Beta 1 and beta 2 adrenergic agonists in exocrine pancreatic secretion in the rabbit

The effect of Dobutamine (a beta 1-adrenergic agonist) and Terbutaline (a beta 2-adrenergic agonist) on exocrine pancreatic secretion was studied in anaesthetized rabbits, simultaneously controlling pancreatic blood flow and blood pressure. The secretion of fluid and ions (bicarbonate, sodium and potassium) was unaffected by the infusion of Dobutamine (8 micrograms.kg-1.min-1) or Terbutaline (10 micrograms.kg-1.min-1). Neither were pancreatic blood flow or mean blood pressure altered. Dobutamine or Terbutaline depress the function of the acinar cells, amylase secretion being more affected by the action of Terbutaline. The results show that beta 1 and beta 2-adrenergic stimulation has no effect on the ductular cells but does decrease the secretion by the acinar cells.     

Plasmid content in Yersinia pestis strains of different origin

Plasmid content in 242 Yersinia pestis strains from various natural plague foci of the U.S.S.R. and other countries was studied. Of these strains, 172 (71%) were shown to carry three plasmids described previously of about 6, 45-50 and 60 MDa, respectively. Twenty strains (8%) from different foci harboured additional cryptic plasmids, most often of about 20 mDa in size. Plasmid pPst displayed considerable constancy of its molecular mass. On the contrary, size variations of pCad (45-49 MDa) and, especially, pFra (60-190 MDa) were found. Molecular mass of these plasmids correlated with the host strain origin.     

Detection of a soluble serum antigen by a new monoclonal antibody ED8 in patients with breast cancer

A murine hybridoma, secreting monoclonal antibody ED8, was generated by immunization with the breast cancer cell line H466B. ED8 reacts with a 300 kDa antigen present on H466B cell surface. The antigen can be detected in serum from breast cancer patients, using ELISA and immunoblotting.     

Isolation and characterization of phage F9-11 from a lysogenicDeleya halophila strain

Thirty-eight strains ofDeleya halophila species were examined for production of phage after mitomycin C induction. Thirty-two of them were able to inhibit growth of some other strains. Phage F9-11, isolated fromD. halophila strain F9-11, showed an isometric head and a noncontractile tail. The effects of salt concentrations variation on the stability and replication of this phage were established. Its replication was possible at a wide range of marine salt concentrations, from 2.5% to 15% (wt/vol). Stability seems to be influenced by osmolarity of medium rather than by NaCl level. The euryhaline character showed by F9-11 phage is evoked as an important factor for the survival of this phage in its environment.     

Response of exocrine pancreatic secretion to CCK in adrenalectomized rats

A study was made of the effect of adrenalectomy over different periods of time (6, 15 and 21 days) on exocrine pancreatic secretion in the rat in basal conditions and under stimulation with CCK. It was observed that adrenalectomy does not alter the rate of pancreatic flow but the response capacity to CCK is depressed. The secretion of total protein and amylase decreases significantly after sixth day, reaching the lowest levels after 21 days. Despite this, after 6 days the adrenalectomized rats showed the same capacity of response to CCK as the non-adrenalectomized animals, while after longer periods of time (15 and 21 days) the response to CCK was inhibited. The fact that the lack of glucocorticoids prevents the maturation of zymogen granules seems to be the main reason why the acinar cells do not increase protein secretion in response to CCK at 15 and 21 days after adrenalectomy. It is concluded that the sensitivity of exocrine pancreas to CCK and the amount of zymogen granules in the acinar cells decrease as a function of the time over which the animals are deprived of glucocorticoids.     

Alterations of pancreatic juice amylase by glucocorticoid levels in the rat

By use of isoelectrofocusing, three isoenzymes with pIs of 8.40, 8.55, and 8.65 were characterized in the amylase fraction of rat pancreatic juice. Enzyme secretion in rat exocrine pancreas is affected by glucocorticoid levels; adrenalectomy led to a significant decrease in protein secretion which was more pronounced in the amylase fraction, in which the isoenzymes with pI 8.55 and 8.65 disappeared. Substitution therapy with hydrocortisone (25 mg/kg/day, for 6 days) restored exocrine pancreatic secretion to almost normal levels. Administration of hydrocortisone to control rats led to structural alterations in enzymes secreted, splitting the amylase isoenzymes with pI 8.40; this was confirmed by crossed immunoelectrophoresis. It is concluded that glucocorticoid levels play an important role in the maintenance of function of exocrine pancreas and it is suggested that, although hydrocortisone fulfills the objective of restoring enzyme secretion diminished by adrenalectomy, it is possible that intensive treatment could have undesirable effects on the structure of enzymes and could involve pancreatic disfunctionality.     

Woronin bodies in arthrinium genus

Woronin bodies are present near all septal pores and in conidia of Arthrinium strains and may regulate cytoplasmic flow in both injured and actively growing healthy colonies. They vary in size and frequency, the central one plugs the septal pores in actively developing colonies and in mature conidia. The septa are thinner in the Woronin-body region.     

Autoradiographic study on [3H]flunitrazepam binding in rat cortex and hippocampus after chronic ethanol treatment

Ethanol alters almost all membrane functions, but it behaves essentially like a benzodiazepine-type GABAergic agonist. The mechanism by which ethanol affects the GABA/benzodiazepine complex is not clear. We studied the possible changes in [³H]flunitrazepam binding induced by chronic ethanol treatment, using light microscopic autoradiography, to try to elucidate the controversy underlying this topic. This technique allows us to measure densities of benzodiazepine receptors in different anatomical brain areas—visual cortex and hippocampus—which seem to constitute the anatomical support for the behavioral and physiological responses affected by ethanol. Autoradiographic studies on the visual cortex and hippocampus from rats chronically treated with ethanol do not show statistically significant differences in the binding of, [³H]flunitrazepam with respect to control animals. Furthermore, we did not find either rostro-caudal or medio-lateral differences, in benzodiazepine receptor densities in each layer of the visual cortex.