Biomedical subjects

A Lange

Publications and source records attributed to A Lange.

245 records · Page 14Linked to original sources

PubMedDate not supplied

The variation of integrated backscatter in human hearts in differing ultrasonic transthoracic views.

It has been shown previously that in normal subjects the interventricular septum imaged in the long-axis view (LAX) and the left ventricular posterior wall imaged in both the LAX and the short-axis view (SAX) exhibit cyclic variation of integrated backscatter (IB) throughout the cardiac cycle, with maximum values occurring at end diastole (ED) and minimum at end systole (ES). The ability to demonstrate this cyclic variation within these myocardial regions in only two ultrasonic views has limited the potential clinical utility of an IB imaging system. To determine whether clinically useful information on the variation of IB is available from different myocardial regions in different ultrasonic views, we measured ED to ES variation of IB from the parasternal and apical views in normal subjects with a radiofrequency acquisition technique. Two independent clinical observers analyzed ED to ES variation of IB from 14 normal volunteers (mean age 32 +/- 6 years; range 21 to 45 years) in reconstructed two-dimensional ultrasonic images obtained from the parasternal LAX and SAX and apical two-chamber (2C) and four-chamber (4C) views. ED to ES variation of IB was measured from manually traced regions of interest (ROI) within the myocardium. These ROIs were chosen interactively and were located within the midposterior wall and the midanteroseptum in LAX views; within the midposterior wall, midanteroseptum, midseptum, and midlateral wall in SAX views; within the midseptum and the midlateral wall in 4C views; and within the midinferior wall and the midanterior wall 2C views. In all analyzed ROIs within the parasternal and apical views, ED to ES variation of IB was found. We have shown that the maximum magnitude of IB was at ES within the midseptum and in 10 out of 14 volunteers in the midanteroseptum measured from SAX views, the midanterior wall from 2C views, and the midlateral wall from 4C views. The rest of the ROIs analyzed exhibited the maximum value of IB cyclic variation at ED. We have confirmed that the ED to ES variation of IB is present not only when measured from the two standard parasternal views but also from the two apical views in all analyzed myocardial walls, and the minimum of this cyclic variation was not always coincident with ES nor the maximum with ED.

Adult↗

PubMedDate not supplied

Doppler tissue imaging: myocardial wall motion velocities in normal subjects.

With a scanner modified for Doppler tissue imaging, mean myocardial velocities (MMV) across the myocardium were measured. The aim of this study was to determine the normal range of the maximum MMV in six standardized phases of the cardiac cycle. The MMV was defined as the average value of the myocardial velocity measured along each M-mode scan line throughout the thickness of the myocardium. The maximum MMV was defined as the maximum value of the MMV during the particular cardiac phase. Simultaneous gray-scale and Doppler tissue imaging M-mode images were taken of the interventricular septum and the left ventricular posterior wall from the parasternal long-axis and short-axis views in 15 normal volunteers (aged 21 to 47 years; mean 32 +/- 6 years). Each cardiac cycle was divided into six phases: atrial contraction, isovolumetric contraction, ventricular ejection, isovolumetric relaxation, rapid ventricular filling, and diastasis. Isovolumetric contraction, isovolumetric relaxation, and diastasis were subdivided into two parts a and b because of changes in the direction of the myocardial movement. For each volunteer, the mean and standard deviation of the maximum MMV were measured for each cardiac phase averaged from 12 cardiac cycles from both long-axis and short-axis views. Finally, the mean and standard deviation were taken for each cardiac phase from 180 cardiac cycles from 15 volunteers. We have found that specific cardiac phases show significant differences in the maximum MMV between the adjoining cardiac phases and significant differences also occur between the maximum MMV measured in the interventricular septum and the left ventricular posterior wall during the same cardiac phases. These normal values provide a standard against which future Doppler tissue imaging M-mode studies of abnormal left ventricular function might be compared.

Adult↗

PubMedDate not supplied

Doppler myocardial imaging: a new method of data acquisition for three-dimensional echocardiography.

The precise morphologic characteristics of any intracardiac tumor have important implications regarding surgical planning and operative repair. Three-dimensional echocardiography has proved to be a valuable clinical technique in this field. Current methods of three-dimensional reconstruction of two-dimensional images are based on the standard gray-scale imaging technique. However, precordial gray-scale data-set information is frequently of suboptimal quality because of data degradation caused by ultrasound attenuation by chest wall structures. This has limited the use of the transthoracic three-dimensional technique to "echogenic" patients. Doppler myocardial imaging (DMI), a new ultrasound technique based on the Doppler principle, is influenced less by chest wall attenuation and in addition offers a better boundary detection algorithm for the cardiac structures. To determine if there may be a potential benefit of DMI to acquire data for three-dimensional reconstruction, a 33-year-old woman with a large intracardiac mass was studied. In this case three-dimensional gray-scale and DMI data sets were compared and contrasted with pathologic information. DMI allowed both the qualification of mass volume and the correct definition of the morphology of the mass. It was also possible to identify the precise site of attachment of the mass to the mitral valve leaflets. The information thus obtained was correlated with both operative and pathologic findings.

Adult↗

PubMedDate not supplied

Gastroesophageal reflux in infants with food allergy.

The authors present results of studies in a group of 58 children aged 4-36 months in whom food allergy has been diagnosed. Esophageal 24-hour pH-metric studies revealed the presence of gastroesophageal reflux (GER) in 27 cases (46.5%). In 13 cases it was primary and independent of the allergic disease, and in 14 children it showed features of secondary gastroesophageal reflux. Conservative treatment appeared ineffective more frequently in the group of infants with primary reflux (in 23.1% of cases) than in children with secondary reflux and food allergy (in 7.1% of cases). In 4 infants fundoplication according to Nissen was performed.

Child, Preschool↗

PubMedDate not supplied

[Serologic and cytochemical examinations for surveillance of cytomegalovirus infection and reactivation after hematopoietic cell transplantation].

UNLABELLED: 208 patients and 1327 blood/platelet donors were monitored for the presence of CMV antibodies. Serological tests were used for the detection of IgM and IgG CMV antibodies and cytochemistry (APAAP) for CMV antigens detection. RESULTS: 1) In haematological patients and in blood/platelet donors proportions of IgG CMV antibodies were similar (about 75%). 2) The presence of IgM-CMV antibodies was significantly more frequent in patients than in donors group (4/208 vs 4/1327, p = 0.0025). 3) CMV early and immediate early antigens (p52, Ad169) were detected in 31 patients. CMV antigenemia occurred in 11/31 patients and were found between 13 and 78 days after BMT. In 11 patients a number of CMV + cells ranged from 12 to 11,500/10(5) (median values 25 positive cells/10(5)). Patients receiving anti thymocyte serum (13/31) were on Ganciclovir pre-emptive treatment. CMV antigenemia positive patients were in similar proportions in the groups receiving and lacking ATG (ATG is a risk factor of CMV reactivation) as a part of conditioning regimen. In addition median value of CMV positive leukocytes was lower in ATG receiving patients than patients lacking ATG. This was likely due to the effective Ganciclovir pre-emptive treatment offered to all patients on ATG.

Adolescent↗

PubMedDate not supplied