900 resultados para Gastrointestinal bleeding
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BACKGROUND: Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses. AIMS: To quantify interferon gamma (IFN-gamma) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation. PATIENTS: Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa. METHODS: Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-gamma and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT). RESULTS: The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-gamma (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-gamma SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-gamma and IL-4 were mainly produced by CD4+ cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-gamma in the basal state, and 0.1% secreted IL-4. CONCLUSIONS: Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-gamma and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases.
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Infiltration of myeloid cells in the tumor microenvironment is often associated with enhanced angiogenesis and tumor progression, resulting in poor prognosis in many types of cancer. The polypeptide chemokine PK2 (Bv8, PROK2) has been shown to regulate myeloid cell mobilization from the bone marrow, leading to activation of the angiogenic process, as well as accumulation of macrophages and neutrophils in the tumor site. Neutralizing antibodies against PK2 were shown to display potent anti-tumor efficacy, illustrating the potential of PK2-antagonists as therapeutic agents for the treatment of cancer. In this study we demonstrate the anti-tumor activity of a small molecule PK2 antagonist, PKRA7, in the context of glioblastoma and pancreatic cancer xenograft tumor models. For the highly vascularized glioblastoma, PKRA7 was associated with decreased blood vessel density and increased necrotic areas in the tumor mass. Consistent with the anti-angiogenic activity of PKRA7 in vivo, this compound effectively reduced PK2-induced microvascular endothelial cell branching in vitro. For the poorly vascularized pancreatic cancer, the primary anti-tumor effect of PKRA7 appears to be mediated by the blockage of myeloid cell migration/infiltration. At the molecular level, PKRA7 inhibits PK2-induced expression of certain pro-migratory chemokines and chemokine receptors in macrophages. Combining PKRA7 treatment with standard chemotherapeutic agents resulted in enhanced effects in xenograft models for both types of tumor. Taken together, our results indicate that the anti-tumor activity of PKRA7 can be mediated by two distinct mechanisms that are relevant to the pathological features of the specific type of cancer. This small molecule PK2 antagonist holds the promise to be further developed as an effective agent for combinational cancer therapy.
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The enteroendocrine cell is the cornerstone of gastrointestinal chemosensation. In the intestine and colon, this cell is stimulated by nutrients, tastants that elicit the perception of flavor, and bacterial by-products; and in response, the cell secretes hormones like cholecystokinin and peptide YY--both potent regulators of appetite. The development of transgenic mice with enteroendocrine cells expressing green fluorescent protein has allowed for the elucidation of the apical nutrient sensing mechanisms of the cell. However, the basal secretory aspects of the enteroendocrine cell remain largely unexplored, particularly because a complete account of the enteroendocrine cell ultrastructure does not exist. Today, the fine ultrastructure of a specific cell can be revealed in the third dimension thanks to the invention of serial block face scanning electron microscopy (SBEM). Here, we bridged confocal microscopy with SBEM to identify the enteroendocrine cell of the mouse and study its ultrastructure in the third dimension. The results demonstrated that 73.5% of the peptide-secreting vesicles in the enteroendocrine cell are contained within an axon-like basal process. We called this process a neuropod. This neuropod contains neurofilaments, which are typical structural proteins of axons. Surprisingly, the SBEM data also demonstrated that the enteroendocrine cell neuropod is escorted by enteric glia--the cells that nurture enteric neurons. We extended these structural findings into an in vitro intestinal organoid system, in which the addition of glial derived neurotrophic factors enhanced the development of neuropods in enteroendocrine cells. These findings open a new avenue of exploration in gastrointestinal chemosensation by unveiling an unforeseen physical relationship between enteric glia and enteroendocrine cells.
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The peptide tyrosine tyrosine (PYY) is produced and secreted from L cells of the gastrointestinal mucosa. To study the anatomy and function of PYY-secreting L cells, we developed a transgenic PYY-green fluorescent protein mouse model. PYY-containing cells exhibited green fluorescence under UV light and were immunoreactive to antibodies against PYY and GLP-1 (glucagon-like peptide-1, an incretin hormone also secreted by L cells). PYY-GFP cells from 15 μm thick sections were imaged using confocal laser scanning microscopy and three-dimensionally (3D) reconstructed. Results revealed unique details of the anatomical differences between ileal and colonic PYY-GFP cells. In ileal villi, the apical portion of PYY cells makes minimal contact with the lumen of the gut. Long pseudopod-like basal processes extend from these cells and form an interface between the mucosal epithelium and the lamina propria. Some basal processes are up to 50 μm in length. Multiple processes can be seen protruding from one cell and these often have a terminus resembling a synapse that appears to interact with neighboring cells. In colonic crypts, PYY-GFP cells adopt a spindle-like shape and weave in between epithelial cells, while maintaining contact with the lumen and lamina propria. In both tissues, cytoplasmic granules containing the hormones PYY and GLP-1 are confined to the base of the cell, often filling the basal process. The anatomical arrangement of these structures suggests a dual function as a dock for receptors to survey absorbed nutrients and as a launching platform for hormone secretion in a paracrine fashion.
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BACKGROUND: P2Y12 antagonist therapy improves outcomes in acute myocardial infarction (MI) patients. Novel agents in this class are now available in the US. We studied the introduction of prasugrel into contemporary MI practice to understand the appropriateness of its use and assess for changes in antiplatelet management practices. METHODS AND RESULTS: Using ACTION Registry-GWTG (Get-with-the-Guidelines), we evaluated patterns of P2Y12 antagonist use within 24 hours of admission in 100 228 ST elevation myocardial infarction (STEMI) and 158 492 Non-ST elevation myocardial infarction (NSTEMI) patients at 548 hospitals between October 2009 and September 2012. Rates of early P2Y12 antagonist use were approximately 90% among STEMI and 57% among NSTEMI patients. From 2009 to 2012, prasugrel use increased significantly from 3% to 18% (5% to 30% in STEMI; 2% to 10% in NSTEMI; P for trend <0.001 for all). During the same period, we observed a decrease in use of early but not discharge P2Y12 antagonist among NSTEMI patients. Although contraindicated, 3.0% of patients with prior stroke received prasugrel. Prasugrel was used in 1.9% of patients ≥75 years and 4.5% of patients with weight <60 kg. In both STEMI and NSTEMI, prasugrel was most frequently used in patients at the lowest predicted risk for bleeding and mortality. Despite lack of supporting evidence, prasugrel was initiated before cardiac catheterization in 18% of NSTEMI patients. CONCLUSIONS: With prasugrel as an antiplatelet treatment option, contemporary practice shows low uptake of prasugrel and delays in P2Y12 antagonist initiation among NSTEMI patients. We also note concerning evidence of inappropriate use of prasugrel, and inadequate targeting of this more potent therapy to maximize the benefit/risk ratio.
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BACKGROUND: Breastfeeding is a leading cause of infant HIV-1 infection in the developing world, yet only a minority of infants exposed to HIV-1 via breastfeeding become infected. As a genetic bottleneck severely restricts the number of postnatally-transmitted variants, genetic or phenotypic properties of the virus Envelope (Env) could be important for the establishment of infant infection. We examined the efficiency of virologic functions required for initiation of infection in the gastrointestinal tract and the neutralization sensitivity of HIV-1 Env variants isolated from milk of three postnatally-transmitting mothers (n = 13 viruses), five clinically-matched nontransmitting mothers (n = 16 viruses), and seven postnatally-infected infants (n = 7 postnatally-transmitted/founder (T/F) viruses). RESULTS: There was no difference in the efficiency of epithelial cell interactions between Env virus variants from the breast milk of transmitting and nontransmitting mothers. Moreover, there was similar efficiency of DC-mediated trans-infection, CCR5-usage, target cell fusion, and infectivity between HIV-1 Env-pseudoviruses from nontransmitting mothers and postnatal T/F viruses. Milk Env-pseudoviruses were generally sensitive to neutralization by autologous maternal plasma and resistant to breast milk neutralization. Infant T/F Env-pseudoviruses were equally sensitive to neutralization by broadly-neutralizing monoclonal and polyclonal antibodies as compared to nontransmitted breast milk Env variants. CONCLUSION: Postnatally-T/F Env variants do not appear to possess a superior ability to interact with and cross a mucosal barrier or an exceptional resistance to neutralization that define their capability to initiate infection across the infant gastrointestinal tract in the setting of preexisting maternal antibodies.
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INTRODUCTION: Platinum agents can cause the formation of DNA adducts and induce apoptosis to eliminate tumor cells. The aim of the present study was to investigate the influence of genetic variants of MDM2 on chemotherapy-related toxicities and clinical outcomes in patients with advanced non-small-cell lung cancer (NSCLC). MATERIALS AND METHODS: We recruited 663 patients with advanced NSCLC who had been treated with first-line platinum-based chemotherapy. Five tagging single nucleotide polymorphisms (SNPs) in MDM2 were genotyped in these patients. The associations of these SNPs with clinical toxicities and outcomes were evaluated using logistic regression and Cox regression analyses. RESULTS: Two SNPs (rs1470383 and rs1690924) showed significant associations with chemotherapy-related toxicities (ie, overall, hematologic, and gastrointestinal toxicity). Compared with the wild genotype AA carriers, patients with the GG genotype of rs1470383 had an increased risk of overall toxicity (odds ratio [OR], 3.28; 95% confidence interval [CI], 1.34-8.02; P = .009) and hematologic toxicity (OR, 4.10; 95% CI, 1.73-9.71; P = .001). Likewise, patients with the AG genotype of rs1690924 showed more sensitivity to gastrointestinal toxicity than did those with the wild-type homozygote GG (OR, 2.32; 95% CI, 1.30-4.14; P = .004). Stratified survival analysis revealed significant associations between rs1470383 genotypes and overall survival in patients without overall or hematologic toxicity (P = .007 and P = .0009, respectively). CONCLUSION: The results of our study suggest that SNPs in MDM2 might be used to predict the toxicities of platinum-based chemotherapy and overall survival in patients with advanced NSCLC. Additional validations of the association are warranted.
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The high energetic costs of building and maintaining large brains are thought to constrain encephalization. The 'expensive-tissue hypothesis' (ETH) proposes that primates (especially humans) overcame this constraint through reduction of another metabolically expensive tissue, the gastrointestinal tract. Small guts characterize animals specializing on easily digestible diets. Thus, the hypothesis may be tested via the relationship between brain size and diet quality. Platyrrhine primates present an interesting test case, as they are more variably encephalized than other extant primate clades (excluding Hominoidea). We find a high degree of phylogenetic signal in the data for diet quality, endocranial volume and body size. Controlling for phylogenetic effects, we find no significant correlation between relative diet quality and relative endocranial volume. Thus, diet quality fails to account for differences in platyrrhine encephalization. One taxon, in particular, Brachyteles, violates predictions made by ETH in having a large brain and low-quality diet. Dietary reconstructions of stem platyrrhines further indicate that a relatively high-quality diet was probably in place prior to increases in encephalization. Therefore, it is unlikely that a shift in diet quality was a primary constraint release for encephalization in platyrrhines and, by extrapolation, humans.
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OBJECTIVE: To assess potential diagnostic and practice barriers to successful management of massive postpartum hemorrhage (PPH), emphasizing recognition and management of contributing coagulation disorders. STUDY DESIGN: A quantitative survey was conducted to assess practice patterns of US obstetrician-gynecologists in managing massive PPH, including assessment of coagulation. RESULTS: Nearly all (98%) of the 50 obstetrician-gynecologists participating in the survey reported having encountered at least one patient with "massive" PPH in the past 5 years. Approximately half (52%) reported having previously discovered an underlying bleeding disorder in a patient with PPH, with disseminated intravascular coagulation (88%, n=23/26) being identified more often than von Willebrand disease (73%, n=19/26). All reported having used methylergonovine and packed red blood cells in managing massive PPH, while 90% reported performing a hysterectomy. A drop in blood pressure and ongoing visible bleeding were the most commonly accepted indications for rechecking a "stat" complete blood count and coagulation studies, respectively, in patients with PPH; however, 4% of respondents reported that they would not routinely order coagulation studies. Forty-two percent reported having never consulted a hematologist for massive PPH. CONCLUSION: The survey findings highlight potential areas for improved practice in managing massive PPH, including earlier and more consistent assessment, monitoring of coagulation studies, and consultation with a hematologist.
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Purpose: This study was designed to test the activity and feasibility of an all-oral regimen of levo-leucovorin and doxifluridine (dFUR) in the treatment of advanced colorectal cancer and to establish whether the pharmacokinetics of dFUR and fluorouracil (FU) are affected by demographic and/or biologic parameters. Materials and Methods: One hundred eight patients with histologically proven colorectal cancer received orally administered levo-leucovorin 25 mg followed 2 hours later by dFUR 1,200 mg/m2 on days 1 to 5, with the cycle being repeated every 10 days. Results: Among 62 previously untreated patients, two complete responses (CRs) and 18 partial responses (PRs) were observed (overall response rate, 32%; 95% confidence interval, 21% to 45%). The median response duration was 4 months (range, 2 to 13) and the median survival time, 14 months. Among 46 pretreated patients, there were three CRs and three PRs (response rate, 13%; 95% confidence interval, 5% to 26%). In this group of patients, the median response duration was 4 months (range, 1 to 12) and the median survival time, 12 months. No toxic deaths were observed. The only World Health Organization (WHO) grade 3 to 4 side effect was diarrhea (32 patients). Conclusion: This regimen is active in previously untreated colorectal cancer patients and combines good compliance with safety. Limited but definite efficacy was also detected in the patients previously treated with FU, which suggests incomplete cross- resistance between the two drugs. The pharmacokinetic results suggest that the conversion rate of dFUR to FU increases between days 1 and 5, but that FU levels remain low in comparison to those measured after classical FU therapy. Under the experimental conditions used in this study, the interpatient variability of pharmacokinetic parameters remains largely unexplained by the tested variables.
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Rheological properties of solder pastes are very important for a high quality surface mount technology process. The stencil/screen printing process of solder pastes is one of the most critical steps in the SMT assembly process, as most of the assembly defects can often be shown to originate from paste rheology and associated poor printing performance. This paper concerns an investigation of the effect of solder paste composition on the rheological properties and behaviour of four different solder pastes. We report on the evaluation of three different paste formulations based on the no-clean flux composition, with different alloy composition, metal content and particle size using a range of rheological characterisation techniques - including viscosity measurements, yield stress, oscillatory and creep-recovery tests. Our results show that in the viscosity test, all solder pastes exhibited a shear thinning behaviour in nature with different highest maximum viscosity. In the region of shear thinning behaviour the paste 3 delivered the best results. Viscosity test helps to understand the solid and cohesive behaviour of solder pastes. Good solid and cohesive behaviour indicates a good paste roll and helps to avoid paste bleeding. The yield stress test has been used to study the effect of temperature on the flow behaviour of solder pastes. Yield stress was measured for a range of temperature from 15deg C to 35deg C with an increment of 5degC. The result indicated a decreasing of the yield stress point if the temperature was increased. Paste 4 has shown the minimum dependence on temperature. The oscillatory test has been used to find out the linear visco-elastic range and to study the solid and liquid like behaviours of solder pastes. Paste 1 indicated the biggest linear visco-elastic region (LVR) and the highest value of G' and G" which means solder paste 1 will be needed a higher squeegee pressure in the printing process. In the creep recovery test paste 4 showed the best- - recovery and the lowest values of creep and recovery compliance which indicated a good printing behaviour. The test also has showed the solder paste with smaller particle size exhibit less recovery
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Were study a horse (Equus caballus), Purebred Spanish Horse, 6 years old, intact male sex, weight about 550kg, from equestrian center in Fregenal Sierra-Extremadura, Spain. History of acute diarrhea, are apply conventional treatment (hydration, anti-inflammatory and antibiotic). Physical examination showed severe profuse, fetid diarrhea deep red, tachypnea. The physiological parameters were: heart rate 60 bpm, respiratory rate 39 rpm and mucous cyanotic. Temperature: 40°C. Hematological examination showed severe leucopenia, decreased total serum protein, albumin and globulin also diminished. Serum chemistry evidenced severe hyponatremia and hypokalemia, with high levels of chlorine indicating metabolic acidosis. A stool analysis, which was negative and showed no eggs or larvae in the samples studied was performed. The microbial culture allowed the isolation of Klebsiella sp. and susceptibility testing showed sensitivity to ampicillin, Cetafzidine, Ciprofloxacin, Cefepine, gentamicin, imipenem, meropenem, Piperaciclina, piperacillin / tazobactam and trimethoprim sulfa resistance. The horse presented systemic complications associated with endotoxemia and death 36 hours after the onset of diarrhea. At necropsy, severe bleeding was observed enterotiflocolitis. The histological sections showed proliferative enteritis characterized by lymphocyte and mononuclear inflammatory infiltrate plasmocytorious mucosa and submucosa, coagulation necrosis, bacteria and short rod type morphology with no specific grouping. In conclusion a case of acute syndrome enterotiflocolitis reported Klebsiella sp. on a horse Purebred Spanish.
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Glucose dependent insulinotropic polypeptide (GIP) is a gastrointestinal hormone with therapeutic potential for type 2 diabetes due to its insulin-releasing and antihyperglycaemic actions. However, development of GIP-based therapies is limited by N-terminal degradation by DPP IV resulting in a very short circulating half-life. Numerous GIP analogues have now been generated exhibiting DPP IV resistance and extended bioactivity profiles. In this study, we report a direct comparison of the long-term antidiabetic actions of three such GIP molecules, N-AcGIP, GIP(LyS(37)PAL) and N-AcGIP(LyS(37)PAL) in obese diabetic (ob/ob) mice. An extended duration of action of each GIP analogue was demonstrated prior to examining the effects of once daily injections (25 nmol kg(-1) body weight) over a 14-day period. Administration of either N-AcGIP, GIP(LyS(37)PAL) or N-AcGIP(LyS37PAL) significantly decreased non-fasting plasma glucose and improved glucose tolerance compared to saline treated controls. All three analogues significantly enhanced glucose and nutrient-induced insulin release, and improved insulin sensitivity. The metabolic and insulin secretory responses to native GIP were also enhanced in 14-day analogue treated mice, revealing no evidence of GIP-receptor desensitization. These effects were accompanied by significantly enhanced pancreatic insulin following N-AcGIP(Lys(37)PAL) and increased islet number and islet size in all three groups. Body weight, food intake and circulating glucagon were unchanged. These data demonstrate the therapeutic potential of once daily injection of enzyme resistant GIP analogues and indicate that N-AcGIP is equally as effective as related palmitate derivatised analogues of GIP. (c) 2006 Elsevier Inc. All rights reserved.
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Glucose-dependent insulinotropic polypeptide (GIP) is a gastrointestinal hormone with a potentially therapeutic role in type 2 diabetes. Rapid degradation by dipeptidylpeptidase IV has prompted the development of enzyme-resistant N-terminally modified analogs, but renal clearance still limits in vivo bioactivity. In this study, we report long-term antidiabetic effects of a novel, N-terminally protected, fatty acid-derivatized analog of GIP, N-AcGIP(LysPAL(37)), in obese diabetic (ob/ob) mice. Once-daily injections of N-AcGIP(LysPAL(37)) over a 14-day period significantly decreased plasma glucose, glycated hemoglobin, and improved glucose tolerance compared with ob/ob mice treated with saline or native GIP. Plasma insulin and pancreatic insulin content were significantly increased by N-AcGIP(LysPAL(37)). This was accompanied by a significant enhancement in the insulin response to glucose together with a notable improvement of insulin sensitivity. No evidence was found for GIP receptor desensitization and the metabolic effects of NAcGIP(LysPAL(37)) were independent of any change in feeding or body weight. Similar daily injections of native GIP did not affect any of the parameters measured. These data demonstrate the ability of once-daily injections of N-terminally modified, fatty acid-derivatized analogs of GIP, such as N-AcGIP(LysPAL(37)), to improve diabetes control and to offer a new class of agents for the treatment of type 2 diabetes.
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The objective of this study was to assess the effectiveness and tolerability of galantamine in patients with mild-to-moderate Alzheimer's disease (AD) in everyday clinical practice. Patient selection was made on 36 sequential patients attending Belfast City Hospital Memory Clinic between December 2000 and June 2001. Patients were treated with galantamine for 6 months, starting from 4 mg twice daily increasing to 8 mg twice daily and then to 12 mg twice daily at 4-weekly intervals. Patients (25 females, 11 males), mean age 78 years (59-90), were diagnosed with probable AD and had a mini-mental state examination (MMSE) score of 10-26. Efficacy was assessed using the MMSE, neuropsychiatric inventory (NPI), neuropsychiatric inventory caregiver distress (NPI-D) scale and the Bristol activities of daily living (B-ADL) scale at baseline and after 3 and 6 months of treatment. Mean improvements were noted on all four measures of efficacy at 3 and 6 months; improvements were significant on the MMSE, NPI and NPI-D at 3 months and on the NPI-D at 6 months. Galantamine was overall well tolerated. The most common adverse events were gastrointestinal, particularly nausea. Four patients stopped treatment due to adverse events, and seven were stabilised on 8 mg twice daily as they were unable to tolerate the target dose. This naturalistic study confirms clinical trial data, which shows galantamine improves cognition and behavioural symptoms and is overall well tolerated. © 2004 Blackwell Publishing Ltd.