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Biomedical subjects

Z Lojda

Publications and source records attributed to Z Lojda.

At least 145 records · Page 8Linked to original sources
PubMed1979

Histochemistry of the human duodenal mucosa with special reference to the gradient of activities of the brush border enzymes.

Histochemical examination of aspiration biopsy specimens of the duodenum in 8 healthy volunteers and 23 patients with various gastrointestinal disorders revealed no characteristic abnormality except for a rather frequent absence of the activity of disacharidases especially of lactase. A distinct difference of disacharidase was established between the duodenum and the jejunum in some individuals. A systematic study of different levels of the upper gastrointestinal tract established the fact that the activity of brush border enzymes of enterocytes starts to appear in individually different parts of the duodenum and sometimes even as low as in the jejunum. The distribution of lysosomal enzymes and the activity of dehydrogenases display differences as well. Consequently specimens from different parts of the duodenal and jejunal mucosa are not equivalent and cannot be used alternatively for diagnostic purposes. Biopsies of duodenal mucosa are not adequate for the diagnosis of the malabsorption syndrome.

Adult↗
PubMed1977

Experimental study on the mechanism of hyperphosphatasaemia in bile flow obstruction.

Extrahepatic bile flow obstruction is followed by a several-fold increase in alkaline phosphatase activity in the liver. This activity passes into the blood. The increase in the activity of the enzyme in the liver can be prevented by inhibitors of RNA and protein synthesis. Inducible alkaline phosphatase was purified from rat liver and 1,000-fold purification was achieved. The incorporation of labbelled precursors (14C amino acids and 14C glucosamine) into the liver alkaline phosphatase was evaluated. No significant difference were found between specific alkaline phosphatase activities and specific radioactivities in the control rats and rats with 7.30 h after bile duct obstruction. The incorporation of 14C-amino acids into the total liver proteins was 20% lower in rats with cholestasis than in the control group. The results are evidence that the liver is the source of elevated alkaline phosphatase activity in serum in cholestasis, and that the production of alkaline phosphatase in the liver is prevented by inhibitors of RNA a protein synthesis. However, the enzyme might be synthesized before the 14C-labelled precursors were applied.

Alkaline Phosphatase↗
PubMed1977

Diagnostic significance of determination of serum alkaline phosphatase intestinal isoenzyme activity in coeliac sprue in childhood.

In a group of 26 child patients with coeliac sprue verified by clinical tests and biopsy, we observed a significant change in the proportion of the intestinal alkaline phosphatase isoenzyme in the serum in correlation to a gluten-free therapeutic diet. In untreated patients, in the active phase of the disease, intestinal AP isoenzyme activity rises in the serum and falls in the intestinal mucosa. In our experience, the change in activity is reversible within 3--5 days of instituting adequate treatment, i.e. a gluten-free diet. No such activity changes were observed in children with other forms of malabsorption syndrome (hepatogenic, pancreatogenic) or in the children in the control group. This test was found to be a suitable and sensitive method for indirect determination of the response of the intestinal mucosa to treatment in children with coeliac sprue.

Adolescent↗
PubMed1977

Histochemical diagnosis of lipidoses.

Contemporary possibilities for the histochemical diagnosis of lipidoses are demonstrated in examples of phospholipidoses, Gaucher's disease, Fabry's disease, sulphatidosis, gangliosidosis and neuronal ceroid-lipofuscinoses.

Biopsy↗
PubMed1977

Possibilities for the cytochemical diagnosis of enzymopathies.

The authors review the contemporary uses of histochemistry for the diagnosis of enzymopathies. Enterokinase, lactase, sucrase and trehalase deficiency can be diagnosed by histochemical methods. In glycogenoses, glycogen storage and glucose-6-phosphatase, acid alpha-glucosidase and phosphorylase deficiencies can be demonstrated. In mucopolysaccharidoses, the accumulation of acid muco-substances and changes in lysosomal enzyme activities can be demonstrated.

Biopsy↗
PubMed1977

Immunohistochemical localization of intestinal glycosidases.

The presence of antigenic determinants of the following enzymes was detected in enterocytes by the indirect immunofluorescence method: 1. lactase in human biopsy material, 2. sucrase-isomaltase during ontogenesis in the rat. 1. Lactase: The antigenic relationship between rat and human lactase, demonstrated with the isolated enzymes, was utilized for the histochemical localization of human lactase. The indirect immunofluorescence method, using guinea pig antiserum to rat lactase, demonstrated the presence of human lactase in the enterocyte brush border. The usefulness of this method for clinical practice resides in the possibility of detecting enzymatically inactive protein immunologically related to lactase in cases of lactase deficiency, thereby facilitating more detailed classification of these diseases. 2. Sucrase-isomaltase: Guinea pig antiserum to rat sucrase-isomaltase (SI) was prepared. It was used to demonstrate antigenic determinants of the enzyme in the enterocyte brush border of the rat during ontogenesis. Structural SI protein is already present in 3-day-old rats, whereas enzyme activity can first be demonstrated histochemically from the 11th day of life and biochemically, in vitro, not until about the 18th day. We consider that this technique can be used for studying the biogenesis of membrane-bound enzymes.

Adult↗