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Biomedical subjects

S C Wu

Publications and source records attributed to S C Wu.

At least 163 records · Page 9Linked to original sources
PubMed1985

End-stage renal disease in Michigan. Incidence, underlying causes, prevalence, and modalities of treatment.

In Michigan from 1974 through 1981 the average annual end-stage renal disease (ESRD) incidence was 7.76 for males and 5.55 for females per 100,000 population. Those over 35 years of age had higher incidence rates. The average incidence for black ESRD patients was 20.75, compared with 4.78 for white ESRD patients. Thus, the risk of ESRD was 4.34 times higher in the black population. In 1981, the stated causes of ESRD in the ESRD population were diabetes mellitus (24.5%), hypertension (24.2%), and glomerulonephritis (20.9%). Black ESRD patients, compared to white, had relative risks of 3.8 for diabetes mellitus, 10.9 for hypertension, and 1.7 for glomerulonephritis. The ESRD point prevalence increased from 11.58 in 1974 to 31.68 in 1981. Males predominated over females; the sex-specific ESRD prevalence in 1981 being 36.74 and 26.83, respectively. Blacks predominated over whites; the black and white ESRD prevalences in 1981 were 80.27 and 24.81, respectively. Prevalence over these years increased faster for older age groups. Hemodialysis at a center has been the major ESRD treatment modality. The percentage of all ESRD patients on home hemodialysis steadily decreased from 1974 through 1981. Similarly, on a percentage basis, fewer patients were transplanted in 1981 than in 1974. The number of ESRD patients treated by chronic ambulatory peritoneal dialysis increased more than sevenfold from 1979 through 1981.

Adolescent↗
PubMed1984

Pharmacologic interventions in acute mesenteric ischemia: improved survival with intravenous glucagon, methylprednisolone, and prostacyclin.

An experimental model of acute mesenteric ischemia following 85 minutes of superior mesenteric artery (SMA) occlusion in male Wistar rats was used in this investigation. Untreated control animals had a 48-hour survival rate of 38% (n = 26), whereas sham laparotomy resulted in a 100% 48-hour survival rate (n = 10). Study groups received intravenous infusions of normal saline solution (16.6 ml/kg/hr; n = 26) or similar volumes of normal saline solution with the addition of glucagon (1.6 micrograms/kg/min; n = 26), dopamine (3.2 micrograms/kg/min; n = 26), or prostacyclin (PGI2) (10.7 ng/kg/min; n = 26). Infusions were begun 15 minutes after initiating 85 minutes of SMA occlusion and were continued for a total of 90 minutes. Glucagon increased the 48-hour survival rate to 85%, significantly greater than both control survival (p less than 0.001) and normal saline solution group survival rates (p less than 0.025). Neither normal saline solution alone nor dopamine significantly increased the 48-hour survival rate, which was 54% in both groups. The PGI2 group survival rate, 65% at 48 hours, was significantly greater than the control rate (p less than 0.05), was not statistically different from the normal saline solution group survival rate, and was 20% less than the glucagon group survival rate, the latter difference approaching statistical significance (p = 0.10). Methylprednisolone (40 mg/kg; n = 26) administered as an intravenous bolus 15 minutes after initiating SMA occlusion significantly increased the 48-hour survival rate to 73% (p less than 0.01), whereas neither intravenous heparin (150 U/kg; n = 26) nor superoxide dismutase (11,900 U/kg; n = 26) were beneficial. Glucagon, methylprednisolone, and PGI2 improved the survival rate in this model of acute mesenteric ischemia.

Animals↗
PubMed1984

Usefulness of stress testing for the evaluation of hypertensive heart disease in young hypertensive subjects.

To investigate the usefulness of stress testing for the evaluation of hypertensive heart disease, 40 subjects, 28 men and 12 women (mean age 30.8 +/- 6.2 years), with mild or moderate hypertension, without ST segment or T wave abnormalities in their resting ECG, were examined. 13 patients (32.5%) showed exercise-induced ST segment depression. The heart rate at rest was significantly higher in the patients with a positive response; 6 of the 7 subjects with electrocardiographic signs of left ventricular hypertrophy (summed SV1 + maximum R V5/V6 voltage of 45 mm or more) had a positive exercise electrocardiographic test. There were no significant differences between positive and negative cases in age, sex, systolic and diastolic blood pressure, or the double product (heart rate X systolic pressure) at rest or during exercise. After resting blood pressure values had been significantly decreased by giving methyldopa with or without diuretics for at least 6 months, there were a regression of left ventricular hypertrophy in the resting ECG and an impressive reduction in the prevalence of exercise-positive responses (to 17.5%). In the 7 patients with positive exercise electrocardiographic tests even after antihypertensive treatment, no significant reduction in blood pressure values during exercise was obtained.

Adult↗
PubMed1984

Chest roentgenograms in diagnosis of traumatic rupture of the aorta. Observer variation in interpretation.

A significant p value is not always a good measure of the clinical value of a diagnostic test. By examining interobserver agreement with respect to chest roentgenogram interpretation, we determined which of seven roentgenographic signs statistically associated with traumatic rupture of the aorta (TRA) are most likely to be useful in clinical practice. Four surgeons and two radiologists were asked to interpret individually, in blinded fashion, the initial chest films of 149 trauma patients who had undergone aortography to rule out TRA. Agreement between all observers, as well as between specialty groups, was examined by chi-square and by calculation of Cohen's kappa statistic, which estimates the extent of agreement. Statistically significant agreement (p = .0000) was found between all observers with regard to mediastinal widening and obscuration of the aortic knob, but other comparisons showed no better than random agreement. Of the seven roentgenographic signs associated with TRA, identification of mediastinal widening and obscuration of the aortic knob show the most consistent interobserver agreement and are the most likely to be useful in clinical practice.

Aorta, Thoracic↗
PubMed1983

Prognostic value of exercise EKG testing in asymptomatic normotensive subjects. A prospective matched study.

We prospectively studied 135 asymptomatic normotensive subjects with exercise-induced ST ischemic depression of 1 mm or more and compared them with 379 controls. At least two controls with negative responses on the exercise electrocardiographic (EKG) test were selected for each case and were matched for age, sex, work, community, and coronary-risk-factors index. The end points considered were the following coronary events: angina pectoris, myocardial infarction, and sudden death. After a median follow-up period of 6.0 years for the cases and 6.4 years for the controls, the relative risk was 5.55 (95 per cent confidence limits, 2.75 to 11.22). Coronary events occurred significantly earlier in the cases than in the controls. Our data also suggest that the exercise EKG response is a particularly good prognostic indicator for myocardial infarction. In addition, our analysis has confirmed the predictive roles of age, smoking, blood pressure, and the coronary-risk-factors index and suggests that the exercise EKG response is an additional independent risk indicator for coronary events.

Adult↗
PubMed1983

Comparison of mediastinal width, mediastinal-thoracic and -cardiac ratios, and "mediastinal widening" in detection of traumatic aortic rupture.

This study was undertaken to determine whether direct measurement of mediastinal width or computation of ratios of measurements of easily detectable mediastinal structures is more effective than the subjective impression of "mediastinal widening" in selecting trauma patients for aortography. A group of five surgeons and radiologists individually read in blinded fashion 149 chest films of trauma victims who had undergone aortography to rule out traumatic rupture of the aorta (TRA). Each made a subjective interpretation of "mediastinal widening," as well as direct measurement of mediastinal width (MW), thoracic width at the level of the mediastinum, cardiac width, and maximum thoracic width. Mediastinal-cardiac (MC), mediastinal-thoracic (MT), and mediastinal-mediastinothoracic (MMT) ratios were calculated. Statistically significant differences were found in all parameters of direct measurement between cases with and without TRA (P from .0001 for MT to .01 for MMT). The critical measurement for mediastinal width separating positive from negative cases was 8.0 cm; the critical ratios were MT = 0.275, MC = 0.555, and MMT = 0.36. Application of these parameters to detect TRA yielded sensitivities of .75 for MW, .68 for MC, .66 for MMT, and .62 for MT. Statistically significant differences between observers' measurements were seen. None of these measurements was as effective as subjective interpretation of mediastinal widening, which had a sensitivity of .91 (P = .0000). We conclude that the subjective impression of mediastinal widening is superior to "objective" direct measurement of mediastinal structures for identification of trauma patients with aortic rupture.

Aorta↗
PubMed1983

Assessment of mediastinal widening associated with traumatic rupture of the aorta.

In order to best determine the reliability and usefulness of widening of the mediastinum (WMED) and other radiographic abnormalities in the selection of trauma patients for aortography to detect traumatic rupture of the aorta (TRA), we designed a blind study in which a panel of radiologists and surgeons reviewed 149 chest films of trauma victims who subsequently underwent aortography to rule out TRA. Sixteen patients had TRA. Panelists identified mediastinal widening (WMED) in 83 of 93 observations on films in cases of TRA (89%). There was a significant association between WMED and TRA found both for the panel as a whole and for each panelist individually (p = 0.0000), making this an extremely reliable sign both in terms of detectability and in signalling the need for aortography. Significant associations with TRA were also found overall for six other radiographic abnormalities but none of these was reliable for all panelists or was as sensitive as WMED in the detection of TRA. Despite the reliability of these signs, panelists making decisions based on the chest film alone failed to recommend aortography in seven of 93 instances of TRA. Direct mediastinal measurements varied by at least 2 cm among panelists in one half of the cases of TRA, and 25% of these (4/16) had at least two measurements of mediastinal width of 7 cm or less. Of all the radiographic signs associated with TRA, widening of the mediastinum is the most reliable, but in this study all observers would not have detected all cases of ruptured aorta using radiographic signs alone. Clinical judgment and consideration of the forces involved in the injury must continue to play an important role in the selection of patients for aortography.

Aortic Rupture↗
PubMed1982

Mass carbon monoxide poisoning: clinical effects and results of treatment in 184 victims.

An epidemiologic and clinical investigation of 184 persons exposed to toxic levels of carbon monoxide (CO) in a public high school has been carried out. Exposure to 500 ppm of CO for periods up to 150 minutes resulted in carboxyhemoglobin (COHb)levels as high as 30% and symptomatic illness in 87% of persons exposed before the possibility of mass CO poisoning was recognized. Severity of symptoms was a reliable basis for triage of victims for immediate hospital treatment, and correlated both with duration of exposure and the length of time it took for victims to feel normal. Therapy consisting of oxygen delivered by mask achieved a half-life for COHb of 137 minutes in hospital-treated patients (compared to 320 minutes with no treatment), but did not fully reverse the symptoms of CO toxicity.

Adolescent↗