599 research outputs found

    The significance of p53 codon 72 polymorphism for the development of cervical adenocarcinomas

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    Infection with the human papillomavirus is an important co-factor in the development of cervical carcinomas. Accordingly, HPV DNA is recognised in most of these tumours. Polymorphism of the p53 gene, codon 72, is also considered a risk factor in the development of cervical carcinoma. However, this finding is contradicted by several observers. In the present investigation, 111 cases of adenocarcinoma of the cervix collected through the Swedish Cancer Registry and 188 controls (females with normal cytology at organised gynaecological screening) were analysed with regard to p53, codon 72, polymorphism using a PCR- and SSCP-based technique. In the controls, 9% showed pro/pro, 44% pro/arg and 47% arg/arg, whereas in the invasive adenocarcinomas, the corresponding figures were 0%, 29% and 71%, respectively. The difference was statistically significant (P = 0.001). HPV DNA was identified in 86 tumours (HPV 18 in 48, HPV 16 in 31 and HPV of unknown type in 7 cases) and 25 tumours were HPV negative. The p53, codon 72, genotypes observed in HPV-positive and HPV-negative cervical adenocarcinomas were not statistically different (P = 0.690). The results indicate that women homozygotic for arg/arg in codon 72 of the p53 gene are at an increased risk for the development of cervical adenocarcinomas. However, this genetic disposition seems to be unrelated to the HPV infection. © 2001 Cancer Research Campaign  http://www.bjcancer.co

    Uneven distribution of HPV 16 E6 prototype and variant (L83V) oncoprotein in cervical neoplastic lesions

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    A previous Swedish study revealed that both prototype and variant HPV16 E6 oncoprotein, occur in about equal numbers in high-grade cervical intraepithelial neoplasia (HCIN), whereas variant HPV16 predominates in invasive cervical squamous carcinoma. Most of the malignant HPV16 variants contain a common mutation, L83V, in the E6 oncoprotein. In the present investigation, 28 HPV16 positive, invasive cervical adenocarcinomas were collected from a total number of 131 adenocarcinomas. These HPV16-positive cases were evaluated with analysis of the E6 gene, using a recently described PCR-SSCP method for identification of the specific mutation (L83V) in the E6 gene. The results obtained were correlated to findings in 103 preinvasive, HCIN, and 31 invasive cervical squamous carcinomas also infected with HPV16. The HPV16 E6 variant L83V was present in 40% of the HCIN lesions, in 54% of the invasive adenocarcinomas, in comparison to 81% of the invasive squamous carcinomas. The difference between HCIN and squamous carcinomas was statistically significant, P< 0.001, whereas the difference between HCIN and invasive adenocarcinomas was not statistically significant, P = 0.604. Prototype HPV16 and its E6 variant L83V are both prevalent in preinvasive and invasive cervical lesions in Swedish women. However, the obvious predominance of HPV16 variant in squamous carcinomas was not seen in adenocarcinomas. A single amino-acid shift in the HPV16 E6 gene appears to result in a different transforming potential in squamous and glandular cervical lesions. © 2000 Cancer Research Campaig

    Peptide ion channel toxins from the bootlace worm, the longest animal on Earth

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    Polypeptides from animal venoms have found important uses as drugs, pharmacological tools, and within biotechnological and agricultural applications. We here report a novel family of cystine knot peptides from nemertean worms, with potent activity on voltage-gated sodium channels. These toxins, named the α-nemertides, were discovered in the epidermal mucus of Lineus longissimus, the ‘bootlace worm’ known as the longest animal on earth. The most abundant peptide, the 31-residue long α-1, was isolated, synthesized, and its 3D NMR structure determined. Transcriptome analysis including 17 species revealed eight α-nemertides, mainly distributed in the genus Lineus. α-1 caused paralysis and death in green crabs (Carcinus maenas) at 1 µg/kg (~300 pmol/kg). It showed profound effect on invertebrate voltage-gated sodium channels (e.g. Blattella germanica Nav1) at low nanomolar concentrations. Strong selectivity for insect over human sodium channels indicates that α-nemertides can be promising candidates for development of bioinsecticidal agents

    Multiple Interactions and the Structure of Beam Remnants

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    Recent experimental data have established some of the basic features of multiple interactions in hadron-hadron collisions. The emphasis is therefore now shifting, to one of exploring more detailed aspects. Starting from a brief review of the current situation, a next-generation model is developed, wherein a detailed account is given of correlated flavour, colour, longitudinal and transverse momentum distributions, encompassing both the partons initiating perturbative interactions and the partons left in the beam remnants. Some of the main features are illustrated for the Tevatron and the LHC.Comment: 69pp, 33 figure

    Tissue-Specific Increases in 11β-Hydroxysteroid Dehydrogenase Type 1 in Normal Weight Postmenopausal Women

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    With age and menopause there is a shift in adipose distribution from gluteo-femoral to abdominal depots in women. Associated with this redistribution of fat are increased risks of type 2 diabetes and cardiovascular disease. Glucocorticoids influence body composition, and 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) which converts inert cortisone to active cortisol is a putative key mediator of metabolic complications in obesity. Increased 11βHSD1 in adipose tissue may contribute to postmenopausal central obesity. We hypothesized that tissue-specific 11βHSD1 gene expression and activity are up-regulated in the older, postmenopausal women compared to young, premenopausal women. Twenty-three pre- and 23 postmenopausal, healthy, normal weight women were recruited. The participants underwent a urine collection, a subcutaneous adipose tissue biopsy and the hepatic 11βHSD1 activity was estimated by the serum cortisol response after an oral dose of cortisone. Urinary (5α-tetrahydrocortisol+5β-tetrahydrocortisol)/tetrahydrocortisone ratios were higher in postmenopausal women versus premenopausal women in luteal phase (P<0.05), indicating an increased whole-body 11βHSD1 activity. Postmenopausal women had higher 11βHSD1 gene expression in subcutaneous fat (P<0.05). Hepatic first pass conversion of oral cortisone to cortisol was also increased in postmenopausal women versus premenopausal women in follicular phase of the menstrual cycle (P<0.01, at 30 min post cortisone ingestion), suggesting higher hepatic 11βHSD1 activity. In conclusion, our results indicate that postmenopausal normal weight women have increased 11βHSD1 activity in adipose tissue and liver. This may contribute to metabolic dysfunctions with menopause and ageing in women

    Beach litter sources around Nuuk, Greenland: An analysis by UArctic summer school graduate course students

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    Modeling studies illustrate the potential for long-range transport of plastics into the Arctic, although the degree to which this occurs remains relatively undocumented. We utilised a teaching exercise at a UArctic summer school graduate course in Nuuk, Greenland to conduct a preliminary in-depth analysis of beach litter sources in the Nuup Kangerlua fjord. Students and instructors collected and analysed 1800 litter items weighing 200 kg from one location in the fjord and another at its mouth. The results suggest a predominance of local sources to macrolitter, rather than long-range transport from Europe. Fisheries-related items and rope were common. Packaging which could be identified was largely suspected to be products distributed in Greenland, and soft plastics, which rarely disperse far from its source, were also common. The results suggest local measures to reduce mismanaged waste and emissions from fisheries are important for reducing marine litter in West Greenland.publishedVersio

    Charmed particle production in hadron-hadron collision

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    In the framework of Quark--Gluon--String Model developed recently in ITEP we calculate spectra of charmed particles DD, DsD_s, Λc\Lambda_c, Ξc\Xi_c, Ωc\Omega_c in hadron--hadron collisions taking into account the decays of SS--wave resonances like DD^*, DsD^*_s, Σc\Sigma_c, Σc\Sigma^*_c, Ξc\Xi^*_c, Ξc\Xi'_c, and Ωc\Omega^*_c. We describe the bulk of the existing data on DD, DD^*, and Λc\Lambda_c production in πp\pi p and pppp collisions and predict the yield of charmed particles in Σp\Sigma^-p and Ξp\Xi^-p reactions at hyperon beam energies of 340  GeV/c340\;GeV/c and 600  GeV/c600\;GeV/c. Because of significant production of baryon resonances our predictions for unfavored fragmentation differ from predictions of other models which do not take resonance production into account.Comment: Latex,19 pages, 12figs. can be received by reques

    Socio-economic status and overall and cause-specific mortality in Sweden

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    <p>Abstract</p> <p>Background</p> <p>Previous studies have reported discrepancies in cause-specific mortality among groups of individuals with different socio-economic status. However, most of the studies were limited by the specificity of the investigated populations and the broad definitions of the causes of death. The aim of the present population-based study was to explore the dependence of disease specific mortalities on the socio-economic status in Sweden, a country with universal health care. Another aim was to investigate possible gender differences.</p> <p>Methods</p> <p>Using the 2006 update of the Swedish Family-Cancer Database, we identified over 2 million individuals with socio-economic data recorded in the 1960 national census. The association between mortality and socio-economic status was investigated by Cox's proportional hazards models taking into account the age, time period and residential area in both men and women, and additionally parity and age at first birth in women.</p> <p>Results</p> <p>We observed significant associations between socio-economic status and mortality due to cardiovascular diseases, respiratory diseases, to cancer and to endocrine, nutritional and metabolic diseases. The influence of socio-economic status on female breast cancer was markedly specific: women with a higher socio-economic status showed increased mortality due to breast cancer.</p> <p>Conclusion</p> <p>Even in Sweden, a country where health care is universally provided, higher socio-economic status is associated with decreased overall and cause-specific mortalities. Comparison of mortality among female and male socio-economic groups may provide valuable insights into the underlying causes of socio-economic inequalities in length of life.</p

    Spectroscopic Studies of the Iron and Manganese Reconstituted Tyrosyl Radical in Bacillus Cereus Ribonucleotide Reductase R2 Protein

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    Ribonucleotide reductase (RNR) catalyzes the rate limiting step in DNA synthesis where ribonucleotides are reduced to the corresponding deoxyribonucleotides. Class Ib RNRs consist of two homodimeric subunits: R1E, which houses the active site; and R2F, which contains a metallo cofactor and a tyrosyl radical that initiates the ribonucleotide reduction reaction. We studied the R2F subunit of B. cereus reconstituted with iron or alternatively with manganese ions, then subsequently reacted with molecular oxygen to generate two tyrosyl-radicals. The two similar X-band EPR spectra did not change significantly over 4 to 50 K. From the 285 GHz EPR spectrum of the iron form, a g1-value of 2.0090 for the tyrosyl radical was extracted. This g1-value is similar to that observed in class Ia E. coli R2 and class Ib R2Fs with iron-oxygen cluster, suggesting the absence of hydrogen bond to the phenoxyl group. This was confirmed by resonance Raman spectroscopy, where the stretching vibration associated to the radical (C-O, ν7a = 1500 cm−1) was found to be insensitive to deuterium-oxide exchange. Additionally, the 18O-sensitive Fe-O-Fe symmetric stretching (483 cm−1) of the metallo-cofactor was also insensitive to deuterium-oxide exchange indicating no hydrogen bonding to the di-iron-oxygen cluster, and thus, different from mouse R2 with a hydrogen bonded cluster. The HF-EPR spectrum of the manganese reconstituted RNR R2F gave a g1-value of ∼2.0094. The tyrosyl radical microwave power saturation behavior of the iron-oxygen cluster form was as observed in class Ia R2, with diamagnetic di-ferric cluster ground state, while the properties of the manganese reconstituted form indicated a magnetic ground state of the manganese-cluster. The recent activity measurements (Crona et al., (2011) J Biol Chem 286: 33053–33060) indicates that both the manganese and iron reconstituted RNR R2F could be functional. The manganese form might be very important, as it has 8 times higher activity
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