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Biomedical subjects

M G Mott

Publications and source records attributed to M G Mott.

At least 37 records · Page 2Linked to original sources

Rapid and specific diagnosis of t(11;22) translocation in paediatric Ewing's sarcoma and primitive neuroectodermal tumours using RNA-PCR.

One case of paediatric Ewing's sarcoma and two peripheral primitive neuroectodermal tumours/extra-osseous Ewing's sarcoma were studied for the characteristic t(11;22) translocation, using a recently described RNA-polymerase chain reaction method (RNA-PCR). PCR products of the expected sizes were obtained from RNA derived from the Ewing's sarcoma and the peripheral primitive neuroectodermal tumours, but not from other paediatric malignancies. Direct sequencing of the RNA-PCR products confirmed the presence of the EWS-FLI-1 fusion transcript. In one case the presence of the translocation was confirmed by cytogenetic analysis. These results highlight the potential use of PCR for the rapid demonstration of diagnostically important tumour specific chromosome rearrangements.

Adolescent↗

Low frequency of mutations in the WT1 coding region in Wilms' tumor.

A series of twenty unselected Wilms' tumors were analysed for alterations in the WT1 tumor suppressor gene. The entire coding region of WT1 was amplified by RNA-PCR, and then screened for mutations by single-strand conformational polymorphism analysis (SSCP). This method was shown to be capable of detecting point mutations in the WT1 gene, by using an experimentally produced mutation. A single mutation, a 226 bp intragenic deletion, was detected in a tumor from a patient with the WAGR syndrome. These results suggest that alterations in the WT1 gene may be involved in only a subset of Wilms' tumors, and that other loci need to be investigated as potential suppressor genes in sporadic Wilms' tumors.

Genes, Wilms Tumor↗

Cardioprotection by ICRF187 against high dose anthracycline toxicity in children with malignant disease.

OBJECTIVE: A pilot study to assess the efficacy of ICRF187 as a protective agent against the cardiotoxic effects of anthracycline drugs used to treat childhood malignancies. DESIGN: A study of cardiac function in children treated receiving ICRF187 ((s)-(+)-1,2 bis (3,5-dioxopiperazenyl) propane) in addition to anthracycline therapy compared with contemporary controls selected retrospectively on the basis of anthracycline dose matching. PATIENTS: Five children in whom recurrence of malignant disease was re-treated with chemotherapy containing anthracycline drugs and additional ICRF187 (supplied on a compassionate-use basis) (cumulative anthracycline doses 550-1650 mg/m2). Five more children with recurrence of malignant disease were re-treated to similar cumulative anthracycline doses (600-1150 mg/m2) without ICRF187. METHODS: Cardiac function was assessed clinically and echocardiographically throughout treatment. Clinical and echocardiographic state were compared before treatment and after completion of therapy within and between groups treated with and without ICRF187. RESULTS: Two patients treated without ICRF187 developed symptomatic congestive cardiac failure from which one died. Another developed considerable but as yet asymptomatic left ventricular dysfunction. No patient receiving additional ICRF187 developed cardiac failure or left ventricular dysfunction. There were no significant differences in cumulative anthracycline dose, dose increase, type of anthracycline used, survival rate, or length of survival between groups. Left ventricular shortening fraction fell by a mean of 1.0% in patients receiving ICRF187 and by a mean of 11% in the patients treated without it (p = 0.04). CONCLUSIONS: ICRF187 seems to have provided highly effective cardioprotection to this small group of children with end-stage malignancy. Severe cardiotoxicity was seen in a similar group treated with comparable anthracycline doses but without ICRF187.

Adolescent↗

Causes of death in a paediatric oncology unit.

The records of 101 patients (64 males and 37 females) registered at Bristol Children's Hospital who died between January 1986 and December 1989 were reviewed to determine the cause of death. Nineteen patients (19%) died without obtaining remission and 6 (6%) in first remission. Seventy-six (75%) died after relapse; three during re-induction and two in second remission. The causes of death were active disease in 85 patients (84%), active disease and infection (4%), active disease and other factors (4%), infection only (3%), toxic cardiomyopathy (2%), graft versus host disease (2%), and second malignancy (1%).

Bone Neoplasms↗

Paternal origin of 11p15 duplications in the Beckwith-Wiedemann syndrome. A new case and review of the literature.

A boy suffering from the Beckwith-Wiedemann syndrome (BWS) was found to have partial trisomy of the short arm of chromosome 11 [46,XY,der(5)t(5;11)(p15.2;p14)]. Both his parents were phenotypically normal, but his father carried a balanced translocation between chromosomes 5 and 11 [46,XY,t(5;11)(p15.2;p14)]. DNA analysis of polymorphic markers on 11p15 confirmed the paternal origin of the duplicated material in the child. This case is the sixth report of paternal duplication of 11p15 in BWS. These results are discussed in relation to the possible role of genomic imprinting in BWS and in Wilms' tumor.

Beckwith-Wiedemann Syndrome↗

The assessment of in vivo somatic mutations in survivors of childhood malignancy.

The assessment of chromosomal mutations in children may provide information about aetiology and risk of second malignancies. A somatic cell mutation assay which determines variant erythrocytes lacking expression of an allelic form of the sialoglycoprotein, glycophorin A, was applied to samples from children before and after receiving potentially genotoxic therapy. Fifty-six children who had received treatment for their malignancy, 15 with malignancy but prior to treatment and 43 control children were assessed for the presence of Nø and NN mutant variant red cells. Control children had mean (s.d.) Nø and NN variant frequencies (Vf) of 9.5 (7.0) and 5.8 (3.3) x 10(6) erythrocytes respectively. Comparison between pre-treatment and control groups demonstrated that prior to chemotherapy, patients with paediatric malignancy do not have mutant frequencies significantly different from the normal population. Children who had received chemotherapy, with or without radiotherapy, showed a significant elevation of both Nø and NN variants over 10 years from the end of treatment. Exposure of children to radiotherapy or known chemical mutagens leads to an increased frequency of variant erythrocytes which is probably the result of in vivo somatic cell mutations. The long term implications have yet to be determined.

Adolescent↗

Inactivation of the remaining allele of the WT1 gene in a Wilms' tumour from a WAGR patient.

A candidate gene (WT1) has recently been described for the 11p13 tumour-suppressor gene involved in the development of Wilms' tumour. This gene encodes a zinc finger protein which can bind to a specific DNA sequence. We have found a 226 base deletion in the mRNA from a unilateral Wilms' tumour, which would cause a frameshift that completely deletes the zinc finger domain. The tumour developed in a patient suffering from the WAGR syndrome, who had a constitutional 11p13 deletion, and so the 226 base deletion represents the inactivation of the remaining WT1 allele in the tumour. This provides further direct evidence that loss of function of WT1 is an essential step in the development of Wilms' tumour.

Abnormalities, Multiple↗

Rhabdomyosarcoma associated with familial adenomatous polyposis.

We report a case of a 16 year old girl with orbital rhabdomyosarcoma who during chemotherapy developed bloody diarrhoea. On investigation she was found to have multiple colonic polyps. Cytogenetic analysis has shown a pattern typical of familial adenomatous polyposis. We present a review of the literature concerning the associations of familial adenomatous polyposis. The association of familial adenomatous polyposis with rhabdomyosarcoma has not been previously reported.

Adenomatous Polyposis Coli↗

Outcome in stage III non-Hodgkin's lymphoma in children (UKCCSG study NHL 86)--how much treatment is needed? United Kingdom Children's Cancer Study Group.

Forty-four children aged 3-13 years with Murphy stage III B cell non-Hodgkin's lymphoma were treated between May 1986 and December 1989. All have been followed up for at least 12 months. The primary site was the abdomen in 37 children, 24 of whom had involvement of other organs or nodal disease outside the abdomen. Twenty-eight received a standard dose regimen (regimen 1) and 16 had a more intensive regimen (regimen 2--MACHO). Fourteen patients (87%) who received MACHO had extensive multi-organ disease compared to 15 (53%) on regimen 1. Most of the latter had only pleural effusions. Thirty-four children are alive relapse free and considering the early relapse pattern in this disease are probably cured (actuarial event free survival = 76%). There has been one relapse (6%) after MACHO, but three toxic deaths. Six patients (21%) on the less intensive regimen have relapsed. Morbidity was high in terms of infection and need for haematological support and hospitalisation in the one third of children electively given the more intensive regimen. It is concluded that the vast majority of children with stage III disease who have disease limited to lymph nodes are curable with a moderately intensive regimen. Those with multiorgan involvement probably require more intensive treatment. It is therefore of importance to clarify prognostic factors in these patients to determine who can be cured with a less intensive regimen and who requires further dose intensification.

Antineoplastic Combined Chemotherapy Protocols↗

Absence from school related to cancer and other chronic conditions.

Absence from school during the first year after starting major treatment for cancer or chronic or orthopaedic conditions was examined. Retrospective data were collected on 72 children and obtained from hospital records, school registers, and interviews with parents and teachers. Median initial absences caused by treatment were 91, 29-5, and 15 days for cancer, chronic, and orthopaedic patients respectively. The mean proportions of the remaining school time in the year occupied by absences caused by treatment and those not caused by treatment were respectively 17% and 17% for oncology patients, 8% and 12% for chronic patients, and 2% and 11% for orthopaedic patients. The only significant factor associated with the amount of absence caused by treatment was the type of illness. Increased absence not caused by treatment was associated with the amount of treatment time and the patient being a girl. The proportion of absence not caused by treatment decreased if the mother was educated beyond the age of 18. The possible reasons for and effects of excess absence are discussed.

Absenteeism↗

Impact of childhood cancer on return to normal schooling.

Most of the research into the psychosocial impact of treatment for cancer in children has concentrated on effects on the family rather than on the children's return to school. Thus parents and teachers were questioned about the problems experienced by 117 children who returned to school after spending time in hospital. The children comprised 51 with cancer and two groups of control children (34 with chronic diseases such as renal disease and cardiac conditions and 32 with orthopaedic conditions such as thoracic scoliosis, club foot, and injuries resulting from trauma). Children in all three groups experienced problems on returning to school, the greatest number and variety occurring in the children treated for cancer and the fewest in the children with orthopaedic conditions. The variety of physical problems was greatest and the variety of academic problems was least, with psychological and behavioural problems intermediate. Several problems seemed to be related to drug treatment. Several children missed a considerable amount of full time education. Many teachers were unsure of the academic expectations and physical capabilities of children returning to school. To facilitate a smooth return to school for a child with cancer improved liaison is needed between the hospital, school, and home during the child's absence and teachers need to be better informed.

Adolescent↗

Cryptosporidiosis and acute leukaemia.

Six children with cryptosporidiosis, concurrently receiving chemotherapy for acute leukaemia (n = 5) and lymphoma (n = 1), are described. Two died with evidence of persistent infection. Modification of the chemotherapy regimens in the other four children was associated with successful eradication of the pathogen and permitted continued treatment of the primary disease.

Child↗