Methicillin-Resistant Staphylococcus aureus ST398 in Swine Farm Personnel, Belgium

We assessed methicillin-resistant Staphylococcus aureus (MRSA) in persons on 49 swine farms in Belgium. Surveys showed that 48 (37.8%) persons carried MRSA ST398 and 1 (0.8%) had concurrent skin infection. Risk factors for carriage were MRSA carriage by pigs, regular contact with pigs and companion animals, and use of protective clothing

Zinc distribution and speciation in Arabidopsis halleri x Arabidopsis lyrata progenies presenting various zinc accumulation capacities

The definitive version is available at http://www.blackwell-synergy.com/loi/nphInternational audienceThe purpose of this study was to investigate the relationship between the chemical form and localization of zinc (Zn) in plant leaves and their Zn accumulation capacity. * An interspecific cross between Arabidopsis halleri sp. halleri and Arabidopsis lyrata sp. petrea segregating for Zn accumulation was used. Zinc (Zn) speciation and Zn distribution in the leaves of the parent plants and of selected F1 and F2 progenies were investigated by spectroscopic and microscopic techniques and chemical analyses. * A correlation was observed between the proportion of Zn being in octahedral coordination complexed to organic acids and free in solution (Zn-OAs + Znaq) and Zn content in the leaves. This pool varied between 40% and 80% of total leaf Zn depending on the plant studied. Elemental mapping of the leaves revealed different Zn partitioning between the veins and the leaf tissue. The vein : tissue fluorescence ratio was negatively correlated with Zn accumulation. * The higher proportion of Zn-OAs + Znaq and the depletion of the veins in the stronger accumulators are attributed to a higher xylem unloading and vacuolar sequestration in the leaf cells. Elemental distributions in the trichomes were also investigated, and results support the role of carboxyl and ⁄ or hydroxyl groups as major Zn ligands in these cells

Control of cell proliferation and differentiation in the normal stomach

During the last decade a basic pathophysiological interest in the gastric kinetic processes led several investigators to intensify research in this field, resulting in significant advances in understanding the normal control factors of cell proliferation and differentiation in the stomach. This review provides a survey of the current knowledge on this subject in the light of recent experimental work.SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

Total biliary diversion and proliferation parameters in colonic mucosa of rats

SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

DNA synthesis, cell proliferation index in normal and abnormal gallbladder epithelium

The observation of mitotic figures in the epithelium of the normal gallbladder is exceptional because cell renewal is occurring at a very slow rate. It is only after using 3H-thymidine and autoradiography to observe the cells in DNA synthesis that evidence of a significant epithelial cell replication has been provided. Because numerous mitotic figures and increased 3H-thymidine uptake have been observed after intraluminal introduction of foreign bodies or after ligation of the common bile duct in animals, mechanical distension has been supposed to represent an important trigger factor of cell proliferation in this hollow organ. An increased epithelial cell renewal was also observed in human gallbladders of patients with a complete obstruction of the common bile duct causing the distension. However, the absence of correlation between the degree of gallbladder distension and the proliferative response was suggesting that factors other than distension could be involved. In studies on experimental lithiasis cell proliferation appeared to be enhanced in the gallbladder epithelium of mice fed on a cholesterol-cholic acid-rich lithogenic diet. The fact that the increase in proliferative activity was preceding the formation of gallstones was another indication that factors other than mechanical stimulation by stretching or by the stones may stimulate cell renewal in this organ. Factors in the bile of animals receiving a lithogenic diet could be involved which might cause cellular death and, hence, a regenerative reaction. Direct mitogenic effect of an unknown factor in the bile of these animals is an alternative possibility. On the other hand the stimulating effect of postprandial hormones on gallbladder cell renewal suggested by the observation of a DNA synthesis peak after feeding has been established. Synthetic cholecystokinin analogues have been shown to increase the proliferative activity and to induce epithelial hyperplasia in this organ. In one recent study using fundusectomy to increase the serum gastrin levels, a significant proliferative stimulation in the gallbladder was also observed. In human gallbladder mitotic activity in gallbladders with gallstones is much higher than in the controls. No correlation between stone number, weight or volume and the proliferative activity was put in evidence, whereas cell renewal appeared to be more influenced by the composition of the stones than by their physical presence. Epithelial DNA synthesis activity was, namely, much higher in gallbladders with cholesterol stones than in those with pigment stones. Whether increased cell turnover and, hence, cellular shedding into the lumen could represent a nucleating factor for cholesterol stones is an attractive working hypothesis. Considering the very high frequency of gallstones in man and also the frequent association of gallbladder cancer and lithiasis, further studies on mitotic activity in this organ are required. In conclusion, data from animal experiments and in vitro studies on human gallbladders indicate that gallbladder epithelial cell proliferation may be influenced by several mechanical, chemical and hormonal factors. The list of these factors is still incomplete while their possible role in gallbladder disease is a fascinating exploration field for future research.SCOPUS: re.jFLWINinfo:eu-repo/semantics/publishe

Cell proliferation and atrophic gastritis in explanted canine gastric mucosa

Atrophic gastritis was induced in 7 mongrel dogs by explanting a full thickness wedge of vascularized mucosa from the gastric greater curvature onto the abdominal wall. Autoradiography of mucosal specimens was carried out after the iv injection of thymidine H3. The labeling index, S phase duration, and cell cycle time were measured in normal and explanted fundic mucosa. The spatial distribution histograms of the labeled cells showed an enlarged area of proliferation. As in human atrophic gastritis, proliferation was shifted toward the mucosal surface. Significantly higher labeling indices were observed in the atrophic mucosa. Shortening of the S phase duration and the cell cycle time was indicated by the curves of the labeled mitoses. Proliferative activity was significantly accelerated in this experimental model of atrophic gastritis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Gastroesophageal reflux triggers proliferative activity of the submucosal glands in the canine esophagus

The effect of experimental gastroesophageal reflux on mitotic activity in the squamous epithelium, as well as in the submucosal glands, of the esophagus was investigated in dogs. The lower esophageal sphincter was destroyed in four dogs using a Wendel cardioplasty, a simple esophagotomy was carried out in four other animals, and four unoperated dogs were taken as controls. Two weeks later, mucosal samples from the esophagus were taken after in vivo labeling of the animals with bromodeoxyuridine. In all mucosal samples the proliferative parameters were estimated in the squamous epithelium, in the submucosal glands and in their excretory ducts. After the cardioplasty, the proliferative parameters were increased (P < 0.05) not only in the esophageal epithelium but also in the submucosal glands and in their excretory ducts (P < 0.05). The amplitude of the proliferative response was more than ten times larger in the latter than that in the surface epithelium. Gastroesophageal reflux is a potent proliferative stimulant to the esophageal squamous epithelium, but also to the cells of the submucosal esophageal glands and their excretory ducts.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Autoradiographic study of cell renewal in fundic mucosa of fasting dogs

Cell renewal in the gastric fundie mucosa of fasting dogs was studied autoradiographically, after intravenous injection of tritiated thymidine. The proliferative population in the gastric pits was delimited, using as reference the limit between foveolar and mucous neck cells. The S-phase duration was measured on the curve of the labelled mitoses and, using the labelling index, the turnover time was calculated. Repeated daily biopsies permitted observation of cell migration. Since the turnover time in our experimental animals was very low, the possible influence of their fasting state was discussed. © 1971 S. Karger AG, Basel.SCOPUS: ar.jinfo:eu-repo/semantics/publishe