Effects of zinc deficiency and supplementation on malondialdehyde and glutathione levels in blood and tissues of rats performing swimming exercise

The aim of the study was to investigate the effects of zinc deficiency and supplementation on lipid peroxidation and glutathione levels in blood and in some tissues of rats performing swimming exercise. Forty adult male Sprague-Dawley rats were divided into four groups: group 1, zinc-deficient consisted of swimming rats; group 2 consisted of zinc-supplemented swimming rats; groups 3 and 4 were the swimming and nonswimming controls, respectively. The levels of malondialdehyde and glutathione were measured after 4 wk of zinc-deficient or zinc-supplemented diet and 30 min of swimming exercise daily. The erythrocyte glutathione levels of groups 2 and 4 were significantly higher than those of groups 1 and 3 (p<0.01). The plasma malondialdehyde level of group 1 was significantly higher than all other groups. The glutathione levels in liver, kidney, striated muscle, and testes of group 2 were higher than in the other groups (p<0.01) and higher in kidney and striated muscle of group 3 than in groups 1 and 4 (p<0.01). The tissue malondialdehyde levels of striated muscle, liver, kidney, and testes of group 1 were significantly higher than for all other groups (p<0.01). Our findings suggest that both swimming exercise and zinc deficiency result in an increase of lipid peroxidation in tissues and that zinc supplementation prevents these alterations by the activation of the antioxidant system.     

Home visiting by general practitioners in England and Wales.

OBJECTIVE--To use data from the fourth national survey of morbidity in general practice to investigate the association between home visiting rates and patients'' characteristics. DESIGN--Survey of diagnostic data on all home visits by general practitioners. SETTING--60 general practices in England and Wales. SUBJECTS--502 493 patients visited at home between September 1991 and August 1992. MAIN OUTCOME MEASURES--Home visiting rates per 1000 patient years and home visiting ratios standardised for age and sex. RESULTS--10.1% (139 801/1 378 510) of contacts with general practitioners took place in patients'' homes. The average annual home visiting rate was 299/1000 patient years. Rates showed a J shaped relation with age and were lowest in people aged 16-24 years (103/1000) and highest in people aged > or = 85 years (3009/1000). 1.3% of patients were visited five or more times and received 39% of visits. Age and sex standardised home visiting ratios increased from 69 (95% confidence interval 68 to 70) in social class I to 129 (128 to 130) in social class V. The commonest diagnostic group was diseases of the respiratory system. In older age groups, diseases of the circulatory system was also a common diagnostic group. Standardised home visiting ratios for the 60 practices in the study varied nearly eightfold, from 28 to 218 (interquartile range 67 to 126). CONCLUSIONS--Home visits remain an important component of general practitioners'' workload. As well as the strong associations between home visiting rates and patient characteristics, there were also large differences between practices in home visiting rates. A small number of patients received a disproportionately high number of home visits. Further investigation of patients with high home visiting rates may help to explain the large differences in workload between general practices and help in allocation of resources to practices.     

Oligomerization domains in the glycan‐binding receptors DC‐SIGN and DC‐SIGNR: Sequence variation and stability differences

Human dendritic cell‐specific intercellular adhesion molecule‐1 grabbing nonintegrin, DC‐SIGN, and the sinusoidal endothelial cell receptor DC‐SIGNR or L‐SIGN, are closely related sugar‐binding receptors. DC‐SIGN acts both as a pathogen‐binding endocytic receptor and as a cell adhesion molecule, while DC‐SIGNR has only the pathogen‐binding function. In addition to differences in the sugar‐binding properties of the carbohydrate‐recognition domains in the two receptors, there are sequence differences in the adjacent neck domains, which are coiled‐coil tetramerization domains comprised largely of 23‐amino acid repeat units. A series of model polypeptides consisting of uniform repeat units have been characterized by gel filtration, differential scanning calorimetry and circular dichroism. The results demonstrate that two features characterize repeat units which form more stable tetramers: a leucine reside in the first position of the heptad pattern of hydrophobic residues that pack on the inside of the coiled coil and an arginine residue on the surface of the coiled coil that forms a salt bridge with a glutamic acid residue in the same polypeptide chain. In DC‐SIGNR from all primates, very stable repeat units predominate, so the carbohydrate‐recognition domains must be held relatively closely together. In contrast, stable repeat units are found only near the membrane in DC‐SIGN. The presence of residues that disrupt tetramer formation in repeat units near the carbohydrate‐recognition domains of DC‐SIGN would allow these domains to splay further apart. Thus, the neck domains of DC‐SIGN and DC‐SIGNR can contribute to the different functions of these receptors by presenting the sugar‐binding sites in different contexts.     

Latency of auditory P300 response is related with cognitive deficits in Obstructive Sleep Apnea Syndrome

Sleep and Biological Rhythms - Obstructive Sleep Apnea Syndrome (OSAS) is characterized by desaturation in blood oxygen level and sleep fragmentation because of repeated upper airway obstruction....     

Molecular characterization of carbapenem-resistant Pseudomonas aeruginosa isolated from four medical centres in Iran

Molecular Biology Reports - Understanding the mechanisms of antibiotic resistance is important for designing new therapeutic options and controlling resistant strains. The goal of this study was to...     

An Analysis of the Proportion of the U.S. Population that Ingests Soil or Other Non-Food Substances

Reliable quantitative data are lacking that document the prevalence of ingestion of soil and other “non-food” substances among U.S. children and adults. This article explores the proportion of the U.S. population that ingests substances such as soil, clay, starch, paint, or plaster. We compiled data from the National Health and Nutrition Examination Survey (NHANES) collected from years 1971–1975 (NHANES I) and 1976–1980 (NHANES II) because these particular surveys asked participants specific questions about non-food ingestion practices. We examined the prevalence of the behavior across multiple demographic variables, such as age, gender, education, and income level. Approximately 1% (NHANES II) to 2.5% (NHANES I) of the U.S. population ingests some type of non-food substance. The most notable variation across the demographic subgroups studied was the difference in estimated prevalence among young children (1 to <3 years) compared to older children and adults. Estimated prevalence was also higher among blacks compared to whites and within lower compared to higher socioeconomic groups. This analysis helps fill data gaps on the relative pattern of non-food ingestion practices on a national scale. This information provides perspective for risk assessors when evaluating exposure variables and for risk managers when weighing risk management alternatives.     

A novel sorting sequence in the beta2-adrenergic receptor switches recycling from default to the Hrs-dependent mechanism

Plasma membrane recycling of G protein-coupled receptors can occur by at least two distinct mechanisms as follows: a "default" mechanism that occurs nonselectively, and a specifically sorted mechanism that requires the endosome-associated protein Hrs. In this study we have defined a sequence in the beta2-adrenergic receptor cytoplasmic tail that confers Hrs dependence on receptor recycling. This sequence resembles acidic dileucine class motifs found in other membrane proteins but is structurally and functionally distinct from previously identified sorting sequences. Mutation of the novel sorting sequence rendered plasma membrane recycling independent of Hrs and independent of a distal PDZ ligand required for Hrs-dependent recycling. We propose that the novel sorting sequence functions to "switch" endocytic trafficking between mechanistically distinct recycling modes, thereby explaining failure of the wild type beta2-adrenergic receptor to recycle efficiently by default.