Mutagenicity studies with N-acetyl-l-aspartic acid

Analytical studies have reported that N-acetyl-l-aspartic acid (NAA) is present at low concentrations in many foods. The current studies were conducted to assess the mutagenicity of NAA using standard OECD guideline in vitro bacterial and in vivo mammalian mutagenicity studies. For comparison and control data, mutagenicity studies were also conducted with its constituent amino acid l-aspartate (ASP) because NAA is metabolized to ASP. The combination of an in vitro method for assessing point mutations in bacteria and an in vivo method to assess clastogenicity in an animal model provided adequate evidence for mutagenicity hazard assessment of NAA. No evidence of mutagenicity was observed in either test system with either NAA or ASP. The results from the current studies demonstrate that the presence of NAA in foods is not likely to represent a risk for mutagenicity.     

Susac's syndrome: Intratympanic therapy for hearing loss and a review of the literature

Two cases of Susac's Syndrome are presented with a discussion of treatment modalities for the associated severe sensorineural deafness. Patients were managed with high dose oral steroids, anticoagulants and immunosuppressive drugs. The addition of intratympanic methylprednisolone injections were added to one patient's regimen with initial improvement but subsequent relapse and progression to profound deafness. The management of Susac's syndrome is difficult and still in need of innovative methods as the standard treatment continues to be ineffective in the long term. Laryngoscope, 119:141–144, 2009     

Acquired Zinc Deficiency in Association with Anorexia Nervosa: Case Report and Review of the Literature

Zinc deficiency, whether a result of an acquired or inherited abnormality of zinc metabolism, is associated with characteristic cutaneous findings. The inherited variety is known as acrodermatitis enteropathica. We present a case of zinc deficiency secondary to starvation induced by anorexia nervosa. Since the cutaneous stigmata of zinc deficiency and anorexia nervosa can initially be subtle and occasionally overlap, we believe that screening zinc levels in patients with anorexia nervosa with prominent cutaneous findings should be considered.     

Using Ecological Momentary Assessment to Examine Antecedents and Correlates of Physical Activity Bouts in Adults Age 50+ Years: A Pilot Study

Background  

National recommendations supporting the promotion of multiple short (10+ minute) physical activity bouts each day to increase overall physical activity levels in middle-aged and older adults underscore the need to identify antecedents and correlates of such daily physical activity episodes.     

Organizational and Environmental Determinants of Hospital EMR Adoption: A National Study

The recent focus on health care quality improvement and cost containment has led some policymakers and practitioners to advocate the adoption of health information technology. One such technology is the Electronic Medical Record (EMR), which is predicted to change and improve health care in the USA. Little is known about factors that influence hospital adoption of this relatively new technology. The purpose of this paper is to determine the national prevalence of EMR adoption in acute care hospitals while examining the organizational and environmental correlates using a Resource Dependence Theoretical Perspective. Significant predictors of hospital EMR use may indicate barriers to use for some hospitals and can be used to guide policy. This study uses a non-experimental cross sectional design to examine hospital EMR use in 2004. A logistic regression approach is used to determine the correlations between hospital EMR use and organizational and environmental characteristics. Hospital EMR use was identified using the HIMSS Analytics data. Organizational and environmental variables were measured using data from the AHA, CMS (financial and case mix) and ARF. Hospital EMR adoption is significantly associated with environmental uncertainty, type of system affiliation, size, and urban-ness. The effects of competition, munificence, ownership, teaching status, public payer mix, and operating margin were not statistically significant. Significant predictors of hospital EMR adoption represent barriers that may prevent certain hospitals from obtaining and using EMRs. These hospitals include those that are smaller, more rural, non-system affiliated, and in areas of low environmental uncertainty. Since EMR adoption may be an organizational survival strategy for hospitals to improve quality and efficiency, hospitals that are at risk of missing the wave of implementation should be offered services and incentives to enable them to implement and maintain EMR systems.     

Abnormal expressions of the subunits of the UDP-<Emphasis Type="Italic">N</Emphasis>-acetylglucosamine: lysosomal enzyme, <Emphasis Type="Italic">N</Emphasis>-acetylglucosamine-1-phosphotransferase,result in the formation of cytoplasmic vacuoles resembling those of the I-cells

Defects in the multimeric enzyme, UDP-N-acetylglucosamine:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (GNPT), result in the diseases of mucolipidosis (ML). This enzyme generates the mannose 6-phosphate residues on newly synthesized lysosomal enzymes for the efficient receptor-mediated transport to lysosomes. The enzyme contains alpha/beta and gamma subunits. Mutations in the alpha/beta subunit result in the classical ML II and IIIA, while defects in the gamma subunit results in the clinically milder ML IIIC. I-cells, a distinct histological feature characterized by the presence of abnormal cytoplasmic vacuoles, are detected in many cell types, most noticeably, in ML II patients. In this study, we investigated the interactions of the alpha/beta and gamma subunits in the pathogenesis of I-cells. We noted low and deranged alpha/beta subunit expressions in human mucolipidosis cell lines. Unexpectedly, high gamma subunit expressions were also observed. In normal mouse fibroblasts, when alpha/beta subunit was suppressed, abnormal cytoplasmic vacuoles were induced, and up-regulation of the gamma subunit was also observed. On the other hand, suppressing the gamma subunit resulted in biphasic responses of the alpha/beta subunit, while abnormal cytoplasmic vacuoles were not formed, regardless of the expression levels of the alpha/beta subunit. Our data suggest reciprocal feedback mechanisms between alpha/beta and the gamma subunits. A fine balance of the expressions of these subunits may play an important role in the formation of I-cells in this group of lysosomal storage disorders.     

Comparison of monounsaturated fat with carbohydrates as a replacement for saturated fat in subjects with a high metabolic risk profile: studies in the fasting and postprandial states

BACKGROUND: In subjects with a high prevalence of metabolic risk abnormalities, the preferred replacement for saturated fat is unresolved. OBJECTIVE: The objective was to study whether carbohydrate or monounsaturated fat is a preferred replacement for saturated fat. DESIGN: Fifty-two men and 33 women, selected to have any combination of HDL cholesterol < or = 30th percentile, triacylglycerol > or = 70th percentile, or insulin > or = 70th percentile, were enrolled in a 3-period, 7-wk randomized crossover study. The subjects consumed an average American diet (AAD; 36% of energy from fat) and 2 additional diets in which 7% of energy from saturated fat was replaced with either carbohydrate (CHO diet) or monounsaturated fatty acids (MUFA diet). RESULTS: Relative to the AAD, LDL cholesterol was lower with both the CHO (-7.0%) and MUFA (-6.3%) diets, whereas the difference in HDL cholesterol was smaller during the MUFA diet (-4.3%) than during the CHO diet (-7.2%). Plasma triacylglycerols tended to be lower with the MUFA diet, but were significantly higher with the CHO diet. Although dietary lipid responses varied on the basis of baseline lipid profiles, the response to diet did not differ between subjects with or without the metabolic syndrome or with or without insulin resistance. Postprandial triacylglycerol concentrations did not differ significantly between the diets. Lipoprotein(a) concentrations increased with both the CHO (20%) and MUFA (11%) diets relative to the AAD. CONCLUSIONS: In the study population, who were at increased risk of coronary artery disease, MUFA provided a greater reduction in risk as a replacement for saturated fat than did carbohydrate.