Influence of film fog on radiographic caries diagnosis

Increasing film speed may potentially jeopardize diagnostic quality because of a more rapid build up of fog and an ensuing decrease in image contrast. A standardized amount of fog was simulated by pre-exposing E-speed dental films before use to obtain images of extracted teeth with and without approximal caries. Three experiments were performed. In the first, no effort was made to compensate for the increased density caused by fog. In the other two, density was kept constant by reducing exposure and developing time respectively. Nine dentists recorded the presence and absence of caries using a rating scale to indicate diagnostic confidence. As a measure of diagnostic accuracy, the area under the binormal ROC curve was used and the values averaged across observers. The results showed that fog, up to a level of base plus fog of 0.6 optical density units, had no influence on the diagnostic accuracy in the absence of any compensation. When exposure was lowered to compensate for the increased density, significantly lower diagnostic accuracy was found. On the other hand, when developing time was decreased, no significant difference was found. Observers ranked radiographs with higher levels of fog as being of lower quality. However, no significant correlation was found between subjective ranking of image quality and diagnostic accuracy obtained from the same radiographs. It is concluded that relatively high levels of fog do not exert a negative influence on approximal caries diagnosis and no attempt should therefore be made to compensate for the increased density.     

急性有机磷农药中毒120例的救治

0　引言　近年来 ,我科在救治急性有机磷农药 (organophos-phorus,OP)中毒方面 ,积累了一些经验 ,现报告如下 .1　对象和方法1 .1　对象　本组 1 2 0例符合《急诊急救学》中的诊断标准 [1 ](男 2 9例 ,女 91例 ) ,年龄 1 .5～ 70岁 ,平均 2 8.6岁 .经口中毒 99例 ,经皮肤中毒 2 1例 .轻度中毒 1 5例 ,中度中毒 42例 ,重度 (含极重度 )中毒 6 3例 . 1 996年 39例 ,1 997年 43例 ,1 998年 38例 . DDV 79例 ,乐果 2 0例 ,混合性中毒 1 0例 ,水胺磷 3例 ,氧化乐果、 391 1、 1 0 5 9、对硫磷各 2例 ,敌百虫 1例 ,药名不详 1 0例 .服毒量 >2 5 …     

Iotrol versus metrizamide in lumbar myelography: a double-blind study

In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population.     

P-fimbriae vaccines

Protection against acute pyelonephritis was induced by immunization of baboons with purified P-fimbriae ofEscherichia coli as vaccines. To test for cross-protective capacity of two different P-fimbriae vaccines we vaccinated baboons with P-fimbriae purified from eitherE. coli strain ER2 or strain JR1 and subsequently challenged the animals withE. coli strain JR1. All vaccinated animals showed elevated antibody titers to P-fimbriae from both of theE. coli strains used. Both vaccines tended to reduce the time of bacteriuria. They partially prevented pyelonephritis and protected against loss of renal function.     

Meniscal injuries: detection using MR imaging

Both retrospective and blinded analyses of thin-section, high-resolution magnetic resonance (MR) images of the knee joint, produced using a solenoid surface coil, indicate that MR imaging is an effective technique for evaluating meniscal injuries. Images of 49 patients were evaluated, and the results were correlated with those of subsequent arthroscopy. A grading scale was developed to rate the index of suspicion of a meniscal tear based on the MR images. Overall, approximately 80% of menisci rated grade 4 (definite tear) or 3 (probable tear) were found to have corresponding tears at arthroscopy. In many other patients with a grade 4 or 3 meniscus in whom a corresponding tear was not found arthroscopically, meniscal tears at other sites or other abnormalities were correctly diagnosed using MR. A majority of the false-positive MR images involved the posterior horns of the menisci, the sites of most false-negative arthroscopic diagnoses. The predictive value of a negative MR image was almost 100%. Even in patients with moderate-to-large effusions, the menisci were accurately evaluated. The results imply that MR imaging is useful in the preoperative evaluation of suspected meniscal tears.     

Affinity-purified human Interleukin I is cytotoxic to isolated islets of Langerhans

Addition of highly purified human Interleukin-1 to the culture medium of isolated rat islets of Langerhans for 6 days led to 88% inhibition of glucose-induced insulin-release, reduction of islet contents of insulin and glucagon to 31% and 8% respectively, and disintegration of the islets. These effects were dose-dependent and reproducible when using three different Interleukin-1 preparations. Highly purified human Interleukin-2, Lymphotoxin, Leucocyte Migration Inhibitory Factor and Macrophage Migration Inhibitory Factor were ineffective. These findings suggest that Interleukin-1 may play an important role in the molecular mechanisms underlying autoimmune B-cell destruction leading to Type 1 (insulin-dependent) diabetes mellitus.     

Creutzfeldt--Jakob Disease in Recipients of Human Growth Hormone in the United Kingdom: A Clinical and Radiographic Study

In the past 3 years there have been five further cases, in additionto one case reported in 1985, of Creutzfeldt-Jakob disease inrecipients of human growth hormone in the United Kingdom. Theclinical findings of two of these cases are described, demonstratinga typical presentation with a predominantly cerebellar syndromeat onset which is not commonly a presenting feature of sporadicCreutzfeldt-Jakob disease. In one case a ^99mTc hexamethylpropylenaminesingle photon emission tomographic scan showed marked impairmentof tracer uptake in the basal ganglia and cerebral cortex ata time when the clinical picture was predominantly cerebellar.This technique may be useful in early diagnosis. In the othercase post mortem examination of the brain showed prominent amyloiddeposition in the cerebellum, which has not been described previouslyin pituitary-hormone related Creutzfeldt-Jakob disease. Thepreviously published cases of growth hormone-related Creutzfeldt-Jakobdisease are reviewed and reasons for the particular clinicalpattern seen are discussed.     

中药天年饮对衰老大鼠脾淋巴细胞增殖转化能力的影响

目的:观察中药天年饮对衰老大鼠抗氧化能力、脾淋巴细胞增殖转化能力及免疫器官指数的影响。方法:实验于2006-04/07在承德医学院基础医学研究所完成。选择清洁级4月龄雄性SD大鼠40只,按随机数字表法分为4组:正常对照组、衰老模型组、天年饮用药组和阴性对照组,每组10只。正常对照组大鼠常规饲养,自由摄食、饮水。衰老模型组、天年饮用药组和阴性对照组大鼠均采用D-半乳糖连续腹腔注射制备亚急性衰老的大鼠模型。衰老模型组大鼠造模成功后不再做任何处理;天年饮用药组大鼠造模成功后每天用天年饮(由炙何首乌、怀牛膝、肉从蓉、淫羊藿、丹参、茯苓等6味中药组成,经熬制后含生药1.5g/mL,购自承德医学院附属肛肠医院)灌胃(8.1g/kg),共30d;阴性对照组大鼠在造模成功后每天用同等剂量的生理盐水灌胃,时间同天年饮用药组大鼠。造模后30d采用噻唑蓝法检测脾淋巴细胞的增殖转化能力,同时分别检测大鼠血清超氧化物歧化酶活性、丙二醛含量以及大鼠的胸腺指数和脾脏指数。结果:纳入动物40只,均进入结果分析。①衰老模型组大鼠血清超氧化物歧化酶活性低于正常对照组、丙二醛含量高于正常对照组,差异有显著性意义[分别为(1.77±0.16),(2.48±0.22)mkat/L,t=2.613,P<0.05;(447.70±31.20),(267.54±40.82)nmol/L,t=11.088,P<0.01];天年饮用药组大鼠血清超氧化物歧化酶活性高于衰老模型组、丙二醛含量低于衰老模型组,差异有显著性意义[分别为(2.33±0.26),(1.77±0.16)mkat/L,t=-2.258,P<0.05;(276.32±23.30),(447.70±31.20)nmol/L,t=13.917,P<0.01]。②衰老模型组大鼠胸腺指数、脾脏指数和脾淋巴细胞的增殖转化能力(A)低于正常对照组,差异有显著性意义(分别为0.0775±0.0309,0.1239±0.0436,t=2.745,P<0.05;0.347±0.099,0.466±0.108,t=2.568,P<0.05;0.388±0.054,0.470±0.063,t=3.125,P<0.01);天年饮用药组大鼠胸腺指数、脾脏指数和脾淋巴细胞的增殖转化能力(A)高于衰老模型组,差异有显著性意义(分别为0.1130±0.0456,0.0775±0.0309,t=2.238,P<0.05;0.451±0.111,0.347±0.099,t=2.211,P<0.05;0.447±0.061,0.388±0.054,t=2.2902,P<0.05)。结论:中药天年饮可提高机体的抗氧化能力及免疫功能,具有延缓衰老的作用。