The association of PIRx with subsequent adverse outcomes (hospitalization and death) provides new evidence of the importance of improving prescribing practices in the nursing home setting.

Objective. To estimate the scope of potentially inappropriate medication prescriptions (PIRx) among elderly residents in U.S. nursing homes (NHs), and to examine associated resident and facility characteristics. Data Sources. The 1996 Medical Expenditure Panel Survey Nursing Home Component (MEPS NHC), a survey of a nationally representative sample of NHs and residents. Study Design. The PIRx, defined by Beers's consensus criteria (1991, 1997), was identified using up to a year's worth of NH prescribed medicine data for each resident. The study sample represented 1.6 million NH residents (n 5 3,372). Results. At a minimum, 50 percent of all residents aged 65 or older, with an NH stay of three months or longer received at least one PIRx in 1996. The most common PIRx involved propoxyphene, diphenhydramine, hydroxyzine, oxybutynin, amitriptyline, cyproheptadine, iron supplements, and ranitidine. Resident factors associated with greater odds of PIRx were Medicaid coverage, no high school diploma, and nondementia mental disorders. Facility factors were more beds and lower RN-to-resident ratio. Factors associated with lower odds of PIRx were fewer medications, residents with communication problems, and being in an accredited NH. Onsite availability of pharmacists or mental health providers was not related. Implications. With quality of care and patient safety as major public health concerns, effective policies are needed to avoid PIRx occurrences and improve the quality of prescribing among elderly residents in NHs. Additional studies are needed to determine the impact of PIRx on this NH population.

An animal model for study of the circadian rhythm in intraocular pressure (IOP) was developed using carefully maintained environmental lighting conditions. Highly predictable, precipitous increases and decreases in IOP of somewhat more than 10 mm Hg were found to be closely correlated with the onset of darkness and light, respectively. The daily spontaneous variations in IOP, once entrained, were maintained in constant darkness, but were eliminated by constant light, as is similarly seen in many mammalian systems. This model provides a novel means of investigating circadian IOP oscillation, which has been shown to be especially amplified in primary open angle glaucoma (POAG). This new rabbit model may also warrant consideration for use in screening ocular antihypertensive drugs since it could obviate the gross physiological manipulations and concomitant side effects inherent in the popular methods of inducing ocular hypertension in animal models.

The dynamical formation and structure of the plasma focus has been studied with a two-dimensional numerical fluid model. The extremely high kinetic energy densities obtained in the numerical fluid experiment as the result of adiabatic compression and viscous heating agree well with experiment. Three features in the plasma focus are isolated: an anode cold source, a hot pinch region, and an axial shock. The anomalously long lifetime of the plasma focus is shown to be the result of axial flow, with stabilization of magnetohydrodynamic modes through the ion stress tensor in the intermediate collisionless, collision-dominated regime. Estimates of the neutron yield based on the numerical fluid experiment concur with experimental yields, and are the result of thermally reacting deuterons in the hot pinch region. The plasma parameters of interest determined from the hot pinch region suggest that the ion distribution function will not have a simple Maxwellian form and this in particular may account for the discrepancy with experiment on the anisotropy in space of the neutron yield.

PURPOSE.In nonocular systems, activation of opioid receptors has been shown to ameliorate tissue damage induced by ischemic stress. The current study was an investigation of whether opioid receptors activated by endogenous or exogenous agonists can ameliorate ischemic retinal injury. METHODS. In an investigation of whether endogenous opioid receptor-activation reduces ischemic injury, the effects of the opioid antagonist naloxone (3 mg/kg; IP) on retinal neuroprotection induced by ischemic preconditioning (IPC) were evaluated. Whether exogenous opioid administration can reduce ischemic retinal injury was determined by pretreating rats with morphine (0.01-10 mg/kg) before injury. Morphometric and electroretinogram (ERG) analyses were used to assess the differences in retinal structure and function. The expression of opioid receptor subtypes was evaluated by Western blot and immunohistochemical analyses. RESULTS. In control animals, 7 days after ischemic retinal injury, ERG a-and b-wave amplitudes were significantly reduced (23% and 41%, respectively). In addition, degeneration of the inner retina resulted in a 34% reduction in overall retina thickness. In animals receiving IPC before ischemic injury, ERG wave forms and retinal morphology were preserved. Pretreatment with naloxone reversed both the functional and structural retinal protection induced by IPC. In animals treated with morphine 24-hours before ischemic injury, ERG waveforms were preserved in a dose-dependent fashion (ED 50 ϭ 0.18 mg/kg), and this protective response was reversed by naloxone pretreatment. Immunohistochemical and Western blot data demonstrated that the ␦-, -, and -opioid receptor subtypes are expressed in the retina. CONCLUSIONS. These data provide evidence that activation of one (or more) opioid receptor(s) facilitates the development of IPC within the retina and can reduce ischemic retina injury.