Temporal dynamics of soil dissolved organic carbon in temperate forest managed by prescribed burning in Northeast China

Dissolved organic carbon (DOC) is an important function of soil organic carbon and sensitive to environmental disturbance. Few studies have explored the variations in soil DOC dynamics and effects on soil physicochemical properties following prescribed burnings. In this study, Pinus koraiensis plantation forests in Northeast China were selected and subjected to prescribed burning in early November 2018. Soil DOC and different soil physicochemical and biological properties in the 0-10 cm and 10-20 cm soil layers were sampled six times within two years after a prescribed burning. In this study, some soil physicochemical (SOC, TN, and ST) and microbial biomass properties (MBC) recovered within two years after a prescribed burning. Compared to the unburned control stands, the post-fire soil DOC concentrations in the upper and lower soil layers increased by 16% and 12%, respectively. Soil DOC concentrations varied with sampling time, and peaked one year after the prescribed burning. Our results showed that soil chemical properties (NH4+-N and pH) rather than biological properties (microbial biomass) were the main driving factors for changes in post-fire soil DOC concentrations. Current study provides an important reference for post-fire and seasonal soil C cycling in plantation forests of Northeast China.

Camrelizumab with Chemoradiotherapy for Locally Advanced Biliary Tract Cancer: Preliminary Results from A Phase II Study

PURPOSE/OBJECTIVE(S)

For locally advanced biliary tract cancer (BTC), capecitabine-based chemoradiotherapy (CRT) is commonly used but has limited benefits. Immunotherapy is potentially effective for BTC and may be synergized with CRT. Followed by gemcitabine and cisplatin (GP) consolidation chemotherapy (CT), we evaluated the safety and efficacy of combined camrelizumab and capecitabine-based CRT for locally advanced BTC.

MATERIALS/METHODS

Patients had stage II-III (T4N0M0, T1-4N+M0) BTC (per the 7th [2010] edition of the American Joint Committee on Cancer staging system) were eligible for CRT (capecitabine plus [50-60 Gy] radiotherapy), to be followed by GP CT. Camrelizumab was given concurrently with CRT. Safety was defined as the incidence and severity of adverse events (AEs), while efficacy was defined as overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and disease control rate (DCR).

RESULTS

Ten patients completed the planned treatment. None experienced grade ≥3 treatment-related AEs during CRT. Grade ≥3 immune-related AEs occurred in 2 of 10 patients (20%) only during GP CT. The mean OS time was 18.2 months (95% confidence interval [CI] 12.9m-23.5m) while the median OS time was 14.1 months (95% CI 10.1m-18.1m). OS rates were 100%, 59%, 44% at 6 months, 1 year and 2 years, respectively. The ORR was 30% while the DCR was 90%. Two patients (20%) obtained OS over 2 years with partial response (25.9m, 29.1m). Median PFS time was 14.1 months (95% CI 9.3m-18.9m).

CONCLUSION

Camrelizumab in combination with concurrent CRT was well tolerated and did not impair delivery of CRT in patients with locally advanced BTC.

[Persistence follow-up of immune memory to hepatitis B vaccine among infants with non- and low-response to primary vaccination after revaccination with three doses]

This study followed up the immune memory after 3-dose revaccination among infants with non-and low-response following primary hepatitis B (HepB) vaccination. About 120 children without self-booster doses were finally included who had anti-HBs<10 mIU/ml (anti-HBs negative) at the time of follow-up, of whom 86 children completed blood sampling and anti-HBs testing. Before the challenge dose, all 86 children were negative for anti-HBs, and the GMC of anti-HBs was<10 mIU/ml. The seropositive conversion rate of anti-HBs was 100% and the GMC of anti-HBs was 886.11 (95%CI: 678.15-1 157.84) mIU/ml after the challenge dose. Compared with those with GMC<7 mIU/ml before the challenge dose, infants with GMC>7 mIU/ml had a higher anti-HBs level after the challenge dose. The β value (95%CI) was 0.82 (0.18-1.46) (P=0.012). Compared with those with GMC<1 000 mIU/ml at primary vaccination, infants with GMC≥1 000 mIU/ml had a higher anti-HBs level after the challenge dose. The β value (95%CI) was 0.78 (0.18-1.38)(P=0.012). The results showed a stronger immune memory was found at 9 years after revaccination among infants with non-and low-response to HepB.

Effects of pyrogenic carbon addition after fire on soil carbon mineralization in the Great Khingan Mountains peatlands (Northeast China)

Wildfires play a critical role in regulating soil carbon (C) budgets in peatland ecosystems, and their frequency and intensity are increasing owing to climate change and human activities. Wildfires not only emit CO₂ during the combustion process but also produce pyrogenic carbon (PyC), which accumulates in the soil C pool and influences soil C decomposition. However, the role of PyC after a fire in peatland soil C mineralization has rarely been examined. This study investigated the effects of PyC addition on peatland soil C mineralization and its potential driving mechanisms using an anaerobic/aerobic incubation experiment with peat soils collected from typical peatlands in the Great Khingan Mountains, Northeast China. The effect of PyC was more pronounced under aerobic conditions than under anaerobic conditions. The mean C- mineralization rates of soil were significantly increased by 45.2 ± 15.5 % and 87.6 ± 14.3 % with 10 % PyC_250°C addition after the initial stage (D7) of aerobic and anaerobic incubation, but PyC_600°C addition caused a to decrease. Compared with PyC_600°C, PyC_250°C addition significantly increased the available N content and altered the soil microbial activities, which may be the primary reason for the increase in C mineralization rates. Furthermore, adding a high concentration of PyC (10 %) reduced the concentration of phenolics but increased phenol oxidase activity, which promoted C mineralization rates. Thus, PyC_250°C addition to peat soils mainly influences the microbial biomass C content through the accumulation of available N and phenolics, which ultimately positively affects C mineralization rates.

[Anti-HBs persistence after primary vaccination with three doses of 5 μg recombinant hepatitis B vaccine among normal and high-responder infants: 10-year of follow-up]

Objective: Assess the 10-year Immune persistence and the predictors after primary vaccination hepatitis B vaccine (HepB) among normal and high-responder infants. Methods: A total of 1 838 Infants of 7-12 months old located in Jinan, Weifang, Yantai and Weihai of Shandong Province who were induced normal or high antibody response (anti-HBs titer ≥ 100 mIU/ml) after primary vaccination (three dose with 0-1-6 procedure) with 5 μg recombinant HepB among newborns were included in the study, in 2009. 3 ml of venous blood samples were collected at baseline survey (T₀) and antibodies against hepatitis B surface antigen (anti-HBs), antibody against hepatitis B core antigen (anti-HBc) and hepatitis B surface antigen (HBsAg) were detected using chemiluminescence microparticle immunoassay (CMIA) method. A self-designed questionnaire was used to collect information including the infant's age, sex, birth weight, premature birth, birth number, delivery location and mother's HBV infection status. In 2014 (followed up for 5 years) and in 2019 (followed up for 10 years) (T₁), 2 ml of venous blood samples were collected. Anti HBS and anti HBC were detected by CMIA method. Those with anti HBS<10 mIU/ml were detected by CMIA method. Multivariate unconditional logistic and linear regression models were used to analyze the influencing factors of anti-HBs positive rate and geometric mean concentration (GMC) at T₁. Results: After 10 years follow-up, 73.94% of the subjects (1 359/1 835) finished the follow-up. 51.15% of the subjects, a total of 625 were boys. The positive rate of anti-HBs was 100% at T₀ and decreased to 53.44% (95%CI: 50.59%-56.26%) at T₁. The average annual decline rate of anti-HBs positive rate from T₀ to T₁ was 6.07%. The GMC of anti-HBs decreased from 607.89 (95%CI: 579.01-642.62) mIU/ml to 16.44 (95%CI: 15.06-18.00) mIU/ml. The average annual decline rate of anti-HBs GMC in 10-year follow-up was 30.30%. Multivariate logistic analysis showed that the positive rate of anti-HBs at T₁ was lower in those who did not vaccinate the first dose in time (OR=0.25, 95%CI:0.07-0.71). Compared with those with GMC<1 000 mIU/ml at T₀, those with GMC ≥ 1 000 mIU/ml had a higher positive rate of anti-HBs at T₁ (OR=2.29, 95%CI:1.76-2.97). Multivariate regression analysis showed that the GMC of anti-HBs at T₁ was lower in those who did not vaccinate the first dose in time (β=-0.50, 95%CI:-1.24-0.24). Compared with those with GMC<1 000 mIU/ml at T₀, those with GMC ≥ 1 000 mIU/ml had a higher GMC of anti-HBs at T₁ (β=0.81, 95%CI: 0.62-1.05). Conclusion: Anti-HBs GMC decreased in 10 years after primary vaccination of 5 μg recombinant hepatitis B vaccine among normal and high-responders. The anti-HBs persistence was mainly associated with whether the first dose was vaccinated in time and the level of anti-HBs at the end of primary vaccination.

[Rates and characteristics for hepatitis B reactivation of inactive hepatitis B carriers in rural communities]

Objective: To analyze the intensity and epidemiological characteristics of hepatitis B virus (HBV) reactivation among inactive HBsAg carriers (IHC) of rural areas in Ji'nan. Methods: In 2018 and 2020, follow-up investigations were conducted on IHC identified in the population physical examination in Zhangqiu district of Ji'nan. The results of the two follow-up visits were compared to analyze the incidence and distribution characteristics of HBV reactivation in IHC at the community level. Results: A total of 424 IHC completed two follow-up visits, and 47 cases of HBV reactivation were found, the cumulative reactivation rate was 11.08%, and the incidence density was 5.46/100 person-years. Multivariate analysis showed that gender, age, smoking, drinking , family history of liver disease and chronic diseases were not associated with HBV reactivation (P>0.05), and baseline HBV DNA load was associated with reactivation (P<0.05), in the HBV DNA level ≥1 000 IU/ml group, the reactivation rate could reach 18.92%. After reactivation, the mean level of ALT increased from baseline and the abnormal rate increased, liver function tended to be abnormal in reactivated patients. 4 (8.51%) reactivators had hepatitis, and 1 (2.13%) had jaundice hepatitis. Conclusions: The incidence of HBV reactivation was higher among IHC in rural communities in Ji'nan. Most of the reactivators were asymptomatic or mildly reactivated. Follow-up of inactive HBsAg patients should be strengthened and changes in ALT and HBV DNA levels should be closely monitored.

[Analysis of capability to pertussis etiology and serological diagnosis for GradeⅡ and Ⅲmedical institutions in Shandong Province in 2018]

Objective: Investigate and analyze the etiology and serological diagnosis capabilities of pertussis in medical institutions in Shandong Province in 2018. Methods: Using the census method, a questionnaire survey was conducted among 603 second and above level medical institutions in Shandong Province. The deadline for the survey was December 2018, and a total of 543 questionnaires have been recovered, and the validity rate of the questionnaires was 90%. Surveyed the pertussis etiology and serology test items (pertussis IgM and IgG, pertussis nucleic acid and pertussis bacterial culture) and the start time of each test item by questionnaire. The reported cases (confirmed cases and clinically diagnosed cases) between January 1, 2012 and December 31, 2018 were derived from the Chinese Disease Control and Prevention Information System according to the onset date. We used indicators such as fixed-base development speed, chain development speed, and chain growth speed for analysis. The chi test was used to analyze the differences in the composition ratio of medical institutions with detection ability in different levels and regions, and analyze the changes in the number of reported cases before and after the development of pertussis etiology and serology testing. Results: A total of 543 medical institutions accounted for 90.0% (543/603) of all secondary and above level medical institutions in the province, 356 secondary medical institutions (65.6%), and 187 tertiary medical institutions (34.4%). There were 10 medical institutions that carry out pertussis IgM, IgG and nucleic acid testing, accounting for 1.8% (10/543) of the surveyed medical institutions respectively. 2 medical institutions that carried out bacterial culture, accounting for 0.4% of the surveyed medical institutions (2/543). 20 medical institutions have carried out the above tests (8 secondary medical institutions and 12 tertiary medical institutions), accounting for 3.7% (20/543). The proportion of tertiary medical institutions with pertussis IgM, IgG detection and nucleic acid detection capabilities [6.42% (12/187)] was significantly higher than that of secondary medical institutions [2.25% (8/356)] (χ²=6.01, P=0.014). From 2012 to 2018, the fixed base ratio development speed of reported cases was 3 834.69% in Shandong Province, among which medical institutions with etiology and serological testing capabilities reached 4 533.33%. In 13 medical institutions, the average annual number of reported cases after pertussis etiology and serological testing were higher than that of reported cases before testing. Conclusion: The ability of pertussis etiology and serology diagnosis of secondary and above medical institutions in Shandong Province needs to be improved.

Aryl hydrocarbon receptor polymorphisms are associated with dry skin phenotypes in Chinese patients with atopic dermatitis

BACKGROUND

Epidermal barrier dysfunction is the initial event in the development of atopic dermatitis (AD). Recent studies have identified a crucial role for the aryl hydrocarbon receptor (AHR) in controlling the gene expression of filaggrin and other skin barrier proteins, suggesting an underlying association between AHR and AD pathogenesis.

AIM

To investigate the role of AHR gene polymorphisms in the susceptibility to AD and in AD-associated phenotypes.

METHODS

We enrolled 487 patients with AD, 210 patients with psoriasis and 226 healthy controls (HCs) from the Han Chinese population, and genotyped two AHR single-nucleotide polymorphisms (rs10249788 and rs2066853) by PCR and subsequent DNA sequencing.

RESULTS

The AHR rs10249788 and rs2066853 polymorphisms were found in both sets of patients (AD and psoriasis) and in HCs, but no significant differences were detected in genotype or allele frequencies between the three groups. However, patients with AD with the rs10249788 (CT/TT) or rs2066853 (AG + AA) genotype were more likely to have severe dry skin scores. In the stratification analysis, the AHR rs2066853 (AG + AA) and rs10249788 (CT + TT) genotypes could predict a higher risk of severe dry skin phenotypes in the male, early-onset and allergic rhinitis subgroups. Furthermore, the combined rs10249788 (CT + TT) and rs2066853 (AG + AA) genotypes led to a higher risk for severe dry skin in patients with AD.

CONCLUSION

AHR polymorphisms are not associated with the risk of AD; however, they may predict a dry skin phenotype in patients with AD.

Interpretation of liver stiffness measurement-based approach for the monitoring of hepatitis B patients with antiviral therapy: A 2-year prospective study

Liver biopsy is not routinely performed in treated chronic hepatitis B. Liver stiffness measurement has been validated for noninvasive liver fibrosis assessment in pretreatment chronic hepatitis B but has not been assessed for fibrosis monitoring during antiviral therapy. Liver stiffness was systemically monitored by Fibroscan^® every 6 months in a cohort of patients with hepatitis B receiving antiviral therapy and compared with liver biopsies at baseline and week 104. A total of 534 hepatitis B e antigen-positive treatment-naive patients receiving telbivudine-based therapy with qualified liver stiffness measurement at baseline and week 104 were analyzed, 164 of which had adequate paired liver biopsies. Liver stiffness decreased rapidly (-2.2 kPa/24 weeks) in parallel with alanine aminotransferase (ALT) from 8.6 (2.6-49.5) kPa at baseline to 6.1 (2.2-37.4) kPa at week 24. Interestingly, liver stiffness decreased slowly (-0.3 kPa/24 weeks) but continually from week 24 to week 104 (6.1 vs 5.3 kPa, P < .001) while ALT levels remained stable within the normal range. More importantly, liver stiffness declined significantly irrespective of baseline ALT levels and liver necroinflammation grades. From baseline to week 104, the proportion of patients with no or mild fibrosis (Ishak, 0-2) increased from 74.4% (122/164) to 93.9% (154/164). Multivariate analysis revealed that percentage decline of 52-week liver stiffness from baseline was independently associated with 104-week liver fibrosis regression (odds ratio, 3.742; P = .016). Early decline of 52-week liver stiffness from baseline may reflect the remission of both liver inflammation and fibrosis and was predictive of 104-week fibrosis regression in treated patients with chronic hepatitis B.

The role of peginterferon in nucleos(t)ide-analogue-treated chronic hepatitis B patients: A review of published literature

Chronic hepatitis B infection (CHB) causes up to 1.0 million deaths annually. Currently, more than 90% of CHB patients worldwide are receiving indefinite nucleos(t)ide analogue (NA) therapy. New strategies for optimizing hepatitis B surface antigen (HBsAg) loss are required for NA-treated patients as the majority are unable to achieve HBsAg loss and may require lifelong therapy. In hepatitis B e antigen (HBeAg)-positive patients, switching from NAs to finite peginterferon (PegIFN) therapy can double HBeAg seroconversion rates. One in five patients who switch to PegIFN can achieve HBsAg loss, whereas patients who continue NA therapy typically do not. In HBeAg-negative NA-treated patients, add-on PegIFN therapy achieves higher, albeit modest, HBsAg loss rates compared with continued NA monotherapy and offers the opportunity for NA-treated patients to achieve the inactive carrier state. In the absence of curative therapies, PegIFN represents a valuable, finite option for NA-treated patients who would otherwise require potentially lifelong therapy.

Dosimetric and clinical toxicity comparison of critical organ preservation with three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and RapidArc for the treatment of locally advanced cancer of the pancreatic head

PURPOSE

We compared dosimetry and clinical toxicity for 3-dimensional conformal radiotherapy (3D-crt), intensity-modulated radiotherapy (imrt), and RapidArc (Varian Medical Systems, Palo Alto, CA, U.S.A.) in locally advanced pancreatic cancer (lapcc). We hypothesized that the technique with better sparing of organs at risk (oars) and better target dose distributions could lead to decreased clinical toxicity.

METHODS

The study analyzed 280 patients with lapcc who had undergone radiotherapy. The dosimetry comparison was performed using 20 of those patients. Dose-volume histograms for the target volume and the oars were compared. The clinical toxicity comparison used the 280 patients who received radiation with 3D-crt, imrt, or RapidArc.

RESULTS

Compared with 3D-crt, RapidArc and imrt both achieved a better conformal index, homogeneity index, V95%, and V110%. Compared with 3D-crt or imrt, RapidArc reduced the V10, V20, and mean dose to duodenum, the V20 of the right kidney, and the liver mean dose. Compared with 3D-crt, RapidArc reduced the V35, and V45 of duodenum, the mean dose to small bowel, and the V15 of right kidney. The incidences of grades 3 and 4 diarrhea (p = 0.037) and anorexia (p = 0.042) were lower with RapidArc than with 3D-crt, and the incidences of grades 3 and 4 diarrhea (p = 0.027) were lower with RapidArc than with imrt.

CONCLUSIONS

Compared with 3D-crt or imrt, RapidArc showed better sparing of oars, especially duodenum, small bowel, and right kidney. Also, fewer acute grades 3 and 4 gastrointestinal toxicities were seen with RapidArc than with 3D-crt or imrt. A technique with better sparing of oars and better target dose distributions could result in decreased clinical toxicities during radiation treatment for lapcc.

Histamine H4 Receptor mediates interleukin-8 and TNF-α release in human mast cells via multiple signaling pathways

Histamine, mainly produced by mast cells, is an important inflammatory mediator in immune response. Recently Histamine H4 Receptor (H4R) was also identified in mast cells, from which pro-inflammatory cytokines and chemokines are released. However, the mechanism of how H4R mediates these cytokines and chemokines release in mast cells was still unclear. To further explore the role of H4R in the immune inflammatory response in mast cells, we tested the release of inflammatory cytokine tumor necrosis factor-α (TNF-α), chemokine interleukin-8 (IL-8) and the relevant signaling pathways activated by H4R on LAD2 cells (a human mast cell line). We found that the release of IL-8 and TNF-α were blocked by inhibitors of PI3K, ERK and Ca2+-Calcineurin-NFAT signaling pathways, while the release of these cytokines and chemokines were enhanced by the inhibitor of P38 signaling pathway. However, inhibitors of the JNK and NF-κB signaling pathways had little effect on the expression of the pro-inflammatory mediators. Moreover, activation of the H4R could induce phosphorylation of ERK, p38 and AKT in mast cells. In conclusion, we found that H4R mediates the release of inflammatory cytokine TNF-α and chemokine IL-8 in human mast cells via PI3K, Ca2+-Calcineurin-NFAT and MAPKs signaling pathways.

Effects of ApoE on intracellular calcium levels and apoptosis of neurons after mechanical injury

OBJECTIVE

The current study aimed to explore the effects of apolipoprotein e (ApoE) on intracellular calcium ([Ca(2+)]i) and apoptosis of neurons after mechanical injury in vitro.

METHODS

A neuron mechanical injury model was established after primary neurons obtained from APOE knockout and wild-type (WT) mice, and four experimental groups were generated: Group-ApoE4, Group-ApoE3, Group-ApoE(-) and Group-WT. Recombinant ApoE4 and ApoE3 were added to Group-ApoE4 and Group-ApoE3 respectively, and Group-ApoE(-) and Group-WT were control groups. Intracellular calcium was labeled by fluo-3/AM and examined using laser scanning confocal microscope and flow cytometry, and the apoptosis of neurons was also evaluated.

RESULTS

The intracellular calcium levels and apoptosis rates of mice neurons were significantly higher in Group-ApoE4 than in Group-ApoE3 and Group-WT after mechanical injury. However, without mechanical injury on neurons, no significant differences in intracellular calcium levels and apoptosis rates were found among all four experimental groups. The effects of ApoE4 on intracellular calcium levels and apoptosis rates of injured neurons were partly decreased by EGTA treatment.

CONCLUSION

Compared with ApoE3-treatment and WT neurons, ApoE4 caused higher intracellular calcium levels and apoptosis rates of neurons after mechanical injury. This suggested APOE polymorphisms may affect neuron apoptosis after mechanical injury through different influences on intracellular calcium levels.

A recombined fusion protein SP5.2/tTF induce thrombosis in tumor blood vessel

Tumor vascular targeting is one of the most promising strategies in tumor therapy. Here we used E.coli to express a recombinant SP5.2/tTF fusion protein, which, as a tumor vascular targeting agent, consists of SP5.2 (a peptide selectively binding and targeting VEGFR-1 on tumor endothelial cells) and truncated tissue factor (tTF)and aimed to explore its anti-tumor activities.The SP5.2/tTF expression construct was synthesized by polymerase chain reaction (PCR) and recombined into plasmid pET22b(+). The fusion gene was verified by restriction mapping and sequencing. SP5.2/tTF was expressed in E. coli and then purified on a nickel-affinity chromatography column. The purified product was detected by SDS-PAGE. The pro-coagulant activity and binding of SP5.2/tTF to human umbilical vein endothelial cells (HUVECs) were monitored by FX activation analysis and fluorescent scanning confocal microscopy, respectively. The effect of SP5.2/tTF on tumor growth was analyzed in BALB/c mice bearing sarcoma 180 (S180) tumor. The tissue localization of SP5.2/tTF and its effect on tumor vessel thrombosis were observed by in vivo fluorescence imaging and histological studies, respectively. The fusion gene was successfully cloned into pET22b(+). SP5.2/tTF was abundantly expressed in bacterial cells and efficiently purified by nickel-affinity chromatography. Functional studies showed that the protein retained both the coagulation activity of tTF and the binding capacity of SP5.2 to HUVECs. In tumor xenograft studies, SP5.2/tTF selectively targeted the tumor, induced thrombosis, and led to retardation and even regression of tumor growth (growth inhibition ratio = 70%, P< 0.05). The recombinant fusion protein SP5.2/tTF inhibited tumor growth by selectively inducing thrombosis in tumor blood vessels.

Detection of Salmonella spp. by a loop-mediated isothermal amplification (LAMP) method targeting bcfD gene

In this study, we developed and validated a loop-mediated isothermal amplification (LAMP) assay for Salmonella detection targeting bcfD gene, a conserved fimbrial operon gene existing in Salmonella. The Salmonella LAMP assay we developed successfully amplified 44 Salmonella strains (14 standard strains and 30 clinical isolates), but none of 9 non-Salmonella standard strains (Proteus mirabilis, Listeria monocytogenes, Escherichia coli, Pseudomonas aeruginosa, Shigella flexneri, Shigella sonnei, Klebsiella pneumoniae, Campylobacter jejuni and Vibrio parahemolyticus). The detection limit was 5 CFU of Salmonella pure culture or 200 CFU of artificially spiked faeces per reaction system (equivalent to 5000 CFU g(-1) of faeces), and this method could directly detect Salmonella in chicken faeces free of pre-enrichment in a reaction time of 25 min. Our experiments show that the LAMP method we developed is a rapid, sensitive, specific and practical method for Salmonella detection. The Salmonella LAMP assay can potentially serve as new on-site diagnostics in the food and agricultural industries.

SIGNIFICANCE AND IMPACT OF THE STUDY

A loop-mediated isothermal amplification (LAMP) assay was established to detect Salmonella targeting bcfD gene, a conserved fimbrial operon gene. The detection limit was 5 CFU of Salmonella pure culture or 200 CFU of artificially spiked faeces per reaction system (equivalent to 5000 CFU g(-1) of faeces), and this method could directly detect Salmonella in chicken faeces free of pre-enrichment in a reaction time of 25 min. The Salmonella LAMP assay is a rapid, sensitive, specific and practical method for Salmonella detection and can potentially serve as new on-site diagnostics in the food and agricultural industries.

Chemerin suppresses murine allergic asthma by inhibiting CCL2 production and subsequent airway recruitment of inflammatory dendritic cells

BACKGROUND

Chemerin has been implicated to play opposing roles, either pro-inflammatory or anti-inflammatory, in various tissue inflammation processes primarily through the regulation of tissue recruitment of immune cells. However, the effect of chemerin in allergic asthma has not yet been explored. We sought to investigate the role of chemerin in the murine model of allergic asthma and explore the underlying mechanism.

METHODS

We examined the effect of intranasal (i.n.) administration of chemerin during antigen challenge in murine models of asthma. Moreover, we examined whether administration of CCL2 or bone marrow-derived dendritic cells (BMDCs) transfer reversed the effects of chemerin on ovalbumin-induced asthma. We finally examined the effect of chemerin on CCL2 expression in activated lung epithelial cells in vitro.

RESULTS

The administration of chemerin attenuated allergic airway inflammation and airway hyperreactivity during antigen challenge. Chemerin treatment caused significant decreases in BALF CD4(+) T-cell accumulation and mRNA expression of Th2-attracting chemokines, CCL17 and CCL22, which was accompanied by significantly decreased BALF CD11c(+) CD11b(+) inflammatory DC accumulation and CCL2 production. Furthermore, airway administration of exogenous CCL2 or adoptive transfer of CD11c(+) CD11b(+) BMDCs abrogated the suppressive effects of chemerin on allergic asthma. Finally, in vitro study showed that chemerin inhibited CCL2 secretion by low-dose LPS-stimulated lung epithelial cells, which led to decreased chemotaxis of BMDCs.

CONCLUSIONS

Our study demonstrates that chemerin plays a protective role in allergic asthma by suppressing airway recruitment of inflammatory CD11c(+) CD11b(+) DCs through the inhibition of CCL2 secretion by active lung epithelial cells.

Abstract P1-07-11: ERa regulates epithelial-mesenchymal transition in breast cancers through suppressing Bmi1 expression

Background: Bmi1, a polycomb-group protein, maintains stem cell self-renewal and is frequently overexpressed in cancers. Upregulation of Bmi1 by Twist1 can promote tumor-initiating capability and Epithelial-mesenchymal transition (EMT) by repressing E-cadherin expression. It has been demonstrated that Post-EMT breast cancer cells express cancer stem cell (CSC) markers including Bmi1, but display decreased ERα expression. ERα is a ligand-activated nuclear hormone receptor that regulates the transcription of E2-responsive genes in diverse target cells. It's reported that ligand-activated ERα could repress slug transcription by binding to the half-site ERE element in its promoter, and then regulate E-cadherin and EMT. Herein, we hypothesized that ERα signaling might regulate E-cadherin and EMT through Bmi1.

Methods: First, we determined Bmi1 and ERα expression at both mRNA and protein levels by quantitative RT-PCR and Western blot in various breast cancer cell lines. Further, we quantitatively analyzed mRNA and protein levels of Bmi1 as well as its down-stream genes including E-cadherin after silencing ERα in T47D cells with siRNA, or after overexpressing ERα in BT549 cells. The chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA) were also performed to investigate whether ERα binds directly to Bmi1 promoter region. Luciferase assay with Bmi1 reporter was performed to ERα mediated regulation. To identify whether ERα regulates EMT, transwell and matrigel invasion, flow cytometry, mammosphere assay and wound healing assay were performed to invasion, metastases and characterize stem-cell properties of EMT. Finally, we analyzed the expression of ERα, Bmi1 and E-cadherin in human breast cancer specimens with immunohistochemistry.

Results: The study showed that Bmi1 inversely correlated with ERα expression in different subtypes of breast cancer cells. We further confirmed that Bmi1 was upregulated at both mRNA and protein levels and E-cadherin was downregulated with siRNA against ERα in T47D cells, and Bmi1 was downregulated and E-cadherin was upregulated when overexpressing ERα in BT549 cells with qRT-PCR and western blot analyses. The present study also demonstrated that ERα could directly binds to the half-ERE region of the Bmi1 gene and repressing Bmi1 expression transcriptionally with CHIP/EMSA and reporter analyses. Overexpression of ERα in BT549 cell significantly decreased levels of migration of transwell and wounding healing, invasiveness, CD44high/CD24low population, and the capabilities of mammosphere formation.

Conclusions: Our results demonstrated that ERα can suppress EMT through transcriptionally down-regulating Bmi-1 and its down-stream genes in human breast cancer cells. The inverse relationship between ERα and Bmi1 expression further supports the epithelial phenotype of ERα positive tumors or mesenchymal phenotype of ERα negative tumors. Our findings provide a novel mechanistic insight into how ERα regulates EMT, and is of valuable for developing biomarkers to predict prognosis and targeted therapies in breast cancers in the future.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-07-11.

Origin of the complex molecular dynamics in functionalized discotic liquid crystals

The molecular dynamics of three dipole functionalized hexa-peri-hexabenzocoronenes have been studied using site-specific NMR techniques and dielectric spectroscopy as a function of temperature and pressure. These probes (i) suggest that the thermodynamic state completely controls the dynamic response, (ii) clarify the origin of two dynamic processes associated with the presence of two glass temperatures, and (iii) provide the first phase diagram for substances of this kind.

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.

Dysregulation of transforming growth factor beta signaling in scleroderma: overexpression of endoglin in cutaneous scleroderma fibroblasts

OBJECTIVE

As an initial approach to understanding the basis of the systemic sclerosis (SSc; scleroderma) phenotype, we sought to identify genes in the transforming growth factor beta (TGF beta) signaling pathway that are up-regulated in lesional SSc fibroblasts relative to their normal counterparts.

METHODS

We used gene chip, differential display, fluorescence-activated cell sorter, and overexpression analyses to assess the potential role of TGF beta signaling components in fibrosis. Fibroblasts were obtained by punch biopsy from patients with diffuse cutaneous SSc of 2-14 months' duration (mean 8 months) and from age- and sex-matched healthy control subjects.

RESULTS

Unexpectedly, we found that fibroblasts from SSc patients showed elevated expression of the endothelial cell-enriched TGF beta receptor endoglin. Endoglin is a member of the nonsignaling high-affinity TGF beta receptor type III family. The expression of endoglin increased with progression of disease. Transfection of endoglin in fibroblasts suppressed the TGF beta-mediated induction of connective tissue growth factor promoter activity.

CONCLUSION

SSc is characterized by overproduction of matrix; that is, genes that are targets of TGF beta signaling in normal fibroblasts. Our findings suggest that lesional SSc fibroblasts may overexpress endoglin as a negative feedback mechanism in an attempt to block further induction of profibrotic genes by TGF beta.

Phase shift at a turning point in a planar optical waveguide

We present a novel matrix approach to proving that the phase shift at a turning point in a planar optical wave-guide is exactly equal to pi rather than to pi/2 or to some other value. We also show the existence of phase contributions from reflected subwaves, which to our knowledge have never been taken into account previously.

DNA-binding of phenylalanyl-tRNA synthetase is accompanied by loop formation of the double-stranded DNA

The phenylalanyl-tRNA synthetase (FRS) from Thermus thermophilus has previously been shown to bind DNA. We demonstrate that the "winged" helix-turn-helix motifs in the duplicate domains B5 are the relevant structural elements for this DNA-binding property. By altering particular amino acids in the "wing", the affinity of the FRS to DNA was significantly reduced. Based on experimental data, which indicate that the FRS prefers a certain DNA structure rather than a particular consensus sequence, we propose a novel loop model for the DNA-binding mode of the FRS. In our model we assume that two segments of the same DNA molecule are bound simultaneously by both B5 domains and are aligned in parallel, while the intervening DNA forms a loop. Due to the limited flexibility of the DNA, loop formation is only possible if the respective intervening DNA stretch exceeds a certain length. Several lines of evidence support this model. (1) We demonstrate by gel retardation assays that the DNA requires a minimal number of ca 80 base-pairs to be bound by the FRS. (2) In the presence of the FRS, DNA longer than ca 80 base-pairs has a significantly increased DNase I accessibility. This agrees well with its known preferential cleavage at positions where the minor grove is on the outside of looped-out DNA molecules. (3) The initial cleavage by DNase I of >80 bp long DNA occurs in the middle of the fragment. In a looped molecule this is the position with the highest accessibility to DNase I. The function of the FRS related to DNA binding is still unknown. Since the FRS exists in the nucleus of rapidly growing mammalian cells, and protein-induced DNA bending or looping contributes to several transcription, replication, and recombination systems in both prokaryotes and eukaryotes, it is likely that the FRS, in addition to its aminoacylation function, influences common cellular processes via DNA binding.

Detection of type 1 cytokines in discoid lupus erythematosus

BACKGROUND

Although multiple studies suggest a dysregulated T-cell cytokine production in systemic lupus erythematosus, the cytokine profile in discoid lupus erythematosus (DLE) lesions is unknown.

OBJECTIVES

To characterize the cytokine profile in DLE by immunohistochemical and molecular methods, and to investigate the role of cytokines in the pathogenesis of DLE.

DESIGN

Patients were evaluated clinically, and biopsy specimens of lesional skin were examined by light microscopy. Reverse transcriptase-polymerase chain reaction and immunohistochemical analysis were performed on 11 biopsy specimens. We investigated the presence of interleukin (IL) 2, interferon gamma (IFN-gamma), IL-4, tumor necrosis factor alpha, (TNF-alpha), and IL-1beta messenger RNA (mRNA) in 8 biopsy specimens of DLE and compared it with 3 biopsy specimens of normal skin.

SETTING

Academic referral research hospital.

PATIENTS

Eight consecutive patients with a clinical and histologic diagnosis of DLE.

RESULTS

Localized DLE was found in 7 patients and widespread in 1. During the 4 years of the investigation, none of the patients developed systemic lupus erythematosus. We found significantly elevated levels of IL-2 and IFN-gamma mRNA in all 8 biopsy specimens of DLE; in contrast, no transcripts of IL-2 or IFN-gamma were detected in 3 biopsy specimens of normal skin (P<.01). Similarly, elevated levels of TNF-alpha mRNA were detected in 8 DLE biopsy specimens, while no TNF-alpha mRNA was detected in 3 biopsy specimens of normal skin (P<.01). No IL-4 or IL-1 beta mRNA was detected in 8 biopsy specimens of DLE lesional skin and 3 biopsy specimens of normal patient skin. Immunohistochemical analysis showed increased staining for IL-2 and IFN-gamma receptors, while no detectable IL-4 receptor was found. No cytokine mRNA or cytokine receptor protein was detected in biopsy specimens of normal skin.

CONCLUSIONS

These findings suggest that DLE is associated with type 1 cytokines characterized by the expression of IL-2 and IFN-gamma. Type 1 cytokines may be critical for induction, development, and maintenance of DLE.

[Detection of HGV RNA in sera from patients with fulminant hepatitis in Shenyang]

HGV RNA was detected by Rt-nested PCR in sera from 49 patients with fulminant hepatitis. The results showed: a) HGV RNA positive rate was 16.3% (8/49) in patients with fulminant hepatitis including 4 subjects with HBV coinfection, 1 subject with HCV coinfection, 2 subjects with HBV and HCV coinfection and 1 subject with HGV infection alone. b) mortality in patients with fulminant hepatitis with HGV infection was 75% (6/8), suggesting that: a) both infection with HGV alone and superinfections of other types of hepatitis virus can result in fulminant hepatitis, b) clinical manifestations of fulminant hepatitis with HGV infection may appear to be more severe and with higher mortality.

Quantitative analysis of metabolic gases by multichannel Raman spectroscopy: use of a newly designed elliptic-spherical integration type of cell holder

We describe the quantitative analysis of some metabolic gases bymultichannel Raman spectroscopy. Raman spectra were measured forair, acetone, ammonia, carbon dioxide, and mixed gas consisting ofacetone, ammonia, and air. We designed a new elliptic-sphericalintegration type of cell holder to obtain the Raman spectra of gaseswith a high signal-to-noise ratio. Concentrations of acetone, ammonia, and carbon dioxide were determined by the peak intensities ofRaman bands at 2940, 3228, and 1385 cm(-1), respectively. To compensate for the fluctuations of Ramanintensities caused by several factors, such as the fluctuations oflaser power, the peak intensity of a band at 2324 cm(-1) dueto nitrogen gas was used as an internal intensity standard. Thecorrelation coefficient between the corrected Raman intensity at 2940cm(-1) and the concentration of acetone was calculated to be0.984 for a concentration range of 2-12 ppm. The detection limitof acetone gas was found to be 2 ppm.

[Polymorphism analysis of 4 loci of X-chromosome in a Chinese population of the Han nationality]

OBJECTIVE

To investigate the polymorphism of 4 loci of X-chromosome in the Hans.

METHODS

Using PCR-SSLP, the authors analysed the polymorphism of DXS1068, DXS7132, DXS6804 and DXS6799 in the X-chromosome in 70 randomly selected female Hans.

RESULTS

The number of alleles in the 4 loci were 5,5,5 and 6 respectively; there were no significant differences between the observed and estimated and genotype probabilities of the 4 loci; the estimates of heterozygosity of 4 loci were 0.6819, 0.6895, 0.7659 and 0.6483 respectively and there were no significant differences between the observed and estimated heterozygosity of the 4 loci.

CONCLUSION

The distribution of alleles and genotype probabilities of 4 loci all observe the Hardy-Weinberg equilibrium.

[A study of genetic patterns of idiopathic epilepsy]

OBJECTIVE

To explore genetic patterns of idiopathic epilepsy (IEP).

METHODS

Using familial analysis, tests for multifactorial inheritance and segregation analysis, we studied 210 pedigrees with IEP found in a population survey in Shangdong province.

RESULTS

The genetic pattern of IEP is not polygenic but is mainly influenced by autosomal recessive disorders. The results of segregation analysis indicate that the genetic pattern of U*U multiplex families and U*A group is autosomal recessive. Only a few cases in U*U group may accept the assumption of autosomal recessive inheritance while the other are sporadic cases. The frequency of sporadic cases is approximately 78.5%. Genetic heterogeneity may influence U*U(f) group and U*U group.

CONCLUSION

Further and careful empirical scrutiny of U*U(f) group and the sporadic cases in U*U group offers the best hope for getting a clear understanding of genetic patterns and mechanisms in IEP.

Quantitative analysis of double-stranded DNA amplified by a polymerase chain reaction employing surface-enhanced Raman spectroscopy

Surface-enhanced Raman spectroscopy (SERS) was utilized for the quantitative analysis of double-stranded (ds) DNA amplified by a polymerase chain reaction (PCR). 4?, 6-Diamidino-2-phenylindole dihydrochloride (DAPI), which intercalates into ds-DNA but does not form a complex with single-stranded (ss) DNA, was added to a DNA solution after amplification by PCR. When the solution was mixed, including ds-DNA-DAPI complexes and free DAPI with silver colloid sol, only free DAPI was adsorbed on the colloid surface. The dye on the colloid gave very intense SERS signals with excitation at 514.5 nm, whereas DAPI engaging in the intercalation with ds-DNA did not show any SERS signal. The SERS spectrum of DAPI on the colloid showed a strong band at 1610 cm(-1) due to the C?N stretching mode, and a linear relationship was observed between the peak intensity of the C?N stretching band and the concentration of free DAPI. Therefore one can determine the concentration of free DAPI by the SERS measurement. The more ds-DNA there is in the solution, the less free DAPI there is. Thus it is possible to quantitatively analyze the ds-DNA amplified by PCR indirectly by using SERS. The correlation coefficient between the peak intensity of the C?N stretching band and the concentration of ds-DNA amplified by PCR was calculated to be 0.988 for a concentration range from 0.1 to 1.3 mg/ml.