3 resultados para CORNEAL COMPENSATION
em DigitalCommons@The Texas Medical Center
Resumo:
The purpose of this study was to examine and describe the changes in physician provider workforce, before and after two regulatory changes were implemented by the Texas Workers' Compensation Commission (TWCC) in August and September of 2003: Fee schedules and the Approved Doctor's List (ADL). The number and type of physicians who participated in the program after the changes went into effect were measured and compared to projections based on natural attrition. In addition, interviews with key stakeholders were conducted regarding the program changes. ^ Collectively, this evidence suggests that physician response followed the same patterns as shown in previous research. The number of physicians who continued to participate and bill the Texas workers' compensation program decreased significantly as a result of the regulatory changes. The consequences of these changes on access and quality of care need to be documented with empirical research. The availability of physicians in the workforce is linked to access to care. The type and location of physicians who remained in the system also have impact on quality and access to care. ^
Resumo:
The potential for significant human populations to experience long-term inhalation of formaldehyde and reports of symptomatology due to this exposure has led to a considerable interest in the toxicologic assessment of risk from subchronic formaldehyde exposures using animal models. Since formaldehyde inhalation depresses certain respiratory parameters in addition to its other forms of toxicity, there is a potential for the alteration of the actual dose received by the exposed individual (and the resulting toxicity) due to this respiratory effect. The respiratory responses to formaldehyde inhalation and the subsequent pattern of deposition were therefore investigated in animals that had received subchronic exposure to the compound, and the potential for changes in the formaldehyde dose received due to long-term inhalation evaluated. Male Sprague-Dawley rats were exposed to either 0, 0.5, 3, or 15 ppm formaldehyde for 6 hours/day, 5 days/week for up to 6 months. The patterns of respiratory response, deposition and the compensation mechanisms involved were then determined in a series of formaldehyde test challenges to both the upper and to the lower respiratory tracts in separate groups of subchronically exposed animals and age-specific controls (four concentration groups, two time points). In both the control and pre-exposed animals, there was a characteristic recovery of respiratory parameters initially depressed by formaldehyde inhalation to at or approaching pre-exposure levels within 10 minutes of the initiation of exposure. Also, formaldehyde deposition was found to remain very high in the upper and lower tracts after long-term exposure. Therefore, there was probably little subsequent effect on the dose received by the exposed individual that was attributable to the repeated exposures. There was a diminished initial minute volume response in test challenges of both the upper and lower tracts of animals that had received at least 16 weeks of exposure to 15 ppm, with compensatory increases in tidal volume in the upper tract and respiratory rate in the lower tract. However, this dose-related effect was probably not relevant to human risk estimation because this formaldehyde dose is in excess of that experienced by human populations. ^
Resumo:
The cornea of the human eye can develop deposits of lipids in the periphery known as corneal arcus. [2, 10] For over a century, these deposits have been of interest as possible indicators of the accumulation of lipids in arterial walls of the heart and body with implications for heart disease. [2, 10, 11, 29] Heart disease is currently the leading cause of death in this country. [5, 29] There have been several publications suggesting an association between the development of atherosclerotic lesions and corneal arcus. [2, 12, 29] Investigators have differed in their interpretation of the relevance of corneal arcus to coronary heart disease or cardiovascular disease. However, there is widespread consensus that the presence of corneal arcus in patients under the age of 50 should prompt physicians to further investigate for dyslipidemia or heart disease. [2, 3, 6, 8, 19] Earlier studies have often suffered from difficulty in determining the presence or severity of atherosclerosis and from inconsistencies in evaluating corneal arcus. This study involves the review of mortality data, medical and social history and standardized slit lamp examination of corneal tissue donors to evaluate the prevalence of corneal arcus in relation to death by CHD or CVD. The prevalence of arcus, odds ratio, and logistic regression was utilized for statistical analysis.^