bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Pacemaker Lead Thrombosis Leading to Massive Pulmonary Embolism
Authors: Karavidas Apostolos , Lazaros George , Matsakas Evangellos , Kouvousis Nicolaos , Samara Christiana , Christoforatou Evangellia , Zacharoulis Apostolos
Published: June 2004

Clinically apparent pulmonary embolism is a rare complication of permanent transvenous pacing catheters. Here we report an unusual case of a 71‐year‐old man who developed massive pulmonary embolism 12 hours after a permanent transvenous pacemaker implantation in the absence of any patient‐related predisposing factor. Transesophageal echocardiography showed a large thrombus within the right atrium closely attached to the pacemaker lead. Anticoagulation with heparin, followed by warfarin therapy, led to a complete resolution of the thrombus. (ECHOCARDIOGRAPHY, Volume 21, July 2004)
The Use of Stress Echocardiography in the Assessment of Mitral Valvular Disease
Authors: Wu Wen‐Chih , Aziz George F. , Sadaniantz Ara
Published: June 2004

Stress echocardiography plays an important role in evaluating asymptomatic patients with significant mitral stenosis and symptomatic patients with only mild disease at rest, as it correlates the exercise‐induced symptoms with changes in transmitral gradients, pulmonary pressures, and mitral valve area. In patients with mitral regurgitation (MR), exercise or dobutamine protocols assess for the change in the degree of regurgitation and the pulmonary artery pressure (PAP) in response to high flow states, and detect underlying left ventricular (LV) dysfunction prior to valvular surgery. Exercise echocardiography also helps in the prognostic assessment of patients with mitral valve prolapse as new MR, or latent LV dysfunction may be provoked to identify a group of high risk individuals with normal resting echocardiographic parameters. Finally, it evaluates the proper functioning of prosthetic mitral valves and helps on the monitoring of transmitral gradients and PAPs after mitral valve surgery. (ECHOCARDIOGRAPHY, Volume 21, July 2004)
An Overview of Stress Echocardiography in the Study of Patients with Dilated or Hypertrophic Cardiomyopathy
Authors: Wu Wen‐Chih , Bhavsar Janak H. , Aziz George F. , Sadaniantz Ara
Published: June 2004

Stress echocardiography is a useful noninvasive modality for measuring dynamic outflow gradient and contractility changes in patients with hypertrophic cardiomyopathy (HCM) or dilated cardiomyopathy (DCM). In patients with HCM, stress echocardiography may determine the degree of outflow tract obstruction at rest and with activity, can detect occult systolic dysfunction in symptomatic patients with a normal resting left ventricular ejection fraction, and can also be utilized to monitor the efficacy of treatment. In individuals suffering from DCM, stress echocardiography is an important aid in the evaluation of the etiology, diagnosis, and prognosis of the disease as well as the functional status of the patient during either exercise or simulated stress conditions. Dobutamine stress echocardiography, by providing a measurement of the myocardial reserve, is a useful tool to predict the systolic recovery and clinical outcome of patients with heart failure. The stress‐induced change in the wall motion score index can also be used as an accurate alternative to predict the peak oxygen consumption rate and exercise capacity of the same patient population. Finally, stress echocardiography has also been used in the identification of the predilated phase of cardiomyopathy in individuals with high clinical suspicion of the disease. (ECHOCARDIOGRAPHY, Volume 21, July 2004)
Miscellaneous Use of Exercise Echocardiography in Patients with Chronic Pulmonary Disease or Congenital Heart Defect
Authors: Sadaniantz Ara , Katz Alan , Wu Wen‐Chih
Published: June 2004

To date, the usage of exercise echocardiography in patients with pulmonary or congenital heart disease has been limited despite its potential for broader applications in different clinical scenarios. Exercise echocardiography can be utilized to determine the extent of pulmonary vascular damage in patients with chronic obstructive pulmonary disease by demonstrating the presence of exertional pulmonary hypertension in subjects with normal pulmonary artery pressures (PAPs) at rest. It is also useful in patients with connective tissue disease to screen for lung involvement by identifying exertional pulmonary hypertension, and in patients with established pulmonary hypertension to choose and monitor the effects of therapeutic interventions on the PAPs. Moreover, the measurement of aortic flow velocity and acceleration by exercise echocardiography may be helpful in the study of dyspnea in patients at risk for both pulmonary disease and congestive heart failure. In patients with congenital heart disease, the measurement of PAP and ventricular function both at rest and during exercise by echocardiography is the cornerstone in the investigation of the etiology of exercise intolerance in these individuals. Lastly, exercise echocardiography can also screen for residual narrowing in patients after repair of the coarctation of the aorta by detecting a significant diastolic gradient in the descending aorta during exercise provocation. (ECHOCARDIOGRAPHY, Volume 21, July 2004)
Noninvasive Assessment of Influence of Resistant Respiration on Blood Flow Velocities Across the Cardiac Valves in Humans—A Quantification Study by Echocardiography
Authors: Yuan Lijun , Cao Tiesheng , Duan Yunyou , Yang Guodong , Wang Zuojun , Ruan Litao
Published: June 2004

The aim of our study is to quantitatively investigate influence of the intrathoracic pressure change on the four cardiac valves' velocities and further verify a new proposal of the mechanism of respiratory influence on hemodynamics. Methods: Thirty healthy volunteers with no cardiopulmonary diseases were included. The intrathoracic pressure changes were measured with self‐designed device. The velocity across the four cardiac valves during spontaneous respiration and with the intrathoracic pressure change at −4, −8, and −12 mmHg, respectively, were recorded simultaneously with the electrocardiogram and respiratory curve. The respiratory variation indices (RVIs) were calculated. The average RVIs of mitral, aortic, tricuspid, and pulmonary valves were 12.54%, 13.19%; 6.23%, 8.27%; 20.27%, 24.36%; and 6.45%, 7.69% with intrathoracic pressure change at −8 mmHg and −12 mmHg, respectively. All the above parameters have a significant difference from those during spontaneous respiration (P < 0.01 or P < 0.001). We concluded that it might be the respiratory intrathoracic pressure change that causes the change of the velocity across the valves. (ECHOCARDIOGRAPHY, Volume 21, July 2004)
Effect of Contrast Agent on the Incidence and Magnitude of Ultrasound‐Induced Lung Hemorrhage in Rats
Authors: O'Brien William D. , Simpson Douglas G. , Frizzell Leon A. , Zachary James F.
Published: June 2004

Objective: To test the hypothesis that inertial cavitation in the vasculature of the lung is not the physical mechanism responsible for ultrasound‐induced lung hemorrhage. Methods: A factorial design was used to study the effects of two types of injected agents (IA; 0.25 ml per rat of saline or Optison® given intravenously) and two levels of pulsed ultrasound exposure (UE; in situ peak rarefactional pressures of 2.74 and 5.86 MPa; respective mechanical indices of 1.02 and 2.14) on the incidence and size of lung lesions. Ten 10‐to‐11‐week‐old Sprague‐Dawley rats were exposed to pulsed ultrasound at each of the four combinations of IA and UE at a center frequency of 3.1 MHz, exposure duration of 10 s, pulse repetition frequency of 1,000 Hz and pulse duration of 1.2 μs. In addition, nine rats served as shams in which no lung hemorrhage occurred. Results: Rats administered contrast agent prior to exposure did not have an increase in lesion occurrence or size compared to rats that received saline with no contrast agent. Conclusions: These results provide further evidence that the mechanism for production of lung hemorrhage is not inertial cavitation. (ECHOCARDIOGRAPHY, Volume 21, July 2004)
A Rare Case of Listeria Monocytogenes Presenting as Prosthetic Valve Bacterial Endocarditis and Aortic Root Abscess
Authors: Makaryus Amgad N. , Yang Rayson , Cohen Ronald , Rosman David , Mangion Judy , Kort Smadar
Published: June 2004

Listeria monocytogenes is a gram‐positive bacillus that is rarely associated with infections in the general population. Those susceptible to this pathogen include neonates, pregnant women, and the immunocompromised. The most common clinical manifestations of listeriosis are bacteremia and meningitis. Endocarditis caused by L. monocytogenes is rare with less than 60 cases reported in the world literature. We report the case of an 81‐year‐old man who suffered aortic prosthetic valve listeria endocarditis, and examine the literature regarding this rare manifestation of human listeriosis.(ECHOCARDIOGRAPHY, Volume 21, July 2004)
Noninvasive Hemodynamics of Aortic Insufficiency Diastolic Opening of the Aortic Valve
Authors: Shah Dipak P. , Korcarz Claudia , Spencer Kirk T. , Lang Roberto M.
Published: June 2004

(ECHOCARDIOGRAPHY, Volume 21, July 2004)
Four‐Month Warfarin Therapy Results in a Dissolution of a Superior Vena Cava Thrombus
Authors: Aggeli Constadina , Brili Stela , Frogoudaki Alexandra , Barbetseas John , Stefanadis Christodoulos
Published: June 2004

(ECHOCARDIOGRAPHY, Volume 21, July 2004)
Isolated Left Ventricular Noncompaction
Authors: Carerj Scipione , Calabrò Maria Pia , Cerrito Marco , Lembo Daniela , Parisi Raffaella , Raffa Santi
Published: June 2004

(ECHOCARDIOGRAPHY, Volume 21, July 2004)
Live Three‐Dimensional Transthoracic Echocardiographic Delineation of Patent Ductus Arteriosus
Authors: Sinha Ashish , Nanda Navin C. , Khanna Deepak , Ilgenli Fikret , Sidhu Maninder , Lloyd Steven G. , Gupta Himanshu , Soto Benigno , Kirklin James K.
Published: June 2004

We report an adult patient with a patent ductus arteriosus in whom live three‐dimensional transthoracic echocardiography provided comprehensive assessment of the morphology and pathophysiology of the lesion. (ECHOCARDIOGRAPHY, Volume 21, July 2004)
Technique and Imaging for Transthoracic Echocardiography of the Laboratory Pig
Authors: Kerut Edmund Kenneth , Valina Christian M. , Luka Todd , Pinkernell Kai , Delafontaine Patrice , Alt Eckhard U.
Published: June 2004

(ECHOCARDIOGRAPHY, Volume 21, July 2004)
Evaluation of Aortic Valve Disorders Using Stress Echocardiography
Authors: Wu Wen‐Chih , Ireland Linda A. , Sadaniantz Ara
Published: June 2004

Stress echocardiography is a safe and valuable test to aid in the diagnosis and management of patients with aortic valve disorders. In patients with suspected severe aortic stenosis (AS) and low aortic gradients secondary to low cardiac output, dobutamine echocardiography distinguishes those patients with contractile reserve (CR) from those without it. By increasing the stroke volume in subjects with CR, true severe AS patients have an increase in transaortic gradients without a significant change in the valve area, whereas patients with pseudostenosis have an increase in the gradients with concomitant increase in the aortic valve area to >1 cm2. Patients without CR are indeterminate in their AS status and have a poor prognosis. The presence of CR is also important in patients suffering from aortic insufficiency, as it may predict the development of symptoms, myocardial dysfunction, or death in the asymptomatic phase of the disease, and the potential for left ventricular functional recovery after valve replacement. Finally, both exercise and dobutamine echocardiography can help in the assessment of valve malfunction or mismatch in patients with aortic valve prostheses experiencing exercise intolerance by correlating the symptoms with the change in the aortic gradients induced during stress testing. (ECHOCARDIOGRAPHY, Volume 21, July 2004)
Driven to Tiers: Socioeconomic and Racial Disparities in the Quality of Nursing Home Care
Authors: MOR VINCENT , ZINN JACQUELINE , ANGELELLI JOSEPH , TENO JOAN M. , MILLER SUSAN C.
Published: June 2004

Nursing home care is currently a two‐tiered system. The lower tier consists of facilities housing mainly Medicaid residents and, as a result, has very limited resources. The nearly 15 percent of U.S. nonhospital‐based nursing homes that serve predominantly Medicaid residents have fewer nurses, lower occupancy rates, and more health‐related deficiencies. They are more likely to be terminated from the Medicaid/Medicare program, are disproportionately located in the poorest counties, and are more likely to serve African‐American residents than are other facilities. The public reporting of quality indicators, intended to improve quality through market mechanisms, may result in driving poor homes out of business and will disproportionately affect nonwhite residents living in poor communities. This article recommends a proactive policy stance to mitigate these consequences of quality competition.
The Growing Pains of Integrated Health Care for the Elderly: Lessons from the Expansion of PACE
Authors: GROSS DIANE L. , TEMKIN‐GREENER HELENA , KUNITZ STEPHEN , MUKAMEL DANA B.
Published: June 2004

The early success of the demonstration Program of All‐Inclusive Care for the Elderly (PACE) led to its designation as a permanent Medicare program in 1997. But the growth in the number of programs and enrollment has lagged and does not meet expectations. This article offers insights into the mechanisms influencing the expansion of PACE, from information obtained in interviews and surveys of administrators, medical directors, and financial officers in 27 PACE programs. Sixteen barriers to expansion were found, including competition, PACE model characteristics, poor understanding of the program among referral sources, and a lack of financing for expansion. This experience offers important lessons for providing integrated health care to the frail elderly.
A Political History of Medicare and Prescription Drug Coverage
Authors: OLIVER THOMAS R. , LEE PHILIP R. , LIPTON HELENE L.
Published: June 2004

This article examines the history of efforts to add prescription drug coverage to the Medicare program. It identifies several important patterns in policymaking over four decades. First, prescription drug coverage has usually been tied to the fate of broader proposals for Medicare reform. Second, action has been hampered by divided government, federal budget deficits, and ideological conflict between those seeking to expand the traditional Medicare program and those preferring a greater role for private health care companies. Third, the provisions of the Medicare Prescription Drug, Improvement, and Modernization Act of 2003 reflect earlier missed opportunities. Policymakers concluded from past episodes that participation in the new program should be voluntary, with Medicare beneficiaries and taxpayers sharing the costs. They ignored lessons from past episodes, however, about the need to match expanded benefits with adequate mechanisms for cost containment. Based on several new circumstances in 2003, the article demonstrates why there was a historic opportunity to add a Medicare prescription drug benefit and identify challenges to implementing an effective policy.
Is Income Inequality a Determinant of Population Health? Part 2. U.S. National and Regional Trends in Income Inequality and Age‐ and Cause‐Specific Mortality
Authors: LYNCH JOHN , SMITH GEORGE DAVEY , HARPER SAM , HILLEMEIER MARIANNE
Published: June 2004

This article describes U.S. income inequality and 100‐year national and 30‐year regional trends in age‐ and cause‐specific mortality. There is little congruence between national trends in income inequality and age‐ or cause‐specific mortality except perhaps for suicide and homicide. The variable trends in some causes of mortality may be associated regionally with income inequality. However, between 1978 and 2000 those regions experiencing the largest increases in income inequality had the largest declines in mortality (r= 0.81,p< 0.001). Understanding the social determinants of population health requires appreciating how broad indicators of social and economic conditions are related, at different times and places, to the levels and social distribution of major risk factors for particular health outcomes.
Modal and Amodal Completion Generate Different Shapes
Authors: Singh Manish
Published: June 2004

Mechanisms of contour completion are critical for computing visual surface structure in the face of occlusion. Theories of visual completion posit that mechanisms of contour interpolation operate independently of whether the completion is modal or amodal—thereby generating identical shapes in the two cases. This identity hypothesis was tested in two experiments using a configuration of two overlapping objects and a modified Kanizsa configuration. Participants adjusted the shape of a comparison display in order to match the shape of perceived interpolated contours in a standard completion display. Results revealed large and systematic shape differences between modal and amodal contours in both configurations. Participants perceived amodal (i.e., partly occluded) contours to be systematically more angular—that is, closer to a corner—than corresponding modal (i.e., illusory) contours. The results falsify the identity hypothesis in its current form: Corresponding modal and amodal contours can have different shapes, and, therefore, mechanisms of contour interpolation cannot be independent of completion type.
The Importance of Being Flexible
Authors: Bonanno George A. , Papa Anthony , Lalande Kathleen , Westphal Maren , Coifman Karin
Published: June 2004

Researchers have documented the consequences of both expressing and suppressing emotion using between-subjects designs. It may be argued, however, that successful adaptation depends not so much on any one regulatory process, but on the ability to flexibly enhance or suppress emotional expression in accord with situational demands. We tested this hypothesis among New York City college students in the aftermath of the September 11th terrorist attacks. Subjects' performance in a laboratory task in which they enhanced emotional expression, suppressed emotional expression, and behaved normally on different trials was examined as a prospective predictor of their adjustment across the first two years of college. Results supported the flexibility hypothesis. A regression analysis controlling for initial distress and motivation and cognitive resources found that subjects who were better able to enhance and suppress the expression of emotion evidenced less distress by the end of the second year. Memory deficits were also observed for both the enhancement and the suppression tasks, suggesting that both processes require cognitive resources.
Patients' dreams and unreal experiences following intensive care unit admission
Authors: Roberts Brigit , Chaboyer Wendy
Published: June 2004

• Dreams and unreal experiences occur commonly in critically ill patients admitted to intensive care unit

• This study describes 31 Patients' dreams and explores the relationship between Patients' subjective recall 12–18 months after intensive care unit discharge and their observed behaviour during their intensive care unit stay

• Semi‐structured interviews revealed that 74% of longer‐term ICU patients (≥3 days) reported dreaming, with the majority also describing frightening hallucinations

• Only two patients reported long‐term negative psychological sequelae, but the short‐term consequence of hallucinations may also have an undiscovered impact on Patients' recovery
Aesthetic physical caring – valuing the visible
Authors: Ryan Jane
Published: June 2004

• The aim of this article was to define the term ‘aesthetics’ in order to demonstrate that aesthetic physical caring is administered to the intensive care patient

• Johns's model of structured reflection (10th version) was used to reflect upon three nursing narratives with intensive care unit nurses and relatives and reveals why physical caring is fundamental for the patient
Education and training for acute care delivery: a needs analysis
Authors: Wood Ian , Douglas Julie , Priest Helena
Published: June 2004

• Technological and clinical advances have led to increased levels of patient dependency and shorter hospital stay, such that they are now often managed on general wards

• Have staff been trained or educated for this change in focus?

• This project was designed to identify the education and training needs of health care professionals in assessing and managing acutely physically ill hospital patients, within the boundaries of one Strategic Health Authority (SHA) in the UK

• Participants identified the knowledge, skills and resources required to assess and manage acutely ill patients

• These issues may be addressed through the provision of an appropriate range of structured educational programmes and experiences with the ultimate aim of improving standards of patient care
Continuing professional development: does it make a difference?
Authors: Tennant Shirley , Field Ray
Published: June 2004

• Continuing professional development (CPD) is costly in terms of both organizational resources and personal time and effort

• It forms an important part of the strategy for modernizing the health service and is an expectation of qualified nurses

• There is little evidence to demonstrate the impact of CPD in terms of improved patient care and services

• A small pilot study was undertaken. A group of intensive therapy unit (ITU) managers developed a goal attainment scale (GAS) to evaluate the impact of an ITU course. Results suggest that the ITU course did make a difference to the development of ITU nurses, but the nurses who did not take the course also developed

• This has implications for service providers and educationalists in terms of expectations, timing and content of courses

• The GAS was a useful tool as an approach to evaluating the impact of CPD but requires more rigorous testing before it can be described as reliable and valid
Stimulation of glucose utilization and inhibition of protein glycation and AGE products by taurine
Authors: Nandhini A. T. A. , Thirunavukkarasu V. , Anuradha C. V.
Published: June 2004

Aim:  Pathological effects of the process of non‐enzymatic glycation of proteins are reflected in chronic complications of diabetes mellitus. We investigated the antiglycating effect of taurine in high fructose fed rats in vivo and the inhibiting potency of taurine in the process of in vitro glycation. Additionally, we investigated whether taurine enhances glucose utilization in the rat diaphragm.

Methods:  Rats fed a high fructose diet (60% total calories) were provided 2% taurine solution for 30 days. The effects of taurine on plasma glucose, fructosamine, protein glycation and glycosylated haemoglobin in high fructose rats were determined. For in vitro glycation a mixture of 25 mm glucose and 25 mm fructose was used as glycating agent, bovine serum albumin as the model protein and taurine as the inhibitor. Incubations were carried out in a constant temperature bath at 37 °C for 3–30 days. Amadori products and advanced glycation end products (AGEs) formed were measured. In vitro utilization of glucose was carried out in the rat diaphragm in the presence and absence of insulin in which taurine was used as an additive.

Results:  The contents of glucose, glycated protein, glycosylated haemoglobin and fructosamine were significantly lowered by taurine treatment to high fructose rats. Taurine prevented in vitro glycation and the accumulation of AGEs. Furthermore, taurine enhanced glucose utilization in the rat diaphragm. This effect was additive to that of insulin and did not interfere with the action of insulin.

Conclusions:  These results underline the potential use of taurine as a therapeutic supplement for the prevention of diabetic pathology.
Mechanism of activation of the tonic component of contraction in myocytes of guinea pig heart
Authors: Mackiewicz Urszula , Emanuel Krzysztof , Lewartowski Bohdan
Published: June 2004

Aim: 
Contractions of myocytes of guinea pig heart consist of a phasic component relaxing independently on the voltage and a tonic component relaxing upon repolarization. We found previously that Ca2+ activating the tonic component is released from the sarcoplasmic reticulum. In this study, we analysed the mechanism of activation and maintenance of this release.

Methods:  Experiments were performed at 37 °C in ventricular myocytes of guinea pig heart. Voltage‐clamped myocytes were stimulated by the pulses of the duration of 300 ms to 15–45 s from the holding potential of −40 to +5 mV. [Ca2+]i was monitored as fluorescence of Indo‐1 and contractions were recorded with the TV edge‐tracking system.

Results:  Myocytes responded to the short and long pulses with phasic contraction or Ca2+ transient followed by the sustained contraction or increase in [Ca2+]i. Repolarization brought about relaxation. 10 mmol L−1 Ni2+ blocking Na+/Ca2+ exchange superfused during the tonic component increased its amplitude. Superfusion of Ca2+‐free solution during sustained contraction brought about relaxation both in normal cells and in cells superfused with Ni2+ despite preserved sarcoplasmic reticulum Ca2+ content assessed with caffeine spritz. Relaxing effect of Ca2+‐free solution was not affected by carboxyeosin, a blocker of sarcolemmal Ca2+‐ATPase. Tonic component of contraction and of Ca2+ transient was inhibited by 200 μmol L−1 ryanodine, a blocker of Ca2+ release channels of the sarcoplasmic reticulum and by 20 μmol L−1 nifedipine, a blocker of L‐type ICa.

Conclusion:  Tonic component of contraction results from Ca2+ release via the sarcoplasmic reticulum Ca2+ channels activated by sustained, nifedipine‐sensitive and Ni2+‐insensitive Ca2+ influx. Alternatively, the SR Ca2+ release is activated by voltage, the dihydropyridine receptors acting like voltage sensors.
Ischaemia in working muscles potentiates the exercise‐induced sweating response in man
Authors: Eiken O. , Mekjavic I. B.
Published: June 2004

Aim:  The purpose was to examine whether graded ischaemia in the working muscles affects the rate of sweating and the control of exercise core temperature.

Methods:  Eight subjects performed cycle ergometry exercise in the supine position with (ischaemic exercise) and without (control exercise) restriction of blood flow in the contracting muscles, accomplished by exposure of the legs to a supra‐atmospheric pressure of 6.6 kPa. Each subject performed one exhaustive incremental work rate trial and one steady‐state exercise trial (at 33% of control peak work rate), in both the control and ischaemia conditions.

Results:  Ischaemia decreased work performance by 45% so that in this condition the steady‐state work rate level corresponded to 63% of ischaemic peak work rate. Ischaemia did not affect the oesophageal temperature equilibrium in the steady‐state trials, but potentiated the exercise sweating response. Exercise responses of mean arterial pressure, heart rate and pulmonary ventilation were potentiated by ischaemia.

Conclusion:  During ischaemic exercise sweat secretion was potentiated by non‐thermal and/or local thermal stimuli.
Effect of acute hyperoxia during exercise on quadriceps electrical activity in active COPD patients
Authors: Gosselin N. , Durand F. , Poulain M. , Lambert K. , Ceugniet F. , Préfaut C. , Varray A.
Published: June 2004

Aims: 
This study investigated whether acute hyperoxia improves electrical muscle activity in active chronic obstructive pulmonary disease (COPD) patients with mild hypoxemia (rest PaO2 = 9.1 ± 0.4 kPa).

Methods:  Two identical incremental exercise tests were performed by nine patients while breathing either air or 30% oxygen. Pulmonary gas exchanges, venous concentrations of lactate and pyruvate, and the electromyographic signal of the quadriceps muscle (vastus lateralis and vastus medialis) were sampled each minute.

Results:  Peak working capacity increased significantly in hyperoxia (94.4 ± 5.2W) compared with normoxia (85.4 ± 5.8W, P < 0.01). During hyperoxic exercise and for a given work load, oxygen uptake was increased (P < 0.001) and ventilation decreased (P < 0.05). Lactate concentration was significantly decreased (P < 0.01) at isowork level and during recovery (respectively – 26% and at least – 15%). In the quadriceps muscle, M‐wave amplitude (P < 0.05), root mean square (P < 0.01) and root mean square/oxygen uptake ratio (P < 0.001) were significantly increased during hyperoxic exercise compared with room air. Although median frequency values did not differ between conditions, the median frequency was significantly decreased for higher exercise intensity in hyperoxic condition. These modifications reflected better aerobic metabolism, later emergence of muscle fatigue, and greater muscle excitability and activation for the same level of exercise under hyperoxic condition.

Conclusion:  These data suggest that the acute addition of oxygen in active COPD patients improves their muscle electrical activity during dynamic exercise. Hypoxemia‐induced skeletal muscle dysfunction most probably acts through mechanisms based on oxygen availability.
Comparison of vascular distensibility in the upper and lower extremity
Authors: Eiken O. , Kölegård R.
Published: June 2004

Aim:  Because of the great differences in hydrostatic pressure acting along the blood vessels in the erect posture, leg vessels are exposed to greater transmural pressures than arm vessels. The in vivo pressure–distension relationship of arteries, arterioles and veins in the arm were compared with those of the leg.

Methods:  Experiments were performed with the subject (n = 11) positioned in a pressure chamber with an arm or lower leg (test limb) extended at heart level through a hole in the chamber door. Intravascular pressure in the arm/lower leg was increased by stepwise increasing chamber pressure to +180 and +210 mmHg, respectively. Diameters of blood vessels and arterial flow were measured using ultrasonographic/Doppler techniques. Changes in forearm and lower leg volumes were assessed using an impedance technique. The subject rated perceived pain in the test limb.

Results:  The brachial and radial arteries were found to be more distensible than the posterior tibial artery (P < 0.001). Likewise, the distension was more pronounced in the cephalic than in the great saphenous vein (P < 0.001). In the brachial artery, but not in the posterior tibial artery, flow increased markedly at the highest levels of distending pressure (P < 0.001). At the highest intravascular pressures, the rate of change in tissue impedance was greater in the forearm than the lower leg (P < 0.01). At any given level of markedly increased pressure, pain was rated higher in the arm than in the leg (P < 0.001).

Conclusion:  It seems that the wall stiffness of arteries, pre‐capillary resistance vessels and veins adapts to meet the long‐term demands imposed by the hydrostatic pressure acting locally on the vessel walls.
Arterial blood pressure and carotid baroreflex function during arm and combined arm and leg exercise in humans
Authors: Volianitis S. , Yoshiga C. C. , Vogelsang T. , Secher N. H.
Published: June 2004

Aim:  During arm cranking (A) blood pressure is higher than during combined arm and leg exercise (A + L), while the carotid baroreflex (CBR) is suggested to reset to control a higher blood pressure in direct relation to work intensity and the engaged muscle mass.

Method:  This study evaluated the function of the CBR by using neck pressure and neck suction during upright A, L and A + L in 12 subjects and, in order to evaluate a potential influence of the central blood volume on the CBR, also during supine A in five subjects. Exercise intensities for A and L were planned to elicit a heart rate response of c. 100 and 120 beats min−1, respectively, in the upright position and both workloads were maintained during A + L and supine A.

Results:  The CBR operating point, corresponding to the pre‐stimulus blood pressure, was 88 ± 6 mmHg (mean ± SE) at rest. During upright A, L and A + L and supine A it increased to 109 ± 9, 95 ± 7, 103 ± 7 and 104 ± 4 mmHg, respectively, and it was thus higher during upright A than during A + L and supine A (P < 0.05). In addition, the CBR threshold and saturation pressures, corresponding to the minimum and maximum carotid sinus pressure, respectively, were higher during upright A than during supine A, A + L, L and at rest (P < 0.05) with no significant change in the maximal reflex gain.

Conclusion:  These findings demonstrate that during combined arm and leg and exercise in the upright position the CBR resets to a lower blood pressure than during arm cranking likely because the central blood volume is enhanced by the muscle pump of the legs.
Efficacy of a gravity‐independent resistance exercise device as a countermeasure to muscle atrophy during 29‐day bed rest
Authors: Alkner B. A. , Tesch P. A.
Published: June 2004

Aim:  This study determined changes in knee extensor and plantar flexor muscle volume during 29 days of bed rest with or without resistance exercise using a gravity‐independent flywheel ergometer.

Methods:  Seventeen men (26–41 years) were subjected to 29 days of bed rest with (n = 8) or without (n = 9) resistance exercise; Supine Squat (SS) and Calf Press (CP) performed every third day. Quadriceps and triceps surae muscle volume was determined before and after bed rest and force and power were measured during training. Prior to these interventions, reproducibility of this device for training and testing was assessed in 23 subjects who performed bilateral maximal concentric, eccentric and isometric (MVC) knee extensions and plantar flexions over repeated sessions with simultaneous measurements of force, power and electromyographic (EMG) activity.

Results:  Quadriceps and triceps surae muscle volume decreased (P < 0.05) 10 and 16%, respectively, after 29 days bed rest. Exercise maintained quadriceps volume and mitigated triceps surae atrophy. Thus, either muscle showed different response across subject groups (P < 0.05). Force and power output during training were either maintained (P > 0.05) or increased (P < 0.05). EMG amplitude in the training mode was similar (SS; P > 0.05) or greater (CP; P < 0.05) compared with that elicited during MVC. Peak force and power test‐retest coefficient of variation (CV) ranged 5–6% and 7–8% for SS and CP, respectively.

Conclusion:  The present data suggest that this resistance exercise paradigm counteracts quadriceps and abates the more substantial triceps surae muscle atrophy in bedridden subjects, and therefore should be an important asset to space travellers.
Smooth muscle role on pulmonary arterial function during acute pulmonary hypertension in sheep
Authors: Bia D. , Armentano R. , Craiem D. , Grignola J. , Ginés F. , Simon A. , Levenson J.
Published: June 2004

Aim:  We determined the wall mechanical response of the pulmonary artery (PA) to acute pulmonary hypertension induced pharmacologically and by an occlusion maneuver, to study the vascular response of the local segment and its influence in the whole pulmonary circulation.

Methods:  Pulmonary pressure and diameter were measured in six anaesthetized sheep under steady‐state conditions. Transient hypertension in the PA was induced by phenylephrine (PHE) and a high pressure (HP) mechanical occlusion aimed at producing the same pulse and mean pressure responses. A viscoelastic arterial wall model was applied and the elastic (Epd) and viscous (μ) indexes were obtained. The μ/Epd ratio was adopted to quantify the damping performance of the arterial wall segment. The diastolic time constant was used as an indicator of the whole pulmonary buffering function. The systemic pressure was always measured.

Results:  The pulmonary mean, systolic and pulse pressure increases (P < 0.05) were similar during PHE and HP, with respect to control. PHE also induced a systemic pressure rise (P < 0.05). The Epd elastic index increased during HP (P < 0.05) and tended to increase during PHE with respect to control. The viscous index μ only increased with PHE (P < 0.05) with respect to control and occlusion. The diastolic time constant increased with PHE with respect to control (P < 0.05).

Conclusions:  A pressure rise in the PA, induced by an occlusion maneuver, increased local stiffness. Similar pressure rises with smooth muscle activation (PHE), produced both a stiffness and viscous index increase. In PHE resistance increases more than compliance decreases so that the global net effect is a longer decay time. Smooth‐muscle activation enhances the local damping effect (μ/Epd), concomitant with the buffering function improvement.
Effect of acute exercise and training on metabolism of ceramide in the heart muscle of the rat
Authors: Dobrzyń A. , Knapp M. , Górski J.
Published: June 2004

Aim:  The sphingomyelin signalling pathway operates in the heart muscle. There are no data on the effect of exercise on the functioning of this pathway in the myocardium and it was the aim of the present study to examine this question.

Methods:  The experiments were carried out on male Wistar rats, 300–320 g of body weight. They were divided into three groups: (1) control, (2) run 3 h on a treadmill moving with a speed of 1200 m h−1 and set at +10° incline, and (3) trained on a treadmill for 6 weeks. The rats were anaesthetized and samples of the left ventricle were taken. They were immediately frozen in liquid nitrogen. Thereafter, lipids were extracted and ceramide and sphingomyelin were isolated by means of thin layer chromatography. Their fatty acids were identified and quantified by means of gas‐liquid chromatography. In separate heart samples the activity of neutral, Mg2+‐dependent sphingomyelinase and acid sphingomyelinase was determined using labelled sphingomyelin as a substrate.

Results:  Thirteen different ceramides and sphingomyelins were identified based on their fatty acid residue. Exercise markedly reduced the total content of ceramide‐fatty acids and had no effect on the total content of sphingomyelin‐fatty acids. Training did not affect the total content either of ceramide‐, or sphingomyelin‐fatty acids. The activity of both neutral Mg2+‐sphingomyelinase and acid sphingomyelinase was reduced after exercise. Training did not affect the activity of neutral sphingomyelinase and reduced the activity of acid sphingomyelinase.

Conclusion:  It is concluded that acute, prolonged exercise, but not training, markedly affects the operation of the sphingomyelin‐signalling pathway in the heart.
Highly selective iNOS inhibition and sphincter of Oddi motility in the Australian possum
Authors: Sandstrom P. , Woods C. M. , Brooke‐Smith M. , Saccone G. T. P. , Toouli J. , Svanvik J.
Published: June 2004

Aim: 
Inducible nitric oxide synthase (iNOS) plays a major role in acute pancreatitis. Selective inhibitors of iNOS are being developed as therapeutic agents. Sphincter of Oddi (SO) dysfunction may cause pancreatitis and nitric oxide is necessary for SO relaxation. A new highly selective iNOS inhibitor, AR‐C102222AA (AR‐C), is evaluated together with the established iNOS inhibitor, l‐N6‐(1‐iminoethyl)lysine (l‐NIL), and the selective neuronal nitric oxide synthase (nNOS) blocker S‐methyl‐l‐thiocitrulline (SMTC).

Methods:  In anaesthetized Australian Brush‐tailed possums, the effect of topical, i.v. or i.a. administration of these drugs was evaluated on spontaneous SO motility, blood pressure (BP) and pancreatic vascular perfusion. SO motility was recorded by manometry and pancreatic vascular perfusion by laser Doppler fluxmetry. Also, the effect of SMTC and AR‐C on electrical field stimulation (EFS)‐induced non‐cholinergic non‐adrenergic (NANC) SO relaxation in vitro was evaluated.

Results:  Infusion of AR‐C (0.1–30 μmol kg−1) increased SO contraction frequency (P = 0.026) only at the two highest doses. l‐NIL infusion (0.15 to 14.7 μmol kg−1) also increased SO contraction frequency at 8.8 μmol kg−1 (P < 0.05) and reduced SO contraction amplitude at the two highest doses (P < 0.05). SMTC injections (0.5 nmol–2.4 μmol) produced a dose‐dependent increase in SO contraction frequency (P = 0.009), but no effect was seen on the other parameters. In vitro SMTC (40–400 μm) inhibited EFS‐induced NANC relaxation in a dose‐dependent manner (P < 0.0005). In contrast AR‐C (10–500 μm) had no effect on EFS‐induced NANC relaxation (P > 0.05).

Conclusions:  At low doses, AR‐C does not effect SO motility or EFS‐induced NO mediated relaxation. However, high doses of AR‐C and L‐NIL in vivo influenced SO motility by inhibiting nNOS activity and these effects need be considered in relation to therapeutic doses of this agent.
Prevention of postoperative sore throat using capsicum plaster applied at the Korean hand acupuncture point
Authors: Park H. S. , Kim K. S. , Min H. K. , Kim D. W.
Published: June 2004

In a randomised, double‐blind, sham‐controlled study, we compared the efficacy of capsicum plaster (PAS) applied at the Korean hand acupuncture point for the prevention of postoperative sore throat in 150 patients scheduled to undergo abdominal hysterectomy. The K group had PAS applied at the K‐A20 of both hands and placebo tape at both non‐acupoints. The PAS was applied prior to induction of anaesthesia and removed 8 h postoperatively. The sore throat scores of Group K were significantly lower than those of other groups at 24 h following surgery (p = 0.00027). The prevalence of moderate to severe sore throat at 24 h was lower for Group K (0%) than for sham and placebo controls (16%[p = 0.038] and 19%[p = 0.032], respectively). There were no differences in the recovery room of the sore throat scores for all groups. We found that the PAS applied at the K‐A20 was an alternative method for reducing postoperative sore throat.
Mast cell tryptase: a review of its physiology and clinical significance
Authors: Payne V. , Kam P. C. A.
Published: June 2004

Mast cells, which are granulocytes found in peripheral tissue, play a central role in inflammatory and immediate allergic reactions. β‐Tryptase is a neutral serine protease and is the most abundant mediator stored in mast cell granules. The release of β‐tryptase from the secretory granules is a characteristic feature of mast cell degranulation. While its biological function has not been fully clarified, mast cell β‐tryptase has an important role in inflammation and serves as a marker of mast cell activation. β‐Tryptase activates the protease activated receptor type 2. It is involved in airway homeostasis, vascular relaxation and contraction, gastrointestinal smooth muscle activity and intestinal transport, and coagulation. Serum mast cell β‐tryptase concentration is increased in anaphylaxis and in other allergic conditions. It is increased in systemic mastocytosis and other haematological conditions. Serum β‐tryptase measurements can be used to distinguish mast cell‐dependent reactions from other systemic disturbances such as cardiogenic shock, which can present with similar clinical manifestations. Increased β‐tryptase levels are highly suggestive of an immunologically mediated reaction but may also occur following direct mast cell activation. Patients with increased mast cell β‐tryptase levels must be investigated for an allergic cause. However, patients without increased mast cell tryptase levels should be investigated if the clinical picture suggests severe anaphylaxis.
A comparison of the intubating laryngeal mask airway and the Bonfils intubation fibrescope in patients with predicted difficult airways*
Authors: Bein B. , Worthmann F. , Scholz J. , Brinkmann F. , Tonner P. H. , Steinfath M. , Dörges V.
Published: June 2004

Tracheal intubation with the intubating laryngeal mask airway or the Bonfils intubation fibrescope was performed in 80 patients with predicted difficult airways. Mallampati score, thyromental distance, mouth opening and mobility of the atlanto‐occipital joint were used to predict difficult airways. The overall success rate, time to the first adequate lung ventilation and time taken for the successful placement of the tracheal tube were recorded, as well as a subjective assessment of the handling of the device and the incidence of postoperative sore throat and hoarseness. The median [range] time to the first adequate ventilation was significantly shorter with the intubating laryngeal mask airway than with the Bonfils intubation fibrescope (28 [6–85] s vs. 40 [23–77] s, p < 0.005). Tracheal intubation was significantly slower with the intubating laryngeal mask airway than with the Bonfils intubation fibrescope (76 [45–155] s vs. 40 [23–77] s, p < 0.0001. Patients in the Bonfils group suffered less sore throat and hoarseness than those in the other group.
Evaluation of a local anaesthesia regimen following mastectomy
Authors: Talbot H. , Hutchinson S. P. , Edbrooke D. L. , Wrench I. , Kohlhardt S. R.
Published: June 2004

Breast surgery can be emotionally distressing and physically painful. Acute pain following surgery is often related mainly to the axillary surgery and is aggravated by arm and shoulder movement. We conducted a prospective double‐blind, randomised, placebo‐controlled trial to determine the influence of local anaesthetic irrigation of axillary wound drains on postoperative pain during the first 24 h following a modified Patey mastectomy (mastectomy with complete axillary node clearance). The treatment group received bupivacaine irrigation through the axillary wound drain 4‐hourly for 24 h postoperatively. Controls received irrigation with normal saline. Morphine via a patient controlled analgesia pump was used for postoperative analgesia. Morphine consumption, visual analogue and verbal rating pain scores were recorded. There were no statistical differences in morphine requirements or pain scores between the two groups, nor were there differences in anti‐emetic or supplemental analgesic consumption. Bupivacaine irrigation used in this manner does not appear to offer an effective contribution to postoperative analgesia.
Guidelines for the use of fresh‐frozen plasma, cryoprecipitate and cryosupernatant
Authors:   British Committee for Standards in Haematology, Blood Transfusion Task Force (J. Duguid, Chairman), O'Shaughnessy D. F. , Atterbury C. , Bolton Maggs P. , Murphy M. , Thomas D. , Yates S. , Williamson L. M.
Published: June 2004

The indications for transfusing fresh‐frozen plasma (FFP), cryoprecipitate and cryosupernatant plasma are very limited. When transfused they can have unpredictable adverse effects. The risks of transmitting infection are similar to those of other blood components unless a pathogen‐reduced plasma (PRP) is used. Of particular concern are allergic reactions and anaphylaxis, transfusion‐related acute lung injury, and haemolysis from transfused antibodies to blood group antigens, especially A and B. FFP is not indicated in disseminated intravascular coagulation without bleeding, is only recommended as a plasma exchange medium for thrombotic thrombocytopenic purpura (for which cryosupernatant is a possible alternative), should never be used to reverse warfarin anticoagulation in the absence of severe bleeding, and has only a very limited place in prophylaxis prior to liver biopsy. When used for surgical or traumatic bleeding, FFP and cryoprecipitate doses should be guided by coagulation studies, which may include near‐patient testing. FFP is not indicated to reverse vitamin K deficiency for neonates or patients in intensive care units. PRP may be used as an alternative to FFP. In the UK, PRP from countries with a low bovine spongiform encephalopathy incidence is recommended by the Departments of Health for children born after 1 January 1996. Arrangements for limited supplies of single donor PRP of non‐UK origin are expected to be completed in 2004. Batched pooled commercially prepared PRP from donors in the USA (Octaplas) is licensed and available in the UK. FFP must be thawed using a technique that avoids risk of bacterial contamination. Plastic packs containing any of these plasma products are brittle in the frozen state and must be handled with care.