			Home About us Contact

Authors' Hypothesis (author + hypothesis)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Implications of Prognostic Factors and Risk Groups in the Management of Differentiated Thyroid Cancer,

THE LARYNGOSCOPE, Issue 3 2004
Ashok R. Shaha MD
Abstract Objectives/Hypothesis The outcome in differentiated thyroid cancer generally depends on the stage of the disease at the time of presentation; prognostic factors such as age, grade, size, extension, or distant metastasis; and risk groups (eg, low or high risk). The author has reviewed a large number of patients with differentiated thyroid cancer to analyze their hypothesis and to confirm that various risk groups have a major implication in relation to extent of the treatment and outcome. Differentiated thyroid cancers make up 90% of all thyroid tumors. The prognostic factors are well defined, such as age, size of the tumor, extrathyroidal extension, presence of distant metastasis, histological appearance, and grade of the tumor. The author has previously divided the risk groups into low-, intermediate-, and high-risk categories based on prognostic factors. The study describes the author's treatment approach related to the extent of thyroidectomy and adjuvant therapy based on various risk groups and the long-term survival. Study Design Retrospective. Methods In a retrospective review of 1038 patients with differentiated thyroid carcinoma, various prognostic factors were studied by univariate and multivariate analysis. The significant prognostic factors were studied in detail and, based on these prognostic factors, the patients were divided into low-, intermediate- and high-risk groups. The survival curves were plotted by Kaplan-Meier method. Results The long-term survivals in low-, intermediate- and high-risk groups were 99%, 87%, and 57% respectively. Based on these risk groups, a decision tree was made regarding extent of thyroidectomy and adjuvant treatment. In the high-risk group and selected patients in the intermediate-risk group, aggressive surgery including removal of all gross disease and extrathyroidal extension with postoperative radioactive iodine ablation is recommended. In the low-risk group and selected patients in the intermediate-risk group, lobectomy appears to be satisfactory with excellent long-term outcome. The surgical treatment offers the best long-term results in low-risk patients, and the role of adjuvant treatment in this group is questionable. Conclusion The decisions in the management of well-differentiated thyroid cancer should be based on various prognostic factors and risk groups. The long-term survival in the low-risk group is excellent, and consideration should be given to conservative surgical resection depending on the extent of the disease. In the high-risk group and selected patients in the intermediate-risk group, total thyroidectomy with radioactive ablation is warranted. A consideration may be given to external-beam radiation therapy in selected high-risk patients. It is apparent, based on the author's clinical experience and critical retrospective analysis, that the author's hypothesis that risk groups are extremely important in the long-term outcome of patients with differentiated thyroid cancer is correct. Based on various risk groups, the author currently is able to guide the treatment policies for thyroid cancer. [source]

The conditional party mandate: A model for the study of mass and elite opinion patterns

EUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 3 2007
HENRY VALEN
What is the level of issue congruence between voters and elected leaders? The article introduces two ideas for the analysis of mass and elite opinion patterns. First, the authors challenge the unidimensional conception of mass-elite linkages, and argue that the opinion structure of political parties may best be understood in the context of a multidimensional policy space. Second, they contest the proximity logic of the traditional party mandate model. In so doing, they propose the ,conditional party mandate model', arguing that ,direction' rather than ,proximity' attracts voters' interest and attention. The authors contend that in issues of principle significance for a particular party (so-called ,core issues'), the party's voters and representatives will proceed in the same direction, but the representatives will stress their position more strongly than the voters. In issues that are less significant to the parties, the relationship between the two levels will be fortuitous and less clear. The analyses, which are based on elite and mass survey data from the Norwegian political system, support the authors' hypotheses concerning positional issues. When the direction of an issue is given, representatives are more extreme than voters. [source]

Heart Failure and Diabetes: Collateral Benefit of Chronic Disease Management

CONGESTIVE HEART FAILURE, Issue 3 2006
Molly G. Ware MD
To test the hypothesis that a focus on heart failure (HF) care may be associated with inadequate diabetes care, the authors screened 78 patients (aged 64±11 years; 69% male) with diabetes enrolled in an HF disease management program for diabetes care as recommended by the American Diabetes Association (ADA). Ninety-five percent of patients had hemoglobin A1c levels measured within 12 months, and 71% monitored their glucose at least once daily. Most patients received counseling regarding diabetic diet and exercise, and approximately 80% reported receiving regular eye and foot examinations. Mean hemoglobin A1c level was 7.8±1.9%. There was no relationship between hemoglobin A1c levels and New York Heart Association class or history of HF hospitalizations. Contrary to the authors' hypothesis, patients in an HF disease management program demonstrated levels of diabetic care close to ADA goals. "Collateral benefit" of HF disease management may contribute to improved patient outcomes in diabetic patients with HF. [source]

Nested case-control study of lung cancer among pulp and paper workers in relation to exposure to dusts

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 6 2001
Irena Szadkowska-Sta, czyk MD
Abstract Background Numerous studies have indicated an increased risk of lung cancer in pulp and paper industry workers. In a 1990 survey, standardized mortality ratio (SMR) was found to be 122 (95% CI:96,153) for lung cancer in Polish male workers in the pulp and paper industry, and 166 (95% CI:95,270) among workers engaged in paper production. Methods A nested case-control design within a cohort of pulp and paper workers was applied. Seventy-nine lung cancer cases and 237 "healthy" controls were selected from the cohort of 10,460 workers employed during the years 1968,1990, and observed until the end of 1995. Based on personnel files, occupational exposure was reconstructed by experts. Using a questionnaire, data on smoking habits were collected. ORs unadjusted and adjusted for smoking were calculated applying the model of conditional logistic regression. Results Occupational exposure to inorganic dusts (kaolin, lime, cement, brick, grindstone) adjusted for smoking was a significant lung cancer risk factor, with a 4.0-fold risk (95% CI:1.3,12.6), and a dose-response by cumulative dose index. Among organic dusts only wood dust increased albeit insignificantly the risk for those exposed (adjusted for smoking OR,=,2.1, 95% CI:0.9,4.9), but without dose-response relationship. Conclusions Exposure to occupational dust with relatively low content of silica, but at high concentrations may be considered as a factor increasing lung cancer risk. However, the observation made in this study should be viewed with caution as it was based on a small number of cases, and further evidence is needed to confirm or refute the authors' hypothesis. Am. J. Ind. Med. 39:547,556, 2001. © 2001 Wiley-Liss, Inc. [source]

Expression of FasL in squamous cell carcinomas of the cervix and cervical intraepithelial neoplasia and its role in tumor escape mechanism,

CANCER, Issue 5 2006
Ramy Ibrahim M.D.
Abstract BACKGROUND To date, several mechanisms have been described by which malignant cells escape from the immune system. One of these is through the expression of FasL. The authors hypothesized that the Fas/FasL interaction enables cervical carcinoma cells to induce apoptosis of the cells of the immune system and thereby escape from them. METHODS The authors tested the expression of FASL on the surface of cervical carcinoma tissues. Next, they stained the same cervical tissues with anti-human leukocyte common antigen and TUNEL to identify apoptotic cells. An in vitro functional assay was then done to test if the FASL expressed on the surface of cervical carcinoma cell lines was or was not responsible for inducing apoptosis in T-cells. Finally, they compared the expression of FASL on normal and dysplastic cervical tissues. RESULTS Ninety-four percent of the cervical carcinoma tissues the authors tested expressed FasL and the majority of the apoptotic cells in the specimens were leukocytes with very few tumor cells. In the in vitro functional assay, only the Fasl expressing cell line and not the Fasl negative cell line was able to induce apoptosis of the Fas-expressing Jurkat cells. On examining the normal cervical tissues, the authors found that the expression of Fasl was confined to the basal cell layer with loss of expression observed in the suprabasal layers, which made it an immune privileged site. Conversely, there was persistent expression of FasL in the dysplastic layers in cervical dysplasia and squamous cell carcinoma specimens. CONCLUSIONS The findings of the current study support the authors' hypothesis that persistent expression of FasL plays a role in the ability of cervical carcinoma cells to escape from the immune system. Cancer 2006. Published 2006 by the American Cancer Society. [source]