975 resultados para Gastrointestinal tract (GIT) regions


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Mature T-cell and T/NK-cell neoplasms are both uncommon and heterogeneous, among the broad category of non-Hodgkin's lymphomas. Due to the lack of specific genetic alterations in the vast majority of cases, most currently defined entities show overlapping morphologic and immunophenotypic features and therefore pose a challenge to the diagnostic pathologist. The goal of the symposium is to address current criteria for the recognition of specific subtypes of T-cell lymphoma, and to highlight new data regarding emerging immunophenotypic or molecular markers. This activity has been designed to meet the needs of practicing pathologists, and residents and fellows enrolled in training programs in anatomic and clinical pathology. It should be a particular benefit to those with an interest in hematopathology. Upon completion of this activity, participants should be better able to: -To be able to state the basis for the classification of mature T-cell malignancies involving nodal and extranodal sites. -To recognize and accurately diagnose the various subtypes of nodal and extranodal peripheral T-cell lymphomas. -To utilize immunohistochemical and molecular tests to characterize atypical T-cell proliferations. -To recognize and accurately diagnose T-cell lymphoproliferative lesions involving the skin and gastrointestinal tract, and be able to provide guidance regarding their clinical aggressiveness and management -To be able to utilize flow cytometric data to identify diverse functional T-cell subsets.

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BACKGROUND: Adverse effects of combination antiretroviral therapy (CART) commonly result in treatment modification and poor adherence. METHODS: We investigated predictors of toxicity-related treatment modification during the first year of CART in 1318 antiretroviral-naive human immunodeficiency virus (HIV)-infected individuals from the Swiss HIV Cohort Study who began treatment between January 1, 2005, and June 30, 2008. RESULTS: The total rate of treatment modification was 41.5 (95% confidence interval [CI], 37.6-45.8) per 100 person-years. Of these, switches or discontinuations because of drug toxicity occurred at a rate of 22.4 (95% CI, 19.5-25.6) per 100 person-years. The most frequent toxic effects were gastrointestinal tract intolerance (28.9%), hypersensitivity (18.3%), central nervous system adverse events (17.3%), and hepatic events (11.5%). In the multivariate analysis, combined zidovudine and lamivudine (hazard ratio [HR], 2.71 [95% CI, 1.95-3.83]; P < .001), nevirapine (1.95 [1.01-3.81]; P = .050), comedication for an opportunistic infection (2.24 [1.19-4.21]; P = .01), advanced age (1.21 [1.03-1.40] per 10-year increase; P = .02), female sex (1.68 [1.14-2.48]; P = .009), nonwhite ethnicity (1.71 [1.18-2.47]; P = .005), higher baseline CD4 cell count (1.19 [1.10-1.28] per 100/microL increase; P < .001), and HIV-RNA of more than 5.0 log(10) copies/mL (1.47 [1.10-1.97]; P = .009) were associated with higher rates of treatment modification. Almost 90% of individuals with treatment-limiting toxic effects were switched to a new regimen, and 85% achieved virologic suppression to less than 50 copies/mL at 12 months compared with 87% of those continuing CART (P = .56). CONCLUSIONS: Drug toxicity remains a frequent reason for treatment modification; however, it does not affect treatment success. Close monitoring and management of adverse effects and drug-drug interactions are crucial for the durability of CART.

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Background: Experimental evidences demonstrate that vegetable derived extracts inhibit cholesterol absorption in the gastrointestinal tract. To further explore the mechanisms behind, we modeled duodenal contents with several vegetable extracts. Results: By employing a widely used cholesterol quantification method based on a cholesterol oxidase-peroxidase coupled reaction we analyzed the effects on cholesterol partition. Evidenced interferences were analyzed by studying specific and unspecific inhibitors of cholesterol oxidase-peroxidase coupled reaction. Cholesterol was also quantified by LC/MS. We found a significant interference of diverse (cocoa and tea-derived) extracts over this method. The interference was strongly dependent on model matrix: while as in phosphate buffered saline, the development of unspecific fluorescence was inhibitable by catalase (but not by heat denaturation), suggesting vegetable extract derived H2O2 production, in bile-containing model systems, this interference also comprised cholesterol-oxidase inhibition. Several strategies, such as cholesterol standard addition and use of suitable blanks containing vegetable extracts were tested. When those failed, the use of a mass-spectrometry based chromatographic assay allowed quantification of cholesterol in models of duodenal contents in the presence of vegetable extracts. Conclusions: We propose that the use of cholesterol-oxidase and/or peroxidase based systems for cholesterol analyses in foodstuffs should be accurately monitored, as important interferences in all the components of the enzymatic chain were evident. The use of adequate controls, standard addition and finally, chromatographic analyses solve these issues.

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Background: Bacterial populations are highly successful at colonizing new habitats and adapting to changing environmental conditions, partly due to their capacity to evolve novel virulence and metabolic pathways in response to stress conditions and to shuffle them by horizontal gene transfer (HGT). A common theme in the evolution of new functions consists of gene duplication followed by functional divergence. UlaG, a unique manganese-dependent metallo-b-lactamase (MBL) enzyme involved in L-ascorbate metabolism by commensal and symbiotic enterobacteria, provides a model for the study of the emergence of new catalytic activities from the modification of an ancient fold. Furthermore, UlaG is the founding member of the so-called UlaG-like (UlaGL) protein family, a recently established and poorly characterized family comprising divalent (and perhaps trivalent)metal-binding MBLs that catalyze transformations on phosphorylated sugars and nucleotides. Results: Here we combined protein structure-guided and sequence-only molecular phylogenetic analyses to dissect the molecular evolution of UlaG and to study its phylogenomic distribution, its relatedness with present-day UlaGL protein sequences and functional conservation. Phylogenetic analyses indicate that UlaGL sequences are present in Bacteria and Archaea, with bona fide orthologs found mainly in mammalian and plant-associated Gramnegative and Gram-positive bacteria. The incongruence between the UlaGL tree and known species trees indicates exchange by HGT and suggests that the UlaGL-encoding genes provided a growth advantage under changing conditions. Our search for more distantly related protein sequences aided by structural homology has uncovered that UlaGL sequences have a common evolutionary origin with present-day RNA processing and metabolizing MBL enzymes widespread in Bacteria, Archaea, and Eukarya. This observation suggests an ancient origin for the UlaGL family within the broader trunk of the MBL superfamily by duplication, neofunctionalization and fixation. Conclusions: Our results suggest that the forerunner of UlaG was present as an RNA metabolizing enzyme in the last common ancestor, and that the modern descendants of that ancestral gene have a wide phylogenetic distribution and functional roles. We propose that the UlaGL family evolved new metabolic roles among bacterial and possibly archeal phyla in the setting of a close association with metazoans, such as in the mammalian gastrointestinal tract or in animal and plant pathogens, as well as in environmental settings. Accordingly, the major evolutionary forces shaping the UlaGL family include vertical inheritance and lineage-specific duplication and acquisition of novel metabolic functions, followed by HGT and numerous lineage-specific gene loss events.

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Sucroferric oxyhydroxide (VELPHORO(®)) is a polynuclear iron-based phosphate binder recently approved for the treatment of hyperphosphataemia in patients with chronic kidney disease (CKD). As a number of the available phosphate binders do not provide the optimal combination of good efficacy, adequate tolerability and low pill burden, sucroferric oxyhydroxide constitutes a promising alternative. Among the attributes of an ideal phosphate binder is minimal absorption and, hence, low risk of systemic toxicity. Accordingly, the iron-releasing properties and absorption, distribution, metabolism and excretion (ADME) profile of sucroferric oxyhydroxide, as well as the possibility of iron accumulation and toxicity, were investigated in a series of preclinical studies. The effect of sucroferric oxyhydroxide on the progression of vascular calcification was also investigated. Sucroferric oxyhydroxide exhibited a high phosphate-binding capacity and low iron-releasing properties across the physiological pH range found in the gastrointestinal tract. In the ADME studies, uptake of (59)Fe-radiolabelled sucroferric oxyhydroxide was low in rats and dogs (<1% from a 50 mg Fe/kg bodyweight dose), with the majority of absorbed iron located in red blood cells. Long-term (up to 2 years) administration of sucroferric oxyhydroxide in rats and dogs was associated with modest increases in tissue iron levels and no iron toxicity. Moreoever, in uraemic rats, sucroferric oxyhydroxide was associated with reduced progression of vascular calcification compared with calcium carbonate. In conclusion, sucroferric oxyhydroxide offers a new option for the treatment of hyperphosphataemia, with a high phosphate-binding capacity, minimal iron release, and low potential for iron accumulation and toxicity.

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Bacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbial gastrointestinal colonization and dissemination, we show that the fungus Candida albicans inhibits the virulence of the bacterium Pseudomonas aeruginosa by inhibiting P. aeruginosa pyochelin and pyoverdine gene expression, which plays a critical role in iron acquisition and virulence. Accordingly, deletion of both P. aeruginosa pyochelin and pyoverdine genes attenuates P. aeruginosa virulence. Heat-killed C. albicans has no effect on P. aeruginosa, whereas C. albicans secreted proteins directly suppress P. aeruginosa pyoverdine and pyochelin expression and inhibit P. aeruginosa virulence in mice. Interestingly, suppression or deletion of pyochelin and pyoverdine genes has no effect on P. aeruginosa's ability to colonize the GI tract but does decrease P. aeruginosa's cytotoxic effect on cultured colonocytes. Finally, oral iron supplementation restores P. aeruginosa virulence in P. aeruginosa and C. albicans colonized mice. Together, our findings provide insight into how a bacterial-fungal interaction can modulate bacterial virulence in the intestine. Previously described bacterial-fungal antagonistic interactions have focused on growth inhibition or colonization inhibition/modulation, yet here we describe a novel observation of fungal-inhibition of bacterial effectors critical for virulence but not important for colonization. These findings validate the use of a mammalian model system to explore the complexities of polymicrobial, polykingdom infections in order to identify new therapeutic targets for preventing microbial disease.

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AIMS: The aims of the study are to compare the outcome with and without major bleeding and to identify the independent correlates of major bleeding complications and mortality in patients described in the ATOLL study. METHODS: The ATOLL study included 910 patients randomly assigned to either 0.5 mg/kg intravenous enoxaparin or unfractionated heparin before primary percutaneous coronary intervention. Incidence of major bleeding and ischemic end points was assessed at 1 month, and mortality, at 1 and 6 months. Patients with and without major bleeding complication were compared. A multivariate model of bleeding complications at 1 month and mortality at 6 months was realized. Intention-to-treat and per-protocol analyses were performed. RESULTS: The most frequent bleeding site appears to be the gastrointestinal tract. Age >75 years, cardiac arrest, and the use of insulin or >1 heparin emerged as independent correlates of major bleeding at 1 month. Patients presenting with major bleeding had significantly higher rates of adverse ischemic complications. Mortality at 6 months was higher in bleeders. Major bleeding was found to be one of the independent correlates of 6-month mortality. The addition or mixing of several anticoagulant drugs was an independent factor of major bleeding despite the predominant use of radial access. CONCLUSIONS: This study shows that major bleeding is independently associated with poor outcome, increasing ischemic events, and mortality in primary percutaneous coronary intervention performed mostly with radial access.

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Chlamydial infections in koalas can cause life-threatening diseases leading to blindness and sterility. However, little is known about the systemic spread of chlamydiae in the inner organs of the koala, and data concerning related pathological organ lesions are limited. The aim of this study was to perform a thorough investigation of organs from 23 koalas and to correlate their histopathological lesions to molecular chlamydial detection. To reach this goal, 246 formalin-fixed and paraffin embedded organ samples from 23 koalas were investigated by histopathology, Chlamydiaceae real-time PCR and immunohistochemistry, ArrayTube Microarray for Chlamydiaceae species identification as well as Chlamydiales real-time PCR and sequencing. By PCR, two koalas were positive for Chlamydia pecorum whereas immunohistochemical labelling for Chlamydiaceae was detected in 10 tissues out of nine koalas. The majority of these (n=6) had positive labelling in the urogenital tract related to histopathological lesions such as cystitis, endometritis, pyelonephritis and prostatitis. Somehow unexpected was the positive labelling in the gastrointestinal tract including the cloaca as well as in lung and spleen indicating systemic spread of infection. Uncultured Chlamydiales were detected in several organs of seven koalas by PCR, and four of these suffered from plasmacytic enteritis of unknown aetiology. Whether the finding of Chlamydia-like organisms in the gastrointestinal tract is linked to plasmacytic enteritis is unclear and remains speculative. However, as recently shown in a mouse model, the gastrointestinal tract might play a role being the site for persistent chlamydial infections and being a source for reinfection of the genital tract.

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Peutz¿Jeghers syndrome (PJS, MIM175200) is an autosomal dominant condition defined by the development of characteristic polyps throughout the gastrointestinal tract and mucocutaneous pigmentation. The majority of patients that meet the clinical diagnostic criteria have a causative mutation in the STK11 gene, which is located at 19p13.3. The cancer risks in this condition are substantial, particularly for breast and gastrointestinal cancer, although ascertainment and publication bias may have led to overestimates in some publications. Current surveillance protocols are controversial and not evidence-based, due to the relative rarity of the condition. Initially, endoscopies are more likely to be done to detect polyps that may be a risk for future intussusception or obstruction rather than cancers, but surveillance for the various cancers for which these patients are susceptible is an important part of their later management. This review assesses the current literature on the clinical features and management of the condition, genotype¿phenotype studies, and suggested guidelines for surveillance and management of individuals with PJS. The proposed guidelines contained in this article have been produced as a consensus statement on behalf of a group of European experts who met in Mallorca in 2007 and who have produced guidelines on the clinical management of Lynch syndrome and familial adenomatous polyposis.

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The endogenous microbiota, constituting the microbes that live inside and on humans, is estimated to outnumber human cells by a factor of ten. This commensal microbial population has an important role in many physiological functions, with the densest microbiota population found in the colon. The colonic microbiota is a highly complex and diverse bacterial ecosystem, and a delicate balance exists between the gut microbiota and its host. An imbalance in the microbial ecosystem may lead to severe symptoms in and also beyond the gastrointestinal tract. Due to the important role of the gut microbiota in human health, means of its modification have been introduced in the dietary concepts of pro-, pre- and synbiotics. Prebiotics, which are usually carbohydrates, strive to selectively influence beneficial microbes resident in the colon with the aim of modifying the composition and functionality of the commensal microbial population towards a purportedly healthier one. The study of prebiotic effects on colonic micro-organisms is typically done by using human faecal material, though this provides relatively little information on bacterial populations and metabolic events in different parts of the colon. For this reason, several in vitro models have been developed to investigate the gut microbiota. The aim of this doctoral thesis was to screen through some of the promising prebiotic candidates, characterize their effects on the microbiota through the use of two in vitro methods (pure microbial cultures and a colon simulator model) and to evaluate their potential as emerging prebiotics or synbiotics when combined with the probiotic Bifidobacterium lactis . As a result of the screening work and subsequent colon simulation studies, several compounds with promising features were identified. Xylo-oligosaccharides (XOS), which have previously already shown promise as prebiotic compounds, were well fermented by several probiotic Bifidobacterium lactis strains in pure culture studies and in the following simulation studies utilizing the complex microbiota by endogenous B. lactis Another promising compound was panose, a trisaccharide belonging to isomalto-oligosaccharides (IMO) that also was also able to modify the microbiota in vitro by increasing the number of beneficial microbes investigated. Panose has not been widely studied previously and therefore, this thesis work provided the first data on panose fermentation in mixed colonic microbiota. Galacto-oligosaccharide (GOS) is an established prebiotic, and it was studied here in conjunction with another potential polygosaccharide polydextrose (PDX) and probiotic B. lactis Bi-07. In this final study, the synbiotics including GOS were more effective than the constituting pro- or prebiotics alone in modulating the microbiota composition, thus indicating a synergy resulting from the combination. The results obtained in this in vitro work can be, and have already been, utilized in product development aimed at the nutritional modification of the human colonic microbiota. Some of the compounds have entered the human clinical intervention phase to nvestigate in more detail the prebiotic and synbiotic properties seen in these in vitro studies.

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The foreign body ingestion ocurrs often with children, olds, psychiatrics patients, prisoners or after excessive alcoholic ingestion. Most of foreign bodies (80-90%) passes spontaneously, 10 a 20% have to be removed by endoscopy and only one per cent (1%) needs to be removed by surgery. The authors report a case of a 49-year-old woman who swallowed a needle which impacted in cecum. The patient had psychosis maniac-depressive and swallowed the foreign body aiming self-damage. The presence of foreign body in cecum is rare because of physiologic straitments in the gastrointestinal tract. The ingestion of needle corresponds six percent (6%) of swallowed objects aiming self-damage. Colonoscopy served for localization the foreign body and its withdrawal with success. Colonoscopy for removing foreign bodies is a safe and cheap procedure.

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The great majority of the ingested foreign bodies (92,5%) enters into the gastrointestinal tract, and only a few of cases go to the respiratory tract. Eighty to 90% of those that go into the gastrointestinal tract are spontaneously eliminated but 10- 20% must be removed by endoscopy and 1% needs to be surgically removed. The authors report a case of accidental ingestion of a foreign body (toothbrush) by a 20-year-old patient.

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Disphagia is a very common complaint among patients seeking a gastroenterologists. Esophageal motility disorder is a frequent finding, at times associated with pulsion diverticula. We present a case of a 68 year old female patient with thoracic pain and double epiphrenic diverticula. The upper gastrointestinal tract examination revealed two epiphrenic diverticula, one with 6-7 cm and the other measuring 2 cm, located 30 cm from the dental arcade. She underwent surgical treatment to remove the larger diverticula, a long esophageal myotomy and a Belsey-Mark IV antireflux technique. She presented an uneventful recovery and is doing well I8 months following surgery.

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Digestive fistulas are associated with significant morbidity and mortality, representing mayor challenges regarding diagnosis and the requiring management according physiopathologic basis, including hydroeletrolytic therapy, antibiotics, nutritional support, selected surgical handling and skin care. Most of these lesions are postoperative complications, especially in urgency and traumatic situations. Our objective is to revise important aspects regarding gastrointestinal tract fistulas secondary to trauma, emphasizing classification, physiopathology, diagnosis, complications and treatment.

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The rectum is the second most common location of the carcinoid tumors of the gastrointestinal tract. It represents approximately one or two per cent of the rectal neoplasms. Metastases are less frequent and it presents a better prognosis than carcinoid tumors found in the digestive tract. Treatment is surgical and the technique to be used depends fundamentally on the size of the tumor and the degree of in the intestinal wall penetration. Lesions which are greater than one centimeter have been treated with local excision, while the ones greater than two centimeters have been submitted to a radical resection. This article presents a case of rectal carcinoid diagnosed and treated initially as adenocarcinoma by abdominal rectossigmoidectomy. There were no signs of recurrence after a period of five years and six months of post-surgical follow-up. Nowadays the validity of radical resection in the treatment of rectal carcinoids has been much questioned due to the fact that it has not shown a significant raise in survival rate when compared with patients who were submitted to a local resection.