Solute-induced shift of phase transition temperature in Di-saturated PC liposomes: adoption of ripple phase creates osmotic stress

AbstractWe have examined the calorimetric behavior of large liposomes consisting of symmetric saturated chain phosphatidylcholines. Most notably, for systems made in solutions containing solute (e.g., NaCl, glucose, etc.) there was an additional major endotherm just below the main phase transition temperature. The new endotherm was found to represent a population of lipid whose main phase transition was shifted to lower temperature due to an induced osmotic stress across the membrane. Absent for isoosmotic systems, the osmotic stress was created when the liposome internal volume decreased, a consequence of the Lβ′ (gel) to Pβ′ (rippled) phase transition. That is, rippling of the membrane caused vesicle volume to decrease (≥28%) and because the free flow of water outward was restricted by solute, an osmotic gradient was created where none had existed before. The distribution of enthalpy between the new shifted Tm and the expected Tm correlated with the percent of lipid in the outer bilayer and it was concluded that only the outer bilayer sensed the induced stress. Internalized liposome structures were shielded, thus explaining the persistence of the expected Tm in preparations made in solute. The shift in Tm (ΔTm) was discrete and linearly dependent upon lipid chain length for the PC series di-17:0 (ΔTm≈1.4°C) through di-20:0 (ΔTm≈0.6°C), suggesting a structural change (i.e., lipid packing/orientation) was involved. Although freeze-fracture electron microscopy of stressed and unstressed bilayers revealed no differences in ripple periodicity there were differences in surface features and in vesicle shape. The fact that this phenomenon has gone unnoticed for MLVs is probably due to the fact that these systems are known to exclude solute and thus exist under osmotic compression

Adult Attention Deficit Hyperactivity Disorder and Violence in the Population of England: Does Comorbidity Matter?

It is unclear whether the association between Attention Deficit/Hyperactivity Disorder (ADHD) and violence is explained by ADHD symptoms or co-existing psychopathology. We investigated associations of ADHD and its symptom domains of hyperactivity and inattention, among individuals reporting violence in the UK population. Methods We report data from the Adult Psychiatric Morbidity Survey (2007), a representative sample of the household population of England. A randomly selected sample of 7,369 completed the Adult Self-Report Scale for ADHD and the self-reported violence module, including repetition, injury, minor violence, victims and location of incidents. All models were weighted to account for non-response and carefully adjusted for demography and clinical predictors of violence: antisocial personality, substance misuse and anxiety disorders. Results ADHD was moderately associated with violence after adjustments (OR 1.75, p = .01). Hyperactivity, but not inattention was associated with several indicators of violence in the domestic context (OR 1.16, p = .03). Mild and moderate ADHD symptoms were significantly associated with violence repetition, but not severe ADHD where the association was explained by co-existing disorders. Stratified analyses further indicated that most violence reports are associated with co-occurring psychopathology. Conclusions The direct effect of ADHD on violence is only moderate at the population level, driven by hyperactivity, and involving intimate partners and close persons. Because violence associated with severe ADHD is explained by co-existing psychopathology, interventions should primarily target co-existing disorders

The effects of patient characteristics on ADHD diagnosis and treatment: a factorial study of family physicians

<p>Abstract</p> <p>Background</p> <p>Attention Deficit Hyperactivity Disorder (ADHD) is a costly and prevalent disorder in the U.S., especially among youth. However, significant disparities in diagnosis and treatment appear to be predicted by the race and insurance status of patients.</p> <p>Methods</p> <p>This study employed a web-based factorial survey with four ADHD cases derived from an ADHD clinic, two diagnosed with ADHD in actual evaluation, and two not. Randomized measures included race and insurance status of the patients. Participants N = (187) included clinician members of regional and national practice-based research networks and the U.S. clinical membership of the Society of Teachers of Family Medicine. The main outcomes were decisions to 1) diagnose and 2) treat the cases, based upon the information presented, analyzed via binary logistic regression of the randomized factors and case indicators on diagnosis and treatment.</p> <p>Results</p> <p>ADHD-positive cases were 8 times more likely to be diagnosed and 12 times more likely to be treated, and the male ADHD positive case was more likely to be diagnosed and treated than the female ADHD positive case. Uninsured cases were significantly more likely to be treated overall, but male cases that were uninsured were about half as likely to be diagnosed and treated with ADHD. Additionally, African-American race appears to increase the likelihood of medicinal treatment for ADHD and being both African-American and uninsured appears to cut the odds of medicinal treatment in half, but not significantly.</p> <p>Conclusions</p> <p>Family physicians were competent at discerning between near-threshold ADHD-negative and ADHD positive cases. However, insurance status and race, as well as gender, appear to affect the likelihood of diagnosis and treatment for ADHD in Family Medicine settings.</p

European consensus statement on diagnosis and treatment of adult ADHD: The European Network Adult ADHD.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is among the most common psychiatric disorders of childhood that persists into adulthood in the majority of cases. The evidence on persistence poses several difficulties for adult psychiatry considering the lack of expertise for diagnostic assessment, limited treatment options and patient facilities across Europe. METHODS: The European Network Adult ADHD, founded in 2003, aims to increase awareness of this disorder and improve knowledge and patient care for adults with ADHD across Europe. This Consensus Statement is one of the actions taken by the European Network Adult ADHD in order to support the clinician with research evidence and clinical experience from 18 European countries in which ADHD in adults is recognised and treated. RESULTS: Besides information on the genetics and neurobiology of ADHD, three major questions are addressed in this statement: (1) What is the clinical picture of ADHD in adults? (2) How can ADHD in adults be properly diagnosed? (3) How should ADHD in adults be effectively treated? CONCLUSIONS: ADHD often presents as an impairing lifelong condition in adults, yet it is currently underdiagnosed and treated in many European countries, leading to ineffective treatment and higher costs of illness. Expertise in diagnostic assessment and treatment of ADHD in adults must increase in psychiatry. Instruments for screening and diagnosis of ADHD in adults are available and appropriate treatments exist, although more research is needed in this age group