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Biomedical subjects

M J Coppes

Publications and source records attributed to M J Coppes.

At least 73 records · Page 4Linked to original sources
PubMed1994

Primary testicular and paratesticular tumors of childhood.

Testicular and paratesticular neoplasms are uncommon tumors of childhood. Consequently, the experience gained with regard to their optimal management is limited in any given children's cancer centre. Here we review the classification, diagnosis, and staging of testicular and paratesticular neoplasms and subsequently discuss the more frequently occurring ones: germ cell tumors, gonadal stromal tumors, gonadoblastoma, tumors of the supporting tissue, lymphomas and leukemias, tumor-like lesions, secondary tumors, and tumors of the adnexa.

Adolescent↗
PubMed1993

Analysis of WT1 in granulosa cell and other sex cord-stromal tumors.

The molecular genetic events involved in the etiology of granulosa cell, Sertoli cell, and Leydig cell tumors are unknown. The expression of the Wilms' tumor suppressor gene WT1 in granulosa and Sertoli cells prompted us to analyze this gene for mutations in 11 granulosa cell tumors, three Leydig cell tumors, and one Sertoli/Leydig cell tumor. Although most of these tumors express WT1 mRNA, none harbors a WT1 mutation in the zinc finger domains where > 90% of WT1 mutations in sporadic Wilms' tumors have been found. In addition we were able to exclude tumor-specific loss of heterozygosity in 13 of 15 cases. Taken together these results suggest that the WT1 gene is unlikely to play an important role in the development of sex cord-stromal tumors.

Adolescent↗
PubMed1993

Homozygous somatic Wt1 point mutations in sporadic unilateral Wilms tumor.

Wilms tumor may be caused by loss of function of genes at different loci. A Wilms tumor suppressor gene, WT1, at chromosome 11 band p13, has recently been cloned and characterized. WT1 has been implicated in the development of Wilms tumor by virtue of mutations in patients with genitourinary anomalies and susceptibility to Wilms tumor. Homozygous intragenic mutations have been reported in Wilms tumors, but usually not in sporadic unilateral Wilms tumors, which constitute the majority of Wilms tumor cases. Using the single-strand conformational polymorphism assay, we have identified three sporadic unilateral Wilms tumors with homozygous point mutations: one with a de novo germ-line nonsense point mutation within WT1 exon 8, and two carrying a somatic mutation within WT1 exon 10. In all three cases loss of the wild-type allele was demonstrated by tumor loss of heterozygosity. This report provides an example of two somatic mutations in the same tumor expected to inactivate WT1 function.

Amino Acid Sequence↗
PubMed1993

Serum biological markers and paraneoplastic syndromes in Wilms tumor.

Various tumors secrete tumor-specific substances capable of producing signs and symptoms in host organs not caused by direct tumor invasion or organ destruction. These symptoms are collectively referred to as "remote effects" or "paraneoplastic syndromes" of malignancy. Paraneoplastic syndromes are uncommon in childhood cancer. In Wilms tumor several distinct paraneoplastic syndromes have been reported: hypertension, erythrocytosis, hypercalcemia, Cushing syndrome, and acquired Von Willebrand disease. In addition some tumor-specific substances are known to be elevated in patients with a malignancy without causing specific symptoms. These so called "tumor markers" can be used to detect early recurrence in previously treated patients, or in the evaluation of patients undergoing adjuvant therapy. Five of particular interest are erythropoietin, neuron-specific enolase (NSE), hyaluronic acid (HA), hyaluronic acid-stimulating activity (HSA), and hyaluronidase.

Biomarkers, Tumor↗
PubMed1993

James Ewing (1866-1943): "the chief".

"It is a growing conviction that to know cancer in man, one must study the disease most carefully in the human subject. Personally, I do not look for any startling advances or sensational discoveries, since it is much more likely that a steady reduction in the mortality from cancer will come chiefly from a large number of separate factors, of which the most significant appear to be increased control of the conditions leading to cancer, more general recognition of the preliminary stages of the disease, early diagnosis, and treatment of the established disease. From the consideration of these various functions of the modern cancer research hospital, I think that it must be evident that such an institution not only can justify its existence, but fills a very urgent need without which, progress of cancer research would be handicapped, and much relief that might early be extended to cancer victims would be unavailable. Nor is there any doubt that the function of supporting such an institution is properly exercised by the State, which support should be continuous and liberal"--James Ewing [2].

History, 20th Century↗
PubMed1993

Wilms tumor in a patient with Prader-Willi syndrome.

The development of Wilms tumor in a patient with Prader-Willi syndrome prompted us to determine the parental origin of the genes implicated in both disorders because of the sex-specific parent-of-origin effects previously demonstrated for both conditions. A paternal chromosome 15q11-q13 deletion was demonstrated, but no changes were demonstrated in a limited analysis of chromosome 11p, which harbors two Wilms tumor suppressor genes, WT1 and WT2.

Chromosome Deletion↗
PubMed1993

Identical APC exon 15 mutations result in a variable phenotype in familial adenomatous polyposis.

Germ-line mutations in the adenomatous polyposis coli (APC) gene result in familial adenomatous polyposis coli (APC), an inherited syndrome that predisposes affected individuals to early onset of colorectal cancer. Somatic APC mutations also have been detected in sporadic colon tumors. We have used single strand conformational polymorphism (SSCP) analysis to scan a region of the APC gene that frequently is mutated in both APC and sporadic colorectal cancer. Four truncating mutations were found between codons 1060 and 1327 in 17 of 68 unrelated APC individuals. Fourteen of these persons carried either of two previously described five-nucleotide deletions which represent about 20% of APC mutations in these pedigrees. Patients with mutations in this region of exon 15 develop a classic APC colonic phenotype with multiple, diffuse adenomas developing by the second or third decade. However, the density of adenomas and the extracolonic disease manifestations associated with this syndrome are variable among individuals with identical APC mutations.

Adenomatous Polyposis Coli↗
PubMed1993

The role of WT1 in Wilms tumorigenesis.

Genetic alterations in tumor suppressor genes are believed to play an important role in the initiation of childhood and adult malignancies. Tumor-specific loss of heterozygosity for particular chromosomal regions has provided the starting point for the cloning of different tumor suppressor genes, including the Wilms tumor predisposing gene, WT1, at chromosome 11p13. This article reviews the pathology and genetics of Wilms tumor, the cloning of WT1, and the WT1 mutations reported thus far in 15 hereditary and nonhereditary Wilms tumors. The presence of constitutional WT1 mutations in 35 patients with the Denys-Drash syndrome (a syndrome consisting of nephropathy, intersex disorders, and Wilms tumor) is also described. To date, mutations in the WT1 gene have been found in less than 10% of Wilms tumors specimens examined and in greater than 95% of Denys-Drash patients. The possible significance of this observation with regard to both the cellular function of the WT1 protein and the involvement of alternative loci in the development of Wilms tumor is discussed.

Amino Acid Sequence↗
PubMed1992

Inherited WT1 mutation in Denys-Drash syndrome.

Patients with the Denys-Drash syndrome (Wilms' tumor, genital anomalies, and nephropathy) have been demonstrated to carry de novo constitutional mutations in WT1, the Wilms' tumor gene at chromosome 11p13. We report three new cases, two carrying a previously described WT1 exon 9 mutation and one with a novel WT1 exon 8 mutation. However, unlike patients in previous reports, one of our three patients inherited the affected allele from his phenotypically unaffected father. This observation indicates that the WT1 exon 9 mutation affecting 394Arg demonstrated in over one-half of the patients with the Denys-Drash syndrome may exhibit incomplete penetrance. Consequently, familial studies in patients affected by this syndrome are recommended.

Adolescent↗
PubMed1992

Preoperative care of infants with nephroblastoma. The International Society of Pediatric Oncology 6 experience.

The International Society of Pediatric Oncology (SIOP) recommends preoperative treatment in the management of eligible patients with Wilms' tumor. Until 1980, children younger than 12 months of age (infants) at diagnosis had been excluded from the SIOP trials. SIOP 6, conducted from 1980 to 1987, was the first SIOP study to include infants older than 6 months of age. This retrospective analysis of 145 infants registered to SIOP 6 demonstrates that in infants older than 6 months and having favorable histology (FH), a two-drug preoperative chemotherapy (CT) regimen of 4 weeks significantly ameliorated stage distribution as determined at delayed surgery but did not affect a good outcome. However, the CT dose utilized in SIOP 6 resulted in an unacceptable toxicity in this age group, and SIOP 9, the new SIOP study of Wilms' tumor, recommends a reduced dose of CT in infants. Preoperative CT is not recommended in infants younger than 6 months of age. Specifically, the high incidence (29%) of mesoblastic nephroma in this age group does not justify such an approach. Histopathologic diagnosis should be obtained in these patients before any treatment.

Age Factors↗
PubMed1992

Loss of heterozygosity mapping in Wilms tumor indicates the involvement of three distinct regions and a limited role for nondisjunction or mitotic recombination.

Loss of heterozygosity (LOH) for polymorphic markers is a frequently occurring event in some tumors, reflecting the role of allele loss in the development of these tumors. We have determined LOH in 38 cases of Wilms tumor for the 2 known loci on chromosome arm 11p and for a newly detected locus on chromosome arm 16q. Only 7 of the 38 tumors studied showed reduction to homozygosity of 11p13 markers. In 4 of these tumors, reduced expression of WT1 and WIT1, genes located at 11p13 and implicated in Wilms tumorigenesis, was noted. However, this was also found in 2 of 7 tumors showing LOH exclusively of 11p15 markers and in 15 of the remaining 24 tumors in which there was no LOH for 11p markers. This suggests that events not involving mitotic recombination or chromosome nondisjunction are the most common mechanisms for mutations at the 11p Wilms tumor locus. We also noted that mitotic recombination involving 11p15 loci occurred in addition to reduced expression of the 11p13 locus genes in 2 tumors, suggesting a possible interaction between these 2 loci. In addition, LOH for 16q markers was observed in 6 tumors. In one case this was coincident with reduction of WT1 and WIT1 gene expression, and in 3 other cases it occurred in addition to 11p LOH. This indicates that an additional locus on 16q is likely to be involved in Wilms tumorigenesis.

Adolescent↗
PubMed1992

Mycobacterial brain abscess possibly due to bacille Calmette-Guérin in an immunocompromised child.

Disseminated infection with bacille Calmette-Guérin (BCG) is rare, even in immunocompromised patients who receive BCG injections as immunotherapy or immunization. When such infection occurs, it is usually in patients with decreased cellular immunity. A 6-year-old Caucasian girl who was receiving maintenance chemotherapy for acute lymphoblastic leukemia presented with symptoms of meningitis. A temporal-lobe biopsy revealed acid-fast bacilli that were identified as Mycobacterium bovis BCG. Neither the patient nor any family members had been immunized previously. Appropriate therapy resulted in a complete recovery.

Biopsy↗