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Biomedical subjects

S Martínez-Cairo

Publications and source records attributed to S Martínez-Cairo.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of a cytotoxic CD57+ T cell subset from patients with pulmonary tuberculosis.

We investigated the proportion, phenotype, and cytotoxicity of CD8+CD57+ and CD57- T cells in peripheral blood from 20 tuberculosis (TB)-patients and 20 healthy tuberculin skin test-positive donors. Our results showed an increase in CD8+CD57+ T cells from TB-patients as compared with those from age-matched healthy donors (p<0.0001). CD8+CD57+ T cells from TB-patients expressed CD69, perforin, granzyme-A, and a CD28-CD62L-CD161- phenotype without recognition for the alpha-galactosylceramide-CD1d complex. This cell subset also expressed TNF-alpha and IFN-gamma, under phorbol-myristate-acetate/ionomycin stimulation. Interestingly, the cytotoxicity against autologous monocytes was higher in CD57- cells from TB-patients and donors than their CD57+ counterparts, in the presence of Mycobacterium tuberculosis H37Rv culture filtrate. However, only CD8+CD57+ T cells from TB-patients exhibited spontaneous cytotoxicity against monocytes in the absence of antigen. Our results suggest that CD8+CD57+ T cells are a subset of effector cells that could be helpful to evaluate the cell-mediated immune response to M. tuberculosis.

Adult↗
PubMed2001

Chemical characterization of the lectin from Amaranthus leucocarpus syn. hypocondriacus by 2-D proteome analysis.

In this work, we characterized chemically the N-acetyl-D-galactosamine specific lectin from Amaranthus leucocarpus syn hypocondriacus lectin (ALL). It is a dimeric glycoprotein composed by three isoforms with pl at 4.8, 4.9, and 5.2. Circular dichroism analysis indicated that the secondary structure of ALL contains 45% of \bibeta-sheet and 5% of \bialpha-helix. Amino acid sequence of the purified lectin and its isoforms was determined from peptides obtained after trypsin digestion by MALDI-TOF (Matrix assisted laser desorption ionization-time of flight). The tryptic peptides prepared from the purified lectin and the three isoforms showed different degrees (80 to 83%) of identity with the amino acid sequence belonging to a previously described high nutritional value protein from A. hypocondriacus not shown at the time to be a lectin. Furthermore, analysis of tryptic peptides obtained from ALL previously treated with peptide N-glycosidase, revealed a 93% identity with the aforementioned protein. Presence of N-glycosidically linked glycans of the oligomannosidic type and, in minor proportion, of the N-acetyllactosaminic type glycans was determined by affinity chromatography on immobilized Con A.

Amaranthus↗
PubMed2000

Identification of lectin isoforms in juvenile freshwater prawns Macrobrachium rosenbergii (DeMan, 1879).

From the serum of juvenile freshwater prawns, we isolated by affinity chromatography on glutaraldehyde-fixed rat erythrocytes stroma, immobilized in Sephadex G-25, a sialic acid specific lectin of 9.6 kDa per subunit. Comparative analysis against adult organisms purified lectin, by chromatofocusing, showed that the lectin from juvenile specimens is composed by four main isoforms with a pI of 4.2, 4.6, 5.1, and 5.6, whereas the lectin from adults is eluted at pH 4.2. The amino acid composition of the lectin obtained from adult and juvenile stages suggest identity, but the compositions are not identical since a higher content of carbohydrates was found in the lectin from younger organisms. The freshwater prawn lectin showed specificity toward N-acetylated amino sugar residues such as GlcNAc, GalNAc, Neu5Ac and Neu5,9Ac; but in juvenile organisms the lectin showed three times less hemagglutinating activity than the lectin from adults. Both lectins agglutinated rat, rabbit and chicken erythrocytes, indicating that Neu5,9Ac in specific O-glycosydically linked glycans seems to be relevant for the interaction of M. rosenbergii lectins with their specific cellular receptor. Our results suggest that the physicochemical characteristics of the lectin from the freshwater prawn are regulated through maturation.

Agglutination Tests↗
PubMed1999

Relevance of sialoglycoconjugates in murine thymocytes during maturation and selection in the thymus.

Differentiation of most T lymphocytes is characterized not only by the variable expression of CD4/CD8 coreceptor molecules and increased surface density of the T cell antigen receptor, but also by changes in the glycosylation pattern of cell surface glycolipids or glycoproteins. In this work we evaluated the changes in the sialylation pattern in thymus sections from normal and dexamethasone treated mice. We used sialic acid specific lectins, such as Sambucus nigra agglutinin (SNA, NeuAcalpha2,6-Gal specific) and Maackia amurensis agglutinin (MAA, NeuAcalpha2,3-Gal specific). Our results indicate that the sialylation pattern was modified during the maturation process of thymic cells. The immature CD4-CD8- and CD4+CD8+ cortical thymocytes were recognized by SNA, whereas the mature single positive (CD4+ or CD8+) medullary cells, preferentially bound MAA lectin. However, in the corticomedullary region we found not only SNA+ cells, but also MAA+ cells. In the thymus of dexamethasone treated mice, the clusters of thymocytes undergoing apoptosis in the cortex were characteristically stained by SNA. These results suggest that in the initial stages of the differentiation pathway, a great number of thymocytes express an alpha2,6 linked sialic acid on their surface and as they progress to more mature stages there is a change in the sialylation pattern to alpha2,3 linked sialic acids probably due to a regulated expression of different sialyltransferases, which could be modulated by the thymic microenvironment.

Animals↗
PubMed1991

[Meta-analysis: an alternative method in clinical research].

Meta-analysis is a research method which allows for the grouping of results from different studies relating to the same topic. Its main objective is to increase the precision surrounding the original research problem and provide a possibility to answer to different questions. This method has been developed in the areas of physics and the social sciences and has been widely accepted within the medical field. Its main use in medicine is in relation to the evaluation of therapeutic measures, yet its application has extended to the evaluation of diagnostic tests, etiological and prognostic factors. In spite of its development, there are still persisting problems in research difficult to solve because of the heterogeneity of the grouped studies, the identification of the size of the relevant effect and of the application of the results in clinical practice. The growing use of this research method within the medical field calls for its comprehension, as well as the recognition of its advantages and limitations in order for its users to be capable of judging the validity of individual meta-analysis.

Meta-Analysis as Topic↗
PubMed1980

Effect of diphenylhydantoin in serum and secretory IgA concentrations.

Diphenylhydantoin (DFH) treatment for epileptic patients has shown adverse effects such as malignant lymphadenopathy, systemic lupus erithematosus, periarteritis nodosa and recently immunological alterations such as a decreased lymphocytic response to fitohemaglutinin and serum IgA concentration, therefore we thought DFH effect on secretory IgA would be an important finding. This phenomenon might imply a defect in resistance local mechanisms for infection. Two groups of patients were studied: a) 25 children with an established diagnosis of epilepsy, "grand mal" type, that received anticonvulsive treatment with DFH for six months and b) 25 children with a diagnosis of infectious meningoencephalitis that required DFH to control convulsive crisis. Patients with a history of recurrent infections, lymphadenopathies, hepatosplenomegaly, drug allergy, collagenopathies and immunodeficiency were ruled out from this study. In all patients T and B lymphocytes, serum IgA, saliva and duodenal fluid and IgA determinations were made. Results show IgA concentration decrease in saliva and duodenal fluid of epileptic and meningoencephalitic patients (p less than 0.05), as well as lymphocyte T depression in epileptic and non epileptic patients treated with DFH (p less than 0.001).

Adolescent↗
PubMed1980

PMN cell phagocytic function in malnourished patients with zinc uptake.

Zinc effects on phagocytic activity depend upon its serum concentration. According to certain experimental findings, a decrease in zinc serum concentration is parallel to a deficiency in host defense mechanisms and thus we were interested in studying the effect of zinc sulphate in the phagocytic function of polymorphonuclear cells of 15 zinc deficient patients with III degree malnourishment. In all patients, zinc serum determinations were made before and after zinc intake and chemotaxis, phagocytosis and NBT reduction tests were made at 7, 14 and 30 days. Results are compared with an eight patient group with similar clinical and nutritional characteristics observing an improvement in PMN cell phagocytic activity in patients with zinc uptake (p < 0.001). No differences were observed in a chemotaxic phagocytosis and NBT reduction tests in regard to the time during which patients did not receive zinc uptake.

Child, Preschool↗
PubMed1980

Usefulness of concentrated CSF hemagglutination technique for the diagnosis of cerebral cysticercosis.

Determinations were made in concentrated CSF immunoglobulins in two groups of patients with different neurological problems and in patients with surgically confirmed diagnosis of CNS cysticercosis. Antibody vs. cysticercus antigen determinations were also made in concentrated CNS by means of indirect hemagglutination as a procedure to establish CNS cysticercosis. Positive results were obtained in 68 per cent of surgically confirmed cysticercosis. This procedure seems to be more sensitive for CNS cysticercosis diagnosis.

Adolescent↗
PubMed1979

[Coproantibodies in intestinal amebiasis].

E. histolytica tissue invasion induces IgG and IgM and probably IgA serum antibody formation of different types in the intestinal mucosa. 21 children with intestinal invasive amebiasis were studied. Samples were taken from peripheral blood and stools during diagnostic studies and three weeks later. Contraimmunoelectrophoretic antibody determinations and indirect hemagglutination tests IH were made in an attempt to demonstrate its true nature. During the acute phase (first sample), results showed antibodies against amoeba in stools by CIE in 57 per cent and by IH in 80 per cent; in serum, results were 38 and 76 per cent respectively. In the second sample and three weeks after diagnosis was established a decrease in the number of patients with coproantibodies against amoeba was observed and the number of patients with serum antibodies increased. We are also providing evidence that supports the IgG and IgA nature of coproantibodies against amoeba. These results suggest the presence of a local immunological reaction in invasive amebiasis.

Antibodies↗
PubMed1978

Indirect hemagglutination with PPD in cerebrospinal fluid for the tuberculous meningoencephalitis.

Reliability of indirect hemagglutination test was evaluated with PPD in CSF for the diagnosis and prognosis of tuberculous meningoencephalitis. The test was positive 100 percent in 22 patients with this disease and negative in 53 patients from the control group (p = 0.001) with viral or pyogenic infection in the CNS. No correlation was observed between antibody titers and the prognosis of the disease. Modifications of the original technique are described.

Cerebrospinal Fluid↗
PubMedDate not supplied

Amaranthus leucocarpus lectin recognizes human naive T cell subpopulations.

Amaranthus leucocarpus lectin (ALL) is specific for GalNAc residue found in the inner core of Gal beta 1,3GalNAc alpha 1,O-Ser/Thr disaccharide (T-antigen) or GalNAc alpha 1,O-Ser/Thr (Tn-antigen). Flow cytometric analysis using fluorescein-labeled lectin and monoclonal antibodies against human cell surface markers indicated that 5.7% of mononuclear cells from human healthy donors are recognized by ALL. These cells have the phenotype CD2+CD4+CD19- and most of the lymphocytes recognized are also CD27+, CD45RA+ and CD43+. ALL possesses mitogenic activity on lymphocytes after neuraminidase treatment. Our results indicate that the receptors recognized by ALL could be considered surface markers for naive human T lymphocyte subsets.

Flow Cytometry↗
PubMedDate not supplied

[Leukemia of plasma cells].

A case of plasma cell leukemia is reported, together with a review of the literature, including a summary of the signs, symptoms and laboratory findings usually present. The relationship of this leukemic state to ordinary multiple myeloma is discussed.

Autopsy↗
PubMedDate not supplied

[T and B lymphocytes in the peripheral blood of the in-utero malnourished new born infant].

The per centum distribution of T and B lymphocytes was determined in 30 full term newborns showing adequate development for their gestational age and in 42 full term newborns showing in utero malnutrition. A significant decrease (p less than 0.001) of both lymphocytic subpopulations was found in the in utero malnutrition group. The possibility of a decreased efficiency of the immune response in this group of patients is discussed.

B-Lymphocytes↗
PubMedDate not supplied

[Rosette-forming lymphocytes in the peripheral blood of normal children].

The study included 180 healthy children distributted into age groups from newborns to 16 years of age. The subpopulations of early E and EAC (T and B) rosette forming lymphocytes were determined. It was found that the main difference is placed in percentual mean values of the newborn where the value of T lymphocytes is less than for the rest of the ages studied, remaining stable beginning at the age of one year. In newborns, the values of B lymphocytes are greater; later, they drop but remain stable also since the age of one.

Adolescent↗
PubMedDate not supplied

[Concentration and activity of alpha-1-antitrypsin in neonatal hepatitis].

The concentration and activity of alpha 1-antitrypsin were studied in 20 children with the diagnosis of neonatal hepatitis. The concentration of alpha 1-AT was found normal or high in all of the patients (3.6 +/- 0.12 mg/ml). No case was found with PiZZ homozygote type alpha 1-AT deficiency. The activity of alpha l-AT was found decreased in 90% of the patients with neonatal hepatitis (control: 0.86 +/- 0.18 mg. trypsin inhibited by ml. of serum; neonatal hepatitis: 0.49 +/- 0.07 mg/ml.). The possibility that this may correspond to a disorder characteristic of neonatal hepatitis is mentioned.

Female↗
PubMedDate not supplied

[Rosette-forming peripheral lymphocytes, in children with measles].

During measles infection in human beings, depression of cellular immunity appears. The authors studied several groups of children with measles complaining of various degrees of malnutrition in terms of rosette forming lymphocytes in peripheral blood; marked reduction of T lymphocytes were seen in all of the groups during the acute stage of the disease, that persisted up to two weeks after the exanthematous stage. When comparison was established of eutrophic and 1st degree malnourished children with those affected with 3rd degree malnutrition, differences were found in the recovery of the number of rosett-E forming cells.

Child, Preschool↗
PubMedDate not supplied

[Study of the immune system in relatives of children with dermatomyositis].

In view of the fact that relatives of patient with other connective tissue diseases may show immunologic abnormalities, we investigated cellular (PPD, SK-SD, candidine and diphteria-tetanous toxoid cutaneous tests) and humoral (IgG, IgM, IgA. CH50, C3, rheumatoid factor and ANA) immune responses in first degrees relatives (parents and siblings) of children with dermatomyositis. Of the 53 subjects tested, 19 had high values of one or two immunoglobulines; however, the mean Ig value was not different from that of the general population (p greater than 0.1), CH50, C3, rheumatoid factor and ANA were normal or negative. Cutaneous tests made on 46 subjects did not reveal abnormalities. Therefore our conclusion is that first degree relatives of children with dermatomyositis have not significant immunologic abnormalities.

Adolescent↗