Effects of orally administered Euglena gracilis and its reserve polysaccharide, paramylon, on gastric dysplasia in A4gnt knockout mice

Euglena gracilis is widely utilized as food or supplement to promote human and animal health, as it contains rich nutrients. In this study, we administered spray-dried powder of E. gracilis and paramylon, β-glucan stored in E. gracilis cells, to A4gnt knockout (KO) mice. A4gnt KO mice are a mutant mouse model that spontaneously develops gastric cancer through hyperplasia-dysplasia-adenocarcinoma sequence in the antrum of the stomach, and we observed the effects of E. gracilis and paramylon on the early involvements of A4gnt KO mice. Male and female 10-week-old A4gnt KO mice and their age-matched wildtype C57BL/6J mice were orally administered with 50 mg of E. gracilis or paramylon suspended in saline or saline as a control. After 3-week administration, animals were euthanatized and the stomach was examined histopathologically and immunohistochemically. Gene expression patterns of the stomach, which have been reported to be altered with A4gnt KO, and IgA concentration in small intestine were also analyzed with real-time PCR and ELISA, respectively. Administration of Euglena significantly reduced the number of stimulated CD3-positive T-lymphocytes in pyloric mucosa of A4gnt KO mice and tend to reduce polymorphonuclear leukocytes infiltration. Euglena administration further downregulated the expression of Il11 and Cxcl1 of A4gnt KO mice. Euglena administration also affected IgA concentration in small intestinal contents of A4gnt KO mice. Paramylon administration reduced the number of CD3-positive lymphocytes in pyloric mucosa of A4gnt KO mice, and downregulated the expressions of Il11 and Ccl2 of A4gnt KO mice. Although we found no significant effects on gross and microscopic signs of gastric dysplasia and cell proliferation, the present study suggests that the administration of Euglena and paramylon may ameliorate the early involvements of A4gnt mice through the effects on inflammatory reactions in the gastric mucosa. The cancer-preventing effects should be studied with long-term experiments until actual gastric cancer formation.

Inflammatory cell numbers in the stomach of Japanese subjects with endoscopically normal mucosa without H. pylori infection

Introduction: Since inflammatory cells, such as lymphocytes and plasma cells, normally inhabit the stomach, the border between normal and mild inflammation is difficult to visually determine using the updated Sydney system scale of gastritis. Additionally, eosinophils in the gastric mucosa must be counted to diagnose eosinophilic gastritis. We aimed to determine the normal number of inflammatory cells in patients with endoscopically normal mucosa and without H. pylori infections. Methods: We assessed patients aged 20–79 years, who had undergone upper gastrointestinal endoscopy at Kawasaki Medical School Hospital between January 2010 and December 2014. Inflammatory cells were counted in 1,000 μm2 fields of pyloric and fundic gland mucosal biopsy specimens. We finally included 325 (male, n = 141; female, n = 184; average age = 49.3 years) patients without inflammation who had H. pylori-negative endoscopic results and negative histological findings interpreted based on the updated Sydney System and the Kyoto classification of gastritis. Results: The average numbers of nucleated cells were 83.3 ± 14.2/mm2 and 65.4 ± 12.6/mm2 in the pyloric and fundic gland mucosae, respectively. Inflammatory cells were significantly more abundant in the pyloric mucosa than the fundic gland mucosa (p < 0.05). Age and sex distribution did not significantly differ. Eosinophils were absent or scanty in the gastric mucosae of both glands in all patients. Conclusion: We determined the absolute values of inflammatory cells, including eosinophils, in normal mucosae of pyloric and fundic glands. These findings could be important in defining gastric mucosal inflammation, including eosinophilic gastritis diagnosis.

Innate Immune Responses Associated with Resistance against Haemonchus contortus in Morada Nova Sheep

The immune response against Haemonchus contortus infections is primarily associated with the Th2 profile. However, the exact mechanisms associated with increased sheep resistance against this parasite remains poorly elucidated. The present study is aimed at evaluating mediators from the innate immune response in lambs of the Morada Nova Brazilian breed with contrasting H. contortus resistance phenotypes. Briefly, 287 lambs were characterized through fecal egg counts (FEC) and packed cell volume (PCV) after two independent experimental parasitic challenges with 4,000 H. contortus L3. 20 extreme resistance phenotypes (10 most resistant and 10 most susceptible) were selected, subjected to a third artificial infection with 4,000 L3, and euthanized 7 days later. Tissue samples were collected from abomasal fundic and pyloric mucosa and abomasal lymph nodes. Blood samples were collected at days 0 and 7 of the third parasitic challenge. RNA was extracted from tissue and blood samples for relative quantification of innate immune-related genes by RT-qPCR. For the abomasal fundic mucosa, increased TNFα and IL1β expression levels (P<0.05) were found in the susceptible animals, while resistant animals had IL33 superiorly expressed (P<0.05). Higher levels (P<0.05) of TLR2 and CFI were found in the abomasal pyloric mucosa of resistant animals. TNFα was at higher levels (P<0.05) in the blood of susceptible lambs, at day 0 of the third artificial infection. The exacerbated proinflammatory response observed in susceptible animals, at both local and systemic levels, may be a consequence of high H. contortus parasitism. This hypothesis is corroborated by the higher blood levels of TNFα before the onset of infection, which probably remained elevated from the previous parasitic challenges. On the other hand, resistant lambs had an enhanced response mediated by TLR recognition and complement activation. Nevertheless, this is the first study to directly associate sheep parasitic resistance with IL33, an innate trigger of the Th2-polarized response.

Early Gastric Cancer with Purely Enteroblastic Differentiation and No Conventional Adenocarcinoma Component

Gastric carcinoma with enteroblastic differentiation (GCED) is a rare variant of gastric carcinoma, and a part of GCED produces alpha-fetoprotein. GCED is characterized by cells with clear cytoplasm and a tubulopapillary and solid growth pattern resembling those in the primitive gut. GCED is typically overlaid by a conventional adenocarcinoma (CA) component, implying that CA in the mucosa differentiates into GCED during tumor invasion and proliferation. We present the case of a 73-year-old woman with a 10-mm superficial elevated lesion and a slight central depression at the anterior wall of the lower gastric body. Endoscopic submucosal dissection revealed tumor cells having clear cytoplasm and severely atypical nuclei characteristic of GCED. The growth pattern was predominantly solid and trabecular but included submucosal layer invasion and limited tubular growth. Atrophic pyloric mucosa without intestinal metaplasia surrounded the tumor. Immunohistochemically, the tumor cells were positive for AFP, GPC3, and SALL4. The present patient showed a purely enteroblastic differentiation without a CA component despite the presence of early cancer, indicating that few cases of GCED may arise de novo in the gastric mucosa. GCED is more aggressive compared with CA; therefore, pathologists should be aware that GCED without CA can appear in biopsy specimens of early cancer while making an accurate diagnosis.

Correlation between Different Helicobacter Morphotypes and Histological Changes in Pig Gastric Mucosa

Background: Two distinct morphologic types of bacteria which belong to the Helicobacter species, have been described in pigs: once or twice curved Helicobacter pylori-like bacteria (HLO) and the multicoiled, Gastrospirillum-like bacteria (GLO). The objective of this study was to determine the incidence of Helicobacter spp. using modified Giemsa stain and to define the relationship between presence of Helicobacter spp. and histopathological changes of gastric mucosa in pigs.Materials, Methods & Results: A total of 120 pig stomachs (60 from intensive and 60 from extensive breeding) were enrolled in this study and 240 fragments of fundic and pyloric mucosa were taken for histopathological examination. By modified Giemsa staining of gastric mucosa, Helicobacter-like organisms were confirmed in 4/60 (6.67%) of pigs in intensive and 5/60 (8.33%) of pigs in extensive breeding. The incidence of tightly spiral shaped Gastrospirillum-like organisms in pigs of intensive and extensive breeding were 5/60 (8.33%) and 9/60 (15%), respectively. The severity of gastritis was scored to the Sydney System with some modifications. There was no significant difference between HLO-positive and HLO-negative fundic mucosa in pigs of both breeding systems. In contrary, there was significant difference between HLO-positive and HLO-negative pyloric mucosa of pigs in intensive (P < 0.001) and in extensive breeding (P < 0.05). In intensive breeding, there was significant difference between GLO-positive and GLO-negative fundic mucosa (P < 0.05), while there was no significant difference between GLO-positive and GLO-negative pyloric mucosa.Discussion: The prevalence of Helicobacter spp. bacteria were in coherence with literature data. The higher prevalence of both morfological type of bacteria, were considered in pigs in extensive breeding. the hygienic conditions and managment factors in pigs farm are the possible impact for higher bacterial transmission. The association of high prevalence of H. pylori and poor hygienic condition was shown by epidemiological studies conducted on humans. In both, humans and pigs, the presence of H. pylori correlates with an inflammatory response, but there are differences in inflammatory cell population. In H. pylori infected humans, neutrophils composed the bulk of cellular infiltrate, while in pigs, the primary inflammatory cell was the lymphocyte, which is in accordance to results published by others autors. Thus it indicates that different hosts exhibit a different pathohistological response to the Helicobacter spp. infection. In human as well as in veterinary pathology, the fact of the different pathogenicity of various Helicobacter species is well known. In all HLO-positive pyloric mucosa, moderate to severe focal or diffuse infiltration of mononuclear cells and lymphoid follicles with germinal centers, were observed. A similar conclusion was drawn from results of an experimental infection study in pigs. There was signifficance between HLO-positive and HLO-negative pyloric mucosa in both, intensive and extensive breeding. In the contrast, GLO were not associated with the presence of severe gastritis, but only with mild to moderate superficial infiltration of lymphocytes and plasma cells in both, fundic and pyloric mucosa. There was no significant difference between GLO-positive and GLO-negative pyloric mucosa of pigs in both breeding systems. Despite the low gastritis score of fundic mucosa in pigs in intensive breeding, there was a significance difference between in GLO-positive and GLO-negative fundic mucosa. It is believed that the possible reason of such results is the meals with low fiber content and low particles size. These results suggest that the presence of HLO, but not of GLO is associated with the pyloric gastritis in pigs.