[Mechanisms mediating the inhibitory effects of quercetin against phthalates-induced testicular oxidative damage in rats]

OBJECTIVE

To explore the mechanism underlying the inhibitory effect of quercetin against testicular oxidative damage induced by a mixture of 3 commonly used phthalates (MPEs) in rats.

METHODS

Forty male Sprague-Dawley rats were randomly divided into control group, MPEs exposure group, and MPEs with low-, median- and high-dose quercetin treatment groups. For MPEs exposure, the rats were subjected to intragastric administration of MPEs at the daily dose of 900 mg/kg for 30 consecutive days; Quercetin treatments were administered in the same manner at the daily dose of 10, 30, and 90 mg/kg. After the treatments, serum levels of testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), and testicular malondialdeyhde (MDA), catalase (CAT) and superoxide dismutase (SOD) were detected, and testicular pathologies of the rats were observed with HE staining. The expressions of nuclear factor-E2-related factor 2 (Nrf2), Kelch-like ECH2 associated protein 1 (Keap1) and heme oxygenase 1 (HO-1) in the testis were detected using immunofluorescence assay and Western blotting.

RESULTS

Compared with the control group, the rats with MPEs exposure showed significant reductions of the anogenital distance, weight of the testis and epididymis, and the coefficients of the testis and epididymis with lowered serum testosterone, LH and FSH levels (P < 0.05). Testicular histological examination revealed atrophy of the seminiferous tubules, spermatogenic arrest, and hyperplasia of the Leydig cells in MPEs-exposed rats. MPEs exposure also caused significant increments of testicular Nrf2, MDA, SOD, CAT and HO-1 expressions and lowered testicular Keap1 expression (P < 0.05). Treatment with quercetin at the median and high doses significantly ameliorated the pathological changes induced by MPEs exposure (P < 0.05).

CONCLUSION

Quercetin treatment inhibits MPEs-induced oxidative testicular damage in rats possibly by direct scavenging of free radicals to lower testicular oxidative stress and restore the regulation of the Nrf2 signaling pathway.

Bullying victimization and internalizing and externalizing problems in school-aged children: The mediating role of sleep disturbance and the moderating role of parental attachment

BACKGROUND

Studies have shown that bullying victimization may be related to internalizing and externalizing problems; however, the mechanism underlying this relationship remains unknown. This study explored the mediating role of sleep disturbance and the moderating role of parental attachment.

METHODS

A total of 1543 Chinese primary school students (M age = 8.92 years, SD1.7 years; range, 6-12) completed bullying victimization, sleep disturbance, and parental attachment measures, and provided information on their parents' occupations. The parents or guardians (n = 1995) also completed ratings on their children's internalizing and externalizing problems.

RESULTS

It was found that bullying victimization directly affected internalizing and externalizing problems and also influenced sleep disturbance. Regardless of the parent's socioeconomic status, parental attachment was found to moderate the relationship between bullying victimization and internalizing problems.

CONCLUSIONS

These findings contribute to understanding the partial mediating mechanism of sleep disturbance in the association between bullying victimization and internalizing and externalizing problems. The protective role of parental attachment proved central to preventing internalizing problems in bullied children. Intervention programs that enhance parental attachment and improve sleep quality could assist in mitigating the impact of bullying victimization on internalizing or externalizing problems.

Phenolic sucrose esters: evolution, regulation, biosynthesis, and biological functions

Phenolic sucrose esters (PSEs) are a diverse group of specialized metabolites that are present in several angiosperm lineages. Phylogenetic reconstruction and structural variation suggest that these metabolites may have evolved independently in monocots and dicots. Constitutive variation in PSE abundance across plant organs and developmental stages is correlated with transcriptional regulation of the upstream phenylpropanoid pathway, whereas pathogen induction is regulated by stress-related phytohormones such as ethylene. Shared structural features of PSEs indicate that their biosynthesis may involve one or more hydroxycinnamoyl transferases and BAHD acetyltransferases, which could be identified by correlative analyses of multi-omics datasets. Elucidation of the core biosynthetic pathway of PSEs will be essential for more detailed studies of the biological function of these compounds and their potential medicinal and agricultural applications.

[Expert consensus on measurement and clinical application of serum HBV RNA in patients with chronic HBV infection]

Since the discovery of circulating hepatitis B virus (HBV) RNA in the peripheral blood of patients with chronic hepatitis B in 1996, a growing number of studies have focused on clarifying the biological characteristics and clinical application value of serum HBV RNA. This consensus mainly summarizes the research progress of serum HBV RNA existing profiles, quantitative detection methods, and current clinical applications. In order to better apply this indicator for the clinical management of patients with chronic HBV infection, recommendations on quantitative detection target regions, detection results, and clinical applications are put forward.

[Relationship between parental reproductive age and the risk of overweight and obesity in offspring]

Objective: To explore the role of parental reproductive age on the risk of overweight and obesity in offspring. Methods: The participants were derived from physical examination data of students aged 6-18 years in seven provinces in China, and questionnaire survey was used to collect demographic characteristics and lifestyle information of the students and their parents. A total of 41 567 children with complete data were included. According to the restricted cubic spline curve, maternal reproductive age was divided into three categories, 14-23, 24-28, and 29-38 years, and paternal reproductive age was divided into 14-23, 24-30, and 31-42 years. Multivariate logistic regression model was used to analyze the association between parental reproductive age and parental nutritional status and the risk of overweight and obesity in offspring. Results: The mean age of 41 567 children was (10.6±3.2) years, and the mean paternal and maternal age were (27.9±4.4) years and (25.8±4.0) years, respectively. The detection rate of overweight and obesity was 23.4%. After adjusting factors of children diet and behaviors, the OR(95%CI)of offspring overweight and obesity in groups of fathers aged 24-30 years and mothers aged 24-28 years was 1.11 (1.04-1.18) and 1.16 (1.08-1.24), respectively. When none parents were overweight and obese, the difference of obesity risk was not statistically significant. When both parents were overweight and obese, the OR(95%CI)of offspring overweight and obesity in groups of fathers aged 24-30 years and mothers aged 14-28 years old was 1.27 (1.00-1.62) and 1.33 (1.07-1.65) respectively. Conclusion: Parental reproductive age and parental overweight and obesity status may both increase the risk of overweight and obesity in offspring, with a significant interaction effect.

Visfatin facilitates gastric cancer malignancy by targeting snai1 via the NF-κB signaling

BACKGROUND

Visfatin acts as an oncogenic factor in numerous tumors through a variety of cellular processes. Visfatin has been revealed to promote cell migration and invasion in gastric cancer (GC). Snai1 is a well-known regulator of EMT process in cancers. However, the relationship between visfatin and snai1 in GC remains unclear. The current study aimed to explore the role of visfatin in GC.

METHODS

The RT-qPCR and western blot analysis were used to measure RNA and protein levels, respectively. The cell migration and invasion were tested by Trans-well assays and western blot analysis.

RESULTS

Visfatin showed upregulation in GC cells. Additionally, Visfatin with increasing concentration facilitated epithelial-mesenchymal transition (EMT) process by increasing E-cadherin and reducing N-cadherin and Vimentin protein levels in GC cells. Moreover, endogenous overexpression and knockdown of visfatin promoted and inhibited migratory and invasive abilities of GC cells, respectively. Then, we found that snai1 protein level was positively regulated by visfatin in GC cells. In addition, visfatin activated the NF-κB signaling to modulate snai1 protein expression. Furthermore, the silencing of snai1 counteracted the promotive impact of visfatin on cell migration, invasion and EMT process in GC.

CONCLUSION

Visfatin facilitates cell migration, invasion and EMT process by targeting snai1 via the NF-κB signaling, which provides a potential insight for the treatment of GC.

Maintenance treatment in advanced HER2-negative gastric cancer

Survival for patients with advanced gastric cancer (GC) remains poor. Systemic chemotherapy which has reached a plateau stays the standard first-line (1L) treatment for advanced human epidermal growth-factor receptor 2 (HER2)-negative GC. To maximize the benefit of 1L treatment, the concept of maintenance treatment is constantly being explored. In advanced HER2-negative GC, current clinical guidelines do not recommend a standard maintenance therapy strategy. In addition to the monotherapy maintenance with fluorouracil after 4-6 cycles of 1L chemotherapy, some agents that are active against novel targets have been evaluated in clinical trials for maintenance treatment. Whereas most of these trials do not reach their primary endpoints, they open new horizons for the 1L treatment of advanced HER2-negative GC. Therefore, we reviewed the clinical trials in the field of maintenance treatment in advanced HER2-negative GC and discussed some of the problems in clinical trials.

Diverse biological effects of glycosyltransferase genes from Tartary buckwheat

BACKGROUND

Tartary buckwheat (Fagopyrum tataricum) is an edible cereal crop whose sprouts have been marketed and commercialized for their higher levels of anti-oxidants, including rutin and anthocyanin. UDP-glucose flavonoid glycosyltransferases (UFGTs) play an important role in the biosynthesis of flavonoids in plants. So far, few studies are available on UFGT genes that may play a role in tartary buckwheat flavonoids biosynthesis. Here, we report on the identification and functional characterization of seven UFGTs from tartary buckwheat that are potentially involved in flavonoid biosynthesis (and have varying effects on plant growth and development when overexpressed in Arabidopsis thaliana.) RESULTS: Phylogenetic analysis indicated that the potential function of the seven FtUFGT proteins, FtUFGT6, FtUFGT7, FtUFGT8, FtUFGT9, FtUFGT15, FtUFGT40, and FtUFGT41, could be divided into three Arabidopsis thaliana functional subgroups that are involved in flavonoid biosynthesis of and anthocyanin accumulation. A significant positive correlation between FtUFGT8 and FtUFGT15 expression and anthocyanin accumulation capacity was observed in the tartary buckwheat seedlings after cold stress. Overexpression in Arabidopsis thaliana showed that FtUFGT8, FtUFGT15, and FtUFGT41 significantly increased the anthocyanin content in transgenic plants. Unexpectedly, overexpression of FtUFGT6, while not leading to enhanced anthocyanin accumulation, significantly enhanced the growth yield of transgenic plants. When wild-type plants have only cotyledons, most of the transgenic plants of FtUFGT6 had grown true leaves. Moreover, the growth speed of the oxFtUFGT6 transgenic plant root was also significantly faster than that of the wild type. At later growth, FtUFGT6 transgenic plants showed larger leaves, earlier twitching times and more tillers than wild type, whereas FtUFGT15 showed opposite results.

CONCLUSIONS

Seven FtUFGTs were isolated from tartary buckwheat. FtUFGT8, FtUFGT15, and FtUFGT41 can significantly increase the accumulation of total anthocyanins in transgenic plants. Furthermore, overexpression of FtUFGT6 increased the overall yield of Arabidopsis transgenic plants at all growth stages. However, FtUFGT15 shows the opposite trend at later growth stage and delays the growth speed of plants. These results suggested that the biological function of FtUFGT genes in tartary buckwheat is diverse.

FtMYB8 from Tartary buckwheat inhibits both anthocyanin/Proanthocyanidin accumulation and marginal Trichome initiation

BACKGROUND

Because flavonoids and trichomes play crucial roles in plant defence, their formation requires fine transcriptional control by multiple transcription factor families. However, little is known regarding the mechanism of the R2R3-MYB transcription factors that regulate both flavonoid metabolism and trichome development.

RESULTS

Here, we identified a unique SG4-like-MYB TF from Tartary buckwheat, FtMYB8, which harbours the C2 repression motif and an additional TLLLFR repression motif. The expression profiles of FtMYB8 combined with the transcriptional activity of PFtMYB8 promoter showed that FtMYB8 mRNA mainly accumulated in roots during the true leaf stage and flowering stage and in bud trichomes and flowers, and the expression of this gene was markedly induced by MeJA, ABA and UV-B treatments but repressed by dark treatment. Overexpression of FtMYB8 in Arabidopsis reduces the accumulation of anthocyanin/proanthocyanidin by specifically inhibiting TT12 expression, which may depend on the interaction between FtMYB8 and TT8. Interestingly, this interaction may also negatively regulate the marginal trichome initiation in Arabidopsis leaves.

CONCLUSIONS

Taken together, our results suggest that FtMYB8 may fine-tune the accumulation of anthocyanin/proanthocyanidin in the roots and flowers of Tartary buckwheat by balancing the inductive effects of transcriptional activators, and probably regulate trichome distribution in the buds of Tartary buckwheat.

A R2R3-MYB transcription factor gene, FtMYB13, from Tartary buckwheat improves salt/drought tolerance in Arabidopsis

Abiotic stress causes various negative impacts on plants, such as water loss, reactive oxygen species (ROS) accumulation and decreased photosynthesis. R2R3-MYB transcription factors (TFs) play crucial roles in the response of plants to abiotic stress. However, their functions in Tartary buckwheat, a strongly abiotic and resistant coarse cereal, haven't been fully investigated. In this paper, we report that a R2R3-MYB from Tartary buckwheat, FtMYB13, is not an activator of transcriptional activity but is located in the nucleus. Moreover, compared to the wild type (WT), transgenic Arabidopsis overexpressing FtMYB13 had a lower sensitivity to ABA and caused improved drought/salt tolerance, which was attributed to the higher proline content, greater photosynthetic efficiency, higher transcript abundance of some stress-related genes and the smaller amount of reactive oxygen species (ROS) and malondialdehyde (MDA) in the transgenic lines compared to WT. Consequently, our work indicates that FtMYB13 is involved in mediating plant responses to ABA, as well as salt and drought.

Vacuum Sealing Drainage Therapy for Refractory Infectious Wound on 16 Renal Transplant Recipients

BACKGROUND

Refractory infectious wounds on renal transplantation (RT) recipients significantly prolong hospital stay, increase medical costs, and threaten allograft survival. Vacuum sealing drainage (VSD) therapy is a new technique for managing wounds based on the principle of application of controlled negative pressure. The aim of this study was to summarize the efficacy and safety of VSD therapy in the management of refractory infectious wounds following RT.

MATERIALS AND METHODS

This is a retrospective study of a cohort of 661 consecutive patients who received renal transplants over a period of 3 years in which the data were collected and analyzed retrospectively.

RESULTS

Out of the 661 patients, 16 (2.4%) developed refractory wound infection following RT. Nineteen organisms were identified by culture from all patients, including 10 patients infected with 1 or more bacteria, 2 patients with fungal infection, and 4 patients with both. Specifically, mucormycosis was demonstrated in 4 patients, pan-resistant Klebsiella pneumoniae in 2 patients, and Acinetobacter baumannii in 2 patients. All 16 patients were treated with VSD therapy for a median of 37 days (range, 6-111 days). The number of VSD sets used ranged from 4 to 28 sets (mean, 11.1 sets). A combination of antibiotics, debridement, and VSD therapy lead to 100% (16 of 16) wound healing. No VSD-relevant adverse events were observed.

CONCLUSIONS

VSD therapy is an effective and safe adjunct to conventional treatment modalities for the management of refractory wound infection following RT.

Overexpression of Fagopyrum tataricum FtbHLH2 enhances tolerance to cold stress in transgenic Arabidopsis

bHLH transcription factors play important roles in the abiotic stress response in plants, but their characteristics and functions in Tartary buckwheat (Fagopyrum tataricum), a traditional coarse cereal with a strong stress tolerance, haven't been sufficiently studied. Here, we found that the expression of a bHLH gene, FtbHLH2, was induced significantly by cold treatments in Tartary buckwheat seedlings. Subcellular localization indicated that FtbHLH2 localized in nucleus. Its overexpression in Arabidopsis increased tolerance to cold. The Arabidopsis plants overexpressing FtbHLH2 displayed higher root length and photosynthetic efficiency, and had lower malondialdehyde (MDA) and reactive oxygen species (ROS) after cold treatment compared to wild type (WT) plants. Meanwhile, the expression levels of some stress-related genes in transgenic plants were remarkably higher than that in wild type under normal and/or stress conditions. Furthermore, transgenic Arabidopsis lines with the FtbHLH2 promoter had higher GUS activity after cold stress. On the whole, the results suggest that FtbHLH2 may play a positive regulatory in cold stress of Tartary buckwheat.

Effect of Early Immunosuppression Therapy on De Novo Anti-Human-Leukocyte-Antigen Antibody After Kidney Transplantation

The aim of the study was to investigate the effect of immunosuppression therapy early after kidney transplantation, particularly exposure of mycophenolic acid (MPA) and calcineurin inhibitor (CNI), on posttransplantation de novo HLA antibody production.

METHODS

A single-center retrospective cohort study was performed at the First Affiliated Hospital of Sun Yat-sen University, enrolling the kidney transplant or pancreas-kidney transplant recipients who had surgery between January 2010 and February 2016.

RESULTS

A total of 214 recipients were included in the study with a median follow-up period of 1.06 years. A total of 30 recipients (14.0%) were positive in HLA antibody detection posttransplant with a median follow-up period of 1.46 years. Ten recipients (4.7%) lost their allograft function during follow-up, and 6 of them (60%) developed de novo HLA antibody after graft failure. Multivariate analysis showed that acute rejection significantly increased the risk of de novo HLA antibody (hazard ratio [HR], 2.732). Intensified MPA dosing therapy reduced the risk by 59.8% (HR, 0.402); low-dose CNI therapy increased the risk by 33.3% (HR, 1.333), and the effect of extremely low-dose CNI therapy was even larger (HR, 2.242).

CONCLUSION

The risk of de novo HLA antibody can be decreased by reducing the risk of acute rejection. A tendency was seen in low-dose CNI therapy to increase the risk of de novo HLA antibody, but intensified MPA dosing therapy may provide an umbrella protection effect by reducing the risk. Prospective study was required to confirm the effects.

Higher Incidence of Renal Allograft Glomerulonephritis in Living-Related Donor Kidney Transplantation

Glomerulonephritis recurrence has emerged as one of the leading causes of allograft loss. We aimed to investigate the effect of living-related and deceased donation on the incidence of renal allograft glomerulonephritis and its effect on renal allograft survival.

METHODS

Adult renal allograft recipients with primary glomerulonephritis were enrolled. Transplantation date was from Feb 2004 to Dec 2015. Exclusion criteria included combined organ transplantation, structural abnormality, diabetic nephropathy, hypertension nephropathy, obstructive nephropathy, and primary uric acid nephropathy. The incidence of biopsy-proven allograft glomerulonephritis was compared between the living-related donor group and the deceased donor group. Graft survival was assessed with Kaplan-Meier method, and Cox proportional hazard model was used to evaluate the effect of posttransplant glomerulonephritis on graft outcome.

RESULTS

There were 525 living-related donor kidney transplant recipients (LRKTx) and 456 deceased donor kidney transplant recipients (DDKTx) enrolled. The incidence of IgA nephropathy was 8.8% in the LRKTx group and 1.3% in the DDKTx group (P < .001); the incidence of focal segmental glomerulosclerosis (FSGS) was 3.8% in the LRKTx group and 1.5% in the DDKTx group (P = .03). FSGS increased the risk of graft failure compared with non-FSGS (hazard ratio [HR], 3.703 [1.459-9.397]; P = .006). IgA nephropathy increased the risk of graft failure by over 5 times 5 years after kidney transplantation compared with non-IgA nephropathy, but it did not affect early allograft survival (HR for ≥5 years, 6.139; 95% CI, 1.766-21.345; P = .004; HR for <5 years, 0.385 [0.053-2.814]; P = .35).

CONCLUSIONS

Higher incidence of IgA nephropathy and FSGS in renal allograft was observed in living-related donor kidney transplantation compared with deceased donor kidney transplantation. De novo or recurrent IgA nephropathy and FSGS impaired long-term renal allograft survival.

Recombinant beta interferon could clear the low-dose infected porcine reproductive and respiratory syndrome virus (PRRSV) in MARC-145 cells

Porcine reproductive and respiratory syndrome virus (PRRSV) causes one of the most economically devastating and pandemic porcine diseases. Previous study has shown that MARC-145 cells pretreated with recombinant IFN-β (rIFN-β) couldn't develop cytopathic effect (CPE) of PRRSV. However, up to date, it is not clear whether MARC-145 cells post-treated with rIFN-β could develop CPE of PRRSV. The present work showed that the MARC-145 cells didn't develop the CPE at 120 hr post-infection (p.i.) with low-dose of PRRSV when the cells were pre-treated with rIFN-β (Group 1), post-treated with rIFN-β at 4 hr p.i. (Group 2), or post-treated with rIFN-β at 8 hr p.i. (Group 3), while the MARC-145 cells could develop CPE when the cells were infected with high-dose PRRSV and then treated with rIFN-β at 24 hr p.i.. Furthermore, the indirect immunofluorescence assay confirmed that there were a few N protein-positive cells in the high-dose infected cells in Group 1, Group 2 and Group 3, while there were no N protein-positive cells in the low-dose infected cells in all rIFN-β treatment groups. In addition, the numbers of N protein-positive cells in high-dose infected cells (MOI = 10) in Group 1 were lower than that in Group 2 and Group 3. The results above demonstrated that both pre-treatment with rIFN-β and an earlier post-treatment with rIFN-β could inhibit the PRRSV replication and could clear the low-dose infected PRRSV, which indicated that the rIFN-β had efficient antiviral activities when the cells have been infected with PRRSV.

Dynamic effects of CYP3A5 polymorphism on dose requirement and trough concentration of tacrolimus in renal transplant recipients

WHAT IS KNOWN AND OBJECTIVE

Tacrolimus is a widely used immunosuppressive drug with marked pharmacokinetic variability partly due to CYP3A5 polymorphism. Our study aimed to investigate the dynamic effects of CYP3A5 genotypes on dose requirement and trough concentration (C₀ ) of tacrolimus in renal transplant recipients.

METHODS

A total of 194 Chinese renal transplant recipients received oral tacrolimus twice daily. Whole-blood C₀ of tacrolimus were measured on the 3rd day, 7th day, 14th day, 1st month, 3rd month and 6th month post-transplantation. CYP3A5 genotypes were determined and the recipients were categorized as CYP3A5 expressers (CYP3A5*1 allele carriers) and non-expressers (homozygous CYP3A5*3). The correlated serum creatinine, haematocrit and albumin were also detected.

RESULTS

The allele frequencies for CYP3A5*1/*1, *1/*3 and *3/*3 were 7·7%, 44·8% and 47·4%, respectively. There were no significant variability in serum creatinine, haematocrit and albumin values between CYP3A5 expressers and non-expressers. Larger doses were administered to CYP3A5 expressers than to non-expressers after surgery except the initial dose. C₀ were much lower in CYP3A5 expressers than in non-expressers on the 3rd day, 7th day, 14th day and 1st month post-transplantation (P < 0·01); however, no significant differences were found on the 3rd and 6th months post-transplantation. All of the dose-adjusted C₀ in CYP3A5 expressers were significantly lower than non-expressers (P < 0·01). Less of the recipients achieving target C₀ (4-8 ng/mL) were found in CYP3A5 expressers than in non-expressers after initial dose (35·7% vs. 50%). Meanwhile, CYP3A5 non-expressers were detected having higher C₀ (>8 ng/mL) during 3 months post-transplantation. Besides, the proportions in the two groups both increased gradually over time and up to 91·8% and 94% on the 6th month, respectively.

WHAT IS NEW AND CONCLUSION

There are no significant differences in serum creatinine, haematocrit and albumin values between CYP3A5 expressers and non-expressers. CYP3A5 expressers have decreased dose-adjusted tacrolimus C₀ when compared to non-expressers. Dose-adjusted C₀ of tacrolimus increases in a time-dependent manner in both groups.

[Salvage surgical treatment for local recurrent nasopharyngeal cancer]

The salvage radiation or surgery is the main choice for recurrent nasopharyngeal cancer now. However the recurrent tumor becomes radiation insensitive and meanwhile,morbidity and mortality become higher.Recently the endoscopic salvage surgery has been developed;the collective evidence from a number of such studies suggests that endoscopic nasopharyngectomy is a safe and effective procedure for the treatment of rNPC.This article reviewed related researches about the feasibility,methods, and current situation of endoscopic salvage surgery.

Extracellular DNA traps released by acute promyelocytic leukemia cells through autophagy

Acute promyelocytic leukemia (APL) cells exhibit disrupted regulation of cell death and differentiation, and therefore the fate of these leukemic cells is unclear. Here, we provide the first evidence that a small percentage of APL cells undergo a novel cell death pathway by releasing extracellular DNA traps (ETs) in untreated patients. Both APL and NB4 cells stimulated with APL serum had nuclear budding of vesicles filled with chromatin that leaked to the extracellular space when nuclear and cell membranes ruptured. Using immunofluorescence, we found that NB4 cells undergoing ETosis extruded lattice-like structures with a DNA-histone backbone. During all-trans retinoic acid (ATRA)-induced cell differentiation, a subset of NB4 cells underwent ETosis at days 1 and 3 of treatment. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were significantly elevated at 3 days, and combined treatment with TNF-α and IL-6 stimulated NB4 cells to release ETs. Furthermore, inhibition of autophagy by pharmacological inhibitors or by small interfering RNA against Atg7 attenuated LC3 autophagy formation and significantly decreased ET generation. Our results identify a previously unrecognized mechanism for death in promyelocytes and suggest that ATRA may accelerate ET release through increased cytokines and autophagosome formation. Targeting this cellular death pathway in addition to conventional chemotherapy may provide new therapeutic modalities for APL.

The efficacy and safety of intensified enteric-coated mycophenolate sodium with low exposure of calcineurin inhibitors in Chinese de novo kidney transplant recipients: a prospective study

AIMS

The aim of this study was to investigate the efficacy and safety of a transient intensified enteric-coated mycophenolate sodium (EC-MPS) dosing regimen with low exposure of calcineurin inhibitors (CNIs) in Chinese de novo kidney transplantation.

METHODS

In a 6-month prospective study, a total of 97 recipients were enrolled and assigned to either an intensified EC-MPS dosing (IS) regimen or a standard EC-MPS dosing (SD) regimen. The area under the curve (AUC) of MPA was assessed at week 1 post transplant. The incidences of acute rejection, patient and graft survival, renal allograft function and adverse events were analysed.

RESULTS

The IS regimen displayed a trend of acute rejection risk reduction (IS 2.7% vs. SD 13.3%, p = 0.061) and allograft function improvement (IS 62.8 ± 14.0 ml/min per 1.73 m(2) vs. SD 56.6 ± 18.3 ml/min per 1.73 m(2) , p = 0.084) after 6-month follow-up. MPA-AUC0-12 h was substantially higher in the intensified EC-MPS group than the standard EC-MPS group, though without a significant difference (71.4 ± 41.7 vs. 53.0 ± 27.0 mg·h/l, p = 0.107). The IS regimen did not increase the incidence of adverse effects (IS 54.1% vs. 45.0%, p = 0.39), including diarrhoea or leucopenia.

CONCLUSIONS

The intensified EC-MPS dosing regimen maintaining low-dose CNIs in this study may be beneficial for Chinese adult de novo kidney transplant recipients in terms of acute rejection and allograft function and is safe within 6 months post transplant.

Risk factors for BK virus infection and BK virus-associated nephropathy under the impact of intensive monitoring and pre-emptive immunosuppression reduction

BACKGROUND

BK virus (BKV) nephropathy (BKVN) is an increasingly recognized cause of kidney allograft loss and is thought to be related to the newer, more potent immunosuppressive agents. However, the risk factors for different types of BKV infection under the impact of intensive monitoring and reduction of maintenance immunosuppression are not well understood.

METHODS

Quantitative BKV DNA surveillance in plasma/urine and cytological testing in urine were performed regularly within the first year post-transplantation in 229 kidney recipients. Patients with BK viremia and BKVAN treated with immunosuppression reduction were monitored for BKV every 3-6 months. All the patients were followed up for a minimum of 5 years to exclude later development of BKVAN. Potential variables were compared and analyzed using logistic regression model multivariate analysis to assess and rank the BKV infection-related factors.

RESULTS

Seventy-eight (34.1%) patients had decoy cells, 99 (43.2%) BK viruria, 38 (16.6%) BK viremia, and 7 (3.1%) BKVAN. Risk for decoy cells, BK viruria, and viremia, and BKVAN in univariate analyses were higher with tacrolimus (Tac) and deceased kidney donation. Multivariate analysis showed that Tac ([HR, 2.7; P = .008], [HR, 2.3; P = .016], [HR, 2.9; P = .032]) and deceased kidney donation ([HR, 2.5; P = .004], [HR, 2.6; P = .002], [HR, 2.1; P = .071]) were risk factors for BK decoy cells, BK viruria, and viremia, respectively. BKVAN was inclined to the patients with the combination of Tac and mycophenolate mofetil and longer BKV clearance time.

CONCLUSIONS

Tac and deceased kidney donation are independent risk factors for BKV infection under the impact of therapeutic drug monitoring.

Ontogenesis of the collapsed layer during haustorium development in the root hemi-parasite Santalum album Linn

The structure and development of collapsed layers of the haustorium were studied in Santalum album Linn. Through light and transmission electron microscopy, it was shown that the collapsed layers originated from starch-containing cells when the haustorium developed an internal gland, thickened gradually and ultimately developed into the mantle, which, combined with the sucker, buckled the host root. We report on the presence of inter-collapsed layers for the first time. These layers develop after penetration into the host and are located between the intrusive tissues and the vascular meristematic region, gradually linking the collapsed layers and remains around the sucker. The proliferation of cells in the meristematic region and the 'host tropism' of cortical layers contribute to pressure within the haustorium and result in development of the collapsed layers. Besides, starch-containing cells that turn into collapsed layers are vulnerable to pressure as they lack a large vacuole, have uneven cell wall thickness and a loose cell arrangement. We proposed that the functions of collapsed layers are to efficiently assure that cell inclusion and energy concentrate at the inner meristematic region and are recycled to affect penetration, reinforce the physical connection between the sandalwood haustorium and host root, and supply space for haustorial development.

Anti-TCRβ mAb induces long-term allograft survival by reducing antigen-reactive T cells and sparing regulatory T cells

TCR specific antibodies may modulate the TCR engagement with antigen-MHC complexes, and in turn regulate in vivo T cell responses to alloantigens. Herein, we found that in vivo administration of mAbs specific for mouse TCRβ (H57-597), TCRα or CD3 promptly reduced the number of CD4(+) and CD8(+) T cells in normal mice, but H57-597 mAb most potently increased the frequency of CD4(+) Foxp3(+) Treg cells. When mice were injected with staphylococcal enterotoxin B (SEB) superantigen and H57-597 mAb, the expansion of SEB-reactive Vβ8(+) T cells was completely abrogated while SEB-nonreactive Vβ2(+) T cells remained unaffected. More importantly, transient H57-597 mAb treatment exerted long-lasting effect in preventing T cell responses to alloantigens, and produced long-term cardiac allograft survival (>100 days) in 10 out of 11 recipients. While Treg cells were involved in maintaining donor-specific long-term graft survival, T cell homeostasis recovered over time and immunity was retained against third party allografts. Moreover, transient H57-597 mAb treatment significantly prolonged survival of skin allografts in naïve recipients as well as heart allografts in skin-sensitized recipients. Thus, transient modulation of the TCRβ chain by H57-597 mAb exhibits potent, long-lasting therapeutic effects to control alloimmune responses.

Horizontal gene transfer in herpesviruses identified by using support vector machine

Horizontal gene transfer (HGT) is the probable origin of new genes. Identification of HGT-introduced genes would be helpful to the understanding of the genome evolution and the function prediction of new genes. In this study, a method using support vector machine (SVM) was used to distinguish horizontally transferred genes and non-horizontally transferred genes of mammalian herpesviruses based on the atypical composition identification, with accuracy higher than 95% within a reasonable length of time by using just a common PC. This identified 302 putative horizontally transferred genes, 171 genes being identified for the first time. Although most putative transferred genes are of unknown function, many genes have been discovered or predicted to encode glycoproteins or membrane proteins.

Development of rapid immunoassays for the detection of ractopamine in swine urine

The monoclonal antibodies (mAbs) against ractopamine (Rac) were prepared and their properties identified by indirect competitive enzyme-linked immunoabsorbant assay (ELISA). The IC(50) of mAbs was 2.7 ng ml(-1) towards Rac or 9.3 ng ml(-1) towards Rac-glucuronides and no cross-reactivity (CR) towards other competitors except dobutamine (CR: 3.76%). Based on the mAbs, the Rac-kit (kit) and Rac-strip (strip) were developed to detect Rac residues in swine urine. The strip and kit assay could be performed within 5-10 min and 2 h, respectively, allowing the analysis of urine samples without the need for sample clean-up. The detection limits were 1 ng ml(-1) for kit and 3 ng ml(-1) with the unaided eye, and 0.2 ng ml(-1) with the Strip Reader for strip. The correlation coefficients (R(2)) were 0.988 for kit in the range 0-128.0 ng ml(-1), and 0.987 for strip in the range 0-10.8 ng ml(-1). Comparing the gas chromatography-mass spectrometry (GC-MS) with the kit or strip in swine urine spiked with Rac standards, the differences ranged from 1.4% to 4.5% for kit and 1.0% to 4.7% for strip. However, the differences were greater than 54% for the kit and 55% for the strip test for the analysis of urine from swine treated with Rac. The results obtained from GC-MS using hydrolysed urine samples were generally in good agreement with those obtained from strip or kit using non-hydrolysed urine samples.

Distinctly different expression of cytokines and chemokines in the lungs of two H5N1 avian influenza patients

The pathogenesis of human H5N1 influenza remains poorly understood and controversial. 'Cytokine storm' has been hypothesized to be the main cause of the severity of this disease. However, the significance of this hypothesis has been called into question by a recent report, which demonstrates that inhibition of the cytokine response did not protect against lethal H5N1 influenza infection in mice. Here we showed discrepant findings in two adult H5N1 autopsies and a fetus obtained at autopsy which also raise doubt about this hypothesis. Antigens of 10 cytokines/chemokines which were found to be significantly elevated in previous H5N1-infected patients and in vitro experiments, and mRNA of eight of these, were absent from the lungs of a pregnant woman and her fetus. In contrast, antigens of seven cytokines/chemokines and mRNA of six of these were found to be increased in the lungs of a male autopsy. The cells expressing these cytokines and chemokines were identified as type II pneumocytes, bronchial epithelial cells, macrophages and vascular endothelial cells. Levels of cytokines and chemokines in the serum of the male case were also significantly higher than those of infectious (infection other than by H5N1) and non-infectious controls. In comparison with results from our previous study, it appeared that the male case had increased cytokine/chemokine expression but reduced viral load, while the pregnant female had diminished cytokine/chemokine expression but a significantly increased viral load in the lungs. These disparate findings in these two cases suggest that 'cytokine storm' alone could not be a sufficient explanation for the severe lung injury of this newly emerging disease.

Whole-genome phylogenetic analysis of herpesviruses

A comprehensive phylogenetic analysis of 45 herpesviruses was performed based on whole-genome sequences. We used 4 methods, namely the alignment of conserved gene sequences (excluding 5 herpesviruses), compositional vector tree (CVTree) method, local homology analysis, and gene content analysis. The obtained results showed good consistency between the phylogenetic trees prepared by these methods and likewise, the obtained classification of the herpesviruses was consistent with their current taxonomic designation. The herpesviruses with the ambiguous classification or not assigned in the family or with the newly published genomes were also phylogenetically classified.

Maternal mortality in Yunnan, China: recent trends and associated factors

OBJECTIVE

Yunnan Province, located in southwest China, is one of the poorest province in China. The maternal mortality ratio (MMR) is about twice the national average (56.2/100,000 live births), and in remote mountainous regions, the rate is five times higher. This study aimed to examine the progress in reduction of maternal mortality in the 1990s and early 2000s and the factors associated with this reduction in Yunnan.

DESIGN

A population-based, longitudinal, ecological correlation study.

SETTING

A remote province of China with a proportionately large indigenous population.

POPULATION

Populations at county, prefecture and provincial level.

METHODS

Using maternal mortality data collected at the province, prefecture/region and county levels, trend and time series analyses and multivariate linear regression analyses were performed using SPSS (Version 13).

MAIN OUTCOME MEASURE

MMR and its change over time.

RESULTS

MMR declined substantially in the 1990s at a rate of 3.0% per year. Utilisation of prenatal and obstetric care increased and was significantly correlated with the declining trend in MMR. Hospital delivery was a strong predictor of MMR, independent of social and economic development. Both low income and illiteracy were significantly associated with increased MMR.

CONCLUSIONS

Declines in maternal mortality in Yunnan over the past 14 years appear to reflect health, social and economic interventions implemented in the 1990s. The association of hospital delivery with maternal mortality may be due to the effective management of severe pregnancy and birth complications. Low income and illiteracy were associated with MMR but primarily through their impact on the use of prenatal and obstetric care.

Acetylcholinesterase expression mediated by c-Jun-NH2-terminal kinase pathway during anticancer drug-induced apoptosis

It has been shown that acetylcholinesterase (AChE) expression was induced during apoptosis and the anti-sense oligonucleotides and siRNA of AChE may prevent apoptosis in various cell types. However, the mechanisms underlying AChE upregulation remain elusive. We demonstrated here that c-Jun NH2-terminal kinase (JNK) could mediate AChE expression. In this study, both etoposide and excisanin A, two anticancer agents, induced apoptosis in colon cancer cell line SW620 as determined by Annexin V staining, the cleavage of caspase-3 and the proteolytic degradation of poly (ADP-ribose) polymerase (PARP). The results showed that both the agents upregulated AChE in SW620 cells. In the meantime, JNK was also activated and the expression and phosphorylation of c-Jun increased in SW620 cells exposed to the two agents. The induced AChE mRNA and protein expression could be blocked by SP600125, a specific inhibitor of SAPK/JNK, and small interfering RNA directed against JNK1/2. Transfection with adenovirus-mediated dominant negative c-Jun also blocked the upregulation of AChE expression. Together, these results suggest that AChE expression may be mediated by the activation of JNK pathway during apoptosis through a c-Jun-dependent mechanism.

Senescence and telomere shortening induced by novel potent G-quadruplex interactive agents, quindoline derivatives, in human cancer cell lines

Agents stabilizing G-quadruplexes have the potential to interfere with telomere replication by blocking the elongation step catalysed by telomerase or telomerase-independent mechanism and could therefore act as antitumor agents. In this study, we found that quindoline derivatives interacted preferentially with intramolecular G-quadruplex structures and were novel potent telomerase inhibitors. Treatment with quindoline derivatives reproducibly inhibited telomerase activity in human leukemia K562 cells and colon cancer SW620 cells. N'-(10H-Indolo [3,2-b] quinolin-11-yl)-N, N-dimethyl-propane-1,3-diamine (SYUIQ-5), (one of quindoline derivatives), when added to K562 and SW620 cell culture at nonacute cytotoxic concentrations, increased time of population doublings of K562 and SW620 cells, induced a marked cessation in cell growth and cellular senescence phenotype after 35 and 18 days, respectively. Growth cessation was accompanied by a shortening of telomere length, and induction of p16, p21 and p27 protein expression. However, another compound SYUIQ-7 with greater IC(50) for telomerase had no obvious cellular effect in nonacute cytotoxic concentrations. These results indicate that quindoline derivatives as novel potent G-quadruplex interactive agents induce senescence and telomere shortening in cancer cells and therefore are promising agents for cancer treatment.

The expression of antiapoptotic protein survivin is transcriptionally upregulated by DEC1 primarily through multiple sp1 binding sites in the proximal promoter

Human differentially expressed in chondrocytes (DEC), mouse stimulated with retinoic acid and rat split and hairy related proteins constitute a structurally distinct class of the basic helix-loop-helix proteins. DEC1 is abundantly expressed in tumors and protects against apoptosis induced by serum starvation. In this study, we report that DEC1 antiapoptosis is achieved by inducing survivin, an antiapoptotic protein. In paired tumor-normal tissues, survivin and DEC1 exhibited a paralleled expression pattern. Tetracycline-induced expression of DEC1 in stable lines proportionally increased the expression of survivin. In reporter assays, DEC1 transactivated the survivin promoter but repressed the DEC2 promoter. In contrast to the repression, the activation was delayed and varied depending on serum concentrations and cycle blockers. Studies with reporter mutants located, in the survivin promoter, two Sp1 sites that supported DEC1 transactivation. Electrophoretic mobility shift assay and chromatin immunoprecipitation detected the presence of DEC1 in the survivin promoter. These findings establish that the survivin gene is a transcription target of DEC1, and induction of survivin is at least in part responsible for DEC1 antiapoptosis.

Molecular characteristics of full-length genomic segment A of three infectious bursal disease viruses in China: two attenuated strains and one virulent field strain

The full-length cDNA of genomic segment A of three infectious bursal disease viruses, two attenuated strains (HZ2 and JD1) and one virulent field strain (ZJ2000), was amplified in a single step by reverse transcription-polymerase chain reaction, cloned into pGEM-T Easy Vector, and sequenced. The full length of cloned segment A contains 3259 nucleotides, which includes two partially overlapping open reading fragments (ORFs) ORF1 and ORF2, flanked by 5' and 3' noncoding regions. These strains shared high sequence identity with each other either at the nucleotide or deduced amino acid level. Strains HZ2 and JD1 were highly related to two attenuated strains, CEF94 and P2, whereas ZJ2000 was closely related to two other virulent strains, Cu-1 and Harbin. Substitutions of four amino acids at positions 253, 279, 284, and 330, a common feature of attenuated and most virulent strains, were also observed in these three strains. Two major hydrophilic peaks were conserved in the three strains; however, there are two amino acid substitutions at positions 280 (N to S) and 290 (M to L) in the second minor hydrophilic peak for all three strains, which might have a critical influence on antigenicity. Two amino acid substitutions near the VP2-VP4 cleavage site were identified in virulent strain JZ2000, which might be involved in increasing the virulence of the virus. Phylogenetic analyses indicated that these three Chinese strains are most closely related to some European virulent strains but are distinct from very virulent infectious bursal disease virus and variant strains.

[Identification and location of the toxin protein genes in 56 Bacillus thuringiensis isolates]

Polymerase chain reaction was performed to screen Bacillus thuringiensis isolates for cryI, cryIII, and cryV genes with cryI-, cryIII-, and cryV-specific primers respectively. The results indicated that, in the 56 Bt isolates examined, 7 isolates contain cryI gene, 2 isolates contain cryIII gene, and 21 isolates contain both cryI and cryV genes. The cryV gene was located by Southern hybridization in the large plasmid of about 150 MD molecular mass.

Structural and functional relationship between the receptor recognition and neuraminidase activities of the Newcastle disease virus hemagglutinin-neuraminidase protein: receptor recognition is dependent on neuraminidase activity

The terminal globular domain of the paramyxovirus hemagglutinin-neuraminidase (HN) glycoprotein spike has a number of conserved residues that are predicted to form its neuraminidase (NA) active site, by analogy to the influenza virus neuraminidase protein. We have performed a site-directed mutational analysis of the role of these residues in the functional activity of the Newcastle disease virus (NDV) HN protein. Substitutions for several of these residues result in a protein lacking both detectable NA and receptor recognition activity. Contribution of NA activity, either exogenously or by coexpression with another HN protein, partially rescues the receptor recognition activity of these proteins, indicating that the receptor recognition deficiencies of the mutated HN proteins result from their lack of detectable NA activity. In addition to providing support for the homology-based predictions for the structure of HN, these findings argue that (i) the HN residues that mediate its NA activity are not critical to its attachment function and (ii) NA activity is required for the protein to mediate binding to receptors.