Effects of amlodipine versus diltiazem on morning peak in myocardial ischemic activity in angina pectoris.
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Biomedical subjects
Publications and source records attributed to D Cunningham.
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Twenty-six patients, whose B-cell lymphoma had relapsed after conventional therapies, were treated in a phase I dose escalation study with an immunotoxin consisting of a mouse CD22 monoclonal antibody (RFB4:IgG1K) coupled to chemically deglycosylated ricin A chain (dgA). Two to 12 doses of the immunotoxin were infused intravenously at 48-hour intervals. The peak serum concentration and half-life (T1/2) did not correlate directly with the dose and averaged 3.8 micrograms/mL and 7.8 hours, respectively. The main dose-limiting toxicity was caused by the vascular leak syndrome (VLS) consisting of weight gain, edema, serum albumin decrease, and critically by pulmonary edema. Myalgia occurred frequently and was only dose limiting in one patient who developed rhabdomyolysis. The presence of lymphoma cells in the blood (> or = 10(10)/L) and clinically detectable splenomegaly were associated with reduced toxicity and a shorter T1/2. Nine of 24 evaluable patients (37.5%) made antibody to either mouse Ig or dgA. There were five partial responses (PR) and one complete response (CR) lasting 30 to 78 days. High peak concentrations of immunotoxin in the serum, a long T1/2, and large areas under the curve (AUC) correlated with both clinical response and toxicity. None of three patients with CD5+ lymphomas (including two CLL patients) had more than mild toxicity or responded to the immunotoxin.
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2'-Chlorodeoxyadenosine (2CDA) is a purine analogue selectively active against both resting and dividing lymphoid cells. Twenty-one patients with a variety of previously treated lymphoid malignancies received a total of 41 courses of 2CDA (0.1-0.15 mg/kg/day over 7 days continuous intravenous infusion) on compassionate grounds. The profile of the patient population was as follows: low grade non-Hodgkin's lymphoma (NHL) = 8, intermediate grade NHL = 2, transformed (intermediate grade NHL) = 6, Hodgkin's disease = 1, lymphoplasmacytoid NHL = 3 and lymphoblastic NHL = 1. The overall response rate was 53%, with three patients attaining complete remission (CR) and eight partial remission (PR). Three of 16 patients with primary resistant or resistant recurrent disease entered either CR (1) or PR (2). Ten patients had no response or progressive disease. The latter group was comprised of patients who had extensively pre-treated lymphoplasmacytoid tumours and/or poor performance status (WHO grades 2-4). The median duration of response is 6 months (range 1 to 12 months). Treatment was well tolerated and the chief toxicities were leucopenia and thrombocytopenia which were most pronounced when there was bone marrow involvement. As a result of dose limiting myelotoxicity, a dose escalation to 0.15 mg/kg/day was possible on just three occasions. These data confirm other reports of the activity of 2CDA in low grade NHL and indicate it may have activity in Hodgkin's disease. There was no demonstrable activity in poor performance status patients or those with extensively pre-treated lymphoplasmacytoid tumours.
At a median time of 20 months following high dose melphalan for myeloma, 29 patients relapsed and were treated with induction chemotherapy to maximum response followed by a second course of high dose melphalan. The majority (90%) of patients received 200 mg m-2 with an autologous bone marrow transplant. Sixteen (55%) patients achieved complete remission and 11 (38%) a partial response. The median duration of remission was 17 (4-42) months. The median survival has not been reached, with 50% of patients alive at 58+ months after presentation. The period of neutropenia was similar during both first and second high dose procedures, but the duration of thrombocytopenia was longer in patients receiving melphalan for a second time (median 22 (16-56) days and 41 (18-69) days respectively). There was one treatment-related death due to thrombocytopenic haemorrhage. Repeated administration of high dose melphalan is a feasible approach for patients with relapsed myeloma.
OBJECTIVE: To assess the long-term (four to 10 years) prognostic significance of transient ST segment changes on ambulatory ST segment monitoring after coronary artery bypass grafting (CABG). PATIENTS AND METHODS: 76 patients (67 men, nine women) underwent CABG between 1982 and 1984 (n = 31) and between 1987 and 1988 (n = 45) and at a mean age of 57. All underwent 48 hours of ambulatory ST segment monitoring at a mean of 19 weeks after surgery. The results were available for assessment. All general practitioners were contacted and patients' notes reviewed. Patients were contacted by telephone. Details were recorded of intervening events (acute myocardial infarction, unstable angina, need for further revascularisation, and deaths). Event free survival curves were produced for those with and without transient ST segment changes during routine postoperative ambulatory ST segment monitoring. RESULTS: During 3213 hours of monitoring after CABG, 21 (27.6%) of 76 patients had transient ST segment changes, of which 70% were silent. Over a mean 70 month follow up period, patients with such ischaemic changes were no more likely to have either an objective (myocardial infarction or cardiac death) or subjective (unstable angina or another revascularisation) event than those patients without ischaemic changes. This finding was the same in patients operated on between 1987 and 1988 and between 1982 and 1984. CONCLUSIONS: Although ambulatory ST segment monitoring is becoming increasingly popular in some countries as a routine investigation for ischaemia in various coronary subgroups, the findings of such an investigation, when performed after CABG, do not help to identify a subgroup more likely to have an adverse outcome during up to 10 years of follow up. There seems to be no reason to perform this investigation after surgery, and particularly to refer patients for reinvestigation because of the detection of predominantly silent ST segment changes of uncertain relevance.
PURPOSE: This prospective study of patients treated at the Royal Marsden Hospital Lymphoma Unit was designed to evaluate the role of magnetic resonance imaging (MRI) in the assessment of residual masses evident on computed tomographic (CT) scanning following treatment of lymphoma. PATIENTS AND METHODS: All patients had MRI, gallium-67 single-photon emission CT (67Ga SPECT), and erythrocyte sedimentation rate (ESR) performed within 3 months of completing therapy. Patients were monitored for 1 year posttreatment and observed for signs of relapse. Investigation results were correlated with disease status, and the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) calculated. Time-to-relapse curves were derived and the log-rank test used to determine whether patients with a positive result were more likely to have a relapse within the mass than those with a negative result. RESULTS: Thirty-four patients were studied, 14 of whom relapsed, 11 within the area of residual mass. Overall, MRI had a high specificity (90%), PPV (71%), and NPV (75%), but poor sensitivity (45%). The results for 67Ga SPECT were similar, apart from lower sensitivity (33%). ESR had inferior performance in predicting relapse compared with the other tests. MRI was the only investigation to show statistical significance (P = .14) in predicting relapse, and this was particularly evident in Hodgkin's lymphoma (P = .003). Combining results of 67Ga SPECT and MRI did not improve predictive power. CONCLUSION: These data demonstrate that MRI is a valuable tool in the setting of a residual mass after treatment, giving clinically useful prognostic information. 67Ga SPECT also has a role, but is less effective in predicting relapse than MRI.
A multicentre, randomised vehicle-controlled single-blind dose ranging trial of intravenous recombinant granulocyte colony-stimulating factor (rhuG-CSF) administration after BMT has been performed in 121 patients with non-myeloid malignancies. All the doses of rhuG-CSF used (2-20 micrograms/kg/day) resulted in significant acceleration of neutrophil recovery, and a dose-response effect was apparent (p < 0.05). At the 20 micrograms/kg/day dose of rhuG-CSF the median time taken to achieve a neutrophil count of > 0.5 x 10(9)/1 was reduced from 19 to 13 days (p < 0.001) and the time to achieve a neutrophil count > 1.0 x 10(9)/1 on the first of 3 consecutive days, from 26 to 14 days (p < 0.001). There was a trend to less antibiotic use in the rhuG-CSF recipients and the median time in hospital was markedly reduced by 11-15 days (p < 0.01). There was no toxicity in this study attributable to rhuG-CSF.
The role of vascular alpha 1B-adrenergic receptors in the regulation of arterial pressure (MAP) and heart rate (HR) was examined by assessing the effect of i.v. chloroethylclonidine (CEC; irreversible alpha 1B antagonist) in unanesthetized, normotensive Long-Evans rats. MAP, HR and the pressor response to i.v. phenylephrine (PE) were monitored for 24 hr after saline or CEC (15 mg/kg and 25 mg/kg) injection. Neither i.v. saline nor CEC affected MAP or HR throughout the course of the study, yet the PE response was maximally inhibited (> 75% at 15 min) by both doses of CEC. The PE response recovered by 2 hr at the 15-mg/kg dose but remained inhibited up to 4 hr at 25 mg/kg. At 24 hr, all cardiovascular parameters returned to control levels. CEC (100 microM, 30 min) produced irreversible blockade of norepinephrine-induced contractions in rat aortic rings; prazosin (10 nM) and sodium thiosulphate (1 mM, a reagent that inactivates aziridinium ions) reversed CEC's inhibitory effect. Precyclized CEC and its hydrolysis product beta-hydroxyethylclonidine (beta-HEC) poorly antagonized aortic alpha 1B-receptors. Ex vivo analysis of aortic rings from saline and CEC-treated rats showed that PE-induced contractions were shifted to the right and maximally depressed in a dose-dependent manner after 24 hr. These results suggest that 1) CEC produces long lasting blockade of alpha 1B-adrenoceptors in vitro and in vivo via formation of an aziridinium ion intermediate and 2) vascular alpha 1B-adrenoceptors are not coupled to the tonic physiological regulation of MAP in the rat.
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The primary sequences of the three individual glycoprotein (GP) chains, GPIb alpha, GPIb beta, and GPIX, comprising the normal platelet GPIb/IX receptor for von Willebrand factor (vWF) have recently been determined, opening the possibility for characterization of disorders of this receptor at the molecular level. The presence of a leucine tandem repeat in each of these chains is of particular interest, because such repeats may be involved in associations between polypeptide segments. We now report an autosomal dominant variant of Bernard-Soulier disease associated with the heterozygous substitution of phenylalanine for a highly conserved leucine residue within the GPIb alpha leucine tandem repeat. Affected individuals experienced a moderate bleeding tendency, thrombocytopenia, and an increased mean platelet volume. Platelet aggregation was decreased only in response to ristocetin or to asialo-vWF. The kd for 125I-vWF binding to patients platelets was significantly increased over control values at 0.5 mg/mL ristocetin, but was normal at 1.0 or 1.5 mg/mL ristocetin. While sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed an essentially normal complement of all components of the GPIb/IX complex, a minor amount of a putative proteolytic fragment was identified that migrated faster than GPIb and was immunoreactive with polyclonal anti-GPIb alpha antibody, but not with a monoclonal antibody directed against the 45-Kd amino-terminal region of GPIb alpha. However, because the great majority of patient GPIb alpha comigrates with normal GPIb alpha, the major functional abnormalities of the patient platelets are most likely a consequence of the altered structure of the nonproteolyzed protein. Full concordance within the studied family between phenotypic expression and a heterozygous single nucleotide substitution in genomic DNA coding for a phenylalanine in place of the wild-type leucine at residue 57 of the mature GPIb alpha, absence of this substitution in 266 alleles from the normal population, and the lack of any other abnormality of patient DNA throughout the entire coding sequence for GPIb alpha provide strong support that this substitution may constitute a pathologic point mutation responsible for the observed phenotypic abnormalities. While the roles that leucine tandem repeats may normally play within the GPIb/IX complex are not yet known, the perturbation of such a repeat in GPIb alpha may impair interaction with other components of the complex and/or with the binding of vWF.
A "priming" injection of cyclophosphamide (400 mg/m2 given i.v. on day -7) has been shown to reduce intestinal permeability and thus gut toxicity in patients receiving high-dose melphalan. To determine the optimal timing for this injection, patients receiving 200 mg/m2 melphalan with an autologous bone marrow transplant were randomly assigned to receive cyclophosphamide at 5, 7 or 9 days before the melphalan. The median percentage of [51Cr]-ethylenediaminetetraacetic acid excretion was similar (9.1% vs 7.1% vs 7.7%, respectively), with equivalent duration of WHO grade 2-4 mucositis and diarrhoea being recorded for each group. Thus, the timing of the cyclophosphamide prime is not critical, and the priming injection may be given between 5 and 9 days prior to high-dose melphalan.
Protease nexin-II (PN-II) is a potent chymotrypsin inhibitor that forms SDS-stable inhibitory complexes with epidermal growth factor binding protein, the gamma-subunit of nerve growth factor, and trypsin, and represents the secreted form of the amyloid beta-protein precursor (APP) that contains the Kunitz-type protease inhibitor domain. To determine the expression of PN-II within the peripheral nervous system, human dorsal root ganglia were processed for immunocytochemistry using well-characterized monoclonal antibodies against PN-II and for in situ hybridization studies using 35S-RNA PN-II probes for both APP751 and APP770. Highly specific immunoperoxidase staining of PN-II was demonstrated within the cytoplasm of dorsal root ganglia neurons and their processes in cryostat (fresh frozen) and vibratome (paraformaldehyde-fixed) sections. In situ hybridization using an anti-sense 35S-RNA PN-II probe demonstrated the presence of intense neuronal labeling. Labeling was not observed when the corresponding sense 35S-RNA PN-II probe was used. Although the precise functional role of PN-II/APP is not clear, the accumulation of amyloid beta-protein within the neuropil appears to be one of the earliest events in the pathogenesis of Alzheimer's disease (AD). Thus knowledge of the cell populations expressing the PN-II/APP gene would certainly be helpful for studies of the molecular mechanisms leading to the morphological and functional changes of AD. The results of this study clearly establish the expression of PN-II and its mRNA within the dorsal root ganglia neurons and their processes, and provide another point of departure for studies of the molecular mechanisms underlying the deposition of amyloid beta-protein and its relationships to the formation of neuritic plaques and neurofibrillary tangles.
Abnormal dispersion of repolarization may contribute to the arrhythmogenic physiologic substrate of ventricular arrhythmia. Geographic dispersion of monophasic action potential duration was determined in steady state (drive cycle lengths 600 and 430 ms) between widely spaced right ventricular endocardial sites (geographic dispersion) in 10 control patients with right ventricular disease and complicating ventricular tachycardia (n = 9), 6 patients with right and left ventricular disease and complicating ventricular tachycardia and 7 patients with ischemic heart disease and complicating ventricular tachycardia. No significant difference in geographic dispersion could be demonstrated among the groups. Difference of monophasic action potential duration at adjacent right ventricular endocardial sites (adjacent dispersion) was determined after ventricular extrastimulation during construction of simultaneous electrical restitution curves in the same patient groups. Maximal adjacent dispersion over the electrical restitution curve was compared between disease and control groups. There was a significant difference in observations of maximal adjacent dispersion in patients with right ventricular disease and complicating ventricular tachycardia (range 5 to 85 ms, median 22.5; 14 pairs of sites; p less than 0.05) and patients with right and left ventricular disease and complicating ventricular tachycardia (range 5 to 50 ms, median 17.5; 14 pairs of sites; p less than 0.05) compared with control patients (range 5 to 20 ms, median 10; 15 pairs of sites). This difference was not evident when patients with ischemic heart disease and complicating ventricular tachycardia (range 5 to 25 ms, median 12.5; 12 pairs of sites) were compared with control patients. Maximal percent monophasic action potential shortening from steady state was significantly greater (p less than 0.001) in both groups with greater adjacent dispersions, and prolongation of activation time at monophasic action potential recording sites after premature extrastimulation tended to be greater in patients with right or right and left ventricular disease and complicating ventricular tachycardia. It is concluded that in disease, exaggeration of monophasic action potential shortening after premature ventricular extrastimulation may contribute to the electrophysiologic arrhythmogenic substrate.
Carcinoma of the stomach is increasingly treated with chemotherapy. We describe two cases of intra-abdominal panniculitis in patients after laparotomy and chemotherapy for stomach carcinoma. Intra-abdominal panniculitis can result in mass lesions in the mesentery and omentum. The diagnosis should be considered in patients who have undergone chemotherapy for stomach carcinoma and who develop abdominal masses.
Following a single intravenous dose given pre-chemotherapy, the efficacy and tolerability of oral ondansetron treatment given twice daily was compared with the established three times daily oral supplementary regimen in the prophylaxis of nausea and vomiting induced by cyclophosphamide (greater than or equal to 500 mg/m2) in combination with doxorubicin (greater than or equal to 40 mg/m2) or epirubicin (greater than or equal to 40 mg/m2). Oral ondansetron given twice daily or three times daily was equally effective in controlling nausea and emesis. The twice daily oral treatment prevented emesis in 73% of patients in the first 24 hours and in 65% of patients over 3 days. Both dose schedules were safe and were tolerated well. Twice daily oral ondansetron showed good efficacy for controlling emesis and nausea in oncology outpatients.
OBJECTIVE: To characterise electrical restitution in the intact human heart. PATIENTS AND METHODS: A series of monophasic action potential electrical restitution curves were constructed from a single right ventricular endocardial site in eight patients (three men) without structural heart disease aged 52-68 (mean 55 years). A combination pacing/monophasic action potential electrode was used to pace and record monophasic action potentials at drive cycle lengths of from 350 ms to 1500 ms. Ventricular extrastimuli were delivered at 20 cycle intervals and decreased from the longest coupling interval attainable without escape beats. RESULTS: Restitution curves shifted downward and towards the left; steady state action potential duration shifted from the restitution plateau and descended the curve, the amount of shift being linearly related to drive cycle length in two patients in whom the relation could be assessed; the amount of monophasic action potential shortening was a function of the degree of prematurity and that relation was unaffected by drive rate; the magnitude of restitution and the time constant of the restitution curve were not changed significantly by altered drive cycle length. CONCLUSION: In the intact heart in vivo, electrical restitution (of the monophasic action potential) has similar characteristics to those (of the transmembrane action potential) in cellular preparations in vitro. Thus the alteration of action potential plateau currents by instantaneous rate change or drug effects, which can be directly observed by techniques available to the cellular electrophysiologist, may be indirectly assessed in vivo by characterisation of the effect of these on electrical restitution.
Invasive cardiac electrophysiology studies began as diagnostic studies. The past decade has seen the introduction of several new treatments which have broadened the scope of invasive electrophysiology studies. In particular, the development of catheter ablation techniques increasingly allows curative treatment to be delivered in the catheter laboratory. The workload of electrophysiological procedures has steadily increased in our tertiary referral centre. Over 1000 patients have been treated in the past 20 years and it is projected that 219 new patients will be treated in 1991 and 342 procedures will be carried out. Over 25% of patients now receive either catheter or surgical ablation and almost 80% of these are cured permanently without the need for further drug treatment. The development of safer techniques for catheter ablation has led to its increased use and a decline in surgical ablations. Because catheter ablation is a much simpler and less traumatic procedure than surgical ablation there are great advantages both for the patient and in terms of cost-effectiveness. Antitachycardia pacing, relatively common in 1985, has now largely been supplanted by ablation and implantation of defibrillators. As the tendency to non-pharmacological treatment increases and evidence mounts that cost-effectiveness is greater for electrophysiological treatments, the implications for the funding of electrophysiology services grow. The initially high cost of curative treatment needs to be balanced against the longer term and potentially higher costs of palliative drug treatment. The potential to cure patients with catheter procedures may lead to a greater demand for this expertise and a need for an increase in training and facilities.