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Biomedical subjects

S B Murphy

Publications and source records attributed to S B Murphy.

179 records · Page 10Linked to original sources

Pretreatment cytokinetic studies in 94 children with acute leukemia. Relationship to other variables at diagnosis and to outcome of standard treatment.

The relationship of the pretreatment bone marrow mitotic index (MI) and in vitro 3H-thymidine labeling index (LI) to other variables present at diagnosis and to the outcome of standard therapy was examined in a series of 94 children with acute leukemia (71 ALL, 23 AML). The range of observed values at diagnosis was extremely broad, from less than 1% labeled cells to more than 25%. The median LI% for all patients studied was 5.2%; the median MI% was 0.3%. The values for AML and ALL did not differ significantly despite older age, higher initial white blood cell (WBC) counts, and poorer response to therapy of AML patients. The initial MI and LI were positively correlated with each other, but unrelated to age or initial WBC count in either ALL or AML. However, the LI and MI were significantly higher (p less than 0.01) in the group of 10 children of 54 studied with ALL whose blasts formed spontaneous rosettes with sheep red blood cells at 37 degrees C. The initial LI and MI were not shown to be related to the likelihood of attaining a complete response or to the length of remission in either ALL or AML. There was thus no evidence that either the initial MI or LI% of marrow blasts was of any prognostic significance in children with acute leukemia.

Age Factors↗

Evidence for recruitment and synchronization in leukemia and solid tumors.

In malignant cell populations which are sensitive to drug therapy it does not seem necessary to potentiate treatment with perturbation of the proliferative characteristics. However, in some relatively drug-resistant populations significant advantages can be obtained by recruiting resting cells into the drug-sensitive cell cycle. Further studies of growth-regulatory mechanisms for malignant cell populations may help a great deal in designing better methods of recruiting the resting cells back into active cell division. Synchronization of the dividing cells in a specificially drug-sensitive phase of the cell cycle is another method of potentiating chemotherapeutic effectiveness in relatively drug-resistant cell populations. The biochemical changes induced by sequential drug administration may be equally important in sensitizing the malignant cell to subsequent drug administration.

Antineoplastic Agents↗

A study of childhood non-Hodgkin's lymphoma.

The pathologic and clinical features of 31 cases of childhood non-Hodgkin's lymphoma (NHL) were reviewed retrospectively using Rappaport's classification and a modification of the Ann Arbor staging system. Twenty-nine (93.5%) of the patients had diffuse and 2 (6.5%) had nodular lymphoma. Diffuse histiocytic lymphoma accounted for 10 cases (32.3%), diffuse undifferentiated for 9 (29%), and diffuse lymphocytic, poorly differentiated for 5 (16.1%). Five cases (16.1%) were unclassifiable. No cases of well-differenitated lymphocytic or mixed cell lymphoma were found. A modified classification was attempted, which included also large basophilic cell (LBC), convoluted T-lymphocytic (CTL), and Burkitt's lymphomas. These pathologic subgroups accounted for 35.4%, 16.1%, and 6.5% of the cases, respectively. The patients were almost equally divided between clinically localized and generalized stages, and their survival was stage-dependent. The overall survival was 32.3%; the 3-year survival was 50% for Stages I and II, compared to 7.7% for Stages III and IV. The gastrointestinal tract was the most common site of origin. In 22% of the cases, the disease originated in extra-lymphatic tissues. Central nervous syste, involvement occurred in 10 of 31 children (32%), and a leukemic picture developed in 6 of 31 (19%). The Ctl lymphomas were confined to the mediastinum, whereas the LBC lymphomas arose mostly in Waldeyer's ring and Peyer's patches. We conclude that the extent of the disease as determined by clinical staging had prognostic significance in childhood NHL. The prognostic value of the histological classification could not be clearly established from our data.

Adolescent↗

Lack of correlation of lymphoblast cell size with presence of T-cell markers or with outcome in childhood acute lymphoblastic leukaemia.

The proportion of pretreatment bone marrow macrolymphoblasts was determined in a total of 93 children with acute lymphoblastic leukaemia (ALL) in order to assess the validity of cell size as a prognostic indicator. A macrolymphoblast (MLb) was defined as having a diameter greater than 12 mum, and patient samples were divided simply on the basis of whether they had more or less than 10% MLb present at diagnosis. In a retrospective study of a sample of 47 children treated according to Total Therapy Study VII, the continuous complete remission duration, survival and incidence of CNS disease bore no relationship to the cell size distribution present at diagnosis. A second sample of 46 current patients with untreated ALL was examined both for the presence of surface markers for T- and B-cells and for cell size. Bone marrow blasts from 10 of these 46 children formed rosettes with sheep erythrocytes (E)-- a T-cell marker. E-rosette formation was associated with a constellation of adverse prognostic factors, including older age, very high initial WBC counts, organomegaly, and mediastinal enlargement; yet the presence of this T-cell marker was unrelated to cell size. We conclude that pretreatment lymphoblast cell size is not a reliable prognostic indicator in childhood ALL.

Adolescent↗

The planning of orthopaedic reconstructive surgery using computer-aided simulation and design.

Three-dimensional reconstructions from computed tomographic (CT) images are currently being used clinically in a wide variety of orthopaedic surgical applications. The computer may be used to select the optimum standard artificial joint replacement or to design a custom artificial joint replacement for a particular patient. Where large bony defects exist, the computer may be used to design bone allografts for joint reconstruction and to manufacture models of the bones for use in planning the surgery. In cases where osteotomies are performed to improve the mechanics of the joint, each proposed osteotomy may be simulated on the computer to identify the surgical plan that will optimally normalize the diseased joint.

Adolescent↗

Equal participation of minority patients in U.S. national pediatric cancer clinical trials.

PURPOSE: To determine the ethnic/racial distribution of patients entered in national pediatric cancer clinical trials relative to the patient population served. METHODS: The ethnic/racial distribution of 29,134 patients < 20 years of age entered in clinical trials conducted by the Children's Cancer Group (CCG) and Pediatric Oncology Group (POG) between January 1, 1991 and June 30, 1994 were compared with the expected distribution of patients of the same age in the United States. The latter was predicted from the 1989 to 1991 crude incidence data of the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) program applied to the 1990 United States census. RESULTS: Of the patients on CCG and POG trials, 11.6% were reported to be Hispanic, 10.4% were African-American, and 4.7% were other racial groups. The expected values were 9.1%, 10.7% and 4.3%, respectively. Representation of minority patients was equal or greater than expected for 24 of 27 subgroups analyzed. CONCLUSIONS: In the United States, minority children with cancer are proportionately represented on clinical trials of the two national pediatric cancer cooperative groups. They and their families are provided with an equal opportunity to access clinical cancer trials and the potential benefits of cancer research.

Child↗

Childhood cancer: patterns of protocol participation in a national survey.

Cancer is still the chief cause of death by disease in children, ages one to 14. As improved survival rates have been reported for pediatric cancer patients who are treated on controlled clinical trials, it is important to understand the national utilization of such protocols. In 1993, a survey of childhood cancer was conducted by the Commission on Cancer of the American College of Surgeons. Data regarding type of disease, protocol participation, age, sex, race, insurance, and geographical region were voluntarily submitted by more than 200 hospital cancer registries. Included in this study were 2,208 children and adolescents 21 years of age or younger who were diagnosed in 1987, and 2,293 who were diagnosed in 1992. Pediatric centers (i.e., members of the Pediatric Oncology Group or Children's Cancer Group) submitted 55.1% of the cases and other institutions, 44.9%. It was found that more patients treated at pediatric centers were on protocols (53.8%) than were those treated at other institutions (25.1%). In general, the younger the patient (five years of age or younger), the greater the chance of being on protocol (pediatric centers, 63.7%; others, 42.0%), with very poor adolescent protocol participation (pediatric centers, 34.8%; others, 12.1%). Nevertheless, overall protocol participation was still lower than expected, even in children younger than five years of age, and adolescent participation in controlled clinical trials was low and similar to adult figures. The percentage of childhood cancer cases seen at pediatric centers was smaller than in other series. It was concluded that pediatric cancer centers need to continue to encourage patient participation in controlled clinical trials, with special emphasis on adolescents.

Adolescent↗