Routine coronary angiography after heart transplantation

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Phase II trial of chloroquinoxaline sulfonamide (CQS) in patients with stage III and IV non-small-cell lung cancer

PURPOSE

Chloroquinoxaline sulfonamide (CQS) was one of the first agents identified by the human tumor colony-forming assay (HTCFA) as possessing antitumor activity in non-small-cell lung cancer (NSCLC). Prior phase I studies had suggested that plasma concentrations equivalent to those showing efficacy in the HTCFA could be reliably attained in humans. This phase II study assessed the antitumor activity of CQS while using an adaptive control pharmacokinetic modelling system to attain targeted plasma levels of this novel compound.

METHODS

A group of 20 patients with stage III or IV NSCLC received CQS as a 1-h weekly infusion at an initial dose of 2 g/m2. In all patients, 24-h plasma concentrations of CQS were measured. Patients with levels < 100 micrograms/ml had dose increases determined by their 24-h levels and pharmacokinetic parameters obtained from two prior phase I trials of this agent. These individuals had 24-h CQS levels repeated after their second weeks' treatment and doses were readjusted if the target concentration was not reached. Antitumor response assessment was made every 6 weeks.

RESULTS

Of the 20 patients, 18 attained the target plasma concentration, and 16 of these achieved this initially or with just one dose adjustment. No major objective antitumor responses were observed (major response rate 0%, 95% CI 0-17%). CQS was well tolerated with hypoglycemia being the most clinically significant toxicity.

CONCLUSIONS

When given on this schedule CQS is inactive in NSCLC despite the fact that the target concentration was achieved in 90% of patients. The ability of the HTCFA to identify active agents remains unproved.

High-dose edatrexate with oral leucovorin rescue: a phase I and clinical pharmacological study in adults with advanced cancer

Our objective was to determine the maximum tolerated dose and toxicity of i.v. edatrexate with p.o. leucovorin. Thirty-one adults with advanced solid tumors received edatrexate as a 2-h infusion, once a week for 3 weeks, recycled every 28 days. p.o. leucovorin (10 mg/m2, every 6 h for 10 doses) began 24 h later. All had urinary alkalinization and p.o. hydration. Nine dosage levels ranging from 120 to 3750 mg/m2 were explored. Fatigue, epistaxis, nausea/emesis, mucositis, rash, myalgias, leukopenia, thrombocytopenia, and transient elevations of serum aspartate transferase were observed. Leukoencephalopathy with clinical manifestations occurred in two patients (one had prior cranial irradiation). Pharmacokinetic studies carried out at the 120- and 1080-mg/m2 dose levels revealed no significant difference in the elimination half-life at the two dose levels studied and no significant intrapatient variability between day 1 and day 8 edatrexate administration. Serum edatrexate levels measured using a dihydrofolate reductase inhibition assay correlated with those by high-performance liquid chromatography. Three major and two minor antitumor responses occurred. The maximum tolerated dose was 3750 mg/m2, with grade 3 or 4 leukopenia (one patient), stomatitis (one patient), and leukoencephalopathy (one patient). Because of the occurrence of leukoencephalopathy, further study of high-dose edatrexate with leucovorin rescue is not recommended.

Expression of cytokine messenger RNA after heart transplantation: relationship with rejection and serum cytokines

Different groups of cytokines may initiate or inhibit the rejection process. We used the polymerase chain reaction to study the expression of cytokine mRNA for interleukin (IL)-2, -4, -6 and -10, tumor necrosis factor-alpha, and interferon-gamma in 187 biopsy specimens from 24 human cardiac transplant recipients 5-555 days after transplantation. Cytokine levels in the serum were also measured. Cytokine mRNA was detected in 38.5% of biopsy specimens. IL-10 mRNA was detected more frequently with mild or absent rejection (11.6% in grades 0 and 1 - vs. 1.4% in grades 2 and 3, P=0.01). Up to 90 days after transplantation, IL-2 mRNA was detected more frequently with moderate rejection (13% in grades 2 and 3 vs. 0% in grades 0 and 1, P=0.076), and IL-4 mRNA was detected more frequently with mild or absent rejection (16% in grades 0 and 1 - vs. 0% in grades 2 and 3, P=0.061). More than 90 days after transplantation, IL-2 mRNA was detected more frequently with mild or absent rejection (10% in grades 0 and 1 vs. 0% in grades 2 and 3, P=0.078). Serum IL-4 levels corresponding to biopsy specimens positive for IL-4 mRNA were higher than those corresponding to specimens negative for IL-4 mRNA (59 pg/ml vs. 32 pg/ml medians, P=0.028). Our results suggest that IL-10 and possibly IL-4 (T helper 2 cytokines) may suppress graft rejection, whereas IL-2 (T helper 1 cytokine) may promote cellular rejection. In addition, cytokine profiles may change with length of time after transplantation. The association of elevated serum levels of IL-4 with increased expression of intragraft IL-4 mRNA may suggest release of this cytokine from the graft into the circulation.

Serum cytokines in human heart transplant recipients. Is there a relationship to rejection?

Cytokines are important in the pathogenesis of allograft rejection. Some studies have suggested a positive relationship between serum levels of cytokines and rejection, so this study was designed to investigate the presence of a range of cytokines in a large cohort of cardiac transplant recipients. We used enzyme linked immunosorbent assays (ELISA) to examine sequential serum samples from 28 consecutive heart transplant recipients; length of follow up varied between 2 and 566 days (median 357 days). Serum levels of IL-2, 4, 6, 10, TNF-alpha, and IFN-gamma were measured. We compared these results with detailed data on patients' clinical courses, including histological rejection, infection, and therapeutic use of antithymocyte globulin (ATG). No significant relationship was found between rejection and serum cytokine levels for samples taken more than 30 days after transplantation. Prior to this cytokine levels were significantly disturbed by the use of cytolytic therapy for induction immunosuppression. Serum cytokine levels sometimes showed peaks that appeared to be related to rejection, or occasionally to infection, but these relationships were not consistent. Serum TNF-alpha and IL-6 were consistently elevated within a few days of administration of ATG. We conclude that there is no systematic relationship between serum cytokine levels and histological rejection or infection in cardiac transplant recipients.

Targeting of small-cell lung cancer using the anti-GD2 ganglioside monoclonal antibody 3F8: a pilot trial

The present study evaluated the ability of the anti-GD2 ganglioside monoclonal antibody 3F8 to target tumor sites in patients with small-cell lung cancer (SCLC). Of 12 patients entered into the trial, ten received intravenous 3F8 labeled with 2 or 10 mCi iodine-131. The first five patients had recurrent or progressive disease after chemotherapy. Subsequent patients were studied before starting chemotherapy. Radionuclide scans were performed on days 1, 2, and 3 post-infusion and once between day 5 and day 7. Four patients underwent single-photon emission tomography (SPET) imaging. Radionuclide scans demonstrated localization to all known sites of disease, other than small brain metastases in one patient. SPET/CT scan fusion images confirmed precise localization. No significant toxicity was observed. Mean serum half-life was 64.2 h. Analysis of specimens from one patient who died of unrelated causes 6 days post-infusion confirmed the scan results. The present study demonstrates that 3F8 targets SCLC sites in patients. Further studies of anti-GD2 antibodies with higher doses of antibody and radionuclide are warranted to evaluate their role in SCLC.

A genetic marker of high TNF-alpha production in heart transplant recipients

The cytokine TNF-alpha has been implicated in the pathogenesis of both acute and chronic transplant rejection. Levels of the cytokine are known to vary in a normal population, leading to speculation that high responders may be at greater risk of rejection. Particular TNF region polymorphic markers have been associated with increased TNF-alpha levels and a biallelic polymorphism has been identified at position -308 of the TNF-alpha promoter that may contribute significantly to the interindividual variation in healthy persons. We describe here a new association between a polymorphic locus in the TNF gene region and increased production of TNF-alpha in heart transplant recipients. We studied two microsatellite markers that flank the TNFA gene, as well as a biallelic polymorphism at position -308 of the TNFA promoter, and found that the microsatellite allele TNFd3 was significantly associated with the capacity of leukocytes to produce TNF-alpha in vitro. No association was demonstrated for the promoter region polymorphism. Patients were receiving cyclosporine (CsA) and prednisolone (pred) at the time of sampling, which are known to interrupt 5' regulation of TNFA transcription in T cells and macrophages and may therefore negate the influence of the -308 polymorphism. Because of this we suggest that TNFd3 may be a marker for a 3' repressor region polymorphism that is of importance in immunosuppressed individuals.

Antithymocyte globulin preparations after heart transplantation. Cytokine responses in vivo and in vitro

It is accepted that antithymocyte globulin (ATG) preparations vary in their bioactivity and side effects. However, this is poorly documented in the literature. We compared the clinical course and cytokine response of heart transplant patients who had received either Merieux or Stanford ATG preparations. The serum cytokine response (interleukin [IL]-6, tumor necrosis factor [TNF]-alpha, IL-4, and IL-10) of 28 consecutive heart transplant recipients was measured for 14 days after surgery using ELISAs. The effect of various ATG preparations on cytokine stimulation of whole blood in vitro was also evaluated. There was a much greater in vivo IL-6 and TNF-alpha response to Merieux than to Stanford ATG (P < 0.0005). There was little IL-4 or IL-10 response with either preparation. No side effects could be attributed to either treatment. No significant difference was seen in the frequency of rejection at 30, 90, or 365 days. More infection episodes occurred in the group treated with Stanford ATG at 30 days (0.5 compared with 0.2 episodes/patient; P = 0.097), 90 days (1.2 compared with 0.5 episodes/patient; P = 0.17), and 365 days (2.8 compared with 1.8; P = 0.59), although none of these differences were statistically significant. When tested in vitro for cytokine stimulation, the in vivo pattern was confirmed, with Merieux ATG producing greater levels of TNF-alpha and IL-6 than Stanford ATG. The differences in cytokine stimulation may be reflected in different immunosuppressive activities. Further research to elucidate the important components of immunosuppressive activity while excluding potentially detrimental effects is important.

Atrial arrhythmias and pacing after orthotopic heart transplantation: bicaval versus standard atrial anastomosis

BACKGROUND

Right and left atrial configuration is more normal when the donor left atrium is anastomosed to a recipient left atrial cuff with direct anastomoses of the donor and recipient vena cavas on the right side. The right atrium and sinus node may be less disturbed by the technique of bicaval anastomosis than by the standard procedure.

OBJECTIVE

To compare the incidence of atrial arrhythmias and pacing after bicaval and standard anastomoses.

METHODS

75 patients had heart transplants between January 1991 and December 1993. The notes were reviewed. Nine patients who died within the first 30 days were excluded from further analysis (seven patients with standard anastomoses, one with bicaval anastomosis, and one with a hybrid technique).

RESULTS

66 patients survived for more than 30 days. Thirty five patients had standard anastomoses and 31 bicaval anastomoses. Atrial tachyarrhythmias (atrial fibrillation, atrial flutter, atrial tachycardia, or supraventricular tachycardia) occurred on four days in three patients in the bicaval group compared with 27 days in 13 patients in the standard group (P = 0.009). The relative risk of atrial tachyarrhythmias with standard anastomosis was 5.52 (P = 0.015) compared with that of bicaval anastomosis. Atrial tachyarrhythmias requiring treatment occurred less often in the bicaval group (four episodes in three patients in the bicaval group and eight episodes in four patients in the standard group), and fewer patients with a bicaval anastomosis required temporary pacing (pacing on 20 days in 10 patients in the bicaval group, but pacing on 49 days in 16 patients in the standard group) and late permanent pacing (no patients in the bicaval group and three patients in the standard group), although these differences were not statistically significant. Patients in the bicaval group were discharged from hospital sooner than those in the standard group (mean 24.1 v 29.1 days, P = 0.024).

CONCLUSIONS

The technique of bicaval anastomosis, in addition to theoretical advantages from maintaining a more normal atrial configuration, has a lower incidence of postoperative atrial tachyarrhythmias, may reduce the need for pacing, and allows earlier discharge from hospital.

Ifosfamide plus high-dose cisplatin in patients with non-small cell lung cancer previously treated with chemotherapy

This study determined the maximum tolerated dose (MTD) of ifosfamide that could be given with high-dose cisplatin to non-small cell lung cancer (NSCLC) patients previously treated with non-platin-containing chemotherapy and to assess the efficacy of this combination. Twenty-three patients with inoperable NSCLC treated with one prior chemotherapy regimen received continuous infusion ifosfamide 1.2 g/m2 per day with MESNA for 5 days every 35 days and cisplatin 120 mg/m2. After one patient who received cisplatin as a single dose developed grade 4 nephrotoxicity and myelosuppression, cisplatin was given in four divided doses (30 mg/m2 per day) and the ifosfamide dose was lowered to 1.0 g/m2 per day, infused over 4 days. Dose-limiting grades 3 and 4 leukopenia was seen in 43%. A major objective response rate of 9% was observed. The 1-year survival was 30%, with a median survival of 6.4 months. The MTD of ifosfamide administered with cisplatin (30 mg/m2 per day for 4 consecutive days) to this population of patients is 1.0 g/m2 daily for 4 days. This combination produced limited anticancer activity and significant toxicity. Excessive toxicity was observed when cisplatin was given as a single dose with ifosfamide, and this schedule should not be used.

New chemotherapeutic agents for non-small cell lung cancer

The identification of new chemotherapeutic agents for the treatment of non-small cell lung cancer should proceed in a structured, logical fashion. Agents should be evaluated on the basis of multiple objective and subjective end points. A 15% or greater major objective response rate, demonstrated in multiple single-agent phase II trials, is considered the lower limit for an agent to be deemed clinically active in this disease. A number of drugs previously have been identified in this category, including cisplatin, ifosfamide, mitomycin, paclitaxel, and the vinca alkaloids vinblastine and vindesine. Most of these conventional agents have been explored alone, in a variety of doses and schedules, and in combination. In the last several years clinical development has produced new agents, including chloroquinoxaline sulfonamide, docetaxel, edatrexate, gemcitabine, irinotecan, topotecan, and vinorelbine, which hold promise for more successful treatment of this lethal disease.

Interleukin-10 in human heart transplantation: an in situ hybridization study. The Manchester Transplant Cytokine Group

BACKGROUND

The role of interleukin-10 in graft acceptance and rejection was investigated by analysis of its messenger RNA expression within endomyocardial biopsy material from heart transplant recipients.

METHODS

Forty-six biopsy specimens were analyzed from 19 patients (16 male, 3 female), with an age range of 15 to 62 years (mean = 47 years). Biopsy specimens were "snap" frozen in liquid nitrogen, and 10-microns thick sections were cut and postfixed in 4% paraformaldehyde. Messenger RNA for interleukin-10 was localized with nonradioactively (digoxigenin) labeled complementary DNA probes and detected immunoenzymatically with an antidigoxigenin polyclonal antibody. The histopathologic diagnosis of rejection was made according to the criteria of the Heart Rejection Study group.

RESULTS

Interleukin-10 transcripts were detected in 12 of 36 rejecting biopsy specimens. None of the ten nonrejecting biopsy specimens were positive. Expression within the rejection infiltrate was more prominent in biopsy specimens from milder rejection episodes. By contrast, in biopsy specimens from moderate rejection, expression was mainly within areas of fibrosis. The expression of interleukin-10 transcripts did not relate to the number of previous rejection episodes nor to the histologic grade of the subsequent biopsy specimens.

CONCLUSIONS

This study emphasizes the importance of in situ techniques in localizing cytokine expression in relation to tissue structure and suggests that interleukin-10 may serve a function in the immune regulation of the infiltrate at sites of inflammation, rather than in immune suppression of the rejection process. Further study is necessary to elucidate the precise role of interleukin-10 in transplantation in relation to the overall profile of cytokine expression within the rejection infiltrate.

Paclitaxel (Taxol) and docetaxel (Taxotere): active chemotherapeutic agents in lung cancer

Paclitaxel (Taxol), the prototype of a new class of plant-derived antineoplastic compounds, is a natural product isolated from the Pacific yew. Docetaxel (Taxotere) is a hemisynthetic product derived from the European yew. These agents share a unique mechanism of cytotoxic action by promoting assembly of microtubules and rendering the microtubules resistant to depolymerization. In vitro studies suggest a possible role for radiation sensitization. In Phase I trials, the dose-limiting toxicity was neutropenia for both agents. Other toxicities include infusion-related hypersensitivity reactions, alopecia, neurotoxicity, mucositis, diarrhoea and myalgias. To prevent infusion-related reactions, routine premedication is recommended. Noncumulative cardiac toxicity has been observed with paclitaxel. Fluid retention and rash have been reported with docetaxel. In Phase II studies of paclitaxel in advanced non-small cell lung cancer, response rates of 21% and 24% were observed. In Phase II studies of docetaxel in similar patients, response rates ranging from 28-38% were reported, including patients previously treated with cisplatin. The most common toxicity in these studies was neutropenia. Combination studies with cisplatin and other agents are in progress. Paclitaxel and docetaxel are among the most active chemotherapeutic agents for non-small cell lung cancer patients. Their testing will dominate trials of new therapies in this disease for years to come.

Effectiveness and toxicity of preoperative therapy in stage IIIA non-small cell lung cancer including the Memorial Sloan-Kettering experience with induction MVP in patients with bulky mediastinal lymph node metastases (Clinical N2)

The use of preoperative chemotherapy with mitomycin, vinblastine and cisplatin (MVP) has led to improved complete resection rates and survival in Stage IIIA non-small cell lung cancer with bulky, ipsilateral, mediastinal lymph node metastases (Clinical N2 disease). The addition of preoperative irradiation has also been explored with results not substantially different from preoperative cisplatin-based chemotherapy alone. While preoperative chemotherapy has been shown to be feasible, the toxicity of both the chemotherapy and the subsequent resection is of concern with an overall treatment-related mortality of nearly 8%. The careful selection of patients, swift management of neutropenia, and meticulous perioperative pulmonary care has the potential to reduce the mortality from multimodality therapy. Having shown survival benefit in multiple single-institution and randomized trials, induction chemotherapy followed by surgery or irradiation is now the treatment of choice for patients with Stage IIIA non-small cell lung cancer with mediastinal lymph node metastases.

Phase II trial of a 75-mg/m2 dose of docetaxel with prednisone premedication for patients with advanced non-small cell lung cancer

BACKGROUND

A prior Phase II study of a 100-mg/m2 dose of docetaxel conducted at the Memorial Sloan-Kettering Cancer Center (New York, NY) demonstrated a 38% response rate with grade 3 or 4 neutropenia in 76% of the patients and a grade 2 or greater rash or infusion-related reaction in 41% and 34% of the patients, respectively. The current Phase II study sought to determine the activity of a 75-mg/m2 dose of docetaxel to establish whether this lower dose, combined with prednisone, ameliorates toxicity.

METHODS

Twenty untreated patients with advanced non-small cell lung cancer (NSCLC) received a 1-hour 75-mg/m2 dose of docetaxel every 21 days. Fifty milligrams of prednisone were administered twice the day before chemotherapy and once each of the next 3 days. Patients' disease-related symptoms were assessed prospectively using the Lung Cancer Symptom Scale (LCSS).

RESULTS

All patients were assessable for response and toxicity. Five patients had a major objective response (25%; 95% confidence interval, 11-50%). The median duration of response was 9.1 months. The projected 1-year survival was 71%. Grade 3 or 4 neutropenia occurred in 70% of the patients. Grade 2 or greater rash and infusion-related reactions decreased to 25% each. Analysis of the LCSS measurements found that six of nine component symptoms improved on Day 22, and all improved when baseline measurements were compared with the best value for each patient during the study.

CONCLUSIONS

Docetaxel administered at a dose of 75 mg/m2 every 21 days shows significant antitumor activity in untreated patients with NSCLC: Neutropenia is comparable with that observed at a 100-mg/m2 dose. The number of infusional reactions and rash decreased when docetaxel at this dose was administered with prednisone. Based on response rates observed in trials using a 100-mg/m2 dose with similar degrees of neutropenia, a 100-mg/m2 dose with steroid pretreatment is recommended future trials.

Serum soluble adhesion molecules and cytokines in cardiac allograft rejection. The Manchester Transplant Cytokine Group

AIMS

To examine the relationship between soluble adhesion molecules ICAM-1, E-selectin and VCAM-1, serum cytokines TNF alpha, IL6 and IL2, the IL2 soluble receptor p55 and cardiac rejection in cardiac allograft recipients.

METHODS

Seventy-six serum samples from 56 patients were examined. Samples were taken on the day of biopsy. No patient was experiencing concurrent infection. All the samples were examined for ICAM-1, TNF alpha, IL6 and IL2R p55. A smaller number were examined for E-selectin, VCAM-1 and IL2. Specific enzyme-linked immunosorbent assays were used.

RESULTS

When grade 0 and grade 3a rejection groups were compared a significant difference was seen between IL6 levels (means 32 pg/ml vs 51 pg/ml, medians both 32 pg/ml, p = 0.007), and a significant difference between ICAM-1 levels (medians 207 ng/ml vs 250 ng/ml versus 303 ng/ml, p = 0.045). No patient without rejection had detectable levels of IL6. There was a correlation between ICAM-1 and E-selectin levels (R = 0.6, p = 0.003). There was no correlation between the other parameters and rejection or each other.

CONCLUSIONS

Cytokines and adhesion molecules are of great importance in the mechanisms of transplant rejection and this, in some cases, is reflected in the serum. However, this is not sufficiently consistent to be of diagnostic value.

Wegener's granulomatosis and the heart

Three cases of Wegener's granulomatosis with cardiac complications are described and the relevant published reports are reviewed. The first case of Wegener's granulomatosis was associated with aortic regurgitation and required aortic valve replacement. The second and third cases were associated with pericardial disease requiring pericardiectomy for constructive pericarditis in one case, and haemorrhagic pericarditis with pericardial effusion in the other. Aortic valve involvement in Wegener's granulomatosis is uncommon and valve replacement has been described on only one previous occasion. Pericardial involvement is relatively common pathologically, but pericardial surgery has been described in this condition only twice, once for tamponade and once for constrictive pericarditis after pericardiocentesis. Cardiac involvement is not uncommon in patients with Wegner's granulomatosis and may be clinically important. Diagnosis is aided by estimation of the anti-neutophil cytoplasmic antibody titre.

Do specific HLA antigens predispose to ischaemic heart disease or idiopathic dilated cardiomyopathy?

BACKGROUND

The aetiology of idiopathic dilated cardiomyopathy is believed to have an immunological component. Association with human leucocyte antigens (HLAs) has been previously reported, particularly with HLA-DR4.

AIM

To determine the association of HLA type with diagnosis in a group of patients assessed for heart transplantation.

METHODS

A comparison was made of frequencies of HLA types in patients with a diagnosis of idiopathic dilated cardiomyopathy or (n = 98) ischaemic heart disease (n = 170) and in controls from the North Western region (n = 857).

RESULTS

Neither the patients with idiopathic dilated cardiomyopathy nor those with ischaemic heart disease showed a significant increase or decrease in any HLA frequency compared with the controls.

CONCLUSION

These results suggest that there is no HLA association with idiopathic dilated cardiomyopathy or ischaemic heart disease. This conflicts with the results of some previous studies.

Late symptom recurrence after successful coronary angioplasty: angiographic outcome

OBJECTIVES

To determine the angiographic appearance of the dilated coronary artery and the cause of symptoms in patients who presented with a return of chest pain more than 1 year after successful percutaneous transluminal coronary angioplasty (PTCA).

DESIGN

Retrospective analysis of coronary angiograms and review of case histories.

PATIENTS AND METHODS

112 patients who underwent repeat coronary arteriography for investigation of chest pain 13-105 (median, 30) months after successful coronary angioplasty were studied. All patients were free of symptoms for at least 12 months after the initial angioplasty.

RESULTS

A return of chest pain was attributed to restenosis in 12 patients (11%), to a new lesion or worsening of pre-existing coronary lesion in 56 patients (50%), and to both restenosis and stenosis in non-dilated coronary segments in 10 patients (9%). There was no restenosis in 112 of the 134 dilated lesions (84%). In 34 patients (30%), there was no significant stenosis in either dilated or non-dilated coronary segments.

CONCLUSIONS

In patients undergoing coronary angiography for the investigation of recurrent chest pain more than 1 year after successful coronary angioplasty, the majority of dilated coronary segments had a good angiographic appearance. Late onset angina following PTCA is usually due to new coronary lesions or worsening of pre-existing mild stenosis.

Use of a remotely controlled mechanical pump for coronary arteriography: a study of radiation exposure and quality implications

BACKGROUND

Exposure to radiation is a hazard of invasive cardiology. To minimise the risk it is essential to keep the doses received as low as possible.

AIM

To assess the effect on cardiologist radiation exposure and the quality of coronary artery opacification of the use of a remotely controlled mechanical pump for coronary arteriography. A secondary aim was to assess any disadvantages and safety.

METHODS

319 patients were randomised to have coronary arteriography carried out with contrast injected either by hand or by a remotely controlled mechanical pump. Six cardiologists participated: two catheter laboratories were used and both brachial and femoral approaches were included. The exposure of the cardiologists to radiation was assessed by film badge dosimetry. The badges were worn on the hat. The total time for the procedure, screening time, the dose-area product meter reading, and any complications were recorded for each examination. The quality of arterial opacification was reported on a scale of 0-5.

RESULTS

The mean radiation dose per procedure was 0.011 mSv for hand injection of contrast and 0.005 mSv for mechanical injection (p < 0.01). There were no differences in procedure times or screening times. There were no complications attributable to mechanical injection. Arterial opacification was not significantly different in the two groups (4.01 v 4.03 for the left coronary artery, 4.68 v 4.78 for the right coronary artery). The right coronary artery was consistently better opacified than the left by both techniques (4.59 v 3.89, p < 0.001).

CONCLUSIONS

Use of a remotely controlled mechanical pump for coronary arteriography reduced cardiologist radiation exposure by half. It was not associated with any inconvenience, expense, or complications and produced arterial opacification at least as good as injection by hand.

The loss of repetition priming and automaticity over time as a function of degree of initial learning

Two experiments were performed to investigate the buildup of repetition priming in a lexical decision task with repeated presentations and its decline over the course of 2 months. Priming was found to accumulate as a power function of presentations and to decline as a power function of time. Accuracy measures indicated that the loss rate of priming was unaffected by the amount of initial priming. Response time measures indicated the same result when the experiments were analyzed separately; however, when the data were combined, increased initial priming was associated with greater losses in priming over time. The data were interpreted in terms of automaticity, and the power function decline in priming was taken as support for memory-based models of automaticity. Possible ways to incorporate forgetting into memory-based theories of automaticity are discussed.