Neogenin May Functionally Substitute for Dcc in Chicken

Dcc is the key receptor that mediates attractive responses of axonal growth cones to netrins, a family of axon guidance cues used throughout evolution. However, a Dcc homolog has not yet been identified in the chicken genome, raising the possibility that Dcc is not present in avians. Here we show that the closely related family member neogenin may functionally substitute for Dcc in the developing chicken spinal cord. The expression pattern of chicken neogenin in the developing spinal cord is a composite of the distribution patterns of both rodent Dcc and neogenin. Moreover, whereas the loss of mouse neogenin has no effect on the trajectory of commissural axons, removing chicken neogenin by RNA interference results in a phenotype similar to the functional inactivation of Dcc in mouse. Taken together, these data suggest that the chick neogenin is functionally equivalent to rodent Dcc

Analysis of arterial intimal hyperplasia: review and hypothesis

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Despite a prodigious investment of funds, we cannot treat or prevent arteriosclerosis and restenosis, particularly its major pathology, arterial intimal hyperplasia. A cornerstone question lies behind all approaches to the disease: what causes the pathology? Hypothesis: I argue that the question itself is misplaced because it implies that intimal hyperplasia is a novel pathological phenomenon caused by new mechanisms. A simple inquiry into arterial morphology shows the opposite is true. The normal multi-layer cellular organization of the tunica intima is identical to that of diseased hyperplasia; it is the standard arterial system design in all placentals at least as large as rabbits, including humans. Formed initially as one-layer endothelium lining, this phenotype can either be maintained or differentiate into a normal multi-layer cellular lining, so striking in its resemblance to diseased hyperplasia that we have to name it "benign intimal hyperplasia". However, normal or "benign " intimal hyperplasia, although microscopically identical to pathology, is a controllable phenotype that rarely compromises blood supply. It is remarkable that each human heart has coronary arteries in which a single-layer endothelium differentiates earl

Primary photodynamic therapy with verteporfin for small pigmented posterior pole choroidal melanoma

PURPOSE: The purpose of the study was to investigate the outcomes of primary photodynamic therapy (PDT) for small pigmented posterior pole choroidal melanoma. PATIENTS AND METHODS: Prospective interventional consecutive case series of 15 patients with small pigmented posterior pole choroidal melanoma, who were treated with three sessions of PDT and followed-up thereafter. Risk factors for failure were assessed and outcome measures at presentation were compared to those at last follow-up visit. RESULTS: Tumor control was achieved in 12 (80%) patients in a median follow-up time of 15 months (mean 14, range 8-18). Three patients failed treatment, diagnosed in a median time of 5 months (mean 4, range 3-6), after first PDT. In all failed cases, lesions were 100% pigmented; de novo melanoma rather than transformed nevi and showed a radial growth pattern rather than increased thickness. All failed cases were subsequently successfully treated with radiotherapy. In this cohort, subretinal fluid (SRF) was significantly reduced (P<0.001), vision did not deteriorate (P=0.11) and even improved in patients with subfoveal SRF at presentation (P=0.018), tumor height significantly decreased (P=0.037) and no complications were recorded. CONCLUSION: Primary PDT was found to be a safe and efficient treatment modality for small pigmented posterior pole choroidal melanoma, achieving short-term tumor control in 80% of patients. PDT offers patients the opportunity to preserve vision by avoiding the retinopathy associated with conventional radiation treatments for choroidal melanoma. However, the long-term local control of these tumors remains uncertain

Functionality comparison of 3 classes of superdisintegrants in promoting aspirin tablet disintegration and dissolution

The aims of this study are (1) to compare the disintegration efficiency, and (2) to develop a discriminating test model for the 3 classes of superdisintegrants represented by Ac-Di-Sol, Primojel, and Polyplasdone XL10. Using a digital video camera to examine the disintegration process of tablets containing the same wt/wt percentage concentration of the disintegrants, Ac-Di-Sol was found to disintegrate tablets rapidly into apparently primary particles; Primojel also apparently disintegrated tablets into primary particles but more slowly; Polyplasdone XL10 disintegrated tablets rapidly but into larger masses of aggregated particles. The differences in the size distribution generated in the disintegrated tablets likely contribute to the drug dissolution rate differences found for aspirin tablets with similar disintegration rates. The aspirin tablet matrix is proposed as a model formulation for disintegrant efficiency comparison and performance consistency testing for quality control purposes

A review of central retinal artery occlusion: clinical presentation and management

Central retinal artery occlusion (CRAO) is an ophthalmic emergency and the ocular analogue of cerebral stroke. Best evidence reflects that over three-quarters of patients suffer profound acute visual loss with a visual acuity of 20/400 or worse. This results in a reduced functional capacity and quality of life. There is also an increased risk of subsequent cerebral stroke and ischaemic heart disease. There are no current guideline-endorsed therapies, although the use of tissue plasminogen activator (tPA) has been investigated in two randomized controlled trials. This review will describe the pathophysiology, epidemiology, and clinical features of CRAO, and discuss current and future treatments, including the use of tPA in further clinical trials.DD Varma, S Cugati, AW Lee, and CS Che