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Biomedical subjects

D Hammond

Publications and source records attributed to D Hammond.

At least 127 records · Page 7Linked to original sources
PubMed1979

A follow-up report of long-term survivors of childhood acute lymphoblastic or undifferentiated leukemia. A report for Childrens Cancer Study Group.

From an original group of 229 patients with acute lymphoblastic leukemia or acute undifferentiated leukemia diagnosed in 1963 and 1964, 15 patients who achieved greater than 2 1/2 years continued complete remission were assigned either to continue with maintenance therapy or to discontinue therapy. Five of the 15 patients have died after surviving from six to ten years from the time of diagnosis. Of the remaining ten patients, all are alive and free of disease for more than 14 years from diagnosis. No relapses or deaths have occurred in patients off therapy for greater than five years. In this small series of patients, there was no difference in survival in the continued or discontinued therapy groups. No overt adverse effects of therapy have been seen in the ten surviving patients. These encouraging data need to be extended and confirmed, utilizing patients treated with the more sophisticated therapeutic approaches employed in modern protocols for ALL/AUL. Identification of adverse effects of therapy will require appropriate and careful surveillance of large groups of successfully treated patients.

Acute Disease↗
PubMed1979

Staphylococci-induced human platelet injury mediated by protein A and immunoglobulin G Fc fragment receptor.

Bloodstream infections with staphylococci are accompanied by thromboembolic complications. We have studied the mechanism of the interaction of staphylococci with human blood platelets. Staphylococci that possess protein A, a bacterial receptor for the Fc fragment of immunoglobulin G (IgG), caused aggregation of human platelets in whole plasma accompanied by release of [(3)H]serotonin. These reactions were time and concentration dependent, requiring two or more staphylococci per platelet to give maximal response within 5 min. The interaction between staphylococci and platelets required the presence of cell wall-bound protein A and of IgG with an intact Fc fragment. It did not require an intact complement system. Cell wall-bound protein A (solid phase) was capable of aggregating human platelets in whole plasma. In contrast, free, solubilized protein A (fluid phase) did not cause measurable aggregation, and release of [(3)H]serotonin was reduced. An excess of free, solubilized protein A blocked aggregation of human platelets induced by staphylococci in whole plasma. The role of the Fc fragment of IgG in the staphylococci-human platelet interaction was demonstrated by an experiment in which free, isolated Fc fragment blocked aggregation of platelets in whole plasma induced by staphylococci. Furthermore, binding of (125)I-protein A to human platelets was demonstrated in the presence of complete IgG with intact Fc fragment but not in the presence of the F(ab)(2) fragment. Binding of the protein A-IgG complex to the human platelet Fc receptor was paralleled by the release of [(3)H]serotonin. These results represent a novel example of the interaction of two phylogenetically different Fc receptors, one on prokaryotic staphylococci and the other on human platelets. Their common ligand, IgG, is amplified by one Fc receptor (protein A) to react with another Fc receptor present on human platelets, which results in membrane-mediated aggregation and release reaction occurring in whole plasma. This mechanism can be of significance in the pathomechanism of thromboembolic complications at the site(s) of intravascular staphylococcal infection.

Binding Sites↗
PubMed1979

Childhood leukemia-lymphoma. Heterogeneity of phenotypes and prognoses.

Results are reported on 724 children and adolescents with acute leukemia-lymphoma. One hundred patients had immunologic marker analysis that defined the major phenotypic groups, i.e., T-cell, B-cell (Burkitt), myeloid, and the most frequent form, non-T, non-T "common" or "undifferentiated" acute leukemia. Pre-T, pre-B, and "null" leukemias are included in the latter group. Response to therapy and survival was best in non-T, non-B acute lymphocytic leukemia, intermediate in T-cell disease, and worst in B-cell (Burkitt) disease. Additional factors resulting in decreased survival include elevated peripheral leukocyte count, presence of enlarged nodes, less depression of hemoglobin and platelets, and age greater than 7 years (all associated with 'lymphomatous" disease). Other factors resulting in decreased survival include age under 3 years and depression of serum immunoglobulins. Definition of the heterogeneity of childhood leukemia-lymphoma dictates differing forms of therapy for the various types of these diseases.

Adolescent↗
PubMed1979

Phase II study of VM-26 in acute leukemia, neuroblastoma, and other refractory childhood malignancies: a report from the Children's Cancer Study Group.

VM-26, a semisynthetic podophyllotoxin, was tested for antitumor activity and clinical toxicity in 181 children. The drug was administered iv at weekly intervals, beginning at a dose of 130 mg/2/week. The dose was increased, as tolerated, after 3 and 6 weeks to 150 and 180 mg/m2/week, respectively. The only major toxicity was hematologic, with neutropenia predominating. Anaphylaxis occurred in one patient. The drug demonstrated significant activity in acute lymphocytic leukemia (four responses among 15 patients) and neuroblastoma (ten responses among 31 patients). Objective responses were also noted in one patient each with acute myelogenous leukemia, Hodgkin's disease, histiocytic lymphoma, Wilms' tumor, Ewing's sarcoma, undifferentiated carcinoma, and sacrococcygeal sarcoma. Further trials of VM-26 in these childhood malignancies are warranted.

Acute Disease↗
PubMed1979

Effective dose of L-asparaginase for induction of remission in previously treated children with acute lymphocytic leukemia: a report from Childrens Cancer Study Group.

L-Asparaginase, in the dose of greater than or equal to 6000 IU/sq m three times weekly, was demonstrated to be an effective agent in reinduction of remissions in childhood leukemia. Four hundred thirteen children with acute lymphocytic leukemia were treated with L-asparaginase. Doses i.m. ranged from 300 to 12,000 IU/sq m. None of the patients had received prior asparaginase therapy. 6-Mercaptopurine was given p.o. concurrently. All of the patients had experienced several previous relapses, and their disease was not responsive to 6-mercaptopurine. L-Asparaginase was found to be effective in reinducing remissions at the following rates: 9.5% for 300 IU/sq m; 35.1% for 3,000 IU/sq m; 53.5% for 6,000 IU/sq m; and 62.5% for 12,000 IU/sq m. The drug was given three times weekly for four weeks. Hypersensitivity reactions occurred in 6.5% of patients.

Asparaginase↗
PubMed1979

Evaluation of cyclocytidine in children with advanced acute leukemia and solid tumors.

Cyclocytidine, a slow-release form of cytosine arabinoside, was evaluated in 69 children with advanced acute leukemia and solid tumors. One child with acute lymphocytic leukemia attained a complete remission. This child had received intrathecal cytosine arabinoside prior to the cyclocytidine. Eighteen of the 31 patients with acute lymphocytic leukemia/acute undifferentiated leukemia who did not respond received two or more courses of the drug. There were no responses in 15 children with acute myelogenous leukemia, in 11 children with neuroblastoma, or in 11 children with various solid tumors of childhood. A dose of 600 ng/m2/day for 10 consecutive days is tolerated in children.

Adolescent↗
PubMed1977

Treatment of rhabdomyosarcoma in children with surgery, radiotherapy and chemotherapy.

From May, 1970 through December, 1972, Children's Cancer Study Group entered 112 patients on an amended treatment program for rhabdomyosarcoma and undifferentiated sarcoma in children. These patients had Group II disease with residual tumor remaining after surgery, or metastatic disease at onset. Another group consisted of patients who previously had treatment with surgery and radiotherapy and had recurrent disease. Cyclophosphamide was added to a previously used drug regimen which consisted of actinomycin D and vincristine. The drugs were given sequentially in repeated cycles for 18 months. Of 97 evaluable patients, there were 24 with microscopic residual disease, 37 with gross residual disease, 22 with metastatic disease at onset, and 14 patients who were treated with chemotherapy for the first time with recurrent or metastatic disease. All patients have been followed for 3 or more years. Survival in each group was 70.8%, 43.2%, 27.2%, and 28.2%, respectively. Although the number of complete remissions was greater than with two-drug therapy, survival with three-drug therapy was not significantly different than that seen in the earlier study.

Adolescent↗
PubMed1977

L-Asparaginase, vincristine, and prednisone for induction of first remission in acute lymphocytic leukemia.

L-Asparaginase was added to vincristine and prednisone for induction of first remission in 815 children with acute lymphocytic or acute undifferentiated leukemia. This combination resulted in an overall remission rate of 93%. The addition of L-asparaginse to the standard induction regimen using prednisone and vincristine did not significantly increase the morbidity or mortality rate during the induction period. The most common side effect was transient L-asparaginase-induced hyperglycemia. The safe administration of L-asparaginase i.m. and the dose efficacy of 6000 I.U./sq m were confirmed. For these reasons, L-asparaginase should be combined with vincristine and prednisone for the initial induction of children with acute lymphocytic or acute undifferentiated leukemia.

Adolescent↗
PubMed1976

Septicemia and meningitis in children splenectomized for hodgkin's disease.

Retrospective evaluation of the occurrence of septicemia and meningitis in 200 children who had staging laparotomy iwth splenectomy for Hodgkin's disease revealed 20 episodes occurring in 18 children. Symptoms were usually fulminant; only 10 of these patients survived their episode. Infections occurred eight days to three years after splenectomy. Adolescents, as well as younger children, were affected; half were older than 10 years of age. Leukopenia was not a major factor in onset or survival since the average white-cell count was 12,000 in both survivors and children who died. Pneumonococcus accounted for 50 per cent, and streptococcus for 15 per cent of infections; there was one episode each of Haemophilus influenzae and meningococcus; in 25 per cent, no organism was isolated. Predominance of penicillin-sensitive organisms and high mortality suggest that penicillin prophylaxis and the protection offered by bacterial vaccines should be evaluated in children with Hodgkin's disease whose staging laparotomy includes splenectomy.

Adolescent↗
PubMed1976

Usefulness of cytosine arabinoside (NSC-63878) and prednisone (NSC-10023) in refractory childhood lymphoblastic leukemia.

One hundred forty-three children with refractory lymphoblastic and undifferentiated leukemia (ALL/AUL) were treated with cytosine arabinoside (Ara-C) and prednisone (Pred). The dose and duration of Ara-C was escalated during induction depending on the response seen in the peripheral blood and/or bone marrow. For those achieving a remission, Ara-C was also used to determine its maintenance capabilities. Of the 143 children, 79 attained a clinical remission, 45 having a complete bone marrow remission and 34 having a partial remission. Maintenance of remission with twice weekly Ara-C was short and did not appear to depend on the amount of Ara-C given during induction. The major toxicity of Ara-C was myelosuppression.

Bone Marrow↗
PubMed1975

BCG in the treatment of acute lymphocytic leukemia.

Children with acute lymphocytic leukemia, who were in remission after induction with prednisone and vincristine and consolidation with intravenous methotrexate, were randomized into three groups receiving (1) no further therapy, (2) BCG, and (3) chemotherapy with biweekly methotrexate and monthly prednisone and vincristine. Children continuing in remission after 8 mo on chemotherapy in group 3 were rerandomized into three similar groups, i.e., no therapy, BCG, and chemotherapy. In the primary randomization, the median duration of remission was identical in the groups receiving no therapy or BCG, (4 and 4.3 mo respectively), and both were significantly less than the median duration of remission on chemotherapy which had not been reached prior to secondary randomization at 8 mo. Results of secondary randomization were similar to those of primary randomization. As used in this study, BCG was ineffective in prolonging drug-induced remissions either early in remission or when the leukemic cell population might have been further reduced after 8 mo of maintenance chemotherapy.

Adolescent↗
PubMed1975

Congenital hypoplastic anemia inhibition of erythropoiesis by sera from patients with congenital hypoplastic anemia.

An in vitro marrow culture assay designed to measure erythropoietic capability was used to ascertain the presence of an inhibitor in the sera of patients with congenital hypoplastic anemia (CHA). Marrow cells from nine anemic CHA patients responded to the stimulatory effect of exogenous erythropoietin (EPO) by an increase in heme synthesis in the presence of normal serum. The effect on heme synthesis was less than that observed with normal marrow cells. CHA serum inhibited heme synthesis by both normal and CHA marrow cells. It is concluded that an in-inhibitor of erythropoiesis is present in serum from CHA patients. This inhibitor most likely blocks the EPO-sensitive stem cell receptor sites, causing decreased response to the hormone.

Anemia↗