138 resultados para Polyp
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Aims: To analyze the current literature on combined endoscopic-laparoscopic resection of colon polyps and to compare this new approach to standard laparoscopic colonic resection for polyps not suitable for endoscopic resection. Results: Several studies demonstrated that with a combined endoscopic-laparoscopic approach, polyps were successfully resected in 82-91% with a low morbidity of 3-10% and a short hospital stay of 1-2 days. Segmental laparoscopic resection was necessary in only 9-12%, but had a conversion rate to open surgery of 15% with an average hospital stay of 6-11 days. A cancerous polyp was found in 6-13% after a combined approach, with lymph node metastasis in 6%. Recurrent polyps after a combined endoscopic-laparoscopic resection seem to be rare, but follow-up of most studies is short and incomplete. Conclusion: Combined endoscopic-laparoscopic resection of colon polyps is feasible, safe, and has a high success rate. Malignant lesions can be treated laparoscopically during the same operation, avoiding the need for a second procedure, and with good long-term oncologic outcome.
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BACKGROUND AND STUDY AIMS: Removal of colorectal polyps is routinely performed during withdrawal of the endoscope. However, polyps detected during insertion of the colonoscope may be missed at withdrawal. We aimed to evaluate whether polypectomy during both insertion and withdrawal increases polyp detection and removal rates compared with polypectomy at withdrawal only, and to assess the duration of both approaches. PATIENTS AND METHODS: Patients were included into the study when the first polyp was detected, and randomized into two groups; in group A, polyps ≤ 10 mm in diameter were removed during insertion and withdrawal of the colonoscope, while in group B, these polyps were removed at withdrawal only. Main outcome measures were duration of colonoscopy, number of polyps detected during insertion but not recovered during withdrawal, technical ease, patient discomfort, and complications. RESULTS: 150 patients were randomized to group A and 151 to group B. Mean (± standard deviation [SD]) duration of colonoscopy did not differ between the groups (30.8 ± 15.6 min [A] vs. 28.5 ± 13.8 min [B], P = 0.176). In group A 387 polyps (mean 2.58 per colonoscopy) were detected and removed compared with 389 polyps detected (mean 2.58 per colonoscopy) in group B of which 376 were removed (13 polyps were missed, mean size [SD] 3.2 [1.3] mm; 7.3 % of patients). Patient tolerance was similar in the two groups. CONCLUSIONS: Removal of polyps ≤ 10 mm during withdrawal only is associated with a considerable polyp miss rate. We therefore recommend that these polyps are removed during both insertion and withdrawal.
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BACKGROUND: Peroxisome proliferator activated receptors (PPARs) are nuclear hormone receptors involved in genetic control of many cellular processes. PPAR and PPAR have been implicated in colonic malignancy. Here we provide three lines of evidence suggesting an inhibitory role for PPAR in colorectal cancer development. METHODS: Levels of PPAR mRNA and protein in human colorectal cancers were compared with matched non-malignant mucosa using RNAse protection and western blotting. APC(Min)/+ mice were randomised to receive the PPAR activator methylclofenapate 25 mg/kg or vehicle for up to 16 weeks, and small and large intestinal polyps were quantified by image analysis. The effect of methylclofenapate on serum stimulated mitogenesis (thymidine incorporation), linear cell growth, and annexin V and propidium iodide staining were assessed in human colonic epithelial cells. RESULTS: PPAR (mRNA and protein) expression levels were significantly depressed in colorectal cancer compared with matched non-malignant tissue. Methylclofenapate reduced polyp area in the small intestine from 18.7 mm(2) (median (interquartile range 11.1, 26.8)) to 9.90 (4.88, 13.21) mm(2) (p=0.003) and in the colon from 9.15 (6.31, 10.5) mm(2) to 3.71 (2.71, 5.99) mm(2) (p=0.009). Methylclofenapate significantly reduced thymidine incorporation and linear cell growth with no effect on annexin V or propidium iodide staining. CONCLUSIONS: PPAR may inhibit colorectal tumour progression, possibly via inhibition of proliferation, and may be an important therapeutic target.
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PURPOSE: To investigate choroidal vascular abnormalities in peripheral exudative hemorrhagic chorioretinopathy, using dynamic ultrawide-field fluorescein angiography (FA) and indocyanine green angiography (ICGA).¦DESIGN: Prospective observational case series.¦METHODS: This institutional study comprised a consecutive series of 40 patients (48 eyes) with peripheral exudative hemorrhagic chorioretinopathy. Choroidal vascular abnormalities were assessed with dynamic ultrawide-field (150-degree) FA and ICGA, using the Staurenghi 230 SLO Retina Lens and the Heidelberg scanning laser ophthalmoscope. The main outcome measures were morphologic descriptions of structural vascular abnormalities and choroidal hemodynamics (comparison with 30 normal eyes).¦RESULTS: The peripheral mass lesions were highly exudative and hemorrhagic, and usually associated with a pigment epithelium detachment. FA revealed nonspecific alterations corresponding to the visible fundoscopic changes (window defects, blockage, staining), but no neovascular membrane. However, despite frequent masking, ICGA showed hyperfluorescent polyp-like structures in the choroid of the lesion area in 33 eyes (69%) and an abnormal choroidal vascular network in 24 eyes (50%). The abnormal choroidal vascular network filled in the arterial or early venous phase, while the polyp-like structures filled some seconds later. Optical coherence tomography revealed the typical dome-shaped elevation of the pigment epithelium over the vascular polyps. Peripheral choriocapillaris closure was observed as well as dilated shunting vessels.¦CONCLUSION: Peripheral exudative hemorrhagic chorioretinopathy shares many characteristics (polyp-like choroidal telangiectases, abnormal choroidal vascular networks, exudative and hemorrhagic presentation) with polypoidal choroidal vasculopathy. Clarification of the precise role of these abnormalities requires further studies.
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Chemoprevention is a pragmatic approach to reduce the risk of colorectal cancer, one of the leading causes of cancerrelated death in western countries. In this regard, maslinic acid (MA), a pentacyclic triterpene extracted from wax-like coatings of olives, is known to inhibit proliferation and induce apoptosis in colon cancer cell lines without affecting normal intestinal cells. The present study evaluated the chemopreventive efficacy and associated mechanisms of maslinic acid treatment on spontaneous intestinal tumorigenesis in ApcMin/+ mice. Twenty-two mice were randomized into 2 groups: control group and MA group, fed with a maslinic acid-supplemented diet for six weeks. MA treatment reduced total intestinal polyp formation by 45% (P,0.01). Putative molecular mechanisms associated with suppressing intestinal polyposis in ApcMin/+ mice were investigated by comparing microarray expression profiles of MA-treated and control mice and by analyzing the serum metabolic profile using NMR techniques. The different expression phenotype induced by MA suggested that it exerts its chemopreventive action mainly by inhibiting cell-survival signaling and inflammation. These changes eventually induce G1-phase cell cycle arrest and apoptosis. Moreover, the metabolic changes induced by MA treatment were associated with a protective profile against intestinal tumorigenesis. These results show the efficacy and underlying mechanisms of MA against intestinal tumor development in the ApcMin/+ mice model, suggesting its chemopreventive potential against colorectal cancer.
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Chemoprevention is a pragmatic approach to reduce the risk of colorectal cancer, one of the leading causes of cancerrelated death in western countries. In this regard, maslinic acid (MA), a pentacyclic triterpene extracted from wax-like coatings of olives, is known to inhibit proliferation and induce apoptosis in colon cancer cell lines without affecting normal intestinal cells. The present study evaluated the chemopreventive efficacy and associated mechanisms of maslinic acid treatment on spontaneous intestinal tumorigenesis in ApcMin/+ mice. Twenty-two mice were randomized into 2 groups: control group and MA group, fed with a maslinic acid-supplemented diet for six weeks. MA treatment reduced total intestinal polyp formation by 45% (P,0.01). Putative molecular mechanisms associated with suppressing intestinal polyposis in ApcMin/+ mice were investigated by comparing microarray expression profiles of MA-treated and control mice and by analyzing the serum metabolic profile using NMR techniques. The different expression phenotype induced by MA suggested that it exerts its chemopreventive action mainly by inhibiting cell-survival signaling and inflammation. These changes eventually induce G1-phase cell cycle arrest and apoptosis. Moreover, the metabolic changes induced by MA treatment were associated with a protective profile against intestinal tumorigenesis. These results show the efficacy and underlying mechanisms of MA against intestinal tumor development in the ApcMin/+ mice model, suggesting its chemopreventive potential against colorectal cancer.
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Inorganic polyphosphate (polyP) is found in all living organisms. The known polyP functions in eukaryotes range from osmoregulation and virulence in parasitic protozoa to modulating blood coagulation, inflammation, bone mineralization and cellular signalling in mammals. However mechanisms of regulation and even the identity of involved proteins in many cases remain obscure. Most of the insights obtained so far stem from studies in the yeast Saccharomyces cerevisiae. Here, we provide a short overview of the properties and functions of known yeast polyP metabolism enzymes and discuss future directions for polyP research.
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PURPOSE: To evaluate the accuracy of sonographic endometrial thickness and hysteroscopic characteristics in predicting malignancy in postmenopausal women undergoing surgical resection of endometrial polyps. METHODS: Five hundred twenty-one (521) postmenopausal women undergoing hysteroscopic resection of endometrial polyps between January 1998 and December 2008 were studied. For each value of sonographic endometrial thickness and polyp size on hysteroscopy, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated in relation to the histologic diagnosis of malignancy. The best values of sensitivity and specificity for the diagnosis of malignancy were determined by the Receiver Operating Characteristic (ROC) curve. RESULTS: Histologic diagnosis identified the presence of premalignancy or malignancy in 4.1% of cases. Sonographic measurement revealed a greater endometrial thickness in cases of malignant polyps when compared to benign and premalignant polyps. On surgical hysteroscopy, malignant endometrial polyps were also larger. An endometrial thickness of 13 mm showed a sensitivity of 69.6%, specificity of 68.5%, PPV of 9.3%, and NPV of 98% in predicting malignancy in endometrial polyps. Polyp measurement by hysteroscopy showed that for polyps 30 mm in size, the sensitivity was 47.8%, specificity was 66.1%, PPV was 6.1%, and NPV was 96.5% for predicting cancer. CONCLUSIONS: Sonographic endometrial thickness showed a higher level of accuracy than hysteroscopic measurement in predicting malignancy in endometrial polyps. Despite this, both techniques showed low accuracy for predicting malignancy in endometrial polyps in postmenopausal women. In suspected cases, histologic evaluation is necessary to exclude malignancy.
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Swine influenza (SI) is caused by the type A swine influenza virus (SIV). It is a highly contagious disease with a rapid course and recovery. The major clinical signs and symptoms are cough, fever, anorexia and poor performance. The disease has been associated with other co-infections in many countries, but not in Brazil, where, however, the first outbreak has been reported in 2011. The main aim of this study was to characterize the histological features in association with the immunohistochemical (IHC) results for influenza A (IA), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in lung samples from 60 pigs submitted to Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, during 2009-2010. All of these lung samples had changes characterized by interstitial pneumonia with necrotizing bronchiolitis, never observed previously in the evaluation of swine lungs in our laboratory routine. Pigs in this study had showed clinical signs of a respiratory infection. Swine samples originated from Rio Grande do Sul 31 (52%), Santa Catarina 14 (23%), Paraná 11 (18%), and Mato Grosso do Sul 4 (7%). Positive anti-IA IHC labelling was observed in 45% of the cases, which were associated with necrotizing bronchiolitis, atelectasis, purulent bronchopneumonia and hyperemia. Moreover, type II pneumocyte hyperplasia, alveolar and bronchiolar polyp-like structures, bronchus-associated lymphoid tissue (BALT) hyperplasia and pleuritis were the significant features in negative anti-IA IHC, which were also associated with chronic lesions. There were only two cases with positive anti-PCV2 IHC and none to PRRSV. Therefore, SIV was the predominant infectious agent in the lung samples studied. The viral antigen is often absent due to the rapid progress of SI, which may explain the negative IHC results for IA (55%); therefore, IHC should be performed at the beginning of the disease. This study has shown how important a careful histological evaluation is for the diagnosis. Since 2009, a new histological feature of swine pneumonia in animals with respiratory clinical signs has been observed in samples from pigs with clinical respiratory disease submitted to SPV-UFRGS. In addition, the results proved the importance of histological evaluation for swine herd health management.
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Cystic fibrosis (CF) is a lethal autosomal recessive genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR). Mutations in the CFTR gene may result in a defective processing of its protein and alter the function and regulation of this channel. Mutations are associated with different symptoms, including pancreatic insufficiency, bile duct obstruction, infertility in males, high sweat Cl-, intestinal obstruction, nasal polyp formation, chronic sinusitis, mucus dehydration, and chronic Pseudomonas aeruginosa and Staphylococcus aureus lung infection, responsible for 90% of the mortality of CF patients. The gene responsible for the cellular defect in CF was cloned in 1989 and its protein product CFTR is activated by an increase of intracellular cAMP. The CFTR contains two membrane domains, each with six transmembrane domain segments, two nucleotide-binding domains (NBDs), and a cytoplasmic domain. In this review we discuss the studies that have correlated the role of each CFTR domain in the protein function as a chloride channel and as a regulator of the outwardly rectifying Cl- channels (ORCCs).
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Phosphate (Pi) is one among the most important essential residues in maintenance and inheritance of life, with far diverse physiological role as structural, functional and energy transduction. Phosphate accumulation in wastewaters containing run off of fertilizers and industrial discharges is a global problem that results in algal blooms in bays, lakes and waterways. Currently available methods for removing phosphates from wastewater are based primarily on polyP accumulation by the activated sludge bacteria. PolyP plays a critical role in several environmental and biotechnological problems. Possible relation of interaction between polyP accumulation phenomenon, the low biomass, low Pi uptake, and varying results obtained in response to the impact of sodium chloride, pH, temperature, various inorganic salts and additional carbon sources studied, are all intriguing observations in the present investigation. The results of the present study have evidenced very clearly the scope for potential strains of bacteria from both sea water and marine sediments which could be exploited both for Pi removal in wastewater released by industries and intensive aquaculture practices in to the aquatic environment as well as to harness the potential strains for industrial production of polyP which was wide range of applications.
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Los pólipos del colon son un importante factor de riesgo para el desarrollo de neoplasia, su identificación precoz, remoción y clasificación histológica es fundamental para determinar curación y sobrevida. OBJETIVO: Describir las características de los pólipos del colon resecados en un hospital de tercer nivel de Cundinamarca. METODOS: Estudio descriptivo retrospectivo tipo serie de casos, de pacientes mayores de 18 años sometidos a colonoscopía en quienes se resecaron pólipos de colon, durante el periodo 2009 a 2011. RESULTADOS: Durante el periodo de estudio de realizaron 3267 colonoscopías, se excluyeron los pacientes que no tenían pólipos, sin reporte de patología o en quienes no se recupero la pieza para histología. Se analizaron 381 pacientes con pólipos los cuales fueron incluidos en el análisis final. La localización principal de los pólipos fueron recto y sigmoide 66%, poliposis múltiple se identifico en el 2,9%. Los pólipos hiperplásicos fueron los mas frecuentemente diagnosticado, seguido por adenomas tubulares. En los pacientes que se le realizó resección de múltiples pólipos se diagnosticó cáncer en 2. Las indicaciones de realización de colonoscopía que no están claramente aprobadas pero en las cuales se identificaron y resecaron pólipos son mas del 30%. CONCLUSIONES: La mayoría de pacientes eran mujeres, sigue siendo el sangrado digestivo la principal indicación de realización de colonoscopía. Los pólipos hiperplásicos seguido de los adenomas son el principal hallazgo de patología.
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Studies in cell cultures and animal models provide evidence that probiotics can beneficially influence various stages in development of colon cancer including tumor initiation, promotion and metastasis. For example, oral administration of Lactobacillus and Bifidobacterium strains can prevent genotoxic damage to the colonic epithelium (considered to be an early stage of the carcinogenic process). Administration to rats of probiotics reduced the incidence of carcinogen-induced pre-cancerous lesions (aberrant crypt foci) in the colon. Furthermore a combination of Bifidobacterium longum and inulin (a prebiotic) was more effective than either treatment alone. In this latter study, the dietary treatments were given after exposure to the carcinogen, which suggests that the protective effects were being exerted at the promotional phase of carcinogenesis. L. acidophilus feeding has been shown to decrease the incidence of colon tumors in rats challenged with a carcinogen and B. longum reduced the incidence of carcinogeninduced colon, liver and mammary tumors. There is limited evidence from epidemiological studies for protective effects of products containing probiotics in humans, but a number of recent dietary intervention studies in healthy subjects and in polyp and cancer patients have yielded promising results on the basis of biomarkers of cancer risk and grade of colorectal tumors.
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The strongest markers presently available are precancerous lesions (e. g. polyps or aberrant crypt foci) in humans and precancerous lesions and tumours in animal models. The only marker that presently can be used for a 'reduction of disease risk' claim (type B) for food components is 'polyp recurrence'. Type B claims cannot be made on the basis of results in animal models. All of the other biomarkers examined presently lack validation against the 'true endpoint', the tumour, and thus cannot be used for type B claims. 'Reduction of disease risk' claims in the area of 'diet-related cancer' should be based primarily on human intervention studies using relevant/acceptable endpoints. An important area for future research will be the validation of these surrogate endpoints.
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Hydrocoryne iemanja sp. nov. was found in an aquarium, growing on rhodoliths of coralline algae collected on the southeastern coast of Brazil (20 degrees 40`S 40 degrees 2`W). The colonies were reared through maturity in the laboratory. Each colony had up to 7 sessile, long and thin monomorphic zooids, very extensible and flexible, arising from a chitinous, hard dark-brown plate with minute spines. Medusae budded from near the basal part of hydrocaulus, and were released in immature condition, acquiring fully developed interradial gonads 5-7 days after release. Asexual reproduction by longitudinal fission was observed on the hydrocaulus of the polyps, both for those in normal condition and those with injuries. Fission started at the oral region, extending aborally, with a new hard plate formed in the basal part of hydrocaulus. When fission reached the new hard plate, the new polyp detached, becoming free and sinking to the bottom, starting a new colony. Detached polyps were morphologically indistinguishable from other polyps, being able to produce medusae. Mother and daughter polyps undertook subsequent fissions. This mode of longitudinal fission is distinct from other modes of longitudinal fission, a process known for a few species Of cnidarians. Further studies of this process may shed light on the understanding of the evolutionary pathways in Cnidaria and animals. Hydrocoryne iemanja sp. nov. is distinguishable from its two congeners by the distinct marginal tentacles of the medusae-short and with a median nematocyst knob-an unambiguous character useful even for the identification Of newly liberated medusae.