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Biomedical subjects

E Cuadrado

Publications and source records attributed to E Cuadrado.

At least 19 recordsLinked to original sources
PubMed1995

DNA staining changes associated with apoptosis and necrosis in blood lymphocytes of individuals with HIV infection.

We used flow cytometry to quantitate cells that die by apoptosis or necrosis. The method uses low concentrations of two DNA binding dyes that allow one to establish selective regions for live, apoptotic, and necrotic cells in a rat thymocytes model. Quantitative analysis of blood lymphocyte death in individuals with HIV infection by this technique shows the presence of nonviable cells that exhibit a spectrum of changes in staining by DNA binding dyes. These changes range from typical features of cells undergoing programmed cell death or apoptosis to changes observed in cells that die by accidental death or necrosis. The proportion of cells exhibiting these lethal changes increases significantly in patients who progress to AIDS, but, although cells with staining features associated with apoptosis and necrosis were both found to be increased in in vitro-activated cells from AIDS patients, spontaneous in vivo activation preferentially leads to apoptotic changes without a significant increase of cells exhibiting the staining changes associated with necrosis.

Animals↗
PubMed1995

The contribution of the HLA-A, -B, -C and -DR, -DQ DNA typing to the study of the origins of Spaniards and Basques.

The high polymorphism of the HLA system has been used as a powerful genetic tool to single out individuals and populations. By studying characteristic allele frequencies and extended HLA haplotypes in different populations, it is possible to identify ethnic groups and establish the genetic relationships among them. In the present study, HLA-A, -B, -C, -DR and -DQ typing at the serological/antigenic and the DNA level has been used for the first time to assign specific HLA frequencies and haplotypes to Spaniards and Basques and compare them with frequencies in other populations, particularly with North Africans. Allelic frequencies do not significantly differ between Spaniards and Basques. HLA genetic distances and their respective dendrogram together with the results on complete HLA haplotypes place Basques and Spaniards closer to paleo-North African populations than to other Europeans. This goes in favour of the Basques being a relative genetic isolate coming from the primitive Iberian/paleo-North African people. In addition, a tentative assignment of the most common Spanish HLA haplotypes to the different people who populated Iberia according to historical records has been done.

Alleles↗
PubMed1994

An immunogenetic study of familial scleroderma.

OBJECTIVE: To study the role of the HLA system in the genetic susceptibility to familial systemic sclerosis (SSc). METHODS: HLA class I antigens were determined by classic serological methods and HLA-DRB, -DQA and -DQB genes were analysed by genetic typing in 36 individuals belonging to two families with several individuals affected by SSc. RESULTS: The results did not show any association of the inheritance to SSc with any particular HLA allele in these families but revealed a striking frequency of ANA autoantibodies in healthy spouses of the members of these families. CONCLUSION: The otherwise infrequent familial incidence of SSc does not appear to be primarily linked to the HLA system in this study but it is suggested that other unknown exogenous environmental factors could be implicated in the development of the disease in families.

Adolescent↗
PubMed1993

CD8+CD38+ and CD8+DR+ peripheral blood lymphoid subsets of HIV-infected intravenous drug abusers correlate with CD4+ cell counts and proliferation to mitogens.

Twenty-nine intravenous drug abusers (ivda), with asymptomatic HIV infection at entry, were sequentially studied at 4- to 6-month intervals for variable follow-up periods (mean, 19.6 months). Two of them progressed to AIDS and another one fell into the IV-C2 stage of the CDC classification at the end of the study. CD8+ lymphoid subsets (CD57+, CD38+, and HLA-DR+) were sequentially analyzed in peripheral blood samples along the follow-up. Both absolute number and percentage of cells within these subsets were found significantly increased over those observed in normal controls. Minor changes were appreciated throughout the follow-up. CD8+CD38+ and CD8+DR+ cells increased slightly (P < 0.05), but the CD8+CD57+ subset did not change significantly. In order to determine whether abnormalities in these subsets are associated with immune dysfunction, we looked for correlation between the quantification of CD8+ subpopulations and other parameters of cellular immunity. Percentage of CD8+CD38+ or CD8+DR+ cells inversely correlates with absolute number of CD4+ cells (P < 0.0001), and percentage of CD38+ subset also correlates with the proliferative response to mitogens in lymphoid cultures. Thus, the enumeration of these populations of CD8+ cells may provide some additional information about the immune status of HIV-infected ivda.

ADP-ribosyl Cyclase↗
PubMed1993

Quantification of chicken alpha-fetoprotein: a useful tool in studies of embryo development and pathology.

Chicken alpha-fetoprotein (AFP) from the plasma of 12-day-old chick embryos was purified by electroelution from SDS/PAGE gels, and used to produce polyclonal and monoclonal antibodies. Both reagents were then used to design a sandwich-type enzyme-immunoassay for the quantification of AFP in biological fluids. The assay was used to quantify AFP in the serum and amniotic fluid of chick embryos with abnormalities of the neural tube. Serum AFP was significantly greater in these embryos than in normal ones of similar age. Moreover, substantial amounts of AFP were demonstrated in the amniotic fluid, whereas this protein was undetectable in the amniotic fluid of normal embryos. This method of assay may provide a reliable tool for studies of chick embryogenesis and abnormalities of embryonal differentiation.

Animals↗
PubMed1993

Imbalance of the CD4+ subpopulations expressing CD45RA and CD29 antigens in the peripheral blood of adults and children with Down syndrome.

Peripheral blood lymphoid subsets expressing either CD45RA or CD29 antigens, were quantified in 30 children and 59 adults with Down Syndrome and appropriate age-matched controls, by dual immunofluorescence and flow cytometry. Down's patients, both adults and children, displayed a significant decrease of CD4+CD45RA+ cells in comparison with the observed in their age-matched controls, but no difference was found in the CD4+CD29+ subset. These results show clearly the imbalance of these subpopulations in the peripheral blood of individuals with Down syndrome that result in the inversion of the CD45RA/CD29 ratio, due to a major reduction of the CD45RA subset. No obvious difference was found in the CD45RA/CD29 ratio within the CD4 negative cells. Abnormalities of these subpopulations could be indicative of early senescence of the immune system, since age-related changes in Down's persons were in parallel with those observed in normal individuals and the proportion of both subpopulations were roughly similar in Down's children and normal adults.

Adolescent↗
PubMed1993

[Amniotic and serum alphafetoprotein in the chick embryo with neural tube defect].

Although alpha-feto-protein (AFP) is a widely used marker for human neural tube defects (NTD) little is known about the mechanisms for its increase in the amniotic fluid in this condition. For investigating this issue we developed a chick embryo AFP assay and tested it in a NTD experimental model. AFP obtained by electroelution on PAGE/SDS gels from the plasma of 12-day-old embryos was used to produce rabbit polyclonal and mouse monoclonal antibodies. A specific sandwich-type enzyme-immune-assay was developed using both reagents. Sterile aspiration of 5 ml. of albumen from 602 fertile hen eggs on the 27th hour of incubation (Hamburger stages 8 to 11) led to the appearance of NTD in 36 out of the 270 survivors (13%). Amniotic and seric AFP levels were measured on the 15th day of incubation in NTD chicks (n = 11) and in control ones (n = 9) and the results were compared by non-parametric tests. Serum AFP was five times higher in NTD chicks than in controls (119.2 +/- 32.6 vs 523.3 +/- 173.62 micrograms/ml., p < 0.001) and amniotic AFP was absent in control and very increased in NTD animals (0.15 +/- 0.02 vs 87.14 +/- 84 micrograms/ml., p < 0.001). It is concluded that: 1) serum AFP is intriguingly increased in the chick with NTD; 2) since urine is not diversed into the amniotic sac in the avian embryo, the only source of AFP in its fluid is exudation through an open defect. This conclusion is further supported by the absence of amniotic AFP in a chick with a large closed NTD.

Amniotic Fluid↗
PubMed1993

[The defense against infection in the short bowel syndrome].

The high risk of infection in the short-bowel syndrome (SBS) may be due to malnutrition, lost of lymphoid bowel structures or both. Total parenteral nutrition (TPN) may alleviate the malnutrition, but we do not know what will happen with immune response in SBS with good nutritional state. We have studied the cellular immunity (lymphocytic subsets T4 and T8 and T4/T8 ratio) and the humoral one (IgG, IgM, IgA and B lymphocytes) in blood, spleen and mesenteric lymph nodes, in 12 wistar rats with 80% bowel resection, 6 of them with oral feeding and 6 with TPN, and 6 control rats, during 7 days. The weight increased and the total protein, albumin and prealbumin levels were the same in all groups. There was not difference between the resected groups. No difference was observed in the rate of immunoglobulins and the resected groups showed significatively lower figures than the control group in T4, B lymphocytes and T4/T8 ratio in blood, T4 and T8 in mesenteric nodes and in T4 and T4/T8 ratio in the spleen. These results suggest that the resection of large amounts of bowel could produce a fall in the immune response even when adequate nutritional state is preserved.

Animals↗
PubMed1992

Differential expression of lymphocyte function-associated antigen (LFA-1) on peripheral blood leucocytes from individuals with Down's syndrome.

We analysed the expression of lymphocyte function-associated antigen LFA-1 on the cell surface of peripheral blood lymphocytes, monocytes and granulocytes from 20 children with Down's syndrome. No differences in LFA-1 expression was found within monocytes or granulocytes from either normal or Down's syndrome children; however, a clear-cut difference was observed on lymphoid cells. Both normal and Down's syndrome lymphocytes displayed a bimodal pattern of LFA-1 staining by flow cytometry, with a predominance of cells with low expression in normal population, and an increased proportion of lymphocytes with high level of LFA-1 expression in Down's syndrome children. This difference correlates well with the abnormal proportion of T cell subsets and inversion of CD4/CD8 observed in a majority of our cases, and therefore, it could merely reflect the increase of certain T cell subsets normally expressing higher number of LFA-1 molecules. Taken together, our results do not support an abnormally increased expression of leucocytes integrins in trisomy 21 cells, and raise some doubt about the suggested role of the abnormal cellular expression of LFA-1 in the pathogensis of secondary immunodeficiency associated to Down's syndrome.

Antigens, CD↗
PubMed1992

[Prognostic factors in HIV-infected heroin addicts: a multivariate analysis of nonspecific serological factors in the evolution of the infection].

We present a prognostic analysis of the quantifying of serum levels of beta 2 microglobulin, neopterina, IL-2 soluble receptor and three major classes of immunoglobulins, in a group of 68 heroin-addicts infected by the human immune deficiency virus, type I, clinically assessed for a period of at least three years. High levels of any of these unspecific serologic factors were correlated with the illness progression. Survival curves were generated with the categorized variables, showed a significant decrease on the time interval prior to the diagnosis of AIDS, in the patients with these variables assigned on the higher groups, being neopterine and IgA the more predictive factors when the Cox proportional regression model is applied. We conclude that the quantifying of these unspecific serum factors provides a useful information regarding the clinical evolution of heroin-addicts with HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1988

T-antigen. A prognostic indicator of high recurrence index in transitional carcinoma of the bladder.

Forty biopsies from 36 patients with bladder tumors were tested for T-antigen (TAg) expression on tumor cells on sections untreated or treated with neuraminidase; a 37.5% of tumors showed abnormal expression of TAg either as an aberrant expression, or absence of this antigen after removing sialic acid. These changes were not well correlated with histologic signs of anaplasia or infiltration, nor with other biologic properties of tumor cells such as the expression of blood group antigens (ABH). However, a practical utility of TAg in the study of bladder tumors, is suggested by the analysis of those biopsies with low-grade low-stage tumors, on which the abnormal expression of TAg was more discriminatory than the ABH changes in defining those patients suffering tumors with a particular aggressiveness. Circulating antibody titer was also investigated in 20 patients but all of them displayed titers in the normal range, with independence of the results observed in their corresponding bladder biopsies.

Antigens, Viral, Tumor↗
PubMed1986

Blood group isoantigens ABO (H) in transitional carcinoma of the bladder: a clinicopathological study.

Blood group A, B and H antigens were investigated in 183 paraffin embedded biopsies from 58 patients with transitional cell carcinoma of the urinary bladder, by a modified specific red cell adherence test, direct immunofluorescence with Ulex Europeus lectin and indirect immunoperoxidase method with monoclonal antibodies against blood group antigens. The results were correlated with pathological grade and stage and with the clinical course of patients evaluating the recurrence index and clinical state. Histological findings were roughly correlated with the expression of red cell tissue antigens but not with the presence of precursor H substance in biopsies from patients of blood group A or B, in which a higher proportion of H positive results was appreciated. The clinical course was also related to the presence or absence of blood group antigens in referential biopsies: 90 per cent of negative biopsies corresponded to patients who had high recurrence index whereas 75 per cent of positive biopsies corresponded to patients who had low recurrence index or did not have recurrence for five years; 25 per cent of recurrences observed in patients with referential positive biopsy were invasive whereas the proportion of invasive tumor in recurrence from negative biopsies rises to 73 per cent. In addition, all the final biopsies from patients who died of bladder tumor were negative for blood group antigens. The diagnostic and prognostic significance of these tissue antigens in transitional cell carcinoma of the urinary bladder is discussed, and we conclude that the analysis of blood group antigens in bladder biopsies by established techniques is a useful tool in clinical pathology for the screening and followup of bladder tumors, as previously suggested.

ABO Blood-Group System↗