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Biomedical subjects

N Bunin

Publications and source records attributed to N Bunin.

43 records · Page 3Linked to original sources

Fatal pulmonary microsporidiosis due to encephalitozoon cuniculi following allogeneic bone marrow transplantation for acute myelogenous leukemia.

Microsporidia are ubiquitous obligate eukaryotic intracellular parasites that are now felt to be more akin to degenerate fungi than to protozoa. Microsporidia can be highly pathogenic, causing a broad range of symptoms in humans, especially individuals who are immunocompromised. The vast majority of human cases of microsporidiosis have been reported during the past 20 years, in patients with HIV/AIDS, while only relatively rare cases have been described in immunocompetent individuals. However, microsporidia infections are being increasingly reported in patients following solid-organ transplanation, where the main symptom has been diarrhea. The authors report the first case of pulmonary microsporidial infection in an allogeneic bone marrow transplant recipient in the United States and only the second case in the world. The patient, with a history of Hodgkin disease followed by acute myelogenous leukemia received a T-cell-depleted graft, but succumbed to respiratory failure 63 days post transplantation. An open lung biopsy, taken just before death, was originally thought to show toxoplasmosis. The correct diagnosis of microsporidiosis was made postmortem by light and electron microscopy. DNA polymerase chain reaction analysis confirmed the diagnosis and furthermore revealed it to be the dog strain of the microsporidia species Encephalitozoon cuniculi. Although to date rarely diagnosed, microsporidial infection should also be considered in the differential diagnosis of, e.g., unexplained pulmonary infection in bone marrow transplant patients.

Acute Disease↗

Immune reconstitution after autologous purged bone marrow transplantation in children.

PURPOSE: Immune reconstitution was studied in 30 children who had received purged autologous bone marrow transplantation for neuroblastoma or acute myeloid leukemia (AML). METHODS: Patients with neuroblastoma received high-dose chemotherapy and total body irradiation, and patients with AML received chemotherapy alone. Marrows were purged ex vivo with either antineuroblastoma monoclonal antibodies (neuroblastoma) or 4-hydroperoxycyclophosphamide (AML). Lymphocyte subsets, mitogen stimulation studies, and immunoglobulin levels were studied every 4 months. RESULTS: There were no significant differences between the two groups of patients in lymphocyte number or subsets over time. In both groups, CD2+ and CD4+ cells were below normal in 33% of patients at 12 months. CD4+/CD8+ ratios were below normal for up to 8 months after transplantation and natural killer cells were elevated for up to 2 years in most patients. Median IgG and IgA levels were below the age mean even at 2 years after transplantation, although patients with AML had significantly higher IgG levels at 12 months compared with those with neuroblastoma. Lymphocyte proliferative responses to mitogens were markedly reduced at 4 months but returned to normal at 8 months. Despite the delay in immune reconstitution, there were no life-threatening infections. CONCLUSIONS: There appeared to be little difference in the overall kinetics of immune reconstitution between the children with neuroblastoma, who received total body irradiation and high-dose chemotherapy, and those with AML, who received high-dose chemotherapy alone as their pretransplant preparative regimen.

Acute Disease↗

Growth in children after bone marrow transplantation for acute myelogenous leukemia as compared to acute lymphocytic leukemia.

Previous studies of growth in children following bone marrow transplantation for leukemia have demonstrated poor growth with little ability to "catch-up" two to four years after transplantation. Because of small patient numbers, these studies did not distinguish patients with differing types of leukemia. 12 children with acute myelogenous leukemia who survived over 3 years after transplantation were compared with 12 who survived transplantation for acute lymphoblastic leukemia. The initial height standard deviation scores were similar in both groups prior to transplantation. The height standard deviation scores in the acute lymphoblastic leukemia group decreased for each of the 5 years after transplantation while the height score for the acute myelogenous leukemia group after 5 years was not statistically different from pre-transplantation. The growth of the children with myelogenous leukemia was better possibly because these children were older, had received less cranial irradiation at the time of transplantation, and had a lower incidence of severe chronic graft-versus-host disease.

Adolescent↗

Alternative donor bone marrow transplantation for children with juvenile myelomonocytic leukemia.

The purpose of this study was to evaluate the outcome of children with juvenile myelomonocytic leukemia (JMML) treated with alternative donor bone marrow transplantation (BMT). Twelve consecutive patients with JMML confirmed by in vitro clonogenic assays underwent alternative donor BMT. Ten patients received pretransplant chemotherapy for one to seven cycles (cytosine arabinoside regimens). Eight underwent splenectomy before the transplant. Donors were unrelated for nine patients and partially matched related for three. Conditioning included total body irradiation for all but one patient. Graft-versus-host disease (GVHD) prophylaxis included in vitro partial T-lymphocyte depletion for five patients with cyclosporine arabinoside, and cyclosporine arabinoside and methotrexate for seven. Acute GVHD developed in all patients, and chronic GVHD developed in 7 of 11 evaluable patients. Relapses occurred in two patients, and two died of transplant-related causes. Eight patients remain in remission with a median follow-up of 31 months after the BMT. The event-free survival rate for this series is 64% (95% confidence interval, 27%-85%). The roles of pretransplant chemotherapy and splenectomy for leukemic reduction to prevent relapse, and the use of conditioning regimens with total body irradiation require study in a larger series of patients. GVHD may be beneficial in preventing relapses, which has been the major cause of treatment failure for these patients.

Adolescent↗

Avascular necrosis in children with acute lymphoblastic leukemia.

This study describes the prevalence and demographics of avascular necrosis (AVN) in children with acute lymphoblastic leukemia (ALL). With improving survival of ALL patients on modern chemotherapy regimens, an increasing number of children with AVN will be presenting to orthopaedists. From 1991 to 1996, 202 patients were treated for ALL at a major tertiary pediatric cancer referral center. Eight patients (4.0%) subsequently developed AVN at an average of 30.0 months after beginning chemotherapy. A total of 27 documented joints were involved, with an average of 3.4 joints affected per patient diagnosed with AVN. The subset of patients with high-risk ALL who underwent an aggressive chemotherapy protocol was particularly susceptible to developing AVN. Six of 58 high-risk ALL patients (10.3%) developed AVN at an average of 18.5 months. As ALL patients now frequently survive into adulthood, orthopaedists will be increasingly called on to manage AVN affecting multiple joints in children and young adults.

Adolescent↗