Prehypertension during young adulthood and coronary calcium later in life.

Background: High blood pressure in middle age is a well-established risk factor for cardiovascular disease, but the consequences of low-level elevations during young adulthood are unknown.

Objective: To measure the association between prehypertension exposure before age 35 years and coronary calcium later in life.

Design: Prospective cohort study.

Risk factors for severe hyperbilirubinemia among infants with borderline bilirubin levels: a nested case-control study.

Objective: To estimate the effect of phototherapy and other predictors on the risk of total serum bilirubin (TSB) >or= 25 mg/dL in infants with a TSB of 17 to 22.9 mg/dL at age >or= 48 hours.

Study Design: From a cohort of 285295 infants >or= 34 weeks gestation and >or= 2000 g born between 1995 and 2004 in northern California Kaiser hospitals, we identified 17986 with a TSB of 17 to 22.

Simple, defensible sample sizes based on cost efficiency.

The conventional approach of choosing sample size to provide 80% or greater power ignores the cost implications of different sample size choices. Costs, however, are often impossible for investigators and funders to ignore in actual practice. Here, we propose and justify a new approach for choosing sample size based on cost efficiency, the ratio of a study's projected scientific and/or practical value to its total cost.

A quantitative assessment of follicle size on oocyte developmental competence.

Objective: To quantitatively assess the impact of follicle size on oocyte maturation, fertilization, and embryo quality.

Design: Prospective study.

Setting: Academic medical center.

Feasibility of minocycline and doxycycline use as potential vasculostatic therapy for brain vascular malformations: pilot study of adverse events and tolerance.

Background: Tetracyclines may be useful in preventing pathological vascular remodeling, thus decreasing the risk of spontaneous hemorrhage from brain vascular malformations.

Methods: Arteriovenous malformation (AVM) and intracranial aneurysm patients undergoing noninvasive management were treated with minocycline or doxycycline (200 mg/day) up to 2 years in a prospective open-label safety pilot trial. The primary outcome was to compare dose-limiting intolerance, defined as treatment-related dose reduction or withdrawal between the agents.

Being overweight modifies the association between cardiovascular risk factors and microalbuminuria in adolescents.

Objective: The goal was to determine the association between cardiovascular risk factors and microalbuminuria in a nationally representative sample of adolescents and to determine whether being overweight modifies this association.

Methods: We analyzed cross-sectional data from the National Health and Nutrition Examination Survey (1999-2004) for 2515 adolescents 12 to 19 years of age. Cardiovascular risk factors included abdominal obesity, impaired fasting glucose, diabetes mellitus, insulin resistance, high triglyceride levels, low high-density lipoprotein cholesterol levels, hypertension, smoking, and the metabolic syndrome.

Association of tumor necrosis factor-alpha-238G>A and apolipoprotein E2 polymorphisms with intracranial hemorrhage after brain arteriovenous malformation treatment.

Objective: We previously reported specific genotypes of polymorphisms in two genes, tumor necrosis factor-alpha (TNF-alpha-238G > A) and Apolipoprotein E (ApoE e2), as independent predictors of new intracranial hemorrhage (ICH) in the natural course of untreated brain arteriovenous malformations. We hypothesized that the risk of posttreatment ICH would also be greater in patients with brain arteriovenous malformations with these genotypes.

Methods: Two hundred fifteen patients undergoing brain arteriovenous malformation treatment (embolization, arteriovenous malformation resection, radiosurgery, or any combination of these) were genotyped and followed longitudinally.

Joint modelling of mixed outcome types using latent variables.

After a brief review of the use of latent variables to accommodate the correlation among multiple outcomes of mixed types, through theoretical and numerical calculation, the consequences of such a construction are quantified. The effects of including latent variables on marginal inference in these models are contrasted with the situation for jointly normal outcomes. A simulation study illustrates the efficiency and reduction in bias gains possible in using joint models, and analysis of an example from the field of osteoarthritis illustrates potential practical differences.

Characterization of cystic pancreatic masses: relative accuracy of CT and MRI.

Objective: The objective of our study was to determine the role and relative accuracy of CT and MRI in the characterization of cystic pancreatic masses.

Materials And Methods: We retrospectively identified 58 patients with histopathologically proven cystic pancreatic masses at our institution who underwent preoperative CT (n = 40), MRI (n = 6), or both (n = 12). Two radiologists independently recorded their leading diagnoses with levels of diagnostic certainty (0-100%), their estimates of overall likelihood of malignancy (0-100%), and the morphologic characteristics of the tumors.

Exploring secular trends in the likelihood of receiving treatment for end-stage renal disease.

There is a limited understanding of the forces that drive the steady rise in the number of patients who receive treatment for ESRD. It was hypothesized that this is not simply due to increasing prevalence of chronic kidney disease (CKD) or changes in renal failure risk factors in the population from which ESRD cases develop. A noncurrent cohort study was conducted to quantify the change over time (per year) in the likelihood of receiving ESRD therapy in a cohort of 320,252 individuals who volunteered for health check-ups between 1964 and 1985.

Racial/Ethnic differences in longitudinal risk of intracranial hemorrhage in brain arteriovenous malformation patients.

Background And Purpose: Race/ethnicity is associated with overall incidence of intracranial hemorrhage (ICH), but its impact in patients with brain arteriovenous malformation is unknown. We evaluated whether race/ethnicity was a risk factor for ICH in the natural course in a large, multiethnic cohort of patients with brain arteriovenous malformation followed longitudinally.

Methods: Data were collected prospectively for patients with brain arteriovenous malformation evaluated at the University of California, San Francisco (n=436) and retrospectively through databases and chart review in the 20 hospitals of the Kaiser Permanente Medical Care Program (n=1028).

Estimation of fusiform intracranial aneurysm growth by serial magnetic resonance imaging.

Purpose: Intracranial aneurysm (IA) growth is associated with increased morbidity. We sought to establish a quantitative computational method based on contrast-enhanced MR angiography (CE-MRA) for estimating aneurysmal volume changes over time.

Materials And Methods: Computational volume calculations were tested against a distensible phantom.

Methylenetetrahydrofolate reductase (MTHFR) is associated with ovarian follicular activity.

Objective: Polymorphisms in the MTHFR gene have been associated with decreased cell division and apoptosis. This finding led us to evaluate whether MTHFR polymorphisms were associated with follicular growth within the ovary. More specifically, we investigated the effect of the two common polymorphisms C677T and A1298C in our population of women undergoing ovarian stimulation.

Cluster-randomized trial to improve antibiotic use for adults with acute respiratory infections treated in emergency departments.

Study Objective: We evaluate the effectiveness of an educational program in hospital emergency departments (EDs) targeting reduction in antibiotic overuse for acute respiratory tract infections.

Methods: Sixteen hospitals participated in the cluster randomized trial, selecting a Veterans Administration (VA) and non-VA hospital within each of 8 metropolitan regions. Intervention sites received performance feedback, clinician education, and patient educational materials, including an interactive computer kiosk located in the waiting room.

Women who maintain optimal cognitive function into old age.

Objectives: To determine whether older women who maintain optimal cognitive function into old age differ from those who experience minor cognitive decline typically associated with normal aging.

Design: Prospective cohort study.

Setting: The Study of Osteoporotic Fractures.

Effectiveness of ceftriaxone plus doxycycline in the treatment of patients hospitalized with community-acquired pneumonia.

Background: Limited data exist on the effectiveness of ceftriaxone plus doxycycline in the treatment of patients hospitalized with community-acquired pneumonia (CAP).

Methods: We performed a retrospective cohort study of all adults hospitalized for pneumonia between January 1999 and July 2001 at an academic medical center. Outcomes were compared for patients with CAP treated with ceftriaxone plus doxycycline versus other appropriate initial empiric antibiotic therapies.

House staff team workload and organization effects on patient outcomes in an academic general internal medicine inpatient service.

Background: House staff work-hour regulations have required residency programs to reengineer inpatient services. However, few data describe how house staff workload on a patient's day of admission or on subsequent hospital days influences patient outcomes.

Methods: Retrospective cohort analysis of 5742 adults admitted to an academic general medical service between July 1, 1998, and June 30, 2001.

Relaxing the rule of ten events per variable in logistic and Cox regression.

The rule of thumb that logistic and Cox models should be used with a minimum of 10 outcome events per predictor variable (EPV), based on two simulation studies, may be too conservative. The authors conducted a large simulation study of other influences on confidence interval coverage, type I error, relative bias, and other model performance measures. They found a range of circumstances in which coverage and bias were within acceptable levels despite less than 10 EPV, as well as other factors that were as influential as or more influential than EPV.

Day 2 transfer improves pregnancy outcome in in vitro fertilization cycles with few available embryos.

Objective: Delaying ET to day 3 to optimize embryo selection is well accepted. However, in cases where there are not enough embryos to perform selection, it is not clear whether there is a difference in clinical outcomes with the day of ET.

Design: Cohort study.

Adrenoceptor polymorphisms and the risk of cardiac injury and dysfunction after subarachnoid hemorrhage.

Background And Purpose: Cardiac abnormalities occur commonly after subarachnoid hemorrhage (SAH) and may be caused by excessive release of catecholamines from the myocardial sympathetic nerves. We hypothesized that adrenoceptor polymorphisms resulting in greater catecholamine sensitivity would be associated with an increased risk of cardiac injury.

Methods: This was a prospective cohort study.

MMP-9 expression is associated with leukocytic but not endothelial markers in brain arteriovenous malformations.

Brain arteriovenous malformations (BAVM) have high matrix metalloproteinase-9 (MMP-9) expression, the source of which is unclear. We hypothesized MMP-9 production might be due to inflammation in BAVM. Compared to control brain tissues (n = 5), BAVM tissue (n = 139) had a higher expression (by ELISA) of myeloperoxidase (MPO) (193 +/- 189 vs.

Oocyte degeneration after intracytoplasmic sperm injection: a multivariate analysis to assess its importance as a laboratory or clinical marker.

Objective: Oocyte degeneration has historically been associated with the intracytoplasmic (ICSI) technique. We sought to determine whether oocyte degeneration rates were associated with the technician performing the procedure, the baseline characteristics of the patient, and/or ovarian stimulation variables. We also evaluated whether the degeneration rate could serve as a surrogate marker for implantation potential.

Apolipoprotein E epsilon 2 is associated with new hemorrhage risk in brain arteriovenous malformations.

Objective: Patients with brain arteriovenous malformation (AVM) are at life-threatening risk of intracranial hemorrhage (ICH). Identification of genetic variants associated with increased new ICH risk would facilitate risk stratification and guide therapeutic intervention.

Methods: Brain AVM patients evaluated at University of California, San Francisco or Kaiser Permanente Northern California were followed longitudinally.

Amphetamine exposure is elevated in Parkinson's disease.

Background: Since the 1930's, amphetamine drugs have been used therapeutically and recreationally. High doses are associated with acute injury to axon terminals of dopaminergic neurons. It is unknown whether low dose exposure to amphetamine over a prolonged time period is associated with the development of Parkinson's disease (PD).