Preservation of the bladder in patients with rhabdomyosarcoma.

Purpose: To review the pathologic findings from children with gross residual rhabdomyosarcoma (RMS) of the bladder and compare the treatment outcome of those who underwent cystectomy with those who did not.

Patients And Methods: Primary and follow-up records and pathology specimens for 28 patients with gross residual disease entered onto the intergroup Rhabdomyosarcoma Study (IRS) III were reviewed. These patients were assigned to receive 20 weeks of multiagent induction chemotherapy and 4 weeks of radiotherapy.

Involvement of the P cluster in intramolecular electron transfer within the nitrogenase MoFe protein.

Nitrogenase is the catalytic component of biological nitrogen fixation, and it is comprised of two component proteins called the Fe protein and MoFe protein. The Fe protein contains a single Fe4S4 cluster, and the MoFe protein contains two metallocluster types called the P cluster (Fe8S8) and FeMo-cofactor (Fe7S9Mo-homocitrate). During turnover, electrons are delivered one at a time from the Fe protein to the MoFe protein in a reaction coupled to component-protein association-dissociation and MgATP hydrolysis.

Cyclophosphamide dose escalation in combination with vincristine and actinomycin-D (VAC) in gross residual sarcoma. A pilot study without hematopoietic growth factor support evaluating toxicity and response.

Purpose: The Intergroup Rhabdomyosarcoma Study (IRS) initiated an escalating-dose cyclophosphamide (Cyc) pilot without hematopoietic growth factor (HGF) support in combination with vincristine (Vcr) and actinomycin-D (Amd), known as VAC, to establish a Cyc dose with myelotoxicity comparable to an ifosfamide (Ifos), Vcr, and Amd combination regimen (VAI). A Cyc dose equivalent to Ifos was to be determined when comparable myelotoxicity was achieved.

Patients And Methods: Patients with either rhabdomyosarcoma or undifferentiated soft-tissue sarcoma and gross residual (clinical group III) disease were eligible for the VAC pilot.

Pseudosarcomatous myofibroblastic tumor of the urinary bladder in children: a study of 11 cases with review of the literature. An Intergroup Rhabdomyosarcoma Study.

Pseudosarcomatous myofibroblastic tumor (PMT) is the result of reactive proliferation of myofibroblasts. In children, PMT of the urinary bladder can be mistaken for embryonal rhabdomyosarcoma clinically, radiologically, and by light microscopy. We are reporting the clinical, histological, and immunohistological features of 11 patients with childhood PMT of urinary bladder that were diagnosed initially as a sarcoma, usually rhabdomyosarcoma.

Classification of rhabdomyosarcomas and related sarcomas. Pathologic aspects and proposal for a new classification--an Intergroup Rhabdomyosarcoma Study.

Background: There is a need to develop a single prognostically significant classification of rhabdomyosarcomas (RMS) and other related tumors of children, adolescents, and young adults which would be a current guide for their diagnosis, allow valid comparison of outcomes between protocols carried out anywhere in the world, and should enhance recognition of prognostic subsets.

Method: Sixteen pathologists from eight pathology groups, representing six countries and several cooperative groups, classified by four histopathologic classification schemes 800 representative tumors of the 999 eligible cases treated on Intergroup Rhabdomyosarcoma Study II. Each tumor was classified according to each of the four systems by each of the pathologists.

Electron spin echo envelope modulation spectroscopic analysis of altered nitrogenase MoFe proteins from Azotobacter vinelandii.

Electron spin echo envelope modulation (ESEEM) spectroscopy was used to study changes in the polypeptide environment of the FeMo-cofactor that were elicited by amino-acid substitutions within the nitrogenase MoFe protein alpha-subunit. A previous ESEEM study [Thomann et al. (1991) Proc.

Role of the MoFe protein alpha-subunit histidine-195 residue in FeMo-cofactor binding and nitrogenase catalysis.

Site-directed mutagenesis and gene-replacement procedures were used to isolate mutant strains of Azotobacter vinelandii that produce altered MoFe proteins in which the alpha-subunit residue-195 position, normally occupied by a histidine residue, was individually substituted by a variety of other amino acids. Structural studies have revealed that this histidine residue is associated with the FeMo-cofactor binding domain and probably provides an NH-->S hydrogen bond to a central bridging sulfide located within FeMo-cofactor. Substitution by a glutamine residue results in an altered MoFe protein that binds but does not reduce N2, the physiological substrate.

Renal toxicity of ifosfamide in pilot regimens of the intergroup rhabdomyosarcoma study for patients with gross residual tumor.

Purpose: The purpose of this review is to characterize the nephrotoxicity noted in newly diagnosed patients under 21 years of age after treatment with ifosfamide-containing chemotherapy regimens and local irradiation for localized gross residual rhabdomyosarcoma or undifferentiated sarcoma.

Patients And Methods: From 1987 to 1991, 194 previously untreated patients received vincristine and ifosfamide plus dactinomycin or etoposide for 1-2 years. Ifosfamide was given at 1.

Agreement among and within groups of pathologists in the classification of rhabdomyosarcoma and related childhood sarcomas. Report of an international study of four pathology classifications.

Background: An International Pathology study was conducted to measure the agreement demonstrated among and within groups of pathologists involved in the categorization of childhood rhabdomyosarcoma according to four pathology classifications. Data concerning agreement and survival experience according to patho-new subtypes were used as a basis for selection of a proposed new pathologic classification.

Methods: A random sample of 800 eligible patients was chosen from the Intergroup Rhabdomyosarcoma Study II (IRS-II) and was reviewed by pathologists representing eight institutions.

Epithelioid sarcoma in childhood: An immunohistochemical, electron microscopic, and clinicopathologic study of 11 cases under 15 years of age and review of the literature.

Epithelioid sarcoma in a rare tumor and most of the cases occur in young adults. It is rare in childhood. We have been able to obtain data and histologic material for 11 patients with this disease.