Antiproliferative effect of verapamil alone on brain tumor cells in vitro.

Recent studies have shown that the calcium channel blockers, when combined with standard anticancer drugs, help overcome resistance that often develops to those drugs. Little is known about the effects of the calcium channel blockers themselves on tumor cells. We have studied the effects of one calcium channel blocker, verapamil, on human tumor cell lines in vitro. Our results show a reversible, antiproliferative action of verapamil on human medulloblastoma, pinealoblastoma, glioma, and neuroblastoma tumor lines established from pediatric patients. Growth rates are inhibited 10 to 100% by 10 to 100 microM verapamil with 50% inhibition occurring between 25 and 50 microM verapamil. No cell line proliferates in 100 microM verapamil, yet washing the cells after 72 h of incubation with 100 microM verapamil results in resumed cell growth. Growth inhibition is accompanied by dose-dependent decreases in DNA, RNA, and protein synthesis which occur within minutes after addition of verapamil. DNA flow cytometry on propidium iodide-stained nuclei shows that, after incubation for 48 h with 100 microM verapamil, the medulloblastoma and neuroblastoma tumor lines as well as normal, human foreskin and lung fibroblast cell lines are reversibly blocked throughout the cell cycle with slight increases in G1. Verapamil appears to have no effect on nucleic acid precursors or on calcium influx or efflux in human medulloblastoma cells.

Non-Hodgkin's lymphoma with immunologic phenotype similar to non-T, non-B acute lymphocytic leukemia.

A diagnosis of diffuse poorly differentiated lymphocytic lymphoma was made from a biopsy of a scapular mass on a 24-month-old child. The bone marrow and peripheral blood were not involved in the neoplastic process. Neoplastic cells stained negatively for Sudan black B, myeloperoxidase, periodic acid-Schiff reagent, alpha-naphthyl acetate esterase, and acid phosphatase. In addition, neoplastic cells did not form nonimmune rosettes with sheep erythrocytes or contain surface membrane immunoglobulin. However, neoplastic cells were positive for terminal deoxynucleotidyl transferase and "Ia-like" antigen. We conclude that this non-Hodgkin's lymphoma has a cytochemical and immunologic phenotype similar to that of lymphoblasts from cases of non-T, non-B acute lymphocytic leukemia.

Development of an inhibitor specific to factor VIII: coagulant activity in a patient with platelet-type von Willebrand's disease.

Platelet-type von Willebrand's disease is a recently described autosomal dominant bleeding disorder characterized by decreased ristocetin cofactor activity, lack of the higher molecular weight von Willebrand Factor (vWF) multimers on SDS agarose gel electrophoresis, increased platelet aggregation with low concentrations of ristocetin, and increased ristocetin-induced binding of normal vWF to patient platelets. In this report the authors describe a 17-month-old male with Platelet-type von Willebrand's disease, inherited from the paternal side of his family, who developed an inhibitor specific to Factor VIII:C. The patient's plasma inhibited normal plasma VIII:C and partially purified VIII:C; it did not appear directed against normal VIIIR:Ag or ristocetin cofactor. This antibody is therefore similar to inhibitors that develop in some transfused hemophilia A patients. Since low VIII:C, VIII:CAg, and VIII:C/VIIIR:Ag ratio were encountered in his mother, it is likely that this patient has inherited hemophilia A in addition to Platelet-type von Willebrand's disease.

A treatable cause of ataxia in children.

An 11-year-old black male presenting with severe subacute sensory ataxia, unusual skin hyperpigmentation, megaloblastic anemia, low serum B12 levels, and an abnormal part I Schilling test was diagnosed with pernicious anemia in the context of a polyglandular syndrome. Intrinsic factor and thyroid microsomal antibodies were positive, and thyroid-stimulating hormone levels were undetectable. There was a strong familial aggregation because the mother, a maternal aunt, the maternal grandfather, and the maternal great-grandmother had been diagnosed with pernicious anemia, albeit of unspecified etiology. Spinal magnetic resonance imaging (MRI) demonstrated extensive demyelination of the posterior columns along the entire length of the cord, as well as areas of contrast enhancement. Treatment with cobalamin produced complete remission of the neurologic deficits and normalization of the MRI findings in the short space of 2 months. Although rare, childhood pernicious anemia is a treatable disease that should be included in the differential diagnosis of the sensory ataxias in children. In this article, we review the causes of pernicious anemia in children and discuss the MRI findings.

The aftermath of bone marrow transplant for parents of pediatric patients: a post-traumatic stress disorder.

PURPOSE/OBJECTIVES: To describe the characteristics of a child's bone marrow transplant (BMT) experience that may precipitate a post-traumatic stress disorder (PTSD) in the parent. DATA SOURCES: Published articles, books, and the authors' clinical experience. DATA SYNTHESIS: When viewed from the PTSD framework, parental reactions to a child's BMT offer striking parallels that include assessment of the event as traumatic, re-experiencing the event, intrusive thoughts, and a variety of emotional and cognitive responses. Interventions based on PTSD research can be implemented in clinical settings to diminish and treat these responses. CONCLUSIONS: The PTSD framework holds promise for healthcare providers in devising strategies to help families of children undergoing BMT to cope with the experience. IMPLICATIONS FOR NURSING PRACTICE: Nurses can use orientation, education, coaching, and peer support to help families before BMT and debriefing and counseling after BMT.

Case Report: grandmother, mother and another -- an intergenerational surrogacy using anonymous donated embryos.

Surrogacy and embryo donation remain beneficial but controversial infertility therapies. This is the first report of a pregnancy and subsequent birth of healthy twins following a surrogacy involving a female patient's biological mother as surrogate, but using anonymously donated embryos. Due to the novelty of combining intergenerational surrogacy with embryo donation, the legal side of adoption has taken over 3 years to complete. Intergenerational surrogacy using donated embryos can successfully provide a family with a third generation, offering an alternative to adoption of genetically unrelated children without involvement in the pregnancy. The legal and ethical aspects of the treatment and eventual adoption are discussed.

Spurious elevated platelet counts associated with bacteremia.

Spuriously elevated automated platelet counts secondary to in vivo bacteremia have not been reported previously. Two patients are described with blood cultures positive for Escherichia coli and Klebsiella pneumoniae, respectively, and bacteria present on peripheral blood smear. Those bacteria caused falsely elevated platelet counts to be generated by the Ortho ELT-8. These cases illustrate an unusual artifact and demonstrate that spurious counts can be generated by laser optical blood cell counters.

Acute cytoreduction techniques in the early treatment of hyperleukocytosis associated with childhood hematologic malignancies.

Early and effective cytoreduction for high peripheral white blood cell counts in pediatric patients with acute leukemia may be helpful in preventing complications secondary to hyperviscosity. It also may be a useful adjunct to systemic chemotherapy. As an alternative to automated apheresis for this purpose, manual exchange transfusion is efficacious and does not require hemapheresis instrumentation and disposables and the related special staff. Two patients, a neonate with acute myeloblastic leukemia and a white blood cell count of 422.2 k/microliter as well as a 2 1/2-year-old with an admission diagnosis of acute promyelocytic leukemia and a white blood cell count of 617.4 k/microliter, underwent manual exchange hemotherapy for acute cytoreduction. The procedures were tolerated well, and significant leukocyte removal was achieved, with the respective leukocyte reductions being 81.1 and 68.7%. The techniques available for pediatric cytoreduction are compared, with emphasis on their efficiency and safety and appropriateness for very small children.

Human tumor cells resistant to verapamil.

The efficacy of the calcium channel blocker verapamil for enhancing at low concentrations the cytotoxicity of unrelated antineoplastic drugs and for inhibiting at high concentrations cell proliferation has stimulated interest in the underlying mechanisms of these two diverse effects. We have selected two human brain tumor cell lines (a TE671 medulloblastoma and a A172 glioma line) for resistance against 100 uM verapamil to aid in the elucidation of the mechanism of verapamil's antiproliferative effect. Our first experiments on the selected TE671 medulloblastoma cells show that, in the presence of 100 uM verapamil, these cells grow at a rate similar to that observed for the sensitive cells in the absence of verapamil. This resistant clone continues to exhibit resistance toward verapamil for at least three days after the verapamil has been removed from the growth medium. In contrast to the sensitive cells, the resistant cells show only slight cell cycle phase alterations after removal of verapamil from the growth medium. This, together with an unchanged c-myc gene expression after removal of verapamil, indicates a stable phenotypic alteration that is responsible for the exhibited resistance toward the antiproliferative effects of the drug. Experiments designed to elucidate the mechanism of resistance showed that these cells are not cross-resistant to the antineoplastic drugs vincristine and adriamycin. Also, the resistance is not accompanied by increased amounts of the 170-180 kDa P-glycoprotein that has been implicated in resistance phenomena of cancer cells towards antineoplastic drugs.

Effect of verapamil on cell cycle transit and c-myc gene expression in normal and malignant murine cells.

Verapamil, the prototype calcium channel blocker, reversibly inhibits cell proliferation in many normal and tumour cell lines (Schmidt et al., Cancer Res., 48, 3617, 1988). We have found that two closely related cell lines - B16 murine melanoma cells and B10.BR normal murine melanocytes growing in culture - behave differently in the presence of verapamil, and we are now utilising these two related cell lines to help elucidate the molecular basis of verapamil's antiproliferative effect. In this study, we studied cell cycle phase distribution and c-myc gene expression in both cell lines in the absence of verapamil, during incubation with verapamil and after the cells were washed free of verapamil. Our studies show that 100 microM verapamil rapidly blocks DNA synthesis in melanocytes but not in B16 cells. Similarly, incubation with verapamil for 6-24 h results in a decreased c-myc signal in melanocytes, but a transient increase in c-myc expression in B16 cells. After verapamil is washed from the cells following a 24-h incubation with drug, c-myc expression increases in melanocytes as they begin again to proliferate, but decreases in B16 cells as they begin to die. Our disparate results with these cell lines suggest that c-myc gene expression, regardless of its known involvement in growth control, is not the immediate target for verapamil's inhibitory action.