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Biomedical subjects

A Sudanese

Publications and source records attributed to A Sudanese.

At least 19 recordsLinked to original sources
PubMed1992

Microradiographic and histochemical evaluation of mineralization inhibition at the bone-alumina interface.

Microradiographic and histochemical tests were used to examine the behaviour of the bone tissue close to the alumina coating in cementless hip prostheses which were radiologically stable and explanted because of pain. The presence was detected of a decalcification stripe of the bone tissue with a thickness of about 300 microns, parallel to the prosthesis profile and in appearance not influenced by the roughness of the surface. This phenomenon was attributed to the presence of aluminium ions similarly to what happens in osteomalacic osteodystrophy in nephropathic dialysed patients. It was concluded that the phenomenon must be carefully considered because, in the long term, it could cause failure in the alumina coating.

Aluminum↗
PubMed1990

Ewing's sarcoma of the pelvis.

Two hundred and thirty-nine patients with Ewing's sarcoma were treated at our institution between 1972 and 1987: 42 of these had lesions in the pelvis, 29 were in the wing of the ilium or involved the sacroiliac joint (type I), 5 were periacetabular (type II), and 8 were in the anterior pelvic arch (type III). Radiotherapy alone was used for the primary lesion in 11 cases, adjuvant chemotherapy in 20 and a neoadjuvant protocol in 22. The overall disease-free survival at a mean follow up of 34 months was 19%. There was no difference in survival related to age or the site in the pelvis, none in disease-free survival with adjuvant and neoadjuvant chemotherapy, or in the incidence of local recurrence and metastases in these two groups. Similarly, there was no difference in disease-free survival between operative treatment, with or without radiotherapy, and radiotherapy alone. There was a slight trend towards better local control of the disease in the former group compared to the latter, although this difference was not statistically significant. Our conclusion is that treatment needs to be planned for each individual patient.

Adolescent↗
PubMed1989

Neoadjuvant chemotherapy for localized Ewing's sarcoma of the extremities: preliminary results of a protocol which uses surgery (alone or followed by radiotherapy) for local control.

From June 1983 to December 1985, thirty-eight patients with localized Ewing's sarcoma of the extremities were treated with a protocol that consisted of an initial nine week period of polychemotherapy (vincristine, adriamycin and cyclophosphamide) followed by local therapy and additional chemotherapy (vincristine, adriamycin, cyclophosphamide and dactinomycin) for one year. As local treatment all patients were offered surgery; thirty-two accepted and six refused. These six patients were locally treated with radiotherapy alone (50 Gy). In the remaining patients an amputation was performed in one case and a resection in thirty-one. In resected patients when a wide margin was achieved (24 cases) no further local treatment was performed; when it was marginal (5 cases) or intralesional (2 cases) radiotherapy at lower doses (40 Gy) followed. At mean follow-up of thirty-seven months the percentage of continuously disease-free patients was 50% for those treated with radiotherapy, 76% with surgery, and 85% with surgery and radiotherapy. Eight patients developed metastatic disease and two patients had local recurrence and metastases. The local recurrences were seen in one patient locally treated with surgery and in one locally treated with radiotherapy. Nine major local complications were observed: three in patients treated with radiotherapy, five in patients treated with surgery, and one in a patient treated with surgery and radiotherapy. These results indicate that after induction chemotherapy conservative surgery is possible in almost all cases of Ewing's sarcoma of the extremities and that such treatment is better than radiotherapy alone as local therapy.

Adolescent↗
PubMed1989

Long-term results in 144 localized Ewing's sarcoma patients treated with combined therapy.

The results of 144 previously untreated cases of primary Ewing's sarcoma of bone are reported with a minimum follow-up of 5 years. This series was treated between 1972 and 1982 at Istituto Ortopedico Rizzoli with a combined therapy. The local control of the disease consisted of amputation (ten cases), resection followed by radiation therapy (35-45 Gy) (48 cases) and radiation therapy alone (40-60 Gy) (86 cases). Adjuvant chemotherapy, rigorously standardized, was performed according two different protocols: the first (85 cases treated in the period 1972-1978) consisted of vincristine (VCR) Adriamycin (doxorubicin) (ADM), and cyclophosphamide (EDX); the second (59 cases treated in the period 1979-1982) of VCR, ADM, EDX and dactinomycin (DACT). At a follow-up of 5 to 16 years (median, 9), 59 patients (41%) are continuously disease-free (CDF), 81 (56%) developed metastatic disease and/or local recurrence, and four (3%) had a second malignancy. Three factors seem to be correlated to prognosis: the site of the initial lesion (only 23% of the pelvic lesions are represented in the CDF group versus 46% of the other locations); the chemotherapy protocol (32% of the cases in the first protocol are CDF versus 54% in the second); the type of local treatment (60% of the patients treated with amputation or resection plus radiotherapy versus 28% of those treated with radiation therapy alone are CDF). A local recurrence was observed in 24% of the patients (8% in the group locally treated with surgery or surgery plus radiation therapy versus 36% in the group treated with radiation therapy alone). These data suggest that even though adjuvant chemotherapy can improve the long-term results in localized Ewing's sarcoma patients, this disease still represents, in a high percentage of cases, a lethal process whose final prognosis widely depends on the local control of the lesion. Due to the questionable effect of the radiation therapy alone in controlling the primary lesion and its important side effects, the role of surgery in treating Ewing's sarcoma of bone should be extended.

Adolescent↗
PubMed1989

Raman spectroscopy for the study of porous composite alumina coating.

A new acetabular cup prosthesis made of alumina and bioactive glass was studied and evaluated using nondestructive and noninvasive Raman laser spectroscopy. The prosthesis consists of an alumina socket coated with a double layer of alumina beads bonded to the prosthesis with a layer of glass. Raman spectroscopy showed that both the socket and the beads are composed of alpha-Al2O3 (corundum), while the bioactive glass (alkaline and alkaline earth alumosilicate with a small quantity of zirconium oxide) showed this to have an intermediate structure between that of vitreous silica and that of the alkaline and alkaline earth disilicate glasses. The Raman spectra of the contact surfaces between the bioactive glass and the alumina of the assembled prosthesis and of an alumina disk coated with the same glass showed the presence of new bands which may be correlated with a chemical interaction between the components of the prosthesis.

Aluminum↗
PubMed1988

Radio-induced sarcomas in survivors of Ewing's sarcoma.

Of 255 cases of Ewing's sarcoma recorded at the Bone Tumor Center of the Rizzoli Orthopaedic Institute, 78 patients (irradiated and with a follow-up of longer than 3 years) were considered "at risk" for the development of a second radio-induced sarcoma (RIS). Three of the 78 patients developed an RIS in the irradiated field. Theoretical and statistical analyses were carried out considering different modalities of local treatment. Statistically, the only significant factor was related to the irradiation dose. Surgical resection seems to prevent RIS.

Adolescent↗
PubMed1988

Multilayered bead ceramic composite coating for hip prostheses: experimental studies and preliminary clinical results.

The clinical use of a new ceramic composite material made up of multilayered alumina beads and adhered to a ceramic surface with a high-temperature-melting bioglass is proposed. The result is a structure characterised by a 27% porosity and an average pore diameter of 400 microns. The actual structure of the parts as well as their interface interaction were determined by Raman laser. The mechanical resistance of the adherence of this coating for the ceramic substratum was good enough to resist the stress to which it was submitted when used for a new model of prosthetic acetabulum. Experiments with rabbits revealed the good biocompatibility of the composite. The osteoproductive activity of the tissue surrounding the implant led to the gradual filling of the porosity with trabecular structures. The preliminary results of the clinical experience which began in November 1985, confirm the good compatibility of the ceramic composite.

Aluminum Oxide↗
PubMed1988

Giant-cell tumor of bone with pulmonary metastases. Six case reports and a review of the literature.

Giant-cell tumor of bone rarely metastasizes to the lung. In three of six cases, lesions in lung tissue were histologically benign. In 39 such cases reported in the literature, the treatments were surgical extirpation, chemotherapy, and radiation therapy. Resection was indicated to definitely diagnose the pulmonary lesions as benign giant-cell tumors. Radiation therapy and/or chemotherapy may be beneficial as adjuvant treatment, especially where the lesions are anatomically inaccessible. Some pulmonary lesions spontaneously regress even in the absence of definitive treatment.

Adult↗
PubMed1987

[Therapy of non-metastatic Ewing's sarcoma (pelvis excluded). Results obtained in 48 cases combining local therapy (radiation and/or surgical) and adjuvant chemotherapy with vincristine, adriamycin, dactinomycin and cyclophosphamide].

Combined therapy was used on a consecutive series of 48 patients with extrapelvic Ewing's sarcoma at the Rizzoli Orthopaedic Institute. The adjuvant chemotherapy protocol (VCR, ADM, D-ACT, EDX) was identical in all patients whereas local treatment consisted of amputation, resection and radiation treatment or radiation alone. At a mean follow-up of 58 months (39-78) 30 patients (60%) were free of the disease. This is a significantly higher percentage than that obtained in the same period with adjuvant chemotherapy using only 3 drugs (VCR, ADM, EDX). As far as the type of local treatment is concerned, the percentage of local recurrences and metastases was lower when the primary lesion was treated with surgery or surgery combined with radiotherapy, rather than radiation treatment alone. These suggest that if associated with radiation treatment and chemotherapy, surgery can play an important role that should be considered in the treatment of extrapelvic Ewing's sarcoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Clinical evaluation of 104 hip resection arthroplasties after removal of a total hip prosthesis.

Functional results of resection arthroplasty are currently considered poor. In 104 hip prosthesis removals after either septic or aseptic loosening, pain, walking, joint motility, life style, and patient's opinion were evaluated. A satisfactory result was recorded in 72% of cases. Prognosis is poorer in patients who are young, have septic loosening, and have poor residual mobility. Resection arthroplasty should be considered a salvage procedure in cases of septic loosening and/or bone stock deficiency after a failed total hip arthroplasty.

Adult↗
PubMed1987

Giant-cell tumor of bone.

Of 327 patients who had a giant-cell tumor of bone and were seen at the Istituto Rizzoli, 293 were treated at the Institute, and 280 of these were followed for two to forty-four years. The distribution according to sex and age of the patient and site of the tumor was similar to the distributions in major reports of large series. The tumor usually involved the metaphysis and the epiphysis, but was occasionally limited to the metaphysis, and in only 2 per cent of the patients was it adjacent to an open growth plate. The tumor on occasion invaded the articular space, also involving the ligaments and the synovial membrane. Extension to an adjacent bone through the joint occurred in 5 per cent of the tumors. Our radiographic grading, which is roughly comparable with the staging system of Enneking et al., was Grade I in 4 per cent, II in 74 per cent, and III in 22 per cent of 266 patients before treatment. A pathological fracture was apparent on the first radiograph in 9 per cent of the patients. In the 280 patients with adequate follow-up, 331 surgical procedures were performed. The rate of local recurrence was 27 per cent in the 151 intralesional procedures, 8 per cent in the 122 marginal excisions, and zero in the fifty-eight wide or radical procedures. These results did not correlate with the radiographic grade of the lesion. Of the fifty-one local recurrences that were seen after treatment at our institution, 90 per cent appeared in the first three years after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Giant cell reparative granuloma and other giant cell lesions of the bones of the hands and feet.

The present paper is a clinico-pathologic study of 52 osteolytic lesions containing giant cells, affecting the hands and feet and comprising 11 giant cell reparative granulomas, nine giant cell tumors, six chondroblastomas, and 26 aneurysmal bone cysts. The nature of osteolytic lesions of hands and feet must be carefully established in order to plan appropriate treatment without damaging the surrounding structures. Giant cell reparative granuloma has to be distinguished from other lesions containing giant cells. Clinical and radiologic findings proved of limited diagnostic value; the definitive diagnosis can be established only by histologic examination. Surgical treatment is discussed.

Bone Cysts↗