Successful treatment of systemic lupus erythematosus and pulmonary hypertension with intravenous prostaglandin I2 followed by its oral analogue.

Systemic lupus erythematosus (SLE) is sometimes reported to complicate fatal pulmonary hypertension. A 46-year-old woman, with a ten-year history of SLE and pulmonary hypertension, was admitted to our hospital complaining of dyspnea and chest pain. She suffered pulmonary hemorrhage and after steroid pulse therapy, she underwent continuous intravenous infusion of epoprostenol (prostaglandin I2) with corticosteroid for four weeks, which reduced the pulmonary artery pressure and resistance. Following the successful treatment, beraprost sodium, an oral PGI2 analogue, was given and it maintained pulmonary hypertension remittance for four years.

[Severe carotid artery stenosis in the neck is frequently associated with coronary heart disease].

We have reviewed 15 cases of carotid artery stenosis in the neck, consisting of 11 patients with cerebral ischemia and 4 asymptomatic patients, in relation to associated coronary heart disease. The 15 patients had systemic complications, including hypertension in 87%, diabetes mellitus in 40% and hyperlipidemia in 57%. Systemic vascular complications other than coronary heart disease were present in 27% of the patients. Three of the 15 patients had a history of ischemic heart disease and had been treated by cardiologists. One patient developed angina pectoris on the second day of a cerebral ischemic attack. Coronary angiography (CAG) and simultaneous cerebral angiography following carotid endartectomy (CEA) were performed 4 of the remaining 12 patients, who had symptoms or history of ischemic heart attacks. Three of these four patients had stenotic lesions in their coronary arteries. Another one patient among the remaining 8 developed angina pectoris one year after undergoing CEA. This patient had 3-vessel coronary artery disease. These findings suggest that a strong correlation between stenotic lesions of the carotid arteries in the neck and coronary heart disease, with or without episodes of ischemic heart disease. CAG should be strongly recommended in such patients to assess the severity of complicating ischemic heart disease and to improve the prognosis following CEA.

[An effective case of nitric oxide inhalation therapy in pulmonary hypertensive crisis in cardiopulmonary bypass following palliative operation for ventricular septal defect with pulmonary hypertension].

A 4-month-old female with ventricular septal defect (VSD) and severe pulmonary hypertension (PH) underwent a patch closure for VSD. She could not be weaned from cardiopulmonary bypass (CPB) after the intracardiac repair due to PH crisis. Nitric oxide inhalation therapy during partial CPB enabled her to be weaned from CPB. This therapy could be gradually taped off and quit 7 days after the operation. Nitric oxide inhaled therapy is considered to be an excellent treatment for PH crisis during CPB in congenital cardiac surgery. The causes of PH crisis were also discussed in reference to the date of endothelin-1 (ET-1) measured during the operation.

[Heterogeneity in gastric carcinoma with special reference to DNA content and mitotic activity: histopathologic differentiation].

DNA ploidy was microspectrophotometrically investigated in 46 patients with gastric carcinoma. Measurements of DNA content and mitotic index (MI) were examined in the mucosal, submucosal, muscularis propria, and serosal layers of tumors, respectively. The frequency of cells with values exceeding hexaploid chromosome (6c) and mitotic counting analysis revealed a significantly higher value in the serosa than in the mucosa. This tendency was not evident in differentiated type adenocarcinoma but was noted in those with the undifferentiated type. There were 37 tumors (80.0%) with the same DNA distribution pattern in every layer of the stomach (homogeneous DNA ploidy). Heterogeneity of DNA ploidy was observed in nine tumors (20.0%). Carcinoma with heterogeneous DNA ploidy manifested a significantly higher incidence of metastasis to lymph nodes than did those with the homogeneous type. Characteristically, there was venous permeation preponderance in the differentiated type and peritoneal dissemination preponderance in the undifferentiated type. This evidence of DNA heterogeneity in gastric carcinoma tissue suggests a possible correlation with metastatic behavior.

The interference of acebutolol administration in the measurement of urinary 17-ketosteroid by Zimmermann's method.

A patient with essential hypertension receiving the oral administration of acebutolol, a beta 1-selective adrenergic blocker, showed a marked increase in urinary 17-ketosteroid (17-KS) excretion determined by Zimmermann's method. Since the normal concentration of each fraction of 17-KS was found in this case by gas chromatography, the possibility of an abnormality in steroid metabolism could be excluded from the mechanism of the increase in the measured value for urinary 17-KS. In the urine samples from patients treated with acebutolol, acebutolol and acetylated acebutolol, a main metabolite of acebutolol, were found equally among them. Moreover, acebutolol or acetylated acebutolol resulted in a dose-dependent increase in 17-KS by Zimmermann's method in phosphate buffered saline or in a urine sample. However, the other beta-blockers, such as propranolol, alprenolol and oxprenolol did not show any effect on the determined value for urinary 17-KS. Thus it was concluded that the activated methylene group of acebutolol and acetylated acebutolol may interfere with the measured values obtained by Zimmermann's method.

Superoxide dismutase therapy for myocardial ischemia.

Oxygen derived free radicals have been shown to be generated during reperfusion of ischemic myocardium by a variety of approaches including spin trap probes. Three levels of injury have been described for the reperfused heart. Periods of ischemia of only several minutes can trigger lethal arrhythmias on reperfusion. Anti-oxidants including SOD and or catalase, as well as iron chelators reduce the incidence of these arrhythmias in both dog and rat. Xanthine oxidase inhibitors are equipotent with SOD in this model suggesting that xanthine oxidase is the source of the radicals. Periods of occlusion lasting 10-15 minutes produce a recoverable defect in contractility termed "stunning". SOD plus catalase has been shown to reduce the incidence of stunning in a variety of models including the xanthine oxidase deficient rabbit. Neither agent on its own seemed to be effective against stunning in either the rabbit or the dog. Stunning is more difficult to demonstrate in the rabbit heart, presumably due to its lack of xanthine oxidase. Periods of ischemia in excess of 20 minutes will result in some irreversible cell death (infarction) with reperfusion. While studies using histochemical methods suggesting that SOD plus catalase given at the time of reperfusion could limit necrosis in the dog model, histological studies reveal that infarct size was not modified but rather, SOD appears to interfere with the ability of tetrazolium to histochemically discriminate between living and dead cells. While PEG SOD with its extended plasma half life was reported to reduce infarct size in the dog, it was unable to protect the reperfused rabbit heart. To date, none of the scavengers have been proven to limit infarction suggesting that free radicals contribute to arrhythmias and stunning, but do not kill cells in the reperfused heart.

Tetrazolium artifactually indicates superoxide dismutase-induced salvage in reperfused rabbit heart.

We tested the ability of a single dose of superoxide dismutase to induce salvage of reperfused rabbit myocardium. Infarct size was measured by tetrazolium method following 3, 24, or 72 h of reperfusion. In addition, the 24 h reperfused hearts were examined to determine if the drug induced salvage in those hearts was reflected in the histology. A coronary arterial branch was occluded for 45 min and then allowed to reperfuse for 3, 24 or 72 h. At the end of the reperfusion period the hearts were removed, perfusion stained with triphenyl tetrazolium, and fixed in buffered formalin. The hearts were sectioned and infarct size was determined in all groups. In addition, the 24 h heart slices were prepared for histology with H&E staining. The results revealed that 5 mg/kg hSOD treatment was associated with smaller infarcts in the 3 and 24 h groups but that differences were no longer apparent in the 72 h group. The 24 h control hearts showed good correlation between infarct size by TTC and that by conventional histology. In the 24 h treatment hearts, however, infarcts by TTC averaged only about 1/2 the size of those by conventional histology. We conclude that a single dose of hSOD fails to offer a sustained reduction of infarct size. Furthermore, histology from the 24 h reperfused group revealed that hSOD did not delay the onset of necrosis but rather simply caused dead tissue to retain its ability to reduce the tetrazolium salts.

Superoxide dismutase attenuated post-ischaemic contractile dysfunction in a myocardial xanthine oxidase deficient species.

1. We assessed the effect of polyethylene glycol conjugated superoxide dismutase (PEG-SOD) on myocardial stunning in the rabbit heart in which xanthine oxidase level is extremely low. 2. In open-chest anaesthetized rabbits, the left marginal branch of the coronary artery was occluded for 10 min and then reperfused for 30 min. A group of rabbits (PEG-SOD group) received 1000 units/kg of PED-SOD and another group (control group) was given saline 15 min before the coronary occlusion. 3. Regional systolic thickening fraction (TF) was similarly reduced to approximately -25% of baseline value during ischaemia in both groups. However recovery of TF after reperfusion was significantly better in the PEG-SOD group (n = 9) and TF at 30 min after reperfusion was 70.1 +/- 3.9% of baseline value compared with 44.9 +/- 3.4% in the control group (n = 9; P less than 0.05). Rate-pressure products, left ventricular pressure, and LV dP/dt max were not significantly different between the PEG-SOD treated and untreated control rabbits at any time during the experiment. PEG-SOD did not modify the regional myocardial blood flow (coloured microsphere method) during ischaemia/reperfusion, which was assessed by using separate groups of rabbits. 4. These findings indicate that oxygen free radicals are important in the pathogenesis of myocardial stunning in xanthine oxidase deficient hearts.

Examination of two small-molecule antiperoxidative agents in a rabbit model of postischemic myocardial infarction.

Peroxidation of membrane phospholipid may be a causal contributor to the development of irreversible postischemic myocardial injury. In this study, two small-molecule antiperoxidative agents were tested for their ability to salvage reperfused rabbit myocardium and reduce infarct size as assessed by direct histological evaluation of hearts following a 30-min occlusion of a coronary arterial branch and a 72-h reperfusion period. The compounds tested are novel analogs of alpha-tocopherol (vitamin E), and share with the parent compound an ability to scavenge the peroxyl radicals that propagate and amplify lipid peroxidation initiated by partially reduced oxygen; however, the new analogs are significantly more potent peroxyl-radical scavengers that alpha-tocopherol. Each antiperoxidant (3 mg/kg) was administered by intravenous bolus injection in two stages: 20% of the total dose was given 15 min before occlusion, and the remaining 80% was given 5 min before reperfusion. The results revealed that neither antiperoxidant offered a sustained reduction in infarct size (expressed as a percentage of the region at risk) as compared to a nontreated vehicle control. The implications of the present study with respect to the purported cardioprotective effects of antiperoxidants in the setting of ischemia reperfusion and the pathogenic role of lipid peroxidation in the postischemic heart are discussed.

Superoxide dismutase conjugated to polyethylene glycol fails to limit myocardial infarct size after 30 min ischemia followed by 72 h of reperfusion in the rabbit.

We tested whether recombinant human superoxide dismutase conjugated to polyethylene glycol (PEG-SOD) to prolong its plasma retention time could limit myocardial infarct size in an ischemia-reperfusion model in the rabbit. One group of animals received 1000 units/kg of PEG-SOD as an intravenous bolus 15 min before coronary occlusion. A second group received saline only and served as controls. Under pentobarbital anesthesia, a left coronary branch was occluded for 30 min and then reperfused. The surgical wounds were repaired and the animals were allowed to recover. Seventy-two hours after the coronary occlusion, the heart was excised and the size of the area at risk (ischemic vascular bed) was assessed with fluorescent particles and the infarct size was determined by histology (Hematoxylin-eosin, Azan stain). Infarct size as a percentage of the area at risk was similar between the groups, 46.5 + 2.7 in the PEG-SOD group (n = 8) and 48.9 + 3.1 in the control group (n = 8). There were no significant differences between the groups indicating that PEG-SOD did not limit infarct size in this model.

Human superoxide dismutase failed to limit the size of myocardial infarct after 20-, 30-, or 60-minute ischemia and 72-hour reperfusion in the rabbit.

The effect of superoxide dismutase (SOD) on the size of the myocardial infarct resulting from various durations of ischemia and a 72-hour reperfusion was examined in the rabbit. A coronary branch of the circumflex artery was occluded for 20, 30, or 60 min and then reperfused. Seventy-two hours after the coronary occlusion, the infarct size and the size of the area at risk (vascular bed of occluded coronary artery) were determined by histology (hematoxylin-eosin and Mallory's staining) and by fluorescent particles, respectively. Human SOD (45,000 units/kg) was injected intravenously as a bolus in SOD-treated rabbits, while only saline was administered to control rabbits. The percentage of the area at risk which actually infarcted (%I/AAR) was 25.5 +/- 12.9% (mean +/- S.D.) in the 20-min ischemia control group (n = 9), 19.7 +/- 10.2% in the 20-min ischemia SOD group (n = 9), 44.8 +/- 9.0% in the 30-min ischemia control group (n = 9), 41.0 +/- 6.3% in the 30-min ischemia SOD group (n = 9), 74.2 +/- 13.8% in the 60-min ischemia control group (n = 9), and 76.6 +/- 8.2% in the 60-min ischemia SOD group (n = 7). The %I/AAR was not significantly different between the control and SOD groups for any duration of ischemia. Heart rate, blood pressure, and the size of area at risk were comparable in all six groups. These findings suggested that oxygen-free radicals produced during initial moments of reperfusion were unlikely to contribute to myocardial necrosis regardless of the duration of ischemia in the rabbit.

Progression of myocardial infarction in a collateral flow deficient species.

The effect of a varying period of ischemia on the development of myocardial infarction was investigated in the rabbit. Radiomicrosphere measurements confirmed that the collateral blood flow is almost zero (0.02 +/- 0.01 ml/min/g) and without a significant transmural gradient in the rabbit heart (n = 15). A coronary branch of the left circumflex artery was occluded for 5, 10, 15, 30 or 60 min and then reperfused. The coronary branch was occluded permanently in another group of rabbits. Three days after the coronary occlusion, the infarct size was determined by hematoxylin-eosin and Mallory's staining and the ischemic zone size was determined by fluorescent particles. The results showed that the percentage of the ischemic zone infarcted (% infarction) vs the log of duration of ischemia yielded a sigmoid curve which could be linearized by probit analysis: Probits of % infarction = 3.05 x log (ischemic duration in minutes) + 0.33, r = 0.83, p less than 0.01. The regression equation indicated that 50% of the ischemic myocytes necrotized after 34 min of coronary artery occlusion. Unlike in the dog heart, the infarct of the rabbit heart first appears in the midmyocardium and then progresses towards both the endocardium and epicardium.

Does verapamil limit myocardial infarct size in a heart deficient in xanthine oxidase?

1. The delay of ischaemic myocardial necrosis by verapamil has been reported in the dog heart, which contains a high level of xanthine oxidase, a potential source of cytotoxic free radicals. To test whether the retardation of ischaemic myocyte death by verapamil is not an isolated phenomenon in the xanthine oxidase rich heart, we assessed the effect of verapamil in the rabbit heart, which lacks xanthine oxidase. 2. Verapamil (200 micrograms/kg, i.v. bolus plus 40 micrograms/kg per min) was administered in a group of rabbits (n = 5) to test the haemodynamic response to this agent. The heart rate, blood pressure and left ventricular dp/dt max were reduced by 11, 25 and 57%, respectively, and the plasma concentration of verapamil was maintained at 300-400 ng/mL during the infusion. 3. In other groups of rabbits, the effect of the same dosage of verapamil on the size of myocardial infarct after 20 or 30 min ischaemia and 72 h reperfusion was examined. The verapamil was administered for 45 min, starting 15 min prior to ischaemia. The percentage of area at risk infarcted (%I/AAR) was 15.2 +/- 3.9% in the 20 min ischaemia control group and 15.4 +/- 4.5% in the 20 min ischaemia verapamil group, 49.1 +/- 3.4% in the 30 min ischaemia control group and 41.2 +/- 3.3% in the 30 min ischaemia verapamil group. The %I/AAR was significantly smaller in the 20 min ischaemia control groups and 15.4 +/- 4.5% in the 20 min ischaemia there was no difference in %I/AAR between the control and verapamil treated animals in either the 20 or the 30 min ischaemia groups. 4. These results suggest that verapamil does not delay the transition from reversible to irreversible myocardial injury during coronary occlusion in the rabbit, which like the human, lacks myocardial xanthine oxidase.

The effect of inotropic dose of dobutamine during reperfusion on myocardial infarct size.

We examined whether dobutamine infusion during reperfusion modifies myocardial infarct size in a rabbit ischemia-reperfusion model. Prior to the infarct size study, the hemodynamic response to dobutamine 5, 10, and 15 micrograms/kg/min i.v. was evaluated in the rabbit model. Ten micrograms/kg/min of dobutamine increased the left ventricular dp/dt max by 34.0 +/- 4.9% (n = 7) and the myocardial blood flow from 0.86 +/- 0.16 to 2.19 +/- 0.57 ml/min/g without change in the collateral blood flow (n = 4). The heart rate, systolic and diastolic blood pressures were elevated by only 4.7 +/- 1.0%, 9.4 +/- 3.0%, and 8.0 +/- 3.7%, respectively (n = 7). In the infarct size study, a coronary branch was occluded for 30 min and then reperfused. Seventy-two hours after reperfusion, the myocardium supplied by the occluded artery (area at risk, AAR) and the infarcted area were determined by fluorescent particles and histology (hematoxylin-eosin and modified Mallory's staining), respectively. In the dobutamine treated group (DB group), 10 micrograms/kg/min of dobutamine were infused for 30 min starting immediately after reperfusion, and a comparable volume of saline was infused in the control group. Hemodynamic parameters and the size of AAR were comparable in the control and DB groups. Myocardial infarct size, expressed as the percentage of AAR, was 45.1 +/- 3.9% in the control (n = 11) and 40.2 +/- 2.4% in the DB group (n = 10), which was not significantly different. These findings indicated that the inotropic dose of dobutamine administered during reperfusion did not cause myocardial necrosis by disturbing the recovery process of the myocardium from ischemic injury.