425 research outputs found
Effect of Helicobacter Pylori Eradication on Extent of Duodenal Gastric Metaplasia and Grade of Gastritis
The extent of the regression of duodenal gastric metaplasia (DGM) after the eradication
of Helicobacter pylori infection is controversial. Therefore, we decided to assess the
degree of DGM before, sex weeks and one year after H. pylori eradication. 105 consecutive
Helicobacter pylori positive patients with endoscopically proven duodenal ulcer,
with DGM and Helicobacter pylori infection were recruited for this study. The diagnosis
of Helicobacter pylori infection was based on CLO-test and histology, and DGM was assessed
on four bulb biopsies taken before, sex weeks and one year after Helicobacter
pylori eradication. Histological assessment of Helicobacter pylori associated gastritis
was performed according to the Sydney classification. Follow up study on 98 patients
before, six weeks and one year after the eradication of Helicobacter pylori showed that
the mean extent of DGM did not change significantly after eradication and did not differ
when compared with 14 patients with persisting infection. Our results show that the
inflammatory process related to Helicobacter pylori does not play the main role in the
development of DGM
Applicability ofMathematicalModels in Defining the Behaviour Kinetics Distinction Among Microbial Strains
Mathematical models were applied to define the behaviour kinetics distinction among microbial strains. In the first series of experiments the growth kinetics of microbial colonies of several S. rimosus mutant strains cultivated on agar plates were compared. Then, the interest was focused on the chosen two strains, in order to express mathematically their differences with respect to their colony growth and antibiotic biosynthesis kinetics. Finally, the behaviour of selected three S. rimosus derivative strains at different culture conditions was subjected to the study, with an aim to define strain distinction parameters. Mathematical models based on the three-dimensional
growth concept and describing the microorganism growth, substrate uptake and antibiotic biosynthesis kinetics were developed. The computer simulation was applied to verify the applicability of mathematical models. The excellent agreement of computer simulation with experimental data confirmed the hypothesis that the kinetics parameters can be successfully applied to define the behaviour distinction among different S. rimosus strains. In the case of selected three strains, S. rimosus R6–500, S. rimosus MV9R-1 and
MV9R-2, it was established that they can be distinguished by their growth kinetics parameters, their substrate uptake kinetics parameters and their antibiotic biosynthesis kineticsparameters. The strain S. rimosus R6–500 showed to be superior with respect to all
kinetics parameters, the strain S. rimosus MV9R-2 showed to be slightly inferior to it, whereas the strain S. rimosus MV9R-1 showed to be inferior with respect to the both mentioned strains, especially because it showed the pronounced active biomass reduction
rate at all investigated culture conditions. Based on these and the corresponding previous results one can conclude that appropriate mathematical models can be recommended for defining parameters of microbial behaviour distinction among different microbial strains
of S. rimosus species
Caracterización del medio físico y biótico de la escombrera de Las Minas de Alquife (Granada)
La actividad minera, siempre que se produzca con una cierta intensidad, provoca
alteraciones en el medio natural, desde las más imperceptibles hasta las que representan
claros impactos sobre el medio en que se desarrollan. Este es el caso de la formación de
escombreras por el acopio de materiales procedentes de las actividades extractivas sobre
la superficie del suelo. La tendencia actual en materia medioambiental promueve la
integración de estos espacios en el paisaje, al mismo tiempo que su reutilización con
fines socio-económicos. Una de las actuaciones primordiales para conseguir estos fines
es la recuperación del suelo y la implantación de cubierta vegetal. Previamente al plan
de actuación, se lleva a cabo la caracterización de la situación actual en la que se
encuentra el ecosistema. En este emplazamiento, los suelos, de textura arenosa,
presentan un pH alcalino, una baja capacidad de intercambio catiónico y bajo contenido
en materia orgánica. La vegetación es escasa, dispersa y dominan las especies herbáceas
seguidas de las arbustivas. Dentro de las especies herbáceas los representantes más
abundantes pertenecen a las familias de Gramíneas, Compuestas y Labiadas.
Adicionalmente, se ha evaluado la presencia de micorrizas en las raíces de las especies
dominantes, como indicador del equilibrio microbiológico y potencial bioestabilizador
del suelo, detectándose colonización micorrícica en la mayoría de ellas, si bien su
promedio es muy bajo (5%)
Characterization of VPS34-IN1, a selective inhibitor of Vps34, reveals that the phosphatidylinositol 3-phosphate-binding SGK3 protein kinase is a downstream target of class III phosphoinositide 3-kinase
The Vps34 (vacuolar protein sorting 34) class III PI3K (phosphoinositide 3-kinase) phosphorylates PtdIns (phosphatidylinositol) at endosomal membranes to generate PtdIns(3)P that regulates membrane trafficking processes via its ability to recruit a subset of proteins possessing PtdIns(3)P-binding PX (phox homology) and FYVE domains. In the present study, we describe a highly selective and potent inhibitor of Vps34, termed VPS34-IN1, that inhibits Vps34 with 25 nM ICin vitro, but does not significantly inhibit the activity of 340 protein kinases or 25 lipid kinases tested that include all isoforms of class I as well as class II PI3Ks. Administration of VPS34-IN1 to cells induces a rapid dose-dependent dispersal of a specific PtdIns(3)P-binding probe from endosome membranes, within 1 min, without affecting the ability of class I PI3K to regulate Akt. Moreover, we explored whether SGK3 (serum- and glucocorticoid-regulated kinase-3), the only protein kinase known to interact specifically with PtdIns(3)P via its N-terminal PX domain, might be controlled by Vps34. Mutations disrupting PtdIns(3)P binding ablated SGK3 kinase activity by suppressing phosphorylation of the T-loop [PDK1 (phosphoinositide-dependent kinase 1) site] and hydrophobic motif (mammalian target of rapamycin site) residues. VPS34-IN1 induced a rapid ~50-60% loss of SGK3 phosphorylation within 1 min. VPS34-IN1 did not inhibit activity of the SGK2 isoform that does not possess a PtdIns(3)P-binding PX domain. Furthermore, class I PI3K inhibitors (GDC-0941 and BKM120) that do not inhibit Vps34 suppressed SGK3 activity by ~40%. Combining VPS34-IN1 and GDC-0941 reduced SGK3 activity ~80-90%. These data suggest SGK3 phosphorylation and hence activity is controlled by two pools of PtdIns(3)P. The first is produced through phosphorylation of PtdIns by Vps34 at the endosome. The second is due to the conversion of class I PI3K product, PtdIns(3,4,5)P3 into PtdIns(3)P, via the sequential actions of the PtdIns 5-phosphatases [SHIP1/2 (Src homology 2-domain-containing inositol phosphatase 1/2)] and PtdIns 4-phosphatase [INPP4B (inositol polyphosphate 4-phosphatase type II)]. VPS34-IN1 will be a useful probe to delineate physiological roles of the Vps34. Monitoring SGK3 phosphorylation and activity could be employed as a biomarker of Vps34 activity, in an analogous manner by which Akt is used to probe cellular class I PI3K activity. Combining class I (GDC-0941) and class III (VPS34-IN1) PI3K inhibitors could be used as a strategy to better analyse the roles and regulation of the elusive class II PI3K
Relationship of Gastric Metaplasia and Age, Sex, Smoking and Helicobacter pylori Infection in Patients with Duodenal Ulcer and Duodenitis
Gastric metaplasia is one of the factors in duodenal ulcer appearance. The aim of this study was to investigate the frequency of gastric metaplasia and its connection with age, sex, cigarette smoking and H. pylori infection. In the study 216 patients were included. There were 98 patients with duodenal ulcer, 60 with duodenitis, and 58 healthy control subjects. There was no statistically significant difference in gastric metaplasia frequency according to age and sex. Gastric metaplasia was statistically more significant in patients with duodenal ulcer (p < 0.01). In all the subjects cigarette smoking did not significantly influence gastric metaplasia. In smokers with duodenal ulcer, and those who besides duodenal ulcer and smoking had H. pylori infection gastric metaplasia was more frequent (p < 0.01). However, in patients with duodenal ulcer, there was no statistically significant difference of gastric metaplasia related to H. pylori presence. It may be suggested that H. pylori infection is not of indispensable significance for gastric metaplasia appearance
Validity of the Walter Reed Visual Assessment Scale to measure subjective perception of spine deformity in patients with idiopathic scoliosis
BACKGROUND: The Walter Reed Visual Assessment Scale (WRVAS) was designed to allow idiopathic scoliosis patients to describe their perception of their deformity. In a previous stduy, the scale has shown good correlation with magnitude of the curve METHODS: The study included 70 patients (60 women and 10 men), mean age 19.4 years (range 12–40), with idiopathic scoliosis. Each patient filled out the WRVAS and the SRS-22 questionnaire. Thoracic and lumbar curve angles were determined in standing X-rays and the largest was named Cobbmax. WRVAS internal consistency was assessed with Cronbach's alpha. Correlation coefficients were calculated between Cobbmax and the various WRVAS questions, and Cobbmax and the SRS-22 scales. The correlation between the WRVAS and SRS-22 was also determined RESULTS: Mean magnitudes were thoracic curve, 36.6° and lumbar curve, 33.2°; average Cobbmax was 37.9°. The mean total WRVAS score was 15.6. Mean scores for the various SRS-22 scales were function 4.6, pain 4.3, self-image 3.7, mental health 4.2, and total score 84.1. Internal consistency for the WRVAS was excellent (Cronbach's alpha, 0.9), and there were no signs of collinearity among the seven questions (tolerance range 0.2–0.5). All the items on the WRVAS correlated significantly with Cobbmax (correlation coefficients, 0.4 to 0.7). The correlation between the total WRVAS and total SRS-22 score was -0.54 (P = .0001) and between WRVAS total score and SRS-22 image domain score was -0.57 (p = 0.0001) CONCLUSION: The WRVAS showed excellent internal consistency and absence of collinearity. There was a highly significant correlation between the results of the test and the magnitude of the deformity. The WRVAS correlated significantly with the SRS-22 image scale. The WRVAS is a valid instrument to assess scoliosis patients perception of their deformit
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