289 research outputs found
OCT for glaucoma diagnosis, screening and detection of glaucoma progression.
Optical coherence tomography (OCT) is a commonly used imaging modality in the evaluation of glaucomatous damage. The commercially available spectral domain (SD)-OCT offers benefits in glaucoma assessment over the earlier generation of time domain-OCT due to increased axial resolution, faster scanning speeds and has been reported to have improved reproducibility but similar diagnostic accuracy. The capabilities of SD-OCT are rapidly advancing with 3D imaging, reproducible registration, and advanced segmentation algorithms of macular and optic nerve head regions. A review of the evidence to date suggests that retinal nerve fibre layer remains the dominant parameter for glaucoma diagnosis and detection of progression while initial studies of macular and optic nerve head parameters have shown promising results. SD-OCT still currently lacks the diagnostic performance for glaucoma screening
Small and medium enterprises and economic growth in Algeria through investment and innovation
Small and medium enterprises play a vital role in ensuring the continuity and sustainability of economic development as they constitute an important starting point for economic growth, through their ability to provide job opportunities and their role in diversifying the industrial structure and assisting the main structures in production. These institutions operate at the national level and push them towards facilitating and continuity of their work, which made them of great importance in achieving development and embodiment at the national level. This study aims to highlight the role of small and medium enterprises in pushing the economies of countries towards development, through their contribution in various areas of development, as these institutions have become a strategic option and the most practical alternative to achieve balanced growth, and this can only be achieved with real support for these institutions. Small, and medium enterprises are an important element in economic development, as they are considered a major driver of the countries’ economy and a source for creating wealth and satisfying economic and social needs. They contribute to reducing the unemployment rate, raising the gross domestic product, creating an added value to the economy, and increasing the proportion of international trade exchanges. In completing our scientific research, we relied on a questionnaire distributed to small and medium-sized enterprises in the state of Oran. We also used a set of tools represented in the interview and observation. The study was based on 38 small and medium enterprises in the state of Oran. The obtained result showed the validity of the hypotheses. These institutions contribute greatly to the economic and social growth of the state, as we extracted from the obtained results. 68% of the studied sample contributes to raising the gross domestic product by 95% to creating an added value by 95℅, and 11% of the studied sample exports its products outside Algeria, This is what prompted Algeria to rely on small and medium enterprises to ensure strong economic growth, but this sector still has not risen yet to be a source of wealth and an engine for development for Algeria because there are several obstacles facing small and medium enterprises
Drug fever—an immune-mediated delayed type hypersensitivity reaction to Vinca alkaloids in pediatric oncology patients, possibly mediated by cysteinyl leukotrienes
BackgroundDrug hypersensitivity reactions are common in pediatric hemato-oncology patients due to multiple factors including immune compromise and pharmacological complexities. Fever can signify severe delayed-type hypersensitivity reactions such as drug reaction with eosinophilia and systemic symptoms (DRESS) or drug-induced hypersensitivity syndrome (DIHS). The etiology of fever as an isolated hypersensitivity reaction to chemotherapeutic agents not fully understood. Here, we report three children with intracranial neoplasms experiencing recurrent febrile reactions following Vinca alkaloid-based chemotherapy, mitigated by cysteinyl leukotriene receptor antagonist therapy.MethodsWe present a series of pediatric patients with diverse intracranial neoplasms who developed recurrent fever episodes after multiple courses of Vinca alkaloid-based chemotherapy. Treatment involved prophylactic and post-chemotherapy administration of a cysteinyl leukotriene receptor antagonist to prevent fever episodes and enable completion of chemotherapy regimens without protocol modifications or desensitization.ResultsAll three patients experienced fever consistent with delayed-type hypersensitivity reactions to Vinca alkaloids. Prophylactic use of the leukotriene antagonist Montelukast successfully prevented fever recurrence, allowing uninterrupted completion of chemotherapy courses.ConclusionOur findings suggest that Montelukast, a leukotriene antagonist, may be beneficial in managing fever as a delayed-type hypersensitivity reaction to Vinca alkaloids in pediatric patients. Further research is warranted to elucidate the underlying mechanisms and leukotriene pathways involved in drug-induced fever reactions
Properties of the Vacancy Statistic in the Discrete Circle Covering Problem
Holst (1985) introduced a discrete spacings model that is related to the Bose-Einstein distribution and obtained the distribution of the number of vacant slots in an associated circle covering problem. We correct his expression for its probability mass function, obtain the first two moments, and describe their limiting properties. We also discuss an application of our results to a study of contagion in banking networks
Prodrug converting enzyme gene delivery by L. monocytogenes
<p>Abstract</p> <p>Background</p> <p><it>Listeria monocytogenes </it>is a highly versatile bacterial carrier system for introducing protein, DNA and RNA into mammalian cells. The delivery of tumor antigens with the help of this carrier into tumor-bearing animals has been successfully carried out previously and it was recently reported that <it>L. monocytogenes </it>is able to colonize and replicate within solid tumors after local or even systemic injection.</p> <p>Methods</p> <p>Here we report on the delivery of two prodrug converting enzymes, purine-deoxynucleoside phosphorylase (PNP) and a fusion protein consisting of yeast cytosine deaminase and uracil phosphoribosyl transferase (FCU1) into cancer cells in culture by <it>L. monocytogenes</it>. Transfer of the prodrug converting enzymes was achieved by bacterium mediated transfer of eukaryotic expression plasmids or by secretion of the proteins directly into the host cell cytosol by the infecting bacteria.</p> <p>Results</p> <p>The results indicate that conversion of appropriate prodrugs to toxic drugs in the cancer cells occured after both procedures although <it>L. monocytogenes</it>-mediated bactofection proved to be more efficient than enzyme secretion 4T1, B16 and COS-1 tumor cells. Exchanging the constitutively P<sub>CMV</sub>-promoter with the melanoma specific P<sub>4xTETP</sub>-promoter resulted in melanoma cell-specific expression of the prodrug converting enzymes but reduced the efficiencies.</p> <p>Conclusion</p> <p>These experiments open the way for bacterium mediated tumor specific activation of prodrugs in live animals with tumors.</p
Lamina Cribrosa Microstructure in Nonhuman Primates With Naturally Occurring Peripapillary Retinal Nerve Fiber Layer Thinning
PURPOSE: The lamina cribrosa (LC) is hypothesized to be the site of initial axonal damage in glaucoma with the circumpapillary retinal nerve fiber layer thickness (RNFL-T) widely used as a standard metric for quantifying the glaucomatous damage. The purpose of this study was to determine in vivo, 3-dimensional (3D) differences in the microstructure of the LC in eyes of nonhuman primates (NHPs) with naturally occurring glaucoma.
METHODS: Spectral-domain optical coherence tomography (OCT) scans (Leica, Chicago, IL, USA) of the optic nerve head were acquired from a colony of 50 adult rhesus monkeys suspected of having high prevalence of glaucoma. The RNFL-T was analyzed globally and in quadrants using a semi-automated segmentation software. From a set of 100 eyes, 18 eyes with the thinnest global RNFL-T were selected as the study group and 18 eyes with RNFL-T values around the 50th percentile were used as controls. A previously described automated segmentation algorithm was used for LC microstructure analysis. Parameters included beam thickness, pore diameter and their ratio (beam-to-pore ratio [BPR]), pore area and shape parameters, beam and pore volume, and connective tissue volume fraction (CTVF; beam volume/total volume). The LC microstructure was analyzed globally and in the following volumetric sectors: quadrants, central and peripheral lamina, and three depth slabs (anterior, middle, and posterior).
RESULTS: Although no significant difference was detected between groups for age, weight, or disc size, the study group had significantly thinner RNFL than the control group (P \u3c 0.01). The study group had significantly smaller global and sectoral pore diameter and larger BPR compared with the control group. Across eyes, the global RNFL-T was associated positively with pore diameter globally. BPR and CTVF were significantly and negatively associated with the corresponding RNFL-T in the superior quadrant.
CONCLUSIONS: Global and sectoral microstructural differences were detected when comparing thin and normal RNFL-T eyes. Whether these LC differences are the cause of RNFL damage or the result of remodeling of the LC requires further investigation.
TRANSLATIONAL RELEVANCE: Our findings indicate structural alterations in the LC of NHP exhibiting natural thinning of the RNFL, a common characteristic of glaucomatous damage
Male Microchimerism at High Levels in Peripheral Blood Mononuclear Cells from Women with End Stage Renal Disease before Kidney Transplantation
Patients with end stage renal diseases (ESRD) are generally tested for donor chimerism after kidney transplantation for tolerance mechanism purposes. But, to our knowledge, no data are available on natural and/or iatrogenic microchimerism (Mc), deriving from pregnancy and/or blood transfusion, acquired prior to transplantation. In this context, we tested the prevalence of male Mc using a real time PCR assay for DYS14, a Y-chromosome specific sequence, in peripheral blood mononuclear cells (PBMC) from 55 women with ESRD, prior to their first kidney transplantation, and compared them with results from 82 healthy women. Male Mc was also quantified in 5 native kidney biopsies obtained two to four years prior to blood testing and in PBMC from 8 women collected after female kidney transplantation, several years after the initial blood testing. Women with ESRD showed statistically higher frequencies (62%) and quantities (98 genome equivalent cells per million of host cells, gEq/M) of male Mc in their PBMC than healthy women (16% and 0.3 gEq/M, p<0.00001 and p = 0.0005 respectively). Male Mc was increased in women with ESRD whether they had or not a history of male pregnancy and/or of blood transfusion. Three out of five renal biopsies obtained a few years prior to the blood test also contained Mc, but no correlation could be established between earlier Mc in a kidney and later presence in PBMC. Finally, several years after female kidney transplantation, male Mc was totally cleared from PBMC in all women tested but one. This intriguing and striking initial result of natural and iatrogenic male Mc persistence in peripheral blood from women with ESRD raises several hypotheses for the possible role of these cells in renal diseases. Further studies are needed to elucidate mechanisms of recruitment and persistence of Mc in women with ESRD
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