Biomedical subjects

A Trinidad

Publications and source records attributed to A Trinidad.

40 records · Page 3Linked to original sources

PubMedDate not supplied

Genetic control of acetyl coenzyme A-dependent arylamine N-acetyltransferase, hydrazine N-acetyltransferase, and N-hydroxy-arylamine O-acetyltransferase enzymes in C57BL/6J, A/J, AC57F1, and the rapid and slow acetylator A.B6 and B6.A congenic inbred mouse.

Acetyl coenzyme A-dependent N-acetyltransferase and O-acetyltransferase activities were examined in liver cytosols derived from homozygous rapid acetylator C57BL/6J and A.B6 congenic inbred mouse strains, from homozygous slow acetylator A/J and B6.A congenic inbred mouse strains, and from the (C57BL/6J x A/J)F1 heterozygous acetylator hybrid mouse strain. Acetylator genotype-dependent N-acetyltransferase activity was exhibited for the N-acetylation of p-aminobenzoic acid, 2-aminofluorene, and 4-aminobiphenyl. In contrast, levels of isoniazid N-acetyltransferase and N-hydroxy-3,2'-dimethyl-4-aminobiphenyl O-acetyltransferase activities in mouse liver cytosol appeared to be independent of the arylamine Nat acetylator gene. Although cytosolic N-acetyltransferase activities differed about 2-fold between the parental C57BL/6J and A/J strains for p-aminobenzoic acid, 2-aminofluorene, and 4-aminobiphenyl, the same N-acetyltransferase activities differed about 6-7-fold between the homozygous rapid acetylator A.B6 and the homozygous slow acetylator B6.A congenic inbred strains. Partial purification of acetyl coenzyme A-dependent arylamine N-acetyltransferase activity in the five inbred mouse strains showed one major paraoxon-resistant enzyme in liver cytosol in each of the rapid and slow acetylator mouse strains examined. Levels of partially purified 2-aminofluorene and 4-aminobiphenyl N-acetyltransferase activity were about 7-fold higher in the A.B6 than the B6.A congenic inbred strain. Partial purification of acetyl coenzyme A-dependent isoniazid N-acetyltransferase activity showed catalysis by a paraoxon-resistant enzyme(s) distinct from the major arylamine N-acetyltransferase enzyme(s). These results suggest that isoniazid N-acetyltransferase(s) in mouse liver cytosol is a product of a separate gene that segregates independently of the arylamine Nat gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetyl-CoA C-Acetyltransferase↗

PubMedDate not supplied

[Preservation of hearing in labyrinthectomies for cholesteatoma].

Destruction of the membranous labyrinth can lead to sensorineural hearing loss. This is especially frequent in surgery for active otorrhea. However, destruction of the posterior labyrinth sometimes can be solved without loss of cochlear function. We report three cases of partial labyrinthectomy for intralabyrinthine cholesteatoma without functional loss. Current theories regarding the conservation of hearing are discussed.

Adult↗

PubMedDate not supplied

[Sudden hearing loss and uveitis as a form of presentation of neurosarcoidosis].

Sarcoidosis is a multisystem granulomatous disease of unknown cause with frequent pulmonary, ocular, and lymphatic system manifestations. Central nervous system involvement, although rare (1 to 5%), most commonly affects the cranial nerves. Cranial nerve VIII abnormalities occur in 20% of these patients and are associated with other neuropathies and organ or system involvement. We report a case of neurosarcoidosis that presented as isolated sudden sensorineural hearing loss and uveitis.

Adolescent↗

PubMedDate not supplied

[Oncologic surgery of the larynx after failure of radiotherapy].

The treatment of early-stage laryngeal cancer using either partial surgical techniques or irradiation still is controversial. The performance of rescue surgical procedures after irradiation is related to increased postsurgical complications and lower survival rates. We made a retrospective study of 73 patients who underwent rescue surgery after failure of radiotherapy in our department in the last 10 years. A statistical analysis was made of the complications and survival rate of these patients in accordance with tumor location and clinicopathological stage compared with patients who underwent surgery alone (n = 435). More rescue surgery was performed for glottic carcinomas (52/73) than for supraglottic carcinomas (21/73). No significant differences were found in the complication rate (23.6%) compared with the control group (19.6%). There was a significant reduction in survival in patients who underwent previous irradiation of supraglottic tumors compared with glottic tumors and the control group. In view of these results, we conclude that irradiation is not a good option as an initial treatment for supraglottic tumors and that the procedure of choice should be surgical.

Adult↗