LNK mutations and myeloproliferative disorders

The lymphocyte adaptor protein (LNK) is one of a family of adaptor proteins involved cell signalling and control of B cell populations. It has a critical role in regulation of signalling in hematopoiesis. Lnk negatively regulates cytokine initiated cell signalling and it functions as a negative regulator of the mutant protein in myeloproliferative neoplasms JAK2V617F. A number of mutations in LNK have been described in a variety of myeloproliferative neoplasms some of which have been demonstrated to cause increased cellular proliferation. The majority of mutations occur in exon 2. In a small number of cases idiopathic erythrocytosis with subnormal erythropoietin levels LNK mutations have been found which may account for the clinical phenotype. Thus investigation for LNK mutations should be considered in the investigation of idiopathic erythrocytosis and perhaps other myeloproliferative neoplasms.

Protocol-driven adjustment of ocular hypotensive medication in patients at low risk of conversion to glaucoma

AIM: To investigate the safety and potential savings of decreasing medication use in low-risk patients with ocular hypertension (OH).
METHODS: Patients with OH receiving pressure-lowering medication identified by medical record review at a university hospital underwent examination by a glaucoma specialist with assessment of visual field (VF), vertical cup-to-disc ratio (vCDR), central corneal thickness and intraocular pressure (IOP). Subjects with estimated 5-year risk of glaucoma conversion <15% were asked to discontinue ≥1 medication, IOP was remeasured 1 month later and risk was re-evaluated at 1 year.
RESULTS: Among 212 eyes of 126 patients, 44 (20.8%) had 5-year risk >15% and 14 (6.6%) had unreliable baseline VF. At 1 month, 15 patients (29 eyes, 13.7%) defaulted follow-up or refused to discontinue medication and 11 eyes (5.2%) had risk >15%. The remaining 69 patients (107 eyes, 50.7%) successfully discontinued 141 medications and completed 1-year follow-up. Mean IOP (20.5±2.65 mm Hg vs 20.3±3.40, p=0.397) did not change, though mean VF pattern SD (1.58±0.41 dB vs 1.75±0.56 dB, p=0.001) and glaucoma conversion risk (7.31±3.74% vs 8.76±6.28%, p=0.001) increased at 1 year. Mean defect decreased (-1.42±1.60 vs -1.07±1.52, p=0.022). One eye (0.47%) developed a repeatable VF defect and 13 eyes (6.1%) had 5-year risk >15% at 1 year. The total 1-year cost of medications saved was US$4596.
CONCLUSIONS: Nearly half (43.9%) of low-risk OH eyes in this setting could safely reduce medications over 1 year, realising substantial savings.Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Calmodulin disruption impacts growth and motility in juvenile liver fluke

Background: Deficiencies in effective flukicide options and growing issues with drug resistance make current strategies for liver fluke control unsustainable, thereby promoting the need to identify and validate new control targets in Fasciola spp. parasites. Calmodulins (CaMs) are small calcium-sensing proteins with ubiquitous expression in all eukaryotic organisms and generally use fluctuations in intracellular calcium levels to modulate cell signalling events. CaMs are essential for fundamental processes including the phosphorylation of protein kinases, gene transcription, calcium transport and smooth muscle contraction. In the blood fluke Schistosoma mansoni, calmodulins have been implicated in egg hatching, miracidial transformation and larval development. Previously, CaMs have been identified amongst liver fluke excretory-secretory products and three CaM-like proteins have been characterised biochemically from adult Fasciola hepatica, although their functions remain unknown.

Methods: In this study, we set out to investigate the biological function and control target potential of F. hepatica CaMs (FhCaMs) using RNAi methodology alongside novel in vitro bioassays.

Results: Our results reveal that: (i) FhCaMs are widely expressed in parenchymal cells throughout the forebody region of juvenile fluke; (ii) significant transcriptional knockdown of FhCaM1-3 was inducible by exposure to either long (~200 nt) double stranded (ds) RNAs or 27 nt short interfering (si) RNAs, although siRNAs were less effective than long dsRNAs; (iii) transient long dsRNA exposure-induced RNA interference (RNAi) of FhCaMs triggered transcript knockdown that persisted for ≥ 21 days, and led to detectable suppression of FhCaM proteins; (iv) FhCaM RNAi significantly reduced the growth of juvenile flukes maintained in vitro; (v) FhCaM RNAi juveniles also displayed hyperactivity encompassing significantly increased migration; (vi) both the reduced growth and increased motility phenotypes were recapitulated in juvenile fluke using the CaM inhibitor trifluoperazine hydrochloride, supporting phenotype specificity.

Conclusions: These data indicate that the Ca(2+)-modulating functions of FhCaMs are important for juvenile fluke growth and movement and provide the first functional genomics-based example of a growth-defect resulting from gene silencing in liver fluke. Whilst the phenotypic impacts of FhCaM silencing on fluke behaviour do not strongly support their candidature as new flukicide targets, the growth impacts encourage further consideration, especially in light of the speed of juvenile fluke growth in vivo.

Ocular comorbidities among cataract-operated patients in rural China: the caring is hip Study of Cataract Outcomes and Uptake of Services (SCOUTS), report No. 3.

PURPOSE: To determine the prevalence and impact on vision and visual function of ocular comorbidities in a rural Chinese cataract surgical program, and to devise strategies to reduce their associated burden. DESIGN: Cross-sectional cohort study. PARTICIPANTS: Persons undergoing cataract surgery by one of two recently trained local surgeons at a government-run village-level hospital in rural Guangdong between August 8 and December 31, 2005. INTERVENTIONS: Eligible subjects were invited to return for a comprehensive ocular examination and visual function interview 10 to 14 months after surgery. Prevalent ocular comorbid conditions were identified. MAIN OUTCOME MEASURES: Presenting and best-corrected vision, visual function, and treatability of the comorbidity. RESULTS: Of 313 persons operated within the study window, 242 (77%) could be contacted by telephone; study examinations and interviews were performed on 176 (74%). Examined subjects had a mean age of 69.4+/-10.5 years, 116 (66%) were female, and 149 (85%) had been blind (presenting vision < or = 6/60) in the operative eye before surgery. Among unoperated eyes, 89 of 109 (81.7%) had > or =1 ocular comorbidities, whereas for operated eyes the corresponding proportion was 72 of 211 (34.1%). The leading comorbidity among operated eyes was refractive error (43/72 [59.7%]), followed by glaucoma/glaucoma suspect (14/72 [19.4%]), whereas for unoperated eyes, it was cataract (80/92 [87.0%]), followed by refractive error (12/92 [13.0%]). Among operated eyes with comorbidities, 90.3% (65/72) had > or =1 comorbidities that were treatable. In separate models adjusting for age and gender, persons with > or =1 comorbidities in the operated eye had significantly worse presenting vision (P<0.001) than those without such findings, but visual function (P = 0.197) and satisfaction with surgery (P = 0.796) were unassociated with comorbidities. CONCLUSIONS: Ocular comorbidities are highly prevalent among persons undergoing cataract surgery in this rural Asian setting, and their presence is significantly associated with poorer visual outcomes. The fact that the great majority of comorbidities encountered in this program are treatable suggests that strategies to reduce their impact can be successful.

Influence of corneal structure, corneal responsiveness, and other ocular parameters on tonometric measurement of intraocular pressure.

PURPOSE: To estimate the relationships between ocular parameters and tonometrically measured intraocular pressure (IOP), to determine the influence of ocular parameters on different instrument measurements of IOP, and to evaluate the association of ocular parameters with a parameter called hysteresis. METHODS: Patients presenting at a glaucoma clinic were recruited for this study. Subjects underwent IOP measurement with the Goldmann applanation tonometer (GAT), the TonoPen, and the Reichert Ocular Response Analyzer (ORA), and also measurements of central corneal thickness (CCT), axial length, corneal curvature, corneal astigmatism, central visual acuity, and refractive error. Chart information was reviewed to determine glaucoma treatment history. The ORA instrument provided a measurement called corneal hysteresis. The association between measured IOP and the other ocular characteristics was estimated using generalized estimating equations. RESULTS: Among 230 patients, IOP measurements from the TonoPen read lowest, and ORA read highest, and GAT measurements were closest to the mean IOP of the 3 instruments. In a multiple regression model adjusting for age, sex, race, and other ocular characteristics, a 10 microm increase in CCT was associated with an increase of 0.79 mm Hg measured IOP in untreated eyes (P<0.0001). Of the 3 tonometers, GAT was the least affected by CCT (0.66 mm Hg/10 mum, P<0.0001). Hysteresis was significantly correlated with CCT with a modest correlation coefficient (r=0.20, P<0.0007). CONCLUSIONS: Among parameters related to measured IOP, features in addition to CCT, such as hysteresis and corneal curvature, may also be important. Tonometric instruments seem to be affected differently by various physiologic characteristics.

Effectiveness of diode laser trans-scleral cyclophotocoagulation in patients following silicone oil-induced ocular hypertension in Chinese eyes.

We evaluated the effectiveness of diode laser trans-scleral cyclophotocoagulation (TSCPC) on intraocular pressure (IOP) in nine patients having raised IOP following use of silicone oil (SO) for retinal detachment (RD) surgery in a retrospective observational case series. Diode laser TSCPC was applied at a power setting of 1.75 to 2.5 watts, for two sec with a maximum of 30 applications. The patients were followed up for 40 to 312 weeks. The mean pre-laser IOP was 32.06 mm Hg (SD 7.32). The mean post-laser IOP at one month, three months and six months was 17.89 mm Hg (SD 8.23), 21.89 mm Hg (SD 8.16) and 21.67 mm Hg (SD 7.55) respectively. The final IOP (at the last follow-up) was 19.56 mm Hg (SD 7.85) (P=0.021). Seven of them had undergone SO removal. In our observation, effectiveness of TSCPC in long-term control of SO-induced ocular hypertension was limited as compared to short-term control of IOP.

Comparison of anterior ocular biometry between optical low-coherence reflectometry and anterior segment optical coherence tomography in an adult Chinese population.

PURPOSE: To evaluate the agreement between optical low-coherence reflectometry (OLCR) and anterior segment optical coherence tomography (AS-OCT) for biometry of the anterior segment. SETTING: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. DESIGN: Evaluation of diagnostic technology. METHODS: A series of OLCR (Lenstar LS 900) and AS-OCT measurements of the anterior segment were taken for consecutive subjects aged 35 years and older in a population-based study. The differences and correlations between the 2 methods of ocular biometry were assessed. Agreement was calculated as the 95% limits of agreement (LoA). RESULTS: The mean age of the 776 subjects was 55.2 years ± 12.0 (SD); 54.6% were women. The mean central corneal thickness (CCT) was smaller with OLCR than with AS-OCT (537.84 ± 31.46 μm versus 559.39 ± 32.02 μm) as was anterior chamber depth (ACD) (2.60 ± 0.37 mm versus 2.72 ± 0.37 mm) and anterior chamber width (ACW) (11.76 ± 0.47 mm versus 12.04 ± 0.55 mm) (all P<.001). The 95% LoA between the 2 instruments were -44.80 to 1.71 μm for CCT, -0.17 to -0.06 mm for ACD, and -1.28 to 0.72 mm for ACW. CONCLUSION: Optical low-coherence reflectometry and AS-OCT yielded potentially interchangeable ACD measurements, while the CCT and ACW measurements acquired by the 2 devices showed clinically significant differences.

Phenotype-Based Discovery of 2-[(E)-2-(Quinolin-2-yl)vinyl]phenol as a Novel Regulator of Ocular Angiogenesis

Retinal angiogenesis is tightly regulated to meet oxygenation and nutritional requirements. In diseases such as proliferative diabetic retinopathy and neovascular age-related macular degeneration, uncontrolled angiogenesis can lead to blindness. Our goal is to better understand the molecular processes controlling retinal angiogenesis and discover novel drugs that inhibit retinal neovascularization. Phenotype-based chemical screens were performed using the ChemBridge Diverset^TM library and inhibition of hyaloid vessel angiogenesis in Tg(fli1:EGFP) zebrafish. 2-[(E)-2-(Quinolin-2-yl)vinyl]phenol, (quininib) robustly inhibits developmental angiogenesis at 4–10 μM in zebrafish and significantly inhibits angiogenic tubule formation in HMEC-1 cells, angiogenic sprouting in aortic ring explants, and retinal revascularization in oxygen-induced retinopathy mice. Quininib is well tolerated in zebrafish, human cell lines, and murine eyes. Profiling screens of 153 angiogenic and inflammatory targets revealed that quininib does not directly target VEGF receptors but antagonizes cysteinyl leukotriene receptors 1 and 2 (CysLT_1–2) at micromolar IC₅₀ values. In summary, quininib is a novel anti-angiogenic small-molecule CysLT receptor antagonist. Quininib inhibits angiogenesis in a range of cell and tissue systems, revealing novel physiological roles for CysLT signaling. Quininib has potential as a novel therapeutic agent to treat ocular neovascular pathologies and may complement current anti-VEGF biological agents.

Evaluation of Restorative Dentistry Specialty Registrars’ Clinical Experience of Developmental Disorders: A Survey

Background

Specialty Registrars in Restorative Dentistry (StRs) should be competent in the independent restorative management of patients with developmental disorders including hypodontia and cleft lip/palate upon completion of their specialist training.1 Knowledge and management may be assessed via the Intercollegiate Specialty Fellowship Examination (ISFE) in Restorative Dentistry.2

Objective

The aim of this study was to collate and compare data on the training and experience of StRs in the management of patients with developmental disorders across different training units within the British Isles.

Methods

Questionnaires were distributed to all StRs attending the Annual General Meeting of the Specialty Registrars in Restorative Dentistry Group, Belfast, in October 2015. Participants were asked to rate their confidence and experience of assessing and planning treatment for patients with developmental disorders, construction of appropriate prostheses, and provision of dental implants. Respondents were also asked to record clinical supervision and didactic teaching at their unit, and to rate their confidence of passing a future ISFE station assessing knowledge of developmental disorders.

Results

Responses were obtained from 32 StRs (n=32) training within all five countries of the British Isles. The majority of respondents were based in England (72%) with three in Wales, and two in each of Scotland, Northern Ireland, and the Republic of Ireland. Approximately one third of respondents (34%) were in the final years of training (years 4-6). Almost half of the StRs reported that they were not confident of independently assessing (44%) new patients with a developmental disorder, with larger numbers (72%) indicating a lack of confidence in treatment planning. Six respondents rated their experience of treating obturator patients as ‘poor’ or ‘very poor’. The majority (56%) rated their experience of implant provision in these cases as ‘good’ or ‘excellent’ with three-quarters (75%) rating clinical supervision at their unit as ‘good’ or ‘excellent’. Less than half (41%) rated the didactic teaching at their unit as ‘good’ or ‘excellent’, and only 8 StRs indicated that they were confident of passing an ISFE station focused on developmental disorders.

Conclusion

Experience and training regarding patients with developmental disorders is inconsistent for StRs across the British Isles with a number of trainees reporting a lack of clinical exposure.

Monitoring ocular hypertension, how much and how often? A cost-effectiveness perspective

OBJECTIVE: To assess the efficiency of alternative monitoring services for people with ocular hypertension (OHT), a glaucoma risk factor.

DESIGN: Discrete event simulation model comparing five alternative care pathways: treatment at OHT diagnosis with minimal monitoring; biennial monitoring (primary and secondary care) with treatment if baseline predicted 5-year glaucoma risk is ≥6%; monitoring and treatment aligned to National Institute for Health and Care Excellence (NICE) glaucoma guidance (conservative and intensive).

SETTING: UK health services perspective.

PARTICIPANTS: Simulated cohort of 10 000 adults with OHT (mean intraocular pressure (IOP) 24.9 mm Hg (SD 2.4).

MAIN OUTCOME MEASURES: Costs, glaucoma detected, quality-adjusted life years (QALYs).

RESULTS: Treating at diagnosis was the least costly and least effective in avoiding glaucoma and progression. Intensive monitoring following NICE guidance was the most costly and effective. However, considering a wider cost-utility perspective, biennial monitoring was less costly and provided more QALYs than NICE pathways, but was unlikely to be cost-effective compared with treating at diagnosis (£86 717 per additional QALY gained). The findings were robust to risk thresholds for initiating monitoring but were sensitive to treatment threshold, National Health Service costs and treatment adherence.

CONCLUSIONS: For confirmed OHT, glaucoma monitoring more frequently than every 2 years is unlikely to be efficient. Primary treatment and minimal monitoring (assessing treatment responsiveness (IOP)) could be considered; however, further data to refine glaucoma risk prediction models and value patient preferences for treatment are needed. Consideration to innovative and affordable service redesign focused on treatment responsiveness rather than more glaucoma testing is recommended.