An expert system for the evaluation of historical asbestos exposure as diagnostic criterion in asbestos-related diseases.
(41/73093)
Compensation schemes for asbestos-related diseases have developed different strategies for attributing a specific disease to occupational exposure to asbestos in the past. In the absence of quantitative exposure information that allows a valid estimate of an individual's historical exposure, general guidelines are required to retrospectively evaluate asbestos exposure. A risk matrix has been developed that contains qualitative information on the proportion of workers exposed and the level of exposure in particular industries over time. Based on this risk matrix, stepwise decision trees were formulated for decisions regarding the decisive role of historical asbestos exposure in case ascertainment of asbestosis and mesothelioma. Application of decision schemes will serve to speed up the process of verifying compensation claims and also contribute to a uniform decision-making process in legal procedures. (+info)
Racial differences in the outcome of left ventricular dysfunction.
(42/73093)
BACKGROUND: Population-based studies have found that black patients with congestive heart failure have a higher mortality rate than whites with the same condition. This finding has been attributed to differences in the severity, causes, and management of heart failure, the prevalence of coexisting conditions, and socioeconomic factors. Although these factors probably account for some of the higher mortality due to congestive heart failure among blacks, we hypothesized that racial differences in the natural history of left ventricular dysfunction might also have a role. METHODS: Using data from the Studies of Left Ventricular Dysfunction (SOLVD) prevention and treatment trials, in which all patients received standardized therapy and follow-up, we conducted a retrospective analysis of the outcomes of asymptomatic and symptomatic left ventricular systolic dysfunction among black and white participants. The mean (+/-SD) follow-up was 34.2+/-14.0 months in the prevention trial and 32.3+/-14.8 months in the treatment trial among the black and white participants. RESULTS: The overall mortality rates in the prevention trial were 8.1 per 100 person-years for blacks and 5.1 per 100 person years for whites. In the treatment trial, the rates were 16.7 per 100 person-years and 13.4 per 100 person-years, respectively. After adjustment for age, coexisting conditions, severity and causes of heart failure, and use of medications, blacks had a higher risk of death from all causes in both the SOLVD prevention trial (relative risk, 1.36; 95 percent confidence interval, 1.06 to 1.74; P=0.02) and the treatment trial (relative risk, 1.25; 95 percent confidence interval, 1.04 to 1.50; P=0.02). In both trials blacks were also at higher risk for death due to pump failure and for the combined end point of death from any cause or hospitalization for heart failure, our two predefined indicators of the progression of left ventricular systolic dysfunction. CONCLUSIONS: Blacks with mild-to-moderate left ventricular systolic dysfunction appear to be at higher risk for progression of heart failure and death from any cause than similarly treated whites. These results suggest that there may be racial differences in the outcome of asymptomatic and symptomatic left ventricular systolic dysfunction. (+info)
Trans-sphenoidal surgery for microprolactinoma: an acceptable alternative to dopamine agonists?
(43/73093)
AIMS: Reported cure rates following trans-sphenoidal surgery for microprolactinoma are variable and recurrence rates in some series are high. We wished to examine the cure rate of trans-sphenoidal surgery for microprolactinoma, and to assess the long-term complications and recurrence rate. DESIGN: A retrospective review of the outcome of trans-sphenoidal surgery for microprolactinoma, performed by a single neurosurgeon at a tertiary referral centre between 1976 and 1997. PATIENTS: All thirty-two patients operated on for microprolactinoma were female, with a mean age of 31 years (range 16-49). Indications for surgery were intolerance of dopamine agonists in ten (31%), resistance in six (19%) and resistance and intolerance in four (12.5%). Two patients were from countries where dopamine agonists were unavailable. RESULTS: The mean pre-operative prolactin level was 2933 mU/l (range 1125-6000). All but 1 had amenorrhoea or oligomenorrhoea, with galactorrhoea in 15 (46.9%). Twenty-five (78%) were cured by trans-sphenoidal surgery, as judged by a post-operative serum prolactin in the normal range. During a mean follow-up of 70 months (range 2 months to 16 years) there was one recurrence at 12 years. Post-operatively, one patient became LH deficient, two patients became cortisol deficient and two became TSH deficient. Out of 21 patients tested for post-operative growth hormone deficiency, 6 (28.6%) were deficient. Five patients developed post-operative diabetes insipidus which persisted for greater than 6 months. There were no other complications of surgery. The estimated cost of uncomplicated trans-sphenoidal surgery, and follow-up over 10 years, was similar to that of dopamine agonist therapy. CONCLUSION: In patients with hyperprolactinaemia due to a pituitary microprolactinoma, transsphenoidal surgery by an experienced pituitary surgeon should be considered as a potentially curative procedure. The cost of treatment over a 10 year period is similar in uncomplicated cases to long-term dopamine agonist therapy. (+info)
Microvascular loops and networks as prognostic indicators in choroidal and ciliary body melanomas.
(44/73093)
BACKGROUND: Malignant melanoma of the ciliary body and choroid of the eye is a tumor that disseminates frequently, and 50% of the diagnosed patients die within 10 years. We investigated the hypothesis that, by histopathologic analysis of the arrangement of microvessels (i.e., small blood vessels) in loops and networks, we might be able to differentiate better those patients with a favorable prognosis from those with a poor prognosis. METHODS: We conducted a population-based, retrospective cohort study of melanoma-specific and all-cause mortality for 167 consecutive patients who had an eye surgically removed because of malignant choroidal or ciliary body melanoma during the period from 1972 through 1981. Microvascular loops and networks were evaluated independently by two pathologists who were unaware of patient outcome. RESULTS: Microvascular patterns could be assessed in 134 (80%) of 167 melanoma specimens. The 10-year probability of melanoma-specific survival was worse if microvascular loops (0.45 versus 0.83; two-sided P<.0001) and networks (0.41 versus 0.72, two-sided P<.0001) were present. In multivariate Cox regression analysis of melanoma-specific survival, the hazard ratios were 1.66 (95% confidence interval [CI] = 1.19-2.30) for the presence of loops and networks as a combined three-category variable, 2.36 (95% CI = 1.37-4.05) for the presence of epithelioid cells, 1.11 (95% CI = 1.03-1.19) for the largest basal tumor diameter (evaluated as a continuous variable), and 2.14 (95% CI = 1.25-3.67) for ciliary body involvement. CONCLUSIONS: Patients with malignant uveal melanoma who have a favorable prognosis can be distinguished from those with a poor prognosis by histopathologic analysis of microvascular patterns in uveal melanoma tumor specimens. (+info)
Electrophysiologic effects of adenosine in patients with supraventricular tachycardia.
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BACKGROUND: We correlated the electrophysiologic (EP) effects of adenosine with tachycardia mechanisms in patients with supraventricular tachycardias (SVT). METHODS AND RESULTS: Adenosine was administered to 229 patients with SVTs during EP study: atrioventricular (AV) reentry (AVRT; n=59), typical atrioventricular node reentry (AVNRT; n=82), atypical AVNRT (n=13), permanent junctional reciprocating tachycardia (PJRT; n=12), atrial tachycardia (AT; n=53), and inappropriate sinus tachycardia (IST; n=10). There was no difference in incidence of tachycardia termination at the AV node in AVRT (85%) versus AVNRT (86%) after adenosine, but patients with AVRT showed increases in the ventriculoatrial (VA) intervals (13%) compared with typical AVNRT (0%), P<0.005. Changes in atrial, AV, or VA intervals after adenosine did not predict the mode of termination of long R-P tachycardias. For patients with AT, there was no correlation with location of the atrial focus and adenosine response. AV block after adenosine was only observed in AT patients (27%) or IST (30%). Patients with IST showed atrial cycle length increases after adenosine (P<0.05) with little change in activation sequence. The incidence of atrial fibrillation after adenosine was higher for those with AVRT (15%) compared with typical AVNRT (0%) P<0.001, or atypical AVNRT (0%) but similar to those with AT (11%) and PJRT (17%). CONCLUSIONS: The EP response to adenosine proved of limited value to identify the location of AT or SVT mechanisms. Features favoring AT were the presence of AV block or marked shortening of atrial cycle length before tachycardia suppression. Atrial fibrillation was more common after adenosine in patients with AVRT, PJRT, or AT. Patients with IST showed increases in cycle length with little change in atrial activation sequence after adenosine. (+info)
A retrospective cohort study of male workers exposed to PVA fibers.
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In order to ascertain whether PVA fibers can produce cancer in humans or not, we have conducted a retrospective cohort study of workers exposed to PVA fibers. A total of 447 exposed and 2416 non-exposed male workers who were engaged before 1980 were followed up until the end of 1996. The SMR for all causes was 0.57 (observed 38, 95% CI: 0.41-0.78) for the exposed, and 0.66 (observed 210, 95% CI: 0.58-0.75). As for lung cancer, its SMR was 0.77 (observed 3, 95% CI: 0.15-2.24) for the exposed workers and 0.67 (12 observed, 95% CI: 0.34-1.16) for the non-exposed workers. Lung cancer SMR was 0.86 (observed 2, 95% CI: 0.10-3.11) for the workers with 20 or more years' employment. This study showed no difference in lung cancer risk between the workers exposed to PVA fibers and the non-exposed workers. (+info)
Hypertension in the haemodialysis population: any relationship to 2-years survival?
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BACKGROUND: Few studies have quantified the effect of hypertension on survival in the haemodialysis (HD) population. We have previously reported lack of adverse effect of hypertension on 1-year mortality in a cohort of 649 haemodialysis patients (Am J Kidney Dis 1996; 28: 737-744). We report here the effect of hypertension on 2-year survival in the same cohort of patients. METHODS: We reviewed the complete computerized files on 649 HD patients enrolled in 10 haemodialysis centres in the state of Mississippi, USA. One-month dialysis records for each patient from mid-October 1994 to mid-November 1994 were reviewed. Predialysis mean arterial pressure was calculated as immediate predialysis diastolic pressure plus one-third the difference between systolic and diastolic pressure. Patients were classified as hypertensive if their average pre-MAP was more than 114 mmHg or they were receiving antihypertensive drugs during the study period. Normotensives had a pre-MAP < 114 and were not receiving any antihypertensives. We followed these patients for 2 years to determine their survival and the effect of their BP status, as determined in October 1994, on 2-year mortality. RESULTS: In univariate analysis, hypertension was associated with improved 2-years survival (relative risk 0.64, P=0.08 compared to normotensives). Furthermore, among the hypertensives, good blood pressure control (less than 140/90) was associated with increased relative risk of death at 2 years (RR 1.86, P=0.004). In multivariate analysis, taking age, race, serum albumin, and diabetic status into consideration, there was a 27% reduction in mortality among hypertensives compared to normtensives (RR 0.73, P=0.06). Other factors of significance in multivariate analysis were age (RR 1.03/year, P=0.02), serum albumin (RR 0.36/g, P<0.0001), diabetes mellitus (RR 1.35, P=0.07), and race (RR 0.64, P=0.05). CONCLUSIONS: Our study suggests that hypertension has no adverse effect on survival at 2 years in the haemodialysis population. (+info)
Abysmal prognosis of patients with type 2 diabetes entering dialysis.
(48/73093)
INTRODUCTION: The importance of non-insulin-dependent diabetes mellitus (type II diabetes) as a leading cause of end-stage renal disease is now widely recognized. The purpose of this study was to assess life-prognosis and its predictors in a cohort of patients newly entering dialysis. MATERIAL AND METHODS: Eighty-four consecutive type II diabetes patients (40% of all patients) starting dialysis between 01/01/95 and 31/12/96 were studied retrospectively, focusing on clinical data at inception and life-prognosis after a mean follow-up of 211 days. Patients were divided into three groups, according to onset of renal failure: acute 11% (9/84), chronic 61% (51/84) and acutely aggravated chronic renal failure 28% (25/84). RESULTS: Patients (mean age 67 years) had long-standing diabetes (mean duration approximately 15 years), heavy proteinuria (approximately 3 g/24h) and diabetic retinopathy (67%). The average creatinine clearance (Cockcroft's formula) was 13 ml/min. Cardiovascular diseases were highly prevalent at the start of dialysis: history of myocardial infarction (26%), angina (36%) and acute left ventricular dysfunction (67%). More than 80% of the patients underwent the first session dialysis under emergency conditions, a situation in part related to late referral to the nephrology division (63% for chronic patients). A great majority of the patients were overhydrated when starting dialysis, as evidenced by the average weight loss of 6 kg, during the first month of dialysis, required to reach dry weight. Nearly 64% of the patients presented high blood pressure (> 140/90 mmHg) when starting dialysis despite antihypertensive therapy (mean: 2.3 drugs). The outcome of this type II diabetes population was dramatic: 32% (27/84) died after a mean follow-up of 211 days, mostly from cardiovascular diseases. The rate of recovery of renal function was low in both the acute and the acutely aggravated renal failure group (30% and 24%, respectively). Of note, iatrogenic nephrotoxic agents accounted for renal function impairment in nearly 30% of patients. CONCLUSION: Our observational study illustrates the high burden of cardiovascular diseases contrasting with sub-optimal cardiovascular therapeutic interventions in type II diabetes patients entering dialysis. Factors aggravating renal failure were mainly iatrogenic, and therefore largely avoidable. Late referral generally implied a poor clinical condition at the start of dialysis. (+info)