Search PubMed⌕ Search

Biomedical subjects

K Alexander

Publications and source records attributed to K Alexander.

At least 181 records · Page 10Linked to original sources
PubMed1983

Effects of ethanol on cultured human fibroblasts.

The effects of ethanol on cellular functions of growth and low density lipoprotein uptake were studied with cultured human fibroblasts, WI-38. Cells were grown in basal medium for 24 hr, then incubated in medium containing 0, 100, or 500 mM ethanol for various times. Growth in 100 mM ethanol had little effect, but growth in 500 mM ethanol for 24 or more hours significantly decreased the number of cells per dish and increased the protein, but not the DNA, content, per cell. Exposure to 500 mM ethanol had little effect on protein synthesis but significantly depressed DNA synthesis. It was also evident from microscopy that fewer but larger cells were present. There appeared to be no consistent acute effects of 500 mM ethanol on the uptake of lipoproteins by confluent monolayers of cells. After chronic exposure, uptake was comparable to that of 0 or 100 mM ethanol when expressed as nanogram of lipoprotein/mg of cell protein but higher when expressed as picograms/cell. The results suggest that 500 mM ethanol decreased the rate of cell division but resulted in enlargement of cells.

Cell Differentiation↗
PubMed1983

Effect of treadmill exercise on blood gases and acid-base balance in patients with intermittent claudication.

Blood gases and lactate and pyruvate concentration were measured in arterial and popliteal venous blood in 6 control subjects and 34 patients with intermittent claudication before, during, and after treadmill exercise of 10 min duration. Oxygen saturation, oxygen extraction, base excess, and standard bicarbonate were calculated. The transition from resting supine position to upright position on the treadmill caused the popliteal venous oxygen saturation to fall from 49.4% to 26.3%. In patients, during exercise a further decrease (to 11%) was observed. During treadmill exercise the popliteal venous PO2 did not fall below 16.5 +/- 1.1 mm Hg in the controls. Individual values during exercise varied between 6.4 mm Hg and 17.9 mm Hg in patients. A critical oxygen pressure was reached in 10 patients. Lactate concentration was found to increase to values as high as 14 mmol/l in popliteal venous blood. The lactate-pyruvate ratio varied between 12.9 and 106.3 during exercise, and the corresponding values for venous blood pH were 7.38 and 6.92. Changes in the PCO2, lactate, and pH in arterial and popliteal venous blood showed a significant correlation. The decrease in the base excess was greater than the corresponding increase in the blood lactate concentration. It is concluded that analysis of the acid-base balance in patients with intermittent claudication is best carried out by the regional catheterization technique.

Acid-Base Equilibrium↗
PubMed1982

Lactate and pyruvate changes during treadmill exercise in patients with intermittent claudication.

Exercise and post-exercise metabolism was studied in the legs of 6 healthy individuals without arterial occlusive disease and in 34 patients with intermittent claudication. Venous blood from the popliteal vein was taken intermittently by regional catheterization during and after an exhaustive constant load exercise on a treadmill. Change of lactate and pyruvate was studied in arterial and popliteal venous blood. The mean arterial concentration of pyruvate during exercise was increased less in patients and controls as compared to the lactate concentration in both groups. There was a continuous rise of the arterial pyruvate concentration after exercise in patients in contrast to the controls. During exercise, the difference between the arterio-popliteal venous blood samples in lactate concentrations was significantly higher in patients than in the controls. In general, patients had a significantly higher lactatepyruvate ratio in the popliteal venous blood than in the arterial blood. It is concluded that the onset and degree of anaerobic work is best studied by the regional catheterization technique. This new technique permits to study the spontaneous and reactive metabolic changes in the legs during and after treadmill exercise in patients with intermittent claudication.

Adult↗
PubMed1981

[Carotid auscultation and Doppler sonography of the A. supratrochlearis in cerebral ischemias].

72 patients (117 angiographies ) suffering from transient ischemic attacks or prolonged reversible ischemic neurological deficits have been examined to study the diagnostic accuracy of the Doppler-sonography of the supratrochlear artery and of neck bruits. The specificity and sensitivity of the Doppler examination were 91 and 81%. The specificity and sensitivity of carotid bruits were 80 and 60%. The sensitivity increased to 94% when either a neck bruit or a pathological Doppler-test were interpreted to be indicative of carotid occlusive disease.

Auscultation↗
PubMed1981

Application of marketing principles to improve participation in public health program.

The application of marketing principles to develop a program aimed at increasing participation in a cervical screening program appears to be more effective than the use of sales techniques. Standard methods of promotion such as posters, direct mail, and flyers were generally ineffective. Direct personal contact produced the majority of program participants, and mass media approaches also resulted in significant participant response. A consumer orientation led to development of effective program features designed to satisfy specific consumer needs. Use of female health practitioners, for example, reduced cultural barriers to participation and insured adequate screening in Mexican-American populations.

Adult↗
PubMed1981

The distribution of a specific HLA-B27-associated cell surface component on the tissues of patients with ankylosing spondylitis.

In this paper, we report the presence on Epstein-Barr virus-transformed lymphoblastoid cell lines on platelets and on fibroblasts of an HLA-B27-associated cell surface complex (antigenically related to some antigens of Klebsiella K43 and K21) which is identical to or cross-reactive with the determinant present on the peripheral blood lymphocytes (PBL) of B27-positive patients with ankylosing spondylitis (AS). By contrast, no Klebsiella K43 markers could be demonstrated on the spermatozoa of B27+ AS+ individuals even though these cells expressed the HLA-B27 alloantigen. No B27-associated K43 antigen was detected on the erythrocytes of patients or of normal controls. The B27-associated membrane marker is still detectable on lymphoblastoid cell lines after 20 generations and on fibroblasts after about 10 generations. This finding implies that the continued expression of Klebsiella-modified B27 structure is generally determined and does not require the repeated exposure of the cell surface to Klebsiella antigen. These data suggest that certain non-lymphoid as well as lymphoid cells may be involved in the complex sequence of events leading to the clinical manifestation of AS.

Blood Platelets↗