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S Jayabose

Publications and source records attributed to S Jayabose.

At least 19 recordsLinked to original sources
PubMed2003

TEL-AML1 fusion precedes differentiation to pre-B cells in childhood acute lymphoblastic leukemia.

The TEL-AML1 gene fusion results from a karyotypically cryptic t(12;21) translocation, the most common genetic abnormality in pediatric acute lymphoblastic leukemia (ALL). The presence of the TEL-AML1 fusion in utero, its protracted latency to overt leukemia, and secondary loss of the untranslocated TEL suggest it is an initiating event. Sequences of the TEL-AML1 genomic breakpoint and the immunoglobulin heavy chain (IgH) and/or T-cell receptor (TCR) gene rearrangements were characterized in four pediatric pre-B ALL patients. Analysis of these markers in relapsed patients revealed that immunophenotypically and cytogenetically distinct, and clonally unrelated antigen receptor leukemic cell populations harbored the same initiating TEL-AML1 molecular abnormality. Furthermore, TEL-AML1-positive cells persisted during remission even in the absence of detectable clone-specific IgH and TCR markers. We demonstrate that the TEL-AML1 translocation can occur in vivo during B-cell development before rearrangement of the IgH and TCR genes. We propose, in some cases, that the TEL-AML1 translocation occurs in a stem or B progenitor cell, and that recurrent TEL-AML1-positive pre-B ALL represents a de novo-transformed population that retains the same diagnostic initiating event.

Adolescent↗
PubMed2003

Telomere dynamics in childhood leukemia and solid tumors: a follow-up study.

Telomeres of hematopoietic cells shorten with age, possibly contributing to the aging-associated hematopoietic pathology (immunosenescence, malignant transformation). Accelerated telomere shortening is seen with replicative stress, such as during administration of serial chemotherapy cycles for the treatment of childhood cancer. To define the long-term consequences of pediatric cancer treatment on hematopoietic cell telomere length, we undertook a prospective 4-year follow-up study of a 61-patient cohort of pediatric malignancies in a community-based setting. We found that mononuclear cells (MNC) and granulocytes of children with standard-risk acute lymphoblastic leukemia (ALL) suffered minimal telomere shortening throughout therapy (less than 1 kbp; average follow-up, 20 months), while those of children with solid tumors showed greater and more heterogenous telomere attrition (0.5-2.8 kbp, average follow-up, 9 months). In addition, we evaluated the role of telomerase, the enzyme commonly up-regulated in pediatric leukemic and solid tumor cells for telomere length maintenance, as a disease marker. Serial determinations of telomerase in MNC were useful to confirm disease remission in leukemia, but play no role in the follow-up of children with solid tumors.

Adolescent↗
PubMed2001

Hyperdiploidy in a case of favorable histology Wilms tumor.

Hyperdiploidy is useful in defining histologic variants of Wilms tumor and prognosis in other childhood cancers. We describe a case of hyperdiploid favorable histology Wilms tumor (50,XY,+6,+7,+8,+10,+12,-21[2]/51,idem,+9[6]/46,XY[12]) in a 3-year-old boy, and review the literature for other hyperdiploid childhood renal lesions.

Child, Preschool↗
PubMed2001

Intravenous anti-D immune globulin-induced intravascular hemolysis in Epstein-Barr virus-related thrombocytopenia.

RhoD immune globulin intravenous (anti-D IGIV) increases platelet counts in patients who have not undergone splenectomy and are positive for RhoD with idiopathic thrombocytopenic purpura. After treatment, in most patients, anemia develops as a result of immune-mediated red cell destruction in the spleen. Although intravascular hemolysis (IVH) is not expected, life-threatening IVH has been recently reported by the Food and Drug Administration, and physicians are encouraged to report their experience with patients with idiopathic thrombocytopenic purpura in whom IVH develops after anti-D administration. Severe IVH was observed after treatment with anti-D IGIV in two adolescent girls with acute thrombocytopenia related to Epstein-Barr virus. They did not have hemolytic anemia before treatment. The authors believe that anti-D IGIV triggered an unusual virus-induced immune response causing hemolysis; therefore, anti-D IGIV should not be used in patients with Epstein-Barr virus-related thrombocytopenia, particularly during the acute phase of infection.

Adolescent↗
PubMed2000

Cytogenetic abnormalities during clinical, immunophenotypic, and molecular remission in pediatric acute lymphoblastic leukemia.

The significance of random cytogenetic abnormalities detected in pediatric acute lymphoblastic leukemia (ALL) during remission is unknown. We studied 10 of 72 consecutive ALL patients who developed cytogenetic abnormalities during clinical remission to determine their effect on remission status. The cytogenetic abnormalities occurred at a median of 14.5 months (range 5-72) from the initial diagnosis. Five abnormalities were designated as clonal (monosomy 21 in three metaphases and 64 approximately 69,XXY in three metaphases from one patient at different times, and del(20)(q12q13) in three metaphases, add(13)(q34) in two metaphases, and ?del(19)(p11) in two metaphases from three different patients). Seven abnormalities were previously described: del(5)(q12), del(5)(q33), -7, del(11)(q23), +12, and +13 each in one metaphase, and del(20)(q12q13) in three metaphases). The remaining cytogenetic abnormalities were nonclonal and random. Flow cytometry and analysis of IgH and TcR gene rearrangements showed that all evaluable patients were in immunophenotypic and molecular remission, respectively. Eight patients remain in clinical and molecular remission a median of 9 months (range 7-18) after detecting the cytogenetic abnormality, and the leukemia in two patients has relapsed. During remission, cytogenetic abnormalities may not be a harbinger of leukemia relapse in pediatric ALL; therefore, a wait-and-see approach is prudent.

Aneuploidy↗
PubMed2000

Recurrent urinary tract infections and genitourinary tract abnormalities in the Imerslund-Gräsbeck syndrome.

Two Imerslund-Gräsbeck patients who presented with recurrent urinary tract infections and genitourinary abnormalities are described. The patients were evaluated with abdominal ultrasounds, voiding cystourethrograms, and Schilling tests. Each patient had large postvoid residual urine secondary to a motor-neurogenic bladder. One had a duplication of the distal urethra manifesting as two meatal openings. There was lack of urinary excretion of radioactive vitamin B12 on Schilling tests in both patients. Patients with Imerslund-Gräsbeck syndrome may be predisposed to urinary tract infections because of incomplete bladder emptying. Complete physical and radiological examinations of the genitourinary tract should be performed.

Child↗
PubMed1999

Quantitation of leukemia clone-specific antigen gene rearrangements by a single-step PCR and fluorescence-based detection method.

PCR-based detection of minimal residual disease (MRD) in children with precursor B cell acute lymphoblastic leukemia (pre-B ALL) by amplification of clone-specific antigen gene rearrangements has been labor-intensive. In this study we present a simpler, yet accurate, method to assess and quantitate MRD in pediatric pre-B ALL that utilizes these markers. From the sequence of the immunoglobulin heavy chain (IgH) and T cell receptor (TcR) gene rearrangements characterized at the time of diagnosis or relapse, primers were designed and tested in a clone-specific, single-round PCR assay, then analyzed by fluorescence staining of the PCR products. The most critical step involved an adherence to a new set of guidelines for the design of clone-specific primers. Application of this method to 54 IgH and 13 TcR (nine Vdelta2Ddelta3 and four Ddelta2-Ddelta3) gene rearrangements in 47 patients resulted in an intense band within the region of the predicted molecular weight, confirming the reproducibility of the assay. Quantitative applications of the approach were examined by performing a 10-replicate limiting dilution clone-specific PCR on six diagnostic samples and an asymptotic response model of the Von Krogh form was found to fit the data well. From this model, estimation of leukemic cells of remission bone marrow samples was achieved at a detection sensitivity of 2 x 10(-6). The method is demonstrated on 18 patients whose marrows were prospectively analyzed during therapy. We conclude this methodology is useful in the quick and accurate assessment of MRD in children with pre-B ALL, and could be applied to other DNA quantitation assays.

Antigens, Neoplasm↗
PubMed1999

Randomized double-blind comparison of single high-dose ondansetron and multiple standard-dose ondansetron in chemotherapy-naive pediatric oncology patients.

This prospective, double-blind, randomized study compares the antiemetic efficacy of an equivalent dose of ondansetron administered as a single high dose or as multiple standard doses in pediatric oncology patients. Thirty-one chemotherapy-naive patients were randomized at diagnosis to receive either single high-dose ondansetron (0.6 mg/kg, maximum dose 32 mg) or multiple standard-dose ondansetron (0.15 mg/kg, maximum dose 8 mg, every 4 hr for four doses). Antiemetic efficacy was assessed by an emesis scale described as follows: 1, no nausea or emesis; 2, nauseous but able to eat; 3, nauseous and unable to eat; and 4, emesis. Sixteen patients received high-dose and 15 received standard-dose ondansetron. Patients receiving moderately or severely emetogenic chemotherapy were evenly distributed between the two treatment groups. Eighty-one percent of patients receiving high-dose and 80% receiving standard-dose ondansetron rated 1 or 2 on the emesis scale (p = 0.93). No patient experienced any clinical or laboratory toxicity. Our study suggests that single high-dose ondansetron is as efficacious as the multiple standard-dose regimen and is well tolerated. Its use will facilitate the administration of ondansetron in pediatric patients receiving chemotherapy.

Adolescent↗
PubMed1998

Isochromosome 7q and Wilms tumor.

Isochromosome 7q is a nonrandom cytogenetic abnormality in Wilms tumor. Two notable cases are described: (1) a case of bilateral Wilms tumor in which only the left-sided tumor contained isochromosome 7q and (2) a case of left-sided Wilms tumor in which the tumor contained isochromosome 7q, in addition to four other chromosomal abnormalities associated with Wilms tumor.

Child, Preschool↗
PubMed1998

Telomerase activity and telomere length in pediatric patients with malignancies undergoing chemotherapy.

Telomerase activity and telomere length in mononuclear cells (MNCs) and granulocytes from peripheral blood (PB) and bone marrow (BM) specimens were studied in pediatric acute leukemia (ALL, n = 15; AML, n = 11) and pediatric solid tumor (ST) patients (n = 9) at diagnosis, during and after chemotherapy. In four ST patients, tumor tissue was also available. For comparative analysis, MNCs from healthy donors (n = 53) were analyzed. Telomerase was evaluated using a modified telomeric repeat amplification protocol (TRAP) assay, and telomere length by terminal restriction fragment (TRF) analysis. At diagnosis, high telomerase activity was detected in MNCs from all leukemia patients, which was similar to the activity from ST biopsy specimens. This exceeded by 10- to 20-fold the activity in PB MNCs from ST patients and healthy donors (P < 0.05). Granulocyte fractions lacked telomerase activity in all groups. BM MNCs in leukemia patients revealed a four-fold higher telomerase activity than PB (P = 0.005). After induction chemotherapy and response to treatment, telomerase activity decreased to borderline or undetectable levels in PB MNCs in leukemia (P < 0.01). Average telomeres in PB MNCs from pediatric patients were significantly longer (n = 25; 10.9 kbp) than telomeres in PB and BM MNCs from adult healthy donors (7.45 kbp) (P < 0.0001). At diagnosis, telomeres were shorter from BM compared to PB specimens in leukemia (P < 0.05), and two peak TRFs were observed corresponding to the malignant and normal cell clones. With the attainment of remission, the lower TRF peak, reflecting the leukemic population, was lost. In leukemia patients, mean TRFs increased on average 2.2 kbp after induction chemotherapy, but decreased thereafter on consolidation and maintenance chemotherapy (1 kbp). This was comparable to an average telomere loss of 1.2 kbp in PB specimens from ST patients after chemotherapy. In all patients, telomere loss in granulocytes as compared to MNCs was more pronounced with 1.8 vs 1 kbp, respectively (P = 0.014). Our results demonstrate that at diagnosis, telomerase was consistently and highly upregulated in BM and PB specimens in leukemia, decreased after induction therapy, and correlated with remission. BM specimens in leukemia had higher telomerase activity, probably due to the greater leukemic burden than in PB. Telomeres were significantly longer in children than in adults, but shortened as a consequence of chemotherapy with repeated cycles of hematopoietic regeneration. In acute leukemia, with the loss of the leukemic burden after induction chemotherapy, longer mean TRFs were found, a reflection of the repopulation with normal cells. Our findings suggest that telomerase activity may be useful in the management of childhood malignancies. The significance of telomere length shortening in pediatric patients undergoing chemotherapy and possible telomere regeneration after myelosuppressive treatment remain to be determined.

Adolescent↗
PubMed1998

Infections due to nontuberculous mycobacteria in children with leukemia.

We reviewed the spectrum of infections due to nontuberculous mycobacteria (NTM) in children with leukemia. Three children acquired such infections. One patient developed pneumonia after the cessation of chemotherapy when Mycobacterium xenopi was identified in his lung biopsy specimen. He required 2 years of treatment with antituberculous agents and clarithromycin. Cultures of central and peripheral blood specimens from two patients yielded Mycobacterium fortuitum and Mycobacterium chelonae, respectively. Broviac catheters were likely the source of infection. Removal of the catheters and antibiotic treatment resulted in cure. Central venous catheters in leukemic children are potential sources of infection. For febrile neutropenic children with leukemia who do not respond to antibiotic therapy, cultures positive for diphtheroids or negative routine bacterial and fungal cultures should raise a suspicion for infections due to NTM. Systemic infections may require up to 2 years of therapy. Removal of the infected catheters during persistent or recurrent infections in necessary for control of the infection.

Blood↗
PubMed1997

Prenatally diagnosed neuroblastoma.

BACKGROUND: Prenatally diagnosed neuroblastomas have been reported in increasing numbers over the past several years, and there are now a few reviews based on up to 21 cases. The purpose of this article is to review the clinical and biologic features of prenatally diagnosed neuroblastoma based on a review of 55 cases. METHODS: A review was conducted of 3 cases seen at the study institution and 52 other cases reported thus far in the literature. RESULTS: Prenatal diagnosis was made usually after 32 weeks of gestation. Approximately 93% of the tumors were adrenal in origin, and 44% of these were cystic. Thirty-seven patients (67%) had Stage I disease, 12 (22%) had Stage IV-S disease, and only 3 (5%) had Stage IV disease. The DNA index was favorable (> 1) in 14 of 16 patients studied. None of these 16 patients studied had amplification of the N-myc oncogene. Catecholamines were elevated in only 33% of the patients. The liver was the most common site of dissemination, which was observed in 25% of patients; bone involvement was not observed in any patient. Ultrasonography failed to detect existing hepatic metastasis in three patients. Primary surgical resection was performed in 47 patients (85%). Chemotherapy was given to five patients and radiotherapy to three. Of the 50 patients for whom follow-up information was available, 45 (90%) were alive at a range of 2-120 months from diagnosis. CONCLUSIONS: Prenatally diagnosed neuroblastomas are predominantly adrenal in origin and frequently cystic. The liver is the most common site of dissemination and bone involvement is notably absent. The vast majority of these infants have a favorable stage of disease (I, II, and IV-S) and favorable biologic features, and consequently have an excellent prognosis. Although surgery alone is curative for most patients, a period of observation may avoid surgery in some individuals who may achieve spontaneous regression.

Adrenal Gland Neoplasms↗
PubMed1997

Failure of partial splenectomy to ameliorate the anemia of pyruvate kinase deficiency.

The authors report a case of pyruvate kinase deficiency in a 4-year-old patient who required monthly blood transfusions. A partial splenectomy was performed to decrease the transfusion requirements and at the same time preserve splenic function. After removal of 80% of splenic tissue there was no amelioration of her transfusion needs. She responded well to subsequent total splenectomy performed 6 months later, and is currently well and transfusion independent. Rapid splenic regeneration possibly caused by erythrophagocytosis and extramedullary hematopoiesis is the presumed reason for this patient's failure to respond to partial splenectomy.

Anemia, Hemolytic↗
PubMed1996

Clinical and hematologic effects of hydroxyurea in children with sickle cell anemia.

PURPOSE: This open-label pilot study was designed (1) to determine the effect of hydroxyurea on the hemoglobin level in children with sickle cell anemia, (2) to evaluate the toxicity of hydroxyurea, and (3) to assess any impact of hydroxyurea on the frequency of vaso-occlusive crises (VOCs). PATIENTS AND METHODS: Ten children (group 1) with three or more VOCs of the extremities or two or more VOCs of the lungs (acute chest syndrome) in the preceding 12 months, and five children (group 2) with hemoglobin levels less than 70 gm/L were treated with hydroxyurea in doses of 20 to 35 mg/kg per day. The frequency of VOCs before hydroxyurea therapy was compared with the frequency during therapy, and the peak hemoglobin levels during hydroxyurea therapy were compared with the pretreatment values. RESULTS: One patient in group 1 was removed from the study within 1 month because of nausea. Seven of the remaining nine patients in group 1 had a decrease in the frequency of VOCs. The number of VOCs per patient-year for all 14 patients decreased from 2.5 before hydroxyurea therapy to 0.87 during hydroxyurea therapy, a decrease of 65% (p < 0.00001). Two of five patients in group 2 had an increase in hemoglobin of 27 gm/L and 34 gm/L over the baseline. The median rise in hemoglobin was 19 gm/L (range, 7 to 37) for all 14 patients. Nine patients are still receiving hydroxyurea for a median period of 23 months (range, 18 to 59). CONCLUSIONS: Hydroxyurea decreases the severity of anemia in some patients, and it may decrease the frequency of VOC. Its short-term hematologic toxicity is minimal.

Adolescent↗
PubMed1996

Is contralateral exploration of the kidney necessary in patients with Wilms tumor?

PURPOSE: Surgical exploration of the contralateral kidney in patients with Wilms tumor is standard practice. The introduction of modern imaging techniques (ultrasound, computerized tomography and magnetic resonance imaging) in place of excretory urography has led to a more accurate definition of intrarenal pathology. Is contralateral kidney exploration still necessary in patients with Wilms tumor? MATERIALS AND METHODS: We reviewed the records of 75 patients from 3 medical centers who were evaluated and treated for Wilms tumor in the last 14 years. All children underwent preoperative excretory urography, computerized tomography, ultrasound and/or magnetic resonance imaging. RESULTS: Seven bilateral Wilms tumors were diagnosed preoperatively and confirmed surgically, whereas extensive operative exploration of the contralateral kidney in the other 69 patients revealed no additional pathological condition. This concurred with preoperative radiological findings with 100% sensitivity and specificity. Furthermore, 1 month to 12 years of followup (mean 4.3 years) revealed no tumor in the contralateral kidney. The major postoperative complication was small bowel obstruction in 5 patients 15 to 180 days (mean 77.2) after explorative laparotomy. CONCLUSIONS: In all patients preoperative radiological investigation was accurate in excluding bilaterality. With modern imaging techniques and effective chemotherapy extensive contralateral renal exploration may no longer be mandatory for managing Wilms tumor.

Adolescent↗
PubMed1996

Langerhans cell histiocytosis associated with partial DiGeorge syndrome in a newborn.

PURPOSE: We report the unrecognized association of Langerhans cell histiocytosis (LCH) with partial DiGeorge syndrome. PATIENT AND METHODS: A 7-week-old infant with endocrine and immunologic characteristics of DiGeorge syndrome displayed multisystem involvement of Letterer-Siwe disease at birth. RESULTS: Despite vigorous medical support and chemotherapy, she died at 9 months of age with multisystem failure. CONCLUSIONS: This case supports the role of the thymus n the pathogenesis of LCH.

DiGeorge Syndrome↗