Interaction of Carbohydrates with Phosphatidylcholine Inverse Micelles

Small angle X-ray scattering experiments indicate that egg phosphatidylcholine dissolved in benzene at a concentration of 12–50 mM organizes into approximately isometric inverse micelles with a size that depends upon the amount of water present. These inverse micelles can serve as self-assembled hosts for monosaccharide derivatives. For a given amount of water, addition of carbohydrates causes an increase in the micelle size. In contrast, cyclohexane solutions of egg phosphatidylcholine contain highly anisotropic structures, possibly elongated rods. Monosaccharide derivatives can be extracted into these structures and are bound, at low water content, to the polar head groups. Upon addition of water the sugar is probably displaced from the polar head groups and gains some motional freedom in the water pool which is formed. This fact indicates that the polar head group of phosphatidylcholine interacts, probably by means of hydrogen bond formation, with monosaccharides and brings about their solubilization in nonpolar solvents.     

Cigarette smoking is an independent predictor of nonadherence in HIV-infected individuals receiving highly active antiretroviral therapy.

Current treatment guidelines for the management of HIV-infected individuals emphasize the importance of excellent adherence to antiretroviral medications. We conducted a prospective 24-week study of adherence to lopinavir/ritonavir in a group of 64 subjects using the Medication Event Monitoring System (MEMS). A range of demographic and clinical information, including cigarette smoking status, was collected from each participant. The overall mean adherence rate of the study cohort was 72.8% (SD = 22.2%). Current smokers took 63.5% (SD = 22.1) of prescribed doses, compared with 84.8% (SD = 15.8%) in nonsmokers (p<.001). We found no difference in adherence rates between ex-smokers and subjects who had never smoked. In a multiple linear regression model, factors independently associated with lower adherence rates included current smoking (p = .001), lower CD4+ lymphocyte count at enrollment (p = .04), and lower educational attainment (p = .04). Depression and history of illicit substance use were not associated with nonadherence. In our study cohort, current cigarette smoking was an important and significant marker of inferior adherence to antiretroviral medication.     

Performance of children with ADHD on the Rey-Osterrieth complex figure: a pilot neuropsychological study

This study evaluates the performance of boys with Attention Deficit Hyperactivity Disorder (ADHD) on the Rey-Osterrieth Complex Figure (ROCF) taking into consideration familiality and comorbid psychiatric and learning disorders (LD). Sixty-five children with ADHD performed at developmentally lower levels of Copy Organization and Recall Style than did 45 controls. ADHD children with LD scored significantly lower on Copy Organization than did ADHD children without LD, whereas psychiatric comorbidity and familiality had no effect. These results suggest that a developmental analysis of the ROCF identifies organizational difficulties associated with ADHD and that these impairments cannot simply be attributed to comorbidities associated with ADHD.     

Concurrent task demands and individual differences in the architecture of reading: Discriminating artifacts from real McCoys.

K. R. Paap and R. W. Noel (1991) observed a striking effect in which low-frequency exception words were pronounced faster under a larger memory load although other types of words slowed down. This effect strongly favored dual-route models of pronunciation. S. E. Bernstein and T. H. Carr (1996) reported that only certain selected readers produced Paap and Noel's effect, suggesting individual differences in reading-system architecture. P. M. Pexman and S. J. Lupker (1998) criticized Bernstein and Carr's finding as artifactual and failed to replicate it with a different way of selecting readers. They also failed to support an alternative individual-difference hypothesis of their own. In the current article, the authors developed a new approach to identifying individual differences and applied the approach to a variety of data. They found little evidence of systematic individual differences in the occurrence of Paap and Noel's effect, and indeed, they found little evidence that the effect could be replicated at all. Therefore, they gave up. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multicenter study of case finding in elderly emergency department patients

OBJECTIVES: To assess the feasibility of a brief comprehensive case-finding program for detecting functional, cognitive, and social impairments among elderly ED patients and to estimate the prevalence of unknown, undetected, or untreated impairments elderly patients may have. METHODS: A multicenter prospective study conducted at five private and public hospital EDs in five different communities across the country. Patients aged 60 years and older released to their homes during 52 randomly selected evening and weekend shifts between February 1 and April 30, 1993, were eligible for the case-finding program. They were evaluated by medical students who received special training (instructional videotape, supervised examinations, and conference calls) in the administration of a standardized 17-item protocol that included an interview and simple tests of function. The patients' physicians were notified of the screening results and were asked to return a one-month follow-up questionnaire. The physicians answered whether the presumed problem had been confirmed and whether a treatment plan for a new problem had been developed. RESULTS: Patient acceptance of the case-finding program was good; 252 of 338 eligible patients (75%) agreed to participate, and 281 conditions were detected for 242 screened patients (96%). The most frequently reported problems were with: performing the activities of daily living (79%); vision (55%); lack of influenza vaccination (54%); home environment (49%); mental status (46%); general health (41%); falls (40%); and depression (36%). The physicians returned questionnaires for 153 patients (63%); 76 patients (50%) were evaluated at follow-up visits, during which 47 newly identified problems (62%) were confirmed and treatment plans were developed for 25 problems (53%) among 21 patients. A mean time of 17.7 +/- 10.2 minutes was required to complete the screen. CONCLUSIONS: A brief comprehensive case-finding program for functional, cognitive, and social impairment among elderly ED patients is feasible. The screening uncovered a significant amount of morbidity among older patients visiting EDs.     

Murine NIMA-related kinases are expressed in patterns suggesting distinct functions in gametogenesis and a role in the nervous system

NIMA protein kinase is a major regulator of progression into mitosis in Aspergillus nidulans. Dominant negative forms of NIMA protein prevent entrance into mitosis in HeLa cells, suggesting that mammals have a similar pathway. We have reported previously the isolation of a murine NIMA-related kinase, designated Nek1, and more recently several additional NIMA-related human kinases have been cloned. The existence of several mammalian NIMA-related genes raises the questions of whether the different mammalian members have redundant, overlapping or distinct functions, and whether these functions are related to the role of NIMA in controlling mitosis. To address these questions we have studied the expression patterns of the different murine nek genes. To this end, we isolated a murine nek2 cDNA and compared its patterns of expression, during both gametogenesis and embryogenesis, to those of nek1. Both genes were highly expressed in developing germ cells, albeit in distinct patterns. In both females and males, nek1 is expressed much earlier than nek2, suggesting only limited ability for functional redundancy. Surprisingly, a striking specificity of nek1 expression was found: high levels of nek1 RNA were observed in distinct regions of the nervous system, most notably in neurons of the peripheral ganglia. These patterns suggest that the different mammalian NIMA-related kinases participate in different phases of the meiotic process and may also have functions other than cell cycle control.     

Relation between macroscopic and microscopic dielectric relaxation times in water dynamics

A simplified derivation for the ratio of macroscopic to microscopic relaxation times of polar liquids is based on the Mori-Zwanzig projection-operator technique, with added statistical assumptions. We obtain several useful forms for the lifetime ratio, which we apply to the dynamics of liquid water. Our theoretical single-molecule relaxation times agree with the second Debye relaxation times as measured by frequency-domain dielectric spectroscopy of water and alcohols. From the theory, fast relaxation modes couple to the Debye relaxation time, τ_d, through very large water clusters, and their temperature dependence is similar to that of τ_d. Slower modes are localized to smaller water clusters and exhibit weaker temperature dependence. This is exemplified by the lifetime ratios measured by time-domain dielectric spectroscopy and optical Kerr effect spectroscopy, respectively.