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Biomedical subjects

A Toren

Publications and source records attributed to A Toren.

At least 55 records · Page 3Linked to original sources

Normalization of serum lactic dehydrogenase in beta-thalassemia patients following bone marrow transplantation.

Serum lactic dehydrogenase (LDH) levels are mildly elevated in beta-thalassemia major due to ineffective erythropoiesis. We reviewed the charts of 15 consecutive thalassemic children who underwent allogeneic, T-cell-depleted bone marrow transplantation (BMT) in our department during the last 3 years. Eleven patients had successful engraftment and are alive and well without evidence of disease, according to physical examinations, blood counts, and polymerase chain reaction (PCR) tests, with a median follow-up of 2 years. Two patients died due to transplantation-related complications, and two rejected the graft and received their backup autologous marrow. The LDH levels in the transplanted patients gradually decreased from an average of 952 +/- 155 IU/L 10 days pre-transplant (N = 300-620) to 426 +/- 56 IU/L at the day of transplantation, and stayed at approximately the same level post-transplant (489 +/- 55 IU/L). By contrast, the LDH levels reverted to the pre-transplant value in those patients who rejected their marrow. The significance of this clinical observation for the pathophysiologic mechanism of intramedullary hemolysis and ineffective erythropoiesis in beta-thalassemia major is discussed.

Bone Marrow Transplantation↗

Vincristine treatment triggering the expression of asymptomatic Charcot-Marie-Tooth disease.

A 16-year-old male suffering from Ewing's sarcoma of the pelvis was treated with vincristine as part of his chemotherapeutic protocol. The boy was never known to suffer from any neurological problems. His father had a mild limp, attributed to prolonged "taxi driving," that was never investigated medically. The first course of treatment, which included 2 mg of vincristine, resulted in clinical improvement. However, at the same time the patient developed severe weakness of both upper and lower limbs, areflexia, and gradually a pes cavus deformity. Nerve conduction studies were suggestive of severe peripheral sensorimotor neuropathy, axonal and demyelinative. A definite diagnosis of Charcot-Marie-Tooth was confirmed by molecular analysis showing the typical duplication of 1.5 megabases at 17 p11.2. This unique manifestation of vincristine neurotoxicity is reported and discussed.

Adolescent↗

Minimal residual disease post-bone marrow transplantation for hemato-oncological diseases.

The detection of minimal residual disease (MRD), which is important in cancer treatment, gained special significance in bone marrow transplantation (BMT-) due to the possibility not just to detect but recently also to prevent, treat and reinduce remission in patients that relapsed post-BMT by immunotherapy. The various modern techniques of MRD detection are described including cytogenetics, analysis of restriction fragment length polymorphism, variable number of tandem repeats by Southern Blot or polymerase chain reaction (PCR), microsatellite sequences, PCR amplification products of the Y chromosome or the Amelogenin gene, quantitative PCR and fluorescence in situ hybridization. The role of MRD detection in refinement of indications for BMT, autografting, prediction of relapse, adoptive immunotherapy, mixed chimerism in nonmalignant diseases and in solid organ transplantation is discussed.

Bone Marrow Transplantation↗

Curable and non-curable malignancies: lessons from paediatric cancer.

The tremendous progress achieved in understanding the molecular basis of cancer, was unfortunately not followed by a mutual improvement in the morbidity and mortality of adult cancer. In contrast, the success rate achieved in paediatric oncology has increased significantly during the past 30 years, and more than two-thirds of the children with cancer can now be cured. p53 has been shown to have a central role on apoptosis in various cells. As apoptosis is a final common pathway for much of our anti cancer therapy, resistance to apoptosis due to a normal activity of p53 is an important mechanism of tumor resistance and treatment failure. Contrary to the findings in most adult tumors, where about 50% of the tumors lack p53 activity, the rate of p53 mutations in childhood cancer is surprisingly low. This may be the key to the much better prognosis of children with cancer. In most adult tumors, multiple genetic events, between five and seven, are usually involved. The oncogenes involved in such tumors usually represent those located upstream of the nuclear transcription factors. In most paediatric tumors, in contrast, the initiating event is the activation of nuclear transcription factors secondary to chromosomal translocations. It can be speculated that multiple events activating various components of the signal transduction machinery are needed for tumorigenesis, and hence the evolution and progression of such tumors is slow. Moreover, if the malignant cell has to accumulate multiple mutations, the chances of crippling the apoptotic mechanism are higher. Genomic instability evidenced by microsatellite variation has been found in colon, pancreas, breast, liver and ovarian adult tumors, and not in paediatric tumors. As multiple somatic mutations are needed for the initiation and progression of the common adult malignancies, inherent genomic instability can dispose to accumulation of multiple mutations. All these molecular interactions are discussed with relevance to the difference between non-curable, mostly adult tumors, and curable, mostly paediatric tumors.

Antineoplastic Agents↗

Bronchiolitis obliterans presenting as subcutaneous emphysema and pneumomediastinum: a case report.

We describe a woman post allogeneic bone marrow transplantation (BMT), who presented to the emergency room with subcutaneous emphysema and pneumomediastinum as the first manifestation of bronchiolitis obliterans complicating mild chronic graft versus host disease (GVHD). In contrast to other patients with pneumomediastinum described in the literature, this patient suffered from only mild GVHD. She did not receive methotrexate as GVHD prophylaxis, and the pneumomediastinum was a presenting manifestation rather than a terminal event. In addition, this is the first description of subcutaneous emphysema with this setting. Therefore, bronchiolitis obliterans should be highly suspected in post-BMT patients presenting with pneumomediastinum and subcutaneous emphysema, and prompt therapy should be initiated.

Acute Disease↗

In vitro proliferative advantage of bone marrow cells with tetrasomy 8 in Ewing sarcoma.

We describe a case of a 14.5-year-old boy with a clinically aggressive pelvic Ewing sarcoma. The tumor cells showed the presence of a typical t(11;22)(q24;q12) aberration and gains of chromosomes 8, 10, 14, and 21. To determine the size of the trisomy and tetrasomy 8 clones an interphase analysis by fluorescence in situ hybridization with a centromere-specific chromosome 8 probe was performed. Significant quantitative differences between metaphase and interphase data were obtained. It was shown that culturing of bone marrow cells leads to enrichment of tetrasomy 8 population that may be explained by the proliferative advantage of the tetrasomy 8 cells.

Adolescent↗

Infectious agents and environmental factors in lymphoid malignancies.

A strong association was found to exist between patterns of lymphoid malignancies and socioeconomic status. B-cell lymphomas and T-acute lymphoblastic leukemia are much more prevalent in developing countries where the chances of acquiring infections especially at a younger age are high. B-cell precursor acute lymphatic leukemia, however, are much more prevalent in the Western world. Many infectious agents are associated with lymphatic malignancies. Epstein-Barr virus is involved in African Burkitt's lymphoma, human immunodeficiency virus-related Burkitt's lymphoma, lymphoproliferative syndrome post-transplantation, and Hodgkin's disease. Other infectious agents which may play a role in lymphoproliferative disorders are human immunodeficiency virus in acquired immune deficiency syndrome-associated lymphoma, human T-lymphotropic virus in adult T-cell lymphoma, Helicobacter pylori in mucosa-associated lymphoid tissue lymphoma, theileriosis in lymphoproliferative syndrome in cattle, Avian leukosis virus in chicken bursal lymphoma, and possibly a bacterial infection in immunoproliferative small intestine disease, potentially reversed by antibiotic therapy. The association between infectious agents and hematologic malignancies may be explained by the creation of large populations of activated cells followed by higher occurrences of 'genetic accidents'. This theory may be reinforced in at least some malignancies with the existence of viral proteins which either have complex relationships with key cellular gene products like p53 and Rb which have roles in cell cycle control, or share common motifs with bc1-2, therefore operating as anti-apoptotic elements. Whenever these genes are deranged, cell deoxysibonucleic acid repair or apoptosis are no longer possible, thereby creating a state of genome instability, increased acquisition of mistakes, and increased chances for malignant transformation.

Animals↗

The gray zone between malignant and reactive processes in lymphoproliferative diseases.

The differences between reactive and malignant processes are sometimes blurred. Homogeneity is no longer a requisite for the diagnosis of lymphoma, as witnessed in mucosa-associated lymphatic tissue lymphoma and T-cell-rich B cell lymphoma, which are composed of an admixture of neoplastic clonal B cells and reactive T cells which occasionally are very prominent in the histological picture. Infectious mononucleosis, anaplastic large cell lymphoma, composite lymphoma and Hodgkin's disease, all share many similarities and may actually represent a continuous spectrum of pathological conditions. Immunodeficiency states, whether primary or acquired, are commonly associated with clonal lymphatic malignancies preceded by a polyclonal lymphoproliferative stage, which is usually reversible by reducing immunosuppression. The distinction between these stages is sometimes difficult to assess. Immunologists have so far failed to find a lymphatic tumor-specific antigen, hence, monoclonality is usually based on a constellation of factors, namely homogeneity of the phenotypic expression of few antigens, aberrant expression of antigens and restricted expression of kappa- or lambda-chains in malignancies expressing surface immunoglobulins. Nonrandom chromosomal translocations as well as other aberrations, usually important in the diagnosis of malignancy, are sometimes of limited value. This is mainly due to the existence of translocations [like t(14;18) and t(2;5)] in nonmalignant states, and their non-specificity [the existence of t(8;14) in Burkitt's lymphoma and large cell lymphoma, t(2;5) in Hodgkin's disease and anaplastic large cell lymphoma, and t(14;18) in large cell lymphoma evolving from follicular lymphoma and Burkitt's lymphoma]. The diagnostic tools available in 1995, although usually sufficient, are sometimes unable to distinguish between malignancy and reactivity. Some problematic cases will be more accurately defined as lying in the gray zone, or as belonging to a spectrum ranging between reactivity and malignancy.

Clone Cells↗

Oral tuberculosis following autologous bone marrow transplantation for Hodgkin's disease with interleukin-2 and alpha-interferon immunotherapy.

A patient with Hodgkin's disease (HD) underwent autologous bone marrow transplantation (ABMT). Six months later while receiving interleukin (IL)-2 and alpha-interferon immunotherapy, he developed a painful lesion in his oral cavity with a fistula in the buccal area. Excision biopsy disclosed necrotizing granulomatous inflammation with acid-fast bacillus. The patient received a 9-month course of isoniazide, rifampin and pyrazinamide, and recovered. The possible pathophysiological mechanism is discussed.

Adjuvants, Immunologic↗

Solitary pulmonary cholesteroloma, multiple xanthelasmas and lipemia retinalis complicating hypercholesterolemia after bone marrow transplantation.

A 22-year-old female with diffuse mixed T cell lymphoma in second complete remission underwent allogeneic BMT from her HLA-compatible brother. Transplantation was complicated by acute graft-versus-host disease (GVHD), cytomegalovirus (CMV) infection, and combined hepatotoxic/cholestatic liver disease 45 days post-BMT. Cholesterol levels reached 65 mmol/l, and high density lipoprotein (HDL) cholesterol decreased to 0.23 mmol/l. She developed skin xanthelasmas, lipemia retinalis, and a solitary lung lesion, which was clinically diagnosed as pulmonary cholesteroloma. All these complications resolved following plasmapheresis and hypolipidemic treatment with lovastatin and cholesterol levels normalized.

Adult↗

Soluble IL-6 receptors (sIL-6R) in hematological patients receiving immunotherapy with IL-2/IFN-alpha or donor lymphocytes following bone marrow transplantation.

Soluble interleukin-6 receptor (sIL-6R) has previously been shown to potentiate the activity of interleukin-6 (IL-6) which may display antitumor activity. Therefore, we evaluated sIL-6R levels in the sera of 15 patients who received cytokine-mediated immunotherapy with (IL-2/IFN-alpha), and 15 patients who received cell-mediated immunotherapy post-BMT, in an attempt to reduce the relapse rate. sIL-6R levels were evaluated pre-, during and post-cytokine or cell-mediated immunotherapy, using IL-6R-specific monoclonal antibodies (McAb) and double-sandwich ELISA. In normal controls, sIL-6R levels were found to be 20 +/- 3 ng/ml. sIL-6R levels increased significantly during IL-2/IFN-alpha immunotherapy in comparison to pre- or post-immunotherapy levels (74 +/- 9 ng/ml vs 46 +/- 6 ng/ml, and 50 +/- 9 ng/ml, respectively) (n = 15) (P < 0.05). sIL-6R levels also significantly increased following donor lymphokine activated killer (LAK) cells, given in addition to IL-2, in comparison to base line levels (87 +/- 3 ng/ml vs 60 +/- 2 ng/ml) (n = 6) (P < 0.05). Increased levels of sIL-6R were observed in BMT patients treated with immunotherapy.

Adolescent↗

Two embryonal cancers after in vitro fertilization.

BACKGROUND: In vitro fertilization is not considered to be associated with an increased rate of pediatric malignancies, and only three have been reported in the literature. Two additional rare pediatric tumors in children conceived through this technique are reported. METHODS: Two children 12 and 18 months of age, developed hepatoblastoma and clear cell sarcoma of the kidney, respectively. They were both products of uneventful pregnancies induced by in vitro fertilization. No other environmental, prenatal, or family factor was found. RESULTS: The first child died after a failed remission induction with cisplatin, doxorubicin, and vincristine, whereas the second child is alive with no evidence of disease 18 months after diagnosis and treatment according to NWTS protocol. CONCLUSIONS: A possible association between in vitro fertilization and pediatric malignancies is suggested.

Antibiotics, Antineoplastic↗

Role of interleukin-2 in human hematological malignancies.

Clinical studies with Interleukin-2 (IL-2) in human hematologic malignancies were initiated in the late 1980s. Based on clinical studies on various solid tumors, and laboratory research on hematopoietic cells, IL-2 was shown to be effective in 150 acute myeloid leukemia (AML) patients mainly for maintenance therapy in first complete remission, or with residual blast cells in the marrow. IL-2 has also been shown to be effective in remission induction in 10 patients with chronic myeloid leukemia (CML). The role of IL-2 in lymphoma patients remains to be established. IL-2 alone or in combination with Interferon-alpha, may intensify remission and prolong disease-free survival when given post autologous bone marrow transplantation (BMT) to patients with lymphoma and myeloid leukemia, and to a lesser degree, to patients with acute lymphatic leukemia (ALL). IL-2 in combination with HLA-matched or mismatched peripheral blood lymphocytes was also used post autologous BMT in preliminary studies. IL-2 was administered with or without peripheral blood lymphocytes, for prevention of relapse post T-cell-depleted allogeneic BMT in CML, ALL and AML, with encouraging results. The same strategy was shown to be effective in the reinduction of remission in patients with CML, who relapsed post BMT.

Animals↗

Translocation (2;14)(p13;q32) in CD10+ ;CD13+ acute lymphatic leukemia.

The rare t(2;14)(p13;q32) was previously described in the three pediatric patients with acute lymphatic leukemia. In these cases this abnormality was found at diagnosis, manifested the sole chromosomal abnormality, and was associated with a favorable prognosis. We here describe three cases of leukemia where such translocations were found at relapse, were associated in two of the cases with additional known characteristic chromosomal aberration, and were associated with a grave prognosis. Interestingly enough, the malignant cells of all three patients shared the same surface antigens: CD34, HLA DR, CD10, CD20, and the myeloid marker CD13. The leukemic clone exhibiting t(2;14) probably evolved from a t(1;19)6q- pre-B acute lymphatic leukemia in one of the cases, and from a chronic phase Ph1 chromosome in another. The significance of the translocation and the coexistence of CD10 and CD13 on the same cell are discussed.

Adolescent↗