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Biomedical subjects

R Lambert

Publications and source records attributed to R Lambert.

At least 109 records · Page 6Linked to original sources

Clinical comparison between thallium-201 and Tc-99m-methoxy isobutyl isonitrile (hexamibi) myocardial perfusion imaging for detection of coronary artery disease.

99mTc-hexamibi (methoxy isobutyl isonitrile) is a new 99mTc-hexakis analog that can be used as a myocardial perfusion imaging agent. The purposes of this study were to compare 99mTc-hexamibi to 201Tl-thallous chloride myocardial stress scintigraphy in patients referred for investigation of chest pain and to evaluate the sensitivity of 99mTc-hexamibi in detection of coronary artery disease. One hundred patients were prospectively studied with both 201Tl and 99mTc-hexamibi planar imaging. Sixty five patients had a current coronary angiography. There was a total of 97 significantly (less than or equal to 70%) stenosed major coronary arteries. 99mTc-hexamibi (25 mCi) study was done within a week of the 201Tl scan with similar double products upon standard treadmil stress testing. Rest studies with 99mTc-hexamibi were obtained 24-48 h after the stress test using the same acquisition parameters and dose. Analysis was performed blind by three observers. The left ventricle was divided into five segments in each image. Analysis of 201Tl and 99mTc-hexamibi results in 1500 left ventricle segments showed an overall agreement in 1326/1500 (88.4%) segments. Correlation between the patient diagnosis on the 201Tl and 99mTc-hexamibi studies showed an agreement in 89 patients (89%). 201Tl revealed myocardial uptake defects in 526 segments, detecting 72 out of 97 (74.2%) significantly stenosed coronary arteries and 99mTc-hexamibi detected 513 segments corresponding to 68 (70.1%) stenosed arteries (no significant statistical difference). In conclusion, these results show a good correlation between 201Tl and 99mTc-hexamibi myocardial imaging in the detection of significant coronary artery disease.

Adult

Gallstone disappearance after extracorporeal lithotripsy and oral bile acid dissolution.

Extracorporeal shock-wave cholelithotripsy was carried out in 135 symptomatic patients with radiolucent gallstones, followed by oral bile acid dissolution to assess the resultant stone disappearance rates. Fragmentation was satisfactory (all fragments less than 5 mm in diameter) in 34 patients (25%) after a single session of lithotripsy, and in 65 (48%) after multiple sessions. The overall satisfactory fragmentation rate was significantly higher in patients with single stones less than or equal to 20 mm in diameter when compared with those with larger solitary stones (71% vs. 38%, p less than 0.05), as it also was in all subjects with solitary stones when compared with those with multiple stones (60% vs. 34%, p less than 0.05). After 6, 9, and 12 mo of oral bile acid treatment, the stone-free rates were significantly higher in patients with satisfactory than in those with partial fragmentation (55% vs. 0%, 80% vs. 29%, and 90% vs. 33%, respectively; p less than 0.05). Only 1 of the 7 patients who had previously undergone endoscopic sphincterotomy for concomitant choledocholithiasis was free of stones after 1 yr of dissolution. During dissolution therapy, of the 102 patients in whom fragmentation had occurred, 1 (1%) developed mild acute pancreatitis, 23 (23%) suffered attacks of biliary colic, and 6 (6%) required cholecystectomy. We conclude that the result of fragmentation appears to be a major determinant of the success and rapidity of subsequent oral bile acid dissolution, and that when satisfactory, it allows for complete stone disappearance in most patients within the following year. A comparison of the present results with those of previous original studies suggests that to achieve such satisfactory fragmentation, patients should be selected on the basis of their stone characteristics, which optimally should present as solitary gallbladder calculi less than 20 mm in diameter. Furthermore, real-time ultrasonographic monitoring should be used during lithotripsy with a transducer centered along the shock-wave axis. Despite the innocuousness of the shock waves, the incidence of fragment migration and its possible complications, in our experience, emphasizes the need to restrict at present this nonoperative approach to the treatment of symptomatic gallstone disease.

Adult

[Endosonography in gastroenterology. Update in 1989].

Endosonography consists of exploring the gastrointestinal wall and surrounding tissue with the aid of an ultrasound transducer introduced into the gastrointestinal lumen. High frequency ultrasound (more than 7 MHz) is used and provides high definition imaging. Its principal role is in oncology, and more particularly in the assessment of tumor extension. Regardless of whether it is the rectum, esophagus or stomach being considered, it is possible to predict the depth of tumor invasion in the wall in more than 80% of cases. The determination of invasion of adjacent organs is still somewhat imprecise. Endosonography provides better analysis of lymph nodes than CT scan (70 to 75% precision) and improvements will occur with better description of the criteria of malignancy. It appears interesting for the evaluation of pancreatic and biliary tumors and for follow-up of patients already treated for gastrointestinal cancer. Among its other indications, some have been well established (gastrointestinal submucosal tumors, giant gastropathy) and others require confirmation (villous tumors of the rectum, gastric ulcer).

Bile Duct Neoplasms

Laser treatment of tumors of the papilla of Vater.

Tumors of the papilla of Vater, should be separated from periampullary tumors. They are not always malignant, and recent data from endoscopy series, and pathology studies, supports the adenoma-carcinoma sequence at this level. Adenomas are tubular or villous and are classified according to the degree of dysplasia. The endoscopic pattern separates exophytic tumors, sessile and easily detected, from intracanalar tumors usually detected after sphincterotomy. The malignancy of an exophytic tumor is suspected when it is ulcerated or large (over 3 cm), and is easily confirmed by biopsies. The typing of intracanalar tumors is more difficult. In a 5-year period, an ampullary tumor was detected by ERCP in 52 patients: the tumor was exophytic in 33 and intracanalar in 19. Adenocarcinoma was confirmed in 26 and adenoma in 26, resulting in a 50% ratio. Among the adenomas, 18 were fully benign and 8 had a superficial cancer focus. Therapeutic procedures included: laser photodestruction in 16, snare resection in 16, sphincterotomy in 47, stenting in 8, surgical bypass in 7, cephalic duodenopancreatectomy in 16. The 16 patients treated by laser (Nd:YAG mainly) included 8 adenomas: a complete tumor destruction was obtained in 7 (follow up from 14 to 53 months). Adenomatous recurrence was observed at 2 years in one patient. In 8 other patients the tumor was an adenocarcinoma; Laser photodestruction failed to completely destroy the tumor in 1 patient (operative control), in 7 others it was adopted as a complement to sphincteromy and stenting in palliation, but was not found very effective.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma

Eurotium spp. and echinulin in feed refused by swine.

Feed refused by swine contained a high-propagule density of Eurotium chevalieri Mangin (anamorph, Aspergillus chevalieri (Mangin) Thom and Church), Eurotium amstelodami Mangin (anamorph, Aspergillus amstelodami (Mangin Thom and Church), and Aspergillus candidus Link. Echinulin (8 micrograms/g of feed) was detected in the feed. Isolates of E. chevalieri and E. amstelodami but not A. candidus produced echinulin on rice or cracked corn. Mice refused to drink water containing 90 micrograms of echinulin per ml. This is the first report of the alkaloid echinulin in feed refused by swine.

Alkaloids

Percutaneous aspiration and drainage of hydatid cysts in the liver.

Percutaneous aspiration of hydatid cysts of the liver was performed in 13 patients, and subsequent percutaneous drainage was performed in three of the 13. Aspiration was performed with ultrasound or computed tomographic guidance with 22-gauge to 19-gauge needles. Analysis of the aspirated specimen established the diagnosis of hydatid cysts in nine of the 13 patients. Fragments of the laminated membrane were seen in seven cases, scolices in two cases, and hooklets in two cases. In the four cases with negative results on aspiration, the diagnosis was established with surgical findings in one case and unequivocal immunologic results in three cases. In two patients, a mild allergic reaction with temporary pruritus was observed. In three patients, percutaneous drainage was performed with a 5-F to 8.3-F catheter, and sterilization of the cyst was achieved by injection of a scolicidal agent. No complications occurred at the time of drainage, and no recurrences developed during 6 months to 1 year after drainage.

Adult

[Ultrasonoendoscopy: its indications in esophageal and gastric pathology].

Endoscopic ultrasonography (EUS), which uses a high sonographic frequency (7.5 mHz) is a recently developed diagnostic tool that enables detailed analysis of the digestive wall and visualization of adjacent structures, like the posterior mediastinum through the esophagus. Thus, EUS may provide accurate documentation of the extent of esophagogastric malignancies, and of the adjacent lymph-node involvement. From now, results in preoperative staging compare favourably with CT scan. EUS provides also helpful complementary informations for the diagnosis of giant fold gastropathies or submucosal (or extrinsic) abnormalities. Moreover it may be usefull for the post-therapeutic follow-up of cancers, ulcers or varices.

Esophageal Diseases

Glomerular epithelial cell lesions in rat renal isografts.

Visceral glomerular epithelial cell lesions--microvillus formation, loss of foot processes, osmiophilic inclusion droplets, balloon-like malformation of cell processes, degeneration, necrosis, and loss of cell processes from capillary basement membranes--are found in rat renal isografts 1 mth after transplantation. The lesions, which are most readily recognized in perfusion-fixed material, are essentially focal, affecting neither all glomeruli, nor all cells in any glomerulus, bear no relation to the degree of interstitial nephritis in the graft, and are associated with albuminuria and with focal capillary sclerosis in some glomeruli. They are not restricted to renal isografts but are found in aging rats, in different experimental models of glomerular disease and in clinical glomerular disorders, again in association with proteinuria and glomerulosclerosis. It is therefore proposed that glomerular epithelial cell damage increases capillary permeability and impairs maintenance of the integrity of the capillary wall, leading to proteinuria and focal glomerulosclerosis.

Animals

Conjugated and unconjugated C-21, C-19 and C-18 steroid concentrations in human follicular fluid from hyperstimulated follicles.

Concentrations of unconjugated and glucuronated C-21, C-19 and C-18 steroids have been measured in follicular fluid obtained from women hyperstimulated by a combination of clomiphene citrate, pergonal and hCG. Pregnenolone and its glucuronide are found at approximately 5% of the progesterone values (14,395 +/- 2300 ng/ml). Concentrations of dehydroepiandrosterone glucuronide, androst-5-ene-3 beta, 17 beta-diol glucuronide, dihydrotestosterone glucuronide, androstane-3 alpha, 17 beta-diol glucuronide and androstane-3 beta, 17 beta-diol glucuronide are 2-6-fold higher than those of the related unconjugated steroids, while testosterone glucuronide levels are lower than those of testosterone. The concentrations of androsterone glucuronide reach almost 30-fold those of androsterone (2.56 +/- 0.35 ng/ml). By contrast, estradiol and estrone concentrations are 10-20-fold higher than those of conjugated steroids. Measurement of plasma steroid glucuronides indicated that the concentrations in circulation are markedly lower than those detected in follicular fluid. Our data suggest that the ovary in humans may be a site of glucuronidation.

Chorionic Gonadotropin