Diabetes mellitus and osteoporosis.

Diabetes mellitus (particularly type 2) and osteoporosis are two very common disorders, and both are increasing in prevalence. Adolescents with type 1 diabetes mellitus may not reach potential peak bone mass, putting them at greater fracture risk. In adults with type 2 diabetes, fracture risk is increased and is not explained by the bone mineral density measured by dual-energy X-ray absorptiometry, still considered the gold standard predictor of fracture. In this review, we explore potential mechanisms behind the increased fracture risk that occurs in patients with diabetes, even those with increased bone mineral density. One potential link between diabetes and bone is the osteoblast-produced factor, osteocalcin. It remains to be established whether osteocalcin reflects or affects the connection between bone and glucose metabolism. Several other potential mediators of the effects of diabetes on bone are discussed

Moving into and out of poor urban areas

Newly available geographical information from the Panel Study of Income Dynamics (PSID) is used to estimate a variety of relationships involving high-poverty metropolitan census tracts. The longitudinal data from the PSID show a great deal of geographical mobility even for persistently poor adults, with as many as one fourth of certain groups of these entering and leaving poor urban census tracts in a year. At the same time, solution of the transition matrices for various groups-whites and blacks of various income classes, in families with and without children, living in different types of census tracts-in the early 1980s shows the gradual emptying out of poor urban tracts, particularly of whites and blacks in families without children. As a consequence, despite the great degree of geographical “churning,” poor urban areas gradually become poorer, blacker, and the home of a larger share of black families with children. Some of these aggregate trends had been noticed by researchers comparing these areas in the 1970 and 1980 censuses; our more up-to-date results demonstrate the relationships between the micro and macro data.

Assessment of the effect of a bentonite seal on groundwater storage in underlying waste disposal trenches at Oak Ridge National Laboratory

For a 49-trench section that was sealed in Solid Waste Disposal Area 6, the water-table elevation was periodically measured to assess the effectiveness of the seal for controlling the intrustion of water. Water was found in a majority of trenches throughout the study period (May 1978-December 1979). Mean seasonal water-table fluctuations indicated an average rise of 131 +- 56 cm in waste trenches between October 30, 1978 (minimum level) and February 15, 1979 (maximum level). This mean difference corresponds to an estimated gain of 1000 m/sup 3/ of groundwater storage in the trench area. The measured depths to water in the trenches showed a general correspondence with those in monitoring wells (augered during September 1979) outside the trenches in the undisturbed zone in the downslope southern half of the study area. In contrast, the measured depths to water were relatively greater in wells in the undisturbed zone in comparison with those in trenches in the upslope northern half of the study area. This suggests that perched water tables developed within the trenches in the upslope area. The groundwater table (potentiometric surface) contours essentially followed the topographic contours and indicated a predominant gradient toward the south-southwest, which is in the direction of a backfilled topographic draw with a known seep at its base. The reported hydrologic characteristics of the Oak Ridge area, laboratory studies in the development of bentonite application rates, and simulation studies using a hydrologic computer code suggested that a significant part of the groundwater observed in the study area was associated with groundwater intrusion from the surrounding upslope area

Dermal mononuclear phagocytes

In immune responses of the skin, the connective tissue environment of the dermis plays a decisive role. Large numbers of resident mononuclear phagocytes are located here and these are thought to be crucial for the initiation and regulation of such responses. Surprisingly, the characterization of dermal mononuclear phagocytes, often distinguished as macrophages and dendritic cells (DC), has been limited compared to those in other immune organs and to their Langerhans cell counterparts in the epidermis. This is likely explained by the difficulty to obtain dermal cells in large quantity. In this chapter, we will provide an overview of the current insights on dermal mononuclear phagocytes, using the different technical approaches to study these cells as a guideline. For practical purposes we will focus primarily on the steady-state situation and discuss this for human and mouse skin. In situ analysis using skin sections has indicated that mononuclear phagocytes represent a remarkably large proportion of nucleated cells in the dermis, comprising multiple, phenotypically distinct subsets. Using skin explant cultures or freshly isolated cells from dermal tissue, single cells can be obtained. These approaches confirm the extensive heterogeneity of the dermal mononuclear phagocytes. Interpreting the available data, we propose that a developmental relationship may exist between the major subsets. While the cells migrate upwards from the deeper layers in the dermis they mature and change from endocytic macrophage-like cells to cells with an immunostimulatory DC phenotype, which may leave the dermis via afferent lymphatics to interact with the immune system in skin-draining lymph nodes

Gonadal hormones modulate sex differences in judgments of relative numerousness in meadow voles, Microtus pennsylvanicus

Animals in a variety of taxa discriminate between a greater quantity and a lesser quantity of the same object, an ability that is referred to as relative numerousness judgment. For example, meadow voles can distinguish between areas containing more over-marks by one opposite-sex scent donor and fewer over-marks by another opposite-sex scent donor. Females appear to be able to make better discriminations between more or less over-marks than do males. In that gonadal hormones have been implicated in modulating cognitive function associated with spatial tasks, we tested the hypothesis that high titers of testosterone and estradiol are necessary for male and female voles, respectively, to distinguish between the top- and bottom-scent donors in an area containing mixed over-marks. We gonadectomized voles, giving them either gonadal hormone replacement (testosterone for males and estradiol for females) or no hormone replacement, and tested their spontaneous judgments of distinguishing between the top- and bottom-scent donors in an area containing mixed over-marks; a task involving judgments of relative numerousness. Female voles given replacement estradiol performed better than did female voles not given replacement estradiol in determining the top-scent and bottom-scent males in areas containing mixed over-marks. In contrast, males not treated with replacement testosterone performed better than did males treated with testosterone in determining the top-scent and bottom-scent males in areas containing mixed over-marks. Thus, high titers of estradiol and low titers of testosterone are associated with better performance on tasks involving relative numerousness in female and male voles, respectively. The results of this task on relative numerousness judgments are discussed in relation to the effects of gonadal steroid hormone on spatial ability, a closely related cognitive domain, and the social biology of meadow voles. © 2008 Elsevier Inc. All rights reserved

LABORATORY PROGRESS ON THE DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTE BY DEEP- WELL INJECTION

Results of laboratory studies on the neutralization of Purex-type wastes are reported, including the radiochemical distribution of the fission products in the precipitate and supernate and the effect of sodium and calcium neutralizations on fission-produet separation. The problem of interstitial precipitation encountered when a second incompatible liquid is injected into a formation is discussed. Results indicate a piston-iike displacement of the interstitial liquid by the injected waste with only a small zone of precipitation formed along the contacting edge. Slurry tests were performed to determine the eapacity of various geologic materials for sorption of cesium and strontium from a synthetic Purex-type waste containing carriers and tracers. The materials studied include sands, feldspars, shales, clays, and limestone. The amount of cesium sorbed was found to be a function of several variables, among which are concentration of cesium in the waste, concentration of other cations, amount and nature of the clay material, and composition and amounts of other minerals in the disposal formation. Several types of shales and clay minerals, including illite, bentonite, montmorillonite, kaolinite, halloysite, and Conasauga shale, were slurried with simulated neutralized 6 M Purex waste. Sorption of cesium ranged from 0.6 to 6.0 mg/20 g, respectively, for the various materials tested. Results of slurry tests indicated that if the Purex-type waste were diluted 30 to 1 with concentrated brine, the amount of cesium sorbed per cubic foot would be about 2.7 curies. This is within the 2 to 8 curries/ft/sup 3/ estimated to be safe from thermal considerations. Core tests on a Berea sandstone showed similar sorptive capacities. Sequestering or complexing agents, that is, versenes, did not materially affect the cesium removal, but did result in a decreased sorption of strontium hy clays. Strontium sorption in systems studied ranged from less than 0.2 to 2.0 mg of strontium sorbed per 20 g of clay. Slurry results indicated increased H ion concentration decreases sorption; sorption of cesium is a function of the Na/Ca ratio; the Na/Sr ratio is not as important to strontium removal as pH of the solution; and limestone slightly decreases the amount of cesium sorbed per gram of illite. The results of the sorption studies suggest that undue localized heat production, due to sorption of radioactive materials near the well, can be controlled so that it will not be a serious problem. (auth

Incidence and predisposition of the hip dysplasia in Hungarian shepherd dogs

Dogs with CHD are born with normal hips that later undergo varying degrees of subluxation of the coxofemoral joint. Although the aetiology of CHD is multifactorial, the pathogenesis or stages of change within the affected coxofemoral joint(s) are similar regardless of cause. With the onset of disease, there are progressive structural changes including joint laxity and femoral head subluxation, swelling, stretching, fraying, and eventual rupture of the teres ligament; articular cartilage, eburnation of subchondral bone, DJD and perioarticular ostephyte formation. It is very hard to decide to which extent CHD is multifactorial genetic. If hip dysplasia; then it is likely that the disease is genetic and that the dog will also be a carrier. However, this is unfortunately not enough to prove if a dog will manifest with hip dysplasia or not. environmental factors might play a role as well. This would require a lot of research and studying though; hundreds and more dogs and their pedigrees should be examined before we can draw a conclusion of the disease being multifactorial or not.proceeding

Meadow voles, Microtus pennsylvanicus, can distinguish more over-marks from fewer over-marks

Is it possible that voles have a sense of number? To address this question, we determined whether voles discriminate between two different scent-marking individuals and identify the individual whose scent marks was on top more often than the other individual. We tested whether voles show a preference for the individual whose scent marks was on top most often. If so, the simplest explanation was that voles can make a relative size judgement-such as distinguishing an area containing more of one individual\u27s over-marks as compared to less of another individual\u27s over-marks. We found that voles respond preferentially to the donor that provided a greater number of over-marks as compared to the donor that provided a lesser number of over-marks. Thus, we concluded that voles might display the capacity for relative numerousness. Interestingly, female voles were better able than male voles to distinguish between small differences in the relative number of over-marks by the two scent donors. © Springer-Verlag 2005