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W C Vezina

Publications and source records attributed to W C Vezina.

11 recordsLinked to original sources
PubMed1998

Similarity in gallstone formation from 900 kcal/day diets containing 16 g vs 30 g of daily fat: evidence that fat restriction is not the main culprit of cholelithiasis during rapid weight reduction.

Diets containing essentially no fat, 1-2 g fat per day, have resulted in cholesterol gallstones. Greater fat may result in less gallbladder stasis. Do gallstones form with greater fat content? We studied 272 moderately obese subjects who had normal gallbladder ultrasonograms. The 900 kcal/day liquid diets contained either 16 g fat (N = 94) or 30 g fat (N = 178) each day for 13 weeks. A second gallbladder ultrasound was performed. Sixteen of 94 (17.0%) of the 16-g fat group developed stones with a weight loss of 18 (+/- 7) kg and a body mass index (BMI) decrease of 6 (+/- 2) kg/m2. Twenty of 178 (11.2%) of the 30-g fat group developed stones (P = 0.18, no difference in stone formation) with similar weight loss of 20 (+/- 7) kg (P = 0.08) and BMI decrease of 7 (+/- 2) kg/m2 (P = 0.04). Substantial fat for rapid weight-reducing diets resulted in gallstone formation. Since experiments have shown that our higher fat diet, containing 10 g fat per meal, results in maximal gallbladder emptying, cholelithiasis from rapid weight loss may not be solely attributable to gallbladder stasis.

Case-Control Studies↗
PubMed1994

Normal fasting volume and postprandial emptying of the denervated donor gallbladder in liver transplant recipients.

BACKGROUND/AIMS: Truncal vagotomy causes gallbladder dilatation and possibly cholelithiasis. During liver transplantation, when the gallbladder is transplanted with the donor liver, the gallbladder and liver are extrinsically denervated. The aim of this study was to determine whether extrinsic denervation affects gallbladder volume and postprandial emptying. METHODS: To evaluate fasting gallbladder volume, 26 transplant recipients underwent ultrasonography. Twenty-eight normal volunteers were controls. To evaluate postprandial contractility, seven transplant recipients underwent radionuclide gallbladder-emptying studies. Gastric emptying and cholecystokinin release were simultaneously determined after a fatty meal to exclude a difference in gallbladder stimulus. Sixteen normal volunteers were controls. RESULTS: There were no differences in fasting gallbladder volume or postprandial contractility, gastric emptying, and cholecystokinin release between transplant patients and controls. Median fasting and postprandial gallbladder volumes for the transplant recipients (95% confidence) were 16 mL (12-34 mL) and 3 mL (0-8 mL), respectively, and for controls were 18 mL (13-21 mL; P = 0.73) and 3 mL (1-6 mL; P = 0.97), respectively. CONCLUSIONS: These data do not show gallbladder dilatation or impaired postprandial gallbladder contraction in the extrinsically denervated gallbladder. This finding suggests that gallbladder dilatation may be caused by the unopposed activity of the sympathetic system after truncal vagotomy.

Adult↗
PubMed1992

Subchondral bone infractions in acute ligamentous knee injuries demonstrated on bone scintigraphy and magnetic resonance imaging.

Bone scintigraphy is used to detect radiographically silent fractures. Magnetic resonance imaging (MRI) is currently used to screen knee injuries for cartilage and ligament damage. MRI also delineates bone marrow and fractures. We investigated the bone scintigraphic findings in patients who had subchondral bone injuries demonstrated on MRI. Thirteen patients underwent MRI, three-phase bone scintigraphy with SPECT, and arthroscopic surgery after sustaining acute traumatic hemarthrosis of a knee. They all had clinically unsuspected subchondral bone injuries demonstrated on MRI with normal radiographs and normal overlying articular cartilage at arthroscopy, consistent with occult fractures. All showed focal bone repair on scintigraphy. Two of the 13 patients showed additional bone injuries only on bone scan. Two other patients scintigraphically showed focal bone repair at the medial femoral condyle due to avulsion of the medial collateral ligament. SPECT was easier to interpret than multi-view planar imaging. Bone scintigraphy confirms subchondral fractures demonstrated on MRI but also demonstrates ligament avulsion injuries and additional more subtle bone injuries.

Adolescent↗
PubMed1990

Increased volume and decreased emptying of the gallbladder in large (morbidly obese, tall normal, and muscular normal) people.

Impaired gallbladder emptying has been suggested as a possible factor in the pathogenesis of gallstones. Obese people have an increased incidence of gallstones, but there is no evidence of this in nonobese large people. This study was undertaken to determine if abnormal gallbladder motility is present in obese people. Fasting gallbladder volumes were determined using real-time ultrasound in 18 morbidly obese subjects whose weights were in a steady state [45 kg (100 lb) over ideal weight or twice expected weight for age and height; 9 males, 9 females], 18 age- and sex-matched volunteers of average size, and 18 nonobese large normal males (9 tall, 9 muscular). Gallbladder emptying studies with 99mtechnetium-diisopropyliminodiacetic acid were performed using 200 ml of 10% cream as a stimulus. The small-volume liquid fatty meal contained 113indium-diethylenetriaminepentaacetic acid to control for differences in gastric emptying in obesity. The gallbladder emptying rate in large people, both obese and nonobese, was less than that in normals of average size (p = 0.05). Fasting gallbladder volumes in large people were: obese, 41 ml (37-66 ml) (median; 95% confidence limits); nonobese large normal, 40 ml (27-43 ml). These values were greater than in normals of average size [17 ml (14-21 ml) (p = 0.03)]. Postprandial gallbladder volumes were also greater in large people: obese, 15 ml (8-23 ml); nonobese large normal, 20 ml (13-23 ml) compared with 2 ml (1-5 ml) in normals of average size (p less than 0.05). There were no differences between obese and nonobese large people. There were no differences in gastric emptying rates or in cholecystokinin, gastrin, motilin, and secretin release between obese and normal subjects. Gallbladder volume is crudely proportional to body size. Although fasting and postprandial volumes are greater in obesity, this is also present in nonobese, relatively size-matched controls. These data do not support a role for impaired gallbladder emptying in gallstone formation in obese patients whose weights are in a steady state.

Adult↗
PubMed1988

Platelet aggregation within cerebral arteriovenous malformations.

Turbulence within cerebral arteriovenous malformations (AVM's) may lead to endothelial disruption, platelet aggregation, and thrombus formation. This hypothesis would account for many of the pathological features in AVM's, including intimal hyperplasia and arterial thrombosis with or without organization. In this study, a dual-isotope method employing indium-111-labeled platelets and technetium-99m-labeled red blood cells was used to evaluate in vivo platelet aggregation in 20 patients with AVM's. The use of two isotopes allows subtraction of the blood-pool platelets and calculation of the ratio of the indium deposited:the indium in the blood pool (In(D)/In(BP)). After a 24-hour incubation period, eight of the 20 patients demonstrated platelet aggregation in their AVM's with a mean In(D)/In(BP) ration of 0.71 +/- 0.36 (+/- standard deviation). Seven of these AVM's were available for pathological study and all of them demonstrated evidence of arterial thrombosis of variable age. In the remaining 12 patients, the In(D)/In(BP) ratio was not significantly elevated (mean 0.02 +/- 0.13), indicating the absence of active platelet aggregation during this short interval of study. Five of these AVM's were pathologically examined, four of which showed evidence of arterial occlusion. It is concluded that platelet aggregation is a common occurrence in cerebral AVM's and may account for the dynamic histopathology often seen in these lesions.

Adult↗
PubMed1986

Gastric emptying before and after transverse gastroplasty for morbid obesity.

Twenty-three morbidly obese patients underwent gastric emptying studies (Tc-99m egg salad sandwich--a semisolid meal) preoperatively, and at three months and 12 months postoperatively to evaluate the effect of transverse gastroplasty on gastric emptying and to determine the predictive value of this study for weight loss. At three months pouch emptying was variable with nine of 23 patients having prolonged half-times, and 14 shortened half-times compared with preoperative values, despite both groups having identical weight loss. At 12 months pouch half-times returned to baseline. The data suggests that this type of gastroplasty causes weight loss solely by reducing the gastric volume resulting in reduced meal volume. Weight loss is not related to impaired pouch emptying, which might result in a prolonged feeling of fullness. Gastric emptying studies neither preoperatively nor postoperatively have weight loss predictive value for this particular operation.

Adult↗
PubMed1984

Radionuclide diagnosis of splenic rupture in infectious mononucleosis.

Spontaneous splenic rupture is a rare but serious complication of infectious mononucleosis. Although radionuclide spleen imaging is a well accepted method for diagnosis of traumatic rupture, interpretation can be difficult in the setting of mononucleosis, as tears may be ill-defined and diagnosis hampered by inhomogeneous splenic uptake. Four proven cases of spontaneous rupture are presented, three of which illustrate these diagnostic problems.

Adult↗
PubMed1984

Spontaneous perforation of the common bile duct in infancy detected by 99mTc HIDA scanning.

Bile ascites is a rare cause of mild icterus and abdominal distension in the newborn. An indirect inguinal hernia may also occur. The authors report such a case in a 5-week-old infant. Proof was obtained by abdominal ultrasonography followed by scanning with N-(2,6-dimethyl phenyl carboxymethyl) iminodiacetic acid labelled with technetium 99m (99mTc HIDA) and paracentesis. Laparotomy was carried out at 7 weeks of age and the opening in the common bile duct was closed with excellent results.

Ascites↗
PubMed1982

Platelet interaction within giant intracranial aneurysms.

Turbulence within intracranial aneurysms may result in tearing of the aneurysmal wall, exposing the subendothelial matrix to circulating platelets. In this study, platelet interaction in giant intracranial aneurysms was evaluated by a dual-isotope technique employing In-labeled platelets and Tc-labeled red blood cells. The use of two isotopes allows the subtraction of the blood pool and the calculation of the ratio indium deposited:indium blood pool (In(D)/In(BP)). A ratio greater than zero indicates platelet deposition within aneurysm. Thirteen patients were evaluated in this way, with platelet deposition demonstrated in six. In these six patients, the ratio In(D)/In(BP) was found to be significantly elevated, with a mean value of 0.96 +/- 0.65. Three of these six patients has symptoms of recurrent transient neurological deficits; one of these three suffered a complete stroke following documentation of platelet deposition. In this case, the aneurysm was obtained at surgery and was found to contain intraluminal platelet aggregation when viewed by scanning electron microscopy. In the remaining seven patients, the ratio IN(D)/In(BP) was found not to be significantly elevated (mean -0.03 &/- 0.06), indicating the absence of active platelet deposition. Two of these patients had prior symptoms of cerebral ischemia; one of these was found to have an ulcer in the ipsilateral internal carotid artery which was probably responsible for thromboembolic events to the hemisphere. The authors conclude that platelet aggregation occurs more frequently than previously recognized in giant intracranial aneurysms, and their data substantiate the hypothesis that platelet metabolic products or thrombi originating from a large aneurysm may embolize to distal cerebral vessels.

Adult↗