吸烟与癌

草烟里含有许多毒素,长期大量吸烟不仅会引起气管炎、肺气肿、高血压、心脏病,冠心病以及胃、五官、神经系统疾病,而且还能引起肺癌及唇癌、舌癌、口腔癌、支气管癌等。有人统计了二十多个国家的资料说,肺癌主要是因吸烟引起的,百分之八十的肺癌患者有吸烟历史。吸烟人的肺癌死亡率比不吸烟人多十一倍,四十五岁以上的肺癌患者中,每天吸烟二十五支以上的比不吸烟者多五十倍。英国肺癌死亡率是世界上最高的,目前一千八百     

纸浆和造纸工人中吸烟对肺癌与冠心病的影响评价

吸烟可能引起肺癌或心脏病,是当前环境卫生和劳动保护界中一个争论而混淆不清的难题。芬兰劳保卫生研究中心为此对3520名纸浆和造纸工人,进行了关于吸烟与肺癌和冠心病的影响评价研究。首先,对1981年这些工人中烟瘾大的和中等程度的、两级人数的比例做了评估;然后设计计算出不同岗位的工人吸烟指数,从而估算了该年份不同吸烟程度的工人中,肺癌和冠心病死亡率的比     

吸烟对健康的影响

香烟烟雾中有上千种不同的化合物,其中包括焦油、多环烃,CO和NO_2。这些化合物都影响健康,已推导了致癌的相关性。据统计,吸烟者占肺癌死亡率的85％,慢性阻碍性肺病死亡率的70％,冠心病死亡率的30％,全部死亡率的15％。最近,研究了被动吸烟对健康的影响。被动吸烟者有吸入较小颗粒物和更多NO_2的趋势。这与肺癌和肺功能损害有关,但与心血管病无关。     

被动吸烟与肺功能

有关儿童和成人在家庭中或在工作场所被动吸入香烟烟雾而导致肺功能变化的研究并不多,且结果也不很一致。Tager 等1979年报告了在美国马萨诸塞州波士顿东区对444名5～9岁儿童的研究结果,发现不吸烟儿童最大呼气中段流量(MMEF)指数和父母吸烟人数的多少呈负相关,父母中吸烟人数多,则肺功能差。父母中一人或二人都吸烟的儿童MMEF指数值比父母双亲都不吸烟的儿童分別低0.156和0.355个标准差单位。如果儿童自己也吸烟,则有明显的相加作用。Weize 等在同一地区调查了650名5～9岁儿童,也有类似的发现,父母双亲都不吸烟的儿童比父母双亲都吸烟的儿童MMEF指数大0.522个标准差单位。家     

吸烟与人体健康

在某种意义上说,吸烟也属于大气污染的一部分,吸烟和大气污染一样,给人体健康带来极其严重的危害,因而越来越多地引起人们的关注。我国吸烟的人也较普遍,现在不仅成年男子中吸烟现象普通,妇女吸烟者也较多,而且青少年中也有不少人沾染上了吸烟的恶习。由于吸烟能加速衰老,缩短寿命,还能导致癌症 (特别是肺癌)发病率与死亡率的增加,甚至影响到子孙后代的健康,因而已成为大家日益关心的课题。一、吸烟与总死亡率各国报道的大量资料表明,吸烟者总死亡率比不吸烟者高30～80％,其中以45～54岁年     

为何不吸烟也会得肺癌

统计资料表明,肺癌的绝对发病率每10～15年增加一倍。在许多国家,肺癌已跃居男性恶性肿瘤的第一位。我国北京等城市肺癌发病率和病死率均占各种恶性肿瘤首位。据认为,肺癌日益增多与环境因素密切相关。吸烟引起肺癌已得到公认,那么不吸烟的人又何以会得肺癌呢?大致有以下环境因素。大气污染:大量调查表明,大气污染与居民肺癌发病率和死亡率密切相关,特别是燃煤污染严重地区,肺癌发病率和死亡率显著增加。我国宣威(云南省)农村有室内烧煤习惯,使那里成为我国肺癌高发     

被动吸烟与心理疾病

研究发现,被动吸烟不仅有害身体健康,对心理健康的影响同样不可小觑。研究发现,过多吸食二手烟,会造成被动吸烟者心理压抑,从而增加罹患心理疾病的风险。     

氡——室内的“隐形杀手”

近年内经过科学家的大量调查研究发现,受到高浓度的氡长期辐射可以导致肺癌、白血病以及呼吸道等方面的病变,氡已成为仅次于吸烟的第二大致癌因素。据专家估计,全美国每年大约有2万人死于因氧气引起的肺癌,在香港大约也有13％的肺癌死亡是由建筑物中氡释放引起的。为此,国际原子能机构曾要求其成员国开展“人类环境中的氡”的调查研     

家长吸烟对儿童尿中1-羟基芘的影响

为了解家长吸烟对小学生尿中１－羟基芘的影响,对４个地区小学生２３４份尿样中的１－羟基芘及其学校所在地空气中的苯并芘进行了同步采样分析,结果显示,学生尿中的１－羟基芘浓度与所在学校空气中苯并（ａ）芘的浓度有显著的正相关关系。家长吸烟组学生尿中１－羟基芘浓度均高于家长不吸烟组,但ｔ检验结果差别不显著,根据测定结果的分析,讨论了这种差别的意义。     

儿童被动吸烟易使心脏受损

澳大利亚医学研究人员最近调查发现,儿童被动吸烟成年后易得心脏病。并警告那些吸烟而使子女被动吸烟的父母,他们可能要对子女日后患心脏病负法律责任。这份最新的调查报告指出,被动吸烟的儿童,在15岁时就会出现血管病病兆,从而增加了他们在成年后得心脏病的危险。专家     

Prenatal detection of an Arg→Ter mutation at codon 111 of the pah gene using DNA amplification

A CGA→TGA mutation at codon 111 in exon 3 of the phenylalanine hydroxylase (PAH) gene was recently identified in a Chinese phenylketonuria (PKU) patient. This paper reports the prenatal diagnosis of a Chinese fetus at risk for PKU using DNA amplification with PCR and oligonucleotide hybridization. RFLP analysis revealed that the fetus had inherited a PKU gene from his mother, but his paternal PAH gene was uninformative. PCR amplification of 300 bp which included exon 3 plus the flanking intronic sequences of the PAH gene was performed. The amplified DNA was hybridized with a pair of allele-specific oligonucleotide probes. The results indicated that the fetal DNA carried a PAH 111 Arg→Ter mutant gene inherited from his father. Thus, the fetus was predicted to be affected with PKU.     

Case report: birth after preimplantation genetic diagnosis of a subtle mutation in SMN1 gene

Spinal muscular atrophy (SMA) preimplantation genetic diagnosis (PGD) has been available since 1998. Protocols are based on the detection of the homozygous deletion of exon 7, which are present in 90–98% of SMA patients. A couple where the woman was a heterozygous carrier of the usual SMN1 Del7 mutation and the man was a heterozygous carrier of pMet263Arg substitution in exon 6 of SMN1 gene was referred for PGD. The usual PGD test being unsuitable for this couple, we developed a novel duplex polymerase chain reaction (PCR)-based PGD test for the detection of the mutation pMet263Arg by allele specific amplification, combined with the amplification of D5S641 extragenic polymorphic marker. PCR conditions were established using single control lymphoblasts and lymphocytes from the pMet263Arg substitution carrier. Amplification was obtained in 100% of the 86 single cells tested, amplification refractory mutation system (ARMS) PCR was specific in 100% of single cells tested and a complete genotype (mutation plus D5S641) was achieved in 88% of them. A PGD cycle was performed successfully and a pregnancy was obtained. An unaffected girl was born and postnatal diagnosis confirmed PGD results. This is the first PGD described for SMA because of another mutation than the major homozygous exon 7 deletion of SMN1. In the future, a similar strategy could be adopted for other subtle mutations of this gene. Copyright © 2006 John Wiley & Sons, Ltd.     

Clinical and Environmental Surveillance of Rotavirus Common Genotypes Showed High Prevalence of Common P Genotypes in Egypt

The objective of this study was to compare the prevalence of human rotavirus group A common G and P genotypes in human Egyptian stool specimens and raw sewage samples to determine the most common genotypes for future vaccine development. From 1026 stool specimens of children with acute diarrhea and using nested RT-PCR, 250 samples (24.37%) were positive for human rotavirus group A. Using multiplex RT-PCR, rotavirus common P and G genotypes were detected as 89.20% and 46.40% of the positive clinical specimens respectively. This low percentage of common G genotypes frequency may affect the efficiency of the available live attenuated oral rotavirus vaccines [Rotarix® (human rotavirus G1P[8]) and RotaTeq® (reassortant bovine–human rotavirus G1-4P[5] and G6P[8])], however the percentage of clinical specimens which were negative for common G genotypes but positive for P[8] genotype was 12.00%. From 24 positive raw sewage samples for rotavirus group A VP6 collected from Zenin and El-Gabal El-Asfar wastewater treatment plants (WWTPs), 21 samples (87.50%) were typeable for common P genotypes while 13 samples (54.17%) were typeable for common G genotypes. Phylogenetic analysis of a VP8 partial gene of 45 P-typeable clinical isolates and 20 P-typeable raw sewage samples showed high similarity to reference strains and the majority of mutations were silent and showed lower to non-significant similarity with the two vaccine strains. This finding is useful for determining the most common antigens required for future vaccine development.

     

Prenatal analysis of the insulin receptor gene in a family with leprechaunism

We report on the prenatal diagnosis of a fetus at risk of leprechaunism. We had previously determined the nature of the causative mutation in the insulin receptor gene in this family. The mutation removes a restriction site for the enzyme Mbo II. Genomic DNA was extracted from a chorionic villus sample and the 3′ half of exon 2 was amplified by the polymerase chain reaction (PCR) followed by restriction digest. Using this method, we correctly predicted an unaffected child.     

Verification of Bacteroidales 16S rRNA markers as a complementary tool for detecting swine fecal pollution in the Yangtze Delta

To correctly assess and properly manage the public health risks associated with exposure to contaminated water, it is necessary to identify the source of fecal pollution in a watershed. In this study, we evaluated the efficacy of our two previously developed real time-quantitative PCR (qPCR) assays for the detection of swine-associated Bacteroidales genetic markers (gene 1–38, gene 3–53) in the Yangtze Delta watershed of southeastern China. The results indicated that the gene 1–38 and 3-53 markers exhibited high accuracy (92.5%, 91.7% conditional probability, respectively) in detecting Bacteroidales spp. in water samples. According to binary logistic regression (BLR), these two swine-associated markers were well correlated (P < 0.05) with fecal indicators (Escherichia coli and Enterococci spp.) and zoonotic pathogens (E. coli O157: H7, Salmonella spp. and Campylobacter spp.) in water samples. In contrast, concentrations of conventional fecal indicator bacteria (FIB) were not correlated with zoonotic pathogens, suggesting that they are noneffective at detecting fecal pollution events. Collectively, the results obtained in this study demonstrated that a swine-targeted qPCR assay based on two Bacteroidales genes markers (gene 1–38, gene 3–53) could be a useful tool in determining the swine-associated impacts of fecal contamination in a watershed.     

Mutation analysis for prenatal diagnosis and heterozygote detection of Gaucher disease type III (norrbottnian type)

A single base substitution in exon 10 of the glucocerebrosidase gene was detected in families affected by Gaucher disease (GD) type III. This mutation, which results in the substitution of proline for leucine in position 444 of glucocerebrosidase, has been shown to result in type III GD in a Swedish population. Three fetuses at risk for GD type III were diagnosed as homozygous for the mutation and the pregnancies were terminated. In a fourth pregnancy, one parent was excluded as being a carrier and the risk of having a child affected by GD was ignored. Direct analysis of common mutations causal to GD is now available and improves prenatal diagnosis in families where the molecular defect has been characterized.     

Fetal cerebral hemorrhage due to X-linked GATA1 gene mutation

We report a multiplex family with a GATA1 gene mutation responsible for a massive fetal cerebral hemorrhage occurring at 36 weeks. Two other stillbirth cousins presented with fetal hydrops and congenital hemochromatosis' phenotype at 37 and 12 weeks of gestation. Molecular screening revealed the presence of a c.613G>A pathogenic allelic variation in exon 4 of GATA1 gene in the 3 male siblings and their carrier mothers. The diagnosis of a GATA1 gene mutation may be suspected in cases of male fetuses with intracerebral bleeding, particularly if a history of prior fetal loss(es) and mild maternal thrombocytopenia are also present.     

Preimplantation genetic diagnosis for familial amyloidotic polyneuropathy (FAP)

Preimplantation genetic diagnosis (PGD) was developed more than a decade ago to offer an alternative to prenatal diagnosis for couples at risk of transmitting an inherited disease to their offspring. Portuguese-type familial amyloidotic polyneuropathy (FAP type I), is an autosomal dominant disease presenting an inherited mutation in the gene encoding the plasma protein transthyretin (TTR). We here report the first protocol for single-cell detection of the Met30 mutation in FAP type I and its application to PGD. A nested PCR reaction for exon 2 of the TTR gene was developed. The PCR product was then analysed by restriction enzyme analysis and SSCP allowing the detection of the point mutation. Ten clinical cycles were performed in seven couples. From the 93 metaphase II (MII) injected oocytes, 82 were normally fertilized and 78 were biopsied. A positive signal in the nested PCR reaction was obtained in 61 blastomeres, corresponding to a DNA amplification efficiency of 78.2%. No allele dropout (ADO) or contamination were detected. A biochemical pregnancy was obtained in three cases and a clinical pregnancy in one couple is actually in normal evolution. Copyright © 2001 John Wiley & Sons, Ltd.     

安徽省重大旱灾对称性特征及其趋势判断

基于安徽省14个气象站点1961~2013年逐月降水数据,采用克里金空间插值法、经验正交函数分解法(EOF)和降水距平百分率对安徽省降水的时空变化特征进行分析,并对安徽省旱灾的发生趋势进行判断。结果表明:(1)近53年安徽省年降水量呈上升趋势,但目前处于下降趋势;(2)在空间上降水量自南向北逐渐减小,根据EOF分析,安徽省降水的空间分布表现为长江流域与淮河流域之间降水反向变化的特征,淮河以北地区与其余地区降水反向变化的特征,皖西大别山区和安徽北部降水偏多,其余地区降水偏少的特征;(3)安徽省的重大干旱符合可公度特征并存在时间对称性规律,计算得出2016年左右安徽省可能发生严重干旱,随机概率为61.1%。该研究对安徽省未来农业及经济的稳健发展具有重要意义。