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Objective To investigate the risk factors of pathological discrepancy between biopsy and excisional specimen from gastric low-grade intraepithelial neoplasia (LGIN) and early gastric cancer (EGC). Methods A retrospective analysis was conducted on the data of 235 patients who underwent endoscopic submucosal dissection or surgical resection and diagnosed as LGIN or EGC ( including high-grade intraepithelial neoplasia) by postoperative pathology. Patients were grouped by whether there was significant pathological discrepancy between biopsy and excisional specimen. Univariate and multivariate analyses were used to analyze the risk factors for significant pathological discrepancy. Results Significant pathological discrepancy occurred in 33 cases (14. 0%). Univariate analysis showed that protruding lesion, non-reddish surface, without erosion or ulcer, diffused pathological type and number of biopsy were related to the pathological discrepancy (all P＜0. 05). Multivariate analysis suggested that small number of biopsy blocks (OR＝0. 574, 95%CI: 0. 363-0. 908, P＝0. 018) was an independent risk factor for significant pathological discrepancy. Conclusion The pathological discrepancy between biopsy and excisional specimen from gastric LGIN and EGC are common. Multiple biopsies can improve the accuracy of biopsy and reduce the occurrence of pathological discrepancy with excisional specimen.
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Ion trap performances are investigated based on digital ion trap technique with different collision gases at different pressures. Collision gases of helium (4 amu), nitrogen (28 amu) and argon (40 amu) with various pressures are adopted in ion excitation and dissociation stages to investigate the ion trap performances, including mass resolution, signal intensity, tandem mass spectrometric analysis ability and low-mass cut off (LMCO) effect. It is found that when heavy gas of argon is used, energy can be efficiently transferred and LMCO effect is decreased with higher ion capture and dissociation efficiencies but with low mass resolution. Higher mass resolution is realized with helium as collision gas. Furthermore, at the same gas pressure, heavy gas is beneficial to abundant fragment ions and structural information of precursor ion.
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Theoretical study and experimental test of a new ion trap mass analyzer-ladder electrode linear ion trap (LeLIT) were reported. The LeLIT was composed of two pairs of ladder electrodes and one pair of end-electrodes. By optimizing the geometric structure of ladder electrodes, we optimized the electric field distribution for optimum mass analysis. Since the distribution of electric field can be controlled by the adjustment of LeLIT structure, LeLIT have better performance than rectilinear ion trap theoretically. Due to its simpler structure than hyperbolic electrode LIT, LeLIT can be easily built. In this work, the height, width and field ratio were adjusted for optimizing the property of LeLIT, and a mass resolution of 10150 was obtained when the mass scan speed was 225 Da / s for a LeLIT with X0 ×Y0 = 9 mm×5 mm dimension. The preliminary experimental result showed that the LeLIT has proper tandem mass spectrometric performance as any conventional ion trap mass analyzer.
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Background:Colonoscopy is considered as a standard method for detecting various kinds of colorectal polyps. However,conventional colonoscopy( CC)still has the chance to miss some lesions. Literatures have already reported that transparent hood assisted colonoscopy( THAC)can improve the detection of colorectal polyps. However,the effect of black hood assisted colonoscopy( BHAC)on detection of colorectal polyps is still unclear. Aims:To evaluate the effect of BHAC on detection of colorectal polyps. Methods:A total of 1 076 patients underwent CC and BHAC from Sept. 2014 to April 2015 at Huadong Hospital Affiliated to Fudan University were enrolled in this prospective randomized controlled study. Baseline characteristics,cecal intubation time,withdrawal time,number of polyps,detection rate of polyps,location, size,morphology and pathological diagnosis of polyps between two groups were compared. Results:Compared with CC group,cecal intubation time was significantly shorter in BHAC group than in CC group[(6. 31 ± 3. 51)min vs.(7. 05 ± 4. 15)min,P=0. 002]. No significant differences in withdrawal time and rate of cecal intubation were found between two groups(P>0. 05). Detection rate of polyps was significantly higher in BHAC group than in CC group(65. 4% vs. 48. 7%,P=0. 004). No significant differences in size,morphology of polyps were found between two groups(P>0. 05). Conclusions:Compared with CC,BHAC could significantly improve the detection of colorectal polyps,and shorten cecal intubation time.
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The low mass cutoff ( LMCO) is the main weakness of ion trap when it performs tandem mass analysis by collision induced dissociation (CID). LMCO means that some daughter ions of m/ z are less than about 1 / 3 of the m/ z of parent ion could not be detected during the tandem mass spectrometry processing. A new method which can significantly improve the effect of low mass cutoff was proposed and investigated. By simply changing the scan method of digital potential frequency, some low mass ions can be effectively observed during the tandem mass spectrometric experiment. In the experiment, the frequency of the digital ion trapping power and ion activation power were scanned from lower value to higher value, and some lower mass product ions could be detected during CID process. For example, some lower mass ions were observed during the CID of reserpine precursor ion when the frequency of its digital trapping power was scanned from 500 kHz to 560 kHz. The tandem mass spectra of Reserpine ion showed that the experimental results both from this work and the triple quadrupole mass spectrometer were exactly the same.
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Objective To investigate the association between the nodular gastritis and the eradication of Helicobacter pylori .Methods To the patients with nodular gastritis discovered by gastroendoscopy during 2001～2002, detection of Helicobacter pylori and eradication of it if positive, were performed then followed up after 6 months by endoscopies.Results From 4939 cases of endoscopy thirteen cases of female nodular gastritis were diagnosed, accounted to 0 26% of the total cases examined. The age of patients ranged from 14～49 years, with mean age 29 years.The main symptom is epigastralgia. All cases were found affected with H.pylori . After H.pylori eradication, there is disappearance of the nodular appearance of the gastric antrum under endoscopies and disappearance of the gastric submucosal lymphoid follicles under histological examination.Conclusion Nodular gastritis is the very important manifestation having a high positive predictive value in H.pylori infection.
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Objective Twelve cases with small advanced cole-rectal cancer less than 10 mm in diameter were examined. Methods The endoscopic findings and clinicopathologic data of 12 cases with advanced colorectal cancer less than 10 mm in diameter were compared with those larger than 10 mm in diameter. Results Approximated estimation of the macroscopic types were Ⅱ c in 5 cases, Ⅱ a in 3 cases, and I s in 4 cases respectively. As for the distribution of these lesions, there were 5 in sigmoid colon, 4 in transverse colon, 1 in cecum, and 2 in descending colon. No lesions were detected in rectum. Histologic grade at the deepest invasive portion was shown well, moderately, and poorly differentiated in 2, 8 and 1 case respectively and another case with mucinous adenocarcinomas. Lymphnode metastasis was present in 4 of 12 lesions (33% ). This incidence is rather high, as regards to the small size of each lesion. Endoscopi-cally, all lesions accompanied with converging folds and 7 lesions examined by magnifying colonoscope showed V N pit pattern. Conclusion These results indicated that the advanced colorectal cancers less than 10mm in diameter showing similar characteristics with those of superficial depressed type cancer with likely is the precurser of advanced cancer. The findings of converging folds and pit pattern are considered to be the useful indicators for estimating the depth 'of invasion.
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Objective To evaluate the clinical and endoscopic features of ulcerative colitis(UC). Methods The cases of UC were collected from 1975 to 2001. According to the diagnostic criteria of Chengdu conference, 486 and 490 patients were diagnosed as UC in our hospital from 1975 to 1994 and from 1995 to 2001 respectively. Their records were retrieved and the data were analyzed for sex, age, presentation, the course of the illness and lesion range. Results In the two groups from 1975 to 1994 and from 1995 to 2001, the proportion of patients diagnosed as UC under colonoscopy was increased from 3.51% to 4.44%. The ratio of male to female was 1.67 and 1.25 respectively. The mean age at the diagnosis increased from 42.4 years old to 51.5 years old, and the peak age was between 30 and 49 years old, between 40 and 49 years old and greater than 60 years old respectively. The typical clinical manifestations of UC were bloody mucopurulent stool, diarrhea and abdominal pain. Proctosigmoiditis or proctitis was found in 269 patients (55.4%) and 316(64.5%), left side colitis in 84(17.3%) and 68(13.9%), pancoltitis in 58( 11.9% ) and 70(14.3%) respectively. In the two groups, there were 437( 89.9% ) and 443(90.4%) patients who had the course of less than 10 years respectively. The definitive diagnosis of UC was dependent on biopsy. Conclusions The lesions of UC are commonly located in the left side colon, the course of UC is short, the age of onset is relatively high in the middle and old aged group, and the prevalence of both malignancy and complications is low. Colonoscopy with biopsy is considered to be the major means for the diagnosis of UC.
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Objective To evaluate clinical and endoscopic characteristics of ischemic colitis (IC), and to explore the methods for the early diagnosis of IC. Methods Thirty six patients diagnosed as IC in Hua dong Hospital from June 1975 to December 2000 were reviewed. All patients underwent colonoscopy with biopsy within 5 days of symptoms, and repeated the exam in 2 weeks to 2 months. Results Of the 36 cases (12 men and 24 women, average age 60.5 years old, range 35 84), 31 were over 50 years of age. IC usually presented with sudden onset of left lower quadrant abdominal pain, diarrhea and hematochezia. Patients' ischemic lesions were most often on the left colon. It consisted transient or reversible colitis in 30 cases, stricture colitis in 5 cases and gangrene colitis in only 1 case. Morphologic changes varied with the duration and severity of the injury. Conclusion Colonoscopy with biopsy is the main method for the diagnosis of IC. It should be performed in the early stage of the onset of symptoms.