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Biomedical subjects

A Noronha

Publications and source records attributed to A Noronha.

34 records · Page 2Linked to original sources
PubMed1990

Tau fraction of transferrin is present in human aqueous humor and is not unique to cerebrospinal fluid.

In view of the many similarities between the aqueous humor and the cerebrospinal fluid (CSF), we investigated whether the tau fraction of transferrin, which is believed to be specific for CSF, is also present in aqueous humor. Samples of aqueous humor and CSF from clinically normal individuals were analyzed by SDS-PAGE and isoelectric focusing (IEF), and probed with anti-transferrin antiserum and the lectin Limax flavus agglutinin. Specific bands which corresponded to transferrin and its tau fraction were detected in both fluids. After isolation of these bands by affinity chromatography with anti-transferrin antiserum, we detected a single, diffuse fraction at an apparent molecular weight of 80 kDa in both aqueous humor and CSF. Peptide mapping revealed no detectable difference in this fraction between the two fluids. The detection of the tau fraction in human aqueous humor indicates that this molecule cannot be considered a specific cerebrogenic marker as had been thought previously. In view of the known growth-promoting properties of transferrin, its isolation from both ocular and cranial fluids attains special significance.

Aged↗
PubMed1989

Pericarotid cluster headache.

Cluster headache is generally not associated with recognised disease, and the pathogenesis remains unclear. The onset of typical cluster headaches is reported in a patient with nasopharyngeal carcinoma. The tumor encircled the internal carotid artery but did not extend intracranially. It thus appears possible that cluster headaches may be triggered by processes involving the carotid artery.

Carcinoma, Squamous Cell↗
PubMed1989

Effect of dorsal hippocampal lesion compared to dorsal hippocampal blockade by atropine on reference memory in vision deprived rats.

In order to study the primacy of the hippocampus in place learning function 24 male adult albino rats were hippocampally-lesioned in dorsal hippocampus involving fornical damage (group I); sham operated for comparison with group I (group II); cannulated for instillation of atropine sulphate in the same loci as group I (group III); and cannulated for instillation of saline which served as control for group III (group IV). All the animals were enucleated and their reference memory (long-term memory) was tested, using open 4-arm radial maze. There was loss of reference memory in groups I and III. However, hippocampally-lesioned animals, showed recovery of reference memory deficit within a short period of 10 days or so. Whereas atropinized animals showed persistent reference memory deficit as long as the instillation effect continued. The mechanism involved in the recovery of reference memory in hippocampally-lesioned animals and persistent deficit of reference memory in atropinized animals has been postulated to explain the primacy of hippocampus in the place learning function under normal conditions.

Animals↗
PubMed1988

Activated suppressor cell function in multiple sclerosis--clinical correlations.

Activated suppressor cell function mediated by either freshly isolated peripheral blood mononuclear cells (MNCs), freshly isolated CD8+ lymphocytes or by CD8+ cell lines, has previously been found to be reduced compared to controls in multiple sclerosis (MS) patients with progressive disease (MS-P). In this study, we found that suppressor activity mediated by CD8+ cell lines, derived from MS patients with stable disease (MS-S) patients and maintained in culture for 14 days, was significantly greater (45 +/- 6%) compared to that mediated by MS-P patients' CD8+ cells (11 +/- 4%, P less than 0.005). The MS-S suppressor values were, however, suggestively reduced compared to controls (60 +/- 6%, P less than 0.05). MNC-mediated suppressor values for the MS-S group (61 +/- 5%) did not differ from the control group (67 +/- 6%). Values for the MS-P group (7 +/- 6%) were significantly reduced compared to MS-S and control groups. Cytotoxic activity mediated by CD8+ cell lines showing defective suppressor function did not differ from control values. The cell lines in MS and control did not differ with respect to their rate of proliferation in the presence of IL-2 and OKT3. Suppressor function in this assay was ablated if exogenous IL-2 was removed from the culture media. These data suggest that defective activated suppressor function is characteristic of the progressive form of MS, although a suppressor defect is also partially expressed in stable MS patients when CD8+ cell lines are studied.

Adult↗
PubMed1987

Vitamin E deficiency and neurologic disease in adults with cystic fibrosis.

We report the cases of two adult patients with cystic fibrosis affecting the pancreas and liver, who also had severe vitamin E deficiency and neurologic disease. The most prominent clinical features were abnormal eye movements, diminished reflexes, decreased vibratory and position sense, ataxia, and muscle weakness. Treatment with intramuscular injections of vitamin E partially corrected the neurologic deficits. Vitamin E absorption tests documented severe malabsorption, which was later alleviated by the addition of dessicated ox bile to the regimen of alpha-tocopheryl acetate. These studies suggest that a decreased intraluminal concentration of bile salts is an important factor in the development of severe vitamin E deficiency and in the poor response to oral replacement therapy that is seen in some patients with cystic fibrosis.

Administration, Oral↗
PubMed1986

Defective suppressor cell function mediated by T8+ cell lines from patients with progressive multiple sclerosis.

Activated suppressor cell function, induced with either concanavalin A or OKT3 and mediated by either unfractionated mononuclear cells or "panning" enriched T8+ cells, freshly isolated from peripheral blood, is reduced in patients with progressive multiple sclerosis (MS) as compared with control donors. In this study, we generated T8+ cell lines from the peripheral blood of these same patients and controls. Suppressor activity, mediated by T8+ cells exposed to OKT3 on days 1, 7, and 14 of culture and then treated with mitomycin C on day 16, was significantly reduced in the MS group (mean percent suppression 13% +/- 5) as compared with the control group (68% +/- 6, n = 8, p less than 0.001). No differences were noted in [3H]thymidine uptake by the OKT3-stimulated T8+ cell lines of MS and control groups. Mean percent suppression mediated by T4+ cell lines did not differ between MS and control groups (15% +/- 4, n = 3, vs 22% +/- 2, n = 4). These current data suggest that the previously observed defect in T8+ cell-mediated activated suppressor cell function in MS is a persistent one, favoring the postulate that the defect reflects intrinsic alterations in this cell population rather than a transient effect of serum factors on T8+ cell function.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1986

Accessory cell competence of ovine oligodendrocytes in mitogenic activation of human peripheral T cells.

The multiple sclerosis (MS) plaque is characterized by mononuclear inflammatory cell infiltration, demyelination, loss of oligodendrocytes (OGC), and proliferation of astrocytes. Although antigen-specific, Ia-dependent cellular immune mechanisms have been sought in plaque pathogenesis, Ia-independent T cell activation has not been actively investigated. We examined a potential role of OGC in accessory cell-dependent T cell mitogenesis with the anti-T3 monoclonal antibody OKT3. OGC isolated from ovine white matter on sucrose density gradients were uniformly negative for esterase activity, unlike ovine monocytes. Purified human T cells did not exhibit significant proliferation in 3-day cultures with OKT3, autologous peripheral blood adherent cells (PBAC), or ovine OGC. When T cells were cultured with either PABC or OGC in the presence of OKT3, brisk mitogenesis was observed. Thus, OGC have the capacity to function as accessory cells in the mitogen-induced proliferation of T cells.

Animals↗
PubMed1985

Multiple sclerosis: activated cells in cerebrospinal fluid in acute exacerbations.

Cerebrospinal fluid (CSF) lymphocytes from three young patients undergoing acute exacerbations of multiple sclerosis were studied by flow cytometry. Using a new method that simultaneously measures cell-surface antigens and the cell-cycle phase, we determined that the CSF lymphocytes in these patients were activated. The majority of the activated cells expressed the OKT4 phenotype, while very few expressed the OKT8 phenotype.

Adolescent↗
PubMed1985

Neurologic disorders during pregnancy and the puerperium.

This article focuses on epilepsies, autoimmune diseases such as multiple sclerosis and myasthenia, serious problems associated with stroke and pseudotumor cerebri, and some common problems such as headaches and the carpal tunnel syndrome, examining the effects of pregnancy and the puerperium on these disorders and the influence of these disorders on pregnancy.

Adult↗
PubMed1984

Simultaneous cell surface phenotype and cell cycle analysis of lymphocytes by flow cytometry.

A method for the simultaneous measurement of cell surface components and nucleic acids (DNA and RNA) of human lymphocytes by flow cytometry has been developed, thereby providing a means of analyzing cell surface changes during the various phases of the cell cycle. Unfixed cells were coated with fluorescein-conjugated concanavalin A (F Con A) or surface antigen-specific antibody, fixed sequentially with paraformaldehyde and methanol, treated with specific nucleases, and then stained with propidium iodide. Neither portion of the procedure (cell surface staining, nucleic acid staining) interfered significantly with the other. Cell cycle phases of phytohemagglutinin-stimulated human lymphocytes as determined by this method were comparable with those identified by acridine orange staining. Cell cycle-specific blocking agents were used to additionally demonstrate the specificity of the staining procedure. Simultaneous measurement of cell cycle phase and detection of surface receptors for Con A and T lymphocyte surface determinants was performed with this method.

Adult↗
PubMed1976

Pure motor hemiplegia, medullary pyramid lesion, and olivary hypertrophy.

The case is presented of a 60 years old man who developed sudden right hemiplegia without other accompanying neurological signs and later a spastic hemiparesis. Neuropathological studies indicated an ischaemic lesion of the left medullary pyramid which was accompanied by hypertrophy of the left inferior olivary nucleus. An additional lesion, demyelination of the right gracile tract, is poorly explained. This case represents the second reported instance of pure motor hemiplegia due to a circumscribed lesion in the medullary pyramid and possibly an unique instance of olivary hypertrophy without obvious damage to the central tegmental tract, ipsilateral superior cerebellar peduncle, or contralateral dentate nucleus. The olivary hypertrophy is thought to have arisen from local damage to the termination of the central tegmental fibres at the left inferior olivary nucleus. The question of the development of spasticity in a pure pyramidal tract lesion is discussed.

Hemiplegia↗
PubMedDate not supplied

Four-arm radial open maze (FAROM) as a tool for assessing the effect of atropine in spatial memory of the rats.

Place learning behaviour for working (short term) memory and reference (long term) memory is studied with the Four-arm radial open maze (FAROM) in 18 rats divided equally in three groups. In group I, 0.5 mg of atropine was injected intra-peritoneally 30 minutes before the trial. In group II, saline and in group III Glycopyrrolate were injected instead. Twenty three hours hungry animals were tested on each day in the maze to search for food kept in one of the eight cul-de-sacs of maze. The latency i.e. the time to reach the goal cul-de-sacs, as well as the error score i.e. the number of entries in the non-goal cul-de-sacs were counted during six consecutive trials, per day. Each trial duration was 5 minutes or the time taken by the animal to search the goal compartment whichever was less. The inter-trials period was 10 min and the work was carried out for a period of 3 weeks. The results show that atropine does block effectively both the memory faculties i.e. working and reference memory and that level of memory deficit induced by atropine is related to the rate of drug uptake by the central cholinergic receptors.

Animals↗