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Biomedical subjects

A Montero

Publications and source records attributed to A Montero.

At least 91 records · Page 5Linked to original sources

[Fetal cystic neuroblastoma].

Neuroblastoma is the most common malignant solid tumor in infants less than 1 year old. A case of adrenal cystic neuroblastoma detected by ultrasound in the 37 th week of pregnancy, is reported. The sonographic features of fetal neuroblastoma range from solid to cystic or complex lesions. Early detection of the tumor by prenatal ultrasound permits prompt neonatal treatment and a better outcome.

Adrenal Gland Neoplasms↗

A role for platelet-activating factor in endothelin-1-induced rat mesangial cell proliferation.

Endothelin-1 stimulated the release of bioassayable platelet-activating factor-like material and the incorporation of acetate to PAF in rat mesangial cells, in a dose-dependent manner, with an EC50 of about 10(-9) M. Endothelin-1 also stimulated dose dependently [3H]thymidine incorporation into DNA, protein synthesis and cell growth. The platelet-activating factor antagonists BN-52021 (10(-5) M), and alprazolam (10(-5) M), reduced significantly endothelin-1-stimulated thymidine incorporation into DNA, protein synthesis and cell growth. Platelet-activating factor also stimulated significantly thymidine incorporation into DNA, cell proliferation and protein synthesis. In conclusion, the present results suggest that endothelin-1 induces mesangial cell proliferation through a mechanism involving among others, synthesis and release of platelet-activating factor by these cells.

Animals↗

Nicotinic cholinergic influences in pancreatic secretion induced by intraduodenal alkaline and acid solutions in the rabbit.

1. The effect of hexamethonium on the exocrine pancreatic response to intraduodenal acidification and alkalinization, and the secretin and VIP release after these stimuli, was studied. 2. The hydroelectrolyte secretion after hydrochloric acid and sodium carbonate perfusion was reduced by hexamethonium treated (322 +/- 44% of maximum response in flow rate to sodium carbonate perfusion in untreated animals vs 140 +/- 12% in pretreated animals, and 252 +/- 19% of maximum response in flow rate to HCl in untreated animals vs 166 +/- 11% in pretreated animals). 3. However, hexamethonium has no effect on secretin plasma levels after either intraduodenal acidification or alkalinization. 4. On the contrary, the ganglion blocker significantly (P < 0.01) reduced plasma VIP levels in response to intraduodenal HCl (maximum response 320 +/- 74% in untreated vs 184 +/- 44% in hexamethonium-treated animals). 5. Plasma VIP levels showed a similar increase in both untreated (maximum response: 151 +/- 12%) and ganglion blocked animals (170 +/- 26%) in response to sodium carbonate. 6. These data suggest the existence of complex neural mechanisms in the exocrine pancreatic response to intraduodenal stimuli, these mechanisms being different depending on the intraduodenal stimulus.

Acids↗

Effect of ouabain and hypothalamic, hypophysary inhibitory factor on rat mesangial cell proliferation.

The mitogenic effect of a low-molecular-weight, Na+,K(+)-ATPase inhibitory factor isolated from bovine hypothalamus and hypophysis (hypothalamic hypophysary inhibitory factor, HHIF) and ouabain on cultured rat mesangial cells was examined. Ouabain induced a potent stimulation of the [3H]thymidine incorporation to DNA, ranging from threefold for a dose of 10(-7) M to seven times for 10(-5) M. The amount of proteins per well also increased in a dose-dependent way, which was already significant from basal values for the lower dose used. HHIF also induced a dose-dependent stimulation of [3H]thymidine incorporation into DNA, ranging from 1.7 times for a concentration of 0.02 U/ml to 4.5 times for the concentration of 2 U/ml. The amount of protein per well also increased with HHIF, but the increase was significant only for the higher dose used. These data allow us to conclude that HHIF could play a role in the vascular hypertrophy that is associated with the pathogenesis of hypertension.

Animals↗

Urinary solute transport by ileal segments. I. Effects of nicotinic acid.

This study was conducted to quantify urinary solute transport by the ileum, using an in vivo human model, and to determine the effect of nicotinic acid on this process. Patients were studied under both basal conditions and niacin therapy. The rates of solute transport were established by analysis of excretion indexes for each solute. Potassium and ammonium were absorbed by the ileum, while phosphorus, sodium and bicarbonate were secreted. The percentage excretion index of sodium and bicarbonate increased by approximately 100 and 600% respectively, causing a significant rise in urinary pH. Although not statistically significant, there was a tendency for chloride to be absorbed and for water to pass into the bowel lumen. Nicotinic acid 3 g/day had no significant effect on urinary solute transport.

Ammonia↗

[Medical handling of the tubal pregnancy: results].

We report the outcome of the treatment with intratubal methotrexate (25 mg) administered via laparoscopy in 8 patients with ectopic pregnancy who where treated according to a preestablished protocol. A successful treatment was achieved in 6 patients (75%). Hysterosalpingography was performed in 5 of the patients, and in 4 of them we found bilateral tubal patency. Currently 3 patients have a normal intrauterine pregnancy.

Adult↗

Mechanisms involved in the control of exocrine pancreatic secretion in the interdigestive state in the rabbit.

The effect of rapid wash-out of the duodenum with phosphate buffered saline on exocrine pancreatic secretion and plasma levels of secretin, VIP, gastrin and CCK was studied. Furthermore, the possible nervous role in this effect was checked after atropine and hexamethonium treatment. Rapid wash-out significantly increased protein output (35.0 micrograms/min, in the control group without duodenal perfusion and 72.15 micrograms/min, in the perfused group) and the plasma levels of CCK (from 5.2 to 13.17 fmol/ml). Intravenous infusion of atropine significantly reduced the protein output (from 78.19 to 32.45 micrograms/min) and the plasma levels of CCK (from 10.1 to 5.55 fmol/ml), with no change in the remaining parameters in the intraduodenally perfused group. Intravenous administration of hexamethonium significantly stimulated hydroelectrolyte secretion (from 6.99 to 15.15 microliters/min) and the plasma levels of VIP (from 4.8 to 7.3 fmol/ml) and reduced the protein output (from 61.47 to 30.75 micrograms/min) and the plasma levels of CCK (from 14.56 to 6.25 fmol/ml) in the intraduodenally perfused group. Our results suggest that, in the interdigestive state, the exocrine pancreatic secretion of the rabbit is tonically inhibited. This inhibition can be divided into two different mechanisms: on the one hand there is a decrease in enzyme secretion produced by a duodenal factor and mediated by CCK and muscarinic mechanisms and on the other, there is an inhibition of hydroelectrolyte secretion with no duodenal participation which is probably controlled by nervous non-muscarinic mechanisms and VIP involvement.

Animals↗

[Orthotopic heart transplant. Study of early morbimortality (< or = 30 days). Experience at the Reina Sofía Hospital (Córdoba)].

From may 1986 to december 1991, we have performed 90 heart transplantation in the Hospital "Reina Sofía" from Córdoba. In the present study we analyze the early morbidity and mortality in a retrospective study on complications and factors determining its incidence. Seventy patients were male (86%) and 13 female (14%). Age ranged from 12 and 65 years. The 31% of patients needed in pharmacological support before transplantation, 15 of them were operated in a emergency situation because of cardiogenic shock. The pulmonary resistances oscillated between 0.5 and 8.7 units/m2 (Wood) (mean 2.5 +/- 1.4 units/m2). The mean time of ischaemia was 136 +/- 38 minutes (range 5-255 min). Hospital mortality (< or = 30 days) was 8.8% (8/90). No predictive factors from donor and recipient were found. Three main influences on complications were analyzed: a) influence of myocardial temperature, b) role of hematic cardioplegia, and c) usefulness of Aprotinin. Eighteen patients (20%) developed severe bradyarrhythmia needing a pacemaker in the post-operative period. We found a significant relationship with myocardial temperature (4.3 +/- 2.1 vs 6.2 +/- 2.6; p < 0.05) and transport solution temperature (5.8 +/- 2.3 vs 7.3 +/- 1.9; p < 0.05). No significant influence was found on the time of ischaemia, previous heart disease, previous treatment with Amiodarona, clinical condition, etc.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

The activation antigen CD69 is selectively expressed on CD8+ endomyocardium infiltrating T lymphocytes in human rejecting heart allografts.

We analyzed the presence of T-cell subsets (CD4/CD8) and the activation markers CD25 and CD69 in the cellular infiltrates of endomyocardium biopsies taken from transplanted human hearts. The results indicate that CD25 was present within specimens mainly infiltrated by CD4+ cells. In contrast, CD69 was found in infiltrated biopsies by CD8+ cells, as determined by single immunofluorescence. Double immunoenzymatic staining was used to investigate the cellular distribution of the activation markers studied in some representative cases. Thus, CD25 was found on both CD4+ and CD8+ cells while CD69 molecule was selectively expressed on CD8+ T-cell subset. These results suggest that CD69 is a surface molecule relevant to the CD8+ cell-mediated graft rejection events of allografted human hearts.

Antigens, CD↗

Cholinergic mechanisms for secretin release after intraduodenal alkalinization in the anaesthetized rabbit.

Exocrine pancreatic response to duodenal perfusion with alkaline solutions (pH 11.4) was studied in the anaesthetized rabbit; secretin and vasoactive intestinal polypeptide (VIP) levels in portal plasma were measured and the contribution of cholinergic mechanisms was also evaluated. Intraduodenal perfusion of sodium carbonate stimulated flow rate and bicarbonate output to a maximum of 322 +/- 44 and 609 +/- 105% respectively compared with basal levels. Significant increases of plasma secretin levels, with a maximum of 267 +/- 38% as compared with basal, were also observed. A lower increase in VIP levels (maximum of 151 +/- 12%) was seen. All these effects, except the VIP response, were substantially inhibited by atropine. Our results show that exocrine pancreatic response to intraduodenal sodium carbonate is specifically focused on hydroelectrolytic secretion. Keeping in mind what occurs after intraduodenal alkaline phosphate buffer administration (at the same pH as sodium carbonate: 11.4) it seems that about 50% of the pancreatic response to sodium carbonate may be ascribed to pH and the remaining 50% to the carbonate anion. Moreover, this response would mainly be mediated by secretin, whose release can be facilitated by a cholinergic reflex.

Alkalies↗

[The medical management of tubal pregnancy. Preliminary experience].

We present 3 cases of tubal pregnancy treated with methotrexate. According to the success that we have been obtaining, and the reports of the literature, we propose a local protocol of management of the unruptured tubal pregnancy using a single injection of intratubal methotrexate.

Adult↗

Characterization of the nuclear receptors of triiodothyronine (T3) by immunocytochemistry under electron microscopy.

By immunocytochemical methods, using colloidal gold particles coupled to antibodies, it is possible to label the occupied nuclear T3 receptors and observe them by electron microscopy. We carried out some experiments to validate these methods by testing the absence of non-specific binding of the antibodies to subcellular structures different from the T3 receptors. So, we have verified that the number of occupied T3 receptors in tissues from normal rats is lower in kidney cells than in heart and liver ones, a finding which is an agreement with data reported by others. The occupation of the receptors increases after T3 administration and decreases by triiodothyroacetic acid (Triac) administration to the rats, due to the displacement of T3 from the receptors with the latter. Our results are similar to those of the other authors using radioactive tracers. Non-specific binding was not detected. The occupied T3 receptors labelled with colloidal gold particles are located most commonly in the hetero/euchromatin interface. From our results we conclude that the colloidal gold particles observed by electron microscopy specifically label occupied T3 receptors, and the determination of the thyroid status at cellular level can be achieved using electron microscopy after labelling the receptors by immunocytochemistry with colloidal gold particles coupled to antibodies.

Animals↗

[Systemic lupus erythematosus and AIDS. Difficulties in the differential diagnosis].

AIDS and systemic lupus erythematosus (SLE) share clinical and laboratory features that may difficult a differential diagnosis. We report five patients who presented diagnostic problems, two of them with SLE diagnosis and HIV-1 false-reactive screening tests, and the other three with AIDS diagnosis and clinical features fulfilling four or more ARA-clinical criteria for the diagnosis of SLE. It is recommended that tests for HIV-1 antibodies in patients with symptoms of SLE, be carried out by at least three different methods, with direct HIV-1 antigen detection as final confirmatory technique. On the other hand, as also proposed for Sjogren syndrome, the presence of HIV-1 or its antigens, established through cell-cultures or direct blood detection, should be considered as exclusion criteria for SLE diagnosis.

Acquired Immunodeficiency Syndrome↗