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Biomedical subjects

J C Voltarelli

Publications and source records attributed to J C Voltarelli.

At least 37 records · Page 2Linked to original sources
PubMed1991

HLA antigens in Brazilian patients with paracoccidioidomycosis.

Eighty patients with paracoccidioidomycosis were typed for 43 HLA specificities from loci A, B, C and DR. A highly significant increased frequency of HLA-B40 (relative risk 29.2) and HLA-Cw1 (relative risk 8.8) were found in patients compared to control subjects. The frequencies HLA-A2, B7 and B21 were also increased in patients and haplotypes-B40-Cw1 and -A2-B40 were positively correlated with the disease. DR antigen frequencies were not significantly altered in the patients and evidence of a protective effect was not found for any of the 43 antigens tested. These findings further support the involvement of the HLA system in the genetic susceptibility to paracoccidioidomycosis and the importance of ethnic variability in this association.

Adolescent↗
PubMed1990

In vitro comparison of two methods of T cell depletion associated with different rates of graft failure after allogeneic marrow transplantation.

Clinical trials in another center have shown a substantially lower risk of graft failure associated with T cell depletion by treatment of donor marrow with the use of an antibody against CD6 compared to depletion with a mixture of eight antibodies previously used for clinical trials in our center. In order to evaluate mechanisms possibly responsible for this difference, we compared lymphoid cell surface phenotypes and in vitro functions in marrow cells treated by complement-mediated lysis with anti-T12 (CD6) or with the eight antibody mixture. Treatment with the eight antibody mixture produced more than three log depletion of precursors for IL-2-producing cells (pIL-2) and approximately one log depletion of precursors for NK cells. On the other hand, treatment with anti-T12 produced approximately one log depletion of pIL-2 and had no effect on NK precursors. Additional studies were carried out with treated marrow cells cultured in medium containing recombinant IL-2. Compared to cells treated with the eight antibody mixture, the marrow cells that remained after anti-T12 treatment had more cytotoxic activity against K562, Daudi and an EBV-transformed human B cell line during the first 6 days of culture, but marrows treated by the two methods showed similar cytotoxic activity after 10 days of culture. Cultures from marrow treated with anti-T12 contained more CD3+ and CD6+ cells than cultures from marrow treated with the eight antibody mixture.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1990

Human spleen and peripheral blood lymphocytes activated by interleukin-2 have similar phenotypic and functional characteristics.

Phenotypic markers and cytotoxic function were monitored in cultures of normal human mononuclear cells obtained from peripheral blood or spleen and stimulated by recombinant interleukin-2 (IL-2; 1,500 U/ml). Fresh spleen cells contained less than 5% natural killer (NK) cells (CD3-NKH1+), which increased about threefold after activation with IL-2. In both spleen and peripheral blood cultures, T cells with the NKH1 marker showed the highest relative increment among all cell types studied. Lymphokine-activated killer (LAK) cells from peripheral blood and spleen displayed very similar cytotoxic activity against K562, Daudi, and COLO carcinoma cell lines. Killing of the three targets peaked at 7 days of culture. Antibody-dependent cell cytotoxicity against a B-cell line was mediated by both circulating and splenic LAK cells from 2 to 14 days of culture. Cell sorting experiments showed that K562 targets were killed by both CD5+NKH1+ and CD5-NKH1+ cells whereas Daudi targets are only killed by CD5-NKH1+ activated NK cells from both spleen and peripheral blood. In summary, human spleen LAK cells have similar phenotypic and functional properties to circulating LAK cells, and they may be used for adoptive immunotherapy of human cancer.

Antigens, Differentiation↗
PubMed1989

CD8+/DR+/CD25--T-lymphocytes associated with marrow graft failure.

Phenotypic and functional characteristics of peripheral blood mononuclear cells (PBMC) were studied in eight patients with poor graft function following HLA-identical T cell-depleted marrow transplantation. Similar patients with good graft function and normal individuals were used as controls. Freshly isolated PBMC from patients with failing grafts contained more CD3+ and CD8+ cells than PBMC from well engrafted patients. The CD8+ cells appeared activated insofar as they expressed DR antigens, but they did not express the low affinity IL-2 receptor recognized by Tac antibody (CD25) and they did not have increased cytolytic activities. After culture with phytohemagglutinin (PHA) and IL-2, PBMC from patients with poor graft function contained fewer CD2+ and CD4+ cells than cultured PBMC from patients with good graft function. Cultured cells from patients with poor graft function acquired lymphokine activated killer (LAK) activity against NK-sensitive and NK-insensitive targets, but still did not express CD25. Host-mediated anti-donor cytotoxic activity could be demonstrated in one patient only after presensitization with donor cells and culture with IL-2 and PHA. The abnormalities in T cell activation observed in patients with poor graft function did not correlate with the donor or host origin of lymphoid cells. These data indicate that some cases of graft failure may be associated with defective T cell maturation. These abnormalities may simply represent a consequence of marrow failure or they may actually contribute to failure by not providing critical hematopoietic accessory functions.

Antigens, CD↗
PubMed1987

Frequency of HLA antigens in a Brazilian type I diabetic population.

1. Sixty-five Brazilian, patients with type I, insulin-dependent diabetes mellitus (IDDM) and 100 unaffected individuals were typed for HLA-A, -B, -C and DR antigens. 2. A significantly higher frequency of HLA-A2 (48% of the patients versus 21% of the controls), B15 (20% of the controls), DR3 (57% of the patients versus 28% of the controls) and DR4 (54% of the patients versus 23% of the controls) was found for IDDM patients compared to the controls. 3. In contrast, DR2 (11% of the patients versus 31% of the controls) and DR7 (3% of the patients versus 21% of the controls) were lower in diabetics, but the difference was not significant. 4. The data reported here, when compared with those of other studies, emphasize the ethnic variability in HLA-IDDM associations.

Brazil↗
PubMed1986

Cherubism, gingival fibromatosis, epilepsy, and mental deficiency (Ramon syndrome) with juvenile rheumatoid arthritis.

This is a report on four persons in one family with a condition similar to that described by Ramon et al [Oral Surg 24:436-48, 1967] in two sibs born to a consanguineous couple. Our patients also had mental deficiency, epilepsy, cherubism due to fibrous dysplasia of the maxillae, gingival fibromatosis, hypertrichosis, and stunted growth. This appears to be an autosomal recessive trait in both families. Our patients are the second set reported with this syndrome; they also have juvenile rheumatoid arthritis, which was not described in the family reported by Ramon et al [Oral Surg 24:436-48, 1967]. We conclude that the Ramon syndrome should also include juvenile rheumatoid arthritis.

Arthritis, Juvenile↗
PubMed1986

Cell-mediated immunity in Brazilian hemophilia patients.

The purpose of this study was to correlate the immunological features of healthy hemophiliac A patients treated with commercial cryoprecipitates with those who received factor VIII concentrates associated or not with cryoprecipitates. The absolute number of total lymphocytes, T3, T4 and B lymphocytes did not differ for either group of patients or the controls. The number of T8 lymphocytes was higher in the group treated only with cryoprecipitates than for the controls. The T4/T8 lymphocyte ratios for both groups of patients were significantly lower than in the controls. This was due to a decrease in the percentage of T4 and increase of T8 lymphocytes. K cell activity was lower in both groups of patients than the controls. These results indicate that both cryoprecipitates and commercial factor VIII concentrate replacements had similar effects on the development of lymphocyte abnormalities.

Adolescent↗
PubMed1985

T-lymphocyte subpopulations in the peripheral blood and bone marrow of patients with aplastic anemia.

A decrease in the absolute number of total lymphocytes, OKT3+ and OKT4+ lymphocytes, and a normal number of OKT8+ lymphocytes were found in the peripheral blood of patients with aplastic anemia. The OKT4:OKT8 ratio was decreased in patients due to a reduction in the percentage of OKT4+ cells and 3 out of 18 patients had a ratio less than 1. The values of the OKT4:OKT8 ratio were not associated either with the severity of the disease or with treatment with androgens. There was no correlation between the OKT4:OKT8 ratio and the number of transfusions received by patients. On the other hand, studies performed with bone marrow lymphocytes showed that the OKT4:OKT8 ratio for both patients and controls was lower than that of the peripheral blood. Since the ratio of OKT4:OKT8 cells in aplastic and control bone marrow was similar no direct pathogenic role can be assigned to the marrow for the imbalance detected in the peripheral blood.

Adolescent↗
PubMed1985

Experimental nephropathy induced by human polyclonal light chains.

We describe the nephrotoxic effects of a preparation of light chains (LC) obtained by reduction and alkylation of human IgG. The acute renal lesions in rats are dependent upon the dose and route of LC administration. The kidney alterations were not observed in animals treated with comparable amounts of human albumin or the F(ab')2 fragment of human IgG. Intravenous bolus injection of 120 mg LC into 80-100 g hydropenic rats induced extensive cast formation in distal and collecting renal tubules, which were similar to the human "myeloma kidney". In contrast, the slow infusion of the same amount of LC over 1 h produced degenerative changes in the proximal tubular cells without extensive cast formation. The morphological alterations of the kidney were investigated by classical histological methods, by immunofluorescence and in thin sections stained with toluidine blue. Urinary excretion and kidney content of the lysosomal enzyme N-acetyl-beta-D-glucosaminidase were increased only in the group of animals infused with LC. These findings may be relevant to the pathogenesis of human nephropathy occurring in multiple myeloma and in some autoimmune diseases.

Acute Kidney Injury↗
PubMed1984

Antibody-dependent cellular cytotoxicity in some lymphoreticular diseases.

Antibody-dependent cellular cytotoxicity mediated by K cells against chicken erythrocytes was measured in 113 patients with malignant lymphoreticular disorders and compared with 230 controls. The results were expressed as the specific cytotoxicity of a fixed number of cells and also by cytotoxic capacity, which measures the number of cytolytic units in 1 ml of blood. The values for cytotoxic capacity were normal in the group of untreated patients with non-Hodgkin's lymphomas, multiple myeloma or chronic lymphocytic leukemia and in most of the patients with Hodgkin's disease or acute lymphoblastic leukemia. However, decreased specific cytotoxicity was observed in these same lymphoid leukemia patients, which may be due to dilution of effector cells. The effect of chemotherapy in reducing K-cell activity is more evident in patients with multiple myeloma, followed by patients with Hodgkin's disease, and finally by patients with non-Hodgkin's lymphomas. No case of K-cell neoplastic disease was observed in this series.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1984

T-cell subsets in patients with aplastic anemia.

Abnormalities of lymphocyte subpopulations have been described in patients with aplastic anemia. In the present report we extend these studies by measuring T cell subsets identified by the presence of Fc receptors for IgM (T mu-lymphocyte) and IgG (T gamma-lymphocyte) in 22 patients and in 48 normal controls. The absolute number of T mu and T gamma lymphocytes was normal in the majority of cases. The percentages of T mu cells was increased in 4 cases and decreased in 2; T gamma cells were increased in 6 patients. The levels of serum immunoglobulins did not correlate with the T mu/T gamma ratio. The pathogenesis of aplastic anemia is discussed in terms of these immunological abnormalities.

Adult↗
PubMed1983

Antibody-dependent cellular cytotoxicity in chronic human Chagas disease.

Antibody-dependent cellular cytotoxicity mediated by granulocytes (ADGC) or lymphocytes (ADLC) was assessed in 23 patients with chronic Chagas disease. The results of ADGC against T. cruzi were normal. ADLC against chicken erythrocytes was significantly reduced in patients as compared with normal controls. Possible causes of this abnormality were investigated.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1983

K-cell activity in aplastic anaemia.

K-cell activity was measured by specific cytotoxicity and cytotoxic capacity in 29 patients with aplastic anaemia. 9 patients had a reduction of the specific cytotoxicity and 12 had a decreased cytotoxic capacity. The decreased cytotoxic capacity correlates with the severity of aplastic anaemia. Some of the possible causes of the reduction of this activity were investigated.

Adolescent↗
PubMed1983

Some immunological studies in aplastic anaemia.

Peripheral blood studies in 29 patients with aplastic anaemia showed decrease in the mean numbers of total lymphocytes, T and B lymphocytes and monocytes. Quantitation of serum immunoglobulins carried out in 22 patients showed normal results in most cases. Although the significance of these immunological changes in the development of aplastic anaemia is not established they may represent a factor in addition to neutropenia in the pathogenesis of infections in this disease.

Adolescent↗