The Medical Network: saying "no" to human rights abuses.
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Canada↗
Biomedical subjects
D Payne
Publications and source records attributed to D Payne.
Ringing in the new year: the change processes and reported outcomes of resolutions.
This study tracked the coping processes and self-reported outcomes of 213 adults making New Year's resolutions in order to identify prospective variables which predict successful self-change and to examine the relative effectiveness of various coping strategies. Prior to January 1st, participants provided information on their resolutions, demographic characteristics, and five variables previously associated with positive outcome. Subsequent telephone interviews ascertained short-term retrospective accounts of the utilization of 14 coping strategies and self-reported outcomes over six months. Readiness to change and self-efficacy, but not social support or behavioral skills, prospectively predicted successful outcome at both one week and one month. Successful resolvers were also found to report employing significantly more behavioral strategies and less self-blame and wishful thinking than unsuccessful resolvers. These findings are discussed within the context of previous research on self-initiated change, and several implications for clinical practice are offered.
Adaptation, Psychological↗
Surgical therapy for drug-refractory ventricular tachycardia: results with mapping-guided subendocardial resection.
Surgical therapy with mapping-guided subendocardial resection was used in 30 patients with drug-refractory ventricular tachycardia. Results of preoperative, intraoperative and postoperative electrophysiologic evaluation and long-term clinical follow-up are reported. Left ventricular aneurysm was located in the inferior wall in 8 patients and in the anterior wall in 22. Left ventricular mapping was performed in 15 patients preoperatively and in all 30 patients intraoperatively. Subendocardial resection was supplemented with cryoablation in 26 patients and with laser photocoagulation in 4. Coronary bypass surgery was performed in 27 patients. The surgical mortality rate was 10%; the three deaths were due to cardiogenic shock, pneumonia and sepsis, respectively. At postoperative electrophysiologic study, ventricular tachycardia was inducible in 8 (30%) of 27 patients. Previously ineffective antiarrhythmic drugs were effective in preventing the induction of ventricular tachycardia in four of these eight patients. Two of the remaining four patients received an automatic implantable cardioverterdefibrillator; the other two were treated with amiodarone. At a mean follow-up period of 18 +/- 17 months (range 1 to 52), there has been one sudden death and one nonfatal recurrence of ventricular tachycardia in the 18 patients without inducible arrhythmias postoperatively. Among the eight patients with inducible ventricular tachycardia after subendocardial resection, there has been one nonfatal ventricular tachycardia recurrence. Thus, among the 27 patients surviving surgery, 17 (63%) were cured with surgery alone, and another 7 (26%) had their ventricular tachycardia controlled with drugs (n = 5) or the defibrillator (n = 2). Inability to completely map the tachycardia, a clinical history of cardiac arrest requiring resuscitation and the presence of myocardial infarction within 2 months predicted postoperative arrhythmia inducibility and recurrence.
Adult↗
Development of a blood culture medium and a standard in vitro microtest for field-testing the response of Plasmodium falciparum to antifolate antimalarials.
The history of the development of the WHO standard in vitro microtest is summarized, and the rationale and methodology that were used to broaden the system for the testing of antifolate drugs such as sulfadoxine and pyrimethamine (in addition to chloroquine, mefloquine, quinine and amodiaquine) are explained. Additional information is given concerning the composition of the basic and replenishment test kits and the means of procuring them.
Animals↗
Skull radiography after recent trauma--a review.
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Humans↗
In vitro microtest for chloroquine resistance of Plasmodium falciparum.
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Animals↗
Did medicated salt hasten the spread of chloroquine resistance in Plasmodium falciparum?
With acknowledged difficulties in achieving satisfactory compliance rates for the large-scale delivery of many antiporositic drugs, the use of medicated salt has often been seen as a useful way to improve the level o f treatment in target populations. Iodinated salt is said to have contributed to a decline in endemic goitre, and salt medicated with chloroquine and/or other antimalorials, or with diethylcarbomazine, has been widely used in public health programmes against malaria and filariosis respectively. In this article, however, David Payne suggests that chloroquinized salt programmes may have been a major factor in promoting chloroquine resistance in Plasmodium falciparum.
Journal Article↗
Combined modality treatment for resected advanced non-small cell lung cancer: local control and local recurrence.
The purpose of this study was to compare the effect of post-operative thoracic radiation with or without systemic chemotherapy on survival and recurrence patterns in patients subjected to thoracotomy with curative intent, but subsequently found to have residual tumor in the resected margin or metastasis in the highest paratracheal lymph node. All patients were treated with postoperative mediastinal irradiation and randomized to receive or not receive combination chemotherapy (cytoxan, adriamycin, and platinum) for 6 months beginning concurrently with radiation. Of the 172 patients randomized, 164 were eligible for analysis. The mean time since randomization for the eligible patients is 4.2 years. Radiation therapy was administered to all patients by split course regimen [20 Gy in 5 fractions over 5 days]. Two such courses were given with a 3-week interval. The initial recurrence rates for both in-field recurrence and distant relapse were reduced in the combined postoperative radiation therapy and chemotherapy group, although only the latter difference achieved statistical significance (p = 0.01). Also, local recurrence overall (not restricted to initial recurrences) is examined as a function of histology, extent of residual disease after resection, and T and N status. The treatment effect achieves statistical significance only for patients with macroscopic residual (p = .023) or T3 tumor (p = .010). The combined therapy group of patients have a significantly longer recurrence-free survival [p = 0.006 by the two-sided Mantel-Haenszel logrank test] which fails, however, to translate to a significant difference in overall survival (p = 0.146). Median survival of the entire group is 14.5 months with 34% alive 2 years after resection. Most of the initial recurrences (82%) have been systemic, with brain being the most common site. Distant failure, therefore, remains an important problem even in the favorable prognosis subset of patients with advanced NSCLC, but combined modality approaches can produce improved recurrence-free survival.
Adenocarcinoma↗
Complications of treatment of small cell carcinoma of the lung. Experience from a recent Canadian trial.
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Adult↗
Use and limitations of light microscopy for diagnosing malaria at the primary health care level.
Recent developments in diagnostic techniques for malaria, particularly DNA probes and sero-immunology, have raised questions as to how these techniques might be used to facilitate malaria diagnosis at the most peripheral levels of the primary health care system. At present, malaria diagnosis is based on the light microscope and is likely to remain so in the immediate future. This article describes how the diagnosis of malaria by light microscopy has been improved over the years, and expresses the need for further improvement while concomitant research into other standardized and simplified techniques for the diagnosis of malaria is vigorously pursued.
Animals↗
Why physicians should oppose the death penalty.
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Attitude of Health Personnel↗
Spread of chloroquine resistance in Plasmodium falciparum.
Malaria resistant to chloroquine has now been confirmed in more than 40 countries. The drug was introduced in 1934, but was not in large-scale use until the early 1950s. Anecdotal reports suggest that resistance emerged as early as 1957 both in Colombia and along the then Cambodia-Thailand border area. But by 1960, resistance in these areas was confirmed - and may represent two separate events. Resistance spread rapidly, with a new focus of resistance confirmed in East Africa by 1977. Chloroquine resistance represents a severe problem both for prophylaxis and treatment of malaria. In this aricle, David Payne traces the spread of resistance and discusses some of its implications.
Journal Article↗
Characterization of the Cryptosporidium antigens from sporulated oocysts of Cryptosporidium parvum.
The antigenic constituents of sporulated Cryptosporidium parvum oocyst antigens were characterized with antisera from mice immunized against C. parvum. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver staining defined the major proteins. Six of seven lectins used recognized as many as 15 bands. The lectins concanavalin A, Dolichos biflorus, and wheat germ agglutinin showed strong activity against the same eight bands with molecular weights ranging from 72,000 to greater than 100,000. An enzyme-linked immunosorbent assay was used to detect antibody to C. parvum. Antibody binding was significantly decreased by heat and enzymatic treatment with trypsin, protease, and mixed glycosidases. C. parvum antigens were further defined by the reactivity of immune sera with a C. parvum sonicate preparation separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrophoretically transferred to nitrocellulose paper. Antisera from orally infected mice consistently recognized four antigens with molecular weights ranging from 72,000 to greater than 100,000. These antigens also bound concanavalin A. Treatment of the antigen preparation with mixed glycosidases reduced the reactivity of antisera with most antigens with molecular weights greater than 60,000. The data suggest that the antigenic composition of C. parvum is complex and that carbohydrates alone or in association with lipids or proteins may be important in the immune response to C. parvum.
Animals↗
Sequential chemotherapy and radiation for nasopharyngeal cancer: absence of long-term benefit despite a high rate of tumor response to chemotherapy.
Between April 1981 and December 1983, patients with locoregional carcinoma of the nasopharynx were treated with two courses of chemotherapy administered before radiation therapy. Chemotherapy consisted of methotrexate, bleomycin, and cisplatin, which were administered at 3-week intervals, and radiation therapy was scheduled to commence 3 weeks after the start of the second course. Forty-nine of 51 consecutive patients were treated; only one patient progressed on chemotherapy, and of 36 patients with measurable neck nodes, eight had complete and 19 had partial clearance (greater than 50% decrease in cross-sectional area) of these nodes when assessed before initiation of radiotherapy. Despite the high rate of tumor response (75%; 95% confidence limits, 59% to 91%), the actuarial survival and disease-free survival curves were almost identical to those recorded for a consecutive group of 140 historical controls of similar stage distribution treated with radiation alone. This chemotherapy provided a high rate of tumor remission, but did not appear to convey long-term benefit to patients when used before radiation therapy.
Actuarial Analysis↗
Canadian multicenter randomized trial comparing sequential and alternating administration of two non-cross-resistant chemotherapy combinations in patients with limited small-cell carcinoma of the lung.
In order to assess the effect of scheduling of chemotherapy on the outcome of patients with limited small-cell lung cancer (SCLC), the Clinical Trials Group of the National Cancer Institute of Canada carried out a randomized trial comparing the alternation of cyclophosphamide, Adriamycin (Adria Laboratories, Columbus, OH; doxorubicin) and vincristine (CAV) with etoposide (VP-16) and cisplatin for six cycles to the administration of these two combinations in a sequential fashion (three cycles of CAV followed by three of VP-16/cisplatin). Three hundred eligible patients were enrolled on the trial from September 1981 to October 1984. All responding patients were also treated after completion of chemotherapy with thoracic irradiation in randomly allocated doses of 2,000 and 3,750 cGy. The complete response (CR) rate to chemotherapy was slightly, but not significantly, higher on the alternating arm (52% v 44%, P = .20). However, there was no difference in disease-free or overall survival on the alternating and sequential arms, respectively (47.3 weeks v 45.1 weeks, P = .26; 61.7 weeks v 59.5 weeks, P = .56). Data on the effect of radiotherapy dose on survival are not yet mature, but it does not appear the results of this portion of the trial will alter the interpretation of the chemotherapy comparison. Patient characteristics favorably influencing survival were female sex, good performance status, younger age, and absence of supraclavicular node involvement. Two interpretations of these and other results in SCLC are suggested: (1) the difference between the schedules used is too small for the predictions of the Goldie-Coldman model to be realized in a trial of this size, or (2) VP-16/cisplatin is actually a superior regimen and any schedule that exposes patients to these drugs early in treatment will produce improved results.
Adult↗
Lymphoma simulating uveitis (masquerade syndrome).
The authors present three recent cases of intraocular lymphoma. All three patients presented with apparent hypopyon and uveitis. Although the diagnosis was a difficult one to make, an aspiration of the anterior chamber with appropriate cytologic studies was conclusive in one case. The neoplasm may masquerade as any type of intraocular inflammation, anterior or posterior. We discuss the management and prognosis of these patients and review 68 cases from the world literature. Radiation therapy plays an important palliative role in this condition.
Adult↗
Development of an in vitro microtest for determining the susceptibility of Plasmodium falciparum to sulfadoxine-pyrimethamine: laboratory investigations and field studies in Port-au-Prince, Haiti.
An in vitro microtest for assessing the susceptibility of Plasmodium falciparum to sulfadoxine-pyrimethamine (S-P) was developed following WHO guidelines. Paraaminobenzoic acid and folic acid were depleted in the culture medium used, the test wells were predosed with sulfadoxine and pyrimethamine at a constant ratio of 80:1, and the parasites were incubated for 48 hours. Optimum parasite multiplication was obtained with a 2% erythrocyte suspension in medium supplemented with 12% serum. During in vitro studies with laboratory-adapted isolates, response patterns were obtained which distinguished 3 isolates with documented in vivo sensitivity to S-P from 2 isolates with documented in vivo resistance to S-P. In addition, among the three S-P-sensitive isolates, one isolate that was pyrimethamine-resistant in vitro had a higher S-P inhibitory endpoint than 2 isolates that were pyrimethamine-sensitive in vitro. The S-P microtest was further evaluated in combined in vivo and in vitro studies in Port-au-Prince, Haiti. Twenty-six patients infected with P. falciparum were treated with standard doses of S-P, resulting in prompt clearance of parasitaemia, with no recurrence in the 24 patients who completed a 28-day follow-up period. Parallel in vitro tests with pyrimethamine alone showed 3 pyrimethamine-resistant isolates out of 22 successful tests on the patients' blood samples. In 23 successful S-P tests, the known in vivo S-P-sensitive parasites were inhibited at S-P concentrations that were generally lower for in vitro pyrimethamine-sensitive isolates than for in vitro pyrimethamine-resistant ones.
Animals↗
Primary radiation therapy for juvenile nasopharyngeal angiofibroma.
Evidence is presented of the effectiveness and relative lack of serious toxicity of external beam megavoltage radiation therapy (RT) as primary treatment for juvenile nasopharyngeal angiofibroma. The importance of careful radiological evaluation of tumor extent prior to irradiation is stressed, and only moderate dose RT is required. Fifty-five patients have been treated by RT and followed for from 3 to 26 years. Forty-four of 55 patients (80%) had permanent tumor control following a single course of 3000 cGy to 3500 cGy over 3 weeks. Surgical resection or a second course of RT controlled the tumor in all 11 patients in whom regrowth occurred. Angiofibromas involute slowly after RT so that 50% of patients still had visible masses in the nasopharynx 12 months after treatment, but only 10% had any visible abnormality 36 months after RT. Retreatment was necessary only if symptoms recurred, and continued follow-up showed that most asymptomatic nasopharyngeal masses resolved completely. Acute and late toxicity rates were low. Two patients developed tumors in the head or neck following RT. There was no significant clinical impairment of growth or endocrine function. A single course of external beam megavoltage radiation to 3000 cGy in 3 weeks is an effective first treatment for patients with juvenile nasopharyngeal angiofibroma.
Adolescent↗