Use of protein G for preparation and characterization of rabbit antibodies against rat adipose tissue hormone-sensitive lipase

The newly described immunoglobulin G-binding streptococcal surface protein, protein G, was used to prepare and characterize rabbit antibodies. The antibodies were directed against rat hormone-sensitive lipase, the rate-limiting enzyme in the hydrolysis of the triacylglycerols stored in adipose tissue. Antiserum was obtained after two injections with 20 micrograms enzyme protein, and the immunoglobulin fraction was obtained using a protein G-based solid-phase radioimmunoassay. The hydrolysis of acylglycerols by the enzyme was inhibited by the antibodies, and the enzyme could be efficiently removed from a solution using the antibodies and heat-killed streptococci expressing surface protein G. By Western blot and detection with 125I-protein G, the antibodies were found to selectively bind to hormone-sensitive lipase and to a smaller extent to two minor contaminants, possibly proteolytic fragments of the lipase. The amount of 125I-labelled protein G bound to the lipase on the blot was quantitatively related to the amount of enzyme protein down to the detection limit 10 ng.     

Studies on cardiac distribution and function of neuropeptide Y

High concentrations of a novel peptide, neuropeptide Y, have been demonstrated in the guinea-pig and canine heart and in the latter, a particularly high concentration was found in the region of the coronary vasculature (126 +/- 31 pmol g-1). Intra-arterial infusion of neuropeptide Y for 30 s into the coronary artery of the intact, innervated dog heart resulted in a rapid and short-lasting reduction of blood flow from 38 +/- 4 to 31 +/- 3 ml min-1 (P less than 0.05) to resume control level, 39 +/- 5 ml min-1, within 5 min. These injections were unaccompanied by changes in heart rate and aortic pressure, while there was an associated small reduction in dP/dt, used as a measure for changes in contractility. In vitro studies using the isolated, paced papillary muscle from cat, guinea-pig and rat, and spontaneously beating right atria from the guinea-pig, demonstrated no effect of NPY on active tension or beating frequency. The results indicate that NPY has vasoconstrictor properties, but under the test circumstances to lack both positive and negative inotropic and chronotropic effects.     

Central hemodynamic effects of adrenaline with special reference to beta 2-adrenergic influence on heart rate and cardiac afterload in anesthetized cats

Central hemodynamic responses evoked by i.v. infusions of adrenaline and noradrenaline were studied in normovolemic anesthetized cats with intact adrenoceptors, after selective beta 2-blockade (ICI 118,551), and after nonselective beta-blockade propranolol). The results demonstrated the presence of an important beta 2-adrenergic component in the integrated response to 'physiological' doses of adrenaline contributing to increased cardiac output, decreased total peripheral resistance and virtually unchanged mean arterial blood pressure. Corresponding beta 2-adrenergic effects of noradrenaline were small. The beta 2-adrenergic effects of adrenaline on the heart seemed to be both direct and indirect. A moderate direct chronotropic response mediated by beta 2-adrenoceptors apparently was present but there was no evidence of a direct beta 2-adrenergic inotropic effect. An indirect, quite marked effect on the heart was accomplished by a beta 2-adrenergic vasodilator interaction with the alpha-adrenergic vasoconstrictor influence on the systemic resistance vessels. This caused a net decrease in total peripheral resistance, thereby preventing an undue increase in cardiac afterload (arterial pressure) which seemed to be essential for evoking 'optimal' increases in cardiac output. It is suggested that such adrenaline evoked indirect, beta 2-adrenergic improvement of cardiac performance is of functional importance in reflex sympatho-adrenal circulatory control.     

Treatment of the mucosa with local anaesthetics in ulcerative colitis

A new paradigm for the treatment of ulcerative colitis has recently been presented: Treatment of the mucosa with lidocaine (2%) enemas for prolonged periods. This therapy was introduced based on the hypothesis that hyperreactive autonomic nerves may play a pathogenetic role in the disease. One hundred consecutive patients have now been treated and the results presented. Theproctitis patients all responded to the treatment, despite previous therapeutic failures in more than two-thirds of the cases. They were treated for 3–12 weeks, but 68% had a relapse (observation period 20 months). Of the 49 patients withproctosigmoiditis, two-thirds had chronic symptoms resistant to previous therapy. One of these patients did not respond to lidocaine, but developed fulminant total colitis. The other patient had therapeutic failure with lidocaine but responded well to subsequent cortisone enemas. The patients were treated until the subsets of T-lymphocytes ( and ) disappeared from the mucosa. This occurred in parallel with symptomatic relief and eventual healing in 83% of the patients after treatment for 6–34 weeks. Of all the patients with proctosigmoiditis, 42% presented with recurrent symptoms (observation period 16 months). Of the 17 patients withleft-sided colitis, all went primarily into remission within 2–4 months, but 23% had a relapse (observation period 13 months). The 6 patients withtotal colitis had symptomatic relief and improvement of histology when treated over 3–8 months. One patient had recurrence after 12 months. Treatment with a local anaesthetic in ulcerative colitis is a new approach to mucosal inflammation. The beneficial effects may be due to blockade of certain neural effects, such as epithelial proliferation and shedding and congestion of the mucosal vasculature, with actions on cells of the immune system.This work was supported by grants from the Swedish MRC (2207, 5520), the Assar Gabrielsson Foundation, and the Ulf Widengren Foundation.     

Effects of conditioned stimulus pre-exposure on human electrodermal conditioning to fear-relevant and fear-irrelevant stimuli

The effects of conditioned stimulus (CS) pre-exposure and fear-relevance of the CS on human Pavlovian electrodermal conditioning were investigated. A differential delayed conditioning paradigm was used with a CS-unconditioned stimulus (US; shock) interval of 8 s. In Experiment 1, 64 subjects were randomized into four groups, two of which received fear-relevant stimuli and the other two fear-irrelevant stimuli. Half of the subjects were pre-exposed to the to-be-CSs and the other half to two not-to-be-CSs, with 15 exposure of each stimulus. During acquisition, subjects received 8 reinforced and 8 nonreinforced CS+ and CS- trials, and during the extinction phase 15 nonreinforced trials of each CS. Pre-exposure to the to-be-CSs retarded conditioning for the first and second interval anticipatory responses (FIRs and SIRs); that is, a latent inhibition effect was demonstrated, although the results for the FIR were inconclusive. The expected effects of fear-relevance were not revealed. Experiment 2 addressed the question whether the long pre-exposure period interfered with the frequently observed "preparedness effect" of higher resistance to extinction to fear-relevant stimuli. The design was similar to that of Experiment 1, but for half of the subjects the acquisition phase was initiated immediately after a short rest period, and for the other half acquisition started after an extended rest period, equal to the duration of the pre-exposure phase in Experiment 1. Twenty extinction trials of each CS were presented. A reliable difference in arousal in terms of spontaneous fluctuations was produced by the rest periods, but although differential conditioning was observed, no effect of fear-relevance was seen during extinction.     

In vitro appearance of large human histamine-containing basophilic cells

The appearance of large human basophilic cells containing histamine was followed to reflect cell maturation in cultures of peripheral blood leukocytes. Aliquots were taken on day 0 and after 7, 9-10 and 14 days in culture, and the basophilic cell numbers were determined in 200 microliter cytospin specimens stained with Wright's stain. The number of small basophils initially present declined during the culture period. The number of spontaneously appearing large basophilic cells varied among the cultures from different individuals and was slightly, though not significantly, higher in atopic individuals than in normals. In cultures of cells from atopic individuals, the number of large basophilic cells was reproducibly increased by the addition of appropriate allergen to the cultures. In cultures of cells from normal individuals, the number was increased two- to six-fold by adding conditioned medium (CM), either from 3-day cultures of cells from atopic individuals stimulated with allergen or with CM from the Mo T cell leukemic line. The addition of mitomycin C decreased the number of large basophilic cells and cycloheximide abrogated their appearance.     

Familial occurrence of histiocytosis.

The clinical and histological findings of four children with lethal histiocytosis are reported. The children belonged to two sibships and originated from a Swedish geographical isolate. Consanguinity between the parents was established for one of the sibships, belonging to a pedigree in which malignant disease occurred in two generations. The observations indicate that the type of histiocytosis investigated is caused by homozygosity for a single recessive gene. The association between histiocytosis and malignancy is discussed.