The art of nursing: the experience of patients and nurses.

Historical and contemporary conceptualizations of nursing have not addressed the art of nursing from an experiential research approach. This study explores patients' and nurses' experiences of the art of nursing using a phenomenological-hermeneutic approach to enquiry that allows for exploration of the empirical experience. Explicating a paradigm of the art of nursing, five distinct metathemes express nursing as art and describe the complex artistic processes that are lived through the nurse and patient.

The persistence of hepatitis B antigen in the bloodmeal of the potential medicinal leech, Asiaticobdella buntonensis.

The persistence of the hepatitis B virus surface antigen (HBsAg) was used as an index of the survival time of this virus within the gastro-intestinal tract of the potential southern African medicinal leech, Asiaticobdella buntonensis. HBsAg was tested for in blood/faecal material at five intervals over 15 weeks. Samples from both the midgut and the rectum remained positive for the entire test period, although with decreasing strength.

Bacteriological investigation of the occurrence and antibiotic sensitivities of the gut-flora of the potential southern African medicinal leech, Asiaticobdella buntonensis (Hirudinidae).

The lack of availability of medicinal leeches is a major impediment to the widespread use of leech therapy for treatment of congested flaps and replants in southern Africa. An investigation into the suitability of an alternative leech, the indigenous southern African leech, Asiaticobdella buntonensis, was therefore started. The risk of hospital-acquired infection related to the use of leeches and the antibiotic sensitivities of bacteria isolated from the gastro-intestinal tract of wild-caught leeches were investigated.

Snail predation by larvae of Sepedon scapularis Adams (Diptera: Sciomyzidae), a potential biocontrol agent of snail intermediate hosts of schistosomiasis in South Africa.

Malacophagous larvae of the fly Sepedon scapularis Adams were shown experimentally to be effective predators of three species of aquatic pulmonate snails tested as prey: Bulinus africanus (Krauss) an important intermediate host of Schistosoma haematobium (Bilharz), Bulinus tropicus (Krauss) and the invasive species Physa acuta Draparnaud. Survival of S. scapularis larvae from instar to instar was negatively affected by the size of prey snails, since larvae tended to be asphyxiated by the mucous secretions of the snails, or by the larval hydrofuge hairs becoming entangled in snail faeces.

Pulmonary venous flow velocity: relation to hemodynamics, mitral flow velocity and left atrial volume, and ejection fraction.

Abnormal pulmonary venous flow velocity patterns are present in multiple cardiac disease states, but the determinants of pulmonary venous flow velocity have not been fully elucidated. To determine the relative importance of several proposed factors that could influence pulmonary venous flow, anatomic, hemodynamic, and Doppler mitral and pulmonary venous flow velocity data were compared in 50 consecutive patients undergoing cardiac catheterization for clinical reasons. Pulmonary venous diastolic flow velocity was most strongly related to left ventricular isovolumetric relaxation time (r = -0.

A preliminary parasitological analysis of fecal samples from a wild population of Costa Rican squirrel monkeys (Saimiri oerstedi).

Fecal samples (n = 18) were obtained from a wild population of squirrel monkeys, Saimiri oerstedi, in Costa Rica. The parasite cysts, eggs, and larvae recovered from these samples are described.

Diastolic mitral regurgitation with atrioventricular conduction abnormalities: relation of mitral flow velocity to transmitral pressure gradients in conscious dogs.

Diastolic mitral regurgitation is a common finding that can be detected with use of Doppler echocardiographic techniques in patients with atrioventricular (AV) conduction abnormalities. With use of simultaneous hemodynamic and Doppler techniques, mitral flow velocity, mitral valve motion and transmitral pressure gradient were studied during 50 cardiac cycles each of spontaneous or atrial paced first- and second-degree AV block in five lightly sedated dogs. Diastolic mitral regurgitation was detected during atrial relaxation on all beats in which ventricular contraction was delayed greater than 190 ms.

Doppler flow velocity patterns of the superior vena cava, inferior vena cava, hepatic vein, coronary sinus, and atrial septal defect: a guide for the echocardiographer.

Pulsed-wave Doppler provides the echocardiographer the advantage of range resolution; confusion as to the source of Doppler shift information is unusual. One area of the heart that may lead to interpretive difficulties, however, is the right atrium because the right atrium receives blood flow from three venous sources and from the left atrium when an atrial septal defect is present. Our article presents information on the normal pulsed-wave Doppler spectral displays for the superior vena cava, inferior vena cava, hepatic vein, and coronary sinus.

Experimental cardiac tamponade: a hemodynamic and Doppler echocardiographic reexamination of the relation of right and left heart ejection dynamics to the phase of respiration.

A hallmark of cardiac tamponade is pulsus paradoxus. However, the exact mechanism of pulsus paradoxus and the relation of left and right ventricular ejection dynamics remain controversial, with some studies suggesting an inverse relation in ventricular filling and ejection and others citing a more important role for the effects of right heart ejection dynamics delayed by transit through the pulmonary artery bed. To specifically reexamine this issue, six sedated but spontaneously breathing dogs were studied during experimental cardiac tamponade with use of extensive hemodynamic instrumentation and Doppler methods.

Visualization of the hepatic veins: new approaches for the echocardiographer.

Visualization and cardiac Doppler interrogation of the hepatic veins has become an important and integral part of the routine echocardiographic examination. The challenge lies in adequate visualization of the hepatic veins by use of the standard subcostal approach. This article proposes alternate approaches when the standard view yields unsatisfactory visual and cardiac Doppler information.

Systemic toxic effects associated with high-dose verapamil infusion and chemotherapy administration.

Aside from its more conventional uses as a cardiovascular drug, the calcium channel blocker verapamil has recently been added to chemotherapeutic regimens to reduce drug resistance in B-cell and other neoplasms that express the P-glycoprotein. We recently treated patients with continuous-infusion verapamil (0.15 mg/kg per hour to 0.

Experimental pericardial effusion: relation of abnormal respiratory variation in mitral flow velocity to hemodynamics and diastolic right heart collapse.

Pericardial effusion is associated with an abnormal increase in respiratory variation in mitral flow velocity. However, the relation of the changes in flow velocity to pericardial pressure, hemodynamics and two-dimensional echocardiographic findings is not established. Therefore, 11 sedated dogs with extensive hemodynamic instrumentation were studied with two-dimensional and Doppler echocardiography during four stages of progressively larger pericardial effusion.

Influence of incremental changes in heart rate on mitral flow velocity: assessment in lightly sedated, conscious dogs.

To determine the effect of increasing heart rate on mitral flow velocity variables, the time constant of left ventricular isovolumic relaxation and the transmitral pressure gradient, 16 lightly sedated, conscious dogs were studied with Doppler echocardiography during incremental right atrial pacing (n = 16) or the administration of atropine (n = 8) or isoproterenol (n = 8). With increasing heart rate, similar changes were seen with all three interventions and included: 1) mitral flow velocity in early diastole and the early diastolic transmitral pressure gradient either changed minimally or did not change; 2) mitral flow velocity at the start of and as a result of atrial contraction progressively increased; 3) the "absolute" increase in mitral flow velocity and transmitral pressure gradient at atrial contraction demonstrated a biphasic response, initially decreasing as heart rate increased, but then increasing again when atrial contraction occurred in close proximity (less than 70 ms) to mitral valve opening; 3) mitral flow velocity at atrial contraction did not exceed mitral flow velocity in early diastole until atrial contraction was within 70 ms of mitral valve opening and the two velocity peaks were nearly fused; and 4) the largest transmitral pressure gradient and mitral flow velocity occurred at the fastest heart rates, when left atrial contraction preceded mitral valve opening. Major differences among methods included: 1) variable changes in PR interval (+14.

Canoeists and waterborne diseases in South Africa.

The prevalence of urinary schistosomiasis (Schistosoma haematobium) in canoeists in South Africa was estimated from examinations of urine samples taken from participants in the 1988 and 1989 Duzi Canoe Marathons on the Umsinduzi/Umgeni river in Natal. As an indicator of water quality during races, water samples were taken from the river for bacteriological analysis. Results showed a very low prevalence of S.

Variability of Doppler echocardiographic indexes of left ventricular filling in transplant recipients and in normal subjects.

This study examines the reproducibility and variability of pulsed wave Doppler versus continuous wave Doppler ultrasound indexes of left ventricular filling in cardiac allograft recipients and in normal subjects. The following indexes were studied: isovolumic relaxation time, pressure half-time, peak early mitral flow velocity, and peak mitral flow velocity after atrial systole. Intraobserver and interobserver variability were assessed by regression analysis.

Doppler studies of vena cava flows in human fetuses. Insights into normal and abnormal cardiac physiology.

We examined vena cava Doppler flow velocity tracings from 69 fetuses between 22 and 40 weeks' gestation. Twenty-three fetuses had arrhythmias. Fifteen fetuses had absent end-diastolic Doppler velocities in the umbilical artery, a condition associated with intrauterine growth retardation, and 15 normal fetuses with normal umbilical artery Doppler velocity ratios were matched by gestational age.

Flow velocity acceleration in the left ventricle: a useful Doppler echocardiographic sign of hemodynamically significant mitral regurgitation.

Doppler echocardiography is a sensitive method to detect mitral regurgitation in patients with both native and prosthetic valves. However, estimates of the amount of mitral regurgitation remain semiquantitative, and even severe mitral regurgitation may be underestimated in the presence of markedly eccentric regurgitant jets or acoustic shadowing of the left atrium by mitral or aortic prostheses. This report describes the Doppler findings in 10 patients with severe native valve mitral regurgitation (angiographic grade III or IV) and in 15 patients with severe bioprosthetic mitral regurgitation that required valve replacement.

The structure of the shell and polar plugs of the egg of the whipworm, Trichuris trichiura (Nematoda: Trichuridae) from the Samango monkey (Cercopithecus albogularis).

The structure of the shell of the egg of Trichuris trichiura was examined using light microscopy as well as scanning and transmission electron microscopy. The results confirmed its three-layered structure and provided evidence that the cores of the polar plugs, which could be seen to be extensions of the shell's middle layer, could be lost en bloc, either mechanically or chemically, and in this way probably provided an exit for the first stage larva at hatching.

Human fetal tricuspid and mitral deceleration time: changes with normal pregnancy and intrauterine growth retardation.

Studies in instrumented adults have shown an association between Doppler echocardiography-derived atrioventricular valve deceleration times and ventricular function. To determine how gestational age affects deceleration time in the tricuspid and mitral valve, pulsed Doppler ultrasonographic examinations were performed in 54 normal human fetuses. In addition, 26 fetuses with growth retardation and the absence of end-diastolic Doppler velocities in the umbilical artery were examined.

Differentiation of constrictive pericarditis and restrictive cardiomyopathy by Doppler echocardiography.

Doppler ultrasound recordings of mitral, tricuspid, aortic, and pulmonary flow velocities, and their variation with respiration, were recorded in 12 patients with a restrictive cardiomyopathy and seven patients with constrictive pericarditis. Twenty healthy adults served as controls. The patients with constrictive pericarditis showed marked changes in left ventricular isovolumic relaxation time and in early mitral and tricuspid flow velocities at the onset of inspiration and expiration.

Mitral prosthesis malfunction. Comparative Doppler echocardiographic studies of mitral prostheses before and after replacement.

To assess the influence of mitral prosthesis malfunction on various Doppler echocardiographic indexes, we studied the changes in the peak mitral flow velocity during early diastolic filling phase (Vmax), the mean transprosthesis pressure drop from the simplified Bernoulli equation, the mitral valve area by the pressure half-time method, and the left ventricular isovolumic relaxation time in 15 patients before and after replacement of the malfunctioning mitral prosthesis using continuous wave Doppler echocardiography. Examination of the 15 replaced prostheses revealed a torn or perforated leaflet in 12 valves and a sewing ring dehiscence in one valve. Additional restricted leaflet motion (classified as mild obstruction) was seen in three of these 13 valves.

A hemodynamic and Doppler echocardiographic study of ventricular function in long-term cardiac allograft recipients. Etiology and prognosis of restrictive-constrictive physiology.

Conventional hemodynamic measurements and Doppler echocardiography were used to assess ventricular physiology of the human cardiac allograft and to examine the influence of pertinent clinical factors on chronic myocardial performance. Sixty-four patients (18-55 years old; mean, 39 years) undergoing routine annual hemodynamic assessment were studied. Blood-flow velocity properties across the mitral, tricuspid, and aortic valves were analyzed from Doppler ultrasound recordings.

Lipomatous hypertrophy of the interatrial septum: characterization by transesophageal and transthoracic echocardiography, magnetic resonance imaging, and computed tomography.

Lipomatous hypertrophy of the interatrial septum is a benign condition that must be distinguished from other space-occupying lesions of the atria. Patients with this disorder generally have chronic pulmonary disease and thus are difficult to image with conventional transthoracic two-dimensional echocardiography. Transesophageal echocardiography can provide high quality imaging of intracardiac structures in patients who lack adequate transthoracic echocardiographic windows as a result of pulmonary disease.