PCB concentrations in lake trout (Salvelinus namaycush) are correlated to habitat use and lake characteristics.

This study considers the importance of lake trout habitat as a factor determining persistent organochlorine (OC) concentration. Lake trout is a stenothermal, cold water species and sensitive to hypoxia. Thus, factors such as lake depth, thermal stratification, and phosphorus enrichment may determine not only which lakes can support lake trout but may also influence among-lake variability in lake trout population characteristics including bioaccumulation of OCs. A survey of 23 lakes spanning much of the natural latitudinal distribution of lake trout provided a range of lake trout habitat to test the hypothesis that lake trout with greater access to littoral habitat for feeding will have lower concentrations of OCs than lake trout that are more restricted to pelagic habitat. Using the delta13C stable isotope signature in lake trout as an indicator of influence of benthic littoral feeding, we found a negative correlation between lipid-corrected delta13C and sigmaPCB concentrations supporting the hypothesis that increasing accessto littoral habitat results in lower OCs in lake trout. The prominence of mixotrophic phytoplankton in lakes with more contaminated lake trout indicated the pelagic microbial food web may exacerbate the biomagnification of OCs when lake trout are restricted to pelagic feeding. A model that predicted sigmaPCB in lake trout based on lake area and latitude (used as proximate variables for proportion of littoral versus pelagic habitat and accessibility to littoral habitat respectively) explained 73% of the variability in sigmaPCBs in lake trout in the 23 lakes surveyed.

New 1-aryl-4-(biarylmethylene)piperazines as potential atypical antipsychotics sharing dopamine D(2)-receptor and serotonin 5-HT(1A)-receptor affinities.

This paper describes the syntheses of several 1-aryl-4-(biarylmethylene)piperazines and the results of the determination of their affinity for D(2) and 5-HT(1A) receptors. A selection of these compounds was evaluated in vivo, resulting in the identification of a drug candidate which is being clinically evaluated as a potential atypical antipsychotic with reduced extrapyrimidal side effects.

[Esophageal stenosis in epidermolysis bullosa hereditaria]. / Osophagusstenose bei Epidermolysis bullosa hereditaria.

Benign esophageal strictures in the upper esophagus may be caused by systemic diseases. A rare reason for esophageal strictures are the mechanobullous disorders marked by blister formation following relatively minor trauma, e.g. epidermolysis bullosa. In this report we present a 63-year-old patient who had suffered from epidermolysis bullosa simplex since birth. The epicutaneous symptoms were no longer present but an esophageal stricture had developed. The stricture was treated by X-ray-controlled balloon dilation twice, with a functionally good result. We suggest managing a recurrence recidiv of stricture with balloon dilation to minimize trauma and prevent further lesions.

[Longitudinal study of 24-hour blood pressure behavior in pregnancy and puerperium in patients with normal pregnancy, pre-eclampsia and HELLP syndrome]. / Longitudinalstudie zum 24-Stunden-Blutdruckverhalten in Schwangerschaft und Wochenbett bei Patientinnen mit normaler Schwangerschaft, Präeklampsie und HELLP-Syndrom.

Ante- and postpartum noninvasive 24-hour ambulatory blood pressure measurements were performed in 18 normotensive pregnants and 36 patients with mild (n = 16) or severe preeclampsia (n = 12) or HELLP-syndrome (n = 8). In contrast to normotensive pregnancy (n = 18) displaying a decline of systolic and diastolic blood pressure in comparison with normotensive non-pregnant, preeclamptic women demonstrate significantly elevated blood pressure profiles before delivery that remain elevated up to the eighth week postpartum. 9 out of 12 patients with severe preeclampsia and 6 of 8 women with HELLP-syndrome show a nocturnal increase of blood pressure within the first week postpartum and a non-dipping up to the eighth week after delivery. As a result of this, in preeclamptic women blood pressure control should be extended into the night and antihypertensive therapy should include a sufficient evening dose.

Silver stain for proteins in ultrathin polyacrylamide gels: a sensitive precipitation technique.

A rapid and highly sensitive silver stain for visualization of proteins on ultrathin isoelectric focusing gels is described. This procedure is based on the specific interaction of silver and bromide ions in the presence of proteins and appears to involve a precipitation reaction. The technique requires only two reaction solutions, a silver nitrate and a potassium bromide solution. Silver consumption is very low because the silver nitrate solution is reusable. This procedure is well established for proteins separated by isoelectrofocusing in ultrathin gels.

Mortality among personnel exposed to diesel exhaust.

Some epidemiological studies have suggested a carcinogenic effect from diesel exhausts and also an increased risk of cardiovascular disease. This cohort study of bus garage employees was undertaken to elucidate further the health effects of diesel exhaust exposure with regard to mortality from cancer and cardiovascular disease. The cohort encompassed 694 men and was followed from 1951 through December 1983. The results showed no significant differences between observed and expected number of deaths in cancer or cardiovascular disease in total or with regard to different degrees of exposure or various requirements of exposure and induction-latency time. The so-called healthy worker effect was relatively weak for cardiovascular disease, but this phenomenon showed no pattern in relation to exposures. The relatively small size of the cohort does not allow for the exclusion of a slightly increased incidence of cancer of certain sites, however.

Cancer mortality among leather tanners.

Workers were studied at a tannery that operated from 1873 to 1960, once one of the biggest in Scandinavia. The results show a slight numerical increase of deaths from cancer of the stomach and a significant, threefold excess mortality from cancer of the pancreas. Even in view of critical questions about validity it seems likely that this excess might be related to exposure to chemicals in tannery work.

Radon in homes--a possible cause of lung cancer.

An earlier case-referent study [Scand j work environ & health 5 (1979) 10-15] has indicated a possible relationship between lung cancer and exposure to radon and radon daughters in dwellings. Indoor radon concentrations seem to depend on both building material and leakage of radon from the ground. This new study, in a rural area, is a further attempt to elucidate the etiology of lung cancer, taking into consideration type of house and ground conditions, as well as smoking habits. Although the choice of a rural study population helped to eliminate various confounding exposures in the urban environment, it limited the size of the study because of the rareness of lung cancer in rural populations. Long-term residents, 30 years or more in the same houses, were studied, and again an association was found between lung cancer and estimated exposure to radon and radon daughters in homes. The data also seem to indicate the possibility of a multiplicative effect between smoking and exposure to radon and radon daughters in homes, but there was also some confounding between these factors in the data.

Cell culture studies on neurofibromatosis (von Recklinghausen). II. Occurrence of glial cells in primary cultures of peripheral neurofibromas.

The occurrence of glial cells in primary cultures established from peripheral neurofibromas of 18 patients with neurofibromatosis (von Recklinghausen) is described. The spindle-shaped cells can be distinguished from fibroblasts on the basis of morphological and ultrastructural criteria. As demonstrated by immunocytochemical analysis, the spindle cells express S-100 protein. Neither glial fibrillar acidic protein nor myelin basic protein can be detected in these cells. In many respects the spindle cells resemble immature Schwann cells in culture.

Herbicide exposure and tumor mortality. An updated epidemiologic investigation on Swedish railroad workers.

An earlier cohort study of Swedish railroad workers indicated a possible relationship between exposure to herbicides and an increased overall tumor morbidity and mortality. The cohort of 348 individuals has now been followed through October 1978. In this updated analysis of the causes of death among railroad workers, the observed number of tumor deaths was higher than expected, especially among individuals exposed in the earlier years of the study to both amitrol and phenoxy acids. However, the excess tumor mortality among persons exposed to amitrol became more moderate, and the earlier, slightly increased tumor mortality among people exposed to phenoxy acids more pronounced. No specific type of tumor predominated although there were three stomach cancers and three lung cancers. The result of the previous analysis of deaths among these railroad workers has been confirmed as to an excess of tumors, but the aspects of causal relationships to specific agents remain rather unclear, especially since workers exposed to a combination of amitrol and phenoxy acids seem to be the most seriously affected. However, the result, being in agreement with animal data and other epidemiologic studies, suggests a need for the careful handling of amitrol and phenoxy acids as increasingly suspicious carcinogens.

Chemical studies on the silver staining of nucleoli.

The uptake of Ag-ions by isolated nucleoli of rat liver cells was studied. Nucleolar proteins separated by electrophoresis were examined for selective silver-staining. A mechanism for preferential Ag-staining of the nucleoli is discussed.

[Drug therapy of chronic arterial occlusive diseases of the lower extremities with butalamine-HCl]. / Pharmakotherapie chronisch arterieller Verschlusskrankheiten der unteren Extremitäten mit Butalamin-HCl.

In a multicentre study a total of 113 patients suffering from disturbed blood flow conditions of the lower extremities (type II Fontaine) were treated with butalamine hydrochloride tablets, each containing 80 mg of the active principle. In 96% of the cases given a daily dose of 3 x 2 tablets and in 82% of those treated with a daily dose of 3 x 1 tablet both subjective and objective clinical symptoms, such as walking distance and Ratschow's testing parameters, were found to be improved. In view of the findings that metabolic functions as well as systemic blood flow conditions were not affected and that the drug was furthermore well tolerated by the gastrointestinal system, butalamine hydrochloride proved to be an effective therapeutic in long-term treatment of patients suffering from blood flow disorders of the lower extremities.

Lung cancer and residency--a case-referent study on the possible impact of of exposure to radon and its daughters in dwellings.

In view of the well-known urban-rural difference in lung cancer rates, remaining also after standardization for smoking, it is suggested that low levels of radon and its daughters in dwellings might be of etiologic importance to this disease. To test this hypothesis, a case-referent (case-control) study was undertaken in a rural area; it considered residency in wooden houses (assumed to be associated with low-level exposure to radon and its daughters), "mixed type" houses (medium exposure) and stone houses (high-level exposure) among cases of lung cancer and referents (controls). The results indicate an increased risk of lung cancer among residents in "mixed type" and stone houses. Additional studies are highly desirable to confirm or refute these findings, which, if valid, mean increasing lung cancer hazards caused by a decrease in ventilation in future energy saving unless special measures are undertaken to reduce radon daughters in dwellings.

Cytological and histochemical studies on the mechanism of the selective silver staining of nucleolus organizer regions (NORs).

A new silver staining method is presented (Ag-II staining) providing a rapid and reproducible way to selective silver staining of nucleolus organizer regions (NORs). In comparison with other techniques, such as the Ag-AS method and the Ag-I method, factors influencing silver stainability are discussed. Histochemical studies on the nature of the NOR-specific silver precipitate were performed either by employing various pretreatments or by inhibiting the participation ("blocking") of the various proteins or protein compounds in the staining reaction. The results would seem to indicate that the interactions of silver-ions with the carboxyl groups of acidic proteins which are involved in the rRNA-transcription process are mainly responsible for the selective silver staining of NORs.