Prevalence of chronic kidney disease in an urban Mexican population

BACKGROUND: The present study was primarily designed to assess the prevalence of chronic kidney disease in a Mexican urban population residing in Mexico and to evaluate certain biologic and socioeconomic conditions as risk factors for the development of renal disease. METHODS: A population-based cross-sectional survey was conducted, which included 3564 patients of either gender aged >18 years, who were randomly selected from lists of patients assigned to primary care facilities in the city of Morelia. A questionnaire about personal current health status, kidney disease, diabetes, hypertension, or heart disease in close relatives, anthropometric and blood pressure measurements, and blood and urine samples to measure glucose, blood urea nitrogen, and creatinine was obtained for each patient. Creatinine clearance (Ccr) was calculated by the Cockcroft-Gault formula. Patients were classified in 1 of the 5 Ccr categories established by the Kidney Disease Outcomes Quality Initiative guidelines. RESULTS: The prevalence rate of Ccr < 15 mL/min was 1142 per million population, and that of Ccr <60 mL/min 80,788 per million population. Alcohol and tobacco consumption, female gender, age >65 years, educational level < primary school, and income < US $4.00/day were significantly associated with reduced Ccr. CONCLUSION: Chronic kidney disease prevalence in this population is similar to that seen in industrialized countries. If these figures are similar to those of the entire Mexican population, only l out of 4 patients requiring renal replacement therapy in the country currently has access to it.     

Low-dose cholinesterase inhibitors do not induce delayed effects on cerebral blood flow and metabolism

The acetylcholinesterase (AChE) inhibitors sarin and pyridostigmine bromide (PB) have been proposed as causes of neurobehavioral dysfunction in Persian Gulf War veterans. To test possible delayed effects of these agents, we exposed rats to low (subsymptomatic) levels of sarin (0.5 LD₅₀ s.c. 3 times weekly) and/or PB (80 mg/L in drinking water) for 3 weeks. Controls received saline s.c. and tap water. At 2, 4 and 16 weeks after exposure, regional cerebral blood flow (rCBF) and glucose utilization (rCGU) were measured in conscious animals with the Iodo-¹⁴C-antipyrine and ¹⁴C-2 deoxyglucose methods, respectively.

Two weeks after exposure, PB+sarin caused significant rCBF elevations, but no changes in rCGU, in neocortex, with lesser effects on allocortex. Four weeks after exposure, the same general pattern was found with sarin. Only a few changes were found at 16 weeks post-treatment. The predominant effects of sarin or PB+sarin on rCBF at earlier times after treatment are consistent with the well known direct cerebral vascular effect of cholinergic agonists. The lack of changes in rCBF and rCGU observed at 16 weeks after treatment does not support the hypothesis that repeat exposure to low-dose cholinesterase inhibitors can generate permanent alterations in cerebral activity.     

Airbags and Eye Injuries: Epidemiology, Spectrum of Injury, and Analysis of Risk Factors

Although airbags measurably reduce the overall risk of injury to adults (including eye injury), and death from motor vehicle accidents, injuries attributed to airbag deployment have been reported. To identify reported cases of ocular trauma related to airbag deployment, a MEDLINE search from 1991 to 2000 was performed. A total of 263 injuries in 101 patients were identified. Patient demographics, details of the accident, specific ocular structures injured, and visual outcomes when available where tabulated and analyzed. The most common of these affect the eyes. Damage to the orbit and virtually every ocular and adnexal structure has been seen. Although most injuries are self-limited and do not significantly compromise vision, some result in severe, permanent visual loss. Most common is damage to anterior structures due to either blunt, contusive forces and/or chemical injury. Posterior segment trauma is less common but generally more visually devastating because of the involvement of the retina or optic nerve. Data are not available to determine whether the wearing of eyeglasses or previous intraocular surgery affects the nature, severity, or outcome of these injuries. Awareness of the spectrum of airbag-associated ocular trauma will help physicians recognize these problems early and optimize their management. Data derived from analyses of these injuries will be critical to the development of safer, more effective devices.     

Cultural influences on developmental processes and outcomes: implications for the study of development and psychopathology

The purpose of this paper is to trace the role of culture as an explanatory construct in developmental processes and outcomes, and its implications in the understanding of developmental psychopathology. Literature reviews were conducted by historical period: 1930-1939, 1960-1969, and 1990-1999. The percentage of the total articles and chapters pertaining to cultural issues increased as a function of time. Both conceptual and methodological continuities and discontinuities were observed among the three periods. The preponderance of comparative studies using deficit models still remains, but more enlightened alternative conceptual models, within culture studies, and measures of cultural processes, are emerging. In contrast, although contextual influences are considered important in developmental psychopathology, the field lags in its empirical consideration of cultural influences. The need to seriously address these issues will increase as globalization and rapid cultural change become even more the norm than the exception.     

Biochemical characterization of stage-specific isoforms of aspartate aminotransferases from Trypanosoma cruzi and Trypanosoma brucei

Three genes encoding putative aspartate aminotransferases (ASATs) were identified in the Trypanosoma cruzi genome. Two of these ASAT genes, presumably corresponding to a cytosolic and mitochondrial isoform, were cloned and expressed as soluble His-tagged proteins in Escherichia coli. The specific activities determined for both T. cruzi isozymes were notably higher than the values previously reported for Trypanosoma brucei orthologues. To confirm these differences, T. brucei mASAT and cASAT were also expressed as His-tagged enzymes. The kinetic analysis showed that the catalytic parameters of the new recombinant T. brucei ASATs were very similar to those determined for T. cruzi orthologues. The cASATs from both parasites displayed equally broad substrate specificities, while mASATs were highly specific towards aspartate/2-oxoglutarate. The subcellular localization of the mASAT was confirmed by digitonin extraction of intact epimastigotes. At the protein level, cASAT is constitutively expressed in T. brucei, whereas mASAT is down-regulated in the bloodstream forms. By contrast in T. cruzi, mASAT is expressed along the whole life cycle, whereas cASAT is specifically induced in the mammalian stages. Similarly, the expression of malate dehydrogenases (MDHs) is developmentally regulated in T. cruzi: while glycosomal MDH is only expressed in epimastigotes and mitochondrial MDH is present in the insect and mammalian stages. Taken together, these findings provide evidence for a metabolically active mitochondrion in the mammalian stages of T. cruzi, and suggest that the succinate excreted by amastigotes more likely represents a side product of an at least partially operative Krebs cycle, than an end product of glycosomal catabolism.