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J O Defraigne

Publications and source records attributed to J O Defraigne.

At least 73 records · Page 4Linked to original sources
PubMed1994

Preservation of cortical microcirculation after kidney ischemia-reperfusion: value of an iron chelator.

Treatment of suprarenal aneurysms and renal artery reconstructions are both responsible for normothermic ischemia of the kidney (during clamping) followed by reperfusion (declamping). During reflow through an organ undergoing ischemia the production of free radicals can be associated with cell injury and a no-reflow phenomenon characterized by perfusion defects after a period of transient hyperemia. The objectives of this study were to demonstrate the existence of this phenomenon in the kidney undergoing ischemia followed by reperfusion and to test the potential protection afforded by an iron chelator (desferrioxamine) since free radical reactions are catalyzed by iron. Adult New Zealand white rabbits were divided into the following three groups: group A, 15 minutes of ischemia plus 10 minutes of reperfusion; group B, 60 minutes of ischemia plus 10 minutes of reperfusion; and group C, 60 minutes of ischemia plus 10 minutes of reperfusion combined with infusion of desferrioxamine (50 mg/kg). Cortical microcirculation in the kidney was measured by laser Doppler flowmeter before ischemia and 1, 5, and 10 minutes after reperfusion. Vitamin E content was determined in the cortex of the left kidney after 10 minutes of reperfusion and compared with that of the right (control) kidney. After 1 minute of reperfusion the cortical microcirculatory flow was significantly increased in all three groups (reactive hyperemia). In groups A and C blood flow returned to preclamping values after 10 minutes of reperfusion; however, blood flow in group B remained significantly reduced (29.2% +/- 10.5%) after 5 minutes of reperfusion with a further reduction to 48.5% +/- 5.7% after 10 minutes. These findings were correlated with the dosage of vitamin E since the vitamin E content was greatly reduced by 46.7% +/- 7.8% in group B but did not change significantly in groups A and C. This study shows that 60 minutes of normothermic ischemia is followed by a significant reduction in cortical microcirculatory flow (no-reflow phenomenon). Infusion of an iron chelator (desferrioxamine), however, which decreases the intensity of lipid peroxidation induced by the free radicals, preserves the microcirculatory flow.

Animals↗
PubMed1994

Mechanical flow obstruction after heart transplantation diagnosed by TEE.

We report a case of mechanical flow obstruction after heart transplantation caused by a prominent left atrium suture with a "pursestring" effect. The diagnosis was achieved by transesophageal echocardiography. The mean transstenotic gradient was measured at 13 mm Hg. Because of the profound hemodynamic and multisystemic failure, no surgical correction was attempted. The postmortem examination confirmed the stenosis at the level of the left atrium.

Color↗
PubMed1994

Direct evidence of free radical production after ischaemia and reperfusion and protective effect of desferrioxamine: ESR and vitamin E studies.

After surgical renal revascularisation, warm renal ischaemia due to renal artery cross-clamping contributes to postoperative renal dysfunction. After reperfusion, free radicals are thought to be a significant cause of injury. Nevertheless, indisputable proof of free radical production is scarce, partly because of their transient nature. In this study, electron paramagnetic resonance and vitamin E levels were used to demonstrate the free radical production after renal ischaemia and reperfusion. Rabbit kidneys were submitted either to 15 or 60 minutes of ischaemia followed by reperfusion. A spin trap agent (alpha-phenyl-N-tert-butyl nitrone (PBN), 20mg/ml, 1 ml/min) was infused during reperfusion directly into the left renal artery via an aortic catheter before declamping. Blood samples were selectively drawn from the left renal vein for ESR analysis (Varian spectrometer E109) of lipidic residues extracted from blood samples. The vitamin E content of the left renal cortex was determined by HPLC procedure. The right renal cortex was used as a control for the vitamin E values. In the venous effluent, ESR analysis revealed the formation of a spectrum consisting of a triplet of asymmetric doublets. This signal resulted from the spin trapping by PBN of a mixture of both oxygen- and carbon- centred lipidic radicals. The amplitude of the signal which is proportional to the amount of free radicals was significantly higher after 60 minutes ischaemia than after 15 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Misdiagnosed malignancy in transplanted organs.

The case reports of three patients who received cancer-bearing organs at this institution are presented. A fourth recipient, who was to be transplanted with a cancerous kidney, was spared this disastrous complication. The relevant data regarding the donors is also alluded to, with special reference to the type and site of the primary malignancy. Following these case reports, the implications of these issues, their possible prevention, and further management are discussed.

Adult↗
PubMed1993

Evidence for free radical formation during human kidney transplantation.

Fourteen patients undergoing kidney transplantation were studied for evidence of the production of free radicals as assessed by the measurement of vitamin E (an index of lipid peroxidation) and of myeloperoxidase (a marker of neutrophil activation) in the systemic blood. Early (2 min) and late revascularization (30 min) of the kidney were respectively associated with a significant decrease of 35.5 and 40% of the initial level of plasma vitamin E. This consumption paralleled to the decrease of the vitamin E/total lipids ratio, a better indicator of vitamin E status. Heparin administration preceding renal artery clamping resulted in a twofold significant increase of baseline plasma myeloperoxidase (MPO) level (523 +/- 214 ng/ml). At kidney reperfusion, MPO concentration rose again and reached a maximum value of 1,653 +/- 882 ng/ml, indicating the presence of considerable neutrophil activation. A return to the baseline value was observed after 30 min of reperfusion. A short discussion about the possible origin of this MPO increase is given. Taken together, these data strongly suggest that free radical production, leading to lipid peroxidation phenomena, can occur within the early phase of kidney revascularization. Preliminary data using electron spin resonance with the spin-trapping technique strengthen this hypothesis.

Adult↗
PubMed1993

The effect of technical conditions and storage medium composition on the phosphomonoesters to inorganic phosphate ratio determined by 31P nuclear magnetic resonance spectroscopy in rabbit kidney.

Using 31P nuclear magnetic resonance spectroscopy, we compared the state of the high-energy phosphates in rabbit kidneys stored at 4 degrees C for 24 hr with 3 different solutions: Ringer (Rg), University of Wisconsin (UW), and Euro-Collins (EC) solutions. We found the highest phosphomonoester/inorganic phosphate (MP:Pi) ratio in the group of kidneys stored in the Rg solution (Rg, 0.93 +/- 0.04; UW, 0.36 +/- 0.02; EC, 0.28 +/- 0.02). This medium has been demonstrated in previous physiological studies to give poor results in terms of organ preservation compared to the solutions that mimic the "intracellular" fluid, such as the EC and UW solutions. Because the commonly used cold storage solutions contain phosphates, which superimpose on the intracellular Pi and, thus, can distort the results, we attempted to eliminate the contaminating solution around the kidney and in the vasculature by flushing the kidney with a phosphate-free solution (Rg). The MP:Pi ratio increased in the UW and EC groups (UW, 0.82 +/- 0.04; EC, 0.64 +/- 0.04) in identical proportion in the 2 groups. It remained highest in the Rg group (1.02 +/- 0.03). Comparisons of data before and after flush showed that external phosphate contamination was not predominant. There was no equilibrium in phosphate distribution between intra- and extracellular spaces at 24 hr of storage. We conclude that the validity of the MP:Pi ratio, as a viability index of renal transplant, might have to be restricted to comparisons of kidneys preserved in the same storage conditions. Therefore, it would be necessary to establish normal and pathological values of this ratio for each cold storage solution.

Animals↗
PubMed1993

In vivo free radical production after cross-clamping and reperfusion of the renal artery in the rabbit.

Postischaemic reperfusion injury is often attributed to the generation of oxygenated free radicals which may subsequently promote lipid peroxidation in cell membranes. Electron paramagnetic resonance spectroscopy in association with the spin trap molecule alpha-phenyl-N-tert-butyl-nitrone allowed direct confirmation of lipid free radical production after renal ischaemia-reperfusion in an in vivo rabbit model. A 60-min period of ischaemia followed by reperfusion caused free radical production twofold greater than after 15 min of ischaemia. Glutathione and alpha-tocopherol have been measured in renal tissue, as indirect markers of lipid peroxidation. After 15 min of ischaemia followed by 10 min of reperfusion, the mean(s.e.m.) glutathione content of the ischaemic kidney was slightly but significantly reduced by 11.9(2.5)% (P < 0.003). The content of alpha-tocopherol was unchanged. However, 10 min of reperfusion following 60 min of ischaemia led to significant decrease in mean(s.e.m.) content of both glutathione (30.4(3.7)%) (2.23(0.2) versus 3.14(0.18) mumol/g wet tissue, P < 0.001) and alpha-tocopherol (46.1(7.8)%) (0.57(0.10) versus 1.09(0.14) micrograms/g wet tissue, P < 0.001) when compared to the control kidney. Under these experimental conditions, desferrioxamine (15 mg/kg administered intravenously before inducing ischaemia), a drug known to limit free radical production, significantly limited the decrease of alpha-tocopherol to 20.8(6.4)% (0.83(0.08) versus 1.05(0.04) micrograms/g wet tissue, P < 0.05), but did not prevent glutathione consumption in the reperfused kidney.

Animals↗
PubMed1992

Aneurysm of the ascending aorta after cardiac transplantation.

We report the case of a 57-year-old female cardiac transplant patient in whom an aneurysm of the recipient side of the ascending aorta developed 1 year after transplantation. Although a mycotic origin was the likely cause, histologic examination diagnosed an atherosclerotic aneurysm.

Aortic Aneurysm↗
PubMed1991

Right aortic arch with aberrant left subclavian artery. Report of two cases.

Two cases of adult asymptomatic right aortic arch with an aberrant subclavian artery are reported. They were discovered at time of coronary surgery. Preoperative coronary arteriography failed to demonstrate the anomalies. In one case, the right arch was suspected on chest x-ray and preoperative barium oesophagography. In one case, the proximal suture of one saphenous bypass graft was performed on the left common carotid artery. Right aortic arch is a malformation rarely discovered in adults. It generally produces no symptoms when not associated with cardiac disease.

Abnormalities, Multiple↗
PubMed1991

[Massive hemobilia. Review of the literature. Apropos of 2 cases].

Two cases of hemobilia are reported; the first caused by a liver biopsy procedure, and the second ensuing an accidental liver laceration. In both cases, arteriography led to diagnosis and the ligature of the right hepatic artery stopped the hemorrhage with complete success. A review of the literature emphasizes the nowadays leading prevalence of iatrogenic hemobilia followed by those resulting from blunt abdominal liver trauma. Diagnostic facilities are reviewed and selective arteriography is stressed as being the more useful technique. From a therapeutical standpoint interventional radiology and surgery are both given their own place.

Adult↗
PubMed1991

[Sternal osteitis and mediastinitis after coronary artery bypass graft surgery].

Between 1980 and 1987, 31 cases of osteitis (n = 9) and/or mediastinitis (n = 22) were observed after 2,801 consecutive aorto-coronary bypasses (1.1%). Three types of treatment were used: 1) sternal debridement with osteosynthesis and continuous mediastinal irrigation (n = 25); 2) sternal and mediastinal debridement with open drainage without osteosynthesis (n = 2); 3) incision and debridement of sternal abscesses (n = 4). The overall mortality was 26% (8/31), i.e. 11% (1/9) for isolated osteitis and 32% (7/22) for mediastinitis. Four factors were statistically associated with infection: reoperation for hemorrhage (19.4%, p less than 0.001); preoperative diabetes (25%, p less than 0.001), postoperative low cardiac output (55%, p less than 0.001), postoperative respiratory insufficiency (45%, p less than 0.001).

Aged↗