3,388 research outputs found

    Correlation between oesophageal acid exposure and dyspeptic symptoms in patients with nonerosive reflux disease.

    Get PDF
    Oesophageal acidification induces dyspeptic symptoms in healthy individuals. This study aimed to evaluate the correlation between oesophageal acid exposure and dyspeptic symptoms in patients with nonerosive reflux disease. METHODS: A total of 68 patients with dominant symptoms of heartburn, negative upper gastrointestinal endoscopy and concomitant dyspeptic symptoms participated in the study. The severity of dyspepsia and reflux-related symptoms was evaluated, and 24-h gastro-oesophageal pH-monitoring study was performed in all patients at baseline and after 4 weeks of therapy with esomeprazole 40 mg. RESULTS: Oesophageal basal acid exposure was pathological in 43 patients and normal in 25 patients, with a similar prevalence and severity of individual dyspeptic symptoms in the two groups. A significant correlation between reflux and dyspepsia scores was observed in the subgroup of patients with normal, but not in those with abnormal pHmetry (r=0.4, P=0.04 and r=0.2 P=0.07, respectively). After esomeprazole, a reduction in severity of dyspepsia (>or=50% with respect to baseline) was observed, independent of improvement of reflux-associated symptoms. Improvement in dyspepsia was, however, similar in patients with normal and abnormal basal acid exposure (14/25 vs. 33/43, respectively, P=NS). CONCLUSION: Dyspeptic symptoms coexist in a subset of nonerosive reflux disease patients, but prevalence and severity of the symptoms seems to be independent of oesophageal acid exposure

    Rapamycin inhibits mTOR/p70S6K activation in CA3 region of the hippocampus of the rat and impairs long term memory

    Get PDF
    The present study was aimed at establishing whether the mTOR pathway and its downstream effector p70S6K in CA3 pyramidal neurons are under the modulation of the cholinergic input to trigger the formation of long term memories, similar to what we demonstrated in CA1 hippocampus. We performed in vivo behavioral experiments using the step down inhibitory avoidance test in adult Wistar rats to evaluate memory formation under different conditions. We examined the effects of rapamycin, an inhibitor of mTORC1 formation, scopolamine, a muscarinic receptor antagonist or mecamylamine, a nicotinic receptor antagonist, on short and long term memory formation and on the functionality of the mTOR pathway. Acquisition was conducted 30 min after i.c.v. injection of rapamycin. Recall testing was performed 1h, 4h or 24h after acquisition. We found that (1) mTOR and p70S6K activation in CA3 pyramidal neurons were involved in long term memory formation; (2) rapamycin significantly inhibited mTOR and of p70S6K activation at 4h, and long term memory impairment 24h after acquisition; (3) scopolamine impaired short but not long term memory, with an early increase of mTOR/p70S6K activation at 1h followed by stabilization at longer times; (4) mecamylamine and scopolamine co-administration impaired short term memory at 1h and 4h and reduced the scopolamine-induced increase of mTOR/p70S6K activation at 1h and 4h; (5) mecamylamine and scopolamine treatment did not impair long term memory formation; (6) unexpectedly, rapamycin increased mTORC2 activation in microglial cells. Our results demonstrate that in CA3 pyramidal neurons the mTOR/p70S6K pathway is under the modulation of the cholinergic system and is involved in long-term memory encoding, and are consistent with the hypothesis that the CA3 region of the hippocampus is involved in memory mechanisms based on rapid, one-trial object–place learning and recall. Furthermore, our results are in accordance with previous reports that selective molecular mechanisms underlie either short term memory, long term memory, or both. Furthermore, our discovery that administration of rapamycin increased the activation of mTORC2 in microglial cells supports a reappraisal of the beneficial/adverse effects of rapamycin administration

    Deregulated expression of TCL1 causes T cell leukemia in mice

    Get PDF
    The TCL1 oncogene on human chromosome 14q32.1 is involved in the development of T cell leukemia in humans. These leukemias are classified either as T prolymphocytic leukemias, which occur very late in life, or as T chronic lymphocytic leukemias, which often arise in patients with ataxia telangiectasia (AT) at a young age. The TCL1 oncogene is activated in these leukemias by juxtaposition to the α or β locus of the T cell receptor, caused by chromosomal translocations t(14:14)(q11:q32), t(7:14)(q35:q32), or by inversions inv(14)(q11:q32). To show that transcriptional alteration of TCL1 is causally involved in the generation of T cell neoplasia we have generated transgenic mice that carry the TCL1 gene under the transcriptional control of the p56(lck) promoter element. The lck-TCL1 transgenic mice developed mature T cell leukemias after a long latency period. Younger mice presented preleukemic T cell expansions expressing TCL1, and leukemias developed only at an older age. The phenotype of the murine leukemias is CD4-CD8+, in contrast to human leukemias, which are predominantly CD4+CD8-. These studies demonstrate that transcriptional activation of the TCL1 protooncogene can cause malignant transformation oft lymphocytes, indicating the role of TCL1 in the initiation of malignant transformation in T prolymphocytic leukemias and T chronic lymphocytic leukemias

    praja2 regulates KSR1 stability and mitogenic signaling

    Get PDF
    The kinase suppressor of Ras 1 (KSR1) has a fundamental role in mitogenic signaling by scaffolding components of the Ras/MAP kinase pathway. In response to Ras activation, KSR1 assembles a tripartite kinase complex that optimally transfers signals generated at the cell membrane to activate ERK. We describe a novel mechanism of ERK attenuation based on ubiquitin-dependent proteolysis of KSR1. Stimulation of membrane receptors by hormones or growth factors induced KSR1 polyubiquitination, which paralleled a decline of ERK1/2 signaling. We identified praja2 as the E3 ligase that ubiquitylates KSR1. We showed that praja2-dependent regulation of KSR1 is involved in the growth of cancer cells and in the maintenance of undifferentiated pluripotent state in mouse embryonic stem cells. The dynamic interplay between the ubiquitin system and the kinase scaffold of the Ras pathway shapes the activation profile of the mitogenic cascade. By controlling KSR1 levels, praja2 directly affects compartmentalized ERK activities, impacting on physiological events required for cell proliferation and maintenance of embryonic stem cell pluripotency

    Fracture Risk in Type 2 Diabetes: Current Perspectives and Gender Differences

    Get PDF
    Type 2 diabetes mellitus (T2DM) is associated with an increased risk of osteoporotic fractures, resulting in disabilities and increased mortality. The pathophysiological mechanisms linking diabetes to osteoporosis have not been fully explained, but alterations in bone structure and quality are well described in diabetic subjects, likely due to a combination of different factors. Insulin deficiency and dysfunction, obesity and hyperinsulinemia, altered level of oestrogen, leptin, and adiponectin as well as diabetes-related complications, especially peripheral neuropathy, orthostatic hypotension, or reduced vision due to retinopathy may all be associated with an impairment in bone metabolism and with the increased risk of fractures. Finally, medications commonly used in the treatment of T2DM may have an impact on bone metabolism and on fracture risk, particularly in postmenopausal women. When considering the impact of hypoglycaemic drugs on bone, it is important to balance their potential direct effects on bone quality with the risk of falling-related fractures due to the associated hypoglycaemic risk. In this review, experimental and clinical evidence connecting bone metabolism and fracture risk to T2DM is discussed, with particular emphasis on hypoglycaemic treatments and gender-specific implications

    Bifid T waves in leads V2 and V3 in children: a normal variant

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>The T wave is rarely bifid, apart from patients with long QT syndrome or subjects treated with antiarrhythmic drugs. At times, a U wave partially superimposed upon the T wave is responsible for an apparently bifid T wave. Bifid T waves, in contrast, have been described in normal children in the past, but the phenomenon has not received any attention in recent years, to the extent that it is not mentioned in current textbooks of paediatric cardiology. Aim of the present study was to determine the incidence and clinical counterpart of bifid T waves in a paediatric population.</p> <p>Methods</p> <p>We selected 604 consecutive children free from clinically detectable heart disease; subjects whose electrocardiogram showed a bifid T wave underwent a complete clinical and echocardiographic examination. In addition, the electrocardiograms of 110 consecutive adults have also been analyzed. A T wave was considered as bifid whenever it was notched, being the 2 peaks separated from each other by a notch with duration ≥ 0.02 sec and voltage ≥ 0.05 mV. Moreover, in 7 children with bifid T wave in lead V2 further precordial recordings were obtained: a small electrode was gradually moved from V1 to V3, and 4 additional leads were recorded: 2 between V1 an V2, and 2 between V2 and V3.</p> <p>Results</p> <p>A bifid T wave was observed in 110 children (18,3%), with a relatively age-related incidence; the highest rate of bifid T waves (53%) occurred in the group of 5-year-old children. The bifid T wave was detected only in lead V2 in 51 cases (46,4%), only in lead V3 in 5 cases (4,6%), in both leads V2 and V3 in 50 cases (45,4%), and in leads other than V2 and V3 in 4 cases (3,6%). In the adult group, none of the examined electrocardiograms showed bifid T waves in any lead.</p> <p>In the bifid T wave paediatric population, the echocardiogram did not reveal any abnormality, apart from 3 subjects which had an asymptomatic mitral valve prolapse; a trivial mitral and/or tricuspid regurgitation detected by color Doppler, as well as a patent foramen ovale in infants, were not considered as abnormal findings. The QTc interval was normal in all of the subjects; the average QTc interval was not different in the bifid T wave population (402 ± 46 msec) with respect to the control group (407 ± 39 msec).</p> <p>Conclusion</p> <p>The incidence of bifid T waves in leads V2 and V3 in normal children is high, and awareness of this phenomenon avoids possible misinterpretations leading to a diagnosis of ECG abnormalities.</p

    Role of S128R polymorphism of E-selectin in colon metastasis formation

    Get PDF
    The extravasation of cancer cells is a key step of the metastatic cascade. Polymorphisms in genes encoding adhesion molecules can facilitate metastasis by increasing the strength of interaction between tumor and endothelial cells as well as impacting other properties of cancer cells. We investigated the Ser128Arg (a561c at the nucleotide level) polymorphism in the E-selectin gene in patients with metastatic colon cancer and its functional significance. Genotyping for a561c polymorphism was performed on 172 cancer patients and on an age-matched control population. The colon cancer group was divided into groups with (M(+)) and without observable metastasis (M(-)). For in vitro functional assays, Huvec transfected cells expressing wild-type (WT) or the S128R variant of E-selectin were established to study in vitro binding ability and signal transduction processes of T84 colon cancer cell line. Our results demonstrated that the Arginine(128) allele was more prevalent in the M(+) group than in the M(-) group or normal controls (p < 0.005; odds ratio, 1.56; 95% confidence interval (CI) 1.16-1.92; p < 0.001, odds ratio = 1.65; CI = 1.24-1.99, respectively). In vitro, S128R E-selectin transfected Huvec cells, supported increased adhesion as well as increased cellular signaling of T84 cancer cells compared to WT E-selectin and mock-transfected Huvec cells. These findings suggest that the E-selectin S128R polymorphism can functionally affect tumor-endothelial interactions as well as motility and signaling properties of neoplastic cells that may modulate the metastatic phenotype
    • …
    corecore