Biomedical subjects

D Sabah

Publications and source records attributed to D Sabah.

12 recordsLinked to original sources

PubMed2001

The role of 99mTc-MIBI scintigraphy in the assessment of MDR1 overexpression in patients with musculoskeletal sarcomas: comparison with therapy response.

The occurrence of multidrug resistance (MDR), which is in part due to the overexpression of P-glycoprotein (Pgp), is a major problem in neoadjuvant therapy of malignant musculoskeletal tumours. The aim of this study was to investigate the role of technetium-99m hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy for functional imaging of the MDR1 phenotype in patients with musculoskeletal sarcomas. We aimed to compare 99mTc-MIBI uptake and washout kinetics with the expression of Pgp and with chemotherapy response. Twenty-five patients (16 males and 9 females, aged between 8 and 65 years) with malignant musculoskeletal tumours were studied. After injection of 555-740 MBq 99mTc-MIBI, dynamic flow images of the involved area were obtained for 3 min, and planar images were acquired at 10 min and 1 h. From the dynamic images, a tumour perfusion index (TPI) was obtained using Patlak-Rutland analysis. Tumour to background (T/B) ratios of both early and delayed images and percent wash-out rate (WR%) of 99mTc-MIBI were calculated. Immunohistochemical analysis of Pgp was performed on biopsy specimens and the degree of expression was graded according to a semiquantitative scoring system, from 0 to 6. After neoadjuvant therapy, tumour response was assessed by examining the ratio of viable cells and by detecting percent necrosis. Scintigraphic results were compared with Pgp status and therapy response. Irrespective of the Pgp status, all patients showed significant perfusion and 99mTc-MIBI uptake in early images. There was not a significant correlation between T/B ratios of early and delayed images and Pgp expression. We observed a positive correlation between WR% and Pgp status (r=0.61, P<0.01), and the wash-out rate of 99mTc-MIBI was significantly higher in patients with high Pgp expression than in those with a low Pgp score (33% +/- 9% vs 17% +/- 9%). Therapy response was determined in 21 of 25 patients, and in only 5 of 21 cases was the percent necrosis more than 90%. Neither Pgp expression rate nor WR% was found to show a significant correlation with percent necrosis in the bulk tumour specimens. In conclusion, the initial uptake of 99mTc-MIBI in bone and soft tissue sarcomas did not correlate with Pgp expression. A relationship was found between the wash-out rate of 99mTc-MIBI and the Pgp score, with a significant difference in WR% being observed between patients with high and patients with low Pgp expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

A severely disabling disorder: fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare hereditary disorder characterised by progressive heterotopic ossification of the soft tissues. The resulting progressive immobilisation of the limbs, jaw and chest wall generally leads to severe disability. We present an 18-year-old girl with advanced FOP. She had three operative interventions to excise her ectopic bones but all resulted in failure. Treatment strategies for this disorder should include the avoidance of exacerbating factors.

Adolescent↗

PubMed2001

Correlation of 99mTc-sestamibi uptake with blood-pool and osseous phase 99mTc-MDP uptake in malignant bone and soft-tissue tumours.

Technetium-99m-sestamibi (99mTc-MIBI) imaging is a well-established modality in oncologic investigations. The current study aimed to investigate whether any relationship could be found between 99mTc-MIBI uptake and local perfusion in malignant bone and soft-tissue tumours. It also aimed to compare 99mTc-MIBI images with those of technetium-99m-methylene diphosphonate (99mTc-MDP) bone scintigraphy with regard to the activity distribution pattern, intensity and lesion extension. The study group included 24 patients with various bone and soft-tissue tumours. Three-phase bone scintigraphy and 99mTc-MIBI studies were performed within the same week before any surgical and therapeutic intervention. Images were evaluated visually and quantitatively using regions of interest (ROIs) over the lesion and adjacent normal tissue. The 99mTc-MIBI study was positive with varying degrees of uptake (range, 1.4-5.3). The mean 99mTc-MIBI uptake and 99mTc-MDP blood-pool and osseous phase activity ratios were 2.5 +/- 0.5, 2.8 +/- 1.0 and 5.5 +/- 4.0, respectively. The correlation between the 99mTc-MIBI uptake and blood-pool ratios was 0.70 (P<0.05). While activity distribution patterns were in agreement in 99mTc-MIBI and blood-pool images in the majority of cases, 99mTc-MIBI better delineated tumour viability and extension in five cases. In conclusion, 99mTc-MIBI accumulation shows a reasonable correlation with blood-pool uptake assuming the presence of multifactorial mechanisms in addition to local hyperaemia. Better delineation of tumour outlines and cellular activity seems to be an advantage of 99mTc-MIBI scintigraphy which may be helpful in the evaluation of musculoskeletal tumours.

Adolescent↗

PubMed2000

Transsacral usage of a pure island TRAM flap for a large sacral defect: a case report.

A pedicled transverse rectus abdominis musculocutaneous (TRAM) flap was used to reconstruct a large sacral defect retroperitoneally. Muscle and superiorly located skin were elevated on the deep inferior epigastric pedicle. The flap was transposed retroperitoneally from the abdominal wall to the sacral region of the patient. The selection criteria for this particular flap are discussed and compared with other reconstructive choices.

Abdomen↗

PubMed1999

Assessment of chemotherapy-induced changes in bone sarcomas: clinical experience with 99Tcm-MDP three-phase dynamic bone scintigraphy.

The aim of this study was to evaluate the value of three-phase dynamic bone scintigraphy (TPBS) in the assessment of the response of bone sarcomas to pre-operative chemotherapy and to correlate serial scintigraphic changes with histological findings. The study group comprised 27 patients (osteogenic sarcoma, n = 20; Ewing's sarcoma, n = 5; malignant fibrous histiocytoma, n = 2) with a mean age of 19.2 years. All patients received 99Tcm-methylene diphosphonate TPBS before and after pre-operative chemotherapy. Each phase of the imaging procedure was interpreted qualitatively and quantitatively. The percentage of tumour necrosis was analysed on resection materials following surgery. Histologically, 12 patients were non-responsive (tumour necrosis less than 90%) and 15 patients were responsive (tumour necrosis more than 90%). A decrease in the tumour blood flow ratio and extension were the most notable findings in the responders. The mean change in the tumour blood flow ratio following therapy was 58.7 +/- 8.3% and 19.9 +/- 26.6% (P < 0.005) in responders and non-responders respectively. The accuracy of three-phase imaging and static bone scintigraphy was 88% and 74% respectively. Since bone scintigraphy is a valuable technique owing to its ability to detect distant metastases in clinically early disease, TPBS should be helpful in monitoring therapy effects without any additional cost or radiation dose.

Adolescent↗

PubMed1997

Liposarcoma of soft tissue: MRI findings with pathologic correlation.

OBJECTIVE: To evaluate the MRI findings of liposarcomas of different histologic types and correlate these with the histopathologic features. DESIGN: The MR images of seven liposarcomas were reviewed retrospectively to assess the tumor size, location, margination, signal characteristics and enhancement patterns in different histologic types. PATIENTS: Seven liposarcomas comprising three well-differentiated, two myxoid and two pleomorphic types were evaluated. RESULTS AND CONCLUSION: All tumors showed well-defined and mostly lobulated margins. The well-differentiated liposarcomas were composed mainly of fat with septations or nodules, were hyperintense on T2-weighted images, and demonstrated faint enhancement or no enhancement following intravenous contrast. Myxoid liposarcomas were homogeneous or mildly heterogeneous and a pseudocapsule was present in one case. Pleomorphic types showed a markedly heterogeneous internal structure. Both myxoid and pleomorphic lesions-showed moderate or marked heterogeneous enhancement after contrast administration. Well-differentiated liposarcomas may be differentiated from other types of the tumor by their largely lipomatous appearance. The malignancy grade increases in parallel with tumor heterogeneity and contrast enhancement.

Adult↗

PubMed1996

[The crisis of internal medicine].

The rapid technological progress in medicine has lead to a better physiopathologic and etiological knowledge of adult diseases, producing a fragmentation of internal medicine and a great development of its subspecialties. Furthermore, specialization grants a professional, scientific and academic status. Contrarywise technological enrichment has impoverished the human relationship of clinical practice. The training at the Medical School has a great responsibility towards General Internal Medicine, and the technical capacity of teachers should be revised. The practical tutorial teaching at the hospital should be accomplished by Internists with a general clinical orientation. Outpatient clinics should be incorporated as places where a more clinical and less technological medicine could be taught. Internship should be a period in which General Internal Medicine should be valorized, continuing in post-graduate training and continuous teaching. General Internal Medicine is going through a crisis; Medical Schools and the Medical society have the responsibility to overcome it.

Chile↗

PubMed1987