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Brown, Emery N., Patricia M. Meehan, and Arthur P. Dempster. A stochastic differential equation model of diurnal cortisol patterns. Am J Physiol Endocrinol Metab 280: E450-E461, 2001.--Circadian modulation of episodic bursts is recognized as the normal physiological pattern of diurnal variation in plasma cortisol levels. The primary physiological factors underlying these diurnal patterns are the ultradian timing of secretory events, circadian modulation of the amplitude of secretory events, infusion of the hormone from the adrenal gland into the plasma, and clearance of the hormone from the plasma by the liver. Each measured plasma cortisol level has an error arising from the cortisol immunoassay. We demonstrate that all of these three physiological principles can be succinctly summarized in a single stochastic differential equation plus measurement error model and show that physiologically consistent ranges of the model parameters can be determined from published reports. We summarize the model parameters in terms of the multivariate Gaussian probability density and establish the plausibility of the model with a series of simulation studies. Our framework makes possible a sensitivity analysis in which all model parameters are allowed to vary simultaneously. The model offers an approach for simultaneously representing cortisol's ultradian, circadian, and kinetic properties. Our modeling paradigm provides a framework for simulation studies and data analysis that should be readily adaptable to the analysis of other endocrine hormone systems. circadian rhythms; deconvolution; kinetics; sensitivity analysis; ultradian rhythms

States that SC-52151, an HIV-1 protease inhibitor, was developed as an ethanol-based elixir and subsequently as a self-emulsifying drug delivery system (SEDDS) to improve bioavailability. What was done to evaluate formulation and treatment effects of the inhibitor.

Part II. Focuses on nursing management and protocol for using the Swan-Ganz balloon flotation catheter. Preparations for using the catheter; Procedure in inserting the catheter in the pulmonary artery; Guidelines in applying initial dressing after the insertion; Catheter removal. INSETS: Gathering the necessities;Setting up the system;Catheter insertion;What can go wrong and what to do about it

Twenty patients were enrolled in a phase I clinical trial of atevirdine, a nonnucleoside reverse transcriptase inhibitor (NNRTI), given in combination with zidovudine for treatment of human immunodeficiency virus type 1 (HIV-1) infection. Fifteen patients had received no previous antiretroviral therapy. HIV-1 isolates obtained at 6-week intervals were tested for sensitivity to atevirdine and zidovudine. Two patients developed a rash within 2 weeks of enrollment, and 1 of these developed concomitant fever and hepatitis. No hematopoietic, neurologic, or pancreatic toxicities were observed. Atevirdine had considerable initial interpatient pharmacokinetic variability. Forty-seven percent of patients treated with atevirdine plus zidovudine had increased CD4 lymphocyte counts, and HIV isolates from 62% of patients remained sensitive to atevirdine after 24 weeks of therapy. Atevirdine plus zidovudine was well-tolerated. Additional studies should be done to determine the role of atevirdine in the therapy for HIV infection. [ABSTRACT FROM PUBLISHER]

Purpose: To describe the noise, sleep opportunities, and patient disturbances in a 30-bed pediatric intensive care unit (PICU) and to use those data to guide interventions to promote a more healing PICU environment. A secondary aim was to build a more therapeutic work environment for the interprofessional team practicing in the PICU. Background/Significance: Today's PICUs are not healing milieus. Immediately upon admission, the child's routine and sleep pattern are replaced by a well-intentioned but not patient-centered PICU routine. Although criticality drives PICU therapies, much can be done to create a more healing environment that facilitates sleep and rest in critically ill patients and to provide a calmer environment for families. Benefits of environmental control also affect the interprofessional team practicing within the PICU environment. Method: We prospectively monitored noise levels throughout our 30-bed PICU using Quietyme, a system that combines sensors and analytics to monitor environmental noise, light, and temperature. Sensors were plugged into existing electrical outlets at the head of each bed and in adjacent hallways and common areas. The sensors sent continuous data wirelessly to a central hub where the Quietyme's dashboard provided real-time data by bed space and unit. Using Quietyme's analytics, we describe our unit's noise levels in decibels, reporting the range of the weekly mean; sleep opportunities (90-minute segments per 24 hours with below average noise levels), and patient disturbances (periods when sound levels rise above 65 dB). Results: Our loudest bed space was 80.6 dB (range, 75.5-83.5 dB), our quietest was 35.6 dB (34.5-37 dB), and our average was 44.4 dB (40.9-46.6 dB). (Note: A 10-dB increase is the equivalent of doubling the volume]. The unit was quieter on nights by 1.84 dB and on weekends by 0.7 dB. Comparing areas of the unit, we identified a louder cluster of rooms (beds 16-19; 70.7 dB) and quieter area (beds 12-14; 67.2 dB). According to Quietyme analytics, nights offered twice as many sleep opportunities as days (days, n = 642; nights, n = 1186), and days had twice as many patient disturbances as nights (days, n = 14 775; nights, n = 7556). Our unit was loudest at 7 am (shift change) and between 9 am and 11 am (interprofessional rounds). Conclusion: These data validated that our unit is often louder than existing recommendations from the World Health Organization and Environmental Protection Agency that sound in hospitals not exceed 40 and 45 dB, respectively. Quietyme provided objective data and recommendations to improve our current state. Next steps include risk adjusting these data by patient criticality and using Quietyme light data to better enable nurses to create sleep and rest opportunities for patients. [ABSTRACT FROM AUTHOR]