Automatic cone photoreceptor segmentation using graph theory and dynamic programming

Geometrical analysis of the photoreceptor mosaic can reveal subclinical ocular pathologies. In this paper, we describe a fully automatic algorithm to identify and segment photoreceptors in adaptive optics ophthalmoscope images of the photoreceptor mosaic. This method is an extension of our previously described closed contour segmentation framework based on graph theory and dynamic programming (GTDP). We validated the performance of the proposed algorithm by comparing it to the state-of-the-art technique on a large data set consisting of over 200,000 cones and posted the results online. We found that the GTDP method achieved a higher detection rate, decreasing the cone miss rate by over a factor of five.OCIS codes: (100.0100) Image processing, (170.4470) Ophthalmology, (110.1080) Active or adaptive optics     

Discussion of the “Executive Summary of the PhRMA Working Group on Adaptive Designs in Clinical Drug Development”

The problem of evaluating the long-term effects of recombinant human deoxyribonuclease (rhDNase) on forced expiratory volume in one second (FEV₁) in cystic fibrosis (CF) patients was considered. A two-stage mixed effects model, incorporating relevant predictive variables, captured the diverse patterns of decline of FEV₁ for patients with different demographic characteristics. Based on the results of modeling the dropout process, it is clear that the probability of early dropout was closely related to patient's responsiveness to rhDNase treatment. Failure to consider the existence of informative censoring severely biased the estimates of the rate of decline and affected the interpretation of the results.     

Combined BRAFV600E- and SRC-inhibition induces apoptosis,evokes an immune response and reduces tumor growth in an immunocompetent orthotopic mouse model of anaplastic thyroid cancer

Anaplastic (ATC) and refractory papillary thyroid cancer (PTC) lack effective treatments. Inhibition of either oncogenic BRAF or SRC has marked anti-tumor effects in mouse models of thyroid cancer, however, neither drug induces notable apoptosis. Here we report that the SRC-inhibitor dasatinib further sensitizes BRAF^V600E-positive thyroid cancer cells to the BRAF^V600E-inhibitor PLX4720. Combined treatment with PLX4720 and dasatinib synergistically inhibited proliferation and reduced migration in PTC and ATC cells. Whereas PLX4720 did not induce robust apoptosis in thyroid cancer cells, combined treatment with dasatinib induced apoptosis in 4 of 6 lines. In an immunocompetent orthotopic mouse model of ATC, combined PLX4720 and dasatinib treatment significantly reduced tumor volume relative to PLX4720 treatment alone. Immune cell infiltration was increased by PLX4720 treatment and this effect was maintained in mice treated with both PLX4720 and dasatinib. Further, combined treatment significantly increased caspase 3 cleavage in vivo relative to control or either treatment alone. In conclusion, combined PLX4720 and dasatinib treatment induces apoptosis, increases immune cell infiltration and reduces tumor volume in a preclinical model of ATC, suggesting that the combination of these FDA-approved drugs may have potential for the treatment of patients with ATC or refractory PTC.     

Influence of Caudovirales Phages on Humoral Immunity in Mice

Bacteriophages are promising antibacterial agents. Although they have been recognized as bacterial viruses and are considered to be non-interacting with eukaryotic cells, there is growing evidence that phages may have a significant impact on the immune system via interactions with macrophages, neutrophils, and T-cell polarization. In this study, the influence of phages of podovirus, siphovirus, and myovirus morphotypes on humoral immunity of CD-1 mice was investigated. In addition, tissue distribution of the phages was tested in these mice. No common patterns were found either in the distribution of phages in mice or in changes in the levels of cytokines in the sera of mice once injected with phages. Importantly, pre-existing IgM-class antibodies directed against capsid proteins of phages with myovirus and siphovirus morphotypes were identified in mice before immunization. After triple immunization of CD1-mice with phages without any adjuvant, levels of anti-phage serum polyclonal IgG antibodies increased. Immunogenic phage proteins recognized by IgM and/or IgG antibodies were identified using Western blot analysis and mass spectrometry. In addition, mice serum collected after immunization demonstrated neutralizing properties, leading to a substantial decrease in infectivity of investigated phages with myovirus and siphovirus morphotypes. Moreover, serum samples collected before administration of these phages exhibited some ability to reduce the phage infectivity. Furthermore, Proteus phage PM16 with podovirus morphotype did not elicit IgM or IgG antibodies in immunized mice, and no neutralizing activities against PM16 were revealed in mouse serum samples before and after immunization.     

Recurrent urinary tract infection and urinary Escherichia coli in women ingesting cranberry juice daily: a randomized controlled trial

ObjectiveTo compare the time to urinary tract infection (UTI) and the rates of asymptomatic bacteriuria and urinary P-fimbriated Escherichia coli during a 6-month period in women ingesting cranberry vs placebo juice daily.Patients and MethodsPremenopausal women with a history of recent UTI were enrolled from November 16, 2005, through December 31, 2008, at 2 centers and randomized to 1 of 3 arms: 4 oz of cranberry juice daily, 8 oz of cranberry juice daily, or placebo juice. Time to UTI (symptoms plus pyuria) was the main outcome. Asymptomatic bacteriuria, adherence, and adverse effects were assessed at monthly visits.ResultsA total of 176 participants were randomized (120 to cranberry juice and 56 to placebo) and followed up for a median of 168 days. The cumulative rate of UTI was 0.29 in the cranberry juice group and 0.37 in the placebo group (P=.82). The adjusted hazard ratio for UTI in the cranberry juice group vs the placebo group was 0.68 (95% confidence interval, 0.33-1.39; P=.29). The proportion of women with P-fimbriated urinary E coli isolates during the intervention phase was 10 of 23 (43.5%) in the cranberry juice group and 8 of 10 (80.0%) in the placebo group (P=.07). The mean dose adherence was 91.8% and 90.3% in the cranberry juice group vs the placebo group. Minor adverse effects were reported by 24.2% of those in the cranberry juice group and 12.5% in the placebo group (P=.07).ConclusionCranberry juice did not significantly reduce UTI risk compared with placebo. The potential protective effect we observed is consistent with previous studies and warrants confirmation in larger, well-powered studies of women with recurrent UTI. The concurrent reduction in urinary P-fimbriated E coli strains supports the biological plausibility of cranberry activity.Trial Registrationclinicaltrials.gov Identifier: NCT00128128     

Graphene Network Organisation in Conductive Polymer Composites

A latex technique is used to prepare graphene/polystyrene and graphene/poly(propylene) composites with varying GR loadings. Their electrical properties and the corresponding volume organisation of GR networks are studied. Percolation thresholds for conduction are found to be about 0.9 and 0.4 wt% for GR/PS and GR/PP with maximum obtained conductivities of 12 and 0.4 S m^?1 for GR loadings of 2 wt%, respectively. Investigations using SEM and electrical conductivity measurements show that for the preparation conditions used GR forms an isotropic 3D network in the PS matrix, but GR forms a 2D network in the PP matrix. The different GR network organisations are possibly forced by the different melt flow behaviour of the matrix polymers during processing and the subsequent crystallisation of PP.     

MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb study

Most elderly patients admitted for hip fracture suffer functional decline. Previous studies with MK-0677 in hip fracture patients suggested possible benefits to functional recovery. This is a randomized, double-blind study of 123 elderly hip fracture patients assigned to receive 25 mg/day of MK-0677 (n = 62) or placebo (n = 61). Primary outcomes were a rank analysis of change during the study in objective functional performance measurements and insulin-like growth factor-1 (IGF-1) levels in blood. At 24-weeks, the mean stair climbing power increased by 12.5 W in the MK-0677 group (95% confidence interval (CI) = −10.95-35.88; p = 0.292) compared with placebo. Gait speed increased by a 0.7-score difference in the means (95% CI = 0.17-1.28; p = 0.011). There was no improvement in MK-0677 treated patients in several other functional performance measures. The MK-0677 group experienced fewer falls during the study compared to placebo and smaller number of patients who had any falls (p = 0.096). Levels of IGF-1 in treated patients increased by 51.4 ng/ml (95% CI = 34.42-68.44; p < 0.001) compared to placebo. Trial was terminated early due to a safety signal of congestive heart failure in a limited number of patients. In hip fracture patients treated with 25 mg/day MK-0677, the increase in plasma IGF-1 levels was not paralleled by improvement in most functional performance measures. MK-0677 has an unfavorable safety profile in this patient population.     

Celecoxib delays cognitive decline in an animal model of neurodegeneration

Cyclooxygenase-2 (COX-2) is thought to play a role in the pathogenesis of various neurodegenerative disorders. However, clinical trials with COX-2 inhibitors have yielded contradictory results. In the present study we investigated whether COX-2 plays a role in the behavioral and cognitive impairments seen in olfactory bulbectomized rats. These impairments arise from neurodegenerative processes. First, we determined the time course of the OBX-induced behavioral (hyperactivity) and cognitive changes (fear memory) and how these correlate with changes in COX-2 mRNA expression in hippocampus. This experiment showed that the major impairments in behavior and cognition developed between Days 3 and 14 after OBX surgery, which correlated with changes in mRNA levels of COX-2, which increased at Days 7 and 14 after surgery but not anymore at day 28. In a subsequent experiment, rats were treated, starting two days before surgery, with the COX-2 inhibitor celecoxib (10mg/kg, dissolved in drinking water) for 4 weeks. OBX-induced hyperactivity in the open field was normalized after 2 weeks of celecoxib treatment, but not longer after 4 weeks. Celecoxib partly rescued fear learning and memory deficits without affecting spatial memory. The effects of celecoxib on fear memory lasted up to 1 week posttreatment, but disappeared thereafter. Our results show that COX-2 plays a limited role (both in magnitude and time) in the development of the OBX syndrome.     

Delayed cerebral ischemia and spreading depolarization in absence of angiographic vasospasm after subarachnoid hemorrhage

It has been hypothesized that vasospasm is the prime mechanism of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). Recently, it was found that clusters of spreading depolarizations (SDs) are associated with DCI. Surgical placement of nicardipine prolonged-release implants (NPRIs) was shown to strongly attenuate vasospasm. In the present study, we tested whether SDs and DCI are abolished when vasospasm is reduced or abolished by NPRIs. After aneurysm clipping, 10 NPRIs were placed next to the proximal intracranial vessels. The SDs were recorded using a subdural electrode strip. Proximal vasospasm was assessed by digital subtraction angiography (DSA). 534 SDs were recorded in 10 of 13 patients (77%). Digital subtraction angiography revealed no vasospasm in 8 of 13 patients (62%) and only mild or moderate vasospasm in the remaining. Five patients developed DCI associated with clusters of SD despite the absence of angiographic vasospasm in three of those patients. The number of SDs correlated significantly with the development of DCI. This may explain why reduction of angiographic vasospasm alone has not been sufficient to improve outcome in some clinical studies.