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Biomedical subjects

A Ayala

Publications and source records attributed to A Ayala.

At least 253 records · Page 14Linked to original sources
PubMed1986

Malic enzyme levels are increased by the activation of NADPH-consuming pathways: detoxification processes.

The administration to rats of either t-butyl hydroperoxide or phenobarbital, compounds that are metabolized through detoxification processes, produces an increase in specific activity of the NADPH-consuming enzymes, glutathione reductase and NADPH-cytochrome c reductase. These compounds also produce a very significant increase in the specific activity of malic enzyme. Immunoprecipitation with a specific antibody for malic enzyme indicates that specific activity changes are the result of corresponding changes in the amounts of enzyme protein present. The administration of 1,3-bis(chloroethyl(-1-nitrosourea (a glutathione reductase inhibitor) together with t-butyl hydroperoxide abolishes any stimulation of malic enzyme activity. These results indicate that an increase in NADPH consumption induces the synthesis of malic enzyme. Alternatively, a protection of enzyme degradation cannot be rigorously excluded.

Adipose Tissue↗
PubMed1986

Osteoid osteoma and osteoblastoma of the talus. A report of 40 cases.

Forty patients with osteoid osteoma or osteoblastoma of the talus are presented. Clinical and radiographic findings, histologic features, and therapy of these lesions are discussed. The body of the talus was involved in two patients, all other lesions being located in the neck of the bone. Subperiosteal lesions accounted for 75% of cases, and medullary lesions for 25%. Thirty of the 40 lesions were paraarticular. Five radiographic appearances in the talus are discussed: subperiosteal target lesions of the neck (54%); medullary lesions of the neck (20%); subperiosteal radiolucent lesions of the neck (13%); medullary lesions of the body (5%); and exostotic osteoid osteoma of the talar neck (3%).

Adult↗
PubMed1986

Sacral osteoid osteoma and osteoblastoma: a report of 13 cases.

The authors present 13 cases (nine males and four females) of osteoid osteoma and osteoblastoma of the sacrum. All patients were less than 20 years old. Clinical and radiographic findings, histological features, and therapy of these rare lesions are discussed. Surgical excision with a posterior approach is considered the treatment of choice, except for tumors localized in the body of S-1, which require an anterior approach. The prognosis is good, even when the neoplasm has been incompletely removed. Nevertheless, a marginal or wide resection is the recommended surgical treatment. Radiotherapy is necessary only for inoperable tumors.

Adolescent↗
PubMed1986

Orchiectomy in advanced germ cell cancer following intensive chemotherapy: a comparison of systemic to testicular response.

A total of 16 patients with advanced germ cell cancer underwent initial chemotherapy that was followed by a delayed orchiectomy for an unrecognized primary in 3 and for life-threatening distant metastatic cancer in 13. Of these patients 13 had a complete and 3 had a partial remission at the time of the delayed orchiectomy. Of the former 13 patients 3 (23 per cent) had persistent viable tumor in the testis. To date all 3 patients have remained free of disease for more than 12, 20 and 30 months, respectively, without further therapy. One early relapse (1 month) was found in the remaining 10 patients with a complete remission and without viable disease in the testis. Of the 3 patients with a partial remission 1 had residual tumor in the testis and disease progressed despite further therapy. There was no evidence of tumor in the testis in the other 2 patients. These data document the presence of a differential response of germ cell tumors in the primary and metastatic sites. Post-chemotherapy orchiectomy for a suspicious primary tumor of the testis is necessary because of the risk of persistent primary disease. The post-chemotherapy pathological findings in the resected primary tumor do not reflect the systemic response.

Combined Modality Therapy↗
PubMed1985

Control of primary osteosarcoma with chemotherapy.

High-dose methotrexate with citrovorum factor "rescue" (MTX-CF) produced an apparent complete response of the primary tumor in three patients with osteosarcoma. The response was sustained with MTX-CF, intra-arterial cis-diamminedichloroplatinum II (CDP) and Adriamycin (doxorubicin) for 18 months. Treatment was then electively discontinued. Local recurrence occurred in two patients, 6 and 4 months later, respectively. MTX-CF was reinstated and a complete response was again achieved in one patient. This has been maintained for 15+ months with MTX-CF and intra-arterial CDP administered for 13 of the 15+ months. Reinduction with MTX-CF failed in the second relapsed patient but an apparent remission was again achieved with radiation and intra-arterial CDP. This has been maintained with intravenous CDP, cyclophosphamide and phenylalanine mustard for 14+ months. A complete response in the primary tumor was still present in the nonrelapsed patient, 42 months from diagnosis. All patients have remained free of pulmonary metastases, 40+ to 42+ months from diagnosis.

Adolescent↗
PubMed1985

Comparison of intra-arterial cis-diamminedichloroplatinum II with high-dose methotrexate and citrovorum factor rescue in the treatment of primary osteosarcoma.

A randomized two-arm study was undertaken to determine relative tumoricidal effects of intra-arterial cis-diamminedichloroplatinum II (I/A-CDP) and high-dose methotrexate with citrovorum factor rescue (MTX-CF) in the treatment of the primary tumor in patients with osteosarcoma. Responses were evaluated by clinical, radiographic, angiographic, and pathologic parameters. Fifteen patients were randomized to receive MTX-CF and 15 to I/A-CDP. In the MTX-CF arm there were four responses (three complete responses, one partial response) whereas in the I/A CDP arm there were nine responses (seven complete responses, two partial responses). Two patients who failed MTX-CF and requested alternative treatment with I/A-CDP also responded. The total I/A-CDP response was 11/17.

Adolescent↗
PubMed1985

Computed tomography of osteosarcoma after intraarterial chemotherapy.

The response to intraarterial cis-diamminedichloroplatinum II (CDP) chemotherapy was evaluated by computed tomography (CT) in 33 patients with pathologically proved osteosarcoma of the long or flat bones. Twenty-one of the 33 patients had a CT scan before chemotherapy was started. In the other 12 patients, a CT scan was obtained after at least two courses of treatment, and additional studies were performed during the course of therapy. In those patients responding to treatment, the posttherapy scan revealed a remarkable decrease or complete disappearance of the associated soft-tissue mass and clear reestablishment of the fat planes between the muscle bundles that had been obscured. There was sharp definition of the peripheral margins of the calcified healing neoplasm, and the calcification in the healing tumor could be differentiated easily from that of the original bone neoplasm. The findings of CT were compared with those of conventional studies and pathologic results. CT was more accurate than conventional studies in detecting healing process and diagnosis of remission.

Adolescent↗
PubMed1984

The prognostic significance of endodermal sinus tumor histology among patients treated for stage III nonseminomatous germ cell tumors of the testes.

A retrospective study was undertaken to determine the prognostic significance of endodermal sinus tumor (EST) elements in 56 patients with Stage III nonseminatous germ cell tumors of the testes (NSGCTT). The study patients were treated with conventional vinblastine, bleomycin and cisplatinum chemotherapy prior to our recognition of EST as a distinct entity. Twenty-one (37.5%) of the patients had EST elements in their tumors. Nineteen patients had EST in their primary testis tumor, whereas two had EST in metastatic sites only. Prognostic criteria (tumor volume, Dixon-Moore classification and chemotherapy vinblastin and bleomycin [VB] and VB plus cisplatin [VB + P] ) were similar in EST and non-EST patients. Long-term disease-free survival was significantly poorer for patients with Stage III NSGCTT containing EST (38%) compared with those not containing EST (71%) (P = 0.04). All 12 patients with small volume disease (III-B1-III-B2), independent of the presence of EST, are alive and free of disease for more than 2 years. Only 6 of 18 patients (33%) with advanced disease and EST are alive and free of disease, whereas 17 of 26 (65%) of patients with advanced disease not containing EST are alive and free of disease (P = 0.074). The addition of single agent bolus cisplatin to the treatment of patients with advanced disease achieved no improvement in survival. Endodermal sinus tumor must be included in future studies of advanced Stage III NSGCTT as an important prognostic variable.

Abdominal Neoplasms↗
PubMed1983

Osteosarcoma: intra-arterial treatment of the primary tumor with cis-diammine-dichloroplatinum II (CDP). Angiographic, pathologic, and pharmacologic studies.

Intra-arterial CDP was utilized to treat the primary tumor in 11 pediatric patients with osteosarcoma and in one with malignant fibrous histiocytoma. The investigation commenced with a phase I-II pilot study in four osteosarcoma patients. A dose of 150 mg/m2 was found to be safe and effective in producing a clinical response. This was followed by a definitive study in the remaining seven osteosarcoma patients and in the one malignant fibrous histiocytoma patient. The results were assessed by specific clinical, pharmacologic, radiographic and pathologic criteria. The overall response in the definitive study was 50% with two patients exhibiting total tumor destruction. The success of intra-arterial CDP was attributed to its ability to achieve high local drug concentration and tumor penetration. This was demonstrated by pharmacologic studies.

Adolescent↗
PubMed1983

Renal cell carcinoma in children.

Data from four pediatric hospitals concerning 20 children treated for renal cell carcinoma (RCC) from 1964-1978 were reviewed. Median age of the patients (pts) was 11.8 years (range, 14 months-19 years). Twelve were male and eight female; 17 were white and three black. Most patients presented with pain and hematuria with or without a palpable mass. An intrarenal tumor was detected at IV urography (17 pts), arteriography (2 pts), or at surgery (1 pt). Treatment consisted of nephrectomy in 15 pts, renal biopsy (4 pts), or no surgery (1 pt), followed by chemotherapy (5 pts), radiation therapy (1 pt), or both (7 pts). Ten pts died of distant metastases at a median of one year (range, 0.2 to two years) after diagnosis. The other 10 pts (50%) survive free of relapse at a median of 4 years (range, two to ten years) from diagnosis. Proportions surviving free of recurrent disease two or more years by National Wilms' Tumor Study (NWTS) Group were 5/5 in Group I, 3/7 in Group II, 1/3 in Group III, and 1/5 in Group IV; by age at diagnosis, 6/6 in those under 11 years old and 4/14 in those 11 or older; and by type of surgery, 10/15 who had nephrectomy and 0/5 with limited or no surgery. The data indicate that radiation and chemotherapy had only minor if any influences on relapse-free survival. We conclude that (1) RCC in children is similar to its counterpart in adults; (2) RCC has a worse prognosis than Wilms' tumor except for the earliest stage; (3) nephrectomy alone is adequate treatment for Group I RCC, and (4) young age (less than 11 years old) may be prognostically favorable.

Adenocarcinoma↗
PubMed1983

Eosinophilic granuloma of bone: diagnosis and management.

Fifty patients with eosinophilic granuloma of bone were reviewed. Thirty-one lesions were in the head and neck, 24 in the extremities, seven in the pelvis, and five in the ribs. The lesions were lytic with ill-defined margins, endosteal erosion, and solid periosteal reaction. The diagnoses were obtained by surgical biopsy in 36 patients and by percutaneous biopsy in 14. Twenty-six lesions were treated with radiotherapy, 14 by surgery, and nine by surgery and radiotherapy. The last 14 cases have been treated by percutaneous injection of methylprednisolone sodium succinate into the lesion. Healing was obtained in every lesion. There were no complications.

Adolescent↗
PubMed1983

Treatment of primary osteosarcoma with intra-arterial and intravenous high-dose methotrexate.

In an effort to achieve high concentrations and prolonged exposure times, high-dose methotrexate (MTX) was administered by the intra-arterial route over 6 hours at a dose of 12.5 g/m2 to nine patients with osteosarcoma. This was followed by citrovorum factor (CF) rescue, which was initiated 12 hours after completion of the infusion (MTX-CF). The regimen achieved high local concentrations over a finite period. No toxicity was encountered. Treatment was administered at weekly intervals, during which intravenous MTX-CF was interposed if facilities for intra-arterial administration were not available. However, despite increases in local venous concentrations and exposure times, only four of nine patients (44%) responded. This is similar to responses achieved with 7.5 g/m2 (48%) with CF initiated 2 hours after completion of the infusion. Higher MTX doses, intra-arterial administration, and prolongation of cytotoxic exposure time did not confer a therapeutic advantage as opposed to "conventional" intravenous high doses.

Adolescent↗