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Biomedical subjects

R Lambert

Publications and source records attributed to R Lambert.

At least 37 records · Page 2Linked to original sources
PubMed1990

Response to calcium of skinned gallbladder smooth muscle from newborn and adult guinea pigs.

Guinea pig gallbladder smooth muscle contractility undergoes a period of postnatal maturation. Because tissues from adult animals contract more forcefully than tissues from newborn animals when stimulated with agonists that activate the contractile process through different mechanisms (receptor activation, membrane depolarization), we proposed that factors unrelated to the mechanism of action of the agonist may contribute to the difference in force development between the age groups. Our study tested this hypothesis by examining the in vitro contractile response to calcium of membrane skinned muscle preparations from newborn and adult guinea pigs. Cell membranes were permeabilized using a Triton X-100 (0.5%) skinning solution. The muscle strips were rinsed in relaxing solution then contracted with calcium. The contracting solution contained either 1, 5, 10, or 20 microM calcium. Each muscle strip was stimulated with a single concentration of calcium. The results can be summarized as follows: 1) the maximal response of the skinned preparations did not differ from that of membrane intact preparations; 2) tissues from each age group contracted in a dose-response manner with the maximal response occurring at 10 microM calcium; and 3) at each calcium concentration, tissues from adult animals developed more active force than tissues from newborn animals. The data suggest that the postnatal maturation of gallbladder smooth muscle contractility includes factors involved in calcium activation of the excitation-contraction coupling process.

Acetylcholine↗
PubMed1990

Therapeutic upper gastrointestinal endoscopy. Past, present, and future.

Therapeutic procedures in upper gastrointestinal endoscopy are usually performed with the patient under sedation, and there is a clear advantage with video endoscopy. The endoscopy assistant needs full training on the appropriate and safe use of equipment and accessories. Complications of procedures should be detected early and managed appropriately. Indications, results, and perspectives of endoscopic procedures are reviewed for the following situations: gastrointestinal bleeding, caustic injury, foreign bodies, advanced and superficial cancer, dysplasia, reflux esophagitis, motility disorders, and nutritional assistance. Consolidation of current methods and systematic evaluation of the results of therapeutic endoscopy are important tasks for the near future.

Duodenal Diseases↗
PubMed1990

[Lactulose].

Explore the source record for details and available documents.

Cell Membrane Permeability↗
PubMed1989

Contribution of endoscopy to diagnosis and treatment of tumors of the ampulla of Vater.

In a series of 52 patients presenting with tumors of the ampulla of Vater, endoscopic procedures, especially endoscopic sphincterotomy and snare biopsies, permitted histologic classifications as follows: adenocarcinoma: 50%, adenoma: 35%, and adenoma with cancer: 15%. In 37% of cases, the papilla was normal endoscopically and the tumor was detected only after sphincterotomy. Destruction of adenomas by snare resection, laser photoradiation, or both after sphincterotomy was attempted in 11 patients. Subsequent biopsies revealed persistence or recurrence of adenomatous tissue in only one case and complete destruction of adenomas, with a mean duration of follow-up of 39 months, in the 10 other cases. Palliative treatment by endoscopic procedures was performed in 21 patients and was effective for a mean of 45 months for adenomas and for a mean of 6 months for adenocarcinomas, with a mortality of 10%. To avoid repeated sphincterotomy in patients requiring palliative treatment, the data support the early use of endobiliary prostheses. Endoscopic palliative treatment is not indicated, however, for infiltrative tumors that can induce rapid duodenal obstruction.

Adenocarcinoma↗
PubMed1989

Esophageal squamous cell carcinoma associated with gastric adenocarcinoma.

Adenocarcinoma of the stomach occurred in six of 425 consecutive patients with esophageal squamous cell cancer. In two cases, the gastric cancer, which was recognized at 17 and 29 months, respectively, after the nonsurgical treatment of the esophageal tumor, was treated by surgical resection. In three cases, the tumors which were diagnosed simultaneously, were treated by surgery (one case) resection of the gastric tumor and nonsurgical therapy for the esophageal tumor (one case), and nonsurgical therapy for both tumors (one case). In one case, a gastric cancer was resected 6 years before diagnosis of an esophageal tumor and a second cancer in the gastric stump. A nonsurgical protocol was then adopted for both tumors. The association of these two cancers raises questions concerning their epidemiology, diagnosis, prognosis, and management. There is room for nonsurgical multimodality protocols and, in association with surgery, survival was prolonged for more than 1 year in five of six patients.

Adenocarcinoma↗
PubMed1989

Lymphocytic gastritis versus varioliform gastritis. A historical series revisited.

A historical series of varioliform gastritis published in 1978 by Lambert et al. (Digestion 1978; 17: 159-167) was revisited by two pathologists. The histological preparations from 35 patients were reread and interpreted in the light of endoscopic data found in the files. The results demonstrate a strict correlation between clinical diffuse varioliform gastritis and a recently recognized histopathological entity--lymphocytic gastritis, which is characterized by intense lymphocytic infiltration of the surface and foveolar epithelium. The rare discrepancies occur in Crohn's disease and in varioliform gastritis limited to part of the stomach, mostly the antrum.

Crohn Disease↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1989

[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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗