Biomedical subjects
Publications and source records attributed to A M Taha.
Pseudocyst of the pancreas is an uncommon problem in pediatric practice, and when related to gallstones, it is rare. A 13-year-old male adolescent with pseudocyst of the pancreas associated with cholelithiasis and chronic cholecystitis presented with a peculiar clinical picture. The etiology, pathophysiology, diagnosis, and treatment of pancreatic pseudocysts and gallstone pancreatitis in children are discussed.
Torsion of the gallbladder is rare. However, the surgeon should be aware of it and that unusual presentations in the elderly make early diagnosis very difficult. A 100-year-old white female presented with right-sided abdominal pain and was found to have acute torsion of the gallbladder. The clinical picture, diagnostic tests, and operative findings are outlined. Serial evaluations of the patient's condition and a high index of suspicion are essential elements for prompt recognition and early surgical management.
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A method is described for quantitative determination of the sympathomimetic amines ephedrine HCl and phenylephrine HCl. The method is based on the interaction of N-alkylvinylamine formed from the condensation of the free secondary amine group and acetaldehyde with chloranil to give a vinylamino-substituted quinone. The colored product for ephedrine HCl and phenylephrine HCl exhibits 2 maxima at about 320 and 680 nm. All variables were studied to optimize reaction conditions. The relationship between absorbance and concentration was linear within 1-25 micrograms/mL under the conditions studied for both drugs at both wavelengths. The method has been applied to the analysis of some pharmaceutical formulations including tablets and eye drops with good recoveries (98.75-100.4%).
The relationship between the thymus and the pathogenesis of myasthenia gravis is reviewed. Ten cases of myasthenia gravis who underwent thymectomy at the American University Hospital of Beirut are presented. The various pathologic features of the thymus encountered in myasthenia gravis are presented. The indications for thymectomy and the results of surgical intervention on the course of the disease are reviewed. The conclusion is made that thymectomy should be done on all patients with generalized myasthenia gravis irrespective of age, sex, duration of disease or pathological features of the thymus.
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The natural abundance 13C-NMR spectra of tropine, atropine, scopolamine, cocaine, atropine methonitrate, and dl-tropic acid were determined at 22.63 MHz. With the aid of proton decoupling techiniques and by comparison with analogous simpler compounds, it was possible to make self-consistent and unambiquous assignments of all carbon resonances for these alkaloids. Some important chemical shift trends were observed and should be useful in the identification of similar systems.
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Binary mixtures of weak and strong UV-absorbing alkaloids were analyzed by a charge-transfer spectrophotometric method, utilizing iodine in ethylene dichloride as the acceptor. In the uncomplexed form, the strong absorbing alkaloid (papaverine, quinine, ergotamine, or reserpine) was measured at a wavelength where there was no interference from weak absorbers (at 335, 332, 315, or 300 nm, respectively). The weak absorbing alkaloid (ephedrine, codeine, atropine, or homatropine methylbromide) was determined by computing its contribution to the total charge-transfer band at 295 nm where absorbance was linearly additive for mixtures. The greater increase in the original epsilon-values of the weak absorbers upon complexation with iodine relative to the corresponding increase in the epsilon-values of the strong absorbers led to good recoveries even at the low dose ratios of the weakly absorbing, and often more potent, alkaloids.
The spectroscopic characteristics of the interaction of alkaloids with picrolonic acid were studied. In solvents of low and intermediate polarity, the presence of alkaloids caused a red shift of the 322 nm band of nonionized picrolonic acid to 355 nm, corresponding to the anionic resonance band. There was also a considerable increase in absorptivity, which was dependent on both the basicity (pKa) and molar concentration of the alkaloid present. Arylamines, aromatic N-heterocycles, and alkaloids lacking an aliphatic amine moiety did not show observable shifts. The interaction was developed into a spectrophotometric assay for the following alkaloids in pharmaceutical preparations: atropine, ephedrine, codeine, emetine, quinine, and strychnine. The method is sensitive to 2 mug alkaloid/ml, with an accuracy of not equal to 1.5% and a standard deviation of not equal to 1.05 - 1.31%.
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Explore the source record for details and available documents.
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