Investigation and remediation of houses affected by radon phenomena connected with earlier exploration of silver and uranium ore

The sources of gamma radiation inside buildings affected by earlier silver and uranium mining activities are discussed. Possibilities how to reduce gamma dose rates from building materials were studied on several houses located in the old mining town Jáchymov. Results of the efficiency analysis are presented. Experience obtained up to now indicates that it is almost impossible to reduce the gamma dose rates in such buildings to the level corresponding with the natural background, because some of the gamma radiation sources cannot be completely removed from the building structures.     

Alumina gel injections into the temporal lobe of rhesus monkeys cause complex partial seizures and morphological changes found in human temporal lobe epilepsy

The goal of the present study was to determine whether alumina gel injections into temporal lobe structures cause complex partial seizures (CPS) and pathological changes observed in human temporal lobe epilepsy. Rhesus monkeys with alumina gel injections in the amygdala, perirhinal and entorhinal cortices, or Ammon's horn and dentate gyrus all initially displayed focal pathological electroencephalographic (EEG) slowing limited to the site of injection. After clinical seizures developed, they also displayed widespread pathological EEG slowing over both hemispheres, interictal and ictal epileptiform EEG abnormalities limited to the mesial-inferior temporal lobe on the side of injection, and different degrees of spread to other ipsilateral and contralateral structures. Noninjected control and nonepileptic monkeys with injections into the middle and inferior temporal gyri displayed no hippocampal neuronal loss or mossy fiber sprouting. When alumina gel was injected into the amygdala, CPS began within 3-6 weeks and degeneration of neurons and gliosis occurred in the perirhinal cortex or the hippocampus, with consequent sprouting of mossy fibers in the dentate gyrus. Dispersion of the granule cell layer was also observed. Other monkeys with alumina gel in the perirhinal and entorhinal cortices developed CPS within 2-3 weeks after the injections and displayed mossy fiber sprouting only after 4 weeks after the injections. Alumina gel in Ammon's horn and the dentate gyrus also induced CPS, but mossy fiber sprouting was limited to sites immediately adjacent to the injection, probably because none survived more than 4 weeks after the injections. This nonhuman primate model of CPS displayed similar anatomical, behavioral, and EEG features as observed in human temporal lobe epilepsy and provides opportunities to analyze the chronological sequence of epileptogenesis and to test potential therapies.     

Screening for gestational diabetes mellitus in adolescent pregnancies

OBJECTIVE: Our purpose was to determine the incidence of gestational diabetes mellitus in an adolescent population and to determine the cost of screening. STUDY DESIGN: A retrospective review of 509 adolescent pregnancies was performed. The incidence of gestational diabetes mellitus was determined and the cost of screening analyzed. RESULTS: Five hundred nine adolescent pregnancies were screened for gestational diabetes mellitus with a 1-hour, 50 gm oral glucose challenge test. Twenty-three of the screens (4.5%) had positive results at a plasma glucose level of > or = 140 mg/dl. Three-hour 100 gm oral glucose tolerance tests were performed on screen-positive women, six of whom were diagnosed with gestational diabetes mellitus, for an incidence of 1.18%. The cost per case diagnosed was $2733. CONCLUSIONS: The incidence of gestational diabetes mellitus in an adolescent population is low. The cost of universal screening may be prohibitive in this population. Large prospective studies are needed to better analyze outcome data and efficacy of screening in adolescent pregnancies.     

Sex roles and sexual selection

Sexual selection has been portrayed as acting predominantly on males who compete with each other over copulatory access to females; selection was considered to be driven by females choosing between males at the pre- or postcopulatory level. However, a broader view of sexual selection is now emerging. Examining male discrimination between females and female-female competition has been beneficial in identifying factors influencing the direction and strength of sexual selection. Furthermore, consideration of processes such as sexual coercion or genetic incompatibility, which indirectly influence an individual's set of copulation partners, gamete set or their offspring success, has helped to clarify the ways in which sexual selection may operate. Moreover, there is increasing evidence that not all copulations translate directly to paternity and that paternity does not necessarily translate into successful offspring. Postcopulatory and postfertilization mechanisms that influence not only paternity share but offspring recruitment now require further consideration. The benefits to each sex of copulating with particular partners or with more than one partner remains an area of debate. More carefully designed studies which eliminate alternative possibilities or quantify the relative importance of different selective pressures will also benefit from considering that not all copulations function solely to inseminate or receive sperm. It is also now clear that not all individuals of one sex follow the same strategy. Examining the variation between individuals in reproductive behaviour, fertilization success and offspring success will be important in establishing the selective pressures and mechanisms underlying the operation of sexual selection. (c) 1998 The Association for the Study of Animal Behaviour.     

Prostaglandin f2alpha treatment in vivo, but not in vitro, stimulates protein kinase C-activated superoxide production by nonsteroidogenic cells of the rat corpus luteum

Luteal regression is associated with the generation of reactive oxygen species (ROS). To determine the nature of the ROS generator, cells isolated from luteinized rat ovaries were examined for ROS production using luminol-amplified chemiluminescence (LCL). Cells cultured for 2-48 h exhibited minimal LCL, but there was a significant (30- to 50-fold), rapid (maximum at 3-5 min), and dose-dependent increase in LCL in response to phorbol ester (phorbol 12-myristate 13-acetate; TPA; ED50 = 0.03 microM) and diacylglycerol (1,2-dioctanoyl-glycerol; ED50 = 30 microM). The TPA-induced response was cell number dependent and was virtually abolished by superoxide dismutase, freezing, or heating (95 degrees C for 5 min). Zymosan, known to induce a phagocytic response in leukocytes, stimulated a superoxide (O2-.) response with a slow onset (maximum at 40 to 60 min) and a maximum about one third of that observed for TPA. The response to TPA and zymosan was inhibited by the NADPH/NADH-oxidase inhibitor, diphenylene iodonium (ID50 = 5 microM for TPA), but not by the mitochondrial inhibitors, potassium cyanide, rotenone, or sodium azide. Fractionation of cells by centrifugal elutriation showed that TPA-stimulated O2-. production coeluted with the nonsteroidogenic cells and that little, if any, O2-. generation coeluted with the steroidogenic cells. Cells isolated 1, 2, and 4 h after in vivo treatment with a luteolytic dose of prostaglandin F2alpha (PGF2alpha) showed a significant increase in TPA-stimulated O2-. production at 2 h, whereas luteal cells or corpora lutea incubated directly with 1 microM PGF2alpha did not show any increase in response. Corpora lutea isolated from naturally regressed ovaries (18 days after ovulation) showed a significantly elevated level of TPA-stimulated O2-. production. In conclusion, there is a superoxide generator in luteinized ovaries that is activated through a protein kinase C pathway, localized in nonsteroidogenic cells, transiently increased during PGF2alpha-induced luteolysis in vivo, and elevated during natural luteal regression.     

Differences in the treatment of coronary heart disease between countries as revealed in the Scandinavian Simvastatin Survival Study (4S)

AIM: To assess differences in treatment of ischaemic heart disease in the Scandinavian countries. METHODS AND RESULTS: The Scandinavian Simvastatin Survival Study (4S) lasted 5.4 years and showed that death rates in 4444 patients with coronary heart disease were 30% lower in those treated with simvastatin to lower serum cholesterol than in those given placebo. Apart from this main result, the 4S provided detailed information on rates of death and other manifestations of coronary heart disease, as well as on use of non-lipid forms of therapy. There were substantial differences in 4S placebo group rates of mortality, coronary deaths and major coronary events between countries. Surgical and medical therapy varied importantly between countries. CONCLUSIONS: Major inter-country differences in rates of death and myocardial infarction in patients with coronary heart disease were likely to be due to a composite of differences in baseline characteristics including smoking. They occurred in a setting of very uneven exploitation of the potential for improving survival of patients with ischaemic heart disease.     

Colour Doppler ultrasound in the diagnosis, management and follow-up of a digital flexor pulley injury

We present the case of a rock climber with a rupture of the A3 flexor sheath pulley. The diagnosis was confirmed with Colour Doppler Imaging (CDI) and with B-mode ultrasound imaging, and the surgical repair was evaluated in the same way. Vertical displacement of the flexor tendon meant that using CDI measurements of the longitudinal movements was not possible. However, using computer analysis of digitized B-mode images from texture patterns identified in the tendons, the vertical and longitudinal components of movement during flexion were calculated. The repair of the pulley was shown to produce tendon movement ratios nearer those of the control digit of the opposite hand.     

Homologous pairing in stretched supercoiled DNA

By using elastic measurements on single DNA molecules, we show that stretching a negatively supercoiled DNA activates homologous pairing in physiological conditions. These experiments indicate that a stretched unwound DNA locally denatures to alleviate the force-driven increase in torsional stress. This is detected by hybridization with 1 kb of homologous single-stranded DNA probes. The stretching force involved (approximately 2 pN) is small compared with those typically developed by molecular motors, suggesting that this process may be relevant to DNA processing in vivo. We used this technique to monitor the progressive denaturation of DNA as it is unwound and found that distinct, stable denaturation bubbles formed, beginning in A+T-rich regions.     

Sexual dimorphism in the physiques of World Championship divers

The aim of this study was to evaluate sexual dimorphism in male (n = 43) and female (n = 39) springboard and platform divers at the 1991 World Diving Championships in Perth, Western Australia. In addition to recording the age, height and body mass of each diver, measurements were taken of 8 skinfolds, 13 girths, 8 breadths and depths, and 11 lengths. The derived variables were somatotype, sum of 6 skinfolds (SUM6) and height-adjusted proportional z-scores. The mean (+/- s) values for the males were: age, 22.2 +/- 4.6 years; height, 171 +/- 9 cm; body mass, 66.7 +/- 10.2 kg; somatotype, 2.0-5.3-2.4 +/- 0.5-1.0-0.8; SUM6, 45.9 +/- 11.4 mm. For the females, these values were: age, 20.9 +/- 3.8 years; height, 161 +/- 6 cm; body mass, 53.7 +/- 5.5 kg; somatotype, 2.8-3.8-2.8 +/- 0.7-1.0-0.9; SUM6, 65.6 +/- 17.0 mm. The males were taller, heavier, more mesomorphic, less endomorphic and had a smaller SUM6 than the females (P < 0.01). A series of discriminant function analyses were applied to groups of variables. Wilks' lambda and the overall F-ratio were highly significant (P < 0.001), with correct classification of sex reaching 84-99%. The best combinations of variables were as follows: (1) absolute size, 3 girths + SUM6, or body mass + SUM6 + height (Wilks' lambda = 0.17-0.35); (2) relative size, 2 girths + SUM6 + body mass. Combinations of breadths and lengths, skinfolds, or somatotype components, were less successful, with 84-87% classified correctly (Wilks' lambda = 0.40-0.48). We conclude that, in addition to the expected absolute size differences, sexual dimorphism between male and female divers can be explained by differences in relative size, skinfolds and somatotype, and that these differences may have implications for coaching and selection in diving.     

Ethical aspects of in vitro fertilization and embryo transfer

In vitro fertilization and embryo transfer (IVF-ET) confronts moral reflection with a wide range of concerns. Some are similar to those raised by artificial insemination such as the procurement of sperm, the goods of marriage and donor gametes. Others are unique to IVF-ET such as surrogacy, the status of the embryo and cryopreservation.