Cold pressor test in diagnosis of coronary artery disease: echophonocardiographic method.

The cold pressor test was used to induce myocardial ischaemia in patients with coronary artery disease and the rise in left ventricular filling pressure used as the index of myocardial ischaemia. Left ventricular filling pressure was derived from a non-invasive echophonocardiographic method. A study group of 19 consecutive patients with chest pain underwent the cold pressor test before coronary angiography. Eighteen responded with a rise in filling pressure exceeding 30% and, of these, 17 had serious coronary artery disease (three single vessel, one two vessel, and 13 triple vessel disease; one had coronary artery spasm only). The remaining patient, who showed no rise in filling pressure, did not have coronary artery disease. None of 15 normal controls showed a rise greater than 5% (patients with coronary artery disease versus normal controls p less than 0.001). The cold pressor test would be suitable for patients who cannot or should not exercise and may be combined with exercise electrocardiograms to improve the information content, as it uses a different marker of myocardial ischaemia.     

Distribution of Na+, K+-ATPase α-Subunit Isoforms in Rat Pituitary

The distributions of alpha-subunit isoforms of the Na+,K(+)-ATPase in rat pituitary were determined by immunoblotting and immunohistochemistry. Immunoreactivity for all three forms is present in the neural lobe, whereas the anterior lobe contains only alpha 1 and alpha 2. Most areas of the intermediate lobe exhibit faint immunoreactivity for only alpha 1, but thin strands of cells which stain strongly for all three isoforms are also present in this lobe. The previously reported ouabain inhibitable Na+,K(+)-ATPase activity in the neural lobe is consistent with the presence of both alpha 2 and alpha 3 subunits.     

Ets-1 and Ets-2 protooncogene expression in theca cells of the adult mouse ovary.

We have investigated the mRNA expression of the Ets-1 and Ets-2 genes in murine gonads and found expression in adult ovaries. In situ hybridization experiments show that the Ets genes are predominantly expressed in theca cells and cells of ovarian interstitium. By gel retardation experiments we detected DNA binding proteins in ovaries that specifically bind to the ETS motif, suggesting the expression of Ets or Ets-related proteins. Our results raise the possibility of Ets-2 involvement in ovarian pathology seen in patients with Down's syndrome.     

Impact of mild experimental acidification on short term invertebrate drift in a sensitive British Columbia stream

We report daytime drift behavior of lotic macroinvertebrates following short term (12 h) additions of HCl or HCl plus AlCl₃ to a circumneutral softwater (alkalinity ca. 100 µeq 1^-1) mountain stream in British Columbia, Canada. Addition of HCl (pH reduced from 7.0 to 5.9) resulted in an overall tripling of invertebrate drift density with rapid (< 1 h) increases in chironomid Diptera and Trichoptera. Small Ephemeroptera also entered the drift at high densities, but were delayed about 6 h. Addition of AlCl₃ (0.71 to 0.95 mg 1^-1 total Al³⁺) in HCl (stream pH reduced to 5.9) resulted in an overall 6-fold increase in invertebrate drift, with rapid increases by Ephemeroptera and delayed responses by chironomids and Trichoptera. These results suggest that the behavior of several macroinvertebrates from low alkalinity, unacidified streams can be altered by simulations of short-term, mild acidic deposition events. Further, the magnitude and timing of entry into the drift varies among taxonomic groups with the presence or absence of low concentrations of aluminum ions.     

Bead rings at the endoplasmic reticulum-golgi complex boundary: morphological changes accompanying inihibition of intracellular transport of secretory proteins in arthropod fat body tissue

Golgi complex beads are 10-nm particles arranged in rings on the smooth surface of rough endoplasmic reticulum (ER) makind the forming face of the Golgi complex (GC). In arthropod cells they stain specifically with bismuth. Their morphology has been studied after treatment with reagents known to interfere with GC function. Inhibitors of oxidative phosphorylation (antimycin A, cyanide, and anoxia), but not an inhibitor of glycolysis (iodoacetate), both cause the bead rings to collapse and the GC saccules to round up, and inhibit transition vesicle (TV) formation. Cycloheximide blocks protein synthesis on ribosomes but does not stop TV formation or disrupt bead rings, even after prolonged treatment (6 h) to allow emptying of the rough ER cisternae. Thus the collapse of bead rings is not attributable to inhibition of protein synthesis, and the ring structure of beads does not require continued protein synthesis and secretion for its maintenance. Valinomycin has effects on the GC similar to those of antimycin A, but {"type":"entrez-nucleotide","attrs":{"text":"A23187","term_id":"833253","term_text":"A23187"}}A23187, monensin, and lasalocid do not affect bead ring structure or TV formation. These results are consistent with valinomycin’s secondarily uncoupling mitochondria, which collapses bead rings and prevents TV formation. Thus inhibitors of oxidative phosphorylation do not influence the beads through cation movement. Because mononsin and lasalocid block secretion at the level of the condensing vacuoles, bead rings are not influenced by blocks in secretion distal to them or by the backup of secretory material. These experiments are consistent with inhibitors of oxidative phosphorylation collapsing bead rings by decreasing intracellular ATP. The concomitant block to TV formation and the collapse of bead rings suggests that integrity of the bead rings is essential for the transport of secretory material from the rough ER to the GC.     

The characterization of growth factor activity in human brain

The purification of fibroblast growth factor from bovine brain has been reported (Gospodarowicz, D., Bialecki, H., and Greenberg, G. (1978) J. Biol. Chem. 253, 3736-3743). Westall et al. (Westall, F. C., Lennon, V. A., and Gospodarowicz, D. (1978) Proc. Natl. Acad. Sci. U. S. A. 75, 4675-4678) showed that bovine brain fibroblast growth factor was composed of three fragments derived by limited proteolysis from myelin basic protein. In the present study using similar purification methods, we isolated a fraction enriched in growth factor activity from human brain. The mitogenic activity could not be resolved from myelin basic protein by chromatographic procedures but, upon isoelectric focusing, the mitogen and myelin basic protein were readily dissociated. At least two potent growth factors (pI values 7.2 to 7.4 and 8.1 to 8.6) were identified. Studies of a relatively crude basic extract of human brain suggested that the brain may contain a number of growth factors.