迟发性维生素K缺乏性颅内出血患儿血浆心钠素与低钠血症的关系

目的探讨迟发性维生素K缺乏性颅内出血患儿心钠素(ANP)水平变化与低钠血症的关系及其临床意义。方法应用放射免疫分析技术检测108例颅内出血患儿不同病程的血浆ANP水平,同时检测血清钠的含量,选取25例健康同龄儿作为对照。结果(1)颅内出血急性期血浆ANP水平均高于对照组(P<0·05);昏迷组患儿ANP升高更明显(P<0·01);(2)颅内出血患儿血浆ANP与血清钠水平呈负相关(γ=-0·748,P<0·05)。结论(1)迟发性维生素K缺乏性颅内出血患儿血浆ANP水平反映脑损伤严重程度;(2)ANP参与迟发性维生素K缺乏性颅内出血患儿低钠血症的形成过程。     

改进探针标记法斑点杂交在轮状病毒VP7分型中的应用

目的建立一种更加简便的A组人轮状病毒（HRV）核酸斑点杂交VP7分型方法,以便用于对HRV流行情况进行调查。方法在HRV VP7编码基因各G基因型间高度变异而型内高度保守区域设计分型探针,在该区域的两侧相对保守区域设计一对通用引物,利用PCR分别将地高辛标记HRV 5种常见型别（G1～4,G9型）的DNA探针,建立基于VP7的斑点杂交方法;选取经抗原检测和聚丙烯酰胺凝胶电泳（PAGE）检测均为HRV阳性的2006至2008年住院腹泻患儿粪便标本200份,RT-PCR扩增VP7全基因,并对扩增阳性产物应用斑点杂交方法进行G型别分析。结果建立的斑点杂交方法在5种型别探针间无交叉反应,各型探针的检测灵敏度可达到10 pg。200份PAGE阳性标本中162份RT-RCR扩增VP7基因阳性,斑点杂交显示G1型41例(25.3%),G2型2例(1.2%),G3型63例(38.9 %),G9型35例(21.6%),混合感染19例（11.7%）,杂交未分出型2例(1.2%),未检测到G4型HRV。结论本研究所建立的斑点杂交方法敏感度和特异度强,适合在HRV大规模分子流行病学调查时应用。通过该方法的初步应用,发现北京地区婴幼儿HRV除了常见的G1、G2和G3型外,还有G9型感染。     

CD437诱导HepG2细胞凋亡及机制的初步研究

目的 探讨CD437对HepG2细胞凋亡诱导作用及其对线粒体膜电位变化的影响.方法 ①MTT比色法观察CD437对HepG2细胞增殖的影响,倒置显微镜下观察细胞生长情况.An-nexin V-FITC/PI标记后,流式细胞术检测细胞凋亡.②罗丹明123(Rhodamine123,Rh123)荧光探针染色后,荧光显微镜下观察活细胞线粒体改变,并经流式细胞仪分析线粒体膜电位变化.结果 ①1 μmol/L CD437干预HepG2细胞24h后,实验组细胞早期凋亡率(18.26±5.31)%高于对照组(P<0.05),实验组细胞继发死亡率(20.31±3.70)%也高于对照组(P<0.05),CD437可导致细胞早期凋亡.②流式细胞仪结果表明CD437诱导HepG2细胞24 h后,实验组荧光强度为4.40±0.09,较对照组荧光强度5.34±0.12变弱(n=12,P<0.05),实验组整个峰向左移动,HepG2细胞线粒体膜电位水平下降.荧光倒置显微镜下观察发现,对照组罗丹明123荧光强度很强,大量细胞发出强烈荧光,实验组HepG2细胞内罗丹明123荧光强度很弱,很少见到强荧光细胞.结论 CD437可能通过降低线粒体膜电位水平而抑制HepG2细胞增殖并且诱导其凋亡.     

Assessing exposure risks for freshwater tilapia species posed by mercury and methylmercury

Waterborne and dietborne exposures of freshwater fish to mercury (Hg) in the forms of inorganic (Hg(II)) and organic (methylmercury or MeHg) affect their growth, development, and reproduction. However, an integrated mechanistic risk model framework to predict the impact of Hg(II)/MeHg on freshwater fish is lacking. Here, we integrated biokinetic, physiological and biogeographic data to calibrate and then establish key risk indices—hazardous quotient and exceedance risk—for freshwater tilapia species across geographic ranges of several major rivers in Taiwan. We found that Hg(II) burden was highest in kidney followed by gill, intestine, liver, blood, and muscle. Our results showed that Hg was less likely to pose mortality risk (mortality rate less than 5 %) for freshwater tilapia species. However, Hg is likely to pose the potential hazard to aquatic environments constrained by safety levels for aquatic organisms. Sensitivity analysis showed that amount of Hg accumulated in tilapia was most influenced by sediment uptake rate. Our approach opens up new possibilities for predicting future fish population health with the impacts of continued Hg exposure to provide information on which fish are deemed safe for human consumption.     

微生物酶催化腈类化合物的研究进展

目的对腈水解酶的研究进展进行综述。方法参考国内外20余篇文献,介绍腈水解酶具有的优良特点、经济价值以及现阶段存在的问题。结果腈水解酶作为生物催化剂水解腈类化合物,具有高效性、高选择性、反应条件温和、环境污染小、成本低等优点。但也存在活性低、稳定性差等缺点。结论利用腈水解酶催化氰类化合物水解具有良好的应用前景和巨大的经济价值。     

Anti-inflammatory,analgesic and antioxidant activities of 3,4-oxo-isopropylidene-shikimic acid

Context 3,4-Oxo-isopropylidene-shikimic acid (ISA) is an analog of shikimic acid (SA). SA is extracted from the dry fruit of Illicium verum Hook. f. (Magnoliaceae), which has been used for treating stomachaches, skin inflammation and rheumatic pain.

Objective To investigate the anti-inflammatory, analgesic and antioxidant activities of ISA.

Materials and methods Analgesic and anti-inflammatory activities of ISA were evaluated using writhing, hot plate, xylene-induced ear oedema, carrageenan-induced paw oedema and cotton pellets-induced granuloma test, meanwhile the prostaglandin E₂ (PGE₂) and malondialdehyde (MDA) levels were assessed in the oedema paw tissue. ISA (60, 120 and 240?mg/kg in mice model and 50, 120 and 200?mg/kg in rat model) was administered orally, 30?min before induction of inflammation/pain. Additionally, ISA was administered for 12 d in rats from the day of cotton pellet implantation. The active oxygen species scavenging potencies of ISA (10^?3–10^?5 M) were evaluated by the electron spin resonance spin-trapping technique.

Results ISA caused a reduction of inflammation induced by xylene (18.1–31.4%), carrageenan (7.8–51.0%) and cotton pellets (11.4–24.0%). Furthermore, ISA decreased the production of PGE₂ and MDA in the rat paw tissue by 1.0–15.6% and 6.3–27.6%, respectively. ISA also reduced pain induced by acetic acid (15.6–48.9%) and hot plate (10.5–28.5%). Finally, ISA exhibited moderate antioxidant activity by scavenging the superoxide radical and hydroxyl radical with IC₅₀ values of 0.214 and 0.450?μg/mL, respectively.

Discussion and conclusion Our findings confirmed the anti-inflammatory, analgesic and antioxidant activities of ISA.     

Natural and synthetic flavonoid modulation of TRPC5 channels

Background and Purpose

The TRPC5 proteins assemble to create calcium‐permeable, non‐selective, cationic channels. We sought novel modulators of these channels through studies of natural products.

Experimental Approach

Intracellular calcium measurements and patch clamp recordings were made from cell lines. Compounds were generated by synthetic chemistry.

Key Results

Through a screen of natural products used in traditional Chinese medicines, the flavonol galangin was identified as an inhibitor of lanthanide‐evoked calcium entry in TRPC5 overexpressing HEK 293 cells (IC₅₀ 0.45 μM). Galangin also inhibited lanthanide‐evoked TRPC5‐mediated current in whole‐cell and outside‐out patch recordings. In differentiated 3T3‐L1 cells, it inhibited constitutive and lanthanide‐evoked calcium entry through endogenous TRPC5‐containing channels. The related natural flavonols, kaempferol and quercetin were less potent inhibitors of TRPC5. Myricetin and luteolin lacked effect, and apigenin was a stimulator. Based on structure–activity relationship studies with natural and synthetic flavonols, we designed 3,5,7‐trihydroxy‐2‐(2‐bromophenyl)‐4H‐chromen‐4‐one (AM12), which inhibited lanthanide‐evoked TRPC5 activity with an IC₅₀ of 0.28 μM. AM12 also inhibited TRPC5 activity evoked by the agonist (−)‐Englerin A and was effective in excised outside‐out membrane patches, suggesting a relatively direct effect. It inhibited TRPC4 channels similarly, but its inhibitory effect on TRPC1–TRPC5 heteromeric channels was weaker.

Conclusions and Implications

The data suggest that galangin (a natural product from the ginger family) is a TRPC5 inhibitor and that other natural and synthetic flavonoids contain antagonist or agonist capabilities at TRPC5 and closely related channels depending on the substitution patterns of both the chromone core and the phenyl ring.

Abbreviations

LPC

lysophosphatidylcholine

S1P

sphingosine 1‐phosphate

     

Identification and expression profile of a new cytochrome P450 isoform (CYP414A1) in the hepatopancreas of Venerupis (Ruditapes) philippinarum exposed to benzo[a]pyrene, cadmium and copper

With the objective to identify promising molecular biomarkers for marine pollution monitoring, a new cytochrome P450 gene was identified from Venerupis (Ruditapes) philippinarum and classified as a member of a new subfamily, CYP414A1. Phylogenetic analysis showed that CYP414A1 was closely related to members of the CYP2 family. CYP414A1 mRNA expression was significantly induced by 50 μg/L B[a]P at 96 h, while no significant change was found in 5 μg/L B[a]P-exposed samples. For heavy metals exposure, the expression of CYP414A1 was significantly up-regulated by Cd but sharply depressed by Cu exposure. These results suggested that CYP414A1 responded to various xenobiotics stresses, and could be used as a candidate biomarker of heavy metals and B[a]P.     

Neighbourhood matters: perceptions of neighbourhood cohesiveness and associations with alcohol, cannabis and tobacco use

Introduction and Aims. To examine relationships between perceived neighbourhood cohesion and alcohol, tobacco and cannabis consumption in New Zealand. Design and Methods. A two‐level random intercept regression model was used to examine the extent to which perception of neighbourhood cohesion (at the individual and area level) was associated with the frequency of substance (alcohol, tobacco and cannabis) consumption, after controlling for demographics and deprivation. This study is based on data from two national Health Behaviours Surveys (Drugs and Alcohol) conducted in 2003 and 2004 in New Zealand. Data were collected by computer‐assisted telephone interviewing with two complementary computer‐assisted cellphone interviewing samples. The combined sample consists of 6346 men and 8411 women (n = 14 757) distributed across 1572 census area units. Results. Perception of neighbourhood cohesion was significantly associated with the level of alcohol, tobacco and cannabis consumption. Individuals who perceived their neighbourhood as more cohesive had higher annual frequency of alcohol consumption but lower consumption on a typical drinking occasion. Higher perceived neighbourhood cohesion was also associated with a decrease in the probability of tobacco and cannabis use and of the amounts consumed. Area‐level analysis suggested that aggregate census area unit‐level neighbourhood cohesion exerted a significant additional contextual effect on the frequency of tobacco and cannabis consumption over and above individual perceptions of neighbourhood cohesiveness. Discussion and Conclusions. This study provides empirical evidence that perceptions of the neighbourhood social environment are associated with people's substance consumption patterns. Increasing residents' sense of neighbourhood cohesion might prove a promising way to decrease health‐damaging consumption behaviours. [Lin E‐Y, Witten K, Casswell S, You RQ. Neighbourhood matters: Perceptions of neighbourhood cohesiveness and associations with alcohol, cannabis and tobacco use. Drug Alcohol Rev 2012;31:402–412]