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We have used the Ilizarov technique for the management of subarticular defects after the excision of giant-cell tumours in the proximal tibia in five patients. The defect was reconstructed with a segment of 5 to 6 cm obtained from the diaphysis of the affected tibia and by autogenous bone graft from the iliac crest. The newly developed defect in the diaphysis was reconstructed by distraction using the Ilizarov apparatus. Bone grafting at the docking site was performed soon after positioning the bone segments. The mean length of the bone defect was 5.7 cm and the mean duration of external fixation was 233 days. The relative blood flow in the leg measured by 99mTc angiography increased by 1.7 to 2.3 times that of the control level during distraction and consolidation. When seen at a mean of 43 months all patients showed a normal range of motion in the knee and ankle with no collapse of the articular surfaces.

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We studied the effects of the plasminogen activator inhibitor-1 (PAI-1), the urokinase-type plasminogen activator (uPA) and their antibodies on hematogeneous pulmonary metastases formation of human fibrosarcoma in athymic mice. We used a human fibrosarcoma cell line (HT-1 080) with low metastatic potential, and a subpopulation of HT-1 080 (HT-1 080-P4) with high metastatic potential which was selected by repeating injections into the tail veins of athymic mice. We examined the effects of these drugs on pulmonary metastases formation according to Wexler's method and the number of tumor cell emboli in the lung subsequent to an injection of radio-labeled tumor cells. Pulmonary metastases formation from HT-1 080 was not affected by any of the tested drugs. Pulmonary metastases from HT-1 080-P4 increased with uPA and anti-uPA antibody injections. PAI-1 slightly increased pulmonary metastases from HT-1 080-P4, and the anti-PAI-1 antibody decreased it (60.9 + 27.7% of control, p < 0.05). While none of the drugs altered the number of HT-1 080 cells in the lung at 24, 48 and 72 hours after the injection, PAI-1 increased the number of HT-1 080-P4 cells in the lung, whereas uPA and PAI-1 decreased it. The result that these drugs did not affect the metastatic potential of HT-1 080 but only that of HT-1 080-P4, indicates that fibrinolysis plays an important role in hematogenous pulmonary metastases formation of tumor cells with high metastatic potential. The effects of uPA suggest that uPA facilitates pulmonary metastasis formation probably due to an increase in the invasive ability of tumor cells. The effects of PAI-1 and its antibody of HT-1 080-P4 cells suggest that PAI-1 may facilitate tumor cell lodgement in vessels and the anti-PAI-1 antibody could be able to suppress pulmonary metastases of tumor cells with high metastatic potential by inhibition of tumor cell lodgement in vessels.

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We report on the effects of intraarterial cisplatin and caffeine with/without doxorubicin on high-grade spindle cell sarcomas of bone and soft tissue based on the fact that caffeine enhances cytocidal effects of DNA-damaging agents. Intraarterial cisplatin and caffeine with/without doxorubicin was preoperatively given three times to ail patients and two courses of high-dose methotrexate with the citrovorum factor and vincristine were administered to the patients with skeletal spindle cell sarcoma. Tumor response was assessed radiographically and histologically. Seventeen (90%) of 19 patients with bone sarcoma and 7 (70%) of 10 patients with soft-tissue sarcoma showed good response. All patients with osteosarcoma demonstrating good radiological response underwent marginal excision without subsequent local tumor recurrence. Histologically, there were no viable cells in resected specimen of 14 patients with bone sarcoma. Other 8 cases with soft-tissue sarcoma treated by unplanned surgery were included to assess side effects. Twenty-five out of 37 patients are still free of disease. There was local tumor recurrence in 2 patients who did not respond to the chemotherapy. Toxic effects noted in the clinical study included moderate myelosuppression, nausea and vomiting, renal insufficiency and cutaneous injury. No toxic effects were directly attributable to 1.2-1.5 g/m(2) caffeine. The intraarterial infusion of cisplatin and caffeine combined with/without doxorubicin was tolerable in all patients and led to good response in high-grade spindle cell sarcomas. In patients with good response, limb-salvage surgery can be conducted safely without local relapse and good limb function is preserved by chemotherapy and marginal excision.

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A case of malignant Triton tumor which consists of a malignant schwannoma accompanied by rhabdomyo-sarcomatous elements is reported. Only a small number is known in literature. The patient survived for four years without any sign of local recurrence or metastasis although an extremely poor prognosis for this neoplasm is reported. The therapy consisted of wide resection, irradiation and pre-and postoperative combination chemotherapy. The effect of multi-agent antineoplastic drugs on the differentiation of rhabdomyosarcoma cells and the relevant literature is discussed.

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An architecture and the algorithms for matrix multiplication using optical flip-flops (OFFs) in optical processors are proposed based on residue arithmetic. The proposed system is capable of processing all elements of matrices in parallel utilizing the information retrieving ability of optical Fourier processors. The employment of OFFs enables bidirectional data flow leading to a simpler architecture and the burden of residue-to-decimal (or residue-to-binary) conversion to operation time can be largely reduced by processing all elements in parallel. The calculated characteristics of operation time suggest a promising use of the system in a real time 2-D linear transform.