Biomedical subjects

E Youssef

Publications and source records attributed to E Youssef.

8 recordsLinked to original sources

PubMed2003

Study of erythrocyte shape changes in schistosomiasis.

The aim of this work was to study the red cell morphology in different stages of schistosomiasis. Patients were divided into three groups according to the stage of the disease. For each patient, complete clinical examination, liver function tests, renal function tests, complete blood picture, scanning electron microscopy for erythrocytes (SEM) and abdominal ultrasonography were done. Abnormal morphologic changes of a total discoid flat cells of 70.14%, margin changes of 12.34% and 3.55% of cup forms were found. To our knowledge, these marked changes were not reported in any other disease. No statistical differences were found between red cell shape changes and stage of liver disease. There was a positive correlation between portal vein diameter and percentage of flat discoid forms and a negative correlation between surface changes and clinical stage of liver disease. These changes are known to be accompanied by reduction of red cell deformability and impaired capillary flow.

Adult↗

PubMed2001

Locally advanced nasopharyngeal cancer.

The Head and Neck Cancer Intergroup phase III clinical trial (Int 0099) for patients with locally advanced, squamous cell carcinomas (SCC) of the nasopharynx (or NPC) has been recently completed in the United States. The results of this study have defined the new standard of treatment for the group of patients studied. Patients with untreated, locally advanced stages III and IV NPC were randomized to a conventional course of radiation, or to radiation given concurrently with chemotherapy followed by three courses of combination chemotherapy. The 3-year progression-free survival (PFS) and overall survival (OS) were 24% versus 69% (P < 0.001) and 46% versus 76% (P < 0.001) for the control and experimental groups, respectively. Recent updates of these survival figures show that they have not changed appreciably. The considerable improvement in OS versus PFS for the patient group receiving radiation alone is accounted for primarily by re-treatment with concurrent radiation-chemotherapy, combination chemotherapy, and isolated salvage neck dissections. Highly significant differences in local control (41% vs 14%) and distant metastases (35% vs 13%) were demonstrated in favor of the chemoradiation treatment arm. The median age for these patients was 51 years, with a 2:1 male to female ratio. Although many patients had a significant history of tobacco exposure with or without alcohol use or abuse, only 24% had keratinizing or well-differentiated squamous (World Health Organization I) type tumors. Whether these results can be extrapolated to the more common Asian variety (WHO II and III) of advanced NPC must be addressed in future clinical trials.

Adult↗

PubMed2001

Detection of the 67-kD laminin receptor in prostate cancer biopsies as a predictor of recurrence after radical prostatectomy.

OBJECTIVES: Reliable prognostic indicators are needed for a better pretherapeutic assessment of the agressiveness of organ-confined prostate cancer (PC) lesions. The 67-kD laminin receptor (67LR) is a cell-surface-associated protein involved in the acquisition of the invasive and metastatic phenotype of a variety of human cancer cell types. We have previously shown that 67LR detection in PC tissues from radical prostatectomy (RP) specimens is an independent predictor of biochemical (PSA) relapse in patients with clinically localized PC. In this study, we assessed 67LR detection in diagnostic PC biopsies as a predictor of biochemical relapse after RP. METHODS: Diagnostic biopsy and subsequent RP tissue specimens from 151 patients with clinically localized PC were immunohistochemically analyzed for 67LR expression. The level of 67LR expression was evaluated by both intensity and extent of the staining. Clinicopathological preoperative and postoperative parameters, including 67LR expression, were correlated with each other and tested as predictors of biochemical relapse. RESULTS: 67LR was detected in 67.5 and 68.2% of biopsies and RPs, respectively. 67LR detection in RP specimens was an independent predictor of relapse. The level of 67LR expression in the biopsy was significantly associated with the biopsy Gleason score (p<0.05) but failed to predict the pathological stage (p>0.1). Biochemical progression-free estimates for patients whose biopsy did or did not express the protein differed with only borderline statistical significance (p = 0.05). Multivariate analysis identified biopsy Gleason score as the only independent preoperative predictor of recurrence. Significant discrepancies in levels of 67LR expression were found between matched biopsy and RP specimens (p<0.05), with exact agreement rates <40%. CONCLUSIONS: 67LR detection in PC biopsies was not a significant preoperative predictor of outcome after RP. Heterogeneity of 67LR expression and biopsy sampling errors most likely represented the main reasons for discordant results between biopsy and RP specimens.

Adenocarcinoma↗

PubMed2000

Dosimetric improvements following 3D planning of tangential breast irradiation.

PURPOSE: To evaluate the dosimetric difference between a simple radiation therapy plan utilizing a single contour and a more complex three-dimensional (3D) plan utilizing multiple contours, lung inhomogeneity correction, and dose-based compensators. METHODS AND MATERIALS: This is a study of the radiation therapy (RT) plans of 85 patients with early breast cancer. All patients were considered for breast-conserving management and treated by conventional tangential fields technique. Two plans were generated for each patient. The first RT plan was based on a single contour taken at the central axis and utilized two wedges. The second RT plan was generated by using the 3D planning system to design dose-based compensators after lung inhomogeneity correction had been made. The endpoints of the study were the comparison between the volumes receiving greater than 105% and greater than 110% of the reference dose, as well as the magnitude of the treated volume maximum dose. Dosimetric improvement was defined to be of significant value if the volume receiving > 105% of one plan was reduced by at least 50% with the absolute difference between the volumes being 5% or greater. The dosimetric improvements in 49 3D plans (58%) were considered of significant value. Patients' field separation and breast size did not predict the magnitude of improvement in dosimetry. CONCLUSION: Dose-based compensator plans significantly reduced the volumes receiving > 105%, >110%, and volume maximum dose.

Breast Neoplasms↗

PubMed1999

External beam radiotherapy for painful osseous metastases: pooled data dose response analysis.

PURPOSE: Although the effectiveness of external beam irradiation in palliation of pain from osseous metastases is well established, the optimal fractionation schedule has not been determined. Clinical studies to date have failed to demonstrate an advantage for higher doses. To further address this issue, we conducted a pooled dose response analysis using data from published Phase III clinical trials. METHODS AND MATERIALS: Complete response (CR) was used as an endpoint because it was felt to be least susceptible to inconsistencies in assessment.The biological effective dose (BED) was calculated for each schedule using the linear-quadratic model and an alpha/beta of 10. Using SAS version 6.12, the data were fitted using a weighted linear regression, a logistic model, and the spline technique. Finally, BED was categorized, and odds ratios for each level were calculated. RESULTS: CR was assessed early and late in 383 and 1,007 patients, respectively. Linear regression on the early-response data yielded a poor fit and a nonsignificant dose coefficient. With the late-response data, there was an excellent fit (R-square = 0.842) and a highly significant dose coefficient (p = 0.0002). Fitting early CR to a logistic model, we could not establish a significant dose response relationship. However, with the late-response data there was an excellent fit and the dose coefficient was significantly different from zero (0.017 +/- 0.00524; p = 0.0012). Application of the spline technique or removal of an outlier resulted in an improved fit (p = 0.048 and p = 0.0001, respectively). Using BED of < 14.4 Gy as a reference level, the odds ratios for late CR were 2.29-3.32 (BED of 19.5-51.4 Gy, respectively). CONCLUSION: Our results demonstrate a clear dose-response for pain relief. Further testing of high intensity regiments is warranted.

Bone Neoplasms↗

PubMed1989

Recurrent tumors of the head and neck, pelvis, and chest wall: treatment with hyperthermia and brachytherapy.

Cancer that recurs after surgery and radiation therapy remains a major problem. The claimed effectiveness of thermobrachytherapy in patients with this problem prompted the present study. Forty-six lesions (20 head and neck, 18 pelvic, seven chest wall, and one limb sarcoma) in 38 patients were treated with interstitial hyperthermia that sandwiched the use of Ir-192 with the aim of delivering 2,000-6,000 cGy, depending on prior dose and tissue tolerance. Complete regression occurred in 19 (54%) of 35 evaluable cases. More than 58,000 measured temperature points were analyzed to develop a representative quantitative measure, the "modal thermal dose," that represented the temperature reported most often during heating sessions. The pattern was plotted in each case. No significant relation was found between heating patterns and tumor response. Of all the prognostic factors studied, the radiation dose was the most significant, with a complete response rate being 78% when the total radiation dose exceeded 6,000 cGy, compared with 8% when the dose was lower than 5,000 cGy (P less than .005). The tumor volume also was important, with smaller lesions responding much better than larger ones (P = .1).

Brachytherapy↗

PubMed1988

Changes in T-cell subsets after radiation therapy.

The T-cell subsets of 129 patients with cancer were counted before and after radiation therapy. The cells were labeled with monoclonal antibodies that were specific for each type of T cell. Significant changes after therapy were decreases in the proportion of T-helper/inducer cells, pan-T cells, and in the ratio of T-helper/inducer to T-suppressor/cytotoxic cells. There was an increase in the percentage of T-suppressor/cytotoxic cells. When the site of the primary cancer was considered, genitourinary cancer and cancer of the head and neck both showed a decreased percentage of T-helper/inducer cells and a reduced ratio of T-helper/inducer to T-suppressor/cytotoxic cells. The percentage of pan-T cells in head and neck cancer and the ratio of T-helper/inducer to T-suppressor/cytotoxic cells in breast cancer were decreased. The percentage of T-helper cells was particularly decreased by radiation therapy in advanced stages of cancer, in higher grade tumors, and in larger tumors. The absolute numbers of various T-cell subsets were decreased in all groups.

Antibodies, Monoclonal↗

PubMedDate not supplied

The value of postlumpectomy mammogram in the management of breast cancer patients presenting with suspiciouis microcalcifications.

PURPOSE: It is recommended that patients with breast cancer who present with mammographically detected microcalcification should undergo postlumpectomy mammogram with magnification views to ensure adequate removal of all clinically demonstrable disease. The value of postlumpectomy mammogram has not been adequately examined in the literature. This report aims to quantify the value of such a study. MATERIALS AND METHODS: Retrospective review identified 90 breast cancer patients referred to our department between 1992 and 1997 who met all of the following criteria: (1) patients were considered for breast conserving management; (2) patients had suspicious microcalcifications on diagnostic mammograms; (3) the mammographic lesions were thought to be removed entirely on postexcision specimen radiographs; (4) surgical excisions were thought to be adequate on the basis of a review of the histologic pathology reports; and (5) postlumpectomy mammograms with magnification views were obtained. Fifty patients had invasive adenocarcinoma and 40 patients had ductal carcinoma in situ. The margins of last resection were clear, close, or focally involved in 70, 13, and seven patients, respectively. Patient records were reviewed to determine whether postlumpectomy mammograms demonstrated residual microcalcifications. RESULTS: Sixteen patients (17%) were found to have residual microcalcifications on postlumpectomy mammograms. Twelve patients underwent either local re-excision (seven patients) or simple mastectomy (five patients). Re-excision was not performed in four patients. Residual malignant cells were found in eight patients (67% of the re-excision group and 9% of the whole group). Six of these patients had their tumors initially resected with clear margins and the remaining two patients had their tumors initially resected with close margins. CONCLUSIONS: Postlumpectomy mammograms with magnification views detected residual clinical disease in a significant proportion of patients. Our result supports the routine use of this test, even when satisfactory postexcision specimen radiographs and adequate lumpectomy resection margins are obtained. This finding is particularly true for patients with ductal carcinoma in situ.

Breast Neoplasms↗