tbuckley/cabot-search huggingface dataset:
A 75-Year-Old Man With Depression
Authors: Kurt Kroenke
Journal: JAMA (2002)

Our website uses cookies to enhance your experience. By continuing to use our site, or clicking "Continue," you are agreeing to our Cookie Policy | Continue JAMA HomeNew OnlineCurrent IssueFor Authors Publications JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry (1919-1959) Podcasts Clinical Reviews Editors' Summary Medical News Author Interviews More JN Learning / CMESubscribeJobsInstitutions / LibrariansReprints & Permissions Terms of Use | Privacy Policy | Accessibility Statement 2023 American Medical Association. All Rights Reserved Search All JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Forum Archive JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry Input Search Term Sign In Individual Sign In Sign inCreate an Account Access through your institution Sign In Purchase Options: Buy this article Rent this article Subscribe to the JAMA journal
Analysis of the properties of binding of calcium-channel activators and inhibitors to dihydropyridine receptors in chick heart membranes.
Authors: A C Maan, M M Hosey
Journal: Circulation Research (1987)

The interaction of 1,4-dihydropyridine derivatives with their receptors on voltage-dependent calcium channels in cardiac membranes was studied to determine if there are basic differences in the binding properties of ligands that cause inhibition or activation of calcium channels. The binding characteristics of 6 pure stereoisomers, (-) and (+)202-791, (-) and (+)Bay k 8644, (-) and (+)PN 200-110, as well as racemic Bay k 8644 and nitrendipine, were compared. Competition studies using the cold ligands and 3 different radiolabelled dihydropyridines, (+)[3H]PN 200-110, (+/-)[3H]nitrendipine, and (+/-)[3H]Bay k 8644, showed that, for each combination tested, the labelled dihydropyridine could be displaced by the cold dihydropyridine. The binding reactions were markedly affected by temperature. The Kd values for most compounds were significantly higher (5-19 times) at 0 degrees than at 37 degrees C. In contrast, the affinity of (+)PN 200-110 was similar at 0 degrees and 37 degrees C, but slightly higher at 25 degrees C. A thermodynamic analysis indicated that the binding of the two pure isomers that are Ca2+-channel activators ("agonists"), (-)Bay k 8644 and (+)202-791, was driven entirely by enthalpy and was associated with an unfavorable decrease in entropy. This was in marked contrast to the binding of the inhibitors ("antagonists"). The binding of (+)PN 200-110 and nitrendipine at low temperatures was driven largely or entirely by entropy. Other antagonist-binding reactions were driven mainly by enthalpy but were associated with favorable increases in entropy. The affinity of the three radiolabelled ligands for the dihydropyridine receptor differed 100 times and appeared to be due to large differences in dissociation rate constants for each of the ligands. The rates of dissociation of (+)[3H]PN 200-110 and (+/-)[3H]nitrendipine, but not of (+/-)[3H]Bay k 8644, were significantly slowed by diltiazem, a calcium-channel inhibitor that binds to another receptor on the calcium channel. The results show that there were marked differences in the binding of the various dihydropyridines and suggest that the energetics of binding of Ca2+-channel activators and inhibitors may be fundamentally different.
Mechanisms of differential growth of heart ventricles in newborn pigs.
Authors: C J Peterson, V Whitman, P A Watson, H G Schuler, H E Morgan
Journal: Circulation Research (1989)

The left ventricular free wall (LVFW) grew approximately three times faster than the right ventricular free wall (RVFW) during the first 10 days of life in neonatal pigs. Faster growth was associated with proportional increases in total RNA and messenger RNA. These findings indicated that greater capacity for protein synthesis was a major factor in accelerated growth. Despite faster growth, heart content of ribosomal subunits was higher in piglets than in 60-day-old pigs or adult rats, suggesting a relatively slower rate of peptide chain initiation than elongation. When hearts from 5-day-old pigs were perfused in vitro, protein synthesis was more rapid in the LVFW than in the RVFW. In the absence of added insulin, the higher rate was due to both greater efficiency and greater capacity for protein synthesis. In the presence of the hormone, greater capacity was responsible for the increased rate of protein synthesis in the LVFW as compared with the RVFW.
Temporally Compartmentalized Expression of Ephrin-B2 during Renal Glomerular Development
Authors: Takamune Takahashi, Keiko Takahashi, Sebastian Gerety, Hai Wang, David J. Anderson, Thomas O. Daniel
Journal: Journal of the American Society of Nephrology (2001)

Glomerular development proceeds through the spatially ordered and sequential recruitment, proliferation, assembly, and differentiation of endothelial, mesangial, and epithelial progenitors. The molecular determinants of cell-cell recognition and targeting in this process have yet to be defined. The Eph/ephrin family of membrane receptors and counter-receptors are critical participants of developmental vascular assembly in extrarenal sites. Renal expression patterns of ephrin-B2 and EphB4 were investigated using mice expressing beta-galactosidase under control of ephrin-B2 or EphB4 promoters. The earliest glomerular expression of ephrin-B2 was identified in a subset of differentiating comma-stage glomerular epithelial cells (podocyte progenitors) adjacent to the vascular cleft where endothelial progenitors are subsequently recruited. Epithelial ephrin-B2 expression was accompanied by expression in endothelial and mesangial cells as capillary assembly progressed. At or near completion of glomerular maturation, epithelial ephrin-B2 expression was extinguished, with persistence in glomerular endothelial cells. Throughout development, one of several ephrin-B2 receptors, EphB4, was persistently and exclusively expressed in endothelial cells of venous structures. The findings show sequential ephrin-B2 expression across glomerular lineages, first in a distinct subset of podocyte progenitors and subsequently in endothelial cells of the developing glomerulus. Given targeting functions for Eph/ephrin family proteins, the findings suggest that ephrin-B2 expression marks podocyte progenitors at the site of vascular cleft formation, where expression may establish an "address" to which endothelial and mesangial progenitors are recruited. Thus, the present results suggest that ephrin-B2 and EphB interactions play an important role in glomerular microvascular assembly.
Vitamin D and Cardiovascular Disease
Authors: P.E. Norman, J.T. Powell
Journal: Circulation Research (2014)

Vitamin D plays a classical hormonal role in skeletal health by regulating calcium and phosphorus metabolism. Vitamin D metabolites also have physiological functions in nonskeletal tissues, where local synthesis influences regulatory pathways via paracrine and autocrine mechanisms. The active metabolite of vitamin D, 1α,25-dihydroxyvitamin D, binds to the vitamin D receptor that regulates numerous genes involved in fundamental processes of potential relevance to cardiovascular disease, including cell proliferation and differentiation, apoptosis, oxidative stress, membrane transport, matrix homeostasis, and cell adhesion. Vitamin D receptors have been found in all the major cardiovascular cell types including cardiomyocytes, arterial wall cells, and immune cells. Experimental studies have established a role for vitamin D metabolites in pathways that are integral to cardiovascular function and disease, including inflammation, thrombosis, and the renin–angiotensin system. Clinical studies have generally demonstrated an independent association between vitamin D deficiency and various manifestations of degenerative cardiovascular disease including vascular calcification. However, the role of vitamin D supplementation in the management of cardiovascular disease remains to be established. This review summarizes the clinical studies showing associations between vitamin D status and cardiovascular disease and the experimental studies that explore the mechanistic basis for these associations.
10-year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1): a multicentre randomised trial
Authors: Alison Halliday, Michael Harrison, Elizabeth Hayter, Xiangling Kong, Averil Mansfield, Joanna Marro, Hongchao Pan, Richard Peto, John Potter, Kazem Rahimi, Angela Rau, Steven Robertson, Jonathan Streifler, Dafydd Thomas
Journal: The Lancet (2010)
Influence of Extracellular K <sup>+</sup> Concentration on Cable Properties and Excitability of Sheep Cardiac Purkinje Fibers
Authors: GRACIELA DOMINGUEZ, HARRY A. FOZZARD
Journal: Circulation Research (1970)

Conduction velocity was increased from 3.5 m/sec to 4.1 m/sec in sheep cardiac Purkinje fibers when the superfusing Tyrode solution was changed from 2.7 mM K + to 4.0 mM K + . Further increase to 7.0 mM K + resulted in a fall in conduction velocity to 3.3 m/sec. To understand the nature of the cellular change responsible for this effect, cable analyses were made. With increases in extracellular K + concentration membrane resistance decreased and membrane capacitance did not change. Resistance of the myoplasm tended to fall in 7.0 mM [K] o . Since these effects did not explain the change in conduction velocity, excitability was studied by strength-duration curves using intracellular micropipettes for current passage and recording. Increase in K + from 2.7 to 4.0 mM resulted in a shift of the entire curve to the left, with a fall in rheobasic current from 121 to 104 nanoamperes and a fall in the time constant from 2.79 to 2.4 msec. Normalized plotting of stimulating current over rheobasic current (I/I Rh ) against duration of stimulating current over the time constant (t/τ) suggested that the curves were not basically different. The increase in K + from 2.7 to 4.0 mM was associated with a depolarization of the resting membrane, consistent with alteration in the potassium equilibrium potential, but no change in the absolute membrane potential for threshold. In this way, the changes in membrane voltage and charge necessary for excitation were reduced in 4.0 mM [K] o .
Longitudinal propagation of contraction in the isolated conduit coronary arteries of humans and pigs.
Authors: H Araki, N Sakaino, N Furusho, K Nishi
Journal: Circulation Research (1989)

We examined the longitudinal propagation of contraction in isolated human and pig coronary arteries. Epicardial coronary arteries of about 2 cm were cut open longitudinally, and the tension development of circular muscles was measured simultaneously at three sites (both cut ends and the midportion of the segment). Cyclic tension changes arising at one site of human coronary artery propagated smoothly to the other sites, and the whole length of segment worked as a single unit. Contraction induced by locally applied prostaglandin F2 alpha or histamine also propagated in four of seven preparations. The remaining three human and all seven pig coronary arteries showed propagation of such drug-induced contraction after treatment with 10 mM tetraethylammonium (TEA). In pig coronary arteries treated with TEA, electrical stimulation evoked a reproducible local contraction and its propagation. Propagation velocity was 9.0 +/- 0.7 at 0.8 mM calcium concentration and increased to 11.1 +/- 0.9 and 13.1 +/- 1.4 mm/sec as calcium concentration rose to 1.8 mM and 7.2 mM, respectively. Local contraction did not propagate at calcium concentrations of 0.2 mM or less. The calcium antagonist diltiazem decreased the propagation velocity dose dependently and blocked propagation of contraction at 0.3 microM without significant effects on the magnitude of local contraction. We conclude that smooth propagation of contraction develops in epicardial coronary arteries of humans and pigs and that the propagation may depend on calcium influx.
The influence of game scheduling on medical encounters at the USA Cup soccer tournament
Authors: Nathan G Waibel, William O Roberts, Scott Lunos
Journal: British Journal of Sports Medicine (2011)

OBJECTIVEL To investigate the influence of playing multiple games on multiple days on youth soccer medical encounter rates.Prospective cohort survey study.Medical facility at the 2008 Schwan's USA Cup soccer tournament.Players presenting to the medical facility for game-related medical evaluation.Date, game and half of game for each medical encounter.Game play-related medical encounters per 1000 match hours (MH).211 players surveyed with 195 eligible and completed questionnaires. There were 4.06, 5.14 and 3.92 medical encounters/1000 MH on 11, 12 and 13 July, respectively, with no significant difference in injury incidence. There was no difference in medical encounter rates of second games compared with first games of the day (p=0.126). Daily medical encounter rates were 5.65, 8.95, 7.83, 6.94 and 4.62/1000 MH on 15, 16, 17, 18 and 19 July, respectively, with statistically significant differences on 16 July (p<0.001) and 17 July (p=0.022) compared with 15 July. Encounter rates of second games compared with first games of the day showed no difference (p=0.385). A linear test for trend from 15 to 19 July was not significant (p=0.092).The USA Cup format did not show either increased medical encounter rates from the cumulative total of games played or a consistently increased rate in the second game of the day compared with the first. Players, coaches, parents and administrators can feel confident that this tournament format does not pose an additional risk of injury.
Effect of Simvastatin and Antioxidant Vitamins on Atrial Fibrillation Promotion by Atrial-Tachycardia Remodeling in Dogs
Authors: Akiko Shiroshita-Takeshita, Gernot Schram, Joel Lavoie, Stanley Nattel
Journal: Circulation (2004)

There is evidence for a role of oxidant stress and inflammation in atrial fibrillation (AF). Statins have both antioxidant and antiinflammatory properties. We compared the effects of simvastatin with those of antioxidant vitamins on AF promotion by atrial tachycardia in dogs.We studied dogs subjected to atrial tachypacing (ATP) at 400 bpm in the absence and presence of treatment with simvastatin, vitamin C, and combined vitamins C and E. Serial closed-chest electrophysiological studies were performed in each dog at baseline and 2, 4, and 7 days after tachypacing onset. Atrioventricular block was performed to control ventricular rate. Mean duration of induced AF was increased from 42+/-18 to 1079+/-341 seconds at terminal open-chest study after tachypacing alone (P<0.01), and atrial effective refractory period (ERP) at a cycle length of 300 ms was decreased from 117+/-5 to 76+/-6 ms (P<0.01). Tachypacing-induced ERP shortening and AF promotion were unaffected by vitamin C or vitamins C and E; however, simvastatin suppressed tachypacing-induced remodeling effects significantly, with AF duration and ERP averaging 41+/-15 seconds and 103+/-4 ms, respectively, after tachypacing with simvastatin therapy. Tachypacing downregulated L-type Ca2+-channel alpha-subunit expression (Western blot), an effect that was unaltered by antioxidant vitamins but greatly attenuated by simvastatin.Simvastatin attenuates AF promotion by atrial tachycardia in dogs, an effect not shared by antioxidant vitamins, and constitutes a potentially interesting new pharmacological approach to preventing the consequences of atrial tachycardia remodeling.
Physical activity improved significantly in patients with chronic obstructive pulmonary disease non responrders to an outpatient pulmonary rehabilitation program (PRP)
Authors: Laura Malagrinò, Barbara Vagaggini, Francesco Costa, Gianna Decusatis, Claudia De Simone, Sandra Antonelli, Sabrina Santerini, Giulia Lenzini, Pierluigi Paggiaro
Journal: European Respiratory Journal (2014)

Background: physical activity (PA) has been reported to be reduced in severe chronic obstructive pulmonary disease (COPD) and Pulmonary Rehabilitation is well known to improve exercise capacity in those subjects.

Aim: to examine the variation in physical activity after a Pulmonary Rehabilitation Program (PRP) in COPD patients .

We examined 28 patients (mean age 68.7 yrs) with moderate-severe COPD(FEV1 55.1%).They wore the Armband Sensorwear for 6 consecutive days before and after a 10-week outpatient PRP.

Total Day Energy Expenditure(TDEE) and Active Energy Expenditure (AEE) significantly improved after PRP in the whole sample (TDEE :227+/-419 cal prePRP vs 2350+/-131 cal postPRP; p=0.026, AEE :298.7+/-220.3 cal prePRP vs 538.6+/-483.4 cal postPRP; p=0.03).

When we divided the patients according to the response to the 6MWT (responders >/= 36 non-responders /= 4, non-responders <4),we observed that non-responders in both group significantly improved in physical activity parameters.

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In some patients with moderate-to-severe COPD a PRP may improve some parameters of physical activity measured with the Armband Sensorwear although the same treatment is no effective in terms of 6MWT or SGRQ.
Betulinic Acid Inhibits Prostate Cancer Growth through Inhibition of Specificity Protein Transcription Factors
Authors: Sudhakar Chintharlapalli, Sabitha Papineni, Shashi K. Ramaiah, Stephen Safe
Journal: Cancer Research (2007)

Abstract Betulinic acid is a pentacyclic triterpene natural product initially identified as a melanoma-specific cytotoxic agent that exhibits low toxicity in animal models. Subsequent studies show that betulinic acid induces apoptosis and antiangiogenic responses in tumors derived from multiple tissues; however, the underlying mechanism of action is unknown. Using LNCaP prostate cancer cells as a model, we now show that betulinic acid decreases expression of vascular endothelial growth (VEGF) and the antiapoptotic protein survivin. The mechanism of these betulinic acid–induced antiangiogenic and proapoptotic responses in both LNCaP cells and in tumors is due to activation of selective proteasome-dependent degradation of the transcription factors specificity protein 1 (Sp1), Sp3, and Sp4, which regulate VEGF and survivin expression. Thus, betulinic acid acts as a novel anticancer agent through targeted degradation of Sp proteins that are highly overexpressed in tumors. [Cancer Res 2007;67(6):2816–23]
Notes of a Case of Incontinence of Urine, from Malformation
Authors: T. M. Madden
Journal: BMJ (1884)

hi*%ory was 'as follows She had beet cop'fifiii 'October 7tiVt hb6 nifith child.The placenta wis-sTetaiiXd, ' and'.iid':toAtou, a'week subsequently phl'til setin, et thbe right k b - cine enormously swollen.Wheh slie was' admitted to, hospital, the puse was 120, the temperature 102.80.The 'usual remedies wefee p-' ILd; the symptoms became aggravated, hectic supervened, and her life seemed to be in the balance.A large pelvic abscess fobmied, *hich was opened, and continued to discharge for a month.From, thiW thne recovery was rapid and satisfactory; and, at the end of adiser month, the patient left hospital.The point of interest in oaiilection with this case of phlegmasia in the right legiis-that tlhis patiJent was unable to lie on her left side, and, as a mitter of fact- had been on her right side continuously from the time of hert oonfinement.CASE iI.-Mrs.R., aged 32, was admitted on January 4th, 1884, suffering from phlegmasia in the right leg.She had been delivered of hor fourth child seven days previously, had a difficult labour, and con- sidIrable hwmorrhage subsequently.This patient, too, persistently 1at on her right side, owing to some chest-affection.In her case, the syptoms were less aggravated than in the former, and recovery more rapid; but posture in this case, as in the other, suggested the probable cause, and accounted for the limb involved.
Enzymolysis of glomerular immune deposits in vivo with dextranase/protease ameliorates proteinuria, hematuria, and mesangial proliferation in murine experimental IgA nephropathy.
Authors: L Gesualdo, S Ricanati, M O Hassan, S N Emancipator, M E Lamm
Journal: Journal of Clinical Investigation (1990)

The therapeutic effects of saccharolytic and proteolytic enzymes were investigated in models of IgA nephropathy. Mesangial glomerulonephritis was induced in mice by intravenous injection of preformed soluble immune complexes of dextran sulfate and either IgA (J 558) or IgM (MOPC 104 E) anti-dextran MAb (passive model) or by immunization with DEAE dextran (active model). In the passive model, only 30-40% of dextranase-treated mice given IgA or IgM immune complexes had mesangial Ig or dextran deposits, compared with 100% of saline-treated controls (P less than 0.01). There was no significant difference in mice given only protease. In the active model, dextranase and protease separately each reduced glomerular dextran and C3 deposits, and hematuria (P less than 0.01). Dextranase also reduced the glomerular IgA deposits (20 vs. 100% of saline-treated mice) and the frequency and severity of mesangial matrix expansion (both P less than 0.02), but did not reduce the modest IgG or IgM codeposits. Protease reduced IgG and IgM deposits, proteinuria and mesangial hypercellularity compared with saline (P less than 0.02), but did not diminish IgA, and had no effect on mesangial matrix expansion. The combination of dextranase plus protease attenuated all components of glomerular injury as judged by clinical and pathological parameters, but inactivated dextranase plus inactivated protease had no effect on any parameter. We conclude that enzymatic digestion of antigen and antibody can reduce immune deposits, mesangial proliferation, proteinuria, and hematuria in experimental glomerulonephritis.
MicroRNA-21 Modulates the Levels of Reactive Oxygen Species by Targeting <i>SOD3</i> and <i>TNF<b>α</b> </i>
Authors: Xiangming Zhang, Wooi-Loon Ng, Ping Wang, LinLin Tian, Erica Werner, Huichen Wang, Paul Doetsch, Ya Wang
Journal: Cancer Research (2012)

MicroRNA-21 (miR-21) is an oncomir overexpressed in most human tumors in that it promotes malignant growth and progression by acting on multiple targets. Here, we broaden the impact of miR-21 in cancer by showing that it regulates the formation of reactive oxygen species (ROS) that promote tumorigenesis. Key targets of miR-21 in mediating this function were SOD3 and TNFα. We found that miR-21 inhibited the metabolism of superoxide to hydrogen peroxide, produced either by endogenous basal activities or exposure to ionizing radiation (IR), by directing attenuating SOD3 or by an indirect mechanism that limited TNFa production, thereby reducing SOD2 levels. Importantly, both effects contributed to an elevation of IR-induced cell transformation. Our findings, therefore, establish that miR-21 promotes tumorigenesis to a large extent through its regulation of cellular ROS levels.
BTS guidelines for the insertion of a chest drain
Authors: D Laws, E Neville, J Duffy
Journal: Thorax (2003)

These guidelines have been replaced by BTS Pleural Disease Guideline 2010  Superseded By BTS Pleural Disease Guideline 2010: BTS Guidelines for the Management of Pleural Disease. Thorax 2003 May; 58(Suppl 2): 1–59.
975 METHIONINE-CHOLINE METABOLISM IS INVOLVED IN THE PATHOGENESIS OF NONALCOHOLIC STEATOHEPATITIS
Authors: K. Tokumitsu, K. Ogasawara, M. Maki, A. Hirose, Y. Nozaki, M. Takahashi, M. Ono, S. Iwasaki, T. Saibara, S. Onishi
Journal: Journal of Hepatology (2008)