Binding and functional characteristics of beta adrenergic receptors in the intact neutrophil

Beta adrenergic receptors have been previously characterized in human neutrophil sonicates. In the present study the intact neutrophil has been assessed for the number and affinity of beta adrenergic binding sites by using the antagonist DNA. Agonist and antagonist potencies, characterized by their effect on DHA binding and cyclic AMP accumulation, are compared with agonist inhibition of lysosomal enzyme (beta glucuronidase) release. Criteria for beta adrenergic receptor identification were successfully demonstrated. At 30 degrees C, beta adrenergic binding was rapid (t 1/2 2 min) and reversible (t 1/2 9 min). Receptor binding was saturable, revealing approximately 900 high-affinity receptors per neutrophil with DHA concentrations of 0.1 to 10 nM. By utilizing both equilibrium and kinetic techniques, the KD was determined to be approximately 0.6 nM. Agonists and antagonists competed for DHA binding in a manner consistent with their effect on cyclic AMP generation. Rank order potency was suggestive of a beta-2 receptor: isoproterenol greater than epinephrine greater than norepinephrine. Stereoselectivity was shown by the greater potency of L-propranolol compared to the D isomer. A high degree of receptor-adenylate cyclase coupling efficiency was suggested by the observation that with only 1% receptor occupancy isoproterenol stimulated 50% maximal cyclic AMP generation. Finally, there was an excellent correlation between the isoproterenol concentration which resulted in 50% of maximal inhibition of beta glucuronidase release (Ki) and that causing 50% maximal cyclic AMP stimulation (Kact), suggestive of a close relationship between beta adrenergic-induced adenylate cyclase activation and beta adrenergic regulation of neutrophil lysosomal enzyme release. The data presented suggest that the use of the intact neutrophil for study of the beta adrenergic receptor is feasible and may provide information which is considerably more closely related to modulation of physiological function by neurohormones than is possible with disrupted cell preparations.     

Studies on levamisole--induced agranulocytosis

Widespread clinical trials of leavo-tetramisole (levamisole) as an immunopotentiating agent in rheumatoid arthritis, metastatic carcinoma, and immunodeficiency states have been complicated by agranulocytosis (AGC) in 2.5%-13% of patients. Other than a relationship with prolonged high dosage, very little is known regarding the pathogenesis of levamisole-induced AGC. Whereas leukoagglutination was negative, fluorochromatic microgranulocytotoxicity (GCY) tests were positive with serum from 10 of 10 acutely neutropenic patients. The antibody was IgM, reacted with 100% of unrelated granulocytes, but not with T or B lymphocytes. Some sera also reacted with monocytes and the myeloid cell line, K-562. Tests for antigen-antibody complexes or cold autoantibodies were negative. Although clinical evidence strongly suggests a haptene (drug) mechanism, in vitro mixing experiments were also negative. An alternative choice parallels the model of aldomet- induced Coombs'-positive hemolytic anemia. Finally, GCY first became positive 2-3 mo prior to the onset of AGC on two patients, suggesting the possibility of identifying those at risk well before the onset of neutropenia.     

Marrow transplantation for children with acute lymphoblastic leukemia in second remission

Fifty-seven children between the ages of 3 and 17 years with acute lymphoblastic leukemia (ALL) in chemotherapy-induced second bone marrow remission were given cyclophosphamide, total body irradiation, and bone marrow transplants from HLA-matched donors. Sixteen died of transplant- related complications. Eighteen relapsed between 56 and 833 days after transplantation, and 16 died of leukemia. Two survive in remission off treatment following chemotherapy. Twenty-three survive in continuous remission from 1.4 to 10.4 years after transplantation and the actuarial analysis shows disease-free survival of 40% with a plateau extending from 2.5 to 10.4 years.     

Long-term results of open mitral valve reconstruction for mitral stenosis

Open mitral reconstruction for rheumatic mitral stenosis (MS) was performed in 120 patients, 101 women and 19 men, aged 22 to 75 years (mean 49). Nine patients were functional class II, 106 class III, 5 class IV; 13 only underwent noninvasive studies, including echocardiography, before surgery, while 107 had preoperative cardiac catheterization studies. The latter showed a mean valve area of 1.09 cm2 and a pulmonary artery wedge to left ventricular mean diastolic gradient of 14 mm Hg. Cardiopulmonary bypass was used in all patients for open reconstruction under direct vision. Superior commissurotomy was done in 115 patients, inferior in 114, papillary muscles were incised and chordae lengthened in 39 and calcium was excised from valve leaflets in 23. Suture or ring anuloplasty was not required in any patient. The series was begun January 1972 and terminated in January 1984. Personal follow up was conducted in July 1984. There were no operative deaths in the 120 patients. There were 5 late deaths, all from noncardiac causes. The mean follow-up time was 53 months. The actuarial probability of survival at 10 years was 95 +/- 2%. Thromboemboli occurred in 9 patients; the probability of freedom from thromboemboli at 10 years was 91 +/- 3% and the linearized rate was 1.8%/patient-year of follow-up. Reoperation was required in 9 patients, an absolute incidence of 7.5% and an annual incidence of 1.7%/patient year. At 10 years the probability of freedom from reoperation was 84 +/- 5%.     

Biliary lithotripsy: early observations in 106 patients. Work in progress

One hundred six patients underwent extracorporeal shock wave lithotripsy for cholelithiasis. Of these, 28 patients underwent cholangiographically guided lithotripsy for bile duct stones to assist nonoperative stone removal by endoscopic or radiologic intervention. Fragmentation occurred in 20 of 28 cases (71%) with an average of two lithotripsy sessions. Hemobilia was observed in four patients (14%) for a 24-hour period. Seventy-eight of the 106 were outpatients with symptomatic cholecystolithiasis with one to five calculi who underwent cholecystographic or ultrasound-(US) guided shock wave lithotripsy as definitive therapy. US examination showed stone fragmentation in 86% of cases. With an average of 1.6 treatment sessions and 4,750 shocks, fragments were 4 mm or smaller in 46% of patients. Nine percent of patients had no fragments after an average of 10 weeks, but long-term follow-up is not yet available. Two patients developed acute pancreatitis attributable to fragment passage and one patient acute cholecystitis, likely due to cystic duct obstruction by a fragment.     

In vivo phosphocreatine and ATP in piglet cerebral gray and white matter during seizures

The creatine kinase (CK) reaction is thought to be important in coupling ATP metabolism and regulating ADP concentration in tissues with high and variable ATP turnover, including cerebral gray matter (GM). There is low phosphocreatine (PCr), low CK reaction rates, and high mitochondrial CK (MiCK) isoenzyme activity in GM compared to white matter (WM). To compare the CK reaction in GM and WM when ATP metabolism is high, CK reactants and reaction rates were measured in predominantly GM and WM slices in vivo in 2 and 14-day old piglets during pentylenetetrazole (PTZ) seizures using ³¹P nuclear magnetic resonance (NMR) 1-dimensional chemical shift imaging (CSI). Arterial pressure, temperature, and blood gasses were stable at both ages. Before seizures, the PCr/nucleoside triphosphate (NTP) ratio was higher in WM than GM at both ages with a developmental increase seen in WM. The CK reaction rate constant increased in both regions between 2 and 14 days. During seizures, PCr/NTP increased in GM at 14 days due to increased PCr while the ratio and PCr decreased in WM. The NTP was more stable in WM and GM at both ages. The CK reaction rate decreased in both regions more at 2 than at 14 days. Thus, brain ATP, deduced from NTP, is stable during seizures in the piglet. In GM stable ATP is associated with a unique increase in PCr concentration.     

Antianginal Response to Once-Daily Diltiazem CD in Patients Receiving Concomitant β-Blockers,Long-Acting Nitrates,or Both

Study Objective . To determine the safety and efficacy of diltiazem CD 180 mg administered once/day in patients with chronic stable angina inadequately controlled with β-blockers, long-acting nitrates, or both. Design . Multicenter, randomized, double-blind, placebo-controlled, parallel-group trial. Setting . Medical clinics in the private and academic sectors. Patients . Of 172 patients, 170 completed the 2-week double-blind treatment period. Interventions . Patients received either diltiazem CD 180 mg or placebo once/day in combination with existing antianginal therapy. Measurements and Main Results . The time to termination of exercise tolerance testing, 24 hours after the dose increased significantly in the diltiazem CD group (37.2 sec) compared with the placebo group (21.3 sec, p=0.0438). Time to onset of angina during exercise testing also increased (57.6 vs 35.0 sec, respectively, p=0.0324), as did time to moderate angina (37.5 vs 20.6 sec, respectively, p=0.0354). The rates of total angina attacks and of angina attacks on exertion were significantly reduced in the diltiazem CD group versus placebo (p<0.05). Significant reductions in systolic and diastolic blood pressures and heart rate-blood pressure product measured at rest, submaximum exercise, and exercise termination were observed in diltiazem CD-treated patients compared with placebo (p<0.05). The frequency of treatment-related adverse events was identical in the two groups, 15.1%. Conclusion . Diltiazem CD 180 mg once/day is an effective, safe, and beneficial initial dosage when added to existing antianginal therapy.