Automated quantification of thyrotropin by radial partition immunoassay

We describe a radial partition enzyme immunoassay in which fully automated quantification of human thyrotropin (hTSH) takes less than 11 min. This "sandwich"-type assay involves two monoclonal antibodies, both specific for the intact hTSH molecule. The solid phase consists of tabs of glass-fiber filter paper containing a pre-immobilized monoclonal anti-hTSH antibody complexed with a goat antibody specific for the Fc region of mouse IgG. The patient's sample is first applied to the central "reaction zone" of the tab, wherein hTSH binds to the immobilized antibody. Application of a buffered solution containing enzyme-labeled Fab' fragments of the second monoclonal anti-hTSH antibody initiates "sandwich" formation. A wash buffer containing a fluorogenic substrate elutes unbound conjugate to the tab periphery. The bound enzyme conjugate is quantified by measuring the rate of increase in fluorescence in the reaction zone of the tab, then converting the rate to clinical units by comparison with a stored calibration curve. The clinical utility and performance of the present assay compare favorably with those of other sensitive assays for hTSH.     

Patellofemoral joint: kinematic MR imaging to assess tracking abnormalities

The patellofemoral joint was imaged with magnetic resonance (MR) in the axial plane while the knee was positioned from 0 degrees to 32 degrees of flexion (nine positions). These multiple sequential images obtained within the early phases of flexion of the knee were viewed in a "cine-loop" format, producing a kinematic study that clearly demonstrated the relationship of the patella to the trochlear groove. Four healthy subjects and one patient with known bilateral subluxing patellae were studied. The preliminary results suggest that kinematic MR imaging of the patellofemoral joint is potentially useful for the evaluation of patellar tracking abnormalities.     

Superior mesenteric artery is more important than inferior mesenteric artery in maintaining colonic mucosal perfusion and integrity in rats

Mucosal hemodynamics (by reflectance spectrophotometry) and mucosal damage (by histologic examination) following acute colonic ischemia were evaluated in different anatomic locations in the colon of anesthetized rats. The reflectance spectrophotometer provides an index of mucosal hemoglobin concentration (IHB) and an index of oxygen saturation of hemoglobin (ISO₂). The patterns of ischemia without congestion (IHB, ISO₂) during superior mesenteric artery occlusion, and ischemia with congestion (IHB, ISO₂) during portal vein occlusion, previously demonstrated in the stomach and duodenum, are also applicable to the colon. The significant linear correlations between changes (as percent of baseline) in IHB, ISO₂, and hydrogen gas clearance suggest that changes in these indices are adequate indicators of changes in colonic mucosal perfusion. Superior mesenteric artery ligation produced significant reductions in both indices, and an increase in damage in the mucosa of the cecum, transverse colon, splenic flexure, and left colon, but not the rectum. Inferior mesenteric artery ligation produced only slight reduction in these indices and minimal damage only in the mucosa of the splenic flexure. These results support the hypothesis that the superior mesenteric artery is more important than the inferior mesenteric artery in maintaining colonic perfusion and colonic mucosal integrity in the rat.Supported by the American Society for Gastrointestinal Endoscopy Career Development Award (H850208, H870212), Veterans Administration Medical Research Funds; and in part by research grants (0162-01, 0162-02; 0291-01) from the Smokeless Tobacco Research Council, Inc.; and by funds provided by the Cigarette and Tobacco Surtax Fund of the State of California through the Tobacco Related Disease Research Program of the University of California.     

Sensory recovery in transplanted toes

This study reports the results of 30 patients who entered a program of sensory reeducation following toe-to-thumb transfer. Results were analyzed after subdividing the patients into those whose injury had produced severe scarring (fibrotic group, N = 15) and those with clean, more distal amputations (non-fibrotic group, N = 15). Patients who were unable to complete sensory reeducation were considered as "drop-out" controls. Although the follow-up time was less than 1 year, the group receiving sensory reeducation did improve to a greater degree and more quickly than the controls, with the level of two-point discrimination recovered being better than that originally present in the toe.     

A two-site sandwich immunoradiometric assay of human lymphotoxin with monoclonal antibodies and its applications

Three monoclonal antibodies (MoAbs L49-15, L81-11 and L238-14) were raised against recombinant human lymphotoxin (rLT) derived from E. coli containing the cDNA sequence specifying LT. MoAb L81-11 strongly neutralised the cytotoxicity of LT derived either from E. coli or the RPMI 1788 lymphoblastoid cell line, whilst the other two MoAbs were only weakly neutralising in this respect. L81-11 and L238-14 MoAbs bound to different antigenic determinants on the rLT molecule, but neither bound to other lymphokines such as the structurally related tumour necrosis factor (TNF). As such, these MoAbs were ideal reagents for immunoassay of LT and a very sensitive, highly specific immunoradiometric assay (IRMA) was developed. This assay was rapid to perform and was capable of detecting as little as 10 pg/ml of LT. Application of the LT IRMA in combination with previously developed human gamma-interferon (IFN-gamma) and human TNF-specific IRMA (Crane et al., 1985; Meager et al., 1987) permitted independent estimations of these three substances to be carried out in parallel. By these means, it was found that RPMI 1788 produced both LT and TNF, but not IFN-gamma. Extensive analyses on cytokine (monokine and lymphokine) preparations derived from a variety of activated lymphocytes are also reported. Co-production of LT, TNF and IFN-gamma was a common finding, even occurring in alloantigen-specific T helper cell clones.     

Critical ovarian hyperstimulation syndrome in a coasted in-vitro fertilization patient

We report an instance of critical ovarian hyperstimulation syndrome in a highly responsive in-vitro fertilization patient despite the preventive measure of a 4 day 'coast' interval during which no gonadotrophins were administered while gonadotrophin-releasing hormone agonist therapy continued until serum oestradiol concentrations fell below 3000 pg/ml.      

Incidence and determinants of moderate COPD (GOLD II) in male smokers aged 40–65 years: 5-year follow up

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major health problem with an estimated prevalence of 10-15% among smokers. The incidence of moderate COPD, as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), is largely unknown. AIM: To determine the cumulative incidence of moderate COPD (forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC] <0.7 and FEV1 <80% predicted) and its association with patient characteristics in a cohort of male smokers. DESIGN: Prospective cohort study. SETTING: The city of IJsselstein, a small town in the Netherlands. METHOD: Smokers aged 40-65 years who were registered with local GPs, participated in a study to identify undetected COPD. Baseline measurements were taken in 1998 of 399 smokers with normal spirometry (n = 292) or mild COPD (FEV1/FVC <0.7 and FEV1 >or=80% predicted, n = 107) and follow-up measurements were conducted in 2003. RESULTS: After a mean follow-up of 5.2 years, 33 participants developed moderate COPD (GOLD II). This showed an estimated cumulative incidence of 8.3% (95% CI = 5.8 to 11.4) and a mean annual incidence of 1.6%. No participant developed severe airflow obstruction. The risk of developing moderate COPD in smokers with baseline mild COPD (GOLD I) was five times higher than in those with baseline normal spirometry (one in five versus one in 25). CONCLUSIONS: In a cohort of middle-aged male smokers, the estimated cumulative incidence of moderate COPD (GOLD II) over 5 years was relatively high (8.3%). Age, childhood smoking, cough, and one or more GP contacts for lower respiratory tract problems were independently associated with incident moderate COPD.     

Glutaraldehyde-treated bioprosthetic substitute for rabbit Achilles tendon

The biomechanical properties and histocompatibility of a glutaraldehyde-treated xenograft were examined after implanting it in 27 rabbits. This xenograft was used as an Achilles tendon substitute placed in vivo for 2 to 48 wk. The specimens were then subjected to mechanical strength testing using a specially constructed tensioning device. The contralateral Achilles tendon was used as the reference baseline. Mechanical testing showed that the strength of the implanted graft increased to 33.5% of the normal side at week 10 and to 79.5% at week 14. The host generated a fibrous cord around the xenograft, linking the two ends of the Achilles tendon. Light and electron microscopic examination showed fibroblastic infiltration of varying magnitude in all specimens but no statistical correlation between degree of infiltration and duration of implantation was found. Also, there was no histological evidence of immunological rejection within the 48 wk of study.     

Molecular subtyping of Vibrio cholerae O1 and O139 by pulsed-field gel electrophoresis in Hong Kong: correlation with epidemiological events from 1994 to 2002

Two hundred twenty isolates of Vibrio cholerae O1 and O139 collected from 1994 to 2002 in Hong Kong were analyzed by pulsed-field gel electrophoresis (PFGE). Chromosomal DNAs from all V. cholerae isolates in agarose plugs were digested with the restriction enzyme NotI, resulting in 20 to 27 bands. Sixty distinctive PFGE patterns in the range of 10 to 300 kb were noted among 213 isolates typeable by PFGE. By comparing the common PFGE patterns obtained from four well-defined outbreaks of V. cholerae O1 and O139 with those obtained from other, epidemiologically unrelated isolates during the study period, indistinguishable and similar PFGE patterns were identified, indicating their close relatedness, in agreement with the results of epidemiological investigations. Heterogeneous PFGE patterns (with four to six banding differences), however, were identified among strains that were imported from other parts of Asia, including Indonesia, India, and Pakistan. Correlations with epidemiological information further support the usefulness of PFGE as an epidemiological tool in laboratory investigations of suspected outbreaks. Standardization of PFGE methodology will allow international comparison of fingerprint patterns and will form the basis of a laboratory network for tracking V. cholerae.