Differential response of two cell lines sequentially irradiated with low X-ray doses

An experiment was designed to compare the effect of repeated low doses of X-rays in two different cell lines: one transformed, epithelial like and aneuploid Chinese hamster ovary K-1 (CHO-K1); the other originated from a human primary culture, fibroblast, diploid and non-transformed, MRC-5. CHO and MRC-5 cells were cultured for 14 or eight passages, respectively. Irradiation was performed once per passage when cells were in the quiescent state (90?–?95% in G1/G0). Cells were exposed to 10.0 mSv X-ray doses. Ionizing radiation did not induce apoptosis or necrosis in the exposed CHO cell population. Significant increases of low-level damaged cells (degrees 1 and 2) were found for the 14 cycles of radiation when compared with controls, except for the first irradiation cycle. No significant increases in the frequency of cells with severe damage were observed. The frequency of MRC-5 cells with low-level damage increased significantly when compared with controls for radiation cycles seven and eight. Significant increases of apoptosis, necrosis and severe damage were found only for the highest dose. Transformed and non-transformed cell types responded differently to direct and indirect damage using low-dose repeat exposures to ionizing radiation. Though more investigation is needed to understand the mechanisms of radiation effects in chronic low-dose-exposed cell populations, cellular type should be taken into account in the design of in vitro experiments for understanding low-dose-irradiation effects.     

LOCALIZED LEPROMATOUS LEPROSY AND ITS RESPONSE TO CHEMO-IMMUNOTHERAPY

Background. This is an unusual presentation of lepromatous leprosy (ll ) in a young boy, 12 years of age. The study forms part of a large scale immunotherapeutic trial with Mycobacterium w (M.w) antileprosy vaccine. The trial is being conducted in two major hospitals in New Delhi, India. Materials and Methods. This patient presented with three lesions: one on each forearm and the third on the left leg. He was classified initially as borderline tuberculoid leprosy. Slit-skin smears and histopathology from the lesions proved the diagnosis to be lepromatous leprosy with a bacterial index (bi ) 6+. The initial lepromin test was negative. The patient was treated with chemo-immunotherapy (standard multidrug therapy and immunotherapy with Mycobacterium w vaccine). Results. Investigations after 1 year (15 months) of multidrug therapy and three doses of vaccine, showed a remarkable fall in the bi from 6 to 0 in the lesions, a lepromin positivity of 5 mm, and a histological upgrading from lepromatous leprosy to borderline tuberculoid. Immunologic studies at 15 months revealed a good LTT response and high levels of cytokines, specifically IL-2 and IFN-γ. Conclusions. This report presents an LL patient with disease limited to a few sites. It stresses the importance of slit-smear and biopsy in all patients of leprosy, and it highlights the upgrading observed on administration of chemo-immunotherapy.     

外源性一氧化氮对创伤愈合过程中一氧化氮合酶表达及瘢痕形成的影响

目的:应用组织化学、免疫组织化学及计算机辅助图像分析方法,观察外源性一氧化氮在创伤愈合过程不同时间,对一氧化氮合酶表达和胶原形成的影响,探讨其在促进创伤愈合和抑制病理性瘢痕形成中的机制。方法:实验于2004-09/2006-03在河北省人民医院整形烧伤外科及河北省人民医院临床医学研究中心完成。以硝普钠为一氧化氮供体,将60只大鼠随机分为对照组及硝普钠0.5,1,2,4mmol/L组,每组12只,通过建立大鼠创伤模型,并分别在创面局部应用50g/L葡萄糖溶液、0.5,1,2,4mmol/L硝普钠,观察及测量创伤后3,7,10,14d的肉芽组织生长情况、一氧化氮合酶的表达情况和肉芽组织中羟脯氨酸含量。结果:60只大鼠全部进入结果分析。①形态学观察:对照组于创伤后14d可完全愈合;硝普钠0.5mmoL/L组及1mmoL/L组肉芽组织生长良好,且愈合时间较对照组提前三四天;硝普钠2mmoL/L组及4mmoL/L组愈合情况不良,完全愈合时间延迟,皮肤张力较低,炎症反应明显。②一氧化氮合酶蛋白表达:大鼠皮肤创伤后角质形成细胞、汗腺、毛囊和骨骼肌细胞以及创伤后肉芽组织的炎症细胞、成纤维细胞、血管内皮细胞均不同程度的表达一氧化氮合酶蛋白。对照组在第3天和第14天分别呈现一氧化氮合酶阳性颗粒表达高峰,而硝普钠各组仅在第7～10天出现表达一氧化氮合酶阳性高峰,呈先增加后减少的趋势。③羟脯氨酸含量:对照组从创伤后第3,7,10,14天羟脯氨酸含量进行性增加[依次为(1.637±0.127),(2.250±0.169),(2.420±0.201),(2.908±0.241)mg/g];硝普钠0.5mmol/L组在创伤后第3,7天羟脯氨酸含量低于对照组[(1.435±0.147),(1.766±0.211)mg/g,P<0.05或P<0.01],而在第10天和第14天羟脯氨酸含量均高于对照组[(3.128±0.240),(3.437±0.239)mg/g,P<0.01];硝普钠1mmol/L组和2mmol/L组在第10天和第14天的羟脯氨酸含量明显高于对照组[(1mmol/L组:(3.244±0.245)(3.582±0.282)mg/g,P<0.01;硝普钠2mmol/L组:(3.666±0.263),(4.301±0.268)mg/g,P<0.01);硝普钠4mmol/L组仅在创伤后第3天表现比对照组多[(1.912±0.139)mg/g,P<0.01),其余均与对照组水平相近。结论:局部应用外源性一氧化氮具有显著的促修复作用,主要体现在伤后第7～10天,小剂量的一氧化氮促进创面愈合的作用远远大于大剂量一氧化氮。     

COVID-19 vaccine immunogenicity among chronic liver disease patients and liver transplant recipients: A meta-analysis

Background/AimsData of coronavirus disease 2019 (COVID-19) vaccine immunogenicity among chronic liver disease (CLD) and liver transplant (LT) patients are conflicting. We performed meta-analysis to examine vaccine immunogenicity regarding etiology, cirrhosis status, vaccine platform and type of antibody.MethodsWe collected data via three databases from inception to February 16, 2022, and reported pooled seroconversion rate, T cell response and safety data after two vaccine doses.ResultsTwenty-eight (CLD only: 5; LT only: 18; both: 2; LT with third dose: 3) observational studies of 3,945 patients were included. For CLD patients, seroconversion rate ranged between 84% (95% confidence interval [CI], 76–90%) and 91% (95% CI, 83–95%), based predominantly on neutralizing antibody and anti-spike antibody, respectively. Seroconversion rate was 81% (95% CI, 76–86%) in chronic hepatitis B, 96% (95% CI, 93–97%) in non-alcoholic fatty liver disease, 85% (95% CI, 75–91%) in cirrhosis and 85% (95% CI, 78–90%) in non-cirrhosis, 86% (95% CI, 78–92%) for inactivated vaccine and 89% (95% CI, 71–96%) for mRNA vaccine. The pooled seroconversion rate of anti-spike antibody was 66% (95% CI, 55–75%) after two doses of mRNA vaccines and 88% (95% CI, 58–98%) after third dose among LT recipients. T cell response rate was 65% (95% CI, 30–89%). Prevalence of adverse events was 27% (95% CI, 18–38%) and 63% (95% CI, 39–82%) among CLD and LT groups, respectively.ConclusionsCLD patients had good humoral response to COVID-19 vaccine, while LT recipients had lower response.     

Scatter radiation exposure during knee arthrography

Knee arthrography, as performed at the authors' institution, was simulated and scattered radiation exposure to a radiologist's gonads, thyroid, and eye lens was measured with a sensitive ionization chamber. Results show that radiologists who regularly conduct knee arthrography examinations can incur doses to the gonads that are less than 6% of the U.S. limits, and to the thyroid and eye that are approximately 10% of the U.S. limits. Since the scatter radiation from overhead imaging of stress views constituted most (greater than or equal to 60%) of the dose to the lens of the eye and the thyroid, spot imaging was evaluated as a substitute for overhead imaging in the assessment of the anterior cruciate ligament. This substitution resulted in no loss of clinical information and has now completely replaced overhead imaging of stress views at this institution.