Seasonal variation of melatonin secretion across various segments of the gastrointestinal tract in rats

Objective:To investigate whether melatonin(MT)secretion in different parts of the gastrointestinal tract(GIT)exhibits seasonal variations and its correlation with immune regulation.Methods: Sixty Sprague-Dawley rats were divided into control and model groups,and the pineal gland was removed in the model group.Stomach,jejunum,ileum,and colon tissues were obtained during the spring equinox,summer solstice,beginning of autumn,autumn equinox,and winter solstice.The levels of MT,MT receptors(MR),arylalkylamine N-acetyltransferase(AANAT),hydroxyindole-O-methyltransferase(HIOMT),interleukin-2(IL-2),and interleukin-10(IL-10)in the GIT were measured using enzyme-linked immunosorbent assay.Results: Except for the stomach,the jejunum,ileum,and the colon showed seasonal tendencies in MT secretion.In the control group,MT secretion in the jejunum and ileum was the highest in the long summer,and colonic MT secretion was the highest in winter.In the model group,MT levels in the colon were highest in the summer.The seasonal rhythms of the MR,AANAT,HIOMT,IL-2,and IL-10 in the colon were roughly similar to those of MT,and changed accordingly after pinealectomy.Conclusions: Gastrointestinal MT secretion is related to seasonal changes,and MT secretion in each intestinal segment is influenced by different seasons.The biological effects of MT in the gut are inextricably linked to the mediation of MR,and a hormone-receptor linkage exists between MT and MR.The effect of seasonal changes on the gastrointestinal immune system may be mediated through the regulation of seasonal secretion of MT.

Malignant melanoma:An important differential diagnosis for clear cell sarcoma of the gastrointestinal tract

A case report by Liu et al describes the characteristics of metastatic clear cell sarcoma(CCS)of the pancreas and provides valuable therapeutic insights for this rare malignancy.This case is interesting because of its rarity,suggesting that the pancreas may be a potential target organ for CCS,either primary or metastatic.At the same time,the authors also emphasize the importance of regular postoperative follow-up for timely detection of recurrent lesions,as CCS is characterized by a high degree of malignancy and a high rate of recurrent metastases.Considering that CCS of the gastrointestinal tract is easily confused with malignant melanoma(MM)of the gastrointestinal tract,here we compare the clinical features,histopathological and immunohistochemical characteristics,diagnosis,treatment,and prognosis of CCS and MM of the gastrointestinal tract,hoping to provide a reference for clinical work.

Endoscopic resection for calcifying fibrous tumors of the gastrointestinal tract

BACKGROUND Calcifying fibrous tumors(CFTs)are rare mesenchymal lesions that can occur in various sites throughout the body,including the tubular gastrointestinal(GI)tract.AIM To analyze the clinical findings of 36 patients with GI tract CFTs to provide guidance for diagnosis and treatment.METHODS This retrospective study included 36 patients diagnosed with CFTs of the GI tract.We collected demographic and clinical information and conducted regular follow-ups to assess for local recurrence.RESULTS The stomach was the most commonly involved site,accounting for 72.2%of the 36 CFTs.Endoscopic mucosal resection(n=1,2.8%),endoscopic submucosal dissection(n=14,38.9%),endoscopic full-thickness resection(n=16,44.4%),and submucosal tunneling endoscopic resection(n=5,13.9%)were used to resect calcifying fibrous tumors.Overall,34(94.4%)CFTs underwent complete endoscopic resections with a mean procedure time of 39.8±29.8 min.The average maximum diameter of the tumors was 10.6±4.3 cm.No complications,such as bleeding or perforation,occurred during an average hospital stay of 2.9±1.2 d.In addition,two patients developed new growth of CFTs near the primary tumor sites,and none of the patients developed distant metastases during the follow-up period.CONCLUSION GI tract CFTs are rare and typically benign tumors that can be effectively managed with endoscopic procedures.

Clinical issues and challenges in imaging of gastrointestinal diseases:A minireview and our experience

Imaging techniques play a crucial role in the modern era of medicine,particularly in gastroenterology.Nowadays,various non-invasive and invasive imaging modalities are being routinely employed to evaluate different gastrointestinal(GI)diseases.However,many instrumental as well as clinical issues are arising in the area of modern GI imaging.This minireview article aims to briefly overview the clinical issues and challenges encountered in imaging GI diseases while highlighting our experience in the field.We also summarize the advances in clinically available diagnostic methods for evaluating different diseases of the GI tract and demonstrate our experience in the area.In conclusion,almost all imaging techniques used in imaging GI diseases can also raise many challenges that necessitate careful consideration and profound expertise in this field.

Advancements and challenges in gastrointestinal imaging

A recent review by Gulinac et al,provides an in-depth analysis of current clinical issues and challenges in gastrointestinal imaging.This editorial highlights the advancements in imaging techniques,including the integration of artificial intelligence and functional imaging modalities,and discusses the ongoing relevance of traditional nuclear medicine tests.The future of gastrointestinal imaging looks promising,with continuous improvements in resolution,enhanced ability to analyze color and texture beyond visual diagnosis,faster image processing,and the application of molecular imaging and nanoparticles expected to enhance diagnostic accuracy and clinical outcomes.

Gastrointestinal contrast-enhanced ultrasonography for diagnosis and treatment of peptic ulcer in children

BACKGROUND The detection rate of peptic ulcer in children is improving,with development of diagnostic procedures.Gastroscopy is the gold standard for the diagnosis of peptic ulcer,but it is an invasive procedure.Gastrointestinal contrast-enhanced ultrasonography(CEUS)has the advantages of being painless,noninvasive,nonradioactive,easy to use,and safe.AIM To investigate the clinical value of CEUS for diagnosis and treatment of peptic ulcer in children.METHODS We investigated 43 children with digestive tract symptoms in our hospital from January 2021 to June 2022.All children were examined by routine ultrasound,gastrointestinal CEUS,and gastroscopy.The pathological results of gastroscopy were taken as the gold standard.Routine ultrasonography was performed before gastrointestinal CEUS.Conventional ultrasound showed the thickness of the gastroduodenal wall,gastric peristalsis,and the adjacent organs and tissues around the abdominal cavity.Gastrointestinal CEUS recorded the thickness of the gastroduodenal wall;the size,location and shape of the ulcer;gastric peristalsis;and adjacent organs and tissues around the abdominal cavity.The results of routine ultrasound and gastrointestinal ultrasound were compared with those of gastroscopy to evaluate the diagnostic results and coincidence rate of routine ultrasound and gastrointestinal CEUS.All children received informed consent from their guardians for CEUS.This study was reviewed and approved by the hospital medical ethics committee.RESULTS Among the 43 children,17(15 male,2 female)were diagnosed with peptic ulcer by gastroscopy.There were 26 children with nonpeptic ulcer.There were eight cases of peptic ulcer and 35 of nonpeptic ulcer diagnosed by conventional ultrasound.The diagnostic coincidence rate of peptic ulcer in children diagnosed by conventional ultrasound was 79.1%(34/43),which was significantly different from that of gastroscopy(P=0.033).It indicates that the coincidence rate of gastrointestinal contrast-enhanced ultrasound and gastroscope is low.Fifteen cases of peptic ulcer and 28 of nonpeptic ulcer were diagnosed by CEUS.The diagnostic coincidence rate of peptic ulcer in children was 95.3%(41/43).There was no significant difference between CEUS and gastroscopy(P=0.655).It indicates that the coincidence rate of gastrointestinal contrast-enhanced ultrasound and gastroscope is high.CONCLUSION Gastrointestinal CEUS has a high coincidence rate in the diagnosis of peptic ulcer in children,and can be used as a preliminary examination method.

Interleukin-1β:Friend or foe for gastrointestinal cancers

Gastrointestinal(GI)cancer is a malignancy arising in the digestive system and accounts for approximately a third of increasing global cancer-related mortality,especially in the colorectum,esophagus,stomach,and liver.Interleukin-1β(IL-1β)is a leukocytic pyrogen recognized as a tumor progression-related cytokine.IL-1βsecretion and maturation in inflammatory responses could be regulated by nuclear factor-kappaB-dependent expression of NLR family pyrin domain containing 3,inflammasome formation,and activation of IL-1 converting enzyme.Several studies have documented the pro-tumorigenic effects of IL-1β in tumor microenvironments,promoting proliferation and metastatic potential of cancer cells in vitro and tumorigenesis in vivo.The application of IL-1β inhibitors is also promising for targeted therapy development in some cancer types.However,as a leukocytic pro-inflammatory cytokine,IL-1β may also possess anti-tumorigenic effects and be type-specific in different cancers.This editorial discusses the up-to-date roles of IL-1β in GI cancers,including underlying mechanisms and down-stream signaling pathways.Understanding and clarifying the roles of IL-1β would significantly benefit future therapeutic targeting and help improve therapeutic outcomes in patients suffering from GI cancer.

Improved viability of trehalose on Lactobacillus plantarum embedded with whey protein concentrate/pullulan in simulated gastrointestinal conditions and its application in acid juice

Trehalose(TRE)was used to improve the gastrointestinal tolerance of Lactobacillus plantarum embedded with whey protein concentrate/pullulan(WPC/PUL)hydrogel and the embedded L.plantarum was applied to juice.The study indicated that 5%TRE significantly increased the viable counts of L.plantarum embedded in WPC/PUL hydrogel from(8.83±0.03)to(9.14±0.04)(lg(CFU/g))in simulated gastric juice(SGJ)and from(9.13±0.04)to(9.38±0.04)(lg(CFU/g))in simulated intestinal juice,respectively.The addition of TRE improved the glass transition temperature of WPC/PUL hydrogel and decreased the hardness and its solubility in SGJ,which may be responsible for the improved protection of WPC/PUL hydrogels on L.plantarum.In addition,TRE increased the viable counts of L.plantarum in WPC/PUL probiotic microcapsule juice at low pH and high temperature during storage.

Clinical analysis of multiple primary gastrointestinal malignant tumors:A 10-year case review of a single-center

BACKGROUND Multiple primary malignant tumors(MPMTs)was first described by Billroth as early as 1889,with the first report published by Warren and Gates in 1932.Since then,numerous cases have been reported.A literature review of 1104269 patients with cancer revealed that the incidence of MPMTs ranged from 0.73 to 11.7%.In recent years,however,there has been a significant upward trend in the incidence of this phenomenon,which may be associated with many different factors,including the advancement of modern diagnostic procedures facilitating the examination and diagnosis of more MPMTs,increased exposure to chemotherapy and radiotherapy that exacerbate the risk of new malignant tumors in patients with cancer,and prolonged survival of patients with cancer allowing sufficient time for the development of new primary cancers.AIM To analyze the incidence,clinical features,treatment factors,prevalence,and prognosis of patients with MPMTs in the gastrointestinal tract treated in a single center.Additionally,we analyzed the different tumor combinations,time interval between the occurrence of tumors,and staging.METHODS This retrospective cohort study analyzed 8059 patients with pathologically confirmed gastrointestinal malignant tumors treated at the Gansu Province Hospital in Lanzhou,Gansu,China between June 2011 and June 2020.Of these,85 patients had MPMTs.The clinical features,treatment factors,prevalence,and prognosis of this latter cohort were analyzed.RESULTS The incidence of MPMTs in patients with gastrointestinal malignant tumors was 1.05%(85/8059),including 83 double primary malignant tumors and two triple primary malignant tumors of which 57(67.06%)were synchronous MPMTs(SMPMTs)and 28(32.94%)were metachronous MPMTs(MMPMTs).The most frequent associations were found between the rectum colon cancers within the SMPMT category and the gastric-colon cancers within the MMPMT category.For the MMPMTs,the median interval was 53 months.The overall 1-,3-and 5-year survival rates from diagnosis of the first primary cancer were 91.36%,65.41%,and 45.97%,respectively;those from diagnosis of the second primary cancer were 67.90%,29.90%,and 17.37%,respectively.CONCLUSION MPMTs in the gastrointestinal tract have a high incidence and poor prognosis.Thus,it is necessary to perform both gastroscopy and colonoscopy in patients with gastrointestinal tumors.Multidisciplinary comprehensive diagnosis and treatment may improve the diagnosis rate and treatment efficiency of MPMTs.

Nomogram to predict gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions:Clinical significance

Transoral endoscopic resections in treating upper gastrointestinal submucosal lesions have the advantages of maintaining the integrity of the gastrointestinal lumen,avoiding perforation and reducing gastrointestinal fistulae.They are becoming more widely used in clinical practice,but,they may also present a variety of complications.Gas-related complications are one of the most common,which can be left untreated if the symptoms are mild,but in severe cases,they can lead to rapid changes in the respiratory and circulatory systems in a short period,which can be life-threatening.Therefore,it is important to predict the occurrence of gas-related complications early and take preventive measures actively.Based on the authors'results in the prepublication of the article“Nomogram to predict gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions,”and in conjunction with our evaluation and additions to the relevant content,radiographs may help screen patients at high risk for gas-related complications.Controlling blood glucose levels,shortening the duration of surgery,and choosing the most appropriate surgical resection may positively impact the prognosis of patients at high risk for gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions.

Efficacy of a Kiwifruit Extract (PhenActivTM) on Gastrointestinal Tract Function: A Randomised Double-Blind Placebo-Controlled Study

Objective: Gastrointestinal (GI) discomfort is experienced by millions of people every day. This study aimed to evaluate the effect of PhenActivTM, a novel green kiwifruit extract, on gastrointestinal tract (GIT) function in otherwise healthy adults. Methods: 41 healthy adults with mild GI discomfort were enrolled in this double-blind, randomized, placebo-controlled study. Participants were randomized to either take 3.0 g/day of PhenActivTM or a placebo for 6 weeks. Interviews were conducted at baseline, week 3 and week 6, with participants completing questionnaires regarding GI symptoms. Frequency of bowel movements was self-recorded daily. Results: There were no differences in daily and weekly defecation frequency and stool characteristics in either group. The active and placebo groups significantly improve GSRS scores (p , only the active group had a significant improvement in the IBSSS and PAC-QOL scores (p < 0.05) from baseline. Neither group had changes in sleep quality, quality of life and fatigue, plasma zonulin concentrations or macular pigment optical density scores. The product was well tolerated with no GI disturbances or adverse events being reported. Conclusion: Supplementation of 3.0 g/day of PhenActivTM for 6 weeks did not improve defecation frequency or stool composition in healthy adults, but did improve perceived symptoms of GIT function, including symptoms of functional GIT disorders, IBS and constipation. The product was well tolerated and future trials investigating higher doses with more participants and/or a different population would be beneficial.

Prognostic value of T cell immunoglobulin and mucin-domain containing-3 expression in upper gastrointestinal tract tumors:A meta-analysis

BACKGROUND There is a lack of robust prognostic markers for upper gastrointestinal(GI)tract cancers,including esophageal,gastric,and esophagogastric junction cancers.T cell immunoglobulin and mucin-domain containing-3(TIM3)plays a key immunomodulatory role and is linked to the prognosis of various cancers.However,the significance of TIM3 in upper GI tract tumors is still uncertain.AIM To investigate the prognostic value of TIM3 expression in upper GI tract tumors.METHODS A literature search was conducted on the PubMed,Embase,and Web of Science databases for relevant studies published until June 2023.After screening and quality assessment,studies that met the criteria were included in the metaanalysis.Statistical methods were used for the pooled analysis to assess the association of TIM3 expression in upper GI tract tumors with the prognosis and clinicopathological parameters.The results were reported with the hazard ratio(HR)and 95%confidence interval(CI).RESULTS Nine studies involving 2556 patients with upper GI tract cancer were included.High TIM3 expression was associated with a worse prognosis in upper GI tract cancer(HR:1.17,95%CI:1.01-1.36).Positive expression of TIM3 in gastric cancer was correlated with the T and N stage,but the difference was not statistically significant.However,TIM3 overexpression was significantly correlated with the TNM stage(odds ratio:1.21,95%CI:0.63-2.33;P<0.05).TIM3 expression showed no association with the other clinicopathological parameters.CONCLUSION High expression of TIM3 in the upper GI tract cancer is associated with a worse prognosis and advanced T or N stages,indicating its potential value as a prognostic biomarker.These findings may provide a basis for the personalized treatment of upper GI tract cancers.

Association of plant-based diets with the risk of upper gastrointestinal tract cancers:A systematic review and meta-analysis

Background:Diets rich in red or processed meat have been linked to an increased risk of cancers within the digestive system.It has been suggested that a plant-based diet may have protective effects against digestive system cancers.This study aimed to determine the association between plant-based diets and upper gastrointestinal tract cancers(UGTC).Methods:We conducted a systematic review and meta-analysis of observational studies.We searched the PubMed,Medline,Embase,and Web of Science databases for articles published up to September 30,2023.We pooled the risk ratios(RR)with the corresponding 95%confi-dence intervals(CI)using fixed or random-effects models.Results:Our meta-analysis included 16 studies(30 results).The data revealed a strong inverse association between a high intake of plant-based diets and UGTC(RR=0.60,95%CI=0.49-0.72),specifically gastric cancer(GC,RR=0.53,95%CI=0.42-0.67)and esophageal can-cer(EC,RR=0.63,95%CI=0.42-0.96).This relationship was not significant for gastric cardia cancer(GCA)or esophagogastric junctional cancer(EGJC,RR=0.76,95%CI=0.47-1.22).A subgroup analysis showed the association was significant in studies from Asia and Europe,as well as in studies utilizing indices such as a vegetarian diet,Mediterranean diet,the plant-based diet index,and principal component analy-sis(PCA)dietary patterns.There was no indication of publication bias among the analyzed studies.Conclusions:This meta-analysis highlights the potential health benefits of plant-based diets in preventing UGTC,particularly regarding esophageal squamous cell carcinoma(ESCC)and GC.Nevertheless,additional research is required to validate these results and explore the un-derlying mechanisms.

Gastrointestinal Diseases Classification Using Deep Transfer Learning and Features Optimization

Gastrointestinal diseases like ulcers, polyps’, and bleeding areincreasing rapidly in the world over the last decade. On average 0.7 millioncases are reported worldwide every year. The main cause of gastrointestinaldiseases is a Helicobacter Pylori (H. Pylori) bacterium that presents in morethan 50% of people around the globe. Many researchers have proposeddifferent methods for gastrointestinal disease using computer vision techniques.Few of them focused on the detection process and the rest of themperformed classification. The major challenges that they faced are the similarityof infected and healthy regions that misleads the correct classificationaccuracy. In this work, we proposed a technique based on Mask Recurrent-Convolutional Neural Network (R-CNN) and fine-tuned pre-trainedResNet-50 and ResNet-152 networks for feature extraction. Initially, the region ofinterest is detected using Mask R-CNN which is later utilized for the trainingof fine-tuned models through transfer learning. Features are extracted fromfine-tuned models that are later fused using a serial approach. Moreover, anImproved Ant Colony Optimization (ACO) algorithm has also opted for thebest feature selection from the fused feature vector. The best-selected featuresare finally classified using machine learning techniques. The experimentalprocess was conducted on the publicly available dataset and obtained animproved accuracy of 96.43%. In comparison with state-of-the-art techniques,it is observed that the proposed accuracy is improved.

Nomogram to predict gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions

BACKGROUND Gas-related complications present a potential risk during transoral endoscopic resection of upper gastrointestinal submucosal lesions.Therefore,the identification of risk factors associated with these complications is essential.AIM To develop a nomogram to predict risk of gas-related complications following transoral endoscopic resection of the upper gastrointestinal submucosal lesions.METHODS We collected patient data from the First Affiliated Hospital of the Army Medical University.Patients were randomly allocated to training and validation cohorts.Risk factors for gas-related complications were identified in the training cohort using univariate and multivariate analyses.We then constructed a nomogram and evaluated its predictive performance based on the area under the curve,decision curve analysis,and Hosmer-Lemeshow tests.RESULTS Gas-related complications developed in 39 of 353 patients who underwent transoral endoscopy at our institution.Diabetes,lesion origin,surgical resection method,and surgical duration were incorporated into the final nomogram.The predictive capability of the nomogram was excellent,with area under the curve values of 0.841 and 0.906 for the training and validation cohorts,respectively.CONCLUSION The ability of our four-variable nomogram to efficiently predict gas-related complications during transoral endoscopic resection enhanced postoperative assessments and surgical outcomes.

Connection between inflammation and carcinogenesis in gastrointestinal tract: Focus on TGF-β signaling

Inflammation is a primary defense process against various extracellular stimuli,such as viruses,pathogens,foods,and environmental pollutants.When cells respond to stimuli for short periods of time,it results in acute or physiological inflammation.However,if the stimulation is sustained for longer time or a pathological state occurs,it is known as chronic or pathological inflammation.Several studies have shown that tumorigenesis in the gastrointestinal (GI) tract is closely associated with chronic inflammation,for which abnormal cellular alterations that accompany chronic inflammation such as oxidative stresses,gene mutations,epigenetic changes,and inflammatory cytokines,are shared with carcinogenic processes,which forms a critical cross-link between chronic inflammation and carcinogenesis.Transforming growth factor (TGF)-β is a multi-potent cytokine that plays an important role in regulation of cell growth,apoptosis and differentiation.Most importantly,TGF-β is a strong anti-inflammatory cytokine that regulates the development of effector cells.TGF-β has a suppressive effect on carcinogenesis under normal conditions by inhibiting abnormal cell growth,but on the other hand,many GI cancers originate from uncontrolled cell growth and differentiation by genetic loss of TGF-β signaling molecules or perturbation of TGF-β adaptors.Once a tumor has developed,TGF-β exerts a promoting effect on the tumor itself and stromal cells to enhance cell growth,alter the responsiveness of tumor cells to stimulate invasion and metastasis,and inhibited immune surveillance.Therefore,novel development of therapeutic agents to inhibit TGF-β-induced progression of tumor and to retain its growth inhibitory activities,in addition to anti-inflammatory actions,could be useful in oncology.In this review,we discuss the role of TGF-β in inflammation and carcinogenesis of the GI tract related to abnormal TGF-β signaling.

Endoscopy dissection of small stromal tumors emerged from the muscularis propria in the upper gastrointestinal tract:Preliminary study

AIM:To investigate the feasibility and safety of the treatment of an upper gastrointestinal(GI) submucosal tumor with endoscopic submucosal dissection(ESD).METHODS:A total of 20 patients with esophageal and gastric submucosal tumors emerged from the muscular layer identified by endoscopic ultrasonography were collected from January 2009 to June 2010.Extramural or dumbbell-like lesions were excluded by an enhanced computerized tomography(CT) scan.All patients had intravenous anesthesia with propofol and then underwent the ESD procedure to resect these submucosal tumors.The incision was closed by clips as much as possible to decrease complications,such as bleeding or perforation,after resection of the tumor.All the specimens were collected and evaluated by hematoxylin,eosin and immunohistochemical staining,with antibodies against CD117,CD34,desmin,α-smooth muscle actin and vimentin to identify the characteristics of the tumors.Fletch's criteria was used to evaluate the risk of gastrointestinal stromal tumors(GISTs).All patients underwent a follow-up endoscopy at 3,6 and 12 mo and CT scan at 6 and 12 mo.RESULTS:The study group consisted of 5 men and 15 women aged 45-73 years,with a mean age of 60.2 years.Three tumors were located in the esophagus,9 in the gastric corpus,4 in the gastric fundus,3 lesions in the gastric antrum and 1 in the gastric angulus.Apart from the one case in the gastric angulus which was abandoned due to being deeply located in the serosa,94.7%(18/19) achieved complete gross dissection by ESD with operation duration of 60.52±30.32 min.The average maximum diameter of tumor was 14.8±7.6 mm,with a range of 6 to 30 mm,and another lesion was ligated by an endoscopic ligator after most of the lesion was dissected.After pathological and immunohistochemical analysis,12 tumors were identified as a GI stromal tumor and 6 were leiomyoma.Mitotic count of all 12 GIST lesions was fewer than 5 per 50 HPF and all lesions were at very low(9/12,75.0%) or low risk(3/12,25.0%) according to Fletch's criteria.Procedure complications mainly included perforation and GI bleeding;perforation occurred in 1 patient and conservative treatment succeeded by a suturing clip and no post-operative GI bleeding occurred.All patients were followed up for 6.5±1.8 mo(range,3-12 mo) by endoscopy and abdominal CT.Local recurrence and metastasis did not occur in any patient.CONCLUSION:ESD shows promise as a safe and feasible technique to resect esophageal and gastric submucosal tumors and the incidence of complications was very low.Clinical studies with more subjects and longer follow-up are needed to confirm its treatment value.

Narrow band imaging with magnification for the diagnosis of lesions in the upper gastrointestinal tract

Endoscopy plays an important role in the diagnosis and management of gastrointestinal(GI)tract disorders.Chromoendoscopy has proven to be superior to white light endoscopy for early detection of various GI lesions.This has however been fraught with problems.The use of color stains,time taken to achieve an effect and the learning curve associated with the technique has been some of the pitfalls.Narrow band imaging(NBI)particularly in combination with magnifying endoscopy may allow the endoscopist to accomplish a fairly accurate diagnosis with good histological correlation similar to results achieved with chromoendoscopy.Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsies and could ultimately prove to be cost effective.Various studies have been done demonstrating the utility of this novel technology.This article will review the impact of NBI in the diagnosis of upper gastrointestinal tract disorders.

Multiple primary malignant tumors of upper gastrointestinal tract:A novel role of ^(18)F-FDG PET/CT

AIM: To evaluate the capacity of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for detecting multiple primary cancer of upper gastrointestinal (UGI) tract. METHODS: Fifteen patients (12 without cancer histories and 3 with histories of upper GI tract cancer) were investigated due to the suspicion of primary cancer of UGI tract on X-ray barium meal and CT scan. Subsequent whole body 18F-FDG PET/CT scan was carried out for initial staging or restaging. All the patients were fi nally confi rmed by endoscopic biopsy or surgery. The detection rate of multiple primary malignant cancers was calculated based on 18F-FDG PET/CT and endoscopic examinations.RESULTS: 18F-FDG PET/CT scan was positive in 32 suspicious lesions, 30/32 were true positive primary lesions, and 2/32 were false positive. In 15 suspicious lesions with negative 18F-FDG PET/CT scan, 12/15 were true negative and 3/15 were false negative. Among the 15 patients, 12 patients had 29 primary synchronous tumors confirmed by pathology, including 8 cases of esophageal cancers accompanied with gastric cancer and 4 of hypopharynx cancers with esophageal cancer. The other 3 patients had 4 new primary metachronous tumors, which were multiple primary esophageal cancers. PET/CT imaging detected local lymph node metastases in 11 patients. Both local lymph node metastases and distant metastases were detected in 4 patients. On a per-primary lesion basis, the sensitivity, specificity, accuracy, negative predictive value and positive predictive value of 18F-FDG PET/CT for detecting multiple primary cancer of UGI tract were 90.9%, 85.7%, 89.4%, 80% and 93.7%, respectively. CONCLUSION: The whole body 18F-FDG PET/CT may play an important role in evaluating the multiple primary malignant tumors of UGI tract cancer.

Predicting liver metastasis of gastrointestinal tract cancer by diffusion-weighted imaging of apparent diffusion coefficient values

AIM: To determine if efficacy of chemotherapy on liver metastasis of gastrointestinal tract cancer can be predicted by apparent diffusion coefficient(ADC) values of diffusion-weighted imaging(DWI). METHODS: In total, 86 patients with liver metastasis of gastrointestinal tract cancer(156 metastatic lesions) diagnosed in our hospital were included in this study. The maximum diameters of these tumors were compared with each other before treatment, 2 wk after treatment, and 12 wk after treatment. Selected patients were classified as the effective group and the ineffective group, depending on the maximum diameter of the tumor after 12 wk of treatment; and the ADC values at different treatment times between the two groups were compared. Spearman rank correlation was used to analyze the relationship between ADC value and tumor diameter. Receiver operating characteristic curve(ROC curve) was used to analyze the ADC values before treatment to predict the patient's sensitivity and specificity degree of efficacy to the chemotherapy. RESULTS: There was no difference in age between the two groups and in maximum tumor diameter before treatment and 2 wk after treatment. However, after 12 wk of treatment, maximum tumor diameter in the effective group was significantly lower than that in the ineffective group(P < 0.05). Before treatment, ADC values in the ineffective group were significantly higher than those in the effective group(P < 0.05). There was no difference in ADC values between the effective and ineffective groups after 2 and 12 wk of treatment. However, ADC values were significantly higher after 2 and 12 wk of treatment compared to before treatment in the effective group(P < 0.05). Spearman rank correlation analysis showed that ADC value before treatment and the reduced percentage of the maximum tumor diameter after 12 wk of treatment were negatively correlated, while the increase in the percentage of the ADC value 12 wk after treatment and the decrease in the percentage of the maximum tumor diameter were significantly positively correlated. The results of the ROC curve showed that ADC value with a chemotherapy ineffective threshold value of 1.14 × 10-3 mm2/s before treatment had a sensitivity and specificity of 94.3% and 76.7%, respectively. CONCLUSION: DWI ADC values can be used to predict the response of patients with liver metastasis of gastrointestinal tract cancer to chemotherapy with high sensitivity and relatively high specificity.