PubMed Health⌕ Search

Biomedical subjects

F Bartos

Publications and source records attributed to F Bartos.

At least 19 recordsLinked to original sources
PubMed1979

Polyamines: an unrecognised cardiovascular risk factor in chronic dialysis?

The significance of raised polyamine (P.A.) levels in chronic-dialysis patients is unknown. Since these biologically active substances have hormone-like properties and promote cell-growth in plant and animal tissues, it is possible that they stimulate proliferation of arterial smooth-muscle cells (S.M.C.)--a central process in atherogenesis--and thereby contribute to the rapidly accelerated cardiovascular disease observed during dialysis. Such a role for P.A. is supported by tissue-culture studies, which show not only that P.A.-rich serum from dialysis patients stimulates S.M.C. growth, but also that this mitogenic effect is lost when P.A. are selectively removed from uraemic serum and restored by their addition. Although these observations provide new insights into possible mechanisms of atherogenesis, they are not surprising in view of the many known biological actions of P.A.

Arteries↗
PubMed1979

Purification of rabbit antispermine antiserum by affinity chromatography.

Immunoglobulins G were isolated from a crude rabbit antispermine antiserum using a protein A-Sepharose CL-4B column. Affinity chromatography coupling spermine to the Sepharose matrix was employed for separation of antispermine antibodies from these immunoglobulins. Four fractions of antispermine antibodies were isolated by stepwise elution with solutions at pH range from 4 to 1. Binding constants were determined and cross-reactivity with other polyamines was tested for each fraction of antibodies. Highly specific antispermine antibodies were found in fraction IV.

Animals↗
PubMed1978

1-N-Acetylspermidine: occurrence in normal human serum.

Using gas chromatography mass spectrometry following derivatization (N-trifluoroacetylation), 1-N-acetylspermidine was found to occur in normal human serum at a level of approximately 0.008--0.5 nmol ml(-1), i.e. about two orders of magnitude lower than the corresponding spermidine level. No evidence for the occurrence in serum of the isomeric 8-N-acetylspermidine was found. Mass spectra of authentic samples of trifluoroactylated 1-N- and 8-N-acetylspermidine are presented.

Acetylation↗
PubMed1978

Effect of glucocorticoids and stress on 14C-thymidine incorporation into DNA and on mitosis in regenerating rat liver.

Hydrocortisone sodium succinate (65 mg/kg body weight), Zn-ACTH (40 U/kg) and the intraperitoneal injection of Celite (200 mg/kg) decrease the incorporation of 14C-thymidine into the DNA of regenerating rat liver by about 60%. This decrease is not followed by a corresponding inhibition of cell division. The agents applied at the end of G1 phase or in the S phase of the cell cycle probably change thymidine metabolism and the observed decrease of thymidine incorporation does not represent true inhibition of DNA synthesis. The experiment with regenerating liver slices has shown that this disproportion is partly caused by decreased 14C-thymidine transport into the cells.

Anesthesia↗
PubMed1978

Influence of D-penicillamine on the formation of elastin and its cross-links.

The amount of insoluble elastin and its content of desmosine cross-links were investigated in aortas of chick embryos, to which D-penicillamine was administered on the 6th or 14th--16th day of incubation. D-Penicillamine was shown to alter the formation and maturation of elastin. Using lower doses (less than 50 mg) the weight of pooled aortic elastin is higher as compared with controls (related to 1 mg of elastin or to total weight of elastin). Increased isodesmosine:desmosine ratio in these samples indicates that this elastin is very young. On the other hand, a high dose of D-penicillamine (100 mg) decreased the content of elastin and also of its desmosine cross-links. The authors explain their findings by counteraction of two factors due to administration of penicillamine: the increased solubility of "insoluble elastin", and the decreased cross-link formation.

Amino Acids↗
PubMed1978

Influence of cyclic AMP on DNA synthesis in slices of regenerating rat liver.

DNA synthesis in slices of regenerating rat liver is inhibited by adenosine cyclic 3',5'-monophosphate [cAMP]. The number of cells synthesizing DNA as assayed by 2-14C-thymidine incorporation is reduced by 65% in the presence of 10(-3) M cAMP. The inhibition of cAMP is not specific; other adenosine compounds, N6,O2,-dibutyryl adenosine 3',5'-monophosphate, 5'AMP and adenosine have the same effect. Moreover, the concentration of cAMP in the cell required for this inhibition is much higher than the normal levels of cAMP in liver cells.

Adenosine↗
PubMed1978

Radioimmunoassay of spermidine in human serum.

Specific antispermidine antibodies were produced following immunization of New Zealand white rabbits with a spermidine-thyroglobulin conjugate of high (greater than 200:1) hapten-carrier molar ratio. The harvested antispermidine rabbit antiserum was characterized and a radioimmunoassay procedure developed. The specificity of this antibody was tested against cadaverine, putrescine, spermine, monoacetylputrescine, N-8-acetylspermidine and other compounds of similar molecular structure. Negligible cross-reactivity was observed with putrescine (2.1%), cadaverine (0.6%), spermine (0.3%), diaminopropane (less than 0.1%), and no cross-reaction was found with monoacetylputrescine, N-8-acetylspermidine, histamine, L-lysine and L-ornithine. The spermidine values on serum of five healthy volunteers were determined by RIA and compared with values by gas chromatographymass spectrometry. Statistical evaluation of the results were highly agreeable. Antibody titer, intra-assay precision and analytical accuracy were tested. The assay requires only 20 microliter of serum and has picomole sensitivity. The sensitivity, specificity and small sample requirement make this procedure an effective tool for spermidine analysis.

Animals↗
PubMed1978

Stereospecific antibodies to methadone. II. Synthesis of d- and 1-methadone antigens.

Diastereomeric methadols were prepared by reduction of the methadone enantiomers. Resulting methadols, after purification and characterization by mass spectrometry, were succinylated. The hemisuccinyl derivatives were conjugated with thyroglobulin via carbodiimide condensation. The conjugates of d- and of 1-methadol hemisuccinyl-thyroglobulin were employed as the antigens for immunization of white New Zealand rabbits in order to obtain specific anti d- and anti 1-methadone antisera.

Animals↗
PubMed1978

Elastin fibers formation in the liver of carbon tetrachloride-treated rats.

Elastin fibers formation was previously found to be an important feature of advanced human liver cirrhosis. Now it has been shown that chronic carbon tetrachloride administration to rats can be used to simulate this condition experimentally. Elastin fibers are found in the septa of connective tissue surrounding parenchymal nodules. Elastin content in liver measured as hydroxyproline insoluble in 0.1 N NaOH is increased about 3 times after a 4 month carbon tetrachloride treatment.

Animals↗