1,218 research outputs found
Adolescent D-amphetamine treatment in a rodent model of attention deficit/hyperactivity disorder: impact on cocaine abuse vulnerability in adulthood
RATIONALE: Stimulant medications for attention-deficit/hyperactivity disorder (ADHD) in adolescents remain controversial with respect to later development of cocaine abuse. Past research demonstrated that adolescent methylphenidate treatment increased several aspects of cocaine self-administration during adulthood using the spontaneously hypertensive rat (SHR) model of ADHD. Presently, we determined effects of the alternate stimulant medication, d-amphetamine, on cocaine self-administration.
OBJECTIVES: We tested the hypothesis that adolescent d-amphetamine would not increase cocaine self-administration in adult SHR, given that d-amphetamine has a different mechanism of action than methylphenidate.
METHODS: A pharmacologically relevant dose of d-amphetamine (0.5 mg/kg) or vehicle was administered throughout adolescence to SHR and two control strains, Wistar-Kyoto (WKY) and Wistar (WIS). Three aspects of cocaine abuse vulnerability were assessed in adulthood after discontinuing adolescent treatments: acquisition rate and dose-related responding under fixed (FR) and progressive (PR) ratio schedules.
RESULTS: Adult SHR acquired cocaine self-administration faster and self-administered more cocaine across multiple doses compared to WKY and WIS under FR and PR schedules, indicating that SHR is a reliable animal model of comorbid ADHD and cocaine abuse. Relative to vehicle, SHR and WIS with adolescent d-amphetamine treatment self-administered less cocaine upon reaching acquisition criteria, and WIS additionally acquired cocaine self-administration more slowly and had downward shifts in FR and PR cocaine dose-response curves. WKY with adolescent d-amphetamine treatment acquired cocaine self-administration more quickly relative to vehicle.
CONCLUSIONS: In contrast to methylphenidate, adolescent d-amphetamine did not augment cocaine self-administration in SHR. Adolescent d-amphetamine treatment actually protected against cocaine abuse vulnerability in adult SHR and WIS.National Institutes of Health grant DA011716 and the Clara Mayo Memorial Fellowship at Boston University. (DA011716 - National Institutes of Health; Clara Mayo Memorial Fellowship at Boston University)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5026317/Published versio
Lessons Learned From a Collaborative to Improve Care for Patients With Diabetes in 17 Community Health Centers, Massachusetts, 2006
INTRODUCTION: In 2006, the Massachusetts League of Community Health Centers convened a collaborative to systematically improve health care delivery for patients with diabetes in 17 community health centers. Our goal was to identify facilitators of and barriers to success reported by teams that participated in this collaborative.
METHODS: The collaborative\u27s activities lasted 13 months. At their conclusion, we interviewed participating team members. We asked about their teams\u27 successes, challenges, and take-home messages for future collaborative efforts. We organized their responses into common themes by using the Chronic Care Model as a framework.
RESULTS: Themes that emerged as facilitators of success included shifting clinic focus to more actively involve patients and to promote their self-management; improving the understanding and implementation of professional guidelines; and expanding staff roles to accommodate these goals. Patient registries were perceived as beneficial but lacking adequate technical support. Other barriers were staffing and time constraints.
CONCLUSION: Cooperative efforts to improve health care delivery for people with diabetes may benefit from educating the health care team about guidelines, establishing a stronger role for the patient as part of the health care team, and providing adequate technical instruction and support for the use of clinical databases
Limitations and challenges of EIT-based monitoring of stroke volume and pulmonary artery pressure.
Electrical impedance tomography (EIT) shows potential for radiation-free and noninvasive hemodynamic monitoring. However, many factors degrade the accuracy and repeatability of these measurements. Our goal is to estimate the impact of this variability on the EIT-based monitoring of two important central hemodynamic parameters: stroke volume (SV) and pulmonary artery pressure (PAP).
We performed simulations on a 4D ([Formula: see text]) bioimpedance model of a human volunteer to study the influence of four potential confounding factors (electrode belt displacement, electrode detachment, changes in hematocrit and lung air volume) on the performance of EIT-based SV and PAP estimation. Results were used to estimate how these factors affect the EIT measures of either absolute values or relative changes (i.e. trending).
Our findings reveal that the absolute measurement of SV via EIT is very sensitive to electrode belt displacements and lung conductivity changes. Nonetheless, the trending ability of SV EIT might be a promising alternative. The timing-based measurement of PAP is more robust to lung conductivity changes but sensitive to longitudinal belt displacements at severe hypertensive levels and to rotational displacements (independent of the PAP level).
We identify and quantify the challenges of EIT-based SV and PAP monitoring. Absolute SV via EIT is challenging, but trending is feasible, while both the absolute and trending of PAP via EIT are mostly impaired by belt displacements
Direct observation of charge inversion by multivalent ions as a universal electrostatic phenomenon
We have directly observed reversal of the polarity of charged surfaces in
water upon the addition of tri- and quadrivalent ions using atomic force
microscopy. The bulk concentration of multivalent ions at which charge
inversion reversibly occurs depends only very weakly on the chemical
composition, surface structure, size and lipophilicity of the ions, but is
dominated by their valence. These results support the theoretical proposal that
spatial correlations between ions are the driving mechanism behind charge
inversion.Comment: submitted to PRL, 26-04-2004 Changed the presentation of the theory
at the end of the paper. Changed small error in estimate of prefactor ("w" in
first version) of equation
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Tolerability and safety of the intake of bovine milk oligosaccharides extracted from cheese whey in healthy human adults.
Mechanistic research suggests a unique evolutionary relationship between complex milk oligosaccharides and cognate bifidobacteria enriched in breast-fed infants. Bovine milk oligosaccharides (BMO) were recently identified as structurally and functionally similar to human milk oligosaccharides. The present single-blind three-way crossover study is the first to determine the safety and tolerability of BMO consumption by healthy human participants (n 12) and its effects on faecal microbiota and microbial metabolism. Participants consumed each supplement (placebo-control; low- and high-BMO doses) for eleven consecutive days, followed by a 2-week washout period prior to initiating the next supplement arm. Low and high BMO doses were consumed as 25 and 35 % of each individual's daily fibre intake, respectively. Safety and tolerability were measured using standardised questionnaires on gut and stomach discomfort and stool consistency. Faecal extracts were profiled for bacterial populations by next-generation sequencing (NGS) and bifidobacteria presence was confirmed using quantitative PCR. Urine was analysed for changes in microbial metabolism using nuclear magnetic resonance spectroscopy (1H-NMR). Consumption of both the low and high BMO doses was well tolerated and did not change stool consistency from baseline. Multivariate analysis of the NGS results demonstrated no change in faecal microbiota phyla among the placebo-control and BMO supplement groups. In conclusion, BMO supplementation was well tolerated in healthy adults and has the potential to shift faecal microbiota toward beneficial strains as part of a synbiotic treatment with probiotic cultures that selectively metabolise oligosaccharides
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