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Biomedical subjects

S Barlas

Publications and source records attributed to S Barlas.

10 recordsLinked to original sources
PubMed2000

Usefulness of exchange transfusion in acute liver failure due to severe falciparum malaria.

Acute hepatic failure is a rare and serious complication of severe falciparum malaria. The management of uncomplicated falciparum malaria comprises of specific antimalarial drugs and supportive therapy. In a few patients who are critically ill because of severe falciparum malaria and heavy parasitaemia, exchange transfusion has been used. We describe a young male Saudi patient who presented with a 2-day history of fever, jaundice, and confusion. On examination he was deeply jaundiced, confused, and irritable. There were no signs of chronic liver disease. His laboratory workup revealed a markedly raised direct hyperbilirubinaemia and transaminases with prolonged prothrombin time. His serology was negative for HbsAg, HBc IgM, anti-HCV, HAV IgM, HEV IgM, and IgG. He was initially treated with parenteral quinine and other supportive treatment, without any improvement of his clinical and laboratory parameters. At this stage he was treated with whole blood exchange transfusion. He slowly improved, with complete normalization of his liver function tests and prothrombin time.

Adult↗
PubMed1999

Overconfidence: It Depends on How, What, and Whom You Ask.

Many studies have reported that the confidence people have in their judgments exceeds their accuracy and that overconfidence increases with the difficulty of the task. However, some common analyses confound systematic psychological effects with statistical effects that are inevitable if judgments are imperfect. We present three experiments using new methods to separate systematic effects from the statistically inevitable. We still find systematic differences between confidence and accuracy, including an overall bias toward overconfidence. However, these effects vary greatly with the type of judgment. There is little general overconfidence with two-choice questions and pronounced overconfidence with subjective confidence intervals. Over- and underconfidence also vary systematically with the domain of questions asked, but not as a function of difficulty. We also find stable individual differences. Determining why some people, some domains, and some types of judgments are more prone to overconfidence will be important to understanding how confidence judgments are made. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Behçet's disease. An insight from a vascular surgeon's point of view.

Behçet's syndrome is a multisystem inflammatory disease with unknown aetiology, vasculitis being its major pathological feature. It runs an undulating course of exacerbations and remissions with a frequency that usually abates with the passage of time. Following its first description in the medical literature in 1937, many clinical manifestations, including recurrent ulcerations, eye and urogenital lesions, pulmonary and vascular involvement with thrombus and aneurysm formation, arthritis and neurological features were reported. Various studies undertaken in two Medical Faculties of Istanbul University showed that more than 5000 patients have fulfilled three or more International Behçet's Disease Study Group Criteria and thus can be diagnosed as Behçet's Disease. A total of 142 cases with pulmonary, 30 cases with arterial (non-pulmonary) and 10 cases with cardiac involvement were demonstrated since 1978. A group of 174 neuro-Behçet's Disease patients (cerebral venous and vena caval thrombosis as the cause of intracranial hypertension, extracranial vertebral artery dissection) was evaluated. Our collected data showed that surgery with special techniques and in highly selected cases may be useful if used with adjuvant medical therapy, but might be fatal or unsuccessful in the majority. No means of aggressive surgical or interventional therapy has a role in altering the course of the pathology itself when used alone and thus medical treatment is crucial to suppress the exacerbations.

Angiography↗
PubMed1998

Survival rates in patients with primary malignant brain tumors stratified by patient age and tumor histological type: an analysis based on Surveillance, Epidemiology, and End Results (SEER) data, 1973-1991.

OBJECT: The authors present population-based survival rate estimates for patients with malignant primary brain tumors based on an analysis of 18 years of data obtained from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute. METHODS: Estimates of survival rates at 2 and 5 years after diagnosis for patients with specific histological tumor types were categorized by patient's age at diagnosis (< or = 20 years, 21-64 years, and 65 years or older) and by the time period in which the patients were diagnosed (1973-1980, 1981-1985, 1986-1991). Where appropriate, survival estimates were adjusted for changing patterns in the mean age at diagnosis. CONCLUSIONS: The authors observed a pattern of declining survival rates in patients with increasing age of the patient at diagnosis for most histological groups and overall improvements in survival rates of patients across these time periods adjusting for age at diagnosis. There were improvements in 2- and 5-year survival rates over the three time periods for children and adults with medulloblastoma and for adults with astrocytoma and oligodendroglioma. Improvements in survival rates for pediatric patients with medulloblastoma have leveled off in the most recent time period, and gender differences in survival rates for patients with this tumor, which were present in the 1970s, have disappeared. Clinically significant improvements in survival rates were not apparent in patients aged 65 years and older. Changes in diagnostic and treatment procedures since the mid-1970s have resulted in improved survival rates for patients diagnosed as having medulloblastoma, oligodendroglioma, and astrocytoma, controlling for age at diagnosis. Glioblastoma multiforme continues to be the most intractable brain tumor.

Adult↗
PubMed1997

Changes in diagnostic decision-making after a computerized decision support consultation based on perceptions of need and helpfulness: a preliminary report.

We examined the degree to which attending physicians, residents, and medical students' stated desire for a consultation on difficult-to-diagnose patient cases is related to changes in their diagnostic judgments after a computer consultation, and whether, in fact, their perceptions of the usefulness of these consultations are related to these changes. The decision support system (DSS) used in this study was ILIAD (v4.2). Preliminary findings based on 16 subjects' (6 general internists, 4 second-year residents in internal medicine, and 6 fourth-year medical students) workup of 136 patient cases indicated no significant main effects for 1) level of experience, 2) whether or not subjects indicated they would seek a diagnostic consultation before using the DSS, or 3) whether or not they found the DSS consultation in fact to be helpful in arriving at a diagnosis (p > .49 in all instances). Nor were there any significant interactions. Findings were similar using subjects or cases as the unit of analysis. It is possible that what may appear to be counter-intuitive, and perhaps irrational, may not necessarily be so. We are currently examining potential explanatory hypotheses in our ongoing current, larger study.

Attitude to Computers↗
PubMed1992

[Comparison of the Wright, indirect Coombs and enzyme immunoassay IgG methods for the diagnosis of chronic brucellosis].

Incomplete IgG and IgA class immunoglobulins are formed in chronic brucellosis and these antibodies do not detect with classical Wright agglutination test (WAT). However these antibodies are measured with indirect Coombs and enzyme immune assay (EIA) techniques. In this study 90 patients serum samples were tested with WAT, indirect Coombs and EIA. All of the patients had chronic brucellosis. EIA was used to determine the levels of brucella specific IgG antibodies in 44 patients whose WATs were negative and indirect Coombs assays were positive and 46 patients whose WATs and indirect Coombs tests were negative. Thirty-seven (84.08%) of the 44 patients whose WAT negative and indirect Coombs positive were found positive for EIA IgG. Sixteen (34.7%) of the 46 patients whose WAT and indirect Coombs negative were found positive EIA IgG. The importance of EIA and indirect Coombs tests was discussed at the diagnosis of chronic brucellosis.

Adult↗
PubMedDate not supplied

Effects of a decision support system on the diagnostic accuracy of users: a preliminary report.

OBJECTIVES: To assess the effects of incomplete data upon the output of a computerized diagnostic decision support system (DSS), to assess the effects of using the system upon the diagnostic opinions of users, and to explore if these effects vary as a function of clinical experience. DESIGN: Experimental pilot study. Four clusters of nine cases each were constructed and equated for case difficulty. Definitive findings were omitted from the case abstracts. Subjects were randomly assigned to one of four clusters and were trained on the DSS prior to use. SUBJECTS: The study involved 16 physicians at three levels of clinical experience (six general internists, four residents in internal medicine, and six fourth-year medical students), from three academic medical centers. PROCEDURE: Each subject worked up nine cases, first without and then with ILIAD consultation. They were asked to offer up to six potential diagnoses and to list up to three steps that should be the next items in the diagnostic workup. Effects of DSS consultation were measured by changes in the position of the correct diagnosis in the lists of differential diagnoses, pre- and post-consultation. RESULTS: The DSS lists of diagnostic possibilities contained the correct diagnosis in 38% of cases, about midway between the levels of accuracy of residents and attending general internists. In over 70% of cases, the DSS output had no effect on the position of the correct diagnosis in the subjects' lists. The system's diagnostic accuracy was unaffected by the clinical experience of the users.

Decision Making↗