Spokewise iridotomy combined with Descemet stripping automated endothelial keratoplasty in iridocorneal endothelial syndrome

PurposeIridocorneal endothelial (ICE) syndrome is a progressive anterior segment disorder that can be tricky to treat. Keratoplasty is commonly used to treat corneal edema in ICE syndrome. However, glaucoma is an important risk factor affecting graft survival. To address this question, we designed a retrospective cohort study to evaluate the effect of Spokewise Iridotomy (SI) on Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) Grafts in Iridocorneal Endothelial (ICE) Syndrome.MethodsThis was a retrospective cohort study. A total of 29 patients were included; 31 eyes with ICE syndrome underwent DSAEK at Peking University Third Hospital between June 2015 and June 2022, including 11 eyes with combined SI during DSAEK. The aim was to explore the effect of SI on vision, glaucoma control, complications, peripheral anterior synechiae recurrence, endothelial cell count, and graft survival.ResultsThe median follow-up time was 30.83 months (mo.) in the SI+Endothelial Keratoplasty (EK) group and 6.17 mo in the EK group. The 2-year cumulative survival rate of grafts in the SI+EK group was 100%, compared with the 6-month and 1-year cumulative survival rates of 80.2 and 63.2%, respectively, in the EK group (p = 0.043). The SI+EK group had a lower incidence of immediate postoperative complications (p = 0.005), fewer postoperative anti-glaucoma medications (AGMs) (p = 0.029), smaller peripheral anterior synechiae recurrence (p = 0.001), and significant visual acuity improvement (p < 0.05). More AGMs were used in failed grafts (p = 0.002).ConclusionSI can help control intraocular pressure, improve visual acuity, and increase graft survival after DSAEK in ICE syndrome patients

Isolation of mouse mesenchymal stem cells with normal ploidy from bone marrows by reducing oxidative stress in combination with extracellular matrix

<p>Abstract</p> <p>Background</p> <p>Isolation of mouse MSCs (mMSCs) with normal ploidy from bone marrow remains challenging. mMSCs isolated under 20% O₂are frequently contaminated by overgrown hematopoietic cells, and could also be especially vulnerable to oxidative damage, resulting in chromosomal instability. Culture under low oxygen or extracellular matrix (ECM) improves proliferation of MSCs in several species. We tested the hypothesis that culture under low oxygen in combination with ECM prepared from mouse embryonic fibroblast (MEF-ECM) could be used to purify proliferative mMSCs, and to reduce oxidative damage and maintain their chromosomal stability.</p> <p>Results</p> <p>Optimization of culture conditions under 20% O₂resulted in immortalization of mMSCs, showing extensive chromosome abnormalities, consistent with previous studies. In contrast, culture under low oxygen (2% O₂) improved proliferation of mMSCs and reduced oxidative damage, such that mMSCs were purified simply by plating at low density under 2% O₂. MEF-ECM reduced oxidative damage and enhanced proliferation of mMSCs. However, these isolated mMSCs still exhibited high frequency of chromosome abnormalities, suggesting that low oxygen or in combination with MEF-ECM was insufficient to fully protect mMSCs from oxidative damage. Notably, antioxidants (alpha -phenyl-t-butyl nitrone (PBN) and N-acetylcysteine (NAC)) further reduced DNA damage and chromosomal abnormalities, and increased proliferation of mMSCs. mMSCs isolated by the combination method were successfully used to generate induced pluripotent stem (iPS) cells by ectopic expression of Oct4, Sox2, Klf4 and c-Myc.</p> <p>Conclusions</p> <p>We have developed a technique that allows to reduce the number of karyotypic abnormalities for isolation of primary mMSCs and for limited culture period by combination of low oxygen, MEF-ECM, antioxidants and low density plating strategy. The effectiveness of the new combination method is demonstrated by successful generation of iPS cells from the isolated mMSCs. However, a culture system for mMSCs still is needed to prevent all the anomalies, especially after a long-term culture period.</p

Role of endothelial Nox2 NADPH oxidase in angiotensin II-induced hypertension and vasomotor dysfunction

NADPH oxidase (Nox)-derived reactive oxygen species (ROS) are known to be involved in angiotensin II-induced hypertension and endothelial dysfunction. Several Nox isoforms are expressed in the vessel wall, among which Nox2 is especially abundant in the endothelium. Endothelial Nox2 levels rise during hypertension but little is known about the cell-specific role of endothelial Nox2 in vivo. To address this question, we generated transgenic mice with endothelial-specific overexpression of Nox2 (Tg) and studied the effects on endothelial function and blood pressure. Tg had an about twofold increase in endothelial Nox2 levels which was accompanied by an increase in p22phox levels but no change in levels of other Nox isoforms or endothelial nitric oxide synthase (eNOS). Basal NADPH oxidase activity, endothelial function and blood pressure were unaltered in Tg compared to wild-type littermates. Angiotensin II caused a greater increase in ROS production in Tg compared to wild-type aorta and attenuated acetylcholine-induced vasorelaxation. Both low and high dose chronic angiotensin II infusion increased telemetric ambulatory blood pressure more in Tg compared to wild-type, but with different patterns of BP change and aortic remodeling depending upon the dose of angiotensin II dose. These results indicate that an increase in endothelial Nox2 levels contributes to angiotensin II-induced endothelial dysfunction, vascular remodeling and hypertension

Variation in Soil Methane Fluxes and Comparison between Two Forests in China

Methane (CH4) is a vital greenhouse gas with a 28-fold higher global warming potential than carbon dioxide when considering a molar basis for the time horizon of 100 years. Here, we investigated the variation of soil CH4 fluxes, soil physiochemical properties, and CH4-related bacteria community composition of two forests in China. We measured CH4 fluxes using static chambers and analyzed soil bacterial communities using next-generation high-throughput sequencing in a temperate broad-leaved deciduous forest at Baotianman Nature Reserve (TBDF-BTM) and a tropical rainforest at Jianfengling National Natural Reserve (TRF-JFL). Our results showed that the soils from both sites were CH4 sinks. Significant variation in soil CH4 fluxes was found at TBDF-BTM exclusively, while no seasonal variation in the CH4 uptake was observed at TRF-JFL. The CH4 fluxes at TBDF-BTM were substantially higher than those at TRF-JFL during all seasons. One genus of methanotrophs and three genera of methylotrophs were detected at both sites, though they had no direct relationship with soil CH4 fluxes. Water-filled pore space and soil total carbon content are the main factors controlling the soil CH4 fluxes at TBDF-BTM. At TRF-JFL, the soil CH4 fluxes showed no significant correlations with any of the soil properties. This study improves our understanding of soil CH4 fluxes and their influencing factors in forests in different climatic zones and provides a reference for future investigation of forest soil CH4 fluxes, the forest ecosystem carbon cycle, and the forest CH4 model