Melatonin protects rat thymus against oxidative stress caused by exposure to microwaves and modulates proliferation/apoptosis of thymocytes.

The aim of the study was to evaluate the effect of melatonin on oxidative stress, DNA fragmentation, apoptsis and proliferation in thymus tissue of rats exposed to microwaves. Wistar rats were divided in four groups: I - treated with saline; II - treated with melatonin; III - microwaves exposed; IV - microwaves exposed and melatonin treated. Melatonin (2 mg/kg i.p.) was administered daily. Animals were sacrificed after 20, 40 and 60 days. A significant increase in malondialdehyde and carbonyl group content, as well as decrease in catalase and increase in xanthine oxidase activity were registered under microwave exposure. Melatonin prevented the increase in malondialdehyde and carbonyl group content, and reversed the effect on catalase and xanthine oxidase activity. Both, alkaline and acid DNase activity were increased due to microwave exposure. Furthermore, microwaves caused increase in apoptosis rate (detected using Annexin V-FITC/PI kit) and reduced proliferative capacity of thymocytes (induced by ConA). However, melatonin caused decrease in alkaline and acid DNase activity, decrease in apoptotic rate and increase in proliferation rate of thymocytes. Melatonin exerts protective effects on rat thymocytes by modulating processes of apoptosis and proliferation, and causes decrease in DNA fragmentation and oxidative stress intensity under exposure to microwaves.

The effect of ursodeoxycholic acid on oxidative stress level and DNase activity in rat liver after bile duct ligation.

Accumulation of hydrophobic bile acids (BAs) during cholestasis plays an important role in apoptosis initiation as well as oxidative stress increase in liver cells. Ursodeoxycholic acid (UDCA) acts as a protector in BA-induced cell injury.The aim of the study was to evaluate the effect of UDCA on oxidative stress level and DNase I and II activity caused by liver injury in bile duct ligation (BDL) rats.Wistar rats were divided in four groups: group 1, control (sham-operated); group 2, sham-operated and injected with UDCA (30 mg/kg); group 3,animals with BDL; and group 4,UDCA-treatedcholestatic rats. Animals were sacrificed after 9 days. Malondialdehyde (MDA; lipid peroxidation end-product) level and protein-molecule oxidative modification (carbonyl group content) significantly increased in BDL rat liver. Catalase (CAT) activity in liver tissue was found to be decreased in BDL rats. In addition, xanthine oxidase (XO) activity, which is thought to be one of the key enzymes producing reactive oxygen species, was found to be increased in the cholestatic group. The apoptotic effect in cholestasis was probably triggered by the increased activation of DNase I and II. The protective effect of UDCA on liver tissue damage in BDL rats, in comparison to cholestatic liver, were 1) decrease of MDA levels, 2) increased CAT activity, 3) reduced XO activity, and 4) effect on terminal apoptotic reaction, shown as a decrease in DNase I and II activity.Therefore, UDCA may be useful in the preservation of liver function in cholestasis treatment.

Clinical efficacy of riboflavin and ultraviolet light inactivated fresh frozen plasma evaluated with INR-quantification.

Treatment of blood products by riboflavin and ultraviolet (UV) light prevents of white blood cell (WBC) replication and inactivates of pathogens. The aim of this study was to determine the effects of the inactivation by riboflavin and UV light upon plasma clinical performance, based on effect on the pretransfusion international normalized ratio (INR). A prospective, controlled randomized study included 60 patients who received transfusion of plasma on the Clinic for hematology of Clinical Centre in Nis. Experimental group (EG; 30 patients) was treated with Mirasol-inactivated fresh frozen plasma (FFP) and control group (CG; 30 patients) was transfused with noninactivated FFP. Besides pretransfusion vs. posttransfusion INR, the improvement in INR patient's plasma level per one FFP unit transfused was evaluated. Total of 68 units of FFP were transfused to patients of CG (2.24±0.83 units per patient). Patients of EG received 84 units of Mirasol-inactivated plasma (i.e. 2.80±1.19 units per patient). There was significant increase in number of FFP transfusions that normalized coagulation parameters in EG compared to CG (p=0.039). Also, there was a significant improvement of INR after every FFP unit application (p=0.046). We found a linear relationship between pretransfusion INR and improvement of INR (r=0.97; p<0.001). Plasma treated with riboflavin and UV light retains hemostatic competence and can be used efficiently in the therapy of congenital or acquired coagulopathies, but in larger quantity as compared to noninactivated FFP volume.

Melatonin arrests excessive inflammatory response and apoptosis in lipopolysaccharide-damaged rat liver: A deeper insight into its mechanism of action.

Sepsis is a life-threatening organ dysfunction. An animal model mimicking sepsis utilizes lipopolysaccharide (LPS), an endotoxin recognized as the most potent bacterial mediator of sepsis. Melatonin (MLT), an effective anti-inflammatory and antioxidant agent, is a promising adjunctive drug for sepsis. This study aimed to estimate the potential of MLT in preventing LPS-induced liver damage in Wistar rats by determining the levels of serum and tissue biochemical markers that reflect liver state and function, i.e., serum levels of transaminases and albumin, as well as a panel of oxidative stress-related biomarkers. Additionally, a pathohistological analysis of liver tissue was conducted. Pre-treatment with MLT prevented an LPS-induced increase in serum and tissue liver damage markers and a decrease in the tissue antioxidant capacity, in both enzymatic and non-enzymatic systems. Micromorphological liver tissue changes mirrored the alterations observed in the biochemical status. In rats with LPS-induced sepsis, melatonin was shown to be a crucial antioxidant and anti-inflammatory agent, with vital roles in the alleviation of oxidative stress, causing an increase of the antioxidant capacities and the improvement of the liver's microscopic appearance.

Transfusion-transmissible infections among Serbian blood donors: declining trends over the period 2005-2017.

BACKGROUND: The mass migrations experienced by the Western Balkans in the past decades have significantly changed the demographic structures and have probably altered the prevalence of transfusion-transmitted infections (TTIs) among blood donors. However, data on the prevalence of TTIs in the Western Balkans countries remain incomplete. This study reports the prevalence of TTIs among blood donors in Serbia in the period 2005-2017. MATERIALS AND METHODS: Between January 2005 and December 2017, in the four largest Serbian transfusion centres, mandatory serology tests for screening HBV, HCV, HIV and syphilis infection were used for all blood donations. RESULTS: Of the total of 1,660,019 blood donations made, 3,377 (0.203%) were positive for one of the TTIs: 1,440 (0.087%), 1,055 (0.064%), 215 (0.013%), and 667 (0.040%) were positive for HBV, HCV, HIV and syphilis, respectively. Serbia showed a declining trend of prevalence of HBV and HCV infection, while prevalence of HIV and syphilis remained unchanged. Prevalence of TTIs varied between different transfusion centres and showed a north-to-south upward trend. DISCUSSION: The reported prevalence of TTIs among blood donors in Serbia was low and continued to follow a declining trend over the period of study.

Evaluation of platelet activation in leukocyte-depleted platelet concentrates during storage.

Structural and functional changes in platelets during storage can lead to the loss of platelet reactivity and response. Our aim was to evaluate leukocyte-depleted platelet concentrates on storage days 0, 3 and 5, obtained by in-line filtration. In non-filtered platelet concentrates (NF-PC) group, 180 whole blood units were collected with quadruple blood bags and then compared to another group of 180 whole blood units (leukocyte-depleted platelet concentrates [LD-PC]), collected in Imuflex Whole Blood Filter Saving Platelets (WB-SP) bags with an integrated leukoreduction filter, with regard to the platelet quality and characteristics. The efficacy of the two techniques for platelet concentrate preparation was evaluated by white blood cell (WBC) and platelet count on day 0. The partial pressure of oxygen (pO2), pH, platelets positive for P-selectin (CD62P), CD63, cluster of differentiation 42b (CD42b), phosphatidylserine (PS), and mitochondrial membrane potential (MMP) were analyzed during the storage in both groups. A significantly lower WBC count and higher platelet count was observed in LD-PC compared to NF-PC group, indicating the overall efficacy of the first technique. During the 5-day storage, pH and pO2 decreased in both groups. In LD-PC group, higher pH, increased pO2 and decreased platelet surface expression of CD62P, CD63 and PS were observed compared to NF-PC group. In both groups, the percentage of CD42b positive platelets and MMP did not change significantly during the 5-day period. The assessment of different markers of platelet activation may be an effective tool in evaluating the quality of platelets during storage. A better understanding of platelet activation may provide new insights for developing a novel therapeutic approach in the manipulation of platelet aggregation.

The Effects of Melatonin on Oxidative Stress Parameters and DNA Fragmentation in Testicular Tissue of Rats Exposed to Microwave Radiation.

BACKGROUND: Microwaves from mobile phones are one of the environmental toxicants that are capable of compromising male fertility by inducing oxidative stress and apoptosis in the testes. Melatonin is a lipophilic tryptophan indole amine and a potent antioxidant. OBJECTIVES: The aim of the study was to evaluate the effect of melatonin treatment on oxidative stress parameters and DNA fragmentation in the testicular tissue of rats exposed to microwave radiation (4 h/day). MATERIAL AND METHODS: Adult Wistar rats were divided in 4 groups: I--treated with saline; II--treated with melatonin; III--exposed to microwaves; IV--exposed to microwaves and treated with melatonin. The melatonin (2 mg/kg ip) was administered daily. The animals were sacrificed after 20, 40 and 60 days. RESULTS: Melatonin treatment prevented previously registered increases in malondialdehyde after only 20 days. Furthermore, it reversed the effects of microwave exposure on xanthine oxidase (after 40 days) and acid-DNase activity (after 20 days). However, neither protein carbonyl content nor catalase and alkaline Dnase activity were changed due to melatonin treatment. CONCLUSIONS: Melatonin exerts potent antioxidant effects in the testes of rats exposed to microwaves by decreasing the intensity of oxidative stress; it also reduces DNA fragmentation.

[Evaluation of coagulation factors in fresh frozen plasma treated with riboflavin and ultraviolet light].

BACKGROUND/AIM: Pathogen inactivation in blood products using riboflavin and ultraviolet (UV) light represents a proactive approach to blood safety, not only for known infectious agents but also for new ones or not yet recognized as threats to the blood supply. This method inactivates a virus, bacteria, fungus, or protozoan pathogen from the blood product without damaging its function or shelf-life. The aim of the study was to study the influence of photoinactivation using riboflavin on the concentration of coagulation factors and coagulation inhibitors in plasma that was treated before freezing. METHODS: The examination included 30 units of plasma, separated from whole blood donated by voluntary blood donors around 6 h from the moment of collection. They were treated by riboflavin (35 mL) and UV rays (6.24 J/mL, 265-370 nm) on Mirasol aparature (Caridian BCT Biotechnologies, USA) in approximate duration of 6 min. The samples for examining were taken before (K - control units) and after illumination (I - illuminated units). RESULTS: Comparing the middle values of coagulation factors in the control and illuminated units we noticed their statistically significant decrease in illuminated units (p < 0.001), but the activity of coagulation ones was still in the reference range. The most sensitive coagulation factors to photoinactivation were FVIII, FIX and FXI (21.99%, 20.54% and 17.26% loss, respectively). Anticoagulant factors were better preseved than coagulation factors. CONCLUSION: Plasma separated from whole blood donation within 6 h, treated with riboflavin and UV light within 6 h from separation and frozen at temperature below -30 degrees C within 24 h, shows good retention of pro- and anticoagulation activity.

[Red blood cells transfusions in oncological patients treated with radio- and chemotherapy].

BACKGROUND/AIM: Anemia is one of the most frequent hematology disorders in patients with malignant diseases. It has a great influence on reduction of the quality of life, so it requires early diagnosis and an adequate treatment. The aim of this study was to present and analyze the treatment of anemia using red blood cell transfusions in patients with malignancies, to analyze adequate use of red blood cell transfusions according to hemoglobin concentration, and also the influence of the treatment of malignant disease on the level of anemia and use of red blood cells transfusion. METHODS: This retrospective analysis included the data on the use of red blood cells in Oncological Clinic of Clinical Center Nis in a period from the 1st January 2008 to the 31st December 2008. RESULTS: None of the patients received the whole blood. In this period, 735 patients received 1006 units of red blood cells (red blood cell concentrate, resuspended, washed, filtered). An average use of red blood cell transfusion was 1.37 unit per oncological patient who received transfusion. The use of red blood cell units was adequate (87.60% of patients received transfusion of red cells when Hgb < 80 g/L). During radio- and chemotherapy we noticed a decrease of hematological parameter values. The patients of the experimental group were dependant on red blood cells transfusion. Statistically, a significant decrease of hemoglobin level was observed in patients treated only with radiotherapy who are the greatest consumers of red blood cells. Two patients were registered who more likely to have febrile nonhemolytic transfusion reactions. Posttransfusion alloimmunization occurred in 0.68% of the patients. CONCLUSION: The use of red blood cells in oncological patients is in compliance with the up to date tendencies and recommendations published in clinical guidelines. For the purpose of efficient transfusion support in patients with malignant diseases, we have to follow the newest knowledge and attitudes about clinical use of blood products.

[Pathogen inactivation in fresh frozen plasma using riboflavin and ultraviolet light: effects on plasma proteins and coagulation factor VII].

BACKGROUND/AIM: Riboflavin (vitamin B2) activated by ultraviolet (UV) light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa) in all blood products. The aim of this study was to establish the influence of the process of photo inactivation in pathogens using riboflavin and UV rays on the concentration of coagulation factor VIII:C (FVIII:C) and proteins in plasma that were treated before freezing. METHODS: The examination included 20 units of plasma, separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. The units were pooled and separated in to two groups: one consisted of 10 control units and the other of 10 experimental units. Experimental units of the plasma were treated by riboflavin (35 mL) and UV rays (6.24 J/mL, 265-370 nm) on Mirasol aparature (Caridian BCT Biotechnologies, USA) in approximate duration of 6 minutes. Furthermore, 35 mL of saline solution was added to the control plasma. One sample for examining was taken from the control plasma (KG) and two residual were taken from experimental plasma after the addition of riboflavin either before (EG1) or post illumination (EG2). Results. Comparing the mean values of FVIII:C (%) we noticed statistically significantly higher level in the EG1 group than in the EG2 group (65.00 +/- 4.52 vs. 63.20 +/- 4.73; t = 4.323, p = 0.002), while between the KG and experimental groups (EG1 and EG2) there was no statistically significant difference in the concentration of FVIII:C. There was a statistically significant decrease of albumin concentration (g/L) in the EG2 group comparing to the KG (33.35 +/- 0.94 vs. 31.94 +/- 0.84; t = 3.534, p = 0.002), but there was no mentioned difference in albumin concentration between the KG and the EG1, so as between the EG1 and the EG2. CONCLUSION: Plasma inactivated by riboflavin and UV rays (Mirasol PRT system, Caridian BCT, U.S.A.) keeps all the characteristics of conventional plasma, so it could be used for the treatment of pathological conditions that demand transfusion of fresh frozen plasma, or in patients with thrombotic thrombocytopenic purpure when we use therapeutic exchange of plasma.

[Effects of use of riboflavin and ultraviolet light for pathogen inactivation on quality of platelet concentrates].

BACKGROUND/AIM: Pathogen inactivation in blood and blood products is one of the major means to achieve a zero risk blood supply and improve transfusion safety. Riboflavin (vitamin B2) activated by ultraviolet (UV) light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa) in all blood products. The aim of this study was to establish the influence of the process of pathogens photoinactivation using riboflavin and UV rays on the biochemical and functional characteristics of platelet concentrates prepared from "buffy coat". METHODS: The examination included 80 platelet concentrates prepared from "buffy coat", which was separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. Concentrates were pooled, filtered and separated unton two groups: one consisted of 10 control units and the other of 10 examined units (pooled platelet concentrates). Examined units of the platelets were treated by riboflavin (35 mL) and UV rays (6.24 J/mL, 265-370 nm) on Mirasol aparature (Caridian BCT Biotechnologies, USA) in approximate duration of 6 min. A total of 35 mL of saline solution was added to the control units. The samples for examining were taken from the control and examined units initially (K0, I0), after the addition of saline (K1) and riboflavin (I1), after illumination (I2), first day of storage (K3, I3) and the fifth day of storage (K4, I4). The following parameters were measured: platelet count and platelet yield, residual erythrocyte and leukocyte count, pH, pO2, pCO2 and bacterial contamination. RESULTS: All the measured parameters showed a statistically significant decrease comparing to K0 and I0; all the results of the first day of platelet storage showed statistically significant decrease comparing to K1 and I1, and all the results of the fifth day of platelet storage (K4, I4) showed a statistically significant decrease comparing to K1 and K3 and to I1 and I3. There was no the mentioned difference in the measured parameters between K4 and I4 (the end of storage--the fifth day). All the platelet units were sterile till the seventh day, when the investigation ended. CONCLUSION: Platelet concentrates inactivated by riboflavin and UV rays (Mirasol PRT sistem, Caridian BCT, USA) keep all the characteristics assessed by the Guide to the preparation, use and quality assurance of blood components (Council of Europe), during the whole storage period (five days). The obtained data were correlated with existing up to date literature and demonstrated that Mirasol treated platelets were safe and could be incorporated effectively in the routine blood bank and transfusion setting.

[Determination of fibrin glue with antibiotics on collagen production in colon anastomosis].

BACKGROUND/AIM: Fibrin glue is used as a matrix for local application of antibiotics. The aim of this study was to determine whether application of fibrin glue in combination with antibiotics can strengthen collagen production, prevent dehiscence of colon anastomoses due to infection, and reduce frequency of mortality and morbidity comparing to the control group and the group with fibrin glue application. METHODS: The adult male Wistar rats divided into three groups were used in the experiment. The group 1 was the control one (after partial colon resection, colonic anastomoses performed were not treated), while to the group 2 and the group 3 were applied fibrin glue and fibrin glue with antibiotics (clindamycin and ceftriaxon) on the site of anastomoses, respectively. Quality of colonic anastomoses were estimated by means of determination of collagen (L-hydroxyproline) amount in the collon wall with anastomoses and histological analysis of this colon segment using light and electronic microscope on the days 5, 7 and 13 postoperatively. RESULTS: The highest morbidity rate was registered in the group 1 (30%), then in the group 2 (13.3%) and the lowest one in the group 3 (3.33%; p < 0.05 vs group 1). Mortality rate was significantly higher in the group 1 than in the group 3 (20% and 0%, respectively; p < 0.05). In the postoperative course, the highest concentrations of collagen in the colon wall on the site of anastomoses, which was confirmed by both light and electronic microscopy, were found in the group 3. CONCLUSION: The application of fibrin glue with antibiotics on colon anastomoses reduces the number of dehiscence, provides good mechanical protection and shorten the time of anastomoses healing.

Prevention of pocket related complications with fibrin sealant in patients undergoing pacemaker implantation who are receiving anticoagulant treatment.

AIM: The aim of our study was to establish the efficiency of fibrin sealant in the prevention of pocket related complications in patients undergoing pacemaker implantation who are receiving anticoagulant treatment. METHODS: The study was performed on 40 and 41 patients prospectively randomized into treatment and control groups who underwent pacemaker implantation procedure between January 2002 and July 2004 at the Pacemaker Center - Clinical Centre Nis, Serbia. Both groups of patients were receiving anticoagulant treatment with either heparin or warfarin. Surgical procedures between the groups differed only in the application of fibrin sealant prior to wound closure in the treatment group. RESULTS: In the treatment group, there were no pocket related complications while in the control group six patients (14.63%) had minor haematomas that required no treatment. Four patients (9.76%) had significant haematomas (two patients were treated conservatively while the other two needed reintervention). The INR in the treatment group was 2.76+/-0.85 and in the control group 2.65+/-0.79 (P=ns). In the follow-up period (2-27 months) no late complications were registered in either group. CONCLUSION: Fibrin sealant is an effective haemostatic agent. The results obtained in our study show that the administration of fibrin sealant in patients receiving anticoagulant treatment eliminates postoperative haematomas after pacemaker implantation.