[Current status and prospects of genetic research on IgA nephropathy]

IgA nephropathy is the most common primary glomerulonephritis worldwide, and genetic factors may play an important role in its pathogenesis. Following candidate gene association analysis and genome-wide linkage study, genome-wide association studies (GWAS) have found multiple susceptibility genes related to the pathogenesis and clinical phenotype of IgA nephropathy. Meanwhile, structural variation and epigenetic changes are also closely related to IgA nephropathy. Genetic variants have been found to explain about 11% of its heritability. In the current era of genomic medicine, how to find more susceptible genes/loci, whole genome sequencing studies (WGS) provide clues to further understand the genetic variation of IgA nephropathy. How to find the cell type-specific susceptibility genes associated with IgA nephropathy, multi-omics studies will conduct comprehensive analysis via single-cell sequencing, expression quantitative trait locus (eQTL) and genomics to find the pathogenic genes and offer insights into the development of targeted drugs, which will be the trend and direction of future research.

Evidence for Band Renormalizations in Strong-Coupling Superconducting Alkali-Fulleride Films

There has been a long-standing debate about the mechanism of the unusual superconductivity in alkali-intercalated fullerides. In this Letter, using high-resolution angle-resolved photoemission spectroscopy, we systematically investigate the electronic structures of superconducting K_{3}C_{60} thin films. We observe a dispersive energy band crossing the Fermi level with the occupied bandwidth of about 130 meV. The measured band structure shows prominent quasiparticle kinks and a replica band involving the Jahn-Teller active phonon modes, which reflects strong electron-phonon coupling in the system. The electron-phonon coupling constant is estimated to be about 1.2, which dominates the quasiparticle mass renormalization. Moreover, we observe an isotropic nodeless superconducting gap beyond the mean-field estimation (2Δ/k_{B}T_{c}≈5). Both the large electron-phonon coupling constant and large reduced superconducting gap suggest a strong-coupling superconductivity in K_{3}C_{60}, while the electronic correlation effect is suggested by the observation of a waterfall-like band dispersion and the small bandwidth compared with the effective Coulomb interaction. Our results not only directly visualize the crucial band structure but also provide important insights into the mechanism of the unusual superconductivity of fulleride compounds.

[Concerns about COVID-19-associated liver injury]

Patients infected with 2019-nCoV/SARS-CoV-2 are usually accompanied with liver injury, which may correlates with the severe forms of the disease. The pathogenesis of COVID-19-associated liver injury is not only related to the underlying liver diseases, viral cholangitis, systemic inflammatory response, and hypoxic liver injury, but also to multiple factors that lead to liver injury in patients. Therefore, during the course of treatment, the patient's liver function should be closely monitored, and attention should be paid to the occurrence of drug-induced liver injury.

[Analysis of articles on dental pulp biology research in China published in international journals from 2011 to 2020]

Objective: To analyze the articles on research of dental pulp biology in China and to understand the situation of China in the entire field of dental pulp biology around the world in order to provide references for further in-depth research in dental pulp biology in China. Methods: Based on Web of Science core collection database, the articles published in the international journals in the field of dental pulp biology from 2011 to 2020 were retrieved and identified. Six indicators including research scale, academic influence, high-ranking and the high-influence journals, research areas, international partnership and project funding were statistically analyzed. Results: Totally 1 215 articles were published by Chinese researchers, which is the most in the research field of dental pulp biology. The total number of citations was 18 328, however the average number of citations of above mentioned articles was slightly lower than that of the world average. The number of articles published in Natural Index Journals and Journal of Dental Research is lower than that of the United States. The research areas of dental pulp biology in China were not only in dentistry, oral surgery and medicine, but also in cell biology, experimental medicine, materials science, engineering, molecular biology and applied microbiology. Articles of internationally cooperated researches were scarce. Most of the researches of dental pulp biology field conducted in China were supported by the National Natural Science Foundation of China. Conclusions: Although there were fruitful research outcomes in the field of dental pulp biology from 2011 to 2020, the academic influence of these researches still needed to be improved. It was recommended that great efforts should be made in developing interdisciplinary, inter-unit and international cooperation, focusing on hotspot and major projects, actively applying for and using of project fundings in order to produce more high-quality research outcomes.

[Effect of Echinococcus granulosus hydatid cyst fluid protein on allergic rhinitis induced by ovalbumin in mice]

OBJECTIVE

To investigate the protective effect of Echinococcus granulosus hydatid cyst fluid protein (HCFP) on ovalbumin (OVA)-induced allergic rhinitis (AR) in mice.

METHODS

Twenty-four BALB/c mice at ages of 8 to 10 weeks, each weighing approximately 20 g, were randomly divided into four groups, including groups A (blank control group), B (blank intervention group), C (AR model group) and D (AR+HCFP intervention group), with 6 mice in each group. On days 0, 2, 4, 6, 8, 10 and 12, mice in groups A, B, C and D were injected with 200 μL sterile phosphate buffered saline (PBS), 200 μL sterile PBS containing 20 μg HCFP, 200 μL sterile PBS containing 50 μg OVA and 5 mg Al(OH)₃ gel, and 200 μL sterile PBS containing 50 μg OVA, 5 mg Al(OH)₃ gel and 20 μg HCFP, respectively. On days 14 to 20, mice in groups A, B, C and D were administered with 40 μL sterile PBS, 40 μL sterile PBS containing 20 μg HCFP, 40 μL sterile PBS containing 2 mg OVA and 40 μL sterile PBS containing 2 mg OVA and 20 μL HCFP by nasal drop, respectively. Mouse behavioral changes were observed and behavioral scores were estimated. The serum levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-5, IL-10, transforming growth factor-β (TGF-β) and OVA-specific IgE antibody (OVA-sIgE) were measured using enzyme-linked immunosorbent assay (ELISA), and the pathological changes of mouse nasal mucosa were observed by hematoxylin and eosin (HE) staining.

RESULTS

The mean behavioral score was significantly greater in Group C (6.83 ± 0.50) than in groups A (1.17 ± 0.52) and B (1.33 ± 0.52) (P < 0.05), while a lower mean behavioral score was estimated in Group D (3.50 ± 0.50) than in Group C (P < 0.05). There were significant differences among the groups in terms of serum IFN-γ (F = 4.08, P < 0.05), IL-4 (F = 275.90, P < 0.05), IL-5 (F = 96.82, P < 0.05), IL-10 (F = 77.67, P < 0.05), TGF-β (F = 9.98, P < 0.05) and OVA-sIgE levels (F = 44.69, P < 0.05). The serum IFN-γ level was significantly lower in Group C than in groups A, B and C (P < 0.05), and the serum levels of IL-4, IL-5 and OVA-sIgE were significantly higher in Group C than in groups A, B and C (P < 0.05), while the serum IL-10 and TGF-β levels were significantly greater in Group D than in Group C (P < 0.05). Microscopy showed apparent loss of nasal mucosa cilia, increased number and enlargement of goblet cells, interstitial edema and submucous vascular dilation in Group C, while the pathological changes of nasal mucosa were alleviated in Group D relative to Group C.

CONCLUSIONS

E. granulosus HCFP has a protective activity against OVA-induced allergic rhinitis in mice.

[Current status of hyperkalemia in dialysis patients in China]

Objective: To investigate the prevalence and associated factors of hyperkalemia in dialysis patients. Methods: Patients underwent hemodialysis (HD) and peritoneal dialysis (PD) from multi-center databases were recruited from January 2017 to December 2019, and those aged ≥18 years and with dialysis duration ≥3 months were included to analyze the prevalence and related factors of hyperkalemia. Results: A total of 12 364 patients were enrolled in the study, and 6 836 cases were men. The average age of the patients was (51±15) years. Among these patients, 4 230 cases underwent HD while 8 134 received PD. Hyperkalemia was detected in 20.7% (2 554/12 364) of the patients while hypokalemia was found in 17.0%(2 102/12 364) of the patients. Multivariate logistic regression showed that HD (OR=2.25, 95%CI: 1.54-3.30), diabetes mellitus (DM) (OR=1.65, 95%CI: 1.17-2.32), high body mass index (BMI) (OR=1.06, 95%CI: 1.03-1.09), high levels of serum albumin (OR=1.04, 95%CI: 1.01-1.07) and phosphorus (OR=3.12, 95%CI: 2.44-4.00), low levels of serum bicarbonate (OR=0.89, 95%CI: 0.87-0.92), triglycerides (OR=0.76, 95%CI: 0.68-0.85) and creatinine (OR=0.95, 95%CI: 0.90-0.99), usage of angiotensin converting enzyme inhibitor/Angiotensin Ⅱ receptor antagonist (ACEI/ARB, OR=1.38, 95%CI: 1.11-1.72) and beta-blocker (OR=1.32, 95%CI: 1.07-1.64) were associated with hyperkalemia. Conclusions: Hyperkalemia occurred in 20.7% of the dialysis patients. HD, DM, high BMI, high levels of serum albumin and phosphorus, low levels of serum bicarbonate, triglycerides and creatinine, use of ACEI/ARB were associated with hyperkalemia.

[Protective effect of recombinant adult serine protease inhibitor from Trichinella spiralis on sepsis-associated acute kidney injury in mice]

OBJECTIVE

To investigate the protective effect of recombinant adult serine protease inhibitor from Trichinella spiralis (TsadSPI) on sepsis-associated acute kidney injury in mice.

METHODS

A total of 18 male BALB/c mice were randomly divided into the sham-operation group, the model group, and the TsadSPI treatment group, of 6 mice in each group. Sepsis-associated acute kidney injury was modeled in the model group and TsadSPI treatment group by cecal ligation puncture (CLP), while mice in the sham-operation group were only given exploratory laparotomy without ligation or perforation of the cecum. After 30 min of CLP, mice in the sham-operation group and the model group were intraperitoneally injected with PBS (100 μL), and mice in the TsadSPI treatment group were intraperitoneally injected with PBS (100 μL) containing TsadSPI (2 μg). At 12 h following modeling, the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (Cr) and urea nitrogen (BUN) were measured to assess the liver and kidney functions, and the changes of the mouse kidney structure were observed using HE staining. In addition, the serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 and transforming growth factor (TGF)-β were measured using an enzyme-linked immunosorbent assay (ELISA), and the myeloid differentiation factor 88 (MyD88) and nuclear factor kappa-B (NF-κB) p65 expression was determined in kidney tissues using immunohistochemical staining.

RESULTS

At 12 h following CLP, there were significant differences in the serum levels of ALT (F = 41.031, P < 0.001), AST (F = 54.757, P < 0.001), Cr (F = 24.142, P < 0.001) and BUN (F = 214.849, P < 0.001) among the three groups, and higher levels of ALT, AST, Cr and BUN were measured in model group than in the sham-operation group (P < 0.001), while lower ALT, AST, Cr and BUN levels were found in the TsadSPI treatment group than in the model group (P < 0.001). HE staining showed severe mouse kidney injuries following CLP, and TsadSPI treatment resulted in remarkable alleviation of the injury. ELISA measured significant differences in the TNF-α (F = 47.502, P < 0.001) and IL-6 levels (F = 222.061, P < 0.001) among the three groups, and showed a remarkable reduction in the TNF-α and IL-6 levels in the TsadSPI treatment group as compared to those in the model group (P < 0.001). In addition, there were significant differences in serum IL-10 (F = 16.227, P < 0.001) and TGF-β levels (F = 52.092, P < 0.001) among the three groups, and higher IL-10 and TGF-β levels were seen in the TsadSPI treatment group than in the model group (P < 0.001). Immunohistochemical staining showed greater MyD88 expression and a higher nuclear positive rate of NF-κB p65 in kidney tissues in the model group than in the TsadSPI treatment group.

CONCLUSIONS

TsadSPI may reduce the MyD88 expression and nuclear positive rate of NF-κB p65 in mouse kidney tissues to up-regulate the expression of immunomodulatory factors and down-regulate the expression of pro-inflammatory cytokines, thereby protecting sepsis-associated acute kidney injury.

Combination of LINE-1 hypomethylation and RASSF1A promoter hypermethylation in serum DNA is a non-invasion prognostic biomarker for early recurrence of hepatocellular carcinoma after curative resection

Hepatocarcinogenesis, a multistep process, involves not only genetic mutations but also epigenetic alterations. Widespread of global DNA hypomethylation is accompanied with specific regional hypermethylation especially at tumor suppressor genes' promoters. The aim of this study is to determine the efficacy of combined DNA methylation analysis of a global DNA methylation marker - LINE-1 and a tumor suppressor gene highly associated with the malignancy of HCC- RASSF1A in serum as a novel prognostic marker for diagnosis of early recurrence after curative resection.LINE-1 was hypomethylated in 66.7% (70/105) and RASSF1A promoter was hypermethylated in 73.3% (77/105) of HCC serum DNA samples by methylation specific PCR, but in none of the healthy controls: LINE-1 hypometylation (0/50) and RASSF1A hypermethylation (0/50). A significant association was found between LINE-1 hypomethylation and clinical pathologic features including HBsAg positivity (p=0.009), tumor size (p=0.001) and AFP levels (p<0.001). Besides, significant correlation was detected between RASSF1A promoter hypermethylation and lymph nodes metastasis (p=0.045).The results of Kaplan-Meier estimates of survival suggested that LINE-1 hypomethylation was highly associated with poor survival of patients (disease-free survival p=0.002, overall survival p=0.0123). More importantly, co-evaluation of LINE-1 hypomethylation and RASSF1A promoter hypermethylation was found to be significantly correlated to early recurrence and poor prognosis (disease-free survival p=0.0001, overall survival p=0.05) in patients after curative resection.In conclusion, our study showed that the combined examination of LINE-1 hypomethylation and RASSF1A promoter hypermethylation was effective in predicting early recurrence of HCC after curative resection. Patients with dual positivity of LINE-1 hypomethylation and RASSF1A promoter hypermethylation should be supplied with more intensive care and close follow-up after they undergo tumor resection.

[Incidence of neonatal asphyxia and contributing factors for the develpment of severe asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture: a multicenter study]

OBJECTIVE

To investigate the incidence of neonatal asphyxia and possible contributing factors for the development of severe asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture, China.

METHODS

A total of 16 hospitals in Hubei Enshi Tujia and Miao Autonomous Prefecture were selected as research centers. A retrospective analysis was performed for the clinical data of 22 294 live births in these 16 hospitals from January to December, 2016 to investigate the incidence rate of neonatal asphyxia and possible contributing factors for the development of severe asphyxia.

RESULTS

Of the 22 294 neonates born alive, 733 (3.29%) were diagnosed with neonatal asphyxia, among whom 627 had mild asphyxia and 106 had severe asphyxia. The neonates with low maternal education level, maternal anemia during pregnancy, chorioamnionitis, abnormal amniotic fluid, abnormal umbilical cord, placenta previa, placental abruption, Tujia Minority, preterm birth, and low birth weight had a higher incidence of severe asphyxia (P<0.05).

CONCLUSIONS

The incidence rate of neonatal asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture is higher. Low maternal education level, maternal anemia during pregnancy, chorioamnionitis, abnormal amniotic fluid, abnormal umbilical cord, placenta previa, placental abruption, Tujia Minority, preterm birth, and low birth weight may be related to the development of severe neonatal asphyxia.

Optimal expression and purification of sapelovirus A structural protein VP1, and its immunogenicity in mice

Sapelovirus A (SV-A) is a positive-sense single-stranded RNA virus which is associated with acute diarrhea, pneumonia and reproductive disorders. The virus capsid is composed of four proteins, and the functions of the structural proteins are unclear. In this study, we expressed SV-A structural protein VP1 and studied its antigenicity and immunogenicity. SDS-PAGE analysis revealed that the target gene was expressed at high levels at 0.6 mM concentration of IPTG for 24 h. The mouse polyclonal antibody against SV-A VP1 protein was produced and reached a high antiserum titer (1: 2,048,000). Immunized mice sera with the recombinant SV-A VP1 protein showed specific recognition of purified VP1 protein by western blot assay and could recognize native SV-A VP1 protein in PK-15 cells infected with SV-A by indirect immunofluorescence assay. The successfully purified recombinant protein was able to preserve its antigenic determinants and the generated mouse anti-SV-A VP1 antibodies could recognize native SV-A, which may have the potential to be used to detect SV-A infection in pigs.

Cancer deaths and cases attributable to lifestyle factors and infections in China, 2013

Background

The burden of cancer in China is high, and it is expected to further increase. Information on cancers attributable to potentially modifiable risk factors is essential in planning preventive measures against cancer. We estimated the number and proportion of cancer deaths and cases attributable to ever-smoking, second-hand smoking, alcohol drinking, low fruit/vegetable intake, excess body weight, physical inactivity, and infections in China, using contemporary data from nationally representative surveys and cancer registries.

Methods

The number of cancer deaths and cases in 2013 were obtained from the National Central Cancer Registry of China and data on most exposures were obtained from the China National Nutrition and Health Survey 2002 or 2006 and Global Adult Tobacco Smoking 2010. We used a bootstrap simulation method to calculate the number and proportion of cancer deaths and cases attributable to risk factors and their corresponding 95% confidence intervals (CIs), allowing for uncertainty in data.

Results

Approximately 718 000 (95% CI 702 100-732 200) cancer deaths in men and 283 100 (278 800-288 800) cancer deaths in women were attributable to the studied risk factors, accounting for 52% of all cancer deaths in men and 35% in women. The numbers for incident cancer cases were 952 500 (95% CI 934 200-971 400) in men and 442 700 (437 200-447 900) in women, accounting for 47% of all incident cases in men and 28% in women. The greatest proportions of cancer deaths attributable to risk factors were for smoking (26%), HBV infection (12%), and low fruit/vegetable intake (7%) in men and HBV infection (7%), low fruit/vegetable intake (6%), and second-hand smoking (5%) in women.

Conclusions

Effective public health interventions to eliminate or reduce exposure from these risk factors, notably tobacco control and vaccinations against carcinogenic infections, can have considerable impact on reducing the cancer burden in China.

Carcass traits, meat quality, antioxidant status and antioxidant gene expression in muscle and liver of Hu lambs fed perilla seed

The effects of perilla (Perilla frutescens L.) seed on carcass traits, meat quality, antioxidant status and antioxidant gene expression in the liver and muscle of Hu lambs were investigated in this study. Sixty Hu lambs (23.02 ± 1.36 kg) were randomly divided into four experimental groups receiving diets containing 0%, 5%, 10% or 15% perilla seed (CD, 5%PFSD, 10%PFSD and 15%PFSD, respectively). The addition of perilla seed had no significant impacts on carcass traits (p > .05). There were no differences in pH, meat colour, drip loss, cooking loss or shear force among the four treatments (p > .05). Addition of perilla seed increased (p < .05) deposition of intramuscular lipids but had no effect on other chemical components in the longissimus dorsi (LD) (p > .05). The 15%PFSD diet decreased the total antioxidant capacity (T-AOC) and malondialdehyde (MDA) content in the liver (p < .05 for both) but increased the activity of these antioxidant enzymes in LD (p < .05 for both). Compared to CD, addition of perilla seed increased superoxide dismutase (SOD) and glutathione peroxidase (GPX) expression in the liver and LD (p < .05 for all). These results indicate that perilla seed supplementation in lambs' diets can increase deposition of intramuscular lipids and improve muscular oxidative status and meat quality.

Interleukin-27 augments the inhibitory effects of sorafenib on bladder cancer cells

Both sorafenib and interleukin-27 (IL-27) are antineoplastic drugs. This study aimed to investigate the synergistic effect of these two drugs on bladder cancer cells. HTB-9 and T24 cells were stimulated with IL-27 (50 ng/mL), sorafenib (2 μM) or the synergistic action of these two drugs. The cells without treatment acted as control. Cell proliferation, apoptosis and invasion were measured by bromodeoxyuridine assay, flow cytometry and modified Boyden chamber, respectively. Simultaneously, both modified Boyden chamber and scratch assay were used to assess cell migration. Finally, the phosphorylation levels of key kinases in the Akt/mechanistic target of rapamycin (mTOR)/mitogen-activated protein kinase (MAPK) pathway, and expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 were detected by western blot analysis. Stimulation with IL-27 or sorafenib repressed proliferation, migration and invasion but promoted apoptosis, and the effects were all enhanced by the combination of these two drugs in HTB-9 cells. The effect of the combined treatment on bladder cancer cells was verified in T24 cells. Additionally, the phosphorylation levels of AKT, mTOR and MAPK as well as the expression levels of MMP-2 and MMP-9 were all decreased by a single treatment of IL-27 or sorafenib, and further decreased by the combined treatment of these two drugs. The combination of IL-27 and sorafenib inhibited proliferation, migration and invasion and promoted apoptosis of bladder cancer cells compared with mono-drug treatment. Additionally, the AKT/mTOR/MAPK pathway might be implicated in the functional effects by down-regulations of MMP-2 and MMP-9.

[Effect of molar ligation and local Porphyromonas gingivalis inoculation on alveolar bone loss in the mouse]

OBJECTIVE

To compare the extent and time course of alveolar bone loss and osteoclast activation in two murine models of periodontal disease: molar ligation and Porphyromonas gingivalis (P. gingivalis) oral inoculation.

METHODS

A split-mouth design was applied to two groups of mice (C57BL6, 6-8 weeks old, n=24 in both groups), resulting in four treatment groups: (1) Control group: unligated upper right 2nd molars receiving CMC only, (2)Ligature group: ligation of a 9-0 suture around the upper left 2nd molar, (3) P. gingivalis group: unligated upper right 2nd molar receiving P. gingivalis challenge only, (4)Ligature+P.gingivalis group: ligation of the upper left 2nd molar in combination with oral inoculation with 109 colony-forming units(CFU) P. gingivalis. Alveolar bone loss was measured as the cementoenamel junction and alveolar bone crest (CEJ-ABC) distance. In the study, 48 C57BL6 mice were designed and treated as described above, and osteoclasts were counted on histological sections following tartrate-resistant acid phosphatase (TRAP) staining and counts were normalized to alveolar bone surface distance. Then 36 C57BL6 mice were investigated, of which 30 were ligated a 9-0 silk ligature around the 2nd molar in the left maxillary quadrant and 6 were not ligated. After ligation for 1 week, the ligatures in 12 mice were taken off for either 1 week or 2 weeks. The CEJ-ABC distance of the 6 mice without ligation was baseline. The CEJ-ABC distances were measured and analyzed. The data were analyzed with one-way ANOVA.

RESULTS

Molar ligation induced marked alveolar bone loss after 3, 6, 9 and 12 weeks [(0.16±0.04) mm, (0.16±0.02) mm, (0.18±0.03) mm, (0.17±0.02) mm], vs. corresponding controls [(0.09±0.03)mm,(0.10±0.01)mm,(0.12±0.04)mm,(0.12±0.01)mm] and P. gingivalis group [(0.09±0.03)mm, (0.12±0.01)mm,(0.12±0.02)mm,(0.10±0.01)mm], P<0.05. Combined treatment with molar ligation and P. gingivalis did not further increase the CEJ-ABC distance. Evidence for osteoclast activation was found one day after molar ligation, and TRAP-positive cell numbers peaked on day 3 (12±4 vs. control 2±2, P<0.01). After taking off ligature following ligation for 2 weeks, it showed significantly regrowth of alveolar bone compared with that before removal of the ligature on day 7 [(0.07±0.02)mm vs. (0.13±0.01)mm, P<0.01].

CONCLUSION

Molar ligation is a rapid and effective way to induce periodontal bone loss in mice. Osteoclast activation occurs within 24 hours of ligature placement, and the extent of bone loss well exceeds that of the P.gingivalis-induced bone loss. Removing ligature after periodontal disease might help bone regeneration by regrowth of the alveolar bone.

[Effect of hypoxia-inducible factor-2α/stearoyl-CoA desaturase-1 pathway on biological behaviors of hepatoma cells induced by hypoxia]

Objective: To investigate whether hypoxia-inducible factor-2α (HIF-2α) affects the biological behaviors of hepatoma cells through regulating stearoyl-CoA desaturase-1 (SCD1) in a hypoxic environment. Methods: HepG2 and SMMC-7721 cells were exposed to 1% O₂ to establish the hypoxic models. After hepatoma cells were stimulated by hypoxia for 0, 3, 6, 12, and 24 hours, fluorescent quantitative PCR and Western blot were used to measure the mRNA and protein expression of HIF-2α and SCD1 over time. HIF-2α interfering plasmids and SCD1 inhibitor CAY10566 were used to divide the cells into blank group (nomoxia), hypoxic group (1% O₂ for 12 h), hypoxic negative control group (negative HIF-2α plasmid+1% O2 for 12 h), hypoxic interference group (HIF-2α interfering plasmid+1% O₂ for 12 h), hypoxic CAY group (CAY10566 10 μmol+1% O₂ for 12 h), and hypoxic interference+CAY group (HIF-2α interfering plasmid+CAY10566 10 μmol+1% O₂ for 12 h). Western blot was used to measure the protein expression of HIF-2α and SCD1 in hepatoma cells, CCK8 assay was used to measure the proliferative capacity of hepatoma cells, Annexin-V/PE flow cytometry was used to measure the apoptosis of hepatoma cells, and transwell invasion assay was used to measure the invasion of hepatoma cells. A one-way analysis of variance was used to compare the means of multiple samples. Results: Both HepG2 and SMMC-7721 cells showed increasing mRNA and protein expression of HIF-2α and SCD1 over the time of hypoxic induction. After the expression of HIF-2α was downregulated in a hypoxic environment, hepatoma cells showed a significant reduction in the protein expression of SCD1; inhibition of SCD1 expression had no significant effect on the protein expression of HIF-2α in hepatoma cells. After HIF-2α was interfered with and SCD1 expression was inhibited, HepG2 and SMMC-7721 cells showed significantly greater reduction in the protein expression of SCD1 than those with HIF-2α or SCD1 inhibition alone (0.53±0.04 vs 1.12±0.04 or 1.12±0.04; 0.44±0.10 vs 0.90±0.10 or 0.99±0.13) (HIF-2α: F_hepG2 = 1026.89, P_hepG2 = 0.00, F_SMMC-7721 = 2186.22, P_SMMC-7721 = 0.00; SCD1: F_hepG2 = 1347.93, P_hepG2 = 0.00, F_SMMC-7721 = 46.43, P_SMMC-7721 = 0.00). Inhibition of the expression of HIF-2α or SCD1 reduced the proliferation and invasion of HepG2 and SMMC-7721 cells and promoted apoptosis (P < 0.05); interference and downregulation of HIF-2α combined with inhibition of SCD1 expression by CAY10566 achieved significantly greater reductions in proliferation and invasion and a significantly greater increase in apoptosis rate of hepatoma cells, compared with inhibition of HIF-2α or SCD1 alone (P <0.05). Conclusion: HIF-2α/SCD1 pathway may be one of the important mechanisms for hypoxia to regulate the energy metabolism of hepatoma cells and affect their biological behaviors.

Genetic background of Escherichia coli isolates from peritoneal dialysis patients with peritonitis and uninfected control subjects

Escherichia coli is the most common cause of Gram-negative peritonitis resulting in peritoneal function deterioration as well as poor clinical outcome in continuous ambulatory peritoneal dialysis (PD) patients. In this study, we analyzed the phylogenetic background and genetic profile of the E. coli isolates and sought to determine the characteristics of specific bacteria associated with peritonitis. E. coli isolates from 56 episodes of peritonitis in 46 PD patient cases and rectal isolates from 57 matched PD control patient cases were compared for both phylogenetic groups and the presence of virulence factors (VFs). There were no significant differences in terms of demographic data between the peritonitis and control groups. Peritonitis isolates exhibited a significantly greater prevalence of 8 VFs. In multivariate logistic regression analysis, kpsMT II (group 2 capsule synthesis) was the strongest VF predictor of peritonitis (OR = 8.02; 95%CI = 3.18-20.25; P < 0.001), followed by traT (serum-resistance-associated outer membrane protein) (OR = 3.83; 95%CI = 1.33-11.03; P = 0.013). The pathogenic groups of E. coli contained a higher concentration of individual VFs compared to the commensal groups. The prevalence of pathogenic E. coli was much higher in peritoneal isolates than rectal isolates (64.3 vs 31.6%, P = 0.001). Our results indicate that the E. coli peritonitis and rectal isolates are different in PD patients. The specific VFs associated with peritonitis isolates may directly contribute to the pathogenesis of peritonitis.

Serum uric acid predicts cardiovascular mortality in male peritoneal dialysis patients with diabetes

BACKGROUND AND AIMS

Serum uric acid may predict mortality in diabetic patients and dialysis patients. However, the relationship between serum uric acid and prognosis in diabetic peritoneal dialysis (PD) patients is unclear.

METHODS AND RESULTS

We conducted a cohort study of 1278 incident PD patients, (mean age 47.6 years), of which 328 (25.7%) had diabetes and 289 (22.6%) had diabetic nephropathy. During a median follow-up period of 30.7 months, 231 deaths occurred, of which 126 were ascribed to cardiovascular events. Mean serum uric acid was lower for diabetic patients than non-diabetic patients (6.8 ± 1.3 vs. 7.4 ± 1.4 mg/dL, respectively; P < 0.001). Cox regression models were adjusted for glycated hemoglobin, dialysis-related factors, traditional risk factors, and treatments. After adjustments, the highest sex-specific tertile of uric acid was associated with an increased risk of cardiovascular mortality (HR, 2.26; 95% CI, 1.14-4.48) compared to the lowest tertile in diabetic patients. Adjusted HRs per 1 mg/dL higher uric acid for all-cause and cardiovascular mortality were 1.09 (95% CI, 0.91-1.32) and 1.42 (95% CI, 1.13-1.79) for diabetic men and 1.06 (95% CI, 0.83-1.35) and 1.12 (95% CI, 0.78-1.61) for diabetic women, respectively. Elevated serum uric acid predicted a higher risk of all-cause and cardiovascular mortality in non-diabetic men but not in non-diabetic women.

CONCLUSIONS

Elevated serum uric acid is an independent predictor of cardiovascular mortality in diabetic male PD patients.

Analysis of polymorphisms in the FUT1 and TAP1 genes and their influence on immune performance in Pudong White pigs

FUT1 and TAP1 have been identified as candidate genes that offer resistance against Escherichia coli F18 infection, with the AA genotype in FUT1 and the GG genotype in TAP1 conferring resistance. In order to confirm polymorphisms at FUT1 M307 and TAP1 G729, and evaluate their influence on immunity performance in Pudong White pigs, we performed polymerase chain reaction-restriction fragment length polymorphism analysis, measured immune indices, and compared the results with those observed in Large White pigs. The AA genotype of FUT1 was first discovered in Pudong White pigs and has not been found in other Chinese domestic pig breeds. The frequency of the AA genotype in Pudong White and Large White pigs was 0.018 and 0.052, respectively. The GG genotype of TAP1 was also detected in the two breeds, with a frequency of 0.708 and 0.695, respectively. Chi-square fitness analysis of both genes showed that these loci deviated from Hardy-Weinberg equilibrium in the two breeds (P < 0.05). No significant differences were observed in interleukin-6 (IL-6) and IL-10 levels among the three genotypes at FUT1 and TAP1 in the two breeds (P > 0.05). Individuals for all genotypes of TAP1 in both pig breeds had similar TNF-α levels (P > 0.05), implying that Pudong White pigs may have the same ability for hepatocyte inflammatory response and B cell differentiation as Large White pigs. These differences have a degree of influence on Pudong White pig's immune ability to resist F18 or other infections.

Ligation of the intersphincteric fistula tract plus a bioprosthetic anal fistula plug (LIFT-Plug): a new technique for fistula-in-ano

AIM

Ligation of the intersphincteric fistula tract and reinforcement with a bioprosthetic graft are two recently reported procedures that have shown promise in the treatment of anal fistula. This study was undertaken to validate combining ligation of the intersphincteric fistula tract plus bioprosthetic anal fistula plug and report our preliminary results and experience.

METHOD

Twenty-one patients with transsphincteric anal fistula were treated with ligation of the intersphincteric fistula tract plus concurrent bioprosthetic plug of the anal fistula. We evaluated healing time, fistula closure rate and postoperative anal function according to the Wexner continence score.

RESULTS

No mortality or major complications were observed. Median operative time was 20 (range 15-40) min. After a median follow-up of 14 (range 12-15) months, the overall success rate was 95% (20/21), with a median healing time of 2 (range 2-3) weeks for external anal fistula opening and 4 (range 3-7) weeks for intersphincteric groove incision. Only 1 (5%) patient reported rare incontinence for gas postoperatively (Wexner score 1).

CONCLUSIONS

Ligation of the intersphincteric fistula tract plus a bioprosthetic anal fistula plug is an easy, safe, effective and useful alternative in the management of anal fistula. Further randomized controlled studies are necessary to better evaluate long-term results.

Diabetic retinopathy in predicting diabetic nephropathy in patients with type 2 diabetes and renal disease: a meta-analysis

AIMS/HYPOTHESIS

The aim of this meta-analysis is to determine the predictive value of diabetic retinopathy in differentiating diabetic nephropathy from non-diabetic renal diseases in patients with type 2 diabetes and renal disease.

METHODS

Medline and Embase databases were searched from inception to February 2012. Renal biopsy studies of participants with type 2 diabetes were included if they contained data with measurements of diabetic retinopathy. Pooled sensitivity, specificity, positive predictive value, negative predictive value and other diagnostic indices were evaluated using a random-effects model.

RESULTS

The meta-analysis investigated 26 papers with 2012 patients. The pooled sensitivity and specificity of diabetic retinopathy to predict diabetic nephropathy were 0.65 (95% CI 0.62, 0.68) and 0.75 (95% CI 0.73, 0.78), respectively. The pooled positive and negative predictive value of diabetic retinopathy to predict diabetic nephropathy were 0.72 (95% CI 0.68, 0.75) and 0.69 (95% CI 0.67, 0.72), respectively. The area under the summary receiver operating characteristic curve was 0.75, and the diagnostic odds ratio was 5.67 (95% CI 3.45, 9.34). For proliferative diabetic retinopathy, the pooled sensitivity was 0.25 (95% CI 0.16, 0.35), while the specificity was 0.98 (95% CI 0.92, 1.00). There was heterogeneity among studies (p < 0.001), and no publishing bias was identified.

CONCLUSIONS/INTERPRETATION

Diabetic retinopathy is useful in diagnosing or screening for diabetic nephropathy in patients with type 2 diabetes and renal disease. Proliferative diabetic retinopathy may be a highly specific indicator for diabetic nephropathy.

Generation of polarization-entangled photon pairs via concurrent spontaneous parametric downconversions in a single χ(2) nonlinear photonic crystal

We propose a scheme for generating polarization-entangled photon pairs using a χ((2)) nonlinear photonic crystal, which is designed for enabling two concurrent quasi-phase-matched spontaneous parametric downconversion processes. Beamlike photon pairs produced from each process are collinear but noncollinear with the pump. Moreover, the source we design works in a postselection-free way and applies to both degenerate and nondegenerate cases. Combining possible waveguide technologies, our scheme may provide an integrated polarization entanglement source.

Zoledronate inhibits phosphate and bone morphogenetic protein 2-induced extracellular calcification of vascular smooth muscle cells in vitro

The aim of this study was to explore the effects of the bisphosphonate zoledronate on calcification induced by inorganic phosphate (Pi) and/or bone morphogenetic protein 2 (BMP-2) and the underlying mechanisms. Primary vascular smooth muscle cells (VSMCs) from rats were treated with 3 mM Pi or 3 mM Pi/BMP-2, with and without addition of zoledronate; 1.4 mM Pi served as a control. Calcium deposits, expression of core binding factor α-1 (Cbfa-1), osteopontin (OPN), parathyroid pituitary-specific transcription factor (Pit)-1 and Pit-2, and Pi uptake of VSMCs was determined. The calcification of VSMCs induced by elevated Pi or Pi/BMP-2 was significantly inhibited by zoledronate. The expression of Cbfa-1, OPN and Pit-1 was increased significantly after treatment with an elevated level of Pi or Pi/BMP-2, and this expression was significantly suppressed by addition of zoledronate. Pi uptake of VSMCs increased following treatment with elevated Pi and significantly decreased by addition of zoledronate. These results indicated that zoledronate effectively inhibited calcification induced by Pi/BMP-2, and this may have been achieved by means of the downregulation of expression of calcification-related proteins and uptake of Pi.

Purification and characterization of an antimicrobial peptide, insect defensin, from immunized house fly (Diptera: Muscidae)

The house fly, Musca domestica L. (Diptera: Muscidae), is involved in phoretic movement of pathogenic agents, but it has a very efficient defense mechanism against infection. It is believed that antimicrobial peptides play a significant role in the defense system of the house fly. Here, we isolated a peptide from the immunized house fly pupae, measured its molecular mass (3987.6 Da) by matrix-assisted laser desorption ionization/time of flight-mass spectrometry, and determined its amino acid sequence by using the Procise Protein Sequencing System (Applied Biosystems, Foster City, CA). The peptide was confirmed as a member of the insect defensin family. It displayed high activity against gram-positive bacteria but lower activity against gram-negative bacteria and fungi. Reverse transcription-polymerase chain reaction showed that the house fly defensin gene was constitutively expressed in naive pupae and strongly up-regulated after immunization. House fly defensin is an amphiphilic peptide with a structure similar to that of the CSalphabeta scaffold of insect defensin A from the flesh fly, Phormia terraenovae Robineau-Desvoidy. To our knowledge, this is the first isolated and characterized house fly antimicrobial peptide, and our work may provide useful information for developing pharmacologically active antimicrobial agents.

Pharmacokinetic/pharmacodynamic modelling of 2-acetyl-4(5)-tetrahydroxybutyl imidazole-induced peripheral lymphocyte sequestration through increasing lymphoid sphingosine 1-phosphate

2-Acetyl-4(5)-tetrahydroxybutyl imidazole (THI) has been shown to reduce rodent peripheral blood lymphocytes through increasing lymphoid sphingosine 1-phosphate (S1P) by inhibiting S1P lyase. The objective of this study was to characterize the relationship between systemic THI exposure, splenic S1P concentrations, and lymphopenia in rats. Following the oral administration of 10 and 100 mg kg(-1) THI to male rats, THI was rapidly absorbed and reached a plasma peak level at 1 h post-dosing. Splenic S1P increased and reached the peak level at 24 h. Blood lymphocyte count decreased as the splenic S1P level increased. THI plasma concentration was linked to splenic S1P concentration using an indirect model incorporated with a four-step signal transduction model. In turn, the S1P level was directly coupled with blood lymphocyte number. The integrated model simultaneously captured the splenic S1P and blood lymphocyte responses. This pharmacokinetic-biomarker-pharmacodynamic model resolved the remarkable discrepancy between plasma THI concentration and the pharmacological response and quantitatively described the relationship of THI exposure, S1P, and lymphopenic response.

Identification of related QTLs at late developmental stage in rice (Oryza sativa L.) under two nitrogen levels

QTL underlying related traits at the late developmental stage under two different nitrogen levels were investigated in rice using a population of chromosome segment substitution lines (CSSL) derived from a cross between Teqing and Lemont. A total of 31 QTLs referring 5 traits, that is, plant height (PH), panicle number per plant (PN), chlorophyll content (CC), shoot dry weight (SDW) and grain yield per plant (YD), were detected. Under normal N level, 3 QTLs were detected for each trait, while under low N level, 5, 4, 5 and 2 QTLs were detected for PH, PN, CC and SDW respectively. Most of the QTLs were located on chromosome 2, 3, 7, 11 and 12. QTLs controlling different traits or the same trait under different N levels were mapped on the same or adjacent intervals, forming several clusters in rice chromosomes. More than two traits were controlled by QTLs on one of four intervals (RM30-RM439, RM18-RM478, RM309-RM270, and RM235-RM17), suggesting that there were some pleiotropic effects. It was supposed that some QTLs only detected at low N level might be associated with the ability to tolerate the low N stress in rice.

Dissection of additive, epistatic effect and Q x E interaction of quantitative trait loci influencing stigma exsertion under water stress in rice

Four flowering related traits, spikelet number per panicle (SNP), percentage of single exserted stigma (PSES), dual exserted stigma (PDES) and total exserted stigma (PES) of a RI population with 185 lines under water stress and non-stress conditions for 2 years, were investigated in a drought tolerance screening facility. ANOVA results showed high significance between years, lines, and water stress treatments, together with interactions among them in pairs. Highest phenotypic correlation was found between PSES and PES (r = 0.9752***), followed by PDES and PES (r = 0.7150***), and PSES and PDES (r = 0.5424***). Based on a linkage map of 203 SSR markers, six main effect QTLs were detected for SNP and three or four main effect QTLs were associated with PSES, PDES and PES under stress or non-stress conditions. There were one to nine pairs of epistatic QTLs influencing SNP and stigma exsertion. The contribution rates of additive and epistatic effects seemed to be in a low magnitude for most cases (0.76%-9.92%) while a few QTLs or QTL pairs explained more than 10% of total variance. Some main effect QTL and epistasis were commonly detected among PSES, PDES and PES, explaining the high positive correlation between them. Few QTLs were detected under both water stress and non-stress condition, implying that drought had severe impact on the genetic behaviors of both spikelet number and stigma exsertion.

Detection and Molecular Characterization of a 'Candidatus Phytoplasma asteris'-Related Strain Infecting Sasa fortunei in China

Bamboos are ecologically and economically valuable plants. Young shoots of almost all species are edible, either raw or cooked, and are major components of Asian cuisine while culms are used for furniture or handicrafts as well as fuel wood. Symptoms indicative of phytoplasma disease were observed on Sasa fortunei (van Houtte) Fiori during a survey in Yangling, Shaanxi Province, China during 2007. Symptoms included internode shortening, a mosaic pattern on leaves of diminished size, stunted growth, and death of entire plants. Total nucleic acids were extracted from leaf veins of 10 diseased plants and 6 symptomless plants with a modified cetyltrimethylammoniumbromide (CTAB) method (1). Phytoplasma infection of plants was demonstrated by a nested PCR assay employing primer pair R16mF2/R16mR1 followed by R16F2n/R16R2 (2), which generated a 16S rDNA product of approximately 1.2 kb from all symptomatic plants only. Restriction fragment length polymorphism analysis by digestion of nested PCR products with restriction enzymes AluI and MseI indicated that S. fortunei plants contained group 16SrI (aster yellows), subgroup B phytoplasmas. Sequencing and phylogenetic analysis of phytoplasma 16S rDNA from S. fortunei (GenBank Accession No. FJ501958) revealed this strain to be very similar (99.7 and 99.6%, respectively) to phytoplasmas previously associated with Henon bamboo (Phyllostachys nigra) witches'-broom (GenBank Accession No. AB242433) (4) and sasa (S. borealis) witches'-broom (GenBank Accession No. AB293421) in Korea but less so (98.6%) to bamboo (Phyllostachys spp.) witches'-broom (GenBank Accession No. AY635145) disease in China (3). To our knowledge, this is the first report of a 'Ca. Phytoplasma asteris'-related strain infecting S. fortunei in China. References: (1) E. Angelini et al. Vitis 40:79, 2001. (2) D. E. Gundersen and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (3) C. Hong et al. Plant Prot. 31:39, 2005. (4) H. Jung et al. J. Gen. Plant Pathol. 72:261, 2006.

First Report of Elm Yellows Phytoplasma Infecting Clover in China

In the summer of 2008, phyllody and enlarged petioles resembling symptoms of phytoplasma infection were observed on clover (Trifolium repens) plants in lawns on the campus of Northwest A&F University. Typical phytoplasma-like bacteria were observed in the phloem cells when ultra-thin sections from leaf midrib tissues were examined with transmission electron microscopy. Nested PCR assays were used to verify the association of phytoplasma with the disease. Total DNA was extracted from the phloem of leaf midribs from 20 symptomatic plants and six symptomless plants using the modified CTAB method (1). Using the phytoplasma universal primer pair R16mF2/R16mR1 followed by specific primers R16F2n/R16R2 (4), PCR products of 1.4 and 1.2 kb were amplified, respectively, from symptomatic plants only. Jujube witches'-broom (JWB) and paulownia witches'-broom (PaWB) phytoplasma DNA samples served as controls and were used to study group relationships. After sequencing of the 16S rDNA fragment (GenBank Accession No. FJ436792), a BLAST search determined that the clover phytoplasma shared closest homology (99.6%) with JWB (GenBank Accession No. FJ154846) phytoplasmas compared with lesser identity (90.4%) with PaWB (GenBank Accession No. EF199937). Subsequent restriction fragment length polymorphism analysis of the PCR-amplified 1.2-kb 16S rDNA R₁₆(1)F₁/R₁ fragment indicated that the phytoplasma associated with the disease belongs to subgroup 16SrV-B of the elm yellows phytoplasma group. Clover phyllody phytoplasma were previously reported to infect clover in Canada (GenBank Accession No. L33762) (3) and Italy (GenBank Accession No. X77482) (2). The phytoplasma reported here shared 86.7 and 90.0% identity with the clover phyllody phytoplasma above, respectively, much lower than that with Elm yellows phytoplasma group. To our knowledge, this is the first report of Elm yellows phytoplasma infecting clover in China. References:(1) E. Angelini et al. Vitis 40:79, 2001. (2) G. Firrao et al. Eur. J. Plant Pathol. 102:817, 1996. (3) N. A. Harrison et al. Plant Pathol. 52:147, 2003. (4) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.

Transforming spatial entanglement using a domain-engineering technique

We study the spatial correlation of a two-photon entangled state produced in a multistripe periodically poled LiTaO3 crystal by spontaneous parametric down-conversion. The far-field diffraction-interference experiments reveal that the transverse modulation of domain patterns transforms the spatial mode function of the two-photon state. This result offers an approach to prepare a novel type of two-photon state with a unique spatial entanglement by using a domain-engineering technique.

Frequency self-doubling optical parametric amplification: noncollinear red-green-blue light-source generation based on a hexagonally poled lithium tantalate

Simultaneous generation of noncollinear red, green, and blue light from a single hexagonally poled lithium tantalate is reported. It results from the frequency self-doubling optical parametric amplification process, a process of second-order harmonic generation cascaded optical parametric amplification in a single-pass setup. The temperature and spectrum detuning characters of each cascaded quasi-phase-matching process are studied. This unique red-green-blue light source has potential applications in laser display and other laser industries.

Induction treatment of proliferative lupus nephritis with leflunomide combined with prednisone: a prospective multi-centre observational study

To evaluate the efficacy and safety of leflunomide in the treatment of proliferative lupus nephritis, a prospective multi-centre observational study was conducted. Patients with biopsy proven proliferative lupus nephritis were assigned to receive either leflunomide or cyclophosphamide with concomitant prednisone. Leflunomide was given orally with a loading dose of 1 mg/kg/day for 3 days followed by 30 mg/day. Intravenous cyclophosphamide was administered monthly at a dose of 0.5 g/m2 of body-surface area. A total of 110 patients were enrolled, 70 in the leflunomide group and 40 in the cyclophosphamide group. The complete remission rate in the leflunomide group was 21% and partial remission rate 52%, as compared with 18% and 55%, respectively, in the cyclophosphamide group. Renal parameters and systemic lupus erythematosus disease activity index improved significantly and similarly in both groups. Serum creatinine decreased or stabilized in both treatment groups. No significant difference was noted with respect to clinical outcome between groups. Repeat biopsy also showed a significant reduction of active lesions in kidney pathology after 6 months of leflunomide treatment. Major adverse events, similar in both treatment groups, included infection, alopecia and hypertension. Leflunomide, compared with cyclophosphamide, in combination with prednisone was effective in the induction therapy of proliferative lupus nephritis and was generally well-tolerated.

Smad7 gene transfer inhibits peritoneal fibrosis

Fibrosis mediated by transforming growth factor-beta (TGF-beta) is a common cause of peritoneal dialysis (PD) failure. In a model of peritoneal fibrosis, we tested the effect of Smad7, an inhibitor of TGF-beta signaling, using an ultrasound-microbubble-mediated delivery system. Rats were given daily PD for 4 weeks and received Smad7 or control plasmid transfer. The ultrasound technique enhanced Smad7 expression in a dose-dependent manner in more than 80% of the peritoneal cells after 3 days. The expression decreased by 14 days, but this was corrected by a second gene transfer. The overexpression of Smad7 substantially inhibited Smad2/3 activation, TGF-beta, plasminogen activator inhibitor-1, extracellular matrix, and myofibroblast mRNA, and protein expression in the peritoneal cells. The decreased peritoneal injury included the rise of mass transfer of glucose, a reduction of the ultrafiltration rate, and fibrotic thickening. Our studies suggest that ultrasound-mediated Smad7 gene delivery may be useful in the prevention or treatment of dialysis-induced peritoneal fibrosis.

QTLs influencing panicle size detected in two reciprocal introgressive line (IL) populations in rice (Oryza sativa L.)

Two sets of reciprocal introgression line (IL) populations, i.e., ILs with Lemont as recurrent parent (IL_LT) and ILs with Teqing as recurrent parent (IL_TQ), were developed and evaluated for traits representing panicle size, including primary branch number (PBN), secondary branch number (SBN), and spikelet number per panicle (SNP). Together with the regression to recurrent parent by advanced backcross, transgressive segregations were observed for all traits. Correlation and regression analysis showed that SBN had much higher contribution to SNP than PBN. It was confirmed by the QTL analysis that many common loci were detected between SBN and SNP, in comparison with single common locus between PBN and SNP. One and three main effect QTLs (M-QTLs) were detected for PBN in IL_LT and IL_TQ, respectively. Six M-QTLs per trait per populations were associated with SBN and SNP. Less number and lower contribution of epistasis were detected in IL populations in comparison with mapping result from F2 or RI population. There were only four QTLs in fourteen loci (near 30%) commonly detected in both reciprocal IL populations implying the large impact of genetic background on QTLs expression.

Grain yield responses to moisture regimes in a rice population: association among traits and genetic markers

Drought is a major constraint to rice (Oryza sativa L.) production in rainfed and poorly irrigated environments. Identifying genomic regions influencing the response of yield and its components to water deficits will aid our understanding of the genetic mechanism of drought tolerance (DT) of rice and the development of DT varieties. Grain yield (GY) and its components of a recombinant inbred population developed from a lowland rice and an upland rice were investigated under different water levels in 2003 and 2004 in a rainout DT screening facility. Correlation and path analysis indicated that spikelet fertility (SF) was particularly important for grain yield with direct effect (P=0.60) under drought stress, while spikelet number per panicle (SN) contributed the most to grain yield (P=0.41) under well-watered condition. A total of 32 quantitative trait loci (QTLs) for grain yield and its components were identified. The phenotypic variation explained by individual QTLs varied from 1.29% to 14.76%. Several main effect QTLs affecting SF, 1,000-grain weight (TGW), panicle number (PN), and SN were mapped to the same regions on chromosome 4 and 8. These QTLs were detected consistently across 2 years and under both water levels in this study. Several digenic interactions among yield components were also detected. The identification of genomic regions associated with GY and its components under stress will be useful to improve drought tolerance of rice by marker-aided approaches.

Attention to the hiding iodine deficiency in pregnant and lactating women after universal salt iodization: A multi-community study in China

BACKGROUND

Monitoring of iodine nutrition depends chiefly on the urinary iodine concentration in representative samples from the population. International groups have recommended school-age children as a convenient group for surveys, because of their accessibility and young age, but the relevance of this group to others, especially pregnant women, is not well established.

OBJECTIVE

The purpose was to compare different approaches to assessing iodine nutrition within communities, especially for pregnant and lactating women.

DESIGN

In an urban and a rural site from each of the 11 Chinese provinces, covering a wide geographic and socioeconomic range, we measured the iodine content of household salt and drinking water, the thyroid volume in school children, and the urinary iodine concentration in five population subsets; in some sites we also assessed iodine in breast milk and thyroid size in adult women.

RESULTS

The median urinary iodine concentrations for pregnant and lactating women were well below those of the schoolchildren from the same community in most study sites, the difference between medians, at overall level, being about 50 microg/l for the pregnant and 40 microg/l for the lactating, respectively. When ranked by median urinary iodine concentrations at overall level, the order of the groups was: all infants, schoolchildren, women of childbearing age, lactating women and pregnant women in both urban and rural sites. This relative distribution was constant among the study sites. From it, we derived a relationship to predict the median values for other groups, based on the data of schoolchildren. The median iodine content of salt was 30.9 ppm in urban sites and 31.3 ppm in rural sites, respectively, close to the nationally mandated 35 mg/kg. Water had low iodine content (3.7 microg/l) in both urban and rural sites except in a rural site from Tianjin. Ultrasonography showed that 6.5% of 1329 children in urban sites and 5.3% of 1431 children in rural sites had thyroid enlargement. Breast milk had a median iodine content of 135.9 microg/l in the urban and 157.5 microg/l in the rural. The goiter prevalence by palpation was low (2.0%) among all women examined (3367), but higher in pregnant women (2.7%) than in lactating women or other adult women.

CONCLUSIONS

An effective iodized salt program has brought iodine sufficiency to most of China, but pregnant women in some areas may still risk deficiency and need further supplements. We suggest other countries and international agencies pay more attention to pregnancy, where iodine deficiency has its worst consequences.

The main effects, epistatic effects and environmental interactions of QTLs on the cooking and eating quality of rice in a doubled-haploid line population

Amylose content (AC), gel consistency (GC) and gelatinazation temperature (GT) are three important traits that influence the cooking and eating quality of rice. The objective of this study was to characterize the genetic components, including main-effect quantitative trait loci (QTLs), epistatic QTLs and QTL-by-environment interactions (QEs), that are involved in the control of these three traits. A population of doubled haploid (DH) lines derived from a cross between two indica varieties Zhenshan 97 and H94 was used, and data were collected from a field experiment conducted in two different environments. A genetic linkage map consisting of 218 simple sequence repeat (SSR) loci was constructed, and QTL analysis performed using QTLMAPPER 1.6: resolved the genetic components into main-effect QTLs, epistatic QTLs and QEs. The analysis detected a total of 12 main-effect QTLs for the three traits, with a QTL corresponding to the Wx locus showing a major effect on AC and GC, and a QTL corresponding to the Alk locus having a major effect on GT. Ten digenic interactions involving 19 loci were detected for the three traits, and six main-effect QTLs and two pairs of epistatic QTLs were involved in QEs. While the main-effect QTLs, especially the ones corresponding to known major loci, apparently played predominant roles in the genetic basis of the traits, under certain conditions epistatic effects and QEs also played important roles in controlling the traits. The implications of the findings for rice quality improvement are discussed.

Gene actions of QTLs affecting several agronomic traits resolved in a recombinant inbred rice population and two backcross populations

To understand the types of gene action controlling seven quantitative traits in rice, we carried out quantitative trait locus (QTL) mapping in order to distinguish between the main-effect QTLs (M-QTLs) and digenic epistatic QTLs (E-QTLs) responsible for the trait performance of 254 recombinant inbred lines (RILs) from rice varieties Lemont/Teqing and two backcross hybrid (BCF1) populations derived from these RILs. We identified 44 M-QTL and 95 E-QTL pairs in the RI and BCF1 populations as having significant effects on the mean values and mid-parental heterosis of heading date, plant height, flag leaf length, flag leaf width, panicle length, spikelet number and spikelet fertility. The E-QTLs detected collectively explained a larger portion of the total phenotypic variation than the M-QTLs in both the RI and BCF1 populations. In both BCF1 populations, over-dominant (or under-dominant) loci were more important than additive and complete or partially dominant loci for M-QTLs and E-QTL pairs, thereby supporting prior findings that overdominance resulting from epistatic loci are the primary genetic basis of inbreeding depression and heterosis in rice.

Comparison of cancer survival in UK and Australia: rates are higher in Australia for three major sites

Relative survival of patients diagnosed with cancers of the colorectum, lung and female breast from Yorkshire, UK and New South Wales (NSW), Australia in 1992–2000 were compared using multiple regression models to adjust for various factors. Statistically significant differences were observed for all sites, Yorkshire patients having a 47–58% higher risk of excess death than those of NSW.

Conical second harmonic generation in a two-dimensional chi(2) photonic crystal: a hexagonally poled LiTaO3 crystal

A new type of conical second-harmonic generation was discovered in a 2D chi((2)) photonic crystal-a hexagonally poled LiTaO3 crystal. It reveals the presence of another type of nonlinear interaction-a scattering involved optical parametric generation in a nonlinear medium. Such a nonlinear interaction can be significantly enlarged in a modulated chi((2)) structure by a quasi-phase-matching process. The conical beam records the spatial distribution of the scattering signal and discloses the structure information and symmetry of the 2D chi((2)) photonic crystal.

Gene actions of QTLs affecting several agronomic traits resolved in a recombinant inbred rice population and two testcross populations

To understand the types of gene action controlling seven quantitative traits in rice, QTL mapping was performed to dissect the main effect (M-QTLs) and digenic epistatic (E-QTLs) QTLs responsible for the trait performance of 254 recombinant inbred lines (RILs) of "Lemont/Teqing", and two testcross (TC) F(1) populations derived from these RILs. The correlation analyses reveal a general pattern, i.e. trait heritability in the RILs was negatively correlated to trait heterosis in the TC hybrids. A large number of M-QTLs and E-QTLs affecting seven traits, including heading date (HD), plant height (PH), flag leaf length (FLL), flag leaf width (FLW), panicle length (PL), spikelet number per panicle (SN) and spikelet fertility (SF), were identified and could be classified into two predominant groups, additive QTLs detected primarily in the RILs, and overdominant QTLs identified exclusively in the TC populations. There is little overlap between QTLs identified in the RILs and in the TC populations. This result implied that additive gene action is largely independent from non-additive gene action in the genetic control of quantitative traits of rice. The detected E-QTLs collectively explained a much greater portion of the total phenotypic variation than the M-QTLs, supporting prior findings that epistasis has played an important role in the genetic control of quantitative traits in rice. The implications of these results to the development of inbred and hybrid cultivars were discussed.

[Molecular mapping of QTLs for rice milling yield traits]

QTLs of three milling yield traits, including brown rice (BR,%), milled rice (MR,%) and head milled rice (HR,%), were mapped using a set of 212 Lemont/Teqing RI population, an RFLP linkage map with 182 markers and a mixed model approach(QTLMapper V1.0). The population showed continuous distributions with transgressive segregation on both sides for all traits while HR had a wider variation than BR and MR. One and four main effect QTLs were detected for MR and HR. Two QTLs for HR(QHr6 and QHr7) had large additive effects. Twelve, five and sixteen pairs of digenic epistatic loci were associated with BR, MR and HR respectively. Epistasis was more important than main effect QTLs according to the mapping result. A complex relationship was observed for epistatic pairs mapped in same trait or among different traits by sharing intervals.

Novel chiral imidazole cyclophane receptors: synthesis and enantioselective recognition for amino acid derivatives

Novel chiral imidazole cyclophane receptors were synthesized by highly selective N-alkylation of the imadazolyl 1N-position of the bridged histidine diester 2 with the dibromide in the presence of NaH; these receptors exhibit good chiral recognition toward the enantiomers of L- and D-amino acid derivatives (up to KD/KL = 3.52, delta delta G0 = -3.11 kJ mol-1) in CHCl3 at 25.0 degrees C.

Immulectin-2, a lipopolysaccharide-specific lectin from an insect, Manduca sexta, is induced in response to gram-negative bacteria

A lipopolysaccharide-specific lectin, immulectin-2, was isolated from plasma of the tobacco hornworm, Manduca sexta. Immulectin-2 has specificity for xylose, glucose, lipopolysaccharide, and mannan. A cDNA clone encoding immulectin-2 was isolated from an Escherichia coli-induced M. sexta larval fat body cDNA library. The cDNA is 1253 base pairs long, with an open reading frame of 981 base pairs, encoding a 327-residue polypeptide. Immulectin-2 is a member of the C-type lectin superfamily. It consists of two carbohydrate recognition domains, which is similar to the organization of M. sexta immulectin-1. Immulectin-2 was present at a constitutively low level in plasma of control larvae and increased 3-4-fold after injection of Gram-negative bacteria or lipopolysaccharide. Immulectin-2 mRNA was detected in fat body of control larvae, and its level increased dramatically after injection of E. coli. The concentration of immulectin-2 in plasma did not change significantly after injection of Gram-positive bacteria or yeast, even though its mRNA level was increased by these treatments. Compared with immulectin-1, immulectin-2 has a more restricted specificity for binding to Gram-negative bacteria. Immulectin-2 at low physiological concentrations agglutinated E. coli in a calcium-dependent manner. It also bound to immobilized lipopolysaccharide from E. coli. Binding of immulectin-2 to lipopolysaccharide stimulated phenol oxidase activation in plasma. The properties of immulectin-2 are consistent with its function as a pattern recognition receptor for detection and defense against Gram-negative bacterial infection in M. sexta.

Osteopontin expression in progressive renal injury in remnant kidney: role of angiotensin II

BACKGROUND

Osteopontin (OPN) is a macrophage chemotactic and adhesion molecule and has been shown to play a role in glomerular and tubulointerstitial injury in several kidney disease models.

METHODS

The present study examined whether OPN expression is involved in the progression of renal disease following subtotal (5/6) nephrectomy (STNx) in rats and whether angiotensin II (Ang II) mediates the up-regulation of renal OPN expression and macrophage accumulation in this model by administering valsartan, an Ang II type I (AT1) receptor antagonist, or ramipril, an angiotensin-converting enzyme (ACE) inhibitor.

RESULTS

In normal and sham-operated rat kidneys, OPN was expressed in a few tubules (<5%) and was absent in glomeruli. Following STNx (weeks 2 to 16), there was substantial up-regulation of OPN mRNA and protein expression in glomeruli [2 to 12 cells/glomerular cross section (gcs)] and tubular epithelial cells (20 to 75% OPN+). The up-regulation of OPN expression was associated with macrophage accumulation within the kidney, severe proteinuria, loss of renal function, and severe histologic damage, including tubulitis and tubulointerstitial fibrosis (all P < 0.001). Treatment with either valsartan or ramipril completely abrogated the up-regulation of OPN mRNA and protein expression in glomeruli and tubules. The reduction in OPN expression was associated with a significant inhibition of macrophage accumulation and progressive renal injury (P < 0.001).

CONCLUSION

An up-regulation of OPN expression may play a role in progressive renal injury following STNx. Inhibition of OPN expression may be one of the mechanisms by which Ang II blockade attenuated renal injury after renal ablation.