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Biomedical subjects

T Bowen

Publications and source records attributed to T Bowen.

17 recordsLinked to original sources

Recognition of an in vivo immune response to human neuroblastoma modulation of antigen expression by retinoic acid.

Neuroblastoma is one of the most common solid tumors of childhood and is notable for its ability to spontaneously regress and, in some instances, to differentiate to less malignant ganglioneuromas. Since immune mechanisms may account for these phenomena, identification of in vivo immune responses to tumor cell surface antigens may be important to the progression of the disease. As determined by analysis on the fluorescence-activated cell sorter, sera from 10 of 18 neuroblastomas patients were found to contain antibodies to a cell surface antigen present on subpopulations of cells from human neuroblastoma cell lines maintained in vitro. Eight human neuroblastoma cell lines were examined and found to vary in reactivity with sera. Induction of differentiation of cell lines with retinoic acid (RA) in vitro resulted in most cell lines bearing higher percentages of positive cells but with a decreased mean cell fluorescence. Preliminary Western blot analysis of lysates of the human cell lines NMB/N7, SMS-KAN, and SK-N-MC showed two principal antigen bands on reducing gels. Comparison of sera from different individuals on lysates of cell lines showed reactivity principally with bands of 105-110 kD and 65-70 kD and an additional minor band of slightly lower molecular weight with the higher titer sera. The ability of different sera to recognize a common antigen pattern suggests that this represents an immunodominant cell surface antigen. Examination of reactivity of other cell lines in this system showed that positive sera reacted with all neuroblastoma lines examined, one neuroepithelioma (SK-N-MC), two melanoma lines (MeWo, G361), and one adrenal-derived adenocarcinoma (SW-13).

Antibody Formation

Essential thrombocythemia associated with recurrent abortions and fetal growth retardation.

Essential thrombocythemia (ET) is one of the myeloproliferative disorders characterized by an elevated platelet count, usually greater than 1,000 X 10(9)/L. It may be associated with either hemorrhagic or thrombotic tendencies. Although it usually affects older people, we have recently encountered two young women with ET who had a total of six spontaneous abortions before the end of the first trimester. During her most recent pregnancy, one of the patients underwent plateletpheresis on four separate occasions before the 12th week. She reached 34 weeks but demonstrated evidence of fetal growth retardation and pre-eclampsia. At delivery there were scattered villus infarcts in the placenta. Based on this patient and previous reports in the literature, we postulate that the spontaneous abortions, fetal growth retardation, and pre-eclampsia may be related to the thrombocytosis and suggest that the use of antiplatelet agents throughout pregnancy should be seriously considered in such cases.

Abortion, Habitual

Bone marrow transplantation for acute monocytic leukemia following the treatment of Hodgkin's disease.

A 32-year-old woman developed acute monocytic leukemia within a year of treatment for Hodgkin's disease with chemotherapy and radiation. Residual leukemia was present in the bone marrow after two induction courses of high-dose Ara-C. She received a bone marrow transplant from an HLA- and DR-identical sister and remains in complete remission more than 2 years after transplantation. Only one other instance of a remission greater than 2 years after transplantation for secondary acute leukemia could be found in the literature. Although bone marrow transplantation may be carried out successfully in these patients, it is possible that they may be more vulnerable to transplant-related complications because of their previous exposure to chemotherapy and radiation. Only further study can clarify this matter and determine the best time for the procedure and which regimen should be used.

Adult

Compliance with postpartum Rh isoimmunization prophylaxis in Alberta.

A retrospective review of obstetric records for 1979 in two major Calgary hospitals was undertaken to determine the rate of compliance with postpartum Rh isoimmunization prophylaxis in Alberta. The charts of 4528 women ranging in age from 13 to 46 years were reviewed. The prevalence rate of Rh negativity was found to be 16%. Of the 710 Rh-negative women 490 (69%) were eligible to receive Rh immune globulin (RhIG); that is, they had no anti-D antibodies, and the baby/fetus was Rh-positive or Rh-unknown. RhIG had been administered to 93.6% of the eligible women; the compliance rate ranged from 66.7% for obstetric emergencies (i.e., spontaneous abortion, antepartum or early-pregnancy hemorrhage, or ectopic pregnancy) to 98.2% for postpartum diagnoses. In more than half (54.7%) of the women who underwent amniocentesis Rh type was not determined; the implications of this finding are discussed. Although poor compliance with postpartum RhIG administration is not a reason for withholding antepartum administration of RhIG, maximum compliance with the more cost-effective programs should be attained before antepartum programs are fully implemented.

Adolescent

Hepatitis B virus DNA is enriched in polymorphonuclear leukocytes.

DNA hybridization and cell separation techniques were used to determine which blood components contained hepatitis B viral DNA sequences. Free monomer-length hepatitis B virus was found in large amounts in the polymorphonuclear leukocyte cell fraction in two of five HBsAG-positive patients. In these two patients, viral DNA sequences were not detected in the plasma or platelet fraction, whereas the mononuclear cell DNA contained small amounts of a 7.2 kb size unintegrated hepatitis B genome. These studies indicate that the major reservoir of unit-length viral DNA in the asymptomatic hepatitis B carriers studied here was in the polymorphonuclear leukocyte fraction. The basis for the presence of the viral DNA within these cells is presently unknown, but may relate to viral replication within, or phagocytosis of virus by, these cells.

Carrier State

Immunologic response in vitro after thymechtomy in patients with myasthenia gravis.

Thymectomy in adult animals impairs immune functions such as lymphocyte response to phytohemagglutinin (PHA) and to allogeneic cells. The responses of lymphocytes from 18 myasthenia gravis patients, 12 of whom had undergone thymectomy, were studied; the interval between thymectomy and investigation ranged from 1 month to 26 years (mean, 9.5 years). Peripheral blood lymphocytes were cultured in autochthonous plasma or homologous AB serum. In vitro responses to stimulation with PHA, concanavalin A and allogeneic monomuclear cells were within the 95% range of normal responses in all patients. Because our findings contrast with the definite immune defects resulting from thymectomy found in adult animals, longer follow-up is needed.

Adolescent

Computerizing records for continuing education.

The system was devised as a joint project by members of the Nursing Education Department, secretarial staff, and Information Services. The nursing education department members identified needed outcomes. The secretaries described what was necessary to simplify data entry. The information services personnel had the technical expertise to interpret the input from the others and put the system together. All members of this project were essential to its development. The reports provide information about classes, attendees, and educational budgets. The reports also meet requirements of the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), Occupational Safety and Health Administration (OSHA), and state continuing education regulations.

Education, Nursing, Continuing