Helicobacter pylori infection up-regulates gland mucous cell-type mucins in gastric pyloric mucosa

Background. Two types of mucous cell are present in gastric mucosa: surface mucous cells (SMCs) and gland mucous cells (GMCs), which consist of cardiac gland cells, mucous neck cells, and pyloric gland cells. We have previously reported that the patterns of glycosylation of SMC mucins are reversibly altered by Helicobacter pylori infection. In this study, we evaluated the effects of H. pylori infection on the expression of GMC mucins in pyloric gland cells. Methods. Gastric biopsy specimens from the antrums of 30 H. pylori‐infected patients before and after eradication of H. pylori and 10 normal uninfected volunteers were examined by immunostaining for MUC6 (a core protein of GMC mucins), α1,4‐N‐acetyl‐glucosaminyl transferase (α4GnT) (the glycosyltransferase which forms GlcNAcα1‐4Galβ‐R), and GlcNAcα1‐4Galβ‐R (a GMC mucin‐specific glycan). Results. MUC6, α4GnT, and HIK1083‐reactive glycan were expressed in the cytoplasm, supranuclear region, and secretory granules in pyloric gland cells, respectively. The immunoreactivity of MUC6 and α4GnT, but not of GlcNAcα1‐4Galβ‐R, in the pyloric gland increased in H. pylori‐associated gastritis, and after the eradication of H. pylori, the increased expression of MUC6 and α4GnT in the gastric mucosa of H. pylori‐infected patients decreased to almost normal levels. This up‐regulation was correlated with the degree of inflammation. Conclusions. In addition to the synthesis of GMC mucins increasing reversibly, their metabolism or release may also increase reversibly in H. pylori‐associated gastritis. The up‐regulation of the expression of gastric GMC mucins may be involved in defense against H. pylori infection in the gastric surface mucous gel layer and on the gastric mucosa.     

Helicobacter pylori infection increases cell kinetics in human gastric epithelial cells without adhering to proliferating cells

We investigated the effect of H. pylori infection on cell proliferation of gastric mucosa using immunostaining for H. pylori or Ki67. H. pylori cells attached to surface mucous cells covering luminal surface and the upper part of gastric foveolae, and up-regulated the proliferative activity of gastric epithelial cells without adhering to the proliferating epithelial cells.     

Isolation of rice genes possibly involved in the photoperiodic control of flowering by a fluorescent differential display method

To better understand the molecular mechanisms of the photoperiodic regulation of rice, a short-day plant, we isolated 27 cDNAs that were differentially expressed in the photoperiod-insensitive se5 mutant from approximately 8,400 independent mRNA species by the use of a fluorescent differential display (FDD). For this screening, we isolated mRNAs at five different time points during the night and compared their expression patterns between se5 and the wild type. Of 27 cDNAs isolated, 12 showed diurnal expression patterns often associated with genes involved in the determination of the flowering time. In se5, expression of nine cDNAs was increased. Five of these cDNAs were up-regulated under SD, suggesting that they may promote flowering under SD. They included genes encoding a cDNA containing a putative NAC domain, the fructose-bisphosphate aldolase, and a protease inhibitor. Expression of three cDNAs was decreased in se5 but not photoperiodically regulated. These cDNAs included a rice homolog of Arabidopsis GIGANTEA (GI), lir1, and a gene for myo-inositol 1-phosphate synthase, all of which were previously shown to be under the control of circadian clocks. The expression patterns of the rice homolog of GI, OsGI, were similar to those of the Arabidopsis GI, suggesting the conservation of some mechanisms for the photoperiodic regulation of flowering between these two species.     

Air trapping and arboreal locomotor adaptation in primates: a review of experiments on humans

A review was made of experiments on humans in which air trapping by glottis closure during three-dimensional movements were examined in four subjects including former Olympic gymnasts. In brachiation and horizontal bar exercises, the behaviour of the larynx was monitored with a fiberoptic endoscope, and EMG-data were recorded from shoulder muscles. The results revealed that immobilization of the polyaxial connection between the shoulder girdle and the thorax by air trapping occurs in phases of extreme loading of the upper limbs. The closure of the airway by the larynx in humans serves three functions: first, the prevention of errors in deglutition; second, the production of vocal sounds; third, the retention of air inside the thoracic cavity. The latter function, air trapping, allows the immobilization of the rib cage for the muscular fixation of the shoulder blade on the trunk in movements that imply unusually high external forces acting on the upper limbs. This morphological-functional innovation probably has been made when early mammals invaded the three dimensional arboreal habitat, because it gave the tree-dwelling early primates the device to anchor themselves by the arms alone and to avoid falling out of trees. The specific functional characteristic of primates is the hermetic closure of the vocal and vestibular folds by rapidly contracting muscles in the folds. So the closure of the glottis, which in humans seems primarily an adaptation to the production of vocal tones, seems to go back to the adaptation of Tertiary arboreal primates to movements in a three-dimensional environment. Our conclusions are in agreement with the results of other contributions to this volume.     

Anatomical and histological observations of the stomach of Françis' leaf monkeys (Presbytis francoisi)

The anatomical and histological structure of the stomach was examined in François' leaf monkeys (Presbytis francoisi). The stomachs consisted of three parts, the saccus, the tubus gastricus and pars pylorica, and had well-developed taeniae and many haustra. The cardiac gland region occupied the saccular forestomach and the anterior half of the tubus gastricus, while the fundic gland region occupied the posterior half of the tubus gastricus. The pyloric gland region occupied the entire pars pylorica. In the mucosa of the cardiac gland region, villus-like processes were observed. The mucosae of the cardiac and pyloric gland regions contained not only neutral mucins but also acid mucins.     

Differential expression of moesin in cells of hematopoietic lineage and lymphatic systems

 Moesin is a member of the ERM family consisting of ezrin, radixin, and moesin. The protein is located in the plasma membrane similarly to ezrin and radixin, and is thought to regulate cellular movements and morphological changes. Using monoclonal antibody CR-22, the specificity of which against human moesin was confirmed by immunoprecipitation and western blotting analysis, we immunohistochemically stained various formalin-fixed and paraffin-embedded human tissues, in particular, clots of bone marrow and lymphatic tissues, to examine moesin expression in cells of hematopoietic lineage and lymphatic systems. In the bone marrow, moesin was expressed in myeloid cells, while little staining was detected in erythroid cells. Moesin was highly expressed in both the center and the periphery of mature megakaryocytes. In the lymphatic tissues, moesin was strongly expressed by T-lymphocytes in the paracortex. In the mantle zone, the periphery of the germinal center, moesin was expressed by small lymphocytes which were identified as B-lymphocytes. Furthermore, in areas of inflammation, moesin was expressed in both the center and the periphery of neutrophils, whereas in some neutrophils in distant areas, moesin was localized at the cellular periphery. These results suggest that differential expression of moesin in these cells is involved in their morphology and specialized functions. Accepted: 19 December 1997     

Ca2+ reversibly inhibits active rotation of chloroplasts in isolated cytoplasmic droplets ofChara

Summary The effects of Ca²⁺ and other cations on chloroplast rotation in isolated cytoplasmic droplets ofChara were investigated by iontophoretically injecting them. Chloroplast rotation stopped immediately after Ca²⁺ injection and recovered with time, suggesting the existence of a Ca²⁺-sequestering system in the cytoplasm. The Ca²⁺ concentration necessary for the stoppage was estimated to be >10^–4M. Sr²⁺ had the same effect as Ca²⁺. Mn²⁺ and Cd²⁺ induced a gradual decrease in the rotation rate with low reversibility. K⁺ and Mg²⁺ had no effects. Ba²⁺ had effects sometimes similar to Ca²⁺ or Sr²⁺ and sometimes similar to Mn²⁺ or Cd²⁺.Reversible inhibition by Ca²⁺, together with its specificity, strongly supports the hypothesis that a transient increase in the Ca²⁺ concentration in the cytoplasm upon membrane excitation directly stops the cytoplasmic streaming inCharaceae internodes (Hayama et al. 1979).     

Immunophenotypic difference of keratin expression in normal mammary glandular cells from five different species.

The immunohistochemical reactivity of human, monkey, shrew, rat and mouse normal mammary glands was examined using methacarn-fixed paraffin-embedded specimens and acetone-fixed frozen sections using the avidinbiotin-peroxidase method for cell phenotype comparison. Actin was visualized using anti-smooth muscle actin antibody and keratin expression was determined by employing 12 different monoclonal antibodies. All these antibodies cross-reacted specifically with the species examined. Basal (myoepithelial) cells from all species showed muscle-specific actin according to reactivity with HHF35 monoclonal antibody. Keratin expression showed significant phenotypic differences among species. In human and monkey, AEL-KS2, KL1, CK8.13, AE3 and 34BE12 stained luminal cells as well as basal cells. AE1, RPN1165, CK4.62, 35BE11, M20 and RPN1162 labeled only luminal cells whereas 312C8-1 preferentially bound to basal cells. In shrews, AEL-KS2, CK8.13 and AE3 reacted to both cell types, AE1 reacted only with luminal cells, and 35BE12 and 312C8-1 selectively stained basal cells. In rodents, AEL-KS2 reacted to both cell types, CK8.13, AE3, 34BE12 and 312C8-1 stained rat basal cells, and 34BE12 and 312C8-1 reacted to mouse basal cells. The data represents cytoskeletal differences among species.     

Mapping and characterization of antigenic epitopes and the nucleic acid-binding domains of the VP6 protein of bluetongue viruses.

Heterologously expressed VP6 and truncated VP6 proteins of bluetongue virus (BTV) serotype 11 purified to near homogeneity were used for structure and function analyses. The yield of the expressed VP6 was host cell dependent. Six antigenic epitopes of VP6 of BTV were identified and mapped by immunoblot analyses and enzyme-linked immunosorbent assay with oligoclonal antibodies. These determinants were surface accessible and conserved among the cognate VP6 proteins of five U.S. BTV serotypes. The amino acid sequences and sizes of these six antigenic epitopes were determined, and their precise locations were also mapped and confirmed by deletion analyses. The nucleic acid binding activities of VP6, confirmed by electrophoretic mobility shift assay, were concentration dependent. The binding activities and affinities of the purified expressed VP6 protein towards double-stranded RNA and double-stranded DNA were similar. Two domains of VP6, corresponding to three of the six antigenic epitopes, were responsible for the nucleic acid binding activities and have been mapped within 28 amino acids near the middle and 11 residues near the carboxyl terminus of VP6 by electrophoretic mobility shift assay and deletion mutant analyses. Synthetic oligopeptides corresponding to these three regions also exhibited similar concentration-dependent nucleic acid binding activities.