Influence of adenosine on basal myocardial function: observations in anaesthetised, domestic swine

Data from experiments in isolated cardiac muscle preparations indicate that adenosine in high concentration (10(-3) mol X litre-1) exerts a negative inotropic effect on the myocardium under basal conditions. The following study was performed to test the hypothesis that adenosine exerts a similar negative inotropic effect when administered in an intact animal model in a dose sufficient to cause maximal coronary vasodilatation. Six open chest anaesthetised pigs were studied as follows. Ultrasonic length sensors were placed in the endocardium of the free wall of the left ventricle in a region perfused by the left anterior descending (LAD) coronary artery. Large increases in endocardial blood flow in response to adenosine administration, which could enhance segmental function ("garden hose effect"), were prevented by inserting an artificial stenosis (73% reduction in lumenal diameter) in the proximal third of the LAD. Measurements of haemodynamics, regional myocardial blood flow (microsphere technique), and regional systolic function were made at control 1, at the end of 10 min of intracoronary adenosine infusion (3.0 mumol X min-1) at a dose which exceeded that previously shown to cause maximal coronary vasodilatation and at second control 20 to 40 min after discontinuation of adenosine infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective evaluation of local xenogeneic graft-versus-host reaction by computerized radioisotope imaging (CRI)

The local xenogeneic graft-versus-host reaction (GVHR) assay has been used clinically to evaluate cellular immune competence and experimentally to monitor the immunomodulatory effects of several drugs. By employing a computerized radioisotope imaging (CRI) technique, we were able to perform the assay with smaller numbers of mononuclear cells (MNC) and to rid it entirely of any bias. Measuring the local GVHR by CRI compares well with the conventional measurement of the volume (correlation coefficient r = 0.619; P less than 0.001). A clear-cut distinction was documented between normal donors and cancer patients (P less than 0.001) when 10 X 10(6) or more MNC were used in the assay. This is an improvement over the previous, conventional testing of local GVHR which required injection of 20 X 10(6) MNC in order to achieve a similar resolution. The indications for the presence of immune competence have therefore been redefined using the local GVHR index as determined by CRI according to the scale of MNC injected. Thus, immunocompetence is considered present if the CRI index is greater than or equal to 1.2 for 10 X 10(6) MNC, greater than or equal to 2.0 for 15 X 10(6) MNC and greater than or equal to 2.6 for 20 X 10(6) MNC.

Immune restoration and/or augmentation of local graft versus host reaction by traditional Chinese medicinal herbs

The in vitro restorative effect of aqueous extracts from two traditional Chinese medicinal herbs were studied in 19 cancer patients and in 15 normal healthy donors. Using the local graft versus host (GVH) reaction as a test assay for T-cell function, the extract from astragalus membranaceus (10 microgram/ml) induced a restored reaction in nine of ten patients with an increase in local GVH reaction from 18.2 plus/minus 15.8 mm3 to 112.9 plus/minus 94.2 mm3 (P less than 0.01). The extract from ligustrum lucidum, likewise effected an immune restoration in nine of 13 cancer patients with an increase in local GVH reaction from 32.3 plus/minus 36.1 mm3 to 118 plus/minus 104.9 mm3 (P less than 0.01). This degree of immune restoration appears to be complete as it equals the local GVH reaction observed among untreated mononuclear cells from normal healthy donors (82.8 plus/minus 41.1 mm3, P greater than 0.1). These results suggest that both extracts of the traditional Chinese medicinal herbs contain potent immune stimulants which may provide the rational basis for their therapeutic use as biological response modifiers.

Isolation of genome-enzyme complex from cytoplasmic polyhedrosis virus of silkworm Bombyx mori

The genome-enzyme complex is isolated from the silkworm cytoplasmic polyhedrosis virus with DEAE-Sephadex column chromatography after ultraviolet irradiation. The genome-enzyme complex shows both RNA-polymerase and methyltransferase activities while using 3H-UTP and [3H-methyl]-S-adenosyle-L-methionine as substrates. Like the double-stranded RNA genome of CPV, the genome-enzyme complex could be separated into nine segments on polyacrylamide gel electrophoresis. It is demonstrated that the RNA polymerase and methyl-transferase are tightly bound to the double-stranded RNA genome and that the individual segments of the genome-enzyme complex all possess RNA-polymerase and methyltransferase activities. It appears that each segment of the double-stranded RNA genome is transcribed independently.