Historical trends of organochlorine pesticides (OCPs) recorded in sediments across the Tibetan Plateau

Sediment cores from four lakes across the Tibetan Plateau were used as natural archives to study the time trends of organochlorine pesticides (OCPs). The total concentrations of dichlorodiphenyltrichloroethane (ΣDDT) and hexachlorocyclohexane isomers (ΣHCH) were in the range of 0.04-1.61 and 0.08-1.88 ng/g based on dry weight (dw), while the input fluxes were in the range of 0.3-236 and 0.7-295 pg/cm²/y in the core sediments, respectively. The input fluxes of ΣDDT and ΣHCH generally peaked in sediment layers corresponding to the 1970s-1990s and peaked in top sediment layers. The ratio of α/γ-HCH decreased in the top layer sediments, implying that the contribution of lindane (pure γ-HCH) has been increasing in recent years. In addition, the ratio of o,p'-DDT/p,p'-DDT increased significantly over the last 15-20 years, suggesting that dicofol (characterized by high ratio of o,p'-DDT/p,p'-DDT about 7.0) has recently become a relatively more important source of DDT compared to technical DDT itself. The time trends of OCPs recorded in lake sediments examined the impact on such remote alpine regions by human activities.

A novel upwind stabilized discontinuous finite element angular framework for deterministic dose calculations in magnetic fields

Angular discretization impacts nearly every aspect of a deterministic solution to the linear Boltzmann transport equation, especially in the presence of magnetic fields, as modeled by a streaming operator in angle. In this work a novel stabilization treatment of the magnetic field term is developed for an angular finite element discretization on the unit sphere, specifically involving piecewise partitioning of path integrals along curved element edges into uninterrupted segments of incoming and outgoing flux, with outgoing components updated iteratively. Correct order-of-accuracy for this angular framework is verified using the method of manufactured solutions for linear, quadratic, and cubic basis functions in angle. Higher order basis functions were found to reduce the error especially in strong magnetic fields and low density media. We combine an angular finite element mesh respecting octant boundaries on the unit sphere to spatial Cartesian voxel elements to guarantee an unambiguous transport sweep ordering in space. Accuracy for a dosimetrically challenging scenario involving bone and air in the presence of a 1.5 T parallel magnetic field is validated against the Monte Carlo package GEANT4. Accuracy and relative computational efficiency were investigated for various angular discretization parameters. 32 angular elements with quadratic basis functions yielded a reasonable compromise, with gamma passing rates of 99.96% (96.22%) for a 2%/2 mm (1%/1 mm) criterion. A rotational transformation of the spatial calculation geometry is performed to orient an arbitrary magnetic field vector to be along the z-axis, a requirement for a constant azimuthal angular sweep ordering. Working on the unit sphere, we apply the same rotational transformation to the angular domain to align its octants with the rotated Cartesian mesh. Simulating an oblique 1.5 T magnetic field against GEANT4 yielded gamma passing rates of 99.42% (95.45%) for a 2%/2 mm (1%/1 mm) criterion.

Hox genes reveal genomic DNA variation in tetraploid hybrids derived from Carassius auratus red var. (female) × Megalobrama amblycephala (male)

Background

Allotetraploid F₁ hybrids (4nF₁) (AABB, 4n = 148) were generated from the distant hybridization of Carassius auratus red var. (RCC) (AA, 2n = 100) (♀) × Megalobrama amblycephala (BSB) (BB, 2n = 48) (♂). It has been reported that Hox gene clusters are highly conserved among plants and vertebrates. In this study, we investigated the genomic organization of Hox gene clusters in the allotetraploid F₁ hybrids and their parents to investigate the polyploidization process.

Results

There were three copies of Hox genes in the 4nF₁ hybrids, two copies in RCC and one copy in BSB. In addition, obvious variation and pseudogenization were observed in some Hox genes from 4nF_1.

Conclusion

Our results reveal the influence of polyploidization on the organization and evolution of Hox gene clusters in fish and also clarify some aspects of vertebrate genome evolution.

Electronic supplementary material

The online version of this article (10.1186/s12863-017-0550-2) contains supplementary material, which is available to authorized users.

Does thyroid dysfunction increase the risk of breast cancer? A systematic review and meta-analysis

PURPOSE

To investigate the relationship between hypothyroidism, hyperthyroidism, thyroid hormone replacement, and the risk of breast cancer.

METHODS

We searched the PubMed, Cochrane Library, EMbase, Web of Science, and China Biology Medicine (CBM) databases through June 2016 to identify researches that assessed the relationship between thyroid dysfunction and the risk of breast cancer together with the impact of thyroid hormone substitution treatment on incidence of breast cancer. Quality of evidence was assessed per outcome, using GRADE.

RESULTS

A total of 13 population-based studies including 24,808 participants were identified as eligible for this meta-analysis. A meta-analysis of 12 researches illustrated that hypothyroidism was not related to the risk for breast cancer [odds ratio (OR) = 0.83, 95% confidence interval (CI) 0.64-1.08, P = 0.162]. 10 researches illustrated that hyperthyroidism was also not related to the risk of breast cancer (OR = 1.03, 95% CI 0.83-1.30, P = 0.767). The impact of therapy was evaluated in six researches; there was no proof of a relationship between thyroid hormone substitution treatment and breast cancer with an overall OR of 0.83 (95% CI 0.57-1.21, P = 0.965).

CONCLUSIONS

Our meta-analysis illustrated that thyroid dysfunction may not be related to increased risk of breast cancer as well as the thyroid hormone substitution treatment did not reduce the incidence of breast cancer; while this study has some confounders that might weaken the results of this meta-analysis, we believe that the findings provide valuable information for stakeholders concerned with outcomes in patients with thyroid dysfunction.

Prevalence and pathogen load of Campylobacter spp., Salmonella enterica and Escherichia coli O157/O145 serogroup in sheep faeces collected at sale yards and in abattoir effluent in Western Australia

OBJECTIVE

Develop a multiplex quantitative PCR assay to investigate the prevalence and shedding of Escherichia coli O157/O145, Salmonella spp. and Campylobacter spp. in sheep at sale yards and abattoirs.

METHODS

A qPCR for E. coli O157/O145 was developed, validated and multiplexed with an existing qPCR for Campylobacter and Salmonella enterica. The absolute numbers of E. coli O157/O145, Campylobacter and Salmonella in control samples was determined using droplet digital PCR. These were then used as the controls in the multiplex qPCR on a total of 474 sheep faecal samples collected from two saleyards over a 4-month period (April-July 2014) and 96 effluent samples from an abattoir.

RESULTS

The mutiplex qPCR was specific with a sensitivity of 5 organisms/μL faecal DNA extract for Campylobacter, S. enterica and E. coli O157/O145. The overall prevalence of Campylobacter, S. enterica and E. coli O157/O145 in faecal samples was 5.7%, 3.6% and 8.4% and in effluent samples was 18.8%, 6.3% and 5.2%, respectively. The pathogen loads of Campylobacter, S. enterica and E. coli O157/O145 in faecal and effluent samples was also determined via mutiplex qPCR.

CONCLUSIONS

The overall prevalences of Campylobacter, S. enterica and E. coli O157/O145 were generally low (<6%), but point prevalences ranged considerably in healthy sheep (up to 26% for E. coli O157/O145). Further work to determine risk factors for shedding of bacterial organisms in meat sheep in the pre-slaughter period (on-farm, sale yards and lairage at abattoirs) could further reduce the risk of contamination of meat products.

Antiviral activity of shikonin ester derivative PMM-034 against enterovirus 71 in vitro

Human enterovirus 71 (EV71) is the major causative agent of hand, foot, and mouth disease (HFMD), particularly in infants and children below 4 years of age. Shikonin is a bioactive compound with anti-inflammatory, antiviral, and antibacterial activities derived from the roots of the Chinese medicinal herb Lithospermum erythrorhizon. This study aimed to examine the antiviral activity of PMM-034, a shikonin ester derivative, against EV71 in rhabdomyosarcoma (RD) cells. Cytotoxicity of PMM-034 on RD cells was determined using WST-1 assay. Dose- and time-dependent effects of PMM-034 on EV71 replication in RD cells were determined using plaque reduction assay. mRNA expression levels of EV71/VP1 and pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) were determined by real-time RT-PCR, and EV71/VP1 and phospho-p65 protein expressions were determined by western blot analysis. PMM-034 exhibited only weak cytotoxicity against RD cells. However, PMM-034 exhibited significant antiviral activity against EV71 in RD cells with 50% inhibitory concentration of 2.31 μg/mL. The VP1 mRNA and protein levels were significantly reduced in cells treated with PMM-034. Furthermore, relative mRNA expression levels of IL-1β, IL-6, IL-8, and TNF-α significantly decreased in the cells treated with PMM-034, while the phospho-p65 protein expression was also significantly lower in the treated cells. These results indicated that PMM-034 suppressed the expressions of pro-inflammatory cytokines in RD cells, exhibiting antiviral activity against EV71, as evidenced by the reduced VP1 mRNA and protein levels in PMM-034-treated cells. Thus, PMM-034 is a promising candidate for further development as an EV71 inhibitor.

Low temperature difference thermoacoustic prime mover with asymmetric multi-stage loop configuration

Environmentally friendly and low-cost technologies to recover low-grade heat source into usable energy can contribute to ease the energy shortage. Thermoacoustic technology is expected as one promising approach in this ascendant field. In this work, the multi-stage looped thermoacoustic prime movers with asymmetric configuration, which can provide travelling-wave resonator and appropriate acoustic field for efficient regenerator, have been proposed and experimentally studied. The presented looped thermoacoustic prime movers can start to oscillate with quite low temperature difference along the regenerator. The lowest onset temperature difference obtained in the experiments is only 17 °C (the corresponding heating temperature is 29 °C), which can be achieved in both three-stage and four-stage looped thermoacoustic prime movers, with CO2 of 1 MPa or 1.5 MPa as the working fluid. An electric generator driven by a three-stage looped thermoacoustic prime mover with low heating temperature was tested to achieve the acoustic to electric conversion.

[Sirt1 inhibited oxidized low-density lipoprotein induced smooth muscle cells inflammatory response]

Objective: To investigate the mechanism of inflammation of smooth muscle cells induced by oxidized low-density lipoprotein through Sirt1 in the atherosclerosis. Methods: The expression of Sirt1 had been measured in the plaque tissues of human and mice. The affection of overexpression of SIRT1 on the oxLDL induced-inflammatory response and ROS generation had been detected in this study. Results: Sirt1 decreased in smooth muscle cells region of human plaque. And in the smooth muscle cells region of mice plaque, Sirt1 was also significantly decreased about 5-fold (P<0.05). Although, oxLDL promoted inflammatory cytokines secretion and ROS generation, but this affection had been reversed by upregulating Sirt1. Conclusion: oxLDL regulated smooth muscle cells inflammatory response via Sirt1. Thus, Sirt1 is a signaling molecular regulating smooth muscles inflammatory response in the process of atherosclerosis.

Effect of 1,25(OH2D3 on the proliferation of human mesangial cells and their expression of Ki67

Previous studies have found that 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃ or VD₃] exerts many biological effects, including the inhibition of cell proliferation and induction of apoptosis, but its mechanism of action remains unclear. The goal of our investigation was to explore the effects of 1,25(OH)₂D₃ on the proliferation of cultured human mesangial cells and their expression of Ki67 in vitro, and to establish its mechanism of action. Cultured human mesangial cells were randomly divided into the following four groups: normal control (N group; administered Dulbecco's modified Eagle's medium containing 5% fetal bovine serum), proliferation [epidermal growth factor (EGF) group; administered 10 μg/L EGF], VD₃ intervention [administered 10^-8 M 1,25(OH)₂D₃], and proliferation and intervention [EGF+VD₃ group; administered 10 μg/L EGF and 10^-8 M 1,25(OH)₂D₃]. Cells were incubated for 48 h with the corresponding treatment, and fluorescence immunocytochemistry and reverse transcription-quantitative polymerase chain reaction were used to detect expression of Ki67 protein and mRNA, respectively. Compared to the N group, Ki67 levels were found to be higher in the EGF group but significantly lower in the VD₃ intervention group. Moreover, expression of Ki67 by cells in the EGF+VD₃ group was significantly lower than that of those in the EGF group. All of these differences were statistically significant (P < 0.05). In conclusion, 1,25(OH)₂D₃ inhibited Ki67 expression and the proliferation of human mesangial cells; therefore, Ki67 may be regarded as a potent therapeutic target in mesangial proliferative glomerulonephritis.

5-HT3A -driven green fluorescent protein delineates gustatory fibers innervating sour-responsive taste cells: A labeled line for sour taste?

Taste buds contain multiple cell types with each type expressing receptors and transduction components for a subset of taste qualities. The sour sensing cells, Type III cells, release serotonin (5-HT) in response to the presence of sour (acidic) tastants and this released 5-HT activates 5-HT₃ receptors on the gustatory nerves. We show here, using 5-HT_3A GFP mice, that 5-HT₃ -expressing nerve fibers preferentially contact and receive synaptic contact from Type III taste cells. Further, these 5-HT₃ -expressing nerve fibers terminate in a restricted central-lateral portion of the nucleus of the solitary tract (nTS)-the same area that shows increased c-Fos expression upon presentation of a sour tastant (30 mM citric acid). This acid stimulation also evokes c-Fos in the laterally adjacent mediodorsal spinal trigeminal nucleus (DMSp5), but this trigeminal activation is not associated with the presence of 5-HT₃ -expressing nerve fibers as it is in the nTS. Rather, the neuronal activation in the trigeminal complex likely is attributable to direct depolarization of acid-sensitive trigeminal nerve fibers, for example, polymodal nociceptors, rather than through taste buds. Taken together, these findings suggest that transmission of sour taste information involves communication between Type III taste cells and 5-HT₃ -expressing afferent nerve fibers that project to a restricted portion of the nTS consistent with a crude mapping of taste quality information in the primary gustatory nucleus.

Identification of a novel HLA-A allele, HLA-A*02:505, by sequence-based typing in a patient with tuberculosis

The novel allele HLA-A*02:505 was identified in a tuberculosis patient by human leukocyte antigen sequence-based typing.

Increased prevalence and risk of non-alcoholic fatty liver disease in overweight and obese patients with Type 2 diabetes in South China

AIMS

To investigate the prevalence of and risk factors for non-alcoholic fatty liver disease in overweight and obese patients with Type 2 diabetes mellitus.

METHODS

We recruited patients with Type 2 diabetes with a BMI ≥ 24 kg/m² , who visited the diabetes clinics of 60 hospitals in 21 cities in Guangdong Province, China from August 2011 to March 2012. Anthropometric measurements, biochemical tests and abdominal ultrasonography were performed for all the patients.

RESULTS

The study included 3861 patients (1860 men) with a mean ± sd (range) age of 58.91 ± 13.06 (18-90) years. Non-alcoholic fatty liver disease was found in 1751 patients (45.4%), with a significantly higher prevalence among men than women (48.0 vs 42.9%). The peak of non-alcoholic fatty liver disease prevalence was in patients with a BMI of 34-35 kg/m² , those with a triglyceride/HDL cholesterol ratio of 5.5-6.0, men aged < 30 years and women aged 40-50 years. Assessment using the BARD (BMI, aspartate aminotransferase/alanine aminotransferase ratio, diabetes) score system showed that the prevalence of advanced fibrosis was 80.52% in all patients and that women had a higher prevalence than men (86.52 vs 74.16%). Multiple logistic regression analyses showed that dyslipidaemia, BMI and 2-h postprandial plasma glucose were independent risk factors for non-alcoholic fatty liver disease, while heart rate and female gender were protective factors.

CONCLUSION

The prevalence of non-alcoholic fatty liver disease in overweight and obese patients with Type 2 diabetes in South China is high. Multiple metabolic disorders were significantly associated with non-alcoholic fatty liver disease in overweight and obese patients with Type 2 diabetes.

Temperature-tunable Fano resonance induced by strong coupling between Weyl fermions and phonons in TaAs

Strong coupling between discrete phonon and continuous electron–hole pair excitations can induce a pronounced asymmetry in the phonon line shape, known as the Fano resonance. This effect has been observed in various systems. Here we reveal explicit evidence for strong coupling between an infrared-active phonon and electronic transitions near the Weyl points through the observation of a Fano resonance in the Weyl semimetal TaAs. The resulting asymmetry in the phonon line shape, conspicuous at low temperatures, diminishes continuously with increasing temperature. This behaviour originates from the suppression of electronic transitions near the Weyl points due to the decreasing occupation of electronic states below the Fermi level (E_F) with increasing temperature, as well as Pauli blocking caused by thermally excited electrons above E_F. Our findings not only elucidate the mechanism governing the tunable Fano resonance but also open a route for exploring exotic physical phenomena through phonon properties in Weyl semimetals.

The study of lattice vibrations coupled to electronic excitations may provide an avenue for exploring exotic physical phenomena. Here, Xu et al. observe a Fano resonance in the Weyl semimetal TaAs, revealing evidence for a strong coupling between phonons and Weyl fermions.

A prospective study of health-related quality of life of boys with severe haemophilia A in China: comparing on-demand to prophylaxis treatment

INTRODUCTION

Treatment for boys with haemophilia in China is rapidly improving; however, comprehensive outcomes have not been examined prospectively.

AIM

The aim of this study was to evaluate the effect of short-term full-dose prophylaxis compared to on-demand treatment, on the Health-Related Quality of Life (HR-QoL) of boys with severe haemophilia A (HA) in China.

METHODS

Boys with severe HA (FVIII<1%) completed 3 months of on-demand treatment and 3 months of full-dose prophylaxis (25 FVIII IU per kg 3x per week). The primary outcomes were child- and parent-reported Canadian Hemophilia Outcomes - Kids Life Assessment Tool (CHO-KLAT) scores. The number and type of bleeds and Activities Scale for Kids (ASK) scores were also recorded.

RESULTS

Analyses included 23 boys between 4 and 15.9 years of age. The number of bleeds decreased by 94% on prophylaxis (P < 0.0001, Wilcoxon Signed-Rank test). The mean child-reported CHO-KLAT scores for boys ≥7 years (n = 20) was 61.4 (±10.9) during on-demand treatment and 61.9 (±11.4) following short-term prophylaxis (P = 0.72, paired t-test). The mean parent-reported CHO-KLAT score during the on-demand phase was 54.4 (±10.5) with an increase of 3.8 points (±8.1; P = 0.04, paired t-test) following prophylaxis.

CONCLUSIONS

Child-reported CHO-KLAT scores were lower in boys with severe HA in China than reported in countries with access to full-dose prophylaxis. Boys reported higher HR-QoL scores than their parents. Small improvements in ASK scores were noted following the prophylaxis phase. These changes were only significant in the parent-reported CHO-KLAT scores. Longer term prospective clinical trials are needed in China to determine the impact of prophylaxis on HR-QoL in boys with severe HA.

Spectrum of ATP7B mutations and genotype-phenotype correlation in large-scale Chinese patients with Wilson Disease

Wilson disease (WD), an inherited disorder associated with ATP7B gene, has a wide spectrum of genotypes and phenotypes. In this study, we developed a rapid multiplex PCR-MassArray method for detecting 110 mutant alleles of interest, and used it to examine genomic DNA from 1222 patients and 110 healthy controls. In patients not found to have any mutation in the 110 selected alleles, PCR-Sanger sequencing was used to examine the ATP7B gene. We identified 88 mutations, including 9 novel mutations. Our analyses revealed p.Arg778Leu, p.Arg919Gly and p.Thr935Met showed some correlations to phenotype. The p.Arg778Leu was related to younger onset age and lower levels of ceruloplasmin (Cp) and serum copper, while p.Arg919Gly and p.Thr935Met both indicated higher Cp levels. Besides, the p.Arg919Gly was related to neurological subtype, and p.Thr935Met showed significant difference in the percentage of combined neurological and visceral subtype. Moreover, for ATP7B mutations, the more severe impact on ATP7B protein was, the younger onset age and lower Cp level presented. The feasibility of presymptomatic DNA diagnosis and predicting clinical manifestation or severity of WD would be facilitated with identified mutations and genotype-phenotype correlation precisely revealed in the study.

Abstract P1-02-08: Provista-002: A prospective, multi-center study to determine the effectiveness of a biomarker assay to distinguish benign from invasive breast cancer in women with BI-RADS 3, 4 and 5 imaging reports

This abstract was not presented at the symposium.

Force-Induced H2S by PDLSCs Modifies Osteoclastic Activity during Tooth Movement

Hydrogen sulfide (H₂S), a gasotransmitter, has been recently linked to mesenchymal stem cell (MSC) function and bone homeostasis. Periodontal ligament stem cells (PDLSCs) are the main MSCs in PDL, which respond to mechanical force to induce physiological activities during orthodontic tooth movement (OTM). However, it is unknown whether mechanical force might induce endogenous H₂S production by PDLSCs to regulate alveolar bone homeostasis. Here, we used a mouse OTM model to demonstrate that orthodontic force-induced endogenous H₂S production in PDL tissue was associated with macrophage accumulation and osteoclastic activity in alveolar bone. Then, we showed that mechanical force application induced cystathionine β-synthase (CBS) expression and endogenous H₂S production by PDLSCs. Moreover, blocking endogenous H₂S or systemically increasing H₂S levels could decrease or enhance force-induced osteoclastic activities to control tooth movement. We further revealed how force-induced H₂S production by PDLSCs contributed to the secretion of monocyte chemoattractant protein-1 (MCP-1) and the expression of receptor activator of nuclear factor-κB ligand/osteoprotegerin (RANKL/OPG) system by PDLSCs. The secretion and expression of these factors controlled macrophage migration and osteoclast differentiation. This study demonstrated that PDLSCs produced H₂S to respond to and transduce force signals. Force-induced gasotransmitter H₂S production in PDLSCs therefore regulated osteoclastic activities in alveolar bone and controlled the OTM process through the MCP-1 secretion and RANKL/OPG system.

[Clinical effect analysis of endovascular repair for aortic pseudoaneurysms in 13 cases]

Objective: To discuss the clinical safety and efficacyof endovascular aneurysm repair (EVAR) for aortic pseudoaneurysms. Methods: From October 2008 to October 2015, 13 patients (11 male, 2 female, with a mean age of 55.6) with aortic pseudoaneurysms treated by EVAR wereenrolled. All the 13 casesunderwentcomputed tomographic arteriography (CTA). The etiology diagnosis withdescendingaortic pseudoaneurysms, infected abdominal aortic pseudoaneurysms, abdominal aortic pseudoaneurysmsin Behcet's syndrome, and uncertain reasons were 4, 4, 4, and 1 case, respectively. Results: In this group, 14 stentswere planted.All the patients hadno accidents and complications in perioperative period.Twelve patients were successfully followed up, 1 patient died of recurrent abdominal aortic pseudoaneurysmsin Behcet's syndrome, and 1 patient with recurrent infected abdominal aortic pseudoaneurysm wascured by pseudoaneurysm resection and extra-anatomic bypass grafting. Concluson: EVAR is a safe and effective option for aortic pseudoaneurysms.

Changes of platelet parameters in early severe preeclampsia

3ummary Objective: The aim of this study was to investigate the changes and clinical values of platelet parameters in different types of severe preeclampsia (SP).

MATERIALS AND METHODS

The pregnant women with SP or normal conditions were selected for the study, the platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW). and plateletcrit (PCT) were tested every four weeks, starting from 12(+1) to 16 gestational weeks, to compare the difference in platelet parameters between SP and normal pregnant women.

RESULTS

PLT, MPV, and PDW of the early onset group exhibited statistically significant differences than the normal group from 20(+1) gestational weeks, and PCT of the early onset group exhibited statistically significant differences than the normal group from 28(+1) gestational weeks (p < 0.05); PLT, MPV, and PDW of the late onset group exhibited statistically significant differences than the normal group (p < 0.05), while PCT of the late onset group exhibited no statistically significant difference than the normal group from 12(+1) gestational weeks until childbirth (p > 0.05). The comparison between the early onset group and the late onset group revealed that there existed statistically significant differences in PLT, MPV, and PDW (p < 0.05), but PCT showed no statistically significant difference throughout the pregnancy period (p < 0.05).

CONCLUSIONS

The changes of platelet parameters in early onset SP patients were earlier than the late onset group, and the difference was statistically significant (p < 0.05). Measuring the platelet parameters could better reveal early-stage SP, thus guiding more personalized clinical treatments to better protect maternal and child safety.

Colloidal synthesis and magnetic properties of anisotropic-shaped spinel CuCr2Se4 nanocrystals

Anisotropic-shaped CuCr₂Se₄ nanocrystals have been synthesized by thermal decomposition and reaction of novel mixed metal–oleate complexes with selenium in a high-boiling point organic solvent, trioctylamine.

H.E.S.S. Limits on Linelike Dark Matter Signatures in the 100 GeV to 2 TeV Energy Range Close to the Galactic Center

A search for dark matter linelike signals iss performed in the vicinity of the Galactic Center by the H.E.S.S. experiment on observational data taken in 2014. An unbinned likelihood analysis iss developed to improve the sensitivity to linelike signals. The upgraded analysis along with newer data extend the energy coverage of the previous measurement down to 100 GeV. The 18 h of data collected with the H.E.S.S. array allow one to rule out at 95% C.L. the presence of a 130 GeV line (at l=-1.5°, b=0° and for a dark matter profile centered at this location) previously reported in Fermi-LAT data. This new analysis overlaps significantly in energy with previous Fermi-LAT and H.E.S.S.

RESULTS

No significant excess associated with dark matter annihilations was found in the energy range of 100 GeV to 2 TeV and upper limits on the gamma-ray flux and the velocity weighted annihilation cross section are derived adopting an Einasto dark matter halo profile. Expected limits for present and future large statistics H.E.S.S. observations are also given.

Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with H.E.S.S

The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using γ-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant γ-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section ⟨σv⟩. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach ⟨σv⟩ values of 6×10^{-26}  cm^{3} s^{-1} in the W^{+}W^{-} channel for a DM particle mass of 1.5 TeV, and 2×10^{-26}  cm^{3} s^{-1} in the τ^{+}τ^{-} channel for a 1 TeV mass. For the first time, ground-based γ-ray observations have reached sufficient sensitivity to probe ⟨σv⟩ values expected from the thermal relic density for TeV DM particles.

PDL Progenitor–Mediated PDL Recovery Contributes to Orthodontic Relapse

Periodontal ligament (PDL) is subjected to mechanical force during physiologic activities. PDL stem/progenitor cells are the main mesenchymal stem cells in PDL. However, how PDL progenitors participate in PDL homeostasis upon and after mechanical force is largely unknown. In this study, force-triggered orthodontic tooth movement and the following relapse were used as models to demonstrate the response of PDL progenitors and their role in PDL remodeling upon and after mechanical force. Upon orthodontic force, PDL collagen on the compression side significantly degraded, showing a broken and disorganized pattern. After force withdrawal, the degraded PDL collagen recovered during the early stage of relapse. Correspondingly, increased CD90+ PDL progenitors with suppressed expression of type I collagen (Col-I) were observed upon orthodontic force, whereas these cells accumulated at the degradation regions and regained Col-I expression after force withdrawal during early relapse. Our results further showed that compressive force altered cell morphology and repressed collagen expression in cultured PDL progenitors, which both recovered after force withdrawal. Force withdrawal–induced recovery of collagen expression in cultured PDL progenitors could be regulated by transforming growth factor–β (TGF-β), a key molecule for tissue homeostasis and extracellular matrix remodeling. More interesting, inhibiting the regained Col-I expression in CD90+ PDL progenitors by blocking TGF-β interrupted PDL collagen recovery and partially inhibited the early relapse. These data suggest that PDL progenitors can respond to mechanical force and may process intrinsic stability to recover to original status after force withdrawal. PDL progenitors with intrinsic stability are required for PDL recovery and consequently contribute to early orthodontic relapse, which can be regulated by TGF-β signaling.

Hydrogen Sulfide Regulates Homeostasis of Mesenchymal Stem Cells and Regulatory T Cells

Hydrogen sulfide (H₂S) has long been known as a toxic gas. However, recently accumulated evidence suggests that H₂S contributes to a variety of physiologic and pathologic processes. Endogenous H₂S production is regulated by multiple enzymes that are differentially expressed in the cardiovascular, neuronal, immune, renal, respiratory, gastrointestinal, reproductive, liver, and endocrine systems. Alteration of H₂S metabolism may affect multiple signaling pathways and tissue homeostasis. The growing number of diverse targets for which H₂S serves as a gasotransmitter has been extensively reviewed elsewhere. In this review, the authors discuss current emerging evidence that H₂S regulates mesenchymal stem cell and T-cell functions.

Prepubertal exposure to T-2 toxin advances pubertal onset and development in female rats via promoting the onset of hypothalamic–pituitary–gonadal axis function

T-2 toxin, a naturally produced Type A trichothecene mycotoxin, has been shown to damage the reproductive and developmental functions in livestocks. However, whether T-2 toxin can disturb the pubertal onset and development following prepubertal exposure remains unclear. To clarify this point, infantile female Sprague–Dawley rats were given a daily intragastric administration of vehicle or T-2 toxin at a dose of 375 μg/kg body weight for 5 consecutive days from postnatal day (PND) 15–19 (PND15–PND19). The days of vaginal opening, first diestrus, and first estrus in regular estrous cycle were advanced following T-2 toxin treatment, indicating prepubertal exposure to T-2 toxin induced the advancement of puberty onset. The relative weights of uterus and ovaries and the incidence of corpora lutea were all increased in T-2 toxin-treated rats; serum hormone levels of luteinizing hormone and estradiol and the messenger RNA expressions of gonadotropin-releasing hormone (GnRH) and GnRH receptor also displayed marked increases following exposure to T-2 toxin, all of which were well consistent with the manifestations of the advanced puberty onset. In conclusion, the present study reveals that prepubertal exposure to a high level of T-2 toxin promotes puberty onset in infantile female rats by advancing the initiation of hypothalamic–pituitary–gonadal axis function in female rats.

Sedimentary records of polycyclic aromatic hydrocarbons (PAHs) in remote lakes across the Tibetan Plateau

Sediment cores from five lakes across the Tibetan Plateau were used as natural archives to study the time trends of polycyclic aromatic hydrocarbons (PAHs). The depositional flux of PAHs generally showed an increasing trend from the deeper layers towards the upper layer sediments. The fluxes of PAHs were low with little variability before the 1950s, and then gradually increased to the late 1980s, with a faster increasing rate after the 1990s. This temporal pattern is clearly different compared with those remote lakes across the European mountains when PAHs started to decrease during the period 1960s-1980s. The difference of the temporal trend was attributed to differences in the economic development stages and energy structure between these regions. PAHs are dominated by the lighter 2&3-ring homologues with the averaged percentage over 87%, while it is notable that the percentage of heavier 4-6 ring PAHs generally increased in recent years, which suggests the contribution of local high-temperature combustion sources becoming more predominant.

Identification of mutations in the F8 and F9 gene in families with haemophilia using targeted high-throughput sequencing

INTRODUCTION

At present, many methods are available for the genetic diagnosis of haemophilia, including indirect linkage analysis, direct sequencing. However, these methods are time-consuming, labourious, and limited in their application. Therefore, the development of new, more effective techniques is necessary.

AIM

To detect the F8 and F9 gene mutations in patients with haemophilia and their female relatives in 29 haemophilia A (HA) and 11 haemophilia B (HB) families.

METHODS

FVIII

C and FIX:C were analyzed using one-stage method, and factor VIII and factor IX inhibitors were tested using the Bethesda method. Intron 22 and one inversions were identified using long-distance polymerase chain reaction (PCR) and standard PCR. Non-inversion mutations of the F8 and F9 gene were identified by targeted high-throughput sequencing. All mutations were verified by Sanger sequencing.

RESULTS

Intron 22 inversion was detected in eight HA families and intron one inversion was detected in one HA family. Apart from the inversion mutations, 20 mutations were identified in HA families, including 17 previously reported and three novel mutations: c.5724G>A (p.Trp1908*), c.6116-1_6120delGAGTGTinsTCC (p.Lys2039Ilefs*13), and c.5220-2A>C. We found a complex rearrangement in HA: intron one inversion concomitant with exon one deletion. In HB, eight recurrent mutations were detected, including six missense mutations and two nonsense mutations.

CONCLUSION

Targeted high-throughput sequencing is an effective technique to detect the F8 and F9 gene mutations, especially for the discovery of novel mutations. The method is highly accurate, time-saving and shows great advantage in uncovering large deletion mutations and also in distinguishing the wild-type genotype and heterozygous large deletions.

Molecular analysis of MLH1 variants in Chinese sporadic colorectal cancer patients

Single nucleotide polymorphisms (SNPs) in mismatch repair genes, especially in the MLH1 gene, are closely associated with susceptibility to hereditary nonpolyposis colorectal cancer. However, few relevant findings are available regarding the association between sporadic colorectal cancer (SCRC) and SNPs of MLH1 in Chinese patients. Therefore, the present study aimed to describe the pathogenic association between three important MLH1 polymorphisms and SCRC in the Chinese population. Peripheral blood samples from 156 SCRC patients and 311 healthy controls were collected. DNA was purified from peripheral blood, and the V384D, R217C, and I219V polymorphisms were evaluated using high-resolution melting analysis and direct sequencing. The association between the three important MLH1 polymorphisms and clinical pathological features of the SCRC patients was analyzed. In addition, PMS2-MLH1 protein interactions were determined by co-immunoprecipitation (Co-IP) to determine the protein functional alteration induced by these SNPs. Among the three polymorphisms, V384D was significantly associated with the risk of SCRC (OR = 31.36, P < 0.0001). The allele frequencies were 4.81 and 0.16% in the SCRC group. No association was found between SCRC and R217C, or between SCRC and I219V. Moreover, the allele frequency of R217C was significantly higher in the SCRC patients younger than 60 years than in those older than 60 years. Co-IP showed that the MLH1 R217C, V384D, and I219V variants had relative binding abilities with PMS2 of 0.59, 0.70, and 0.80, respectively, compared with the wild-type. These findings suggest that MLH1 V384D could be a promising genetic marker for susceptibility to SCRC.