OpenKBP-Opt: an international and reproducible evaluation of 76 knowledge-based planning pipelines

Objective.To establish an open framework for developing plan optimization models for knowledge-based planning (KBP).Approach.Our framework includes radiotherapy treatment data (i.e. reference plans) for 100 patients with head-and-neck cancer who were treated with intensity-modulated radiotherapy. That data also includes high-quality dose predictions from 19 KBP models that were developed by different research groups using out-of-sample data during the OpenKBP Grand Challenge. The dose predictions were input to four fluence-based dose mimicking models to form 76 unique KBP pipelines that generated 7600 plans (76 pipelines × 100 patients). The predictions and KBP-generated plans were compared to the reference plans via: the dose score, which is the average mean absolute voxel-by-voxel difference in dose; the deviation in dose-volume histogram (DVH) points; and the frequency of clinical planning criteria satisfaction. We also performed a theoretical investigation to justify our dose mimicking models.Main results.The range in rank order correlation of the dose score between predictions and their KBP pipelines was 0.50-0.62, which indicates that the quality of the predictions was generally positively correlated with the quality of the plans. Additionally, compared to the input predictions, the KBP-generated plans performed significantly better (P< 0.05; one-sided Wilcoxon test) on 18 of 23 DVH points. Similarly, each optimization model generated plans that satisfied a higher percentage of criteria than the reference plans, which satisfied 3.5% more criteria than the set of all dose predictions. Lastly, our theoretical investigation demonstrated that the dose mimicking models generated plans that are also optimal for an inverse planning model.Significance.This was the largest international effort to date for evaluating the combination of KBP prediction and optimization models. We found that the best performing models significantly outperformed the reference dose and dose predictions. In the interest of reproducibility, our data and code is freely available.

A Critical Heuristics Approach for Approximating Fairness in Method Engineering

Information system (IS) development projects often fail because of unclear wishes and needs of concerned parties, or because the developed IS or the used system development method (SDM) is not fully supported by concerned parties. In this study it is investigated how stakeholders that are concerned with the SDM are identified and involved in the engineering of such methods. The Critical Systems Heuristics (CSH) method can be used to identify stakeholders in method engineering, along with their concerns. CSH is meta-modelled and reviewed in twelve interviews with practitioners in software development, system engineering, and consultancy in order to evaluate its applicability in an organizational context. Subsequent modifications made to the contemporary CSH method are validated in an expert validation session. The resulting evolved CSH method enables method engineers to take into account their challenges and contexts, and the method can be instantiated for organizations that engineer methods for internal or external use.

Lipoprotein(a) is a strong risk factor for Aortic Valve Calcium

Background

Aortic valve calcium (AVC) is an important hallmark of aortic valve stenosis, which is the most common valvular heart disease in the Western world. Studies suggesting an important role for lipoprotein(a) [Lp(a)] in the etiology of AVC are accumulating, yet population-based evidence is scarce. Therefore, we investigated the association of Lp(a) with the presence of AVC in two large cohorts.

Methods

A total of 2412 participants from the population-based Rotterdam Study (52% women, mean age=69.6±6.3), and 859 asymptomatic persons from the Amsterdam Medical Center outpatient clinic for familial premature (non-valvular) atherosclerosis (57%women, mean age=45.9±11.6) underwent blood sampling to determine serum Lp(a) and non-enhanced cardiac CT-scan to assess AVC. We combined both cohorts and investigated the association of Lp(a) with the presence and amount of AVC using logistic and linear regression models, adjusting for age, sex, smoking, body mass index, non-high density lipoprotein cholesterol and use of antihypertensive medication.

Results

Out of a total of 3271 subjects with an average age of 63.4±7.98, AVC was present in 844 (25.8%) individuals. Higher levels of Lp(a) were associated with the presence of AVC, independent of age, sex and cardiovascular risk factors [Odds ratio (OR) per 1-SD increase in Lp(a): 1.39 (95% CI:1.27; 1.51). In persons with AVC, a higher level of Lp(a) was also related to larger volume of AVC [β per 1-SD increase in Lp(a): 0.76 (95% CI:1.27; 1.51)]. All findings were similar across both cohorts.

Conclusion

Lp(a) is a prominent and independent marker of the presence and amount of AVC in the general population. Future studies investigating the effect of Lp(a) lowering on the progression of AVC are warranted.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): NESTOR program for geriatric research, the Netherlands Heart Foundation, the Netherlands Organization for Scientific Research, the Health Research and Development Council (28-2975 and 97-1-364), and the Municipality of Rotterdam

Feasibility and outcomes of a goal-directed physical therapy program for patients with metastatic breast cancer

PURPOSE

To evaluate the feasibility and outcomes of a tailored, goal-directed, and exercise-based physical therapy program for patients with metastatic breast cancer (MBC).

METHODS

This was an observational, uncontrolled feasibility study. The physical therapy intervention was highly tailored to the individual patient's goals, abilities, and preferences and could include functional, strength, aerobic, and relaxation exercises. Feasibility outcomes were participation rate (expected: 25%), safety, and adherence (percentage of attended sessions relative to scheduled sessions). Additional outcomes were goal attainment, self-reported physical functioning, fatigue, health-related quality of life, and patient and physical therapist satisfaction with the program.

RESULTS

Fifty-five patients (estimated participation rate: 34%) were enrolled. Three patients did not start the intervention due to early disease progression. An additional 22 patients discontinued the program prematurely, mainly due to disease progression. Median intervention adherence was 90% and no major intervention-related adverse events occurred. A goal attainment score was available for 42 patients (of whom 29 had completed the program and 13 had prematurely dropped out). Twenty-two (52%) of these patients achieved their main goal fully or largely and an additional 15 patients (36%) partially. Eighty-five percent would "definitely recommend" the program to other patients with MBC. We observed a modest improvement in patient satisfaction with physical activities (Cohen's d_z 0.33).

CONCLUSION

The tailored intervention program was feasible in terms of uptake, safety, and outcomes and was highly valued by patients and physical therapists. However, disease progression interfered with the program, leading to substantial dropout.

TRIAL REGISTRATION

NTR register: NTR6475.

Canadian Stroke Best Practice Recommendations for Acute Stroke Management: Prehospital, Emergency Department, and Acute Inpatient Stroke Care, 6th Edition, Update 2018

The 2018 update of the Canadian Stroke Best Practice Recommendations for Acute Stroke Management, 6th edition, is a comprehensive summary of current evidence-based recommendations, appropriate for use by healthcare providers and system planners caring for persons with very recent symptoms of acute stroke or transient ischemic attack. The recommendations are intended for use by a interdisciplinary team of clinicians across a wide range of settings and highlight key elements involved in prehospital and Emergency Department care, acute treatments for ischemic stroke, and acute inpatient care. The most notable changes included in this 6th edition are the renaming of the module and its integration of the formerly separate modules on prehospital and emergency care and acute inpatient stroke care. The new module, Acute Stroke Management: Prehospital, Emergency Department, and Acute Inpatient Stroke Care is now a single, comprehensive module addressing the most important aspects of acute stroke care delivery. Other notable changes include the removal of two sections related to the emergency management of intracerebral hemorrhage and subarachnoid hemorrhage. These topics are covered in a new, dedicated module, to be released later this year. The most significant recommendation updates are for neuroimaging; the extension of the time window for endovascular thrombectomy treatment out to 24 h; considerations for treating a highly selected group of people with stroke of unknown time of onset; and recommendations for dual antiplatelet therapy for a limited duration after acute minor ischemic stroke and transient ischemic attack. This module also emphasizes the need for increased public and healthcare provider’s recognition of the signs of stroke and immediate actions to take; the important expanding role of paramedics and all emergency medical services personnel; arriving at a stroke-enabled Emergency Department without delay; and launching local healthcare institution code stroke protocols. Revisions have also been made to the recommendations for the triage and assessment of risk of recurrent stroke after transient ischemic attack/minor stroke and suggested urgency levels for investigations and initiation of management strategies. The goal of this updated guideline is to optimize stroke care across Canada, by reducing practice variations and reducing the gap between current knowledge and clinical practice.

Late rather than early responses of human dendritic cells highlight selective induction of cytokines, chemokines and growth factors by probiotic bacteria

The probiotic properties of commensal bacteria including lactobacilli and bifidobacteria are likely to be determined at least in part by their effects on dendritic cells. Like traditional immune stimulants such as lipopolysaccharides (LPS), probiotic bacteria promote maturation of cultured human dendritic cells (DC) by inducing elevated expression of MHC-II and co-stimulatory molecules. Different effects have been reported on cytokine induction, especially of major regulatory cytokines such as TNF-α, IL-12 and IL-10. Yet, these previous analyses have failed to reveal consistent differences between such effects of probiotics on the one hand, and of LPS on the other. Selective response markers for probiotics, however, would be important for our understanding of their biological properties and for a rational selection of strains for in vivo studies. In this study, we compared in detail both early and late effects on cultured human DC of 4 different probiotics with those of LPS. At the early stages of stimulation, all stimuli induced qualitatively very similar responses in DC at the level of surface markers and secretion of cytokines and chemokines. A lower immune stimulatory effect was observed by Bifidobacterium animalis BB-12 as compared to lactobacilli. Late responses, on the other hand, tended to diverge. Microarray transcript profiling for 268 cytokines, chemokines, growth factors and their receptors after 2 days of culture revealed various transcripts to be selectively induced by certain probiotics but not LPS. Our data indicate that late rather than early DC responses may be helpful to clarify the divergent biological effects of probiotics on human innate immune responses.

Wet-wrap treatment using dilutions of tacrolimus ointment and fluticasone propionate cream in human APOC1 (+/+) mice with atopic dermatitis

BACKGROUND

Wet-wrap treatment (WWT) with diluted topical steroids is widely used in atopic dermatitis (AD). Mice with transgenic overexpression of human apolipoprotein C1 (APOC1) in the liver and the skin are not only characterized by hyperlipidaemia and raised IgE levels, but also by pruritic dermatitis and a disturbed skin barrier function, providing a novel in vivo mouse model for AD.

OBJECTIVES

We investigated an adapted WWT method in the AD model in APOC1 mice in order to establish its efficacy.

METHODS

The effect of topical 0.1% and 0.03% tacrolimus ointment, tacrolimus base ointment, different dilutions of 0.05% fluticasone propionate (FP) cream and emollient on the development of dermatitis in APOC1 mice was investigated. WWT was performed with 0.03% tacrolimus ointment or 0.017% FP cream.

RESULTS

AD in APOC1 mice responded to topical treatment with tacrolimus or FP. In contrast to tacrolimus treatment, FP treatment was associated with loss of body weight. WWT reinforced several therapeutic aspects, notably improvements in transepidermal water loss and in epidermal thickness. WWT using tacrolimus 0.03% ointment was more effective than WWT using FP 0.017% cream.

CONCLUSIONS

AD in APOC1 mice responds to treatment with (diluted) tacrolimus or FP; treatment with FP cream, but not tacrolimus ointment, was associated with weight loss. In this study, the adapted WWT using tacrolimus or FP in mice had a limited improving effect as compared with open application of tacrolimus or FP.

Targeting the tetraspanin CD81 blocks monocyte transmigration and ameliorates EAE

Leukocyte infiltration is a key step in the development of demyelinating lesions in multiple sclerosis (MS), and molecules mediating leukocyte-endothelial interactions represent prime candidates for the development of therapeutic strategies. Here we studied the effects of blocking the integrin-associated tetraspanin CD81 in in vitro and in vivo models for MS. In an in vitro setting mAb against CD81 significantly reduced monocyte transmigration across brain endothelial cell monolayers, both in rodent and human models. Interestingly, leukocyte as well as endothelial CD81 was involved in this inhibitory effect. To assess their therapeutic potential, CD81 mAb were administered to mice suffering from experimental autoimmune encephalomyelitis (EAE). We found that Eat2, but not 2F7 mAb directed against mouse CD81 significantly reduced the development of neurological symptoms of EAE when using a preventive approach. Concomitantly, Eat2 treated animals showed reduced inflammation in the spinal cord. We conclude that CD81 represents a potential therapeutic target to interfere with leukocyte infiltration and ameliorate inflammatory neurological damage in MS.

Autoantibodies against alpha B-crystallin, a candidate autoantigen in multiple sclerosis, are part of a normal human immune repertoire

Human T-cell responses to the stress protein alpha B-crystallin in multiple sclerosis (MS)-affected brain samples are dominant when compared to other myelin antigens. The establishment of the apparent autoimmune repertoire against this antigen has been suggested to involve cross-priming during viral infection. Yet, another possibility would be that determinant spreading during ocular inflammation could generate a response to alpha B-crystallin, since it is also a major component of the eye. In this study, we compared serum IgG, IgA and IgM repertoires against a range of eye lens-derived ocular antigens using sera from healthy control subjects and MS patients with or without uveitis. This comparison revealed that among ocular antigens, alpha B-crystallin is the dominant target antigen for serum autoantibodies in both MS patients and healthy controls. Uveitis generally did not affect the antibody reactivity profile. These data provide further support for the notion that a normal adult human immune system is selectively reactive to alpha B-crystallin and they indicate that this responsiveness is unlikely to result from determinant spreading following ocular inflammation.

Carboxyl-terminal fragment of amyloid precursor protein and hydrogen peroxide induce neuronal cell death through different pathways

Carboxyl-terminal fragments (CTs) of the amyloid precursor protein have been shown to be highly neurotoxic and are though to contribute to the neuropathology of Alzheimer's disease. We compared the effects of expressing CT99 in the human neuroblastoma MC65 with the effects of hydrogen peroxide on the parental SK-N-MC cells. CT99 and hydrogen peroxide generated a different pattern of free radicals and their toxic effects were differentially protected by a battery of antioxidants. Hydrogen peroxide caused a cell cycle arrest at phase S and apoptosis mediated through caspase-3 activation in a pattern similar to that described for amyloid-beta neurotoxicity. However, CT99 apoptosis appeared to be mediated through an unidentified mitochondrial pathway. Both oxidative injury types induced heme oxygenase-1 expression as a neuroprotective response. Overall we found a coincidence in the nonespecific stress oxidative effects of CT99 and hydrogen peroxide, but clear differences on their respective potencies and pathways of neurotoxicity.

The Canadian C-spine rule for radiography in alert and stable trauma patients

CONTEXT

High levels of variation and inefficiency exist in current clinical practice regarding use of cervical spine (C-spine) radiography in alert and stable trauma patients.

OBJECTIVE

To derive a clinical decision rule that is highly sensitive for detecting acute C-spine injury and will allow emergency department (ED) physicians to be more selective in use of radiography in alert and stable trauma patients.

DESIGN

Prospective cohort study conducted from October 1996 to April 1999, in which physicians evaluated patients for 20 standardized clinical findings prior to radiography. In some cases, a second physician performed independent interobserver assessments.

SETTING

Ten EDs in large Canadian community and university hospitals.

PATIENTS

Convenience sample of 8924 adults (mean age, 37 years) who presented to the ED with blunt trauma to the head/neck, stable vital signs, and a Glasgow Coma Scale score of 15.

MAIN OUTCOME MEASURE

Clinically important C-spine injury, evaluated by plain radiography, computed tomography, and a structured follow-up telephone interview. The clinical decision rule was derived using the kappa coefficient, logistic regression analysis, and chi(2) recursive partitioning techniques.

RESULTS

Among the study sample, 151 (1.7%) had important C-spine injury. The resultant model and final Canadian C-Spine Rule comprises 3 main questions: (1) is there any high-risk factor present that mandates radiography (ie, age >/=65 years, dangerous mechanism, or paresthesias in extremities)? (2) is there any low-risk factor present that allows safe assessment of range of motion (ie, simple rear-end motor vehicle collision, sitting position in ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline C-spine tenderness)? and (3) is the patient able to actively rotate neck 45 degrees to the left and right? By cross-validation, this rule had 100% sensitivity (95% confidence interval [CI], 98%-100%) and 42.5% specificity (95% CI, 40%-44%) for identifying 151 clinically important C-spine injuries. The potential radiography ordering rate would be 58.2%.

CONCLUSION

We have derived the Canadian C-Spine Rule, a highly sensitive decision rule for use of C-spine radiography in alert and stable trauma patients. If prospectively validated in other cohorts, this rule has the potential to significantly reduce practice variation and inefficiency in ED use of C-spine radiography.

Canadian CT head rule study for patients with minor head injury: methodology for phase II (validation and economic analysis)

Prospective validation on a new set of patients is an essential test of a new decision rule. However, many clinical decision rules are not prospectively assessed to determine their accuracy, reliability, clinical sensibility, or potential impact on practice. This validation process is important because many statistically derived rules or guidelines do not perform well when tested in a new population. The methodologic standards for a validation study are similar to those described in the article on phase I for derivation studies in the August 2001 issue of Annals of Emergency Medicine. The goal of phase II is to prospectively assess the accuracy, reliability, and acceptability of the decision rule in a new set of patients with minor head injury. This will determine the clinical utility of the rule and is essential if such a rule is to be widely adopted into clinical practice.

The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation)

Head injuries are among the most common types of trauma seen in North American emergency departments, with an estimated 1 million cases seen annually. "Minor" head injury (sometimes known as "mild") is defined by a history of loss of consciousness, amnesia, or disorientation in a patient who is conscious and talking, that is, with a Glasgow Coma Scale score of 13 to 15. Although most patients with minor head injury can be discharged without sequelae after a period of observation, in a small proportion, their neurologic condition deteriorates and requires neurosurgical intervention for intracranial hematoma. The objective of the Canadian CT Head Rule Study is to develop an accurate and reliable decision rule for the use of computed tomography (CT) in patients with minor head injury. Such a decision rule would allow physicians to be more selective in their use of CT without compromising care of patients with minor head injury. This paper describes in detail the rationale, objectives, and methodology for Phase I of the study in which the decision rule was derived. [Stiell IG, Lesiuk H, Wells GA, McKnight RD, Brison R, Clement C, Eisenhauer MA, Greenberg GH, MacPhail I, Reardon M, Worthington J, Verbeek R, Rowe B, Cass D, Dreyer J, Holroyd B, Morrison L, Schull M, Laupacis A, for the Canadian CT Head and C-Spine Study Group. The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation). Ann Emerg Med. August 2001;38:160-169.]

The Canadian CT Head Rule for patients with minor head injury

BACKGROUND

There is much controversy about the use of computed tomography (CT) for patients with minor head injury. We aimed to develop a highly sensitive clinical decision rule for use of CT in patients with minor head injuries.

METHODS

We carried out this prospective cohort study in the emergency departments of ten large Canadian hospitals and included consecutive adults who presented with a Glasgow Coma Scale (GCS) score of 13-15 after head injury. We did standardised clinical assessments before the CT scan. The main outcome measures were need for neurological intervention and clinically important brain injury on CT.

FINDINGS

The 3121 patients had the following characteristics: mean age 38.7 years); GCS scores of 13 (3.5%), 14 (16.7%), 15 (79.8%); 8% had clinically important brain injury; and 1% required neurological intervention. We derived a CT head rule which consists of five high-risk factors (failure to reach GCS of 15 within 2 h, suspected open skull fracture, any sign of basal skull fracture, vomiting >2 episodes, or age >65 years) and two additional medium-risk factors (amnesia before impact >30 min and dangerous mechanism of injury). The high-risk factors were 100% sensitive (95% CI 92-100%) for predicting need for neurological intervention, and would require only 32% of patients to undergo CT. The medium-risk factors were 98.4% sensitive (95% CI 96-99%) and 49.6% specific for predicting clinically important brain injury, and would require only 54% of patients to undergo CT.

INTERPRETATION

We have developed the Canadian CT Head Rule, a highly sensitive decision rule for use of CT. This rule has the potential to significantly standardise and improve the emergency management of patients with minor head injury.

T- and B-cell nonresponsiveness to self-alphaB-crystallin in SJL mice prevents the induction of experimental allergic encephalomyelitis

The myelin-associated stress protein alphaB-crystallin triggers strong proliferative responses and IFN-gamma production by human T cells and it is considered a candidate autoantigen in multiple sclerosis. In this study we examined the capacity of alphaB-crystallin or peptides derived thereof to induce experimental autoimmune encephalomyelitis (EAE) in SJL mice. Despite extensive efforts to induce EAE using active immunization with whole alphaB-crystallin, using adoptive transfer of lymphocytes or using peptide immunizations, no clinical or histological signs of EAE could be induced. SJL mice were unable to mount proliferative T-cell responses in vitro or delayed-type hypersensitivity responses in vivo to self-alphaB-crystallin. Also, immunization with self-alphaB-crystallin did not lead to any antibody response in SJL mice while bovine alphaB-crystallin triggered clear antibody responses within 1 week. Immunizations with alphaB-crystallin-derived peptides led to the activation of IL-4-producing Th2 cells and only a few IFN-gamma-producing Th1 cells. Peptide-specific T cells showed no cross-reactivity against whole alphaB-crystallin. The inability of SJL mice to mount proinflammatory T-cell responses against self-alphaB-crystallin readily explains the lack of EAE induction by immunization with whole protein or peptides derived from it. T- and B-cell nonresponsiveness is associated with constitutive expression of full-length alphaB-crystallin in both primary and secondary lymphoid organs in SJL mice, which is seen in other mammals as well, but not in humans.

Variation in ED use of computed tomography for patients with minor head injury

STUDY OBJECTIVE

To determine the frequency of utilization, yield for brain injury, incidence of missed injury, and variation in the use of computed tomography (CT) for ED patients with minor head injury.

METHODS

This retrospective health records survey was conducted over a 12-month period in the EDs at seven Canadian teaching institutions. Included in this review were adult patients who sustained acute minor head injury, defined as witnessed loss of consciousness or amnesia and a Glasgow Coma Scale score of 13 or greater. Data were collected by research assistants who were trained to select cases and abstract data in a standardized fashion according to a resource manual. Subsequently, patient eligibility was reviewed by the study coordinator and principal investigator.

RESULTS

Of the 1,699 patients seen, 521 (30.7%) were referred for CT, and 418 (79.8%) of these scans were negative for any type of brain injury. Overall, 105 (6.2%) of these patients sustained acute brain injury, including 9 (.5%) with an epidural hematoma Cochran's Q test for homogeneity demonstrated significant variation between the seven centers for rate of ordering CT (P < .0001), from a low of 15.9% to a high of 70.4%. All five cases of "missed" hematoma occurred at the institutions with the highest and third highest rates of CT use. After controlling for possible differences in case severity and patient characteristics at each hospital, logistic regression analysis revealed that five of seven hospitals were significantly associated with the use of CT (respected odds ratios [OR], .4, .5, .5, 3.2, and 4.7). Three of the centers (two with the highest ordering rates) showed significant heterogeneity in the ordering of CT among their attending staff physicians, from a low of 6.5% to a high of 80.0%.

CONCLUSION

There was considerable variation among institutions and individual physicians in the ordering of CT for patients with minor head injury. Although emergency physicians were selective when ordering CT, the yield of radiography was very low at all hospitals. None of the cases of "missed" intracranial hematoma came from the lowest ordering institutions, indicating that patients may be managed safely with a selective approach to CT use. These findings suggest great potential for more standardized and efficient use of CT of the head, possibly through the use of a clinical decision rule.

Variation in emergency department use of cervical spine radiography for alert, stable trauma patients

OBJECTIVE

To, assess the emergency department use of cervical spine radiography for alert, stable adult trauma patients in terms of utilization, yield for injury and variation in practices among hospitals and physicians.

DESIGN

Retrospective survey of health records.

SETTING

Emergency departments of 6 teaching and 2 community hospitals in Ontario and British Columbia.

PATIENTS

Consecutive alert, stable adult trauma patients seen with potential cervical spine injury between July 1, 1994, and June 30, 1995.

MAIN OUTCOME MEASURES

Total number of eligible patients, referral for cervical spine radiography (overall, by hospital and by physician), presence of cervical spine injury, patient characteristics and hospitals associated with use of radiography.

RESULTS

Of 6855 eligible patients, cervical spine radiography was ordered for 3979 (58.0%). Only 60 (0.9%) patients were found to have an acute cervical spine injury (fracture, dislocation or ligamentous instability); 98.5% of the radiographic films were negative for any significant abnormality. The demographic and clinical characteristics of the patients were similar across the 8 hospitals, and no cervical spine injuries were missed. Significant variation was found among the 8 hospitals in the rate of ordering radiography (p < 0.0001), from a low of 37.0% to a high of 72.5%. After possible differences in case severity and patient characteristics at each hospital were controlled for, logistic regression analysis revealed that 6 of the hospitals were significantly associated with the use of radiography. At 7 hospitals, there was significant variation in the rate of ordering radiography among the attending emergency physicians (p < 0.05), from a low of 15.6% to a high of 91.5%.

CONCLUSIONS

Despite considerable variation among institutions and individual physicians in the ordering of cervical spine radiography for alert, stable trauma patients with similar characteristics, no cervical spine injuries were missed. The number of radiographic films showing signs of abnormality was extremely low at all hospitals. The findings suggest that cervical spine radiography could be used more efficiently, possibly with the help of a clinical decision rule.

Multicentre trial to introduce the Ottawa ankle rules for use of radiography in acute ankle injuries. Multicentre Ankle Rule Study Group

OBJECTIVE

To assess the feasibility and impact of introducing the Ottawa ankle rules to a large number of physicians in a wide variety of hospital and community settings over a prolonged period of time.

DESIGN

Multicentre before and after controlled clinical trial.

SETTING

Emergency departments of eight teaching and community hospitals in Canadian communities (population 10,000 to 3,000,000).

SUBJECTS

All 12,777 adults (6288 control, 6489 intervention) seen with acute ankle injuries during two 12 month periods before and after the intervention.

INTERVENTION

More than 200 physicians of varying experience were taught to order radiography according to the Ottawa ankle rules.

MAIN OUTCOME MEASURES

Referral for ankle and foot radiography.

RESULTS

There were significant reductions in use of ankle radiography at all eight hospitals and within a priori subgroups: for all hospitals combined 82.8% control v 60.9% intervention(P < 0.001); for community hospitals 86.7% v 61.7%; (P < 0.001); for teaching hospitals 77.9% v 59.9%; (P < 0.001); for emergency physicians 82.1% v 61.6%; (P < 0.001); for family physicians 84.3% v 60.1%; (P < 0.001); and for housestaff 82.3% v 60.1%; (P < 0.001). Compared with patients without fracture who had radiography during the intervention period those who had no radiography spent less time in the emergency department (54.0 v 86.9 minutes; P < 0.001) and had lower medical charges ($70.20 v $161.60; P < 0.001). There was no difference in the rate of fractures diagnosed after discharge from the emergency department (0.5 v 0.4%).

CONCLUSIONS

Introduction of the Ottawa ankle rules proved to be feasible in a large variety of hospital and community settings. Use of the rules over a prolonged period of time by many physicians of varying experience led to a decrease in ankle radiography, waiting times, and costs without an increased rate of missed fractures. The multiphase methodological approach used to develop and implement these rules may be applied to other clinical problems.

Relationship of ribonucleic Acid metabolism in embryo and aleurone to alpha-amylase synthesis in barley

RNA metabolism of embryo and aleurone of barley grains (Hordeum vulgare L. cv. Himalaya) was studied to elucidate the role of these tissues in the control of alpha-amylase synthesis and germination. The extent of (3)H-uridine incorporated into various RNA classes of the embryo during the first 12 hours of germination was low but constant. Subsequently, there was a rapid increase in RNA synthesis of all fractions. In the aleurones, after 16 hours, a gradual decrease in (3)H-uridine incorporation was observed, and by the time the synthesis of RNA in the aleurones had stopped, alpha-amylase level was at its highest in the grain.On transfer to accelerated aging conditions (43 C; 85% relative humidity), the grains lost their viability within 4 weeks. That this was due to a rapid deterioration of the embryo and not of the aleurone was apparent in studies on alpha-amylase formation, RNA metabolism, and ATP content in grains in various physiological states reported here. Results presented here also reveal a marked influence of the embryo and GA(3) on the quality of the newly synthesized RNAs. Aleurones which lacked the impulse of embryo or GA(3) were capable of synthesizing RNA but these RNAs were less heterodisperse than RNAs from aleurones which were under the influence of an embryo or GA(3).

Embryoless Wheat Grain: A Natural System for the Study of Gibberellin-induced Enzyme Formation

Yorkstar wheat, grown in New York State, has a high percentage (10-11) of grains without embryos. The embryoless grains have viable aleurone layers and show no sign of injury. These grains are able to support alpha-amylase synthesis only in the presence of gibberellin A(3) (GA(3)). In the absence of GA(3) some protein synthesis occurs in embryoless grains during the early hours of soaking, indicating that such activity occurs prior to and independent of GA(3) induction of alpha-amylase. The level of beta-amylase on a dry weight basis is the same in embryoless and normal grains and decreases with time of soaking. In the presence of GA(3), beta-amylase decreases at a slower rate. Isoenzymes of alpha-amylase from GA(3)-treated embryoless and normal grains show quantitative as well as qualitative differences. Cycloheximide (60 mug/ml) completely inhibits the synthesis of alpha-amylase by embryoless grains. Of the RNA synthesis inhibitors, actinomycin D (60 mug/ml) was ineffective while 6-methylpurine (60 mug/ml) gave 65% inhibition without decreasing the number of isoenzymes.

[Formation of α-amylase isozymes during germination of barley]

The α-amylase formed in germinating barley has been separated into six isozymes by means of polyacrylamide gel electrophoresis. These isozymes do not appear from the beginning of germination but are formed gradually so that after six days all six α-amylase isozymes are present.When gibberellic acid is added to the culture medium the production of the α-amylase isozymes is accelerated considerably, whereas the addition of kinetin has no influence at all on the formation of the α-amylase isozymes.The α-amylase induced by gibberellic acid in the aleurone layers of isolated barley endosperms apparently consists of five isozymes, a number that does not change upon further incubation.The action of phytohormones such as gibberellic acid and kinetin on the formation of α-amylase and its isozymes during the germination of barley is discussed.

Variations de quelques aclivités enzymatiques (peroxydase, catalase, AIA-oxydase) et de la teneur en polyphénols au cours de la germination de I'Orge. Influence de la kinétine

Peroxidase catalase, IAA-oxidase and polyphenol content of growing barley coleoptile. Effect of kinetin. - Kinetin strongly inhibits root and coleoptile growth of germinating barley in the dark. Treated coleoptiles become senescent before the untreated ones. Soluble proteins content, peroxidase, catalase and IAA-oxidase activity were greatly increased in treated coleoptiles while the level of polyphenols was reduced. These biochemical effects joined with the other property of kinetin to diminish α-amylase synthesis in the endosperm are discussed in relation to growth and in connection with the classic view of a cytokinin retarded senescence.

Effets de l'acide gibbérellique et de la kinétine sur le développement de l'activitéα-amylasique durant la croissance de l'Orge

Effects of gibberellic acid and kinetic on α-amylase production during the germination of barley. - The action of gibberellic acid and kinetin, alone or combined at different concentrations, has been studied on α-amylase production in whole barley seedlings and in embryoless endosperms in course of the six first days of development in the dark. The classic activation of α-amylase synthesis by gibberellic acid has been confirmed both in whole seeds and in embryoless endosperms. Kinetin inhibits α-amylase synthesis after the third day of germination but has no effect on isolated endosperms. When gibberellic acid and kinetin are given simultaneously gibberellic acid stimulated during the three first days just as it does alone, kinetin inhibits after the third day also as it was alone so that the two regulators act, without interactions, at different stages in the time. These effects of kinetin are be independent. A critical examination of the techniques used in the literature in the stud of amylase is made.