Mentoring in health services management: reflections on an evolving training ground.

Since the University of Chicago Health Management program was first initiated in 1932, programs and health delivery organizations have dealt with the issue of how to best provide a meaningful transition from academia to entry-level management. Today, new challenges face the same old questions: New federal legislation and increased demand for a finite supply of services cause increased revenue and expense pressures and result in the need for a higher performance level by a well-coordinated management team. In addressing these challenges, mentoring is an essential requirement for survival and success in health services. The long-term success of future practitioners will require both an understanding and incorporation of mentoring in their skill set. The University of Virginia Medical Center recently sponsored a health management education summit to examine the role of mentoring in health services administration education. Leading the program were John Westerman, former interim president of Association of University Programs in Healthcare Administration and chief executive officer emeritus of the University of Minnesota Health System, and R. Edward Howell, chief executive officer of the University of Virginia Medical Center. Summit participants included individuals who had completed administrative fellowship training programs. What follows is a review of the discussions during the summit, including a valuation of the health services fellowship as a learning experience as well as structure and essential elements of administrative mentoring programs.

Reactive uptake of nitric acid onto sodium chloride aerosols across a wide range of relative humidities.

Reactive uptake coefficients for nitric acid onto size-selected (d(ve) = 102 and 233 nm) sodium chloride aerosols are determined for relative humidities (RH) between 85% and 10%. Both pure sodium chloride and sodium chloride mixed with magnesium chloride (X(Mg/Na) = 0.114, typical of sea salt) are studied. The aerosol is equilibrated with a carrier gas stream at the desired RH and then mixed with nitric acid vapor at a concentration of 60 ppb in a laminar flow tube reactor. At the end of the reactor, the particle composition is determined in real time with a laser ablation single particle mass spectrometer. For relative humidities above the efflorescence relative humidity (ERH), the particles exist as liquid droplets and the uptake coefficient ranges from 0.05 at 85% RH to >0.1 near the ERH. The droplet sizes, relative humidity and composition dependencies, are readily predicted by thermodynamics. For relative humidities below the ERH, the particles are nominally "solid" and uptake depends on the amount of surface adsorbed water (SAW). The addition of magnesium chloride to the particle phase (0.114 mole ratio of magnesium to sodium) facilitates uptake by increasing the amount of SAW. In the presence of magnesium chloride, the uptake coefficient remains high (>0.1) down to 10% RH, suggesting that the displacement of chloride by nitrate in fine sea salt particles is efficient over the entire range of conditions in the ambient marine environment. In the marine boundary layer, displacement of chloride by nitrate in fine sea salt particles should be nearly complete within a few hours (faster in polluted areas)-a time scale much shorter than the particle residence time in the atmosphere.

Elevated cerebrospinal fluid pressure in patients with Alzheimer's disease.

BACKGROUND: Abnormalities in cerebrospinal fluid (CSF) production and turnover, seen in normal pressure hydrocephalus (NPH) and in Alzheimer's disease (AD), may be an important cause of amyloid retention in the brain and may relate the two diseases. There is a high incidence of AD pathology in patients being shunted for NPH, the AD-NPH syndrome. We now report elevated CSF pressure (CSFP), consistent with very early hydrocephalus, in a subset of AD patients enrolled in a clinical trial of chronic low-flow CSF drainage. Our objective was to determine the frequency of elevated CSFP in subjects meeting National Institutes of Neurological and Communicative Diseases and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria for AD, excluding those with signs of concomitant NPH. METHODS: AD subjects by NINCDS-ADRDA criteria (n = 222), were screened by history, neurological examination, and radiographic imaging to exclude those with clinical or radiographic signs of NPH. As part of this exclusion process, opening CSFP was measured supine under general anesthesia during device implantation surgery at a controlled pCO2 of 40 Torr (40 mmHg). RESULTS: Of the 222 AD subjects 181 had pressure measurements recorded. Seven subjects (3.9%) enrolled in the study had CSFP of 220 mmH20 or greater, mean 249 +/- 20 mmH20 which was significantly higher than 103 +/- 47 mmH2O for the AD-only group. AD-NPH patients were significantly younger and significantly less demented on the Mattis Dementia Rating Scale (MDRS). CONCLUSION: Of the AD subjects who were carefully screened to exclude those with clinical NPH, 4% had elevated CSFP. These subjects were presumed to have the AD-NPH syndrome and were withdrawn from the remainder of the study.

Chemistry of particle inception and growth during alpha-pinene ozonolysis.

A flow-tube reactor was used to study the formation of particles from alpha-pinene ozonation. Particle phase products formed within the first 3-22 s of reaction were analyzed online using a scanning mobility particle sizer and two particle mass spectrometers. The first, a photoionization aerosol mass spectrometer (PIAMS), was used to determine the molecular composition of nascent particles between 30 and 50 nm in diameter. The second, a nano-aerosol mass spectrometer (NAMS), was used to determine the elemental composition of individual particles from 50 nm to below 10 nm in diameter. Molecular composition measurements with PIAMS confirm that both the stabilized Criegee intermediate and hydroperoxide channels of alpha-pinene ozonolysis are operative. However, these channels alone cannot explain the high oxygen content of the particles measured with NAMS. The carbon-to-oxygen mole ratios of suspected nucleating agents are in the range of 2.25-4.0, while the measured ratios are from 1.9 for 9 nm particles to 2.5 and 2.7 for 30 and 50 nm particles, respectively. The large oxygen content may arise by cocondensation of small oxygenated molecules such as water or multistep reactions with ozone, water, or other species that produce highly oxygenated macromolecules. In either case, the increasing ratio with increasing particle size suggests that the aerosol becomes less polar with time.

Novel ventriculo-peritoneal shunt in Alzheimer's disease cerebrospinal fluid biomarkers.

Alzheimer's disease is an age-related dementia and its incidence is rising in developed countries as the population ages. Amyloid plaques and tau-rich neurofibrillary tangles are pathologic hallmarks of the disease. Treatment is symptomatic, consisting of compounds that block enzymatic acetylcholine degradation (acetylcholinesterase inhibitors). Cognitive benefits of the four approved antidementia drugs are typically modest and limited in duration. While Alzheimer's disease is undoubtedly multifactorial in cause, advancing age is the most important risk factor. Any robust theory of pathogenesis must account for the profound influence of age on the emergence of Alzheimer's disease. There is evidence that senescent changes in cerebrospinal fluid production, circulation, turnover and clearance of amyloid beta-peptides may be a key factor in the onset and progression of Alzheimer's disease. The effect of increasing cerebrospinal fluid circulation and turnover in Alzheimer's disease patients by implanting a novel, low-flow drainage system (COGNIshunt) has been studied and promising trends in cognitive stabilization and improvement in cerebrospinal fluid biomarkers have been found.

Alzheimer's disease, normal-pressure hydrocephalus, and senescent changes in CSF circulatory physiology: a hypothesis.

There is evidence that production and turnover of CSF help to clear toxic molecules such as amyloid-beta peptide (Abeta) from the interstitial-fluid space of the brain to the bloodstream. Two changes in CSF circulatory physiology have been noted as part of ageing: first, a trend towards lower CSF production, hence a decrease in CSF turnover; and second, greater resistance to CSF outflow. Our hypothesis is that, all else being equal, the initially dominant physiological change determines whether CSF circulatory failure manifests as Alzheimer's disease (AD) or as normal-pressure hydrocephalus (NPH). If CSF production failure predominates, AD develops. However, if resistance to CSF outflow predominates, NPH results. Once either disease process takes hold, the risk of the other disorder may rise. In AD, increased deposition of Abeta in the meninges leads to greater resistance to CSF outflow. In NPH, raised CSF pressure causes lower CSF production and less clearance of Abeta. The disorders may ultimately converge in vulnerable individuals, resulting in a hybrid as has been observed in several clinical series. We postulate a new nosological entity of CSF circulatory failure, with features of AD and NPH. NPH-AD may cover an important subset of patients who carry the diagnosis of either AD or NPH.

Downregulation of cerebrospinal fluid production in patients with chronic hydrocephalus.

OBJECT: The goal of this study was to determine the effect of hydrocephalus on cerebrospinal fluid (CSF) production rates in patients with acute and chronic hydrocephalus. METHODS: The authors studied CSF production both in patients presenting with acute and chronic hydrocephalus, and patients with Parkinson disease (PD) of a similar mean age, whose CSF production was known to be normal. A modification of the Masserman method was used to measure CSF production through a ventricular catheter. The CSF production rates (means +/- standard deviations) in the three groups were then compared. The patients with PD had a mean CSF production rate of 0.42 +/- 0.13 ml/minute; this value lies within the normal range measured using this technique. Patients with acute hydrocephalus had a similar CSF production rate of 0.4 +/- 0.13 ml/minute, whereas patients with chronic hydrocephalus had a significantly decreased mean CSF production rate of 0.25 +/- 0.08 ml/minute. CONCLUSIONS: The authors postulate that chronic increased intracranial pressure causes downregulation of CSF production.