Pyrethroids used indoors--immune status of humans exposed to pyrethroids following a pest control operation--a one year follow-up study.

A multiparametric analysis of immune components was performed in blood and serum of 61 voluntary persons before and after (1 day, 3 days, 4-6 months, 10-12 months) a professional pest control operation (PCO) using pyrethroids. Following parameters were included in the study (1) immunological parameters of the humoral defence, i.e. immunoglobulins of the classes A, G, M and E, complement components C3c and C4, acute phase proteins such as acid alpha 1-glycoprotein, haptoglobin, C-reactive protein; (2) mediators and receptors of immunity, i.e. neopterin, soluble interleukin-2 receptor (sIL-2R), soluble interleukin-6 receptor (sIL-6R), soluble tumor necrosis factor receptor (sTNF RII); (3) immunological markers of the cellular defence, i.e. white blood cell counts and lymphocyte (sub)populations such as total lymphocytes (CD2), mature lymphocytes (CD3), T-helper/inducer cells (CD4), T-suppressor/cytotoxic cells (CD8), B-cells (CD20), natural killer cells (CD56), as well as the ratio of CD4/CD8. The medians of all investigated immune components found before and for all time intervals after pyrethroid application were within the reference interval with respect to the total collective. Within this physiological range the investigated parameters showed a trend to lower values predominantly during the early phase (1 and 3 days) after PCO, partially being significant. Significant decreases were no more present in the late phase (6 to 12 month) after PCO indicating reversibility. Atopics did not differ in the immune response after PCO as compared to non-atopics. Obtained results suggest a modulation of immune components after a correct performed PCO within the physiological range towards lower values during the first days. However these immune changes are considered to be subtle and underlying compensatory mechanisms of immunoregulation.     

Fluoride varnishes (Duraphat): A meta-analysis

Abstract – In the present article we analyze a series of studies designed to detect the caries preventive effect of Duraphat by means of meta-analysis. Meta-analysis is a collection of statistical methods designed to investigate and to summarize a series of investigations. It may be a valuable tool to complement traditional narrative reviews. During the last years meta-analysis has attracted increasing interest in sociology, psychology and medicine. In order to find previous studies concerned with the clinical effects of Duraphat we applied a systematic literature search. Papers were included independent of results when they fulfilled a checklist of well defined methodological selection criteria. In order to aggregate the results of the Duraphat-studies we used different complementary statistical approaches: Firstly, the so-called file drawer problem is considered. This may help to get a better insight into the problem of underreporting non-significant results or publication bias. It was found to be very unlikely that underreporting of non-significant results could reverse the conclusion into an overall null-result. After that, the in homogeneity between studies is investigated. The overall variation of caries reduction R is separated into two components: A between study component of variance and a variance pertaining to the individual studies (random effects model). It was found that the overall variation is dominated by the between studies variation and not by the sampling variation. Due to the pronounced variation between studies the confidence interval of the overall effect size (R = 0.38) is quite large (95%-Cl: 0.19–0.57). The heterogeneity of our studies naturally suggested exploring possible sources thereof by investigating the dependence of caries reduction on variables characterizing the studies. It was found that caries reduction is negatively correlated with study duration. This finding provided a study-duration-adjusted effect of caries reduction.     

Trauma-related disorders in psychiatrists' and general practitioners' private practice in Switzerland

A questionnaire addressing traumatic stress related issues was mailed to every third psychiatrist in private practice and to every fifth general practitioner in Switzerland (N=1406, number of returns 517 (37%). Trauma-related disorders seem to be underdiagnosed. Patients suffering from rape, accidents and war related trauma were most often mentioned. Psychiatrists knew more about specific treatment possibilities than general practitioners. Only 14% of the responding clinicians were satisfied with the existing therapeutic services for trauma victims; more psychiatrists voiced a need for their improvement. A majority suggested interdisciplinarity and the cooperation of institutions and therapists in private practice for the treatment of trauma-related disorders. It is proposed that further education should be tailored according to the target professional group.     

Nucleolar organizer regions (Ag-NORs) in multinuclear osteoclasts

Osteoclasts are multinuclear bone-resorbing cells. Little is known about regulation of gene expression in these cells and how it changes during the aging of an osteoclast, which is indicated by an increasing number of nuclei. Silver staining of nucleolar organizer regions, so-called Ag-NORs, allows us to assess the activity of rRNA expression. Using this technique, we show that individual nuclei of osteoclasts can be stained specifically and that the majority of individual nuclei contained Ag-NORs. The number and size of Ag-NORs varied, indicative of difference in the progression of the cell cycle through the G₁ phase. The relative activity of Ag-NORs was not synchronized on the level of individual nuclei, regardless of the number of nuclei per osteoclast. Surprisingly, the total activity of Ag-NOR appeared to be correlated to the total nuclear area of an osteoclast. We conclude that regulation of gene expression in multinuclear osteoclasts most likely occurs on the level of individual nuclei. Received: Jan. 12, 1998 / Accepted: May 25, 1998     

The effects of glucose, fructose, and sucrose ingestion during exercise

The purpose of this study was to compare the physiological, sensory, and exercise performance responses to ingestion of 6% glucose, 6% fructose, and 6% sucrose solutions during cycling exercise. Twelve subjects completed three sessions consisting of 115 min of intermittent cycle ergometer exercise at 65-80% of VO2max followed by a timed performance bout requiring the completion of 600 pedal revolutions. During each of five 4-min rest periods, subjects consumed 3 ml.kg LBM-1 of one of the beverages. Beverages were presented in counterbalanced, double-blind fashion. Heart rate, VO2, plasma urate, plasma lactate, respiratory exchange ratio, and carbohydrate combustion rates changed similarly among beverage treatment. However, fructose was associated with lower plasma glucose and serum insulin, a larger loss of plasma volume, greater gastrointestinal distress and relative perceived exertion ratings, and higher plasma or serum concentrations of free fatty acids, fructose, and cortisol values than sucrose or glucose (P less than 0.05). Compared to sucrose and glucose, fructose feeding also resulted in lower lactate and HR values during the performance bout (P less than 0.05). Mean +/- SE cycling performance times were faster with sucrose and glucose than with fructose: 419.4 +/- 21.0 s, 423.9 +/- 21.2 s, and 488.3 +/- 21.1 s, respectively (P less than 0.05). Relative to 6% solutions of sucrose and glucose, ingestion of a 6% fructose beverage is associated with gastrointestinal distress, compromised physiological response, and reduced exercise capacity.     

Novel magnesium ion-selective microelectrodes based on a neutral carrier

Two types of Mg²⁺-selective microelectrodes baed on a synthetic neutral carrier and containing poly-(vinyl chloride) (PVC) are described. The first is applicable to intracellular Mg²⁺ assays and suffers no interference from alkali and all other alkaline-earth metal cations. The second can be used for determining intra- as well as extracellular Mg²⁺ activities, but Ca²⁺ and especially lipophilic cations (e.g. acetylcholine) may interfere. Cyclohexanone is used for dissolving the PVC-containing membrane phases thus avoiding problems encountered with the much more volatile tetrahydrofuran. The procedure gives a higher output of working microelectrodes and can also be applied with other membrane phases.     

Recombinant CD30 ligand and CD40 ligand share common biological activities on Hodgkin and Reed-Sternberg cells

The CD30 ligand (CD30L) and CD40L are members of the tumor necrosis factor (TNF) protein superfamily. CD30L and CD40L are mainly expressed as membrane-bound proteins by activated T cells. CD30L and CD40L are costimulatory for T cell proliferation and activation. Further, CD40L is a critical signal for T cell-dependent activation of B cells. Primary and cultured Hodgkin and Reed-Sternberg (H-RS) cells, the neoplastic component of Hodgkin's disease (HD), express high levels of the counterreceptors CD30 and CD40. We have found that both the recombinant CD30L and CD40L enhanced interleukin (IL)-6, TNF and lymphotoxin (LT)-α release from cultured H-RS cells. In addition, CD40L, but not CD30L, induced IL-8 secretion. CD30L and CD40L seem to share some redundant biological activities involved in the deregulated secretion of cytokines known to play a central role in the clinical presentation and pathology of HD. Further, CD30L enhanced surface expression of intercellular adhesion molecule-1 (ICAM-1/CD54) on cultured H-RS cells, which is frequently overexpressed on primary H-RS cells. CD30L- and CD40L-enhanced CD54 surface expression is followed by elevated shedding of CD54, as shown by detection of elevated 82-kDa soluble (s) CD54 levels in culture supernatants after stimulation with both ligands. CD30L and CD40L share common pleiotropic biological activities on CD30⁺/CD40⁺ H-RS cells and are elements of the cytokine and cell contact-dependent activation network typical for HD, a tumor of cytokine producing cells.     

Studies on neurotransmitter binding in senile dementia. Comparison of Alzheimer's and mixed vascular-Alzheimer's dementias

Binding of 3H-labeled agonists and antagonists to muscarinic-cholinergic, alpha- and beta-adrenergic, dopaminergic, serotoninergic, and opiate receptors was studied in four regions of the neocortex and in hippocampus, thalamus, putamen, and caudatus in autoptic material from patients with senile dementia of Alzheimer type and of mixed vascular-Alzheimer pathogenesis. Different patterns of changes in ligand binding were found for the two groups. Some of these changes were quantitatively correlated with the histological scores of plaques and neurofibrillary tangles.