Cost-effectiveness of antenatal anti-D prophylaxis

This paper estimates the incremental cost-effectiveness of providing antenatal anti-D prophylaxis in varying dose sizes to either primigravidae or all Rh D negative women. It presents a model for calculating the net cost per 1000 'at risk' women based on the costs of anti-D prophylaxis and the future NHS costs avoided. Incremental cost-effectiveness is measured in terms of the net cost per Rh D-alloimmunization and the net cost per Rh HD loss prevented. Programmes for Rh D negative primigravidae are more cost-effective than the same dose protocol extended to all Rh D negative women. The 1 x 1250 iu programme is the most cost-effective option.

Evaluating the benefits of antenatal screening: an alternative approach

This paper presents an alternative method of valuing the benefits of antenatal screening programmes based on individual preferences. The methods of benefit measurement used to date, namely averted costs, QALYs, and willingness to pay, are critically reviewed. The alternative method assumes that screening can be regarded as an investment in improved information, and that the benefits of screening can be measured by the value placed upon this information. The information is valued by presenting individuals with standard gamble questions framed in terms of a prenatal diagnostic choice. The approach is developed in the context of antenatal screening for Down's syndrome and for cystic fibrosis carrier status. Some empirical testing of the approach is reported for the latter.

Decision making with respect to diagnostic testing: a method of valuing the benefits of antenatal screening

This paper outlines a model for valuing the benefits of antenatal screening based on the analysis of individual decision making with respect to consequent diagnostic testing. Central to the model is the idea that the benefits of screening can be measured by valuing the improved information generated from screening. The model is developed in the context of antenatal carrier screening for cystic fibrosis (CF). Benefits are assessed by surveying women in the general population in order to establish their preferences for two alternative methods of CF carrier screening-stepwise and couple screening. Preferences are elicited using standard-gamble questions in which women from a population-based random sample are asked to trade off risk of fetal loss with improved information from diagnostic testing. A series of standard-gamble questions is employed to elicit utility values for each of the possible information outcomes from screening. The expected utilities of both screening methods are calculated at both individual and group levels. The results suggest that the use of individual decision making with respect to diagnostic testing as a means of valuing the benefits of screening may have wide applications.

Toxicity testing with communities: microcosms, mesocosms, and whole-system manipulations

Present ecotoxicological methodology is not adequate for providing evidence for decisions on sustainable use of the planet, maintenance of ecosystem services, or ecosystem health. However, particularly in the area of ecosystem health, promising beginnings have been made. Presumably, if ecosystems are maintained in robust health, then sustainability and reliable delivery of ecosystem services should result. On the other hand, one cannot ignore either human population size or expectations of affluence. Whether the number of ecosystems in robust health will be adequate for appropriate delivery of ecosystem services not only for existing generations but for future generations still has very unacceptably high levels of uncertainty. All ecosystems are dynamic, and one of the problems will be distinguishing normal cyclical or successional changes from trends away from established norms. Furthermore, toxicity tests are extremely useful for determining deleterious effects and those concentrations at which no-observable-deleterious effects occur. They are not suitable for determining how successfully various materials are being reincorporated into natural systems without disturbing ecological integrity. In a very real sense, however, this is a toxicological problem because, like vitamins and other essential materials for humans, excessive amounts of at least some types can be deleterious as can other materials such as ordinary table salt. It seems inevitable that different criteria, standards, endpoints, and methodologies that revolve around sustainability, ecosystem services, and reincorporating extracted and manufactured materials into natural systems following their use by human society will be required. Furthermore, ecosystems are different, both structurally and functionally, in different climatic zones, different altitudes, different soil conditions, and the like. Therefore, widespread uniform standards seem unlikely to function well, particularly for toxic materials. Prescriptive legislation, as opposed to that requiring site-specific professional judgment, is not likely to serve well under these circumstances. How success will be determined, how deleterious effects will be supported by evidence, and how effective extrapolations from one system to another will be are just a few of the many questions that need resolution. Finally, both temporal and spatial scales of systems under examination must increase, as will the diversity of information used as a basis for professional judgment. All of these factors are occurring in other areas of human societies, increasing globalization, and entry into the information age. Thus, the trends for ecotoxicology are in many ways quite similar to those in other professions as well.

Ecosystem services: an essential component of sustainable use

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Restoration of urban waterways and vacant areas: the first steps toward sustainability

Increased population pressure and human activities have significantly altered the effectiveness of functions of ecosystems ("ecosystem services") at the local and regional scale. Of primary importance is the decrease in water quality due to urban storm water runoff. A number of communities have initiated restoration strategies to improve water quality standards. One such strategy is the incorporation of riparian walkways with native flora. As a result of such restoration efforts, habitats for native fauna have improved, and the number and diversity of wildlife have increased in urban settings. Restoration of urban habitats also provides social and economic benefits to the surrounding community. Efforts to mitigate the loss of ecological resources by restoring native habitats on lots that cannot be developed or on abandoned lots hold a high, unrealized potential. Habitat restoration not only provides natural diversions to urban surroundings, but also enlightens and educates individual citizens about the importance of balanced ecosystems and the role of humans within ecosystems. Education is the primary step toward creating ecologically sustainable communities.

Maximizing the benefits of thrombolytic therapy for acute myocardial infarction

Thrombolytic therapy is a huge advance in the management of acute myocardial infarction (AMI). The results of large clinical trials over the past 9 years have unequivocally demonstrated its benefit: of every 1000 patients treated 30 will be saved, at a cost of two cases of nonfatal cerebral hemorrhage and seven of noncerebral major hemorrhage. The concurrent use of acetylsalicylic acid increases the benefit of thrombolytic therapy. Sales figures for thrombolytic agents indicate that their use in Canada is less than optimal and lags behind that in several European countries. Major educational efforts are needed to promote awareness of the efficacy of thrombolytic therapy and of optimal approaches for maximizing its potential benefit for patients with AMI.

Unrealistic optimism: a behavioural sciences classroom demonstration project

Unrealistic optimism may contribute to risky health practices and to a delay in seeking treatment for medical conditions, as most individuals perceive themselves to be at little risk for various disorders. It is thus an important concept to present to medical students as part of their behavioural sciences training. Social psychological concepts such as unrealistic optimism may appear, on initial presentation to students, to be a misjudgement based on faulty understanding of risk estimates by the general population. This project aimed to teach the principle of unrealistic optimism by having students document their own beliefs about health risks. Students rated their own risk, relative to other classmates, of experiencing a range of 17 health problems. Questionnaires were completed by two classes of medical students (n = 257). Class results showed varying levels of unrealistic optimism for all 17 conditions. Males and females differed significantly on three of the 17 conditions. Student data were obtained rapidly in a large didactic setting and served to illustrate the concept of unrealistic optimism which was subsequently taught in class. Such exercises may be a useful teaching aid to students providing them with feedback on their own cognitive processes and illustrating that they display cognitive distortions similar to those of patients.

The occurrence of heritable Mu excisions in starving cells of Escherichia coli

A strain of Escherichia coli constructed by Shapiro has a segment of Mu bacteriophage DNA inserted between the araC and lacZ genes. Excision events that produce an in-frame fusion of lacZ to araB result in a cell (here designated Ara-Lac+) that can grow on lactose if arabinose is present as an inducer. Whether or not these excision events occur in the absence of selection for the Ara-Lac+ phenotype has figured prominently in the debate of the phenomenon known as 'directed' or 'adaptive' mutation. In an attempt to settle the issue, we have used classic fluctuation tests to show that cells capable of producing a clone of descendants that are phenotypically Ara-Lac+ do, indeed, arise in stationary phase cultures kept starving in depleted minimal medium. We found that Ara-Lac+ progenitors arise rapidly under these conditions, in contrast to the delayed appearance of Ara-Lac+ mutants when cells are incubated on lactose-arabinose minimal plates. Similar results are reported in the accompanying paper by Maenhaut-Michel and Shapiro, who used indirect selection to isolate Ara-Lac+ cells in the absence of selection. However, their sequencing data have introduced a new unexpected complication to the interpretation of all such experiments, and it is no longer clear exactly when the fusions arise.

Estimating the effects of toxicants on ecosystem services

Numerous functions of ecosystems are essential to the quality of human life, including the provision of food, the decomposition of sewage, the provision of portable water, and the replacement of breathable air. Although attributes of ecosystems directly of use to human societies are not the only ones worth protecting, emphasizing their services may be the most effective means of communicating risks of toxicants to the general public. However, although spatial and temporal scales of experiments to assess risk vary relatively little, actual spatial scales vary considerably, from local environments to global ecosystems. Generally, models are used to bridge these gaps in scale. In this paper, we examine ways in which toxicity test endpoints have been developed to describe effects of pollutants on essential ecosystem functions and the ways in which results are then extrapolated to scales that risk managers can use.

Dephosphorylation of the small heat shock protein Hsp27 in vivo by protein phosphatase 2A

The phosphorylation of the Hsp27 complex is rapidly altered in MRC-5 cells when they are exposed to mitogens, cytokines, stress, or serine/threonine protein phosphatase inhibitors. Here we performed experiments to identify which cellular protein phosphatase (PP1, PP2A, or PP2B) is responsible for the in vivo phosphorylation/dephosphorylation of Hsp27. In their purified forms, PP2A dephosphorylates Hsp27 more effectively than PP2B, whereas PP1 is weakly active. Measurements of enzyme activity of lysates derived from inhibitor-treated cells indicated that Hsp27 phosphatase activity is equally sensitive to okadaic acid (PPI/PP2A inhibitor) and cyclosporin (PP2B inhibitor) and that both okadaic acid and cyclosporin treatment inhibited Hsp27 phosphatase activity additively. Together the in vitro data suggest that both PP2A and PP2B can dephosphorylate Hsp27. However, the phosphorylation of Hsp27 in vivo is only affected when cells are treated with PP1 and PP2A inhibitors (okadaic acid, calyculin A) or cantharidin (PP2A inhibitor), but not the PP2B inhibitor, cyclosporin A, suggesting PP2A to be the main enzyme dephosphorylating Hsp27 in the cells. Purification and immunoblotting of Hsp27 phosphatase from MRC-5 cells also suggest it to be PP2A and not PP1 or PP2B. The ability of PP2A to dephosphorylate Hsp27 is shown to be regulated by the phosphorylation state of PP2A itself.

Extrapolation methods for setting ecological standards for water quality: statistical and ecological concerns

: Extrapolation methods form the basis for most recent techniques used to set 'safe' levels of toxicants for ecosystems. Most methods use information from several single species toxicity tests to predict safety factors for protecting all species in all communities in a nation or group of nations. There are a number of statistical and ecological concerns with this approach. These include assumptions about the shape of the distribution of tolerance to a toxicant, the ability to extrapolate information on laboratory species and condition to field species and condition and to the condition of communities and ecosystems, and assumptions about the appropriateness of laboratory measures relative to ecosystem measures. The approach has not been validated for safety and, before the approach is fully applied, needs to be validated. Other methods can be used with the extrapolation approach to reduce uncertainties.

Contracts: problems and prospects

This article focuses on the important role played by contract prices in the new NHS. The power of prices to both inform and misinform the allocation of resources is highlighted. Orthopaedic surgery is used as a case study to indicate not only the obstacles to prices leading to improvements in efficiency but also the substantial scope for the prices set to convey valuable information on relative costs. Whether the purchaser-provider split will lead to an improved use of scarce resources will depend on several factors. One of the most important of which will be the development of sophisticated contracts embodying accurate price information.

The balance of ecological destruction and repair

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Nine-year follow-up study of a plasma-derived hepatitis B vaccine in a rural African setting

One hundred and one of 255 recipients of a plasma-derived hepatitis B vaccine were evaluated in 1990, 9 years after the first vaccine dose in a study in Zambia to evaluate the efficacy of one, two, or three doses. In 1983, 2 years after the first vaccine dose, antibody to the hepatitis B surface antigen (anti-HBs) had been detectable in 90 of these 101 participants (89%). In 1990, anti-HBs was still detectable in 72 of 101 (71%), and was present at a protective level (> or = 10 mIU/mL) in 68 of 101 (67%). Although the original vaccine study elicited a protective level of antibody in a greater percentage of children and adolescents than in adults, there were no significant differences among the three groups at 9 years. (In 1990, anti-HBs was still detectable in 52 of 70 [74%] who had had no serologic markers of the hepatitis B virus in 1981, and a protective level was detected in 47 of 70 [67%].) A protective level of anti-HBs was detected in 1990 in 26 of 36 (72%) recipients of three doses and in 23 of 31 (74%) recipients of two doses; the slightly lower prevalence among recipients of one dose (19 of 34 [56%]) was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Sometimes sensitive, seldom specific: a review of the economics of screening

As the policy relevance of screening has increased, the application of the techniques of economic evaluation to screening has become widespread. This paper critically reviews the literature, and in so doing, highlights several ways in which future evaluations might be improved. These include: the adoption of a broader perspective regarding the questions to be addressed and the relevant margins; a reconsideration of the nature of the benefits and how they might be valued; and a greater emphasis being placed upon the role of individual behaviour and its potential impact on the outcome of economic evaluations.

Inactivation of a redox-sensitive protein phosphatase during the early events of tumor necrosis factor/interleukin-1 signal transduction

Isoforms of heat shock protein (Hsp) 27 were used as intracellular markers to study tumor necrosis factor/interleukin-1 (TNF/IL-1) regulation of protein phosphatases in primary human fibroblasts. These isoforms were rapidly phosphorylated to varying degrees when fibroblasts were treated with either TNF, IL-1, okadaic acid, calyculin A, ARS, epidermal growth factor, fibroblast growth factor, H2O2, buthionine sulfoximine, N-ethylmaleimide, diethylmaleimide, or iodoacetate. However, inhibitors of protein kinases A and C, tyrosyl protein kinases, and general protein kinases had no effect on the enhanced phosphorylation of these isoforms in TNF, IL-1, okadaic acid, or calyculin A-stimulated cells, suggesting that the activation of protein kinases by itself is insufficient to produce these changes. Isoforms of 32P-labeled Hsp27 were dephosphorylated during cold-chases with excess phosphate in the absence but not in the presence of TNF/IL-1 or inhibitors of protein phosphatases suggesting that inactivation of protein phosphatase(s) plays a role in TNF/IL-1 signal transduction. Assays of phosphatase activity of cytosolic fractions from TNF or okadaic acid treated human fibroblasts showed an inactivation of protein phosphatase activity against the 32P-labeled Hsp27 protein substrates. In vitro assays of partially purified phosphatase activity from primary human fibroblasts with Hsp27 substrate also showed the protein phosphatase activity to be inhibited by ARS. Like okadaic acid, ARS mimics TNF in inducing specific patterns of cellular protein phosphorylation. Taken together these findings are consistent with the hypothesis that a SH-dependent protein phosphatase is inactivated during the early events of TNF/IL-1 signal transduction, hence inhibitors of protein phosphatases and SH modifying compounds can mimic the early effects of TNF/IL-1 on cells.

Ecotoxicological testing: small is reliable

The focus of environmental regulations has changed significantly since the introduction of the bioassay as a standard means of assessing environmental impact. Prominent in this change is an increasing emphasis on protecting the integrity of natural ecosystems, which incorporate community- and system-level properties as well as organismal and population processes. Consequently, support for the use of multispecies testing has widened to include not only ecologists in academia but environmental scientists in the regulatory and industrial sector as well. The reason for this trend is clear: the additional environmental realism gained from tests utilizing communities of organisms allows for greater insight into the potential hazard of chemicals and other forms of human activity to natural ecosystems that cannot be obtained from single species tests alone. Many of the problems cited for multispecies testing early in their evolution as a hazard assessment tool have been refuted or overcome. In particular, the use of natural microbial communities minimizes several shortcomings typically associated with multispecies toxicity testing. This article includes the utility of microcosm and mesocosm tests using aquatic microbial communities as hazard assessment tools in conjunction with accumulating information on their performance in toxicity testing protocols. An increasing body of experimental evidence supports an expansion in the use of these tests for a variety of regulatory and research purposes. A shift in research focus is needed, however, to answer remaining questions and further refine standard protocols for these valuable ecotoxicological tools.

The threshold problem in ecotoxicology

The most commonly used threshold in environmental toxicology is the LC50 (or modifications thereof) where 50% of the organisms die or are otherwise affected at a certain concentration of a chemical for a particular time of exposure under specified environmental conditions. Most commonly, this particular threshold is derived from single species laboratory tests low in environmental realism. If the field of ecotoxicology truly examines the effects of chemicals on ecosystems (i.e., complex multivariate systems), serious consideration must be given to thresholds other than those now commonly used in the field of environmental toxicology. Attributes at the community and ecosystem level of organization are not demonstrated at lower levels of biological organization, for example, energy flow and nutrient spiralling. Key issues are whether extrapolation is possible from one threshold to another within a level of biological organization and from one level of biological organization to another for thresholds that do not exist at many levels. Thresholds may be artefacts of testing procedures and may not exist in natural systems. Nevertheless, society must make management decisions about risk with available methods, including those designed to identify some point or threshold below which no deleterious effects are observed. However, these methods and their assumptions deserve more explicit and systematic examination than they have received thus far.

Mechanisms of directed mutation

Spontaneous mutants arise among nondividing populations of Escherichia coli in apparent response to selective conditions. In this report we investigate several hypotheses to account for the role of selection in the production of these "directed" or "adaptive" mutations. We found that the Lac+ phenotypes of some mutants that arise late after lactose selection are due to suppressor mutations that are unlinked to the mutant lacZ allele; thus the production of these Lac+ mutants does not require an information flow from successful proteins back to the DNA that encodes them. Transcriptional induction of the lac operon, even in the presence of another, utilizable carbon source, did not stimulate the occurrence of Lac+ mutants in the absence of lactose, indicating that the role of the selective agent is not merely to induce transcription. The absence of two DNA repair pathways-methyl-directed mismatch repair and alkylation repair-also did not result in an accumulation of Lac+ mutants in the absence of lactose, suggesting that these repair pathways are not normally responsible for correcting transient variants that might arise in the absence of selection. However, in one case the Lac+ mutation is likely to be due to a miscoding lesion occurring on the nontranscribed DNA strand, indicating that, at least in this instance, DNA replication is required before directed mutations can arise.

Discounting and health benefits: another perspective

This paper reviews the argument advanced by Parsonage and Neuburger that the non-monetary benefits of health programmes should be discounted at a lower rate than that used for financial flows. The conceptual issues raised in that paper are discussed and others, such as the tradability of non-monetary benefits and the link between individual and social discount rates, are introduced. The collection and assessment of more evidence is needed before Parsonage and Neuburger's proposition can be supported.

Response to mitoxantrone in advanced breast cancer: correlation with expression of c-erbB-2 protein and glutathione S-transferases

Sixty-eight patients with advanced breast cancer were treated with mitoxantrone and clinical responses assessed. Expression of c-erbB-2 protein and cytosolic glutathione S-transferase (GST) isoenzymes pi, alpha and mu by the primary tumours of these patients was determined immunohistochemically, and correlated with treatment response. Tumours overexpressing c-erbB-2 (n = 16, 23%) showed a lower response rate (50% vs 58%) and shorter duration of response to treatment, compared with c-erbB-2 negative tumours. These associations were not statistically significant but survival following start of treatment was significantly shorter in the c-erbB-2 positive group. For each GST isoenzyme, the response rate and duration of response of the group showing enzyme expression did not differ significantly from those with negatively staining tumours. These data do not support a role for expression of GSTs alone in resistance to mitoxantrone monotherapy in advanced breast cancer. The poorer post treatment survival of patients with c-erbB-2 positive tumours suggests they could be selected for more intensive treatment regimens.

Relationship between c-erbB-2 protein product expression and response to endocrine therapy in advanced breast cancer

Of 221 patients with breast cancer of known epidermal growth factor receptor (EGFR) and oestrogen receptor (ER) status, 99 had developed recurrences during the period of follow-up (range 3-60 months, median 24 months). Of these, 72 received endocrine therapy as first-line treatment for relapse. Immunohistochemical assessment of c-erbB-2 protein product expression was made using paraffin-embedded tumour tissue from 65 of these 72 patients. Including patients whose disease remained stable for more than 6 months with those showing an objective response (CR or PR for more than 3 months), only one (7%) of 14 c-erbB-2 positive tumours responded to endocrine manipulation compared with 19 (37%) of 51 c-erbB-2 negative tumours (P less than 0.05). Coexpression of c-erbB-2 reduced the response rate of ER positive patients from 48% to 20% and of ER negative cases from 27% to 0% (P less than 0.01). EGFR and c-erbB-2 protein appeared to have additive effects in reducing the likelihood of response, and none of eight patients with EGFR positive, c-erbB-2 positive tumours derived benefit from endocrine therapy. The results of this study suggest that c-erbB-2 protein overexpression, a marker of poor prognosis in breast cancer, is associated with a lack of response to endocrine therapy on relapse, and particularly in combination with EGFR may be useful in directing therapeutic choices.

Immunohistochemical demonstration of glutathioneS-transferases in primary human breast carcinomas

The expression of cytosolic glutathione S-transferase (GST) isoenzymes has been assessed in a series of 74 primary human breast carcinomas using an immunohistochemical method. GST pi was detected in sections from all 74 tumours; it was expressed by non-epithelial (stromal and inflammatory) cells in 62 tumours (84 per cent), but by tumour epithelium in only 35 (47 per cent). Non-neoplastic mammary epithelium was uniformly positive for GST pi. Expression of GST alpha and mu was observed in 19 and 42 per cent of the tumours, respectively, and was largely confined to the neoplastic component. Lack of staining of tumour epithelium for GST pi was significantly associated with poorer tumour differentiation (higher grade). There was no association between expression of any of the three isoenzymes and either menopausal status or expression of c-erbB-2 oncogene protein product. Immunohistochemistry is a useful method for the investigation of expression and cellular localization of GSTs within tumours; such data are needed to improve our understanding of the role of these enzymes in neoplasia and in resistance to cytotoxic drug therapy.

How should results from completed studies influence ongoing clinical trials? The CAFA Study experience

Seven randomized studies during the past 5 years have evaluated or are evaluating the efficacy of warfarin or aspirin or both in decreasing the risk of embolic events in patients with nonrheumatic atrial fibrillation. By March 1990, two of the studies had been published, both of which showed a statistically significant decrease in embolic events in patients treated with warfarin and a low rate of major bleeding events. The investigators associated with the other ongoing studies were forced to consider how these results should affect the decision to recruit and continue follow-up of patients in their own studies. The Steering Committee of the Canadian Atrial Fibrillation Anticoagulation (CAFA) study thought the newly published results from other studies were valid, clinically important, and generalizable. The committee considered the following options for the CAFA study: continue patient recruitment as planned, provide the data available in CAFA to its External Safety and Efficacy Monitoring Committee for analysis to determine whether the CAFA data already showed a benefit of warfarin, stop patient recruitment but continue to follow patients in the group to which they were assigned, stop the trial immediately and perform a final analysis, and attempt to perform a meta-analysis of all data available from all trials. The Steering Committee of CAFA decided that the evidence of benefit with warfarin, from the two published studies, was sufficiently compelling as to stop recruitment into CAFA without any preliminary examination of the CAFA data.

Issues in the early termination of the aspirin component of the Physicians' Health Study. Data Monitoring Board of the Physicians' Health Study

The Physicians' Health Study is a randomized, double-blind, placebo-controlled prevention trial of 22,071 US physicians, using a factorial design to evaluate the role of aspirin in the prevention of cardiovascular mortality and beta carotene in the reduction of cancer incidence. After approximately 5 years of follow-up, the aspirin component was terminated, 3 years ahead of schedule. Several factors were considered in the decision to terminate, including a cardiovascular mortality rate markedly lower than expected in both aspirin and placebo subjects, precluding the evaluation of the primary aspirin hypothesis, and a highly significant (P < .00001) and impressive (44%) reduction in the risk of first myocardial infarction in the aspirin group. Issues in the decision to terminate are described in this report.

Adaptive reversion of a frameshift mutation in Escherichia coli

Mutation rates are generally thought not to be influenced by selective forces. This doctrine rests on the results of certain classical studies of the mutations that make bacteria resistant to phages and antibiotics. We have studied a strain of Escherichia coli which constitutively expresses a lacI-lacZ fusion containing a frameshift mutation that renders it Lac-. Reversion to Lac+ is a rare event during exponential growth but occurs in stationary cultures when lactose is the only source of energy. No revertants accumulate in the absence of lactose, or in the presence of lactose if there is another, unfulfilled requirement for growth. The mechanism for such mutation in stationary phase is not known, but it requires some function of RecA which is apparently not required for mutation during exponential growth.

Sleep disturbance in depression reconsidered

The well documented observation of a characteristic sleep disturbance in depression has been accorded a good deal of significance. Several current hypotheses regarding the etiology of depression, are based on these findings. However, a review of the descriptive studies shows that care has not generally been taken either to restrict or objectively measure daytime sleep. Evidence is presented suggesting that daytime sleep may occur in depressed patients more frequently than commonly thought and that, in normal subjects, daytime napping can result in nocturnal sleep changes similar to those seen in depressed patients. A model is proposed in which the nocturnal sleep disturbance in depression reflects the occurrence, during the daytime, of frank slow wave sleep or periods of large amplitude, slow wave EEG activity as a consequence of a dampening of the circadian rhythm of sleep propensity.

Report of the Canadian Cardiovascular Society's consensus conference on the Management of the Postmyocardial Infarction Patient

In October 1989, the Canadian Cardiovascular Society announced a program to achieve consensus on important issues in the care of patients with cardiovascular disease. This report on the management of the postmyocardial infarction patient represents the first in a series of these consensus conferences. The process for establishing consensus recommendations involved several steps. A primary panel of 11 experts from various fields was selected to review the available clinical evidence and to make a list of recommendations about management decisions in the postmyocardial infarction period. The initial report was distributed to a secondary panel of 16 reviewers* representing allied health care constituencies from across Canada. On the basis of the critical reviews and feedback from these reviewers, a revised report was distributed to all members (over 800) of the Canadian Cardiovascular Society for further review and feedback. This iterative approach resulted in a penultimate report that was presented at a plenary session of the annual scientific meeting of the Canadian Cardiovascular Society on Oct. 18, 1990, in Halifax, NS. On the basis of discussion and feedback from this symposium, the consensus review was completed.

Beta-2-adrenoceptor agonists up-regulate the in vitro Fc epsilon receptor II/CD23 expression on, and release from, the promonocytic cell line U937 and human blood monocytes

The possible regulatory role of beta 2-adrenoceptor agonists in the modulation of CD23 on the human promonocytic cell line U937 and on human monocytes was investigated. Incubation for 48 h in the presence of interleukin-4 (IL-4; 30 U/ml) induced optimal expression and release of CD23 on both U937 cells and human monocytes. When a beta 2-adrenoceptor agonist, either salbutamol or fenoterol, was added to U937 cells or monocytes both the IL-4-induced CD23 expression and release were markedly up-regulated. This effect was dose-dependent, starting at 10 nM and reaching a maximum at 1 microM final concentration of either salbutamol or fenoterol. The potentiating effect of salbutamol and fenoterol on CD23 expression and release was not observed when a beta-adrenoceptor antagonist, either D,L-propranolol (1 microM) or butoxamine (1 microM), was added to the incubation medium. The alpha-adrenoceptor agonist norepinephrine (1 microM) was ineffective in enhancing the IL-4-induced expression and release of CD23 from U937 cells or human monocytes, demonstrating the specificity of the beta 2-adrenoceptor-mediated effect. In the absence of IL-4, a moderate but significant increase in the CD23 expression on U937 cells and human monocytes by these drugs was observed, as compared to the basal values. These results indicate that, besides their bronchodilator effect, beta 2-adrenoceptor agonists may regulate IgE-dependent processes.