156 research outputs found
Emblica officinalis and its enriched tannoids delay streptozotocin-induced diabetic cataract in rats
Inhibition of aldose reductase by tannoid principles of Emblica officinalis: Implications for the prevention of sugar cataract
Black shale deposition and early diagenetic dolomite cementation during Oceanic Anoxic Event 1: The mid-Cretaceous Maracaibo Platform, northwestern South America
Thin laterally continuous organic-rich dolomitic marlstones were deposited in the extended Late Aptian - Early Albian epicontinental sea of northwestern South America. These intervals are the proximal equivalents of thick hemipelagic black shale-ammonitic floatstone couplets, deposited in the distally stepped, differentially subsiding part of the Maracaibo Platform. The marlstones reflect the dynamic conditions resulting from orbital forcing mechanisms and can be genetically related to (1) minor sea-level changes, (2) proximal turnovers in marine productivity, and (3) sudden climate shifts affecting mid-Cretaceous shoaling upward, shallow marine, carbonate cyclicity. Therefore, the marlstones may well be linked to the multiple environmental perturbations collectively referred to as Oceanic Anoxic Event 1. The interstitial euhedral dolomite has a medium crystallinity, and exhibits unusual textural relations with framboidal pyrite and gypsum. The authigenic mineral assemblage also includes quartz, Ca-F apatite, and barite, which together with the chemical signals of dolomite, point to an unsteady climate regime. Bulk-rock biomarker parameters, rare earth element geochemistry, and iron speciation data point to widespread photic zone anoxia and transient shallow marine euxinia by the time of deposition, with climatic instability driving the delivery of oxidized detritus from the hinterlands. These conditions led to a schizohaline redox stratified environment favorable to dolomite precipitation. In such a depositional setting, the bio-utilization of Fe, Mn, and sulfur for organic matter respiration sustained elevated pore-water alkalinity and pH, and allowed for the pre-compactional growth of interstitial dolomite
Erythrocyte aldose reductase activity and sorbitol levels in diabetic retinopathy
PurposeActivation of polyol pathway due to increased aldose reductase (ALR2) activity has been implicated in the development of diabetic complications including diabetic retinopathy (DR), a leading cause of blindness. However, the relationship between hyperglycemia-induced activation of polyol pathway in retina and DR is still uncertain. We investigated the relationship between ALR2 levels and human DR by measuring ALR2 activity and its product, sorbitol, in erythrocytes.MethodsWe enrolled 362 type 2 diabetic subjects (T2D) with and without DR and 66 normal subjects in this clinical case-control study. Clinical evaluation of DR in T2D patients was done by fundus examination. ALR2 activity and sorbitol levels along with glucose and glycosylated hemoglobin (HbA1C) levels in erythrocytes were determined.ResultsT2D patients with DR showed significantly higher specific activity of ALR2 as compared to T2D patients without DR. Elevated levels of sorbitol in T2D patients with DR, as compared to T2D patients without DR, corroborated the increased ALR2 activity in erythrocytes of DR patients. However, the increased ALR2 activity was not significantly associated with diabetes duration, age, and HbA1C in both the DR group and total T2D subjects.ConclusionsLevels of ALR2 activity as well as sorbitol in erythrocytes may have value as a quantitative trait to be included among other markers to establish a risk profile for development of DR
Aldo-keto reductases in the eye
Aldose reductase (AKR1B1) is an NADPH-dependent aldo-keto reductase best known as the rate-limiting enzyme of the polyol pathway. Accelerated glucose metabolism through this pathway has been implicated in diabetic cataract and retinopathy. Some human tissues contain AKR1B1 as well as AKR1B10, a closely related member of the aldo-keto reductase gene superfamily. This opens the possibility that AKR1B10 may also contribute to diabetic complications. The goal of the current study was to characterize the expression profiles of AKR1B1 and AKR1B10 in the human eye. Using quantitative reverse transcriptase-PCR and immunohistochemical staining, we observed expression of both AKR genes in cornea, iris, ciliary body, lens, and retina. Expression of AKR1B1 was the highest in lens and retina, whereas AKR1B10 was the highest in cornea. Lenses from transgenic mice designed for overexpression of AKR1B10 were not significantly different from nontransgenic controls, although a significant number developed a focal defect in the anterior lens epithelium following 6 months of experimentally induced diabetes. However, lenses from AKR1B10 mice remained largely transparent following longterm diabetes. These results indicate that AKR1B1 and AKR1B10 may have different functional properties in the lens and suggest that AKR1B10 does not contribute to the pathogenesis of diabetic cataract in humans
Black shale deposition and early diagenetic dolomite cementation during Oceanic Anoxic Event 1: The mid-Cretaceous Maracaibo Platform, northwestern South America
Inhibition of aldose reductase by dietary antioxidant curcumin: Mechanism of inhibition, specificity and significance
AbstractAccumulation of intracellular sorbitol due to increased aldose reductase (ALR2) activity has been implicated in the development of various secondary complications of diabetes. In this study we show that curcumin inhibits ALR2 with an IC50 of 10μM in a non-competitive manner, but is a poor inhibitor of closely-related members of the aldo-keto reductase superfamily, particularly aldehyde reductase. Results from molecular docking studies are consistent with the pattern of inhibition of ALR2 by curcumin and its specificity. Moreover, curcumin is able to suppress sorbitol accumulation in human erythrocytes under high glucose conditions, demonstrating an in vivo potential of curcumin to prevent sorbitol accumulation. These results suggest that curcumin holds promise as an agent to prevent or treat diabetic complications
Radial distribution of a single-pass amplified radiation in the active elements of CuBr lasers
The paper presents the results of study of single-pass amplified radiation distribution of copper bromide vapor laser active elements used in high-speed laser monitors. The possibility of modifying the profile of a single-pass amplified light beam by changing the copper bromide vapor concentration is demonstrated. This means of influence on the radiation profile seems to be easiest due to implementation by varying only one parameter of operation. Gaussian, ring-shaped or flat profiles can be achieved depending on the temperature of the containers with copper bromide. The diameter of the beam becomes narrower when increasing the concentration of copper bromide vapor. This feature is characteristic of the discharge tubes as small (diameter 2.5, length 5 cm) and large (diameter 5 cm, length 90 cm) active volume
PLANNING OF POSITIVE AGING STRATEGIES AND PSYCHOLOGICAL WELL-BEING DURING LATE ADULTHOOD
The research addresses the characteristics of aging planning in the period of late adulthood. Retrospective and current plans for aging were analyzed, as well as their relationship with psychological well-being. Two aging strategies were considered: active and relaxed. A comparative analysis of aging planning was carried out depending on the chosen strategy. It was shown that both strategies were productive, differing in the resources that underlie them.В работе рассматриваются особенности планирования старения в период поздней взрослости. Анализируются ретроспективные и актуальные планы относительно старения, их связи с психологическим благополучием. Рассматриваются две стратегии старения: активная и спокойная. Проводится сравнительный анализ планирования старения в зависимости от выбранной стратегии. Показано, что обе стратегии являются продуктивными, различаясь ресурсами, которые лежат в их основе.Проект поддержан грантом РНФ № 22-28-00869
Analysis of the diagnostic and economic impact of the combined artificial intelligence algorithm for analysis of 10 pathological findings on chest computed tomography
BACKGROUND: Artificial intelligence technology can help solve the significant problem of missed findings in radiology studies. An important issue is assessing the economic benefits of implementing artificial intelligence.
AIM: To evaluate the frequency of missed pathologies detection and the economic potential of artificial intelligence technology for chest computed tomography compared and validated by experienced radiologists.
MATERIALS AND METHODS: This was an observational, single-center retrospective study. The study included chest computed tomography without IV contrast from June 1 to July 31, 2022, in Clinical Hospital in Yauza, Moscow. The computed tomography was processed using a complex artificial intelligence algorithm for 10 pathologies: pulmonary infiltrates, typical for viral pneumonia (COVID-19 in pandemic conditions); lung nodules; pleural effusion; pulmonary emphysema; thoracic aortic dilatation; pulmonary trunk dilatation; coronary artery calcification; adrenal hyperplasia; and osteoporosis (vertebral body height and density changes). Two experts analyzed computed tomography and compared results with artificial intelligence. Further routing was determined according to clinical guidelines for all findings initially detected and missed by radiologists. The hospital price list determined the potential revenue loss for each patient.
RESULTS: From the final 160 computed tomographies, the artificial intelligence identified 90 studies (56%) with pathologies, of which 81 (51%) were missing at least one pathology in the report. The second-stage lost potential revenue for all pathologies from 81 patients was RUB 2,847,760 (27,017 or CNY 185,824).
CONCLUSION: Using artificial intelligence as an assistant to the radiologist for chest computed tomography can dramatically minimize the number of missed abnormalities. Compared with the normal model without artificial intelligence, using artificial intelligence can provide 3.6 times more benefits. Using advanced artificial intelligence for chest computed tomography can save money
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