Biomedical subjects

A L Taylor

Publications and source records attributed to A L Taylor.

95 records · Page 6Linked to original sources

PubMedDate not supplied

Left ventricular diastolic dysfunction in children and young adults with Marfan syndrome.

Adults with Marfan syndrome (MFS) demonstrate abnormal aortic elastic properties manifest by decreased aortic distensibility and increased aortic stiffness. Left ventricular (LV) diastolic dysfunction has been reported in adults with MFS. The objective of this study was to assess the frequency of LV diastolic dysfunction in a group of children and young adults with MFS and to determine whether diastolic dysfunction is associated with hemodynamic alterations of the aorta. Review of echocardiographic findings in 40 patients with MFS was performed to assess LV size, systolic function, isovolumic relaxation time (IVRT), mitral inflow velocities, deceleration time (DT) of mitral E wave, and aortic root dimension. No patient had significant valvar disease or was on any cardiac medication at the time of study. A group of 40 age and sex-matched healthy subjects undergoing echocardiography served as controls. Significant differences in LV diastolic function were found between MFS patients and controls. MFS patients had prolonged DT and IVRT and decreased mitral E/A ratio, suggesting impaired LV relaxation. No relationship between aortic root dimension and diastolic performance was identified. Left ventricular diastolic dysfunction may be an early marker of myocardial involvement in young MFS patients occurring independently of aortic root dilatation.

Adolescent↗

PubMedDate not supplied

False inferior pseudoaneurysm: two-dimensional and Doppler echocardiographic findings.

The noninvasive differentiation of true aneurysm from pseudoaneurysm is sensitively and specifically accomplished with two-dimensional echocardiography. Recent reports suggest that Doppler flow patterns may further enhance the specificity of the diagnosis of pseudoaneurysm. We present a patient with ventriculographic and two-dimensional echocardiographic features of an inferior pseudoaneurysm. Doppler examination, however, failed to show phasic flow characteristic of a small communicating orifice between two larger chambers. At surgery, a large posterolateral true aneurysm was found. Thus the addition of Doppler flow patterns to imaging information may help to distinguish pseudoaneurysms from true aneurysms.

Cardiac Catheterization↗

PubMedDate not supplied

Echocardiographic diagnosis of pneumopericardium and hydropneumopericardium.

Pneumopericardium and hydropneumopericardium are rare conditions in which hemodynamic compromise is common. Loss of the M-mode and two-dimensional image coincident with the systolic phase of each cardiac cycle and swirling echogenic bubbles within the pericardial space produce a distinctive M-mode and two-dimensional echocardiographic appearance. This provides an additional method for prompt diagnosis.

Adult↗

PubMedDate not supplied

Continuous recombinant bacterial fermentations utilizing selective flocculation and recycle.

Selective recycle has successfully been used to maintain an unstable plasmid-bearing bacterial strain as dominant in a continuous reactor, whereas the culture reverts to 100% segregant cells when selective recycle is not used. The plasmid-bearing strain is slower growing and flocculent; however, when the cells lose their plasmid, the resulting segregant cells are nonflocculent and grow at a faster rate due to their decreased metabolic burden. Both types of cells exit a chemostat and enter an inclined settler where the flocculent plasmid-bearing cells are separated from the nonflocculent segregant cells by differential sedimentation. The underflow from the cell separator, which is enriched with plasmid-bearing cells, is recycled back to the chemostat, while the segregant cells are withdrawn off the top of the settler and discarded. The experimental results agree well with selective recycle reactor theory. On the basis of the theory, a criterion is presented that has been shown to successfully predict whether or not a selective recycle reactor can maintain a plasmid-bearing strain.

Biotechnology↗

PubMedDate not supplied

Can beta-hydroxybutyrate be detected at the bedside by in vitro oxidation with hydrogen peroxide.

The diagnosis of ketoacidosis with an inordinately high plasma and urinary concentration ratio of beta-hydroxybutyrate (beta-OHB) to acetoacetate (AcAc) is difficult, because only AcAc and acetone react with the diagnostic reagents used clinically to detect ketones. The purpose of this study was to assess the validity of the claim that beta-OHB can be identified with a simple modification of the usual bedside test for ketones, using hydrogen peroxide (H2O2) and Ketostix (Ames Division, Miles Laboratories, Inc., Elkhart, Indiana). Unfortunately, the lowest detectable concentration of urinary beta-OHB was 50 mmol/L, and serum beta-OHB could not be detected at levels less than 100 mmol/L, a clinically irrelevant level. The relative insensitivity, the inapplicability to serum, and the potential hazard of the routine use of 30% H2O2 by practicing physicians or houseofficers render the method of limited value.

3-Hydroxybutyric Acid↗