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Biomedical subjects

J Woo

Publications and source records attributed to J Woo.

At least 361 records · Page 20Linked to original sources

Outcome of primary sclerosing cholangitis. Analysis of long-term observation of 38 patients.

The natural history and prognostic factors of primary sclerosing cholangitis (PSC) are poorly defined. We reviewed our experience with PSC to determine its natural history and whether any factors on presentation or during follow-up were indicative of a favorable or unfavorable prognosis. Thirty-eight patients were followed up for 75.1 +/- 58.7 months; 17 (45%) had a poor outcome, defined as the occurrence of death (11 patients [29%]), variceal hemorrhage, hepatic encephalopathy, or hepatic transplantation. We found the following: the rate of progression of PSC is highly variable; an asymptomatic presentation may not indicate a more favorable outcome or prolonged survival; a serum bilirubin value of four times or more the upper limit of normal, particularly if sustained so as to exclude a reversible cause, is indicative of late-stage disease with a likelihood of subsequent poor outcome and death; and variceal hemorrhage may occur before the terminal stage of the disease.

Adolescent↗

Controlling the cost of quality control.

In the present era of expanding technology coexisting with economic constraint, appropriate quality control criteria to monitor laboratory performance must take into consideration not only analytic precision and medical utility, but also cost effectiveness. In this review, the effect of existing criteria on the clinical laboratory, the regulator, and the vendor is explored. Factors that contribute to excessive quality control cost are delineated. Strategies for developing a cost-effective quality control program are proposed.

Costs and Cost Analysis↗

Primary nongestational choriocarcinoma of the ovary.

Primary choriocarcinoma of the ovary arising, presumably, from a germ cell is extremely rare. The patient, a 16 year old girl who presented with dysuria and frequency of micturition developed fatal haemoperitoneum due to rupture of a pure primary nongestational ovarian choriocarcinoma.

Adolescent↗

Intramuscular cimetidine and ranitidine as prophylaxis against gastric aspiration syndrome--a randomized double-blind study.

Preoperative cimetidine 300 mg or ranitidine in 50 and 100 mg doses were administered intramuscularly to 120 patients in a randomized double-blind study. The volume and pH of gastric aspirate samples obtained after tracheal intubation and before extubation were measured. The pH of gastric aspirate was higher following ranitidine 100 mg than ranitidine 50 mg or cimetidine 300 mg at both intubation and extubation (p = 0.006). In addition, fewer patients tended to be "at risk" of pulmonary aspiration syndrome (pH less than or equal to 2.5) after ranitidine 100 mg than ranitidine 50 mg or cimetidine 300 mg. Preoperative intramuscular ranitidine 100 mg was found to be suitable for use in protection against gastric aspiration syndrome.

Adolescent↗

A double-blind comparison of cimetidine and ranitidine as prophylaxis against gastric aspiration syndrome.

Preoperative cimetidine, ranitidine, or placebo were administered, orally or intravenously to 190 patients in a double-blind study. The volume and pH of gastric aspirate samples, obtained after tracheal intubation and before extubation, were measured. Both cimetidine and ranitidine produced higher mean pH levels and thus fewer patients "at risk" should gastric aspiration occur (pH less than or equal to 2.5) than did placebo. Intravenous ranitidine (in both 40- and 80-mg doses) produced fewer patients at risk in the event gastric aspiration should occur than did cimetidine, 300 mg, and the 80-mg dose produced a higher mean pH level. Oral ranitidine, 150 mg, produced a significantly higher mean pH level than did oral cimetidine, 300 mg, and tended to give fewer patients at risk. The volumes of gastric contents aspirated were similar following each of the drugs except that the volume was significantly less two hours following oral ranitidine, 150 mg, than after oral cimetidine, 300 mg.

Administration, Oral↗

Homogeneous enzyme immunoassay for tobramycin evaluated and compared with a radioimmunoassay.

We evaluated a commercially available homogeneous enzyme immunoassay (EMIT, Syva Co.) for tobramycin against a reference radioimmunoassay (RIA) method. Between-assay precision (CV) was 2.9% at 6.2 mg/L and 3.0% for values in the range of 1.0-7.6 mg/L. Accuracy based on a recovery experiment (1.0-13.0 mg/L) yielded an analytical recovery of 88-112%. A correlation study with 75 sera from patients on tobramycin therapy showed that EMIT = 0.984 RIA - 0.0808, r = 0.993. Neither the EMIT nor the RIA procedure was affected by the presence of gentamicin, amikacin, and vancomycin. Absorbance data from the EMIT system calculated with the conventional RIA logit-log algorithm correlate well with results generated by the Syva data-handling system (logit-log = 1.077 Syva - 0.318, r = 0.998). A reagent stability study indicated that the EMIT reagents, once reconstituted, remain stable for at least 17 days when stored at refrigerated temperatures, or 11 days if stored at room temperature, thus enabling frequent "stat" assays without the need to prepare a calibration curve each time.

Anti-Bacterial Agents↗

Biochemical evidence of myocardial injury after severe head trauma.

Serum levels of creatine kinase (CK) and its myocardial isoenzyme (CK-MB) were measured and serial ECG recorded in 24 male and 6 female patients with severe head trauma. All patients were comatose, but no patient sustained a spinal or chest injury. Total CK activity was elevated in at least one sample in each patient. Elevated CK-MB activity was found in 28 patients. The serial CK-MB data did not follow the same pattern as that of patients suffering from myocardial infarctions. The mean CK-MB remained elevated for at least 3 days after injury, although individual patterns were variable. ECG abnormalities included prolonged corrected QT interval (QTc) in 90% and a variety of nonspecific ST segment and T wave changes in 53%. These ECG findings are consistent with other clinical studies of severe neurological disorders, particularly cerebrovascular accidents. The elevated CK-MB activity indicates that ongoing myocardial damage occurs in patients with severe head injury. Although the underlying mechanism is not entirely clear, an excessive release of catecholamines is the most likely mechanism accounting for diffuse myocardial damage, prolonged elevated CK-MB values and the observed ECG abnormalities.

Adolescent↗

Albumin and beta 2-microglobulin radioimmunoassays applied to monitoring of renal-allograft function and in differentiating glomerular and tubular diseases.

Blood and urine were samples daily from 11 renal-allograft recipients from one to six weeks after the transplant. Clearances of both albumin (Calb) and beta2-microglobulin (C beta 2 mu) were significantly increased in all 11 patients. Five patients (Group I) with acute allograft rejection showed markedly increased Calb and moderately increased C beta 2 mu, concurrent with decreased creatinine clearance (CCr). Five other patients (Group II) with no evidence of rejection demonstrated episodes of grossly increased C beta 2 mu with minimally increased but stable Calb and normal CCr. One patient had no evidence of rejection nor indications of glomerular or tubular proteinuria. While changes in serum beta 2-microglobulin concentration closely paralleled those of serum creatinine in the Group II patients, the results diverged in the Group I patients because the increase in serum beta 2-microglobulin exceeded that of serum creatinine and preceded the increased in creatinine by one to five days, suggesting that measurement of serum beta 2-microglobulin might afford earlier indication of the nature and extent of renal damage in the allograft recipients.

Beta-Globulins↗