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Biomedical subjects

L Benson

Publications and source records attributed to L Benson.

At least 37 records · Page 2Linked to original sources
PubMed1998

A Rejection Threshold in Justice Evaluations: Effects on Judgment and Decision-Making.

This research examined the process through which justice evaluations are formed. Using image theory's screening process we hypothesized that a rejection threshold exists with regard to violations of just treatment (e.g., laying off an employee without notice). If the number of violations exceeds the decision-maker's threshold, a negative justice evaluation results. Nonviolations (e.g., providing laid-off employees with a generous severance package) were hypothesized to only influence justice evaluations when violations do not exceed the threshold. Three studies compared the impact of justice violations and nonviolations on fairness evaluations. We also examined differences in fairness evaluations operationalized as judgments vs decisions. Results indicated that when making judgments about fairness, both violations and nonviolations are equally important. However, when one has to decide on a course of action based on considerations of fairness, nonviolations are only considered if fewer than three violations have been encountered. These results identify important distinctions between judgment and decisions and have implication for research examining outcomes of justice evaluations. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Hypersensitivity myocarditis caused by an allergic reaction to cefaclor.

An adolescent girl was seen with acute heart failure 6 days after the onset of a viral illness and otitis media treated with cefaclor. An endomyocardial biopsy specimen revealed active myocarditis with an eosinophilic infiltrate typical of hypersensitivity myocarditis. The patient showed dramatic improvement within 48 hours after withdrawal of the drug and administration of corticosteroids and immunoglobulin.

Biopsy↗
PubMed1998

Low temperature aqueous electrospray ionization mass spectrometry of noncovalent complexes.

In the present study we describe conditions that permit the characterization of noncovalent protein-substrate complexes in aqueous solution by microspray electrospray ionization-mass spectrometry (ESI-MS), using a heated transfer capillary at low temperature (45 degrees C). Specifically, we examined the binding of calmodulin to two polypeptides; the calmodulin-binding domain of calmodulin-dependent protein kinase II (CamK-II) and melittin. Calmodulin, a well known calcium-binding protein, binds to a number of small amphipathic peptides in a calcium-dependent manner. Our results directly show that both peptides form equimolar complexes with calmodulin only in the presence of calcium. The stoichiometry necessary for the formation of each complex was 1:1:4 for calmodulin:peptide (melittin or CamK-II):Ca2+, respectively. Furthermore, it is demonstrated that the detection of the complex in ESI-MS is source temperature dependent.

Calcium-Calmodulin-Dependent Protein Kinases↗
PubMed1997

Balloon angioplasty of recurrent coarctation: a 12-year review.

OBJECTIVES: This study was undertaken to investigate the long-term outcome of balloon angioplasty for recurrent coarctation of the aorta in a large series of patients. BACKGROUND: Balloon angioplasty has become the standard treatment for residual or recurrent aortic coarctation. Despite the widespread use of this treatment modality, there are few data outlining the long-term outcome of a large patient cohort. METHODS: Clinical, echocardiographic, hemodynamic and angiographic data on 90 consecutive patients who underwent balloon angioplasty between January 1984 and January 1996 were reviewed. RESULTS: Mean systolic pressure gradients were reduced from 31 +/- 21 to 8 +/- 9 mm Hg after dilation (p = 0.0001). The mean diameter of the stenotic site, measured in the frontal and lateral views, increased by 38% and 35%, respectively (p = 0.001). Neurologic events occurred in two patients, with one death. An aortic tear occurred in one patient, requiring surgical intervention. Optimal results were defined as a postprocedure gradient < 20 mm Hg and were obtained acutely in 88% of patients. At long-term follow-up (12 years), 53 (72%) of 74 patients with an early optimal result remained free from reintervention. Transverse arch hypoplasia, defined as an arch dimension < 2 SD below the mean for age, was the primary predictor of the need for reintervention. CONCLUSIONS: Although the majority of patients undergoing percutaneous balloon angioplasty for recoarctation of the aorta will achieve long-term benefit, the need for further surgical intervention in those with transverse arch hypoplasia remains high.

Adolescent↗
PubMed1997

A phase I trial and pharmacokinetic evaluation of CI-980 in patients with advanced solid tumors.

CI-980 is a synthetic mitotic inhibitor that binds to the colchicine binding site of tubulin. It demonstrates broad activity against human and murine tumor models and shows no cross resistance with tumor models whose mechanism of resistance is mediated by P-glycoprotein (MDR-1). A phase I study was completed in 25 patients with solid tumors using a 24-hour infusion schedule, with courses repeated every 3 weeks. Eight dose levels were tested between 1.2 and 15.6 mg/m2. The maximum tolerated dose was 14.4 mg/m2. Neutropenia was dose-related but not dose-limiting; thrombocytopenia was infrequent. CNS toxicities were dose-limiting and consisted of dizziness, headache, loss of coordination, loss of consciousness, nervousness, and other symptoms. These events occurred near the end of the infusion and were reversible, usually within 24 hours. One patient who was to be treated at dose level 8 (intended dose was 19.2 mg/m2; actual dose was 15.6 mg/m2) became encephalopathic prior to completion of the infusion. Other adverse events included gastrointestinal toxicities (nausea, vomiting, anorexia, constipation, stomatitis, dyspepsia, bleeding, cheilitis), IV site erythema, fever, and fatigue. A partial response was observed in one patient with colon cancer and reductions in CA-125 levels were observed in 2 patients with ovarian cancer. Pharmacokinetics were linear and dose-proportional. Results indicate high systemic clearance and wide tissue distribution. Mean pharmacokinetic parameter values: T1/2 = 5.52 hours, plasma clearance 1163 mL/min/m2, and Vdss 376 L/m2.

Adult↗
PubMed1997

Complication of ventricular demand pacing after orthotopic heart transplantation: unusual case of pacemaker syndrome in an infant.

BACKGROUND: Sinus node dysfunction is the most common indication for antibradycardiac permanent pacing after heart transplantation. Lack of atrioventricular synchrony during pacing can result in symptoms ranging from mild chest discomfort to severe manifestations such as dyspnea, hypotension, and cardiovascular collapse, all of which are ascribed to pacemaker syndrome. In infants pacemaker syndrome is often only recognized in the face of marked hemodynamic compromise. RESULTS: This report details an unusual account of pacemaker syndrome in an infant after orthotopic heart transplantation. CONCLUSIONS: Careful assessment of atrioventricular synchrony is important after infant transplantation.

Angina Pectoris↗
PubMed1996

An additional mitochondrial tRNA(Ile) point mutation (A-to-G at nucleotide 4295) causing hypertrophic cardiomyopathy.

A third point mutation in the mitochondrial tRNA(Ile) gene associated with hypertrophic cardiomyopathy and respiratory chain dysfunction in heart is reported. An A-to-G transition at nucleotide position 4295 was shown to be highly evolutionarily conserved, never present in control individuals, and to segregate with the disease. A PCR-based diagnostic test and endomyocardial biopsies were used to detect both the biochemical deficiency and the level of heteroplasmy in heart. The implications of this new mitochondrial DNA point mutation are discussed.

Adenine↗
PubMed1996

Natural history of Alström syndrome in early childhood: onset with dilated cardiomyopathy.

Alström syndrome is an autosomal recessive disorder characterized by cone-rod dystrophy, obesity, hearing impairment, and diabetes caused by insulin resistance. By reviewing the charts of eight patients followed for periods of 2 to 22 years, we established the natural history of this syndrome during childhood. Five patients, in four families, were seen between the ages of 3 weeks and 4 months with a dilated cardiomyopathy, a previously unrecognized feature of the syndrome. Photophobia and nystagmus were first documented in the eight patients between the ages of 5 months and 15 months. In all patients, electroretinography initially showed a severe cone impairment with mild (2/8) or no (6/8) rod involvement. Electroretinograms, obtained again at ages 9 to 22 years for four patients, revealed extinguished rod-and-cone responses. Obesity developed during childhood in seven patients, in at least three of them before age 2 years. Hearing impairment (5/8) and diabetes/glucose intolerance (4/8) were diagnosed at the end of the first decade or during the second decade. This constellation of features should facilitate early diagnosis of the syndrome.

Adolescent↗
PubMed1996

HMO partnering: the provider dilemma.

While the growth of HMOs has slowed patient visits to doctors, it also has created a deluge of press clippings. On July 16, 1996, three articles on the subject appeared in the Wall Street Journal, front section. The headlines painted a vivid picture of the forces acting on HMOs and providers alike (Figure 1). The articles portended more change for healthcare. The "shake-out," a term applied to industries in serious transformation, brings shedding of excess capacity and loss of jobs and income. Providers, in particular, find themselves in a difficult dilemma. They must not only cut costs as reimbursement drops, but also retain patients with good outcomes and high quality service. Patient retention means keeping the individual patient from switching to another provider and keeping the insurer's group of patients as an authorized provider for that insurer. The relationship between provider and HMO lies at the heart of the provider dilemma. The HMO structure, which shifts financial risk for care, is quickly setting the standard, for healthcare pricing, medical standards, and management practices. Understanding and responding to HMO needs are vital to competitive advantage and survival. The article discusses the inherent dilemma of HMO and provider partnering and suggests provider responses.

Accounting↗
PubMed1994

Cardiac dysfunction late after cardiotoxic therapy for childhood cancer.

Despite a wealth of data documenting acute cardiac injury from anthracycline therapy and/or mediastinal radiotherapy used for childhood cancer, little information is available on the long-term consequence of these insults. Twenty-nine patients (mean age 15 +/- 4.3 years) from The Late Effects Follow-Up Clinic For Childhood Cancer study, who had been in continuous, complete remission and off chemotherapy for a minimum of 2 years (mean follow-up 7.2 +/- 3.2) were studied. All patients had normal ejection fractions before and during cancer therapy and all were in New York Heart Association class I at the time of study. Systolic and diastolic functions were assessed by 2-dimensional echocardiography, Doppler flow velocity, and radionuclide angiography, and results were compared with normal control subjects. Left ventricular mass and mass index were significantly reduced in the patient population. Fractional shortening was decreased overall and end-systolic wall stress was much higher in patients than in controls. However, contractility, as assessed by the relation of wall stress to rate-corrected velocity of shortening, was decreased by > or = 2 SDs in only 6 of 28 patients, and the force-mass relation was actually increased in the patient group as a whole. Mitral valve inflow velocities were significantly increased but the pattern was abnormal. These results suggest a pattern consistent with a thin-walled, complaint left ventricle with reduced muscle mass performing under above-normal levels of wall stress. Contractility measurements were normal or increased in the group, but some patients clearly demonstrated development of reduced contractile function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Polyethylene glycolated interleukin-2 as maintenance therapy for acute myelogenous leukemia in second remission.

Seven patients in second complete remission of acute myeloid leukemia (AML) aged 19-65 years were treated with polyethylene glycolated interleukin-2 (PEG IL-2), 1 x 10(6) U/M2 IV weekly as the sole postremission therapy. Second remission duration was in the range of 4-49+ months, and three patients had a second remission duration substantially longer than their first (6, 21+, and 42+ months). The results suggest that PEG IL-2 may prolong second remission duration in AML and that a prospective randomized study designed to test that idea is warranted.

Adult↗
PubMed1994

Heparin therapy in pediatric patients: a prospective cohort study.

Current guidelines for heparin therapy in pediatric patients have been extrapolated from trials in adult patients without rigorous evaluation of efficacy and safety. We prospectively monitored consecutive pediatric patients receiving systemic doses of heparin over 10 mo at one institution using a predetermined nomogram to monitor maintenance therapy. Sixty-five consecutive children; 38 males and 27 females, received systemic doses of heparin. Thirty children had deep venous thrombosis and/or pulmonary embolism; 11 had arterial thrombi, most frequently after diagnostic angiography; and the remaining 24 received heparin prophylactically, for congenital heart disease. Twenty-nine (45%) of the 65 patients were less than 1 y of age and 22 (34%) were 10 y or older. Congenital heart disease was the predominant diagnosis under 1 y and deep venous thrombosis in older children. After a bolus dose of 50 U/kg, 39% of children (n = 30) achieved a minimal level activated partial thromboplastin time (APTT). Sixty-eight percent of children achieved a minimal level APTT by 24 h and 81% by 48 h. For all 65 children, APTT values were within the therapeutic range 43% of the time. APTT values outside the therapeutic range were twice as likely to be low as high. The average amount of heparin required to maintain therapeutic APTT values for children was 22 U/kg/h: 28 U/kg/h for infants < 1 y and 20 U/kg/h for the rest. Bleeding was rare (2%) and mild. Documented recurrent thrombotic disease was more common (7%) with associated morbidity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗