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Biomedical subjects

G Roseau

Publications and source records attributed to G Roseau.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Echoendoscopy: a new technic for studying esophago-gastric subepithelial tumors and extrinsic compression].

The value of endoscopic ultrasonography in the diagnosis of subepithelial tumors and extrinsic compression of the esophagus and the stomach was evaluated in 34 patients with 21 subepithelial tumors and 13 extrinsic compressions. Endoscopic ultrasonography was always performed after axial-vision fiberscopy anal routine biopsy specimens were obtained. Computed tomography was also done in all cases of extrinsic compression. Distinction between subepithelial tumor and extrinsic compression was made in all patients by endoscopic ultrasonography and in 5 cases by fiberscopic examination with biopsy specimens. Localization and intramural spread of subepithelial tumors were correctly determined in 12 of 13 cases by endoscopic ultrasonography (diagnostic accuracy: 92 percent). The echoendoscopic semiology of 21 subepithelial tumors was retrospectively established. The histologic nature of some of these tumors can be suggested by these signs. Endoscopic ultrasonography is superior to computed tomography in the evaluation of esogastric extrinsic compressions, particularly in the diagnosis of posterior mediastinal carcinomatosis and of tumoral invasion of the deep parietal layers. We conclude that endoscopic ultrasonography is currently the best procedure in the assessment of subepithelial tumors and extrinsic compressions of the esophagus and the stomach.

Carcinoma↗
PubMed1990

[Endoscopic ultrasonic diagnosis and cancer of the esophagus. Results of a prospective comparative study with x-ray computed tomography in 51 surgically treated patients].

To investigate whether endoscopic ultrasonography could improve the preoperative staging of esophageal carcinoma we prospectively studied 56 tumors in 51 patients between March 1987 an March 1988. The results for assessing local and regional extension and preoperative staging were compared with those of computed tomography, surgery, and pathological findings. When the procedure was complete (n = 25) the accuracy of parietal spread assessment was 85.7 percent; sensitivity for nodal involvement was 83.3 percent versus 50 percent for computed tomography with an accuracy of 97.6 percent versus 96.4 percent; the discrimination between superficial and advanced cancer was 100 percent; the accuracy for preoperative staging using the Japanese classification was 84 percent. When the procedure was not complete (stenosis), endoscopic ultrasonography was complementary to computed tomography: local invasion of anatomical structures (n = 16) was better assessed by combined endoscopic ultrasonography and computed tomography (n = 11) than by endoscopic ultrasonography (n = 8) or computed tomography (n = 6) alone. We conclude that endoscopic ultrasonography is the best procedure for staging esophageal carcinoma without stenosis; further miniaturization of the transducer is necessary to improve results in the case of narrow stenosis.

Adenocarcinoma↗
PubMed1990

[Results of endoscopic ultrasonography in the preoperative assessment of rectal cancer].

Endoscopic transrectal ultrasonography is performed with an ultrasonic transducer (7.5 MHz or 12 MHz) in the tip of a side viewing endoscope. Its accuracy to assess the depth of rectal cancer invasion was prospectively studied in 27 patients. The ultrasonic examination was correct in 23 cases; in 4 cases, the stricturing tumour could not be passed by the probe. The depth of invasion was correctly appreciated in 24 of the 27 cases (accuracy of 89%). The 6 superficial lesions were all correctly detected with endoscopic transrectal ultrasonography. Therefore, endoscopic transrectal ultrasonography appears to be a very promising method in the pretherapeutic staging of rectal cancer.

Aged↗
PubMed1989

[Endoscopic ultrasonography of the digestive tract].

Endoscopic ultrasonography of the digestive tract provides for a precise ultrasonic study of the accessible gastrointestinal walls (oesophagus, stomach, duodenum, rectum) and, through these walls, of the adjacent organs (lymph node clusters, posterior mediastinum, pancreas, extrahepatic biliary ducts and perirectal environment). This method is better than computerized tomography to evaluate the local and regional extension of oesophageal and cardial carcinomas producing little or no stenosis and of rectal carcinomas. It is the examination of choice to detect a perianastomotic recurrence of these cancers and to evaluate submucosal tumours of the digestive tract and thick fold stomach diseases. Its use in the aetiological diagnosis of obstacles in the biliary tract and in the pretherapeutic assessment of pancreatic and biliary tract cancers seems to be very promising.

Biliary Tract Diseases↗
PubMed1989

[Primary rectal lymphoma: value of rectal endosonography].

The authors report a case of primary rectal lymphoma characterized by dyspareunias and a raised erythematous rectal mucosa visible at rectoscopy. They stress the difficulty of the diagnosis, requiring deep biopsies, and the advantage of endorectal sonography. Its efficacy in defining the parietal and depth spread is evaluated between 90-95 p. cent, while it is lower (72%) regarding node invasion.

Adult↗
PubMed1987

[Malignant degeneration of Ménétrier disease].

Gastric cancer was found in a patient in whom Menetrier's disease had been diagnosed 18 months before. In Menetrier's disease, incidence of cancer is as high as 14% of cases. But in only 5 cases of literature including the present one, has the time sequence been clearly documented. Metachronous tumours may be found 1 to 5 years after giant hypertrophic gastritis has been diagnozed. Such data make medical management, including anti-secretory drugs and periodic endoscopic survey, hazardous. We suggest that in documented Menetrier's disease elective total gastrectomy should still be considered as a treatment of choice.

Adenocarcinoma↗
PubMed1978

Transient-phase studies on the arginine kinase reaction.

1. The initial formation of arginine phosphate by arginine kinase was studied in the time range 2.8--50 ms by the quenched-flow method. 2. A transient burst phase of product formation was obtained, the amplitude of which was temperature-dependent. At 35 degrees C it was 0.64 mol arginine phosphate/mol arginine kinase and at 12 degrees C, 0.25 mol/mol. 3. These results show that for the reaction pathway of arginine kinase the rate-limiting step follows the formation of arginine phosphate on the enzyme. This is in contrast to the creatine kinase reaction where no transient phase was observed [Engelborghs, Y., Marsh, A. & Gutfreund, H. (1975) Biochem. J. 151, 47--50]. 4. The rate-limiting step on the arginine kinase reaction pathway is only slightly affected by temperature: the change in Kcat with temperature is due to a change of an equilibrium constant pertaining to at least two previous steps.

Animals↗
PubMed1978

Cryoenzymologic studies on arginine kinase: solvent, temperature and pH effects on the overall reaction.

The overall reaction catalyzed by the phosphotransferase arginine kinase was studied at normal and subzero temperatures. Ethylene glycol was used as the antifreeze and its effects on the Km values of substances, kcat and pH profiles were investigated in detail. a) The Km values for the substrate (2 mM for ATP and 0.6 mM for arginine) were little affected by the solvent composition or temperature of the reaction mixture. b) At concentration of ethylene glycol higher than 40% there was a sharp drop of enzyme activity. c) Ethylene glycol induces a large shift in the enzymic pK D) At -5 degrees C in 40% of solvent there was a break in the Arrhenius plot suggesting a change of the rate-limiting step. The relevance of these results to the reaction pathway of arginine kinase is discussed. In addition, controlled perturbations induced by cosolvent and temperature appear as useful tools for further kinetic investigations.

Animals↗
PubMed1976

[Tryptic hydrolysis extended to the level of aspartyl bonds].

A quantitative modification of free carboxyl groups in peptides and proteins can be obtained, under mild conditions, by reacting them with ethylenediamine in the presence of N-ethyl-N'-(3-dimethylaminopropyl)-Carbodimide. Aminoethylasparagine and aminoethylglutamine side chains are thus generated in place of the corresponding carboxylic ones. The first kind of residue because of its structure closer to that of lysine, is a point of greater potential trypsic cleavage than the second one. The specificity and yields of this enzymatic cleavage reaction and its possible application in sequence studies are discussed.

Amino Acid Sequence↗
PubMedDate not supplied

Endoscopic ultrasonography in the staging and follow-up of epidermoid carcinoma of the anal canal.

Epidermoid (squamous cell) carcinomas of the anal canal are relatively rare, accounting for less than 3% of all malignant tumors affecting the large intestine. Radiation therapy alone or combined with chemotherapy is the treatment of choice. To be effective, this requires initially correct staging and accurate follow-up. Endoscopic ultrasonography plays an essential role, which, during a period of 20 months, we applied to 20 patients. This made possible initial staging according to the TNM classification system. Follow-up examinations showed reduction in size of lesions in all cases. Three patients required early post-radiation surgical intervention because of rectal or vaginal invasion or lymph node metastases. Recurrence in 3 patients, evident by mural expansion on consecutive ultrasound examinations, was diagnosed at 6, 10, and 12 months. In all 6 patients requiring surgical intervention, good correlation was observed between ultrasonic images and operative findings.

Aged↗