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Biomedical subjects

W C Wu

Publications and source records attributed to W C Wu.

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

The radiologic detection of duodenal ulcers: effects of examiner variability, ulcer size and location, and technique.

Study of 91 endoscopically verified duodenal ulcers compared the effects of examiner variability, ulcer size and location, and radiographic technique on ulcer detection. Radiologic sensitivity of 61.5% was found for the entire group of 91 ulcers. Examiner variability was the strongest determinant of success; sensitivities for individual examiners ranged from 44.4% to 80%. Ulcer size was a second factor in radiologic detectability; ulcers 5 mm or larger were detected at a higher rate (80.0%) than those less than 5 mm (64.5%). Sensitivities of 65.9% and 57.4% were recorded for single- and double-contrast examinations, respectively, a statistically insignificant difference.

Adult↗
PubMed1985

Positive predictive value and examiner variability in diagnosing duodenal ulcer.

The positive predictive value of a diagnosis of duodenal ulcer was studied in 255 patients with 274 ulcers diagnosed radiographically. Retrospective analysis of the radiographic examinations and correlation with endoscopy assessed examiner variability, ulcer size, duodenal bulb deformity, and the confidence level of the ulcer diagnoses. For all diagnoses, the overall positive predictive value was 57% with individual predictive values of 47%, 54%, and 70% among three examiners. The individual predictive values correlated directly with the average level of confidence of the diagnoses for each examiner. The sensitivity of the individual examiner for ulcer detection had an inverse relation to the examiner's positive predictive value, confirming that higher sensitivities are achieved at the expense of an increased false-positive rate.

Duodenal Ulcer↗
PubMed1985

Edrophonium: a useful provocative test for esophageal chest pain.

Esophageal motility disorders may be an important cause of noncardiac chest pain. To improve our diagnostic yield, we studied the use of edrophonium as a provocative test for inducing esophageal chest pain in 50 symptomatic patients without coronary artery disease and in 25 age-matched controls. Edrophonium (80 micrograms/kg of body weight, intravenous bolus) induced chest pain in 15 (30%) patients and in no controls. Edrophonium increased esophageal amplitude and repetitive contractions to a similar degree in all subjects, but the change in duration (101 +/- 13% [SE] was significantly greater (p less than 0.02) in patients in whom chest pain was induced. Drug specificity was assessed in 9 patients during cardiac catheterization, but no significant change was seen in coronary artery diameter, blood pressure, or heart rate. Further clinical testing using a placebo control confirmed a positivity rate of 28% in 125 unselected patients with chest pain referred to our laboratory; false-positive tests were infrequent (5.6%). No important side effects were seen. Edrophonium is useful for provoking esophageal chest pain.

Adult↗
PubMed1985

Respiratory complications of gastroesophageal reflux.

Gastroesophageal reflux (GER) and its many manifestations are extremely common problems. The pulmonary manifestations are the least well understood and are often unrecognized. We reviewed the available literature on the subject of respiratory tract symptoms secondary to chronic GER in an attempt to promote wider recognition of this relationship. We hope that this review will call attention to the potential importance of GER in those patients in whom such a mechanism might be responsible for pulmonary symptoms.

Adrenergic beta-Agonists↗
PubMed1984

The extent of successful colonoscopy: a second assessment using modern equipment.

Records of 200 consecutive and unselected colonoscopies were reviewed to determine both the success in viewing the entire colon and the average extent of colon visualized, using the most modern equipment. Colonoscopy was completed to the cecum or ileum in 82.5% of studies, and an average of 93.8% of the colon was viewed. These data show considerable improvement compared to those previously reported by us. However, the significant number of incomplete colonoscopies still suggests that colonoscopy and barium enema examination must remain complementary for maximum detection of colonic lesions.

Barium Sulfate↗
PubMed1984

Radiographic evaluation of the achalasic esophagus immediately following pneumatic dilatation.

Sixteen patients with achalasia of the esophagus were treated by fluoroscopically guided pneumatic dilatation. All patients were examined radiographically immediately following dilatation. The caliber of the esophagogastric region increased from a pretreatment mean of 5.3 mm to 9.6 mm following dilatation. The margins of the dilated area remained smooth in 6 patients (38%) and became irregular in 10 (62%). Initial symptomatic improvement was found in 14 patients (88%) with a mean follow-up of 1.7 months. One (6%) perforation occurred, necessitating surgery. The radiographic appearance of the esophagogastric region following pneumatic dilatation, however, poorly predicted patient response.

Adult↗
PubMed1984

Inhibition by calmodulin of calcium/phospholipid-dependent protein phosphorylation.

Calmodulin was previously found to inhibit the Ca2+/phospholipid-dependent phosphorylation of an endogenous substrate, called the 87-kilodalton protein, in a crude extract prepared from rat brain synaptosomal cytosol. We investigated the mechanism of this inhibition, using Ca2+/phospholipid-dependent protein kinase and the 87-kilodalton protein, both of which had been purified to homogeneity from bovine brain. Rabbit brain calmodulin and some other Ca2+-binding proteins inhibited the phosphorylation of the 87-kilodalton protein by this kinase in the purified system. Calmodulin also inhibited the Ca2+/phospholipid-dependent phosphorylation of H1 histone, synapsin I, and the delta subunit of the acetylcholine receptor, with use of purified components. These results suggest that calmodulin may be a physiological regulator of Ca2+/phospholipid-dependent protein kinase.

Animals↗
PubMed1984

Esophageal radionuclide transit tests. Potential false-positive results.

Esophageal radionuclide transit testing is a sensitive technique for assessing esophageal clearance. Experience with the technique in 150 patients has led to an awareness of several pitfalls which might lead to false-positive results. Potential problems may be grouped into technical factors, clinical aspects, and misinterpretations. Examples of these are presented and techniques to minimize such problems are discussed.

Deglutition Disorders↗
PubMed1984

Clinical applications of oesophageal motility studies?

Technological advances in the investigation of oesophageal motility have resulted in progressive awareness of gastro-oesophageal reflux disease and motor disorders of the oesophagus as causes of obscure "noncardiac" chest pain, as well as for unexplained swallowing difficulties. Oesophageal motility studies should also be undertaken before surgery for reflux oesophagitis.

Deglutition Disorders↗
PubMed1983

Sensitivity of single-contrast radiology in esophageal disease: a study of 240 patients with endoscopically verified abnormality.

Single-contrast radiology of the esophagus was correlated with endoscopy in 240 patients with the following endoscopically verified abnormalities: esophagitis 170, rings 28, malignancies 19, varices 9, miscellaneous 14. For all the abnormalities except mild esophagitis, the overall sensitivity of the radiology in these 240 patients was 92%. All 19 cancers were diagnosed radiologically, whereas 90% of moderate and severe esophagitis was detected. The single-contrast examination thus reliably identified clinically significant disease of the esophagus. Comparison of these results to recent reports employing double-contrast technique suggests that claims of superiority for the double-contrast esophagram over the single-contrast study are not supported.

Adult↗
PubMed1983

The gravitational field and brain function.

The frontal cortex is recognized as the highest adaptive control center of the human brain. The principle of the "frontalization" of human brain function offers new possibilities for brain research in space. There is evolutionary and experimental evidence indicating the validity of the principle, including it's role in nervous response to gravitational stimulation. The gravitational field is considered here as one of the more constant and comprehensive factors acting on brain evolution, which has undergone some successive crucial steps: "encephalization", "corticalization", "lateralization" and "frontalization". The dominating effects of electrical responses from the frontal cortex have been discovered 1) in experiments under gravitational stimulus; and 2) in processes potentially relating to gravitational adaptation, such as memory and learning, sensory information processing, motor programing, and brain state control. A brain research experiment during space flight is suggested to test the role of the frontal cortex in space adaptation and it's potentiality in brain control.

Acceleration↗
PubMed1983

Colon polyp morphology on double-contrast barium enema: its pathologic predictive value.

The morphologic appearance of 96 polyps seen on double-contrast barium enema was reviewed to assess the predictive value of various signs described to diagnose malignancy. Size, surface contour, basal indentation, and pedunculation were studied. Sessile polyps had an appreciable incidence of malignancy, with size being the best indicator of that risk. Pedunculation was found to be a reliable sign of benignity in predicting the absence of malignant invasion into the adjacent colonic wall. Polyps under 1 cm and having a smooth contour were invariably benign. Conversely, polyps larger than 1 cm with a lobulated contour and basal indentation had a significant incidence of malignancy.

Adenoma↗
PubMed1982

Treatment of vincristine-induced ileus with sincalide, a cholecystokinin analog.

Sincalide, a synthetic analog of cholecystokinin capable of stimulating bowel motility, has been administered to 12 patients with symptoms and signs of vincristine-induced ileus. Patients were given intravenous infusions of sincalide 0.01 microgram/kg/h over 2-24 h (mean, 8 h) for 1-12 days (mean, 5 days), usually until all evidence of ileus had resolved. Improvement was noted within 48 h of initiation of therapy in eight patients (75%), whereas marginal or no responses were observed in four patients. The mean duration of ileus was 3.6 days in responders and 7.7 days in nonresponders. Toxicity was minimal and consisted of diarrhea in two patients, in whom symptoms promptly resolved with discontinuation of the drug. Further explorations of this promising agent in the treatment of vincristine-induced ileus appears warranted.

Cholecystokinin↗
PubMed1982

Calcium/phospholipid regulates phosphorylation of a Mr "87k" substrate protein in brain synaptosomes.

Depolarization-induced calcium influx into rat cerebral cortex synaptosomes increased the phosphorylation of several synaptosomal proteins as examined by 32Pi incorporation. A phosphopeptide mapping technique involving NaDodSO4/polyacrylamide gels has been used to show that phosphorylation of a Mr 87,000 substrate protein is stimulated by depolarization-induced calcium influx. Phosphorylation of this Mr 87,000 substrate occurred in synaptosomal cytosol and was markedly stimulated by calcium/phosphatidylserine. Calmodulin inhibited this phosphorylation reaction. This substrate for calcium/phospholipid-dependent protein kinase is enriched in and appears to be specific to neurons.

Animals↗