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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 667 records · Page 37Linked to original sources

Effects of sulindac on myeloid precursors growth in vitro.

We have studied the effects of sulindac and its main active metabolites on human bone marrow progenitors. Granulocytic-macrophagic colony forming units (CFU-GM) techniques were used for assessment. As in vitro inhibitory action of this drug or its metabolites on CFU-GM growth could not be demonstrated. These results refute the clinically presumed toxicity of sulindac on human bone marrow progenitors at pharmacological doses.

Bone Marrow↗

Cholinergic mechanisms in intestinal phase insulin secretion in rats.

The present study was designed to examine the role of neural cholinergic mechanisms in intestinal phase insulin secretion during increasing intraduodenal instillation rates of the test meals. In groups of 12 anesthetized rats arterial insulin levels rose significantly in relation to the increase of the rate at which the liver extract/sucrose was instilled intraduodenally (0.15, 0.5 and 1.5 ml/min). The injection of atropine (10 micrograms/kg) 5 min prior to the intraduodenal infusion of the test meals abolished this rate-dependent augmentation of insulin levels completely. Similarly, no effect of increasing intraduodenal infusion rates of the meal was observed in islet-transplanted rats. These data demonstrate that neural - at least in part muscarinic cholinergic - mechanisms participate in intestinal phase insulin secretion of rats supporting previous observations about the importance of neural factors in the regulation of postprandial insulin release.

Acetylcholine↗

Effects of aldosterone and deoxycorticosterone on food intake and body weight.

Aldosterone (.25 mg/kg) or deoxycorticosterone (3 mg/kg) in combination with corticosterone was administered daily to female adrenalectomized rats. The mineralocorticoids increased food intake and weight gain well beyond that of controls receiving only corticosterone injections. The weight gain was not wholly dependent on increased food intake, as separate groups of animals maintained on a restricted (10 g of laboratory chow/day) diet also displayed significant mineralocorticoid-stimulated weight gain. Although carcass composition was not directly determined, the undifferentiated wet/dry tissue ratios, hematocrit values, and nasoanal lengths found across groups suggest that the observed effect of mineralocorticoids was on body fat. Aldosterone and deoxycorticosterone can have important actions on energy metabolism as well as on sodium regulation.

Aldosterone↗

Acute respiratory failure and tracheal obstruction in patients with intrathoracic goiter.

Four cases of acute life-threatening tracheal obstruction due to intrathoracic goiter are reported. Acute respiratory insufficiency caused by an upper airway obstruction in patients with intrathoracic goiter is exceptional. In 3 of 4 cases reported, the histologic study showed multiple foci of recent hemorrhage, the mechanism probably responsible for these episodes.

Adult↗

Activation of BCL1 cells by polyclonal activators and inhibition of growth and IgM secretion by anti-IgM.

Bacterial lipoprotein (LP) and lipopolysaccharide (LPS) both activated an in vitro line of the B-cell tumour BCL1 to IgM secretion, as determined by the protein A plaque assay. LPS but not LP activation was inhibited by polymyxin B. Activation with both LPS and LP resulted in a less than additive response. Several clones of BCL1 were tested, and all responded to both LPS and LP. Both LPS and LP induced broad dose-response curves in normal lymphocytes, recently cloned BCL1 cells, and cloned and synchronized (G1 phase) BCL1 cells. This suggests that the dose-response curve cannot be due to accumulation of responding cells with different threshold sensitivities for activation. We cannot exclude the possibility that the broad dose-response curve is due to a heterogeneity of the LPS or LP preparation. The results indicate that LPS and LP induce similar signals in BCL1 cells. Furthermore, binding to the cell membrane and activation of BCL1 cells by LPS or LP seem to be separate events. An anti-IgM antiserum inhibited spontaneous DNA synthesis and spontaneous and LP-induced IgM secretion of BCL1 cells. Equal inhibition was observed with F(ab')2 fragments but not with Fab fragments of the antiserum, suggesting that cross-linking of IgM bound to the cell surface membrane-induced inhibition. Supernatants from concanavalin A (Con A)-activated spleen cells induced BCL1 cells to secrete IgM. Fab anti-IgM added alone to BCL1 cells did not induce IgM secretion. Furthermore, Fab anti-IgM plus Con A supernatant did not induce a higher response than the supernatant alone. This suggests that inductive signals via the IgM receptor do not occur in BCL1 cells.

Animals↗

Lack of in vitro colony formation in a patient with severe aplastic anemia after spontaneous autologous hematologic reconstitution.

A case of idiopathic severe aplastic anemia with spontaneous complete remission is described. Hematologic parameters normalized spontaneously 94 days after onset. However, the ability of the patient's bone marrow cells to form granulocytic-macrophagic colony-forming units (CFU-GM) or erythroid burst-forming units (BFU-E) was depressed until the 288th day, in spite of the normalization of blood counts. Incubation of the patient's bone marrow cells with antilymphocytic globulin prior to the culture experiment normalized the number of CFU-GM and BFU-E in correlated studies. Coculture of a target marrow with several concentrations of the patient's lymphocytes or serum resulted in a complete inhibition of CFU-GM. BFU-E growth was inhibited by the patient's lymphocytes, but not by serum, which rather showed burst-promoting activity. The inhibitory effect on target bone marrow persisted for 288 days, when it disappeared concomitantly with the restoration of spontaneous CFU-GM and BFU-E growth.

Anemia, Aplastic↗