Effect of nipradilol on silent myocardial ischemia, plasma beta-endorphin, and bradykinin in chronic stable angina

HYPOTHESIS

This study was undertaken to investigate the effect of nipradilol on the total ischemic burden and on plasma levels of beta-endorphin and bradykinin.

METHODS

Sixteen patients with chronic stable angina were subjected to exercise treadmill testing and 24-h ambulatory electrocardiogram (ECG).

RESULTS

Nipradilol significantly decreased both mean heart rate and mean pressure rate product at submaximal and maximal exercise. It significantly improved exercise-induced maximal ST-segment depression from -2.7 +/- 0.5 mm to -1.3 +/- 0.6 mm (p < 0.05) and reduced the number of leads with significant ST-segment depression (4.0 +/- 1.2 vs. 2.0 +/- 1.8, p < 0.05). Silent ischemic episodes recorded in 24-h ambulatory ECG were significantly decreased by nipradilol administration, concomitantly with a decrement of mean heart rate and observed maximal heart rate. Patients with exercise-induced silent myocardial ischemia showed significantly increased plasma levels of beta-endorphin during both the placebo and nipradilol phases of the study. However, during the nipradilol phase, bradykinin did not change significantly at rest and at peak exercise.

CONCLUSION

Nipradilol effectively controls exercise-induced myocardial ischemia and silent myocardial ischemic episodes, and does not influence the response of plasma levels of beta-endorphin to exercise stress testing in patients with exercise-induced silent myocardial ischemia.

Hypercalcemia associated with infantile fibrosarcoma producing parathyroid hormone-related protein

We describe a 7-month-old boy who manifested severe hypercalcemia associated with mesenchymal neoplasm. A huge hypervascular tumor on the neck had been detected in prenatal ultrasonography. Surgical removal of the entire tumor at birth was not indicated, because the tumor was diagnosed as hemangioma. Chemotherapy and radiotherapy were attempted, but there was no effect on tumor growth. When the infant was 6 months old, the serum calcium level increased rapidly, associated with the expansion of the tumor. Hypophosphatemia due to phosphaturia was also observed. Serum PTH was undetectable, whereas the serum concentration of carboxyl-terminal (C-terminal) fragments of PTH-related protein (PTH-rP) was markedly elevated. Northern blot analysis and immunostaining demonstrated the expression of PTH-rP in the tumor. The tumor was transplantable to nude mice and caused elevation of circulating PTH-rP in the animals. Histological examination of the patient's bone revealed an increased number of osteoclasts. These findings were consistent with humoral hypercalcemia of malignancy caused by the excess production of PTH-rP. The tumor was identified histologically as infantile fibrosarcoma, which has not been reported as a cause of humoral hypercalcemia of malignancy to date. The expression of PTH/PTH-rP receptor messenger ribonucleic acid was detected in the tumor by the RT-PCR, suggesting that PTH-rP may have exerted its effect in the tumor in an autocrine/paracrine manner. In addition to the systemic effect of PTH-rP manifested as hypercalcemia, the PTH-rP secreted from the neoplasm could have been a local factor involved in the growth of the tumor.

The evolution of immunosuppression with FK506 in pediatric living-related liver transplantation

The effects of three FK506 induction regimens on pediatric living-related liver transplantation (LRLT) were studied retrospectively in terms of patient survival and adverse side effects. The patients consisted of 120 children, ranging from 3 to 210 months of age, who underwent a total of 122 LRLTs with a minimum follow-up of 6 months. Immunosuppression consisted of FK506 and low-dose steroids. FK506 was given in 3 ways: (1) high-dose intravenous (i.v.) induction, with FK506 begun at a dose of 0.15 mg/kg/day for the first 16 patients; (2) low-dose i.v. induction, with FK506 begun at a dose of 0.06 mg/kg/day for the next 45 patients; and (3) per os (p.o.) induction, with FK506 begun orally from the day prior to LRLT and continued postoperatively. Whole-blood trough levels of FK506 were monitored daily. Trough levels in the high induction group were often as high as 100 ng/ml compared with the level of 20 ng/ml in the p.o. induction group. Patient survivals were 75%, 89%, and 80% in the high-i.v. vs. low-i.v. vs. p.o. groups. The incidences of acute rejection were 12.5%, 22.2%, and 26.4%, and the incidences of viral infection were 56%, 38%, and 11% in the respective groups. Major adverse effects occurred with higher frequency in the high-i.v. induction group. Oral FK506 induction therapy at a dose of 0.15 mg/kg/day starting from the day before LRLT was safer and associated with a lower incidence of viral infection than therapy with i.v. FK506.

Angioscopic identification of coronary thrombus in patients with postinfarction angina

OBJECTIVES

The purpose of this study was to determine the prevalence of intracoronary thrombus and associated anatomic abnormalities in patients with postinfarction angina using coronary angioscopy and angiography.

BACKGROUND

Postinfarction angina, previously studied by angiographic methods only, identifies patients at high risk for sudden death, recurrent angina and refractory angina. The recent development of coronary angioscopy, which permits direct observation of a thrombus or atheroma and is especially used for the detection of intraluminal changes, encourages a reexamination of the pathogenesis of postinfarction angina.

METHODS

Fifty-one consecutive patients with a diagnosis of acute myocardial infarction underwent cardiac catheterization. Coronary angiography followed immediately by coronary angioscopy was performed in 17 patients with and 34 without postinfarction angina during the same period of time (10.2 +/- 3.7 or 15.7 +/- 5.5 days [mean +/- SD]) after the onset of acute myocardial infarction.

RESULTS

The frequency of thrombus, as observed by angioscopy, was significantly higher in patients with than without postinfarction angina (17 of 17 vs. 5 of 34, respectively, p < 0.01). There were no significant differences between groups with respect to degree of stenosis in the infarct-related artery, number of vessels with significant stenosis, presence of collateral flow, type of therapy and risk factors.

CONCLUSIONS

Infarct-related artery thrombus is universally present in postinfarction angina and may be the primary pathogenic factor. Angioscopy is much more sensitive than coronary angiography for the detection of coronary thrombus.

Osteogenesis by human osteoblastic cells in diffusion chamber in vivo

Osteogenic potential of osteoblastic cells isolated from human bone was evaluated by a diffusion chamber method. Cells placed in diffusion chambers were implanted intraperitoneally into the athymic mice. The diffusion chambers cultured in vivo were harvested and examined after implantation for 6-8 weeks. The content of the chamber was proved by a soft roentogenogram to contain the radioopaque area. Light microscopic study revealed that this area was made up of bone-like nodule. Within the diffusion chambers, the cell layers were observed alongside the interior surface of the membrane filters, and mineralized nodules were formed among the cell layers. The mineralized nodules were confirmed by staining with the von Kossa technique for calcium mineral deposits. In electron microscopic study, the osteoblastic cells had a relatively large nuclei, and an abundant rough endoplasmic reticulum produced numerous extracellular matrix. In the bone-like nodules, the osteoblastic cells were surrounded by a heavily mineralized matrix with nonmineralized matrix separating the osteoblastic cells from the mineralized matrix. The mineralized matrix contained well-banded collagen fibrils. Matrix vesicles and collagen fibrils which were closely associated with mineral deposition were observed at the mineralizing front. These results together with our previous report [13] indicate that isolated human osteoblastic cells possessed osteogenic potential in vivo as well as mineralization activity in vitro.

The effects of orally administered atenolol on the coronary hemodynamics and prostaglandin metabolism in angina pectoris patients

The effects of oral atenolol on coronary hemodynamics and prostaglandin metabolism have been investigated in 8 chronic stable angina pectoris patients who underwent the supine bicycle ergometer. At rest, atenolol taken orally reduced the pressure-rate product significantly (P < 0.05) but did not significantly affect the coronary sinus blood flow or the coronary sinus pressure. During exercise, atenolol also reduced the pressure-rate product significantly (P < 0.05) but did not significantly affect the coronary sinus blood flow, the coronary sinus pressure, or the coronary vascular resistance. Atenolol also did not significantly affect the thromboxane B2/6-keto prostaglandin F1 alpha ratio in the arterial blood before and after exercise but did reduce this ratio in the coronary sinus blood by 15% from 1.9 +/- 1.1 to 1.5 +/- 0.46 (P < 0.10) after exercise. These results indicate that atenolol taken orally does not significantly depress the coronary hemodynamics. However, the effects of atenolol on the prostaglandin metabolism could not be clearly determined.

Angioscopy in variant angina: coronary artery spasm and intimal injury

Studies in pigs and dogs show that intimal injury is related to coronary artery spasm; it is not known whether intimal injury is related to coronary artery spasm in human beings. We examined intima at the site of coronary artery spasm by percutaneous transluminal coronary angioscopy in 10 of 13 consecutive patients with variant angina. Coronary artery spasms occurred spontaneously or were induced by intracoronary acetylcholine (10-100 micrograms). Angioscopy showed intimal injuries (haemorrhage, flap, thrombus, or ulcer) in 4 of the 10. We suggest that intimal injury is related to coronary artery spasm in human beings.

[Leiomyosarcoma of ileocecal mesentery--a case report]

We report a case of leiomyosarcoma whose origin was near the root of ileocecal mesentery and extended into the retroperitoneum. Preoperative imaging examination, including CT, MRI and angiography clearly displayed its origin and retroperitoneal extension. These results contributed to treatment planning.

Plasma volume contraction in portal hypertension

The effect of blood volume contraction induced by a 4-week regimen of spironolactone (100 mg/day) or furosemide (40 mg/day) on the hepatic venous pressure gradient (HVPG), an indicator of portal hypertension, was evaluated in patients with cirrhosis and no ascites. In the spironolactone group (n = 15), HVPG decreased significantly from 16.5 +/- 0.9 mmHg (mean +/- S.E.M.) to 12.9 +/- 1.0 mmHg (P < 0.005) and total blood volume contracted significantly from 4338 +/- 231 ml to 4006 +/- 203 ml (n = 14, P < 0.01). Although the HVPG changes did not correlate significantly with changes in measured total blood volume or in simultaneously determined systemic haemodynamics, a significant inverse correlation (r = -0.74, P < 0.01, n = 12) was found between the HVPG change and posttreatment plasma aldosterone levels, attesting to the effectiveness of spironolactone therapy in lowering HVPG. In the furosemide group (n = 10), neither HVPG (13.7 +/- 0.3 mmHg vs. 13.6 +/- 0.9 mmHg) nor total blood volume (4961 +/- 153 ml vs. 4964 +/- 162 ml) declined significantly. These results show that long-term administration of spironolactone to patients with cirrhosis and no ascites produced a significant reduction in HVPG that may have been due to gradual, sustained volume contraction. Thus, spironolactone may prove to be an effective treatment for portal hypertension in cirrhosis without ascites.

Angioscopy, coronary thrombi and acute coronary syndromes

Coronary angioscopy is a new diagnostic imaging technique in which optic fibres are used to directly observe the intracoronary lumen. Angioscopy provides a full colour, high resolution, three-dimensional image of the intracoronary artery surface morphology. Studies using angioscopy revealed that the frequency of coronary thrombi in patients with acute coronary syndromes was higher than previous studies, based on arteriography, had reported. Arteriographic recognition of thrombus in unstable angina was from 1.3% to 52%. On the other hand, thrombi were observed in 88% by angioscopy in patients with rest angina in our study. Whereas ordinary arteriography provides only two-dimensional black and white images, angioscopy can distinguish between a thrombus and a plaque, even if the clot is very small. In a study of 17 unstable angina and 22 myocardial infarction patients, the frequencies of coronary thrombi in the two groups were essentially the same. Grayish-white thrombi were observed in most of the unstable angina patients but in none of the infarction patients. On the other hand, red or mixed red and white thrombi were observed in all infarction patients but in only a few unstable angina patients. This difference may account for the contrasting results of thrombolytic therapy.

The pathogenesis of an impending infarction and its treatment--an angioscopic analysis

To clarify the pathogenesis of an impending infarction and to investigate the difference between the pathogenesis of an acute myocardial infarction and an impending infarction, we have performed percutaneous transluminal coronary angioscopy in 13 patients with an impending infarction and in 13 patients with an acute myocardial infarction. As a result, coronary thrombi were observed in 12 of the 13 patients with an impending infarction, and a similar frequency of thrombi was observed in the patients with an acute myocardial infarction. Further, grayish white thrombi were observed in 9 of 12 patients with an impending infarction, but no such thrombi were noted in those with an acute myocardial infarction. Reddish thrombi, however, were observed in all patients with acute myocardial infarction, whereas such thrombi were observed in only 3 of 12 patients with an impending infarction. Informatively, occlusive thrombi occurred more frequently in patients with an acute myocardial infarction than in those with an impending infarction. As a thrombus plays an important role in an impending infarction, we also evaluated the effect of anticoagulant and thrombolytic therapy for an impending infarction in 79 patients. The incidence of recurrent angina and a subsequent acute myocardial infarction were significantly higher in non-heparin-treated patients and in thrombolytic-treated patients than in heparin-treated patients. In conclusion, a thrombus plays an important role in the pathogenesis of an impending infarction and in an acute myocardial infarction, though the characteristics of the thrombus differ in each instance. This difference may account for the differing results of thrombolytic therapy. Heparin was found an effective treatment for myocardial ischemia in an impending infarction.

The effectiveness of coronary angioscopy in detecting intraluminal pathologic changes

We have evaluated the feasibility of percutaneous transluminal coronary angioscopy for detecting intraluminal pathological changes as a diagnostic tool, and investigated the pathogenesis of two acute coronary disorders, acute myocardial infarction and unstable angina. Twelve patients with an acute coronary disorder and 20 patients who underwent percutaneous transluminal coronary angioplasty were selected for this comparison between the diagnostic accuracy of angioscopy and arteriography. One hundred and thirty patients were investigated by angioscopy as follows in order to investigate the pathogenesis of their acute coronary disorders: 22 within 8 h of onset acute myocardial infarction; 28 from one day to 2 months since onset recent myocardial infarction; 37 with an old myocardial infarction; 26 with unstable angina; and 23 with stable angina. Our results have indicated thrombi were detected more frequently by angioscopy than by arteriography (p less than 0.01). Also, thrombi, intimal irregularities, and xanthomatous atheromas were observed more frequently in patients with acute myocardial infarction, recent myocardial infarction, and unstable angina. It is concluded that coronary angioscopy is a much more sensitive method for detecting intraluminal changes, and that a thrombus overlying a rupture in the lining of plaque plays a major role in an acute coronary disorders, and that the fragile, lipid-rich gruel atheroma may precede its rupture.

Evaluation of vitamin D-binding protein and vitamin D metabolite loss in children on continuous ambulatory peritoneal dialysis

We measured the serum concentration of vitamin D-binding protein (DBP) in children with chronic renal failure (CRF). We also evaluated the relationships between the peritoneal loss of vitamin D metabolites, DBP and albumin in nine children on continuous ambulatory peritoneal dialysis (CAPD). The serum levels of DBP in children with CRF were significantly higher than in normal children. The mean serum DBP level in CRF children undergoing CAPD was slightly lower than in CRF patients who were not on dialysis. In patients on CAPD, the peritoneal loss of 25-hydroxyvitamin D (25OHD) showed a significant positive correlation with the DBP concentration in the dialysate (r = 0.855, P less than 0.005). In contrast, the peritoneal loss of 1,25-dihydroxyvitamin D (1,25(OH)2D) showed a significant correlation with the loss of albumin in the dialysate (r = 0.779, P less than 0.01). The synthesis of 1,25(OH)2D3 is reduced in advanced renal failure, and the peritoneal losses of the active vitamin D sterols in patients on CAPD may aggravate this deficiency. We recommend that supplementation of active form of vitamin D, such as 1 alpha-hydroxyvitamin D3 or 1,25(OH)2D3, is important in CAPD patients, particularly those with elevated peritoneal loss of DBP and/or albumin.

Long-term haemodynamic effects of a 4-week regimen of nipradilol, a new beta-blocker with nitrovasodilating properties, in patients with portal hypertension due to cirrhosis. A comparative study with propranolol

To study the long-term effects of pharmacological combination therapy, a comparison was made of the haemodynamic changes in patients with cirrhosis and portal hypertension following a 4-week treatment of propranolol or nipradilol, a new nonselective beta-blocker with nitrovasodilating effect. Nipradilol (12 mg/dag, n = 12) significantly diminished wedged hepatic venous pressure (WHVP, 25 +/- 16%), the hepatic venous pressure gradient (HVPG, 20 +/- 12%), and estimated hepatic blood flow (EHBF, 18 +/- 16%). Propranolol (30 mg/day, n = 11) also caused a significant reduction in WHVP (22 +/- 21%) and HVPG (24 +/- 21%), but not in EHBF. The percentage of portal pressure reduction and the frequency of nonresponders did not differ between the nipradilol and propranolol groups. Both agents reduced heart rate by approx. 20%. Nipradilol, however, did not cause a significant reduction in cardiac index (CI) versus a 14% reduction by propranolol. Pulmonary capillary wedge pressure and central venous pressure, an index of preload, were decreased slightly in the nipradilol group. When nonresponders were excluded, there was a significant correlation of the percentage of reduction between WHVP and CI or systemic vascular resistance, in the nipradilol group. These results indicate that nipradilol may have potent hypotensive effects on portal hypertension, similar but not superior to propranolol. Nipradilol, at the dosage used in the present study, did not appear to exert a nitrovasodilating effect to enhance the portal pressure reduction induced by beta-blocking action.

Differences in plasma beta-endorphin and bradykinin levels between patients with painless or with painful myocardial ischemia

To verify whether plasma beta-endorphin and bradykinin affects the pathophysiology of myocardial ischemia and the perception of cardiac pain, 35 patients with coronary artery disease were subjected to treadmill testing and 48-hour Holter ECG monitoring to measure their pain thresholds. Patients were divided into two groups during exercise testing: group 1 (N = 19) who had ST segment depression, and group 2 (N = 16), who had chest pain. Both groups were then compared with 12 age-matched control subjects. Pain thresholds were measured after Holter ECG monitoring, and blood samples were drawn before and immediately after exercise. No statistical differences were noted between groups 1 and 2 with regard to the severity of myocardial ischemia as assessed by ST segment depression or exercise tolerance time. The frequency of the episodes of silent myocardial ischemia in group 1 was found to be significantly (p less than 0.05) higher than that in group 2. The duration of the episodes of silent myocardial ischemia in group 1 was 41.9 minutes (range 3 to 343 minutes), which was significantly (p less than 0.05) longer than that in group 2 (11.5 minutes; range 0 to 74). The pain threshold in group 1 was a statistically (p less than 0.05) higher value than that in group 2. Although the resting plasma beta-endorphin level in group 1 was not statistically significantly different from values in either group 2 or the control group, during exercise the plasma beta-endorphin levels in both group 1 and the control group were significantly (p less than 0.05) elevated in comparison with their resting levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioscopic evaluation of coronary-artery thrombi in acute coronary syndromes

BACKGROUND

Disruption of an atherosclerotic plaque in a coronary artery followed by the formation of a thrombus is believed to be the cause of both unstable angina and acute myocardial infarction. Although thrombolytic therapy is efficacious in patients with acute myocardial infarction, for unknown reasons it is far less effective in patients with unstable angina. We postulated that there might be differences in the composition of the coronary-artery thrombi in unstable angina and acute myocardial infarction.

METHODS

To investigate the appearance of coronary-artery thrombi, we performed percutaneous transluminal coronary angioscopy in 15 patients with unstable angina and 16 with acute myocardial infarction. Angioscopy was performed within 48 hours after an episode of pain at rest in the patients with unstable angina and within 8 hours of onset in those with acute myocardial infarction.

RESULTS

Angioscopy revealed coronary thrombi in all but two patients (one in each group). Of the 29 patients with thrombi, those with unstable angina were frequently observed to have grayish-white thrombi (10 of 14, 71 percent), but none were seen in the 15 patients with acute myocardial infarction (P less than 0.01). By contrast, reddish thrombi were observed in all 15 patients with acute myocardial infarction who had thrombi, but in only 4 of the 14 patients with unstable angina and thrombi (P less than 0.01). As assessed by coronary angiography, occlusive thrombi occurred frequently in patients with acute myocardial infarction (13 of 16 patients) but were not seen in any of the 15 patients with unstable angina (P less than 0.01).

CONCLUSIONS

Coronary-artery thrombi play an important part in the pathogenesis of unstable angina and acute myocardial infarction. However, the appearance of the thrombi is different in the two conditions, possibly reflecting differences in the composition of age of the thrombi or the presence or absence of blood flow in the artery. This difference may account for the contrasting results of thrombolytic therapy.

Painless myocardial ischemia in elderly patients compared with middle-aged patients and its relation to treadmill testing and coronary hemodynamics

We compared painless ST-segment depression (1 mm greater than or equal to 80 ms and lasting greater than or equal to 60 s) in elderly patients with coronary artery disease (greater than or equal to 65 years, mean 67 years; n = 22) and that of middle-aged patients (less than 60 years, mean 54 years; n = 20) by Holter monitoring for 24 hours to determine the relationship between episodes of painless myocardial ischemia, findings of treadmill testing, and coronary hemodynamics. Coronary arteriographic findings (Gensini score) and ejection fraction (EF) did not differ between the two groups. Painless ST-segment depression was found to be 77% in the older age group versus 45% in the middle-aged group (p less than 0.05). However, treadmill exercise score, ST-segment depression, and ST-segment integral achieved did not differ significantly between the two groups. Within 2 weeks after the above testing, coronary hemodynamic study was performed. The increment of coronary sinus flow in the older age group was 1.4 +/- 0.3 versus 1.8 +/- 0.3 in the middle-aged group (p less than 0.05), and the change of lactate extraction ratio from the basal condition in the older age group was -50 +/- 40% versus -2 +/- 15% in the middle-aged group (p less than 0.05). We conclude that episodes of painless myocardial ischemia in elderly patients with aging may be associated with the impairment of the coronary vascular reserve and easier anaerobic myocardial metabolism by pacing stress despite similar findings of coronary artery disease and EF in both groups.

Differences in infarct size with lidocaine as compared with bretylium tosylate in acute myocardial ischemia and reperfusion in pigs

The effects of the antiarrhythmic drugs lidocaine and bretylium tosylate on myocardial necrosis were studied in anesthetized pigs subjected to 60-min coronary occlusion followed by 3-h reperfusion. Group A (n = 7) received lidocaine (average dose +/- SD = 1,828 +/- 515 mg) before and during coronary occlusion and after reperfusion; the other series (group B, n = 7) received bretylium tosylate (3,457 +/- 1,323 mg). Infarct size was 16.3 +/- 14.7% in the lidocaine group as compared with 68.6 +/- 12.6% (p less than 0.01) in the bretylium group. In vitro release of superoxide anion from porcine granulocytes was studied using the lucigenin-dependent chemiluminescence technique. Lidocaine significantly reduced the peak chemiluminescence response to zymosan from 3.34 +/- 0.44 without lidocaine to 2.23 +/- 0.46 (p less than 0.01) and 1.06 +/- 0.17 mV (p less than 0.001), with lidocaine concentrations of 20 and 200 micrograms/ml, respectively. Bretylium had no effect on the chemiluminescence response. Adherence of porcine granulocytes to plastic was also reduced from 332 +/- 32 cells/mm2 (no lidocaine) to 247 +/- 35 and 206 +/- 26 cells/mm2 with lidocaine concentrations of 20 and 200 micrograms/ml, respectively (p less than 0.001). Bretylium had no significant effect. Eight additional bretylium-treated pigs received either rabbit antiporcine granulocyte serum (group C, n = 4) to reduce circulating granulocytes or nonimmune serum (group D, n = 4). Infract size in the granulocyte-depleted pigs was 26.6 +/- 5.6% as compared with 51.4 +/- 5.5% in pigs that received nonimmune serum (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)