680 research outputs found
Results and safety profile of trainee cataract surgeons in a community setting in East Africa
Purpose: To evaluate the results and safety profile of assistant medical officer ophthalmologists (AMO-O) performing cataract surgery in the last stage of their surgical training, before their appointment to local communities. Methods: We retrospectively analyzed the records of patients who underwent cataract surgery by AMO-Os at Dar es Salaam, Comprehensive Community Based Rehabilitation for Tanzania Disability Hospital between September 2008 and June 2011. Surgical options were either extracapsular cataract extraction (ECCE) or manual small incision cataract surgery (MSICS), both with polymethylmethacrylate intraocular lens implantation. Results: Four hundred and fourteen patients were included in the study. Two hundred and twenty-five (54%) underwent ECCE and 189 had MSICS. Mean logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity (UCVA) improved from 2.4 Ā± 0.6 preoperatively to 1.3 Ā± 0.8 1 week postoperatively (t-test, P < 0.001) and to 1.1 Ā± 0.7 3 months postoperatively (t-test, P < 0.001). Mean logMAR best-corrected visual acuity (BCVA) was 0.7 Ā± 0.5 1 week postoperatively and 0.6 Ā± 0.5 3 months postoperatively. There was no significant difference in mean logMAR UCVA (P = 0.7) and BCVA (P = 0.7) postoperatively between ECCE and MSICS. 89.5% achieved BCVA better than 6/60 and 57.3% better than 6/18 with a follow-up of 3 months. Posterior capsule rupture and/or vitreous loss occurred in 34/414 patients (8.2%) and was more frequent (P = 0.047) in patients undergoing ECCE (10.2%) compared with MSICS (5.3%). Conclusion: AMO-O cataract surgeons at the end of their training offer significant improvement in the visual acuity of their patients. Continuous monitoring of outcomes will guide further improvements in surgical skills and minimize complications.
In the era of phacoemulsification for cataract surgery, extracapsular cataract extraction (ECCE) and manual small incision cataract surgery (MSICS) are still widely held to be the techniques of choice for the developing world.[1],[2],[3],[4],[5] Both MSICS and ECCE are affordable[6] and are considered safe and effective for the treatment of cataract patients in community eye care settings. MSICS appears to provide better postoperative uncorrected visual acuity (UCVA)[1] and faster rehabilitation[7] compared with ECCE although the technique is more challenging.
In Tanzania, in addition to medical doctors, there is a special cadre of health professionals, created to care for the large population, called assistant medical officers (AMOs). AMOs can specialize in ophthalmology for 2 years and become AMO ophthalmologists (AMO-O) who perform cataract surgery. AMO-O's are a subtype of nonphysician cataract surgeons previously described by Lewallen et al.[8] AMO-Os deliver high-volume cataract surgery in community eye care settings and are essential in reducing the backlog of cataract-related visual disability. AMO-Os are more likely to set up their practice and stay in rural areas than ophthalmologists tied to larger centers and in addition, their training is shorter and less expensive compared to ophthalmologists.[8],[9]
Ensuring sufficient training of AMO-Os in cataract surgery is necessary to achieve good visual outcomes and maintain low rates of complications. This is particularly important in an African community setting, where follow-up may not be optimal and management of complications more challenging. In this study, we evaluate the results and safety profile of AMO-O cataract surgeons. The surgeries were supervised by trainers and performed entirely by the AMO-O in the last stage of their surgical training (6-9 months), before operating independently in their local communities. Patients with diabetes were excluded from the surgical cohort for AMO-Os
Willingness to participate in future HIV prevention studies among gay and bisexual men in Scotland, UK: a challenge for intervention trials
This article examines willingness to participate in future HIV prevention research among gay and bisexual men in Scotland, UK. Anonymous, self-complete questionnaires and Orasure GĆ¤Ć³ oral fluid samples were collected in commercial gay venues. 1,320 men were eligible for inclusion. 78.2% reported willingness to participate in future HIV prevention research; 64.6% for an HIV vaccine, 57.4% for a behaviour change study, and 53.0% for a rectal microbicide. In multivariate analysis, for HIV vaccine research, greater age, minority ethnicity, and not providing an oral fluid sample were associated with lower willingness; heterosexual orientation and not providing an oral fluid sample were for microbicides; higher education and greater HIV treatment optimism were for behaviour change. STI testing remained associated with being more willing to participate in microbicide research and frequent gay scene use remained associated with being more willing to participate in behaviour change research. Having an STI in the past 12 months remained significantly associated with being willing to participate in all three study types. There were no associations between sexual risk behaviour and willingness. Although most men expressed willingness to participate in future research, recruitment of high-risk men, who have the potential to benefit most, is likely to be more challenging
RNase L Mediates Transient Control of The Interferon Response Through Modulation of The Double-stranded RNA-Dependent Protein Kinase PKR
The transient control of diverse biological responses that occurs in response to varied forms of stress is often a highly regulated process. During the interferon (IFN) response, translational repression due to phosphorylation of eukaryotic initiation factor 2Ī±, eIF2Ī±, by the double-stranded RNA-dependent protein kinase, PKR, constitutes a means of inhibiting viral replication. Here we show that the transient nature of the IFN response against acute viral infections is regulated, at least in part, by RNase L. During the IFN antiviral response in RNase L-null cells, PKR mRNA stability was enhanced, PKR induction was increased, and the phosphorylated form of eIF2Ī± appeared with extended kinetics compared with similarly treated wild type cells. An enhanced IFN response in RNase L-null cells was also demonstrated by monitoring inhibition of viral protein synthesis. Furthermore, ectopic expression of RNase L from a plasmid vector prevented the IFN induction of PKR. These results suggest a role for RNase L in the transient control of the IFN response and possibly of other cytokine and stress responses
RNase L Mediates Transient Control of The Interferon Response Through Modulation of The Double-stranded RNA-Dependent Protein Kinase PKR
The transient control of diverse biological responses that occurs in response to varied forms of stress is often a highly regulated process. During the interferon (IFN) response, translational repression due to phosphorylation of eukaryotic initiation factor 2Ī±, eIF2Ī±, by the double-stranded RNA-dependent protein kinase, PKR, constitutes a means of inhibiting viral replication. Here we show that the transient nature of the IFN response against acute viral infections is regulated, at least in part, by RNase L. During the IFN antiviral response in RNase L-null cells, PKR mRNA stability was enhanced, PKR induction was increased, and the phosphorylated form of eIF2Ī± appeared with extended kinetics compared with similarly treated wild type cells. An enhanced IFN response in RNase L-null cells was also demonstrated by monitoring inhibition of viral protein synthesis. Furthermore, ectopic expression of RNase L from a plasmid vector prevented the IFN induction of PKR. These results suggest a role for RNase L in the transient control of the IFN response and possibly of other cytokine and stress responses
Multifrequency Photo-polarimetric WEBT Observation Campaign on the Blazar S5 0716+714: Source Microvariability and Search for Characteristic Timescales
Here we report on the results of the WEBT photo-polarimetric campaign
targeting the blazar S5~0716+71, organized in March 2014 to monitor the source
simultaneously in BVRI and near IR filters. The campaign resulted in an
unprecedented dataset spanning \,h of nearly continuous, multi-band
observations, including two sets of densely sampled polarimetric data mainly in
R filter. During the campaign, the source displayed pronounced variability with
peak-to-peak variations of about and "bluer-when-brighter" spectral
evolution, consisting of a day-timescale modulation with superimposed hourlong
microflares characterized by \,mag flux changes. We performed an
in-depth search for quasi-periodicities in the source light curve; hints for
the presence of oscillations on timescales of \,h and \,h do
not represent highly significant departures from a pure red-noise power
spectrum. We observed that, at a certain configuration of the optical
polarization angle relative to the positional angle of the innermost radio jet
in the source, changes in the polarization degree led the total flux
variability by about 2\,h; meanwhile, when the relative configuration of the
polarization and jet angles altered, no such lag could be noted. The
microflaring events, when analyzed as separate pulse emission components, were
found to be characterized by a very high polarization degree () and
polarization angles which differed substantially from the polarization angle of
the underlying background component, or from the radio jet positional angle. We
discuss the results in the general context of blazar emission and energy
dissipation models.Comment: 16 pages, 17 Figures; ApJ accepte
FOXN1 forms higher-order nuclear condensates displaced by mutations causing immunodeficiency
The transcription factor FOXN1 is a master regulator of thymic epithelial cell (TEC) development and function. Here, we demonstrate that FOXN1 expression is differentially regulated during organogenesis and participates in multimolecular nuclear condensates essential for the factorās transcriptional activity. FOXN1ās C-terminal sequence regulates the diffusion velocity within these aggregates and modulates the binding to proximal gene regulatory regions. These dynamics are altered in a patient with a mutant FOXN1 that is modified in its C-terminal sequence. This mutant is transcriptionally inactive and acts as a dominant negative factor displacing wild-type FOXN1 from condensates and causing athymia and severe lymphopenia in heterozygotes. Expression of the mutated mouse ortholog selectively impairs mouse TEC differentiation, revealing a gene dose dependency for individual TEC subtypes. We have therefore identified the cause for a primary immunodeficiency disease and determined the mechanism by which this FOXN1 gain-of-function mutant mediates its dominant negative effect
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