Amphetamine disrupts P50 suppression in normal subjects.

BACKGROUND: P50 suppression is viewed as an operational measure of sensory "gating" that is reduced in patients with schizophrenia and their family members. Previous reports have demonstrated that neural gating is regulated by monoaminergic tone in rodent models of P50 suppression. METHODS: In this study, 11 healthy subjects participated in P50 event-related potential recordings at baseline and after either oral administration of dextroamphetamine (.3 mg/kg) or placebo, to determine if the administration of a monoaminergic agonist produces P50 suppression deficits similar to those observed in patients with schizophrenia. RESULTS: As hypothesized, amphetamine disrupted the suppression of the P50 event-related potential. There was a statistically significant decrement in P50 suppression during the amphetamine challenge condition (t10 = 3.15, p < .01, mean difference = -44.1%, d = -2.5) relative to the baseline P50 condition. A comparison of P50 suppression in the placebo and amphetamine conditions (both after a baseline recording session) revealed a significant amphetamine-induced disruption of P50 suppression (t6 = 3.71, p < .01, mean difference = -54.4%, d = -3.14). CONCLUSIONS: The biochemical alterations associated with an amphetamine-induced disruption of P50 suppression in this study may be related to the pathophysiology of P50 suppression deficits in schizophrenia. The findings are consistent with several careful examinations of suppression deficits in rodent models that have identified the monoaminergic regulation of P50 suppression. These data indicate that amphetamine induces a disruption of P50 suppression in normal subjects.     

Effects of religiosity and racial socialization on subjective stigmatization in African-American adolescents

The direct effects of religiosity and racial socialization on subjective stigmatization among 50 African-American adolescents were investigated. A stigma is a characteristic about which others hold negative attitudes and stereotypes. Subjective stigmatization measures the degree to which an individual internalizes such negative attitudes and stereotypes toward a social group of which he or she is a member. Participants who showed strong commitment to the church were more destigmatized than were participants who did not. Further, participants who received racial socialization messages stemming from a single "primary" category were more destigmatized than those who did not. Unexpectedly, the more racial socialization messages participants received, the more self-stigmatized they were. The importance of religiosity and racial socialization in the lives of African-American adolescents are discussed.     

Marketing syringe/needle exchange programs

In an effort to bring the AIDS epidemic under control among the highest risk population of injecting drug users, Syringe/Needle Exchange Programs are being considered, developed and implemented. This paper looks at some of the programs in the United States in various stages of development. Also discussed will be the medical, social and political issues surrounding Needle Exchange Programs.     

The on-eye dehydration of proclear compatibles lenses.

PURPOSE: The purpose of the study was to evaluate the on-eye dehydration over time, of molded omafilcon A lenses (Proclear Compatibles) compared to a range of frequent replacement lenses. METHODS: Ten subjects wore a Proclear Compatibles lens in one eye and a control lens in the other eye for 4-, 8- and 12-hours. The control lenses were Acuvue, Soflens 66 and Optima frequent replacement lenses. Each subject wore three different pairs of lenses for each time period in a masked, randomized fashion. A gravimetric technique was used to determine lens water content. RESULTS: The Proclear Compatibles lenses showed significantly less relative dehydration than the Acuvue and Soflens 66 lenses. The Acuvue and Soflens 66 lenses showed a significant increase in relative dehydration with increasing wearing time. Subjective comfort was graded higher with the Proclear Compatibles than with the Acuvue lenses. There was a significant negative correlation between Acuvue dehydration and subjective ratings of comfort. CONCLUSIONS: The study showed that Proclear Compatibles lenses dehydrate significantly less than the other frequent replacement high-water content lenses. The Acuvue and Soflens 66 lenses showed increasing dehydration during the 4-12 hour wearing period.     

Endoscopic Treatment of Vesicoureteral Reflux with Collagen: Preliminary Report and Cost Analysis

Purpose

We determined therapeutic and operative cost efficacy of endoscopic collagen injection for vesicoureteral reflux.

Materials and Methods

We performed a multicenter study of 10 male and 23 female sequential patients (45 renal units) with vesicoureteral reflux and a surgical indication. Patients were skin tested with collagen and when negative, they underwent endoscopic injection. Renal ultrasound/ cystography was done 3 months after treatment. Cost analysis was performed at 1 institution.

Results

Reflux was grade I in 2 renal units, II in 18, III in 15 and IV in 10. The majority of cases were single systems with primary reflux. We performed 1 treatment in 32 renal units, 2 in 6, 3 in 6 and 4 in 1. Cure was evident in 31 of 38 renal units (81.6 percent) and 21 of 27 patients (78 percent) 3 months after the last injection. Patient morbidity was minimal. Operative cost per renal unit was $1,599.68 for collagen injection and $9,144.47 for reimplantation.

Conclusions

Endoscopic injection of collagen is effective treatment for vesicoureteral reflux. Furthermore, it causes minimal morbidity and may effect cost savings in health care management.     

Seizures and civilian head injuries

Although several studies have reported on the risk of "early seizures" (seizures occurring within 7 days following a head injury), the reported proportions of patients experiencing these seizures vary from 1.4 to 15%. This wide divergence may be due to problems with methodology such as case selection and definitions of head injury and early seizures. In a series of 702 patients admitted with a head injury to Cook County Hospital (CCH), Chicago, Illinois, 29 (4.1%) had early seizures. This proportion is twice as high as one previously reported in a comparable series. This may reflect an actual difference between the two series or a case selection bias serving to elevate the proportion of patients with early seizures at CCH.     

Preoperative and postoperative voice analysis of uvulopalatopharyngoplasty patients.

While clinical studies almost universally report few speech and voice complications from uvulopalatopharyngoplasty, there is a paucity of prospective studies concerned with formal acoustic and perceptual evaluation of these patients. This study compares preoperative and postoperative recordings of 32 uvulopalatopharyngoplasty patients. Fast Fourier Transform analyses were made of both long-term spectra of a reading passage and the resonant characteristics of three vowels. Fundamental frequency and reading time were quantified. Polysomnographic studies of these patients were also compared. Finally, listener judgments of "better voice" were made on preoperative and postoperative pairs of the same patients performing a reading task. While the polysomnographic data demonstrated statistically significant improvement in the physical condition of the patients, no perceptual or acoustic measure of voice or speech was significant when preoperative and postoperative scores were compared.     

Cyclosporin A induced internalization of the bile salt export pump in isolated rat hepatocyte couplets.

Isolated rat hepatocyte couplets were used to perform the comparative study of two widely used immunosuppressors, cyclosporin A (CsA) and tacrolimus (FK506) on hepatocanalicular function. We assessed canalicular function by counting the percentage of couplets that were able to accumulate the fluorescent cholephile, cholyl-lysyl-fluorescein (CLF), into the canalicular vacuole between the two cells, i.e., canalicular vacuole accumulation (CVA) of CLF. Compared to controls (DMSO-treated cells), CsA, in the approximate range of concentrations used therapeutically, caused inhibition of CVA of CLF, disorganization of the bile salt export pump (Bsep) localization at canalicular level resulting in its relocation into the cell, and disruption of the pericanalicular F-actin cytoskeleton. In contrast, FK506, at both approximately therapeutic and supratherapeutic concentrations, had no deleterious effect upon CVA of CLF, upon the localization of the bile salt transporter at the canalicular membrane, or on the organization of the pericanalicular F-actin cytoskeleton. These results point to transporter and cytoskeletal disorganization as contributors or determinants of CsA-induced cholestasis at canalicular level, whereas FK506 does not appear to produce these cholestasis-determining responses even at supratherapeutic concentrations.