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N Gomez

Publications and source records attributed to N Gomez.

28 records · Page 2Linked to original sources
PubMed1992

HLA-DQA1 and MLC among HLA (generic)-identical unrelated individuals.

We modified a previously published PCR-RFLP for DQA1 typing (1) and examined the predictive value of HLA-DQA1 in mixed lymphocyte cultures (MLC) among matched (HLA generic types) pairs of unrelated individuals. There were 61/102 (60%) pairs with positive MLC, one-third of which could be predicted by DQA1* typing alone. DQA1 matching and MLC reactions were classified into 3 groups: 1) DQA1 mismatches showing positive MLC: 19/102 (19%); 2) DQA1 matches showing negative MLC: 41/102 (40%); 3) DQA1 identical showing positive MLC: 42/102 (41%). Five different HLA haplotypes that result from non-random association of HLA generic types (high delta haplotypes) were overrepresented in the individuals tested. One of these haplotypes carrying HLA-B7, DR2 was found associated with three different DQA1 alleles (*0201, *0103, *0102). The remaining four high delta haplotypes were associated with one DQA1 allele in all independent examples tested: HLA-A1, B8, DR3 with DQA1*0501; HLA-A26, B38, DR4 with DQA1*0301; HLA-A2, Bw62, DR4 with DQA1*0301 and HLA-A1, Bw57, DR7 with DQA1*0201. Forty per cent of the negative MLC were explained in part by the excessive number of individuals carrying two of these four haplotypes, which probably carry determinants in linkage disequilibrium with HLA. Nineteen per cent of HLA-identical (generic types) unrelated pairs show positive MLC reactions and all of them are DQA1* mismatched, suggesting that DQA1* allele typing should be used to screen samples prior to performing MLC.

Alleles↗
PubMed1992

Effects of the diet consumed during the pregnancy on the lipids content in maternal and fetal rat lungs.

This study was designed to determine if the quantity of lipids in the diet fed to pregnant rats would affect the deposition of fat in the fetal lung. Wistar rats were fed with two different diets during pregnancy: Standard Diet (StD; 4.000 cal/g) and High Fat Carbohydrate Free Diet (HFCFD; 6.000 cal/g). The rats consumed daily the same amount of calories from these different diets. The concentrations of triglycerides (TG), phospholipids (PL), total, esterified and free cholesterol (TC, EC and FC, respectively) were determined in serum and lung from pregnant rats as well as from their 19 day old fetuses. In the serum of rats fed with HFCFD, the cholesterol concentration increased in relation to that of rats fed with StD. In pregnant rat lung, the PL concentrations decreased and the TC, EC and FC concentrations increased with HFCFD in relation to StD. The triglycerides were not modified in any case. The lipidic composition of the sera and fetal lung were not changed by the two diets consumed by pregnant rats. This may be a biological protective mechanism to assure an adequate synthesis of alveolar surfactant.

Animals↗
PubMed1992

[Free myocutaneous flap of the latissimus dorsi in cervicofacial surgery].

Free myocutaneous latissimus dorsi transplants are exceptionally used in cervicofacial surgery. The authors have performed an anatomical study of 23 non-embalmed subjects, using injections of neoprene latex and barium sulfate into the axillary artery and dye injections. Dissections, arteriographs and corrosion show that the lower scapular pedicle is constant, with an average length of 9.5 cm and a caliber that is sufficient for vasuclar microsurgery. Eight patients with large T4 cervicocephalic neoplasms were operated, including two with tongue tumors, one with a tumor of the oropharynx, two oromandibular lesions, two lesions of the maxillary sinus and a neuroblastoma involving the middle level of the facial structures. A free myocutaneous latissimus dorsi transplant was used. The transplant was revascularised by neck vessels using microsurgical techniques. Complete success was obtained in all eight patients. Good functional, cosmetic and morphological results were obtained as a rule. In cervicofacial surgery, the authors have thus chosen and used a free myocutaneous latissimus dorsi transplant in three topographic indications: for the oropharynx, to fill large cavities, especially the maxillary sinus, and to fill the middle level of the facial structures and of the base of the skull.

Adult↗
PubMed1991

Investigations of the possible glycosylation of monoamine oxidase B from pig leucocytes.

Monoamine oxidase B (MAO B) from pig liver has been reported to be a sialoglycoprotein. However, when that enzyme from pig lymphocytes and granulocytes was separated by polyacrylamide gel electrophoresis after labelling with the specific irreversible inhibitor [3H]pargyline, staining with 1-ethyl-2-[3-(1-ethyl-naphtho [1,2d] thiazolin-2-ylidene)-2-methylpropenyl] naphtho [1,2d] thiazolium bromide ("Stains-all") failed to detect the presence of sialic acid residues. Treatment of the enzyme in disrupted lymphocytes and granulocytes, or in mitochondrial fractions prepared from them, with neuraminidase resulted in a decrease in MAO activity. However, after the enzyme was rendered soluble by treatment with octylglucoside, treatment with neuraminidase had no effect on the activity. These results indicate that sialic acid residues are not an intrinsic component of MAO B, although associated material containing such groups appears to affect the activity of the membrane-bound enzyme. The activities of membrane-bound preparations of MAO B from pig lymphocytes and granulocytes were unaffected by treatment with trypsin or beta-chymotrypsin. After the preparations had been rendered soluble by treatment with octylglucoside there was a decrease in the activity on treatment with beta-chymotrypsin, but trypsin treatment had no effect. Thus solubilization resulted in residues sensitive to cleavage by the former enzyme becoming accessible to it. Tryptic and chymotryptic peptides separated from the sodium dodecyl sulphate denatured enzymes by polyacrylamide gel electrophoresis revealed no differences between MAO B prepared from lymphocytes and granulocytes.

Animals↗
PubMed1986

Determination of monoamine oxidase concentrations in rat liver by inhibitor binding.

The concentrations of monoamine oxidase-A and -B have been determined in mitochondria, mitochondrial outer membranes and microsomes from Sprague-Dawley and Wistar rats by determining the binding of tritium-labelled pargyline. Although the amounts of each form present depended on the source and the preparation method, this was paralleled by the specific activity such that the molecular turnover number was found to remain constant. The catalytic constants, kcat/Km, which represents the apparent second-order rate constant for the combination of enzyme and substrate, were about 0.13 and 2.1 sec-1 X microM-1 for 5-hydroxytryptamine and 2-phenethylamine, respectively, regardless of the source. Estimations of the amounts of the two forms by determining the concentrations of the inhibitors clorgyline, (-)-deprenyl, J-508 or pargyline necessary to give complete inhibition were shown to give overestimates of the true values because of the non-specific binding of these inhibitors to sites other than the monoamine oxidase active site.

Animals↗
PubMed1980

Professional and lay observers' impressions of preschoolers wearing hearing aids.

This study determined whether professional and lay observers had similar impressions of preschoolers wearing hearing aids and if the size of the aid affected ratings. Stimuli consisted of three photographic slides of nine normally-hearing and speaking male preschoolers wearing (1) a body-type hearing aid, (2) a post-auricular type aid, and (3) no aid. Slides were accompanied by taped speech samples. Stimuli were presented to 75 professional and 75 lay observers who rated the children on a semantic differential scale containing 15 adjectives. Ratings were submitted to a factor analysis revealing Factor I as achievement and Factor II as appearance. Results of MANOVAs revealed that neither professional nor lay observers discriminated against the children on appearance regardless of the presence of a hearing aid, but that both groups rated them significantly poorer on achievement when an aid was present. Lay observers' ratings showed a bias against the size of the aid, while professionals exhibited negative impressions whenever an aid was present, regardless of its size. These findings indicate that the "hearing aid effect" was present on variables of achievement even for normal-hearing preschoolers.

Attitude↗
PubMed1976

Lobomycosis. An electronmicroscopic, histochemical and immunologic study.

A 73-year-old woman from Guyana had nodular keloidal lesions on her face which had persisted for 56 years. A biopsy of the lesion revealed lobomycosis, a rare fungal infection. Microscopically, numerous fungi were seen in giant cells and macrophages. The macrophages had abundant pink reticulated cytoplasm. These macrophages in lobomycosis, considered by some in the past to be granular myoblastoma cells, were rich in glycoproteins and appeared to be "Gaucher-like cells" in electronmicrographs. Further, a transition of macrophages containing organisms to Gaucher-like cells was noted. Antibodies to the fungus were demonstrated in the patient's serum by counter immunoelectrophoresis and indirect immunofluorescence studies. We postulate that the Gaucher-like cells formed because of the inability of host macrophages to digest glycoproteins in the capsule of this unusual fungus.

Aged↗