In vivo absorption, in vitro simulated digestion and fecal fermentation properties of polysaccharides from Pinelliae Rhizoma Praeparatum Cum Alumine and their effects on human gut microbiota

Polysaccharides from Pinelliae Rhizoma Praeparatum Cum Alumine (PPA) have various biological activities, but their properties after oral administration are not clear. In this study, the absorption, digestion and fermentation properties of PPA were studied using in vivo fluorescence tracking, in vitro simulated digestion and fecal fermentation experiments. The absorption experiment showed that fluorescence was only observed in the gastrointestinal system, indicating that PPA could not be absorbed. Simulated digestion results showed that there were no significant changes in the molecular weight, Fourier transform infrared spectroscopy (FT-IR) spectrum, monosaccharides and reducing sugar of PPA during the digestion process, showing that the overall structure of PPA was not damaged. However, the carbohydrate gel electrophoresis bands of PPA enzymatic hydrolysates after simulated digestion were significantly changed, indicating that simulated digestion might impact the configuration of PPA. In vitro fermentation showed that PPA could be degraded by microorganisms to produce short chain fatty acids, leading to a decrease in pH value. PPA can promote the proliferation of Bacteroideaceae, Megasphaera, Bacteroideaceae, and Bifidobacteriaceae, and inhibit the growth of Desulfobacteriota and Enterobacteriaceae. The results indicated that PPA could treat diseases by regulating gut microbiota, providing a scientific basis for the application and development of PPA.

[Pulse oximetric saturation/fraction of inspired oxygen and partial pressure of oxygen/fraction of inspired oxygen in diagnosing acute respiratory distress syndrome: which is better?]

Acute Respiratory Distress Syndrome (ARDS) is distinguished by hypoxemia, contributing to heightened morbidity, elevated mortality rates, and substantial healthcare expenses, thereby imposing a significant burden on patients and society. Presently, effective treatments for ARDS are lacking, emphasizing the pivotal role of early diagnosis and timely intervention in its successful management. The partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2, P/F) has traditionally served as a crucial metric for assessing patient hypoxemia and disease severity. While relatively accurate, its reliance on advanced technical expertise and specific medical equipment conditions constrains its implementation in areas with underdeveloped medical standards, resulting in missed diagnoses and treatments for ARDS patients. Conversely, the Pulse oximetric saturation/fraction of inspired oxygen (SpO2/FiO2, S/F) has garnered increasing attention owing to its straightforward, non-invasive, and sustainable monitoring attributes. This article seeks to meticulously compare the correlation, accuracy, and clinical feasibility of S/F with P/F in ARDS diagnosis, so as to propose diagnostic indicators for more quickly and accurately assessing the oxygenation status of ARDS patients.

Ambient nitrogen dioxide and cardiovascular diseases in rural regions: a time-series analyses using data from the new rural cooperative medical scheme in Fuyang, East China

Most of studies relating ambient nitrogen dioxide (NO₂) exposure to hospital admissions for cardiovascular diseases (CVDs) were conducted among urban population. Whether and to what extent these results could be generalizable to rural population remains unknown. We addressed this question using data from the New Rural Cooperative Medical Scheme (NRCMS) in Fuyang, Anhui, China. Daily hospital admissions for total CVDs, ischaemic heart disease, heart failure, heart rhythm disturbances, ischaemic stroke, and haemorrhagic stroke in rural regions of Fuyang, China, were extracted from NRCMS between January 2015 and June 2017. A two-stage time-series analysis method was used to assess the associations between NO₂ and CVD hospital admissions and the disease burden fractions attributable to NO₂. In our study period, the average number (standard deviation) of hospital admissions per day were 488.2 (117.1) for total CVDs, 179.8 (45.6) for ischaemic heart disease, 7.0 (3.3) for heart rhythm disturbances, 13.2 (7.2) for heart failure, 267.9 (67.7) for ischaemic stroke, and 20.2 (6.4) for haemorrhagic stroke. The 10-μg/m³ increase of NO₂ was related to an elevated risk of 1.9% (RR: 1.019, 95% CI: 1.005 to 1.032) for hospital admissions of total CVDs at lag0-2 days, 2.1% (1.021, 1.006 to 1.036) for ischaemic heart disease, and 2.1% (1.021, 1.006 to 1.035) for ischaemic stroke, respectively, while no significant association was observed between NO₂ and hospital admissions for heart rhythm disturbances, heart failure, and haemorrhagic stroke. The attributable fractions of total CVDs, ischaemic heart disease, and ischaemic stroke to NO₂ were 6.52% (1.87 to 10.94%), 7.31% (2.19 to 12.17%), and 7.12% (2.14 to 11.85%), respectively. Our findings suggest that CVD burdens in rural population are also partly attributed to short-term exposure to NO₂. More studies across rural regions are required to replicate our findings.

[Effects of Rehmanniae Radix and Rehmanniae Radix Praeparata on proteomics and autophagy in mice with type 2 diabetes mellitus induced by high-fat diet coupled with streptozotocin]

To compare the pancreatic proteomics and autophagy between Rehmanniae Radix-and Rehmanniae Radix Praeparata-treated mice with type 2 diabetes mellitus(T2DM). The T2DM mouse model was established by high-fat diet coupled with streptozotocin(STZ, intraperitoneal injection, 100 mg·kg~(-1), once a day for three consecutive days). The mice were then randomly assigned into a control group, low-(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix groups, low-(150 mg·kg~(-1)) and high-dose(300 mg·kg~(-1)) catalpol groups, low-(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix Praeparata groups, low-(150 mg·kg~(-1)) and high-dose(300 mg·kg~(-1)) 5-hydroxymethyl furfuraldehyde(5-HMF) groups, and a metformin(250 mg·kg~(-1)) group. In addition, a normal group was also set and each group included 8 mice. The pancreas was collected after four weeks of administration and proteomics tools were employed to study the effects of Rehmanniae Radix and Rehmanniae Radix Praeparata on protein expression in the pancreas of T2DM mice. The expression levels of proteins involved in autophagy, inflammation, and oxidative stress response in the pancreatic tissues of T2DM mice were determined by western blotting, immunohistochemical assay, and transmission electron microscopy. The results showed that the differential proteins between the model group and Rehmanniae Radix/Rehmanniae Radix Prae-parata group were enriched in 7 KEGG pathways, such as autophagy-animal, which indicated that the 7 pathways may be associated with T2DM. Compared with the control group, drug administration significantly up-regulated the expression levels of beclin1 and phosphorylated mammalian target of rapamycin(p-mTOR)/mTOR and down-regulated those of the inflammation indicators, Toll-like receptor-4(TLR4) and Nod-like receptor protein 3(NLRP3), in the pancreas of T2DM mice, and Rehmanniae Radix showed better performance. In addition, the expression levels of inducible nitric oxide synthase(iNOS), nuclear factor erythroid 2-related factor 2(Nrf2), and heine oxygenase-1(HO-1) in the pancreas of T2DM mice were down-regulated after drug administration, and Rehmanniae Radix Praeparata demonstrated better performance. The results indicate that both Rehmanniae Radix and Rehmanniae Radix Praeparata can alleviate the inflammatory symptoms, reduce oxidative stress response, and increase the autophagy level in the pancreas of T2DM mice, while they exert the effect on different autophagy pathways.

Selenium attenuates the association of co-exposure to arsenic, cadmium, and lead with cognitive function among Chinese community-dwelling older adults

The effects of interactions between the toxic and essential metal mixtures on cognitive function are poorly understood. This study aims to identify the joint association of arsenic (As), cadmium (Cd), and lead (Pb) with cognitive function in older adults and the moderating role of selenium (Se), zinc (Zn), and copper (Cu) in this association. This study included 1000 community-dwelling older adults. Cognitive function was assessed by the Mini-Mental State Examination (MMSE). Blood concentrations of As, Cd, Pb, Se, Zn, and Cu were measured using inductively coupled plasma mass spectrometry. Linear regression and Bayesian kernel machine regression (BKMR) models were applied to assess the individual and joint associations of As, Cd, and Pb with cognitive function and to examine whether Se, Zn, and Cu (individually and as a mixture) modified these associations. In the adjusted single-metal models, both Cd (β = - 0.37, 95% CI: - 0.73 to - 0.01) and Pb (β = - 0.44, 95% CI: - 0.86 to - 0.02) were associated with MMSE scores, while Se (β = 0.71, 95% CI: 0.30 to 1.13) exhibited a positive relationship with MMSE scores. Univariate exposure-response functions from BKMR models showed similar results. Moreover, the toxic metal mixture (As, Cd, and Pb) exhibited a significant negative association with MMSE scores in a dose-response pattern, with Pb being the greatest contributor within the mixture. The negative association of Pb alone or the toxic metal mixture with MMSE scores became weaker at higher concentrations of Se within its normal range, especially when Se levels were greater than the median (89.18 μg/L). Our findings support that Se can attenuate the negative associations of exposure to single Pb or the As, Cd, and Pb mixtures with cognitive function. Future prospective studies are needed to replicate our findings.

Omega-3 polyunsaturated fatty acids inhibit cardiomyocyte apoptosis and attenuate sepsis-induced cardiomyopathy

OBJECTIVES

Sepsis can cause myocardial injury, which is one of the leading causes of death in critically ill patients. Fish oil rich in omega-3 polyunsaturated fatty acids (PUFAs) in ultralong chains has immunomodulatory effects and can inhibit the production of various critically ill proinflammatory cytokines. Therefore, this study focused on whether ω-3 PUFAs have a protective effect on sepsis-induced cardiomyopathy (SIC).

METHODS

Male 6-8 weeks old C57BL/6 mice were pretreated with 3% special fish oil supplement rat food for seven consecutive days prior to surgery. Cecal ligation and puncture (CLP) was perfromed to induce polymicrobial sepsis.The cardiac function was assessed by echocardiography, apoptosis of cardiomyocyte were detected by TUNEL assay and Western blotting, and the level of TNF-α, IL-6, and IL-1β in plasma was determined 24h after CLP.

RESULTS

Pretreatment with omega-3 PUFAs attenuated cardiomyocyte apoptosis, decreased the production of proinflammatory cytokines, attenuated the SIC, and improved the survival rate of septic mice induced by CLP.

CONCLUSIONS

ω-3 PUFAs alleviate SIC through attenuating cardiomyocyte apoptosis, which provides a new direction for the prevention and treatment of SIC.

Angiotensin-(1-7) ameliorates sepsis-induced cardiomyopathy by alleviating inflammatory response and mitochondrial damage through the NF-κB and MAPK pathways

BACKGROUND

There is no available viable treatment for Sepsis-Induced Cardiomyopathy (SIC), a common sepsis complication with a higher fatality risk. The septic patients showed an abnormal activation of the renin angiotensin (Ang) aldosterone system (RAAS). However, it is not known how the Ang II and Ang-(1-7) affect SIC.

METHODS

Peripheral plasma was collected from the Healthy Control (HC) and septic patients and Ang II and Ang-(1-7) protein concentrations were measured. The in vitro and in vivo models of SIC were developed using Lipopolysaccharide (LPS) to preliminarily explore the relationship between the SIC state, Ang II, and Ang-(1-7) levels, along with the protective function of exogenous Ang-(1-7) on SIC.

RESULTS

Peripheral plasma Ang II and the Ang II/Ang-(1-7) levels in SIC-affected patients were elevated compared to the levels in HC and non-SIC patients, however, the HC showed higher Ang-(1-7) levels. Furthermore, peripheral plasma Ang II, Ang II/Ang-(1-7), and Ang-(1-7) levels in SIC patients were significantly correlated with the degree of myocardial injury. Additionally, exogenous Ang-(1-7) can attenuate inflammatory response, reduce oxidative stress, maintain mitochondrial dynamics homeostasis, and alleviate mitochondrial structural and functional damage by inhibiting nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thus alleviating SIC.

CONCLUSIONS

Plasma Ang-(1-7), Ang II, and Ang II/Ang-(1-7) levels were regarded as significant SIC biomarkers. In SIC, therapeutic targeting of RAAS, for example with Ang-(1-7), may exert protective roles against myocardial damage.

The association between essential trace element mixture and atherosclerotic cardiovascular disease risk among Chinese community-dwelling older adults

The evidence about the association of the essential trace element (ETE) mixture with atherosclerotic cardiovascular disease (ASCVD) amongst older adults is limited. This study aims to evaluate the associations of single ETEs and the ETE mixture with the 10-year ASCVD risks and its predicting factors in Chinese community-dwelling older adults. A total of 607 community-dwelling older adults were included in this study. Blood levels of vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), and selenium (Se) were assessed by inductively coupled plasma mass spectrometry. The predicted 10-year ASCVD risk was calculated using the Prediction for ASCVD Risk in China (China-PAR) equations. Traditional linear regressions and Bayesian kernel machine regression (BKMR) were used to assess the associations of single ETEs and the ETE mixture with the 10-year ASCVD risks and its predicting factors such as systolic blood pressure (SBP), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), diabetes, and waist circumference (WC). In linear regression models, blood Cr levels were negatively associated with the 10-year ASCVD risks after adjustment for covariates (β =  - 0.07, 95% CI =  - 0.11 ~  - 0.03); The 3th quartile (Q3) of Se levels was also associated with a lower 10-year ASCVD risks when compared with the lowest quartile (Q1) of Se levels (β_Q3 vs. _Q1: - 0.12, 95% CI =  - 0.22 ~  - 0.02). In BKMR models, the negative associations of Cr and Se with the 10-year ASCVD risks were observed. Higher blood levels of ETE mixture were associated with decreased 10-year ASCVD risks in a dose-response pattern, with Cr having the highest value of the posterior inclusion probability (PIP) within the mixture. Furthermore, a positive association between Cr and HDL-C and a negative association between Se and SBP were found in both linear regression and BKMR models. Cr and Se were negatively associated with the 10-year ASCVD risks, individually and as a mixture. ETE mixture showed a linear dose-response association with decreased 10-year ASCVD risks, with Cr being the most important component within the mixture. The negative association of the ETE mixture with the 10-year ASCVD risks may be attributed to Cr and Se, mainly mediated by HDL-C and SBP, respectively. Further cohort studies are needed to clarify this association.

Losartan attenuates sepsis-induced cardiomyopathy by regulating macrophage polarization via TLR4-mediated NF-κB and MAPK signaling

Sepsis-induced cardiomyopathy (SIC) is a serious complication of sepsis with high mortality but no effective treatment. The renin angiotensin (Ang) aldosterone system (RAAS) is activated in patients with sepsis but it is unclear how the Ang II/Ang II type 1 receptor (AT1R) axis contributes to SIC. This study examined the link between the Ang II/AT1R axis and SIC as well as the protective effect of AT1R blockers (ARBs). The Ang II level in peripheral plasma and AT1R expression on monocytes were significantly higher in patients with SIC compared with those in non-SIC patients and healthy controls and were correlated with the degree of myocardial injury. The ARB losartan reduced the infiltration of neutrophils, monocytes, and macrophages into the heart and spleen of SIC mice. Additionally, losartan regulated macrophage polarization from the M1 to the M2 subtype via nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thereby maintaining the mitochondrial dynamics balance in cardiomyocytes and reducing oxidative stress and cardiomyocyte apoptosis. In conclusion, the plasma Ang II level and AT1R expression on plasma monocytes are an important biomarker in SIC. Therapeutic targeting of AT1R, for example with losartan, can potentially protect against myocardial injury in SIC.

Rutin Inhibits Cardiac Apoptosis and Prevents Sepsis-Induced Cardiomyopathy

Rutin is a flavanol-type polyphenol that consists of flavanol quercetin and the disaccharide rutinose, which has been reported to exert various biological effects such as antioxidant and anti-inflammatory activities. It is not clear whether rutin has a protective effect on sepsis-induced cardiomyopathy (SIC). In this study, we used male C57BL/6 mice and cecal ligation and puncture (CLP) surgery to establish the model of SIC. Rutin was precautionarily treated (50, 100, 200 mg/kg per day, 7 days) before CLP. The results showed that rutin pretreatment (100, 200 mg/kg per day, 7 days) reduced the mortality of murine sepsis. We chose the 100 mg/kg dose for further studies. Mice were pretreatment with rutin (100 mg/kg per day, 7 days) before subjected to CLP, and myocardial tissue and blood samples were collected 24 h after CLP. Serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and cTNT decreased, while interleukin-10 (IL-10) increased with rutin pretreatment. The cardiomyocytes apoptosis and mitochondrial dysfunction were also alleviated with rutin pretreatment. In conclusion, this study confirmed the efficacy of rutin-enriched diet in the prophylaxis of cardiac apoptosis and cardiac injury induced by CLP in mouse model. It provides a potential new approach on SIC prophylaxis in sepsis.

[HIV infection status and related factors in men who have sex with men in sentinel surveillance in Shanxi province, 2010, 2015 and 2020]

Objective: To understand the infection status of HIV and related factors in men who have sex with men (MSM) in Shanxi province in 2010, 2015 and 2020. Methods: According to the sentinel surveillance protocol, continuous cross-sectional survey were conducted to collect the information about basic characteristics, general demographic characteristics, AIDS knowledge awareness, high-risk sexual behavior, sexually transmitted diseases, intervention services and HIV infection rate of the MSM in Shanxi in 2010, 2015 and 2020. Results: In 2010, 2015 and 2020, a total of 2 708 MSM were included in this study. There were significant differences in HIV infection rate among three years (χ²=23.76, P<0.001) with an increasing trend with year (trend χ² =17.34, P<0.001). The rates of anal sex, commercial sex and heterosexual behavior in the past 6 months were 77.62% (2 102/2 708), 5.91% (160/2 708) and 28.14% (762/2 708) respectively, and the rates of consistent use of condom were 52.52% (1 104/2 102), 63.13% (101/160) and 23.49%(179/762) respectively, and the rate of consistent condom use was low. Results from multivariate logistic regression analysis showed that different cities, having educational level of junior high school or below, being recruited through internet, voluntary counseling and testing, suffering from sexually transmitted diseases, occasional condom use in anal sex in the past 6 months were the correlative factors of HIV infection of MSM. Conclusions: The HIV infection rate of MSM in Shanxi increased year by year from 2010, 2015 to 2020. The HIV/AIDS-related risk behavior persisted, and the proportion of condomuse adherence was low, and the HIV detection rate was low in the MSM, so targeted and effective measures should be taken to promote the condom use adherence and regular HIV testing in MSM.

The association between essential trace element mixture and cognitive function in Chinese community-dwelling older adults

BACKGROUND

The evidence about the effect of essential trace element (ETE) mixture on cognitive function amongst older adults is limited. This study aims to evaluate the associations of single ETEs and ETE mixture with cognitive function using a representative sample of community-dwelling older adults in China.

METHODS

A total of 3814 older adults were included in the study. Urinary concentrations of selenium (Se), vanadium (V), cobalt (Co), strontium (Sr), and molybdenum (Mo) were detected by inductively coupled plasma mass spectrometry. Cognitive function in older adults was assessed using the Chinese version of the Mini-Mental State Examination (MMSE). Linear regression and Bayesian kernel machine regression (BKMR) were performed to explore the associations of single ETEs and ETE mixture with cognitive function, respectively.

RESULTS

Linear regression showed that urinary levels of Se and V were positively associated with MMSE scores in the adjusted single-element models. BKMR also showed marginally positive associations of Se and V with MMSE scores. Moreover, higher urinary levels of ETE mixture were significantly associated with increased MMSE scores in a dose-response pattern, and Se was the most important contributor within the mixture. Both Se and V demonstrated positive additive effects on the associations of other ETEs with MMSE scores, whereas Co had a negative additive effect.

CONCLUSIONS

V and Se are positively associated with cognitive function, individually and as a mixture. ETE mixture exhibits a linear dose-response association with improved cognitive function, with Se being the most important component within the mixture. Mixture analyses rather than single ETE analyses may provide a real-world perspective on the relationship between ETE mixture and cognitive function. Further cohort studies are needed to clarify the association of multiple ETEs with cognitive function.

[Rehmanniae Radix and Rehmanniae Radix Praeparata improve diabetes induced by high-fat diet coupled with streptozotocin in mice through AMPK-mediated NF-κB/NLRP3 signaling pathway]

This study investigated the differential mechanisms of Rehmanniae Radix and Rehmanniae Radix Praeparata in improving diabetes in mice through AMPK-mediated NF-κB/NLRP3 signaling pathway. The diabetic mouse model was established with high-fat diet coupled with streptozotocin(STZ, intraperitoneal injection, 100 mg·kg~(-1), once a day for three consecutive days), after which the mice were randomly divided into model group, low-dose(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix groups, low-dose(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix Praeparata groups, catalpol group(250 mg·kg~(-1)), 5-hydroxymethylfurfural(5-HMF) group(250 mg·kg~(-1)), metformin group(250 mg·kg~(-1)), with the normal group also set. The organ indexes of heart,liver, spleen, lung, kidney and pancreas were calculated after four weeks of administration. The pathological changes and fibrosis of pancreas, kidney and liver in mice were observed by hematoxylin-eosin(HE) staining and Masson staining. Western blot was used to determine the expression levels of Toll-like receptor-4(TLR4), nuclear factor-κB(NF-κB), Nod-like receptor protein 3(NLRP3),interleukin-1β(IL-1β), adenosine monophosphate-activated protein kinase(AMPK), phosphorylated AMPK(p-AMPK) in the pancreas, kidney and liver of mice. Compared with the model group, the administration groups witnessed significant decrease in the liver,spleen, kidney, pancreas and fat indexes of diabetic mice, and there was no significant difference in heart and lung indexes. The pathological states and fibrosis of pancreatic, kidney and liver tissues were significantly improved after administration. Additionally, the expression levels of TLR4, NF-κB and NLRP3 in pancreas, kidney and liver of diabetic mice were significantly lowered. The expression levels of p-AMPK/AMPK were enhanced significantly in kidney and liver of mice in Rehmanniae Radix group while in pancreas, kidney and liver in Rehmanniae Radix Praeparata group. This suggests that Rehmanniae Radix and Rehmanniae Radix Praeparata differ in the mechanism of regulating energy metabolism of multiple organs and thereby exerting anti-inflammatory effects to alleviate symptoms of diabetic mice.

The associations between urinary metals and metal mixtures and kidney function in Chinese community-dwelling older adults with diabetes mellitus

BACKGROUND

Previous studies have found associations between single toxic metals, such as arsenic and cadmium, and kidney function in adults with diabetes. However, studies with regards to other metals and metal mixtures are still limited.

OBJECTIVE

Our study aimed to investigate the associations between urinary concentrations of 5 selected metals and metal mixtures and kidney function using a sample of older adults with diabetes mellitus in Chinese communities.

METHODS

In a sample of older adults (n = 5186), 592 eligible subjects were included in this study. Urinary concentrations of 5 metals, i.e., arsenic (As), cadmium (Cd), vanadium (V), cobalt (Co), and thallium (Tl), were measured by inductively coupled plasma mass spectrometer (ICP-MS). Estimated glomerular filtration rate (eGFR) was calculated and dichotomized into indicator of chronic kidney disease (CKD). Logistic analysis and Bayesian kernel machine regression (BKMR) were used to explore the associations between single metals and metal mixtures and CKD, respectively.

RESULTS

Urinary levels of As and V were positively correlated with CKD (OR=2.37, 95% CI: 1.31-4.30 for As; OR=2.24, 95% CI: 1.25-4.03 for V), when compared the 4th quartile with the 1st quartile. After adjustment for potential confounders, the significant association between As and CKD still existed (OR=2.73, 95% CI: 1.23-6.07). BKMR analyses showed strong linear positive associations between As and V and CKD. Higher urinary levels of the mixture were significantly associated with higher odds of CKD in a dose-response pattern. As and V showed the highest posterior inclusion probabilities.

CONCLUSION

Urine As and V were positively associated with CKD in older adults with diabetes mellitus, separately and in a mixture. The metals mixture showed a linear dose-response association with the odds of CKD. The analyses of mixtures, rather than of single metals, may provide a real-world perspective on the relationship between metals and kidney function.

The Influence of Lower Temperature Induction of Valsa mali on the Infection of Apple Trees

Apple valsa canker (AVC), caused by Valsa mali, is one of the most important diseases of apple trees in China. AVC occurred severely along with cold winter or cold spring. However, the effect of lower temperature on V. mali is poorly understood. This study evaluated the influence of lower temperature pretreatment of V. mali on the infection of apple twigs and leaves. The results showed that exposing V. mali to lower temperatures (between -10°C and 10°C) for more than 18 h significantly increased the disease severity of apple leaves and twigs, with a higher lesion area ratio (LAR), lesion length, and disease incidence (DI) than that at 25°C. In addition, cold treatment ranging from -5°C to 10°C promoted colony growth. Meanwhile, the relative expression of four cell wall degrading enzyme (CWDE)-related genes pretreated at -5°C and 5°C were significantly higher than that at 25°C. The results indicated that the virulence of V. mali mycelium is sensitive to lower temperatures. After sensing lower temperature changes, V. mali can adjust its infection of apple trees by regulating the expression of pathogenicity gene and growth rate. Spring has very frequent temperature changes, and V. mali is highly invasive in this season. Therefore, more attention should be paid in spring to protecting apple trees from infection of V. mali, by reducing pruning wound formation in spring and applying protective agents to pruning wounds in time.

[Effect analysis of sequential laser application in treating the hypertrophic scars of burn children at early stage]

Objective: To explore the effects of sequential application of intensive pulsed light and carbon dioxide laser in treating the hypertrophic scars of burn children at early stage. Methods: A retrospective cohort before-after control study in the same patients was conducted. From January 2016 to December 2018, 145 burn children with hypertrophic scar at the early stage who met the inclusion criteria were admitted to the First Hospital of Jilin University, including 82 males and 63 females, aged 1 to 12 (3 (2, 6)) years. All the children were firstly treated with intense pulsed light therapy (no anesthesia or intravenous-inhalation combined anesthesia) at an interval of once per month, and then changed to carbon dioxide laser therapy (topical anesthesia or intravenous-inhalation combined anesthesia) when the degree of scar hyperemia was reduced, at an interval of once every 3 months, for a total of 3 times. Before the first intense pulsed light treatment (hereinafter referred to as before the first treatment) and 3 months after the last carbon dioxide laser treatment (hereinafter referred to as after the last treatment), scar scoring was evaluated by Vancouver Scar Scale (VSS), and scar hyperemia (denoted as hemoglobin level) was measured with Antera 3D^® camera. The times of intense pulsed light, the time of single treatment, the anesthesia method, and the time of intravenous-inhalation combined anesthesia of intense pulsed light and carbon dioxide laser treatment were analyzed. After the last treatment, Likert Scale was used to evaluate the efficacy satisfaction of both doctors and patients. Adverse reactions were recorded during the treatment. Data were statistically analyzed with Wilcoxon signed rank sum test, and paired sample t test. Results: The color, vascular distribution, thickness, and softness scores, and total score in VSS scoring of scars of children after the last treatment were significantly lower than those before the first treatment (Z=-6.05, -10.34, -9.84, -9.28, -10.43, P<0.01). The hemoglobin level of scar of children after the last treatment was 1.86±0.24, significantly lower than 2.27±0.32 before the first treatment (t=17.65, P<0.01). A total of 411 times of intense pulsed light therapy were performed, (2.8±0.6) times per person, and the single treatment time was 35 (20, 45) s. There were 392 times (95.38%) without anesthesia, and 19 times (4.62%) with intravenous-inhalation combined anesthesia with time of 6 (5, 8) min. The single treatment time of carbon dioxide laser therapy was 5 (3, 10) min. There were 364 times (83.68%) of topical anesthesia and 71 times (16.32%) of intravenous-inhalation combined anesthesia with time of 10 (8, 15) min. After the last treatment, the efficacy satisfaction scores of doctors and patients were (4.3±0.7) and (3.8±1.0) points, respectively. Blisters occurred in 5 cases after intense pulsed light treatment, which were healed naturally after drainage. One child developed local skin infection, skin redness and swelling accompanied by purulent exudate after carbon dioxide laser treatment, which was improved after skin disinfection and external use of mupirocin ointment. No inflammatory pigmentation, worsening of hyperplasia of scar, erythema, or other skin adverse reactions or anesthetics-related adverse reactions occurred in any child. Conclusions: Sequential application of intense pulsed light and carbon dioxide laser to treat the hypertrophic scars of burn children at early stage can obviously improve the appearance and texture of scar, with higher satisfaction of doctors and patients and fewer adverse reactions.

[A deep learning-based lung nodule density classification and segmentation method and its effectiveness under different CT reconstruction algorithms]

Objective: To evaluate the diagnostic value of the lung nodule classification and segmentation algorithm based on deep learning among different CT reconstruction algorithms. Methods: Chest CT of 363 patients from June 2019 to September 2019 in Radiology Department of Tianjin Medical University Chu Hsien-I Memorial Hospital were retrospectively collected in this study, each of which consisted of images by three different reconstruction methods (lung reconstruction, mediastinal reconstruction, bone reconstruction).These collected data were used as testing set and a total of 4 185 Chest CTs including the public data set and the constructed private data set were used as the training set. A model combines 3D deep convolutional neural network and recurrent neural network under a multi-task joint learning algorithm for lung nodule classification and segmentation were constructed. The well-trained method was tested on 363 test cases using two metrics, i.e., the accuracy of the density classification and the Dice coefficient of nodule segmentation. The performances under three reconstruction methods were statistically analyzed according to the variance analysis among three different reconstruction methods. Results: The average classification accuracies of the nodule under three reconstruction methods were 98.67%±5.70%, 98.38%±6.61% and 97.89%±7.32%. Specifically, the accuracies of the solid nodules under three reconstruction methods were 98.79%±5.58%, 98.49%±6.89% and 97.90%±7.41% and the accuracies of the sub-solid nodules were 97.57%±10.19%, 98.52%±7.77% and 98.52%±7.77%. There was no significant difference in the classification accuracy of pulmonary nodules under three different reconstruction algorithms (all P>0.05). The average Dice coefficients of nodule segmentation was 79.87%±5.78%, 79.02%±6.04% and 79.31%±5.95%. There was no significant difference in the average Dice coefficients of nodule segmentation under three different reconstruction algorithms (all P>0.05). Conclusion: Deep learning algorithm which combined with 3D convolutional neural network and recurrent neural network has demonstrated relatively stable in classification and segmentation of lung nodules under different CT reconstruction method.

[Analysis of anxiety, depression and related factors in patients with chronic lumbocrural pain before minimally invasive surgery]

OBJECTIVE

To investigate anxiety and/or depression status of patients with chronic lumbocrural pain, and to further analyze related risk factors of anxiety and/or depression .

METHODS

Retrospective analysis of the medical data of patients who suffered from chronic lumbocrural pain caused by lumbar disc herniation and/or lumbar spinal stenosis and received minimally invasive surgery from March 2018 to April 2018. General data (including age, gender, education levels, past history, sleep order and medical insurance), numeric rating scale(NRS), Japanese Orthopedic Association(JOA) back pain scale and hospital anxiety and depression scale(HADS) were collected for analysis. The basic demographic data and clinic data were analyzed, possible related risk factors associated were analyzed by univariate analysis, and multivariate Logistic regression analysis was further used to find the relative independent risk factors and included all the predictive variables with P values less than 0.05 as covariates.

RESULTS

A total of 91 patients met the inclusion criteria and finished this study, the mean HADS score for anxiety was 8.1±4.2, 48(52.7%) respondents were screened positive for anxiety, while the rest 43(47.3%) patients had negative anxiety state, the mean HDDS score for depression was 6.9±4.9, 38(41.8%) respondents were screened positive for depression, and the rest 53(58.2%) patients were not depressed, and 56(61.5%) patients experienced anxiety or depression. There were significant difference in sleep disorder, JOA score and leg NRS score between the patients with and without anxiety(P<0.05), and the significant differences were also found in age, sleep disorder and JOA score between the patients with and without depression(P<0.05), Logistic regression analysis further showed that the JOA score and sleep disorder were risk factors for anxiety, and the JOA score was risk factor for depression.

CONCLUSION

Patients with chronic lumbocrural pain are often accompanied by anxiety and/or depression before minimally surgery, the low JOA score and sleep disturbance increased the risk of presenting anxiety, and the low JOA score increased the risk of developing depression. It is necessary to evaluate mental status and related risk factors before surgery.

Cepharanthine, a bisbenzylisoquinoline alkaloid, inhibits lipopolysaccharide-induced microglial activation

Activation of microglial cells in the brain has been considered to be associated with various neurodegenerative diseases (NDD). In this study, cepharanthine, a bisbenzylisoquinoline alkaloid, was found to inhibit lipopolysaccharide (LPS)-induced microglial activation. Cepharanthine suppressed the release of nitric oxide (NO) by LPS-activated primary mouse cortical microglia and/or BV2 microglial cell line. Cepharanthine reduced LPS-induced mRNA expression of inducible NO synthase (iNOS), but it did not display direct NO-scavenging activity up to 100 μM in sodium nitroprusside (SNP) solution. Further studies revealed that cepharanthine suppressed the release of cytokines (TNF-α, IL-1β, and IL-6) by LPS-activated microglial cells. Cepharanthine may have potential in the treatment of neurodegenerative diseases accompanied by microglial activation.

[Blood-cooling and hemostasis effects of Rehmanniae Radix before and after carbonizing]

To compare the blood-cooling and hemostasis effects of Rehmanniae Radix before and after carbonizing on rats with blood heat and hemorrhage syndrome. The blood heat and hemorrhage syndrome rat model was established. Indexes including rectal temperature,whole blood viscosity,plasma viscosity,thrombin time(TT),activated partial thromboplastin time(APTT),prothrombin time(PT),fibrinogen content(FIB),red blood cell(RBC),hemoglobin(Hb),hematocrit(HCT),blood platelet count(PLT),mean platelet volume(MPV),serum IL-1,serum IL-6 and lung histopathology were detected to investigate the blood-cooling and hemostasis effects of Rehmanniae Radix and its carbonized products. Compared with the blank control group,the rectal temperature was significantly increased with rise of the high,middle and low whole blood viscosities and plasma viscosity(P<0.05); both the high and low whole blood restore viscosity and the high and low whole blood relative viscosity were increased significantly(P< 0.05); TT,APTT and PT were notably prolonged with the increase in FIB content(P<0.05); RBC,Hb and HCT increased significantly(P< 0.05); concentrations of serum IL-1 and IL-6 were also increased(P< 0.05) in model group. Additionally,obvious hemorrhages in lung and stomach were observed in rats of the model group. Rehmanniae Radix and its carbonized products can significantly reduce rectal temperature,high middle and low whole blood viscosities and plasma viscosity(P<0.05). TT and APTT were shortened,with lower expression of FIB in group of Rehmannia Radix and its carbonized products. Hemorrhages of lung and stomach were improved by Rehmannia Radix and its carbonized products. The results indicated that Rehmannia Radix before and after carbonizing had the hemostasis and blood-cooling effects by promoting coagulation,improving blood rheology and inhibiting expressions of IL-1 and IL-6.

Latent Infection of Valsa mali in the Seeds, Seedlings and Twigs of Crabapple and Apple Trees is a Potential Inoculum Source of Valsa Canker

A real-time quantitative PCR assay using a species-specific primer pair was developed to rapidly and accurately quantify Valsa mali, the causative pathogen of apple Valsa canker (AVC), in crabapple seeds, crabapple seedlings, apple twigs and apple seeds. Surveys were conducted in different regions, and crabapple or apple seeds were collected for V. mali detection by qPCR assay. Our results showed that 12.87% to 49.01% of crabapple seeds collected from different regions were positive for V. mali. The exopleura and endopleura were the two major areas of V. mali infection in crabapple seeds. The presence of V. mali infection in crabapple seeds was also confirmed by a high-throughput sequencing approach. With the growth of crabapple seedlings, the concentration of V. mali gDNA in crabapple seedlings gradually increased until eight or more leaf blades emerged. One-year-old twigs from an apple scion nursery were infected with V. mali, and only apple seeds from infected apple trees showing evident Valsa canker symptoms carried V. mali. In conclusion, this study reports that crabapple seeds and apple seeds carried V. mali as latent inoculum sources. V. mali infected not only apple tissues but also crabapple seedlings, which are the rootstocks of apple trees. This study indicated that the inoculum sources for AVC vary. Application of a novel qPCR assay can potentially improve the accuracy of early diagnosis, and is helpful to reveal the epidemic regularity of AVC.

[Analysis of clinical characteristics of discordant structural malformations in one of monochorionic diamnionic twins]

Objective: To analyze the clinical characteristics of structural malformations in one of monochorionic diamnionic twins (MCDA). Methods: The clinical data of 77 MCDA patients with structural malformations diagnosed by ultrasound were retrospectively reviewed from January 2012 to May 2017. The distribution of structural malformations, prenatal chromosomal karyotyping and pregnancy outcomes were analyzed. Results: (1)Among the 77 MCDA patients with structural malformations, the single malformation accounted for 79%(61/77), the multiple malformations accounted for 21%(16/77). And there were a total of 94 types of malformations, the top three malformations were neurological malformations (32%, 30/94), cardiovascular malformations (29%, 27/94) and twin reversed arterial perfusion sequence (TRAPS;10%,9/94).(2)Among the 77 patients with structural malformation, 64 cases (83%, 64/77) were examined for fetal chromosomes, of whom 14 cases (22%,14/64) were examined for fetal chromosomes of both twins, with 1 case (1/14) of discordant fetal chromosome. (3)Among the 77 patients, 4 cases (5%, 4/77) with severe fetal malformations terminated pregnancy. Totally 29 cases (38%,29/77) with severe malformations were treated with selective fetal reduction, among whom 7 cases (24%, 7/29) experienced unexplained fetal death within 24 hours after the operation; 2 cases (7%, 2/29) happened inevitable abortion, and 2 cases (7%, 2/29) underwent unexplained fetal death during the late pregnancy. Of the remaining 44 patients (57%,44/77) with expectant treatment, 13 cases (30%,13/44) occurred twin transfusion syndrome (Ⅱ-Ⅳ), and were treated with fetoscopic laser occlusion. Eight patients had 2 survival twins, 4 patients delivered 1 survival twin, and 1 patient had dead twins. Conclusions: The most common malformations in MCDA twins are the nervous malformations, cardiovascular malformations and TRAPS. The chromosome karyotype of MCDA twins with structural malformations are sometimes discordant, and separate samling of the twins is suggested for prenatal diagnosis. Selective fetal reduction could be given to severe structural malformation in MCDA patients safely and effectively. For non-severe structural malformation in MCDA patients with twin transfusion syndrome, fetoscopic laser occlusion is safe and effective.

[Surgical results and sagittal alignment analysis of different fusion levels for degenerative scoliosis]

Objective: To retrospectively investigate the effects of long segment fusion and short segment fusion on lumbar sagittal alignment and quality of life in patients with degenerative scoliosis. Methods: From January 2011 to December 2014, 75 patients with degenerative scoliosis were treated with pedicle screw fixation. Total of 56 females and 19 males were included in this study. Fifty-four patients underwent short-segment fusion (≤3 segments) and 21 patients underwent long-segment fusion (>3 segments). The average age of the patients was (63±8) years. The patients were followed-up for a mean time of (2.9±1.3) years. The postoperative follow-up included Cobb angle, pelvic tilt, sacral slope, lumbar lordosis, visual analogue scale of pain on lumbar and lower extremities and Oswestry disability index. Fusion levels, blood loss, surgery length and postoperative hospital stay were recorded. All above parameters were evaluated statistically with Student's t test. Results: The short segment fusion group averaged (1.8±0.7) segments, and the long segment fusion group averaged (5.2±1.6) segments. Coronal Cobb angle changed from (21.3±7.8) degrees preoperatively to (15.3±5.6) degrees at final follow-up in short-segment fusion group (t=2.315, P=0.024) and from (44.5±11.2) degrees preoperatively to (11.4±5.8) degrees at the final follow-up in long-segment fusion group (t=8.214, P<0.01). In the short segment fixation group, the preoperative lumbar lordosis changed from (44.3±9.7) degrees to (48.9±8.2) degrees at final follow-up (t=2.123, P=0.038), and it changed from (25.3±9.5) degrees to (52.1±11.2) degrees in the long segment fusion group (t=5.982, P<0.01). The sacral slope in the short segment fusion group increased from (22.6±6.8) degrees preoperatively to (34.1±7.5) degrees at the final follow-up (t=2.872, P=0.006), and it increased from (12.1±9.5) degrees to (37.8±8.4) degrees in long segment fusion group (t=7.314, P<0.01). The pelvic tilt in the short segment fusion group changed from (23.5±5.5) degrees preoperatively to (19.5±4.7) degrees at final follow-up (t=2.217, P=0.031), and it decreased from (27.1±6.1) degrees to (22.9±4.3) degrees in the long segment fusion group(t=2.131, P=0.045). The visual analogue scale of pain on lumbar and lower extremities and Oswestry disability index were all improved after the operation in both groups. Conclusions: Both short segment fusion and long segment fusion can achieve satisfactory surgical results and improves the spinal-pelvic parameters. Short segment fusion can reduce surgery trauma and shorten hospital stay relative to long segment fixation.

[Preliminary investigation on processing mechanism of Kansui Radix by liquorice based on thermal analysis technology]

In the thermal analysis, the pyrolysis characteristics of crude Kansui Radix, alcohol extract of Kansui Radix, petroleum ether extract, chloroform extract, ethyl acetate extract, n-butanol extract, and licorice vinegar were analyzed with simulated air (N₂-O₂ 4:1) as the carrier gas, at a temperature increase rate of 10 °C·min⁻¹ and a volume flow rate of 60 mL·min⁻¹, respectively. The results showed that due to the different polarity of the extraction solvent, the type and quantity of the chemical components contained in each polar part were different, and with the increase in the amount of solid powder of licorice, the peak of the maximum heat loss rate occurred in advance. For petroleum ether, chloroform, and ethyl acetate fractions, (157.40±1.06), 3.50, (25.83±1.66) °C in advance respectively, but the weight loss rate of the chloroform fraction was increased by (2.62±5.19) °C, while decreased by (33.90±1.72), (19.28±1.11) °C for the petroleum ether and ethyl acetate fractions. So we can conclude that with the addition of licorice, the pyrolysis rate of the petroleum ether and chloroform fractions in the toxic part of Kansui Radix was increased; the temperature point at the peak of the maximum weight loss rate was decreased, and the ethyl acetate fraction (effective part) showed a decrease in temperature rising process, but its overall ratio of weight loss and weight loss rate were relatively small, retaining the effect of medicinal ingredients. This proved the mechanism of licorice system Kansui Radix on attenuating toxicity after processing and the scientificity and rationality of licorice system Kansui Radix. At the same time, as the proportion of glycyrrhizin was increased, the peak of the maximum heat loss rate of petroleum ether, chloroform and ethyl acetate fractions occurred in advance; the peak temperature was decreased, with easy pyrolysis. Among them, the thermogravimetric rate of the mixture of petroleum ether and chloroform fractions (10:1) was relatively large, with a low peak temperature, while ethyl acetate fraction showed opposite results. This conclusion has certain guiding significance for the ratio of gansui to licorice.

Incidence and risk factors for multiple medical complications in adult degenerative scoliosis long-level fusion

Adult degenerative scoliosis (ADS) surgery is known for its high incidence of complications. The propose of this study was to determine current complication rates and the predictors of medical complications in surgical ASD patients. A retrospective study of 153 ADS patients who underwent long level spinal fusion with 2-year follow-up between 2012 and 2017. The patient- and surgical-related risk factors for each individual medical complication were identified by using univariate testing. All patients were divided into groups with and without medical complication, infection, neurological complications, and cardiopulmonary complications, respectively. Potential risk factors were identified using univariate testing. Multivariate Logistic regression was used to evaluate independent predictors of medical complications. The total medical complication incidence was 26.1%. Patient-related independent risk factors for the development of medical complications included diabetes, smoking; for infection were diabetes and smoking; for neurological complications were BMI and diabetes; for cardiopulmonary complications were hypertension, smoking and cardiac comorbidity. Surgical-related independent risk factors for the development of medical complications were fusion level, operative time, osteotomy, blood transfusion and LOS; for infection were fusion level, blood transfusion, and LOS; for neurological complication were fusion level, osteotomy and blood transfusion; for cardiopulmonary complication were fusion level. Diabetes and smoking were the most common patient-related independent risk factors increase the development of each individual medical complication. On the other hand, fusion levels and blood transfusion were the most common surgical-related independent risk factors increase the development of each individual medical complication. Prevention of these risk factors can reduce the incidence of complications in Chinese patients with ADS surgery.

Risk factors for medical complications after long-level internal fixation in the treatment of adult degenerative scoliosis

PURPOSE

This study evaluates baseline patient characteristics and surgical parameters for risk factors of medical complications in ASD patients received posterior long level internal fixation.

METHODS

Analysis of consecutive patients who underwent posterior long-level instruction fixation for adult degenerative scoliosis (ADS) with a minimum of two year follow-up was performed. Pre-operative risk factors, intraoperative variables, peri-operative radiographic parameters, and surgical-related risk factors were collected to analyze the effect of risk factors on medical complications. Patients were separated into groups with and without medical complication. Then, complication group was further classified as major or minor medical complications. Potential risk factors were identified by univariate testing. Multivariate logistic regression was used to evaluate independent predictors of medical complications.

RESULTS

One hundred and thirty-one ADS patients who underwent posterior long segment pedicle screws fixation were included. Total medical complication incidence was 25.2%, which included infection (12.2%), neurological (11.5%), cardiopulmonary (7.6%), gastrointestinal (6.1%), and renal (1.5%) complications. Overall, 7.6% of patients developed major medical complications, and 17.6% of patients developed minor medical complications. The radiographic parameters of pre-operative and last follow-up had no significant difference between the groups of medical complications and the major or minor medical complications subgroups. However, the incidence of cerebrospinal fluid leak (CFL) in patients who without medical complications was much lower than that with medical complications (18.4 vs. 42.4%, P = 0.005). Independent risk factors for development of medical complications included smoking (OR = 6.45, P = 0.012), heart disease (OR = 10.07, P = 0.012), fusion level (OR = 2.12, P = 0.001), and length of hospital stay (LOS) (OR = 2.11, P = 0.000). Independent risk factors for development of major medical complications were diabetes (OR 6.81, P = 0.047) and heart disease (OR = 5.99, P = 0.049). Except for the last follow-up, Oswestry Disability Index and visual analog scale of the patient experienced medical complications trend higher score; the clinical outcomes have no significant difference between the medical and major complications groups.

CONCLUSION

Heart disease comorbidity is an independent risk factor for both medical and major medical complications. Smoking, fusion level, and LOS are independent risk factors for medical complication. Diabetes is the independent risk factors for major medical complications.

Do alkyl groups on aromatic or aliphatic structure directing agents affect water stabilities and properties of hybrid iodoargentates?

Two types of in situ formed structure directing agents (SDAs) including aromatic triphenylphosphine (PPh₃)- and aliphatic piperazine (H₂pp)-derivative cations were used to synthesize five new hybrid iodoargentates, namely (EtPPh₃)Ag₃I₄ (1, Et = ethyl), (n-PrPPh₃)Ag₃I₄ (2, n-Pr = n-propyl), (i-PrPPh₃)Ag₅I₆ (3, i-Pr = isopropyl), (Me₄pp)_0.5AgI₂ (4, Me = methyl), and (H₃app)₂(Ag₂I₆)·2I·2H₂O (5, app = N-aminoethylpiperazine). A comparative study of the two types of SDAs on the structures, stabilities and properties of hybrid iodoargentates was performed in detail. Structurally, except for (EtPPh₃)⁺ and (n-PrPPh₃)⁺, which both directly form (Ag₃I₄)^- anionic chains in 1 and 2, three SDAs generate hybrid iodoargentates different from each other with inorganic anions ranging from a 0-D (Ag₂I₆)^4- dimer to 1-D α-type (AgI₂)^- and (Ag₅I₆)^- chains. With regard to the electronic structures, aromatic PPh₃-derivative cations make noticeable contributions to the bottom of the conduction bands, while aliphatic pp-derivative cations make nearly no contribution to the frontier orbitals, clearly indicating their different ways to adjust the band gaps. With regard to stability, the decomposition temperatures of 1-3 in the range of 324-349 °C are noticeably higher than the values of 217 and 225 °C for 4 and 5. Furthermore, 1-4 exhibit good water stabilities, which is ascribed to the alkylation reactions precluding the formation of strong hydrogen bonds between alkylated SDAs and extraneous H₂O molecules. Contrarily, the presence of typical hydrophilic [double bond, length as m-dash]NH₂⁺, [triple bond, length as m-dash]NH⁺ and -NH₃⁺ groups on the protonated (H₃app)³⁺ cation makes 5 sensitive to water and a hydrolysis reaction occurs to generate a cubic AgI phase. Finally, 1-3 exhibit high photocatalytic efficiencies for the degradation of rhodamine B (RhB) dye in wastewater under visible light. All conclusions obtained here will help a lot in the synthesis of stable functional metal halide-based hybrids.

[Perioperative stroke effectively treated by an acute stroke team including anesthesia department: a case report]

Perioperative stroke is cerebral infarction occurring in the perioperative period. The incidence of perioperative stroke in non-cardiac, and non-neurologic surgery is about 0.7%, but the mortality can be as high as 26% to 40%. The outcome of the patients with perioperative stroke can be disastrous. Here we report a case of perioperative ischemic stroke that occurred after surgery of lumbar decompression and pedical screw fixation. A 76-year-old female admitted to our hospital because of lumbar spinal stenosis. Her medical history included hypertension and diabetes for ten years. Her personal history included a smoking history of 60 years by 2 cigarettes per day, not quitting. Her carotid artery ultrasound showed multiple low echo plaques on the right side and multiple high echo plaques on the left side of the carotid artery, but without distinct stenosis. Other examinations and tests showed no distinct abnormality. She went on a lumbar decompression and pedical screw fixation uneventfully. The blood loss was 400 mL and autologous blood transfusion 150 mL. The arterial blood pressure (ABP) maintained during 100-130 mmHg/60-80 mmHg (1 mmHg=0.133 kPa). Sixty minutes after she recovered from general anesthesia, the patient developed symptoms of slurred speech and right limbs weakness. The anesthesio-logist evaluated the patient immediately with National Institute of Health Stroke Scale (NIHSS). The NIHSS score was 11 and a stroke was highly suspected. The acute stroke team was therefore initiated and fast responded. Within 4 h, digital subtraction angiography (DSA) was proceeded, which showed the M1 segment of the left middle cerebral artery was occluded and the local stenosis of her right middle cerebral artery was up to 80%. After the successful embolectomy by Solitaire stent, the left middle cerebral artery reflowed and the forward blood flow was thrombolysis in myocardial infarction (TIMI) grade 3. The patient was discharged after 33 days after the surgery with a NIHSS of 9. Our case provides an example that an acute stroke team that included the department of anesthesiology can be beneficial to the patients' perioperative strokes. During the perioperative period, anesthesiologists should be included into the acute stroke team, because anesthesiologists and anesthesia nurses might be first observers of those early onset strokes. Our case also put forward this thought that a standard peri-operative stroke evaluation tool, like NIHSS, should be discussed and applied to facilitate and accelerate the initiation of perioperative acute stroke team.

Relationship between ncRNAs and gastric cancer: meta-analysis

OBJECTIVE

This study was designed to investigate the action and mechanism of cordyceps polysaccharide on rat acute liver failure (ALF).

METHODS

Sixty rats were randomly divided into five groups: normal group, model group, and cordyceps polysaccharide groups with high, middle and low doses (20, 10 and 5 mg/ml). Apoptosis was detected through TUNEL method. Protein expressions of caspase 1, IL-18, IL-10, VEGF, and SDF-1α in liver tissue are detected by Western Blot. PCNA and sIRPα1 contents were measured by PCR method. Rat ALF is modeled with a D-galactosamine induced by lipopolysaccharide (LPS).

RESULTS

The results after modelling showed tissue HE staining wiith typical manifestation of acute liver injury. Compared with the medicated group, serum ALT and AST, as well as hepatocyte apoptosis are significantly higher in the liver failure group, in a time-dependent way. This suggests that medication can effectively inhibit the expression of caspase 1, IL-18, and IL-10, while simultaneously increasing the expression of VEGF and SDF-1α, as well as of PCNA and sIRPα1. Cordyceps polysaccharide can alleviate the immune inflammatory response in acute liver failure, and may be specifically homing to the damaged liver, thus promoting the secretion of VEGF, proliferation of hepatocyte, regeneration of liver vessels, and repair of liver tissues.

CONCLUSION

Medication can reduce the IL-10 level, regulate the equilibrium of pro-inflammatory and anti-inflammatory factors, and decrease the level of caspase 1 and IL-18 (Tab. 2, Fig. 1, Ref. 18).

[Topping-off surgery versus double-segment fusion for treatment of lumbar degenerative disease with mid-long term follow-up]

Objective: To compare the mid-long term clinical effect of Topping-off surgery and lumbar fusion surgery for two-segmental lumbar degenerative disease. Methods: From March 2009 to March 2012, one hundred and twenty-six consecutive patients (Topping-off surgery and two-segment PLIF surgery) were studied in Orthopedics Department, Beijing Chao-Yang Hospital, Capital Medical University.The VAS and ODI were used to assess clinical symptoms.All patients underwent flexion/extension radiographs examinations before surgery, 1, 2 years and last follow-up postoperatively.Lumbar lordosis, sacral slop, data of Coflex segment and adjacent segment (disc height index, range of motion, foraminal height, foraminal width and Pfirrmann classification of intervertebral disc in MRI) were recorded.The paired double-tailed t test was used to analyze the differences in the results from baseline to each postoperative time point.The paired double-tailed t test was used in both groups to analyze the differences in the results from baseline to each postoperative time point.The Chi-square test was used to evaluate the differences between the incidences of adjacent segment degeneration(ASD) in the groups. Logistic regression analysis was used to analyze risk factors for developing radiographic ASD. Results: In topping-off group, 60 patients, average operation time was (134.5±10.2) min. The average blood loss was (301.5±64.6) ml.In fusion group, 68 patients, average age (58.3±4.6) years.The average follow-up time was (47.5±5.1) months.The average operation time was (158.6±19.3) min (P=0.000). The average blood loss was (413.6±131.3) ml (P=0.000). Sex, age, body mass index and intervertebral disc grading were matched between the two groups.Better improvement in VAS back pain score was noted in the topping-off group over the fusion group (P=0.030). Both groups achieved good recovery in ODI and improvement in VAS leg pain and back pain scores at last follow-up postoperatively.In the Topping-off group, FH increased from 10.5 mm at baseline to 11.8 mm at 1 year after surgery (P=0.000) and then decreased mildly in the third postoperative year, while in the fusion group, showed no significant change at all postoperative time points.In the fusion group, the disc height and FW at the same segment were no significant change after first year follow-up, while ROM was significantly decreased after surgery (P=0.000). Foraminal height, foraminal width and intervertebral disc height of adjacent segment of Coflex implant level were found decreased at the end of the postoperative follow-up, while compared with preoperative data no significant difference (P>0.05). At last follow-up, eight patients (13.3%) in the Topping-off group and eighteen patients (26.5%) in the fusion group developed ASD (P=0.033). Conclusions: Topping-off surgery compared with two-segment lumbar fusion surgery can achieve a good result in cases with pre-existing mild or moderate adjacent segment degeneration, restrict the adjacent segment's range of motion and reduce the adjacent segment degeneration. Under strict indications, Topping-off surgery is an acceptable alternative to fusion surgery for the treatment of two-segment lumbar disease.

[Efficacy of Coflex in the treatment of lumbar spondylolisthesis]

Objective: To study the clinical results of Coflex and lumbar posterior decompression and fusion in the treatment of lumbar degenerative spondylolisthesis at L(4-5). Methods: Thirty-eight patients with Grade Ⅰ degenerative spondylolisthesis, from January 2008 to December 2011 in Beijing Chaoyang Hospital, Capital Medical University were reviewed, and patients were divided into two groups by randomness. Group A was treated with Coflex and group B with pedicle instrumentation and interbody fusion. Fifteen patients were included in group A, and 23 patients were included in group B. In group A, the average age was (56.3±9.1) years. In group B, the average age was (58.2±11.2) years. The clinical results were evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI). Slip distance (SD) was measured before and after surgery, and the changes of intervertebral angle at index level and adjacent level were also recorded. Results: The follow-up period was 36 to 68 months, with the average of (39±14) months in the both groups. The operation time and bleeding volume of patients in group A were significantly less than that of group B (P<0.05). In both groups, the difference of ODI and VAS before operation and postoperative follow-up were statistically significant (P<0.05). There was no significant difference between lumbar intervertebral angle and the sliding distance in group A at all time points. In the group B, there was a significant increase in the intervertebral angle and the sliding distance at L(3-4) and L(5)-S(1 )level after surgery, the difference at upper and below adjacent segment before and after surgery were statistically significant. Conclusions: Coflex interspinous dynamic stabilization system has same excellent clinical results as pedicle screw instrumentation and fusion surgery for the treatment of L(4-5) degenerative spondylolisthesis; no significant progression of spondylolisthesis been observed during more than 3 years follow-up, and no obvious adjacent segment degeneration has been found.

Contribution of the Alternative Respiratory Pathway to PSII Photoprotection in C3 and C4 Plants

The mechanism by which the mitochondrial alternative oxidase (AOX) pathway contributes to photosystem II (PSII) photoprotection is in dispute. It was generally thought that the AOX pathway protects photosystems by dissipating excess reducing equivalents exported from chloroplasts through the malate/oxaloacetate (Mal/OAA) shuttle and thus preventing the over-reduction of chloroplasts. In this study, using the aox1a Arabidopsis mutant and nine other C3 and C4 plant species, we revealed an additional action model of the AOX pathway in PSII photoprotection. Although the AOX pathway contributes to PSII photoprotection in C3 leaves treated with high light, this contribution was observed to disappear when photorespiration was suppressed. Disruption or inhibition of the AOX pathway significantly decreased the photorespiration in C3 leaves. Moreover, the AOX pathway did not respond to high light and contributed little to PSII photoprotection in C4 leaves possessing a highly active Mal/OAA shuttle but with little photorespiration. These results demonstrate that the AOX pathway contributes to PSII photoprotection in C3 plants by maintaining photorespiration to detoxify glycolate and via the indirect export of excess reducing equivalents from chloroplasts by the Mal/OAA shuttle. This new action model explains why the AOX pathway does not contribute to PSII photoprotection in C4 plants.

Overexpression of Selenoprotein SelK in BGC-823 Cells Inhibits Cell Adhesion and Migration

Effects of human selenoprotein SelK on the adhesion and migration ability of human gastric cancer BGC-823 cells using Matrigel adhesion and transwell migration assays, respectively, were investigated in this study. The Matrigel adhesion ability of BGC-823 cells that overexpressed SelK declined extremely significantly (p < 0.01) compared with that of the cells not expressing the protein. The migration ability of BGC-823 cells that overexpressed SelK also declined extremely significantly (p < 0.01). On the other hand, the Matrigel adhesion ability and migration ability of the cells that overexpressed C-terminally truncated SelK did not decline significantly. The Matrigel adhesion ability and migration ability of human embryonic kidney HEK-293 cells that overexpressed SelK did not show significant change (p > 0.05) with the cells that overexpressed the C-terminally truncated protein. In addition to the effect on Matrigel adhesion and migration, the overexpression of SelK also caused a loss in cell viability (as measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) colorimetric assay) and induced apoptosis as shown by confocal microscopy and flow cytometry. The cytosolic free Ca2+ level of these cells was significantly increased as detected by flow cytometry. But the overexpression of SelK in HEK-293 cells caused neither significant loss in cell viability nor apoptosis induction. Only the elevation of cytosolic free Ca2+ level in these cells was significant. Taken together, the results suggest that the overexpression of SelK can inhibit human cancer cell Matrigel adhesion and migration and cause both the loss in cell viability and induction of apoptosis. The release of intracellular Ca2+ from the endoplasmic reticulum might be a mechanism whereby the protein exerted its impact. Furthermore, only the full-length protein, but not C-terminally truncated form, was capable of producing such impact. The embryonic cells were not influenced by the elevation of free Ca2+ level in cytosol, probably due to their much greater tolerance to the variation.

[Influence of sevoflurane concentration and stimulation voltage on motor evoked potentials in intraspinal tumor surgery]

OBJECTIVE

To evaluate the effects of increasing end-tidal concentrations of sevoflurane and increasing stimulation voltage on motor evoked potentials, so as to provide evidence in making anesthesia plan for intraspinal tumor surgery.

METHODS

In the study, 48 patients scheduled to undergo intraspinal tumor surgery [American Society of Anesthesiology,(ASA) I-II, 18-65 years old] were enrolled. After general anesthesia induction, the patients were assigned to receive sevoflurane anesthesia of increasing end-tidal concentration in the sequence of 0.0%, 0.5%, 1.0% and 1.5% respectively, under a background of propofol and remifentanil. All the observations were done before the important steps of surgery. Remifentanil infusion rate was 0.2 μg /(kg×min), while the propofol infusion rate was adjusted to maintain the bispectral index values within the range of 30-50. At each concentration, 4 stimulation voltages of 300 V, 400 V, 500 V and 600 V were employed to elicit motor evoked potentials (MEPs). The amplitude and latency of each MEP were compared. The success ratio was also recorded.

RESULTS

The concentration of sevoflurane and the stimulation voltage had impacts on the amplitude and latency of MEPs. Under each stimulation voltage, the MEPs amplitude decreased following increasing end-tidal sevoflurane concentrations, and significant differences were found in comparing 1.5% sevoflurane (left 20.50 μV, 70.71 μV, 135.97 μV, 190.00 μV , right 14.29 μV, 50.71 μV, 73.10 μV, 77.50 μV) with 0.0% sevoflurane (left 143.00 μV, 388.10 μV, 484.53 μV, 500.00 μV, right 176.00 μV, 407.60 μV, 384.35 μV, 451.00 μV) and 0.5% sevoflurane (left 100.00 μV, 362.57 μV, 444.05 μV, 435.00 μV, right 115.00 μV, 207.15 μV, 258.34 μV, 358.50 μV), left χ(2)= 27.46,P<0.01, right χ(2)= 60.49,P<0.01; left χ(2)= 20.73,P<0.01, right χ(2)= 55.05,P<0.01;left χ(2)= 34.25,P<0.01,right χ(2)=33.58,P<0.01;left χ(2)= 28.61,P<0.01 ,right χ(2)= 49.04,P<0.01; while there were no statistical differences in the latency changes (P=0.26). Under each end-tidal sevoflurane concentration, the MEPs amplitude increased following increasing stimulation voltages, and significant differences were found in comparing 300 V (left 143.00 μV, 100.00 μV, 61.50 μV, 20.50 μV , right 176.00 μV, 115.00 μV, 41.07 μV, 14.29 μV) with 400 V (left 388.10 μV, 362.57 μV, 198.81 μV, 70.71 μV, right 407.60 μV, 207.15 μV, 89.00 μV, 50.71 μV) and 500 V (left 484.53 μ V, 444.05 μV, 216.24 μV, 135.97 μV, right 384.35 μV, 258.34 μV, 187.50 μV, 73.10 μV) and 600 V (left 500.00 μV, 435.00 μV, 344.00 μV, 190.00 μV, right 451.00 μV, 385.50 μV, 156.00 μV, 77.50 μV), left χ(2)= 45.55,P<0.01, right χ(2)= 25.73,P<0.01; left χ(2)= 46.67,P<0.01, right χ(2)= 55.30,P<0.01;left χ(2)= 47.36,P<0.01,right χ(2)= 47.82,P<0.01; left χ(2)= 38.67,P<0.01, right χ(2)= 45.87,P<0.01; while the latencies were decreased, and significant differences were found in comparing 300 V with 400 V and 500 V and 600V(left F=7.50,P=0.01 , right F=13.33,P<0.01), but the differences had little clinical significance. The success ratio decreased by increasing end-tidal sevoflurane concentration, and significant differences were found in comparing 1.5% sevoflurane (left 43.8%,70.8%, 77.1%,81.3%, right 37.5%,60.4%,75.0%,66.7%) with 0.0% sevoflurane (left 79.2%,87.5%,95.8%,93.8%, right 75.0%,95.8%,95.8%, 95.8%) and 0.5% sevoflurane (left 72.9%,89.6%,95.8%,95.8%, right 66.7%,89.6%,95.8%, 97.9%); the success ratio increased by increasing stimulation voltage, and significant differences were found in comparing 300 V(left 79.2%,72.9%,62.5%,43.8%, right 75.0%,66.7%,60.4%, 37.5%)with 400 V(left 87.5% ,89.6%,77.1%,70.8% , right 95.8%,89.6%,79.2%,60.4%)and 500 V(left 95.8%,95.8%,91.7%,77.1%, right 95.8%,95.8%,81.3%,75.0%)and 600 V (left 93.8%, 95.8%,89.6%,81.3%, right 95.8%,97.9%,89.6%,66.7%), but there were no statistical differences in the success ratio of MEPs between the group with stimulation voltage of 600 V , end tidal sevoflurane concentration of 1.5% and the group with stimulation voltage of 300 V, end tidal sevoflurane concentration of 0.0% (P=0.22).

CONCLUSION

Sevoflurane inhibited MEPs in a dose-dependent manner. It can decrease the amplitudes and prolong the latencies. But increasing stimulation voltage will facilitate MEPs monitoring and increase the success ratio. Sevoflurane can be used in larger parts of MEPs monitoring surgery by increasing the stimulation voltage.

Evaluation of the predictors of postoperative aggravation of shoulder imbalance in severe and rigid thoracic or thoracolumbar scoliosis

OBJECTIVE

To study the predictors of postoperative aggravation of shoulder imbalance in severe and rigid thoracic or thoracolumbar scoliosis.

METHODS

In this study, 49 patients with severe and rigid thoracic or thoracolumbar scoliosis were analyzed retrospectively. The patients underwent whole-spine anteroposterior and lateral radiography preoperatively and postoperatively. On the radiographs, we measured parameters, including T1 tilt, radiographic shoulder height (RSH), proximal curve, middle curve, distal curve, apical vertebral translation (AVT) of the middle curve, thoracic trunk shift (TTS), coronal balance, and sagittal balance. We regarded RSH and T1 tilt as postoperative shoulder balance parameters and divided the patients into improved and aggravated groups of shoulder imbalance. Univariate analysis, receiver operating characteristic (ROC) curve, and multivariate logistic regression analyses were used in the statistical analyses.

RESULTS

The RSH was -17.01 ± 21.85 mm before surgery and 4.76 ± 18.11 mm at follow-up. The T1 tilt angle was -10.20° ± 19.53° before surgery and -2.72° ± 13.48° at follow-up. The results of the univariate analysis suggest that preoperative RSH and proximal to middle curve change ratio were significantly higher in the patients in the improved RSH group (p < 0.01). In addition, preoperative RSH, preoperative T1 tilt, and apical vertebral translation of the middle curve were significantly higher, and preoperative proximal curve, postoperative proximal curve, and preoperative distal curve were significantly lower in the patients with improved T1 tilt group (p < 0.01). In a binary logistic regression analysis, preoperative RSH [B = -0.120, odds ratio (OR) = 0.887, p = 0.006] was found to be an independent predictor of postoperative aggravation of RSH. Similarly, preoperative T1 tilt (B = -0.488, OR = 0.614, p = 0.001) was found to be an independent predictor of postoperative aggravation of T1 tilt. Moreover, the relationship between changes in RSH and T1 tilt was either concordant or discordant.

CONCLUSION

Several radiographic parameters were found to affect postoperative aggravation of RSH and T1 tilt. In particular, preoperative RSH and T1 tilt were found to be independent predictive factors of postoperative aggravation of RSH and T1 tilt, respectively.

Significant association between lower pulse pressure and increasing levels of a novel type of phospholipid

The aim of this study was to analyze the association between pulse pressure and a novel type of phospholipid with solubility similar to that of lysophosphatidic acid (LPA), designated as AP, which was reported to be elevated during ischemia. In this cross-sectional study, 416 hypertensive patients and 252 controls aged between 35 and 70 years were enrolled consecutively. Fasting blood samples were extracted for assays of phospholipids and other biomarkers. Compared to controls, the hypertensive patients had higher levels of both LPA [odds ratio (OR) = 3.83] and AP (OR = 4.30). Changes in blood pressure did not affect the levels of LPA or AP. However AP, but not LPA, levels were significantly higher in patients with lower or higher pulse pressure (Pearson χ(2) = 11.239, P = 0.001). For patients whose pulse pressure was ≤60 mmHg, plasma levels of AP were significantly negatively correlated with pulse pressure. However, this was not observed for LPA and nine other biomarkers, including lipoproteins. Plasma levels of AP increased in hypertensive patients with higher or lower pulse pressure. Thus, attention should be paid to the possibility of cerebral ischemia in hypertensive patients when they have abnormal pulse pressure, especially for those with relatively low pulse pressure.

[Study on thermoanalysis-based calamina processing]

Thermogravimetry (TG), TG-MS, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM)-energy dispersive spectrometer(EDS) were adopted to investigate the pyrolysis characteristics of calamina. According to the findings of the qualitative and quantitative studies on the changes in the content of relevant elements, the whole shape, the functional groups, and the volatile components of calamina before and after being pyrolyzed, the 200-360, 580-750 degrees C were two sensitive temperature ranges related to the changes in effective component during calamina processing. Thermal weight loss was observed for ZnCO3, Zn(OH)2 and ZnCO3-2Zn(OH)2-H2O under 200-360 degrees C and for CaCO3 under 580-750 degrees C. The results of studies on chemical reaction kinetics showed good linear relations. This experiment integrated relevant methods and theories of physical chemistry and science of traditional Chinese medicine processing, and interpretes calamina processing techniques and mechanism, in order to provide a good example for modem studies on other traditional Chinese medicine processing.

[Research on processing mechanism of Zushima which was stir-fried with licorice based on TG-DTG]

OBJECTIVE

To investigate the processing mechanism of Zushima which was stir-fried with licorice.

METHOD

Study of pyrolysis characteristics for extraction of Zushima effective part, petroleum ether, chloroform, ethyl acetate, n-butanol parts and the mixture of Zushima effective parts and licorice solid powder according to the proportion of 10: 1, 10: 2, 10: 3 was carried out in the thermogravimetric analyzer, the simulation of air (N2-O2 4:1) was chosen as carrier gas and heating rate was 5 degrees C x min(-1).

RESULT

Compared with TG-DTG curve of Zushima effective parts, the major weightloss temperature range of petroleum ether extraction which has strong stimulation was 320-390 degrees C, 0.69% x min(-1) weightlessness rate peak gradually moved forward with the addition of licorice powder, finally it was merged with the peak around 265 degrees C. In addition, effective department of Zushima at 291, 516 degrees C for 2.38% x min(-1) and 2.42% x min(-1) thermal weightlessness rate peak shift to lower temperature, the moving range were about 20-26, 19-50 degrees C, the former was significantly reduced, the latter was significantly increased.

CONCLUSION

In the course of programmed temperature heating, petroleum ether department was easy to lose with the addition oflicorice solid powder. At the same time, the main efficacy components of Zushima had a slow loss rate, which supported the processing mechanisms of TG-DTG method to research traditional Chinese medicine, and verified irritating characteristics that stimulus reduced after stir-fried with licorice.

[Role of mitochondrial alternative oxidase (AOX) pathway in photoprotection in Rumex K-1 leaves]

Taking Rumex K-1 leaves as test materials, this paper studied the role of mitochondrial alternative oxidase (AOX) pathway in photoprotection under different light intensities. Under low light intensity (200 micromol x m(-2) x s(-1)), and after treated with salicylhydroxamic acid to inhibit the AOX pathway, the leaf actual photochemical efficiency of PS II, linear electron transport rate of photosynthesis, and photosynthetic O2 evolution rate all decreased significantly while the non-Q(B) reducing reaction center had a significant increase, indicating that under low light, the photoinhibition was aggravated while the scavenging enzymes of reactive oxygen species (ROS) increased, which avoided the over-accumulation of ROS and partially alleviated the photoinhibition of Rumex K-1 leaves. Under high light intensity (800 micromol x m(-2) x s(-1)), the inhibition of AOX pathway caused more severe photoinhibition, and the increased activities of ROS scavenging enzymes were insufficient to prevent the over-accumulation of ROS. This study demonstrated that AOX pathway played an important role in the photoprotection in Rumex K-1 leaves under both high and low light intensities, and the role of AOX pathway in photoprotection under high light could be irreplaceable by the other photoprotection pathways in chloroplast.

[Effects of cucumber leaf's PS II activity and electron transfer on its PS I activity in recovery process after chilling-induced photoinhibition]

Taking Cucumis sativus L. (Jinchun No. 4) as test material, through the determination of chlorophyll-a fluorescence transient and light absorbance at 820 nm, and in combining with chlorophyll quenching, this paper studied the recovery of cucumber leaf' s PS I and PS I activities and the interactions between PS I and PS II in the recovery process at room temperature (25 degrees C) and under different light intensities (0, 15, and 200 micromol x m(-2) x s(-1)) after six hours of low temperature (4 degrees C) and strong light (200 micromol x m(-2) x s(-1)) stress. Different extent of photoinhibition of the PS II and PS I occurred after the stress. During the recovery process at room temperature, the PS II activity recovered quickly and was insensitive to light intensity, while the PS I activity recovered quickly under weak light intensity (15 micromol x m(-2) x s(-1)) but slowly under strong light intensity (200 micromol x m(-2) x s(-1)), suggesting that after the chilling-induced photoinhibition, the reduced electron transfer from PS II to PS I protected the PS I from further inhibition, accelerating the recovery of PS I activity. In the breeding of chilling-resistant species of cucumber, it should not only pursue the higher chilling-resistance of PS II and faster recovery of PS II after chilling-induced photoinhibition, but also pay more attention to the coordinating of PS I and PS II during and after the chilling-induced photoinhibition. In the culture of cucumber, after chilling happened, a practical method to reduce light intensity would help the recovery of cucumber leaf PS I activity to protect the photosynthetic apparatus against photoinhibition.

The mitochondrial alternative oxidase pathway protects the photosynthetic apparatus against photodamage in Rumex K-1 leaves

BACKGROUND

It is known that excess reducing equivalents in the form of NADPH in chloroplasts can be transported via shuttle machineries, such as the malate-oxaloacetate (OAA) shuttle, into the mitochondria, where they are efficiently oxidised by the mitochondrial alternative oxidase (AOX) respiratory pathway. Therefore, it has been speculated that the AOX pathway may protect plants from photoinhibition, but the mechanism by which this protection occurs remains to be elucidated.

RESULTS

The observation that the malate-OAA shuttle activity and the AOX pathway capacity increased markedly after intense light treatment in Rumex K-1 leaves indicates that excess NADPH was transported from the chloroplasts and oxidised by the AOX pathway. The inhibition of the AOX pathway by salicylhydroxamic acid (SHAM) caused the over-reduction of the photosystem I (PSI) acceptor side, as indicated by the increases in the extent of reduction of P700+. Furthermore, the photosynthetic linear electron flow was restricted, which was indicated by the decreases in the PSII electron transport rate (ETR) and the photosynthetic O₂ evolution rate. The restriction of the photosynthetic linear electron flow, which generates the thylakoid ΔpH, inevitably decreased the de-epoxidation of the xanthophyll cycle (ΔPRI). Therefore, the induction of non-photochemical quenching (NPQ) was suppressed when the AOX pathway was inhibited. The effect of the inhibition of the AOX pathway on NPQ induction was less at 20 mM NaHCO₃ than at 1 mM NaHCO₃. The suppression of NPQ induction by the inhibition of the AOX pathway was also observed during the induction phase of photosynthesis. In addition, the inhibition of the AOX pathway increased the accumulation of hydrogen peroxide (H₂O₂), suggesting that the AOX pathway functions as an antioxidant mechanism.

CONCLUSIONS

The inhibition of the AOX pathway resulted in the rapid accumulation of NADPH in the chloroplasts, which caused the over-reduction of the PSI acceptor side. Furthermore, the restriction of the photosynthetic linear electron flow due to the inhibition of the AOX pathway limited the generation of the thylakoid ΔpH and suppressed the induction of NPQ. Therefore, the mitochondrial AOX pathway protected the photosynthetic apparatus against photodamage by alleviating the over-reduction of the PSI acceptor side and accelerating the induction of NPQ in Rumex K-1 leaves.

Mitochondrial alternative oxidase pathway protects plants against photoinhibition by alleviating inhibition of the repair of photodamaged PSII through preventing formation of reactive oxygen species in Rumex K-1 leaves

The purpose of this study was to explore how the mitochondrial AOX (alternative oxidase) pathway alleviates photoinhibition in Rumex K-1 leaves. Inhibition of the AOX pathway decreased the initial activity of NADP-malate dehydrogenase (EC 1.1.1.82, NADP-MDH) and the pool size of photosynthetic end electron acceptors, resulting in an over-reduction of the photosystem I (PSI) acceptor side. The over-reduction of the PSI acceptor side further inhibited electron transport from the photosystem II (PSII) reaction centers to the PSII acceptor side as indicated by an increase in V(J) (the relative variable fluorescence at J-step), causing an imbalance between photosynthetic light absorption and energy utilization per active reaction center (RC) under high light, which led to the over-excitation of the PSII reaction centers. The over-reduction of the PSI acceptor side and the over-excitation of the PSII reaction centers enhanced the accumulation of reactive oxygen species (ROS), which inhibited the repair of the photodamaged PSII. However, the inhibition of the AOX pathway did not change the level of photoinhibition under high light in the presence of the chloroplast D1 protein synthesis inhibitor chloramphenicol, indicating that the inhibition of the AOX pathway did not accelerate the photodamage to PSII directly. All these results suggest that the AOX pathway plays an important role in the protection of plants against photoinhibition by minimizing the inhibition of the repair of the photodamaged PSII through preventing the over-production of ROS.