Effect of inflammatory factor‐induced cyclo‐oxygenase expression on the development of reperfusion‐related no‐reflow phenomenon in acute myocardial infarction

No reflow after reperfusion therapy for myocardial infarction is a strong predictor of clinical outcome. Increased levels of inflammatory factors, including C‐reactive protein (CRP), in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI) may affect myocardial perfusion. However, why the no‐reflow phenomenon increases in inflammation stress after PCI is not clear. The aim of the present study was to determine the effects and molecular mechanisms underlying the effects of CRP on the expression of cyclo‐oxygenase (COX) on the development of the no‐reflow phenomenon. There was a significant increase in plasma levels of CRP and interleukin (IL)‐6 in no‐reflow patients, suggesting that inflammatory factors play an important role in the development of the no‐reflow phenomenon. The mechanisms involved were further evaluated after reperfusion in a rat model mimicking the no‐reflow phenomenon. Compared with normal reflow rats, there were significant increases in both COX‐1 and COX‐2 in cardiac tissue from no‐reflow rats. The COX inhibitor indomethacin (5 mg/kg, i.p.) significantly reduced the no‐reflow area. In another series of experiments, human coronary artery endothelial cells (HCAEC) were treated with CRP at clinically relevant concentrations (5–25 μg/mL). C‐Reactive protein significantly increased COX‐1 and COX‐2 levels in a time‐ and concentration‐dependent manner. In addition, extracellular signal‐regulated kinase (ERK) and Jun N‐terminal kinase (JNK) were activated in CRP (5, 10, 25 μg/mL)‐treated HCAEC cultures. Furthermore, the ERK inhibitor pd98059 (30 μmol/L) and the JNK inhibitor sp600125 (10 μmol/L) blocked CRP‐induced COX‐1 and COX‐2 expression for 12 h. Together, the findings of the present study suggest that CRP can promote the development of the no‐reflow phenomenon by increasing COX‐1 and COX‐2 expression, which is regulated, in part, via ERK and JNK activity.     

Higher intake of carotenoid is associated with a lower risk of colorectal cancer in Chinese adults: a case–control study

Purpose

The associations between specific carotenoid intake and colorectal cancer risk remain inconsistent. The aim of this study was to examine the association between specific dietary carotenoid intake with colorectal cancer risk in Chinese adults.

Method

From July 2010 to October 2013, 845 eligible colorectal cancer cases and 845 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate logistical regression models were used to calculate the odds ratio (OR) and 95 % confidence intervals (95 % CIs) of colorectal cancer risk after adjusting for various confounders.

Results

A strong inverse association was found between β-cryptoxanthin intake and colorectal cancer risk. Compared with the lowest quartile, the highest quartile intake showed a risk reduction of 77 % (OR 0.23, 95 % CI 0.17–0.33, P _trend < 0.01) after adjustment for various confounding variables. The inverse associations were also observed for α-carotene (OR 0.50, 95 % CI 0.37–0.68, P _trend < 0.01), β-carotene (OR 0.67, 95 % CI 0.49–0.91, P _trend < 0.01), and lycopene (OR 0.51, 95 % CI 0.37–0.70, P _trend < 0.01). There was no statistically significant association between lutein/zeaxanthin intake and colorectal cancer risk. These findings were consistent across cancer site, sources of controls, and smoking status. The inverse associations between dietary α-carotene, β-cryptoxanthin, and lycopene intake and colorectal cancer risk were found in both males and females, while inverse associations between β-carotene intake and colorectal cancer risk were only observed in males.

Conclusions

Consumption of α-carotene, β-carotene, β-cryptoxanthin, and lycopene was inversely associated with colorectal cancer risk. No significant association was found between lutein/zeaxanthin intake and colorectal cancer risk.

     

Photoluminescence mechanism and applications of Zn-doped carbon dots

Heteroatom-doped carbon dots (CDs) with excellent optical characteristics and negligible toxicity have emerged in many applications including bioimaging, biosensing, photocatalysis, and photothermal therapy. The metal-doping of CDs using various heteroatoms results in an enhancement of the photophysics but also imparts them with multifunctionality. However, unlike nonmetal doping, typical metal doping results in low fluorescence quantum yields (QYs), and an unclear photoluminescence mechanism. In this contribution, we detail results concerning zinc doped CDs (Zn-CDs) with QYs of up to 35%. The zinc ion charges serve as a surface passivating agent and prevent the aggregation of graphene π–π stacking, leading to an increase in the QY of the Zn-CDs. Structural and chemical investigations using spectroscopic and first principle simulations further revealed the effects of zinc doping on the CDs. The robust Zn-CDs were used for the ultra-trace detection of Hg²⁺ with a detection limit of 0.1 μM, and a quench mechanism was proposed. The unique optical properties of the Zn-CDs have promise for use in applications such as in vivo sensing and future phototherapy applications.

Zinc ions, acting as a surface passivating agent, prevented the aggregation of graphene π–π stacking and increased the quantum yield of Zn-carbon dots.     

Reduction responsive and surface charge switchable polyurethane micelles with acid cleavable crosslinks for intracellular drug delivery

Previously we synthesized redox sensitive polyurethane micelles, core crosslinked by diisocyanates (PU-CCL). To improve the intracellular drug release and tumor cellular toxicity of anticancer drugs loaded into polyurethane micelles, we now describe redox sensitive polyurethane micelles with tunable surface charge switchabilities, crosslinked with pH cleavable Schiff bonds, as anticancer drug carriers. Different amounts of 1,6-diaminohexane were connected onto the pendant carboxyl groups of amphiphilic multi-blocked polyurethane (PU-SS-COOH), resulting in polyurethanes with various ratios of pendant carboxyl and amine groups (denoted as PU-SS-COOH-NH₂-1, PU-SS-COOH-NH₂-2 and PU-SS-COOH-NH₂-3). The surface charge switched as the pH was increased for PU-SS-COOH-NH₂-1, PU-SS-COOH-NH₂-2 and PU-SS-COOH-NH₂-3. Then the PU-SS-COOH-NH₂-3 micelles, dissolved in water, were crosslinked by glutaraldehyde resulting in surface charge switchable and reduction responsive polyurethane micelles with acid cleavable crosslinks (PU-ACCL). The crosslinked polyurethane micelles (PU-ACCL) demonstrated superior particle stability in phosphate buffered saline (PBS, pH = 7.4) solution without reducing agents, whereas the drug release rate was markedly accelerated by the addition of glutathione (GSH). Notably, the drug release from PU-ACCL was further accelerated in acidic fluid as the result of acid induced cleavage of the crosslinks. In vitro cytotoxicity studies demonstrated that doxorubicin (DOX)-loaded PU-ACCL micelles displayed increased cytotoxicity against tumor cells which was comparable to that obtained for DOX loaded into uncrosslinked polyurethane micelles. The reduction responsive and surface charge switchable polyurethane micelles with acid cleavable crosslinks, which have superior extracellular stability and provide rapid intracellular drug release, may hold great potential as a bio-triggered drug delivery system for cancer therapy.

Previously we synthesized redox sensitive polyurethane micelles, core crosslinked by diisocyanates (PU-CCL).     

Synthesis of MoS2 nanosheets for mercury speciation analysis by HPLC-UV-HG-AFS

Mercury species have aroused wide concern in the past several decades due to their high toxicity. However, it is still difficult to detect ultra-trace mercury species due to their biochemical transformation in complex samples. To establish a simpler and more sensitive method for pre-concentration and determination of trace mercury species, molybdenum disulfide (MoS₂) nanosheets with sulfur-rich characteristics and enlarged interlayer spacing were prepared by a hydrothermal method coupled with a sonication-assisted liquid exfoliation method and acted as solid-phase extraction adsorbent. The nano-MoS₂ had high adsorption capacity, fast adsorption rate and excellent selectivity towards mercury ions (Hg²⁺), methyl mercury (MeHg⁺) and ethyl mercury (EtHg⁺) in a wide pH range and complex matrices. And it could be easily regenerated by 4 mol L⁻¹ HCl and reused several times. After optimizing HPLC-UV-HG-AFS conditions, a great linearity (1.0–10.0 μg L⁻¹, R² = 0.999 for Hg²⁺, MeHg⁺ and EtHg⁺), lower detection limits (0.017, 0.037 and 0.021 ng mL⁻¹ for Hg²⁺, MeHg⁺ and EtHg⁺, respectively), relative standard deviations (<5%) and addition recoveries of the samples within 82.75–113.38% were observed. In summary, trace inorganic and organic mercury species in environmental and biological samples could be selectively enriched by the prepared nano-MoS₂ and efficiently seperated and detected by HPLC-UV-HG-AFS. The present study will help provide a better strategy for environmental monitoring and health assessment of mercury pollutants.

As-synthesized few-layered molybdenum disulfide nanosheets were used as solid-phase extraction absorbent for ultra-trace mercury speciation analysis by HPLC-UV-HG-AFS.     

Novel SrTiO3/NaTaO3 and visible-light-driven SrTiO3/NaTaO3:N nano-heterojunctions with high interface-lattice matching for efficient photocatalytic removal of organic dye

SrTiO₃/NaTaO₃ (STO/NTO) heterojunction photocatalysts were successfully constructed by decorating NaTaO₃ nanocubes with SrTiO₃ nanoparticles via a hydrothermal method. The structure of the perovskites NaTaO₃ and SrTiO₃ bear some resemblance to each other, which increases the interface lattice match for promoting the migration of photogenerated carriers between the STO/NTO interfaces. In comparison to pristine NaTaO₃ and SrTiO₃ samples, the STO/NTO composites exhibited remarkably improved capacity for the degradation of rhodamine B (RhB) under ultraviolet (UV) light (λ < 400 nm) irradiation. Furthermore, the partial replacement of O²⁻ by N³⁻ in the TaO ₆ octahedron narrowed the band gap of NaTaO₃, which significantly enhanced the photocatalytic performance of the SrTiO₃/NaTaO₃:N (STO/NTON) heterojunction under visible light (λ > 400 nm). Finally, the possible band structures of the STO/NTO and STO/NTON photocatalysts were proposed, which indicated that an n–n type heterojunction was constructed with a staggered gap for fast separation of photogenerated electron–hole pairs.

Novel SrTiO₃/NaTaO₃ and visible-light-driven SrTiO₃/NaTaO₃:N nano-heterojunctions with high interface–lattice match were synthesized for efficient photocatalytic removal of organic dye.     

超声检查和MRI在产前诊断胎儿Dandy-Walker变异型中的对比研究

目的回顾性分析胎儿头颅超声检查(US)和MRI在产前诊断胎儿Dandy-Walker变异型(DWV)中的应用价值。方法选择2011年1月至2013年9月在四川大学华西第二医院经胎儿头颅US疑诊为胎儿DWV的11例胎儿为研究对象,并同时对其进行头颅MRI检查。对疑诊为胎儿DWV者随访至引产后或生后1年,以引产后胎儿的尸检结果或随访1年后对患儿再次进行头颅MRI检查结果及其临床表现作为诊断DWV的金标准,并统计学比较胎儿头颅US及MRI产前诊断该病的正确率。本研究遵循的程序符合四川大学华西第二医院人体试验委员会制定的伦理学标准,得到该委员会批准,征得受试对象监护人知情同意,并与之签署临床研究知情同意书。结果经头颅US疑诊为胎儿DWV的11例胎儿,同时进行头颅MRI检查结果为:正常胎儿为6例,诊断为胎儿DWV为5例。根据胎儿DWV诊断的金标准,胎儿头颅MRI对胎儿DWV的产前诊断正确率显著高于头颅US,且差异有统计学意义(100.0%vs45.4%,P=0.012)。结论胎儿头颅US是产前诊断胎儿中枢神经系统疾病的首选方法。对US疑诊为胎儿DWV者进一步采取头颅MRI检查确诊,是临床诊断胎儿DWV的必要补充。     

睾丸精原细胞瘤临床病理学特点分析

目的探讨睾丸精原细胞瘤的临床病理特征。方法对6例睾丸精原细胞瘤的临床表现和组织学形态进行分析。结果 6例睾丸精原细胞瘤患者年龄25~42岁,巨检显示肿瘤呈卵圆形,最大径15cm,包膜完整,切面为灰白色;镜下均为典型精原细胞瘤的临床病理学特征;免疫组化检测显示人胎盘碱性磷酸酶(PLAP)及CD117表达阳性,1例灶性表达甲胎蛋白(AFP),1例灶性表达CD30,人绒毛膜促性腺激素(HCG),CKpan,扁豆凝集素(LCA)和Vimentin均为表达阴性。结论睾丸精原细胞瘤好发于中年男性,隐睾是高危因素,诊断主要依据典型的病理组织学特点及免疫组化检测结果。