A longitudinal study of semen quality in pesticide spraying danish farmers

It was hypothesized that occupational exposure to pesticides during a spraying season causes changes in semen quality that might be detected in a longitudinal study. We analyzed the within-person changes in semen quality and reproductive hormones across a spraying season in groups of farmers using and not using pesticides. A total of 248 men collected two semen samples (participation rate: 32%). The median sperm concentration declined significantly from the first to the second sample in both groups, but there was no statistical difference in the decline between the two groups, unadjusted or adjusted. Only minor changes were found in sperm morphology, vitality, motility, sperm chromatin denaturation (SCSA), and reproductive hormones, and the differences in changes between the two groups were nonsignificant, or, in the opposite direction to the expected. There was no relation between the changes in sperm parameters in relation to pesticide exposure variables. In conclusion, use of pesticides by Danish farmers is not a likely cause of short-term effects on semen quality and reproductive hormones.     

Glial cell expression of hepatocyte growth factor in vitreoretinal proliferative disease

The hepatocyte growth factor (HGF) has been crucially implicated in the development of proliferative retinal diseases; however, it is unclear whether retinal glial cells express or respond to HGF. Therefore, we examined the expression of HGF and of the receptor for HGF, c-Met, by immunohistochemical costaining with glial fibrillary acidic protein (GFAP) in epiretinal membranes of patients with proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR), respectively. Furthermore, it was determined whether cells of the human retinal glial cell line, MIO-M1, secrete HGF protein, and whether HGF stimulates proliferation and chemotaxis, and secretion of the vascular endothelial growth factor (VEGF). Neuroretinas of patients with PVR express elevated mRNA level for HGF in comparison to control retinas. In epiretinal membranes of patients with PVR or PDR, immunoreactivity for HGF and for c-Met, respectively, partially colocalized with immunoreactivity for GFAP. Fetal bovine serum and basic fibroblast growth factor, but not heparin-binding epidermal or platelet-derived growth factors, evoked HGF secretion by cultured retinal glial cells. HGF displayed only a marginal effect on cell proliferation while it stimulated chemotaxis. HGF promoted the secretion of VEGF, via activation of the phosphatidylinositol-3 kinase. It is concluded that glial cells in epiretinal membranes express both HGF protein and c-Met receptors. The results suggest an autocrine/paracrine role of HGF in glial cell responses during proliferative vitreoretinal disorders as well as in retinal neovascularization, by stimulating of VEGF release.     

Decrease of some metabolic and physiologic effects of diazoxide by propranolol in rat

Summary Diazoxide significantly decreased the blood pressure and relaxed the uterine muscle in anaesthetized normotensive rats. A marked elevation of blood glucose followed the intravenous injection of diazoxide. The hyperglycemic and the uterine relaxing response could be significantly decreased by injection of propranolol prior to diazoxide. The hypotensive effect was not diminished by propranolol, however. In liver and uterus the content of cAMP was increased following diazoxide treatment in vivo. The rise in cAMP could be completely inhibited by propranolol, indicating a -receptor stimulation being the cause of the cAMP elevation.     

Expression pattern of the cell cycle promoter cyclin e in benign extravillous trophoblast and gestational trophoblastic lesions: correlation with expression of Ki-67.

In this study, a specific monoclonal antibody was used to immunohistochemically investigate correlated expression of the cell cycle promoter cyclin E and the proliferation marker Ki-67 in benign extravillous trophoblast and gestational trophoblastic lesions. Our data show that cyclin E is expressed in the normal extravillous trophoblast, with strongest levels of expression in the cell columns of anchoring villi. Differences could be observed in expression of Ki-67 in both normal extravillous trophoblast and gestational trophoblastic lesions. In the extravillous trophoblast of the cell columns, expression of cyclin E started more distal compared with Ki-67 and was maintained (with less intensity) into the deeper layers of interstitial trophoblast. In the benign trophoblastic lesions (exaggerated placental site [EPS] and placental site nodule [PSN]) and in the trophoblast proliferations on the surface of hydropic villi of hydatidiform moles (HM), the percentage of cells expressing cyclin E was higher than of those expressing Ki-67. The same observation could be made for a case of placental site trophoblastic tumor (PSTT). In contrast, choriocarcinomas (N=8), which are definitely malignant tumors, showed an opposite pattern, with a much higher percentage of strongly Ki-67-positive cells compared with cyclin E-positive cells. We conclude that cyclin E is expressed in benign extravillous trophoblast and gestational trophoblastic lesions, where a ratio cyclin E/Ki-67<1 characterizes choriocarcinomas, whereas PSTT and the benign lesions (HM, EPS, PSN) show expression of cyclin E in a higher percentage of cells than Ki-67 (cyclin E/Ki-67 ratio >1).     

Avoidance of dental visits: the predictive validity of three dental anxiety scales

The purpose of this study was to determine the sensitivity, specificity, positive and negative predictive values for Corah's Dental Anxiety Scale (DAS) and two modified versions of it (MDAS; MDAS/4). A questionnaire was mailed to a simple random sample of 1,190 25-year-old residents in the west of Norway in 1997. Half the sample received DAS, the other half MDAS. The response rate after one reminder was 62%. The respondents completed the scales, gave demographic particulars and answered one question about dental visiting habits during the last 5 years plus an open-ended question about reasons for nonattendance. Using the answers to the latter question as validating criterion, it was found that, for all scales, sensitivity decreased while specificity improved when changing from a liberal to a stringent cut-off point. The scales gave low positive predictive values (≤0.26), but high negative predictive values (≥0.98). Since DAS and MDAS/4 gave almost identical findings, the two samples were combined. At a cut-off point ≥13 sensitivity was 0.83, specificity 0.84, positive predictive value 0.18 and negative predictive value 0.99. The corresponding estimates when the cut-off point was ≥15 were 0.67, 0.90, 0.22 and 0.98. It is concluded that, in this test, DAS and the two versions of MDAS gave acceptable, or near acceptable sensitivity, specificity and negative predictive values, but far too low positive predictive values to be useful for prediction at the individual level.