Esin Yulug

Time-dependent variations in ischemia-modified albumin levels in mesenteric ischemia.

OBJECTIVES The objective was to determine the value of ischemia-modified albumin (IMA) in the diagnosis of mesenteric embolism. The authors investigated whether or not plasma IMA levels rose in the acute period in a rat model of mesenteric ischemia and the related time-dependent changes. METHODS In this randomized, controlled, nonblinded trial, 36 mature female Wistar rats were divided into six groups: three control (Groups I, III, and V) and three ischemia (Groups II, IV, and VI). In the control groups, blood was sampled at 30 minutes (Group I), 2 hours (Group III), and 6 hours (Group V) following a simple laparotomy. In the ischemia groups, following laparotomy, the superior mesenteric artery (SMA) was clamped using a bulldog clamp, and blood samples were taken at 30 minutes (Group II), 2 hours (Group IV), and 6 hours (Group VI). RESULTS Plasma IMA levels in the ischemia groups were significantly higher compared to those of the control groups (p < 0.004). In addition, levels were higher in the 6-hour blood samples of the ischemia group than in the 2-hour and 30-minute samples (p < 0.001). Serum IMA was also higher in the 2-hour blood samples of the ischemia group than in the 30-minute samples (p < 0.001). CONCLUSIONS These preliminary findings suggest that serum IMA levels may represent a significant parameter in the early diagnosis of acute mesenteric ischemia and that further studies are necessary.

The effects of carbon dioxide pneumoperitoneum on ovarian blood flow, oxidative stress markers, and morphology during laparoscopy: a rabbit model.

OBJECTIVE To determine the effect of CO(2) pneumoperitoneum on the ovaries in an experimental pneumoperitoneum model. DESIGN Experimental controlled study. SETTING University hospital. PATIENT(S) Sixteen adult female conventional rabbits. INTERVENTION(S) Group I (8 rabbits) was not subjected to intra-abdominal pressure (IAP). In group II (8 rabbits), IAP insufflation was performed at 12 mm Hg. In total, 60 minutes of pneumoperitoneum and 10 minutes of reperfusion were maintained. Ovarian blood flow (OBF) was studied using laser Doppler flowmetry. The time points of OBF measurements were as follows: OBFbaseline, 10 minutes before insufflation; OBF30min, 30 minutes after pneumoperitoneum; OBF60min, 60 minutes after pneumoperitoneum; and OBFreperfusion, 10 minutes after pneumoperitoneum desufflation. Mean OBF changes during CO(2) pneumoperitoneum (OBFmean) were also assessed. MAIN OUTCOME MEASURE(S) Blood perfusion units, tissue malondialdehyde values, and histopathologic damage scores. RESULT(S) In group II, mean OBF values were significantly lower than in group I, especially for OBF30min, OBF60min, OBFreperfusion, and OBFmean. The mean tissue malondialdehyde value for group II was significantly higher than in the control group (104.48 +/- 20.07 nmol/g vs. 64.12 +/- 8.77 nmol/g, respectively). Compared with group I, in group II histologic specimens of the ovaries had higher scores for follicular cell degeneration, vascular congestion, hemorrhage, and inflammatory cell infiltration. CONCLUSION(S) Pneumoperitoneum, even at normal IAP levels, leads to significant oxidative stress-induced biochemical and histologic damage to the ovaries.

Ischemia-modified albumin in the diagnosis of pulmonary embolism: an experimental study

STUDY OBJECTIVE We designed this experimental study to determine the value of ischemia-modified albumin in the diagnosis of pulmonary embolism. METHODS Twenty-four mature female New Zealand rabbits were divided into 4 groups, each consisting of 6 animals. These were classified into group 1 ,the control group; group 2, the deep venous thrombosis group; group 3, the deep venous thrombosis with pulmonary embolism group; and group 4, the pulmonary embolism-alone group. Deep venous thrombosis was produced by ligation of the iliac vein. To establish pulmonary embolism, 2 clots were administered from the iliac vein. Blood samples were taken from all the groups at hours 0, 1, 3, and 6 for ischemia-modified albumin measurement. RESULTS Pulmonary embolism was established in all the rabbits in groups 3 and 4, and this was confirmed by tomographic and histologic findings. Measurement of mean ischemia-modified albumin levels for all rabbits at hours 0, 1, 3, and 6 revealed that mean ischemia-modified albumin levels in groups 3 and 4 were statistically significantly higher than those in groups 1 and 2. There was no difference between the mean ischemia-modified albumin levels in groups 1 and 2 nor between groups 3 and 4. The alteration in ischemia-modified albumin levels over time was statistically significant. CONCLUSIONS The results of our experimental study demonstrate that ischemia-modified albumin levels may be useful in the diagnosis of pulmonary embolism.

Effects of Resveratrol on Methotrexate-Induced Testicular Damage in Rats

This study investigated the probable protective effects of resveratrol (RES), an antioxidant, against methotrexate- (MTX-) induced testis damage. Twenty-four male Sprague Dawley rats were randomly divided into four groups: control, RES, MTX, and MTX + RES groups. Rats were sacrificed at the end of the experiment. Plasma and tissue malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activity in tissue, testicular histopathological damage scores, and testicular and epididymal epithelial apoptotic index (AI) were evaluated. The MTX group had significantly higher plasma and tissue MDA levels and significantly lower SOD and CAT activity than those of the control group. In the MTX + RES group, plasma and tissue MDA levels decreased significantly and SOD activity rose significantly compared to the MTX group. The MTX group had significantly lower Johnsens testicular biopsy score (JTBS) values than those of the control group. JTBS was significantly higher in the MTX + RES group than in the MTX group. AI increased in the testis and epididymis in the MTX group and significantly decreased in the MTX + RES group. Our results indicate that RES has protective effects against MTX-induced testis damage at the biochemical, histopathological, and apoptotic levels.

How Does Colistin-Induced Nephropathy Develop and Can It Be Treated?

ABSTRACT Colistin is an old antibiotic used in the treatment of Gram-negative infections. It was once suspended because of its nephrotoxic effect but has since been reintroduced due to multidrug-resistant bacterial infections. The pathogenesis of colistin-associated nephropathy has not been clarified, and there is currently no effective therapeutic or prophylactic agent available. The aim of this study was to investigate the roles of caspase-associated apoptosis and caspase 1, calpain 1, inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) expression in the pathogenesis of colistin-associated nephrotoxicity and the effect of grape seed proanthocyanidin extract (GSPE) in preventing it. Twenty-four rats were divided into three groups: control, colistin, and colistin plus GSPE (colistin+GSPE). Colistin-associated nephropathy was induced by the administration of 300,000 IU/kg of body weight/day colistin intraperitoneally for 7 days. The experiment was discontinued on the seventh day. Blood was collected for measurements of blood urea nitrogen (BUN) and creatinine levels. Histopathological examination of kidney tissue and caspase 1 and 3, iNOS, eNOS, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL), and calpain 1 staining was also performed. Significant increases in BUN levels; creatinine levels; renal histopathological scores; and TUNEL, caspase 1 and 3, calpain 1, iNOS, and eNOS staining were observed for the colistin group compared to the control group. Significant decreases in BUN levels; creatinine levels; renal histopathological scores; and TUNEL, caspase 1 and 3, calpain 1, iNOS, and eNOS staining were observed in the colistin+GSPE group compared to the colistin group. Our study shows, for the first time in the literature, that caspase-mediated apoptosis, iNOS, caspase 1, and calpain 1 are involved in the pathogenesis of colistin-associated nephropathy. GSPE had a renoprotective effect, as shown by the lowered levels of these mediators.

The short term effects of resveratrol on ischemia–reperfusion injury in rat testis

PURPOSE The purpose of this study was to identify changes taking place in the rat testis at the 24th hour of reperfusion following testicular torsion and to evaluate the effects of resveratrol (RSV), a powerful antioxidant, in preventing these changes using novel biochemical parameters and histopathology. METHODS Eighteen adult male rats were divided into three groups: Sham-operated (S), torsion/detorsion (T/D), and T/D+RSV groups. In the T/D group, testicular ischemia was achieved by rotating the left testis 720° clockwise for 4h. In the T/D+RSV group, 20mg/kg RSV was administered intraperitoneally 30 min before detorsion. All rats were sacrificed 24h after detorsion. Serum and tissue malondialdehyde (MDA) concentrations, ischemia modified albumin (IMA), total oxidative status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), and histopathological damage score were analyzed. RESULTS Serum MDA, IMA, TOS, and OSI levels rose significantly in the T/D group. Serum MDA and IMA values were lower in the T/D+RES groups, but not significantly. OSI and TOS values were lower in the T/D+RES group, and the difference was significant. TAS values decreased significantly in the T/D group and rose in the T/D+RSV group, but not significantly. Ipsilateral tissue MDA values were significantly elevated in the T/D group and decreased in the T/D+RSV group, but not significantly. Apoptosis and histopathological damage increased significantly in the T/D group and decreased significantly in the T/D+RSV group. In the contralateral testis, apoptosis increased significantly in the T/D group. It decreased significantly in the T/D+RSV group. CONCLUSIONS Our findings show that RSV had a protective effect against oxidative damage induced with a testicular T/D model, especially at the antiapoptotic and histopathological level. OSI may be a good guide to the clinical status of testicular T/D.

Ovarian-Protective Effects of Clotrimazole on Ovarian Ischemia/Reperfusion Injury in a Rat Ovarian-Torsion Model

Background/Aims: To evaluate the ovarian-protective effects of clotrimazole on ovarian ischemia/reperfusion injury in a rat ovarian-torsion model. Methods: 32 Sprague-Dawley rats were randomly divided into four groups: (1) ischemia group (n = 8) in which only left adnexal torsion was performed for 2 h, but no treatment was given; (2) vehicle group (n = 8) in which left adnexal torsion was performed for 2 h and at the end of 2 h ischemia polyethylene glycol (3% PEG, 1 ml, i.p.) was administered and a 24-hour reperfusion was continued; (3) clotrimazole group (n = 8) in which left adnexal torsion was performed for 2 h and at the end of 2 h ischemia clotrimazole (30 mg/kg, i.p.) was administered and a 24-hour reperfusion was continued, and (4) control group (sham-operated, n = 6) in which no adnexal torsion and no treatment were given. The criteria for ovarian ischemia were follicular cell degeneration, vascular congestion, hemorrhage and infiltration by inflammatory cells. Each specimen was scored for each criterion (0, none; 1, mild; 2, moderate; 3, severe). Results: Clotrimazole significantly decreased plasma levels of serum malondialdehyde, ischemia-modified albumin, and total oxidant status. Conclusion: This study showed the ovarian-protective effects of clotrimazole on ovarian ischemia/reperfusion injury.

A comparison of the effects of N-acetylcysteine and ethyl pyruvate on experimental testicular ischemia-reperfusion injury

OBJECTIVE To compare the effects of N-acetylcysteine (NAC) and ethyl pyruvate (EP) on experimental testicular ischemia-reperfusion (I/R) injury. DESIGN Randomized, controlled, experimental study. SETTING University hospital. ANIMAL(S) Twenty-four mature male Wistar rats. INTERVENTION(S) Rats were divided into four groups: control group, torsion-detorsion (T/D) group, EP group, and NAC group. In the pretreatment of the NAC and EP groups, 20 mg/kg NAC and 50 mg/kg EP were given intraperitoneally (IP) 30 minutes before detorsion. MAIN OUTCOME MEASURE(S) Serum ischemia-modified albumin (IMA), tissue and serum malondialdehyde, and myeloperoxidase activity levels and histopathological damage scores were then compared. RESULT(S) Ethyl pyruvate and N-acetylcysteine exhibited a protective effect against I/R injury. Of the biochemical parameters evaluated as a result of testicular I/R, only IMA levels were significantly elevated. There was a strong and significant correlation between serum IMA levels and histopathological injury scores, and the increase in serum IMA level exhibited a strong parallel with the increase in histopathological injury. In the EP group, although the histopathological injury score was similar to that of the control group, serum IMA levels were significantly elevated. CONCLUSION(S) Both NAC and EP, the effects of which on I/R injury are evaluated in the present study, reduce such injury in testicular torsion-detorsion. Comparing their effects on IMA levels, NAC may be regarded as a relatively more effective treatment than EP.

Effects of Human Amniotic Fluid on Fracture Healing in Rat Tibia

BACKGROUND Human amniotic fluid (HAF), including hyaluronic acid (HA) and several growth factors, has been used experimentally in tendon, nerve, and cartilage regeneration and in bone defects because of its positive stimulating effects on regeneration potential. This study was performed to investigate whether HAF was effective on fracture healing. MATERIALS AND METHODS We created 36 tibial fractures in 20-week-old Wistar rats that were divided into three groups. In group 1, fracture lines were instilled with HAF collected at 18th week of the gestation and, in group 2, fracture lines were instilled with HAF obtained at the end of the gestation. HAF which was collected from different period of gestation was used, because the concentration of HA and growth factors in HAF varies considerably during gestation. Group 3 was used as an operative control group. RESULTS Fracture-healing score was highest in group 1 radiologically at the 3rd and 5th week (P = 0.037, P = 0.018, respectively). In the scintigraphic evaluation, metabolic activity at the fracture site was observed in group 1 more than the others at the 3rd week (P = 0.010). Histologically, the highest scores were obtained from group 1 as compared to other groups at the 3rd and 5th week. In the 5th week, predominant cartilage with some woven bone was observed in group 3, while predominantly woven bone with some cartilage was observed in group 1 (P = 0.036). CONCLUSIONS Our data suggest that HAF had a positive effect on fracture healing in rat tibia, and also this positive effect was observed more in group 1.

Acute increase in plasma D-dimer level in ovarian torsion: an experimental study

BACKGROUND Torsion of the ovary is a rare but serious cause of gynecologic surgical emergency. Specific laboratory markers that support the preoperative diagnosis of ovarian torsion are not currently available in the clinical routine. The aim of this study was to investigate the diagnostic value of plasma D-dimer level as an early indicator of ovarian torsion in an experimental rat ovarian torsion model. METHODS Sixteen female adult Sprague-Dawley rats were used for this controlled experimental study. Eight rats in the sham operation group (Group I) underwent a surgical procedure similar to Group II but the ovary was not occluded. In Group II (eight rats), a torsion model was created by using atraumatic vascular clips just above and below the right ovary for a 2-h period of ischemia. Right ovaries were surgically removed at the end of the procedure in each group. Blood was sampled before and after operation to assess plasma D-dimer levels. The main outcome measure was ovarian histopathologic findings scores and plasma D-dimer levels. RESULTS There was no significant difference in pre-operative plasma D-dimer levels (0.5963 ± 0.2047 mg/l in Group I, 0.6344 ± 0.1348 mg/l in Group II, P = 0.815, Mann-Whitney U-test). However, mean plasma D-dimer value for Group II was significantly higher than that in the control group (1.2267 ± 0.3099 versus 0.6213 ± 0.2346 mg/l, respectively, Mann-Whitney U-test, P < 0.001), following 2 h of ovarian torsion. Ovarian tissue damage scores were also statistically significantly different among groups. CONCLUSIONS If the observations made in a rat model are extended to humans, plasma D-dimer measurement may be a valuable parameter in the early diagnosis of ovarian torsion.