4,941 research outputs found

    Heteromeric TRPV4/TRPC1 channels mediate calcium-sensing receptor-induced nitric oxide production and vasorelaxation in rabbit mesenteric arteries.

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    Stimulation of calcium-sensing receptors (CaSR) by increasing the external calcium concentration (Ca(2+)]o) induces endothelium-dependent vasorelaxation through nitric oxide (NO) production and activation of intermediate Ca(2+)-activated K(+) currents (IKCa) channels in rabbit mesenteric arteries. The present study investigates the potential role of heteromeric TRPV4-TRPC1 channels in mediating these CaSR-induced vascular responses. Immunocytochemical and proximity ligation assays showed that TRPV4 and TRPC1 proteins were expressed and co-localised at the plasma membrane of freshly isolated endothelial cells (ECs). In wire myography studies, increasing [Ca(2+)]o between 1 and 6mM induced concentration-dependent relaxations of methoxamine (MO)-induced pre-contracted tone, which were inhibited by the TRPV4 antagonists RN1734 and HC067047, and the externally-acting TRPC1 blocking antibody T1E3. In addition, CaSR-evoked NO production in ECs measured using the fluorescent NO indicator DAF-FM was reduced by RN1734 and T1E3. In contrast, [Ca(2+)]o-evoked perforated-patch IKCa currents in ECs were unaffected by RN1734 and T1E3. The TRPV4 agonist GSK1016790A (GSK) induced endothelium-dependent relaxation of MO-evoked pre-contracted tone and increased NO production, which were inhibited by the NO synthase inhibitor L-NAME, RN1734 and T1E3. GSK activated 6pS cation channel activity in cell-attached patches from ECs which was blocked by RN1734 and T1E3. These findings indicate that heteromeric TRPV4-TRPC1 channels mediate CaSR-induced vasorelaxation through NO production but not IKCa channel activation in rabbit mesenteric arteries. This further implicates CaSR-induced pathways and heteromeric TRPV4-TRPC1 channels in regulating vascular tone

    Methyl-CpG-binding protein 2 mediates overlapping mechanisms across brain disorders

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    MECP2 and its product, Methyl-CpG binding protein 2 (MeCP2), are mostly known for their association to Rett Syndrome (RTT), a rare neurodevelopmental disorder. Additional evidence suggests that MECP2 may underlie other neuropsychiatric and neurological conditions, and perhaps modulate common presentations and pathophysiology across disorders. To clarify the mechanisms of these interactions, we develop a method that uses the binding properties of MeCP2 to identify its targets, and in particular, the genes recognized by MeCP2 and associated to several neurological and neuropsychiatric disorders. Analysing mechanisms and pathways modulated by these genes, we find that they are involved in three main processes: neuronal transmission, immuno-reactivity, and development. Also, while the nervous system is the most relevant in the pathophysiology of the disorders, additional systems may contribute to MeCP2 action through its target genes. We tested our results with transcriptome analysis on Mecp2-null models and cells derived from a patient with RTT, confirming that the genes identified by our procedure are directly modulated by MeCP2. Thus, MeCP2 may modulate similar mechanisms in different pathologies, suggesting that treatments for one condition may be effective for related disorders

    Survey of Predatory Coccinellids (Coleoptera: Coccinellidae) in the Chitral District, Pakistan

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    An extensive survey of predatory Coccinellid beetles (Coleoptera: Coccinellidae) was conducted in the Chitral District, Pakistan, over a period of 7 months (April through October, 2001). A total of 2600 specimens of Coccinellids were collected from 12 different localities having altitudes from 1219.40–2651.63 m. Twelve different species belonging to 9 genera of 3 tribes and 2 sub-families were recorded. Two sub-families, viz, Coccinellinae Latreille, 1807 and Chilocorinae Mulsant, 1846 were identified. The following 8 species belonged to family Coccinellinae Latreille 1807 and tribe Coccinellini Latreille 1807: Coccinella septempunctata Linnaeus, 1758, Hippodamia (Adonia) variegata Goeze, 1777, Calvia punctata (Mulsant, 1846), Adalia bipunctata (Linnaeus, 1758),Adalia tetraspilota (Hope, 1831), Aiolocaria hexaspilota Hope 1851, Macroilleis (Halyzia) hauseri Mader, 1930,Oenopia conglobata Linnaeus, 1758. Only one species namely Halyzia tschitscherini Semenov, 1965 represented tribe Psylloborini of the sub-family Coccinellinae Latreille, 1807. Three species occurred from sub-family Chilocorinae Mulsant 1846 and tribe Chilocorini Mulsant 1846: Chilocorus rubidus Hope, 1831, Chilocorus circumdatus (Gyllenhal, 1808), Priscibrumus uropygialis (Mulsant, 1853). From the aforementioned species 6 were recorded for the first time from Pakistan: Chilocorus circumdatus, Calvia punctata, Adalia bipunctata, Macroilleis (Halyzia) hauseri, Priscibrumus uropygialis, and Oenopia conglobata

    A low balance between microparticles expressing tissue factor pathway inhibitor and tissue factor is associated with thrombosis in Behçet’s Syndrome

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    Thrombosis is common in Behçet’s Syndrome (BS), and there is a need for better biomarkers for risk assessment. As microparticles expressing Tissue Factor (TF) can contribute to thrombosis in preclinical models, we investigated whether plasma microparticles expressing Tissue Factor (TF) are increased in BS. We compared blood plasma from 72 healthy controls with that from 88 BS patients (21 with a history of thrombosis (Th+) and 67 without (Th−). Using flow cytometry, we found that the total plasma MP numbers were increased in BS compared to HC, as were MPs expressing TF and Tissue Factor Pathway Inhibitor (TFPI) (all p 0.7 had a history of clinical thrombosis. We conclude that TF-expressing MP are increased in BS and that an imbalance between microparticulate TF and TFPI may predispose to thrombosis

    Clinical evaluation of smartphone-based fluorescence imaging for guidance and monitoring of ALA PDT

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    India has one of the highest rates of oral cancer incidence in the world, with an estimated 80,000 new cases per year, accounting for 30% of reported cancers. In rural areas, a lack of adequate medical infrastructure contributes to unchecked disease progression and dismal mortality rates. PDT emerges as a potential modality which can be implemented in resource limited settings, while photosensitizer fluorescence can be leveraged for treatment guidance. Here, as part of an ongoing clinical study evaluating low-cost technology for ALA PDT treatment, we evaluated the capability of a simple smartphone-based device for imaging ALA-induced PpIX fluorescence. The imaging device itself consists of an annulus of 405nm LEDs for PpIX excitation with emission filter in the center mounted over the phone camera. 18 subjects having <2 cm diameter (mean size; ~1.38 cm2) lesions with micro-invasive (≤5 mm. depth) moderately/well-differentiated squamous cell carcinoma were administered 60 mg/kg ALA in oral solution and imaged before and after delivery of 100 J/cm2 total light dose to the lesion surface. We will present comparative analysis of pre-and post-treatment fluorescence, white light, and ultrasound images. In general, PpIX fluorescence images obtained prior to therapeutic light delivery are able to resolve lesion margins while dramatic photobleaching in post-treatment images confirms the irradiated zone. Overall this approach is able to generate sufficient fluorescence contrast for treatment guidance and monitoring photobleaching while the use of a smartphone-based device provides a low-cost, widely available platform with potential for telemedicine integration

    Clinical assessment of a low-cost, hand-held, smartphone-attached intraoral imaging probe for ALA PDT monitoring and guidance

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    India has one of the highest rates of oral squamous cell carcinoma (OSCC) in the world, with an incidence of 15 per 100,000 and more than 70,000 deaths per year. The problem is exacerbated by lack of medical infrastructure and routine screening, especially in rural areas. This collaboration recently developed, and clinically validated, a low-cost, portable and easy-to-use platform for intraoral photodynamic therapy (PDT) specifically engineered for use in global health settings. Here, we explore the implementation of our low-cost PDT system in conjunction with a small, handheld smartphone-coupled, multichannel fluorescence and white-light oral cancer imaging probe, which was also developed for global health settings. Our study aimed to use this mobile intraoral imaging device for treatment guidance and monitoring PDT using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PS; PpIX) fluorescence. A total of 12 patients with 14 lesions having moderately/well-differentiated micro-invasive OSCC lesions (<2 cm diameter, depth <5 mm) were systemically administered with three doses of 20mg/kg ALA (total 60mg/kg). Lesion site PpIX and auto fluorescence was analyzed before/after ALA administration, and again after light delivery (fractionated, total 100 J/cm^{2} of 630nm red LED light). Quantification of relative PpIX fluorescence enables lesion area segmentation to improve guidance of light delivery and reports extent of photobleaching. These results indicate the utility of this approach for image-guided PDT and treatment monitoring while also laying groundwork for an integrated approach, combining cancer screening and treatment with the same hardware

    Appetite suppressants and valvular heart disease - a systematic review

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    Background Although appetite suppressants have been implicated in the development of valvular heart disease, the exact level of risk is still uncertain. Initial studies suggested that as many as 1 in 3 exposed patients were affected, but subsequent research has yielded substantially different figures. Our objective was to systematically assess the risk of valvular heart disease with appetite suppressants. Methods We accepted studies involving obese patients treated with any of the following appetite suppressants: fenfluramine, dexfenfluramine, and phentermine. Three types of studies were reviewed: controlled and uncontrolled observational studies, and randomized controlled trials. Outcomes of interest were echocardiographically detectable aortic regurgitation of mild or greater severity, or mitral regurgitation of moderate or greater severity. Results Of the 1279 patients evaluated in seven uncontrolled cohort studies, 236 (18%) and 60 (5%) were found to have aortic and mitral regurgitation, respectively. Pooled data from six controlled cohort studies yielded, for aortic regurgitation, a relative risk ratio of 2.32 (95% confidence intervals 1.79 to 3.01, p < 0.00001) and an attributable rate of 4.9%, and for mitral regurgitation, a relative risk ratio of 1.55 (95% confidence intervals 1.06 to 2.25, p = 0.02) with an attributable rate of 1.0%. Only one case of valvular heart disease was detected in 57 randomized controlled trials, but this was judged unrelated to drug therapy. Conclusions The risk of valvular heart disease is significantly increased by the appetite suppressants reviewed here. Nevertheless, when considering all the evidence, valvulopathy is much less common than suggested by the initial, less methodologically rigorous studies
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