α核素非均匀微观分布对细胞微剂量的影响

目的探讨放射免疫治疗中α核素在细胞水平上非均匀微观分布对细胞S因子的影响。方法利用蒙特卡罗方法随机模拟α粒子的发射;基于连续慢化近似模型,根据α粒子剩余射程-能量的关系,采用插值法计算α粒子入射动能和出射动能,得到其在靶区内的能量沉积。以213Po为例,计算了不同细胞大小及核素不同微观分布（均匀分布、中心分布、随核素距细胞中心的距离线性递增、线性递减、指数递增、指数递减）下细胞对细胞的S因子。结果213Po均匀分布下的S（C←C）与Hamacher给出的结果符合得很好;不同微分布下的S（C←C）有显著差别。分析表明,核素不同微观分布所造成的α粒子在靶区内运动的平均弦长的显著变化,以及由此产生的α粒子平均碰撞阻止本领的变化,是造成细胞S因子有显著差别的主要原因。结论放射性核素非均匀微分布类型显著影响细胞S因子的大小,在估算细胞吸收剂量时应予以重视。     

Lung function, smoking and survival in severe alpha 1-antitrypsin deficiency, PiZZ

Lung function, smoking, age and mortality data in 158 adult severe alpha₁-antitrypsin deficient, PiZZ individuals, followed from 1963 to 1982 were analyzed. Low initial FEV₁ value was significantly associated with increased mortality (p < 0.005). A 3 yr mortality rate of 40% was found in individuals whose initial FEV₁ values were less than 30% of that predicted. In contrast, the corresponding 3-yr mortality among those whose initial FEV₁ values were between 30 and 65% of that predicted was only 7%. Smokers were found to have significantly lower FEV₁ levels (p = 0.008) and higher mortality (p < 0.005) than non-smokers. The difference between current and ex-smokers in mortality and FEV₁ level were not statistically significant (p = 0.9 and p>0.25, respectively). Cross-sectional analysis of the initial FEV₁ values indicated a significant decline (p < 0.005) of FEV₁ with increasing age. This decline was greater among smokers than non-smokers. Longitudinal analysis of FEV₁ rates of decline in 80 cases with follow-up FEV₁ measurements failed to detect any significant differences between smokers and non-smokers, but was performed late in the disease process. The application of these results to the planning of studies on replacement therapy, smoking intervention strategy and longitudinal follow-up is discussed.     

宫颈癌组织中HPV16 E7序列多态性分析

目的探讨广东地区宫颈癌组织中HPV16肿瘤相关性抗原E7基因序列的多态性.方法采用通用引物PCR直接测序法对宫颈癌标本中的HPV分型,从含有HPV16型的标本中采用自行设计的多重引物通过巢式PCR扩增出HPV16E7,经DNA序列测定法检测其基因变异,进而寻找其热点突变.结果50例宫颈癌组织HPV-DNA的检出率为78%,其中HPV16和HPV18型混合感染18例,单纯HPV16型感染15例.33例含有HPV16型的标本中扩增出25例HPV16E7,其中17例647位核苷酸“T”变异“C”,导致相应的蛋白质由天冬氨酸变异为丝氨酸.结论广东地区宫颈癌组织中HPV16E7DNA序列发生碱基替换的区域主要在647位至846位,热点突变点为Nt647和Nt846.     

Cerebrospinal fluid-filtration reduces TNF alpha in bacterial meningitis-CSF

A 37 year old male was admitted with the diagnosis of bacterial meningitis. Pneumococci were seen in the Gram stain of the cerebrospinal fluid. The clinical condition did not suggest severely raised intracranial pressure, there were no localizing signs and symptoms. CSF was turpid, with 20.100/3/mm³, mainly polymorphonuclear cells. Tumor necrosis factor alpha in CSp was greatly increased with 813 pg/ml. Parallel to the application of intravenous Penicillin G a CSF filtration was carried out. Within 214 h 225 ml CSF were filtrated through a Pall-filter, using a bidirectional pump. Cell count dropped to 720/3 cells/mm³, TNF-alpha to 39 pg/ml. The clinical course was uneventful, on day 12 the patient could be discharged without sequelae. CSF filtration may be a highly effective method to reduce from the CSF pathogenetically important cytokines, such as TNF-alpha, being responsible for intrathecal/meningeal inflammatory processes and triggered by cell-wall components of bacteria, e.g. pneumococci.     

Trichloroethanol is not a metabolite of alpha chloralose

Head space capillary gas chromatography was used to detect alpha chloralose and its potent metabolite, trichloroethanol in clinical and forensic cases. Although alpha chloralose was identified in blood and urine in all cases, trichloroethanol was never detected. In a fatal case the alpha chloralose concentration in blood was 151.3 mg/l. It was concluded that trichloroethanol is not a metabolite of alpha chloralose.     

A method for reducing background tracks in plastic detectors

The purpose of the present study was to reduce background tracks by removing a given surface layer of the 250 μm thick lexan polycarbonate foils before exposure to alpha particles. Ethylenediamine solution was used for taking layers from the surface of the foils.     

Are transforming properties of the bovine papillomavirus E5 protein shared by E5 from high-risk human papillomavirus type 16?

The E5 proteins of bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 16 (HPV-16) are small (44-83 amino acids), hydrophobic polypeptides that localize to membranes of the Golgi apparatus and endoplasmic reticulum, respectively. While the oncogenic properties of BPV-1 E5 have been characterized in detail, less is known about HPV-16 E5 due to its low expression in mammalian cells. Using codon-optimized HPV-16 E5 DNA, we have generated stable fibroblast cell lines that express equivalent levels of epitope-tagged BPV-1 and HPV-16 E5 proteins. In contrast to BPV-1 E5, HPV-16 E5 does not activate growth factor receptors, phosphoinositide 3-kinase or c-Src, and fails to induce focus formation, although it does promote anchorage-independent growth in soft agar. These variant activities are apparently unrelated to differences in intracellular localization of the E5 proteins since retargeting HPV-16 E5 to the Golgi apparatus does not induce focus formation.     

Antibody response to a synthetic peptide derived from the human papillomavirus type 6/11 L2 protein in recurrent respiratory papillomatosis: Correlation between southern blot hybridization,polymerase chain reaction,and serology

Recurrent respiratory papillomatosis (RRP) is the most common benign tumour of the larynx, affecting both children and adults. We present a series of 25 patients, including 10 cases of juvenile multiple, 8 cases of adult solitary, and 7 cases of adult multiple RRP. Biopsy tissue from each patient was screened by Southern blot hybridization and polymerase chain reaction for the presence of human papillomavirus (HPV) DNA. Sera from patients and age- and sex-matched controls were tested for the presence of HPV-specific antibodies using a synthetic pep-tide derived from the minor capsid protein (L2) of HPV 6/11. By Southern blot hybridization and/or polymerase chain reaction, biopsies from all patients were positive for HPV 6/11 DNA. There was no difference in antibody response between cases and controls. Female cases and controls had significantly higher antibody titers than male subjects. A correlation was observed between the HPV-specific antibody level and the number of surgery-necessitating recurrences. © 1994 Wiiey-Liss, Inc.     

MEG Characterization of Spontaneous Alpha Rhythm in the Human Brain

The present piece of research studied the spontaneous alpha rhythm of the human brain by combining the use of a whole-cortex neuromagnetometer and Magnetic Resonance Imaging. Single trials of spontaneous brain activity were recorded from ten human subjects asked to rest, with their eyes either closed or open, in relaxed wakefulness. MEG measurements were conducted over a period of one and a half years. The replicability of the results was confirmed for eight subjects out of ten. For three subjects, the alpha rhythm did not show any reductions due to the opening of the eyes. Both field map pattern and location of the estimated source were persistently stationary during each of the bursts of oscillations of the alpha rhythm. Dipoles were concentrated in clusters, indicating the existence of several spatially distributed sources. The calcarine fissure, the parieto-occipital sulcus and the surrounding occipital and parieto-occipital areas were identified as cortical sites of the brain where the alpha rhythm may originate. For four subjects, the majority of the sources were located near or in the calcarine fissure, while for five subjects, they were located near or in the parieto-occipital sulcus and for the remaining subject they were equally divided between the two generation sites.     

宫颈病变程度与人类乳头瘤病毒(16、18型)负荷的关系

目的探讨宫颈病变程度与人类乳头状瘤病毒(HPV)16、18型负荷的关系。方法采用实时荧光定量聚合酶链反应(FQ-PCR)方法,检测宫颈不同病变活检组织及石蜡包埋标本中HPV16、18型感染状况。结果正常宫颈上皮感染HPV16、18型阳性率为3%,CINⅠ、Ⅱ、Ⅲ级和宫颈癌感染HPV16、18阳性率分别为45.7%,69.5%,72.2%和74.6%。正常宫颈与CIN,宫颈癌HPV16、18阳性率差异有极显著性(P<0.0001)。宫颈糜烂(Ⅰ°、Ⅱ°、Ⅲ°),CIN(Ⅰ、Ⅱ、Ⅲ级)及鳞癌HPV16、18阳性标本平均拷贝数分别为:3.58×103、1.80×105、1.19×107,随着病变程度加重而逐渐增加,差异有极显著性(P<0.0001)。结论宫颈病变程度与HPV16、18型负荷呈正相关。对宫颈病变组织标本行HPV16、18型检测,对判断宫颈病变发展趋势,积极处理癌前病变,阻断病程、预防宫颈癌的发生将起到重要作用。