tbuckley/cabot-search huggingface dataset:
Multicomponent indices to predict survival in COPD
Authors: Martin R. Miller
Journal: European Respiratory Journal (2014)

The recent article by MARIN et al. [1] compared various multicomponent indices of chronic obstructive pulmonary disease (COPD) severity to see which best predicted survival and concluded ADO (age, dyspnoea and forced expiratory volume in 1 s (FEV1)) and BODE (body mass index, airflow obstruction, dyspnoea and exercise capacity) were the most valid.However, these were only the most valid of the indices they have considered.As committed researchers the authors should be looking to see how much better they can serve their patients with COPD and they have failed to consider refining the current indices in the light of available evidence.In these indices lung function is used as per cent of predicted which is a flawed method and has been shown not to be the best way of using lung function with respect to predicting survival [2,3].I agree with the authors' statement that age, as for many other nonmodifiable factors, should have limited value in the clinical stratification of COPD.Per cent of predicted attempts to take age, sex and height into account, but leaves biases from each within the index.Young cystic fibrosis (CF) patients dying with airflow obstruction have FEV1 values that are just as low as middle-aged COPD patients dying of respiratory failure, so using per cent of predicted values will defeat survival analysis since the CF patient will have a much lower per cent of predicted value than the older COPD subject.Relating lung function values to predicted values is only of use when determining if the value is unexpected or abnormal.Severity of airflow obstruction, which relates to survival, is better defined by other means such as FEV1 divided by powers of height [2,3] or by FEV1 quotient [3,4].The authors should have considered using lung function in these ways within their multicomponent indices, since a preliminary study has indicated that the power of BODE to predict survival in COPD was dramatically increased by using FEV1 in this way [5].Until researchers working in the field of COPD explore their data fully and challenge accepted norms we are likely to be limited by second best results from research studies and poorer treatments for our patients.Lung function values expressed as % predicted are not the most appropriate measure of airflow obstruction severity http://ow.ly/qxLdp
Test of Environmental Exposure to Arsenic and Hearing Changes in Exposed Children
Authors: V. Bencko, K. Symon
Journal: Environmental Health Perspectives (1977)

Arsenic determination was carried out on hair, urine, and blood samples taken from groups of 10-year-old boys, each numbering 20 to 25 individuals, residing in a region polluted by arsenic. In all the examined materials considerably elevated concentrations of arsenic were found. The relation of the observed levels of arsenic to the distance of the place of residence up to a distance of more than 30 km from the source of the emissions was studied. On the basis of the results obtained, the most advantageous material for estimation of nonoccupational exposure to arsenic seems to be hair, in spite of some problems with the decontamination procedure involved. Considerable variability among individual arsenic values in the hair makes group examination a necessity. Hearing changes were analyzed in a group of 56 10-year old children residing near a power plant burning local coal of high arsenic content. The results of both audiometric and clinical examination were compared with those of control group numbering 51 children of the same age living outside the polluted area. The highly standardized audiometric and clinical examination were completed with a questionnaire analysis concerning the personal medical histories of the children. The obtained data were elaborated statistically by means of the χ2– test. In the case of air conduction, important hearing losses were found at frequencies of 125, 250 and 8000 Hz, especially at the lowest frequency range. Significant degrees of hearing loss were found in bone conduction as well as in the corresponding ranges of frequencies. The high statistical significance of the hearing impairments found points to very low probability of their being only an “accidental” finding. The possibility of toxic damage to the ear cannot yet be excluded.
Radioisotopic bolus technique as a test to detect circulatory deficit associated with cerebral death. 142 studies on 80 patients demonstrating the bedside use of an innocuous IV procedure as an adjunct in the diagnosis of cerebral death.
Authors: JKorein, PBraunstein, IKricheff, ALieberman, NChase
Journal: Circulation (1975)

A portable radioisotopic technique was developed to demonstrate cerebral circulatory deficit, as part of a collaborative study to define and diagnose cerebral death simply and rapidly, in comatose, apneic patients with electrocerebral silence. The method involves an intravenous injection of 2mCi of 99mTcO4, and recording time/activity curves over the cranial cavity and a femoral artery simultaneously, using twin probe radioisotope detector equipment. Eight comatose, apneic patients had 142 studies in conjunction with clinical electroencephalographic and other laboratory evaluations. The results indicate that the absence of a bolus tracing from the head, as contrasted to the usual bolus seen is indicative of significant circulatory deficit to the cerebrum. This test may be used as an adjunct in confirming the diagnosis of cerebral death. A normal bolus tracing should be simultaneously observed over a femoral artery and this is used as a control. The method is safe and simple and offers significant informat...
Self-Assessment of Medical Knowledge
Authors: J. R. E.
Journal: Annals of Internal Medicine (1968)

Editorials1 January 1968Self-Assessment of Medical KnowledgeJ. R. E.J. R. E.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-68-1-247 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptKnowledge itself is power—FRANCIS BACONAbout the time this issue of the ANNALS reaches you many members of the American College of Physicians will be closeted with themselves taking a look at the state of their own medical knowledge. They are participating in what appears to be a completely new idea in postgraduate medical education: the Medical Knowledge Self-Assessment Program.The idea briefly is this. The most critical factor in a physician's continuing education is motivation; he mustwantto continue to learn. Such motivation is more likely if he recognizes specific deficiencies in his useful medical knowledge. ThisProgram... This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byCorrelates of Professional Obsolescence: Part IOn The Making and Use of PhysiciansJ. R. E. 1 January 1968Volume 68, Issue 1Page: 247-249KeywordsContinuing medical educationMedical educationMotivation ePublished: 1 December 2008 Issue Published: 1 January 1968 PDF downloadLoading ...
Increased capillary hydraulic conductivity induced by atrial natriuretic peptide.
Authors: V HHuxley, V LTucker, K MVerburg, R HFreeman
Journal: Circulation Research (1987)

The small molecular weight peptide, atrial natriuretic peptide (ANP), produces marked sodium and water excretion. The peptide, extracted from several species of vertebrate heart, also has been shown to increase glomerular filtration and reduce plasma volume. Several mechanisms have been proposed to account for the action of the peptide but remain undefined. In the present report, the ANP-induced alterations in transcapillary water movement were directly assessed. The modified Landis technique was used to measure single capillary hydraulic conductivity (Lp) of vessels from the frog mesenteric circulation. In 6 individual microvessels, Lp was measured under control conditions and again during perfusion with 10 X 10(-6) M ANP. The Lp increased in each vessel by a mean of 3.79-fold (+/- 2.09 SD). In 4 of these vessels, an additional measurement of Lp was repeated under control conditions; the capillary filtration coefficient returned to control levels. It was concluded that ANP directly and reversibly elevate...
Variability, reproducibility, and applications of precordial ST-segment mapping following acute myocardial infarction.
Authors: THardarson, HHenning, R AO'Rourke, J SKarliner, WRyan, JRoss
Journal: Circulation (1978)

In 58 patients with uncomplicated acute anterior myocardial infarction, a mean decline in the sum of ST segments (sigmaST) of 34% was observed when comparing sigmaST values recorded at 3-6 hours with those recorded at 6-9 hours after the onset of symptoms (P less than 0.05). The mean absolute difference between 19 paired readings 1-2 hours apart was 2.9 +/- 3.0 mm and between 29 readings 2-4 hours apart 3.0 +/- 3.0 mm. However, the mean absolute difference between 38 paired readings 4-8 hours apart was 12.2 +/- 11.8 mm with a wide range of differences. Left ventricular failure and pericarditis were also associated with significantly higher sigmaST values. We conclude that there is a complex relationship between ST-segment elevation and a number of clinical factors during the first 48 hours after infarction. Nevertheless, precordial mapping remains a useful method for the evaluation of short-term (less than 4 hours) therapeutic interventions, if other relevant variables are unaltered and if carefully match...
Intervention ventriculography. Comparative value of nitroglycerin, post-extrasystolic potentiation and nitroglycerin plus post-extrasystolic potentiation.
Authors: V SBanka, M MBodenheimer, RShah, R HHelfant
Journal: Circulation (1976)

The comparative value of nitroglycerin (TNG), post-extrasystolic potentiation (PESP) and their combination (TNG + PESP) to unmask asynergic residual contraction was examined, each patient serving as his own control. Twelve of 13 hypokinetic zones improved both with TNG and PESP. One remained unchanged with either. Of 15 akinetic zones, four improved with both TNG and PESP, while ten remained unchanged. One akinetic zone, although improved with TNG, remained unchanged with PESP. Four dyskinetic zones did not change with either. Six asynergic zones responding to TNG alone demonstrated further augmentation with TNG + PESP. However, none of 13 TNG unresponsive zones improved with TNG + PESP. Thus, TNG, PESP, and TNG + PESP are each equally capable of unmasking asynergic residual contractile ability.
Determinants of smooth muscle injury during balloon angioplasty.
Authors: T AFischell, GGrant, D EJohnson
Journal: Circulation (1990)

To study the determinants of smooth muscle injury during balloon angioplasty, we conducted a series of experiments to examine the effects of degree of arterial stretching, duration of balloon inflation, and arterial precontraction on smooth muscle injury after balloon angioplasty in isolated, perfused whole-vessel segments of rabbit aortas and dog carotid arteries. Freshly dissected rabbit thoracic aortas and dog carotid arteries were mounted in a muscle bath-perfusion chamber and perfused at 80 mm Hg. The proximal half of each aorta was dilated with a 5-mm (41 +/- 6% stretch), 6-mm (64 +/- 6% stretch), or 8-mm (97 +/- 9% stretch) balloon angioplasty catheter, and the uninjured half of each vessel served as the control. The vasoconstrictor behavior of the dilated segment was then assessed by dose-response testing; long-axis, ultrasonic imaging combined with computerized edge-detection image processing was used to measure changes in segmental internal vessel diameters that were induced by phenylephrine. A ...
The effect of lidocaine on reentry within the His-Purkinje system in man.
Authors: J NRuskin, MAkhtar, A NDamato, J RFoster
Journal: Circulation (1980)

The effects of intravenous lidocaine were assessed in 11 patients with normal intraventricular conduction in whom reentry within the His-Purkinje system (RE-HPS) occurred consistently over a narrow range of ventricular (S1S2) coupling intervals. RE-HPS was characterized by a spontaneous beat (V3) inducible by critically timed premature stimuli (S2) during constant ventricular drive (S1S1), and was dependent upon critical retrograde conduction delay within the HPS (S2H2 interval). Lidocaine abolished RE-HPS in six of 11 patients (group 1) and shortened the zone of RE-HPS in five of 11 patients (group 2). In group 1 after lidocaine, critical S2H2 intervals for RE-HPS were not attained at any S1S2 in four patients and critical S2H2 intervals were equaled but not exceeded in two patients without resulting in RE-HPS. In group 2 after lidocaine. RE-HPS was present in all patients at S2H2 intervals comparable to control values; however, significantly closer S1S2 intervals were necessary to achieve these requisit...
Effects of stroke volume and velocity of ejection on end-systolic pressure of canine left ventricle. End-systolic volume clamping.
Authors: HSuga, KYamakoshi
Journal: Circulation Research (1977)

To study the effects of contraction mode on ventricular end-systolic pressure-volume relationship, we compared the end-systolic pressure of isovolumic contraction with that of ejecting contraction at an identical end-systolic volume. The left ventricle of excised cross-circulated canine hearts was fitted with a water-filled balloon. The balloon was connected to a hydraulic pump that allowed the ventricle to contract to a preset constant end-systolic volume (19-37 ml) from a variable end-diastolic volume. At each of control, enhanced, and depressed levels of contractility, differences of end-systolic pressures of steady state isovolumic and ejecting contractions were evaluated while stroke volume and velocity of ejection were widely varied. The end-systolic pressure in the ejecting contraction tended to decrease by 5-15% from that of the isovolumic beat with increases in either stroke volume to 20-25 ml or peak velocity of ejection to about 800 ml/sec. There was no obvious difference in the results at diff...
Two-dimensional ultrasonic tissue characterization: backscatter power, endocardial wall motion, and their phase relationship for normal, ischemic, and infarcted myocardium.
Authors: P JFitzgerald, M DMcDaniel, E LRolett, J WStrohbehn, D HJames
Journal: Circulation (1987)

To understand the possible differences in reflected ultrasonic energy from normal, ischemic, and infarcted myocardium, we studied 20 open-chest dogs with a commercially available two-dimensional ultrasonic scanner. Echocardiographic radiofrequency images of anterior myocardium were obtained serially during complete coronary occlusion for 2 hr (n = 15) or 5 hr (n = 10), or after temporary coronary clamping for 15 min with release for 1 hr (n = 5). We investigated two variables: the cyclic backscatter power and the phase difference among endocardial wall motion (EWM), cyclic backscatter power (BSP), and left ventricular pressure (LVP). The cyclic BSP decreased from a control (nonischemic) level of 5.1 +/- 0.8 to 2.3 +/- 0.7 dB during ischemia (up to 30 min after coronary ligation). The phase difference between the EWM and BSP progressed from a control (nonischemic) value of 38 +/- 20 to 115 +/- 23 degrees during ischemia. For the infarction period (2 to 5 hr after coronary ligation), the cyclic BSP progress...
Hormones regulating cardiovascular function in patients with severe congestive heart failure and their relation to mortality. CONSENSUS Trial Study Group.
Authors: KSwedberg, PEneroth, JKjekshus, LWilhelmsen
Journal: Circulation (1990)

There is a varying hormonal activation in heart failure. To be able to evaluate this activation and relate it to prognosis, we took blood samples at baseline and after 6 weeks from 239 patients with severe heart failure (all in New York Heart Association class IV) randomized to additional treatment with enalapril or placebo. In this study (CONSENSUS), which has previously been reported, there was a significant reduction in mortality among patients treated with enalapril. The present data show in the placebo group a significant positive relation between mortality and levels of angiotensin II (p less than 0.05), aldosterone (p = 0.003), noradrenaline (p less than 0.001), adrenaline (p = 0.001), and atrial natriuretic factor (p = 0.003). A similar relation was not observed among the patients treated with enalapril. Significant reductions in mortality in the groups of patients treated with enalapril were consistently found among patients with baseline hormone levels above median values. There were significant...
Efficient gene transfer into myocardium by direct injection of adenovirus vectors.
Authors: R JGuzman, PLemarchand, R GCrystal, S EEpstein, TFinkel
Journal: Circulation Research (1993)

Previous studies have established that gene transfer into myocardial cells in vivo is detectable after direct injection of plasmid DNA. Recently, adenovirus vectors have been shown to provide an efficient method for gene transfer into a wide range of tissues. Therefore, this study sought to assess the efficiency and stability of adenovirus-mediated gene transfer into myocardium and to compare this method with that using plasmid-based gene transfer techniques. Adult rats underwent myocardial injection via a subdiaphragmatic approach. Gene transfer efficiency was compared using direct injection of an adenovirus vector encoding for the marker gene beta-galactosidase (beta-gal), a control adenovirus vector encoding for the cystic fibrosis transmembrane conductance regulator gene, a plasmid encoding for beta-gal, or a control plasmid. Hearts infected with an adenovirus vector containing the beta-gal gene showed significantly increased beta-gal enzymatic activity compared with hearts injected with beta-gal plas...
Ineffectiveness of high‐dose methotrexate for prevention of <scp>CNS</scp> relapse in diffuse large <scp>B</scp>‐cell lymphoma
Authors: Robert Puckrin, Haidar El Darsa, Sunita Ghosh, Anthea Peters, Carolyn Owen, Douglas Stewart
Journal: American Journal of Hematology (2021)

Abstract Central nervous system (CNS) relapse affects 5% of diffuse large B‐cell lymphoma (DLBCL) patients and portends a poor prognosis. Prophylactic intravenous high‐dose methotrexate (HD‐MTX) is frequently employed to reduce this risk, but there is limited evidence supporting this practice. We conducted a multicenter retrospective study to determine the CNS relapse risk with HD‐MTX in DLBCL patients aged 18–70 years treated in Alberta, Canada between 2012 and 2019. Provincial guidelines recommended HD‐MTX for patients at high‐risk of CNS relapse based upon CNS‐IPI score, double‐hit lymphoma, or testicular involvement. Among 906 patients with median follow‐up 35.3 months (range 0.29–105.7), CNS relapse occurred in 1.9% with CNS‐IPI 0–1, 4.9% with CNS‐IPI 2–3, and 12.2% with CNS‐IPI 4–6 ( p &lt; .001). HD‐MTX was administered to 115/326 (35.3%) high‐risk patients, of whom 96 (83.5%) had CNS‐IPI score 4–6, 45 (39.1%) had double‐hit lymphoma, and four (3.5%) had testicular lymphoma. The median number of HD‐MTX doses was two (range 1–3). Central nervous system relapse risk was similar with versus without HD‐MTX (11.2% vs. 12.2%, p = .82) and comparable to previous reports of high‐risk patients who did not receive CNS prophylaxis (10–12%). In multivariate and propensity score analyses, HD‐MTX demonstrated no association with CNS relapse, progression‐free survival, or overall survival. This study did not demonstrate a benefit of prophylactic HD‐MTX in this high‐risk patient population. Further study is required to determine the optimal strategy to prevent CNS relapse in DLBCL.
Electrocardiographic findings in patients with obstructive and nonobstructive hypertrophic cardiomyopathy.
Authors: D DSavage, S FSeides, C EClark, W LHenry, B JMaron, F CRobinson, S EEpstein
Journal: Circulation (1978)

One hundred and thiry-four patients with hypertrophic cardiomyopathy were evaluated by standard 12-lead electrocardiography. Normal electrocardiograms were extremely uncommon, occurring in less than 7% of each subgroup of patients (i.e., those with or without either symptoms or obstruction to left ventricular outflow), with the exception of those who were both asymptomatic and had no left ventricular outflow obstruction. Even in this subgroup, however, normal electrocardiograms occurred in only 27% of patients. Repolarization abnormalities and left ventricular hypertrophy were the most common abnormalities, occurring in 81% and 62%, respectively, of the total population. A broad spectrum of other electrocardiographic abnormalities was found, but none was unique to hypertrophic cardiomyopathy. Patients with vs those without electrocardiographic left ventricular hypertrophy or left atrial abnormality had significantly (P less than 0.005) greater mean ventricular septal thickness (22 +/- 0.6 vs 19 +/- 0.6 mm...
Three-dimensional left ventricular deformation in hypertrophic cardiomyopathy.
Authors: A AYoung, C MKramer, V AFerrari, LAxel, NReichek
Journal: Circulation (1994)

BACKGROUNDIn hypertrophic cardiomyopathy, ejection fraction is normal or increased, and force-length relations are reduced. However, three-dimensional (3D) motion and deformation in vivo have not been assessed in this condition. We have reconstructed the 3D motion of the left ventricle (LV) during systole in 7 patients with hypertrophic cardiomyopathy (HCM) and 12 normal volunteers by use of magnetic resonance tagging.METHODS AND RESULTSTransmural tagging stripes were automatically tracked to subpixel resolution with an active contour model. A 3D finite-element model was used to interpolate displacement information between short- and long-axis slices and register data on a regional basis. Displacement and strain data were averaged into septal, posterior, lateral, and anterior regions at basal, midventricular, and apical levels. Radial motion (toward the central long axis) decreased slightly in patients with HCM, whereas longitudinal displacement (parallel to the long axis) of the base toward the apex was ...
Pulmonary arterial V waves in mitral regurgitation: clinical and experimental observations.
Authors: RGrose, JStrain, M VCohen
Journal: Circulation (1984)

Pulmonary arterial early diastolic waves (V waves) were investigated in patients and experimental animals with mitral regurgitation. V waves exceeding systolic pressure in the pulmonary artery were recorded in the main pulmonary artery with micromanometer catheters both in patients and animals, eliminating the possibility of catheter artifact. In experimental animals, aortic closure preceded pulmonic closure by 33 +/- 12 msec at baseline. With the creation of acute mitral insufficiency, a pulmonary arterial V wave occurred in six of eight animals. Early pulmonic valve closure occurred only in the six animals with a pulmonary arterial V wave. In these animals, pulmonic closure preceded aortic closure by 28 +/- 7 msec during mitral insufficiency (p less than .05). Of 70 patients with severe mitral regurgitation at cardiac catheterization, 14 had a pulmonary arterial V wave. In five patients recordings with micromanometer catheters were made and early pulmonic closure was also observed in four of these patie...