Search PubMed⌕ Search

Biomedical subjects

S Ivanov

Publications and source records attributed to S Ivanov.

At least 163 records · Page 9Linked to original sources
PubMed1989

[A case report of Sugiura's operation].

With a brief review of the literature the authors present two basic operative groups: with shunted and nonshunted operations, performed in portal hypertension, complicated by esophageal varices. A report is made of the first performance of Sugiura's operation in Bulgaria. It gives very low mortality, survival was 7 years and encephalopathy was not observed.

Esophageal and Gastric Varices↗
PubMed1989

[The diagnosis and immediate treatment results in retroperitoneal tumors].

Immediate results of treatment of 20 patients with primary retroperitoneal tumors treated over a period of 5 years (1980-1985) at the Research Institute of Oncology in Sofia are reported. Attempt is made for anamnestic analysis, aimed at elucidating the semiotics of the disease. Analysis of the diagnostic methods serves to give recommendations for "first-rate" diagnostic procedure--computer tomography when a retroperitoneal tumor is suspected. Complex therapeutic approach consisting of radical operation and adjuvant radiation treatment is advised.

Adolescent↗
PubMed1988

Effect of hydrocortisone on sialyltransferase activity in the rat small intestine during maturation. Changes along the villus-crypt axis and in fetal organ culture.

Sialyltransferase activity was assayed in rat intestinal cells isolated as fractions reflecting the villus-crypt axis of differentiation. In 13-day-old rats both endo- and exogenous sialyltransferase activity reached their maximum in undifferentiated crypt cells and their peaks overlapped. In contrast, sialyltransferase of the adult intestine was 4-fold lower than that of sucklings in the crypts, with slight tendency to be transferred to the villus cells. Hydrocortisone applied to 10-day-old rats caused three days later a precocious drop of sialyltransferase activity in the crypt cells. Unlike in vivo, glucocorticoid responsiveness was accompanied by increased sialyltransferase activity in fetal small intestine cultivated for 17 days.

Animals↗
PubMed1988

A modified, event-related potential-based guilty knowledge test.

Subjects chose and pretended to steal one object from a box of nine. They then watched a visual display of verbal representations of objects including their chosen object or one of eight novel objects on each trial. They were told to count one of the novel objects and that although they were welcome to try to beat our test, they would be unable to avoid noticing the chosen object. P3 responses were obtained only to counted and to chosen objects in 7 of 10 subjects not eliminated for artifact or noncooperation.

Guilt↗
PubMed1988

Effect of fluororotic acid on the sialylation of the chicken liver, hepatoma MC-29 and serum glycoconjugates.

Fluororotic acid, an orotic acid analogue which interferes with the nucleotide and RNA biosynthesis, was tested to determine its effect on: a) 14C-glucosamine and 14C-N-acetylmannosamine incorporation into acid-soluble nucleotide-sugars and into b) glycoconjugates from chicken liver and hepatoma induced by the avian leukosis strain Mc-29. In vivo metabolism studies indicated that this agent alters the nucleotide biosynthesis in both tissues investigated and causes a decrease in the sialylation rate of liver, hepatoma and serum glycolipids and glycoproteins.

Animals↗
PubMed1987

Isolation and characterization of chicken liver and hepatoma Mc-29 endoplasmic reticulum and Golgi apparatus membranes and biosynthesis of their glycoconjugates.

Rough and smooth endoplasmic reticulum (ER) membranes and trans-Golgi apparatus (GA) fraction, intermediate GA fraction, and cis-GA fraction from White Leghorn chicken liver and hepatoma Mc-29 were isolated. Their purity was checked by electron microscopy and by determination of the activity of the marker enzymes. Rough and smooth membranes were also identified by calculation of the ratio between the content of RNA and the total phospholipids. It was found that the membrane fractions were pure enough. The tumor exhibited a decreased amount of ER and a small GA when compared when the ER and GA in the liver. The biogenesis of membrane glycoconjugates was followed by in vivo experiments either with [14C]glucosamine or by double labeling with [14C]N-acetylmannosamine and [3H]leucine. The radioisotope studies indicated that the synthesis rate of protein in liver and hepatoma rough ER was nearly the same, but in the tumor cells the glycosylation of the nascent polypeptide chain and the formation of glycolipids were significantly decreased.

Animals↗
PubMed1986

Characterization of sialyltransferases from serum of normal and hepatoma Mc-29 bearing chickens.

Sialyltransferase was measured in serum of normal and hepatoma Mc-29 bearing chickens. By preparative isoelectric focusing the multiple forms of sialyltransferase from both kind of serums was studied as well. By using influenza virus neuraminidase an attempt was made for partial structural characterization of the sialylation sites in asialofetuin applied as exogenous acceptor for sialyltransferase determination. It was established an elevated serum sialyltransferase activity in tumor bearing chickens with tumor an enzyme form was detected with pI-4.99 identical with an enzyme form described previously in solubilized plasma membrane preparations from hepatoma Mc-29. Monitoring of multiple forms of serum glycosyltransferases may be of value in answering the problem concerning the tissue origin of serum enzymes.

Animals↗