反应釜的“内窥镜”——β内酰胺抗生素（β-Lactam Antibiotics）的合成

在化学和药物工业中．科学家或工程师们最想知道的是反应物质在反应釜里进行的实际情况。为此．他们尝试了各种办法，其中多为离线测试．速度慢．不能在实际条件下进行。而原位红外却能弥补所有这些不足．像反应釜的一个“内窥镜”，通过实时跟踪反应物、中间物和产物的瞬时变化．准确提供反应趋势．路线、终点、各个过程转化率等信息。这项技术在国外已经得到广泛使用．在制药行业，世界排名前20位的药物公司如辉瑞、施贵宝、史克、默克等都是该产品的用户。

用“内窥镜”检查“身体”

本刊讯 2005年伊始，银行、保险和电信等行业都对自身的系统管理投入了更大的关注，尤其是随着行业竞争的加剧，新应用新业务的不断提出，对这些行业提出了更加严格的要求。

Public Screening for Early Carcinoma of Gastric Cardia: Rule of Carcinogenetic Development Observed by Endoscopy

Objective： To study the rule of development of early cancer of gastric cardia in vivo in public screening. Methods： A prospective cohort study on gastric cardiac cancer was performed in the high incidence area of cancer of esophagus and stomach in china. 106 subjects had been examined regularly by endoscopy to observe the change of mucosa in high incident area of gastric cardiac carcinoma developing at the root of gastric cardiac ridge by taking biopsy specimen. All specimens were diagnosed through normal pathological process to study the prognosis of pro-cancer lesions of gastric cardia. Results： The results of 106 subjects who had been observed for 4 years were： （1） Of 8 normal persons, 3 stayed normal, 4 turned to chronic gastritis, 1 developed early gastric cardiac cancer. （2） Of 61 persons with chronic gastritis, 11 were observed to have gland atrophy, 4 mild atypical hyperplasia, and 2 highly atypical hyperplasia. （3） Of 9 subjects showing atrophic chronic gastritis, 5 revealed no change, and 4 became chronic gastritis. （4） Of 22 subjects who revealed mild atypical hyperplasia, 17 resolved, 4 showed no change, and 1 advanced to highly atypical hyperplasia. （5） One person with highly atypical hyperplasia reverted to mild atypical hyperplasia. （6） Of 5 subjects with early gastric cardiac cancer without any treatment, 1 became advanced cancer, 1 still stayed in early cancer stage, and 3 turned to atypical hyperplasia. Conclusion： The development of early cancer of gastric cardia would proceed through the stages of chronic gastritis, gland atrophy, and atypical hyperplasia. （2） The early cancer and pre-cancer lesions of gastric cardia is reversible, though possessing malignant possibility.

A 2.4GHz Low Power ASK Transmitter for Wireless Capsule Endoscope Applications

A 2.4GHz ASK transmitter suitable for a low power wireless capsule endoscope system is presented. A mixer-based frequency up-conversion transmitter architecture is employed to achieve a high data rate. A pseudodifferential stacked class-A power amplifier using the current reuse technique is proposed to save power. The transmitter mainly includes two parts： a 20MHz ASK modulator based on a constant amplitude phase lock loop （PLL） and a direct up-conversion RF circuit. This design, implemented in a TSMC 0.25μm CMOS process, achieves a - 23. 217dBm output power with a data rate of 1Mbps and dissipates 3.17mA of current with a single 2.5V power supply.

Endoscopic submucosal dissection for gastrointestinal neoplasms

Endoscopic submucosal dissection (ESD) is an advanced technique of therapeutic endoscopy for superficial gastrointestinal neoplasms. Three steps characterize it:injecting fluid into the submucosa to elevate the lesion, cutting the surrounding mucosa of the lesion, and dissecting the submucosa beneath the lesion. The ESD technique has rapidly permeated in Japan for treatment of early gastric cancer, due to its excellent results of en- bloc resection compared to endoscopic mucosal resection (EMR). Although there is still room for improvement to lessen its technical difficulty, ESD has recently been applied to esophageal and colorectal neoplasms. Favorable short-term results have been reported, but the application of ESD should be well considered by three aspects:(1) the possibility of nodal metastases of the lesion, (2) technical difficulty such as location, ulceration and operator’s skill, and (3) organ characteristics.

Diagnostic procedures for submucosal tumors in the gastrointestinal tract

This review is part one of three, which will present an update on diagnostic procedures for gastrointestinal (GI) submucosal tumors (SMTs). Part two identifies the classification and part three the therapeutic methods regarding GI SMTs. Submucosal tumors are typically asymptomatic and therefore encountered incidentally. Advances in diagnostic tools for gastrointestinal submucosal tumors have emerged over the past decade. The aim of this paper is to provide the readers with guidelines for the use of diagnostic procedures, when a submucosal tumor is suspected. Literature searches were performed to find information on diagnostics for gastrointestinal submucosal tumors. Based on the searches, the optimal diagnostic procedures and specific features of the submucosal tumors could be outlined. Standard endoscppy, capsule endoscopy and push-and-pull enteroscopy (PPE) together with barium contrast X-ray do not alone provide sufficient information, when examining submucosal tumors. Endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI) and fluorodeoxyglucose-labeled positron emission tomography (FDG-PET) are recommended as supplementary tools.

Capsule endoscopy:Current status in obscure gastrointestinal bleeding

Capsule endoscopy (CE) is a safe, non invasive diagnostic modality for the evaluation of small bowel lesions. Obscure gastrointestinal bleeding (OGIB) is one of the most important indications of capsule endoscopy. Capsule endoscopy has a very high diagnostic yield especially if the bleeding is ongoing. This technique appears to be superior to other techniques for the detection of suspected lesions and the source of bleeding. Capsule endoscopy has been shown to change the outcome in patients with obscure gastrointestinal (GI) bleed.

In vitro activity of moxifloxacin and piperacillin/sulbactam against pathogens of acute cholangitis

AIM：To analyze the in vitro activity of moxifloxacin and piperacillin/sulbactam against pathogens isolated from patients with acute cholangitis. METHODS： In this prospective study a total of 65 patients with acute cholangitis due to biliary stone obstruction （n = 7）, benign biliary stricture （n = 16）, and malignant biliary stricture （n = 42） were investigated with regard to spectrum of bacterial infection and antibiotic resistance. Pathogens were isolated from bile cultures in all study patients. In 22 febrile patients, blood cultures were also obtained. In vitro activity of moxifloxacin and piperacillin/ sulbactam was determined by agar diffusion. RESULTS： Thirty-one out of 65 patients had positive bile and/or blood cultures. In 31 patients, 63 isolates with 17 different species were identified. The predominant strains were Enterococcus species （26/63）, Ecoli （13/63） and Klebsiella species （8/63）. A comparable in vitro activity of moxifloxacin and piperacillin/sulbactam was observed for E.coli and Klebsiella species. In contrast, Enterococcus species had higher resistances towards moxifloxacin. Overall bacteria showed antibiotic resistances in vitro of 34.9% for piperacillin/sulbactam and 36.5% for moxifioxacin.CONCLUSION： Enterococcus species, E.co/i and Klebsiella species were the most common bacteria isolated from bile and/or blood from patients with acute cholangitis. Overall, a mixed infection with several species was observed, and bacteria showed a comparable in vitro activity for piperacillin/sulbactam and moxifloxacin.

Efficacy, risk factors and complications of endoscopic polypectomy: Ten year experience at a single center

AIM: To examine the efficacy and complications of colonoscopic resection of colorectal polypoid lesions. METHODS: We retrospectively reviewed 1354 polypectomies performed on 1038 patients over a ten- year period. One hundred and sixty of these were performed for large polyps, those measuring ≥ 20 mm. Size, shape, location, histology, the technique of polypectomy used, complications, drugs assumption and associated intestinal or extra intestinal diseases were analyzed. For statistical analysis, the Pearson χ2 test, NPC test and a Binary Logistic Regression were used. RESULTS: The mean patient age was 65.9 ± 12.4 years, with 671 men and 367 women. The mean size of polyps removed was 9.45 ± 9.56 mm while the size of large polyps was 31.5 ± 10.8 mm. There were 388 pedunculated and 966 sessile polyps and the most common location was the sigmoid colon (41.3%). The most frequent histology was tubular adenoma (55.9%) while for the large polyps was villous (92/160 -57.5%). Coexistent malignancy was observed in 28 polyps (2.1%) and of these, 20 were large polyps. There were 17 procedural bleeding (1.3%) and one perforation. The statistical analysis showed that cancer is correlated to polyp size (P < 0.0001); sessile shape (P < 0.0001) and bleeding are correlated to cardiac disease (P = 0.034), tubular adenoma (P = 0.016) and polyp size.CONCLUSION: The endoscopic resection is a simple and safe procedure for removing colon rectal neoplastic lesions and should be considered the treatment of choice for large colorectal polyps. The polyp size is an important risk factor for malignancy and for bleeding.

Perspective on the practical indications of endoscopic submucosal dissection of gastrointestinal neoplasms

Endoscopic submucosal dissection (ESD) is a new endoluminal therapeutic technique involving the use of cutting devices to permit a larger resection of the tissue over the muscularis propria. The major advantages of the technique in comparison with polypectomy and endoscopic mucosal resection are controllable resection size and shape and en bloc resection of a large lesion or a lesion with ulcerative findings. This technique is applied for the endoscopic treatment of epithelial neoplasms in the gastrointestinal tract from the pharynx to the rectum. Furthermore, some carcinoids and submucosal tumors in the gastrointestinal tract are treated by ESD. To determine the indication, two aspects should be considered. The first is a little likelihood of lymph node metastasis and the second is the technical resectability. In this review, practical guidelines of ESD for the gastrointestinal neoplasms are discussed based on the evidence found in the literature.

Usefulness of endoscopic ultrasonography in preoperative TNM staging of gastric cancer

AIM： To evaluate the value of endoscopic ultrasono- graphy （EUS） in the preoperative TNM staging of gastric cancer. METHODS ： Forty-one patients with gastric cancer （12 early stage and 29 advanced stage） proved by esophagogastroduodenoscopy and biopsies preoperatively evaluated with EUS according to TNM （1997） classification of International Union Contrele Cancer （UICC）. Pentax EG-3630U/Hitachi EUB-525 echo endoscope with real-time ultrasound imaging linear scanning transducers （7.5 and 5.0 MHz） and Doppler information was used in the current study. EUS staging procedures for tumor depth of invasion （T stage） were performed according to the widely accepted five-layer structure of the gastric wall. All patients underwent surgery. Diagnostic accuracy of EUS for TNM staging of gastric cancer was determined by comparing preoperative EUS with subsequent postoperative histopathologic findings. RESULTS： The overall diagnostic accuracy of EUS in preoperative determination of cancer depth of invasion was 68.3% （41/28） and 83.3% （12/10）, 60% （20/12）, 100% （5/5）, 25% （4/1） for T1, T2, T3, and T4, respectively. The rates for overstaging and understaging were 24.4% （41110）, and 7.3% （4113）, respectively. EUS tended to overstage T criteria, and main reasons for overstaging were thickening of the gastric wall due to perifocal inflammatory change, and absence of serosal layer in certain areas of the stomach. The diagnostic accuracy of metastatic lymph node involvement or N staging of EUS was 100% （17/17） for NO and 41.7% （24/10） for N＋, respectively, and 66% （41127） overall.Misdiagnosing of the metastatic lymph nodes was related to the difficulty of distinguishing inflammatory lymph nodes from malignant lymph nodes, which imitate similar echo features. Predominant location and distribution of tumors in the stomach were in the antrum （20 patients）, and the lesser curvature （17 patients）, respectively. Three cases were found as surgically unresectable （T4 N＋）, and included as being correctly diagnosed by EUS. CONCLUSION： EUS is a useful diagnostic method for preoperative staging of gastric cancer for T and N criteria. However, EUS evaluation of malignant lymph nodes is still unsatisfactory.

Endoscopic submucosal dissection for stomach neoplasms

Recent advances in techniques of therapeutic endoscopy for stomach neoplasms are rapidly achieved. One of the major topics in this field is endoscopic submucosal dissection （ESD）. ESD is a new endoscopic technique using cutting devices to remove the tumor by the following three steps： injecting fluid into the submucosa to elevate the tumor from the muscle layer, pre-cutting the surrounding mucosa of the tumor, and dissecting the connective tissue of the submucosa beneath the tumor. So the tumors are resectable in an en bloc fashion, regardless of the size, shape, coexisting ulcer, and location. Indication for ESD is strictly confined by two aspects： the possibility of nodal metastases and technical difficulty, which depends on the operators. Although long-term outcome data are still lacking, short-term outcomes of ESD are extremely favourable and laparotomy with gastrectomy is replaced with ESD in some parts of therapeutic strategy for early gastric cancer.

Therapeutic procedures for submucosal tumors in the gastrointestinal tract

This review is part three of three and will present an update on the therapeutic options and procedures concerning gastrointestinal (GI) submucosal tumors (SMTs). The aim of this paper is to investigate the treatments of GI SMTs and to present a case of a gastrointestinal stromal tumor (GIST). Literature searches were performed to find information on therapy for GI SMTs. Based on these searches, the optimal therapeutic procedures could be outlined. The choice of treatment of localized tumors is endoscopic resection if possible or, alternatively, laparoscopic resection or surgical resection by an open procedure. However, benign SMTs should only be excised if symptoms are present, and GISTs should be treated with particular precautions. Irresectable or recurrent GISTs may be successfully treated with the tyrosine kinase inhibitor, imatinib.

Congenital tracheoesophageal fistula successfully diagnosed by CT esophagography

Tracheoesophageal fistula （TEF） or bronchoesophageal fistula may be congenital, inflammatory, neoplastic, or secondary to trauma. Congenital TEF or bronchoesophageal fistula is usually associated with esophageal atresia and is readily diagnosed in infancy. But if it is not associated with esophageal atresia, it may persist until adulthood. Some theories have been proposed to explain this delay in diagnosis. We present a case of a 70-year-old man with congenital TEF. The TEF was successfully diagnosed by multidetector-row CT esophagography.

How good is endoscopic ultrasound for TNM staging of gastric cancers? A meta-analysis and systematic review

AIM: To evaluate the accuracy of endoscopic ultrasound (EUS) for staging of gastric cancers. METHODS: Only EUS studies confirmed by surgery were selected. Only studies from which a 2 × 2 table could be constructed for true positive, false negative, false positive and true negative values were included. Articles were searched in Medline, Pubmed, Ovid journals, Cumulative index for nursing & allied health literature, International pharmaceutical abstracts, old Medline, Medline nonindexed citations, and Cochrane control trial registry. Two reviewers independently searched and extracted data. The differences were resolved by mutual agreement. 2 × 2 tables were constructed with the data extracted from each study. Meta-analysis for the accuracy of EUS was analyzed by calculating pooled estimates of sensitivity, specifi city, likelihood ratios, and diagnostic odds ratio. Pooling was conducted by both the Mantel-Haenszel method (fi xed effects model) and DerSimonian Laird method (random effects model). The heterogeneity of studies was tested using Cochran's Q test based upon inverse variance weights. RESULTS: Initial search identified 1620 reference articles and of these, 376 relevant articles were selected and reviewed. Twenty-two studies (n = 1896) which met the inclusion criteria were included in this analysis. Pooled sensitivity of T1 was 88.1% (95% CI: 84.5-91.1) and T2 was 82.3% (95% CI: 78.2-86.0). For T3, pooled sensitivity was 89.7% (95% CI: 87.1-92.0). T4 hada pooled sensitivity of 99.2% (95% CI: 97.1-99.9). For nodal staging, the pooled sensitivity for N1 was 58.2% (95% CI: 53.5-62.8) and N2 was 64.9% (95% CI: 60.8-68.8). Pooled sensitivity to diagnose distant metastasis was 73.2% (95% CI: 63.2-81.7). The P for chi-squared heterogeneity for all the pooled accuracy estimates was > 0.10. CONCLUSION: EUS results are more accurate with advanced disease than early disease. If EUS diagnoses advanced disease, such as T4 disease, the patient is 500 times more likely to have true anatomic stage of T4 disease.

Capsule endoscopy: Improving transit time and image view

AIM： To evaluate the effect of various methods of small bowel preparation on the transit time and the quality of visualization of the entire small bowel mucosa. METHODS： Ninety-five patients underwent capsule endoscopy （CE） by easily swallowing the capsule. They were divided into three study groups according to the preparation used： group A （n = 26） by polyethylene glycol （PEG） liter or with sodium phosphate （SP） 12 h prior to the CE study; group B （n = 29） by erythromycin 1 h prior to the CE study; and group C （n = 40） without any preparation. Visualization ranged from good to satisfactory to poor. RESULTS： The gastric emptying time in the group prepared with erythromycin was shorter but without statistical significance and the small bowel transit time was unaffected. In elderly subjects prepared by PEG or SP, the gastric emptying time was significantly longer （163.7 rain, P = 0.05）. The transit times of the three sub-groups were not affected by gender or pathology. The grade of cleaning of the entire study group was 3.27±1.1. The erythromycin group presented significantly the worst quality of images （P = 0.05） compared to the other sub-groups. Age, gender, and pathology had no effect on the quality of the cleaning of the small bowel in the sub-groups. One （1.05%） case had no natural excretion. CONCLUSION： Erythromycin markedly reduces gastric emptying time, but has a negative effect on the quality of the image in the small bowel. The preparation of elderly subjects with PEG or SP has a negative effect on the small bowel transit time.

Risk factors for bleeding after endoscopic mucosal resection

AIM： To clarify the risk factors for bleeding after endoscopic mucosal resection （EMR）. METHODS： A total of 297 consecutive patients who underwent EMR were enrolled. Some of the patients had multiple lesions. Bleeding requiring endoscopic treatment was defined as bleeding after EMR. Odds ratios （OR） with 95% confidence intervals （CI）, calculated by logistic regression with multivariate adjustments for covariates, were the measures of association. RESULTS： Of the 297 patients, 57 （19.2%） patients with bleeding after EMR were confirmed. With multivariate adjustment, the cutting method of EMR, diameter, and endoscopic pattern of the tumor were associated with the risk of bleeding after EMR. The multivariate-adjusted OR for bleeding after EMR using endoscopic aspiration mucosectomy was 3.07 （95%CI, 1.59-5.92） compared with strip biopsy. The multiple-adjusted OR for bleeding after EMR for the highest quartile （16-50 mm） of tumor diameter was 5.63 （95%CI, 1.84-17.23） compared with that for the lowest （4-7 mm）. The multiple-adjusted OR for bleeding after EMR for depressed type of tumor was 4.21 （95%CI, 1.75-10.10） compared with elevated type. CONCLUSION： It is important to take tumor charactedstics （tumor size and endoscopic pattern） and cutting method of EMR into consideration in predicting bleeding after EMR.

Endorectal ultrasonography versus phased-array magnetic resonance imaging for preoperative staging of rectal cancer

AIM: To compare the diagnostic accuracy of pelvic phased-array magnetic resonance imaging (MRI) and endorectal ultrasonography (ERUS) in the preoperative staging of rectal carcinoma. METHODS: Thirty-four patients (15 males, 19 females) with ages ranging between 29 and 75 who have biopsy proven rectal tumor underwent both MRI and ERUS examinations before surgery. All patients were evaluated to determine the diagnostic accuracy of depth of transmural tumor invasion and lymph node metastases. Imaging results were correlated with histopathological findings regarded as the gold standard and both modalities were compared in terms of predicting preoperative local staging of rectal carcinoma. RESULTS: The pathological T stage of the tumors was: pT1 in 1 patient, pT2 in 9 patients, pT3 in 21 patients and pT4 in 3 patients. The pathological N stage of the tumors was: pN0 in 19 patients, pN1 in 9 patients and pN2 in 6 patients. The accuracy of T staging for MRI was 89.70% (27 out of 34). The sensitivity was 79.41% and the specificity was 93.14%. The accuracy of T staging for ERUS was 85.29% (24 out of 34). The sensitivity was 70.59% and the specificity was 90.20%. Detection of lymph node metastases usingphased-array MRI gave an accuracy of 74.50% (21 out of 34). The sensitivity and specificity was found to be 61.76% and 80.88%, respectively. By using ERUS in the detection of lymph node metastases, an accuracy of 76.47% (18 out of 34) was obtained. The sensitivity and specificity were found to be 52.94% and 84.31%, respectively. CONCLUSION: ERUS and phased-array MRI are complementary methods in the accurate preoperative staging of rectal cancer. In conclusion, we can state that phased-array MRI was observed to be slightly superior in determining the depth of transmural invasion (T stage) and has same value in detecting lymph node metastases (N stage) as compared to ERUS.

Intraductal biliary and pancreatic endoscopy: An expanding scope of possibility

Intraductal endoscopy describes the use of an endoscope to directly visualize the biliary and pancreatic ducts. For many years, technological challenges have made performing these procedures difficult. The "mother-baby" system and other various miniscopes have been developed, but routine use has been hampered due to complex setup, scope fragility and the time consuming, technically demanding nature of the procedure. Recently, the SpyGlass peroral cholangiopancreatoscopy system has shown early success at providing diagnostic information and therapeutic options. The clinical utility of intraductal endoscopy is broad. It allows better differentiation between benign and malignant processes by allowing direct visualization and targeted sampling of tissue. Therapeutic interventions, such as electrohydraulic lithotripsy (EHL), laser lithotripsy, photodynamic therapy, and argon plasma coagulation (APC), may also be performed as part of intraductal endoscopy. Intraductal endoscopy significantly increases the diagnostic and therapeutic yield of standard endoscopic retrograde cholangiography (ERCP), and as technology progresses, it is likely that its utilization will only increase. In this review of intraductal endoscopy, we describe in detail the various endoscopic platforms and their diagnostic and clinical applications.

Type 2 diabetes mellitus affects eradication rate of Helicobacter pylori

AIM: To study the eradication rate of Helicobacter pylori (Hp) in a group of type 2 diabetes and compared it with an age and sex matched non-diabetic group.METHODS: 40 diabetic patients (21 females, 19 males;56±7 years) and 40 non-diabetic dyspeptic patients (20females, 20 males; 54±9 years) were evaluated. Diabetic patients with dyspeptic complaints were referred for upper gastrointestinal endoscopies; 2 corpus and 2 antral gastric biopsy specimens were performed on each patient. Patients with positive Hp results on histopathological examination comprised the study group. Non-diabetic dyspeptic patients seen at the Gastroenterology Outpatient Clinic and with the same biopsy and treatment protocol formed the control group.A triple therapy with amoxycillin (1 g b.i.d), clarithromycin (500 mg b.i.d) and omeprazole (20 mg b.i.d.) was given to both groups for 10 days. Cure was defined as the absence of Hp infection assessed by corpus and antrum biopsies in control upper gastrointestinal endoscopies performed 6weeks after completing the antimicrobial therapy.RESULTS: The eradication rate was 50 % in the diabetic group versus 85 % in the non-diabetic control group (P＜0.001).CONCLUSION: Type 2 diabetic patients showed a significantly lower eradication rate than controls which may be due to changes in microvasculature of the stomach and to frequent antibiotic usage because of recurrent bacterial infections with the development of resistant strains.