Submucosa Of Stomach Research Articles

Effect of MDSC-targeted TFF2-MSA with PD-1 blockade therapy in advanced gastric cancer models.

e16037 Background: Recent studies revealed chemotherapy increases anti-PD1 response of gastric cancer (GC) by reducing myeloid-derived suppressor cells (MDSCs). However, a more specific MDSC-targeted treatment is needed to further improve anti-PD1 efficacy in advanced GC. Trefoil factor family 2 (TFF2), a partial agonist of CXCR4 and a secreted anti-inflammatory peptide, can suppress MDSC expansion. Here, we developed a novel MDSC-targeted peptide TFF2-MSA and investigated whether it can synergize with anti-PD1 in syngeneic GC mouse models. Methods: Murine serum albumin (MSA) was fused to murine TFF2 to generate TFF2-MSA peptide with an extended serum half-life. ACKP (Atp4b-Cre; Cdh1-/-; LSL-KrasG12D; Trp53-/-) GC cells developed from a highly malignant diffuse GC mouse model were grafted subcutaneously into HDC-GFP transgenic mice in which the immunosuppressive histidine decarboxylase (HDC)-expressing myeloid cells were traced with GFP. These recipient mice then received either TFF2-MSA or anti-PD-1 antibody or both when tumors reached 150 mm3. At the endpoint, flow cytometry analysis was performed to examine immune profiles. In parallel, a group of the s.c. tumor bearing mice were followed up for survival differences in response to the treatments. In the orthotopic model, ACKP-luc cells were implanted to stomach submucosa, and recipient mice received the same treatments started after 1 week. In the metastasis model, subcutaneous flank tumors were resected in ACKP-grafted mice once tumors reached 500 mm3 to permit spontaneous lung metastasis, and mice then received the same treatments. Results: While either TFF2-MSA or PD-1 antibody showed little benefit as a single agent (TGI 15% and 25% respectively, p>0.05), their combination dramatically suppressed ACKP s.c. tumor growth (TGI 78%, p<0.0001) and markedly prolonged median survival (64 days vs. 32.5 days in control) in a synergistic manner. The combination therapy efficiently reduced tumor HDC-GFP+ MDSCs by 67%, and profoundly increased tumor-infiltrating cytotoxic CD8+ T cells by 18 fold. The myeloid/lymphoid progenitor and output ratio in the bone marrow were decreased by the combination, to a similar level of tumor-free mice. While standard chemotherapy (5-fluorouracil and oxaliplatin) showed no efficacy, adding chemotherapy to the combination further improved treatment efficacy (TGI 91%) and extended median survival to 73 days. In addition, in the orthotopic model, the TFF2-MSA/PD-1 antibody combination eradicated GC in 80% mice without recurrence compared to 0% with either monotherapy. Finally, the combination of TFF2-MSA/PD-1 antibody significantly reduced 80% lung metastasis (vs. control, p<0.0001), compared to minimal inhibition with either monotherapy (p>0.05). Conclusions: Targeting MDSCs using TFF2-MSA synergizes with PD-1 blockade therapy in advanced and metastatic syngeneic mouse models of gastric cancer.

Preclinical evaluation of sentinel node localization in the stomach via mannose-labelled magnetic nanoparticles and indocyanine green

BackgroundGastrectomy with extended (D2) lymphadenectomy is considered standard of care for gastric cancer to provide the best possible outcomes and pathologic staging. However, D2 gastrectomy is a technically demanding operation and reported to be associated with increased complications and mortality. Application of sentinel lymph node (SLN) concept in gastric cancer has the potential to reduce patient morbidity; however, SLN techniques are not established for gastrectomy, in part due to lack of practical tracers. An effective and convenient tracer with enhanced SLN accumulation is critically needed.MethodsMannose-labelled magnetic tracer ‘FerroTrace’ and fluorescent dye indocyanine green (ICG) were injected laparoscopically into the stomach submucosa of 8 healthy swine under general anaesthesia. Intraoperative fluorescence imaging was used to highlight draining lymphatic pathways containing ICG, while preoperative T2-weighted MRI and ex vivo magnetometer probe measurements were used to identify nodes containing FerroTrace. Lymphadenectomy was performed either robotically (n = 2) or via laparotomy (n = 6).ResultsMixing ICG and FerroTrace ensured concurrence of fluorescent and magnetic signals in SLNs. An initial trial with robotic dissection removed all magnetic LNs (n = 4). In the subsequent laparotomy study that targeted all ICG-LNs based on intraoperative fluorescence imaging, dissection removed an average of 4.7 ± 1.2 fluorescent, and 2.0 ± 1.3 magnetic LNs per animal. Both MRI and magnetometer detected 100% of SLNs (n = 7). FerroTrace demonstrated high specificity to SLNs, which contained 76 ± 30% of total lymphotropic iron, and 88 ± 20 % of the overall magnetometer signal.ConclusionsThrough utilisation of this dual tracer approach, SLNs were identified via preoperative MRI, visualised intraoperatively with fluorescence imaging, and confirmed with a magnetometer. This combination pairs the sensitivity of ICG with SLN-specific FerroTrace and can be used for reliable SLN detection in gastric cancer, with potential applications in neoadjuvant therapy.Graphical abstract

Abstract 5088: MDSC-targeted TFF2-MSA synergizes with PD-1 blockade therapy in diffuse-type gastric cancer

Abstract Aims: Recent studies revealed myeloid-derived suppressor cell (MDSC) in the tumor microenvironment as an appealing therapeutic target to sensitize intestinal-type gastric cancer (GC) to PD-1 blockade therapy. However, whether MDSC inhibition can improve survival in the more aggressive diffuse-type GC is unknown. Trefoil factor family 2 (TFF2), a secreted anti-inflammatory peptide, suppresses MDSC expansion partly via CXCR4 receptor. Here, we developed a novel MDSC-targeted peptide TFF2-MSA and investigated whether it can synergize with anti-PD1 to prolong survival in syngeneic diffuse GC mouse models. Methods: Murine serum albumin (MSA) was appended to the murine TFF2 to generate TFF2-MSA peptide with an extended serum half-life. ACKP (Atp4b-Cre; Cdh1-/-; LSL-KrasG12D; Trp53-/-) GC cells developed from a highly malignant diffuse GC mouse model were grafted subcutaneously into HDC-GFP transgenic mice in which the more immunosuppressive histidine decarboxylase (HDC)-expressing myeloid cells were traced with GFP. These recipient mice subsequently received either TFF2-MSA or anti-PD-1 antibody or both. Further, to assess treatment efficacy in inhibiting spontaneous lung metastasis, subcutaneous flank tumors were resected in ACKP cell-grafted mice once tumors reached 500 mm3, and mice then received treatment with TFF2-MSA or anti-PD-1 or the combination. At the endpoint, flow cytometry and histopathological analyses were performed to examine immune profiles and tumor metastasis. In another model, ACKP-luc cells were implanted orthotopically to stomach submucosa, and recipient mice received the same treatments started from 1 week later to assess their efficacy. Results: While either TFF2-MSA or PD-1 antibody showed little benefit as a single agent (TGI 15% and 25% respectively, p>0.05), their combination dramatically suppressed ACKP s.c. tumor growth (TGI 78%, p<0.0001) and markedly prolonged median survival (64 days vs. 32.5 days in control) of host mice in a synergistic manner. The combination therapy efficiently reduced HDC-GFP+ MDSCs (by 67% vs. control, p<0.01), and profoundly increased tumor-infiltrating cytotoxic CD8+ T cells (by 18 fold, p<0.001). Further, while standard chemotherapy (5-fluorouracil and oxaliplatin) showed limited efficacy in this model, addition of chemotherapy to the TFF2-MSA/PD-1 antibody combination further improved treatment efficacy (TGI 91%) and extended median survival to 73 days. In addition, combination of TFF2-MSA/PD-1 antibody significantly reduced 80% lung metastasis (vs. control, p<0.0001), in contrast to minimal inhibition observed with either monotherapy (p>0.05). Finally, in the orthotopic model, the combo regimen eradicated GC in 50% mice compared to 0% in either monotherapy treatment. Conclusion: Targeting MDSCs using TFF2-MSA synergizes with PD-1 blockade therapy in advanced and metastatic syngeneic mouse models of diffuse-type GC. Citation Format: Jin Qian, Sandra Ryeom, Bruce Daugherty, Seth Lederman, Timothy C. Wang. MDSC-targeted TFF2-MSA synergizes with PD-1 blockade therapy in diffuse-type gastric cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5088.

Preclinical evaluation of a dual magnetic and fluorescence-guided approach for sentinel lymph node biopsy in the stomach.

337 Background: Gastrectomy with extended (D2) lymphadenectomy is considered as a standard of care for gastric cancer to provide best possible outcomes and pathologic staging. However, D2 gastrectomy is technically demanding operation and reported to be associated with increased complications, including bleeding, pancreatitis, abscess, chylous ascites, and mortality. Application of sentinel lymph node mapping in gastric cancer has the potential to reduce patient morbidity, while facilitating detailed pathology processing required to accurately identify nodal metastases. However, sentinel lymph node biopsy techniques are not established for gastrectomy because of a lack of practical tracers; an effective and convenient tracer that exclusively accumulates in sentinel lymph nodes is critically needed. Methods: A lymphotropic tracer solution consisting of mannose-labelled magnetic nanoparticles (SPIONs) and a fluorescent dye (indocyanine green, ICG) was injected laparoscopically into the stomach submucosa of 6 healthy female domesticated pigs while under general anaesthesia. Intraoperative laparoscopic fluorescence imaging was used to highlight draining lymphatic pathways containing ICG, while a combination of T2-weighted MRI and magnetometer probe detection were used to identify nodes containing SPIONs. Results: Mixing the ICG dye and SPIONs ensured concurrence of fluorescent and magnetic signals in the sentinel nodes. Average tracer accumulation time before dissection was 5 hours. On average 4.5 fluorescent nodes (range 2–7) were removed, of which 2 (average) were also magnetic (range 1–4). Magnetic nodes could be identified using both preoperative MRI and intraoperative magnetometer probe. The mannose label of the SPIONs produced a strong binding affinity to macrophages, and in combination with particle size (80 nm) results in enhanced retention in the sentinel nodes. On average, after 5 hours accumulation time, the sentinel nodes contained 4.1% of the SPION injected dose and 88% of the magnetometer counts. Conclusions: Through the co-injection of fluorescent and mannose-labelled magnetic tracers, lymphatic drainage pathways can be determined preoperatively with MRI, visualised with intraoperative fluorescence cameras, and SLNs confirmed with magnetometer. Although ICG flows through multiple echelons, in doing so it creates a lymphatic roadmap to guide surgeons. The addition of magnetic particles provides sentinel node discrimination, so in combination, these two tracers could greatly enhance the capability to detect SLNs in gastric cancer.

Development of a Novel Orthotopic Gastric Cancer Mouse Model

BackgroundGastric cancer metastasis is a highly fatal disease with a five-year survival rate of less than 5%. One major obstacle in studying gastric cancer metastasis is the lack of faithful models available. The cancer xenograft mouse models are widely used to elucidate the mechanisms of cancer development and progression. Current procedures for creating cancer xenografts include both heterotopic (i.e., subcutaneous) and orthotopic transplantation methods. Compared to the heterotopic model, the orthotopic model has been shown to be the more clinically relevant design as it enables the development of cancer metastasis. Although there are several methods in use to develop the orthotopic gastric cancer model, there is not a model which uses various types of tumor materials, such as soft tissues, semi-liquid tissues, or culture derivatives, due to the technical challenges. Thus, developing the applicable orthotopic model which can utilize various tumor materials is essential.ResultsTo overcome the known limitations of the current orthotopic gastric cancer models, such as exposure of tumor fragments to the neighboring organs or only using firm tissues for the orthotopic implantation, we have developed a new method allowing for the complete insertion of soft tissue fragments or homogeneously minced tissues into the stomach submucosa layer of the immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mouse. With this completely-closed transplantation method, tumors with various types of tissue may be used to establish orthotopic gastric cancer models without the risks of exposure to nearby organs or cell leakage. This surgical procedure was highly reproducible in generating forty-eight mouse models with a surgery success rate of 96% and tumor formation of 93%. Among four orthotopic patient-derived xenograft (PDX) models that we generated in this study, we verified that the occurrence of organotropic metastasis in either the liver or peritoneal cavity was the same as that of the donor patients.ConclusionHere we describe a new protocol, step by step, for the establishment of orthotopic xenograft of gastric cancer. This novel technique will be able to increase the use of orthotopic models in broader applications for not only gastric cancer research but also any research related to the stomach microenvironment.

Double-balloon endolumenal intervention platform with flexible grasper to expedite colonic endoscopic submucosal dissection.

Endoscopic submucosal dissection (ESD) of colonic lesions can be quite challenging owing to the very thin colon wall1 and limited expandability of the colonic submucosal space, which is in stark contrast to the forgiving esophageal and stomach submucosa.1 In addition, the colonic muscularis propria can be easily disrupted with inadvertent cauterization by the dissection knife or simply via pressure from the endoscope. Colonic looping and the lesion’s location behind folds or around flexures can add to the difficulty of the procedure.

Inferior vagal ganglion galaninergic response to gastric ulcers.

Galanin is a neuropeptide widely expressed in central and peripheral nerves and is known to be engaged in neuronal responses to pathological changes. Stomach ulcerations are one of the most common gastrointestinal disorders. Impaired stomach function in peptic ulcer disease suggests changes in autonomic nerve reflexes controlled by the inferior vagal ganglion, resulting in stomach dysfunction. In this paper, changes in the galaninergic response of inferior vagal neurons to gastric ulceration in a pig model of the disease were analyzed based on the authors' previous studies. The study was performed on 24 animals (12 control and 12 experimental). Gastric ulcers were induced by submucosal injections of 40% acetic acid solution into stomach submucosa and bilateral inferior vagal ganglia were collected one week afterwards. The number of galanin-immunoreactive perikarya in each ganglion was counted to determine fold-changes between both groups of animals and Q-PCR was applied to verify the changes in relative expression level of mRNA encoding both galanin and its receptor subtypes: GalR1, GalR2, GalR3. The results revealed a 2.72-fold increase in the number of galanin-immunoreactive perikarya compared with the controls. Q-PCR revealed that all studied genes were expressed in examined ganglia in both groups of animals. Statistical analysis revealed a 4.63-fold increase in galanin and a 1.45-fold increase in GalR3 mRNA as compared with the controls. No differences were observed between the groups for GalR1 or GalR2. The current study confirmed changes in the galaninergic inferior vagal ganglion response to stomach ulcerations and demonstrated, for the first time, the expression of mRNA encoding all galanin receptor subtypes in the porcine inferior vagal ganglia.

Clinical and endoscopic features of 49 cases of gastric inflammatory fibroid polyp

Objective To summarize the endoscopic appearance, endoscopic ultrasound findings and histopathological characteristics of gastric inflammatory fibroid polyp (IFP) in order to improve diagnosis of IFP. Methods From September 2011 to November 2016, 49 patients with pathologically comfirmed gastric IFP, who underwent endoscopy in Taizhou Hospital of Zhejiang Province, were enrolled. The medical history, endoscopic examination, treatment and follow-up were retrospectively analyzed. Results Among 49 patients with gastric IFP (16 males and 33 females; average age 54 years) the maximum diameter of 33 cases (67.3%) was between 1.0 cm and 2.0 cm. Forty-eight cases had single lesion and one case had multiple lesions. The lesions of 17 cases (34.7%) were located at the anterior wall of gastric antrum, the lesions of seven cases (14.3%) were at the posterior wall of gastric antrum, the lesions of seven cases (14.3%) were at the lesser curvature of gastric antrum and the lesions of seven cases (14.3%) were at the great curvature of gastric antrum. Among the lesions of 41 patients who received endoscopic ultrasonography, 28 lesions were located in the submucosa of stomach, 13 lesions were located in mucosa and muscularis mucosa. The rate of misdiagnosis of endoscopic ultrasonography was 29.3%(12/41). The endoscopic ultrasound findings of the lesions included 26 hypoechoic structures, 11 hyperechoic structures and four slightly hypoechoic structures. The lesions of all the patients were successfully removed by endoscopic polypectomy without any complication. Thirty-seven lesions were treated by endoscopic submucosal dissection (ESD) and 12 lesions by endoscopic mucosal resection (EMR). All the patients were not clearly diagnosed before operation and were finally diagnosed by pathological examination. Postoperative pathological examination showed that in the suhmucosa and mucosa lamina propria, spindle-shaped cells proliferated and arranged in an interwoven pattern or cells around vessels or mucosal glands formed vortex-like or onion skin-like pattern. Forty-seven patients were followed up and the median follow-up time was 31 months. All patients survived withont recurrence or metastasis until the submission of this paper. Conclusions The rate of misdiagnosis of gastric IFP is high before operation, and the diagnosis is depended on histopathological examination. Endoscopic resection is the first choice because the diameter of most lesions are less than 5 cm. Key words: Gastrointestinal diseases; Diagnosis; Inflammatory fibroid polyp of the stomach; Endoscopic findings; Treatment

Stomach wall structure and vessels imaging by acoustic resolution photoacoustic microscopy.

AIMTo image stomach wall blood vessels and tissue, layer-by-layer.METHODSWe built up the acoustic resolution photoacoustic microscopy (AR-PAM) system for imaging layered tissues, such as the stomach wall. A tunable dye laser system was coupled to a fiber bundle. The fibers of the bundle were placed in nine directions with an incident angle of 45° around a high-frequency ultrasound transducer attached to the acoustic lens. This structure formed a dark field on the tissue surface under the acoustic lens and the nine light beams from the fibers to be combined near the focal point of the acoustic lens. The sample piece was cut from a part of the porcine stomach into a petri dish. In order to realize photoacoustic depth imaging of tumor, we designed a tumor model based on indocyanine green (ICG) dye. The ICG solution (concentration of 129 μM/mL) was mixed into molten gel, and then a gel mixture of ICG (concentration of 12.9 μM/mL) was injected into the stomach submucosa. The injection quantity was controlled by 0.1 mL to make a small tumor model.RESULTSAn acoustic resolution photoacoustic microscopy based on fiber illumination was established and an axial resolution of 25 μm and a lateral resolution of 50 μm in its focal zone range of 500 μm has been accomplished. We tuned the laser wavelength to 600 nm. The photoacoustic probe was driven to do B-scan imaging in tissue thickness of 200 μm. The photoacoustic micro-image of mucosa and submucosa of the tissue have been obtained and compared with a pathological photograph of the tissue stained by hematoxylin-eosin staining. We have observed more detailed internal structure of the tissue. We also utilized this photoacoustic microscopy to image blood vessels inside the submucosa. High contrast imaging of the submucosa tumor model was obtained using ICG dye.CONCLUSIONThis AR-PAM is able to image layer-by-layer construction and some blood vessels under mucosa in the stomach wall without any contrast agents.

Inflammatory fibroid polyp - a cause of small bowel obstruction

Introduction Inflammatory fibroid polyps (IFPs) are rare, benign tumours originating from the submucosa of stomach or small bowel. They account for only 0.1-3.0% of all gastric polyps. Histogenesis remains unknown. In adults, benign tumours such as IFPs are an uncommon cause of small bowel obstruction. Case description A 54 year old male patient with known hypertension presented to the emergency department with a 24 hour history of sudden onset and severe right iliac fossa pain, which progressively worsened. He was pyrexial on admission, had decreased appetite and had significant weight loss over the previous few months. There were no other gastrointestinal symptoms. The clinical examination and laboratory findings were consistent with a diagnosis of appendicitis. However, a CT scan of the abdomen and pelvis was suggestive of small bowel obstruction. This scan was reported by two radiologists due to the inconclusive aetiology of the small bowel obstruction. Though the first impression was acute-on-chronic crohn’s disease, on further analysis of the images a well defined oval shaped homogenous mass was noted in the distal ileum. An MRI scan confirmed terminal ileal inflammatory changes with intraluminal cystic changes. The patient underwent a laparoscopic right hemicolectomy. Intraoperatively, a cystic mass in the terminal ileum was found to be causing small bowel obstruction. Histology revealed that the mass was composed of fusiform and stellate shaped stromal cells with marked oedema and eosinophilia consistent with the diagnosis of IFP. The patient had an uneventful postoperative recovery. Results and Conclusions Despite the fact that inflammatory fibroid polyps are very rare lesions, they should be taken into consideration as a differential diagnosis in patients presenting with small bowel obstruction, as prompt surgical resection is the only known effective treatment.

Gastric impaction in an Indian Rock Python (Python molurus molurus)

A case of gastric impaction and resultant systemic toxemia in an Indian Rock Python is being reported. Grossly, stomach was found over-distended and impacted with greyish semisolid pasty odourless mass. Microscopically, mucosa and submucosa of stomach were found severely inflamed. Diffuse hepatic necrosis, nephrosis and pulmonary haemorrhages were evident. The cause of death was attributed to systemic toxemia as a result of gastric impaction.

Sa1398 Submucosal Injection Pressure in the Upper Gastrointestinal Tract

Endoscopic injection has different uses, endoscopist controls site of injection and an assistant “feels” the resistance applied, in a non-standardized technique. Moreover between anesthesiologist injection pressure for peripheral blockade has not correlation, now includes controled pressure techniques, as well as in Radiology, Oftalmology, Reumatology, decreasing operators variability. In Endoscopy measure of injection pressure is referred for endoscopic mucosal resection and submucosal dissection, in studies about injectable solutions kinds as objetive.Objetives: To determine the injection pressure in ex vivo porcine esophagus and stomach submucosa, and evaluate differences between the pressures of their anatomical regions.Justification: Determine objectively the injection pressure as a tool that could facilitate the technical and reduce variability between operators.

Establishment of a nude mouse model of highly metastatic gastric lymphoma constructed with orthotopic transplantation of surgical specimen

To construct a mouse model of highly metastatic gastric lymphoma with orthotopic transplantation of human primary gastric lymphoma specimen. A fresh surgical specimen of primary gastric lymphoma was obtained intraoperatively and implanted into the submucosa of stomach in nude mice. Tumor formation, invasion, metastasis, morphological characteristics under light microscopy and electron microscopy, immunohistochemistry,and the karyotype of orthotopically transplanted tumor cells were studied. An orthotopic highly metastatic model of human primary gastric lymphoma in nude mice(HGBL-0305) was successfully established. Histopathology of transplanted tumors showed primary gastric diffuse large B cell lymphoma. CD19, CD20, CD22 and CD79alpha were positive, while CD3 and CD7 were negative. The number of chromosome ranged from 56 to 69. DNA index(DI) was 1.47+/-0.12(i.e. heteroploid). Until now, HGBL-0305 model has been maintained for 45 generations by orthotopic passage for almost 4 years in nude mice. A total of 156 nude mice were used for transplantation. The growth rate and resuscitation rate of liquid nitrogen cryopreservation of transplanted tumor cells were both 100%. The autonomic growth of the transplanted tumor cells invaded and destructed all the layers of the nude mice stomach. The metastasis rates of liver, spleen, lymph node, and peritoneal seeding were 69.5%, 55.6%, 45.7%, and 30.5%, respectively. An orthotopic highly metastatic model of human primary gastric lymphoma in nude mice is successfully established. HGBL-0305 model may simulate the natural course of primary gastric lymphoma in human and provides an ideal animal model for studies on pathogenesis, metastasis biology and anti-metastatic therapies of primary gastric lymphoma.

Highly metastatic nude mouse model of human primary gastric lymphoma constructed by surgical orthotopic transplantation and in vivo continuous screening method

To develop a series of high metastatic models of human gastric malignant lymphoma in nude mice by orthotopic transplantation. Two histologically intact primary and hepatic metastatic fragments derived from surgical specimen of a patient with primary gastric lymphoma were implanted into the submucosa of stomach in nude mice. Highly metastatic and specific organ metastatic models were screened by selective orthotopic passage in nude mice. Transplantability, invasion, metastasis, morphological characteristics (light microscopy, electron microscopy and immunohistochemistry), karyotypic analysis and DNA content of orthotopically transplanted tumors were studied. Primary and hepatic metastatic fragments of primary gastric lymphoma were successfully transplanted in nude mice. Two nude mouse models of human primary gastric lymphoma, termed HGBL-0304 (hepatic metastasis model) and HGBL-0305 (high metastasis model), were developed, exhibiting different metastasis biology. Histopathology of transplanted tumors showed primary gastric diffuse large B cell lymphoma. Two models have been maintained for 45 generations by orthotopic passage in nude mice. A total of 419 nude mice were used for transplantation. The growth rate and resuscitation rate of liquid nitrogen cryopreservation of transplanted tumors were both 100%. Significant difference in metastasis biology was exhibited in four aspects of metastasis time, organ metastatic rate, the extent of hepatic metastasis and survival of cancer-bearing mice. The metastatic rates of liver, spleen, lymph nodes and peritoneal seeding in HGBL-0304 and HGBL-0305 models were 100% and 69.5%, 94.3% and 55.6%, 62.6% and 45.7%, and 43.5% and 30.5%. The onset time for metastases of liver, spleen, lymph nodes and peritoneal seeding was 2 w and 5 w, 3 w and 6 w, 2 w and 3 w, 3 w and 6 w respectively. The extent of hepatic metastasis in HGBL-0304 and HGBL-0305 models displayed diffuse involvement of the whole liver and mainly right lobe invasion of liver respectively. The mean survival time of HGBL-0304 and HGBL-0305 models was 54.3d and 106.9 d respectively. Surgical orthotopic implantation combined with in vivo selective passage screening is an effective method for establishing highly metastatic and specific organ metastatic models of human malignant lymphoma in nude mice. The study is the first time to establish hepatic metastasis and high metastasis nude mouse models of human primary gastric lymphoma with the same original patient and different potentials of invasion and metastasis.

Histopathologic study on the effects of methionine in reduction of hepatotoxicity and gastritis due to co-administration of gentamicin and indomethacin in rats

Gentamicin is a wide spectrum aminoglycoside used against gram negative bacterial infections, therapeutic does of this drug resulted in nephrotoxicity and hepatotoxicity. Indomethacin is one of the NSAIDs with side effects on stomach, liver and Kidney. Co-administration of indomethacin and gentamicin may resulted in exaggeration of their side efects .In this research, 42 male Sprague dawley rats were divided randomly into 6 equal groups. In the period of 14 days group 1-6 received normal saline (I.P), gentamicin (I.M), indomethaci (I.M), gentamicin (I.M) plus indomethacin (I.M), L-methionine (I.P), and gentamicin (I.M) plus indomethacin (I.M) and L-methionine(I.P) respectively once a day. In day 15, rats were euthanized and histopathologic slides of the liver and stomach were prepared. Histopathologic examination revealed and edema in tunica mucosa and submucosa of stomach in group 3 and 4, and mild hemorrahage in tunica mucosa of stomach of group 3 .In group 2 and 4 capillarization , deformed hepatocytes , apoptosis and mononuclear cell infiltration in portal area were seen in liver . Fibrosis of portal area was obvious in group 4. For the first time the results of the peresent study showed that methionine can prevent form side effects of Co-administration of indomethacin and gentamicin in liver and stomach.

The direct comparison of health and ulcerated stomach tissue: A multiple probe microdialysis sampling approach

The ability to directly compare gastric ulcerated and healthy tissue would aid in the understanding of the physiological differences between these tissue types. Presently, these comparisons can only be drawn by the use of separate animal groups, which results in increased study variability. The focus of this research was to develop a four-probe microdialysis sampling approach to directly compare ulcerated and healthy tissue in the same animal. After controlled chemical ulcer induction, probes were implanted in the ulcerated and healthy stomach submucosa, stomach lumen and in the blood. To assess the significance of this multiple probe approach, drug concentrations in each probe location were monitored after selected compounds were dosed to the ligated stomach by oral gavage. Analysis of the dialysate samples was performed by HPLC-UV and concentration-time curves and pharmacokinetics analyses were used to determine differences between these tissue types.

RARE GASTRIC CALCIFYING FIBROUS PSEUDOTUMOR REMOVED BY ENDOSCOPIC SUBMUCOSAL DISSECTION

We report a case of a calcifying fibrous pseudotumor of the stomach that we resected using endoscopic submucosal dissection (ESD). A 61-year-old male with a gastric submucosal tumor was admitted to our hospital for treatment. By upper gastrointestinal tract endoscopy, a smooth-surfaced submucosal tumor measuring 2 cm in diameter was observed in the anterior wall of the middle body of the stomach. By endoscopic ultrasonography, a mass was observed in the stomach submucosa; the mass had a well-defined boundary. Internally, the mass was heterogeneous and hypoechoic; high spots were scattered throughout the mass. Continuity between the mass and the muscularis mucosae and muscularis propria was not observed. Strongly suspecting that this mass was a gastrointestinal stromal tumor arising from the stomach, we resected the mass by ESD for total biopsy. Histopathologically, the mass consisted of proliferation of eosinophilic collagen fibers with plasma cell infiltration and lymphoid follicle proliferation. Calcification was also observed in some parts of the mass. Thus, the mass was identified as calcifying fibrous pseudotumor. Calcifying fibrous pseudotumor of the stomach is extremely rare and its histogenesis remains unclear; however, its morphology became distinct by comparing endoscopic/radiological and histopathological findings.

Eradication of Helicobacter pylori induces apoptosis and inhibits proliferation of heterotopic proliferative glands in infected Mongolian gerbils

Mongolian gerbils infected with Helicobacter pylori (H. pylori ) develop heterotopic proliferative glands (HPGs) in the glandular stomach submucosa. To investigate the effects of H. pylori eradication on cell turnover in HPGs, three antibiotics, lansoprazole, amoxicillin and clarithromycin, were administered at 50 or 75 weeks after inoculation of H. pylori, and the stomachs were excised for histological examination at 1, 2, 4, 8 or 25 weeks thereafter. The HPGs were classified into gastric type (G-type) and others (GI + I-type), which included both pure intestinal (I-type) and gastric-and-intestinal mixed type (GI-type). Apoptosis and cell proliferation were evaluated by means of TUNEL assay and BrdU labeling, respectively. At 8 weeks post-eradication, apoptotic indices were significantly increased in the eradication group (G-type: 2.5%; GI + I-type: 7.2%) compared to the non-eradication group (G-type: 0.6%; GI + I-type: 2.1%: P < 0.01), while BrdU labeling indices were significantly decreased (G-type: 1.9%; GI + I-type: 6.8% as compared with 4.3% and 13.2%, respectively, P < 0.01 for both). At 25 weeks, the apoptotic indices were similarly higher [G-type: 0.4 (eradication group) vs. 0.2% (non-eradication group); GI + I-type: 5.8 vs. 1.1%, both P < 0.01], and the BrdU labeling indices (G-type: 0.8 vs. 2.2%, P < 0.01; GI + I-type: 5.1 vs. 11%, P < 0.05) continued to be lower in HPGs. Furthermore, there were highly significant reductions in the areas of HPGs at 8 and 25 weeks post-eradication. These findings demonstrated that eradication results in apoptosis and reduction of proliferation of HPGs in H. pylori-infected gerbils, these lesions thus being apparently reversible through regulation of cell kinetics.

Canine histiocytic syndrome manifested as ulcerative gastroenterocolitis, skin lesions and lymphadenopathy - a case report

Histiocytic syndrome was diagnosed in a 7-year-old boxer bitch using histological and immunohistochemical methods. Necropsy confirmed the presence of enlarged superficial lymph nodes, two large ulcerated oval cutaneous masses one on the left lateral thoracic wall and one near to the vulva. In the gastrointestinal tract there were multiple ulcers apparently overlying nodules located in the submucosa of stomach, ulcers in the ileocaecal valve, and enlargement of lymphoid nodules in the small intestine manifested ulcerative gastroenteritis. Histologically, the thoracic wall mass showed infiltration of the tissue by macrophages with cytoplasmic vacuoles. The vacuoles contained PAS-positive polysaccharides. The macrophages were positive for alpha-1-antitrypsin and lysozyme by immunostaining. Lysozyme is a marker for phagocytic macrophages/histiocytes and may be used to confirm cells of this lineage in cases when there is any doubt.

Biaxial strength of multilaminated extracellular matrix scaffolds

Xenogeneic extracellular matrix (ECM) can be harvested and configured to function as a bioscaffold for tissue and organ reconstruction. The mechanical properties of the ECM vary depending upon the tissue from which it is harvested. Likewise, the manufacturing steps required to develop ECMs into medical grade devices will affect the surface morphology and the mechanical properties of the bioscaffold; important properties for constructive tissue remodeling. The present study compared the ball-burst strength of five different ECM scaffolds before and after treatment with peracetic acid (PAA): porcine small intestinal submucosa (SIS), porcine urinary bladder submucosa (UBS), porcine urinary bladder matrix (UBM), a composite of UBS+UBM, and canine stomach submucosa (SS). This study also compared the mechanical properties of 2- and 4-layer ECM scaffolds. Results showed 2-layer SS devices had the highest ball-burst value of all 2-layer ECM devices. Moreover, all 4-layer ECM devices had similar ball-burst strength except for 4-layer UBM devices which was the weakest. PAA-treatment decreased the ball-burst strength of SS and increased the ball-burst strength of UBS 2-layer devices. This study showed the material properties of the ECM scaffolds could be engineered to mimic those of native soft tissues (i.e. vascular, musculotendinous, etc) by varying the number of layers and modifying the disinfection/sterilization treatments used for manufacturing.