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Biomedical subjects

A Bardoń

Publications and source records attributed to A Bardoń.

17 recordsLinked to original sources
PubMed1990

Ribonuclease and its inhibitor in red blood cells in CF.

A disturbed activity of ribonuclease (RNAase) and its natural inhibitor was found in cystic fibrosis patients (CF); Heterozygotes had normal RNAase but increased inhibitor activities; both groups compared with age-matched controls. RNAase is involved in the breakdown of RNA. In the cell it is bound to an inhibitor and thus inactive (Bardoń 1976). Quantitative and qualitative differences of RNAase are found in CF (reviewed in Bardoń 1987).

Adult↗
PubMed1987

Cystic fibrosis. Carbohydrate metabolism in CF and in animal models for CF.

Cystic fibrosis (CF) is a chronic genetic disease mainly affecting the exocrine glands. Its main clinical symptoms are: abnormal production of mucus which blocks the airways, pancreatic insufficiency and increased sweat electrolytes. In the present investigation a series of enzymes and metabolites--mainly of carbohydrate metabolism--was investigated in biological fluids from CF homozygotes, CF heterozygotes and healthy controls under different conditions. CF homozygotes--and to a lesser degree CF heterozygotes--had increased activity of ribonuclease, and increased concentrations of electrolytes and lactate in their saliva and urine at rest. Saliva of CF patients also had augmented levels of protein. When healthy persons were submitted to anaerobic effort, the activity of ribonuclease and the concentrations of protein, electrolytes and lactate increased in their saliva, and thereby, mimicked the values found in the saliva of cystic fibrosis patients at rest. An abnormal response to a sucrose load was found in both CF-homozygotes and CF-heterozygotes. Greater increase in both glucose and lactate concentrations in the blood as well as a more rapid clearance of these metabolites was observed after the sucrose intake. A possible cause for these findings could be a disturbed carbohydrate metabolism in CF. Therefore, enzymes and metabolites connected to the metabolic pathway of glucose were investigated in CF fibroblasts and in animal models for CF. An increased activity of glycolytic enzymes in CF fibroblast were shown. Similar increases in activities of glycolytic enzymes were found in cells of submandibular glands of rats that were killed in a state of induced metabolic acidosis. These cells also showed increased protein and mucus contents, and elemental changes similar to those observed in fibroblasts of cystic fibrosis patients. Contrary to this, decreased activities of the enzymes of the glycolytic pathway were found in the submandibular gland of chronically reserpinized rats. The end-products of glycolysis, pyruvate and lactate, were also decreased, whereas the concentration of phosphoenolopyruvate and creatinphosphate were increased, possibly causing acidosis in the gland. Thus a disturbed glycolytic pathway in CF cells and a decreased intracellular pH might play an important role in the pathogenesis of this disease.

Acidosis↗
PubMed1985

The chronically reserpinized rat: decreased glycolytic activity in the submandibular gland.

Some of the enzymes and metabolites of the glycolytic pathway of an animal model for cystic fibrosis (the chronically reserpine-treated rat) were investigated. The activities of the enzymes phosphofructokinase (P less than 0.002), enolase (P less than 0.03), pyruvate kinase (P less than 0.005), and lactate dehydrogenase (P less than 0.009) were decreased whereas the activity of glycerol-3-phosphate dehydrogenase was unaffected in the submandibular glands of the treated animals. For metabolites, the reserpine treatment resulted in an increased concentration of glycogen (P less than 0.0002) and phosphoenolpyruvate (P less than 0.001) and a decreased concentration of pyruvate (P less than 0.005) and lactate (P less than 0.002) in the glands. The concentration of glucose and glycerate-2-phosphate was unaffected. The perchloric acid-soluble part of the proteins was also increased (P less than 0.0001) in the submandibular glands of the reserpine-treated animals, as was the activity of ribonuclease. These findings point to a disturbance in the metabolism of glucose and a possible acidosis in the submandibular glands of this animal model for cystic fibrosis.

Animals↗
PubMed1985

Effect of metabolic acidosis on glycolysis in rat submandibular glands.

A decreased intracellular pH of exocrine glands could be an important factor in the pathogenesis of cystic fibrosis. Metabolic acidosis was induced in rats by adding ammonium chloride to the drinking water. An increased content of both total proteins and glycoproteins was found in the submandibular glands of the treated animals. The activities of the glycolytic enzymes - hexokinase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase - were also increased in these glands, whereas the activity of creatine phosphokinase was unchanged. The changes of protein concentration and enzyme activities in the submandibular gland of acidotic rats agree with findings in patients with cystic fibrosis and cultured fibroblasts from these patients. The acidotic rat might be a new promising animal model for cystic fibrosis research. The finding of increased enzyme activities in acidotic rats is, however, contrary to findings in other animal models of the disease.

Acidosis↗
PubMed1980

Properties of purified salivary ribonuclease, and salivary ribonuclease levels in children with cystic fibrosis and in heterozygous carriers.

Alkaline acid- and thermo-stable ribonuclease was isolated from human saliva of healthy subjects, children with cystic fibrosis, and from parents of the latter. The enzyme was purified about 180-200 times, and its ionic requirements, and specificity towards various substrates, characterized and compared with those for human pancreatic ribonuclease. The level of acid- and thermo-stable ribonuclease activity was five times higher in terms of enzyme level per ml saliva, and three times higher in terms of salivary protein, for 62% of children with cystic fibrosis, and for 73% of carrier subjects, relative to co-nrol groups. Assay of the level of this ribonuclease activity appears to be a promising diagnostic tool for detection of heterozygote carriers.

Adult↗
PubMed1979

[Determination of the ribonuclease activity of the duodenal contents of children as a test in the differential diagnosis of cystic fibrosis and pancreatic exocrine insufficiency].

Ribonuclease activity was determined in the duodenal contents of healthy children, in children with cystic fibrosis and with pancreatic exocrine insufficiency. Assays were made at 7.0, in 0.05 M buffer without and with 0.35 M NaCl. The ratio of activity in 0.35 M NaCl to that in buffer alone was found to be 2.4 +/- 1.3 for children with cystic fibrosis as compared with 12 +/- 5 for the control group and children with pancreatic exocrine insufficiency.

Amylases↗
PubMed1976

Human pancreatic-type ribonucleases with activity against double-stranded ribonucleic acids.

Purified acid-thermostable ribonuclease (Ribonucleate 3'-pyrimidino-oligonucleotidohydrolase, EC 3.1.4.22) from human pancreas degrades double-stranded RNA at 2% the rate for single-stranded RNA. The activities against single-stranded RNA and double-stranded RNA were shown to be due to a single enzyme with properties similar to bovine pancreatic RNAase A. For purposes of comparison the activities against double-stranded RNA of crystalline ribonucleases of the whale, rat and cow were assayed and found to be 0.4%, 0.03% and 0.003%, respectively, of their activities against single-stranded RNA. Both human serum and urine contain RNAse components of pancreatic origin which hydrolyze double-stranded RNA at 2% and 0.4%, respectively, of the rates against single-stranded RNA. By contrast, purified acid-thermostable RNAases from human spleen and liver hydrlyze double-stranded RNA at least 20-fold more slowly than human pancreatic RNAase, relative to the corresponding rates against single-stranded RNA. The human pancreatic and serum enzymes exhibit appreciable activity against the poly(C) component of the double-stranded poly(I)-poly(C); they also attack poly(C) itself at approximately 25 times the rate for poly(U) and at more than 50 times the rate for single-stranded RNA.

Animals↗
PubMed1976

Purification and properties of human acid-thermostable ribonucleases, and diagnosis of childhood pancreatic fibrosis.

Acid-thermostable ribonucleases were isolated from human pancreas, duodenal contents, liver, spleen, serum and urine, and purified 15--1000-fold. The pH optima, ionic requirements, and some of the specificity requirements, of these enzymes were investigated. The isolated enzymes formed two distinct groups: (a) The ribonucleases of the pancreas, duodenal contents and fraction A of serum and urine exhibit a pH optimum of 8.5, are inhibited by An2+ and Cu2+, and relatively rapidly hydrolyze the synthetic substrate uridine 3'-(alpha-naphthylphosphate); (b) the ribonucleases of the liver and spleen, and of fractions B of the serum and urine, with a pH optimum of 7, are less sensitive to An2+ and Cu2+, and exhibit negligible activity versus uridine 3'-(alpha-naphthylphosphate). Determination of the serum level of pancreatic-type ribonuclease activity, with the use of uridine 3'-(alpha-naphthylphosphate) or RNA as substrates, appears to be a valid diagnostic tool for pancreatic fibrosis in children.

Child↗
PubMed1975

[Ribonuclease activity in the serum of children of various ages (author's transl)].

The normal levels of ribonuclease activity in the serum of children of both sexes of various ages. The children into four age groups: thee 1st grous--from 1 to 7 days of age, the 2nd--from 1 to 12 months, 3rd--from 1 to 3 years, 4th--from 7 to 14 years of age. The ribonuclease activity amounted, in the various age groups, respectively tto: 1st group--0.27+0.07 ug/ml of serum, 2nd--0.21+0.06 ug/ml, 3rd--0.15+0.04 ug/ml, 4th--0.14+0.04 ug/ml.

Adolescent↗