Drinking and recreational boating fatalities: a population-based case-control study.

Context: Alcohol is increasingly recognized as a factor in many boating fatalities, but the association between alcohol consumption and mortality among boaters has not been well quantified.

Objectives: To determine the association of alcohol use with passengers' and operators' estimated relative risk (RR) of dying while boating.

Design, Setting, And Participants: Case-control study of recreational boating deaths among persons aged 18 years or older from 1990-1998 in Maryland and North Carolina (n = 221), compared with control interviews obtained from a multistage probability sample of boaters in each state from 1997-1999 (n = 3943).

Radio-frequency coil selection for MR imaging of the brain and skull base.

Radio-frequency coils play a crucial role in the quest for optimal magnetic resonance (MR) image resolution. Given the growing variety of specialized coils available for neuroradiologic imaging applications, it is critical that radiologists use a coherent strategy for successfully matching these coils to specific imaging situations. First, fundamental concepts of coil design are reviewed.

Medicare fees and small area variations in breast-conserving surgery among elderly women.

This study used data from Medicare files, the American Hospital Association's Annual Survey of Hospitals, and the 1990 census to investigate whether Medicare fees for breast-conserving surgery (BCS) and mastectomy (MST) affected the rate of BCS across 799 3-digit ZIP code areas in 1994. The full model, which was based on the conceptual framework of the supply of and demand for different treatments, explained 51 percent of the variation in BCS rates. Medicare fees were statistically significant and had the hypothesized effects: a 10 percent higher BCS fee was associated with a 7 to 10 percent higher BCS rate, while a 10 percent higher MST fee was associated with a 2 to 3 percent lower proportion receiving BCS.

Properties of single M-type KCNQ2/KCNQ3 potassium channels expressed in mammalian cells.

1. The single channel properties of KCNQ2/KCNQ3 channels underlying neuronal voltage-dependent M-type potassium currents were studied in cell-attached patches from transfected Chinese hamster ovary (CHO) cells. Macroscopic currents produced by homo- and heteromeric KCNQ2/KCNQ3 channels were measured using the perforated-patch whole-cell technique.

The Microbiology and Management of Acute and Chronic Rhinosinusitis.

Although most cases of rhinosinusitis are benign, the disruption of quality of life due to disease symptoms leads patients to seek early medical care. Ongoing debates dispute the definition, bacteriology, and medical management of chronic sinusitis, while the criteria for acute sinusitis are relatively well established. Chronic rhinosinusitis remains poorly categorized, and authors differ in opinions of symptoms, time course, and bacteriology of the infections, as well as proper medical management.

Are urban safety-net hospitals losing low-risk Medicaid maternity patients?

Objective: To examine data on Medicaid and self-pay/charity maternity cases to address four questions: (1) Did safety-net hospitals' share of Medicaid patients decline while their shares of self-pay/charity-care patients increased from 1991 to 1994? (2) Did Medicaid patients' propensity to use safety-net hospitals decline during 1991-94? (3) Did self-pay/charity patients' propensity to use safety-net hospitals increase during 1991-94? (4) Did the change in Medicaid patients' use of safety-net hospitals differ for low- and high-risk patients?

Study Design: We use hospital discharge data to estimate logistic regression models of hospital choice for low-risk and high-risk Medicaid and self-pay/charity maternity patients for 25 metropolitan statistical areas (MSAs) in five states for the years 1991 and 1994. We define low-risk patients as discharges without comorbidities and high-risk patients as discharges with comorbidities that may substantially increase hospital costs, length of stay, or morbidity. The five states are California, Florida, Massachusetts, New Jersey, and New York.

The microbiology of chronic rhinosinusitis: results of a community surveillance study.

In view of the rapidly changing patterns of antibiotic resistance, community surveillance studies are providing important information to help guide practitioners in making their choice of antibiotics. For this community surveillance study, we performed a retrospective chart review of nasal and sinus culture data obtained from 83 patients with typical symptoms of chronic rhinosinusitis who visited a community otolaryngologist in Rochester, New York. Pathogens were isolated in 59 of these patients (71%).

Measuring and predicting surgeons' practice styles for breast cancer treatment in older women.

Background: Few measures exist to assess physicians' practice style, and there are few data on physicians' practice styles and patterns of care.

Objectives: To use clinical vignettes to measure surgeons' "propensity" for local treatments for early-stage breast cancer and to describe factors associated with propensity.

Research Design And Subjects: A cross-sectional mailed survey with telephone follow-up of a random sample of 1,000 surgeons treating Medicare beneficiaries in fee-for-service settings.

Alternative splicing of KCNQ2 potassium channel transcripts contributes to the functional diversity of M-currents.

The region of alternative splicing in the KCNQ2 potassium channel gene was determined by RNase protection analysis of KCNQ2 mRNA transcripts. Systematic analysis of KCNQ2 alternative splice variant expression in rat superior cervical ganglia revealed multiple variant isoforms. One class of KCNQ2 splice variants, those that contained exon 15a, was found to have significantly different kinetics to those of the other isoforms.

An ERG channel inhibitor from the scorpion Buthus eupeus.

The isolation of the peptide inhibitor of M-type K(+) current, BeKm-1, from the venom of the Central Asian scorpion Buthus eupeus has been described previously (Fillipov A. K., Kozlov, S.

Estimating rock and slag wool fiber dissolution rate from composition.

A method was tested for calculating the dissolution rate constant in the lung for a wide variety of synthetic vitreous silicate fibers from the oxide composition in weight percent. It is based upon expressing the logarithm of the dissolution rate as a linear function of the composition and using a different set of coefficients for different types of fibers. The method was applied to 29 fiber compositions including rock and slag fibers as well as refractory ceramic and special-purpose, thin E-glass fibers and borosilicate glass fibers for which in vivo measurements have been carried out.

Rhinosinusitis. An overview of current management measures in acute and chronic infection.

Rhinosinusitis is a common inflammatory bacterial infection of the paranasal sinuses and nasal cavity. Viral infection is often the inciting event. The ensuing inflammation obstructs the narrow ostiomeatal complex, causing facial pain and pressure, nasal obstruction, congestion, postnasal drainage, and mucopurulence.

Physicians' responses to Medicare fee schedule reductions.

Background: Relatively little empirical research has addressed physicians' responses to fee changes under the Medicare Fee Schedule.

Objectives: We analyzed Medicare claims data for ophthalmologists and orthopedic surgeons for the years 1991 through 1994 to evaluate the relative importance of profit-maximizing and target-income theories in determining physicians' supply responses to specific Medicare fee reductions.

Research Design: This study was designed to estimate the impact of fee reductions for cataract extractions and major joint repair/replacement procedures through pooled cross-section time series data.

Estimation of dissolution rate from in vivo studies of synthetic vitreous fibers.

Although the dissolution rate of a fiber was originally defined by a measurement of dissolution in simulated lung fluid in vitro, it is feasible to determine it from animal studies as well. The dissolution rate constant for a fiber may be extracted from the decrease in long fiber diameter observed in certain intratracheal instillation experiments or from the observed long fiber retention in short-term biopersistence studies. These in vivo dissolution rates agree well with those measured in vitro for the same fibers.

Collagen as a model system to investigate the use of aspirin as an inhibitor of protein glycation and crosslinking.

Aspirin has been shown to be a powerful inhibitor of post-Amadori Maillard reactions, although the exact mechanism of this action remains unclear. We have used corneal and scleral collagen as a model system: (i) to assess how aspirin, either alone or in combination with sugars, affects the surface charge distribution along the collagen fibrils; (ii) to see how sugars and/or aspirin affect the swelling properties of the cornea; and (iii) to see if sugars and/or aspirin change the distribution of water within the corneal stroma as the tissue swells. Charge changes were detected by examining changes in the uptake of phosphotungstate ions as seen in the electron microscope.

Measuring the effects of managed care on physicians' perceptions of their personal financial incentives.

Using data from the 1997 Resurvey of Young Physicians (N = 1,549), this study examines whether several measures of physicians' contractual arrangements with health plans are associated with their perceptions of overall financial incentives to either decrease or increase the volume of services to patients. Results indicate the following factors were significantly associated with an increased likelihood of reporting an incentive to decrease services: a gatekeeper arrangement with a compensation incentive; the perception of a high risk of plan deselection for physicians with high costs; the perception that referrals received depended on the costs of care provided; communication prohibiting or discouraging the disclosure to patients of the physician's financial relationship with the health plan; receiving capitation payments from at least one plan; and employment in a health maintenance organization. Being compensated on a fee-for-service basis or receiving a salary with incentive or bonus provisions (compared to straight salary) were associated with an increased likelihood of reporting an incentive to increase services to patients.

Patterns of breast carcinoma treatment in older women: patient preference and clinical and physical influences.

Background: Older women have high rates of breast carcinoma, and there are substantial variations in the patterns of care for this population group.

Methods: The authors studied 718 breast carcinoma patients age 67 years and older who were diagnosed with localized disease between 1995 and 1997 from 29 hospitals in 5 regions. Data were collected from patients, charts, and surgeons.

A laser-powered hydrokinetic system for caries removal and cavity preparation.

Background: Laser systems have been developed for the cutting of dental hard tissues. The erbium, chromium:yttrium-scandium-gallium-garnet, or Er,Cr:YSGG, laser system used in conjunction with an air-water spray has been shown to be efficacious in vitro for cavity preparation.

Methods: The authors randomly selected subjects for cavity preparation with conventional air turbine/bur dental surgery or an Er,Cr:YSGG laser-powered system using a split-mouth design.

Posthospitalization home health care use and changes in functional status in a Medicare population.

Objective: The objective of this work was to estimate the effect of Medicare beneficiaries' use of home health care (HHC) for 6 months after hospital discharge on the change in functional status over a 1-year period beginning before hospitalization.

Data Sources And Study Setting: Data came from the Medicare Current Beneficiary Survey, which is a nationally representative sample of Medicare beneficiaries, in-person interview data, and Medicare claims for 1991 through 1994 for 2,127 nondisabled, community-dwelling, elderly Medicare beneficiaries who were hospitalized within 6 months of their annual in-person interviews.

Study Design: Econometric estimation with the instrumental variable method was used to correct for observational data bias, ie, the nonrandom allocation of discharged beneficiaries to the use of posthospitalization HHC.

A three-coil comparison for MR angiography.

The purpose of this work was to compare intracranial magnetic resonance angiography (MRA) image quality using three different radiofrequency coils. The three coil types included a reduced volume quadrature birdcage coil with endcap, a commercially available quadrature birdcage head coil, and a four-element phased-array coil. Signal-to-noise ratio (SNR) measurements were obtained from comparison studies performed on a uniform cylindrical phantom.

Physicians' ethical beliefs about cost-control arrangements.

Background: Although much has been written about the ethics of new methods of health care financing, little is known about the extent to which physicians experience these cost-control arrangements as ethical problems.

Method: A cross-sectional telephone survey of 1,549 physicians, 8 to 17 years after residency, randomly selected from 75 US metropolitan service areas (response rate, 74.0%).

Estimating in vitro glass fiber dissolution rate from composition.

A method is presented for calculating the dissolution rate constant of a borosilicate glass fiber in the lung, as measured in vitro, from the oxide composition in weight percent. It is based upon expressing the logarithm of the dissolution rate as a linear function of the composition. It was found that the calculated dissolution rate constant agreed with the measured value within the variation of the measured data in a set of compositions in which the dissolution rate constant ranged over a factor of 100.

Inhibition of KCNQ1-4 potassium channels expressed in mammalian cells via M1 muscarinic acetylcholine receptors.

1. KCNQ1-4 potassium channels were expressed in mammalian Chinese hamster ovary (CHO) cells stably transfected with M1 muscarinic acetylcholine receptors and currents were recorded using the whole-cell perforated patch technique and cell-attached patch recording. 2.