Discrepancies between thyrotropin (TSH) measurement by four sensitive immunometric assays

A comparison of four different commercial immunometric thyrotropin (TSH) assays (Amerlite R TSH-30 Ultrasensitive assay from Kodak, BeriLux R hTSH from Behring Werke, Delfia R hTSH Ultra from Wallac and IMX R Ultrasensitive hTSH from Abbott) was made by measuring serum TSH in 81 consecutive patients referred to hospital for various reasons with a serum TSH less than 0.8 mlU/l in the IMX assay. The analytical and functional assay sensitivities of each of the assays were analysed. Even though three of the methods had a sensitivity corresponding to third generation assays, we could only demonstrate an overall agreement of serum TSH when comparing two of the kits. The measurements in Delfia Ultra and Berilux showed good agreement (P = 0.7, paired t-test and bias = 0.003 mIU/l), while the comparisons between the other assays showed different measurements (P < 0.00001, paired t-test and bias more than 0.07 mIU/l). Differences in the calibrators used in the assays might explain some of the discrepancy, although all methods were calibrated according to the same international standard. Also, differences in the specificity of the TSH monoclonal antibodies used in the assays might be an evident explanation and further studies of the specificity of the monoclonal antibodies are needed. An international collaborative study to clarify reasons for the differences between the TSH assays and to standardize the measurements is recommended.     

Program- and method-related determinants of first DMPA use duration in rural Bangladesh

This article examines the determinants of first-time use durations of the injectable contraceptive Depo Medroxy Progesterone Acetate (DMPA) for rural Bangladeshi women. The method's side effects were defined by 200 first-time users in Matlab district during lengthy, open-ended interviews. Women with many children used the method longer than did women of low parity. Those who experienced side effects had shorter use durations than those who did not, and those who cited heavy bleeding as their main problem discontinued use soonest. Women whose husbands approved of family planning had significantly longer use durations than those whose husbands disapproved. Respondents who adopted DMPA because of perceived positive aspects of the drug used it longer than those who chose it for other reasons. Results of the study underscore the importance of viewing side effects in a specific social and cultural context. Expanded side-effects counseling for women and their husbands is needed.     

Endoneurial localisation of microvascular damage in human diabetic neuropathy

Twenty diabetic patients with neuropathy underwent clinical and neurophysiological evaluation together with a detailed morphometric assessment of capillary pathology in endoneurial and epineurial microvascular beds of the sural nerve. Morphological data were compared with ten non-diabetic control subjects. There were no significant differences in control subjects between basement membrane area, endothelial cell area, endothelial cell profile number or luminal area of endoneurial when compared with epineurial capillaries. In contrast, when compared with epineurial capillaries, endoneurial capillaries from diabetic patients demonstrated a significant increase in basement membrane (p < 0.001) and endothelial cell (p < 0.001) area and a significant reduction in luminal area (p < 0.001). There was no significant difference in endothelial cell profile number between endoneurial and epineurial capillaries amongst diabetic patients. Previous studies have demonstrated a good correlation between the degree of microangiopathy and measures of neuropathic severity. In the present study increased endoneurial capillary basement membrane area was significantly related to reduced peroneal nerve conduction velocity (p < 0.001), myelinated fibre density (p < 0.001) and elevated vibration (p < 0.05) and thermal (p < 0.001) perception. Increased endothelial cell area and reduced luminal size were related to a reduced peroneal nerve conduction (p < 0.05, p < 0.01, respectively), reduced myelinated fibre density (p < 0.05, p < 0.01) and elevated thermal perception (p < 0.05, p < 0.001). Epineurial capillary basement membrane, endothelial cell and luminal area failed to relate to measures of neuropathic severity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thymosin beta-10 accelerates apoptosis

The 5 Kd (MW), retinoic acid responsive thymosin beta-10 protein is expressed at relatively high levels in embryonic tissues, and its mRNA is abundant in a variety of tumors and tumor cell lines. Recently this protein (together with other members of the same protein family) was found to be a major intracellular G-actin binding protein. In the present study, plasmid-driven overexpression of thymosin beta-10 gene results in increased susceptibility of permanently transfected fibroblasts to undergo apoptosis. Conversely, knockout of the endogenous gene via overexpression of the antisense mRNA inhibited cell death induced by TNF-alpha and calcium ionophore A23187. Differential expression of thymosin beta-10 influenced cell proliferation, cell morphology, and expression/distribution of the antiapoptotic protein bcl-2. The presence of increased cytoplasmic thymosin beta-10 precipitated significant disruption of phalloidin-stained actin stress fibers while knockout of thymosin expression promoted F-actin assembly. These and other observations suggest that thymosin beta-10 (a) plays a significant and possibly obligatory role in cellular processes controlling apoptosis possibly by acting as an actin-mediated tumor suppressor, (b) perhaps functions as a neoapoptotic influence during embryogenesis, and (c) may mediate some of the pro-apoptotic anticancer actions of retinoids.     

Transcutaneous balloon angioplasty in the treatment of subclavian steal syndrome. Characteristics of vertebral basal flow with transcranial Doppler technique

Subclavian steal syndrome (SSS) appears when the origin of the subclavian artery (SA) is occluded or stenosed. Introduction of transcranial Doppler sonography (TCD) provided an opportunity to evaluate parameters of the blood flow in the vertebral (VA) and basilar artery (BA). Measurements of blood flow velocities performed at rest and after the brachial hyperemia test allow one to classify hemodynamic types of SSS. The aim of the study was to categorize types of steal and to compare the differences of flow patterns before and after percutaneous transluminal SA balloon angioplasty (SA-PTA). Fourty-eight patients with angiographically confirmed SSS (aged from 27 to 68 years, mean 53; 2/1 f/m ratio) were examined with 2 MHz range-gated, pulsed transcranial Doppler device (TC 2-64B EME). Both VA and BA were evaluated by the transoccipital approach at rest and during the brachial hyperemia. In 5 cases (10.4%) permanent reversal blood flow in the BA was observed (complete basilar steal). In flow in the BA blood flow was in the normal direction at rest and altered (reversed or decreased) when induced with brachial hyperemia test (transient basilar steal). In the next 14 patients (29.2%) permanently reversed VA blood flow was observed with only a slight or no alterations of the BA flow after the hyperemia test (complete vertebral steal). In the last 19 cases (39.6%) alterations of the VA blood flow without changes in BA flow were observed (latent vertebral steal). Between 1991 and 1994 twenty seven symptomatic patients with different hemodynamic types of SSS were treated with SA-PTA. TCD evaluation of VA's and BA using the hyperemia test was performed before, 3 to 7 days and 3 months after morphologically and hemodynamically successful subclavian artery balloon PTA. Normal results of vertebrobasilar examinations were obtained in 26 cases after this procedure. In one case the latent vertebral steal was detected. The 28 months mean follow-up revealed no significant changes in TCD flow patterns recorded from VA's and BA. After collecting data of about 60 patients with SSS we examined with TCD we conclude that: in patients with a hemodynamically significant SA stenosis the presence of reversed ipsilateral VA blood flow (a radiologic steal) its not a good determinant of either the presence or type of presenting symptoms and after successful PTA or recanalisation and PTA of SA in almost all cases we examined close to normal TCD recordings in BA and VA.