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Biomedical subjects

S Sorensen

Publications and source records attributed to S Sorensen.

At least 19 recordsLinked to original sources
PubMed2004

Measuring validity of self-reported symptoms among people with HIV.

Symptoms are important indicators of health and treatment for people with HIV. Symptoms are measured by patient self-report, but there has been little attention to what is the best method of elicitation. We compared three methods (presence, frequency, and bother) commonly used to measure HIV self-reported symptoms. CD4+ T lymphocyte count and health-related quality of life (HRQL) scales were used to test validity in 160 people with HIV. The average number of symptoms reported was 15.2 (standard deviation 8.4). Correlation coefficients of summary symptom scores using the three methods ranged from -0.30 to -0.36 with HRQL score and from -0.19 to -0.20 with CD4 count (p<0.05). Correlation coefficients of seven specific symptom items with CD4+ counts and HRQL scores for the same concepts were small to moderate (-0.08 to -0.58, p<0.05). For the three methods, the correlation coefficients in general tended to be greater with frequency or bother than presence. However, the differences among the three methods were not statistically significant. We conclude that no single method is superior to the others.

Adult↗
PubMed2002

Improving the development of event-driven control systems in the batch processing industry. A case study.

This paper presents the results of an academia-industry collaborative project whose main objective was to test novel techniques for the development of event-driven control systems in the batch processing (e.g., pharmaceutical, fine chemicals, food) industries. Proposed techniques build upon industrial standards and focus on (i) formal synthesis of phase control logic and its automatic translation into procedural code, and (ii) verification of the complete discrete-event control system via dynamic simulation. In order to test the techniques in an engineering environment, a complete discrete-event control system was produced for a benchmark batch process plant based on a standard development method employed by one of the industrial partners. The control system includes functional process specification, control architecture, distributed control system (DCS) proprietary programming code for procedural control at equipment, unit, and process cell levels, and human-machine interfaces: A technical assessment of the development method and the obtained control system was then carried out. Improvements were suggested using the proposed techniques in the specification, code generation and, verification steps. The project assessed the impact of these techniques from both an engineering and economic point of view. Results suggest that the introduction of computer aided engineering (CAE) practices based on the benchmarked techniques and a structured approach could effect a 75% reduction of errors produced in the development process. This translates into estimated overall savings of 7% for green-field projects. Figures were compared with other partners' experience. It is expected that the work load on a given project will shift, increasing the load on process engineers during the specification stage and decreasing the load on the software engineers during the code writing.

Algorithms↗
PubMed2001

Prospective multicenter study of pregnancy outcomes in women with heart disease.

BACKGROUND: The maternal and neonatal risks associated with pregnancy in women with heart disease receiving comprehensive prenatal care have not been well defined. METHODS AND RESULTS: We prospectively enrolled 562 consecutive pregnant women with heart disease and determined the outcomes of 599 pregnancies not ending in miscarriage. Pulmonary edema, arrhythmia, stroke, or cardiac death complicated 13% of pregnancies. Prior cardiac events or arrhythmia, poor functional class or cyanosis, left heart obstruction, and left ventricular systolic dysfunction independently predicted maternal cardiac complications; the cardiac event rate can be predicted using a risk index incorporating these predictors. Neonatal complications (20% of pregnancies) were associated with poor functional class or cyanosis, left heart obstruction, anticoagulation, smoking, and multiple gestations. CONCLUSIONS: Pregnancy in women with heart disease is associated with significant cardiac and neonatal complications, despite state-of-the-art obstetric and cardiac care. Maternal cardiac risk can be predicted with the use of a risk index.

Adolescent↗
PubMed2000

Semi-inclusive lambda and K(S) production in p-Au collisions at 17.5 GeV/c

The first detailed measurements of the centrality dependence of strangeness production in p-A collisions are presented. Lambda and K(S) dn/dy distributions from 17.5 GeV/ c p-Au collisions are shown as a function of "grey" track multiplicity and the estimated number of collisions, nu, made by the proton. The nu dependence of the Lambda yield deviates from a scaling of p-p data by the number of participants, increasing faster than this scaling for nu</=5 and saturating for larger nu. A slower growth in K(S) multiplicity with nu is observed, consistent with a weaker nu dependence of K&Kmacr; production than YK production.

Journal Article↗
PubMed2000

Melkersson-Rosenthal syndrome: new clinicopathologic findings in 4 cases.

OBJECTIVE: To define the clinicopathologic features of eyelid involvement in Melkersson-Rosenthal syndrome (MRS). METHODS: Four patients with eyelid edema consistent with MRS were evaluated clinically, including diagnostic imaging in 2 patients. Eyelid tissue from these patients was examined by light microscopy and immunohistochemistry. Polymerase chain reaction for herpes simplex virus was performed in 1 case. RESULTS: The 3 men and 1 woman ranged in age from 33 to 74 years. All patients had insidious, painless, nonpitting eyelid edema. Three patients had unilateral edema; one had bilateral, asymmetric involvement. Ipsilateral lip edema was present in 1 case. Computed tomography demonstrated periorbital heterogeneous thickening that corresponded to the microscopic finding of scattered granulomas. All 4 patients demonstrated epithelioid granulomas inside and adjacent to dilated lymphatic vessels. Polymerase chain reaction testing was negative for herpes simplex virus. CONCLUSIONS: Isolated eyelid swelling that mimics thyroid-associated ophthalmopathy may occur in MRS. Computed tomography may be useful in the diagnosis. Biopsy should be performed in all cases of unexplained nonpitting eyelid edema. In the eyelid, MRS is characterized histopathologically by a granulomatous lymphangitis, a finding that seems to be unique to this condition.

Adult↗
PubMed2000

Ultrastructure of human blastocyst-endometrial interactions in vitro.

The interactions of seven human blastocysts with cultured endometrial cells were investigated by light microscopy and transmission electron microscopy. Trophoblastic-endometrial contact was observed at the lateral border of endometrial epithelial cells where trophoblast and endometrial epithelial cells shared apical junctional complexes and desmosomes. The first sign of penetration was invasion of a trophoblastic cytoplasmic protrusion between endometrial epithelial cells. In broad contact areas, lateral displacement of endometrial epithelial cells and formation of a peripheral pseudostratified epithelium were observed. When trophoblastic cells were interposed fully among endometrial epithelial cells, they formed a penetration cone and appeared to dislodge endometrial epithelial cells from the stromal compartment. A single penetration cone only was found in each specimen. Endometrial or trophoblastic degeneration was not observed. Formation of multinucleate (>/= three nuclei per cell) trophoblast cells was not observed, but many cells displayed areas with abrupt disappearance of well-defined plasma membranes, which is indicative of syncytium formation. In this study, adhesion and penetration occurred at the same time. The human blastocysts penetrated the endometrial surface epithelium by intrusive penetration. Epithelial penetration was achieved primarily by cellular syncytiotrophoblast-like cells and the first indications of syncytium formation were observed simultaneously with penetration of the epithelium.

Cell Adhesion↗
PubMed1998

The impact of gastroesophageal reflux disease on health-related quality of life.

BACKGROUND: Gastroesophageal reflux disease (GERD) affects health-related quality of life. METHODS: We enrolled 533 adults with a history of heartburn symptoms for at least 6 months of moderate to severe heartburn in 4 of the 7 days before study entry. Patients were treated with ranitidine 150 mg twice a day for 6 weeks and Gelusil antacid tablets as needed. We measured physician-rated symptoms and the Medical Outcomes Study short-form 36 (SF-36) Health Survey at baseline and after 6 weeks of treatment. Baseline results were compared with normative data for the US population and for patients with selected chronic diseases. Treatment response was defined as no episode of moderate to severe heartburn for 7 days. Statistical significance was set at P <0.001. RESULTS: GERD patients reported significantly worse scores on all 8 SF-36 scales, physical function and well-being, and emotional well-being compared with the general population. Patients with GERD reported worse emotional well-being than patients with diabetes or hypertension. Treatment responders demonstrated significantly less pain and better physical function, social function, vitality, and emotional well-being compared with nonresponders. CONCLUSIONS: Patients with GERD experience decrements in health-related quality of life compared with the general population. The impact of GERD is most striking on measures of pain, mental health, and social function. Successful treatment for GERD results in improvements in health-related quality of life.

Adult↗
PubMed1998

Reliability and validity of physical and mental health summary scores from the Medical Outcomes Study HIV Health Survey.

OBJECTIVES: Health-related quality of life measures are used to evaluate patient outcomes in clinical trials of new treatments for human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Summary index scores, rather than profiles of scale scores, would simplify data analysis and interpretation of findings from clinical trials and comparison across studies. METHODS: Baseline MOS HIV Health Survey scores from two clinical trials of new antiretroviral medications in HIV/AIDS patients (total n = 2253) and an observational study (n = 162) were used to develop physical health summary (PHS) and mental health summary (MHS) scores. Exploratory and confirmatory factor analysis were used to identify the factor structure of the summary scores based on MOS HIV Health Survey scales. Physical health summary and MHS scores were derived and the factor structure proved invariant across the two groups. RESULTS: Reliability of the PHS score was 0.90 to 0.92 and MHS score was 0.91 to 0.94. Mean PHS and MHS scores differed in patient groups defined by HIV disease stage, HIV disease severity, Karnofsky performance status scores, and global ratings of health status. Mean PHS and MHS scores in patient reporting worsening health status were significantly lower than scores of patients reporting stable or improving health status. CONCLUSIONS: The PHS and MHS were reproducible across different samples of HIV/AIDS patients and are reliable and valid measures for demonstrating treatment impact on patient functioning and well-being.

Adult↗
PubMed1998

Integrating patient preferences into health outcomes assessment: the multiattribute Asthma Symptom Utility Index.

STUDY OBJECTIVE: To develop and evaluate a brief, easy-to-administer symptom assessment scale for use as a preference-based outcome measure in clinical trials and cost-effectiveness studies in asthma. DESIGN: Cross-sectional survey with 2-week reproducibility assessment. SETTING: Ambulatory care: university asthma and allergy center. PARTICIPANTS: One hundred sixty-one adults with asthma, 59% female, mean age 35+/-11 years. Mean FEV1 percent predicted was 86+/-17%. INTERVENTIONS: The 11-item Asthma Symptom Utility Index (ASUI). MEASUREMENTS AND RESULTS: Mean ASUI score for this sample was 0.71+/-0.23, with a range from 0.02 to 1.0. The ASUI was reproducible (intraclass correlation coefficient = 0.74) and able to distinguish patients known to differ on disease severity according to clinician ratings (p < 0.001) and by an asthma disease severity scale score (p < 0.001). The instrument was also significantly correlated with FEV1 percent predicted (r = 0.27, p < 0.001), the Asthma Quality of Life Questionnaire (r = 0.77, p < 0.001), and the Health Utilities Index Mark 2 (r = 0.36, p < 0.001). CONCLUSION: The results of this study support the reliability and validity of the ASUI, suggesting it will be a useful, complementary patient outcome measure for clinical trials and cost-effectiveness studies comparing treatment alternatives for persons with asthma.

Adult↗
PubMed1997

Risk and predictors for pregnancy-related complications in women with heart disease.

BACKGROUND: The physiological changes of pregnancy can result in cardiovascular complications in the mother, which in turn may have fetal implications. Prior studies have focused on specific cardiac lesions or identified univariate predictors. There is a need to refine the risk stratification of women with heart disease so they can receive appropriate obstetrical counseling and care. METHODS AND RESULTS: We examined the outcomes of 221 women with heart disease who underwent 276 pregnancies and received their obstetrical care at three Toronto hospitals from 1986 through 1994. Those who underwent therapeutic abortions were excluded. Among the study participants, there were 24 miscarriages and 252 completed pregnancies (pregnancies not ending in miscarriage). Maternal heart failure, arrhythmia, or stroke occurred in 45 completed pregnancies (18%). There were no maternal deaths. Poor maternal functional class or cyanosis, myocardial dysfunction, left heart obstruction, prior arrhythmia, and prior cardiac events were predictive of maternal cardiac complications. These predictors were incorporated into a point score that can be used to estimate the probability of a cardiac complication in the mother. The rate of cardiac complications for a patient with 0, 1, and >1 of the above factors was 3%, 30%, and 66%, respectively. Neonatal complications occurred in 42 completed pregnancies (17%). Neonatal events included death (2), respiratory distress syndrome (16), intraventricular hemorrhage (2), premature birth (35), and small-for-gestational-age birth weight (14). Poor maternal functional class or cyanosis was predictive of neonatal events. CONCLUSIONS: Despite low maternal and neonatal mortality, pregnancy in women with heart disease is associated with significant cardiac and neonatal morbidity. The probability of maternal cardiac or neonatal events can be predicted from baseline characteristics of the mother.

Adolescent↗
PubMed1996

Radioimmunoassay of Antarelix, a luteinizing hormone releasing-hormone antagonist, in plasma and its application for pharmacokinetic study in dogs.

A procedure for the radioimmunoassay (RIA) of Antarelix (teverelix) in plasma has been developed for the pharmacokinetic study of this potent LHRH antagonist in dogs. Antiserum was produced by coupling the deamidated Antarelix analog to bovine serum albumin by a carbodiimide reaction and immunizing rabbits with the conjugate. The crossreactivity of the antiserum with LHRH, LHRH agonist Metereline and LHRH antagonists tested was negligible, except for Antide which displayed a crossreactivity of 33%. No crossreactivity with Antarelix metabolites could be detected. The RIA is suitable for the direct determination of Antarelix in plasma, with a minimum detectable level of 1.12 fmol/assay. The accuracy and precision of the method were assessed with plasma samples spiked with Antarelix at concentrations ranging from 0.4 to 6.4 pmol/ml. The recovery was 104.8% with intra- and interassay CV between 1 and 3.7%. Pharmacokinetic profiles of Antarelix in dogs were established following an i.v. or a s.c. dose of 10 micrograms/kg.

Animals↗
PubMed1995

Incomplete recanalization as an important determinant of Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow after thrombolytic therapy for acute myocardial infarction. TEAM Investigators. Thrombolytic Trial of Eminase in Acute Myocardial Infarction.

The outcome of patients with Thrombolysis in Myocardial Infarction (TIMI) trial grade 2 flow is worse than that of patients with TIMI grade 3 flow after thrombolytic therapy for acute myocardial infarction. It is unclear whether TIMI grade 2 flow represents incomplete recanalization of the culprit lesion or poor distal runoff. The Thrombolytic Trial of Eminase (anistreplase) in Acute Myocardial Infarction (TEAM)-2 and TEAM-3 were randomized trials comparing anistreplase with streptokinase (TEAM-2, n = 370) or with alteplase (tissue plasminogen activator) (TEAM-3, n = 325). We compared the minimal luminal diameter of the culprit lesion in patients with TIMI grade 2 flow with that in patients with TIMI grade 3 flow both 90 minutes (TEAM-2) and 1 day (TEAM-3) after thrombolysis. Patients with TIMI grade 2 flow had a lower residual luminal diameter in the culprit lesion than patients with TIMI grade 3 flow (TEAM-2, 0.58 +/- 0.03 vs 0.79 +/- 0.02 mm, p = 0.0001; TEAM-3, 0.88 +/- 0.04 vs 1.17 +/- 0.03 mm, p = 0.0001, for patients with TIMI grades 2 and 3 flow). Residual percent stenosis was correspondingly higher in patients with TIMI grade 2 flow. At the early angiogram, 66% of patients with TIMI grade 2 flow, but only 35% of those with TIMI grade 3 flow, had a minimal luminal diameter of 0.6 mm (positive predictive value 87%, negative predictive value 35%). Incomplete recanalization of the culprit lesion may thus be an important determinant of TIMI grade 2 flow after thrombolysis. Whether more complete thrombolysis or rescue angioplasty improves outcome in these patients deserves evaluation.

Analysis of Variance↗
PubMed1992

Non-Hodgkin's lymphoma disguised as odontogenic pain.

A patient was treated for infraorbital swelling, nonvital teeth and a periapical lesion. Suspected malignancy, confirmed with an early biopsy, resulted in diagnosis of non-Hodgkin's lymphoma.

Dental Pulp Devitalization↗
PubMed1991

Cerebrospinal fluid pleocytosis in aseptic meningitis: cytomorphic and immunocytochemical features.

We report five cases of aseptic meningitis presenting with high cerebrospinal fluid (CSF) cell counts (260-600 cells/cmm) and mononuclear pleocytosis, suggesting the diagnosis of CNS malignant lymphoma. In four of five cases a reactive background of small lymphocytes, monocytes, and eosinophils was seen. Immunocytochemical studies in all five cases revealed that 100% of the lymphoid cells were T-cells. Three of four cases evaluated for lymphocyte subsets displayed a CD4 to CD8 ratio of 3:1. In the fourth case the CD4:CD8 was 1 to greater than 10; this patient was subsequently proven to have AIDS with HIV meningitis. In this study the cytologic features of the benign atypical lymphoid pleocytosis of aseptic meningitis in contrast to malignant lymphomas in CSF specimens included small or indistinct nucleolus, regular perinucleolar area, smaller widely separated chromatin aggregates, generally ample cytoplasm with perinuclear clearing and polyclonal T-cell immunophenotype.

Adult↗
PubMed1991

CHLVPP chemotherapy with involved-field irradiation for Hodgkin's disease: favorable results with acceptable toxicity.

Patients with Hodgkin's disease who were previously untreated with chemotherapy received the chlorambucil, vinblastine, procarbazine, and prednisone (CHLVPP) regimen plus limited involved-field radiation therapy for treatment of Hodgkin's disease through the Nebraska Lymphoma Study Group. One hundred patients, 87 with newly diagnosed Hodgkin's disease and 13 who relapsed after receiving previous radiation therapy, were treated with this regimen between 1982 and 1989. Complete remissions (CRs) were obtained in 88 of 100 patients (88%), and there have been a total of eight relapses. The overall 3-year failure-free survival was 76%, with good-prognosis patients (ie, Karnofsky performance status greater than or equal to 80) having a 3-year failure-free survival of 87%. Toxicity with this regimen was minimal, with neutropenic fevers reported in 13% of the patient population, moderate alopecia in 5%, and mild to moderate nausea and vomiting in 11% of the patients. As primary induction therapy for Hodgkin's disease, CHLVPP is an effective regimen with a high patient acceptance profile.

Adolescent↗
PubMed1990

The role of membrane skeletal-associated alpha-globin in the pathophysiology of beta-thalassemia.

The beta-thalassemic mouse provides a useful model for testing hypotheses about the pathophysiology in human beta-thalassemia. The clinical picture of these mice and their red blood cell deformability characteristics are quite similar to those observed in human beta-thalassemia intermedia. The creation of transgenic mice that express human beta-globin (beta s) has provided an opportunity to study the effect of increasing the non-alpha-globin chain production on the thalassemic phenotype. A small increase in beta-globin production produces transgenic mice that are healthier, have almost normal hemoglobin values, and whose red blood cell deformability is increased. We quantified and characterized the membrane skeletal-associated globin in normal, transgenic thal/sickle, and thalassemic mice and showed that only alpha-globin was associated with the membrane skeleton in the pathologic red blood cells, and that the degree of rigidity as measured in the rheoscope correlated directly and closely with the amount of membrane skeletal-associated globin in these abnormal red blood cells.

Alpha-Globulins↗