The relationship between air particulate levels and upper respiratory disease in soldiers deployed to Bosnia (1997-1998)

The objective of this study was to determine whether there was a relationship between levels of particulate matter with an aerodynamic diameter of less than 10 microns (PM10) and upper respiratory disease (URD) rates in soldiers deployed to Bosnia in 1997 and 1998. PM10 levels were divided into quartiles and upper and lower 50th percentiles. When all camps were combined, there was a statistically significant association between the PM10 maximum level and URD rates based on Kruskal-Wallis and Mann-Whitney U tests, and the Pearson correlation was statistically significant. Although the relationship was not statistically significant in analyses conducted of the individual camps, the average URD rate increased with each quartile of PM10 maximum exposure. There was no statistically significant association between PM10 average exposure and URD rates, although the average URD rate increased with each quartile of PM10 average exposure. Although these results are not conclusive, there appears to be a relationship between PM10 levels and URD rates in soldiers deployed to Bosnia in 1997 and 1998.     

Do challenging behaviors affect staff psychological well-being? Issues of causality and mechanism

Little explicit attention has been given to the potential impact of client challenging behavior on staff psychological well-being. Relevant research was critically reviewed according to criteria required to establish a causal relationship. Reasonable evidence was found for an association between challenging behavior and staff stress, and some evidence for temporal precedence. However, few researchers had analyzed data enabling alternative explanations to be eliminated. Thus, empirical evidence of a causal relationship between challenging behavior and staff stress is weak. A fourth causality criterion was addressed by suggestion of a mechanism by which challenging behavior may have its effects. I propose that staff negative emotional reactions mediate the impact of challenging behaviors on staff stress and evaluate research evidence for this theory.     

Behavior problems of children with autism, parental self-efficacy, and mental health

Self-efficacy has been identified in the general parenting literature as an important variable affecting parent outcomes. In the present study, 26 mothers and 20 fathers of children with autism reported on their self-efficacy, anxiety, and depression. Teachers rated the behavior problems of the children. Regression analyses showed that self-efficacy mediated the effect of child behavior problems on mothers' anxiety and depression, but there was no evidence that it functioned as a mediator for fathers. However, there was evidence that self-efficacy moderated the effect of child behavior problems on fathers' anxiety. No evidence for the moderating effect of self-efficacy was apparent for mothers. Methodological issues and the theoretical and practical implications of these results are discussed.     

Mechanical hyperalgesia in rats with chronic perfusion of lumbar dorsal root ganglion with hyperglycemic solution

In diabetes, chronic systemic hyperglycemia is associated with pain and other symptoms of peripheral neuropathy. Evaluation of mechanisms causing these symptoms is complicated because of the overlap between the systemic effects of hyperglycemia and its toxic effects within the peripheral nervous system. To address this problem we developed a technique for chronic local in vivo perfusion of rat lumbar dorsal root ganglion (DRG) with a hyperglycemic solution. Osmotic pumps were filled with 30 mM glucose in physiological buffer and implanted in normal adult rats. The output of the catheter attached to the pump was positioned in a hole drilled through the right transverse process of the L₅ vertebrae to perfuse the corresponding DRG. Repetitive tests of foot withdrawal to mechanical stimuli have shown that chronic hyperglycemia localized to the L₅ DRG causes hyperalgesia in the hind limb innervated by perfused ganglion but not in the contralateral limb. Control experiments (DRG perfusion with 5 mM glucose or 5 mM glucose+25 mM mannitol solution) have shown that hyperglycemia-induced hyperalgesia can not be attributed to surgery-related injury or hyperosmolality of the ganglion-perfusing solution. These data demonstrate direct functional toxicity of hyperglycemia in the peripheral nervous system. This technique provides a new approach for in vivo study of chronic effects of physiologically active factors on DRG neuron function.     

Granule neurons generated during development extend divergent axon collaterals to hippocampal area CA3

cAMP is a ubiquitous second messenger, which acts mainly through specific protein kinases that consist of two regulatory and two catalytic subunits. An unsolved problem in cAMP physiology is how it can regulate so many cellular functions through this simple enzymatic cascade. A tentative explanation is related to the different biochemical properties of the four regulatory subunit isoforms (RI alpha and RI beta, RII alpha and RII beta) and to their differential cell and tissue distribution. For example, detergent insoluble aggregates of RI alpha are present in some cholinergic neurons of the adult rat brain. Rat brains, from the embryonic stage to old age, were examined for the presence of highly concentrated clusters of RI alpha. They are present only in some neurons of restricted brain areas, for a limited time span. During development, labeled neurons appear in different brain areas after neuron migration, at a stage of advanced functional maturation. They have their greatest expression after birth but before sexual maturation, and then they slowly decline, persisting only in a few brain areas throughout life. The first appearance, time course, and eventual disappearance is different in the different brain areas: RI alpha clusters appear in brainstem, hypothalamus, and accessory olfactory bulb at a late embryonic stage; in the main olfactory bulb, hippocampus, and medial thalamic nuclei shortly after birth; and in the cortex as late as in the third and fourth postnatal week. During the rat's lifespan, the distribution of these peculiar RI alpha clusters undergo changes that may contribute to shape neuronal responses differentially to agents modifying cAMP levels.     

Bone mineral density during total contact cast immobilization for a patient with neuropathic (Charcot) arthropathy

BACKGROUND AND PURPOSE: Diabetes mellitus (DM)-related neuropathic arthropathy of the foot is a destructive bone and joint process. The effect of cast immobilization and non-weight bearing on bone loss has not been well studied. The purpose of this case report is to describe the changes in bone mineral density (BMD) of the calcaneus in the feet of a patient with acute neuropathic arthropathy during total contact cast immobilization. CASE DESCRIPTION: The patient was a 34-year-old woman with type 1 DM, renal failure requiring dialysis, and a 7-week duration of neuropathic arthropathy of the midfoot. Intervention included total contact casting and minimal to no weight bearing for 10 weeks, with transition to therapeutic footwear. Ultrasound-derived estimates of BMD were taken of both involved and uninvolved calcanei. OUTCOME: Bone mineral density decreased for the involved foot (from 0.25 g/cm(2) to 0.20 g/cm(2)) and increased for the uninvolved foot (from 0.27 g/cm(2) to 0.31 g/cm(2)) during casting. DISCUSSION: The low initial BMD and further loss during casting suggest the need for transitional bracing and a well-monitored return to full activity to minimize the risk of recurrence and progression of foot deformity.     

Parathyroid hormone-related protein and lung biology

Parathyroid hormone-related protein (PTHrP) is expressed in normal and malignant lung and has roles in development, homeostasis, and pathophysiology of injury and cancer. Its effects in developing lung include regulation of branching morphogenesis and type II cell maturation. In adult lung, PTHrP stimulates disaturated phosphatidylcholine secretion, inhibits type II cell growth, and sensitizes them to apoptosis. In lung cancer, PTHrP may play a role in carcinoma progression, or metastasis. The protein could be a useful marker for assessing lung maturity or type II cell function, predicting risk of injury, and detecting lung cancer. PTHrP-based therapies could also prove useful in lung injury and lung cancer.