53 research outputs found

    QUIET PLEASE! Effect of distraction on simulated posterior segment surgical performance

    Get PDF
    Purpose To determine the effect of distraction on posterior segment surgical performance using a virtual reality simulator in expert and novice ophthalmic surgeons. Methods Twenty subjects were given six minutes to read an unpublished research paper and then randomized into two groups. Group 1 subjects were allowed three minutes to complete a standardized vitreoretinal simulated task undistracted. Group 2 subjects were asked six questions on the research paper whilst completing the same task. Each subject then performed the alternate scenario. Finally, all participants were asked six questions on the research paper whilst not operating. Results There was no evidence of a difference in the odometer values (p=0.127), cognitive task score (p=0.390) or overall surgical task scores (p=0.113) between the two groups. The time taken by the distracted group was significantly greater (95% CI -26.03 to -1.67, t-test p=0.028). Conclusion Distraction significantly increases the time taken to perform a simulated vitreoretinal surgical task for all grades of surgeon. More studies are required to understand the impact on different types of distraction on surgical performance

    Pancreas-derived mesenchymal stromal cells share immune response-modulating and angiogenic potential with bone marrow mesenchymal stromal cells and can be grown to therapeutic scale under GMP conditions

    Get PDF
    Background aims: Mesenchymal stromal cells (MSCs) isolated from various tissues are under investigation as cellular therapeutics in a wide range of diseases. It is appreciated that the basic biological functions of MSCs vary depending on tissue source. However, in-depth comparative analyses between MSCs isolated from different tissue sources under Good Manufacturing Practice (GMP) conditions are lacking. Human clinical-grade low-purity islet (LPI) fractions are generated as a byproduct of islet isolation for transplantation. MSC isolates were derived from LPI fractions with the aim of performing a systematic, standardized comparative analysis of these cells with clinically relevant bone marrow-derived MSCs (BM MSCs). Methods: MSC isolates were derived from LPI fractions and expanded in platelet lysate-supplemented medium or in commercially available xenogeneic-free medium. Doubling rate, phenotype, differentiation potential, gene expression, protein production and immunomodulatory capacity of LPIs were compared with those of BM MSCs. Results: MSCs can be readily derived in vitro from non-transplanted fractions resulting from islet cell processing (i.e., LPI MSCs). LPI MSCs grow stably in serum-free or platelet lysate-supplemented media and demonstrate in vitro self-renewal, as measured by colony-forming unit assay. LPI MSCs express patterns of chemokines and pro-regenerative factors similar to those of BM MSCs and, importantly, are equally able to attract immune cells in vitro and in vivo and suppress T-cell proliferation in vitro. Additionally, LPI MSCs can be expanded to therapeutically relevant doses at low passage under GMP conditions. Conclusions: LPI MSCs represent an alternative source of GMP MSCs with functions comparable to BM MSCs

    Human umbilical cord perivascular cells improve human pancreatic islet transplant function by increasing vascularization

    Get PDF
    Islet transplantation is an efficacious therapy for type 1 diabetes; however, islets from multiple donor pancreata are required, and a gradual attrition in transplant function is seen. Here, we manufactured human umbilical cord perivascular mesenchymal stromal cells (HUCPVCs) to Good Manufacturing Practice (GMP) standards. HUCPVCs showed a stable phenotype while undergoing rapid ex vivo expansion at passage 2 (p2) to passage 4 (p4) and produced proregenerative factors, strongly suppressing T cell responses in the resting state and in response to inflammation. Transplanting an islet equivalent (IEQ):HUCPVC ratio of 1:30 under the kidney capsule in diabetic NSG mice demonstrated the fastest return to normoglycemia by 3 days after transplant: Superior glycemic control was seen at both early (2.7 weeks) and later stages (7, 12, and 16 weeks) versus ratios of 1:0, 1:10, and 1:50, respectively. Syngeneic islet transplantation in immunocompetent mice using the clinically relevant hepatic portal route with a marginal islet mass showed that mice transplanted with an IEQ:HUCPVC ratio of 1:150 had superior glycemic control versus ratios of 1:0, 1:90, and 1:210 up to 6 weeks after transplant. Immunodeficient mice transplanted with human islets (IEQ:HUCPVC ratio of 1:150) exhibited better glycemic control for 7 weeks after transplant versus islet transplant alone, and islets transplanted via the hepatic portal vein in an allogeneic mouse model using a curative islet mass demonstrated delayed rejection of islets when cotransplanted with HUCPVCs (IEQ:HUCPVC ratio of 1:150). The immunosuppressive and proregenerative properties of HUCPVCs demonstrated long-term positive effects on graft function in vivo, indicating that they may improve long-term human islet allotransplantation outcomes

    Incidence of submacular haemorrhage (SMH) in Scotland : a Scottish Ophthalmic Surveillance Unit (SOSU) study

    Get PDF
    PURPOSE: Submacular haemorrhage (SMH) is a cause of severe visual loss in neovascular age-related macular degeneration (nAMD). The incidence is uncertain and furthermore there is no widely used classification system nor agreed best practice. The aim of this national surveillance study was to identify the incidence, presenting features and clinical course of new fovea-involving submacular haemorrhage associated with nAMD. METHODS: A questionnaire was sent monthly to every ophthalmic specialist in Scotland over a 12-month period asking them to report all newly presenting patients with acute SMH secondary to nAMD of at least two disc diameters (DDs) in greatest linear diameter. A follow-up questionnaire was sent 6 months after initial presentation. Cases related to other causes were excluded. RESULTS: Twenty-nine cases were reported giving an incidence of 5.4 per million per annum (range 2-15). The mean age was 83 years (range 66-96) and females accounted for 17/29 (59%). Fifteen of the 29 cases (52%) had a past history of AMD, of which 7 had nAMD. Nineteen of the 29 cases (66%) presented within 7 days of onset and the majority had SMH of < 11 DD (20/29, 69%). Treatment options comprised the following: observation (n = 6, 21%), anti-VEGF alone (n = 6, 21%) or vitrectomy with co-application of tissue plasminogen activator (TPA), anti-VEGF and gas (n = 17, 58%). The vitrectomy group experienced the greatest change in vision from logMAR 1.89-1.50 (p = 0.374). Four of 20 (20%) cases with 6 months follow-up suffered a re-bleed at a mean time of 96 days. CONCLUSIONS: The incidence, clinical features and course of a consecutive national cohort of patients with SMH secondary to nAMD are presented

    A description of new albanerpetontid material from the Mesozoic of Europe and its bearing on the systematic position of the group

    Get PDF
    The Albanerpetontidae are a group of salamander-like, fossil amphibians, known from deposits of Middle Jurassic to Miocene age, in Europe, North America and Central Asia. This work presents a detailed description of new albanerpetontid material, consisting of two new articulated albanerpetontid specimens from the Lower Cretaceous of Las Hoyas, Cuenca, Spain, and of dissociated skull and postcranial remains from the Middle Jurassic (Bathonian) of Kirtlington, Oxfordshire and the Early Cretaceous (Berriasian) of Purbeck, Dorset, both England. It also describes in detail Albanerpeton megacephalus from the Early Cretaceous (Albian) of Pietraroia, Italy. Reexamination of the atlas and trunk vertebrae of Prosiren elinorae and a comparison with the albanerpetontid material from Kirtlington indicates that albanerpetontids should not be included in the family Prosirenidae. Similarly, consideration of Fox & Naylor's 13 supposedly diagnostic character states of their new Order Allocaudata casts doubts on its validity. A theory is advanced to account for the development of the unique 'atlas-axis' complex of albanerpetontids based on current theories of tetrapod vertebral resegmentation. An examination of Albanerpeton inexpectatum material from the Miocene of La Grive-Saint-Alban, France and modern plethodontid salamanders, to check for intraspecific variation, casts doubt on the validity of several albanerpetontid species but features of the frontal suggest that more than one genus may be represented. A comparison of albanerpetontid character states with Palaeozoic and Recent amphibians was undertaken to help clarify the phylogenetic position of albanerpetontids. An hypothesis is put forward for the phylogenetic position of albanerpetontids as sister-taxon of frogs and salamanders (+ or - caecilians)

    Obesity and Insulin Resistance Are the Main Determinants of Postprandial Lipoprotein Dysmetabolism in Polycystic Ovary Syndrome

    No full text
    Postprandial dyslipidaemia may be a plausible mechanism by which polycystic ovary syndrome (PCOS) increases cardiovascular risk. We sought to investigate whether the postprandial glucose and insulin and lipid and lipoprotein responses, including that of apolipoprotein B-48 (apoB-48) containing chylomicrons, to a mixed meal are different in obese PCOS women when compared to obese control subjects and whether differences, if any, are related to obesity, insulin resistance (IR), hyperandrogenaemia, or PCOS status. 26 women with PCOS (age 30.4±1.2 years (mean ± SEM), body mass index (BMI) 36.8±1.5 kg/m2) and 26 non-PCOS subjects (age 34.1±0.9 years, BMI 31.5±1.0 kg/m2) were studied before and up to 8 hours following a standard mixed meal. AUC-triglyceride (AUC-TG) was higher and AUC-high-density lipoprotein (AUC-HDL) lower in PCOS women. These differences were not apparent when BMI was accounted for. Insulin sensitivity (SI), AUC-apoB-48, and AUC-apolipoprotein B (AUC-apoB) were found to be independent predictors of AUC-TG, accounting for 55% of the variance. Only AUC-insulin remained significantly elevated following adjustment for BMI. Obesity related IR explains postprandial hypertriglyceridaemia and hyperinsulinaemic responses. Management of obesity in premenopausal women with PCOS is likely to reduce their cardiovascular risk burden
    • …
    corecore