PubMed Health⌕ Search

Biomedical subjects

V K Podgorodnichenko

Publications and source records attributed to V K Podgorodnichenko.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

[Study of the possibility of hyperparathyroidism development in rats exposed to internal irradiation by iodine radioisotope].

The possibility of hyperparathyroidism development secondary to earlier internal irradiation with radioactive iodine was studied experimentally in Wistar rats. This report describes the parathyroid morphology and biochemical findings for animals irradiated with 131I at the doses of 4.5, 40, or 80 Gy. The interval between the radiation exposure of two-month-old rats and their examination for thyroid and parathyroid pathology was 14 months. Neither hypercalcemia nor hypophosphatemia was found. Moreover, the level of calcium in serum slightly decreased following 40 and 80 Gy irradiation. The increased incidence of parathyroid fibrosis and hypofunctional structure transformation were revealed.

Animals↗
PubMedDate not supplied

[The modifying action of calcium antagonists on postirradiation thymidinemia].

Single and long-term per os administration of verapamil, a calcium antagonist, changes the thymidine content of nonirradiated mouse blood. The changes observed depend upon verapamil concentration in the blood. The postirradiation thymidinemia level is the lowest in animals exposed at the time when the thymidine content was minimized by the agent administered.

Administration, Oral↗
PubMedDate not supplied

[Fibronectin from the lymph of healthy persons].

Content of fibronectin was studied in lymph and blood plasma of 24 healthy 23-57 years old men. Concentration of fibronectin in lymph and blood plasma was 44.2 +/- 21.7 mg/ml and 354 +/- 88 mg/ml, respectively. Interrelations were not found between content of fibronectin in lymph and blood plasma as well as between the total content of protein and fibronectin in lymph. Fibronectin in lymph was shown to occur in its intact form using immunoblotting procedure involving monoclonal antibodies to fibronectin. Simultaneously with whole molecules of fibronectin its fragments appear to be present in lymph.

Adult↗
PubMedDate not supplied

[Interferon induction via peroral administration of high-molecular polynucleotides].

High molecular polynucleotides, poly(I).poly(C) and poly(G).poly(C), incorporated into liposomes may be used for serum interferon induction when administered orally. Titres of interferon induced by this method are sufficiently high (320-640 units/ml) and close to those induced by the same preparations administered parenterally (640-1280 units/ml). The use of liposomal polynucleotides results in prolonged (up to 24 hours) circulation of interferon in the blood of mice at a sufficiently high level. Liposomal polynucleotides are low-toxic upon oral intake. The liposome-polynucleotide complex is sufficiently stable on storage, and retains the interferon-inducing activity, if given orally, after 6 months of storage at 4 degrees C in the liquid form.

Administration, Oral↗
PubMedDate not supplied

[Different mechanisms of blood thymidine levels caused by irradiation and polyanion administration].

The administration of dextran sulfate causes an increase in the thymidine content of rat blood comparable with the postirradiation thymidinemia. In contrast to radiation dextran sulfate does not increase polydeoxynucleotide content of thymus. Isoptin, a calcium antagonist, decreases thymidinemia induced by dextran sulfate to a greater extent than that induced by ionizing radiation. Thymidinemia induced by dextran sulfate is supposed to be due to its effect on cell membranes. In radiation-induced thymidineamia this mechanism is of lesser significance.

Animals↗
PubMedDate not supplied

[Interferon-inducing activity of liposome-incorporated double-stranded polynucleotides and the means for its enhancement].

Natural double-stranded RNA (dsRNA) incorporated into liposomes upon parenteral inoculation induces 4 times as much amounts of interferon as inoculation of the equal amount of dsRNA without liposomes. Oral administration of liposome-incorporated dsRNA induces in animals serum interferon in amounts similar to those induced by parenteral inoculation of dsRNA without liposomes (320-640 units/ml). When liposome-incorporated dsRNA is used, interferon induction is prolonged to 24 hours. The prolongation period increases to 5 days after preliminary treatment of animals with "empty" liposomes. In M-19 cell culture, 2-hour treatment with liposome-incorporated dsRNA in a dose of 5-10 micrograms/ml induces a yield of 640-1280 units/ml interferon and 100% antiviral effect. The L-929 culture is more sensitive to dsRNA in liposomes. Even its minimal amounts (0.1-1 microgram/ml) after 2-3-hour contact produce a 100% antiviral effect in the presence of low amounts of interferon in the culture fluid (20-40 units/ml) or in its complete absence.

Animals↗
PubMedDate not supplied

[Characteristics of interferon production from the enteral administration of inducers].

When interferon inducers are administered to animals, autonomous local production of interferon by organs (intestine, liver) occurs alongside with the production of serum interferon. After oral administration of a low molecular interferon inducer, tilorone, the intestine is the main site of interferon synthesis. Here the peak of interferon production precedes that in the serum by 20 hours and exceeds it 16-fold. The sequence of events follows the scheme: intestine--liver--serum. Upon oral administration of high molecular inducers incorporated into liposomes (polyguacyl, lafarin) the predominant site of interferon production is the liver where over 80% of the administered inducer is localized and interferon production is 2-4-fold higher than in the intestine. The sequence of events follows the scheme: liver--intestine--serum.

Administration, Oral↗
PubMedDate not supplied

[The level and immunochemical characteristics of fibronectin in the plasma of irradiated rats].

The electrophoretic and immunoelectrophoretic methods were used to study fibronectin of blood plasma of intact Wistar rats and of those exposed to 1-10 Gy radiation. The increase in the fibronectin concentration 3 days after irradiation was a function of radiation dose. Possible mechanisms of the hyperfibronectinemia development involving mechanisms of endogenous proteolytic fragmentation of glycoprotein, the increase in the protein synthesis and complexation and inhibition of the rate of fibronectin degradation and elimination are discussed.

Animals↗
PubMedDate not supplied

[Changes in the concentration of serum fibronectin in irradiated animals].

A study of the level of fibronectin in blood serum of Wistar rats at different times after gamma-irradiation (7.5 Gy) has demonstrated a considerable increase in its concentration after 3 days. This increase is a function of radiation dose absorbed (within the range from 1 to 10 Gy). The most pronounced changes are observed with serious and extremely serious forms of acute radiation sickness. The administration of cycloheximide 48 h after irradiation removes completely the increase in the level of blood serum fibronectin.

Animals↗
PubMedDate not supplied

[A simple radioimmunological method of determining thymidine in biological fluids].

A simple, sensitive and reproducible radioimmunoassay for determination of thymidine in biological fluids was developed. The technique is based on competition between 3H-thymidine and unlabelled thymidine for antithymidine antibodies. The cross-reactivity of structurally related compounds with the antibody was mostly negligible, except for deoxyuridine. The sensitivity of the assay was 10(-7) M. This radioimmunoassay may be used for measuring content of thymidine in blood serum and urine. A method for direct determination of thymidine in urine was not described before.

Animals↗
PubMedDate not supplied

[Free thymidine in the blood serum of irradiated rats with different levels of cellular depletion of the thymus and spleen].

The levels of the postirradiation thymidinemia, with an equal degree of the proceeding cell depletion of lymphoid organ tissues caused by the administration of dexamethasone and exposure of rats to 3 Gy radiation, markedly varied. Three days after the injection of the hormone, the organism responded to irradiation by an increase in the concentration of thymidine in blood serum in the same manner as intact animals did. The preirradiation with a dose of 3 Gy reduced sharply the ability of the organism to respond the repeated irradiation (after 3 days) by thymidinemia. There was a lesser increase in the thymidine concentration in the blood after the injection of dexamethasone than after irradiation inducing the same cell depletion of the thymus and spleen.

Animals↗
PubMedDate not supplied

[Factors affecting the DNA-binding activity of the blood serum in in patients and healthy persons at low ionic strength].

Interaction of blood serum proteins with native DNA at low ionic strength [0.05 M NaCl and 0.015 M sodium citrate], estimated by adsorption of DNA-protein complex on nitrocellulose filtrs, depended on specific activity, molecular weight of DNA as well as on the amount of DNA and blood serum in the samples. DNA-binding activity of blood serum from the patients should be estimated at such ratio of components, when the blood serum from healthy persons adsorbed minimal quantities of DNA, since the molecular weight and specific activity of the DNA preparations might vary in various samples. As a factor, regulating the rate of DNA binding on filtrs, such amount of blood serum from patients should be added to the samples, which corresponded to the maximal amount of normal blood serum causing no binding with the DNA preparations.

Adsorption↗