腰椎峡部裂的CT诊断

目的：回顾性分析腰椎峡部裂的ＣＴ表现并讨论其诊断与鉴别诊断，材料与方法，２３例患先行腰椎侧位扫描定位图像，采用与椎间盘平行的角度，自病变脊椎的上一椎体下缘边续发描至于下椎体上缘，层厚４或５ｍｍ必要时在峡部行２ｍｍ，层厚扫描，结果；２３例中，累及双侧２１例，单侧２例，发生在Ｌ５１６例，Ｌ４７例，ＣＴ表现为同一脊椎关节突间的低密度裂隙，出瑞椎弓根下缘平面，走行不规则，裂隙可宽可窄，表面不光滑。     

The effect of arteriovenous malformation resection on cerebrovascular reactivity to carbon dioxide

To investigate the cerebral hemodynamic changes associated with obliteration of arteriovenous malformations (AVMs), we studied 26 patients undergoing total microsurgical AVM resection during isoflurane and N2/O2 anesthesia. Detectors were placed 5 to 6 cm from the margin of the lesion and in a homologous contralateral position. Cerebral blood flow (CBF) was measured using the intravenous xenon-133 technique before and after AVM resection, during both hypocapnia and normocapnia at each stage. Intraoperative changes in CBF were related to a risk score system based on the patient's history and preoperative angiograms. Seven otherwise healthy patients undergoing spinal surgery were studied to control for anesthetic effects. Patient demographic and clinical data for the AVM group conformed to the expected strata of a large AVM population. The CBF increased after excision (22 +/- 1 ml/100 g/min before excision to 30 +/- 2 ml/100 g/min after excision; mean +/- SE, n = 25, P less than 0.002) without a hemispheric difference. CO2 reactivity increased slightly after excision (4.2 +/- 0.3% change/mm Hg before excision to 4.7 +/- 0.3% change/mm Hg after excision; n = 14, P less than 0.02). The baseline CBF and CO2 reactivity were not different from the control group. There was a weak correlation between the risk score and the percentage of change in the ipsilateral CBF, with a trend for the patients with the lowest risk to have the lowest CBF changes after resection. There was no relationship between CO2 reactivity and risk grade. None of the patients awoke from anesthesia with unexpected neurological deficits. The highest CBF increases were associated with postoperative brain swelling in one patient and fatal intracerebral hemorrhage in another. Both patients had normal CO2 reactivity before excision. One patient suffered postoperative intracerebral hemorrhage, attributable to technical problems, and had no increase in CBF. We conclude that, with an acute increase in the arteriovenous pressure gradient (and cerebral perfusion pressure) that results from shunt obliteration, there is an immediate global effect of AVM resection to increase CBF. Cerebrovascular reactivity to CO2 remains intact both before and after excision.     

The effect of cigarette smoke on the bovine lens

Smoking has recently been identified from epidemiological studies as a possible cause of cataract but the mechanism involved is not known. Therefore, our laboratory has initiated studies aimed at elucidating these mechanisms. Whole bovine lenses were cultured to examine possible effects of cigarette smoke on amino acid uptake and protein synthesis. Cigarette smoke, filtered to remove nicotine and tar which would not reach the eye in vivo, was bubbled through culture medium. Bovine lenses were incubated in this medium in the presence of [¹⁴C]-leucine for four days. A significant decrease in uptake of [¹⁴C]-leucine and a decrease in protein synthesis were found with smoke treated lenses. This is the first demonstration of an effect of cigarette smoke on the lens. Further work is needed to determine how this metabolic upset is mediated and how it could lead to cataract.     

4125例哈萨克族儿童斜视及弱视调查

本文对本地区五个县九所哈萨克族小学学生共计4125人进行了斜视、弱视的调查。调查对象全部为4—14岁哈萨克儿童。在受检儿童中发现斜视者48例,患病率为1.1％。外斜视32例占66.67％,内斜视16例占33.33％,斜视并有弱视者15例占31.25％。斜视而视力正常者33例占68.75％。在4125例受检儿童中发现弱视139例(209只眼),其患病率为3.37％,双眼弱视70例,单眼弱视69例,二者无显著差异。139例弱视中男性患者73例,女性患者66例,二者亦无差异。209例只弱视眼中轻度弱视84只眼占40.19％,中度弱视104只眼占49.76％,重度弱视21只眼共占10.05％。调查中笔者发现哈萨克族儿童弱视眼尤以屈光不正为多,209例眼中有106只为单纯性远视眼,因此笔者提出如何早期发现屈光不正并予以纠正将有可能防止许多弱视的发生。     

The electrophysiological effects of dicentrine on the conduction system of rabbit heart.

1. The electrophysiological effects of dicentrine, an aporphine alkaloid isolated from the root of Lindera megaphylla, were examined in the Langendorff perfused rabbit heart and rabbit isolated cardiac cells. 2. Standard electrophysiological characters were measured in the Langendorff perfused rabbit heart (control study) and after 5 min exposure to 1, 3 and 9 microM of dicentrine and during the subsequent recovery phase sequentially (n = 7). The same study protocols were performed in 0.5 to 4.5 microM quinidine (n = 7), 18 to 162 microM procainamide and N-acetylprocainamide (n = 7) for comparison. 3. The results showed that the spontaneously beating heart rate and the sinoatrial (SA) and atrioventricular nodal (AH) conduction time were not significantly affected by dicentrine but were significantly suppressed by the higher doses of quinidine (4.5 microM) and procainamide (162 microM). 4. The His-Purkinje conduction time was significantly increased by the higher dose of dicentrine, quinidine and procainamide. 5. The ventricular repolarization time and its effective refractory period were significantly increased by the higher dose of dicentrine and the other agents. 6. The effective refractory period of the atrium, AV node and His-Purkinje system were also significantly increased by dicentrine and the other agents. 7. A voltage clamp study revealed that the prolongation of atrial action potential duration by dicentrine (9 microM) was associated with a significant inhibition of the transient potassium outward current. As well as inhibition of the transient outward current, a significant inhibition of the sodium inward current by dicentrine was found.(ABSTRACT TRUNCATED AT 250 WORDS)     

A case-control study of the effect of environmental sanitation on diarrhoea morbidity in Malawi.

A case-control design has been applied in the evaluation of improved environmental sanitation on diarrhoeal diseases in rural Malawi. The study demonstrates the feasibility of using such an approach to evaluate two levels of water supply and sanitation service quickly and at moderate cost. Sample sizes would need to be increased substantially to evaluate multiple levels of service or to investigate interactions between water supply and sanitation. The results indicate that children living in families who use good quality water supplies and latrines experience 20% less diarrhoea as reported to the health clinics during the warm, rainy season.