306 resultados para Small colon
em Université de Lausanne, Switzerland
Resumo:
Between 1976 and 1991, we observed lesions of the small bowel or colon in 39 patients having sustained blunt abdominal trauma. 70% of the patients presented with concomitant injuries. Except for 3 cases, all the patients presented with abdominal pain on admission. All the patients were operated on. The delay between admission and operation varied between a few minutes and 48 hours. Indication was hemoperitoneum, peritonitis or progressive abdominal pain. Overall morbidity is high, often related to associated disease. 4 patients died (mortality 10%), including 2 patients with isolated intestinal trauma who were operated on after 20 and 36 hours. Due to the lack of specific laboratory or X-ray test, we suggest a high index of suspicion for bowel lesions in blunt abdominal trauma, especially in unconscious patients. Close observation is mandatory. Indication for laparotomy must not be delayed if any doubt exists regarding the integrity of hollow viscus.
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Canonical Wnt signaling plays a critical role in stem cell maintenance in epithelial homeostasis and carcinogenesis. Here, we show that in the mouse this role is critically mediated by Bcl9/Bcl9l, the mammalian homologues of Legless, which in Drosophila is required for Armadillo/beta-catenin signaling. Conditional ablation of Bcl9/Bcl9l in the intestinal epithelium, where the essential role of Wnt signaling in epithelial homeostasis and stem cell maintenance is well documented, resulted in decreased expression of intestinal stem cell markers and impaired regeneration of ulcerated colon epithelium. Adenocarcinomas with aberrant Wnt signaling arose with similar incidence in wild-type and mutant mice. However, transcriptional profiles were vastly different: Whereas wild-type tumors displayed characteristics of epithelial-mesenchymal transition (EMT) and stem cell-like properties, these properties were largely abrogated in mutant tumors. These findings reveal an essential role for Bcl9/Bcl9l in regulating a subset of Wnt target genes involved in controlling EMT and stem cell-related features and suggest that targeting the Bcl9/Bcl9l arm of Wnt signaling in Wnt-activated cancers might attenuate these traits, which are associated with tumor invasion, metastasis, and resistance to therapy.
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Context.-Unlike the small bowel, the colorectal mucosa is seldom the site of metastatic disease. Objective.-To determine the incidence of truly colorectal metastases, and subsequent clinicopathologic findings, in a substantial colorectal cancer population collected from 7 European centers. Design.-During the last decade, 10 365 patients were identified as having colorectal malignant tumors, other than systemic diseases. Data collected included patient demographics, clinical symptoms, treatment, the presence of metastases in other sites, disease-free interval, follow-up, and overall survival. All secondary tumors resulting from direct invasion from malignant tumors of the contiguous organs were excluded, as well as those resulting from lymph node metastases or peritoneal seeding. Results.-Only 35 patients were included (10 men) with a median age of 59 years. They presented with obstruction, bleeding, abdominal pain, or perforation. The leading source of metastases was the breast, followed by melanoma. Metastases were synchronous in 3 cases. The mean disease-free interval for the remaining cases was 6.61 years. Surgical resection was performed in 28 cases. Follow-up was available for 26 patients; all had died, with a mean survival time of 10.67 months (range, 1-41 months). Conclusions.-Colorectal metastases are exceptional (0.338%) with the breast as a leading source of metastases; they still represent a late stage of disease and reflect a poor prognosis. Therefore, the pathologist should be alert for the possibility of secondary tumors when studying large bowel biopsies. Any therapy is usually palliative, but our results suggest that prolonged survival after surgery and complementary therapy can be obtained in some patients.
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Pooled F(ab')2 fragments of three MAbs against distinct epitopes of carcinoembryonic antigen (CEA) were used for radioimmunotherapy of nude mice bearing a subcutaneous human colon carcinoma xenograft. 9-10 d after transplantation when tumor nodules were in exponential growth, 36 mice were treated by intravenous injection of different amounts of 131I-labeled MAb F(ab')2. All 14 mice injected with a single dose of 2,200 (n = 10) or 2,800 microCi (n = 4) showed complete tumor remission. 8 of the 10 mice treated with 2,200 microCi survived in good health for 1 yr when they were killed and shown to be tumor free. Four of nine other mice treated with four fractionated doses of 400 microCi showed no tumor relapse for more than 9 mo. In contrast, all 15 mice injected with 1,600-3,000 microCi 131I-control IgG F(ab')2 showed tumor growth retardation of only 1-4 wk, and 15 of 16 mice injected with unlabeled anti-CEA MAb F(ab')2 showed unmodified tumor progression as compared with untreated mice. From tissue radioactivity distributions it was calculated that by an injection of 2,200 microCi 131I-MAb F(ab')2 a mean dose of 8,335 rad was selectively delivered to the tumor, while the tissue-absorbed radiation doses for the normal organs were: peripheral blood, 2,093; stomach, 1,668; kidney, 1,289; lung, 1,185; liver, 617; spleen, 501; small intestine, 427; large intestine, 367; bone, 337; and muscle, 198. These treatments were well tolerated since out of 19 mice with complete tumor remission only 4 required bone marrow transplantation and 17 were in good health for 6-12 mo of observation. The results demonstrate the selective destruction of established human colon carcinoma transplants by intravenous injection of either single or fractionated doses of 131I-MAb F(ab')2.
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Objective: Small nodal tumor infiltrates are identified by applying multilevel sectioning and immunohistochemistry (IHC) in addition to H&E (hematoxylin and eosin) stains of resected lymph nodes. However, the use of multilevel sectioning and IHC is very time-consuming and costly. The current standard analysis of lymph nodes in colon cancer patients is based on one slide per lymph node stained by H&E. A new molecular diagnostic system called ''One tep Nucleic Acid Amplification'' (OSNA) was designed for a more accurate detection of lymph node metastases. The objective of the present investigation was to compare the performance ofOSNAto current standard histology (H&E). We hypothesize that OSNA provides a better staging than the routine use of one slide H&E per lymph node.Methods: From 22 colon cancer patients 307 frozen lymph nodes were used to compare OSNA with H&E. The lymph nodes were cut into halves. One half of the lymph node was analyzed by OSNA. The semi-automated OSNA uses amplification of reverse-transcribed cytokeratin19 (CK19) mRNA directly from the homogenate. The remaining tissue was dedicated to histology, with 5 levels of H&E and IHC staining (CK19).Results: On routine evaluation of oneH&Eslide 7 patients were nodal positive (macro-metastases). All these patients were recognized by OSNA analysis as being positive (sensitivity 100%). Two of the remaining 15 patients had lymph node micro-metastases and 9 isolated tumor cells. For the patients with micrometastases both H&E and OSNA were positive in 1 of the 2 patients. For patients with isolated tumor cells, H&E was positive in 1/9 cases whereas OSNA was positive in 3/9 patients (IHC as a reference). There was only one case to be described as IHC negative/OSNA positive. On the basis of single lymph nodes the sensitivity of OSNA and the 5 levels of H&E and IHC was 94・5%.Conclusion: OSNA is a novel molecular tool for the detection of lymph node metastases in colon cancer patients which provides better staging compared to the current standard evaluation of one slide H&E stain. Since the use of OSNA allows the analysis of the whole lymph node, sampling bias and undetected tumor deposits due to uninvestigated material will be overcome. OSNA improves staging in colon cancer patients and may replace the current standard of H&E staining in the future.
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BACKGROUND: A new diagnostic system, called one-step nucleic acid amplification (OSNA), has recently been designed to detect cytokeratin 19 mRNA as a surrogate for lymph node metastases. The objective of this prospective investigation was to compare the performance of OSNA with both standard hematoxylin and eosin (H&E) analysis and intensive histopathology in the detection of colon cancer lymph node metastases. METHODS: In total, 313 lymph nodes from 22 consecutive patients with stage I, II, and III colon cancer were assessed. Half of each lymph node was analyzed initially by H&E followed by an intensive histologic workup (5 levels of H&E and immunohistochemistry analyses, the gold standard for the assessment of sensitivity/specificity of OSNA), and the other half was analyzed using OSNA. RESULTS: OSNA was more sensitive in detecting small lymph node tumor infiltrates compared with H&E (11 results were OSNA positive/H&E negative). Compared with intensive histopathology, OSNA had 94.5% sensitivity, 97.6% specificity, and a concordance rate of 97.1%. OSNA resulted in an upstaging of 2 of 13 patients (15.3%) with lymph node-negative colon cancer after standard H&E examination. CONCLUSIONS: OSNA appeared to be a powerful and promising molecular tool for the detection of lymph node metastases in patients with colon cancer. OSNA had similar performance in the detection of lymph node metastases compared with intensive histopathologic investigations and appeared to be superior to standard histology with H&E. Most important, the authors concluded that OSNA may lead to a potential upstaging of >15% of patients with colon cancer.
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Introduction: Approximately one fifth of stage I and II colon cancer patients will suffer from recurrent disease. This is partly due to the presence of small nodal tumour infiltrates, which are undetected by standard histopathology using Haematoxylin & Eosin (H&E) staining on one slice and thus may not receive beneficial adjuvant therapy. A new diagnostic, semi-automatic system, called one-step nucleic acid amplification (OSNA), was recently designed for the detection of cytokeratin 19 (CK19) mRNA as a surrogate for lymph node metastases. The objective of the present investigation was to compare the performance of OSNA with both standard H&E as well as intensive histopathologic analyses in the detection of colon cancer lymph node micro- and macro-metastases.Methods: In this prospective study 313 lymph nodes from 22 consecutive stage I - III colon cancer patients were assessed. Half of each lymph node was analysed initially based on one slice of H&E followed by an intensive histologic work-up (5 levels of H&E and immuno-histochemistry staining for each slice), the other half was analysed using OSNA.Results: All OSNA results were available after less than 40 minutes. Fifty-one lymph nodes were positive and 246 lymph nodes negative with both OSNA and standard H&E. OSNA was more sensitive to detect small nodal tumor infiltrates compared to H&E (11 OSNA pos. /H&E neg.). Compared to intensive histopathologic analyses, OSNA had a sensitivity of 94.5% and a specificity of 97.6% to detect lymph node micro- and macro-metastases with a concordance rate of 97.1%. An upstaging due to OSNA was found in 2/13 (15.3%) initially node negative colon cancer patients.Conclusion: OSNA appears to be a powerful and promising molecular tool for the detection of lymph node macro- and micro-metastases in colon cancer patients. OSNA has a similar performance in the detection of micro- and macro-metastases compared to intensive histopathologic investigations and appears to be superior to standard histology with H&E. Since the use of OSNA allows the analysis of the whole lymph node, the problem of sampling bias and undetected tumor deposits due to uninvestigated material will be overcome in the future and OSNA may thus improve staging in colon cancer patients. It is hoped that this improved staging will lead to better patient selection for adjuvant therapy and consecutively improved local and distant control as well as better overall survival.
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Colorectal cancer frequently disseminates through the portal vein into the liver. In this study, outbred Swiss nude mice were adapted to facilitate the induction of liver metastases by a pre-grafting treatment with 6 Gy total body irradiation and i.v. injection of anti-asialo GM1 antibody. One day later, cultured LS 174T human colon cancer cells were injected into the surgically exposed spleen, which was resected 3 min later. In 48 of 65 mice, a few to several hundred liver metastases were macroscopically observed at dissection 3 to 4 weeks after transplantation. Ten of 10 mice, followed-up for survival, died with multiple large confluent liver metastases. By reducing the radiation dose to 4 or 0 Gy, or omitting the anti-asialo GM1 antibody injection, only 60%, 37% or 50% of mice, respectively, had visible metastases 3 weeks after transplantation. Carcinoembryonic antigen (CEA) measured in tumour extracts was in the mean 25.6 micrograms/g in liver metastases compared with 9.2 micrograms/g in s.c. tumours. Uptake of radiolabelled anti-CEA monoclonal antibody (MAb) in the metastases 12, 24 and 48 hr after injection gave a mean value of 39% of the injected dose per gram of tissue (ID/g). In comparison, MAb uptake in s.c. and intrasplenic tumours or lung metastases gave a mean percentage ID/g of 20, 18 and 15, respectively. Laser-induced fluorescence after injection of indocyanin-MAb conjugate allowed direct visual detection of small liver metastases, including some that were not visible under normal light. Preliminary results showed that mice, pre-treated with 4 Gy irradiation and the anti-asialo GM1 injection, were tolerant to radioimmunotherapy with a total dose of 500 muCi 131I labeled anti-CEA intact MAbs given in 3 injections.
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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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To investigate whether caveolin-1 (cav-1) may modulate inducible nitric oxide synthase (iNOS) function in intact cells, the human intestinal carcinoma cell lines HT29 and DLD1 that have low endogenous cav-1 levels were transfected with cav-1 cDNA. In nontransfected cells, iNOS mRNA and protein levels were increased by the addition of a mix of cytokines. Ectopic expression of cav-1 in both cell lines correlated with significantly decreased iNOS activity and protein levels. This effect was linked to a posttranscriptional mechanism involving enhanced iNOS protein degradation by the proteasome pathway, because (i) induction of iNOS mRNA by cytokines was not affected and (ii) iNOS protein levels increased in the presence of the proteasome inhibitors N-acetyl-Leu-Leu-Norleucinal and lactacystin. In addition, a small amount of iNOS was found to cofractionate with cav-1 in Triton X-100-insoluble membrane fractions where also iNOS degradation was apparent. As has been described for endothelial and neuronal NOS isoenzymes, direct binding between cav-1 and human iNOS was detected in vitro. Taken together, these results suggest that cav-1 promotes iNOS presence in detergent-insoluble membrane fractions and degradation there via the proteasome pathway.
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To determine the feasibility of data transfer, an interlaboratory comparison was conducted on colon carcinoma cell line (DLD-1) proteins resolved by two-dimensional polyacrylamide gel electrophoresis either on small (6 x 7 cm) or large (16x18 cm) gels. The gels were silver-stained and scanned by laser densitometry, and the image obtained was analyzed using Melanie software. The number of spots detected was 1337+/-161 vs. 2382+/-176 for small vs. large format gels, respectively. After gel calibration using landmarks determined using pl and Mr markers, large- and small-format gels were matched and 712+/-36 proteins were found on both types of gels. Having performed accurate gel matching it was possible to acquire additional information after accessing a 2-D PAGE reference database (http://www.expasy.ch/ cgibin/map2/def?DLD1_HUMAN). Thus, the difference in gel size is not an obstacle for data transfer. This will facilitate exchanges between laboratories or consultation concerning existing databases.
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Glutamate and the N-methyl-D-aspartate receptor ligand D-serine are putative gliotransmitters. Here, we show by immunogold cytochemistry of the adult hippocampus that glutamate and D-serine accumulate in synaptic-like microvesicles (SLMVs) in the perisynaptic processes of astrocytes. The estimated concentration of fixed glutamate in the astrocytic SLMVs is comparable to that in synaptic vesicles of excitatory nerve terminals (∼45 and ∼55 mM, respectively), whereas the D-serine level is about 6 mM. The vesicles are organized in small spaced clusters located near the astrocytic plasma membrane. Endoplasmic reticulum is regularly found in close vicinity to SLMVs, suggesting that astrocytes contain functional nanodomains, where a local Ca(2+) increase can trigger release of glutamate and/or D-serine.
Resumo:
As a cause of small intestine occlusion, volvulus is often a consequence of a band or adhesions. Except in infants, it is rarely the primary cause of symptomatology. Between January 1976 and December 1992, 13 patients (7 women and 6 men, mean age of 56.8 years) were admitted in our department for an acute abdomen due to a spontaneous primary volvulus of the small bowel. Clinical examination and laboratory tests did not help in preoperative diagnosis. All patients underwent an explorative laparotomy. Six patients had had prior abdominal surgery but none of them presented adhesion or band. In 8 patients (62%), detorsion was sufficient. Resection of a segment of small bowel was necessary in 4 patients. Gangrenous of the entire bowel was observed in one patient who rapidly died. Two patients presented minor complications. One patient with Down syndrome died of bronchoaspiration. One patient has been reoperated on one year later for recurrence of the volvulus, and underwent a Noble procedure. We conclude that volvulus of the small bowel is a rare cause of acute abdomen that must be remembered. Early surgery is mandatory to reduce the risk of gangrene, which is known to double the mortality. Laparoscopy will be helpful in early diagnosis and therapy.