Long-term straw return improves cooked indica rice texture by altering starch structural, physicochemical properties in South China.

Straw return can improve rice eating quality by modifying starch formation from long-term field trials, whereas the relevant mechanisms are still unknown. A long-term field experiment, including straw removal (CK), straw burning return (SBR), and straw return (SR) was conducted to investigate the starch structure, physicochemical properties, and cooked rice textures of indica early- and late-rice. Compared with CK, SBR and SR enhanced relative crystallinity, amylopectin long chains in both rice seasons, and gelatinization temperatures in late rice. Compared to SBR, SR decreased protein content and amylopectin short chains but increased starch branching degree, breakdown, and stickiness, ultimately contributing to improved starch thermal and pasting properties. Meanwhile, SR decreased hardness, cohesiveness, and chewiness, resulting in cooked texture meliorated, which was mainly attributed to amylopectin chain length and starch granule size. The results suggest that SR increased cooked texture of indica rice by altering starch structural and physicochemical properties.

Starch multiscale structure and physicochemical property alterations in high-quality indica rice quality and cooked rice texture under different nitrogen panicle fertilizer applications.

The starch multiscale structure, physiochemical properties, grain quality and cooked rice texture of high-quality early and late indica were analyzed under nitrogen panicle fertilizer (low panicle fertilizer, LPF; middle panicle fertilizer, MPF; high panicle fertilizer, HPF) treatments and their internal relations were investigated. Compared to the MPF treatment, the starch granules in HPF and LPF had more surface-proteins and irregular voids for high-quality early and late indica rice cultivars, respectively. Nitrogen panicle fertilization application increased amylopectin medium and long chains as well as protein content, resulting in higher relative crystallinity and gelatinization temperatures. Moderate changes in starch multistructures and physicochemical properties such as branching degree, amylopectin medium chain, and pasting viscosities derived from MPF treatment significantly improved processing, appearance qualities and cooked rice texture. Additionally, the decrease in starch branching, gelatinization temperatures, and granule uniformity along with an increase in large granules, breakdown, and △Hgel under MPF treatment were the main reasons for improving rice textural properties.

Grain yield and quality performances of different late-season rice cultivars in response to experimental warming in subtropical China.

Introduction: Climate warming has pronounced effects on rice production in China. However, late-seasons rice cultivars are diverse in double rice cropping systems, and the actual responses in grain yield and quality of different late-season rice cultivars to climate warming are still unclear. Methods: A two-year field warming experiment was conducted by using free-air temperature increase facilities with three widely-planted late-season rice cultivars, including Taiyou398 (TY, short growth duration indica hybrid rice), Jiuxiangnian (JXN, long growth duration indica inbred rice), and Yongyou1538 (YY, long growth duration indica-japonica hybrid rice) in a double rice cropping system in subtropical China. Results: Warming (1.9-2.0°C) had no significant effects on the grain yields of TY and JXN, but significantly decreased that of YY by 4.8% relative to ambient treatment due to a reduction of spikelet number. Compared to ambient treatment, the head rice yields of TY and YY did not change while that of JXN increased by 6.3% under warming conditions. Warming significantly increased the head rice rates of JXN and YY by 6.6% and 7.8%, and the chalky grain rates of TY, JXN, and YY by 79.1%, 21.6%, and 7.6%, respectively. Under warming conditions, the amylose content of JXN and YY decreased significantly by 7.5% and 8.8%, and the setback of three cultivars decreased significantly by an average of 41.5%. Conclusion: Warming could improve the milling and eating qualities of long growth duration late-season rice (JXN and YY) and increase or maintain their head rice yield, even though decreased the grain yield of indica-japonica hybrid rice (YY). These results will provide a better understanding for the selection of suitable late-season rice cultivars under future climate warming conditions.

Low temperature and light combined stress after heading on starch fine structure and physicochemical properties of late-season indica rice with different grain quality in southern China.

Late-season indica rice frequently encounters low temperature (LT) along with low light (LL) after heading in southern China, which deteriorates the grain quality by altering starch quality. However, the detailed effects on starch properties of these stressors remain unclear. Herein, two indica rice cultivars with good and poor grain quality were grown under control (CK), LT, and LT + LL conditions after heading and the structural and physicochemical properties of their starch were evaluated. Compared with CK, LT and LT + LL worsened thermal and pasting properties of starch in the two cultivars, mainly because they increased branch chain branching and A chain (DP ≤12), and decreased average branch chain length and crystallinity. Compared with LT, LT + LL deteriorated the pasting properties of the poor-quality cultivar, such as reducing breakdown (BD), final and peak viscosity, which mainly owing to decreasing the starch branching and crystallinity degrees, and increasing the small starch granules (d < 10 µm). Gelatinization enthalpy and BD both had significant and positive correlations with amylose content, the ratio of amylose and amylopectin, B3 chain and crystallinity. Taken together, these results suggest that LT and LT + LL during grain filling can deteriorate the physicochemical properties of starch in late-season indica rice cultivars by disrupting starch multilevel structure, especially upon LT + LL. In particular, while poor-quality cultivar had poorer physicochemical properties, the good-quality cultivar had poorer thermal properties under LT + LL.

Relation of cooked rice texture to starch structure and physicochemical properties under different nitrogen managements.

Nitrogen management, especially panicle nitrogen fertilization (PNF), can affect cooked rice textures by altering starch quality, but the details are unclear. In this study, the starch multi-level structures, physicochemical properties and cooked rice textures of indica under different nitrogen managements were analysed and their internal relations were investigated. With an increase in PNF, large granules, amylopectin short chains, amylose content, thermal temperatures, setback, and hardness first exhibited decreasing trends and then increasing trends, which were relatively lower under moderate PNF (N3), whereas α-1,6 linkage, relative crystallinity, protein content, enthalpy of gelatinization (△Hgel), peak viscosity, breakdown and stickiness exhibited the opposite trends. N3 treatment significantly increased △Hgel and breakdown and decreased setback, hardness and chewiness, suggesting that it might contribute to better starch thermal stability and pasting properties, ultimately improving cooked rice texture. Nitrogen management affected the texture of cooked rice mainly by improving starch multi-level structures, thermal and pasting viscosities.

Transcriptomic, proteomic, and physiological comparative analyses of flooding mitigation of the damage induced by low-temperature stress in direct seeded early indica rice at the seedling stage.

BACKGROUND: Low temperature (LT) often occurs at the seedling stage in the early rice-growing season, especially for direct seeded early-season indica rice, and using flooding irrigation can mitigate LT damage in rice seedlings. The molecular mechanism by which flooding mitigates the damage induced by LT stress has not been fully elucidated. Thus, LT stress at 8 °C, LT accompanied by flooding (LTF) and CK (control) treatments were established for 3 days to determine the transcriptomic, proteomic and physiological response in direct seeded rice seedlings at the seedling stage. RESULTS: LT damaged chloroplasts, and thylakoid lamellae, and increased osmiophilic bodies and starch grains compared to CK, but LTF alleviated the damage to chloroplast structure caused by LT. The physiological characteristics of treated plants showed that compared with LT, LTF significantly increased the contents of rubisco, chlorophyll, PEPCK, ATP and GA3 but significantly decreased soluble protein, MDA and ABA contents. 4D-label-free quantitative proteomic profiling showed that photosynthesis-responsive proteins, such as phytochrome, as well as chlorophyll and the tricarboxylic acid cycle were significantly downregulated in LT/CK and LTF/CK comparison groups. However, compared with LT, phytochrome, chlorophyllide oxygenase activity and the glucan branching enzyme in LTF were significantly upregulated in rice leaves. Transcriptomic and proteomic studies identified 72,818 transcripts and 5639 proteins, and 4983 genes that were identified at both the transcriptome and proteome levels. Differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) were significantly enriched in glycine, serine and threonine metabolism, biosynthesis of secondary metabolites, glycolysis/gluconeogenesis and metabolic pathways. CONCLUSION: Through transcriptomic, proteomic and physiological analyses, we determined that a variety of metabolic pathway changes were induced by LT and LTF. GO and KEGG enrichment analyses demonstrated that DEGs and DEPs were associated with photosynthesis pathways, antioxidant enzymes and energy metabolism pathway-related proteins. Our study provided new insights for efforts to reduce the damage to direct seeded rice caused by low-temperature stress and provided a breeding target for low temperature flooding-resistant cultivars. Further analysis of translational regulation and metabolites may help to elucidate the molecular mechanisms by which flooding mitigates low-temperature stress in direct seeded early indica rice at the seedling stage.

Water irrigation management affects starch structure and physicochemical properties of indica rice with different grain quality.

The effects of water irrigation management including conventional irrigation (CK), constant flooding irrigation (CFI) and alternate wetting and drying (AWD) on starch structure and physicochemical properties of two indica rice cultivars with good- and poor-quality were evaluated in the field condition with two years. The results showed that AWD could significantly increase peak viscosity, breakdown and gelatinization temperature, decreased setback and gelatinization enthalpy in two indica rice cultivars. However, starch granule size and amylopectin chain length distribution were differed the trends in the rice cultivars and treatments. AWD reduced starch granules size and amylopectin short chain, especially for large starch granules, but increased medium and long chain, which might contribute to better thermal stability and pasting viscosity for good-quality cultivar. Our study indicated that water irrigation management affected starch structure and physicochemical properties of indica rice starch, and would provide favorable information for improvement of rice starch in food industry.

Effects of experimental warming on physicochemical properties of indica rice starch in a double rice cropping system.

To evaluate the actual response of rice starch physicochemical properties to climate warming, a field warming experiment was conducted with four indica rice cultivars using free-air temperature increase (FATI) facility in a double rice cropping system. FATI facility increased rice canopy temperature by 1.4-2.1 °C during the entire growth period. The responses of starch physicochemical properties to experimental warming were basically consistent for both early and late rice. On average, experimental warming increased the starch relative crystallinity, granule average diameter, and amylopectin average chain length by 14.3%, 6.9%, and 2.4%, respectively. These resulted in starch with lower swelling power, water solubility, and pasting viscosity, but higher gelatinization temperatures and gelatinization enthalpy. Our study indicated that experimental warming affected the rice starch physicochemical properties, and would provide some useful information on how to guide the rice starch end use in food and non-food industries under climate warming.

Upregulation of HRD1 promotes cell migration and invasion in colon cancer.

3-Hydroxy-3-methylglutaryl reductase degradation (HRD1) is an E3 ubiquitin ligase that functions by promoting degradation of misfolded proteins in processes such as embryogenesis and rheumatoid arthritis. However, little is known about the role of HRD1 in cancer. The aim of the present study was to investigate the expression pattern and functions of HRD1 in human colon cancer (CC). We found that HRD1 expression was increased significantly in human CC tissues, and its overexpression was associated with TNM stage, tumor differentiation, tumor invasive depth, and distant metastasis. Knockdown of HRD1 using small hairpin (sh) RNA plasmid significantly inhibited CC cell migration and invasion. Furthermore, the silencing of HRD1 decreased the expression of MMP-2 and MMP-9, which is critical for CC cell migration and invasion. Taken together, these results revealed that HRD1 is overexpressed in CC and promotes migration and invasion of CC cells. Inhibition of HRD1 may be considered as an effective anti-CC strategy.

Endoscopic retrograde cholangiopancreatography versus laparoscopic exploration for common bile duct stones in post-cholecystectomy patients: a retrospective study.

BACKGROUND AND OBJECTIVE: Common bile duct (CBD) stones are common in patients even after cholecystectomy. Besides endoscopic retrograde cholangiography (ERCP), laparoscopic common bile duct exploration (LCBDE) is also applied. This study aims to compare clinical indications, therapeutic benefits and complications for these two managements. METHODS: From October 2012 to February 2015, 1072 consecutive patients were diagnosed as choledocholithiasis in our single hospital. Post-cholecystectomy patients who underwent ERCP or LCBDE were included. Clinical data were analyzed, such as success rate, complications, procedure duration, postoperative hospital stay, total cost and recurrence of ductal stones. Prior ERCP, previous biliary anatomic alteration surgeries and lost to follow up were the excluding criteria. RESULTS: 141 patients were included according to the criteria, and 87 cases underwent ERCP and 54 cases underwent LCBDE. Age and sex distribution of patients were comparable between the two groups. The success rate for CBD stones clearance was 97.7% in the ERCP group, compared with 87.0% in the LCBDE group (p=0.03). The mean procedure duration was also significantly shorter in ERCP group (52.0±15.8 vs. 102.9±40.1 min; p<0.001). Postoperative hospital stay was similar (5.5±2.6 vs. 5.9±2.3 days; p=0.40). And no significant difference for postoperative complications (3.4% vs. 11.1%; p=0.15), total cost ($3787.1±1061.5 vs. $3983.54±1257.1, p=0.32), and the rate of bile duct stones recurrence (6.9% vs. 7.4%, p=1.00). CONCLUSIONS: For clearing CBD stones in patients after cholecystectomy, ERCP was more efficient and might be the first choice, while LCBDE might be beneficial for patients with large stones.

Effect of Age on Survival Outcome in Operated and Non-Operated Patients with Colon Cancer: A Population-Based Study.

OBJECTIVE: To know the effect of age on survival outcome in operated and non-operated patients with colon cancer. METHODS: From the Surveillance, Epidemiology, and End Results database, we identified 123,356 patients with colon cancer who were diagnosed between 1996 and 2005, grouped them as older or younger than 40 years and analyzed their 5-year cancer-specific survival (CSS) data, along with some risk factors, using Kaplan-Meier methods and multivariable Cox regression models. RESULTS: The younger group had significantly higher pathological grades (P<0.001), more mucinous and signet-ring histology (P<0.001), advanced AJCC stage (P<0.001), and were more likely to undergo surgery (P<0.001). For surgically treated patients, age did not significantly affect 5-year CSS (younger: 66.7%; older: 67.3%; P = 0.86). Further analysis showed that age was an independent prognostic factor in stage I-IV disease (stage I: P = 0.001; P<0.001 for stages II-IV, in both uni- and multivariate analyses), but not for patients with unknown disease stage (P = 0.52). For non-surgically treated patients, age significantly affected 5-year CSS (younger: 16.2%; older: 12.9%; P<0.001) in univariate analysis; and was an independent prognostic factor (P<0.001) in multivariate analysis. CONCLUSION: The CSS rate for younger CC patients was at least as high as for older patients, although they presented with higher proportions of unfavorable factors and more advanced disease.

Relief of diabetes by duodenal-jejunal bypass sleeve implantation in the high-fat diet and streptozotocin-induced diabetic rat model is associated with an increase in GLP-1 levels and the number of GLP-1-positive cells.

A recently invented duodenal-jejunal bypass sleeve (DJBS) implanted in the duodenum and proximal jejunum has exhibited good glycemic control in diabetes mellitus. However, the specific mechanism by which DJBS placement induces the remission of diabetes is not well known. Previous studies have indicated that changes in the pattern of gut hormone secretion may play a role. The aim of the present study was to explore the role of intestinal L cells and the production of glucagon-like peptide-1 (GLP-1) by these cells in DJBS implantation-induced glycemic control in diabetic rats. A DJBS was placed in the proximal small intestine of rats with diabetes induced by a high-fat diet and low-dose streptozotocin (STZ), and the effects of the DJBS on the remission of diabetes and the GLP-1 levels of plasma and intestinal tissues were investigated 12 weeks after DJBS placement. The number of intestinal GLP-1 positive cells was also counted. When the DJBS had been in place for 12 weeks, the plasma glucose level of the DJBS-implanted rats decreased significantly from 23.33±1.56 mmol/l prior to surgery to 7.70±0.84 mmol/l and the diabetes mellitus was relieved completely; however, diabetic control rats and diabetic rats subjected to sham surgery did not show any improvement. Parallel with the remission of diabetes, the plasma and distal ileum GLP-1 levels of rats in the DJBS implantation group were also higher than those of rats in the diabetic control and sham surgery groups. The number of GLP-1-positive cells in the distal ileum was also higher in the DJBS implantation group than in the diabetic control and sham surgery groups (31.0±2.6 vs. 23.5±4.4 vs. 23.0±3.2 respectively; P<0.01). DJBS implantation effectively led to the remission of diabetes in rats with diabetes induced by a high-fat diet and low-dose STZ when implanted for 12 weeks. The remission of diabetes may be associated with the increase in the number of L cells and elevation of GLP-1 levels induced by DJBS implantation.

Derlin-1 is overexpressed in human colon cancer and promotes cancer cell proliferation.

Derlin-1 is overexpressed in many types of solid tumors and plays an important role in cancer progression. However, the expression pattern and functions of Derlin-1 in human colon cancer are not fully understood. In the present study, we examined Derlin-1 expression in colon cancer cell lines and human tissues and investigated its role in colon cancer. We found that Derlin-1 expression was increased significantly in colon cancer tissues and its overexpression correlated with the tumor differentiation, Dukes stage, invasion, lymph node metastasis, distant metastasis, and poor overall survival. The silencing of Derlin-1 by shRNA led to the growth inhibition of colon cancer cells, which were associated with the promotion of apoptosis. Furthermore, Derlin-1 silencing significantly inhibited the activation of the PI3K/AKT signaling pathway. Taken together, our results showed that Derlin-1 is overexpressed in colon cancer and promotes proliferation of colon cancer cells. Derlin-1 may be a potential therapeutic target for the treatment of colon cancer.

C-Myc-activated long noncoding RNA CCAT1 promotes colon cancer cell proliferation and invasion.

Recently, more and more evidence are rapidly accumulating that long noncoding RNAs (lncRNAs) are involved in human tumorigenesis and misregulated in many cancers, including colon cancer. LncRNA could regulate essential pathways that contribute to tumor initiation and progression with their tissue specificity, which indicates that lncRNA would be valuable biomarkers and therapeutic targets. Colon cancer-associated transcript 1 (CCAT1) is a 2628 nucleotide-lncRNA and located in the vicinity of a well-known transcription factor c-Myc. CCAT1 has been found to be upregulated in many cancers, including gastric carcinoma and colonic adenoma-carcinoma. However, its roles in colon cancer are still not well documented and need to be investigated. In this study, we aim to investigate the prognostic value and biological function of CCAT1 and discover which factors may contribute to the deregulation of CCAT1 in colon cancer. Our results revealed that CCAT1 was significantly overexpressed in colon cancer tissues when compared with normal tissues, and its increased expression was correlated with patients' clinical stage, lymph nodes metastasis, and survival time after surgery. Moreover, c-Myc could promote CCAT1 transcription by directly binding to its promoter region, and upregulation of CCAT1 expression in colon cancer cells promoted cell proliferation and invasion. These data suggest that c-Myc-activated lncRNA CCAT1 expression contribute to colon cancer tumorigenesis and the metastatic process and could predict the clinical outcome of colon cancer and be a potential target for lncRNA direct therapy.

Long non-coding RNA Loc554202 regulates proliferation and migration in breast cancer cells.

Data derived from massive cloning and traditional sequencing methods have revealed that long non-coding RNAs (lncRNA) play important roles in the development and progression of cancer. Although many studies suggest that the lncRNAs have different cellular functions, many of them are not yet to be identified and characterized for the mechanism of their functions. To address this question, we assay the expression level of lncRNAs-Loc554202 in breast cancer tissues and find that Loc554202 is significantly increased compared with normal control, and associated with advanced pathologic stage and tumor size. Moreover, knockdown of Loc554202 decreased breast cancer cell proliferation, induced apoptosis and inhibits migration/invasion in vitro and impeded tumorigenesis in vivo. These data suggest an important role of Loc554202 in breast tumorigenesis.