Correlations between Oxidative DNA Damage, Oxidative Stress and Coenzyme Q10 in Patients with Coronary Artery Disease

The correlation of coronary artery disease (CAD) with pro-oxidant/antioxidant balance and oxidative DNA damage was investigated.Seventy-seven patients with CAD and 44 healthy individuals as control were included in this study. The comparative ratios of ubiquinol-10/ubiquinone-10, 8-hydroxy-2^''-deoxyguanosine/deoxyguanosine and the level of MDA measured by HPLC and the activities of GPX and SOD by colorimetric approach in blood samples obtained from patients with CAD were unraveled.8-OHdG/dG ratios, serum MDA level and GPX activity were found significantly elevated level in serum of CAD patients compared to control group. The SOD activity was observed in stable levels in CAD patients. Ubiquinol-10/ubiquinone-10 ratio was significantly lower in patients with CAD than the controls.The positive correlation was observed between 8-OHdG/dG ratios in both MDA levels and GPX activity, while the significant negative correlation was seemed between the ratio of 8-OHdG/dG and ubiquinol-10/ ubiquinone-10 as well as MDA levels and ubiquinol-10/ ubiquinone-10 ratio.We conclude that, both the disruption of pro-oxidant/antioxidant balance and oxidative stress in DNA may play an important role in the pathogenesis of coronary artery disease.     

Rheologic predictors of the severity of the painful sickle cell crisis

Deformable sickle erythrocytes have been reported by Mohandas and Evans to be more adherent to vascular endothelium than rigid irreversibly sickled cells (ISC). To define the clinical implications of this finding we have determined genetic, hematological, clinical, and rheological characteristics of sickle erythrocytes obtained from 65 patients with sickle cell anemia and fetal hemoglobin (Hb F) levels less than 15%. The alpha-globin gene number had a significant effect on the hematological parameters, the percentage of dense cells, ISC number, and HB A2 levels. The presence or absence of alpha thalassemia, however, had no effect on the frequency and severity of the sickle cell painful crisis (r = 0.06, P greater than .05). RBC deformability, determined by an ektacytometer, showed great heterogeneity among patients with three or four alpha-globin genes. Linear regression analyses of the data showed significant positive correlation of the frequency and severity of the painful crisis with RBC deformability (r = 0.49, P less than .001), and negative correlations with the percentage of dense cells (r = -0.37, P = .002), and the percentage of ISC (r = -0.46, P less than .001). We propose that the more deformable the sickle RBC are, the greater their adherence to vascular endothelium, and the more they cause vaso-occlusive crises, RBC deformability and the percentage of dense cells (or ISC) seem to have a predictive value of the frequency and severity of painful crises in sickle cell anemia.     

Beta 2-integrin and L-selectin are obligatory receptors in neutrophil aggregation [see comments]

We have recently found that antibodies to L-selectin, the homing receptor on neutrophils, are as effective as those to beta 2-integrin at blocking formyl peptide-stimulated aggregation. Therefore, we investigated the requirements for expression of L-selectin and beta 2- integrin on adjacent cells during aggregation. Fluorescence flow cytometry allowed characterization of aggregates on the basis of size and color, as well as antibody binding to these two adhesive molecules. Formyl peptide-stimulated aggregate formation was measured for individual populations fluorescently labeled red (LDS-751) or green (CD44-FITC), and interpopulation red-green cell conjugates. Blocking either the beta 2-integrin or L-selectin adhesive epitope with monoclonal antibody on individual cell populations resulted in an approximately 50% reduction in two-color aggregation as compared with that in unblocked samples. Shedding the L-selectin on a cell population by preincubation with complexes of lipopolysaccharide and its plasma membrane binding protein also decreased aggregation to a control population by approximately 50%. We examined the aggregation of neutrophils from patients genetically deficient in beta 2-integrin and clinically leukocyte adhesion deficient (LAD). LAD adhesion to normal neutrophils was dependent on the expression of L-selectin on LAD cells and beta 2-integrin on normal cells. Thus, the minimum requirement for adhesion between two mixed populations of neutrophils was that one population expressed the beta 2-integrin and the other expressed the L- selectin adhesive epitope.     

Monocytoid B-cell lymphoma: its evolution and relationship to other low- grade B-cell neoplasms

Monocytoid B-cell lymphoma (MBCL) is a newly recognized B-cell neoplasm of uncertain histogenesis. The cytologic features of the neoplastic monocytoid B lymphocytes are virtually identical to those of hairy cell leukemia (HCL). As with HCL, progression of MBCL to a higher histologic grade is very unusual. However, whereas circulating leukemic cells are a characteristic feature of HCL, peripheral blood involvement has not been reported in MBCL. We recently studied a patient with MBCL of the spleen and axillary lymph nodes who developed peripheral blood involvement by MBCL cells. Unlike the cells of HCL, the circulating MBCL cells exhibited strong acid phosphatase activity that was tartrate sensitive. The leukemic cells had the antigenic phenotype IgM lambda, CD20+, CD11c+, CD5-, CD25(TAC)-, and PCA-1-. Immunogenetic studies of both lymph node and peripheral blood cells revealed identical immunoglobulin heavy-chain gene rearrangements. When compared with a series of HCL, the immunophenotype was similar except for the absence of PCA-1 and TAC. Progression of the MBCL to a large cell lymphoma, also expressing IgM lambda, was documented in an abdominal lymph node of this patient. Therefore, although rare, peripheral blood involvement by lymphoma cells may occur during the course of MBCL and should be distinguished from HCL with cytochemical and immunophenotypic studies. In addition, comparison of the clinical, pathologic, and immunologic features of MBCL with those of other low-grade B-cell neoplasms suggests that a close lineage relationship exists between MBCL and HCL.     

Partial purification, characterization, and assay of a slightly acidic insulin-like peptide (ILAs) from human plasma.

An insulin radioreceptor assay (RRA) using human placental microsomal membranes was used to measure insulin-like activity (ILA) extracted from human plasma concentrates (Cohn fraction IV-4) by acid ethanol. The soluble activity (ILAs), chromatographed on Sephadex G-75 in 1 M acetic acid, migrated as a small molecule (fractional elution volume, 0.56) ahead of insulin (fractional elution volume, 0.70), whereas at neutral pH, ILAs migrated as a large molecular weight species. The ILAs peak from acid gel filtration on Sephadex was further purified by chromatography on carboxymethyl cellulose (CMC). The ILAs peak from both Sephadex and CMC diluted parallel to the porcine insulin standard in the insulin RRA and was totally unreactive in an insulin RIA. The CMC-purified material was iodinated and purified by binding to and elution from human placental membranes. The binding of [125I]ILAs to human placental membranes was inhibited only minimally by insulin and proinsulin and not at all by epidermal growth factor, nerve growth factor, glucagon, or lactogenic hormones, including human growth hormone. Multiplication-stimulating activity (MSA) inhibited in a manner parallel to ILAs. A Scatchard plot of the binding data was nonlinear. Sephadex ILAs was subjected to isoelectric focusing. The fractions assayed in both insulin and ILAs RRAs yielded comparable results. Peaks of ILA were observed at pHs 5.3, 6.6, and 8.4. When CMC-ILA was subjected to isoelectric focusing in polyacrylamide, a single peak of activity migrating between pH 6.2-6.8 was seen. [125I]ILAs focused at exactly the same pH. Electrophoresis of CMC-ILAs in acid-urea revealed a sharp peak of activity migrating with one of the five protein bands seen after staining. Again, [125I]ILAs comigrated with unlabeled ILAs. The molecular weight of ILAs, as determined on a calibrated Sephadex G-150 column at neutral pH, was 9,000-10,000 daltons. CMC-ILAs stimulated [14C]glucose incorporation into triglycerides of rat adipose tissue and augmented [3H]thymidine incorporation into human fibroblasts, chicken embryo fibroblasts, and BALB 3T3 cells as well as [35S]sulfate incorporation into macromolecules of rabbit chondrocyte culture medium. In summary, ILAs isolated on the basis of a RRA for insulin is a slightly acidic peptide with some of the biological activities expected of a somatomedin.     

No evidence for a defect in growth hormone binding to liver membranes in thalassemia major

To test the hypothesis of a defect in GH-receptor interaction, which could explain the growth failure of thalassemic children, the binding of [125I]human (h) GH to membrane fractions prepared from liver biopsies was studied. Small amounts of liver were obtained from 6 girls and 11 boys with homozygous beta-thalassemia, aged 3-15 yr, all prepubertal, at the time of splenectomy. Specific binding of [125I]hGH ranged from 0.37-5.11% of the added radioactivity/100 micrograms liver membrane protein, with variations in both receptor number and binding affinity. This 14-fold variation in hGH binding to liver membranes of thalassemic children was comparable to that in membrane fractions of livers obtained from normal donors at the time of liver transplant. The binding of insulin to liver membranes from the thalassemic patients ranged from 9.8-17.9% of the added radioactivity/100 micrograms membrane protein and from 2.8-15.0%/100 micrograms membrane protein in the normal donors. Insulin and GH binding to liver membranes did not vary in a consistent way. A 3-fold difference was found in 5'-nucleotidase activity of the membrane fractions. Histological hepatic modifications were assessed with respect to siderosis and fibrosis. No correlation was found between these parameters and GH binding. These results suggest that possible membrane alterations are not the only reason for the variations in hGH binding. All patients had retarded growth, and all but 2 had low plasma insulin-like growth factor I levels. No relationship was found between the level of GH binding to liver membranes and the growth failure. Thus, a defect in GH binding to liver membranes is probably not the cause of the growth retardation of thalassemic children.     

Familial cystic parathyroid adenomatosis

Although the commonest familial form of primary hyperparathyroidism is parathyroid hyperplasia, a few families have manifested parathyroid adenomas. We describe a family in which four members developed cystic parathyroid adenomas. Although calcium levels returned to normal after resection of the adenoma, a second adenoma would often develop several years later (we have termed this temporal sequence adenomatosis). Each adenoma had a cystic histologic appearance, and three of four normal-sized parathyroid glands also contained many cysts. No other endocrine tumors have appeared, but in three patients the hyperparathyroidism was complicated by fibrous maxillary or mandibular tumors that resembled ossifying fibromas rather than the brown tumors generally found in patients with hyperparathyroidism. Each patient with an adenoma was hypercalciuric, but two were obligate carriers of hypocalciuric hypercalcemia. This familial occurrence of the rare cystic parathyroid adenoma suggests the presence of a distinct hereditary syndrome. The genetic basis may be the simultaneous inheritance of familial hypocalciuric hypercalcemia and another trait that may increase the urinary excretion of calcium.