Simultaneous measurement of gallbladder emptying with cholescintigraphy and US during infusion of physiologic doses of cholecystokinin: a comparison

Both ultrasonography (US) and cholescintigraphy are used to study gallbladder dynamics. The present study was undertaken to determine whether the two methods provide the same or different information relating to gallbladder emptying. Emptying was simultaneously studied with both methods during infusion of graded physiologic doses of cholecystokinin (CCK) in six healthy subjects. Infusion of stepwise increasing doses of CCK, ranging from 0.03 to 0.5 Ivy dog units per kilogram of body weight per hour (IDU/kg.h), induced significant dose-related increases in plasma CCK, decreases in gallbladder volume assessed with US, and gallbladder emptying assessed with cholescintigraphy. The threshold dose for inducing significant gallbladder emptying was 0.13 IDU/kg.h, as determined with both techniques, indicating similar detection limits. There was a highly significant correlation between decreases in gallbladder volume and decreases in radioactive counts over the gallbladder region, with a tendency toward greater gallbladder responses at sonography during the early phase of gallbladder contraction and toward greater responses at cholescintigraphy during the later phase of gallbladder contraction. It is concluded that these methods can be used interchangeably for the quantitation of gallbladder emptying.     

An assessment of Mustard's operation as a palliative procedure for transposition of the great vessels.

Ten patients in whom palliative Mustard operations have been performed for transposition of the great vessels with ventricular septal defect and elevated pulmonary vascular resistance are reported. There has been early or late mortality in this group of patients, and postoperative morbidity has been minimal. Five of them have been recatheterized, and the results indicate substantial improvement in postoperative arterial oxygen saturation with change in pulmonary vascular resistance. The operation is reserved for those patients in whom peripheral desaturation is the major cause of symptomatology. Clinical improvement has been gratifying, and the continued use of the operation in selected patients seen indicated.     

Synchronous growth and aging of Caenorhabditis elegans in the presence of fluorodeoxyuridine.

Fluorodeoxyuridine (FUdR), an inhibitor of DNA synthesis, was examined for its ability to prevent a synchronous population of C. elegans from reproducing without otherwise interfering with the organism's post-maturational development and aging. When a synchronized population was exposed to 400 micrometer FUdR just as the population reached sexual maturity, the FUdR induced complete sterility within five hours by preventing eggs from hatching. Any larvae that hatched from eggs made before the FUdR was added remained small in the presence of FUdR and were easily removed by filtration or sedimentation. FUdR-sterilized adults showed no morphological abnormalities. Age-associated changes seen in controls also occurred in FUdR-treated worms, including atrophy of the gonads, increased pigmentation, sluggishness and increased transparency. Life span was not shortened by FUdR treatment. Our observations suggest that treatment with FUdR under carefully controlled conditions is a reasonable way to maintain synchronously aging populations of C. elegans.     

What kind of research can we realistically expect from the practitioner?

This article attempts to revitalize the scientist-practitioner model of psychotherapy by focusing on the research component of the model. Specifically, it takes a realistic look at the types of research that can be conducted by clinicians in an effort to motivate them to engage regularly in clinical research. Towards this end, five experienced scientist-practitioners explore the advantages, disadvantages, and potential of practitioner-initiated research. The problems and solutions for such research are discussed, and recommendations are offered.