Erg and AP-1 as determinants of glucocorticoid response in acute lymphoblastic leukemia.

Glucocorticoids (GCs) are among the most widely prescribed medications in clinical practice. The beneficial effects of GCs in acute lymphoblastic leukemia (ALL) are based on their ability to induce apoptosis, but the underlying transcriptional mechanisms remain poorly defined. Computational modeling has enormous potential in the understanding of biological processes such as apoptosis and the discovery of novel regulatory mechanisms. We here present an integrated analysis of gene expression kinetic profiles using microarrays from GC sensitive and resistant ALL cell lines and patients, including newly generated and previously published data sets available from the Gene Expression Omnibus. By applying time-series clustering analysis in the sensitive ALL CEM-C7-14 cells, we identified 358 differentially regulated genes that we classified into 15 kinetic profiles. We identified GC response element (GRE) sequences in 33 of the upregulated known or potential GC receptor (GR) targets. Comparative study of sensitive and resistant ALL showed distinct gene expression patterns and indicated unexpected similarities between sensitivity-restored and resistant ALL. We found that activator protein 1 (AP-1), Ets related gene (Erg) and GR pathways were differentially regulated in sensitive and resistant ALL. Erg protein levels were substantially higher in CEM-C1-15-resistant cells, c-Jun was significantly induced in sensitive cells, whereas c-Fos was expressed at low levels in both. c-Jun was recruited on the AP-1 site on the Bim promoter, whereas a transient Erg occupancy on the GR promoter was detected. Inhibition of Erg and activation of GR lead to increased apoptosis in both sensitive and resistant ALL. These novel findings significantly advance our understanding of GC sensitivity and can be used to improve therapy of leukemia.

Study on developmental-behavioural pediatrics training experiences of pediatricians and pediatric trainees working in Nepal.

BACKGROUND: There are growing concerns about developmental, behavioural, social and emotional wellbeing of children throughout the world. A huge gap exists between the instructions provided on medical disciplines and on areas of Developmental-Behavioural Pediatrics (DBP) during pediatric training in our region. OBJECTIVE: This study aims to evaluate the Developmental-Behavioural pediatrics (DBP) training experiences of pediatricians and pediatric trainees during their post graduate training in pediatrics. METHODS: Questionnaires were sent to the pediatricians / trainees and data was analyzed using SPSS software. RESULT: More than 56 % of respondents were satisfied in 10 out of 11 medical disciplines whereas more than 56% were unsatisfied in 10 out of 11 developmental behavioural pediatrics disciplines. This study has demonstrated that between 50-60 % of pediatricians did not see the cases of ADHD, learning difficulty and family dysfunction for a period of three months prior to the survey which are relatively common conditions. Even in post graduate training nearly 66 % of pediatricians were unsatisfied with their instructions in DB pediatrics. CONCLUSION: Pediatricians working in Nepal have difficulties in addressing the issues of developmental pediatrics, raising a question about the need to review the curriculum of post graduate training in Pediatrics.

Ectopic thyroid tissue- A case series

@#<p><strong>OBJECTIVE:</strong> To describe the clinical presentation and course of seven ectopic thyroid patients. <br /><br /><strong>METHODS:<br />Design:</strong> Retrospective Chart Review<br /><strong>Setting:</strong> Tertiary Government Teaching Hospital<br /><strong>Patient:</strong> Seven patients<br /><br /><strong>RESULTS:</strong> Five patients were female and two were male (ratio of 5:2). Three belonged to the 20 to 30 year-old age group, whereas two were below 10 years of age. All seven were biochemically hypothyroid and ectopic thyroid was found to be the only functioning thyroid tissue. Three patients were managed medically with levothyroxine, while ectopic thyroid was excised in four. Ectopic thyroid tissue was autotransplanted in two cases following excision.<br /><br /><strong>CONCLUSION:</strong> The ages of presentation in the present series correspond with the increased physiological demand of thyroid hormone. Thyroid substitution therapy is a must in the presence of clinical and/or biochemical hypothyroidism. Surgical excision should be avoided as far as possible especially if the ectopic tissue is the only functioning thyroid in the body. Surgery is required in selected cases presenting with obstructive symptoms or hemorrhage which are unresponsive to substitution therapy. Auto transplantation of the ectopic thyroid may not provide significant benefit to the patient and more research is warranted in this aspect.</p>

5T4 oncofetal antigen is expressed in high risk of relapse childhood pre-B acute lymphoblastic leukemia and is associated with a more invasive and chemotactic phenotype.

Although the overall prognosis in childhood acute lymphoblastic leukemia (ALL) is good, outcome after relapse is poor. Recurrence is frequently characterized by the occurrence of disease at extramedullary sites, such as the central nervous system and testes. Subpopulations of blasts able to migrate to such areas may have a survival advantage and give rise to disease recurrence. Gene expression profiling of 85 diagnostic pre-B-ALL bone marrow samples revealed higher 5T4 oncofetal antigen transcript levels in cytogenetic high-risk subgroups of patients (P<0.001). Flow cytometric analysis determined that bone marrow from relapse patients have a significantly higher percentage of 5T4-positive leukemic blasts than healthy donors (P=0.005). The high-risk Sup-B15 pre-B-ALL line showed heterogeneity in 5T4 expression, and the derived, 5T4(+) (Sup5T4) and 5T4(-) (Sup) subline cells, displayed differential spread to the omentum and ovaries following intraperitoneal inoculation of immunocompromised mice. Consistent with this, Sup5T4 compared with Sup cells show increased invasion in vitro concordant with increased LFA-1 and VLA-4 integrin expression, adhesion to extracellular matrix and secretion of matrix metalloproteases (MMP-2/-9). We also show that 5T4-positive Sup-B15 cells are susceptible to 5T4-specific superantigen antibody-dependent cellular toxicity providing support for targeted immunotherapy in high-risk pre-B-ALL.

Giant cell tumor of the maxilla

@#OBJECTIVE/strong: To present a rare case of maxillary swelling; its investigation and management.br /br /strongMETHODS/strong:br /strongDesign/strong: Case Report br /strongSetting/strong: Tertiary Government Teaching Hospital br /strongPatient/strong: One br /br /strongRESULTS/strong: A 45-year-old female presented with a right maxillary swelling of six months duration. Radiological investigation revealed a radiolucent lesion arising from the inferior aspect of the right maxilla with no areas of calcification. Incisional biopsy report was consistent with giant cell tumor. The mass was excised via a Weber Ferguson incision under general anesthesia.CONCLUSION/strong: Though rare, giant cell tumor should be considered as one of the differential diagnosis in cases of maxillary swelling. Adequate surgical excision with long-term follow-up should be the treatment of choice for managing a giant cell lesion of the maxilla./p

Temporal changes in the incidence and pattern of central nervous system relapses in children with acute lymphoblastic leukaemia treated on four consecutive Medical Research Council trials, 1985-2001.

Despite the success of contemporary treatment protocols in childhood acute lymphoblastic leukaemia (ALL), relapse within the central nervous system (CNS) remains a challenge. To better understand this phenomenon, we have analysed the changes in incidence and pattern of CNS relapses in 5564 children enrolled in four successive Medical Research Council-ALL trials between 1985 and 2001. Changes in the incidence and pattern of CNS relapses were examined and the relationship with patient characteristics was assessed. The factors affecting outcome after relapse were determined. Overall, relapses declined by 49%. Decreases occurred primarily in non-CNS and combined relapses with a progressive shift towards later (> or =30 months from diagnosis) relapses (P<0.0001). Although isolated CNS relapses declined, the proportional incidence and timing of relapse remained unchanged. Age and presenting white blood cell (WBC) count were risk factors for CNS relapse. On multivariate analysis, the time to relapse and the trial period influenced outcomes after relapse. Relapse trends differed within biological subtypes. In ETV6-RUNX1 ALL, relapse patterns mirrored overall trends whereas in high hyperdiploidy (HH) ALL, these seem to have plateaued over the latter two trial periods. Intensive systemic and intrathecal chemotherapy have decreased the overall CNS relapse rates and changed the patterns of recurrence. The heterogeneity of therapeutic response in the biological subtypes suggests room for further optimization using currently available chemotherapy.

Genome complexity in acute lymphoblastic leukemia is revealed by array-based comparative genomic hybridization.

Chromosomal abnormalities are important for the classification and risk stratification of patients with acute lymphoblastic leukemia (ALL). However, approximately 30% of childhood and 50% of adult patients lack abnormalities with clinical relevance. Here, we describe the use of array-based comparative genomic hybridization (aCGH) to identify copy number alterations (CNA) in 58 ALL patients. CNA were identified in 83% of cases, and most frequently involved chromosomes 21 (n=42), 9 (n=21), 6 (n=16), 12 (n=11), 15 (n=11), 8 (n=10) and 17 (n=10). Deletions of 6q (del(6q)) were heterogeneous in size, in agreement with previous data, demonstrating the sensitivity of aCGH to measure CNA. Although 9p deletions showed considerable variability in both the extent and location, all encompassed the CDKN2A locus. Six patients showed del(12p), with a common region encompassing the ETV6 gene. Complex CNA were observed involving chromosomes 6 (n=2), 15 (n=2) and 21 (n=11) with multiple regions of loss and gain along each chromosome. Chromosome 21 CNA shared a common region of gain, with associated subtelomeric deletions. Other recurrent findings included dim(13q), dim(16q) and enh(17q). This is the first report of genome-wide detection of CNA in ALL patients using aCGH, and it has demonstrated a higher level of karyotype complexity than anticipated from conventional cytogenetic analysis.

Sarcomas of head and neck - A 10 yrs experience.

38 cases of sarcoma of head and neck region were analysed in a retrospective way in relation to age, anatomic location, histological, clinical profile, and surgical approaches. Compared to other types of head and neck neoplasms, such as squamous cell carcinoma, soft tissue sarcomas have low rates of regional metastases. However the biological behaviour of soft tissue sarcoma is more aggressive specially in paediatric age group. In the present series, CT scan was considered as the primary modality of investigation. Surgery generally has been recommended as the primary method of treatment for achieving local control, except in those high-grade tumours arising in sites not amenable to resection. 3-year and 5-year survival rates in this present series 50% and 31.6% respectively.

Adenovirus infection after pediatric bone marrow transplantation: is treatment always necessary?

BACKGROUND: Adenovirus infections are associated with significant rates of morbidity and mortality among children after bone marrow transplantation (BMT). Many transplantation units use molecular virological methods, such as polymerase chain reaction (PCR), for surveillance for adenovirus infection and give preemptive antiviral therapy to children with evidence of disseminated adenovirus infection. This treatment strategy has never been evaluated in clinical trials. METHODS: We retrospectively tested blood samples obtained from a cohort of children who had undergone BMT before the introduction of regular weekly surveillance for adenovirus infection. A total of 273 samples collected from 26 patients between May 1998 and June 2002 were tested for adenovirus infection by quantitative PCR. Virus load was quantified for each sample yielding positive test results, and the clinical notes and virological records of each child were reviewed. RESULTS: Evidence of adenovirus infection was found in 11 children (42%), 7 of whom had not previously had positive test results. Receipt of T cell-depleted transplants was associated with a significantly higher incidence of adenovirus infection during the posttransplantation period. The 2 children who died from adenovirus disease developed infection within 2 weeks after transplantation, and both had very low absolute lymphocyte counts at the time of diagnosis. Seven of 11 children with blood samples that were found to be positive for adenovirus by PCR cleared the virus without antiviral therapy. CONCLUSIONS: Surveillance for adenovirus by PCR is better than symptomatic testing for detecting adenovirus infection. Antiviral therapy may not be necessary for all children who develop adenovirus viremia after BMT.

Identification and molecular characterisation of a CALM-AF10 fusion in acute megakaryoblastic leukaemia.

The t(10;11)(p13;q14-21) is a non-random translocation described in acute lymphoblastic and myeloid leukaemias. It results in the fusion of the gene CALM, which encodes a clathrin assembly protein, on 11q14 to the gene AF10, a putative transcription factor on 10p13. Here we describe for the first time, the occurrence of a CALM-AF10 fusion in a case of acute megakaryoblastic leukaemia. Fluorescence in situ hybridisation and reverse transcriptase polymerase chain reaction were used to confirm the presence of a CALM-AF10 fusion. A novel splice variant of CALM missing nt 1927-2091 was also detected. Though CALM is a cytoplasmic protein, the chimaeric fusion product is able to localise to both the nucleus and cytoplasm. Analysis of the fusion variants suggests, however, that the critical fusion product is likely to be cytoplasmic and contain the interactive leucine zipper of AF10.

Cytogenetic and molecular evidence of marrow involvement in extramedullary acute myeloid leukaemia.

A diagnosis of granulocytic sarcoma was made in a 2-year-old child based on the detection of myelomonocytic blasts in tissue obtained from a subcutaneous nodule with no evidence of concomitant disease in the bone marrow. The child responded to systemic chemotherapy and is in remission 3 years later. An identical clone with an in frame fusion of the MLL and AF10 genes was identified from both tissue and bone marrow samples. The generation of an in frame MLL-AF10 fusion requires complex intra- and interchromosomal exchanges between chromosomes 10 and 11. In this case, an intrachromosomal rearrangement of chromosome 5 was also observed. This case illustrates the presence of systemic disease in extramedullary leukaemia, its response to systemic rather than topical therapy and suggests that the events leading to chromosomal translocations in leukaemia may be part of a generalized intracellular event.

Medical management of Aspergillus flavus endocarditis.

An 11-year-old boy underwent a matched unrelated bone marrow transplant for refractory acute myeloid leukemia. He developed invasive aspergillus pneumonia and endocarditis post-transplant. The fungal endocarditis was successfully eradicated with liposomal amphotericin at the dose of 10 mg/kg/day. Surgical intervention was not required and no serious side effects of liposomal amphotericin were observed at this dose.

Biochemical analyses of the AF10 protein: the extended LAP/PHD-finger mediates oligomerisation.

Leukaemogenesis correlates with alterations in chromatin structure brought about by the gain or loss of interactive domains from regulatory factors that are disrupted by chromosomal translocations. The gene MLL, a target of such translocation events, forms chimaeric fusion products with a variety of partner genes. While MLL appears to be involved in chromatin-mediated gene regulation, the functions of its partner genes are largely speculative. We report the biochemical analysis of the MLL partner gene AF10 and its possible role in leukaemogenesis. AF10 has been reported to be re-arranged with genes other than MLL leading to the same phenotype, a myeloid leukaemia. We have identified a novel protein-protein interaction motif in the AF10 protein comprising the extended LAP/PHD-finger. This domain mediates homo-oligomerisation of recombinant AF10 and is conserved in several proteins, including MLL itself. AF10 binds cruciform DNA via a specific interaction with an AT-hook motif and is localised to the nucleus by a defined bipartite nuclear localisation signal in the N-terminal region.

The cloning, mapping and expression of a novel gene, BRL, related to the AF10 leukaemia gene.

The MLL gene is reciprocally translocated with one of a number of different partner genes in a proportion of human acute leukaemias. The precise mechanism of oncogenic transformation is unclear since most of the partner genes encode unrelated proteins. However, two partner genes, AF10 and AF17 are related through the presence of a cysteine rich region and a leucine zipper. The identification of other proteins with these structures will aid our understanding of their role in normal and leukaemic cells. We report the cloning of a novel human gene (BRL) which encodes a protein containing a cysteine rich region related to that of AF10 and AF17 and is overall most closely related to the previously known protein BR140. BRL maps to chromosome 22q13 and shows high levels of expression in testis and several cell lines. The deduced protein sequence also contains a bromodomain, four potential LXXLL motifs and four predicted nuclear localization signals. A monoclonal antibody raised to a BRL peptide sequence confirmed its widespread expression as a 120 Kd protein and demonstrated localization to the nucleus within spermatocytes.

Prenatal origin of acute lymphoblastic leukaemia in children.

BACKGROUND: There is little current insight into the natural history of childhood leukaemia or the timing of relevant mutational events. TEL-AML1 gene fusion due to chromosomal translocation is frequently seen in the common form of childhood acute lymphoblastic leukaemia. We investigated whether this abnormality arises prenatally. METHODS: We identified, by reverse-transcriptase PCR screening of blood or bone marrow, TEL-AML1 fusion in 12 children, plus a pair of identical twins, aged 2-5 years from Italy and the UK, who had newly diagnosed acute lymphoblastic leukaemia. We amplified and sequenced the genomic TEL-AML1 fusion gene with a long-distance inverse PCR method. Primers were designed that could be used in short-range PCR to screen for patient-specific, leukaemia clone-specific TEL-AML1 genomic fusion sequences in neonatal blood spots from each child. FINDINGS: We initially identified TEL-AML1 fusion sequences in blood spots from the identical twins, diagnosed with concordant acute lymphoblastic leukaemia at age 4 years, who shared a single or clonotypic TEL-AML1 sequence that suggested prenatal origin in one twin. Three children were excluded because control genes could not be amplified. Of the other nine patients, six had positive blood spots. Blood spots that were classified as negative were uninformative. INTERPRETATION: Our findings showed that childhood acute lymphoblastic leukaemia is frequently initiated by a chromosome translocation event in utero. Studies in identical twins show however that such an event is insufficient for clinical leukaemia and that a postnatal promotional event is also required.