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Biomedical subjects

I Yaniv

Publications and source records attributed to I Yaniv.

At least 73 records · Page 4Linked to original sources

Prognostic relevance of genetic alterations in the p32 region of chromosome 1 in neuroblastoma.

Thirty-six neuroblastomas were analysed for chromosome 1p alterations and their prognostic relevance. In 72% (26/36) of the patients, 1p alterations were identified in the tumours using 24 polymorphic loci ranging 1p22-1p36.3. LOH was identified in 25 children, and in 10 additional allelic imbalance was identified. In 1 child allelic imbalance was the sole alteration. Imbalance was termed as gain in intensity of one allele with or without reduction of the second allele (< 50%). The imbalance was identified in adjacent regions to the LOH. Two distinct regions of LOH were identified: 1p36.1-p36.3 and 1p31-p32. The common imbalance regions overlapped the common LOH regions. The children with LOH and imbalance had improved survival (100%) compared to the children with LOH only (26%) after 48 months of follow-up. The imbalance had an advantageous effect that is reflected by the improved outcome in children with other unfavourable clinical features.

Alleles↗

Additional chromosome 1q aberrations and der(16)t(1;16), correlation to the phenotypic expression and clinical behavior of the Ewing family of tumors.

The cytogenetic hallmark of the Ewing family of tumors is t(11,22)(q24;q12) in its simple, complex or variant forms and/or its molecular equivalent EWS/FLI, EWS/ERG rearrangement. Additional secondary consistent chromosomal aberrations include the der(16)t(1;16) and frequently, other chromosome 1q abnormalities leading to 1q overdosage. We studied whether these secondary cytogenetic changes are correlated to clinical features and phenotypic expression which may have a prognostic impact. Successful cytogenetic evaluation was performed in eight patients with a Ewing family tumor. In four of these, in addition to the primary aberration, chromosome 1q overdosage (including two with der (16)t(1;16)) was noted. Out of these four patients, two had metastatic disease at the time of evaluation, while in the other four, disease was localized. Morphologically, the tumors with the additional 1q aberration, revealed the pPNET subtype more frequently than the typical Ewing. They also expressed a higher degree of neural differentiation by neural marker immunocytochemistry, in comparison to tumors without the 1q aberration. Determination of the prognostic significance of this finding requires a longer follow-up with a larger group of patients.

Adolescent↗

Metastatic extraosseous Ewing tumor. Association of the additional translocation der(16)t(1;16) with the variant EWS/ERG rearrangement in a case of cytogenetically inconspicuous chromosome 22.

In Ewing sarcoma and related tumors, recently referred to as the Ewing tumors (ET), t(11;22)(q24q12) and its molecular genetic equivalent, the EWS/FLI-1 rearrangement, characterize approximately 85% of cases, while variant aberrations are rare. A second nonrandom aberration in ET is the unbalanced t(1;16) accompanying the t(11;22) in roughly 17% of cases. We present a 17-year-old man with estraosseous ET and multiple metastases, in whom the only cytogenetically detectable chromosomal aberration was der (16)t(1;16)(q12;q11.2). This finding was confirmed by fluorescence in situ hybridization (FISH). Using the RT-PCR technique, a variant EWS/ERG fusion transcript was noted, resulting from a t(21;22) chromosomal rearrangement which recently demonstrated in roughly 10% of ET. However, data on possible biologic differences in EWS/FLI-1 versus EWS/ERG expressing ET are as yet unavailable. This is the first reported combination of t(1;16) with the EWS/ERG rearrangement. A possible significance of this finding for Ewing tumor progression is discussed.

Adolescent↗

Hodgkin disease in children: reduced tailored chemotherapy for stage I-II disease.

PURPOSE: Between January 1982 and January 1994, 46 children with stage I-II Hodgkin disease were treated with a tailored regimen to maintain a high cure rate while reducing toxicity. PATIENTS AND METHODS: Forty-six previously untreated children with stage I-II Hodgkin disease received four to six courses of cyclophosphamide, oncovin, procarbazine, and prednisone (COPP) alternating with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD), tailored according to clinical response. Staging was based on various imaging modalities and gallium scan, but surgical staging was not performed. Radiotherapy was given only to bulky mediastinal disease. RESULTS: The median age at diagnosis was 13 years (range 4-18) and only 4 of 46 children had B symptoms. The majority (31 of 46) had stage II disease; 10 had bulky mediastinal disease. Nodular sclerosis histology predominated (32 of 46). Gallium scan was positive in 66% of the patients who were evaluated. Forty-three patients (93%) achieved complete remission after planned therapy. Thirty-six patients (78%) received chemotherapy alone, and 10 (22%) received combined-modality treatment. Fifteen children (33%) completed treatment with only four courses of COPP/ABVD. Overall freedom from relapse was 87% and overall survival was 98% with a median follow-up of 5 1/2 years. Long-term treatment-related morbidity was found mainly in patients receiving radiotherapy. CONCLUSION: Comprehensive clinical staging combined with tailored COPP/ABVD therapy according to response results in excellent disease control and may reduce toxicity.

Adolescent↗

Melphalan combined with a carboplatin dose based on glomerular filtration rate followed by autologous stem cell rescue for children with solid tumours.

Carboplatin and melphalan are two drugs whose toxicity profile makes them suitable for use in high doses followed by stem cell rescue. We report the use of high-dose carboplatin, with the dose based on glomerular filtration rate (GFR), combined with melphalan followed by autologous stem cell rescue in children with advanced stage or chemoresistant solid tumours. Thirty children were treated. After multiagent induction chemotherapy before BMT, 13 were in CR, five in VGPR, 11 in PR and one had progressive disease. They received melphalan, 180 mg/m2 and carboplatin, followed by autologous stem cell rescue. The dose of carboplatin was varied by GFR rather than fixed by surface area. The dose given ranged from 0.7 to 2.6 g/m2. Haematological and gastrointestinal toxicities were severe. Life-threatening or fatal toxicity was attributable to opportunistic infection in two cases and regimen-related in two cases. Of the 30 patients, 15 are alive and 13 disease-free at 4-36 months post-BMT. This simple two-drug combination has been used as consolidation of initial remission for patients with high-risk tumours. The toxicity is severe but tolerable. Use of a carboplatin dose based on GFR should optimise effectiveness in patients with good renal function and avoid excessive toxicity where renal function is impaired.

Adolescent↗

Involvement of 11p15 and 3q21q26 in therapy-related myeloid leukemia (t-ML) in children. Case reports and review of the literature.

The cytogenetic findings of therapy-related myeloid leukemia (t-ML) in three children are presented. These included one male patient with acute lymphoblastic leukemia (ALL) who underwent bone marrow transplantation and developed therapy-related myeloproliferative disease (t-MPD) in the female-donor hematopoietic cells 2.5 years after receiving radiation and epipodophyllotoxin therapy for ALL testicular relapse. Bone marrow leukemic cell karyotype revealed 46,XX,add (11)(p15) and a normal female karyotype in the peripheral blood lymphocytes. The other two children, one with ALL and one with ganglioneuroblastoma, developed fatal t-MPD and therapy-related acute myeloblastic leukemia (t-AML) preceded by myelodysplastic syndrome (t-MDS), respectively, 5 years after diagnosis, following administration of alkylating agents and irradiation. Monosomy 7 was present in both, and was combined with inv(3)(q21q26) in the second patient. Our review of the cytogenetic findings in 91 previously reported pediatric patients with t-ML suggested that the involvement of 11p15 and 3q21-->23, 3q24-q26 with or without a combination of translocation 11q23 and -7/7q-, respectively, are nonrandom aberrations of t-ML in children. Comparison of the chromosomal changes in t-ML between the pediatric and an adult series revealed some differences which may result from differences in treatment modalities and which, in addition, may indicate a possible role of genetic and/or age-dependent factors in the pathogenesis of therapy-related leukemogenesis in children.

Antineoplastic Agents↗

Chronic childhood idiopathic thrombocytopenia purpura: long-term follow-up.

An understanding of the natural history of childhood chronic idiopathic thrombocytopenia purpura (ITP) could contribute to a rational therapeutic approach to its treatment, which remains controversial. In our retrospective study of 92 children with ITP, 22 had a chronic course and were followed for 3-14 years (median 8.6 years). Treatment, when indicated, was individualized: 4 patients (18.2%) did not receive any treatment, 14 (63.6%) received steroids only, while 4 (18.2%) were treated with steroids and one of the following: high-dose gamma globulin (4 patients), splenectomy (2 patients) or immunosuppressive therapy (2 patients). During follow-up, 14 patients (63.6%) achieved complete remission, 5 (22.7%) partial remission and only 3 (13.5%) remained severely thrombocytopenic, with minimal bleeding tendency. Eleven patients (50%) responded to the initial prednisone course (1-5 mg/kg/day), but showed a marked decrease in platelet count when steroids were tapered off. In view of the high rates of complete and partial remission and the mild course of the few non-responding patients, it is suggested that with adequate supportive therapy, follow-up problems and fatalities can be kept to a minimum. We believe that aggressive therapy, such as splenectomy, should be reserved for the rare symptomatic and severely thrombocytopenic patient.

Child↗

Genetic alterations involving chromosome 1p in children with neuroblastoma.

Neuroblastoma is a common childhood tumor of the sympathetic nervous system, characterized by N-myc amplification and loss of heterozygosity (LOH) for sequences on chromosomes 1p, 11q and 14q. Using restriction fragment length polymorphism analysis, the constitutional and tumor genotypes were compared for LOH on 1p in 25 children with neuroblastoma at diagnosis: 19 in stages III-IV, 5 in stages I-II and one in IVs. The genetic alterations observed on chromosome 1p were frequent in the early and advanced stages. Thirty-three percent of the alterations were found in patients under the age of 1 year, and in one patient with IVs. It is concluded that 1p alterations were identified in children with neuroblastoma in early stages and infants and thus of no prognostic relevance. 1p genetic alterations may be early events in neuroblastoma.

Blotting, Southern↗

Peripheral blood stem cells as a source for hemopoietic recovery following autologous bone marrow transplantation in childhood malignancy.

In an attempt to improve hemopoietic recovery after autologous bone marrow transplantation (ABMT), a project of peripheral blood stem cells (PBSC) harvest was initiated. Thirty-six children awaiting ABMT underwent 126 PBSC harvests primed by a conventional scheduled chemotherapy course and rGMCSF 5 micrograms/kg per day/s.c. Ages ranged from 12 months to 19 years and weight from 9 to 84 kg. PBSC harvest was carried out using the Fenwall CS 3000 Plus with the small volume collection chamber at a maximum whole blood flow rate of 15-45 ml/min; total volume processed was 1,700-10,000 ml. Total nucleated cells per collection was 0.35-5.62 x 10(8) cells per kg, and the number of CD34+ cells, 0.23-1.1 x 10(6)/kg. The number of colony forming units-granulocyte macrophages (CFU-GM) varied in these heavily pretreated patients from 0 to 5.3 CFU-GM x 10(4)/kg per collection. Immunophenotyping of the cells collected was performed by double staining for CD34, CD33, CD15, CD71, Ia and CD56. Most of the CD34+ cells were found to be CD38+; some were CD33+ and some CD33-. Low coexpression of CD34+ CD71+ cells may correlate with the low proliferating capacity of PBSC as compared to the BM cells. To date 22 children have undergone transplantation using combined autologous PBSC and bone marrow. We conclude that PBSC harvest is a feasible and safe procedure even in small children, and can be successfully performed following scheduled chemotherapy and administration of growth factors, resulting in substantial yield, also in heavily pretreated patients. This procedure is recommended in responding high risk patients at the stage of minimal residual disease and may replace ABMT in the future.

Adolescent↗

Long-term intravenous deferoxamine treatment for noncompliant transfusion-dependent beta-thalassemia patients.

With the introduction of long-term subcutaneous administration of deferoxamine (DFO), there has been a decline in the morbidity and mortality of transfusion-dependent beta-thalassemia patients. However, since the use of subcutaneous DFO is hindered by poor compliance, long-term i.v. DFO therapy has been attempted in order to improve compliance, prevent excessive iron accumulation and extend survival. Thirteen patients (aged 5.4-18.4 years) were started on i.v. home administration of DFO (100 mg/kg per day) via an exteriorized, tunneled right atrial catheter (Hickman type). After a median follow-up of 36 months, the mean ferritin levels had dropped significantly (5,117 +/- 1,737 to 1,816 +/- 1,062 micrograms/l. P = 0.0001). None of the patients developed new endocrine or cardiac diseases due to iron overload. Patients beginning therapy at an early age (< or = 11 years) showed a tendency for improved growth parameters at the end of the treatment period. Two patients developed moderately high frequency sensorineural hearing loss. One patient developed a right atrial thrombus. The line infection rate was low (1.7 episodes per 1,000 patients days). In view of the grave prognosis for iron overloaded patients and the fact that oral chelators are not yet readily available, we recommend this form of therapy for the young, noncompliant beta-thalassemia patient, despite the occasional complications observed.

Adolescent↗

T-cell acute lymphoblastic leukemia following therapy of rhabdomyosarcoma.

Multiple studies have documented an increased risk of secondary malignancies in patients receiving alkylating agents. Secondary leukemia following chemotherapy accounts for about 20% of all secondary neoplasms; most are acute nonlymphocytic. Secondary acute lymphoblastic leukemia has rarely been reported in either adult or childhood cancer. We report the development of acute T-cell lymphoblastic leukemia in a child following successful treatment of a paravertebral embryonal rhabdomyosarcoma (ERS). Southern blot analysis of DNA extracted from the T-cell lymphoblasts, using probes homologous to loci on the short arm of chromosome 11; P-calcitonin, P40.1 and H-ras, did not demonstrate the chromosomal loss of heterozygosity (LOH), a common feature of embryonal rhabdomyosarcoma. The data presented support the assumption that de novo leukemia emerged following treatment of the primary malignancy.

DNA, Neoplasm↗

Recurrent peripheral arterial occlusion by leukemic cells sedimentation in acute promyelocytic leukemia.

A 10-year-old boy presenting with recurrent successive events of peripheral arterial occlusion in both legs, more prominent on the left side, was diagnosed as having acute promyelocytic leukemia. Histological examination of the occluding material showed that it was composed of leukemic blast cells. The boy underwent five operations. Each time the arterial flow was reestablished by removing cylindrical hollow white material obstructing the lumen. However, after the last operation, irreversible ischemia developed, necessitating an above-knee amputation. There was no evidence of disseminated intravascular coagulation. Three months later a right lumbar sympathectomy was performed for relief of causalgic-ischemic pains, with successful results. Preoperative angiography demonstrated irregular narrowing of the right iliac arteries and tibioperoneal trunk stenosis.

Amputation, Surgical↗

Inflammatory pseudotumor in childhood. A diagnostic and therapeutic dilemma.

We describe a case of inflammatory pseudotumor of the lower abdomen in a young child. The urinary bladder and abdominal wall were involved, and the pseudotumor simulated a malignant sarcomatous tumor. Surgical excision was undertaken, and the outcome was favorable. This rare tumor simulates a true neoplasm both clinically and morphologically and presents a diagnostic and therapeutic dilemma. Our case and a review of the literature indicate that an effort should be made to perform a radical excision. This is considered the treatment of choice except if it requires a mutilating procedure.

Abdominal Muscles↗

Autologous bone marrow transplantation in pediatric solid tumors.

During the last 5 years massive chemotherapy and autologous bone marrow transplantation have been increasingly explored in the treatment of pediatric solid tumors, mainly for neuroblastoma, Ewing's sarcoma, rhabdomyosarcoma, Wilms' tumor, germ cell tumors, osteosarcoma, and retinoblastoma. Although the disease course could be changed successfully in most instances, the long-term survival has not yet been improved much over the best available conventional treatments. Despite this, in responding relapsed patients this approach seems promising and may represent the only chance of cure. New and better induction regimens are needed.

Adolescent↗

Heuristics of reasoning and analogy in children's visual perspective taking.

We propose that children's reasoning about others' visual perspectives is guided by simple heuristics based on a perceiver's line of sight and salient features of the object met by that line. In 3 experiments employing a 2-perceiver analogy task, children aged 3-6 were generally better able to reproduce a perceiver's perspective if a visual cue in the perceiver's line of sight sufficed to distinguish it from alternatives. Children had greater difficulty when the task hinged on attending to configural cues. Availability of distinctive cues affixed on the objects' sides facilitated solution of the symmetrical orientations. These and several other related findings reported in the literature are traced to children's reliance on heuristics of reasoning.

Attention↗

Deferoxamine (Desferal)-induced ocular toxicity.

A 4-year-old girl with juvenile chronic myeloid leukemia relapsed after an allogeneic bone marrow transplantation (BMT) and became refractory to conventional chemotherapy. Treatment with two courses of high-dose deferoxamine, an iron chelator (130-180 mg/kg/day), along with low-dose ARA-c (5 mg/kg/day) caused a remarkable decrease of the WBC and fetal Hb. Three days following the last dose of deferoxamine, the patient experienced an acute visual loss, confirmed by electroretinogram (ERG) and visual evoked response (VER). Slight improvement occurred a few days later, but the patient developed severe pancytopenia and died of Klebsiella septic shock. The ocular manifestations were attributed to deferoxamine toxicity in light of the rapid onset after first exposure, the electrophysiological pattern of metabolic damage in the ERG and VER, and the long interval between the last chemotherapy and BMT. The pathogenesis of deferoxamine toxicity is discussed.

Blindness↗