Displaying publications 121 - 140 of 299 in total

Abstract:
Sort:
  1. Kasiman K, Eikelboom JW, Hankey GJ, Lee SP, Lim JP, Lee JH, et al.
    Stroke, 2009 Jun;40(6):2209-11.
    PMID: 19372453 DOI: 10.1161/STROKEAHA.108.535237
    Increased total homocysteine (tHcy) is a risk factor for stroke. This study examines whether the efficacy of B-vitamins in reducing tHcy is modified by ethnicity in a Singaporean ischemic stroke population.
  2. Yu EPK, Reinhold J, Yu H, Starks L, Uryga AK, Foote K, et al.
    Arterioscler Thromb Vasc Biol, 2017 12;37(12):2322-2332.
    PMID: 28970293 DOI: 10.1161/ATVBAHA.117.310042
    OBJECTIVE: Mitochondrial DNA (mtDNA) damage is present in murine and human atherosclerotic plaques. However, whether endogenous levels of mtDNA damage are sufficient to cause mitochondrial dysfunction and whether decreasing mtDNA damage and improving mitochondrial respiration affects plaque burden or composition are unclear. We examined mitochondrial respiration in human atherosclerotic plaques and whether augmenting mitochondrial respiration affects atherogenesis.

    APPROACH AND RESULTS: Human atherosclerotic plaques showed marked mitochondrial dysfunction, manifested as reduced mtDNA copy number and oxygen consumption rate in fibrous cap and core regions. Vascular smooth muscle cells derived from plaques showed impaired mitochondrial respiration, reduced complex I expression, and increased mitophagy, which was induced by oxidized low-density lipoprotein. Apolipoprotein E-deficient (ApoE-/-) mice showed decreased mtDNA integrity and mitochondrial respiration, associated with increased mitochondrial reactive oxygen species. To determine whether alleviating mtDNA damage and increasing mitochondrial respiration affects atherogenesis, we studied ApoE-/- mice overexpressing the mitochondrial helicase Twinkle (Tw+/ApoE-/-). Tw+/ApoE-/- mice showed increased mtDNA integrity, copy number, respiratory complex abundance, and respiration. Tw+/ApoE-/- mice had decreased necrotic core and increased fibrous cap areas, and Tw+/ApoE-/- bone marrow transplantation also reduced core areas. Twinkle increased vascular smooth muscle cell mtDNA integrity and respiration. Twinkle also promoted vascular smooth muscle cell proliferation and protected both vascular smooth muscle cells and macrophages from oxidative stress-induced apoptosis.

    CONCLUSIONS: Endogenous mtDNA damage in mouse and human atherosclerosis is associated with significantly reduced mitochondrial respiration. Reducing mtDNA damage and increasing mitochondrial respiration decrease necrotic core and increase fibrous cap areas independently of changes in reactive oxygen species and may be a promising therapeutic strategy in atherosclerosis.

  3. Reeve AH, Gower G, Pujolar JM, Smith BT, Petersen B, Olsson U, et al.
    Evol Lett, 2023 Feb 01;7(1):24-36.
    PMID: 37065434 DOI: 10.1093/evlett/qrac006
    Tropical islands are renowned as natural laboratories for evolutionary study. Lineage radiations across tropical archipelagos are ideal systems for investigating how colonization, speciation, and extinction processes shape biodiversity patterns. The expansion of the island thrush across the Indo-Pacific represents one of the largest yet most perplexing island radiations of any songbird species. The island thrush exhibits a complex mosaic of pronounced plumage variation across its range and is arguably the world's most polytypic bird. It is a sedentary species largely restricted to mountain forests, yet it has colonized a vast island region spanning a quarter of the globe. We conducted a comprehensive sampling of island thrush populations and obtained genome-wide SNP data, which we used to reconstruct its phylogeny, population structure, gene flow, and demographic history. The island thrush evolved from migratory Palearctic ancestors and radiated explosively across the Indo-Pacific during the Pleistocene, with numerous instances of gene flow between populations. Its bewildering plumage variation masks a biogeographically intuitive stepping stone colonization path from the Philippines through the Greater Sundas, Wallacea, and New Guinea to Polynesia. The island thrush's success in colonizing Indo-Pacific mountains can be understood in light of its ancestral mobility and adaptation to cool climates; however, shifts in elevational range, degree of plumage variation and apparent dispersal rates in the eastern part of its range raise further intriguing questions about its biology.
  4. Reeve AH, Kennedy JD, Pujolar JM, Petersen B, Blom MPK, Alström P, et al.
    Nat Commun, 2023 Dec 11;14(1):8215.
    PMID: 38081809 DOI: 10.1038/s41467-023-43964-y
    The processes generating the earth's montane biodiversity remain a matter of debate. Two contrasting hypotheses have been advanced to explain how montane populations form: via direct colonization from other mountains, or, alternatively, via upslope range shifts from adjacent lowland areas. We seek to reconcile these apparently conflicting hypotheses by asking whether a species' ancestral geographic origin determines its mode of mountain colonization. Island-dwelling passerine birds at the faunal crossroads between Eurasia and Australo-Papua provide an ideal study system. We recover the phylogenetic relationships of the region's montane species and reconstruct their ancestral geographic ranges, elevational ranges, and migratory behavior. We also perform genomic population studies of three super-dispersive montane species/clades with broad island distributions. Eurasian-origin species populated archipelagos via direct colonization between mountains. This mode of colonization appears related to ancestral adaptations to cold and seasonal climates, specifically short-distance migration. Australo-Papuan-origin mountain populations, by contrast, evolved from lowland ancestors, and highland distribution mostly precludes their further colonization of island mountains. Our study explains much of the distributional variation within a complex biological system, and provides a synthesis of two seemingly discordant hypotheses for montane community formation.
  5. Khan PA, Mohammad A, Bansal SL, Lal B, Singh P, Singh R, et al.
    Mol Biotechnol, 2024 Jan 09.
    PMID: 38195817 DOI: 10.1007/s12033-023-01022-4
    Solid waste generation is a huge contributor to environmental pollution issues, and food wastes are prominent in this category due to their large generation on a day-to-day basis. Thus, the settlement of daily food waste is one of the major constraints and needs innovative manufacturing sheme to valorize solid waste in sustainable manner. Moreover, these food wastes are rich in organic content, which has promising scope for their value-added products. In the present study, raw mango seed waste has been biotransformed to produce bacterial hydrolytic enzymes as feedstock. On investigating the impact of substrate, the highest bacterial cellulase production was recorded to be 18 IU/gds FP (filter paper) in 24 h of microbial incubation at 5 g of substrate in solid-state fermentation (SSF). Furthermore, at 40 °C and pH 6.0, 23 IU/gds FP enzyme could be produced in 24 h of SSF. Beside this, on comparing the influence of inorganic and organic nitrogen sources, urea has been found to provide better cellulase production, which yielded 28 IU/gds FP in 24 h of incubation, along with 77 IU/gds BG (β-glucosidase) and 89 IU/gds EG (endoglucanase). On the other hand, Tween-40 and Tween-80, two different surfactants, were employed at a 1.0% concentration for 24 h of incubation. It was noticed that Tween-80 showed complete enzyme activity at 24 h, which was found to be relatively superior to that of Tween-40. This study may have potential utility in enzyme production using mango seed as a food waste for various industrial applications.
  6. Prost S, Armstrong EE, Nylander J, Thomas GWC, Suh A, Petersen B, et al.
    Gigascience, 2019 May 01;8(5).
    PMID: 30689847 DOI: 10.1093/gigascience/giz003
    The diverse array of phenotypes and courtship displays exhibited by birds-of-paradise have long fascinated scientists and nonscientists alike. Remarkably, almost nothing is known about the genomics of this iconic radiation. There are 41 species in 16 genera currently recognized within the birds-of-paradise family (Paradisaeidae), most of which are endemic to the island of New Guinea. In this study, we sequenced genomes of representatives from all five major clades within this family to characterize genomic changes that may have played a role in the evolution of the group's extensive phenotypic diversity. We found genes important for coloration, morphology, and feather and eye development to be under positive selection. In birds-of-paradise with complex lekking systems and strong sexual dimorphism, the core birds-of-paradise, we found Gene Ontology categories for "startle response" and "olfactory receptor activity" to be enriched among the gene families expanding significantly faster compared to the other birds in our study. Furthermore, we found novel families of retrovirus-like retrotransposons active in all three de novo genomes since the early diversification of the birds-of-paradise group, which might have played a role in the evolution of this fascinating group of birds.
  7. Tata MD, Singh R, Bakar AA, Selvindoss P, P K, Gurunathan R
    Asian J Surg, 2008 Apr;31(2):55-8.
    PMID: 18490215
    OBJECTIVE: Appendicectomy is a very common surgical procedure performed by registrars. It is mainly carried out by surgical registrars as an open procedure in many government hospitals. We aimed to evaluate laparoscopic appendicectomy as a laparoscopic training skill in a clinical setting for our registrars.

    METHODS: A retrospective analysis of all attempted laparoscopic appendicectomies over 12 months by experienced surgeons and registrars was done. Factors evaluated were operating time, conversion rate, postoperative hospital stay, morbidity and mortality.

    RESULTS: There was no statistically significant difference in operating time for surgeons and registrars (mean, 53 minutes vs. 60 minutes), conversion rate (10% vs. 11%). Mean hospital stay for patients operated on by surgeons was 3.1 days and 3.2 days for registrars. Morbidity was equal with both surgeons and registrars.

    CONCLUSION: We conclude that laparoscopic appendicectomy is a safe laparoscopic training tool for registrars with basic laparoscopic knowledge who have had a proper apprenticeship, and can be done in a clinical setting.

  8. Cheng ML, Ling DY, Nanu P KP, Nording H, Lim CH
    Med J Malaysia, 2015 Jun;70(3):148-52.
    PMID: 26248776 MyJurnal
    INTRODUCTION: In Malaysia, late stage presentation of breast cancer (stage III or IV) has been a healthcare problem that varies geographically throughout the country. This study aims to understand the factors influencing late stage of breast cancer at presentation among Malaysian women in Segamat Hospital, Johor, which is a district hospital.

    METHODS: A retrospective descriptive study was conducted on secondary data of all newly diagnosed breast cancer women from 1st August 2011 to 28th February 2014. Secondary data includes age, ethnicity, marital status, family history, education level, occupation, presenting symptom, duration of symptom, tumour size, tumour pathology, tumour grading, oestrogen, progesterone and HER-2 receptor status were collected and analysed using SPSS version 20.0.0.

    RESULT: In total, data from 52 women was analysed and two women were excluded for incompleteness as these women defaulted. Late stage at presentation was 59.6% of all new cases (17.3% stage III and 42.3% stage IV). The commonest age group of all women diagnosed with breast cancer was in the 5th decade. Majority of them were Malay, married and housewives with no family history of breast cancer. The statistically significant factors associated with late stage at presentation include Malay ethnicity (p=0.019), presenting symptoms other than breast lump (p=0.047), and duration of breast lump more than 3 months (p=0.009).

    DISCUSSION/CONCLUSION: The study demonstrated presentation at late stage of breast cancer is a major health concern among Malaysian women in district hospital. This may be attributed to different sociocultural beliefs, strong belief in complementary and alternative medicine, lack of awareness, and difficult accessibility to healthcare services.

  9. Sunil M, Vedavijaya T, Thakur RS, Sree P K, Ramana Yella V, Babu Sayana S
    Cureus, 2023 Dec;15(12):e50102.
    PMID: 38186405 DOI: 10.7759/cureus.50102
    BACKGROUND: Abutilon indicum, widely found in India, Sri Lanka, and parts of America and Malaysia, is renowned for its rich bioactive compounds including alkaloids, flavonoids, and sesquiterpene lactones. Due to its diverse pharmacological potential, it has garnered significant attention in traditional medicine. In particular, the ethanolic leaf extract of Abutilon indicum (ELEAI) has demonstrated anti-inflammatory effects, notably targeting the 5-lipoxygenase enzyme pivotal in inflammatory responses.

    OBJECTIVE: This study aimed to elucidate the impact of the ELEAI on proinflammatory marker gene expression induced by isoniazid (INH).

    METHODS: A total of 36 rats were systematically divided into six experimental groups. The control group received DMSO orally for the initial 30 days followed by distilled water for the subsequent 30 days. The INH group received a daily dose of INH (30 mg/kg b.w., i.p.) for 30 days and the rats were then sacrificed on day 30. The ELEAI (250 mg/kg) group was administered INH daily for 30 days, followed by daily post-treatment with ELEAI (250 mg/kg) for another 30 days. Similarly, the ELEAI (500 mg/kg) group received INH daily for 30 days, followed by daily post-treatment with ELEAI (500 mg/kg) for another 30 days. The silymarin (SIL) group was given INH daily for 30 days, followed by post-treatment with SIL at a dose of 100 mg/kg body weight daily for the subsequent 30 days. Finally, the ELEAI (500 mg/kg) alone group was administered distilled water orally for the first 30 days and then received ELEAI at a dose of 500 mg/kg b.w. orally once daily for the next 30 days.

    RESULTS: Continuous INH exposure for a month led to a pronounced increase in proinflammatory genes like TNF-α, TGF-β, and NF-kB and a decrease in the IkB gene in rat liver tissues. Subsequent treatment with SIL (100 mg/kg) and ELEAI (250 and 500 mg/kg) post-INH exposure resulted in a marked decrease in proinflammatory genes and a surge in IkB expression.

    CONCLUSION: The findings suggest that the ELEAI exerts a dose-responsive influence on proinflammatory activities. Notably, A. indicum counteracts inflammation, especially that triggered by bradykinin and prostaglandins. The ELEAI showcases promising therapeutic potential, exhibiting both pro and anti-inflammatory properties and antiproliferative characteristics.

  10. Tan JT, Ng DP, Nurbaya S, Ye S, Lim XL, Leong H, et al.
    J Clin Endocrinol Metab, 2010 Jan;95(1):390-7.
    PMID: 19892838 DOI: 10.1210/jc.2009-0688
    CONTEXT:
    Novel type 2 diabetes mellitus (T2DM) susceptibility loci, identified through genome-wide association studies (GWAS), have been replicated in many European and Japanese populations. However, the association in other East Asian populations is less well characterized.

    OBJECTIVE:
    To examine the effects of SNPs in CDKAL1, CDKN2A/B, IGF2BP2, HHEX, SLC30A8, PKN2, LOC387761, and KCNQ1 on risk of T2DM in Chinese, Malays, and Asian-Indians in Singapore.

    DESIGN:
    We genotyped these candidate single-nucleotide polymorphisms (SNPs) in subjects from three major ethnic groups in Asia, namely, the Chinese (2196 controls and 1541 cases), Malays (2257 controls and 1076 cases), and Asian-Indians (364 controls and 246 cases). We also performed a metaanalysis of our results with published studies in East Asians.

    RESULTS:
    In Chinese, SNPs in CDKAL1 [odds ratio (OR) = 1.19; P = 2 x 10(-4)], HHEX (OR = 1.15; P = 0.013), and KCNQ1 (OR = 1.21; P = 3 x 10(-4)) were significantly associated with T2DM. Among Malays, SNPs in CDKN2A/B (OR = 1.22; P = 3.7 x 10(-4)), HHEX (OR = 1.12; P = 0.044), SLC30A8 (OR = 1.12; P = 0.037), and KCNQ1 (OR = 1.19-1.25; P = 0.003-2.5 x 10(-4)) showed significant association with T2DM. The combined analysis of the three ethnic groups revealed significant associations between SNPs in CDKAL1 (OR = 1.13; P = 3 x 10(-4)), CDKN2A/B (OR = 1.16; P = 9 x 10(-5)), HHEX (OR = 1.14; P = 6 x 10(-4)), and KCNQ1 (OR = 1.16-1.20; P = 3 x 10(-4) to 3 x 10(-6)) with T2DM. SLC30A8 (OR = 1.06; P = 0.039) showed association only after adjustment for gender and body mass index. Metaanalysis with data from other East Asian populations showed similar effect sizes to those observed in populations of European ancestry.

    CONCLUSIONS:
    SNPs at T2DM susceptibility loci identified through GWAS in populations of European ancestry show similar effects in Asian populations. Failure to detect these effects across different populations may be due to issues of power owing to limited sample size, lower minor allele frequency, or differences in genetic effect sizes.
  11. Bein B, Chrysostomakis I, Arantes LS, Brown T, Gerheim C, Schell T, et al.
    bioRxiv, 2024 Sep 27.
    PMID: 39386456 DOI: 10.1101/2024.03.04.583385
    Museum collections harbor millions of samples, largely unutilized for long-read sequencing. Here, we use ethanol-preserved samples containing kilobase-sized DNA to show that amplification-free protocols can yield contiguous genome assemblies. Additionally, using a modified amplification-based protocol, employing an alternative polymerase to overcome PCR bias, we assembled the 3.1 Gb maned sloth genome, surpassing the previous 500 Mb protocol size limit. Our protocol also improves assemblies of other difficult-to-sequence molluscs and arthropods, including millimeter-sized organisms. By highlighting collections as valuable sample resources and facilitating genome assembly of tiny and challenging organisms, our study advances efforts to obtain reference genomes of all eukaryotes.
  12. MacKenzie AR, Langford B, Pugh TA, Robinson N, Misztal PK, Heard DE, et al.
    Philos Trans R Soc Lond B Biol Sci, 2011 Nov 27;366(1582):3177-95.
    PMID: 22006961 DOI: 10.1098/rstb.2011.0053
    We report measurements of atmospheric composition over a tropical rainforest and over a nearby oil palm plantation in Sabah, Borneo. The primary vegetation in each of the two landscapes emits very different amounts and kinds of volatile organic compounds (VOCs), resulting in distinctive VOC fingerprints in the atmospheric boundary layer for both landscapes. VOCs over the Borneo rainforest are dominated by isoprene and its oxidation products, with a significant additional contribution from monoterpenes. Rather than consuming the main atmospheric oxidant, OH, these high concentrations of VOCs appear to maintain OH, as has been observed previously over Amazonia. The boundary-layer characteristics and mixing ratios of VOCs observed over the Borneo rainforest are different to those measured previously over Amazonia. Compared with the Bornean rainforest, air over the oil palm plantation contains much more isoprene, monoterpenes are relatively less important, and the flower scent, estragole, is prominent. Concentrations of nitrogen oxides are greater above the agro-industrial oil palm landscape than over the rainforest, and this leads to changes in some secondary pollutant mixing ratios (but not, currently, differences in ozone). Secondary organic aerosol over both landscapes shows a significant contribution from isoprene. Primary biological aerosol dominates the super-micrometre aerosol over the rainforest and is likely to be sensitive to land-use change, since the fungal source of the bioaerosol is closely linked to above-ground biodiversity.
  13. Casey SC, Vaccari M, Al-Mulla F, Al-Temaimi R, Amedei A, Barcellos-Hoff MH, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S160-83.
    PMID: 26106136 DOI: 10.1093/carcin/bgv035
    Potentially carcinogenic compounds may cause cancer through direct DNA damage or through indirect cellular or physiological effects. To study possible carcinogens, the fields of endocrinology, genetics, epigenetics, medicine, environmental health, toxicology, pharmacology and oncology must be considered. Disruptive chemicals may also contribute to multiple stages of tumor development through effects on the tumor microenvironment. In turn, the tumor microenvironment consists of a complex interaction among blood vessels that feed the tumor, the extracellular matrix that provides structural and biochemical support, signaling molecules that send messages and soluble factors such as cytokines. The tumor microenvironment also consists of many host cellular effectors including multipotent stromal cells/mesenchymal stem cells, fibroblasts, endothelial cell precursors, antigen-presenting cells, lymphocytes and innate immune cells. Carcinogens can influence the tumor microenvironment through effects on epithelial cells, the most common origin of cancer, as well as on stromal cells, extracellular matrix components and immune cells. Here, we review how environmental exposures can perturb the tumor microenvironment. We suggest a role for disrupting chemicals such as nickel chloride, Bisphenol A, butyltins, methylmercury and paraquat as well as more traditional carcinogens, such as radiation, and pharmaceuticals, such as diabetes medications, in the disruption of the tumor microenvironment. Further studies interrogating the role of chemicals and their mixtures in dose-dependent effects on the tumor microenvironment could have important general mechanistic implications for the etiology and prevention of tumorigenesis.
  14. Crous PW, Wingfield MJ, Burgess TI, Hardy GESJ, Barber PA, Alvarado P, et al.
    Persoonia, 2017 Jun;38:240-384.
    PMID: 29151634 DOI: 10.3767/003158517X698941
    Novel species of fungi described in this study include those from various countries as follows: Australia: Banksiophoma australiensis (incl. Banksiophoma gen. nov.) on Banksia coccinea, Davidiellomycesaustraliensis (incl. Davidiellomyces gen. nov.) on Cyperaceae, Didymocyrtis banksiae on Banksia sessilis var. cygnorum, Disculoides calophyllae on Corymbia calophylla, Harknessia banksiae on Banksia sessilis, Harknessia banksiae-repens on Banksia repens, Harknessia banksiigena on Banksia sessilis var. cygnorum, Harknessia communis on Podocarpus sp., Harknessia platyphyllae on Eucalyptus platyphylla, Myrtacremonium eucalypti (incl. Myrtacremonium gen. nov.) on Eucalyptus globulus, Myrtapenidiella balenae on Eucalyptus sp., Myrtapenidiella eucalyptigena on Eucalyptus sp., Myrtapenidiella pleurocarpae on Eucalyptuspleurocarpa, Paraconiothyrium hakeae on Hakea sp., Paraphaeosphaeria xanthorrhoeae on Xanthorrhoea sp., Parateratosphaeria stirlingiae on Stirlingia sp., Perthomyces podocarpi (incl. Perthomyces gen. nov.) on Podocarpus sp., Readeriella ellipsoidea on Eucalyptus sp., Rosellinia australiensis on Banksia grandis, Tiarosporella corymbiae on Corymbia calophylla, Verrucoconiothyriumeucalyptigenum on Eucalyptus sp., Zasmidium commune on Xanthorrhoea sp., and Zasmidium podocarpi on Podocarpus sp. Brazil: Cyathus aurantogriseocarpus on decaying wood, Perenniporia brasiliensis on decayed wood, Perenniporia paraguyanensis on decayed wood, and Pseudocercospora leandrae-fragilis on Leandrafragilis.Chile: Phialocephala cladophialophoroides on human toe nail. Costa Rica: Psathyrella striatoannulata from soil. Czech Republic: Myotisia cremea (incl. Myotisia gen. nov.) on bat droppings. Ecuador: Humidicutis dictiocephala from soil, Hygrocybe macrosiparia from soil, Hygrocybe sangayensis from soil, and Polycephalomyces onorei on stem of Etlingera sp. France: Westerdykella centenaria from soil. Hungary: Tuber magentipunctatum from soil. India: Ganoderma mizoramense on decaying wood, Hodophilus indicus from soil, Keratinophyton turgidum in soil, and Russula arunii on Pterigota alata.Italy: Rhodocybe matesina from soil. Malaysia: Apoharknessia eucalyptorum, Harknessia malayensis, Harknessia pellitae, and Peyronellaea eucalypti on Eucalyptus pellita, Lectera capsici on Capsicum annuum, and Wallrothiella gmelinae on Gmelina arborea.Morocco: Neocordana musigena on Musa sp. New Zealand: Candida rongomai-pounamu on agaric mushroom surface, Candida vespimorsuum on cup fungus surface, Cylindrocladiella vitis on Vitis vinifera, Foliocryphia eucalyptorum on Eucalyptus sp., Ramularia vacciniicola on Vaccinium sp., and Rhodotorula ngohengohe on bird feather surface. Poland: Tolypocladium fumosum on a caterpillar case of unidentified Lepidoptera.Russia: Pholiotina longistipitata among moss. Spain: Coprinopsis pseudomarcescibilis from soil, Eremiomyces innocentii from soil, Gyroporus pseudocyanescens in humus, Inocybe parvicystis in humus, and Penicillium parvofructum from soil. Unknown origin: Paraphoma rhaphiolepidis on Rhaphiolepsis indica.USA: Acidiella americana from wall of a cooling tower, Neodactylaria obpyriformis (incl. Neodactylaria gen. nov.) from human bronchoalveolar lavage, and Saksenaea loutrophoriformis from human eye. Vietnam: Phytophthora mekongensis from Citrus grandis, and Phytophthora prodigiosa from Citrus grandis. Morphological and culture characteristics along with DNA barcodes are provided.
  15. Sartelli M, Weber DG, Ruppé E, Bassetti M, Wright BJ, Ansaloni L, et al.
    World J Emerg Surg, 2017;12:35.
    PMID: 28785301 DOI: 10.1186/s13017-017-0147-0
    [This corrects the article DOI: 10.1186/s13017-016-0089-y.].
  16. Goodson WH, Lowe L, Carpenter DO, Gilbertson M, Manaf Ali A, Lopez de Cerain Salsamendi A, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1:S254-96.
    PMID: 26106142 DOI: 10.1093/carcin/bgv039
    Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology.
  17. Adachi I, Adye T, Ahmed H, Ahn JK, Aihara H, Akar S, et al.
    Phys Rev Lett, 2018 Dec 28;121(26):261801.
    PMID: 30636113 DOI: 10.1103/PhysRevLett.121.261801
    We present first evidence that the cosine of the CP-violating weak phase 2β is positive, and hence exclude trigonometric multifold solutions of the Cabibbo-Kobayashi-Maskawa (CKM) Unitarity Triangle using a time-dependent Dalitz plot analysis of B^{0}→D^{(*)}h^{0} with D→K_{S}^{0}π^{+}π^{-} decays, where h^{0}∈{π^{0},η,ω} denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BABAR and Belle experiments collected at the ϒ(4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6}BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6}BB[over ¯] pairs recorded by the Belle detector. The results of the measurement are sin2β=0.80±0.14(stat)±0.06(syst)±0.03(model) and cos2β=0.91±0.22(stat)±0.09(syst)±0.07(model). The result for the direct measurement of the angle β of the CKM Unitarity Triangle is β=[22.5±4.4(stat)±1.2(syst)±0.6(model)]°. The measurement assumes no direct CP violation in B^{0}→D^{(*)}h^{0} decays. The quoted model uncertainties are due to the composition of the D^{0}→K_{S}^{0}π^{+}π^{-} decay amplitude model, which is newly established by performing a Dalitz plot amplitude analysis using a high-statistics e^{+}e^{-}→cc[over ¯] data sample. CP violation is observed in B^{0}→D^{(*)}h^{0} decays at the level of 5.1 standard deviations. The significance for cos2β>0 is 3.7 standard deviations. The trigonometric multifold solution π/2-β=(68.1±0.7)° is excluded at the level of 7.3 standard deviations. The measurement resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle.
  18. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2020 Sep 04;125(10):102001.
    PMID: 32955327 DOI: 10.1103/PhysRevLett.125.102001
    The first study of charm quark diffusion with respect to the jet axis in heavy ion collisions is presented. The measurement is performed using jets with p_{T}^{jet}>60  GeV/c and D^{0} mesons with p_{T}^{D}>4  GeV/c in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=5.02  TeV, recorded by the CMS detector at the LHC. The radial distribution of D^{0} mesons with respect to the jet axis is sensitive to the production mechanisms of the meson, as well as to the energy loss and diffusion processes undergone by its parent parton inside the strongly interacting medium produced in Pb-Pb collisions. When compared to Monte Carlo event generators, the radial distribution in pp collisions is found to be well described by pythia, while the slope of the distribution predicted by sherpa is steeper than that of the data. In Pb-Pb collisions, compared to the pp results, the D^{0} meson distribution for 4
  19. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Dragicevic M, et al.
    Phys Rev Lett, 2020 Oct 09;125(15):152001.
    PMID: 33095627 DOI: 10.1103/PhysRevLett.125.152001
    Using a data sample of proton-proton collisions at sqrt[s]=13  TeV, corresponding to an integrated luminosity of 140  fb^{-1} collected by the CMS experiment in 2016-2018, the B_{s}^{0}→X(3872)ϕ decay is observed. Decays into J/ψπ^{+}π^{-} and K^{+}K^{-} are used to reconstruct, respectively, the X(3872) and ϕ. The ratio of the product of branching fractions B[B_{s}^{0}→X(3872)ϕ]B[X(3872)→J/ψπ^{+}π^{-}] to the product B[B_{s}^{0}→ψ(2S)ϕ]B[ψ(2S)→J/ψπ^{+}π^{-}] is measured to be [2.21±0.29(stat)±0.17(syst)]%. The ratio B[B_{s}^{0}→X(3872)ϕ]/B[B^{0}→X(3872)K^{0}] is found to be consistent with one, while the ratio B[B_{s}^{0}→X(3872)ϕ]/B[B^{+}→X(3872)K^{+}] is two times smaller. This suggests a difference in the production dynamics of the X(3872) in B^{0} and B_{s}^{0} meson decays compared to B^{+}. The reported observation may shed new light on the nature of the X(3872) particle.
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links