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Background: Anatomical knowledge of the duodenojejunal flexure is necessary for abdominal surgeries, and also important for physiologic studies about the duodenum. But little is known about the anatomy of this region in mammals. Here, we examined comparative anatomy to understand the anatomical formation of the duodenojejunal flexure in mammals.Materials and Methods: The areas around the duonenojejunal flexure were ob-served in mouse, rat, dog, pig, and human, and the anatomical structures around the duodenojejunal junction in the animals were compared with those in human.Results: The superior and inferior duodenal folds, and the superior and inferior duodenal fossae were identified in all examined humans. In pig, the structures were not clearly identified because the duodenum strongly adhered to the retroperitoneum and to the mesocolon. In mouse, rat, and dog, only the plica duodenocolica, which is regarded as the animal counterpart of the superior duo-denal fold in human, was identified, and other folds or fossae were not observed, probably because the duodenum was not fixed to the parietal peritoneum in those animals. Transection of the plica duodenocolica could return the normally rotated intestine back to the state of non-rotation in rat.Conclusions: This study showed the anatomical similarities and dissimilarities of the duodenojejunal flexure among the mammals. Anatomical knowledge of the area is useful for duodenal and pancreatic surgeries, and for animal studies about the duodenum. (Folia Morphol 2018; 77, 2: 286-292). [ABSTRACT FROM AUTHOR]

The structural prerequisites for lipopolysaccharide (LPS) and its partial structures for the activation of the Limulus clotting cascade (Limulus amebocyte lysate [LAL] test) are described and compared with the corresponding requirements for the activation of human immune cells such as mononuclear cells. A necessary, but not sufficient, structural motif for this is the presence of the 4′-phosphate-diglucosamine backbone recognition structure ('epitope') in lipid A. High activity is only expressed by assemblies of endotoxins, but this is largely independent of the type of supramolecular aggregate structure. A particular conformation of the epitope within the lipid A assembly must be present, which is influenced by addition of further saccharide units to the lipid A moiety, but also reacts slightly to the acylation pattern. In contrast, the cytokine production of human immune cells induced by LPS sensitively depends on the type of its aggregate structure. In the case of a hexa-acylated bisphosphorylated lipid A structure, high activity is only observed with cubic inverted aggregates. Furthermore, addition of antimicrobial agents (such as polymyxin B) leads to a nearly complete inhibition of cytokine production, whereas the reduction in the Limulus assay is much lower. These data are important since a reliable determination of endotoxin concentrations, in particular with respect to its ability to elicit severe infections, is of high interest. [ABSTRACT FROM AUTHOR]

BACKGROUND: The relation between Helicobacter pylori infection and gastric cancer has been proven in epidemiological studies and animal experiments. Our aim was to investigate the prophylactic effect of H pylori eradication on the development of metachronous gastric carcinoma after endoscopic resection for early gastric cancer. METHODS: In this multi-centre, open-label, randomised controlled trial, 544 patients with early gastric cancer, either newly diagnosed and planning to have endoscopic treatment or in post-resection follow-up after endoscopic treatment, were randomly assigned to receive an H pylori eradication regimen (n=272) or control (n=272). Randomisation was done by a computer-generated randomisation list and was stratified by whether the patient was newly diagnosed or post-resection. Patients in the eradication group received lansoprazole 30 mg twice daily, amoxicillin 750 mg twice daily, and clarithromycin 200 mg twice daily for a week; those in the control group received standard care, but no treatment for H pylori. Patients were examined endoscopically at 6, 12, 24, and 36 months after allocation. The primary endpoint was diagnosis of new carcinoma at another site in the stomach. Analyses were by intention to treat. This trial is registered with the UMIN Clinical Trials Registry, number UMIN000001169. FINDINGS: At 3-year follow-up, metachronous gastric carcinoma had developed in nine patients in the eradication group and 24 in the control group. In the full intention-to-treat population, including all patients irrespective of length of follow-up (272 patients in each group), the odds ratio for metachronous gastric carcinoma was 0.353 (95% CI 0.161-0.775; p=0.009); in the modified intention-to-treat population, including patients with at least one post-randomisation assessment of tumour status and adjusting for loss to follow-up (255 patients in the eradication group, 250 in the control group), the hazard ratio for metachronous gastric carcinoma was 0.339 (95% CI 0.157-0.729; p=0.003). In the eradication group, 19 (7%) patients had diarrhoea and 32 (12%) had soft stools. INTERPRETATION: Prophylactic eradication of H pylori after endoscopic resection of early gastric cancer should be used to prevent the development of metachronous gastric carcinoma. FUNDING: Hiroshima Cancer Seminar Foundation. [ABSTRACT FROM AUTHOR]

Background: Evidence is accumulating that bile acids are involved in colon cancer development, but their molecular mechanisms remain unexplored. Bile acid has been reported to be associated with induction of the cyclooxygenase-2 (COX-2) gene. Because the human liver-specific organic anion transporter-2 (LST-2/OATP8/OATP1B3) is expressed in gastrointestinal cancers and might transport bile acids to the intracellular space, we studied the molecular mechanisms by which bile acids induce the transcription of COX-2, and the role of LST-2 in colonic cell lines.Methods: Transcriptional activity of COX-2 was measured using a human COX-2 promoter-luciferase assay under various concentrations of bile acids. Electrophoresis mobility shift assays (EMSAs) for peroxisome proliferators-activated receptor (PPAR) alpha and cyclic AMP responsive element (CRE) were performed.Results: The COX-2 promoter was induced by lithocholic acid (LCA), deoxycholic acid (DCA), and chenodeoxycholic acid (CDCA). Deletion and site-directed mutation analyses showed that CRE is the responsive element for LCA. An adenovirus expression system revealed that LST-2 is responsible for induction of COX-2. By EMSA using oligonucleotides of CRE, we observed formation of a specific protein-DNA complex, which was inhibited by a specific antibody against PPARalpha and CRE. A PPARalpha-specific agonist induced transcription of COX-2.Conclusion: These results indicate that COX-2 is transcriptionally activated by the addition of LCA, CDCA, and DCA and that LST-2 plays an important role by transporting bile acid to the intracellular space. Moreover, LCA-dependent COX-2 gene activation consists of a transcriptional complex including PPARalpha and CRE-binding protein. Thus, this induction of COX-2 may participate in carcinogenesis and progression of colorectal cancer cells. [ABSTRACT FROM AUTHOR]

Oral epithelium might be the first barrier against oral bacteria in periodontal tissue. We hypothesized that oral epithelium is endowed with innate immune receptors for bacterial components, which play roles in host defense against bacterial infection without being accompanied by excessive inflammatory responses. We found clear expression of Toll-like receptor (TLR)4 as well as TLR2, and strong expression of NOD1 and NOD2 in normal oral epithelial tissues by immunohisto-chemical analysis. We also showed that primary oral epithelial cells in culture expressed these molecules using PCR, flow cytometry, and immunostaining. In inflamed oral epithelium, cell-surface localizations of TLR2 and TLR4 were more clearly observed than in healthy tissue. Upon stimulation with synthetic ligands for these receptors, the expression of β-defensin 2 was markedly up-regulated. These findings indicate that these molecules in oral epithelial cells are functional receptors that induce antibacterial responses. [ABSTRACT FROM AUTHOR]

Peptidoglycan recognition proteins (PGRPs), a novel family of pattern recognition molecules (PRMs) in innate immunity conserved from insects to mammals, recognize bacterial cell wall peptidoglycan (PGN) and are suggested to act as anti-bacterial factors. In humans, four kinds of PGRPs (PGRP-L, -Iα, -Iβ and -S) have been cloned and all four human PGRPs bind PGN. In this study, we examined the possible regulation of the expression of PGRPs in oral epithelial cells upon stimulation with chemically synthesized pathogen-associated molecular patterns (PAMPs) in bacterial cell surface components:Escherichia coli-type tryacyl lipopeptide (Pam3CSSNA),E. coli-type lipid A (LA-15-PP), diaminopimelic acid containing desmuramyl peptide (γ-d-glutamyl-meso-DAP; iE-DAP), and muramyldipeptide (MDP). These synthetic PAMPs markedly upregulated the mRNA expression of the four PGRPs and cell surface expression of PGRP-Iα and -Iβ, but did not induce either mRNA expression or secretion of inflammatory cytokines, in oral epithelial cells. Suppression of the expression of Toll-like receptor (TLR)2, TLR4, nucleotide-binding oligomerization domain (NOD)1 and NOD2 by RNA interference specifically inhibited the upregulation of PGRP mRNA expression induced by Pam3CSSNA, LA-15-PP, iE-DAP and MDP respectively. These PAMPs definitely activated nuclear factor (NF)-κB in the epithelial cells, and suppression of NF-κB activation clearly prevented the induction of PGRP mRNA expression induced by these PAMPs in the cells. These findings suggested that bacterial PAMPs induced the expression of PGRPs, but not proinflammatory cytokines, in oral epithelial cells, and the PGRPs might be involved in host defence against bacterial invasion without accompanying inflammatory responses. [ABSTRACT FROM AUTHOR]

Two types of synthetic peptidoglycan fragments, diaminopimelic acid (DAP)-containing desmuramylpeptides (DMP) and muramyldipeptide (MDP), induced secretion of interleukin (IL)-8 in a dose-dependent manner in human monocytic THP-1 cells, although high concentrations of compounds are required as compared with chemically synthesized Toll-like receptor (TLR) agonists mimicking bacterial components: TLR2 agonistic lipopeptide (Pam3CSSNA), TLR4 agonistic lipid A (LA-15-PP) and TLR9 agonistic bacterial CpG DNA. We found marked synergistic IL-8 secretion induced by MDP or DAP-containing DMP in combination with synthetic TLR agonists in THP-1 cells. Suppression of the mRNA expression of nucleotide-binding oligomerization domain (NOD)1 and NOD2 by RNA interference specifically inhibited the synergistic IL-8 secretion induced by DMP and MDP with these TLR agonists respectively. In accordance with the above results, enhanced IL-8 mRNA expression and the activation of nuclear factor (NF)-κB induced by MDP or DMP in combination with synthetic TLR agonists were markedly suppressed in NOD2- and NOD1-silenced cells respectively. These findings indicated that NOD2 and NOD1 are specifically responsible for the synergistic effects of MDP and DMP with TLR agonists, and suggested that in host innate immune responses to invading bacteria, combinatory dual signalling through extracellular TLRs and intracellular NODs might lead to the synergistic activation of host cells. [ABSTRACT FROM AUTHOR]

The purpose of our studies is to define the physicochemical parameters involved in the activation of host cells by endotoxin and to characterize the processes operative during endotoxin/membrane interaction with the aim of understanding transmembrane signal transduction mechanisms. To this end, we determined the molecular conformation of the lipid A component of various endotoxins (endotoxic conformation) using X-ray small angle diffraction, their intercalation into reconstituted macrophage membranes with fluorescence resonance energy transfer spectroscopy, and their IL-6 inducing capacity in whole blood. We also investigated their influence on ion channels as a possible primary event in cell activation applying patch-clamp techniques to macrophages. We found a strong influence of the molecular charge on the molecular conformation, and we could show that the presence of charged groups and a cone- or wedge-like molecular conformation of lipid A are prerequisites for the expression of bioactivity. We also obtained strong evidence supporting the idea that the interaction of endotoxin with ion channels is one of the very early events in the interaction with the cell and, most likely, in signal transduction. [ABSTRACT FROM PUBLISHER]

Four compounds corresponding to partial structures of Re-type lipopolysaccharide (LPS) were synthesized for precise investigation of immunological properties of the 3-deoxy-D-manno-2-octulosonic acid (Kdo)-containing inner core and lipid A regions of LPS. The synthetic compounds lack all the ester-bound acyl groups which are present in natural LPS but known to be not essential for the antigenicity. The simplest compound is N,N'-diacylated glucosamine β1-6 disaccharide 4'-monophosphate 2 which corresponds to the des-O-acyl derivative of 1-dephospho lipid A. The other three contain one or two Kdo moieties linked to 2. The most complex one is a tetrasaccharide equivalent to the des-O-acylated 1-dephosphorylated derivative of LPS from Escherichia coli Re-mutant. Syntheses were performed by stepwise condensation of appropriately protected sugar moieties and final hydrogenolytic deprotection. The synthetic des-O-acyl LPS analogs were effectively purified by means of reversed phase HPLC to give homogeneous preparations. [ABSTRACT FROM PUBLISHER]