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Biomedical subjects

O Oto

Publications and source records attributed to O Oto.

At least 19 recordsLinked to original sources

Vasorelaxant effect of iloprost on isolated human internal mammary artery.

In this study, vasodilator effect of iloprost on KCl-induced contraction in human internal mammary artery (IMA) was studied and compared with other vasodilators papaverin and diltiazem. Ring segments of IMA were studied in organ baths for measurement of isometric tension. After the tissues has reached their baseline tension, precontraction was induced by 100 mm KCl and cumulative concentration-relaxation was measured by the application of iloprost (10(-9)-10(-6) m), papaverine (10(-5)-10(-4) m), diltiazem (10(-9)-10(-4) m) or ethanol; a solvent for iloprost; alone. The maximal relaxation of IMA segments to iloprost was 13.5 +/- 2.2%. Iloprost caused significantly limited relaxation when compared with papaverin (106.0 +/- 2.9%) and diltiazem (93.6 +/- 2.5%) (P < 0.001). Papaverin produced the greatest maximal relaxation to KCl-induced contraction of IMA. The potency of iloprost (-log EC(50) = 6.59 +/- 0.19) was significantly higher than those of papaverine (-log EC(50) = 4.21 +/- 0.11) and diltiazem (-log EC(50) = 5.63 +/- 0.06) (P < 0.001). In addition, -log EC(50) of diltiazem was significantly greater than papaverin (P < 0.001). Iloprost appears to be more potent than those of papaverine and diltiazem but it was inefficient in maximal inhibition on KCl-induced contraction. Iloprost may have little benefit in KCl-related vasoconstriction on human IMA segments.

Adult↗

The inversely proportional relation between nitric oxide and lipid peroxidation in atherosclerotic plaque formation in human.

It is known that in the presence of oxygen radicals, anti-atherogenic nitric oxide is converted into pro-atherogenic products, which increase lipid peroxidation. In this study, plaque-free atherosclerotic tissues (n=26), atherosclerotic plaques (n=26) and fetal tissues (n=2; as control) were evaluated. High nitrite, but low malondialdehyde, levels in non-atherosclerotic tissues may show the protective role of nitric oxide from atherosclerosis. In plaque-developed tissues nitrite levels were three times, and lipid peroxidation levels were 10 times, higher than non-plaque developed tissues. In the atherosclerotic plaque forming process, the role of nitric oxide can be discovered according to the lipid peroxidation of tissues. In conclusion, the results of this study show an inversely proportional relation between pro- and anti-atherogenic effects of nitric oxide in the pathogenesis of atherosclerotic vascular diseases.

Arteriosclerosis↗

The effects of heparin coated circuits on pulmonary injury. A clinical study.

AIM: Heparin-coated circuits have dramatic effects on the coagulation cascade, but their role on complement activation has not been clearly defined. In this clinical study the effect of heparin-coated circuits on static lung compliance and pulmonary vascular resistance is described. METHODS: Thirty patients were randomly divided into two groups: with either a heparin-coated circuit or an identical but non-coated circuit control group. In the heparin-coated group, all the blood contacting surfaces were treated with immobilized heparin (Duraflo II.) RESULTS: Early postoperative pulmonary function is determined with measurements of static lung compliance, pulmonary vascular resistance and arterial blood gases. Static lung compliance was significantly better in the heparin coated (HC) group in the early postoperative period (p=0.001). Pulmonary vascular resistance was significantly lower in the heparin-coated (HC) group in the early postoperative period (p=0.001). CONCLUSION: We believe that the method of heparin binding may play a role in its diminished effect on complement activation, but the general augmentation of the circuit's biocompatibility may explain its beneficial effect on pulmonary vascular resistance and static lung compliance.

Anticoagulants↗

Low dose systemic thrombolytic therapy for treatment of deep venous thrombosis.

BACKGROUND: Thrombolytic therapy is still not used widely for treatment of deep vein thrombosis despite its known efficacy. This reluctance to use it stems from worries about its hemorrhagic complications. METHODS: In a 4-year period 97 patients with deep vein thrombosis diagnosed by duplex study were enrolled into the study. Fifty patients received streptokinase as a bolus of 250,000 units followed by 100,000 units/hr with a maximum of 4,000,000 units and 47 patients received anticoagulation with heparin. RESULTS: Minor hemorrhagic complications occurred in 2 patients (4%) in the thrombolytic therapy group. An improvement in the control duplex study was observed in 56% of the patients in the thrombolytic therapy group compared to 5% in the heparin group (p=0.000). The patients treated within 4 days of onset of symptoms had significantly higher success rates compared to those treated later (p=0.000). Higher success rates were obtained for those with either femoral vein or more distal venous thrombosis compared to those with iliac vein and vena cava thrombosis (p=0.007). These results show that systemic low dose streptokinase achieves significantly higher recanalization rates compared to heparin alone. CONCLUSIONS: Hemorrhagic complications at these dose levels are within acceptable ranges. Low dose streptokinase regimen could be beneficial in patients who present within 4 days of femoral or more distal venous thrombosis.

Adolescent↗

Pseudoaneurysm of the right ventricular outflow tract complicating balloon dilatation for tetralogy of fallot.

Balloon dilatation is one of the treatment options in symptomatic infants with tetralogy of Fallot and hypoplastic pulmonary annulus and pulmonary artery. A balloon dilatation was performed on a 28-day-old infant with tetralogy of Fallot with an appropriate balloon. The patient developed two pseudoaneurysms on the right ventricular outflow tract after the procedure which were diagnosed when the patient was admitted for total correction at 20 months of age. This case demonstrates an unusual but potentially life-threatening long-term complication of this procedure.

Aneurysm, False↗

Dissection of the ascending aorta due to metastatic carcinoma.

The association of aortic dissection with a malignancy is a rare finding and previous reports are usually those of primary aortic sarcomas. In this report we present a case with typical ascending aorta dissection associated with metastatic carcinoma originating from the lungs. The metastatic infiltration of the vasovasorum of the aorta by carcinoma cells may have caused aortic dissection by decreasing medial strength and integrity. This is a mechanism of aortic dissection that we have not encountered in previous reports.

Aortic Dissection↗

A cheaper substitute for skin closure in open sternum technique.

Delayed sternal closure is a life saving method in pediatric open heart surgery. We have used a sterile PVC bag sutured to two pieces of chest tubes to close the sternal defect. This is used as a cheaper substitute, which is available in every operating room which can be used as an alternative to PTFE or bovine patch closure.

Cardiac Surgical Procedures↗

Retrograde cerebral perfusion with hypothermic circulatory arrest in a child.

This report describes a 4-year-old boy who presented with infective endocarditis involving the ascending aorta and the arch vessels, with supravalvular aortic stenosis as the underlying pathology. Operation was indicated because of the embolic potential of the vegetations inside the aorta. Retrograde cerebral perfusion was utilized in conjunction with hypothermic circulatory arrest, to flush particulate materials from the arch vessels during operation.

Aortic Valve Stenosis↗

The effect of coronary artery bypass surgery on brain perfusion.

UNLABELLED: Coronary artery bypass grafting (CABG) is one of the major treatment methods of coronary artery disease. CABG is an open-heart surgery that uses cardiopulmonary bypass (CPB). After CPB, it is well known that neurological and neuropsychological complications may occur. The purpose of this study was to evaluate brain perfusion patterns before and after CPB and to locate brain perfusion changes in patients with neurological and neuropsycological complications after CPB. METHODS: Twenty-five patients who underwent open-heart surgery (22 CABG, 3 valve replacement) and 5 patients (4 cholecystectomy, 1 periferic vascular surgery) as a control group were included in the study. The 99mTc-HMPAO injected dose was 925 MBq. Brain perfusion SPECT images were obtained 30-60 min postinjection using a dedicated triple-head brain SPECT camera. Imaging was performed 1 wk before and 4-6 wk after surgery. Technetium-99m-HMPAO brain SPECT slices were evaluated visually and semiquantitatively. RESULTS: None of the patients had severe neurologic complications. Neuropsychological deficits occurred in eight patients after CABG. Cognitive deterioration and depressive mood occurred in five patients. Disorientation, agitation and confusion periods were present in another two patients. Frontal hypoperfusion was found in these patients by visual and semiquantitative evaluations (p = 0.0277) and left parietal hypoperfusion was also present semiquantitatively (p = 0.0277). Visual hallucinations occurred in one patient. Computed tomography of these patients was normal. No perfusion abnormalities were observed in the patient with visual hallucinations and in patients without symptoms after open-heart surgery nor in the control group. Brain SPECT was repeated in two symptomatic patients 5 mo after CABG. Frontal hypoperfusion became normal, and these patients' symptoms disappeared. CONCLUSION: The results of this study indicate that regional cortical hypoperfusion may occur in patients with neuropsychological complications after CABG. Technetium-99m-HMPAO brain SPECT is a useful method to locate and determine brain perfusion changes after CABG.

Brain↗

Ligation of patent ductus arterious by the method of video-assisted thoracoscopic surgery and our other VATS experiences.

In April and May 1996, two cases of PDA ligation were performed firstly in Turkey by the method of video assisted thoracoscopic surgery (VATS) in Dokuz Eylül Medical Faculty, Thoracic and Cardiovascular Surgery Department. There was not any complication in these patients in the postoperative period and they were discharged on the second day in symptom-free condition by the detection of closed ductus in their echocardiographic examination. Between February 1993 and October 1996, a total of 46 patients have undergone interventional application by VATS. While in six of these patients the procedure could not be manipulated because of massive pleural fibrosis, there was no mortality or morbidity among the patients, and they were discharged on average on the second day. The ratio of complications, such as bleeding, air leak, arrhythmia and empyema are so low in these operations, and hospital stay, with return to work time are shorter than with the open technique.

Adolescent↗

The effects of amrinone and glucagon on verapamil-induced myocardial depression in a rat isolated heart model.

1. We measured the ability of glucagon and amrinone, used alone and in combination, to improve the myocardial function in a rat isolated heart model of calcium channel blocker (CCB) cardiotoxicity. 2. Verapamil 10(-4) mol consistently decreased heart rate and cardiac contractile force in our Langendorff rat isolated heart preparations. Glucagon increased the heart rate in a dose-dependent fashion. Amrinone increased the heart rate only at the 1 x 10(-1) mol concentration, and had no significant effect on cardiac contractility. 3. A positive linear correlation was found between the glucagon concentration and the percent recovery of baseline contractile force. 4. Although complete reversal of verapamil-induced myocardial depression occurred at glucagon concentrations of > 3 x 10(-6) mol, amrinone produced only 23.8 +/- 3.6% recovery from baseline at its highest concentration (4 x 10(-3) mol). 5. When glucagon and amrinone were administered together, there was no additional increase over glucagon alone in the increase in contractile force. 6. Glucagon, and not amrinone, is an appropriate agent, capable of reversing verapamil-induced myocardial toxicity in this rat isolated heart model. In vivo studies should be performed to assess whether this may be a reliable therapy in clinical cases.

Amrinone↗

Relationship between high serum digoxin levels and toxicity.

A retrospective study of 1,269 patients on digoxin was done to determine the relationship between serum digoxin levels of 3.0 ng/ml or higher and clinical toxicity. Of 1,269 patients, 58 (4.6%) had digoxin serum levels of 3.0 ng/ml or higher. Clinical evidence of digoxin toxicity was present in only 11 of these patients and premature blood sampling accounted for the high levels in 10 other nontoxic patients. None of the patients with clinical toxicity died. The other 37 patients tolerated the high digoxin levels without exhibiting toxic effect. Low cardiac output, concomitant use of other drugs, and impaired renal function increased the serum digoxin levels in patients with and without clinical toxicity. Appropriate therapeutic digoxin level monitoring and confirmatory laboratory-clinical relationship may have important influences on these results. Additional work on further definition of "toxic" digoxin levels needs to be performed.

Adult↗

Evaluation of some antioxidant enzymes in lung carcinoma tissue.

This investigation was effected to determine the levels of the two antioxidant enzymes, superoxide dismutase (SOD) (EC 1.15.1.1) and catalase (CAT) (EC 1.11.1.6) in lung cancerous tissues and to compare with normal lung tissue in order to evaluate the antioxidant status in lung cancer. Fifteen lung carcinoma tissue samples and the normal counterparts from the same cases were homogenized and the cytosols obtained by ultracentrifugation (100,000 x g). SOD was assayed using a modification of the indirect nitroblue tetrazolium assay method, while CAT was measured by a spectrophotometric method. The data obtained are as follows: 1.42 +/- 0.24 U/mg protein (means +/- SEM) of SOD in lung cancer and 3.13 +/- 0.51 U/mg protein in normal lung tissue and 33.53 +/- 6.09 U/mg protein of CAT in lung cancer and 71.33 +/- 14.38 in normal lung tissue. The differences were found to be significant at the level of P < 0.01 for both enzymes. These low levels of the antioxidant enzymes in lung cancerous tissues can lead to elevated levels of reactive oxygen metabolites, resulting in damage to the key subcellular structures such as DNA, cell membranes, and other vital cellular components.

Carcinoma, Non-Small-Cell Lung↗

Amikacin administration in open heart surgery.

Amikacin is usually administered to the patients during open heart surgery immediately after cardiopulmonary bypass (CPB) because the serum levels of this drug may decrease due to the volume overload and hemodilution caused by intravenously administered fluids (1.2-2 liters prime solution). We investigated whether this application of amikacin is necessary immediately after CPB. A total of ten patients from Dokuz Eylül University Hospital, Department of Thoracic and Cardiovascular Surgery, who were scheduled for open heart surgery were studied. Serum sodium, potassium, blood urea nitrogen and creatinine values of the patients were found to be within normal limits before the operation. Amikacin was administered to patients just before open heart surgery and 2 ml blood samples were collected from all patients 15 minutes after the drug administration, just before cardiopulmonary by-pass (CPB), at the 30th and 60th minutes of the CPB, after CPB and after the cessation of operation, 4 hours after drug administration. A significant decrease was observed between the values of 10 patients by ANOVA (p < 0.05). Serum amikacin values were found to be 9.80 +/- 0.96 micrograms/ml at the end of the operation, 4 hours after the drug administration. Since serum amikacin levels do not fall below the trough concentrations at the end of the fourth hour we conclude that it is unnecessary to repeat the dose at the end of the operation.

Adult↗

A comparison of digoxin concentration--time curves before and after open-heart surgery.

The effects of open heart surgery on serum digoxin concentration--time curves were investigated in 10 cardiac patients receiving 0.25 mg/day digoxin. Blood samples were obtained from the patients immediately before and 1, 2, 3, 5, 8, 16 and 24 h after digoxin administration, both before open-heart surgery and 7 days after surgery. Serum digoxin concentrations, determined by fluorescence polarization immuno-assay, significantly (P < 0.05) increased after surgery, as did the maximum serum concentrations and the areas under the concentration-time curves. After surgery there was a significant increase in the serum gamma-glutamyl transferase concentration and a significant reduction in the total protein concentration. A reduction of digoxin dose may be appropriate for patients who have undergone open-heart surgery.

Adult↗