Biomedical subjects

S Borović

Publications and source records attributed to S Borović.

8 recordsLinked to original sources

PubMed2004

Foley catheter and deep hypothermic circulatory arrest to control bleeding in redo cardiac surgery.

Two cases with catastrophic hemorrhage in redo cardiac surgery are described. In the first one tearing of right ventricle with uncontrolled bleeding occurred during sternal reentry. In the second one, tearing of the right atria occurred while the patient was on cardiopulmonary bypass. In both cases we were able to control bleeding using Foley catheter, which enabled us to proceed to deep hypothermic circulatory arrest to repair heart chambers (due to dense adhesions it was impossible to manage it in any other way). We have found this combined technique to be extremely useful tool to control catastrophic hemorrhage during redo cardiac surgery.

Blood Loss, Surgical↗

PubMed2000

Post-traumatic dynamic changes in the antibody titer against oxidized low density lipoproteins.

Oxidized low density lipoproteins (oLDL) are products of systemic oxidative stress initiated by the mechanism of free radical induced lipid peroxidation. Oxidatively modified epitopes on LDL molecules are immunogenic and antibodies against such epitopes are generated. The aim of the study was to determine whether traumatic injury and consequent oxidative stress are accompanied by changes in the titer of autoantibodies against oLDL, and to determine whether patients with different injuries can be distinguished by measuring their anti-oLDL titer. Sera of twenty-four patients divided into three groups of eight subjects each were investigated by an anti-oLDL ELISA immunoassay: 1) patients with bone fractures, 2) with traumatic brain injury (TBI) and 3) with both bone fractures and TBI. The patients were followed during four weeks after injury and anti-oLDL titers were determined on a weekly basis. The control group consisted of 22 healthy persons. The lowest antibody titer was measured in all groups during the 1st week after injury. While the serum levels of patients with combined injury did not differ from those of the other two groups, the levels of patients with TBI were significantly higher than those of patients with isolated bone fractures. During the four-week convalescence, a gradual and significant increase in the anti-oLDL titer was observed in all patients. However, this value was increased above normal values only in the sera of patients with TBI during the third and the fourth week after injury. Reactive oxygen species (ROS) play an important role in the regulation of bone synthesis and remodelling. Therefore, we assume that the combination of a fracture with TBI-mediated post-traumatic stress response might be related to the altered fracture healing (enhanced osteogenesis) frequently observed in these patients.

Adult↗

PubMed1999

4-Hydroxynonenal as a second messenger of free radicals and growth modifying factor.

Immunohistochemical analysis of the distribution of the lipid peroxidation product 4-hydroxynonenal (HNE) in the brain of baboons exposed to experimental hemorrhagic traumatic shock or sepsis showed that systemic oxidative stress and the thereby generated HNE affect the blood:brain barrier and the regulation of cerebral blood flow determining secondary brain damage. Similarly, HNE was determined during ischemia in the brain blood vessels of rats exposed to ischemia/reperfusion injury of the brain. After reperfusion, HNE disappeared from the blood vessels but remained in neurones and in glial cells. Since HNE modulates cell proliferation and differentiation (including proto-oncogene expression), it is postulated that HNE might have prominent local and systemic effects that are not only harmful but beneficial, too, determining the outcome of various pathophysiological conditions based on oxidative stress.

Aldehydes↗

PubMed1998

Comparison of the effects of Viscum album lectin ML-1 and fresh plant extract (Isorel) on the cell growth in vitro and tumorigenicity of melanoma B16F10.

Numerous findings indicate that specific plant lectins acting against cancer could be major active components of Viscum album extracts, although activity of low molecular weight components (peptides, carbohydrates and alkaloids) might be as essential for the beneficial activity of the plain plant extracts, too. Thus, active principle of Viscum album extracts is still not understood, and is difficult to be analysed because of the complex composition of the extracts and uncertainty of the standardised effectiveness (batch consistency) of the extracts. The aims of this study were to compare the concentration dependent effects of the pure mistletoe lectin (ML-1) with the fresh plant Viscum album extract (Isorel) and its different MW components on the in vitro growth of ConA stimulated lymphocytes, on the growth and tumorigenicity (artificial lung metastases development) of murine melanoma B16F10 cells, and to compare concentration dependent effects of the different types of the Viscum album extracts in vitro (applying novel type of MTT assay). The results obtained indicate that the effects of Isorel used at high dose could be result of toxic activity of the mistletoe lectins ("ML-1 like" activity). Unlike ML-1, if used at low concentrations, Isorel selectively inhibited tumor cells, due the activity of the low MW components. On the other hand, the number of tumor nodules was reduced (in comparison to the control) equally in the lungs of mice injected with B16F10 cells pre-treated in vitro with the plain Viscum album extract or any of its modifications or ML-1. Hence, it is supposed that the beneficial therapeutic effects of Isorel might result from the combined biological activity of the high and the low MW components not lectins only. Similarly, in MTT assay low concentrations of all types of the Viscum album extract showed stronger inhibiting activity for B16F10 and HeLa cells than pure ML-1. According to these results we propose a standardisation of aqueous Viscum album extracts by comparing their and ML-1 concentration dependent activity on the tumor cells in vitro applying MTT bioassay described which should be relevant for further evaluation of their active principle and for improvement of biotherapy of cancer.

Adjuvants, Immunologic↗

PubMed1997

The role of light intensity, irradiation time and photoactive substance concentration in photodynamic therapy of tumors in preclinical research.

The role of physical parameters such as light intensity, irradiation time, light wave-length and photoactive substance concentration during photodynamic therapy is discussed. Optimal values for all these parameters were determined in a well defined biological model based on the treatment of CMC-2 fibrosarcoma implanted in the right hind leg of CBA/HZgr mice.

Animals↗

PubMed1996

Porcine splenic peptides (Polyerga) decrease the number of experimental lung metastases in mice.

Preparations of splenic peptides under the name of Polyerga are being tested in numerous experimental immunomodulating and antitumorous models and are also used during supportive treatment of tumorous patients. Further, the incidence of experimental lung metastases of melanoma cells in mice was significantly reduced if we used Polyerga preparations. The aim of our investigation was to determine whether Polyerga is active directly against tumor cells or whether its activity is manifested by modulating immune and other possible abilities of the organism. To clarify the problem glycopeptides containing Polyerga were incubated with melanoma B16F10 cells in vitro and the plating efficiency of these cells determined when cultivated in medium, or in medium with different doses of the same Polyerga preparation. The cells preincubated in medium only reacted to the addition of increasing doses of Polyerga, 150 pg or more, by raising colonies number. However, 24-h incubation of melanoma cells in the presence of 150 micrograms of Polyerga per ml significantly reduced the number of tumor cell colonies in comparison to the corresponding cell cultures previously not exposed to Polyerga. These in vitro studies were extended to in vivo application using C57B1/GoZgr mice injected i.v. with melanoma cells pretreated with Polyerga in vitro or previously not treated. A group of the treated mice was further injected i.p. with Polyerga. All the mice were killed at a particular time and the number of lung nodules determined. A significant difference to the control values was noticed in each group that used Polyerga, regardless of the exposure of melanoma cells to Polyerga in vitro, in vivo or to combined treatment. The efficiency of Polyerga application 7 days following i.v. injection of control melanoma cells (cultivated in medium only) when the nodules already exist, was further evaluated in a combined treatment using DTIC, a drug of choice in melanomas. The smallest incidence of experimental lung metastases was observed in the group exposed to the combination of DTIC and Polyerga. Polyerga preparation is thus active against melanoma cells, particularly in vivo and if combined with chemotherapy.

Animals↗

PubMed1996

A mathematical model for the effect of red light penetration depth on tumor growth.

The effect of different local temperature increase in normal and tumorous tissue, influenced by red light commonly used in photodynamic therapy, on tumor growth rate was reanalyzed, taking into account the tumor tissue penetration depth of the light used. The rear part of the tumor is definitely not receiving the same light dose, and consequently the same amount of heat energy, as the front part. The effect is taken into account by using a mathematical model of tumor growth for the rear part of the tumor. Positive experimental results of hyperthermia due to the energy deposited by the red light, are more encouraging after such a correction than previously reported.

Animals↗

PubMed1995

Comparison of the values of basic fibroblast growth factor determined by an immunoassay in the sera of patients with traumatic brain injury and enhanced osteogenesis and the effects of the same sera on the fibroblast growth in vitro.

In patients with severe traumatic brain injury, the early healing of fractures is accompanied by hypertrophic callus formation or heterotopic ossifications, which might even result in ankylosis of the affected joints. Analysis of the sera of patients with traumatic brain injury revealed post-traumatic dynamic changes of basic fibroblast growth factor immunoreactivity, similar to those observed during fracture healing associated with enhanced osteogenesis. The aim of this study was to determine whether such changes in basic fibroblast growth factor concentrations could be related to the phenomenon of enhanced osteogenesis. Basic fibroblast growth factor immunoreactivity was determined (using an IEMA kit) in the sera of patients with traumatic brain injury and bone fractures (n = 8) and in the sera of patients with either traumatic brain injury alone (n = 10) or bone fractures alone (n = 7), and the effects of these sera on L929 fibroblast growth were analysed in vitro. The results did not prove a causative relationship between the changes of basic fibroblast growth factor immunoreactivity and in vitro growth promoting effects of the sera. However, it is apparent that, in addition to changes in the growth-promoting activity and basic fibroblast growth factor concentration of serum, other as yet unknown post-traumatic changes can cause enhanced osteogenesis.

Adolescent↗