Prognostic implications of cytogenetic studies in an intensively treated group of children with acute lymphoblastic leukemia

We assessed the prognostic significance of leukemia cell cytogenetics by analyzing bone marrow aspirates obtained at time of diagnosis in 165 children on a single protocol for acute lymphoblastic leukemia (ALL). These children were assigned to six mutually exclusive cytogenetic categories as follows: (1) hyperdiploid, with 50 or more chromosomes (n = 35); (2) hyperdiploid, with 47 to 49 chromosomes (n = 11); (3) diploid (n = 42); (4) pseudodiploid (n = 34); (5) hypodiploid (n = 9); and (6) insufficient data (n = 34). At a median follow-up of 5 years, there were no statistically significant differences between any of these cytogenetic categories in either event-free or overall survival. Those children with chromosomal translocations (n = 26) appeared to fare the same as those lacking translocations (n = 105). The absence of karyotypic prognostic significance was observed not only within the overall group, but also when the results were stratified by standard- risk and high-risk status. Of the specific structural chromosome changes that we studied, only the Philadelphia chromosome (Ph) appeared to confer a poor prognosis, although there were too few such cases to achieve statistical significance. Although we did not detect the event- free survival differences that have been described previously in hyperdiploid, hypodiploid, and pseudodiploid childhood ALL, our findings must be viewed as preliminary given the small number of children in some of the cytogenetic categories. We think that the prognostic implications of these cytogenetic features might have been nullified by improvements in therapy.     

Immunologic characterization of a helper T-cell lymphoma

The lymphocytes of a patient with a T-cell non-Hodgkin's lymphoma with peripheral blood involvement and polyclonal hypergammaglobulinemia were characterized in terms of surface markers and immunologic functions. Using the fluorescence-activated cell sorter and employing various monoclonal antibodies against T-cell surface antigens, it was shown that almost all of the patient's peripheral blood lymphocytes were positive for OKT4 and 9.3, antibodies that recognize helper T-cell subset. The circulating lymphoma cells had typical characteristics for T cells; they formed spontaneous rosettes with sheep erythrocytes and stained with the pan-T-cell antibodies 9.6 and 10.2, but did not react with other anti-T-cell monoclonal reagents such as OKT3, UCHT-1, and 3A1. The cells appeared to be mature by the fact that they did not stain with OKT6, and terminal deoxynucleotidyl transferase was undetectable. Functionally, they were able to provide "help" for antibody production, and they could be stimulated to produce moderate amounts of interleukin-2, while unable to proliferate in response to mitogens. Morphologically, some of the lymphocytes showed a deeply cleaved nucleus.     

Mb1, a plasma membrane antigen selectively expressed by U-937 cells

To examine the plasma membrane characteristics of an immature monocytic cell capable of proliferation, we have developed a murine monoclonal antibody that identifies an antigen, Mb1, found on the surface of U- 937. In immunofluorescence analyses, Mb1 is not expressed by peripheral blood monocytes (freshly isolated, lymphokine-activated, or cultured for seven days), neutrophils, or any other circulating element. It is also absent on human bone marrow mononuclear cells, including the CFU- GM. Among a series of malignant cells from 50 patients with acute myeloid leukemia (including 22 with monocytic or myelomonocytic leukemia), no Mb1 expression was detected. Continuous human cell lines of B or T cell origin were also negative, as were the myeloid lines HL- 60 and K562. Apart from U-937, which uniformly expresses Mb1 in high antigen density, only KG-1 (a myeloblastic line) exhibits Mb1 in low antigen density. Exposure of U-937 to phorbol diester (TPA) under conditions that induce features of macrophage differentiation (including the expression of Mo1) results in a significant reduction in Mb1 expression. Mb1 expression is also reduced as a result of culture of U-937 in medium containing anti-Mb1 antibody (antigenic modulation). On sodium dodecyl sulfate-polyacrylamide gel electrophoresis of radiolabeled immunoprecipitates, Mb1 appears to be a dimeric protein with an estimated molecular weight of 80 kd (43 kd under reducing conditions). Antigenic activity on U-937 is destroyed by treatment with trypsin or papain but is regenerated after 24 hours' culture in enzyme- free medium. Mb1 is a constituent plasma membrane protein of U-937, and its degree of expression relates to the state of cellular differentiation.     

Evaluation of E-rosetting human lymphocytes with OKT11 and other monoclonal antibodies

Monoclonal antibody OKT11 was found to compete with sheep red blood cells for binding sites on human lymphocytes. Preincubation of lymphocytes with OKT11 eliminated E-rosette formation. In a study of 142 peripheral blood samples ranging from 1% to over 90% E-rosette- positive cells, comparison to the percent OKT11-positive cells yielded a correlation coefficient of 0.93. In normal donors, subsets of OKT11+ cells were identified using two-color immunofluorescent staining methods with OKT3, OKT4, and OKT8. On the average, approximately 13% of OKT11+ lymphocytes were OKT3- and 13% of OKT11+ lymphocytes were OKT4- and OKT8-. Based on our double antibody fluorescence intensity data, low antigen density OKT11+ lymphocytes were OKT3-. OKT4+ and OKT8+ lymphocytes in normal peripheral lymphocytes have similar OKT11 antigen density.     

Addition of candesartan to angiotensin converting enzyme inhibitor therapy in patients with chronic heart failure does not reduce levels of oxidative stress

BACKGROUND: Angiotensin II exerts a number of harmful effects in patients with chronic heart failure (CHF) and, through an increase in oxidative stress, is thought to be critical in the development of endothelial dysfunction. Angiotensin II may be elevated in CHF despite treatment with angiotensin converting enzyme (ACE) inhibitors, producing a rationale for adjunctive angiotensin receptor blockade. We investigated whether the addition of angiotensin antagonism to ACE inhibition would reduce oxidative stress and improve endothelial function and exercise tolerance in patients with chronic heart failure. METHODS AND RESULTS: Twenty-eight heart failure patients, who were on stable ACE inhibitor therapy, were randomised to receive adjunctive therapy with candesartan or placebo. Plasma lipid-derived free radicals, TBARS and neutrophil O2-generation, markers of oxidative stress, were measured in venous blood. Arterial endothelial function was assessed as the response of the brachial artery to flow-related shear stress. Exercise capacity was determined by cardiopulmonary exercise testing. Compared with placebo, candesartan had no effect on changes in lipid derived free radicals (-0.1+/-1.2 vs. -0.1+/-1.0 units, respectively, P=NS), TBARS (-2.2+/-1.1 vs. -2.6+/-2.2 micromol/l, respectively, P=NS) or neutrophil O2-generating capacity (-7.3+/-5.1 vs. -8.4+/-7.9 mV/5x10(5) neutrophils, respectively, P=NS). There was no effect on changes in brachial artery flow-mediated dilatation (0.5+/-1.0 vs. 0.8+/-1.3%, respectively, P=NS) nor peak VO2 (1.6+/-0.7 ml/kg per min vs. 1.8+/-0.6 ml/kg per min; P=NS). CONCLUSION: The addition of the candesartan to ACE inhibitor therapy had no effect on oxidative stress and did not improve endothelial function or exercise capacity in patients with CHF.     

Frequent somatic deletion of the 13q12.3 locus encompassing BRCA2 in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) has consistent 13q chromosomal abnormalities detected by conventional cytogenetics. Using interphase cytogenetics we show deletion of a 1-megabase 13q12.3 locus, encompassing the BRCA2 gene, in 80% of 35 CLL cases studied. Homozygous deletion of BRCA2, located within the minimal deletion consensus, was detected in a significant population of cells in 60% of the cases. Deletion of the previously described 13q14 locus (analyzed with RB1 and D13S25 probes) was seen in 63% of the cases. Homozygous deletion of RB1 was seen in one case. Seven of the cases (32%) with D13S25 deletion had a population of cells with homozygous deletion. Deletions at the 13q12 and 13q14 loci result from distinct events because they were not contiguous. These data provide evidence for the existence of a new tumor suppressor locus in B-cell CLL located at 13q12.3. BRCA2, located within the minimal deletion consensus, is a candidate for the gene whose somatic inactivation could play a role in the initiation and or progression of B-cell CLL.     

The impact of HIV-1 infection on child health in sub-Saharan Africa: the burden on the health services

HIV-I infection in sub-Saharan Africa is resulting in substantial child mortality and an increase in the number of sick children presenting to health services. Many of the sick children come to health centres and hospitals, inflating numbers on paediatric wards. The presentations of childhood HIV-I infection are many and varied so that HIV-I infection is the new ‘great imitator’ of other conditions. Some other infections are more severe in HIV-I infected children (specifically bacterial infections and measles). However, there is no clear evidence of consequent rises in the incidence of other childhood infections, though this is likely to be the case for tuberculosis. HIV-I infected children with other infections often respond to locally available anti-microbials, but may require longer courses. Treatment is problematic because of the impossibility of distinguishing infected from uninfected children and because of shortages of medicines, which are being intensified further by the child and adult HIV-I epidemics. Severe HIV disease in adult family members is adding to child morbidity and creating substantial orphanhood. Staff fear nosocomial infection, while simultaneously experiencing falling personal incomes and lacking resources to care for their patients. Substantial numbers of trained staff are being lost because of HIV-I caused disease and death. The reality of HIV-I infection through breast-feeding is not yet appreciated. When this becomes generally apparent, there is a risk that a lethal increase in bottle feeding could occur in some areas. Reduction in the number of new paediatric HIV-I infections in sub-Saharan Africa can be achieved only by ameliorating the adult HIV-I epidemic, reducing unnecessary blood transfusions and ensuring a safe blood supply.     

Fatal graft-versus-host disease in a patient with lymphoblastic leukemia following normal granulocyte transfusion

A woman with lymphoblastic lymphoma was treated with combination chemotherapy. She subsequently became febrile while granulocytopenic and was given unirradiated granulocyte transfusions from normal, unrelated donors. She recovered, but 12 days later noted the onset of progressive skin rash, hepatic dysfunction, diarrhea and pancytopenia and, 22 days after her last granulocyte transfusion, died of gram negative septicemia. Histologic examination of multiple tissues including the skin, liver, and intestinal tract showed changes characteristic of acute graft-versus-hose disease (GVHD). Y-chromatin analysis of the patient's peripheral blood just before death indicated the presence of male cells. HLA typing of lymphocytes and skin fibroblasts from the patient and lymphocytes from the family and granulocyte donors was also consistent with engraftment of cells from one of the male granulocyte donors. This donor most likely was homozygous for one of the patient's halotypes, perhaps facilitating engraftment of his cells and subsequent development of transfusion- induced acute GVHD. Until more precise guidelines can be established, we recommend that all cellular blood products given to patients receiving intensive chemotherapy be irradiated with 1500 rad.     

Esophageal resection for high-grade dysplasia and intramucosal carcinoma: When and how?

High-grade dysplasia (HGD) and intramucosal carcinoma (IMC) in the setting of Barrett’s esophagus have traditionally been treated with esophagectomy. However, with the advent of endoscopic mucosal resection and endoscopic ablative therapies, endoscopic therapy at centers with expertise is now an established treatment of Barrett’s-esophagus-related neoplasia, including HGD and IMC. Esophagectomy is today reserved for more selected cases with submucosal invasion, evidence for lymph node metastasis, or unsuccessful endoscopic therapy.