Objective Although the majority of the ATP in chondrocytes is made by glycolysis rather than by oxidative phosphorylation in mitochondria there is evidence to suggest that reactive oxygen species produced by mitochondrial electron transport help to maintain cellular redox balance in favor of glycolysis. The objective of this study was to test this hypothesis by determining if rotenone, which inhibits electron transport and blocks oxidant production inhibits glycolytic ATP synthesis. Design Bovine osteochondral explants were treated with rotenone, an electron transport inhibitor; or oligomycin an ATP synthase inhibitor; or 2-fluoro-2-deoxy-D-glucose, a glycolysis inhibiter; or peroxide, an exogenous oxidant; or mitoquinone, a mitochondria-targeted anti-oxidant. Cartilage extracts were assayed for ATP, NAD+, and NADH, and culture medium was assayed for pyruvate and lactate after 24 hours of treatment. Imaging studies were used to measure superoxide production in cartilage. Results Rotenone and 2-fluoro-2-deoxy-D-glucose caused a significant decline in cartilage ATP (p < 0.001). In contrast, ATP levels were not affected by oligomycin. Peroxide treatment blocked rotenone effects on ATP, while treatment with MitoQ significantly suppressed ATP levels. Rotenone and 2-fluoro-2-deoxy-D-glucose caused a significant decline in pyruvate, but not in lactate production. NADH:NAD+ ratios decreased significantly in both rotenone and 2-fluoro-2-deoxy-D-glucose-treated explants (p < 0.05). Rotenone also significantly reduced superoxide production Conclusions These findings showing a link between glycolysis and electron transport are consistent with previous reports on the critical need for oxidants to support normal chondrocyte metabolism. They suggest a novel role for mitochondria in cartilage homeostasis that is independent of oxidative phosphorylation.
Context:Intralipid is used to improve clinical outcomes in patients with recurrent pregnancy loss (RPL) or recurrent implantation failure (RIF) with elevated natural killer (NK) cells. Data supporting this practice is conflicting but suggestive of minimal benefit.Aims:The aims of this study are to determine if intralipid infusion improves live birth rates and if is a cost-effective therapy in the RPL/RIF population.Settings and Design:This was a large REI private practice, retrospective cohort study.Subjects and Methods:Charts of 127 patients who received intralipid from 2012 to 2015 were reviewed and compared to historical control data. T-tests and Chi-square analyses evaluated demographics and cycle statistics. Chi-square analyses assessed impact on clinical pregnancy and live birth rates. Cost analysis was performed from societal perspective with a one-way sensitivity analysis.Results:Patients with live births were noted to have a higher average number of previous live births and were more likely to have had a frozen embryo transfer in the intralipid cycle in comparison to those with unsuccessful pregnancy outcomes. Neither clinical pregnancy nor live birth rates were significantly improved from baseline rates quoted in the literature (P = 0.12 and 0.80, respectively). Intralipid increased costs by $681 per live birth. If live birth rates were >40% using intralipid and <51% without intervention, neither strategy was favored.Conclusions:Intralipid does not improve live birth rates and is not cost-effective for patients with RIF or RPL and elevated NK cells. This study supports the growing literature demonstrating the minimal benefit of screening for and treating elevated peripheral NK cells.
Assisted reproductive technology (ART) is responsible for 1.7% of births in the United States annually. Despite a large number of studies promoting the efficacy and safety of these practices, there have been reports of imprinting disorders occurring at higher frequencies in children born through ART. Driven by findings in animal studies, it has been postulated that various ART procedures employed at critical points in embryonic development may predispose the genomic imprinting process to errors. Alterations in DNA methylation patterns at imprinting control centers have been reported by some studies to occur more frequently in children with imprinting disorders conceived by ART compared with spontaneous conception, though these findings are not consistently demonstrated and controversy has surrounded the strength of these associations. The rarity of imprinting disorders with a reliance of studies on disease registry cohorts, wide variations in ART protocols, and a lack of proper control groups limit the ability to substantiate associations between imprinting disorders and ART. Large, prospective cohort studies with a focus on molecular etiologies of these conditions are needed to discern whether a true association exists. Based on current evidence, the absolute risk of imprinting disorders after ART is low and screening for imprinting disorders in children conceived by ART is not warranted.
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