Erythropoietin protects the intestine against ischemia/ reperfusion injury in rats

Previous studies have shown that erythropoietin (EPO) has protective effects against ischemia/reperfusion (I/R) injury in several tissues. The aim of this study was to determine whether EPO could prevent intestinal tissue injury induced by I/R. Wistar rats were subjected to intestinal ischemia (30 min) and reperfusion (60 min). A single dose of EPO (5000 U/kg) was administered intraperitoneally at two different time points: either at five minutes before the onset of ischemia or at the onset of reperfusion. At the end of the reperfusion period, jejunum was removed for examinations. Myeloperoxidase (MPO), malondialdehyde (MDA), and antioxidant defense system were assessed by biochemical analyses. Histological evaluation was performed according to the Chiu scoring method. Endothelial nitric oxide synthase (eNOS) was demonstrated by immunohistochemistry. Apoptotic cells were determined by TUNEL staining. Compared with the sham, I/R caused intestinal tissue injury (Chiu score, 3+/-0.36 vs 0.4+/-0.24, P<0.01) and was accompanied by increases in MDA levels (0.747+/-0.076 vs 0.492+/-0.033, P<0.05), MPO activity (10.51+/-1.87 vs 4.3+/-0.45, P<0.05), intensity of eNOS immunolabelling (3+/-0.4 vs 1.3+/-0.33, P<0.05), the number of TUNEL-positive cells (20.4+/-2.6 vs 4.6+/-1.2, P<0.001), and a decrease in catalase activity (16.83+/-2.6 vs 43.15+/-4.7, P<0.01). Compared with the vehicle-treated I/R, EPO improved tissue injury; decreased the intensity of eNOS immunolabelling (1.6+/-0.24 vs 3+/-0.4, P<0.05), the number of TUNEL-positive cells (9.2+/-2.7 vs 20.4+/-2.6, P<0.01), and the high histological scores (1+/-0.51 vs 3+/-0.36, P<0.01), and increased catalase activity (42.85+/-6 vs 16.83+/-2.6, P<0.01) when given before ischemia, while it was found to have decreased the levels of MDA (0.483+/-0.025 vs 0.747+/-0.076, P<0.05) and MPO activity (3.86+/-0.76 vs 10.51+/-1.87, P<0.05), intensity of eNOS immunolabelling (1.4+/-0.24 vs 3+/-0.4, P<0.01), the number of TUNEL-positive cells (9.1+/-3 vs 20.4+/-2.6, P<0.01), and the number of high histological scores (1.16+/-0.4 vs 3+/-0.36, P<0.05) when given at the onset of reperfusion. These results demonstrate that EPO protects against intestinal I/R injury in rats by reducing oxidative stress and apoptosis. We attributed this beneficial effect to the antioxidative properties of EPO.     

Screening of the antioxidative properties and total phenolic contents of three endemic Tanacetum subspecies from Turkish flora

Methanolic extracts of three different Tanacetum subspecies [Tanacetum densum (Lab.) Schultz Bip. subsp. sivasicum Hub-Mor and Grierson, Tanacetum densum (Lab.) Schultz Bip. subsp. eginense Heywood and Tanacetum densum (Lab.) Schultz Bip. subsp. amani Heywood] which are endemic to Turkish flora were screened for their possible antioxidant activities by two complementary test systems namely DPPH free radical scavenging and beta-carotene/linoleic acid. In DPPH system, the most active plant was T. densum subsp. amani with an IC(50) value of 69.30+/-0.37 microg/ml. On the other hand, T. densum subsp. sivasicum exerted greater antioxidant activity than those of other subspecies in beta-carotene/linoleic acid system (79.10%+/-1.83). Antioxidant activities of BHT, curcumine and ascorbic acid were also determined as positive controls in parallel experiments. Total phenolic constituents of the extracts of Tanacetum subspecies were performed employing the literature methods involving Folin-Ciocalteu reagent and gallic acid as standard. The amount of total phenolics was highest in subsp. sivasicum (162.33+/-3.57 microg/mg), followed by subsp. amani (158.44+/-2.17 microg/mg). Especially, a positive correlation was observed between total phenolic content and antioxidant activity of the extracts.     

Emergence of distinct genotypes of Cryptosporidium parvum in structured host populations

Cryptosporidium parvum is an apicomplexan parasite that infects humans and ruminants. C. parvum isolated from cattle in northeastern Turkey and in Israel was genotyped using multiple polymorphic genetic markers, and the two populations were compared to assess the effect of cattle husbandry on the parasite's population structure. Dairy herds in Israel are permanently confined with essentially no opportunity for direct herd-to-herd transmission, whereas in Turkey there are more opportunities for transmission as animals range over wider areas and are frequently traded. A total of 76 C. parvum isolates from 16 locations in Israel and seven farms in the Kars region in northeastern Turkey were genotyped using 16 mini- and microsatellite markers. Significantly, in both countries distinct multilocus genotypes confined to individual farms were detected. The number of genotypes per farm was higher and mixed isolates were more frequent in Turkey than in Israel. As expected from the presence of distinct multilocus genotypes in individual herds, linkage disequilibrium among loci was detected in Israel. Together, these observations show that genetically distinct populations of C. parvum can emerge within a group of hosts in a relatively short time. This may explain the frequent detection of host-specific genotypes with unknown taxonomic status in surface water and the existence of geographically restricted C. hominis genotypes in humans.     

Helicobacter pylori Infection and Recurrent Abdominal Pain in Turkish Children

Background. Helicobacter pylori infection is primarily acquired in childhood. However, the association between H. pylori infection and recurrent abdominal pain (RAP) remains unclear. Materials and methods. One hundred and forty-one children with and 21 without RAP underwent upper gastrointestinal endoscopy. At least five antral gastric biopsies were obtained from each patient and the presence of H. pylori infection was accepted when at least two out of four tests (histology, direct antral smear, culture, and rapid urease test) were positive. Patients with H. pylori infection underwent triple therapy with omeprazole, clarithromycin, and metronidazole. Results. Eighty-five out of 141 (60.3%) patients with RAP were H. pylori positive whereas 5 out of 21 (20.8%) patients without RAP were (p = .0037). Symptoms were disappeared in 87% of children whose H. pylori infection was eradicated compared with 41% of those in whom the infection was not eradicated (p = .0035). Conclusions. It was concluded that children with RAP and H. pylori infection appear to benefit from eradication therapy in Turkey.     

Diagnostic utility of anti-cyclic citrullinated peptide and anti-modified citrullinated vimentin antibodies in rheumatoid arthritis

Several autoantibodies found in RA are directed to epitopes in citrullinated proteins. One of them is anti modified citrullinated vimentin (Anti-MCV). We tested the value a newly developed ELISA for the detection of antibodies against a genetically modified citrullinated vimentin (anti-MCV) in comparison with an anti-CCP based ELISA system for the diagnosis of RA. Thirty-five patients with RA (mean age; 42.6 +/- 10.87 years, mean disease duration; 9.37 +/- 3.98 years) were enrolled in this study. Twenty -five ankylosing spondylitis (mean age; 35.88 +/- 6.64 years, mean disease duration; 10.25 +/- 4.61 years), and 19 healthy subjects (mean age; 40.26 +/- 5.11 years) served as controls. Anti-CCP antibodies and Anti-MCV antibodies were measured using ELISA. In all RA patients, mean anti- CCP level was 69.07 +/- 90.43 U/ml and anti-MCV level was 665.77 +/- 1040.19 U/ml. In patients with AS, the mean anti-CCP level was 10.7 +/- 5.22 U/ml and anti-MCV level was 40.54 +/- 20.15 U/ml. In healthy controls, the mean anti-CCP level was 11.11 +/- 7.65 U/ml, anti-MCV level was 23.12 +/- 12.04 U/ml. In patients with active RA, the mean serum anti-CCP level was 100.54 +/- 98.07 U/ml and anti-MCV level was 998.74 +/- 1154.93 U/ml. In patients with inactive RA, the mean serum anti-CCP level was 8.77 +/- 1.55 U/ml and anti-MCV level was 27.59 +/- 23.10 U/ml. According to these results; In patients with RA, the mean serum anti-MCV and anti-CCP levels were significantly high compared to patients with AS and healthy controls (p=0.002, p=0.001, p=0.002, p=0.001 respectively). The mean serum anti-MCV and anti- CCP levels were significantly higher in active patients with RA than in inactive patients with RA patients (p=0.001 and p=0.001 respectively). In inactive patients with RA, the mean serum anti-MCV and anti-CCP levels were similar in patients with AS and patients (p=0.484, p=0.308, p=0.09 and p=0.222 respectively). The mean serum anti-MCV levels were correlated with DAS 28 (r=0.531, p=0.001), VAS score (r=0.332, p=0.01), ESR (r=0.458, p=0.001), serum CRP levels (r=0.568, p=0.01), serum RF levels (r=0.529, p=0.001), swollen joints number (r=0.525, p=0.001) and tender joints number (r=0.638, p=0.001). As a result; measurement of serum anti-MCV levels is useful for diagnosis of RA and combined use of anti-MCV and RF may be more useful prognostic factor than either method alone, RF and anti-CCP.     

Tumor control in a model of bone marrow transplantation and acute liver-infiltrating B-cell lymphoma: an unpredicted novel function of cytomegalovirus

Tumor relapse and cytomegalovirus (CMV) infection are major concerns in the therapy of hematopoietic malignancies by bone marrow transplantation (BMT). Little attention so far has been given to a possible pathogenetic interplay between CMV and lymphomas. CMV inhibits stem cell engraftment and hematopoietic reconstitution. Thus, by causing maintenance of bone marrow aplasia and immunodeficiency, CMV could promote tumor relapse. Alternatively, CMV could aid tumor remission. One might think of cytopathogenic infection of tumor cells, induction of apoptosis or inhibitory cytokines, interference with tumor cell extravasation or tumor vascularization, or bystander stimulation of an antitumoral immune response. To approach these questions, the established model of experimental BMT and murine CMV infection was extended by the introduction of liver-infiltrating, highly tumorigenic variant clone E12E of BALB/c-derived B-cell lymphoma A20. We document a remarkable retardation of lymphoma progression. First-guess explanations were ruled out: (i) lymphoma cells were not infected; (ii) lymphoma cells located next to infected hepatocytes did not express executioner caspase 3 but were viable and proliferated; (iii) an inhibitory effect of virus on the formation of tumor nodules in the liver became apparent by day 7 after BMT, long before the reconstitution of immune cells; and (iv) recombinant tumor necrosis factor alpha (TNF-alpha) did not substitute for virus; accordingly anti-TNF-alpha did not prevent the inhibition. Notably, while the antitumoral effect required replicative virus, prevention of cytopathogenic infection of the liver by antiviral CD8 T cells did not abolish lymphoma control. These findings are paradigmatic for a novel virus-associated antitumoral mechanism distinct from oncolysis.     

Effect of vitamin E on follicular cell proliferation and expression of apoptosis-associated factors in rats with 6-N-propyl-2-thiouracil-induced goitrogenesis

We have investigated immunohistochemically the effect of dl-alpha-tocopherol (vitamin E) on thyroid gland with 6-n-propyl-2-thiouracil (PTU)-induced hypothyroidism in rats. The animals were divided into four groups. Rats in group I were designated as control, rats in group II were treated with injections of PTU (10 mg/kg) for 15 days, rats in group III were treated with injections of PTU+vitamin E (10 mg/100 g) for 15 days. Rats in group IV were treated with injections PTU for 15 days and kept for 15 next days after cessation of PTU treatment. At the end of experiment, the animals were killed by decapitation, blood samples were obtained, thyroid tissues were collected and processed for quantitative evaluation of immunohistochemical PCNA (marker of cell proliferation), Bax (pro-apoptotic marker) and Bcl-2 (anti-apoptotic marker) staining. There was an increase in the number of PCNA-immunopositive cells in follicular epithelial cells of group II rats compared with other groups (p<0.05). After vitamin E treatment, the number of PCNA-immunopositive cells decreased (p<0.05) while the number of Bax-immunopositive cells increased (p<0.05). The number of Bcl-2-positive follicular epithelial cells of group IV rats was higher than in those of other groups (p<0.05). The results of this study indicate that hypothyroidism induces cell proliferation in the thyroid gland and vitamin E may promote involution of the gland.     

Influences of different stress models on the antioxidant status and lipid peroxidation in rat erythrocytes

The aim of this study was to investigate the influences of different stress models on the antioxidant status and lipid peroxidation (LPO) in erythrocytes of rats. Swiss-Albino female rats (3 months old) were used in this study. Rats were randomly divided into the following four groups; control group (C), cold stress group (CS), immobilization stress group (IS) and cold+immobilization stress group (CS+IS). Control group was kept in an animal laboratory (22 ±2°C). Rats in CS group were placed in cold room (5°C) for 15 min/day for 15 days. Rats in IS group were immobilized for 180 min/day for 15 days. Rats in CS+IS group were exposed to both cold and immobilization stresses for 15 days. At the end of experimental periods, the activities of glucose-6-phosphate dehydrogenase (G-6-PD), Cu,Zn-superoxide dismutase (Cu,Zn-SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and concentration of reduced glutathione (GSH) were measured. LPO was determined by measuring the contents of thiobarbituric acid-reactive substances (TBARS). Cu,Zn-SOD activity and TBARS concentration were increased after cold and immobilization stresses, but CAT and GSH-Px activities and GSH levels were decreased. Immobilization stress decreased the activity of G-6-PD. The activities of G-6-PD, CAT and GSH-Px, and the level of GSH were lower in CS+IS group than in the control group. Cu,Zn-SOD activity and TBARS levels were increased in CS+IS group when compared with the control group. From these findings, three stress models are thought to cause oxidative stress.     

Effects of high dose retinoic acid on TGF-β2 expression during pancreatic organogenesis

Summary The aim of this study was to investigate the effects of excess all-trans retinoic acid, a vitamin A metabolite, on pancreatic organogenesis and TGF-β2 expression during prenatal development in rats.First group of animals used as control while a single dose of 60 mg/kg all-trans retinoic acid was ingested by the mothers, at day 8 of gestation (before the neurulation period) in group II and at day 12 of gestation (after the neurulation period) in group III, and all embryos were sacrificed at day 18 of gestation. TGF-β2 expression was detected in the capsule, acini and Langerhans islets in the control group. In the pancreas of group II, dilatation and congestion of interlobular vessels were observed. Langerhans islet structures were completely absent. Moreover acinar TGF-β2 immune reactivity was not determined. In group III, acinar expression of TGF-β2 in acid was similar to that in the controls but their Langerhans islets TGF-β2 immune reactivity was significantly less than the controls.In view of the present findings we suggest that TGF-β2 plays important role in pancreatic morphogenesis and administration of excess all-trans retinoic acid before neurulation inhibit TGF-β2 expression disrupted pancreatic morphogenesis particularly Langerhans islets. However, its administration after neurulation had less adverse affect on pancreatic organogenesis and TGF-β2 immune reactivity.     

Protective effects of intraperitoneal vitamin C, aprotinin and melatonin administration on retinal edema during experimental uveitis in the guinea pig

A considerable amount of clinical and experimental evidence exists suggesting the involvement of reactive oxygen substances (ROS) in the aetiology of uveitis. The activated phagocytic system of polymorphonuclear leucocytes in uveitis is involved in the generation of ROS. In addition to their direct free radical scavenging action, aprotinin, melatonin and vitamin C are known to protect against oedema formation and can preserve plasma membrane fluidity and free radical production. Histological changes in the retina that occur during uveitis are not well explained. The purpose of this study was to determine whether vitamin C, aprotinin and melatonin can protect the retina from damage accompanying experimental uveitis (EU). Thirty adult male guinea pigs were divided into five groups of six animals each. The first group was used as control. The right eyes of groups 2, 3, 4 and 5 received an intravitreal injection of bovine serum albumin for induction of experimental uveitis. At the same time and also on the consecutive third day, groups 3, 4 and 5 received intraperitoneal injections of vitamin C (ascorbic acid, 100 mg kg(-1) body wt), aprotinin (20,000 kIU kg(-1) body wt) and melatonin (10 mg kg(-1) body wt), respectively. The animals were killed on the sixth day. The average thickness of the retina and inner plexiform layer for each eye was measured in sagittal section near the optic nerve and expressed in microns. The thickness of the retina and inner plexiform layer in the control group was significantly (p < 0.01) lower than in the group EU as compared with the group EU plus vitamin C, group EU plus aprotinin, group EU plus melatonin (p < 0.05). The thicknesses of the retina and inner plexiform layer in group EU plus vitamin C, group EU plus aprotinin and group EU plus melatonin were significantly (p < 0.01) lower than that in the group EU. The difference in thickness of the retina and inner plexiform layer among the groups 3, 4 and 5 was not significant (p > 0.05). In conclusion, this study demonstrated that oedematous effects of EU on the retina were reduced by the administration of intraperitoneal vitamin C, aprotinin and melatonin, i.e. these antioxidants had significant protective effects on the retina of guinea pigs against oedematous damage in EU. However, the reductive effect of vitamin C on EU was greater than that of aprotinin and melatonin. The intraperitoneal vitamin C, aprotinin and melatonin supplementations may strengthen the antioxidant defence system because of decreased ROS, and these agents may play a role in treating uveitis.