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Biomedical subjects

A Arthur

Publications and source records attributed to A Arthur.

At least 37 records · Page 2Linked to original sources

Bilateral lung abscess associated with a severe masticator space infection.

The clinician should be constantly aware of the danger of aspiration in cases of prolonged sepsis with profuse suppuration. In such cases, it might be wiser to establish dependent extraoral drainage, rather than relying solely on intraoral means. The chances of aspirating septic material and the resultant occurrence of pulmonary abscesses will be lessened.

Acute Disease↗

The development of a male pseudohermaphroditic rat using an inhibitor of the enzyme 5 alpha-reductase.

Incomplete masculinization of the external genitalia occurred in male Sprague-Dawley rats treated with a potent inhibitor of enzyme 5 alpha-reductase at the critical period of sexual differentiation in utero. The studies were performed using the 5 alpha-reductase inhibitor, 4-methyl-4-aza-5-pregnan-3-one-20[s] carboxylate, one of a series of aza steroids known to competitively inhibit the enzyme 5 alpha-reductase. The degree of inhibition of male external genital development was dependent upon the dose of the inhibitor, and at a dose of 36 mg/kg X day, there was complete feminization of the external genitalia of the male animal with a urogenital sinus and a pseudovagina. These studies provide conclusive evidence for the hypothesis that 5 alpha-reductase activity and dihydrotestosterone (17 beta-hydroxy-5 alpha-androstan-3-one) formation are essential for normal differentiation of male external genitalia. Epididymidis, vasa deferentia, and seminal vesicles were present at all doses of the inhibitor, suggesting testosterone dependency. However, confirmation of the testosterone dependency of Wolffian ductal differentiation awaits further studies, particularly comparison studies with the rabbit and dog, since Wolffian ductal differentiation in the rat, unlike the rabbit and dog, is not abolished with the antiandrogen, cyproterone acetate. The presence of prostatic buds, despite complete external genital feminization, was unexpected and suggests that these structures may have different thresholds of response for dihydrotestosterone. Prostatic differentiation may have a much lower threshold, requiring less dihydrotestosterone for differentiation.

5-alpha Reductase Inhibitors↗

Decreased urinary C19 and C21 steroid 5 alpha-metabolites in parents of male pseudohermaphrodites with 5 alpha-reductase deficiency: detection of carriers.

The urinary 5 beta/5 alpha ring A-reduced metabolites of C19 and C21 steroids from obligate carrier parents of male pseudohermaphrodites with 5 alpha-reductase deficiency were analyzed by gas chromatography. Etiocholanolone/androsterone, 11 beta-hydroxyetiocholanolone/11 beta-hydroxyandrosterone, tetrahydrocortisol/allotetrahydrocortisol, and tetrahydrocorticosterone/allotetrahydrocorticosterone were the paired 5 beta/5 alpha-metabolite ratios measured. Increased mean 5 beta/5 alpha ratios were found for all paired metabolites compared to mean ratios in normal subjects. In men, the highest index of discrimination of the carrier state was the tetrahydrocorticosterone/allotetrahydrocorticosterone ratio, while in women, the etiocholanolone/androsterone ratio was more diagnostic. In obligate carrier men, plasma testosterone, dihydrotestosterone, androstenedione, and 17 alpha-hydroxyprogesterone levels were normal, as were testosterone/dihydrotestosterone ratios. These studies demonstrate a generalized defect in 5 alpha-reductase activity involving C19 and C21 steroid metabolism in obligate carrier parents and provide further confirmation of an autosomal recessive mode of inheritance in this condition. The data from parents of sporadic cases of male pseudohermaphrodites with primary 5 alpha-reductase deficiency suggest that there is a carrier rate within the general population, although the exact frequency remains unknown.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

Transposition and transposition immunity of transposon Tn3 derivatives having different ends.

Novel Tn1/3 derivatives that contained either two left- or two right-hand ends of the transposon were constructed in a small plasmid. Both transposed at reasonable frequencies to give normal transposition products, suggesting that only the 38-bp inverted repeats of Tn3 are essential for transposition. Plasmids containing transposon derivatives with only one end (either left or right) undergo transposase-dependent transposition between replicons at much lower frequencies, resulting in co-integrate molecules in which there is no substantial duplication of transposon DNA and that appear to be simple fusions of the two plasmids. Both the right and left halves of the transposon are separately able to confer transposition immunity to the plasmid, this immunity being inseparably linked to transposition proficiency and specificity.

DNA Transposable Elements↗

Remission of Cushing's syndrome during pregnancy.

We present the first report of pregnancy with Cushing's syndrome due to an adrenal cortical adenoma, in which the hypercortisolemia disappeared during the third trimester of pregnancy, but recurred following the delivery of a normal male infant at 38 weeks by Cesarean section. The case is also unique because plasma ACTH levels were elevated during gestation and postpartum. Also, urinary estriol excretion was very low during the third trimester of pregnancy. The relationship of Cushing's syndrome and pregnancy are reviewed. This study points up some of the limitations of the routinely used dynamic tests of pituitary-adrenal function in Cushing's syndrome, and emphasizes the importance of various radiologic procedures in evaluation of patients with Cushing's syndrome.

Adenoma↗

Steroid hormone secretion from a virilizing lipoid cell tumor of the ovary.

The authors report the case of a 23-year-old woman with a virilizing lipoid cell tumor of the ovary. The patient developed precocious puberty at age 4 and from age 5 to 10 years was treated weekly with intramuscular medroxyprogesterone acetate. She began to menstruate spontaneously at age 13, but developed hirsutism, acne, and irregular menses at age 15 followed by secondary amenorrhea at age 20. Steroid analyses demonstrated elevated peripheral plasma levels of testosterone, dihydrotestosterone, androstenedione, 17 alpha-hydroxyprogesterone, progesterone, desoxycorticosterone, estrone, and estradiol. Catheterization of the adrenal and ovarian veins revealed increased secretion of testosterone, dehydroepiandrosterone, androstenedione, 17 alpha-hydroxyprogesterone, progesterone, desoxycortcosterone, and corticosterone, 11-desoxycortisol, cortisol, estrone, and estradiol from the right ovarian vein. At surgery a right ovarian lipoid cell tumor was removed. Incubation studies with the tumor tissue confirmed the presence of gonadal and adrenocortical steroids. The tissue also contained high-affinity human chorionic gonadotropin-luteinizing hormone binding sites with normal binding affinity.

Adrenal Cortex Hormones↗

Cleidocranial dysostosis: a multidisciplinary approach to treatment.

To ensure eruption of the dentition in patients with cleidocranial dysostosis, close collatoration between the oral surgeon and the orthodontist is essential to determine the sequence of extraction, the teeth to be ligated, the preferred technique of ligation, and the approach for surgical exposure.

Child↗

Serious postextraction hemorrhage into the submandibular space: report of case.

A 47-year-old woman had a swelling in the floor of the mouth and in the submandibular area on the left side. About four hours earlier, a dentist had extracted the mandibular left second premolar and first molar. The rate and degree of the distension were alarming; the floor of the mouth was at a level with the incisal edges of the mandibular incisors. Five hours later, the floor of the mouth was elevated about 1 1/2 cm above the incisal edges of the teeth. Treatment of the patient and her unusual sensitivity to meperidine and promethazine that caused a depression into Cheyne-Stokes respiration and hypotension are described.

Blood Pressure↗

Ludwig's angina.

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Drainage↗