Systematic Review of Literature Citing the ISCHEMIA Trial

PURPOSE OF REVIEW

Optimal therapy for patients with chronic coronary artery disease (CCD) has long been a topic under investigation and a subject of debate. Seeking to clarify appropriate management, the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial compared medical management versus coronary angiography for patients with stable ischemic heart disease. Its reception in the medical community has been met with both acclaim and criticism. In light of such disparate views of this trial, a systematic review of the literature citing the ISCHEMIA trial was performed.

RECENT FINDINGS

All articles citing the ISCHEMIA trial on PubMed as of July 21, 2023, were compiled and underwent qualitative analysis. A total of 430 articles were evaluated; 109 (25.3%) did not offer substantial commentary on ISCHEMIA and cite it as background evidence for further study. Of the commentary articles, the majority (224, 52.1%) gave balanced, honest appraisals of the ISCHEMIA trial. A total of 46 (10.7%) strongly praised the trial while another 39 (9.1%) were strongly critical of the results. Almost three-quarters of the literature citing the ISCHEMIA trial was commentary in nature, with roughly equal distribution across the spectrum of praise and criticism. Despite being one of the largest studies on CCD and coronary revascularization ever conducted, the impact of ISCHEMIA on the cardiology community appears to be mixed.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Utilization of computerized tomography and magnetic resonance imaging for diagnosis of traumatic C-Spine injuries at a level 1 trauma center: A retrospective Cohort analysis

Background

Computerized tomography (CT) is a common imaging modality for trauma patients, but there is debate regarding the role of magnetic resonance imaging (MRI) in cervical (C)-spine clearance. We aim to investigate the utilization of CT and MRI imaging in traumatic C-spine clearance and associated outcomes on patients who undergo both imaging modalities.

Methods

A 4-year retrospective review was performed to evaluate the trauma patient imaging algorithm at our institution. The algorithm required CT as a screening examination for traumatic injury patients who are unexaminable because of distracting injury, altered mental status, an abnormal neurological examination, and/or central neck pain. MRI was performed after CT in patients with C-spine injuries identified on CT, those who remained unexaminable, had an abnormal neurological examination, or experienced persistent central neck tenderness. Univariate analyses and adjusted multivariate logistic regression were performed with significance defined as p < 0.05.

Results

805 patients were analyzed. Compared to MRI, CT had a sensitivity of 50.2%, specificity of 76.6%, positive predictive value of 69.7%, and negative predictive value of 59.0% in detecting C-spine injuries. CT and MRI differed significantly in their ability to detect C-spine soft tissue injuries and C1 vertebral fractures (p < 0.05).

Conclusions

MRI is more capable of detecting soft tissue injuries whereas CT is superior in detecting vertebral fractures. Our findings support the need to utilize CT and MRI in conjunction to detect both bony and soft tissue C-spine injuries in traumatically injured patients, who are either unexaminable, have an abnormal neurologic examination, or ongoing central neck tenderness.

Regional Population-Based Workforce Shortages in General Surgery by Practicing Surgeon and Resident Trainee

BACKGROUND

The physician shortage in the United States (US) continues to become more apparent. We aimed to evaluate the relationship between the US physician distribution from 2012-2019 by specialty at the state/regional level relative to the corresponding population growth.

METHODS

US matched residents and practicing physicians from 2012-2019 were extracted from the National Resident Matching Program and Association of American Medical College databases, respectively. Residents and practicing physicians were divided by geographic regions (West, Midwest, South, Northeast), states, and specialties (anesthesiology, emergency medicine, family medicine, general surgery (GS), internal medicine, obstetrics/gynecology and pediatrics).

RESULTS

Entering residents and physicians increased across 7 specialties from 2012-2019 with the exception of GS, which showed .2% decrease in practicing physicians. GS experienced decreases in entering residents in all US regions except the South. All specialties showed a decrease in the people-per-physician (PPP) except GS and pediatrics, which had a 4.1% and 71.3% increase, respectively. EM showed the largest growth overall, both in entering residents and overall workforce.

CONCLUSION

GS experienced slow growth of residents, decreases in practicing physicians and workforce overall, and an increase in PPP from 2012-2019. Our findings suggest that current population growth rate is exceeding the rate of physicians entering the field of GS and highlights the need for interventions to promote the recruitment of GS residents and retainment of attending physicians, particularly for rural areas. Future research to measure surgeon distribution in relation to patient outcomes and the efficacy of recent policy to address shortages can help define additional interventions to address physician shortages moving forward.

Blood Culture Results and Overtreatment Associated With the Use of a 1-Hour Sepsis Bundle

BACKGROUND

Some experts recommend using a 1-h sepsis bundle, but clinical data supporting this strategy are lacking.

OBJECTIVES

We aimed to determine the rate of, and clinical predictors for, bacteremia for patients undergoing a 1-h sepsis bundle, and to determine the percentage of "code sepsis" patients who are ultimately diagnosed with sepsis or a bacterial infection.

METHODS

This retrospective chart review evaluated code sepsis patients from three emergency departments (EDs) that utilize a 1-h sepsis bundle. The primary outcome was the rate of true-positive blood cultures. Secondarily, we analyzed various clinical factors using logistic regression analysis to determine which are associated with bacteremia.

RESULTS

Of the 544 code sepsis patients analyzed, 33.8% (95% confidence interval [CI] 29.9-38.0%) were ultimately diagnosed with sepsis, and 54.6% (95% CI 50.3-58.8%) were diagnosed with a bacterial infection. Exactly 7.0% (95% CI 5.0-9.5%) of the blood cultures performed were true positives. On multivariate logistic regression analysis, temperature > 38°C (100.4°F) or < 36°C (96.8°F), lactate > 4 mmol/L, and indwelling line/device were found to be positively associated with true-positive blood cultures.

CONCLUSION

In a group of code sepsis patients from facilities that use a 1-h sepsis bundle, the majority were ultimately not diagnosed with sepsis, and nearly half did not have a bacterial infection. A small minority of patients had bacteremia. Restricting blood culture ordering in patients with possible sepsis to only those who have increased risk for bacteremia could lead to a more judicious use of blood cultures.

The relationship between biomarkers of fungal allergy and lung damage in asthma

BACKGROUND

Immunological biomarkers are the key to the diagnosis of allergic bronchopulmonary aspergillosis (ABPA) and fungal sensitisation, but how these relate to clinically relevant outcomes is unclear.

OBJECTIVES

To assess how fungal immunological biomarkers are related to fixed airflow obstruction and radiological abnormalities in moderate to severe asthma.

METHODS

Cross-sectional study of 431 asthmatics. Inflammatory biomarkers, lung function and an IgE fungal panel to colonising filamentous fungi, yeasts and fungal aeroallergens were measured. CT scans were scored for the presence of radiological abnormalities. Factor analysis informed the variables used in a k-means cluster analysis. Fixed airflow obstruction and radiological abnormalities were then mapped to these immunological variables in the cluster analysis.

RESULTS

329 (76.3%) subjects were sensitised to ≥ 1 fungi. Sensitisation to Aspergillus fumigatus and/or Penicillium chrysogenum was associated with a lower post-bronchodilator FEV₁ compared with those not sensitised to fungi ((73.0 (95% CI 70.2-76) vs. 82.8 (95% CI 78.5-87.2)% predicted, P < 0.001), independent of atopic status (P = 0.005)), and an increased frequency of bronchiectasis (54.5%, P < 0.001), tree-in-bud (18.7%, P < 0.001) and collapse/consolidation (37.5%, P = 0.002). Cluster analysis identified three clusters: (i) hypereosinophilic (n = 71, 16.5%), (ii) high immunological biomarker load and high frequency of radiological abnormalities (n = 34, 7.9%) and (iii) low levels of fungal immunological biomarkers (n = 326, 75.6%).

CONCLUSIONS AND CLINICAL RELEVANCE

IgE sensitisation to thermotolerant filamentous fungi, in particular A. fumigatus but not total IgE, is associated with fixed airflow obstruction and a number of radiological abnormalities in moderate to severe asthma. All patients with IgE sensitisation to A. fumigatus are at risk of lung damage irrespective of whether they meet the criteria for ABPA.

Isolation of filamentous fungi from sputum in asthma is associated with reduced post-bronchodilator FEV1

Background

Fungal sensitization is common in severe asthma, but the clinical relevance of this and the relationship with airway colonization by fungi remain unclear. The range of fungi that may colonize the airways in asthma is unknown.

Objective

To provide a comprehensive analysis on the range of filamentous fungi isolated in sputum from people with asthma and report the relationship with their clinico-immunological features of their disease.

Methods

We recruited 126 subjects with a diagnosis of asthma, 94% with moderate-severe disease, and 18 healthy volunteers. At a single stable visit, subjects underwent spirometry; sputum fungal culture and a sputum cell differential count; skin prick testing to both common aeroallergens and an extended fungal panel; specific IgE to Aspergillus fumigatus. Fungi were identified by morphology and species identity was confirmed by sequencing. Four patients had allergic bronchopulmonary aspergillosis.

Results

Forty-eight percent of asthma subjects were IgE-sensitized to one fungal allergen and 22% to ≥ 2. Twenty-seven different taxa of filamentous fungi were isolated from 54% of their sputa, more than one species being detected in 17%. This compared with 3 (17%) healthy controls culturing any fungus (P < 0.01). Aspergillus species were most frequently cultured in isolation followed by Penicillium species. Post-bronchodilator FEV₁ (% predicted) in the subjects with asthma was 71(± 25) in those with a positive fungal culture vs. 83 (± 25) in those culture-negative, (P < 0.01).

Conclusion and Clinical Relevance

Numerous thermotolerant fungi other than A. fumigatus can be cultured from sputum of people with moderate-to-severe asthma; a positive culture is associated with an impaired post-bronchodilator FEV₁, which might be partly responsible for the development of fixed airflow obstruction in asthma. Sensitization to these fungi is also common.

Techniques and trouble-shooting in high spatial resolution thin slice MRI for rectal cancer

MRI is increasingly advocated as an optimal method of staging rectal cancer. The technique enables depiction of the relationship of tumour to the mesorectal fascia and may thus identify tumours at risk of positive circumferential margin involvement at surgery. Depth of extramural spread may also be accurately measured and tumour deposits within the mesorectum are shown. It is important that a high spatial resolution technique is used in order to accurately depict these features and care should be taken in ensuring that images acquired cover the entire rectal tumour and mesorectum. This paper describes the technique of high spatial resolution rectal cancer imaging and the potential technical pitfalls in acquiring good quality images. Important factors to consider include: adequate scan duration to achieve high spatial resolution images with sufficient signal to noise ratio, careful positioning of the pelvic phased array coil, use of T2 weighted turbo spin-echo rather than T1 weighted imaging and careful planning of scans to ensure that images are obtained perpendicular to the rectal wall.

Off-site evaluation of liver lesion detection by Gd-BOPTA-enhanced MR imaging

The aim of this study was to determine the efficacy of Gd-BOPTA-enhanced MRI in liver lesion detection in comparison with unenhanced MRI and dynamic CT. The image sets of 148 of 151 patients enrolled in a multicenter German phase-III trial were evaluated by two independent radiologists unaffiliated with the investigating centers. Patients underwent a routine MRI protocol comprising T2- and T1-weighted spin-echo and T1-weighted gradient-echo (GE) sequences pre and 1 h post 0.1 mmol/kg Gd-BOPTA (Bracco-Byk Gulden, Konstanz, Germany). Additionally, a serial T1-weighted GE scan was performed after administration of the first half of the dose. All patients underwent dynamic contrast-enhanced CT. The evaluation was performed with regard to the number and size of lesions detected per patient by each modality or sequence. Furthermore, all pre CM and pre + post CM image sets were analyzed for number of lesions per patient. Both readers detected significantly more lesions in the contrast-enhanced image set compared with the unenhanced image set (32 and 39 %, respectively; p < 0.0001). While contrast-enhanced CT detected a similar number of lesions to unenhanced MRI, it was clearly inferior to contrast-enhanced MRI (reader 1: p = 0.0117; reader 2: p = 0.0225). Of the T1-weighted scans performed, the dynamic and late T1-weighted GE exams contributed most to the increased lesion detection rate (reader 1: p = 0.0007; reader 2: p = 0.0037). The size of the smallest lesion detected by means of MRI was significantly larger in the pre-CM image sets than in the pre + post CM image sets (reader 1: p = 0.001; reader 2: p < 0.0001). Gd-BOPTA-enhanced MRI detected significantly smaller lesions than contrast-enhanced CT (reader 1: p = 0.0117; reader 2: p = 0.0925). Gd-BOPTA-enhanced MR imaging improves liver lesion detection significantly over unenhanced MRI and dynamic CT.

Efficacy of single-dose and multidose rofecoxib in the treatment of post-orthopedic surgery pain

To determine the efficacy of rofecoxib in post-orthopedic surgery pain, we conducted a double-blind, randomized, placebo- and active-comparator-controlled, parallel-group trial. Two hundred eighteen patients enrolled. Day 1 patients received placebo, rofecoxib 50 mg, or naproxen sodium 550 mg. Days 2 through 5, the placebo and naproxen sodium groups received placebo, and the rofecoxib group received rofecoxib 25 or 50 mg. Rofecoxib 50 mg was superior to placebo (P < .05) and similar to naproxen sodium for all single-dose measures of pain relief. Days 2 through 5, the rofecoxib 50 mg group used less supplemental narcotic analgesia (P = .005) and reported less pain on global evaluations (P = .041) when compared with the placebo group; the efficacy of rofecoxib 25 mg fell between that of placebo and rofecoxib 50 mg for these endpoints (P < or = .267). Rofecoxib 50 mg once daily effectively treated post-orthopedic surgery pain.

Numerical study of blood flow in an anatomically realistic aorto-iliac bifurcation generated from MRI data

Magnetic resonance imaging and computational fluid dynamics (CFD) have been used in combination to simulate flow patterns at the human aorto-iliac bifurcation. Vascular anatomy was reconstructed from stacked two-dimensional (2D) time-of-flight images, and revealed asymmetric, nonplanar geometry with curvature in the abdominal aorta and right iliac artery. The left iliac artery was straight and exhibited a smaller take off angle than the right iliac artery. The anatomical reconstruction was used to generate a computational mesh and obtain CFD predictions of flow and wall shear stress (WSS) within the region of interest. The dynamic boundary conditions necessary were specified by 2D cine phase contrast measurements of velocity profiles in each component vessel. Predicted flow patterns were in good quantitative agreement with experiment and demonstrated major differences in WSS distributions between the iliac arteries. This noninvasive approach has considerable potential to evaluate local geometries and WSS as risk factors for arterial disease in individual subjects.

Reconstruction of blood flow patterns in human arteries

Local haemodynamic factors in large arteries are associated with the pathophysiology of cardiovascular diseases such as atherosclerosis and strokes. In search of these factors and their correlation with atheroma formation, quantitative haemodynamic data in realistic arterial geometry become crucial. At present no in vivo non-invasive technique is available that can provide accurate measurement of three-dimensional blood velocities and shear stresses in curved and branching sites of vessels where atherosclerotic plaques are found frequently. This paper presents a computer modelling technique which combines state-of-the-art computational fluid dynamics (CFD) with new noninvasive magnetic resonance imaging techniques to provide the complete haemodynamic data in 'real' arterial geometries. Using magnetic resonance angiographic and velocity images acquired from the aortic bifurcation of a healthy human subject, CFD simulations have been carried out and the predicted flow patterns demonstrate the non-planar-type flow characteristics found in experimental studies.

The combination of magnetic resonance angiography and computational fluid dynamics: a critical review

Computational Fluid Dynamics (CFD) has proven to be a valuable technique in the study of blood flow in arteries because of its capability of obtaining quantitatively velocities and wall shear stress. However, the "bottleneck" problem limiting the application of CFD is the difficulty of constructing anatomically realistic arterial geometries. In this survey, an overview is presented of the progress over the last decade in the development of magnetic resonance angiography (MRA) techniques, medical image processing and CFD, as well as the combination of these techniques in hemodynamics research. It is demonstrated that with modern angiographic techniques such as MRA, noninvasive measurement of human angiograms becomes possible and practical. Together with digital medical image processing and analysis techniques, computational models can be constructed for the "real" human arteries without making any geometric assumptions. When allied with state-of-the-art CFD codes, velocity and wall shear stress distributions, as well as particle trajectories, can be determined in the arteries.

Magnetic resonance image processing and structured grid generation of a human abdominal bifurcation

Magnetic resonance angiography (MRA) offers a non-invasive approach to the acquisition of anatomically accurate human arterial structure. Combining the latest computational fluid dynamics (CFD) techniques with clinical data from MRA, the detailed haemodynamics information in the human circulation system can be obtained. In this paper, a novel computer method is presented, which generates automatically a computational grid for a human abdominal bifurcation from a set of conventional MRA images. The method covers the complete sequence from MR image segmentation, 3-D model construction, grid generation, to grid quality evaluation. Results demonstrate that the computer program developed is capable of generating a good quality grid for human arterial bifurcations from MRA images with minimum user input. The resultant grid can be used directly for further computer simulation of the flow.

Hospital outcomes management: the Care Continuum and Health Outcomes Project

The Care Continuum and Health Outcomes Project is part of a national initiative to build an outcomes management approach in health care. This paper examines the baseline performance of the study. In 1995-96, 7154 Australian Capital Territory hospital inpatients were selected to take part in a five-wave survey over six months. In addition to the survey, the project involved the unit record linkage of routine data collections. A total of 5668 people (79%) agreed to participate in the survey, with 85% of these people agreeing to release their Medicare data. There were significant variations in participation rates between hospitals and wards. Factors contributing to these variations included patient socioeconomic status, disease type and illness severity. In conclusion, the success in establishing the project indicates that it is possible to conduct a broad scientific study within the health system, and that there are strong implications that ongoing scientific evaluations can be embedded within routine clinical practice.

Analysis of cardiac function by MRI and stereology

Design-based stereology and phase contrast magnetic resonance imaging (MRI) were combined to monitor changes in the volume of the four chambers of the human heart during the cardiac cycle. The data set consisted of 18 adjacent slices (or 'scanning levels') of 0.5 cm thickness, perpendicular to the long axis of the body, and encompassing the whole heart of a healthy volunteer. At each scanning level, a cardiac gated MR image was obtained at each of 16 equally spaced time frames within the cardiac cycle. Given stationarity with respect to time, absence of image artefacts and appropriate definition of chamber boundaries, for each time frame unbiased estimates of total blood volume in the relevant heart chambers were efficiently obtained using the Cavalieri method and point counting. Combined with a proper MRI acquisition, modern stereological methods constitute an efficient and reliable tool to quantify cardiac function noninvasively.

Assessment of hemodynamic effects of angiotensin-converting enzyme inhibitor therapy in chronic aortic regurgitation by using velocity-encoded cine magnetic resonance imaging

Long-term treatment with angiotensin-converting enzyme (ACE) inhibitors has beneficial effects in patients with chronic aortic regurgitation by reducing left ventricular volumes and regurgitant fraction. Velocity-encoded cine magnetic resonance imaging can directly measure antegrade (forward stroke volume) and retrograde blood flow (regurgitant volume) in the ascending aorta. Velocity-encoded cine magnetic resonance imaging was used in 9 patients with moderate to severe aortic regurgitation (regurgitant fraction 49% +/- 17%) to measure regurgitant fraction, regurgitant volume, and forward stroke volume at baseline and 3 months after therapy with enalapril (mean dose 29 +/- 13 mg). Ten additional patients with aortic regurgitation without any drug therapy served as a control group. In the treatment group, systolic blood pressure slightly decreased from 132 +/- 20 mm Hg to 121 +/- 14 mm Hg (p = not significant), whereas diastolic blood pressure and heart rate (beats per minute) remained unchanged. Regurgitant fraction decreased in 6 patients (responders) from 49% +/- 19% to 39% +/- 20% (percentage change 24% +/- 14%, p = 0.002) and was unchanged in 3 patients (nonresponder, 49% +/- 19% vs 51% +/- 16%; p = not significant). In the responder group, forward stroke volume increased from 128 +/- 32 ml to 148 +/- 57 ml, whereas regurgitant volume remained unchanged (67 +/- 40 ml vs 65 +/- 51 ml). At baseline, the responder group had a significant higher total vascular resistance than the nonresponder group (998 +/- 538 dyne.sec.cm-5 vs 625 +/- 214 dyne.sec.cm-5; p < 0.05). With enalapril treatment, total vascular resistance in the responder group tended to decrease (891 +/- 576 dyne.sec.cm-5), but slightly increased in the nonresponder group (679 +/- 276 dyne.sec.cm-5). The control group showed no changes in regurgitant fraction, regurgitant volume, forward stroke volume, and total vascular resistance at follow-up.

Unbiased estimation of human body composition by the Cavalieri method using magnetic resonance imaging

The classical methods for estimating the volume of human body compartments in vivo (e.g. skin-fold thickness for fat, radioisotope counting for different compartments, etc.) are generally indirect and rely on essentially empirical relationships--hence they are biased to unknown degrees. The advent of modern non-invasive scanning techniques, such as X-ray computed tomography (CT) and magnetic resonance imaging (MRI) is now widening the scope of volume quantification, especially in combination with stereological methods. Apart from its superior soft tissue contrast, MRI enjoys the distinct advantage of not using ionizing radiations. By a proper landmarking and control of the scanner couch, an adult male volunteer was scanned exhaustively into parallel systematic MR 'sections'. Four compartments were defined, namely bone, muscle, organs and fat (which included the skin), and their corresponding volumes were easily and efficiently estimated by the Cavalieri method: the total section area of a compartment times the section interval estimates the volume of the compartment without bias. Formulae and nomograms are given to predict the errors and to optimize the design. To estimate an individual's muscle volume with a 5% coefficient of error, 10 sections and less than 10 min point counting (to estimate the relevant section areas) are required. Bone and fat require about twice as much work. To estimate the mean muscle volume of a population with the same error contribution, from a random sample of six subjects, the workload per subject can be divided by square root of 6, namely 4 min per subject. For a given number of sections planimetry would be as accurate but far more time consuming than point counting.

A comparison of the effects of single doses of amoxapine and amitriptyline on autonomic functions in healthy volunteers

We have studied the effects of single oral doses of amoxapine (100 mg and 200 mg), amitriptyline (50 mg and 100 mg), and placebo on some autonomic functions in ten healthy volunteers, using a balanced double-blind crossover design. Amitriptyline significantly reduced salivation and it significantly attenuated both miosis evoked by locally applied pilocarpine and sweat secretion evoked by locally applied carbachol. Amoxapine did not significantly alter any of these measures. Neither treatment significantly altered the pupillary light reflex (latency, amplitude, or 75% recovery time). Resting pupil diameter was significantly reduced by the higher dose of amoxapine but was not affected by the other treatments. The higher dose of amoxapine significantly increased supine systolic blood pressure, but did not affect heart rate or diastolic blood pressure; amitriptyline had no effect on any of these cardiovascular measures. These results confirm the antimuscarinic effects of amitriptyline in man, but provide no evidence for antimuscarinic effects of amoxapine.

When doctors went to war

Images

Multiple-hospital survey of ejection-fraction variability using a cardiac phantom

A dynamic cardiac phantom was used to provide identical input data at 11 different nuclear medicine laboratories throughout the Philadelphia area, and the variability in the resulting calculations of ejection fraction (EF) was assessed. The variability observed between different operators using the same computer system averaged 3 EF units, which was similar to that between different observers using different types of computers. In the range of low ejection fractions, however, there was a suggestion that EFs calculated with an MDS computer were slightly lower than those from a DEC computer.