Biogeographic and Ecologic Patterns in Calcareous Nannoplankton in the Atlantic and Pacific Oceans During the Terminal Cretaceous

Calcareous nannoplankton biogeography in the Cretaceous ocean has been analyzed from their floral composition at a time-slice spanning the upper parts of the Micula prinsii Zone (approximately the latest 10-60 kyr of the Cretaceous) at DSDP (Deep Sea Drilling Project) sites from low (160) through middle (3 T) paleolatitudes in both the Northern and the Southern Hemisphere. The study is based on relative abundance data of 44 species at Sites 356, 525A, and 527 from the South Atlantic, Sites 384 and 548A from the North Atlantic, and Site 465A from the Pacific Ocean.La biogeografía de nanoplancton calcáreo en el océano Cretácico se ha analizado a partir de su composición floral en un intervalo de tiempo que abarca las partes superiores de la zona Micula prinsii (aproximadamente los últimos 10-60 kyr del Cretácico) en DSDP (Deep Sea Drilling Project). sitios desde bajas (160) hasta medias (3 T) paleolatitudes en el hemisferio norte y sur. El estudio se basa en datos de abundancia relativa de 44 especies en los Sitios 356, 525A y 527 del Atlántico Sur, los Sitios 384 y 548A del Atlántico Norte y el Sitio 465A del Océano Pacífico

Helicobacter pylori Adapts to Chronic Infection and Gastric Disease via pH-Responsive BabA-Mediated Adherence

International audienceThe BabA adhesin mediates high-affinity binding of Helicobacter pylori to the ABO blood group antigen-glycosylated gastric mucosa. Here we show that BabA is acid responsive-binding is reduced at low pH and restored by acid neutralization. Acid responsiveness differs among strains; often correlates with different intragastric regions and evolves during chronic infection and disease progression; and depends on pH sensor sequences in BabA and on pH reversible formation of high-affinity binding BabA multimers. We propose that BabA's extraordinary reversible acid responsiveness enables tight mucosal bacterial adherence while also allowing an effective escape from epithelial cells and mucus that are shed into the acidic bactericidal lumen and that bio-selection and changes in BabA binding properties through mutation and recombination with babA-related genes are selected by differences among individuals and by changes in gastric acidity over time. These processes generate diverse H. pylori subpopulations, in which BabA's adaptive evolution contributes to H. pylori persistence and overt gastric disease

Decreasing incidence of peptic ulcer complications after the introduction of the proton pump inhibitors, a study of the Swedish population from 1974–2002

<p>Abstract</p> <p>Background</p> <p>Despite a decreasing incidence of peptic ulcer disease, most previous studies report a stabile incidence of ulcer complications. We wanted to investigate the incidence of peptic ulcer complications in Sweden before and after the introduction of the proton pump inhibitors (PPI) in 1988 and compare these data to the sales of non-steroid anti-inflammatory drugs (NSAID) and acetylsalicylic acid (ASA).</p> <p>Methods</p> <p>All cases of gastric and duodenal ulcer complications diagnosed in Sweden from 1974 to 2002 were identified using the National hospital discharge register. Information on sales of ASA/NSAID was obtained from the National prescription survey.</p> <p>Results</p> <p>When comparing the time-periods before and after 1988 we found a significantly lower incidence of peptic ulcer complications during the later period for both sexes (p < 0.001). Incidence rates varied from 1.5 to 7.8/100000 inhabitants/year regarding perforated peptic ulcers and from 5.2 to 40.2 regarding peptic ulcer bleeding. The number of sold daily dosages of prescribed NSAID/ASA tripled from 1975 to 2002. The number of prescribed sales to women was higher than to males. Sales of low-dose ASA also increased. The total volume of NSAID and ASA, i.e. over the counter sale and sold on prescription, increased by 28% during the same period.</p> <p>Conclusion</p> <p>When comparing the periods before and after the introduction of the proton pump inhibitors we found a significant decrease in the incidence of peptic ulcer complications in the Swedish population after 1988 when PPI were introduced on the market. The cause of this decrease is most likely multifactorial, including smoking habits, NSAID consumption, prevalence of Helicobacter pylori and the introduction of PPI. Sales of prescribed NSAID/ASA increased, especially in middle-aged and elderly women. This fact seems to have had little effect on the incidence of peptic ulcer complications.</p

Detectable clonal mosaicism and its relationship to aging and cancer

In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 × 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 × 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases

K-T boundary in DSDP Holes 62-465 and 74-527 (Table 2)

The global extinctions linked to the Cretaceous-Tertiary (K-T) boundary severely affected marine pelagic organisms. The K-T boundary intervals at Deep Sea Drilling Project (DSDP) Site 527 (Leg 74) in the South Atlantic Ocean and Site 465 (Leg 62) in the Pacific Ocean were studied for changes in calcareous nannofossil assemblages from the late Maastrichtian to the early Paleocene. The sections analysed cover 180 kyr of the terminal Cretaceous and 200 kyr of the earliest Tertiary. Absolute and relative abundances of calcareous nannoplankton were calculated for both the entire flora and for individual species. No decrease in the number of species occurs towards the K-T boundary; relative and absolute abundances of different species are fairly stable throughout the terminal 180 kyr of the Cretaceous. At the K-T boundary the calcareous nannoflora shows a drastic and instantaneous decrease in absolute abundance. Typical Cretaceous species became extinct at the K-T boundary, but are present in the lowermost Tertiary as a result of bioturbation and reworking of the sediments. Very few species survived the K-T boundary. The species that occur sporadically in extremely low numbers in the Cretaceous, exhibit stable relative and absolute abundances through the lower Tertiary. Evolving Tertiary species appeared at the boundary and vary only moderately in absolute abundance through the lowermost Paleocene. The productivity of calcareous nannoplankton is determined here as the nannofossil accumulation rate (NFAR), which is suggested as an estimate of surface-water primary productivity. The terminal Cretaceous NFAR values were high and stable. At the K-T boundary the calcareous nannoflora suffered a 70-150-fold decrease in NFAR, indicating a catastrophic event. The Tertiary NFAR values remained low and fairly constant through the first 200 kyr. The productivity of calcareous nanno- plankton in the earliest Tertiary was dominated by the calcareous dinoflagellate Thoracosphaera sp

Impact of training specificity on exercise-induced cardiac troponin elevation in professional athletes : A pilot study

BACKGROUND Release of cardiac biomarkers is common after strenuous endurance exercise, but data on intermittent exercise are scarce. It has not been investigated whether cardiac troponin elevation is influenced depending on the type of exercise that an athlete is adapted to perform. We hypothesized that intermittent but not continuous exercise induces cardiac troponin elevation in professional athletes adapted to high-intensity intermittent exercise. AIM To examine how training specificity impacts high-sensitivity cardiac troponin T (hs-cTnT) release. METHODS Nine professional floorball players participated in the study, which comprised two different exercise tests: a continuous incremental cycle ergometer test and a Yo-Yo Intermittent Recovery 2 (Yo-Yo IR2) test. Serial assessment of hs-cTnT was performed after the cycle ergometer test and the Yo-Yo IR2 test (baseline, 0, 2, 6, and 24 h). RESULTS No hs-cTnT elevation above the myocardial damage cutoff (&gt;= 14 ng/L) was shown after the cycle ergometer test, whereas hs-cTnT levels rose over the cutoff in three of nine participants after the Yo-Yo IR2 test. The hs-cTnT levels peaked at 6 h after both tests, but were significantly higher after the Yo-Yo IR2 test compared to the cycle ergometer test (median hs-cTnT concentration 10.6 ng/L vs 7.8 ng/L, P = 0.038). All levels returned to baseline within 24 h. CONCLUSION In professional athletes adapted to high-intensity intermittent exercise, hs-cTnT was significantly elevated after intermittent but not continuous exercise. This principle of specificity training should be considered when designing future studies to avoid misinterpretation of hs-cTnT elevation

Enhanced DNA damage-induced p53 peptide phosphorylation and cell-cycle arrest in Sjögren's syndrome cells.

BackgroundCells from primary Sjögren's syndrome (SS) patients have been reported to show alterations in DNA repair and p53 expression. The DNA-dependent protein kinase (DNA-PK) autoantigen may be involved in both of these alterations in relation to cellular DNA damage responses. We conducted this study of cell-cycle kinetics and p53 to find additional evidence for an abnormal stress response role in the pathogenesis of SS. DesignDNA-dependent protein kinase activity, p53 peptide phosphorylation and p53 protein levels were determined in gamma-irradiated long-term T lymphocyte cultures. Cell-cycle progression of peripheral blood mononuclear cells was analysed with flow cytometry. ResultsNo significant differences in the DNA-PK activities or p53 protein levels appeared between the SS patients and the healthy individuals. However, patients with the SS hallmark Ro/SS-A and La/SS-B autoantibodies showed enhancement of both p53 peptide phosphorylation (P = 0·036) and G1 cell-cycle arrest (P = 0·015) in response to gamma radiation. ConclusionsSjögren's syndrome cells express an enhanced G1 checkpoint function which may be mediated partly by p53 phosphorylation, suggesting that an abnormal stress response in SS is of relevance for the development of this autoimmune disease