Serosal Layer Research Articles

The Gallbladder ofUranoscopus ScaberL. (Teleost Perciform Fish) is Lined by Specialized Cholecystocytes

The gallbladder of Uranoscopus exhibits a mucosal surface layer of simple columnar epithelium composed of specialized cholecystocytes. The apices show storage and mucous secretions, typical microvilli, and very apical projections extending deep into the luminal contents. Many organelles and heterogeneous vesicles of diverse size fill the cytoplasm, including neutral mucins, mitochondria, peroxisomes, lysosomal bodies, and lipid-rich deposits with cholesterol inclusions. The fibromuscular layer shows little blood supply and contains scattered lymph-like walls with minute cholesterol inclusions. The remaining muscular, subserosal, and serosal or adventitial layers of this species do not show any histologic differences to those of other vertebrates. It was unexpected to find cholesterol inclusions in the fatty deposits of the cholecystocytes, similar to those noted in human cholesterolosis and in some forms of hypercholesterolemia, in this teleostean. In addition, aggregations of mitochondria and anomalous mitochondrial morphologies were found that resemble oncocytoma-like changes.

Clinicopathological observation of gastric cancer with pathological complete response following neoadjuvant chemotherapy

To observe the clinicopathological characteristics of gastric cancer with pathological complete response(pCR) following neoadjuvant chemotherapy. Data of gastric cancer patients who received neoadjuvant chemotherapy from 2002 to 2008 in the Beijing Cancer Hospital were reviewed. Five cases were found to have pCR. The slides were reviewed by two experienced pathologists independently. Histological structure, morphology of tumor cells, morphology and quantity of stromal cells were evaluated. Structure of the gastric wall was distinguishable in all the 5 cases, while distortion and rupture of muscular layer were found in 2 cases. Exudative inflammatory reaction was present in the whole gastric wall including the serosa layer. Three patients had ulcerative lesions with epithelial layer shedding, and atypical hyperplasia was found around the border of the ulcer, and vascular endothelial cells were swollen. Residual distorted necrotic tumor cells resided in 1 case only and no residual tumor cells was present in the other 4 patients. Significant hyperplasia of fibroblasts was present in 4 cases, large amount of lymphocytes infiltration in 3 cases including concurrent plasma cell infiltration in 1 case, multinucleated giant cell reaction in the muscular layer of 1 case, and foam cells aggregation in 1 case with mucinous adenocarcinoma. In addition, there were 2 cases with pCR had lymph node metastasis. For cases with pCR following neoadjuvant chemotherapy, heterogeneity of stromal cells reaction is found in previous tumor site. Furthermore, the response of primary tumor does not necessarily parallel to that of lymph nodes.

Contrast-enhanced ultrasonography of the small bowel in healthy cats.

We characterized the pattern of ultrasonographic contrast enhancement of the small intestinal wall using a commercial contrast medium (Sonovue®) in 10 healthy awake cats. Subjectively, a rapid intense enhancement of the serosal and submucosal layers was followed by gradual enhancement of the entire wall section during the early phase. At peak enhancement, there was a subjective loss of demarcation between intestinal wall layers. In the late phase, there was a gradual wash out of signal from the intestinal wall. Submucosal wash out occurred last. Time‐intensity curves were generated for selected regions in the intestinal wall and multiple perfusion parameters were calculated for each cat. Perfusion parameters included arrival time (7.64 ± 2.23 s), baseline intensity (1.04 ± 0.04 a.u.), time to peak from injection (10.74 ± 2.08 s), time to peak from initial rise (3.1 ± 1.15), peak intensity (8.92 ± 3.72 a.u.), wash‐in rate (2.06 ± 0.70 a.u./s) and wash‐out rate (−1.07 ± 0.91 a.u./s). The perfusion pattern of normal feline small bowel may be useful for characterizing feline gastrointestinal disorders that involve the intestinal wall.

Cortisol affects tight junction morphology between pavement cells of rainbow trout gills in single-seeded insert culture

A primary culture system of rainbow trout gill pavement cells grown on permeable support (single-seeded insert, SSI) was used to examine histological and physiological changes induced by the addition of the corticosteroid hormone cortisol. Pavement cell epithelia were cultured under symmetrical conditions (L15 apical/L15 basolateral) and developed a high transepithelial resistance (TER, 6.84±1.99kΩcm(2), mean±SEM) with a low phenol red diffusion rate (PRD, 0.15±0.03μmoll(-1)/day). Addition of cortisol to the basolateral compartment increased TER twofold and reduced PRD threefold over a 5-day period. A similar increase in TER could be seen after 24h apical freshwater (FW) in control cultures. In cortisol-treated cultures FW exposure did not change TER, but PRD increased significantly. Histochemical staining of the cytoskeleton of cells in SSI culture revealed a morphological partitioning into a single mucosal layer of polarized, polygonal cells featuring cortical F-actin rings which were comparable to F-actin rings of epithelial cells on the lamellar and filamental surface, and several unorganized serosal layers of cells with F-actin stress fibers. Addition of cortisol increased cell density by 18% and in the mucosal layer it led to smaller, less polygonal cells with increased height and increased cell contact area. In transmission electron microscopic images two pairs of cytoplasmatic electron-dense structures confining the zonula occludens apically and basally toward the zonula adhaerens were found. Addition of cortisol increased the distance between those paired structures, hence led to deeper tight junctions. The cortisol-induced increase in barrier properties, therefore, involves a structural fortification of the tight junctions which was not generally modified by a short 24-h apical freshwater stress. These results identify cortisol as a regulator of tight junction morphology between pavement cells of euryhaline fish such as the trout.

Uterine adenocarcinoma with transcoelomic metastases in breeder hens (Gallus domesticus)

Hens involved in a Newcastle disease study were euthanased at regular intervals according to a designed protocol. Of these, 7.14 % (n = 42) of the 82-week-old specific pathogen-free breeder hens were found to have well-delineated firm white to yellowish nodules of varying sizes in the abdominal cavity. Histologically, the nodules were identified as an adenocarcinoma originating in the uterus. Transcoelomic spread was evidenced by the presence of similar neoplastic cells embedded in the serosa and outer longitudinal muscle layer of the intestines as well as the liver.

Endoscopic full-thickness resection without laparoscopic assistance for gastric submucosal tumors originated from the muscularis propria

This study was designed to evaluate the clinical efficacy, safety, and feasibility of endoscopic full-thickness resection (EFR) for gastric submucosal tumors (SMTs) originated from the muscularis propria. Twenty-six patients with gastric SMTs originated from the muscularis propria were treated by EFR between July 2007 and January 2009. EFR technique consists of five major procedures: (1) injecting normal saline into the submucosa and precutting the mucosal and submucosal layer around the lesion; (2) a circumferential incision as deep as muscularis propria around the lesion by the endoscopic submucosal dissection (ESD) technique; (3) incision into serosal layer around the lesion with Hook knife; (4) completion of full-thickness incision to the tumor including the serosal layer with Hook, IT, or snare by gastroscopy without laparoscopic assistance; (5) closure of the gastric-wall defect with metallic clips. EFR was successfully performed in all 26 patients without laparoscopic assistance. The complete resection rate was 100%, and the mean operation time was 105 (range, 60-145)min. The mean resected lesion size was 2.8 (range, 1.2-4.5)cm. Pathological diagnosis of these lesions included gastrointestinal stromal tumors (GISTs) (16/26), leiomyomas (6/26), glomus tumors (3/26), and Schwannoma (1/26). No gastric bleeding, peritonitis sign, or abdominal abscess occurred after EFR. No lesion residual or recurrence was found during the follow-up period (mean, 8months; range, 6-24months). EFR seems to be an efficacious, safe, and minimally invasive treatment for patients with gastric SMT, which makes it possible to resect deep gastric lesion and provide precise pathological diagnosis of it. With the development of EFR, the indication of endoscopic resection may be expanded.

Solitary metastasis of a clear cell ovarian adenocarcinoma to the small bowel mucosa

Metastasis of ovarian carcinoma to the small bowel parenchyma without peritoneal dissemination is uncommon. A 63-year-old woman underwent surgery for a clear cell adenocarcinoma of the ovary and received adjuvant chemotherapy. Eighteen months after the operation, she presented with recurrent occult bowel hemorrhage without evidence of an abdominal mass. Nine months later, a rapidly growing abdominal mass was detected. Laparoscopy revealed a solitary tumor of the ileum covered with an intact serosal layer. Partial ileectomy was performed for tumor resection. Histological examination revealed cells resembling the primary ovarian tumor in the mucosal surface of the small bowel along with an intact serosa. The tumor cells were positive for cytokeratin 7 and negative for cytokeratin 20, suggesting an ovarian origin. This is the first report of solitary metastasis of an ovarian carcinoma to the small bowel parenchyma without peritoneal dissemination. Metastasis to the small bowel should be considered in ovarian carcinoma patients with occult gastrointestinal hemorrhage.

Multicentric Fibromyxoid Peripheral Nerve Sheath Tumor (Multicentric Schwannoma) in a Dromedary Camel (Camelus dromedarius)

During postslaughter inspection of a 4-year-old male dromedary camel (Camelus dromedarius), numerous small nodules to large masses up to 4 cm in diameter were found on the serosal surfaces of forestomachs, large intestines, mesentery, liver, and spleen. Grossly, the masses were discrete, round, smooth, and white to gray that bulged from the serosal layer. Cut surfaces of the masses were discrete, round, white, and relatively homogeneous without any necrotic foci. Histopathologically, the masses were encapsulated and composed of a mixture of round and spindle-shaped cells in loose whorls of neoplastic cells with small elongated hyperchromatic wavy nuclei and a small amount of pale eosinophilic, poorly defined cytoplasm. Masson's trichrome staining showed mild amounts of collagen fibers forming an irregular, loose stroma. In immunohistochemistry, immunoreactivity for the Schwann cell marker (S100) was diffusely positive in the neoplastic cells. The immunoreactivity for CK, c-kit, and CD34 were negative. Ultrastructural examination confirmed the tumor was entirely formed of neoplastic Schwann cells. On the basis of the histopathological, immunohistochemical, and ultrastructural findings, the tumors were diagnosed as multicentric fibromyxoid peripheral nerve sheath tumor (multicentric schwannoma). This tumor has not been previously recorded in camel worldwide.

PERSPECTIVES: A little humour relaxes the gallbladder

PERSPECTIVES: A little humour relaxes the gallbladder

A feasibility and dosimetric evaluation of endoscopic radiofrequency ablation for human colonic and rectal epithelium in a treat and resect trial

Endoscopic radiofrequency ablation (RFA) has been used effectively for ablation of foregut disorders and also may have a role in treating colonic pathology. This study aimed to assess the feasibility of delivering RFA to locations within the colon and to determine a range of safe treatment parameters. Patients undergoing left hemicolectomy or proctocolectomy were evaluated. Focal RFA using a colonoscope-mounted device was delivered to normal segments of the colon and rectum within the planned surgical resection specimen. Endoscopic accessibility and feasibility of delivering heat energy to the colon and rectum were assessed as well as the maximum incurred histologic depth of ablation in relation to the number of applications (2 or 4) and the energy density (12, 15, or 20 J/cm2). A total of 51 ablation zones in 16 patients had available histopathology. None of the sites receiving two applications demonstrated serosal layer alteration compared with 15% of the sites receiving four applications (p=0.11). Muscularis propria alterations were seen in 25% of the two-application sites and 63% of the four-application sites (p<0.05). Increasing energy density from 12 to 20 J/cm2 did not correlate with a deeper ablation effect. Endoscopic RFA is capable of delivering therapy to the distal colon. Injury is limited to the muscularis propria or less depth when no more than two ablations are applied regardless of the energy density used. Based on these feasibility and dosimetry results, the authors will continue investigation using these and smaller energy doses to initiate trials ultimately with patients who have suitable mucosal and submucosal disorders of the lower gastrointestinal tract including chronic, nonulcerated hemorrhagic radiation proctitis and angiodyplasia.

Formed and preformed metabolites: facts and comparisons

The administration of metabolites arising from new drug entities is often employed in drug discovery to investigate their associated toxicity. It is expected that administration of metabolites can predict the exposure of metabolites originating from the administration of precursor drug. Whether exact and meaningful information can be obtained from this has been a topic of debate. This communication summarizes observations and theoretical relationships based on physiological modelling for the liver, kidney and intestine, three major eliminating organs/tissues. Theoretical solutions based on physiological modelling of organs were solved, and the results suggest that deviations are expected. Here, examples of metabolite kinetics observed mostly in perfused organs that did not match predictions are provided. For the liver, discrepancies in fate between formed and preformed metabolites may be explained by the heterogeneity of enzymes, the presence of membrane barriers and whether transporters are involved. For the kidney, differences have been attributed to glomerular filtration of the preformed but not the formed metabolite. For the intestine, the complexity of segregated flows to the enterocyte and serosal layers and differences in metabolism due to the route of administration are addressed. Administration of the metabolite may or may not directly reflect the toxicity associated with drug use. However, kinetic data on the preformed metabolite will be extremely useful to develop a sound model for modelling and simulations; in-vitro evidence on metabolite handling at the target organ is also paramount. Subsequent modelling and simulation of metabolite data arising from a combined model based on both drug and preformed metabolite data are needed to improve predictions on the behaviours of formed metabolites.

Short communication: Transport of 2-hydroxy-4-methyl-thio-butanoic isopropyl ester by rumen epithelium in vitro

Our objective was to evaluate the potential of rumen epithelium to transport 2-hydroxy-4-(methylthio)-butanoic isopropyl ester (HMBi) using the Ussing chamber technique. Rumen tissues were obtained from a nearby slaughterhouse, separated from the muscle and serosal layer as quickly as possible after exsanguination, placed in buffer, and gassed with 95:5 (vol/vol) O2:CO2 before tissue mounting. Two levels of HMBi (0.44 and 0.88mg/mL) and 2 incubation times (120 and 180min) were used in 12 chambers with 3 replicates per treatment with an exposed surface area of 2cm2. Four separate experiments were conducted (n=16). Concentrations of HMBi and methionine hydroxy analog (HMB) were measured by HPLC in rumen-side and serosal-side buffers. Data are expressed as percentage of added HMBi. Initial time samples were taken for comparison with incubated samples. Adding the HMBi-buffer mixture to the rumen side caused an immediate release of HMB (mean=6.3%). Breakdown of HMBi to HMB at initial time was due to hydrolysis reactions at the epithelial surface. Overall, a small and variable amount of HMBi was transferred to the serosal buffer (mean of 0.58% across both times and both concentrations). A larger amount of HMB (8.94%) was isolated in the serosal buffer. Increasing incubation time increased the amount of HMB in the ruminal buffer (34.0% at 120min vs. 43.4% at 180min) and decreased the amount of HMBi (37.9% at 120min vs. 28.1% at 180min). These data indicate that very limited amounts of HMBi may cross the rumen epithelium. The amount of HMB isolated on the serosal side was about 10 times higher than HMBi. The hydrolysis of HMBi to HMB required the presence of rumen tissue or perhaps microbes attached to the tissue. Based on this in vitro system, direct transport from the rumen would not explain rapid blood methionine increases observed when HMBi is fed.

Endoscopic full-thickness resection without laparoscopic assistance for gastric submucosal tumors originated from muscularis propria layer

Objective To evaluate the feasibility and efficacy of endoscopic full-thickness resection （EFR） without laparoscopic assistance for gastric submucosal tumors （SMTs） originated from muscularis propria layer. Methods A total of 20 cases of gastric SMT, originated from muscularis propria, was resected by EFR from July 2007 to August 2009. EFR consisted of five major procedures, including normal saline injection into the submncosa and pre-cut of the mucosal and submucosal layer around the lesion, circumferential incision as deep as muscularis propria around the lesion with endoscopic submucosal dissection （ESD） , incision into serosal layer around the lesion with a Hook knife, full-thickness recection of the tumor including the serosal layer with Hook, IT, or snare on gastroscopy without laparoscopic assistance and closure of the gastric wall with metallic clips. Results Of 20 gastric SMTs, 9 located at the fundus, 11 at the corpus. EFR was successfully performed in all 20 patients without laparoscopic assistance. The complete resection rate was 100% , and the mean operation time was 85 min （60-145 min）. The mean tumor size was 2. 6 cm （ 1.8-3.5 cm）. Pathological examination confirmed gastrointestinal stromal tumors （GISTs） in 13 cases, leiomyoma in 4, glomus tumor in 2 and Schwannoma in 1 patient. No gastric bleeding, peritonitis or abdominal abscess occurred after EFR. Post-operative contrast roentgenography on the third day detected no contrast extravasation into abdominal cavity or disturbance of gastric emptying in any patients. The mean hospitalization time was 5.5 d （3-8 days）. The mean follow-up period was 7 months （ 1-12 months） with no lesion residue or recurrence. Conclusion EFR, efficacious, safe, and minimally invasive for patients with gastric SMTs originated from muscularis propria layer, is able to resect deep gastric lesion and provide precise path- ological information about the lesion. With the development of EFR, the indication of endoscopic resection might be extended. Key words: Endoscopic surgical procedures; Stomach; Submucosal tumor; Endoscopic fullthickness resection

Intraperitoneal Virtual Biopsy by Fibered Optical Coherence Tomography (OCT) at Natural Orifice Transluminal Endoscopic Surgery (NOTES)

IntroductionFibered optical coherence tomography (OCT) in conjunction with natural orifice transluminal endoscopic surgery (NOTES) could provide a facility for rapid, in situ pathological diagnosis of intraperitoneal tissues in a truly minimally invasive fashion. Materials and MethodsA large porcine model was established to test this hypothesis. A standard double channel gastroscope (Olympus) was used to achieve a transgastric access to the peritoneum and initiate the pneumoperitoneum. Magnetic retraction was used to display the sigmoid colon along with its mesentery. A commercially available fibered OCT probe (NIRIS system, Imalux) was inserted via a working channel of the gastroscope and used to assess intraperitoneal tissues. Separately, OCT images of human tissue specimens ex vivo were contrasted with representative standard histopathological slides. ResultsIntraperitoneal OCT provided clear real-time images of both the serosal and muscularis propria mural layers as well as the submuscosal–muscularis interface. Examination of mesenteric lymph nodes (including sentinel nodes) allowed visualization of their subcapsular sinus. Comparison of representative cross-sections however failed to evince sufficient resolution for confident diagnosis. ConclusionThis approach is technically feasible and, if the technology is advanced and proven accurate in human patients, could potentially be used to individualize operative extent prior to definitive resection.

Comparative analysis between clinicopathologic characteristics and prognosis in patients with local and infiltrative gastric cancer

OBJECTIVE To investigate the differences between the clinicopathologic characteristics and prognostic factors in patients with localized and infi ltrative gastric cancer (GC). METHODS Patients with advanced GC, who were admitted to the Department of Surgical Oncology of the First Affiliated Hospital of China Medical University, Shenyang, during a period of January 1980-January 2000, were divided into the localized and infiltrative GC groups. A comparative analysis of the clinicopathologic data and prognosis in the patients enrolled in the study was carried out based on the di ff erent macroscopic types. RESULTS There were significant differences in the sex ratio, tumor location, histologic type, depth of invasion, lymph node metastasis, lymphovascular cancer embolus (LVCE), growth pattern, and degree of radical surgery between the 2 groups. However, there were no significant differences in age, tumor size, and intravenous cancer embolus between the 2 groups. The prognosis of the infi ltrative GC group was poor. There were significant differences in the prognosis of the patients between the 2 groups when tumor infiltration was within the muscular layer or subserosa, yet the di ff erences disappeared once the tumor infiltration was beyond the serosal layer. The prognosis of the patients with localized GC was closely related to tumor location and lymph node metastasis. The prognostic factors of the patients in the infiltrative GC group included lymph node metastasis, depth of invasion, and tumor size. CONCLUSION There are significant differences in the clinicopathologic characteristics and prognosis between the 2 groups. Based on the biological characteristics of the tumors, individualized therapeutic plans will help to improve the treatment outcome.

Histopathological changes of the esophagus of the freshwater eels, Macrognathus aculeatus (Bl.) and Mastacembelus pancalus (Lac.) due to infection of metacercariae of Clinostomum mastacembeli Jaiswal, 1957

Macrognathus aculeatus (Bl.) and Mastacembelus pancalus (Lac.) (Family: Mastacembelidae) are considered to be the most delicious fish in Andhra Pradesh due to the tenderness of their muscles. The metacercariae of Clinostomum mastacembeli Jaiswal, 1957 are found infesting the oesophagus of these fishes heavily. During present studies, histopathological changes caused due to the encystment of metacercariae of C. mastacembeli in the oesophagus of these fishes were observed. The four layers of the oesophagus namely; serosa, muscualris layer, submucosa and mucosa were found severely affected. Histopathological changes included decrease in the lumen diameter of the oesophagus, atrophy and necrosis of epithelial cells of serosa layer, shrinkage of villi due to thickening of muscularis layer and formation of small vacuoles in the sub-mucosal layers.

Gastrointestinal: Eosinophilic enteritis manifesting as brown‐pigmented duodenal ulcers

A 31-year-old man was investigated for chronic lower abdominal pain and leucocytosis. Clinical examination revealed diffuse abdominal tenderness. He has chronic hepatitis B, history of epididymo-orchitis and deep vein thrombosis. Abdominal X-ray was unremarkable and abdominal CT showed increased density of the mesenteric fat with mesenteric lymphadenopathy. EGD showed duodenal ulceration (Figure 1) and colonoscopy was normal. His full blood picture revealed eosinophilia of 6.8 × 109 /L, a remarkable increase from his previous blood test in 2000 which on retrospect, demonstrated eosinophilia of 0.7–1.4 × 109. His duodenal (Figure 2A, H&E stain 200 × magnification, black arrow) and terminal ileal (Figure 2B, H&E stain 400 × magnification, white arrow) biopsies demonstrated eosinophilic infiltration in the lamina propria and submucosa affecting the Burner's glands. Extracellular eosinophilic staining constituents were present. He was treated with proton pump inhibitor and recovered. Eosinophilic enteritis is an increasing recognized condition affecting mainly the stomach and small intestine. There is no consensus as to what constitute eosinophilic enteritis but Talley et al. have identified 3 main diagnostic criteria: (1) the presence of gastrointestinal symptoms, (2) biopsies demonstrating eosinophilic infiltration of one or more areas of the gastrointestinal track, and (3) no evidence of parasitic or extra intestinal disease (as opposed to secondary eosinophilic gastrointestinal disorders). Peripheral eosinophilia is seen in less than 50% of the time. Clinical manifestations depend on level of eosinophilic infiltration. Mucosal layer disease presents as luminal symptoms like diarrhea, vomiting, malabsorption, weight loss and colicky abdominal pain. Muscular layer disease presents as hypertrophy leading to intestinal obstruction. Serosal layer disease, the rarest of all, presents as ascites. This is the form of eosinophilic enteritis that escape diagnosis as biopsy of the mucosal layer often fail to demonstrate presence of eosinophils in the superficial layers. Eosinophilic enteritis may be treated with steroid with 90% rapid symptom resolution, and rarely azathioprine is required. Mast cell stabilizers such as cromolyn and ketotifen have been used with mixed results. A leukotriene receptor antagonist, montelukast has also been tried. Surgical interventions may be required for cases present as intestinal obstruction or perforation. Contributed by

Contrast Enhanced Ultrasound Sonography in Intestinal Acute Graft Versus Host Disease: Advantages of Non-Invasive Anatomic and Physiologic Measurements.

Abstract 4493▪ IntroductionAcute GVHD involving the gastrointestinal tract is now the major cause of non-relapse mortality following allogenic transplant. Diagnosis remains problematic for some patients with pathology in the mid-gut; there is significant sampling error with mucosal biopsy; we lack objective measures of physiologic improvement or worsening in the gut; and duration of immune suppressive therapy remains imprecise. To address these issues, we have serially evaluated intestinal pathology in patients with acute GVHD using a reproducible ultrasound technique as a proof of principle study. Specifically, we examined the hypothesis that contrast-enhanced ultrasound (CEUS) could detect an enhancement of microcirculation during active intestinal acute GVHD as a diagnostic tool and that CEUS could be used to serially assess physiologic changes after treatment. MethodsFour patients (pts) with hematologic malignancy (1 each with ALL, AML, mantle cell lymphoma, and myeloma) received a matched unrelated donor allogenic transplant after a myeloablative (N=2), reduced intensity (N=1), or non-myeloablative (N=1) conditioning. GVHD prophylaxis consisted of cyclosporine with either short course methotrexate (N=3) or mycophenolate mofetil (N=1). All patients developed biopsy-proven intestinal GVHD that was steroid refractory in 2 patients. At GVHD onset, patients were scanned with transabdominal ultrasonography and subsequently by CEUS using a linear phased-array 7.5-MHz transducer. A second generation echo-contrast agent (SonoVue®, Bracco), which consists of microbubbles stabilized by phospholipids and filled with sulphur hexafluoride, was injected i.v. as a bolus (2.4 mL) followed by 5 mL saline flush. Microbubbles have a mean diameter of 2.5 μm and remain within the vascular space allowing real-time imaging of microcirculation. ResultsIn all patients, routine ultrasonography revealed mucosal edema involving the terminal ileum in 3 patients (wall thickness 5.1, 5.8 and 7.9 mm) and the colon in 4 patients (ascending colon 5.8, 6, 8.4 and 18 mm; transverse colon 6 and 12.6 mm; descending colon 11 mm). CEUS at GVHD onset showed an arterial phase (AP) complete enhancement of the entire wall section from the mucosal to the serosal layer (terminal ileum) in 2 patients. There was absence of enhancement only in the outer border of the muscularis propria in 1 patient (pt); there was absence of enhancement both in the outer and in the inner border of the colon wall and enhancement only of the intermediate layer in 1 pt. All patients showed late parenchymal phase (PP) wash out. These enhancement patterns have previously been described in active Crohn's disease (Serra C. et al; 2007). CEUS follow-up findings on serial examinations: 1) allowed us to monitor residual disease in one pt after Infliximab, showing persistent AP enhancement of microcirculation suggesting residual GVHD activity which required further treatment with eventually complete remission; 2) CEUS showed normalization and/or decreased microcirculation enhancement in pts responding to treatment (N=2); 3) CEUS showed AP microcirculation enhancement when GVHD flared (N=2); 4) CEUS showed persistence of AP enhancement of microcirculation after Rituxan (4 doses 375mg/m2/weekly) despite a decrease in ileum wall thickness and in agreement with only a slight improvement of symptoms in one pt when GVHD flared, 5) CEUS showed no improvement of intestinal microcirculation wall enhancement in steroid refractory aGVHD patients who eventually died (N=2). In one of them there was persistence of AP phase enhancement despite improvement of symptoms suggesting still active disease. ConclusionsContrast enhanced US showed intestinal microcirculation wall enhancement and delayed washout at the onset of GVHD symptoms in areas of the intestine inaccessible to endoscopic evaluation. CEUS findings on serial examinations correlated with incomplete responses and flares of GVHD symptoms (microcirculation enhancement) and responses to therapy (decreased microcirculation activity). CEUS may be useful for both diagnosis and prognosis, as it provides both anatomic and physiologic information about intestinal GVHD. These findings prompted us to design a prospective study to evaluate clinical usefulness of CEUS in diagnosis and follow-up of intestinal acute GVHD. Disclosures:No relevant conflicts of interest to declare.

Laparoscopic-assisted transgastric cholecystectomy and secure endoscopic closure of the transgastric defect in a survival porcine model

Natural orifice transluminal endoscopic surgery holds promise for surgical interventions. Before the feasibility of this technique can be established, however, secure sealing of the transluminal access needs to be thoroughly investigated. Following antibiotic prophylaxis and gastric disinfection, nine pigs underwent transgastric cholecystectomy by means of a flexible endoscope with the aid of a transabdominal 5-mm trocar. The gastric wall was punctured and dilated. The gallbladder was retracted with a laparoscopic grasper. The cystic duct and artery were dissected with a flexible monopolar ball electrode. The cystic duct was interrupted with flexible scissors between endoclips. Cholecystectomy was completed and the gallbladder was retrieved through the stomach. The gastric defect was closed using a single modified over-the-scope clip (OTSC) (Ovesco, Tübingen, Germany) and grasping the serosal and muscle layer of the gastric wall. The animals were sacrificed 4 weeks later. Laparoscopic-assisted transgastric cholecystectomy was successful in all cases without significant perioperative complications. All animals survived without postoperative complications. The mean operating time was 128 minutes (range, 85 - 205 minutes). The gastric defect closure resulted in inversion of the gastric wall layers within an average time of 6.8 +/- 5 minutes. At 4 weeks postoperative, only minimal thin adhesions were observed in the right hypochondrium. We found gastric closure using the OTSC to be a reliable tool for closing the transgastric access. Laparoscopic-assisted transgastric cholecystectomy by means of a flexible endoscope was technically feasible, but remains a demanding procedure.

Larvae of Hysterothylacium sp. (Nematoda: Anisakidae) in the sole fish Paralichthys isosceles Jordan, 1890 (Pisces: Teleostei) from the littoral of the state of Rio de Janeiro, Brazil

Sixty specimens of Paralichthys isosceles captured in the southeastern Brazilian coast were investigated for helminths from October 2006 to March 2008. One thousand eight hundred and twenty larvae (third and fourth stages) of Hysterothylacium sp. were recovered from the abdominal cavity, free or inserted in the mesentery, intestine, stomach, stomach wall, liver, spleen, ovaries, and serosas of heart, kidneys, ovaries and abdominal musculature. Gross lesions appeared as nodules in the stomach mucosa and intestinal serosa. Histological examination of these nodules revealed sections of Hysterothylacium sp. larvae inserted in the abdominal musculature, in the submucosa, muscular and serosa layers of the stomach and intestine. Associated granulomas consisted of fibrous connective tissue, macrophages and lymphocytes that surrounded, besides the larvae, necrotic material and tunnels with acidophilic lining, sometimes devoid of inflammatory reaction. The pathological alterations as well as the occurrence of Hysterothylacium sp. are reported for the first time in this host. The parasitic indexes refer to a prevalence of 100%, mean intensity of 30.3, mean abundance of 32 and range of intensity variation from 1 to 596.