The presence of H. pylori in laparoscopic sleeve gastrectomy specimens is associated with increased mucosal thickness, presence of secondary follicles, increased chronic inflammation, and intestinal metaplasia.

Helicobacter pylori is putatively present in over half of the global human population and is recognized as a carcinogenic agent that increases the likelihood of infected patients developing gastric adenocarcinoma or gastric lymphoma. Although there are several means for testing for H. pylori, the gold standard remains the invasive histologic evaluation. The current most popular form of bariatric surgery is the laparoscopic sleeve gastrectomy (LSG) and is the only bariatric surgery which supplies a specimen for histologic evaluation. While non-invasive testing is effective in diagnosing and monitoring H. pylori infection, histological examination of biopsies and resections is the only way to grade chronic inflammation and evaluate specimens for additional pathologies such as intestinal metaplasia. The investigators evaluated 203 sequential LSG specimens collected from a major metropolitan hospital over the period of one year. Specimens were processed to paraffin, stained with hematoxylin and eosin, alcian blue, and immunohistochemistry to determine the presence of H. pylori, chronic inflammation, presence of secondary lymphoid follicles in the mucosa, mucosal thickness, and presence of intestinal metaplasia. Statistical analyses demonstrated a significant positive correlation among all factors examined. The overall positivity rate of H. pylori in LSG specimens was 18.2% but ranged from 6.9-23.8% depending on whether the treating clinician performed routine pre-surgical endoscopy. The presence of H. pylori was associated with a higher average chronic inflammation grade, intestinal metaplasia, thicker mucosa, and presence of lymphoid follicles with germinal centers in the mucosa.

A comparison of staining methods for Helicobacter pylori in laparoscopic vertical sleeve gastrectomy resections.

BACKGROUND: Helicobacter pylori is an important public health concern due to its status as a carcinogenic bacterium. Well adapted to the acidic environment of the human stomach, the variety of strains and virulence factors of the organism when interacting with the host immune system creates an individualistic response. Although estimates suggest that approximately half of the global population is infected with H pylori, the majority of infected persons remain asymptomatic while harboring an increased risk of intestinal metaplasia and gastric cancers. Therefore, appropriate diagnostic testing protocols are imperative. METHODS: This study compared labeling methodologies, including Wright stain, alcian yellow toluidine blue (AYTB), and immunohistochemistry (IHC) on formalin-fixed paraffin-embedded stomach resections from sleeve gastrectomy patients, to detect H pylori infection. RESULTS: Although all 3 labeling methods evidenced similar specificity in H pylori detection, the IHC method was significantly more sensitive. However, the IHC cost per test was approximately 5-fold higher than that of the Wright or AYTB stains, and the technical time required per test was at least 6-fold that of Wright or AYTB. CONCLUSION: Despite the higher cost per test, IHC is the most sensitive and preferred method for determination of H pylori infection.

It's a small world for parasites: evidence supporting the North American invasion of European Echinococcus multilocularis.

Echinococcus multilocularis (Em), the causative agent of human alveolar echinococcosis (AE), is present in the Holarctic region, and several genetic variants deem to have differential infectivity and pathogenicity. An unprecedented outbreak of human AE cases in Western Canada infected with a European-like strain circulating in wild hosts warranted assessment of whether this strain was derived from a recent invasion or was endemic but undetected. Using nuclear and mitochondrial markers, we investigated the genetic diversity of Em in wild coyotes and red foxes from Western Canada, compared the genetic variants identified to global isolates and assessed their spatial distribution to infer possible invasion dynamics. Genetic variants from Western Canada were closely related to the original European clade, with lesser genetic diversity than that expected for a long-established strain and spatial genetic discontinuities within the study area, supporting the hypothesis of a relatively recent invasion with various founder events.

Fibrinogen in equine pregnancy as a mediator of cell adhesion, an epigenetic and functional investigation.

Preimplantation equine embryos synthesize and secrete fibrinogen, which is a peculiar finding as fibrinogen synthesis almost exclusively occurs in the liver. This study investigated the hypothesis that conceptus-derived fibrinogen mediates cell adhesion during fixation. On day 21 of pregnancy, five integrin subunits, including ITGA5, ITGB1, ITGAV, and ITGB1, displayed significantly higher transcript abundance than on day 16 of pregnancy. Endometrial epithelial cells adhered to fibrinogen in an integrin-dependent manner in an in vitro cell adhesion assay. Bilaminar trophoblast and allantochorion expressed fibrinogen transcript, indicating that fibrinogen expression persists past fixation. Preimplantation-phase endometrium, conceptuses, and microcotyledonary tissue expressed components of the clotting cascade regulating fibrin homeostasis, leaving open the possibility that fibrinogen is converted to fibrin. Fibrinogen is likely to have functions beyond mediating cell adhesion, such trapping growth factors and triggering signaling cascades, and has remarkable parallels to the expression of fibrinogen by some tumors. The deposition of fibrinogen within tumor stroma is characteristic of breast carcinoma, and tumor-derived fibrinogen has been implicated in the metastatic potential of circulating tumor cells. DNA methylation of the fibrinogen locus in equine conceptuses was examined in comparison to liver and endometrium, and across the full gene cluster, was significantly higher for endometrium than liver and conceptus. DNA methylation of regulatory regions did not differ between liver and conceptus, and was significantly lower than in endometrium. These results, therefore, support the hypothesis of DNA methylation being a regulator of fibrinogen expression in the conceptus.

Interferon epsilon is constitutively expressed in equine endometrium and up-regulated during the luteal phase.

Interferon epsilon (IFNE) is type I interferon which stands out through its unusual expression profile and differing regulation compared to classic type I interferons such as interferon alpha and interferon beta. Unlike other type I interferons, the expression of IFNE is not stimulated through exposure to viral agents. Expression of IFNE is most abundant in mouse and human endometrium where it is constitutively expressed in luminal and glandular epithelial cells and expression levels are up-regulated with estrogen exposure. The aim of the current study was to determine whether a cycle or pregnancy dependent expression pattern of IFNE is existent in equine endometrium and to localize IFNE expression within the endometrium. Additionally, endometrial explant culture and culture of mixed epithelial/stromal cells populations was used to determine the effects estrogen and seminal plasma on IFNE transcript abundance. Samples collected during diestrus and pregnancy expressed significantly higher levels of IFNE than samples obtained from anestrous or estrous mares (P < 0.001). Exposure of mixed endometrial epithelial/stromal cell populations and endometrial explants to 10% seminal plasma and estradiol 17-beta did not affect IFNE expression levels (P > 0.05). Upon in situ hybridization, staining was exclusively present in luminal and glandular epithelial cells, with stromal displaying absent staining intensity. Both diestrous and pregnant samples were characterized by markedly stronger staining of glandular epithelial cells than anestrous and estrous samples. The progesterone-dependent increase in IFNE abundance during the estrous cycle likely implies that IFNE is part of the innate immune system in endometrium that gives protection against uterine infections during progesterone-dominated phase of the estrous cycle.

Temporal changes in plasma markers of oxidative stress following laparoscopic sleeve gastrectomy in subjects with impaired glucose regulation.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is an effective treatment for obesity and associated metabolic complications. Obesity and type 2 diabetes are associated with increased oxidative stress. Previous studies have examined changes in plasma oxidative stress after laparoscopic Roux-en-Y gastric bypass, but there is limited evidence of the effects of LSG. OBJECTIVES: To examine the effects of LSG on plasma thiobarbituric acid reactive substances (TBARS) and total antioxidant status (TAOS) at 1 and 6 months after LSG in patients with obesity and impaired glucose regulation. SETTING: University hospital, United Kingdom. METHODS: Twenty-two participants with impaired glucose homeostasis undergoing LSG (body mass index 50.1 kg/m2, glycated hemoglobin 53 mmol/mol) were studied. Measurements of fasting and 120-minute TBARS and TAOS were performed during an oral glucose tolerance test preoperatively and postoperatively. RESULTS: Compared with preoperative levels, significant decreases were seen 6 months postoperatively in fasting TBARS (61.0±17.9 versus 39.4±13.8 ng/mL, P = .04) and 120-minute TBARS (76.0±29.5 versus 46.5±16.3 ng/mL, P = .02). No significant changes were observed in plasma TAOS. No significant association was observed between changes in TBARS and other clinical or biochemical measures. CONCLUSION: We observed a significant reduction in TBARS, a global measure of lipid peroxidation 6 months after LSG in participants with obesity and impaired glucose regulation.