Non-smoking wives of heavy smokers have a higher risk of lung cancer: a study from Japan.
Hirayama T.
Abstract
In a study in 29 health centre districts in Japan 91 540 non-smoking wives aged 40 and above were followed up for 14 years (1966-79), and standardised mortality rates for lung cancer were assessed according to the smoking habits of their husbands. Wives of heavy smokers were found to have a higher risk of developing lung cancer and a dose-response relation was observed. The relation between the husband's smoking and the wife's risk of developing lung cancer showed a similar pattern when analysed by age and occupation of the husband. The risk was particularly great in agricultural families when the husbands were aged 40-59 at enrolment. The husbands' smoking habit did not affect their wives' risk of dying from other disease such as stomach cancer, cervical cancer, and ischaemic heart disease. The risk of developing emphysema and asthma seemed to be higher in non-smoking wives of heavy smokers but the effect was not statistically significant. The husband's drinking habit seemed to have no effect on any causes of death in their wives, including lung cancer. These results indicate the possible importance of passive or indirect smoking as one of the causal factors of lung cancer. They also appear to explain the long-standing riddle of why many women develop lung cancer although they themselves are non-smokers. These results also cast doubt on the practice of assessing the relative risk of developing lung cancer in smokers by comparing them with non-smokers.
Br Med J (Clin Res Ed). 1981 Jan 17;282(6259):183-5.
Thursday, March 10, 2011
Wednesday, March 9, 2011
Three Domains of LIFE!!
An ancient divergence among the bacteria.
Balch WE, Magrum LJ, Fox GE, Wolfe RS, Woese CR.
Abstract
The 16S ribosomal RNAs from two species of methanogenic bacteria, the mesophile Methanobacterium ruminantium and the thermophile Methanobacterium thermoautotrophicum, have been characterized in terms of the oligonucleotides produced by digestion with T1 ribonuclease. These two organisms are found to be sufficiently related that they can be considered members of the same genus or family. However, they bear only slight resemblance to "typical" Procaryotic genera; such as Escherichia, Bacillus and Anacystis. The divergence of the methanogenic bacteria from other bacteria may be the most ancient phylogenetic event yet detected--antedating considerably the divergence of the blue green algal line for example, from the main bacterial line.
J Mol Evol. 1977 Aug 5;9(4):305-11.
Balch WE, Magrum LJ, Fox GE, Wolfe RS, Woese CR.
Abstract
The 16S ribosomal RNAs from two species of methanogenic bacteria, the mesophile Methanobacterium ruminantium and the thermophile Methanobacterium thermoautotrophicum, have been characterized in terms of the oligonucleotides produced by digestion with T1 ribonuclease. These two organisms are found to be sufficiently related that they can be considered members of the same genus or family. However, they bear only slight resemblance to "typical" Procaryotic genera; such as Escherichia, Bacillus and Anacystis. The divergence of the methanogenic bacteria from other bacteria may be the most ancient phylogenetic event yet detected--antedating considerably the divergence of the blue green algal line for example, from the main bacterial line.
J Mol Evol. 1977 Aug 5;9(4):305-11.
Tuesday, March 8, 2011
Pandemics new and old!!!
Structural basis of preexisting immunity to the 2009 H1N1 pandemic influenza virus.
Xu R, Ekiert DC, Krause JC, Hai R, Crowe JE Jr, Wilson IA.
Department of Molecular Biology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Abstract
The 2009 H1N1 swine flu is the first influenza pandemic in decades. The crystal structure of the hemagglutinin from the A/California/04/2009 H1N1 virus shows that its antigenic structure, particularly within the Sa antigenic site, is extremely similar to those of human H1N1 viruses circulating early in the 20th century. The cocrystal structure of the 1918 hemagglutinin with 2D1, an antibody from a survivor of the 1918 Spanish flu that neutralizes both 1918 and 2009 H1N1 viruses, reveals an epitope that is conserved in both pandemic viruses. Thus, antigenic similarity between the 2009 and 1918-like viruses provides an explanation for the age-related immunity to the current influenza pandemic.
Science. 2010 Apr 16;328(5976):357-60. Epub 2010 Mar 25.
Xu R, Ekiert DC, Krause JC, Hai R, Crowe JE Jr, Wilson IA.
Department of Molecular Biology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Abstract
The 2009 H1N1 swine flu is the first influenza pandemic in decades. The crystal structure of the hemagglutinin from the A/California/04/2009 H1N1 virus shows that its antigenic structure, particularly within the Sa antigenic site, is extremely similar to those of human H1N1 viruses circulating early in the 20th century. The cocrystal structure of the 1918 hemagglutinin with 2D1, an antibody from a survivor of the 1918 Spanish flu that neutralizes both 1918 and 2009 H1N1 viruses, reveals an epitope that is conserved in both pandemic viruses. Thus, antigenic similarity between the 2009 and 1918-like viruses provides an explanation for the age-related immunity to the current influenza pandemic.
Science. 2010 Apr 16;328(5976):357-60. Epub 2010 Mar 25.
Friday, March 4, 2011
Mass Extinction!!
Has the Earth's sixth mass extinction already arrived?
Barnosky AD, Matzke N, Tomiya S, Wogan GO, Swartz B, Quental TB, Marshall C, McGuire JL, Lindsey EL, Maguire KC, Mersey B, Ferrer EA.
Abstract
Palaeontologists characterize mass extinctions as times when the Earth loses more than three-quarters of its species in a geologically short interval, as has happened only five times in the past 540 million years or so. Biologists now suggest that a sixth mass extinction may be under way, given the known species losses over the past few centuries and millennia. Here we review how differences between fossil and modern data and the addition of recently available palaeontological information influence our understanding of the current extinction crisis. Our results confirm that current extinction rates are higher than would be expected from the fossil record, highlighting the need for effective conservation measures.
Nature. 2011 Mar 3;471(7336):51-7.
Barnosky AD, Matzke N, Tomiya S, Wogan GO, Swartz B, Quental TB, Marshall C, McGuire JL, Lindsey EL, Maguire KC, Mersey B, Ferrer EA.
Abstract
Palaeontologists characterize mass extinctions as times when the Earth loses more than three-quarters of its species in a geologically short interval, as has happened only five times in the past 540 million years or so. Biologists now suggest that a sixth mass extinction may be under way, given the known species losses over the past few centuries and millennia. Here we review how differences between fossil and modern data and the addition of recently available palaeontological information influence our understanding of the current extinction crisis. Our results confirm that current extinction rates are higher than would be expected from the fossil record, highlighting the need for effective conservation measures.
Nature. 2011 Mar 3;471(7336):51-7.
HORSES!!
Dietary Change and Evolution of Horses in North America
Matthew C. Mihlbachler1,2,*, Florent Rivals3, Nikos Solounias1,2, and Gina M. Semprebon4
Abstract
The evolution of high-crowned molars among horses (Family Equidae) is thought to be an adaptation for abrasive diets associated with the spread of grasslands. The sharpness and relief of the worn cusp apices of teeth (mesowear) are a measure of dietary abrasion. We collected mesowear data for North American Equidae for the past 55.5 million years to test the association of molar height and dietary abrasion. Mesowear trends in horses are reflective of global cooling and associated vegetation changes. There is a strong correlation between mesowear and crown height in horses; however, most horse paleopopulations had highly variable amounts of dietary abrasion, suggesting that selective pressures for crown height may have been weak much of the time. However, instances of higher abrasion were observed in some paleopopulations, suggesting intervals of stronger selection for the evolution of dentitions, including the early Miocene shortly before the first appearance of Equinae, the horse subfamily in which high-crowned dentitions evolved.
Science 4 March 2011: Vol. 331 no. 6021 pp. 1178-1181
Matthew C. Mihlbachler1,2,*, Florent Rivals3, Nikos Solounias1,2, and Gina M. Semprebon4
Abstract
The evolution of high-crowned molars among horses (Family Equidae) is thought to be an adaptation for abrasive diets associated with the spread of grasslands. The sharpness and relief of the worn cusp apices of teeth (mesowear) are a measure of dietary abrasion. We collected mesowear data for North American Equidae for the past 55.5 million years to test the association of molar height and dietary abrasion. Mesowear trends in horses are reflective of global cooling and associated vegetation changes. There is a strong correlation between mesowear and crown height in horses; however, most horse paleopopulations had highly variable amounts of dietary abrasion, suggesting that selective pressures for crown height may have been weak much of the time. However, instances of higher abrasion were observed in some paleopopulations, suggesting intervals of stronger selection for the evolution of dentitions, including the early Miocene shortly before the first appearance of Equinae, the horse subfamily in which high-crowned dentitions evolved.
Science 4 March 2011: Vol. 331 no. 6021 pp. 1178-1181
Thursday, March 3, 2011
Epigenetics!!
Epigenetic differences arise during the lifetime of monozygotic twins.
Fraga MF, Ballestar E, Paz MF, Ropero S, Setien F, Ballestar ML, Heine-Suñer D, Cigudosa JC, Urioste M, Benitez J, Boix-Chornet M, Sanchez-Aguilera A, Ling C, Carlsson E, Poulsen P, Vaag A, Stephan Z, Spector TD, Wu YZ, Plass C, Esteller M.
Abstract
Monozygous twins share a common genotype. However, most monozygotic twin pairs are not identical; several types of phenotypic discordance may be observed, such as differences in susceptibilities to disease and a wide range of anthropomorphic features. There are several possible explanations for these observations, but one is the existence of epigenetic differences. To address this issue, we examined the global and locus-specific differences in DNA methylation and histone acetylation of a large cohort of monozygotic twins. We found that, although twins are epigenetically indistinguishable during the early years of life, older monozygous twins exhibited remarkable differences in their overall content and genomic distribution of 5-methylcytosine DNA and histone acetylation, affecting their gene-expression portrait. These findings indicate how an appreciation of epigenetics is missing from our understanding of how different phenotypes can be originated from the same genotype.
Proc Natl Acad Sci U S A. 2005 Jul 26;102(30):10604-9. Epub 2005 Jul 11.
Fraga MF, Ballestar E, Paz MF, Ropero S, Setien F, Ballestar ML, Heine-Suñer D, Cigudosa JC, Urioste M, Benitez J, Boix-Chornet M, Sanchez-Aguilera A, Ling C, Carlsson E, Poulsen P, Vaag A, Stephan Z, Spector TD, Wu YZ, Plass C, Esteller M.
Abstract
Monozygous twins share a common genotype. However, most monozygotic twin pairs are not identical; several types of phenotypic discordance may be observed, such as differences in susceptibilities to disease and a wide range of anthropomorphic features. There are several possible explanations for these observations, but one is the existence of epigenetic differences. To address this issue, we examined the global and locus-specific differences in DNA methylation and histone acetylation of a large cohort of monozygotic twins. We found that, although twins are epigenetically indistinguishable during the early years of life, older monozygous twins exhibited remarkable differences in their overall content and genomic distribution of 5-methylcytosine DNA and histone acetylation, affecting their gene-expression portrait. These findings indicate how an appreciation of epigenetics is missing from our understanding of how different phenotypes can be originated from the same genotype.
Proc Natl Acad Sci U S A. 2005 Jul 26;102(30):10604-9. Epub 2005 Jul 11.
Tuesday, March 1, 2011
Bacteria that degrade nerve agents!!!
Inactivation of organophosphorus nerve agents by the phosphotriesterase from Pseudomonas diminuta.
Dumas DP, Durst HD, Landis WG, Raushel FM, Wild JR.
Department of Chemistry, Texas A&M University, College Station 77843.
Abstract
The phosphotriesterase from Pseudomonas diminuta was tested as a catalyst for the hydrolysis of phosphofluoridates. The purified enzyme has been shown to hydrolyze the phosphorus-fluorine bond of diisopropyl fluorophosphate, isopropyl methylphosphonofluoridate, and 1,2,2-trimethylpropylmethylphosphonofluoridate at pH 7.0, 25 degrees C, with turnover numbers of 41, 56, and 5 s-1, respectively. The enzymatic rate enhancement for the hydrolysis of sarin at pH 7.0 is 2.2 X 10(7). The turnover number for paraoxon hydrolysis is 2100 s-1. The enzyme does not hydrolyze methanesulfonyl fluoride, phenylmethylsulfonyl fluoride, or O-p-nitrophenyl phenylsulfonate nor do these compounds inactivate or inhibit the ability of the enzyme to hydrolyze diethyl p-nitrophenyl phosphate. The breadth of substrate utility and the efficiency of the hydrolytic reaction exceed the more limited abilities of other prokaryotic and eukaryotic enzymes that catalyze similar reactions. The substantial rate enhancement exhibited by this enzyme for the hydrolysis of a wide variety of organophosphorus nerve agents make this enzyme the prime candidate for the biological detoxification of insecticide and mammalian acetylcholinesterase inhibitors.
Arch Biochem Biophys. 1990 Feb 15;277(1):155-9.
Dumas DP, Durst HD, Landis WG, Raushel FM, Wild JR.
Department of Chemistry, Texas A&M University, College Station 77843.
Abstract
The phosphotriesterase from Pseudomonas diminuta was tested as a catalyst for the hydrolysis of phosphofluoridates. The purified enzyme has been shown to hydrolyze the phosphorus-fluorine bond of diisopropyl fluorophosphate, isopropyl methylphosphonofluoridate, and 1,2,2-trimethylpropylmethylphosphonofluoridate at pH 7.0, 25 degrees C, with turnover numbers of 41, 56, and 5 s-1, respectively. The enzymatic rate enhancement for the hydrolysis of sarin at pH 7.0 is 2.2 X 10(7). The turnover number for paraoxon hydrolysis is 2100 s-1. The enzyme does not hydrolyze methanesulfonyl fluoride, phenylmethylsulfonyl fluoride, or O-p-nitrophenyl phenylsulfonate nor do these compounds inactivate or inhibit the ability of the enzyme to hydrolyze diethyl p-nitrophenyl phosphate. The breadth of substrate utility and the efficiency of the hydrolytic reaction exceed the more limited abilities of other prokaryotic and eukaryotic enzymes that catalyze similar reactions. The substantial rate enhancement exhibited by this enzyme for the hydrolysis of a wide variety of organophosphorus nerve agents make this enzyme the prime candidate for the biological detoxification of insecticide and mammalian acetylcholinesterase inhibitors.
Arch Biochem Biophys. 1990 Feb 15;277(1):155-9.
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