Primary gastric lymphoma

AIM:The purpose of this review is to describe the variousaspects of primary gastric lymphoma and the treatmentoptions currently available.METHODS:After a systematic search of Pubmed,Medscapeand MDconsult,we reviewed and retrieved literature regardinggastric lymphoma.RESULTS:Primary gastric lymphoma is rare however,theincidence of this malignancy is increasing.Chronic gastritissecondary to Helicobacter pylori (H pylori) infection has beenconsidered a major predisposing factor for MALT lymphoma.Immune histochemical marker studies and molecular biologyutilizing polymerase chain reaction have facilitated appropriatediagnosis and abolished the need for diagnostic surgicalresection.Advances in imaging techniques including MagneticResonance Imaging (MRI) and Endoscopic Ultrasonography(EUS) have helped evaluation of tumor extension and invasion.The clinical course and prognosis of this disease is dependenton histopathological sub-type and stage at the time ofdiagnosis.Controversy remains regarding the best treatmentfor early stages of this disease.Chemotherapy,surgery andcombination have been studied and shared almost comparableresults with survival rate of 70-90%.However,chemotherapypossesses the advantage of preserving gastric anatomy.Radiotherapy alone has been tried and showed good results.Stage IIIE,IVE disease treatment is solely by chemotherapyand surgical resection has been a remote consideration.CONCLUSION:We conclude that methods of diagnosis andstaging of the primary gastric lymphoma have dramaticallyimproved.The modalities of treatment are many and probablychemotherapy is superior because of high success rate,preservation of stomach and tolerable complications.     

Effects of gastric pacing on gastric emptying and plasma motilin

AIM:To investigate the effects of gastric pacing on gastricemptying and plasma motilin level in a canine model of gastricmotility disorders and the correlation between gastricemptying and plasma motilin level.METHODS:Ten healthy Mongrel dogs were divided into:experimental group of six dogs and control group of fourdogs.A model of gastric motility disorders was establishedin the experimental group undergone truncal vagotomycombined with injection of glucagon.Gastric half-emptyingtime (GEt_(1/2)) was monitored with single photon emissioncomputerized tomography (SPECT),and the half-solid testmeal was labeled with an isotope-~(99m)mTc sulfur colloid.Plasmamotilin concentration was measured with radioimmunoassay(RIA) kit.Surface gastric pacing at 1.1-1.2 times the intrinsicslow-wave frequency and a superimposed series of highfrequency pulses (10-30 Hz) was performed for 45 rnin dailyfor a month in conscious dogs.RESULTS:After surgery,GEt_(1/2) in dogs undergone truncalvagotomy was increased significantly from 56.35±2.99 minto 79.42±1.91 rain (P<0.001),but surface gastric pacingmarkedly accelerated gastric emptying and significantlydecreased GEt_(1/2) to 64.94 1.75 min (P<0.001) in animalsundergone vagotomy.There was a significant increase ofplasma level of motilin at the phase of IMCⅢ(interdigestivemyoelectrical complex,IMCⅢ) in the dogs undergone bilateraltruncal vagotomy (baseline vsvagotomy,184.29±9.81 pg/mlvs 242.09±17.22 pg/ml;P<0.01).But plasma motilinconcentration (212.55±11.20 pg/ml;P<0.02) was decreasedsignificantly after a long-term treatment with gastric pacing.Before gastric pacing,GEt_(1/2) and plasma motilin concentrationof the dogs undergone vagotomy showed a positivecorrelation (r=0.867,P<0.01),but after a long-term gastricpacing,GEt_(1/2) and motilin level showed a negative correlation(r=-0.733,P<0.04).CONCLUSION:Surface gastric pacing with optimal pacingparameters can improve gastric emptying parameters andsignificantly accelerate gastric emptying and can resumeor alter motor function in a canine model of motilitydisorders.Gastric emptying is correlated well with plasmamotilin level before and after pacing,which suggests that motilin can modulate the mechanism of gastric pacing byaltering gastric motility.     

Cutaneous gastric electrical stimulation alters gastric motility in dogs: New option for gastric electrical stimulation?

Background and Aim:  We investigated the effects of cutaneous gastric electrical stimulation (CGES) on gastric myoelectrical activity, postprandial antral contractions and gastric tone in dogs.
Methods:  CGES was carried out via abdominal surface electrodes over the stomach. After an overnight fast, gastric slow waves were recorded from the serosal electrodes in six dogs at a frequency of 4.4 cycles/min (c.p.m.) or 10 c.p.m. Nine dogs were used for the measurement of postprandial antral contractions. Gastric tone at baseline and during CGES was measured in six of the dogs.
Results:  We found that: (i) CGES at 4.4 c.p.m. decreased slow wave frequency (5.1 vs 4.6 c.p.m., P  < 0.05) and increased slow wave power (−6.2 vs 2.7 c.p.m., P  < 0.05); CGES at 10 c.p.m. increased slow wave frequency (5.1 vs 9.2 dB, P  < 0.05) and decreased normal slow waves (85.4% vs 60.0%, P  < 0.05); (ii) CGES at 10 c.p.m. significantly suppressed postprandial antral contractions ( P  < 0.01); (iii) CGES had no effects on gastric tone.
Conclusions:  CGES is capable of altering gastric slow waves and inhibiting gastric motility. It may have therapeutic potential for treating eating disorders, such as obesity. However, clinical studies are needed to explore the potential of CGES.     

A p53 genetic polymorphism of gastric cancer： Difference between early gastric cancer and advanced gastric cancer

INTRODUCTIONGastric cancer is one of the most common malignancies worldwide,although the overall incidence of gastric cancer has been decreasing over the past few decades.Chronic H pylori infection and dietary factors,such as those high in salt or nitrate…     

Should peri-gastrectomy gastric acidity be our focus among gastric cancer patients?

AIM:To investigate the necessity and correctness of acid suppression pre-and post-gastrectomy among gastric carcinoma(GC)patients.METHODS:From June 2011 to April 2013,99 patients who were diagnosed with GC or adenocarcinoma of the gastroesophageal junction(typeⅡorⅢ)and needed surgical management were enrolled.They all underwent gastrectomy by the same operators[35undergoing total gastrectomy(TG)plus Roux-en-Y reconstruction,34 distal gastrectomy(DG)plus Billroth I reconstruction,and 30 proximal gastrectomy(PG)plus gastroesophagostomy].We collected and analyzed their gastrointestinal juice and tissues from the preoperational day to the 5th day post-operation,and 6 mo post-surgery.Gastric pH was detected with a precise acidity meter.Gastric juice contents including potassi-um,sodium and bicarbonate ions,urea nitrogen,direct and indirect bilirubin,and bile acid were detected using Automatic Biochemical Analyzer.Data regarding tumor size,histological type,tumor penetration and tumornode-metastasis(TNM)stage were obtained from the pathological records.Reflux symptoms pre-and 6 mo post-gastrectomy were evaluated by reflux disease questionnaire(RDQ)and gastroesophageal reflux disease questionnaire(GERD-Q).SPSS 16.0 was applied to analyze the data.RESULTS:Before surgery,gastric pH was higher than the threshold of hypoacidity(4.25±1.45 vs 3.5,P=0.000),and significantly affected by age,tumor size and differentiation grade,and potassium and bicarbonate ions;advanced malignancies were accompanied with higher pH compared with early ones(4.49±1.31vs 3.66±1.61,P=0.008).After operation,gastric pH in all groups was of weak-acidity and significantly higher than that pre-gastrectomy;on days 3-5,comparisons of gastric pH were similar between the 3 groups.Six months later,gastric pH was comparable to that on days 3-5;older patients were accompanied with higher total bilirubin level,indicating more serious reflux(r=0.238,P=0.018);the TG and PG groups had higher RDQ(TG vs DG:15.80±5.06 vs 12.26±2.14,P=0.000;PG vs DG:15.37±3.49 vs 12.26±2.14,P=0.000)and GERD-Q scores(TG vs DG:10.54±3.16 vs9.15±2.27,P=0.039;PG vs DG:11.00±2.07 vs 9.15±2.27,P=0.001)compared with the DG group;all gastric juice contents except potassium ion significantly rose;reflux symptom was significantly associated with patient’s body mass index,direct and indirect bilirubin,and total bile acid,while pH played no role.CONCLUSION:Acidity is not an important factor causing unfitness among GC patients.There is no need to further alkalify gastrointestinal juice both pre-and postgastrectomy.     

Are gastric mucosal macrophages responsible for gastric injury in acute pancreatitis?

AIM:To investigate the protective effect of clodronatecontaining liposomes against severe acute pancreatitis(SAP)-triggered acute gastric mucosal injury(AGMI) in rats.METHODS:Clodronate- and phosphate-buffered saline(PBS)-containing liposomes were prepared by reverse-phase evaporation.The SAP rat model was established by injecting sodium taurocholate into the pancreatic subcapsular space.Sprague-Dawley rats were randomly divided into three groups:control(C),SAP plus PBS-containing liposome(P) and SAP plus clodronate-containing liposome(T).Serum tumor necrosis factor(TNF)-α levels were estimated by ELISA.Pathological changes in the gastric mucosa and pancreas were observed by hematoxylin and eosin(HE) staining.Apoptotic cells were detected by terminal deoxynucleotidyl transferase d UTP nick end labeling staining.The numbers of macrophages in the gastric mucosa were analyzed by CD68 immunohistochemical staining.RESULTS:The liposomes had a mean diameter of 150 ± 30 nm.The TNF-α levels were significantly higher in the P group than that in the C group(2 h,145.13 ± 11.50 vs 23.2 ± 2.03; 6 h,245.06 ± 12.11 vs 30.28 ± 6.07,P < 0.05),and they were significantly lower in the T group than that in the P group(2 h,93.24 ± 23.11 vs 145.13 ± 11.50; 6 h,135.18 ± 13.10 vs 245.06 ± 12.11,P < 0.05).The pathological scores of the pancreas were lower in the T group than in the P group(2 h,1.88 ± 0.83 vs 4.13 ± 0.83; 6 h,2.87 ± 0.64 vs 6.25 ± 0.88,P < 0.01).The pathological scores of the gastric mucosa were also lower in the T group than in the P group(2 h,1.12 ± 0.64 vs 2 ± 0.75; 6 h,1.58 ± 0.53 vs 3 ± 1.31,P < 0.05).In addition,increased CD68 levels were observed in the gastric mucosa of the P group compared with the C group.Clodronate-containing liposomes decreased the CD68 levels in the mucosa of the T group.The apoptotic indexes of the gastric mucosa were higher in the T group than in the P group(2 h,15.7 ± 0.92 vs 11.5 ± 1.64; 6 h,21.12 ± 1.06 vs 12.6 ± 2.44,P < 0.01).CONCLUSION:Gastric macrophages contribute to the pathogenesis of gastric injury in SAP.Clodronatecontaining liposomes have protective effects against AGMI in rats with SAP.     

Helicobacter pyloriin gastric corpus of patients 20 years after partial gastric resection

AIM:To determine the long-term prevalence of Helicobacterpylori(H pylori)gastritis in patients after partial gastricresection due to peptic ulcer,and to compare the severityof Hpylori-positive gastritis in the corpus mucosa betweenpartial gastrectomy patients and matched controls.METHODS:Endoscopic biopsies were obtained from 57patients after partial gastric resection for histologicalexamination using hematoxylin/eosin and Warthin-Starrystaining.Gastritis was graded according to the updatedSydney system.Severity of corpus gastritis was comparedbetween Hpylori-positive partial gastrectomy patients andHpylori-positive duodenal ulcer patients matched for ageand gender.RESULTS:In partial gastrectomy patients,surgery wasperformed 20 years(median)prior to evaluation.In 25patients(43.8%)Hpyloriwas detected histologically inthe gastric remnant.Gastric atrophy was more common inH pylori-positive compared to H pylori-negative partialgastrectomy patients(P<0.05).The severity of corpusgastritis was significantly lower in Hpylori-positive partialgastrectomy patients compared to duodenal ulcer patients(P<0.01).There were no significant differences in theactivity of gastritis,atrophy and intestinal metaplasiabetween the two groups.CONCLUSION:The long-term prevalence of Hpylorigastritisin the gastric corpus of patients who underwent partialgastric resection due to peptic ulcer disease is comparableto the general population.The expression of Hpylorigastritisin the gastric remnant does not resemble the gastric cancerphenotype.     

Comparison of nuclear matrix proteins between gastric cancer and normal gastric tissue

AIM:To study the alteration of nuclear matrix proteins(NMPs)in gastric cancer.METHODS:The NMPs extracted from 22 cases of gastriccancer and normal gastric tissues were investigated bySDS-PAGE technique and the data were analyzed usingGenetools analysis software.RESULTS:Compared with normal gastric tissue,theexpression of 30 ku and 28 ku NMPs in gastric cancerdecreased significantly(P=0.002,P=0.001,P<0.05).Nosignificant difference was found in the expression of thetwo NMPs between the various differentiated grades(P=-0.947,P=-0.356)and clinical stages of gastric cancer(P=0.920,P=0.243,P>0.05).CONCLUSION:The results suggested that the alterationof NMPs in gastric cancer occurred at the early stage ofgastric cancer development.     

Is gastric cancer preventable?

Gastric cancer is a major health burden worldwide and prevention is the most promising strategy to control the disease. The available scientific evidence indicates that curing Helicobacter pylori infection results in a modest retardation of the precancerous process but does not prevent all cancers. Individuals at the highest risk should be cured of their infection and monitored endoscopically to detect dysplasia and "early" cancer, amenable to successful treatment.     

Is it possible to differentiate gastric GISTs from gastric leiomyomas by EUS？

AIM： To evaluate the ultrasonography （EUS） features of gastric gastrointestinal stromal tumors （GISTs） as compared with gastric leiomyomas and then to determine the EUS features that could predict malignant GISTs.
METHODS： We evaluated the endoscopic EUS features in 53 patients with gastric mesenchymal tumors confirmed by histopathologic diagnosis. The GISTs were classified into benign and malignant groups according to the histological risk classification.
RESULTS： Immunohistochemical analyses demonstrated 7 leiomyomas and 46 GISTs. Inhomogenicity, hyperechogenic spots, a marginal halo and higher echogenicity as compared with the surrounding muscle layer appeared more frequently in the GISTs than in the leiomyomas （P 〈 0.05）. The presence of at least two of these four features had a sensitivity of 89.1% and a specificity of 85.7% for predicting GISTs. Except for tumor size and irregularity of the border, most of the EUS features were not helpful for predicting the malignant potential of GISTs. On multivariate analysis, only the maximal diameter of the GISTs was an independent predictor. The optimal size for predicting malignant GISTs was 35 mm. The sensitivity and specificity using this value were 92.3% and 78.8%, respectively.
CONCLUSION： EUS may help to differentiate gastric GISTs from gastric leiomyomas. Once GISTs are suspected, surgery should be considered if the size is greater than 3.5 cm.     

Pathological characteristics of gastric leiomyoblastoma

AIM:To determine the pathological characteristics of gastricleiomyoblastoma.METHODS:All tissues were obtained during surgery orgastroscopy.Tissue specimens for examination by lightmicroscope were 1 cm×1 cm×1 cm in size,fixed in 40 g/Lneutral buffered formaldehyde,embedded in paraffin,andstained with hematoxylin and eosin.The fresh tissues obtainedfor electron microscopy were 1 mm×1 mm×1 mm in size,and fixed in phosphate buffered 30 g/L glutaraldehyde,postfixed in 10 g/L osmium tetroxide and dehydrated ingraded alcohol,embebbed in Epon 812.Ultrathin sectionsof 50 nm were stained with uranyl acetate and lead citrateand examined under a JEM-2000 EX transmission electronmicroscope.RESULTS:The most important histopathological featureof leiomyoblastoma was the predominance of large,roundedor polygonal cells with characteristic perinuclear clear zonein cytoplasms.The tumor cells arranged in patch,celljunction or junctional complex could be found occasionallybetween cells under electron microscope.Most of theneoplastic cytoplasms were filled with myofilaments,densebodies,and dense patches.Rough endoplasmic reticulumdilatated as lakes,and large quantities of protein secretionsof intermediate electron density were found in the dilatedcisternae.Intracisternal segregation could also be found.The nuclei were round or oval,and anomalous nuclei werefound in part of cells.CONCLUSION:The diagnosis of gastric leiomyoblastomacan be confirmed by electron microscopy.The clearappearance of tumor cells is due to the dilation of roughendoplasmic reticulum,not fat droplets,glycogens or mucusin cytoplasm.Huang XF,Wang CM,Pan BR,Dai XW,Fang L,Yang JJ,Yu H,Ren J.Pathological characteristics of gastric leiomyoblastoma.World J Gastroenterol 2004;10(21):3182-3184http://www.wjgnet.com/1007-9327/10/3182.asp     

Effects of Radix Rehmanniae on gastric acid secretion and gastric ulcr formation in rats

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Expression of gastric cancer—associated MG7 antigen in gastric cancer,precancerous lesions and H.pylori—associated gastric diseases

AIM: To investigate the relationship between the antigen MG7 antigen expression and gastric cancer as well as precancerous condition; to study the relationship between the MG7 antigen expression and H. pyloriinfection in benign gastric lesions in order to find out the effect of H. pylori infection on the process of gastric cancer development.METHODS: The level of MG7 antigen expression was determined by immunohistochemical method in 383 gastric biopsied materials. The intestinal metaplasia was determined by histochemistry method. The H. pyloriinfection was determined by HE stain, PCR and ELISA in 291 specimens, among which only 34 cases of H. pylori-associated gastric lesions were followed up.RESULTS: The positive rate of MG7 expression in normal gastric mucosa, intestinal metaplasia, dysplasia and gastric cancer increased gradually in ascending order (P＜0.01). The positive rate of MG7 antigen expression in type Ⅲ intestinal metaplasia of gastric mucosa was higher than that of type Ⅰand Ⅱ intestinal metaplasia, being highly significant (P＜0.05).The positive rate of MG7 antigen expression in superficial gastritis, atrophic gastritis and gastric cancer increased gradually (11.9 %, 64.8 %, 91.2 %, P＜0.01). There was no significant difference between H.pylori-negative and H. pyloripositive intestinal metaplasia, atrophic gastritis and dysplasia of gastric epithelium in the positive rate of MG7 antigen expression. There was no expression of MG7 antigen in H. pylori-negative superficial gastritis. The positive rate of MG7 expression in H. pylori-positive superficial gastritis was 20.5 %, and the difference between them was significant (P＜0.05). During following up, one of the three H. pylori negative cases turned positive again, and its MG7 antigen expression turned to be stronger correspondingly. 3 of 31 H. pyloripositive cases were detected as early gastric cancer, among which one with "+++" MG7 antigen expression was diminished after H. pylori eradication.CONCLUSION: MG7 antigen expression is highly specific in gastric cancer and can be used as a good marker for screening of gastric cancer; type Ⅲ intestinal metaplasia, atrophic gastritis and dysplasia should be followed up and MG7 antigen expression has high clinical value in the dynamic follow-up study; although the positive -MG7 in positiveH. pylorisuperficial gastritis show benign morphology in features, there is still the potential risk of developing into gastric cancer, hence special attention should be paid to those showing increasing MG7 antigen expression.     

Prognostic factors in patients with node-negative gastric carcinoma： A comparison with node-positive gastric carcinoma

AIM: To identify the clinicopathological characteristics of lymph node-negative gastric carcinoma, and also to evaluate outcome indicators in the lymph node-negative patients. METHODS: Of 2848 gastric carcinoma patients, 1524 (53.5%) were lymph node-negative. A statistical analysis was performed using the Cox model to estimate outcome indicators. RESULTS: There was a significant difference in the recurrence rate between lymph node-negative and lymph node-positive patients (14.4% vs 41.0%, P<0.001). The 5-year survival rate was significantly lower in lymph node-positive than in lymph node-negative patients (31.1% vs 77.4%, P<0.001). Univariate analysis revealed that the following factors influenced the 5-year survival rate: patient age, tumor size, depth of invasion, tumor location, operative type, and tumor stage at initial diagnosis. The Cox proportional hazard regression model revealed that tumor size, serosal invasion, and curability were independent, statistically significant, prognostic indicators of lymph node-negative gastric carcinoma. CONCLUSION: Lymph node-negative patients have a favorable outcome attributable to high curability, but the patients with relatively large tumors and serosal invasion have a poor prognosis. Curability is one of the most reliable predictors of long-term survival for lymph node-negative gastric carcinoma patients.     

Do we need gastric acid?

Evidence from comparative anatomy and physiology studies indicates that gastric acid secretion developed during the evolution of vertebrates approximately 350 million years ago. The cellular mechanisms that produce gastric acid have been conserved over the millennia and therefore proton pump inhibitors have pharmacological effects in almost all relevant species. These observations suggest that gastric acid provides an important selective advantage; however, in modern-day humans the need for gastric acid can be questioned in light of the widespread use of safe and effective pharmacologic acid suppression. The Kandahar Working Group addressed questions concerning the need, production and effects of gastric acid, specifically: (1) motility in the upper gastrointestinal (GI) tract; (2) neuroendocrine factors; (3) digestive and mucosal processes; (4) microbiology, and (5) central processes and psychological involvement. We addressed each topic with the individual models available to answer our questions including animal versus human studies, pharmacologic, surgical as well as pathophysiologic states of acid suppression.     

Is gastric nodularity a sign for gastric inflammation associated with Helicobacter pylori infection in children?

The aim of this study was to investigate the accuracy of using gastric nodularity (GN) as a marker for gastric inflammation associated with Helicobacter pylori infection in children. A retrospective analysis of 395 upper endoscopies done in children between 1990-1996 was performed. Demographics, clinical symptoms, endoscopic features, rapid urease test (RUT), and histological results were collected from each report. GN was found in 13 (3.5%) children. GN showed a significant correlation with age but not with gender. Multiple regression analysis showed a significant correlation between GN and gastritis with RUT but not with other histological determinants alone (gastritis, RUT, or H. pylori organisms). Nevertheless, GN had a poor accuracy rate to determine H. pylori-associated gastritis (sensitivity, 61%; positive predictive value, 12%). GN is a poor predictor for gastric inflammation associated with H. pylori infection in children. During endoscopy, gastric biopsies should always be obtained in children to establish the presence of mucosal inflammation.     

Synchronous and metachronous occurrence of gastric adenocarcinoma and gastric lymphoma：A review of the literature

The occurrence of both primary gastric lymphoma and gastric adenocarcinoma in the same patient is a rare entity. The possible causative factors of synchronous or metachronous occurrence of both malignancies and varieties in the treatment modalities are reviewed according to published cases in English language medical literature.     

Gene expression profile differences in gastric cancer, pencancerous epithelium and normal gastric mucosa by gene chip

AIM: To study the difference of gene expression in gastric cancer (T), pericancerous epithelium (P) and normal tissue of gastric mucosa (C), and to screen an associated novel gene in early gastric carcinogenesis by oligonudeotide microarray. METHODS: U133A (Affymetrix, Santa Clara, CA) gene chip was used to detect the gene expression profile difference in T, P and C, respectively. Bioinformatics was used to analyze the detected results. RESULTS: When gastric cancer was compared with normal gastric mucosa, 766 genes were found, with a difference of more than four times in expression levels. Of the 766 genes, 530 were up-regulated (Signal Log Ratio [SLR]>2), and 236 were down-regulated (SLR<-2). When pericancerous epithelium was compared with normal gastric mucosa, 64 genes were found, with a difference of more than four times in expression levels. Of the 64 genes, 50 were up-regulated (SLR>2), and 14 were down-regulated (SLR<-2). Compared with normal gastric mucosa, a total of 143 genes with a difference in expression levels (more than four times, either in cancer or in pericancerous epithelium) were found in gastric cancer (T) and pericancerous epithelium (P). Of the 143 genes, 108 were up-regulated (SLR>2), and 35 were down-regulated (SLR<-2). CONCLUSION: To apply a gene chip could find 143 genes associated with the genes of gastric cancer in pericancerous epithelium, although there were no pathological changes in the tissue slices. More interesting, six genes of pericancerous epithelium were up-regulated in comparison with genes of gastric cancer and three genes were down-regulated in comparison with genes of gastric cancer. It is suggested that these genes may be related to the carcinogenesis and development of early gastric cancer.