Observational study on perioperative outcomes of pelvic exenteration / 中华胃肠外科杂志

Objective: To investigate the surgical indications and perioperative clinical outcomes of pelvic exenteration (PE) for locally advanced, recurrent pelvic malignancies and complex pelvic fistulas. Methods: This was a descriptive study.The indications for performing PE were: (1) locally advanced, recurrent pelvic malignancy or complex pelvic fistula diagnosed preoperatively by imaging and pathological examination of a biopsy; (2)preoperative agreement by a multi-disciplinary team that non-surgical and conventional surgical treatment had failed and PE was required; and (3) findings on intraoperative exploration confirming this conclusion.Contraindications to this surgical procedure comprised cardiac and respiratory dysfunction, poor nutritional status,and mental state too poor to tolerate the procedure.Clinical data of 141 patients who met the above criteria, had undergone PE in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2018 to September 2022, had complete perioperative clinical data, and had given written informed consent to the procedure were collected,and the operation,relevant perioperative variables, postoperative pathological findings (curative resection), and early postoperative complications were analyzed. Results: Of the 141 included patients, 43 (30.5%) had primary malignancies, 61 (43.3%) recurrent malignancies, 28 (19.9%) complex fistulas after radical resection of malignancies,and nine (6.4%)complex fistulas caused by benign disease. There were 79 cases (56.0%) of gastrointestinal tumors, 30 cases (21.3%) of reproductive tumors, 16 cases (11.3%) of urinary tumors, and 7 cases (5.0%) of other tumors such mesenchymal tissue tumors. Among the 104 patients with primary and recurrent malignancies, 15 patients with severe complications of pelvic perineum of advanced tumors were planned to undergo palliative PE surgery for symptom relief after preoperative assessment of multidisciplinary team; the other 89 patients were evaluated for radical PE surgery. All surgeries were successfully completed. Total PE was performed on 73 patients (51.8%),anterior PE on 22 (15.6%),and posterior PE in 46 (32.6%). The median operative time was 576 (453,679) minutes, median intraoperative blood loss 500 (200, 1 200) ml, and median hospital stay 17 (13.0,30.5)days.There were no intraoperative deaths. Of the 89 patients evaluated for radical PE surgery, the radical R0 resection was achieved in 64 (71.9%) of them, R1 resection in 23 (25.8%), and R2 resection in two (2.2%). One or more postoperative complications occurred in 85 cases (60.3%), 32 (22.7%)of which were Clavien-Dindo grade III and above.One patient (0.7%)died during the perioperative period. Conclusion: PE is a valid option for treating locally advanced or recurrent pelvic malignancies and complex pelvic fistulas.

Photoinduced remote regioselective radical alkynylation of unactivated C-H bonds.

A method for the remote regioselective alkynylation of unactivated C(sp3)-H bonds in diverse aliphatic amides by photogenerated amidyl radicals has been developed. The site-selectivity is dominated via a 1,5-hydrogen atom transfer (HAT) process of the amide. Mild reaction conditions and high regioselectivity are demonstrated in this methodology.

Photoredox-Catalyzed Difunctionalization of Unactivated Olefins for Synthesizing Lactam-Substituted gem-Difluoroalkenes.

Herein, the synthesis of lactam-substituted gem-difluoroalkenes has been developed through a photoredox-catalyzed radical cascade reaction. This developed photoredox-catalyzed, Brønsted base-assisted intramolecular 5-exo-trig cyclization/intermolecular radical addition/ß-fluoride elimination reaction offers a simple method for producing lactam, carbamate, or urea-substituted gem-difluoroalkenes with good functional group tolerance and high yields.

Remote Regioselective Radical C-H Functionalization of Unactivated C-H Bonds in Amides: The Synthesis of gem-Difluoroalkenes.

The site-selective functionalization of unactivated aliphatic amines is an attractive and challenging synthetic approach. We herein report a general strategy for the remote site-selective functionalization of unactivated C(sp3)-H bonds in amides by photogenerated amidyl radicals to form gem-difluoroalkenes with trifluoromethyl-substituted alkenes. The site selectivity is controlled by a 1,5-hydrogen atom transfer (HAT) process of the amide. This photocatalyzed transformation shows both chemo- and site-selectivity, facilitating the formation of a secondary, tertiary, or quaternary carbon center.

[Simple nucleus pulposus removal for the treatment of prolapsed and displaced lumbar disc herniation].

OBJECTIVE: To explore the clinical effect of the simple nucleus pulposus removal and small incision interlaminar window in the treatment of prolapsed and displaced lumbar disc herniation. METHODS: From February 2016 to February 2018, 35 patients with single-segment prolapse and displaced lumbar disc herniation were treated by the simple nucleus pulposus removal and small incision interlaminar window under general anesthesia. Among them, there were 21 males and 14 females;aged (42±17) years;27 cases of L4,5 segment, 6 cases of L5S1 segment, 2 cases of L3,4 segment;20 cases on the left side, 13 cases on the right side. Modified Macnab standard was used to evaluate postoperative symptoms and functional recovery. RESULTS: All the operations were successful and the operation time was 30 to 60 min with an average of 40 min, the intraoperative blood loss was 10 to 30 ml with an average of 20 ml. All the patients were followed up for 1 to 3 years with an average of 1.2 years. Thirty-five patients with low back pain and lower limb symptoms were significantly relieved or disappeared. According to modified Macnab standard, 29 cases obtained excellent results, 5 good, and 1 fair. CONCLUSION: Applying the concept of minimally invasive operation, small incision interlaminar window and simple nucleus pulposus removal for the treatment of prolapsed and displaced lumbar disc herniation has the advantages of short operation time, definite curative effect, and less trauma. And it is a safe and effective surgical method under the premise of strict control of the indications.

Integrative analysis of prognostic long non-coding RNAs with copy number variation in bladder cancer / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Copy number variations (CNVs), which can affect the role of long non-coding RNAs (lncRNAs), are important genetic changes seen in some malignant tumors. We analyzed lncRNAs with CNV to explore the relationship between lncRNAs and prognosis in bladder cancer (BLCA). Messenger RNA (mRNA) expression levels, DNA methylation, and DNA copy number data of 408 BLCA patients were subjected to integrative bioinformatics analysis. Cluster analysis was performed to obtain different subtypes and differently expressed lncRNAs and coding genes. Weighted gene co-expression network analysis (WGCNA) was performed to identify the co-expression gene and lncRNA modules. CNV-associated lncRNA data and their influence on cancer prognosis were assessed with Kaplan-Meier survival curve. Multi-omics integration analysis revealed five prognostic lncRNAs with CNV, namely

[Efficacy of thunder-fire moxibustion combined with external applicaion of Shuangbai powder for mild and moderate knee osteoarthritis].

OBJECTIVE: To compare the therapeutic effect between thunder-fire moxibustion combined with external applicaion of Shuangbai powder and thunder-fire moxibustion alone for mild and moderate knee osteoarthritis. METHODS: A total of 70 patients with mild and moderate knee osteoarthritis were randomly divided into an observation group and a control group, 35 cases in each group. In the observation group, thunder-fire moxibustion combined with external applicaion of Shuangbai powder were applied, Thunder-fire moxibustion was applied at Xuehai (SP 10), Liangqiu (ST 34), Neixiyan (EX-LE 4), Yanglingquan (GB 34) and ashi point, external applicaion of Shuangbai powder was given to the affected knee after the treatment of thunder-fire moxibustion. Simple thunder-fire moxibustion was given in the control group. All patients in the two groups were treated once a day, 7 days as one course and the consecutive 4 courses were required, with an interval of 1 day between courses. Before and after treatment, the visual analogue scale (VAS) score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were used to assessed knee pain, stiffness and physical function in the two groups. In addition, the efficacy was evaluated. RESULTS: Compared before treatment, the VAS scores, total scores of WOMAC, pain scores, stiffness scores and physical function scores were reduced after treatment in the two groups (P<0.01), and the scores in the observation group were significantly lower than those in the control group (P<0.01, P<0.05). The total effective rate was 97.0% (32/33) in the observation group, which was superior to 91.2% (31/34) in the control group (P<0.05). CONCLUSION: Thunder-fire moxibustion combined with external applicaion of Shuangbai powder are superior to simple thunder-fire moxibustion in improving the symptoms and delaying the development of the disease for mild and moderate knee osteoarthritis.

Effects of AdipoRon orally on the functions of spleen and pancreas in type 2 diabetic mice / 中国应用生理学杂志

OBJECTIVE@#To observe the effects of AdipoRon orally on the functions of spleen and pancreas in type 2 diabetic mice, in order to present data for clinical application.@*METHODS@#Forty C57/BL6 male mice were randomly divided into 2 groups: normal control group (n=10) and model group (n=30), the former group was fed normally, while the later group was fed with high fat and sugar for 4 weeks.After that, type 2 diabetes model was established in DM group induced by intraperitoneal injection of streptozotocin (STZ, 40 mg/kg).As type 2 diabetes model established successfully, the model mice were randomly divided into three groups (n=10): diabetes mellitus (DM) group, high dose of AdipoRon group (DM + H) and low dose of adiponRon group (DM + L).All the four groups were treated with saline, saline, AdipoRon at the doses of 20 mg/kg and 50 mg/kg by gavages respectively, once a day for 10 days.And then put them to death for collecting blood, pancreas and spleen.Pathological changes of pancreas were observed with a light microscope after HE staining.Protein contents of insulin receptor (INSR), insulin receptor substrate 1( IRS-1) and tumor necrosis factor-α(TNF-α) in pancreatic and spleen tissues were detected by ELISA.The protein level of phosphorylation insulin receptor substrate 1(p-IRS-1) in pancreas was determined by Western blot, and the expression of insulin mRNA in pancreas was tested by RT-PCR.@*RESULTS@#Under the light microscope, it was visible that the pancreatic tissue in NC group was full and closely packed, and the islet was big.Pancreatic tissue of DM mice was incompact and the islet of DM mice was smaller than that of normal mice.As for the mice treated with AdipoRon orally, the pancreatic tissue was full and closely arranged, and the islet was slightly smaller.Compared with NC group, the levels of TNF-α in pancreas and spleen of DM group were increased markedly, the levels of INSR and IRS-1 were decreased, the spleen coefficient, p-IR-1 protein level and insulin mRNA expression in pancreas were decreased, all were significant statistically (P＜0.05).Compared with DM group, the levels of TNF-α in pancreas and spleen of AdipoRon groups were decreased, the levels of INSR and IRS-1 in pancreas and spleen of AdipoRon groups were increased, while the spleen coefficient was increased (P＜0.05).The p-IRS-1 protein level and insulin mRNA expression in pancreas in DM+H group were increased (P＜0.05).Compared with DM + L group, the level of TNF-α was decreased, and the levels of INSR and IRS-1 were significantly increased (P＜0.05) in DM + H group (P＜0.05).@*CONCLUSION@#Oral administration of AdipoRon can protect the spleen and pancreas of diabetic mice by decreasing the inflammatory response, up-regulating the expression of INSR, and increasing p-IRS-1 level in diabetic mice.

The intervention effects of AdipoRon on renal injury in type 2 diabetic mice / 中国应用生理学杂志

OBJECTIVE@#To study the effects of adiponin receptor agonist (AdipoRon) on renal injury in type 2 diabetic mice.@*METHODS@#The experiment was carried out on 40 SPF C57/BL6 male mice and they were randomly divided into normal control group (=10) and experimental group (=30). Mice in experimental group were given with high sugar and high fat feed in combination with only an intraperitoneal injection of small dose of streptozotocin to build the model of type 2 diabetes (T2DM), which were randomly divided into three groups, model control group (DM), low dose AdipoRon group (DM + L) and high dose AdipoRon group (DM+H)(=10). Then the change of blood glucose was detected. The serum levels of insulin receptor (INSR), insulin receptor substrate-1 (IRS-1) and tumor necrosis factor-α (TNF-α) in mice were measured by ELASA. Pathological changes of renal tissues were observed with a light microscope after HE staining. The expressions of pancreatic duodenal homebox-1 (PDX-1) and insulin mRNA in renal tissues were detected by RT-PCR. The content of phosphated insulin receptor substrate-1 (p-IRS-1) protein in the kidney was determined by Western blot.@*RESULTS@#Compared with DM mice, blood glucose and TNF-α levels in DM + H mice and DM + L mice were significantly reduced (<0.05), while the expressions of INSR,IRS-1 and the content of p-IRS-1 were increased markedly(<0.05), and the expressions of PDX-1 and insulin mRNA in renal tissue were increased significantly(<0.05, <0.01).@*CONCLUSIONS@#Mice treated with AdipoRon have lower blood glucose and TNF-α levels, and higher protein expression levels of INSR, IRS-1, and higher mRNA expression levels of PDX-1 and insulin, and the content of p-IRS-1. All of these indicate that AdipoRon has a certain effects on renal injury in type 2 diabetic mice.

Effect of a mentor-based, supportive-expressive program, Be Resilient to Breast Cancer, on survival in metastatic breast cancer: a randomised, controlled intervention trial.

BACKGROUND: Because of medical advances, metastatic breast cancer (MBC) is now viewed as a chronic disease, rather than an imminent death sentence. Helping women live with this disease requires more than a medical approach to symptoms. Thus, a mentor-based and supportive-expressive program 'Be Resilient to Breast Cancer' (BRBC) was designed to help Chinese women with MBC enhance their resilience levels, biopsychosocial functions, and potentially extend their life span. METHODS: A total of 226 women with MBC were randomly assigned, in a 1 : 1 ratio, to an intervention group (IG) that participated in BRBC or to a control group (CG) that received no intervention. Be Resilient to Breast Cancer was conducted for 120 min once a week. Primary outcomes were cancer-specific survival and secondary outcomes were resilience, Allostatic Load Index (ALI), anxiety, depression, and quality of life (QoL). The Cox proportional-hazards model was used for survival analysis and growth mixture models were performed for secondary outcomes. RESULTS: Be Resilient to Breast Cancer did not significantly prolong 3- or 5-year survival (median survival, 36.7 months in IG and 31.5 months in CG). The hazard ratio for death was 0.736 (95% CI, 0.525-1.133, P=0.076; univariate Cox model) and 0.837 (95% CI, 0.578-1.211, P=0.345; multivariate Cox analysis). The IG improved in anxiety (ES=0.85, P<0.001), depression (ES=0.95, P<0.001), QoL (ES=0.55, P<0.001), resilience (ES=0.67, P<0.001), and ALI (ES=0.90, P<0.001) compared to CG. CONCLUSIONS: BRBC does not improve survival of women with MBC in this study, though longer follow up is warranted. It positively impacts resilience, QoL, ALI, and emotional distress.

Dwarf and tiller-enhancing 1 regulates growth and development by influencing boron uptake in boron limited conditions in rice.

Boron (B) is essential for plant growth, and B deficiency causes severe losses in crop yield. Here we isolated and characterized a rice (Oryza sativa L.) mutant named dwarf and tiller-enhancing 1 (dte1), which exhibits defects under low-B conditions, including retarded growth, increased number of tillers and impaired pollen fertility. Map-based cloning revealed that dte1 encodes a NOD26-LIKE INTRINSIC PROTEIN orthologous to known B channel proteins AtNIP5;1 in Arabidopsis and TASSEL-LESS1 in maize. Its identity was verified by transgenic complementation and RNA-interference. Subcellular localization showed DTE1 is mainly localized in the plasma membrane. The accumulation of DTE1 transcripts both in roots and shoots significantly increased within 3h of the onset of B starvation, but decreased within 1h of B replenishment. GUS staining indicated that DTE1s are expressed abundantly in exodermal cells in roots, as well as in nodal region of adult leaves. Although the dte1 mutation apparently reduces the total B content in plants, it does not affect in vivo B concentrations under B-deficient conditions. These data provide evidence that DTE1 is critical for vegetative growth and reproductive development in rice grown under B-deficient conditions.

Effect of salinomycin on metastasis and invasion of bladder cancer cell line T24

Objective: To explore the effect of salinomycin on the metastasis and invasion of bladder cancer cell line T24 by regulating the related protein expression in the process of epithelial-mesenchymal transition (EMT), and to provide experimental basis for the treatment of urological tumors. Methods: The bladder cancer cell line T24 was cultured in vitro. The rat bladder tumor model was established in vivo. The rats were randomized into two groups, among which the rats in the experiment group were given intraperitoneal injection of salinomycin, while the rats in the control group were given intraperitoneal injection of normal saline. The change of tumor cells in the two groups was observed. Transwell was used to detect the cell migration and invasion abilities, Real-time PCR was used to detect the expression of mRNA, while Western-blot was utilized for the determination of the expressions of E-cadherin and vimentin proteins. Results: The metastasis and invasion abilities of serum bladder cancer cell line T24 after salinomycin treatment in the experiment group were significantly reduced when compared with those in the control group, and the tumor metastasis lesions were decreased from an average of 1.59 to 0.6 (P < 0.05). T24 cell proliferation in the experiment group was gradually decreasing. T24 cell proliferation at 48 h was significantly lower than that at 12 h and 24 h (P < 0.05). T24 cell proliferation at 24 h was significantly lower than that at 12 h (P < 0.05). T24 cell proliferation at each timing point in the experiment group was significantly lower than that in the control group (P < 0.05). The serum mRNA level and E-cadherin expression in the tumor tissues in the experiment group were significantly higher than those in the control group, while vimentin expression level was significantly lower than that in the control group (P < 0.05). Conclusions: Salinomycin can suppress the metastasis and invasion of bladder cancer cells, of which the mechanism is probably associated with the inhibition of EMT of tumor cells.

Effect of salinomycin on metastasis and invasion of bladder cancer cell line T24

OBJECTIVE@#To explore the effect of salinomycin on the metastasis and invasion of bladder cancer cell line T24 by regulating the related protein expression in the process of epithelial-mesenchymal transition (EMT), and to provide experimental basis for the treatment of urological tumors.@*METHODS@#The bladder cancer cell line T24 was cultured in vitro. The rat bladder tumor model was established in vivo. The rats were randomized into two groups, among which the rats in the experiment group were given intraperitoneal injection of salinomycin, while the rats in the control group were given intraperitoneal injection of normal saline. The change of tumor cells in the two groups was observed. Transwell was used to detect the cell migration and invasion abilities, Real-time PCR was used to detect the expression of mRNA, while Western-blot was utilized for the determination of the expressions of E-cadherin and vimentin proteins.@*RESULTS@#The metastasis and invasion abilities of serum bladder cancer cell line T24 after salinomycin treatment in the experiment group were significantly reduced when compared with those in the control group, and the tumor metastasis lesions were decreased from an average of 1.59 to 0.6 (P < 0.05). T24 cell proliferation in the experiment group was gradually decreasing. T24 cell proliferation at 48 h was significantly lower than that at 12 h and 24 h (P < 0.05). T24 cell proliferation at 24 h was significantly lower than that at 12 h (P < 0.05). T24 cell proliferation at each timing point in the experiment group was significantly lower than that in the control group (P < 0.05). The serum mRNA level and E-cadherin expression in the tumor tissues in the experiment group were significantly higher than those in the control group, while vimentin expression level was significantly lower than that in the control group (P < 0.05).@*CONCLUSIONS@#Salinomycin can suppress the metastasis and invasion of bladder cancer cells, of which the mechanism is probably associated with the inhibition of EMT of tumor cells.

Overexpression of folate biosynthesis genes in rice (Oryza sativa L.) and evaluation of their impact on seed folate content.

Folate (vitamin B9) deficiency is a global health problem especially in developing countries where the major staple foods such as rice contain extremely low folates. Biofortification of rice could be an alternative complement way to fight folate deficiency. In this study, we evaluated the availability of the genes in each step of folate biosynthesis pathway for rice folate enhancement in the japonica variety kitaake genetic background. The first enzymes GTP cyclohydrolase I (GTPCHI) and aminodeoxychorismate synthase (ADCS) in the pterin and para-aminobenzoate branches resulted in significant increase in seed folate content, respectively (P < 0.01). Overexpression of two closely related enzymes dihydrofolate synthase (DHFS) and folypolyglutamate synthase (FPGS), which perform the first and further additions of glutamates, produced slightly increase in seed folate content separately. The GTPCHI transgene was combined with each of the other transgenes except ADCS to investigate the effects of gene stacking on seed folate accumulation. Seed folate contents in the gene-stacked plants were higher than the individual low-folate transgenic parents, but lower than the high-folate GTPCHI transgenic lines, pointing to an inadequate supply of para-aminobenzoic acid (PABA) precursor initiated by ADCS in constraining folate overproduction in gene-stacked plants.

Dissecting genetic networks underlying complex phenotypes: the theoretical framework.

Great progress has been made in genetic dissection of quantitative trait variation during the past two decades, but many studies still reveal only a small fraction of quantitative trait loci (QTLs), and epistasis remains elusive. We integrate contemporary knowledge of signal transduction pathways with principles of quantitative and population genetics to characterize genetic networks underlying complex traits, using a model founded upon one-way functional dependency of downstream genes on upstream regulators (the principle of hierarchy) and mutual functional dependency among related genes (functional genetic units, FGU). Both simulated and real data suggest that complementary epistasis contributes greatly to quantitative trait variation, and obscures the phenotypic effects of many 'downstream' loci in pathways. The mathematical relationships between the main effects and epistatic effects of genes acting at different levels of signaling pathways were established using the quantitative and population genetic parameters. Both loss of function and "co-adapted" gene complexes formed by multiple alleles with differentiated functions (effects) are predicted to be frequent types of allelic diversity at loci that contribute to the genetic variation of complex traits in populations. Downstream FGUs appear to be more vulnerable to loss of function than their upstream regulators, but this vulnerability is apparently compensated by different FGUs of similar functions. Other predictions from the model may account for puzzling results regarding responses to selection, genotype by environment interaction, and the genetic basis of heterosis.

Observation on the effect of repaglinide combined with metformin in treatment of patient with type 2 diabetes / 中国基层医药

ObjectiveTo explore the application value of repaglinide combined with metformin in type 2 diabetes therapy.Methóds92 patients with type 2 diabetes were randomly divided into study group and control group.Two groups of patients were given repaglinide treatment,patients in study group given metformin treatment.The blood lipid,glucose metabolism,body weight change and clinical outcomes were compared belween the groups.ResultsCompared with the control group,study group the cure rate and total effective rate was significantly increased,as high as 58.7％ and 97.8％,the ineffective rate was significantly decreased,only 2.2％,there were significant differences ( x2 =2.64,3.59,3.59,P ＜ 0.05 ).The fasting and 2h postprandial blood glucose and glycated hemoglobin and other indicators of glucose metabolism in the study group were significantly decreased,there were also significant differences(P ＜ 0.05 ).The triglycerides and cholesterol and other lipid levels and body mass index in the study group were significantly decreased,there were significant differences ( P ＜ 0.05 ).ConclusionRepaglinide combined with metformin in type 2 diabetes treatment was remarkable for type 2 diabetes to further improve the clinical efficacy.

A comparative study of long-term results after hypospadias surgery / 中国医师进修杂志

Objective To compare the long-term results of hypospadias surgery and analyze the influencing factors. Methods Sixty-four hypospadiac patients were followed up, cosmetic and sexual functional results were assessed by hypospadiac patients and surgeon using a designed questionnaire and 5-item version of the international index of erectile function (IIEF-5). Selected 35 adult as normal controls. Maximum flow rate and average flow rate Were used to assess evaluation of voiding function. Results All cases were followed up for 3-11 (7.5 ± 2.3) years. The satisfaction with the long-term results of penile appearance had significant differences between hypospadiac patients and surgeon,hypospadiac patients were less satisfied than surgeon (P< 0.05 or < 0.01). No significant differences were noted between hypospadiac patients and normal controls regarding the maximum flow rate [(23.37 ±2.92), (24.41 ±2.94) ml/s], average flow rate [(16.84± 1.75), (17.34 ±2.14) ml/s] and erectile function [(22.31 ± 1.94), (22.80 ± 1.73) pointe](P> 0.05). The average penile lengths[(5.93 ± 1.06) cm] and circumferences[(6.17 ±0.83) cm] of hypospadiac patients under flaccid conditions after operation were significantly shorter than those of normal controls [ (7.38 ± 0.79 ), ( 7.53 ± 0.75 ) cm ] ( P < 0.01). The important factors to influence the results including the age at which surgery was completed, hypospadiac severity, the number of operation and complication. ConclusionsIt is useful to improve the long-term efficacy by minimizing the number of operation and complication, and treating hypospadiac patients earlier. Surgeon should pay more attention to the long-term cosmetic results of hypospadias surgery.

The distribution of japonica rice cultivars in the lower region of the Yangtze River valley is determined by its photoperiod-sensitivity and heading date genotypes.

There are generally four recognized classes of japonica rice cultivars grown in the lower region of the Yangtze River valley. The geographical distribution of the four classes is latitude-dependent. Variation for heading date (HD) among 29 japonica rice cultivars grown in the lower region of the Yangtze River valley and belonging to the four classes was characterized, and their sensitivity to variations in photoperiod and temperature was analyzed. All of the cultivars were sensitive to both photoperiod and temperature. A regression analysis showed that HD is closely correlated with photoperiod sensitivity (PS). The PS of the four classes increased gradually from the medium maturing middle (MMM) types, through the late maturing middle (LMM) and early maturing late (EML) types to the medium maturing late (MML) types. Crosses with tester lines established that almost all of the cultivars carry the dominant early-heading allele at Ef-1, the photoperiod insensitive allele e(2) and the PS alleles E(1) or E(1) (t). Most of the MMM, LMM and MML types carry the insensitive allele e(3), while EML types have either E(3) or E(3) (t). At Se-1, MMM and LMM types have Se-1(e), some EML types have Se-1(e) and others Se-1(n), while the MML types are mostly Se-1(n). The PS of some MMM, LMM and EML types is reduced by the presence of hd2. These results show that the distribution of the four rice cultivar classes from high latitude to low latitude regions depended on a gradual increase in PS, which is mainly determined by its HD genotypes.

[Current status and strategies for improvement of rice grain chalkiness].

This paper reviews the current status of correlation between rice chalkiness and other rice quality characters, formative mechanism, and classical and molecular genetics for rice chalkiness. The formation of rice chalkiness proves to be a complicated physiological process and tightly relate to "source-sink" of rice, dynamics of grain filing, biosynthesis and accumulation of starch in endosperm. Rice chalkiness is a complicated quantitative trait, which is controlled by maternal effects, endosperm effects, and cytoplasmic effects. There are some stable quantitative trait loci (QTL) for rice chalkiness on many rice chromosomes. Of them, three genes controlling rice chalkiness, which have an impact on starch synthesis, starch metabolism, and fruit development, have been cloned. But the manipulative network and formative mechanisms of rice chalkiness remain unclear. At present in breeding practice, decrease of rice chalkiness has become one of the main aims in rice quality breeding, especially for indica rice. The direction of genetic research and improvement strategy of rice chalkiness in future were discussed in this review.