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Biomedical subjects

D Reis

Publications and source records attributed to D Reis.

27 records · Page 2Linked to original sources
PubMed1983

Dissociation between hypothalamic catecholamine levels and epinephrine-forming enzyme activity after midbrain hemitransections in the rat.

We found decreased catecholamine (norepinephrine and epinephrine) levels in selective hypothalamic nuclei of the rat after complete midbrain hemitransections. In contrast, the activity of the epinephrine-forming enzyme (phenylethanolamine-N-methyltransferase, PNMT, EC 2.1.1.28) was unchanged in the hypothalamus after the lesions. Our results demonstrate a dissociation between hypothalamic catecholamine levels and PNMT activity, and suggest that hypothalamic PNMT may not be localized in catecholaminergic axons originating in the brainstem.

Animals↗
PubMed1975

Observations with cytochemistry and ultracryotomy on the fine structure of the expanding walls in actively elongating plant cells.

Ultracryotomy with negative staining and cytochemistry (periodic acid - thiocarbohydrazide - silver proteinate test for polysaccharides, in conjunction with mild extractions) were used to study the architecture of the cell wall and its modifications during expansion. Those techniques were applied to the study in situ of the walls of actively elongating parenchyma of mung bean (Phaseolus aureus), and pea (Pisum sativum) root and of collenchyma of celery (Apium graveolens) petioles. These complementary techniques provide information on the 3-dimensional disposition and fine structure of the subunits of the wall. In all the examples examined, the bulk of growing primary wall appears well-ordered and no progressive evolution from a transverse texture near the plasmalemma to a scattered texture near the middle lamella was observed. It seems unlikely that the development of the wall structure in relation to growth could be explained mechanically by a passive shift of the fibrillar elements in response to cellular stress. There is no evidence for an inert change in fibrillar orientation in the major part of the wall. If such occurs the process is limited to the outermost and senescent part of the wall. Thus, the texture observed does not agree with the classical multinet growth hypothesis but rather with the idea of an ordered structure of the primary wall. With the latter, the components should be able to respond in different ways to specific growth regulators and other environmental signals and thus exert a more positive control over the processes of oriented cell growth.

Cell Wall↗
PubMed1973

Immunochemical demonstration of increased accumulation of tyrosine hydroxylase protein in sympathetic ganglia and adrenal medulla elicited by reserpine.

Chronic administration of reserpine to rats increases, in sympathetic ganglia and adrenal medulla, the activity of tyrosine hydroxylase (EC 1.14.3.x), the enzyme catalyzing the rate-limiting step in the biosynthesis of catecholamines. Immunochemical titration of the enzyme in both adrenal gland and innervated superior cervical ganglia demonstrates that enhanced enzyme activity is entirely attributable to accumulation of more specific enzyme protein and not activation of preexistent enzyme molecules.

Adrenal Medulla↗
PubMedDate not supplied

Effect of bupropion on immunodensity of putative imidazoline receptors on platelets of depressed patients.

A substantial number of studies have demonstrated increased imidazoline receptors (I1 binding sites) on platelets of depressed patients and downregulation following antidepressant treatments. Herein, imidazoline receptor binding protein (IRBP) antiserum was used to quantify imidazoline receptors on platelets of depressed patients before and after treatment with the atypical aminoketone antidepressant, bupropion. Western blots revealed an increase in IRBP-immunodensity (p = 0.01, two-tailed) in a 33 kDa protein band in untreated depressed patients (n = 21) as compared with controls (n = 17). This band has been positively correlated with I1 binding sites on platelets. Following 6 weeks' treatment with bupropion, IRBP-immunodensity was downregulated in depressed patients (p = 0.03, paired t-test); predominantly in responders (p = 0.005). Patients non-responsive to bupropion (n = 5) were significantly different from responders (p = 0.05) by exhibiting no elevation in IRBP-immunodensity at pre-treatment and no downregulation of the 33 kDa band after treatment. IRBP-immunodensity was negatively correlated (r = -0.79, p = 0.01) with plasma concentrations of bupropion and its metabolites at week-4 of BUP treatment. Thus, a 33-kDa IRBP on platelet plasma membranes is elevated in depression and normalized in responders to bupropion.

Adolescent↗
PubMedDate not supplied

[Epidemiology of anorexia nervosa. Prevalence of anorexia nervosa in female adolescents from the districts of Lisboa and Setubal].

UNLABELLED: Prevalence studies of anorexia nervosa (AN) have shown differences depending of the country and method applied. The partial syndrome is being emphasized. There has been no epidemiological study done on AN in the Portuguese population of continental Portugal. Our objectives were: 1) to study the prevalence of AN in Portuguese populations; 2) to study the presence of partial syndrome and of body image disturbance; 3) to calculate the number of girls dieting; 4) to correlate with other variables. A population of 2,398 girls ranging 10 to 21 years old, from 30 State secondary schools in the Lisbon and Setubal districts were studied. A questionnaire was answered with questions allowing assessment of all DSM IIIR criteria for AN. RESULTS: Prevalence of AN--0.37%, partial syndrome--12.6%, body image disturbance without weight loss--7%, wish to decrease weight in normal or low weight girls--38%, overweight--15.3%, the peak of age for AN was 15 years, the most prevalent socio-economic class for AN was 2 (scale 1 (higher) to 5). School performance was worse with AN and the age menarche was sooner.

Adolescent↗