Chloramphenicol antibody causing interference in antibody detection and identification tests

Investigation of the serum of three patients with positive antibody detection tests demonstrated the cause in each to be an antibody against chloramphenicol, a bacteriostatic agent used in commercial red blood cell reagents. Washing of these red cells prior to use prevented agglutination. All three examples of anti-chloramphenicol antibody were IgM and were in low titer when tested at room temperature and 37 C in saline. Two of the antibodies bound complement. The possibility of an antibody to an ingredient of the commercial preservative solution should be considered if problems are encountered in tests with unwashed commercial red blood cell reagents.     

Use of a low-ionic-strength medium in manual tests for antibody detection

The present observations confirm the value of suspending red blood cells in a low-ionic-strength medium in the first stage of the indirect antiglobulin test; that is, during the period of incubation with antibody-containing serum. The main advantage of this procedure is to shorten the time of incubation. In this respect a low-ionic-strength medium appears to be superior to albumin as a suspending medium for the red blood cells. A further advantage is to increase the uptake of certain antibodies; this effect was pronounced with selected Rh antibodies believed to be of low affinity.     

抗原抗体联合检测在提高血液透析患者丙肝感染检出率中的应用

目的探讨开展抗原抗体联合检测在提升血液透析治疗患者丙肝感染检出率中的应用价值。方法收集100例血液透析患者的临床资料,分别采用以下方法测定相关参数:ELISA法检测HCV核心抗原、化学发光法检测抗HCV抗体、RTPCR法检测HCV-RNA,统计各检测项目在同一标本中的阳性表达情况,比较单测抗原、抗体与联合检测3个检测方案对于RNA阳性标本的检出率;同时对抗原阳性标本的抗原水平与其RNA拷贝数进行相关性分析并比较抗体阳性标本中其RNA阳性与阴性组组间抗体水平的区别。结果单测抗原或抗体均会造成血透患者丙肝感染的漏检,对于RNA阳性标本的检测中抗原抗体联合检测的检出率最高(P0.05),抗原阳性标本的抗原水平与其对应标本的RNA拷贝数呈正相关关系(r=0.85,P0.05),而抗体阳性标本中其RNA阳性与阴性组的组间抗体水平的差异不具有统计学意义(P0.05)。结论 HCV抗原抗体联合检测能有效提高血液透析治疗患者丙肝感染的检出率,同时HCV核心抗原检测也可作为抗体阳性患者HCV再次感染的监测指标之一。     

Generalized likelihood ratio tests for change detection in diffusion tensor images: application to multiple sclerosis

The automatic analysis of subtle changes between MRI scans is an important tool for monitoring disease evolution. Several methods have been proposed to detect changes in serial conventional MRI but few works have considered Diffusion Tensor Imaging (DTI), which is a promising modality for monitoring neurodegenerative disease and particularly Multiple Sclerosis (MS). In this paper, we introduce a comprehensive framework for detecting changes between two DTI acquisitions by considering different levels of representation of diffusion imaging, namely the Apparent Diffusion Coefficient (ADC) images, the diffusion tensor fields, and scalar images characterizing diffusion properties such as the fractional anisotropy and the mean diffusivity. The proposed statistical method for change detection is based on the Generalized Likelihood Ratio Test (GLRT) that has been derived for the different diffusion imaging representations, based on the core assumption of a Gaussian diffusion model and of an additive Gaussian noise on the ADCs. Results on synthetic and real images demonstrate the ability of the different tests to bring useful and complementary information in the context of the follow-up of MS patients.     

Performance evaluation of four rapid antibody tests for the detection of severe acute respiratory syndrome coronavirus 2

BackgroundThe prompt detection of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is important in the therapeutic management of infected patients. Rapid diagnostic tests are widely used for this purpose. This study aimed to evaluate the clinical performance of four SARS‐CoV‐2 immunoglobulin IgG/IgM rapid diagnostic tests in the detection of SARS‐CoV‐2.MethodsNasopharyngeal and oropharyngeal swabs and/or sputum were collected from 30 patients infected with SARS‐CoV‐2 and 30 healthy volunteers. All specimens were tested using four SARS‐CoV‐2 IgG/IgM rapid diagnostic tests and real‐time polymerase chain reaction. We assessed the clinical sensitivity and specificity of the tests.ResultsThe clinical sensitivity of FREND™, SsmarTest™, BIOCREDIT™, and IVDLAB™ was 96.67%, 100.00%, 100.00%, and 96.67%, respectively, compared to real‐time polymerase chain reaction. The clinical specificity was 96.67%, 100.00%, 86.67%, and 96.67%, respectively.ConclusionThese findings could expedite the detection of SARS‐CoV‐2 and thus reduce the risk of further transmission of the virus.     

Correlation of the percent of positive Chlamydia trachomatis direct fluorescent antibody detection tests with the adequacy of specimen collection

Chlamydia trachomatis is an obligate, intracellular parasite infecting the columnar and transitional cells lining the endocervix, uterus, fallopian tubes, rectum, urethra, and epididymis. We determined if the percent of specimens positive for C. trachomatis in the Microtrak Direct Specimen Test depended on the quality of specimens obtained. Female genital slides (649) were evaluated by the direct fluorescent antibody (DFA) test for the presence and numbers of (a) C. trachomatis elementary bodies and (b) columnar, transitional and squamous epithelial cells, and polymorphonuclear neutrophils (PMNs). Only 138 (21.3%) of the 649 slides were considered to be adequately taken, that is, containing columnar/transitional cells either alone or in conjunction with squamous cells and/or PMNs. Of the 138 adequate slides, 10 (7.2%) were C. trachomatis positive. However, 511 (78.7%) of the 649 slides were judged inadequate; 395 contained only squamous cells and/or PMNs, 19 were too thick to determine cell types, 46 contained only cell debris, and 51 contained neither cells nor debris. Only four (0.78%) of 511 were C. trachomatis positive. Thus adequate specimens containing columnar/transitional cells for C. trachomatis detection had a tenfold increase in the percent of positive results compared to inadequately collected specimens. By using the DFA test, one has the advantage of determining the adequacy of the specimens obtained as well as the presence of chlamydiae.     

中性粒细胞/淋巴细胞比率联合血小板/淋巴细胞比率检测对于重症急性胰腺炎早期预测价值

目的:评估中性粒细胞／淋巴细胞比率（Neutrophil to lymphocyte ratio,NLR）联合血小板/淋巴细胞比率（platelet to lymphocyteratio,PLR）检测(NLR-PLR)对于重症急性胰腺炎(severe acute pancreatitis,SAP)早期预测价值。方法:连...     

Rubella antibody tests in family planning clinics.

Women attending for family planning advice at area health authority and general practitioner clinics were offered a test of rubella antibody status. The acceptance rate was approximately 50 per cent. Of the 100 women tested, 15 were not immune and 8 of these were subsequently vaccinated. In this study, the cost of the service was estimated to be 1-50 pounds per woman, or approximately 5000 pounds to prevent one case of congenital rubella. On this basis the assessment of rubella immunity in women using reliable contraception is considered to be feasible and could prove even more worthwhile on a cost-benefit basis if applied to an entirely nulliparous group.     

Monoclonal antibody for the detection of Clostridium botulinum type A toxin

Hybridomas producing monoclonal antibodies against type A Hall strain Clostridium botulinum toxin were generated by fusing mouse myeloma cell line P3-X63-Ag8.653 with spleen cells of Balb/c mice immunized with C. botulinum type A toxoid. The monoclonal antibody from one hybridoma, identified as No. 424, was selected from 61 others for its high antibody titre. This monoclonal antibody was used in a double-sandwich enzyme-linked immunosorbent assay (ELISA) system to detect type A toxin in culture fluids and in foods. The monoclonal antibody did not react with either C. botulinum toxin types B, C, D, E and F or with other clostridial species tested. This particular monoclonal antibody (No. 424) did not neutralize type A toxin in the mouse bioassay procedure but detected approximately 10 mouse lethal doses of type A toxin/ml culture fluid. Monoclonal antibody and rabbit antitoxin to type A C. botulinum toxin were useful in a double-sandwich ELISA for the rapid and specific detection of type A toxic fluids in culture and in food samples.     

A new approach to the preparation of ACTH antibody by immunization of the rabbit with an antigen-antibody complex.

Immunization with antigen-antibody complex of ACTH produced sensitive ACTH antibody applicable to the radioimmunoassay. The antibody prepared by immunization with the synthetic 1-24 ACTH was mixed with the antigen porcine ACTH, and the mixture was incubated to form the antigen and antibody complex. Two rabbits were initially immunized with this complex, then further immunized with only the porcine ACTH. Both rabbits produced the ACTH antibody with a titer of 1:25,000, which could detect ACTH of 5 pg per tube when applied to the radioimmunoassay of the human ACTH. This antibody showed a strong crossreaction with synthetic 1-24 ACTH, which was confirmed by radioimmunoassay method and immunostaining technique. On the other hand, control animals immunized with only procine ACTH from the beginning showed no production of ACTH antibody. It was concluded that addition of ACTH antibody to the antigen for the first immunization took an important role in eliciting production of the antibody. Possible roles of the antigen-antibody complex for immunization were discussed.     

Fixed ratio or lower limit of normal for the FEV1/VC ratio: relation to symptoms and extended lung function tests

There is no general agreement on the spirometric definition of chronic obstructive pulmonary disease (COPD). The global initiative for obstructive lung disease recommends a fixed ratio between forced expiratory volume in one-second (FEV₁) and forced vital capacity (FVC) of <0·7 (FR) for the diagnosis of COPD. European Respiratory Society and American Thoracic Society favour the use of the fifth percentile of the age-related FEV₁/FVC ratio (the lower limit of normal, LLN). The purpose of this study was to analyse extensive lung function tests in groups of subjects fulfilling none, either or both of the spirometric criteria for COPD. From a previous population-based study, 450 subjects were examined with spirometry, body pletysmography diffusing capacity for CO (D_L,CO), Impulse Oscillometry System (IOS) and answered a questionnaire on respiratory symptoms and diseases. Seventy subjects fulfilled both spirometric COPD criteria (FR+LLN+), 62 subjects the fixed ratio criterion (FR+) only. Of the remaining 318 subjects, 236 were ever smokers (N-ES). Significant differences between all groups were seen for FEV₁ and D_L,CO. Significant differences between groups were also seen for residual volume (RV) and RV/total lung capacity. For IOS, variables and symptoms increasingly abnormal values were seen from never smokers to FR+LLN+. This study shows that subjects meeting both spirometric COPD criteria frequently have symptoms and findings at extended lung function tests compatible with the diagnosis. Also subjects meeting the fixed ratio criterion only tend to have more symptoms and lung function findings compatible with COPD than ever-smoking subjects with FEV₁/VC > 0·7.     

抗核抗体核型检测与特异性抗核抗体谱检测的对比分析

目的：探讨抗核抗体核型与特异性抗核抗体谱的相关性。方法回顾分析本院检验科检测的974例抗核抗体结果,分别用间接免疫荧光法（IIF）检测抗核抗体核型,用条带酶免分析法（LIA）检测特异性抗核抗体谱,分析199例 IIF 与 LIA 同时阳性的结果,比较抗核抗体核型与特异性抗核抗体谱的相关性。结果974例标本中 IIF 阳性249例（阳性率25．6％）,LIA 阳性237例（阳性率24．3％）,两种方法检测阳性率差异无统计学意义（P ＞0．05）,IIF 与 LIA 单项或两项阳性287例（29．5％）,高于IIF 或 LIA 单项检测阳性率,差异有统计学意义（P ＜0．05）。249例 IIF 阳性中 LIA 阳性199例（79．9％）,725例 IIF 阴性中 LIA阴性687例（94．8％）。核颗粒型多见抗 Ro-52抗体,胞浆颗粒型多见抗线粒体 M2抗体,核均质型以抗 dsDNA 抗体、抗核小体抗体多见,着丝点型多见抗着丝点抗体,核仁型多见抗 PM-Scl 抗体。结论IIF-ANA 与 LIA-ANA 有较好的相关性,但也有一定差异,两者联合检测能降低漏检率,对自身免疫性疾病的诊断、病情监测及预后判断有重要意义。     

Technetium 99m sulfur colloid spleen/liver ratio and other liver tests in the diagnosis of cirrhosis.

The results of seven laboratory tests of liver function, including spleen/liver activity ratios obtained by densitometric analysis of scans, are analyzed in 50 patients with proven Laennec's cirrhosis. In this series, the liver scan not only disclosed the liver gross anatomy and structural abnormality and established the best possible site for biopsy examination, but also, the increased splenic activity served as a useful diagnostic indication of Laennec's cirrhosis. Of 50 proven cases of Laennec's cirrhosis, 41 (82%) had abnormal spleen/liver ratios. An abnormal spleen/liver ratio in combination with abnormal results from any one or two other tests was relatively effective in the detection of cirrhosis. The accuracy is improved if the other laboratory tests are chosen from among tests for serum albumin, serum bilirubin, and SGOT. (Liver abnormalities other than cirrhosis can also present an abnormal spleen/liver ratio.) This simple determination extends the value of the liver scan commonly requested in search of metastases, primary lesions, or inflammatory processes, or in preparation for needle biopsy examination.     

2012年大连市医院输血科（血库）输血相容性检测能力评价

目的：通过对大连市医院输血相容性检测的督导评价,进一步规范检测程序,提高检测水平。方法以现场检查和发放自制室间质评样本检测方式对大连市62家医院输血科（血库）输血相容性检测能力进行评价。现场检查包括设备、试剂、开展项目、操作规程和记录5个方面;室间质评项目包括ABO正、反定型,Rh（D）血型,受血者抗体筛选及交叉配血5项。结果督导评价合格医院42家,不合格20家;仅1家医院因未开展抗体筛查项目检测而判为现场检查不合格;二级医院室间质评结果不合格率最高（42．3％）;正、反定型和 Rh （D ）定型试验符合率为100．0％,抗体筛查和交叉配血试验不符合率分别为82．0％、77．4％。结论在保证相对固定人员配置同时加强培训提升检测人员鉴别分析能力是目前提高大连市医院输血科（血库）输血相容性检测能力的重要措施。     

Differential microcalorimetry of the antigen-antibody reaction

High sensitivity of the microcalorimetric method for the registration of immunologic reactions and prospects of the practical application of the method demand an objective interpretation of the results and an explanation of the range of thermistometry findings varying from positive to negative values. The investigations have been carried out with models with known titers of purified antigens and antibodies and with unknown antibody titers. The method has been employed in examinations of children suffering from infectious allergic diseases and from central nervous system abnormalities. The energy processes connected with the negative, zero, or positive results of the reactions, depending on the antibody and antigen concentrations, are explained.     

Relationship of the platelet distribution width/platelet count ratio with thyroid antibody levels in patients with Hashimoto's thyroiditis

ObjectiveI investigated whether the platelet distribution width/platelet count (PDW/PC) ratio, which is an inexpensive and simple test performed for almost all patients, is applicable in the follow-up of patients with Hashimoto’s thyroiditis and examined the relationship of this ratio with thyroperoxidase and thyroglobulin antibody levels.Materials and methodsThe study groups consisted of 67 patients with Hashimoto’s thyroiditis and 17 controls. All participants were aged 20 to 75 and treated the Internal Medicine outpatient clinic of my institution. The PDW/PC ratio and thyroid antibody levels were retrospectively evaluated in patients with normal liver and renal function and normal white blood cell counts, hemoglobin levels, and hematocrit levels.ResultsThyroid antibody levels were significantly higher in patients with Hashimoto’s thyroiditis than in controls. PC was higher in patients with Hashimoto’s thyroiditis, whereas the PDW/PC ratio was lower. However, these differences were not statistically significant.ConclusionIn this study, I did not find a statistically significant relationship between thyroid antibody levels and PDW/PC. However, a weak correlation between these variables was identified.