323 research outputs found

    Customized Corneal Cross-Linking-A Mathematical Model

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    Purpose: To improve the safety, reproducibility, and depth of effect of corneal cross-linking with the ultraviolet A (UV-A) exposure time and fluence customized according to the corneal thickness. Methods: Twelve human corneas were used for the experimental protocol. They were soaked using a transepithelial (EPI-ON) technique using riboflavin with the permeation enhancer vitamin E-tocopheryl polyethylene glycol succinate. The corneas were then placed on microscope slides and irradiated at 3 mW/cm2 for 30 minutes. The UV-A output parameters were measured to build a new equation describing the time-dependent loss of endothelial protection induced by riboflavin during cross-linking, as well as a pachymetry-dependent and exposure time-dependent prescription for input UV-A fluence. The proposed equation was used to establish graphs prescribing the maximum UV-A fluence input versus exposure time that always maintains corneal endothelium exposure below toxicity limits. Results: Analysis modifying the Lambert-Beer law for riboflavin oxidation leads to graphs of the maximum safe level of UV-A radiation fluence versus the time applied and thickness of the treated cornea. These graphs prescribe UV-A fluence levels below 1.8 mW/cm2 for corneas of thickness 540 [mu]m down to 1.2 mW/cm2 for corneas of thickness 350 [mu]m. Irradiation times are typically below 15 minutes. Conclusions: The experimental and mathematical analyses establish the basis for graphs that prescribe maximum safe fluence and UV-A exposure time for corneas of different thicknesses. Because this clinically tested protocol specifies a corneal surface clear of shielding riboflavin on the corneal surface during UV-A irradiation, it allows for shorter UV-A irradiation time and lower fluence than in the Dresden protocol

    Dehydroepiandrosterone modulates endothelial nitric oxide synthesis via direct genomic and nongenomic mechanisms.

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    Abstract Dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are the major circulating steroid hormones in humans, and their levels progressively decline with age. Epidemiological studies suggest that DHEA/DHEAS concentrations may be inversely related to cardiovascular risk, but disagreement exists on this issue. Preliminary studies show that DHEA regulates vascular function, but few data have been published on the mechanisms. We show that DHEA administration to human endothelial cells triggers nitric oxide synthesis, due to enhanced expression and stabilization of endothelial nitric oxide synthase (eNOS). Additionally, DHEA rapidly activates eNOS, through a nontranscriptional mechanism that depends on ERK1/2 MAPK, but not on phosphatidylinositol 3-kinase/Akt. DHEA is not converted to estrogens or androgens by endothelial cells, and its genomic and nongenomic effects are not blocked by antagonists of the estrogen, progesterone, glucocorticoid, or androgen receptors, suggesting that DHEA acts through a specific receptor. Oral DHEA administration to ovariectomized Wistar rats dose-dependently restores aortic eNOS levels and eNOS activity, confirming the effects of DHEA in vivo. Our present data suggest that DHEA may have direct genomic and nongenomic effects on the vascular wall that are not mediated by other steroid hormone receptors, leading to eNOS activation and induction

    Exploring Tablet Interfaces for Product Appearance Authoring in Spatial Augmented Reality

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    Users acceptance of innovative product appearance authoring tools based on Spatial Augmented Reality (SAR) is still limited due to their perception of a high technology complexity and a low performance/functionality of the current interaction systems. The integration of SAR technologies in professional design activities is still marginal, though many studies in this field have already proved their potential as supporting tools. To overcome this barrier, efficient means for interacting with the digital images projected onto the surfaces of real objects are essential. The aim of the current study is to respond to this demand by proposing and validating three UI configurations displayed by an unique and portable device embedded with a touch screen. These interface layouts, designed to cooperate with the output of the SAR system and to not affect the well-known benefits of its augmented environment, provide different types of visual feedback to the user by duplicating, extending or hiding the information already displayed by the projected mock-up. The experimental study reported here, performed with a panel of 41 subjects, revealed that accuracy, efficiency and perceived usability of the proposed solutions are comparable with each other and in comparison to standard desktop setups commonly used for design activities. According to these findings, the research simultaneously demonstrates (i) the high performances achieved by the touch device when coupled with a SAR system during the execution of authoring tasks, (ii) the capability of the projected mock-up to behave as an actual three-dimensional display for the real time rendering of the product appearance and (iii) the possibility to freely select - according to the users preference, the design task or the type of product - one of the three UI configurations without affecting the quality of the result.</p

    Acute inflammatory response in the subcutaneous versus periprosthethic space after incisional hernia repair: an original article

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    BACKGROUND: The acute inflammatory response following mesh implantation has been often evaluated in vitro and in animal models. The aim of this study was to evaluate the acute inflammatory response near the prosthesis in human by analysing some inflammatory indicators.METHODS: We used a cohort of twelve male patients affected by midline incisional hernia, who were admitted for surgical mesh repair. A suction drain was placed between the mesh and rectal muscles whereas, the other one was placed between the subcutaneous tissue and the oblique external sheath. The acute inflammatory response was analyzed by measuring the production of interleukin [IL]-1, IL-10, IL-1ra, C-Reactive Protein (CRP), total proteins, albumin and pH in the drain fluids.RESULTS: The dynamics of CRP and ILs production resulted similar in both drainages. Comparing drain over mesh and subcutaneous drain at all times, IL-1 and CRP values always resulted significantly higher in the first one, whereas IL-1ra and IL-10 values were significantly higher in the last one. Total protein and albumin were similar in both drains at all time; only in the drain over mesh fluid, pH values resulted significantly reduced in the fourth post-operative day.CONCLUSIONS: Our data showed that an acute inflammatory reaction is present in both sites examined. However, it was significantly higher in the space after mesh implantation

    Concomitant Small Cell Neuroendocrine Carcinoma of Gallbladder and Breast Cancer

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    The neuroendocrine carcinoma is defined as a high-grade malignant neuroendocrine neoplasm arising from enterochromaffin cells, usually disposed in the mucosa of gastric and respiratory tracts. The localization in the gallbladder is rare. Knowledge of these gallbladder tumors is limited and based on isolated case reports. We describe a case of an incidental finding of small cell neuroendocrine carcinoma of the gallbladder, observed after cholecystectomy for cholelithiasis, in a 55-year-old female, who already underwent quadrantectomy and sentinel lymph-node biopsy for breast cancer. The patient underwent radiotherapy for breast cancer and six cycles of chemotherapy with cisplatin and etoposide. Eighteen months after surgery, the patient was free from disease. Small cell neuroendocrine carcinoma of the gallbladder has poor prognosis. Because of the rarity of the reported cases, specific prognostic factors have not been identified. The coexistence of small cell neuroendocrine carcinoma of the gallbladder with another malignancy has been reported only once.The contemporary presence of the two neoplasms could reflect that bioactive agents secreted by carcinoid can promote phenotypic changes in susceptible cells and induce neoplastic transformation

    Serum Levels of Soluble IL-2R, CD4 and CD8 in Chronic Active HCV Positive Hepatitis

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    The aim of the present study was to compare serum levels of soluble forms of interleukin-2 receptor, CD4 and CD8, released by lymphocytes during activation ofthe immune system, in patients with histologically verified chronic active hepatitis associated to hepatitis C virus infection, with those in healthy subjects. Significantly higher levels of soluble IL-2R and soluble CD8 were found in patients with chronic active hepatitis compared with controls. In contrast no difference was found for soluble CD4 values in the two groups. No correlations were found for both sIL-2R and sCD8 and these two molecules with other parameters of liver function. These results indicate that in these patients there is a general activation of the immune system, but the lack of correlation with parameters of liver function strengthens the suggestion that this activation does not play a role in the pathogenesis of chronic type C hepatitis

    Thrombotic complications in adult patients with lymphoma: A meta-analysis of 29 independent cohorts including 18 018 patients and 1149 events

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    Thrombotic complications in hematologic malignancies have important clinical implications. In this meta-analysis we sought to obtain accurate estimates of the thrombotic risk in lymphoma patients. Articles were searched in electronic databases and references. Eighteen articles were identified (29 cohorts, 18 018 patients and 1149 events). Pooled incidence rates (IRs) were calculated by the use of a method based on the exact maximum likelihood binomial distribution. The global IR of thrombosis was 6.4% (95% confidence interval [CI] 6.0%-6.8%). The global IRs of venous or arterial events were 5.3% (95% CI, 5.0%-5.7%) and 1.1% (95% CI, 0.9%-1.2%), respectively. The IR of thrombosis observed in subjects with non-Hodgkin lymphoma (NHL) was 6.5% (95% CI, 6.1%-6.9%), significantly greater than that observed for patients with Hodgkin lymphoma (4.7%; 95% CI, 3.9%-5.6%). Within NHL, patients with high-grade disease had a greater risk of events (IR 8.3%; 95% CI, 7.0%-9.9%) than low-grade disease (IR 6.3%; 95% CI, 4.5%-8.9%). This meta-analysis shows that the IR of thrombosis in lymphoma patients is quite high, especially in those with NHL at an advanced stage of the disease. These results may help better defining lymphoma populations at high thrombotic risk, to whom prophylactic approaches could be preferentially applied.Fil: Caruso, Vanesa. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Di Castelnuovo, Augusto. Università Cattolica del Sacro Cuore; ItaliaFil: Meschengieser, Susana. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Lazzari, María Ángela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: De Gaetano, Giovanni. Università Cattolica del Sacro Cuore; ItaliaFil: Storti, Sergio. Università Cattolica del Sacro Cuore; ItaliaFil: Iacoviello, Licia. Università Cattolica del Sacro Cuore; ItaliaFil: Donati, Maria Benedetta. Università Cattolica del Sacro Cuore; Itali

    Comparative transcriptome analysis of stylar canal cells identifies novel candidate genes implicated in the self-incompatibility response of Citrus clementina

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    <p>Abstract</p> <p>Background</p> <p>Reproductive biology in citrus is still poorly understood. Although in recent years several efforts have been made to study pollen-pistil interaction and self-incompatibility, little information is available about the molecular mechanisms regulating these processes. Here we report the identification of candidate genes involved in pollen-pistil interaction and self-incompatibility in clementine (<it>Citrus clementina </it>Hort. ex Tan.). These genes have been identified comparing the transcriptomes of laser-microdissected stylar canal cells (SCC) isolated from two genotypes differing for self-incompatibility response ('Comune', a self-incompatible cultivar and 'Monreal', a self- compatible mutation of 'Comune').</p> <p>Results</p> <p>The transcriptome profiling of SCC indicated that the differential regulation of few specific, mostly uncharacterized transcripts is associated with the breakdown of self-incompatibility in 'Monreal'. Among them, a novel F-box gene showed a drastic up-regulation both in laser microdissected stylar canal cells and in self-pollinated whole styles with stigmas of 'Comune' in concomitance with the arrest of pollen tube growth. Moreover, we identify a non-characterized gene family as closely associated to the self-incompatibility genetic program activated in 'Comune'. Three different aspartic-acid rich (Asp-rich) protein genes, located in tandem in the clementine genome, were over-represented in the transcriptome of 'Comune'. These genes are tightly linked to a DELLA gene, previously found to be up-regulated in the self-incompatible genotype during pollen-pistil interaction.</p> <p>Conclusion</p> <p>The highly specific transcriptome survey of the stylar canal cells identified novel genes which have not been previously associated with self-pollen rejection in citrus and in other plant species. Bioinformatic and transcriptional analyses suggested that the mutation leading to self-compatibility in 'Monreal' affected the expression of non-homologous genes located in a restricted genome region. Also, we hypothesize that the Asp-rich protein genes may act as Ca<sup>2+ </sup>"entrapping" proteins, potentially regulating Ca<sup>2+ </sup>homeostasis during self-pollen recognition.</p
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