16 research outputs found

    The preparations used to study calcium in lens epithelial cells and its role in cataract formation

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    This review summarizes relevant publications and our recent work related to the structure and the function of the lens epithelium and its role in the formation of cataract as well as its correlation with changes in intracellularcalcium, as studied on different types of preparations. It is emphasized that the human lens capsule preparation isolated during the cataract surgery is an adequate source for the studies of lens epithelial cells and we highlight the possibilities for studying the intracellular calcium homeostasis and the cataract

    Photodisruption of a thin membrane near a solid boundary

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    A Nd:YAG laser photodisruption is a well-established tool for intraocular surgery, such as treatment of posterior capsule opacification that affects the visual function. During the intraocular procedure, called laser capsulotomy, the excitation pulse is focused several times just behind the posterior capsule and intraocular lens to create the central opening in the opacified capsule. We built an in vitro experiment to (1) clarify the influence of the distance between the intraocular lens and the posterior capsule on the total pulse energy required for the capsulotomy, and (2) investigate the main mechanisms responsible for the posterior capsule opening. In our in vitro model, different distances between the solid boundary (imitating an intraocular lens) and the membrane (imitating the posterior capsule) simulate different types of posterior capsule opacification. Our results show that procedure efficiency decreases by decreasing distance between the lens and the capsule. We also explain that for smaller distances between the pulse focus and the membrane, plasma and shock wave are responsible for the capsule disruption. Here, a risk of collateral damage significantly increases. On contrary, the membrane and the bubble jet disrupt the membrane, when pulse focus is moved away and the risk of intraocular lens damage decreases. However, the membrane disruption is not very effective, if it is placed near the solid boundary that inhibits the membrane jet

    Microplasma Induced Cell Morphological Changes and Apoptosis of Ex Vivo Cultured Human Anterior Lens Epithelial Cells - Relevance to Capsular Opacification

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    Inducing selective or targeted cell apoptosis without affecting large number of neighbouring cells remains a challenge. A plausible method for treatment of posterior capsular opacification (PCO) due to remaining lens epithelial cells (LECs) by reactive chemistry induced by localized single electrode microplasma discharge at top of a needle-like glass electrode with spot size ~3 mum is hereby presented. The focused and highly-localized atmospheric pressure microplasma jet with electrode discharge could induce a dose-dependent apoptosis in selected and targeted individual LECs, which could be confirmed by real-time monitoring of the morphological and structural changes at cellular level. Direct cell treatment with microplasma inside the medium appeared more effective in inducing apoptosis (caspase 8 positivity and DNA fragmentation) at a highly targeted cell level compared to treatment on top of the medium (indirect treatment). Our results show that single cell specific micropipette plasma can be used to selectively induce demise in LECs which remain in the capsular bag after cataract surgery and thus prevent their migration (CXCR4 positivity) to the posterior lens capsule and PCO formation

    Sentinel node biopsy for conjunctival melanoma

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    Purpose: To evaluate the role of sentinel lymph node (SLN) biopsy in patients with conjuctival melanoma (CjM). Study design: Retrospective observational cohort study and literature review. Subjects: Slovenian patients with CjM are included in the study. Methods: Prospectively collected data of CjM patients treated from June 2005 to December 2016 were retrospectively analyzed. Main outcome measures: The numbers of SLN biopsy procedures, positive and false positive SLN, and local and regional relapses have been described together with overall survival. Results: From June 2005 until December 2016, 24 patients with CjM were treated. The median follow-up time was 65.3 months. The mean Breslow thickness was 1.5 mm (sd = 1.8 mm), and ulceration was present in 29% of cases. Altogether, 14/24 (58%) SLN biopsy procedures were performed. SLN was positive in 2/14 (14%) cases. The estimated 5-year overall survival (OS) of the group was 72.5%, with a median survival of 151 months (95% CI 77–224). From January 2013 to January 2020, five (5/140, 3%) authors reported results comparable to our study. Conclusion: Our results confirm that CjM is a rare disease with approximately 14% of positive SLN. At the moment, there are no firm conclusions regarding who would benefit most from SLN biopsy or whether or not CLND should be offered. Data from literature emphasize the need for consistent and uniform staging and future multicentric studies

    Transmission of pancreatic adenocarcinoma by a single multiorgan donor to two kidney transplant recipients: A case report

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    We present two cases of transmission of a pancreatic adenocarcinoma from a single donor to two kidney transplant recipients. Autopsy of the donor revealed a pancreatic adenocarcinoma that had already spread locally to the regional lymph nodes and had not been detected at the time of organ procurement. Both recipients were carefully monitored, as neither consented to graft nephrectomy. In one patient, the tumor was discovered on surveillance biopsy of the graft approximately 14 months after transplantation, and in the second patient, ultrasound-guided aspiration needle biopsy of a growing formation in the lower pole of the graft revealed poorly differentiated metastatic adenocarcinoma. Both patients were successfully treated with graft nephrectomy and complete discontinuation of immunosuppression. None of the follow-up imaging showed persistent or recurrent malignancy, and both patients were candidates for re-transplantation. These exceptional cases of donor-derived pancreatic adenocarcinoma suggest that removal of the donor organ and restoration of immunity may lead to complete recovery
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