株病毒液 ,使用 3组特异引物经mRT -PCR扩增核酸 ,扩增产物分别采用毛细管电泳技术经Caliper10 0 0微流芯片分析仪自动化检测和经 2 %琼脂糖凝胶电泳法检测。　[结果 ]　设计三组引物对相应甲 1型、甲 3型、乙型流感病毒靶基因的mRT -PCR扩增产物片段分别为 43 0bp、2 10bp、3 91bp ,本实验mRT -PCR扩增产物经 2 %琼脂糖凝胶电泳 ,与Marker比照 ,DNA条带基本在此位点附近 ;产物采用毛细管电泳法经Caliper10 0 0微流芯片分析仪后 ,分别于 413bp、2 0 3bp、3 79bp处出现陡峭的峰 ,如图所示。　[结论 ]　应用微流芯片采用毛细管电泳法可对流感病毒mRT -PCR产物进行定位及相对定量 ,有助于快速诊断流感病毒感染 ,有助于对流感的监测。     

非虚假设非中心法及其临床应用

目的本文提出一种非虚假设非中心法,并说明其临床应用.方法以非虚假设取代虚假设将经典非中心法加以扩展,以Monte Carlo方法展示其行为.结果当最小临床承认差量取零时,它还原为经典方法.其观测功效与预定功效吻合.结论这种方法适用于以治疗-对照差临床意义研究或临床等效性为目的临床试验的设计.     

Postero-medio-anterior approach of the ankle for the pilon fracture

A good view of the operative field is important for better reduction and fixation in surgical treatment of fractures. The exposure of the ankle joint for the pilon fracture is commonly through the anterior approach, or combined with the medical approach. But sometimes it is still difficult to have complete viewing of the articular surface and to apply internal fixation by that approach. In recent years, we developed a "postero-medio-anterior" approach of the ankle joint by one incision. This approach provides an excellent exposure of the anterior, medial and posterior aspects of the ankle joint with a clear view of the articular surface. In our 45 cases of pilon fracture during 1991 to 1995, there was no incisional injury to the neurovascular bundle. Superficial wound edge necrosis was noted in two cases which healed later without further procedure. Therefore, we recommend this approach as a simple and reliable incision for open reduction of pilon fractures.     

电声门图测试对声带占位性病变的筛查价值

目的 探讨电声门图(electroglottography，EGG)测试在声带占位性病变中的筛查价值。方法 对134例声门型喉癌、167例声带良性病变(包括113例声带息肉、17例声带囊肿和37例声带白斑)及62名健康志愿者进行EGG测试，进行组间和组内比较，分析EGG测试的敏感性和特异性。结果 声带良性病变和喉癌组EGG波形和参数多数异常，与健康组之间有显著性差异，且良恶性病变组间亦有差异。但良性病变组内即息肉、囊肿和白斑之间，以及喉癌组内不同T分期之间EGG波形和参数差异多数无统计学意义。结论 电声门图测试在声带占位性病变的筛查中具有较高的敏感性，对区分良恶性病变亦有一定的特异性，但对病变类型和期别的划分无价值。     

兔蜗神经直接动作电位的特征

目的　探讨新西兰大白兔蜗神经直接动作电位 (directcochlearnerveactionpotential,DCNAP)的记录方法和特征 ,建立术中听觉监护动物模型。方法　纯种新西兰大白兔 6只 (12耳 ) ,乙状窦后进路暴露小脑、脑干及双侧桥脑小脑角区 ,插入针状电极于蜗神经 ,记录DCNAP ,并按常规方法记录听性脑干反应 (auditorybrainstemresponse ,ABR)。结果　用本方法记录的DCNAP具有振幅大、波形稳定、重复性好、记录时间短的特点 ,但个体差异较大。结论　在蜗神经桥脑小脑角区用针状电极可以可靠记录到DCNAP ,是术中听觉监护的可行方法     

Resection of suprasellar tumors by using a modified transsphenoidal approach. Report of four cases

Generally accepted contraindications to using a transsphenoidal approach for resection of tumors that arise in or extend into the suprasellar region include a normal-sized sella turcica, normal pituitary function, and adherence of tumor to vital intracranial structures. Thus, the transsphenoidal approach has traditionally been restricted to the removal of tumors involving the pituitary fossa and, occasionally, to suprasellar extensions of such tumors if the sella is enlarged. However, conventional transcranial approaches to the suprasellar region require significant brain retraction and offer limited visualization of contralateral tumor extension and the interface between the tumor and adjacent structures, such as the hypothalamus, third ventricle, optic apparatus, and major arteries. In this paper the authors describe successful removal of suprasellar tumors by using a modified transsphenoidal approach that circumvents some of the traditional contraindications to transsphenoidal surgery, while avoiding some of the disadvantages of transcranial surgery. Four patients harbored tumors (two craniopharyngiomas and two hemangioblastomas) that arose in the suprasellar region and were located either entirely (three patients) or primarily (one patient) within the suprasellar space. All patients had a normal-sized sella turcica. Preoperatively, three of the four patients had significant endocrinological deficits signifying involvement of the hypothalamus, pituitary stalk, or pituitary gland. Two patients exhibited preoperative visual field defects. For tumor excision, a recently described modification of the traditional transsphenoidal approach was used. Using this modification, one removes the posterior portion of the planum sphenoidale, allowing access to the suprasellar region. Total resection of tumor was achieved (including absence of residual tumor on follow-up imaging) in three of the four patients. In the remaining patient, total removal was not possible because of adherence of tumor to the hypothalamus and midbrain. One postoperative cerebrospinal fluid leak occurred. Postoperative endocrinological function was worse than preoperative function in one patient. No other new postoperative endocrinological or neurological deficits were encountered. This study demonstrates the feasibility of using a modified transsphenoidal approach for resection of certain suprasellar, nonpituitary tumors.     

The use of an ambulatory,automatic sleep recording device (QUISI™ Version 1.0) in the evaluation of primary snoring and obstructive sleep apnoea

The use of an ambulatory, automatic sleep recording device (QUISI? Version 1.0) in the evaluation of primary snoring and obstructive sleep apnoea Electroencephalogram (EEG) evaluation with polysomnography (PSG) according to the Rechtschaffen & Kales (R&K) rules is time and cost consumptive, but ambulatory polygraphy systems do not allow EEG recording routinely. As a consequence, the number of sleep disordered events cannot be calculated exactly. QUISI is a one‐channel, self‐applicable ambulatory EEG recording device. The present study was designed as a prospective, non‐randomized clinical trial. This investigation evaluated the results of 40 patients with primary snoring and obstructive sleep apnoea measured with level 1 PSG and QUISI simultaneously. Fifteen patients (37.5%) were primary snorers with normal sleep profiles, whereas 25 patients (62.5%) suffered from obstructive sleep apnoea (OSA) with a Respiratory Disturbance Index (RDI) of 38.6 ± 23.8. The mean total sleeping time (TST) was underestimated by 4.5%, while Sleep Efficiency Index (SEI) was understimated by 4.6% by the QUISI device compared with PSG. The correlation between the QUISI and the PSG estimates for single sleep stages demonstrated only moderate correlation. The statistical significance for sleep stage 2 was r = 0.42, P = 0.002; for sleep stage 3/4, r = 0.31, P = 0.02; and for WAKE, r = 0.33, P = 0.01. Sleep stage 2 as well as sleep stage 3/4 were underestimated by QUISI substantially (difference: ?5.6% and ?10.3%), while WAKE was overestimated by QUISI to a larger amount (difference: +10.4%). Sensitivity and specificity of QUISI to recognize pathological sleep profiles compared with PSG/R&K were 0.92 and 0.96 respectively. QUISI is able to evaluate normal versus altered sleep profiles in patients with primary snoring and OSA. Comparing the quartile ranges, we found substantial differences between QUISI and PSG/R&K. QUISI gives an impression of sleep architecture and objective verification of a sleep disturbance in an ambulant setting but cannot replace the sleep laboratory‐based PSG.