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Single-channel recordings from cultured human retinal pigment epithelial cells.
We have applied patch-clamp techniques to on-cell and excised-membrane patches from human retinal pigment epithelial cells in tissue culture. Single-channel currents from at least four ion channel types were observed: three or more potassium-selective channels with single-channel slope conductances near 100, 45, and 25 pS as measured in on-cell patches with physiological saline in the pipette, and a relatively nonselective channel with subconductance states, which has a main-state conductance of approximately 300 pS at physiological ion concentrations. The permeability ratios, PK/PNa, measured in excised patches were 21 for the 100-pS channels, 3 for the 25-pS channels, and 0.8 for the 300-pS nonselective channel. The 45-pS channels appeared to be of at least two types, with PK/PNa's of approximately 41 for one type and 3 for the other. The potassium-selective channels were spontaneously active at all potentials examined. The average open time for these channels ranged from a few milliseconds to many tens of milliseconds. No consistent trend relating potassium-selective channel kinetics to membrane potential was apparent, which suggests that channel activity was not regulated by the membrane potential. In contrast to the potassium-selective channels, the activity of the nonselective channel was voltage dependent: the open probability of this channel declined to low values at large positive or negative membrane potentials and was maximal near zero. Single-channel conductances observed at several symmetrical KCl concentrations have been fitted with Michaelis-Menten curves in order to estimate maximum channel conductances and ion-binding constants for the different channel types. The channels we have recorded are probably responsible for the previously observed potassium permeability of the retinal pigment epithelium apical membrane
Maine Pediatric and Family Practice Survey Chartbook: Improving Health Outcomes for Children
As part of the IHOC initiative, the Muskie School of Public Service at the University of Southern Maine surveyed pediatric and family practices about how they use data, clinical guidelines and office systems to monitor and improve children’s healthcare quality. The purpose of the survey is to provide baseline information about quality improvement activities in primary care practices serving children in Maine. Survey data will be used to inform IHOC activities and to monitor changes over time. The web-based survey was conducted in the winter of 2011-2012 and sent to practice managers at a sample of 168 practice sites, of which 64% responded. Responding practices represent more than one-quarter of family practices and nearly two-thirds of all pediatric practices in the state. This report summarizes the results of the initial survey and assesses quality improvement activities in pediatric and family practices at baseline
Supporting the advancement of science: Open access publishing and the role of mandates
In December 2011 the United States House of Representatives introduced a new bill, the Research Works Act (H.R.3699), which if passed could threaten the public's access to US government funded research. In a digital age when professional and lay parties alike look more and more to the online environment to keep up to date with developments in their fields, does this bill serve the best interests of the community? Those in support of the Research Works Act argue that government open access mandates undermine peer-review and take intellectual property from publishers without compensation, however journals like Journal of Translational Medicine show that this is not the case. Journal of Translational Medicine in affiliation with the Society for Immunotherapy of Cancer demonstrates how private and public organisations can work together for the advancement of science
Preamble to the 2015 SITC immunotherapy biomarkers taskforce
The Society for Immunotherapy of Cancer (SITC) has regularly hosted workshops and working groups focused on immunologic monitoring and immune biomarkers. Due to advances in cancer immunotherapy, including positive results from clinical trials testing new agents and combinations, emerging new technologies for measuring aspects of immunity, and novel candidate biomarkers from early phase trials, the SITC Immune Biomarkers Taskforce has reconvened to review the state of the art, identify current hurdles to further success and to make recommendations to the field. Topics being addressed by individual working groups include: (1) validation of candidate biomarkers, (2) identification of the most promising technologies, (3) testing of high throughput immune signatures and (4) investigation of the pre-treatment tumor microenvironment. Resultant recommendations will be published in JITC
A CRISPR platform for targeted in vivo screens identifies Toxoplasma gondii virulence factors in mice
Prospective memory functioning among ecstasy/polydrug users: evidence from the Cambridge Prospective Memory Test (CAMPROMPT)
Rationale:
Prospective memory (PM) deficits in recreational drug users have been documented in recent years. However, the assessment of PM has largely been restricted to self-reported measures that fail to capture the distinction between event-based and time-based PM. The aim of the present study is to address this limitation.
Objectives:
Extending our previous research, we augmented the range laboratory measures of PM by employing the CAMPROMPT test battery to investigate the impact of illicit drug use on prospective remembering in a sample of cannabis only, ecstasy/polydrug and non-users of illicit drugs, separating event and time-based PM performance. We also administered measures of executive function and retrospective memory in order to establish whether ecstasy/polydrug deficits in PM were mediated by group differences in these processes.
Results:
Ecstasy/polydrug users performed significantly worse on both event and time-based prospective memory tasks in comparison to both cannabis only and non-user groups. Furthermore, it was found that across the whole sample, better retrospective memory and executive functioning was associated with superior PM performance. Nevertheless, this association did not mediate the drug-related effects that were observed. Consistent with our previous study, recreational use of cocaine was linked to PM deficits.
Conclusions:
PM deficits have again been found among ecstasy/polydrug users, which appear to be unrelated to group differences in executive function and retrospective memory. However, the possibility that these are attributable to cocaine use cannot be excluded
Issues potentially affecting quality of life arising from long-term medicines use: a qualitative study
Background Polypharmacy is increasing and managing large number of medicines may create a burden for patients. Many patients have negative views of medicines and their use can adversely affect quality of life. No studies have specifically explored the impact of general long-term medicines use on quality of life. Objective To determine the issues which patients taking long-term medicines consider affect their day-to-day lives, including quality of life. Setting Four primary care general practices in North West England Methods Face-to-face interviews with adults living at home, prescribed four or more regular medicines for at least 1 year. Interviewees were identified from primary care medical records and purposively selected to ensure different types of medicines use. Interviews were recorded, transcribed and analysed thematically. Results Twenty-one interviews were conducted and analysed. Patients used an average of 7.8 medicines, 51 % were preventive, 40 % for symptom relief and 9 % treatment. Eight themes emerged: relationships with health professionals, practicalities, information, efficacy, side effects, attitudes, impact and control. Ability to discuss medicines with health professionals varied and many views were coloured by negative experiences, mainly with doctors. All interviewees had developed routines for using multiple medicines, some requiring considerable effort. Few felt able to exert control over medicines routines specified by health professionals. Over half sought additional information about medicines whereas others avoided this, trusting in doctors to guide their medicines use. Patients recognised their inability to assess efficacy for many medicines, notably those used for prophylaxis. All were concerned about possible side effects and some had poor experiences of discussing concerns with doctors. Medicines led to restrictions on social activities and personal life to the extent that, for some, life can revolve around medicines. Conclusion There is a multiplicity and complexity of issues surrounding medicines use, which impact on day-to-day lives for patients with long-term conditions. While most patients adapt to long-term medicines use, others did so at some cost to their quality of life
Tau accumulation in autosomal dominant Alzheimer’s disease: a longitudinal [18F]flortaucipir study
Cortical tau accumulation is a key pathological event that partly defines Alzheimer’s disease (AD) onset and is associated with cognitive decline and future disease progression. However, an improved understanding of the timing and pattern of early tau deposition in AD and how this may be tracked in vivo is needed. Data from 59 participants involved in two longitudinal cohort studies of autosomal dominant AD (ADAD) were used to investigate whether tau PET can detect and track presymptomatic change; seven participants were symptomatic, and 52 were asymptomatic but at a 50% risk of carrying a pathogenic mutation. All had baseline flortaucipir (FTP) PET, MRI and clinical assessments; 26 individuals had more than one FTP PET scan. Standardised uptake value ratios (SUVRs) in prespecified regions of interest (ROIs) were obtained using inferior cerebellar grey matter as the reference region. We compared the changes in FTP SUVRs between presymptomatic carriers, symptomatic carriers and non-carriers, adjusting for age, sex and study site. We also investigated the relationship between regional FTP SUVRs and estimated years to/from symptom onset (EYO). Compared to both non-carriers and presymptomatic carriers, FTP SUVRs were significantly higher in symptomatic carriers in all ROIs tested (p 0.05), although increased FTP signal uptake was seen posteriorly in some individuals around the time of expected symptom onset. When we examined the relationship of FTP SUVR with respect to EYO, the earliest significant regional difference between mutation carriers and non-carriers was detected within the precuneus prior to estimated symptom onset in some cases. This study supports preliminary studies suggesting that presymptomatic tau tracer uptake is rare in ADAD. In cases where early uptake was seen, there was often a predilection for posterior regions (the precuneus and post-cingulate) as opposed to the medial temporal lobe, highlighting the importance of examining in vivo tau uptake beyond the confines of traditional Braak staging
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