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Biomedical subjects

A Raad

Publications and source records attributed to A Raad.

5 recordsLinked to original sources

[Management of duodenal adenomatosis in patients with familial adenomatous polyposis].

AIM OF THE STUDY: To review our global management of duodenal adenomas in patients with familial adenomatous polyposis and report the results of different therapeutic approaches. To present the outcome and possible sequels of pancreaticoduodenectomy. PATIENTS AND METHODS: We identified five cases of duodenal adenomas in patients with familial adenomatous polyposis over a period of 10 years (1992-2001), we followed the progression of their Spigelman score. Results of conservative and surgical treatment were collected. RESULTS: Duodenal adenomas were discovered 5-33 years after the first operation for colonic polyposis. The score of Spigelman was as follows: 2, stage 2; 3, stage 3; 1, stage 4. Endoscopic laser therapy followed by Sulindac prescription was proposed in three cases, with only one success. Duodenopancreatectomy was performed in four patients: once the diagnosis of adenoma was made in one patient, due to Spigelman stage 4 with severe dysplasia, because development of intramucosal carcinoma under surveillance in one patient, and after failure or complication of conservative treatment in two others. Worsening of Spigelman score was observed in two out of four patients submitted to conservative therapy. Correlation between Spigelman score and final examination of the specimen was correct in two cases. There was neither significant morbidity nor long-term nutritional sequel after pancreaticoduodenectomy. CONCLUSION: Duodenal adenomas may recur or progress into malignant degeneration under conservative treatment. The pancreaticoduodenectomy is an acceptable solution for stage 4 of Spigelman, especially when severe dysplasia is present.

Adenomatous Polyposis Coli↗

Multi-turn, printed surface coil inductance, and Q optimization.

Wheeler's empirical inductance formula for a multi-turn, close-wound flat coil shows that the maximum inductance for a given length of wire occurs when the outer to inner radius ratios is equal to 15/7. A similar expression is proposed for a flat, printed spiral for surface coil antenna design by modifying one of the coefficients in Wheeler's formula. Measured inductance is in good agreement with this new formula and the optimum radius ratio for maximum inductance or Q is now of the order of 9/5.

Electric Conductivity↗

Optimization of NMR receiver bandwidth by inductive coupling.

We show, by theory and experiment, that inductive coupling can be used in overcoupled mode to widen the bandwidth of a high-Q NMR coil with only a negligible degradation of signal-to-noise ratio over the bandwidth of interest. The receiver bandwidth depends on the coupling coefficient between the NMR coil and the coupling coil rather than on the quality factor of the NMR coil alone. The overall bandwidth can be optimized by a judicious choice of the coupling coefficient. Moreover, this method permits wireless reception without the need for retuning and rematching despite changes of NMR coils or samples. This technique has been incorporated in a 0.1-T imager for clinical routine. It achieves a typical bandwidth five times greater than that using a classic 50-omega matching method.

Humans↗

[Posttraumatic true aneurysm of the left ventricle caused by a shotgun wound].

An asymptomatic aneurysm of the left ventricle was discovered incidentally in a policeman aged 25, who had a history of a severe thoracic injury from a shotgun wound at the age of 15. Electrocardiography showed a transmural antero-lateral infarct; this was later confirmed at ventriculography. Coronary arteriography showed a narrowed anterior descending artery which crossed over the surface of the aneurysm. The cardiac status remained unchanged over an 8 year follow up period. The pathogenesis is discussed: a fold of contused myocardium, or immediate or late traumatic obstruction of the anterior descending artery, or both factors at the same time?

Adolescent↗