Effects of sleeping in a chemical protective mask on sleep quality and cognitive performance

PURPOSE: We wanted to determine whether sleep is disrupted when soldiers sleep in a new chemical protective mask, the M40. Sleep quantity and quality, extent of protection provided by the mask during sleep, and next day performance were assessed. METHOD: After several days of training, 9 male soldiers slept with and without the M40 mask on four occasions. RESULTS: Soldiers were able to tolerate the mask for most or all of the night. However, sleep, as assessed by wrist-worn activity monitors, was significantly disturbed. Minutes (mean +/- SEM) of waking significantly increased, from 25 +/- 2.1 to 86 +/- 8.5 per night (p < 0.001), and number of awakenings rose from 8 +/- 0.6 to 20 +/- 0.9 (p < 0.0001). Soldiers reported that it took longer and was more difficult to fall asleep when wearing the mask. Errors on a choice reaction time task increased significantly and subjects reported greater fatigue and sleepiness the day after sleeping in the mask. Protection provided by the masks varied substantially among subjects and declined over the course of the study. Some soldiers were protected throughout the night but others were only protected intermittently. CONCLUSION: We conclude that sleeping in the chemical protective mask should only be done when necessary, given the adverse effects on sleep and daytime function, as well as the variability of protection, of the mask.     

The changing face of emphysematous cholecystitis

Emphysematous cholecystitis is a variant of acute cholecystitis characterized by the presence of gas in the gall bladder lumen, wall or pericholecystic tissues in the absence of an abnormal communication between the biliary system and the gastrointestinal tract. In the past, the diagnosis has relied on the plain abdominal radiograph (AXR), since there are no clinical features to separate this condition from simple acute cholecystitis. The apparently high mortality and morbidity associated with emphysematous cholecystitis has previously emphasized the importance of emergency cholecystectomy. We have reviewed eight cases of emphysematous cholecystitis presenting to this hospital over the last 5 years. The diagnosis was made on AXR in only one of these cases. Ultrasound (US) scans were performed in all eight cases, of which five were positive and three negative, due to non-visualization of the gall bladder. In the three negative cases, the diagnosis was made on subsequent CT scans. On initial clinical examination, only one of the eight patients appeared systemically unwell and conservative management was employed in five of the patients. The remaining three patients underwent cholecystectomy within 3-5 days because of continuing signs or symptoms. It is concluded that the AXR is relatively insensitive in the diagnosis of emphysematous cholecystitis. As a result of the regular use of US in suspected hepatobiliary disease, emphysematous cholecystitis is being diagnosed with increased frequency, uncovering a broad spectrum of disease ranging from mild to severe. Previously, failure to separate milder cases from simple acute cholecystitis may have been responsible for reports of unremitting severity and progression requiring emergency cholecystectomy. Based on clinical assessment, conservative surgical management is possible in a significant proportion of patients.     

Evidence for a catabolic role of glucagon during an amino acid load

Despite the strong association between protein catabolic conditions and hyperglucagonemia, and enhanced glucagon secretion by amino acids (AA), glucagon's effects on protein metabolism remain less clear than on glucose metabolism. To clearly define glucagon's catabolic effect on protein metabolism during AA load, we studied the effects of glucagon on circulating AA and protein dynamics in six healthy subjects. Five protocols were performed in each subject using somatostatin to inhibit the secretion of insulin, glucagon, and growth hormone (GH) and selectively replacing these hormones in different protocols. Total AA concentration was the highest when glucagon, insulin, and GH were low. Selective increase of glucagon levels prevented this increment in AA. Addition of high levels of insulin and GH to high glucagon had no effect on total AA levels, although branched chain AA levels declined. Glucagon mostly decreased glucogenic AA and enhanced glucose production. Endogenous leucine flux, reflecting proteolysis, decreased while leucine oxidation increased in protocols where AA were infused and these changes were unaffected by the hormones. Nonoxidative leucine flux reflecting protein synthesis was stimulated by AA, but high glucagon attenuated this effect. Addition of GH and insulin partially reversed the inhibitory effect of glucagon on protein synthesis. We conclude that glucagon is the pivotal hormone in amino acid disposal during an AA load and, by reducing the availability of AA, glucagon inhibits protein synthesis stimulated by AA. These data provide further support for a catabolic role of glucagon at physiological concentrations.     

Zoonotic Brugian lymphadenitis. An unusual case with florid monocytoid B-cell proliferation

Human infection with a zoonotic Brugia species in the United States is uncommon. Positive identification of the filarial nematode is required for histopathologic diagnosis. Many cases may go unrecognized because of the nonspecific clinical manifestations and the nondiagnostic histologic changes occurring in involved lymph nodes. A case of zoonotic Brugia lymphadenitis is described in a patient from Rhode Island, in which a small nongravid female worm was identified in a lymph node biopsy specimen. The lymph node also showed a spectrum of reaction changes including the presence of florid monocytoid B-cell proliferation, which has not been described in association with zoonotic Brugian filariasis.     

Asymptotic efficiency properties of least squares in an ultrastructural model

This paper considers the estimation of both the intercept term and the slope parameter in a linear ultrastructural model using direct regression and reverse regression methods. Without assuming the errors to be normally distributed, asymptotic expressions for the bias and the variance of the estimators are derived and analyzed. The effect of departure of the errors from normality is also studied.     

Monocyte procoagulant activity induced by adherence to an artificial surface is reduced by end-point immobilized heparin-coating of the surface

Heparin-coating improves the biocompatibility of blood contacting artificial surfaces. This led us to investigate the impact of heparin-coating (Carmeda AB, Stockholm) of polymetylmetacrylate on the expression of monocyte tissue factor procoagulant activity (TF-PCA) by surface adhesion. Also, the anticoagulant effect of heparin-coating in the presence or absence of adherent procoagulant monocytes was assessed. This is of particular interest, since activation of extrinsic coagulation by adherent monocyte TF-PCA may play a significant role in thrombin generation during extracorporeal circulation. Monocytes exposed to heparin-coated or non-coated polymetylmetacrylate expressed TF-PCA. The heparin coat did not affect the rate of monocyte adhesion. However, heparin-coating reduced the induction of TF-PCA of non-adherent and adherent monocytes by 17 and 33% (p <0.001 and p <0.0003), respectively. Heparin-coating in the absence of monocytes, totally inhibited the clotting of recalcified plasma (p <0.003). In contrast, in the presence of adherent monocytes expressing TF-PCA, surface-bound heparin did not inhibit clotting. However, inclusion of heparin in a plasma concentration of 8.9 IU/ml totally inhibited the activation of coagulation. It is apparent that heparin-coating of an artificial surface is an efficient means to inhibit coagulation of recalcified plasma, but much less so when procoagulant monocytes are adherent to the coated surface. The present findings are of clinical relevance, since monocytes will adhere to blood contacting surfaces of extracorporeal circuits or to implanted vascular prostheses and subsequently express TF-PCA, and this may promote thromboembolism.     

Interferon-gamma upregulates the stromelysin-1 gene expression by human skin fibroblasts in culture

Beliefs about human nature, adult education, adult learners, and moral commitment are at the heart of the educator-learner agreement. In continuing nursing education, it is the point where professional values, morals, and ethical principles meet. Using Husteds' bioethical decision-making model, the values, beliefs, and actions within the educator-learning agreement are identified and organized by the bioethical standards. By relating the bioethical standards to practice, continuing nurse educators can find their own basis for practice and work toward attaining a consistent professional ethical orientation.