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Biomedical subjects

A Koren

Publications and source records attributed to A Koren.

68 records · Page 4Linked to original sources
PubMed1984

Serum immunoglobulin levels in children after splenectomy. A prospective study.

Serum immunoglobulin concentrations (IgG, IgA, and IgM) were measured in 34 children before and after splenectomy. Splenectomy was performed either after trauma or for an underlying hematologic disorder. In the patients with a hematologic disorder, we found a significant decrease in the IgM level after splenectomy. The IgM concentration remained low for a two-year period. Those patients who were "afebrile" during the study period had the lowest IgM levels. No significant changes were observed in the IgM levels in the group that underwent a splenectomy because of trauma. No significant changes were found in IgG or IgA levels in either group. A low IgM level in patients with hematologic disorders may have contributed to a defect in opsonization and to a high incidence of overwhelming infection soon after splenectomy in this group. In the group that underwent a splenectomy because of trauma, the normal IgM level may have protected them and contributed to the lower incidence of infection in this group.

Adolescent↗
PubMed1983

Uncommon sites of bone infarction in a sickle cell anemia patient.

Unusual sites of bone infarction, in the skull and sternum, were observed in a patient suffering from sickle cell anemia. A 99mTc-MDP scan was performed and demonstrated foci of decreased activity in the symptomatic regions. The differentiation of bone infarction from osteomyelitis in sickle cell anemia patients is illustrated.

Anemia, Sickle Cell↗
PubMed1983

Free radicals in tetanic activity of isolated skeletal muscle.

1. The concentration of the free radicals in muscle tissue mitochondria changes with the phase of muscle contraction. 2. Potassium cyanide (KCN) influences the shape of the isotonic tetani mechanograms; the contraction is still strong and qualitatively comparable in amplitude to untreated controls. 3. On the other hand, the correlation between the free radical concentration and muscle contraction is lost. 4. The free radical concentration in isolated mitochondria is influenced by KCN and potassium ferricyanide. 5. The free radical concentration changes due to the electron flow in the respiratory chain. 6. Inhibition of the respiratory phosphorylation by KCN could affect the free radical level.

Animals↗
PubMedDate not supplied

Venous thromboembolism, factor V Leiden, and methylenetetrahydrofolate reductase in a sickle cell anemia patient.

Vaso-occlusive crisis is the most common cause of morbidity in patients with sickle cell anemia (SCA). Central nervous system involvement that leads to hemiplegia is the most frequent neurological complication in those patients. Peripheral deep venous thromboembolism was not reported in SCA patients. Activated protein C resistance is associated with an increased risk of thrombophilia. The authors report an SCA patient with recurrent cerebrovascular accident and deep venous thrombosis. Activated protein C resistance due to factor V Leiden heterozygous and heterozygocity for the methylenetetrahydrofolate reductase were diagnosed and suspected to be the risk factors that contribute to the development of the deep vein thrombosis in this SCA patient.

Activated Protein C Resistance↗
PubMedDate not supplied

Effect of hydroxyurea in sickle cell anemia: a clinical trial in children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia.

This study evaluated the efficacy of hydroxyurea treatment in the prevention of vaso-occlusive crises among children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia. Nineteen children and young adults with severe sickle cell disease were enrolled to the hydroxyurea treatment trial. The incidence of vaso-occlusive crises, acute chest syndrome, hemolytic crises, splenic sequestration episodes, blood transfusions, and hospital days in the 2 years before hydroxyurea (HU) treatment were compared with the same parameters in the first 2 years of treatment. The patients received a mean dose of 21.3 mg/kg/day daily and were treated during a mean period of 40.3 +/- 14 months (range 20 to 68 months). Significant increases were observed after 1 month in the Hgb, MCV, MCH, and MCHC levels and were more notable after 3 months. The increase in the Hgb F level became important after 3 months of HU therapy and was highly significant (p < .001) beyond 6 months. No differences were observed in the RDW, reticulocyte count, Hgb S, and Hgb A2. Severe neutropenia was observed in one case. A decrease in the frequency of vaso-occlusive crises, acute chest syndrome, hemolytic crises, blood transfusions, and days spent in the hospital was demonstrated during the HU treatment period compared to the same period before. The clinical and laboratory response to HU was dramatic in severely affected sickle cell anemia (SCA) patients. The response to HU in children and teenagers with severe sickle cell anemia is similar to the response in adults, and no severe adverse effects were observed.

Adolescent↗
PubMedDate not supplied

Legg-Calvé-Perthes disease, protein C deficiency, and beta-thalassemia major: report of two cases.

Legg-Calvé-Perthes disease is an idiopathic osteonecrosis or avascular necrosis of the capital femoral epiphysis and the associated complications thereof occurring in an immature growing child. The association between osteonecrosis of the femoral head and thrombophilia was postulated by Glueck in 1994. We describe Legg-Calvé-Perthes disease associated with protein C deficiency and beta-thalassemia major in two children among a cohort of 79 beta-thalassemia patients treated in our clinic. The association of thrombophilia, aseptic necrosis of the femoral head, and beta-thalassemia has not been previously described in the literature.

Adolescent↗