Search

Ongoing global climate change is increasing the risk of drought stress in some areas, which may compromise forest health. Such drought events also increase outbreaks of insect herbivores, resulting in plant defoliation. Interactions between drought and defoliation are poorly understood. In a greenhouse experiment, we selected a native species, Quercus acutissima Carr. and an alien species, Quercus rubra L. to explore their physiological responses to drought and defoliation treatments. After the treatments, we determined the seedlings’ physiological responses on Days 10 and 60. Our results showed that the defoliation treatment accelerated the carbon reserve consumption of plants under drought stress and inhibited the growth of both seedling types. Under the drought condition, Q. rubra maintained normal stem-specific hydraulic conductivity and normal growth parameters during the early stage of stress, whereas Q. acutissima used less water and grew more slowly during the experiment. Sixty days after defoliation treatment, the stem starch concentration of Q. acutissima was higher than that of the control group, but the stem biomass was lower. This indicates that Q. acutissima adopted a ‘slow strategy’ after stress, and more resources were used for storage rather than growth, which was conducive to the ability of these seedlings to resist recurrent biotic attack. Thus, Q. acutissima may be more tolerant to drought and defoliation than Q. rubra. The resource acquisition strategies of Quercus in this study suggest that the native Quercus species may be more successful at a long-term resource-poor site than the alien Quercus species.

This study examined the basic regulatory effects and clinical value of metalloproteinase-14 and extracellular matrix metalloproteinase inducer in diabetic retinopathy. Seventy-four patients with diabetic retinopathy (study group/diabetic retinopathy (DR) group) and 48 healthy people (control group) were included in this study. Venous blood of subjects in the two groups was collected and the plasma levels of EMMPRIN, MMP-14, VEGF, and MMP-9 were determined by enzyme-linked immunosorbent assay. The value of applying plasma EMMPRIN and MMP-14 for predicting the prognosis of DR was evaluated using a receiver operating characteristic (ROC) curve with a 1-year follow-up. Human umbilical vein endothelial cells (HUVECs) were cultured in high-glucose conditions. EMMPRIN and MMP-14 mRNA levels were determined by RT-qPCR, EMMPRIN and MMP-14 protein levels were determined by Western blotting, apoptosis was determined by flow cytometry, and the level of angiogenesis was recorded. The levels of EMMPRIN and MMP-14 in the DR group were increased compared with those in the control group. Plasma EMMPRIN was positively correlated with plasma MMP-9 and plasma VEGF, and its area under the curve (AUC) for predicting 1-year adverse outcome of DR was 0.676. Plasma MMP-14 was also positively correlated with plasma MMP-9 and plasma VEGF, and its AUC for predicting 1-year adverse outcome of DR was 0.650. EMMPRIN and MMP-14 were upregulated in high-glucose-induced HUVECs. Downregulation of EMMPRIN resulted in downregulation of MMP-14, and downregulation of MMP-14 and EMMPRIN resulted in decreased apoptosis and angiogenesis of HUVECs. These findings suggest that EMMPRIN promotes endothelial cell apoptosis and angiogenesis in DR through MMP-14, and that plasma EMMPRIN and MMP-14 can help predict the short-term prognosis of DR.

Diabetic retinopathy is one of the major diabetic complications and remains the most common cause of adult blindness among patients with diabetes mellitus. Polygonatum sibiricum polysaccharides (PSP) are a group important component of Polygonatum sibiricum (PS) with anti-diabetic activity. However, the effect and underlying mechanism of PSP on diabetic retinopathy remains unclear. We used high glucose (HG)-stimulated ARPE-19 cells to establish in vitro diabetic retinopathy model. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay was performed to evaluate cell viability of ARPE-19 cells. The changes in the ROS production, malondialdehyde (MDA) content, and activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were detected to indicate oxidative stress. The secretion levels of tumor necrosis factor-alpha (TNF-α) and interleukin-8 (IL-8) were detected by ELISA. The protein levels of TNF-α, IL-8, bcl-2, bax, nuclear Nrf2, and anti-hemeoxygenase-1 (HO-1) were detected by western blot analysis. Our results showed that HG treatment caused a significant reduction in cell viability of ARPE-19 cells. PSP treatment improved the reduced cell viability of ARPE-19 cells. PSP also attenuated HG-induced oxidative stress with decreased ROS production and MDA content, as well as increased the activities of SOD and GPx. In addition, HG significantly increased bax expression and caspase-3 activity, and decreased bcl-2 expression. However, these changes were mitigated by PSP treatment. Furthermore, PSP markedly induced the activation of Nrf2/HO-1 pathway in HG-induced ARPE-19 cells. Knockdown of Nrf2 reversed the protective effects of PSP on HG-induced ARPE-19 cells. Taken together, these findings indicated that PSP protects ARPE-19 cells from HG-induced oxidative stress, inflammation, and cell apoptosis through regulation of Nrf2/HO-1 signaling pathway.

Chunxia Zhong, Haiyan He, Baojie Lin, Shuanghuan Zheng, Meixia Song* Background: There are many surgical prerequisites where the primary anastomosis is not suitable, therefore, neonatal enterostomy or infant enterostomies are required. Stoma reversal is incorporated to help patients benefit from the treatment; however, there are many complications associated with the reversal of enterostomies. No informed consent has been received yet as this is still to be researched. Objective: To analyze the efficiency of the team led by the stoma specialist nurses after neonatal enterostomy in improving the treatment of neonates after enterostomy. Methods: 80 cases of neonatal intestinal fistula patients were divided into observation and control groups according to time sequence, with 40 cases per group. Patients in the control group were given routine nursing care, while patients in the observation group were given a nursing intervention by a team led by specialist enterostomy nurses. The complications and average hospitalization days of neonatal intestinal fistula patients in two groups were compared—along with family members scores, satisfaction surveys before discharge, and nurses' knowledge mastery. Results: Complications, hospitalization time, knowledge level of nurses, scores of family members' pre-discharge assessment, and satisfaction surveys in the observation group were better than those in the control group (P < 0.05). Conclusion: This research has found that the team led by specialist stoma nurses can improve the nursing level of enterostomy and reduce the incidence of complications and hospitalization time of neonatal enterostomy. It has also been found that they can improve the quality of life of children and overall family satisfaction. [Ethiop. J. Health Dev. 2021; 35(4): 380-389] Keywords: Specialized nurses; Enterostomy of newborn; Complications; Knowledge level of family members

Changing precipitation patterns have aggravated the existing uneven water distribution, leading to the alternation of drought and rewatering. Based on this variation, we studied species, namely, Robinia pseudoacacia and Quercus acutissima, with different root forms and water regulation strategy to determine physiological responses to repeated drought-rewatering under different planting methods. Growth, physiological, and hydraulic traits were measured using pure and mixed planting seedlings that were subjected to drought, repeated drought-rewatering (i.e., treatments), and well-irrigated seedlings (i.e., control). Drought had negative effects on plant functional traits, such as significantly decreased xylem water potential (Ψmd), net photosynthetic rate (AP), and then height and basal diameter growth were slowed down, while plant species could form stress imprint and adopt compensatory mechanism after repeated drought-rewatering. Mixed planting of the two tree species prolonged the desiccation time during drought, slowed down Ψmd and AP decreasing, and after rewatering, plant functional traits could recover faster than pure planting. Our results demonstrate that repeated drought-rewatering could make plant species form stress imprint and adopt compensatory mechanism, while mixed planting could weaken the inhibition of drought and finally improve the overall drought resistance; this mechanism may provide a theoretical basis for afforestation and vegetation restoration in the warm temperate zone under rising uneven spatiotemporal water distribution.

Age-related macular degeneration (AMD) is a major cause of progressive and degenerative visual impairment. Although the exact pathogenic mechanism of AMD is still unknown, clinical observations such as the high accumulation of oxidative products and macrophages in retina suggest the importance of oxidative stress and inflammation in AMD. Mouse photoreceptor-derived 661 W cells and human ARPE-19 cells were treated with oxidized phospholipids (Ox-PC) or H2O2 to mimic oxidative damage. The effect of monocyte chemoattractant protein 1 (MCP-1) secreted by retina cells on the migration of monocyte macrophage RAW 264.7 cells was determined using transwell chambers and antibody neutralization assay. MCP-1, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and vascular endothelial growth factor (VEGF) that secreted into supernatant were measured by ELISA and their intracellular expression was detected by qRT-PCR and western blot. Intracellular Ox-PC level was detected by competitive ELISA. The amount of migrated RAW 264.7 cells was counted by flow cytometry. Oxidative damage by both H2O2 and Ox-PC induced the secretion of MCP-1 in human ARPE-19 and mouse 661 W cells. MCP-1 induced by oxidative damage enhanced the migration ability of macrophage RAW 264.7 cells and the secretion of TNF-α, IL-1β and VEGF, which could be reduced by anti-MCP-1 neutralizing antibodies. The results indicated that oxidative damage increases intracellular Ox-PC and the secretion of MCP-1 in retina cells. The increased MCP-1 induced by oxidative damage attracts macrophages to retinas, and macrophages release pro-inflammatory factor and promote the process of AMD.

Auditory phonological processing skills are critical for successful reading development in English not only in native (L1) speakers but also in second language (L2) learners. However, the neural deficits of auditory phonological processing remain unknown in English-as-the-second-language (ESL) learners with reading difficulties. Here we investigated neural responses during spoken word rhyme judgments in typical and impaired ESL readers in China. The impaired readers showed comparable activation in the left superior temporal gyrus (LSTG), but reduced activation in the left inferior frontal gyrus (LIFG) and left fusiform and reduced connectivity between the LSTG and left fusiform when compared to typical readers. These findings suggest that impaired ESL readers have relative intact representations but impaired manipulation of phonology and reduced or absent automatic access to orthographic representations. This is consistent with previous findings in native English speakers and suggests a common neural mechanism underlying English impairment across the L1 and L2 learners.