Effect of cerium oxide on erythrocyte deformability in rat lower extremity ischemia reperfusion injury.

BACKGROUND: Cerium oxide is the oxide form of cerium, which has protective effects in ischemia reperfusion (I/R) injury. The purpose of our study was to look into the effects of this rare-earth metal on erythrocyte deformability in rat lower extremity I/R injury model. MATERIALS AND METHODS: We used 24 Wistar albino rats as subjects in our study. They were divided into 4 groups; randomized control group (group C; n = 6), cerium oxide group 0.5 mg.kg-1, intraperitoneal (group CO; n = 6), I/R group (group I/R; n = 6) and I/R group with cerium oxide 0.5 mg.kg-1 intraperitoneally (group I/R-CO; n = 6). Erythrocyte packs were prepared from heparinized blood samples and deformability measurements were performed. RESULTS: We obtained similar results from the control and I/R-CO groups (p = 0.158). The results in I/R group were evidently higher than those of the control, CO, and IR-CO groups (p < 0.0001, p < 0.0001, p = 0.001, respectively). CONCLUSION: We detected unfavorable effects of I/R on erythrocyte deformability, which may impair blood flow and hence tissue perfusion in infrarenal rat aorta. We also found that cerium oxide had beneficial effects by reversing undesirable effects of I/R. Further studies with larger volume are required to support our promising results (Fig. 1, Ref. 24).

The histopathological effects of levosimendan on liver injury induced by myocardial ischemia and reperfusion.

BACKGROUND: The aim of this study was to evaluate the histological and immunohistochemical effects of levosimendan on liver injury induced by myocardial ischemia and reperfusion (I/R) in a rat model. METHODS: Twenty-four male Wistar Albino rats were randomly divided into the four groups: Group C (Control, n = 6), Group I/R (n = 6), Group BI (I/R group treated with levosimendan before ischemia, n = 6), and Group AI (I/R group treated with levosimendan after ischemia, n = 6). Myocardial I/R was induced by ligation of the left anterior descending coronary artery for 30 min followed by two hours of reperfusion in I/R and I/R+Levosimendan groups. At the end of the study, liver tissue samples were obtained for histopathological and immunohistochemical examination. RESULTS: Masson Trichrome staining revealed significant hepatocyte degeneration and necrosis most marked in portal acinus Zone 3, especially around the central veins in Group I/R. Histopathological changes in Group AI were more similar to the changes in Group I/R. Milder hepatocellular degeneration was found in Group BI, when compared to groups I/R and AI. Immunohistochemical score was found to be significantly higher in Group I/R compared to groups C, BI and AI (p < 0.0001). The scores in groups BI and AI were found to be similar (p = 0.068). CONCLUSION: Levosimendan ameliorates liver injury induced by myocardial IR, especially when administered before induction of ischemia (Fig. 9, Ref. 37).

The protective effects of dexmedetomidine on liver injury-induced myocardial ischemia reperfusion.

PURPOSE: The aim of this study was to evaluate the effect of dexmedetomidine (100 µg/kg-ip) on liver injury-induced myocardial ischemia and reperfusion (IR) in rats. MATERIALS AND METHODS: Twenty-four Wistar Albino rats were separated into four groups. There were four experimental groups (Group C (Control; n = 6), Group IR (ischemia-reperfusion, n = 6), Group D (Dexmedetomidine; n = 6) that underwent left thoracotomy and received ip dexmedetomidine without IR administered via 100 µg/kg ip route 30 minutes before ligating the left coronary artery, and Group IR-D (IR-Dexmedetomidine; n = 6). A small plastic snare was threaded through the ligature and placed in contact with the heart. To produce IR, a branch of the left coronary artery was occluded for 30 min followed by two hours of reperfusion. However, after the above procedure, the coronary artery was not occluded or reperfused in the control rats. At the end of the study, liver tissue was obtained for histochemical and immunohistochemical determination.Some part of tissue samples were stained with Masson-trichrome for the evaluation of ultrastructural changes and inducible nitric oxide synthase (iNOS) expression was evaluated in other part of samples for immunohistochemical examination. RESULTS: Histopathological changes were detected in Group IR when compared with Group C. iNOS expression was found to be increased and stronger particularly in the vascular wall, perisinusoidal space and hepatocytes around vena centralis in this group compared to the control group. Perivascular oedema was detected to be decreased in Group IR-D compared to Group IR. It was also observed that the impairment in the radial arrangement of hepatocytes significantly recovered in Group IR-D. The immunoreactivity was found to be significantly decreased in the assessment of iNOS expression in the same group when compared with Group IR. CONCLUSION: Administration of dexmedetomidine ameliorates liver injury induced by myocardial ischemia and reperfusion (Fig. 8, Ref. 33).

Effect of iloprost on erythrocyte deformability in rat's lower extremity undergoing an ischemia reperfusion injury.

AIM: Ischemia reperfusion injury (I/R) in lower extremity is a frequent and important clinical phenomenon. The protective effect of iloprost on local and distant organ injury due to I/R has been well documented but its effect on erythrocyte deformability needs further investigation. Our aim was to investigate the effect of iloprost on erythrocyte deformability in the infrarenal aorta of rats undergoing I/R. MATERIALS AND METHODS: Our study was conducted with 18 Wistar albino rats. Rats were divided into the 3 groups; the randomized control group (group C; n=6), I/R group without iloprost (group I/R; n=6) and I/R group with iloprost - 10 mcg.kg-1, 30 min infusion (group I/R-I; n=6). Packs of erythrocytes were prepared from heparinized blood samples and deformability measurements were done. RESULTS: The comparisons of the control and I/R-I groups revealed similar results (p=0.951). The values of the IR group were significantly higher than those of the control and IR-I groups (p=0.006, p=0.011, respectively). CONCLUSION: In our study, we detected the unfavourable effects of I/R on erythrocyte deformability, which may lead to disturbance in blood flow and hence tissue perfusion in the infrarenal rat aorta. We also found that Iloprost had beneficial effects by reversing the undesirable effects of I/R (Fig. 1, Ref. 15).

Management of chylothorax with octreotide after congenital heart surgery.

OBJECTIVE: Chylothorax is a rare complication of congenital cardiac surgery that can seriously impair the postoperative course unless treated properly. We present our treatment protocol and results with octreotide, a somatostatin analogue, in cases of chylothorax following congenital heart surgery. MATERIAL AND METHODS: Between March 2006 and December 2009, 12 patients were treated for chylothorax following congenital cardiac surgery. Patients consisted of five females and seven males, with a mean age of 16.6 months (7 days - 36 months). Octreotide was administrated as a continuous intravenous infusion with a dosage of 4-10 µg/kg/h. RESULTS: Chylothorax was successfully resolved in an average of 10.3 days (7-14 days) with octreotide infusion and a strict oral diet containing medium-chain triglycerides. At a mean follow-up of 9.4 months (1-35), all patients are doing well, without any recurrence of chylothorax. CONCLUSION: Octreotide, a long-acting somatostatin analog, is an effective and safe agent for the treatment of postoperative chylothorax and warrants further investigation in a larger series with a greater number of patients.

Use of extracorporeal circulation and selective renal perfusion during the surgical correction of abdominal aortic coarctation.

Coarctation of the abdominal aorta is a rare pathology. Stenosis of visceral and renal arteries may present together with coarctation, which requires specific operation techniques. We present the case of a patient with coarctation of the abdominal aorta associated with stenosis of the celiac trunk, the superior mesenteric and the right renal arteries. Distal aortic perfusion by extracorporeal circulation and selective right renal perfusion techniques were used during the operation to protect the spinal cord and kidney against hypoperfusion and ischemia.

Prosthetic aortic valve endocarditis due to Stenotrophomonas maltophilia complicated by subannular abscess.

Annular abscesses are serious complications of infectious native and prosthetic valve endocarditis. In this patient, we isolated Stenotrophomonas maltophilia, a rare cause of subaortic abscess with high mortality/morbidity rates although virulent gram-positive cocci, S. Aureus in particular, have been the most commonly isolated agents. We treated this case of endocarditis and the subannular abscess observed 1 year after the initial operation by aortic root replacement with resternotomy in addition to appropriate antibiotics.

Improved neo-endothelialization of small diameter ePTFE grafts with titanium coating.

BACKGROUND: Patency of small synthetic bypass grafts is inferior compared to autologous grafts for revascularization procedures. Titanium coating of foreign surfaces has shown to decrease thrombogenicity, enhance biocompatibility and promote adhesion of endothelial cells. The aim of this study was to test the effect of titanium coating of small diameter ePTFE grafts on short term patency, neo-endothelialization and neointimal proliferation. METHODS: Bilateral carotid graft interposition was performed in 5 pigs with uncoated (n=5) and titanium-coated (n=5) ePTFE grafts (internal diameter=4 mm, length=5 cm), thus each pig served as its own control. At the end of the study (30 +/- 3 days), patency and stenosis severity was assessed by carotid angiography. Animals were sacrificed and grafts were excised for histology and scanning electron microscopy. Morphometry of histologic sections was carried out to determine neointimal proliferation and percentage of neo-endothelial coverage. RESULTS: Patency rate was 80% for uncoated and titanium-coated grafts. Quantitative angiography did not show any significant difference in lumen size between two groups. Morphometry revealed a significantly higher cellular coverage with CD31 positive endothelial cells for titanium-coated (84 +/- 19%) than uncoated grafts (48 +/- 26%, p<0.001). There was a non significant trend (p=0.112) towards increased neointimal proliferation in titanium-coated (94 +/- 61 micron2/micron) compared to uncoated grafts (60 +/- 57 micron2/micron). CONCLUSIONS: Patency rate in uncoated and titanium-coated ePTFE grafts is similar at one month. However, titanium coated grafts show a significant improvement in neo-endothelialization compared to uncoated grafts.

A comparative study of recurrent pterygium surgery: limbal conjunctival autograft transplantation versus mitomycin C with conjunctival flap.

OBJECTIVE: To compare the recurrence rate following treatment of recurrent pterygia using one of two techniques-limbal conjunctival autograft transplantation versus low-dose intraoperative mitomycin C (0.2 mg/ml) combined with conjunctival flap closure. DESIGN: Randomized clinical trial. PARTICIPANTS: Eighty-one patients with recurrent pterygia treated by limbal conjunctival autograft transplantation (n= 41) or mitomycin C combined with conjunctival flap (n= 40) participated. INTERVENTION: Limbal conjunctival autograft transplantation or low-dose intraoperative mitomycin C application with conjunctival flap technique was performed on recurrent pterygium cases. MAIN OUTCOME MEASURES: Recurrence of pterygium and postoperative complications. RESULTS: During mean follow-up periods of 16+/-1.9 and 15.5+/-1.5 months, six recurrences (14.6%) in the limbal conjunctival autograft transplantation group and five recurrences (12.5%) in the mitomycin C group were observed (P=0.77). The difference between the mean ages of recurrent (26.4+/-8.0 years) and nonrecurrent (35.8+/-11.9 years) cases for all patients was statistically significant (P=0.014). Technically, limbal conjunctival autograft transplantation seemed to be more difficult. The most frequent complication in limbal conjunctival autograft transplantation was graft edema, whereas that in the mitomycin C group was superficial keratitis. CONCLUSION: Both techniques showed similar recurrence rates in the treatment of recurrent pterygia. Although technically easier to perform, further follow-up is necessary to determine the long-term safety of low-dose intraoperative mitomycin C with conjunctival flap closure. The surgeon's familiarity with either procedure should determine the method of choice.

Acute blindness and putaminal necrosis in methanol intoxication.

PURPOSE: To review the neuro-ophthalmological and radiological findings of acute methyl alcohol intoxication. METHOD: 8 acute methyl alcohol intoxication cases were evaluated. RESULTS: All patients were male and their ages varied between 21 and 55. At the initial examination, 6 to 12 days after methanol intake, visual acuity ranged from no light perception to counting fingers at 2 meters with no color perception. Bilateral dense central scotomas were detected in patients whose vision was slightly preserved. Pupillary light reactions were either absent or sluggish. In 4 cases, edema of the optic disk and the peripapillary nerve fiber layer was observed. Three months later, optic atrophy had developed. Five patients underwent magnetic resonance imaging. Bilateral putaminal hyperintense lesions on T2 weighted images were observed in 3 cases. Two patients died and autopsy permission could not be obtained. Follow-up examination 12 months later revealed optic atrophy in the other six cases, with no improvement in vision. CONCLUSION: Methanol intoxication is detrimental to health, possibly resulting in blindness and occasionally death. In association with ocular signs and the other systemic and laboratory features, the ophthalmologist should be alert to the diagnosis of methanol intoxication in which visual loss may be the only symptom.

Occupational dermatoses from exposure to epoxy resin compounds in a ski factory.

Of 22 workers in a ski factory, occupational allergic contact dermatitis was found in 8. 6 were sensitive to epoxy resin compounds, i.e., epoxy resins, hardeners or diluents, 1 to cobalt in glass-fiber reinforcements, and 1 to formaldehyde in a urea-formaldehyde glue and a lacquer. 4 workers had irritant contact dermatitis from epoxy resin compounds, lacquers, sanding dust, or glass-fiber dust. 3 had contact allergy from a new sensitizer, diethyleneglycol diglycidyl ether, in a reactive diluent. Immediate transfer of workers sensitized to epoxy resin from epoxy exposure prevents aggravation of their dermatitis and broadening of the sensitization to epoxy hardeners, diluents and other compounds.

Properties of a purified nucleolar ribonuclease from Ehrlich ascites carcinoma cells.

A nucleolar ribonuclease specific for single-stranded ribonucleic acid (RNA) has been isolated and extensively purified from Ehrlich ascites carcinoma cells. The enzyme is optimally active at neutral pH and degrades RNA via a 2',3'-cyclic intermediate leaving 3'- or 2',3'-cyclic terminated oligonucleotides. The ribonuclease has an apparent molecular weight of 38 500 as judged by sedimentation equilibrium and is a basic protein having an isoelectric point greater than 9.0. The enzyme preferentially cleaves poly(C) over poly (U), poly(A), or poly(C).poly(I). Limit digestion products of poly(C) degratation are on the average tri-, tetra-, and pentanucleotides. In the partial digestion of yeast 5.8S rRNA, the nucleolar ribonuclease cleaves only CpA phosphodiester bonds. Spermidine, spermine, and histone I inhibit the activity of nucleolar ribonuclease. Antibodies directed toward pancreatic RNase do not cross-react with the Ehrlich nucleolar ribonuclease.

Uridine uptake inhibition in Novikoff hepatoma cells by perturbants of intracellular Ca2+ and K+ levels.

The rate of uptake of uridine into the acid-soluble fraction of Novikoff hepatoma cells is inhibited by low concentrations of the ionophores A23187 and gramicidin and other perturbants of intracellular cation levels. Inhibition of uridine uptake by A23187 is dependent on Ca2+ and is reduced by serum and high levels of Mg2+. The effectiveness of A23187 is dependent on the Ca2+/Mg2+ ratio rather than the absolute concentration of either ion. Inhibition of uridine uptake by gramicidin is not significantly affected by serum or divalent cations. Other effectors of monovalent cation flux such as ouabain and valinomycin also inhibit uridine uptake. These results indicate that net uptake of uridine may be influenced by intracellular levels of certain monovalent and divalent inorganic cations.