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Biomedical subjects

A Czajkowski

Publications and source records attributed to A Czajkowski.

5 recordsLinked to original sources
PubMed1992

Identification of human salivary protease activity toward mucin: differences with caries.

A protease activity directed toward high molecular weight salivary mucus glycoprotein was identified in the secretion of human submandibular salivary gland. The protease exhibited maximum activity at pH 7.0-7.4, and following ammonium sulfate fractionation yielded an active enzyme at 60% saturation which on SDS-PAGE gave 48 and 53kDa protein bands. The enzyme exhibited serine-protease properties by showing susceptibility to phenyl methyl sulfonyl fluoride, alpha 1-antitrypsin, and egg white and soybean inhibitors. The protease activity in submandibular saliva of caries-resistant subjects was found to be 3.8-fold greater than that in saliva of caries-susceptible individuals, thus suggesting that the enzyme expression may be linked to the resistance to caries.

Adult↗
PubMed1992

Expression of salivary mucin bacterial aggregating activity: difference with caries.

The low and high molecular weight mucin forms were isolated from saliva of individuals with different caries status and assessed for their bacterial aggregating potential towards S. mutans and S. sanguis. The high molecular weight mucin from both groups exhibited similar protein and carbohydrate content, but the level of covalently bound fatty acids was lower in the caries-resistant group. The mucin from caries-resistant group showed only a weak inhibitory potential, while no inhibitory activity was observed with the mucin of caries-susceptible group. The low molecular weight mucins from both groups, while displaying compositional similarities, showed a marked variation in the bacterial aggregating activity, and the titer of the mucin from caries-resistant group was at least 128-fold greater than that of caries-susceptible group. The results demonstrate that the bacterial aggregating epitope of salivary mucins is expressed to a greater extent in caries-resistant individuals, and that this epitope is apparently more accessible to bacteria in the low molecular weight mucin form.

Dental Caries↗
PubMed1992

Effect of Helicobacter pylori lipopolysaccharide on the synthesis of sulfated gastric mucin.

The effect of H. pylori lipopolysaccharide on the synthesis and secretion of sulfated mucus glycoprotein in gastric mucosa was investigated. The lipopolysaccharide, while showing no discernible effect on the apomucin synthesis, exerted a profound inhibitory effect on the process of mucus glycoprotein glycosylation and sulfation, and evoked a rapid (within 15 min) inhibition (65%) in both mucin glycosylation and sulfation at its optimal concentration of 100 micrograms/ml. The data on mucin secretory responses indicated that the added lipopolysaccharide caused a 57% stimulation in sulfated mucin secretion within 15 min followed thereafter by inhibition, which reached a maximum of 32% by 45 min. The high molecular weight mucin form predominated in the initial secretion, while prolonged exposure to the lipopolysaccharide caused a significant increase in the low molecular weight mucin form. The results suggest that H. pylori lipopolysaccharide exerts detrimental effect on mucus glycoprotein sulfation and assembly.

Animals↗
PubMedDate not supplied

Does feedback regulation of pancreatic enzyme secretion by duodenal trypsin exist in cholecystectomized patients?

Recent studies have supported the existence of a feedback regulation of pancreatic enzyme secretion in man. The aim of present study was to evaluate whether a feedback regulation of pancreatic enzyme secretion exists in cholecystectomized patients. The study was carried out in 12 healthy volunteers and in 6 cholecystectomized patients, 7-14 years (mean 9 years) after the operation. Pancreatic secretion was stimulated by intraduodenal infusion of L-phenylalanine (100 mmo 1.1-1). The calculated outputs of pancreatic alpha-amylase and lipase were estimated. The feedback phenomenon was studied using consecutive intraduodenal infusion of trypsin (300 mg/h) and aprotinin (1.5 x 10(6) KIU/30 min). In 6 healthy persons, the infusion of trypsin caused a significant decrease (35-45%) in phenylalaninestimulated alpha-amylase and lipase outputs (p less than 0.05). This effect was completely reversed by intraduodenal aprotinin infusion. In contrast, the increase or the inhibition of tryptic activity in the duodenum was without any effect on pancreatic secretion in cholecystectomized patients. A feedback control of pancreatic secretion could not be demonstrated in patients 6-14 years after cholecystectomy.

Adolescent↗