Yoshinori Fujimura

Evidence of M cells as portals of entry for antigens in the nasopharyngeal lymphoid tissue of humans

Abstract The nasopharyngeal tonsils (adenoids) are prominent components of human nasal-associated lymphoid tissues (NALT). However, the role of the nasopharyngeal tonsils in antigen uptake for initiation of the mucosal immune response is unknown. The aims of this study were to describe the ultrastructure and function of the M cells of the human nasopharyngeal tonsils and to clarify their capacity for antigen uptake. Tissues obtained from eight patients undergoing adenectomy were examined by light and electron microscopy. Lymphoepithelium covers the nasopharyngeal lymphoid tissue and consists of ciliary epithelium, non-ciliary epithelial cells, M cells, goblet cells, and many intraepithelial lymphoid cells. M cells have irregular and broad cytoplasm-containing microvilli on their surface and small vesicles in their cytoplasm. Many lymphoid cells were enfolded by M cells. The uptake of horseradish peroxidase (HRP) in the tissue in organ culture was studied using histochemical techniques. Excised adenoid tissue was incubated in RPMI 1640 culture media with HRP for 10, 30, and 60 min. HRP which had adhered to the surface was taken up in vesicles and then transported in vesicles and tubules by M cells. The M cells of nasopharyngeal lymphoid tissue were ultrastructurally and functionally similar to those in human Peyer’s patches and colonic lymphoid follicles. These findings indicate that NALT bears similarities to the gut-associated lymphoid tissue, and its antigen uptake capacity may be important for initiation of immunity in the upper aerodigestive tract.

Serological tests for monitoring Helicobacter pylori eradication treatment.

Metabolic interaction between the intestinal microflora and the host has been suggested to play a role in the pathogenesis of chronic inflammatory bowel disease. Elemental or low-fat, low-residual diets in patients with Crohns disease or ulcerative colitis are reported to decrease anaerobic bacteria and to change the composition of the intestinal microflora. We examined the effect of an indigestible agent, 4G-β-d-galactosylsucrose (lactosucrose), which is selectively utilized by intestinalBifidobacterium, on the composition of the intestinal microflora. After the administration of lactosucrose to two patients with Crohns disease and five patients with ulcerative colitis for 2 weeks, significant induction of the growth ofBifidobacterium was observed, and significant reduction in the population level of Bacteroidaceae was seen. Bowel movements improved in four patients. The intestinal environment, estimated by measuring fecal pH, fecal levels of short-chain fatty acids and putrid products, and the urinary secretion of indican, also improved in these patients. These results suggest that lactosucrose may be useful for patients with chronic inflammatory bowel disease.Metabolic interaction between the intestinal microflora and the host has been suggested to play a role in the pathogenesis of chronic inflammatory bowel disease. Elemental or low-fat, low-residual diets in patients with Crohns disease or ulcerative colitis are reported to decrease anaerobic bacteria and to change the composition of the intestinal microflora. We examined the effect of an indigestible agent, 4G-β-d-galactosylsucrose (lactosucrose), which is selectively utilized by intestinalBifidobacterium, on the composition of the intestinal microflora. After the administration of lactosucrose to two patients with Crohns disease and five patients with ulcerative colitis for 2 weeks, significant induction of the growth ofBifidobacterium was observed, and significant reduction in the population level of Bacteroidaceae was seen. Bowel movements improved in four patients. The intestinal environment, estimated by measuring fecal pH, fecal levels of short-chain fatty acids and putrid products, and the urinary secretion of indican, also improved in these patients. These results suggest that lactosucrose may be useful for patients with chronic inflammatory bowel disease.

Ultrastructural study of M cells from colonic lymphoid nodules obtained by colonoscopic biopsy

The present study was undertaken to investigate ultrastructurally the epithelium covering lymphoid nodules obtained from colonoscopic biopsies of the human colon and rectum. Colonoscopy using the dye spraying contrast, method was performed in nine patients who showed x-ray evidence of lymphonodular hyperplasia. Fifty-two colonoscopical biopsy specimens, of lymphoid nodules were obtained from the ascending, transverse, and descending colon and rectosigmoid region. All specimens were observed by light and electron microscopy. Light microscopy disclosed large lymphoid follicles protruding into the lumen with a “dome-type” configuration. These extended to the lamina propria of the mucosa and were associated with a massive lymphoid aggregation extending as far as the muscularis mucosa from the submucosa. The epithelium covering these nodules contained a few goblet cells and many lymphocytes. Observation of the elevated surface at the apex by scanning electron microscopy revealed M cells with sparse microvilli in the dome epithelium surrounded by crypts. Transmission electron microscopy disclosed M cells enfolding many immature or mature lymphocytes and plasmocytes. The M cells had cytoplasmic microvilli (so-called “microfolds”) on their surfaces, well-developed tubulovesicular systems, and vacuoles in the cytoplasm. The basic structure of the M cells as observed by scanning and transmission electron microscopy was the same as that of M cells in the Peyers patches of humans and mice. The apical surface of the colonic lymphoid follicles in Crohns disease patients was associated with erosions observed by scanning electron microscopy. The erosions proved to be the naked surface of the dome after removal of the epithelium and many holes from 2.0 to 6.0 μm in diameter were observed on the naked surface. At high magnification, lymphocytes were seen projecting from holes (18%) on the naked surface of the dome. These ultrastructural findings indicate that human colonic lymphoid follicles are very similar to those seen in other species.

Uptake of microparticles into the epithelium of human nasopharyngeal lymphoid tissue

The M cells of nasopharyngeal lymphoid tissue (NALT) have been considered to play an important role for vaccine delivery systems in humans. A number of investigations have reported particle uptake data in NALT of rodents. However, there have been no reports indicating any involvement of the nasopharyngeal lymphoid tissue in human vaccination. In the present study, we investigated whether the epithelium of human adenoid tissues might incorporate fluorescent microparticles using electron and fluorescent microscopy. The dissected adenoid tissues were incubated with various sizes and concentrations of fluorescent microparticles for 120 min at 37°C. Furthermore, the effect of surface coatings of microparticles with cations on the uptake into the epithelium of adenoid tissues was investigated. Transmission electron microscopy revealed that microparticles were taken up by the M cells of human nasopharyngeal lymphoid tissues. The NALT-M cells showed greater uptake of the smallest particles, 0.2 µm in diameter, than those of 0.5, 1.0, or 2.0 µm diameter. It was also revealed that surface coatings with poly-l-lysin or chitosan resulted in efficient uptake into the NALT. These results indicate that nasal administration of antigenic microparticles, which were coated with cationic materials, probably leads to a useful method of transnasal vaccination against respiratory and intestinal infections in humans.

Nonpolypoid adenomas of the duodenum in patients with familial adenomatous polyposis (Gardner's syndrome)

BACKGROUND Although duodenal adenomas are very common in familial adenomatous polyposis, we wished to emphasize our experience with finding nonpolypoid adenomas in the duodenum of patients with this disease. METHODS Duodenoscopy was performed in 23 patients with an established diagnosis of familial adenomatous polyposis or Gardners syndrome. RESULTS Endoscopy revealed single or multiple nonpolypoid adenomas of the duodenum in 7 patients (30%). The lesions were smaller than 5 mm and were endoscopically recognized as flat or depressed reddish lesions; one lesion was completely flat and the remaining lesions were flat-topped elevations with a central depression. All of the lesions were histologically diagnosed as tubular adenoma with moderate epithelial atypia. CONCLUSION These findings suggest that duodenal nonpolypoid adenomas are common in familial adenomatous polyposis or Gardners syndrome and that careful surveillance endoscopy seems necessary in patients with this disease.

Risk and preventive factors of low-dose aspirin-induced gastroduodenal injuries: A comprehensive review

The risk of peptic ulcer complications, particularly bleeding, is increased in association with the use of low‐dose aspirin (LDA). Risk factors for upper gastrointestinal (GI) ulcer or bleeding among LDA users include a history of prior GI events, older age, chronic renal failure, combined antithrombotic therapy and nonsteroidal anti‐inflammatory drugs (NSAIDs). Helicobacter pylori and aspirin seem to be independent risk factors for peptic ulcer and bleeding. The studies report conflicting findings about the effect of H. pylori infection on NSAID‐related ulcers, and proton‐pump inhibitors (PPIs) seem to be superior to eradication only to prevent recurrent ulcer bleeding with LDA. Previous studies indicate that hypoacidity related to corpus atrophy, as well as taking PPIs and co‐treatment with angiotensin type 1 receptor blockers (ARBs) and statins seem to reduce peptic ulcer among LDA users. In addition, the interleukin‐1β (IL‐1β)‐511 T allele and angiotensinogen (AGT)‐20 CC, which work as the high‐producer allele of IL‐1β and AGT, are significantly associated with ulcer or ulcer bleeding. The SLCO1B1*1b haplotype, which has the highest transport activity, may diminish the preventive effect of statins or ARBs. The data are still lacking and further prospective studies are needed to identify the specific risk or protective factors for upper GI ulcer and its complications associated with LDA.

Case of early gastric cancer with nodular gastritis

A case of depressed early gastric cancer with nodular gastritis is described. A 47‐year‐old Japanese man was referred to our hospital and admitted for surgical treatment of gastric cancer. Barium upper gastrointestinal study and endoscopy examination showed a 4.5 × 3.0 cm depressed lesion with a deep central ulceration in the anterior wall of the lower corpus. An unusual miliary pattern resembling ‘goose flesh’ was observed endoscopically in the antrum. Biopsy specimens from the tumor showed poorly differentiated adenocarcinoma, and specimens from the antrum showed many lymphoid follicles with a germinal center. Immunoglobulin G antibody and histological tests (Giemsa stain) for Helicobacter pylori were both positive. Early gastric cancer with nodular gastritis was diagnosed and a subtotal gastrectomy was performed. Histological examination of the resected specimen showed a stage I tumor infiltrating a poorly differentiated adenocarcinoma with a depressed lesion in the corpus (type 0 IIc + III) and nodular gastritis in the antrum. The patient is doing well 1 year after surgery.

Expression of Sonic hedgehog (SHH) and CDX2 in the columnar epithelium of the lower oesophagus

BACKGROUND Decreases in Sonic hedgehog (SHH) and CDX2 expression are associated with atrophy and intestinal metaplasia in the gastric mucosa. The pathogenesis of development of Barretts oesophagus is still unclear. OBJECTIVE To examine the gene expression of CDX2 and SHH and their signalling pathways in the columnar epithelium and the association with endoscopic appearance, gastric pH or bile acids. SUBJECTS/METHODS Sixty-three patients with metaplastic columnar epithelium of the lower oesophagus were studied. Whole biopsy specimens and microdissected tissues were examined for messenger RNA. RESULTS BMP4 expression was significantly higher in patients with tubular mucosal patterns of columnar epithelium visualised by Narrow Band Imaging with magnification. The expression of SHH was significantly lower and that of CDX2 was higher in the goblet columnar epithelium than in non-goblet columnar epithelium. CDX2 expression was significantly higher in the patients with hypoacidity than in the others. BMP4 and PTCH1 expression was significantly higher in the group with higher concentrations of deoxycholic acid than in the group with lower concentrations. CONCLUSIONS SHH might be the initial factor inducing columnar metaplasia, and subsequent or simultaneous BMP4 stimuli might induce the CDX2 expression that causes goblet-cell metaplasia.

Distribution of microfold cells(M cells) in human follicle-associated epithelium

The simultaneous production of hepatic lesions and antimitochondrial antibody (AMA) in an experimental animal model is generally considered to be necessary for the elucidation of the etiopathogenesis of primary b i l i a ry cirrhosis (PBC). However, i t has been achieved in only a l imited number of cases 1,2} Two female rabbits were sensitized subcutaneously with Oilmg of pyruvate dehydrogenase (PDH, Sigma Chemical Company, St.Louis, MO) in complete Freunds adjuvant. As controls, two other female rabbits were injected s imi lar ly with human IgG. Antigen challenge was repeated six times at intervals of seven days. Seven weeks after primary immunization, the rabbits were exsanguinated and dissected. Sera samples were assayed by the immunoblott ing and immunofluorescence methods (Medical Biological Laboratories, Nagoya) for antibodies to mitochondria, and l iver specimens were examined histological ly. Two rabbits treated with PDH exhibited AMA t i t e rs of 1:160 or more by the immunofluorescence method and react iv i ty against the 70 KD antigen in PDH complex by the immunoblotting method. Affected interlobular bile duct epithel ia, surrounded by a small number of inflammatory cel ls and granuloma formation consisting of multinucleated giant cel ls, were shown to be scattered by histopathologica] studies on their l ivers (Photos). In the control group, however, no specif ic changes were found, serological]y or histological ly. These results suggested that the mitochondrial antigen (PDH) might play an important role in the occurence of PBC.

Relation between bile acid reflux into the stomach and the risk of atrophic gastritis and intestinal metaplasia: A multicenter study of 2283 cases

The relationship between bile acid reflux into the stomach and the risk of atrophic gastritis and intestinal metaplasia is still not well understood. Towards obtaining a better understanding, concentrations of bile acids were measured.