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Biomedical subjects

J Torres

Publications and source records attributed to J Torres.

At least 19 recordsLinked to original sources
PubMed1992

Sparganum proliferum: an overview of its structure and ultrastructure.

A detailed study of the structure and ultrastructure of Sparganum proliferum was made possible for the first time thanks to the successful in vitro and in vivo maintenance of this rare parasite. Although S. proliferum exhibits many of the classical tegumental and parenchymal structures previously described for other larval cestodes, these are either arranged in a distinct fashion or, in some cases, may be completely different. Among the latter and of special interest are the single or multiple parenchymal cavities, surrounded by tegument, which in some instances appear to act as a primitive digestive tract.

Animals↗
PubMed1992

Sensitivity in culture of epithelial cells from rhesus monkey kidney and human colon carcinoma to toxins A and B from Clostridium difficile.

The effect of toxins A and B from Clostridium difficile on human colon carcinoma cells (HT-29, epithelial), rhesus monkey kidney cells (MA-104, epithelial) and green monkey kidney cells (VERO, fibroblast) was studied. Both toxins caused rounding of HT-29 cells and rounding with projections remaining attached to the substrate in MA-104 and VERO cells; however, the sensitivity to each toxin varies considerably. Toxin A was detected in ng by VERO, pg by HT-29 and fractions of pg by MA-104 cells; for toxin B, pg were detected by VERO, ng by MA-104 and micrograms by HT-29 cells. HT-29 cells were grown with galactose to allow their differentiation to enterocytes, and their sensitivity to the toxins during the process was studied. At early stages, the sensitivity to both toxins was similar, and as the differentiation proceeded, the response to both toxins decreased continuously, and after 16 days no evident morphological effect was observed, even with micrograms amounts of either toxin. In contrast to all cell lines reported to date, HT-29 and MA-104 epithelial cells are exquisitely sensitive to toxin A and less responsive to toxin B. The rounding of HT-29 by these toxins depends on the degree of differentiation of the cell.

Animals↗
PubMed1992

Alpha-adrenoceptors involved on the cardiovascular response induced by mianserin in the pithed rat.

1. The effects of the antidepressant drug mianserin on the cardiovascular responses induced by preganglionic electrical stimulation, and i.v. infusion of the adrenergic agonists noradrenaline (NA, alpha 1 and alpha 2), phenylephrine (alpha 1) and xylazine (alpha 2) in the pithed normotensive rat were studied. 2. Mianserin inhibited in a dose-dependent manner the pressor effect caused by electrical stimulation of spinal cord (Th7-Th9) and the infusion of NA, phenylephrine and xylazine. Cocaine increased the inhibitory effect of mianserin on the pressor effect caused by electrical stimulation and NA. 3. Mianserin blocked the xylazine-induced inhibition of cardiac nerve stimulation effect. 4. These results suggest that mianserin blocks the NA uptake, and it is more effective in blocking presynaptic alpha 2- than postsynaptic alpha-adrenoceptors.

Animals↗
PubMed1992

Gastroprotective and antisecretory effects of ebrotidine.

This study was designed to assess the gastroprotective and secretory effects of ebrotidine, a novel H2-receptor antagonist, in humans. Two groups (A and B) of male subjects with normal gastric mucosa were used. Group A (six subjects) was treated for 3 days with either ebrotidine or placebo in a randomized, crossover study, and on the 4th day 100 ml of 50% ethanol was sprayed on the mucosa via an endoscope. Pretreatment with ebrotidine significantly reduced the endoscopic score of mucosal damage and deep hemorrhagic lesions caused by ethanol as compared with those in placebo-treated subjects. In group B (six subjects) the 24-h pH-metry was assessed with an intraluminal pH electrode placed in the gastric corpus and connected to portable recording apparatus. A single oral dose of ebrotidine (800 mg) caused a significant reduction in circadian acidity and resulted in a marked and significant inhibition of acid secretion for about 6 h on administration. We conclude that ebrotidine is highly effective as a gastroprotective agent, and as an H2-receptor antagonist shows a potent inhibitory effect on gastric acid secretion in humans.

Adult↗
PubMed1992

Gastric acid inhibitory profile of ebrotidine, a novel H2-receptor antagonist in humans.

This study was designed to assess the gastric secretory effects of ebrotidine, a novel H2 receptor antagonist, in humans. Three groups (A, B and C) of male subjects with normal gastric mucosa were used. Group A (6 subjects) was used to determine the dose-dependency of gastric inhibitory effect of ebrotidine on basal and pentagastrin-induced maximal acid output. Group B (8 subjects) was employed to examine the duration of the inhibitory effect of ebrotidine on basal and pentagastrin-induced acid secretion. In group C (6 subjects), the 24h pH-metry was assessed using intraluminal pH-electrode placed in the gastric corpus and connected to a portable recording unit. Single oral dose of ebrotidine (200, 400 or 800 mg) caused a dose-dependent reduction in basal and pentagastrin-induced acid secretion that at a dose of 800 mg amounted to about 89% and 93%, respectively. This inhibition was still observed after 6h and averaged 72% and 50%, respectively. After 12 and 24h upon the drug intake, both basal and pentagastrin-induced acid secretion returned to the control values. Single oral dose of ebrotidine (800 mg) caused a significant reduction in circadian acidity and resulted in a marked and significant reduction of intragastric acidity for about 6h upon the administration. This inhibition was accompanied by a transient increase in basal and postprandial gastrin levels. We conclude that ebrotidine is highly effective inhibitor of basal, pentagastrin-induced and circadian gastric acid secretion in humans.

Administration, Oral↗
PubMed1992

Study on the sensitizing capacity of the new antimycotic sertaconazole in the treatment of cutaneous mycoses.

The sensitizing capacity of 7-chloro-3-[1-(2,4-dichlorophenyl)-2- (1H-imidazol-1-yl)ethoxy-methyl]benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) was studied in a randomized double-blind clinical trial in 78 atopical volunteers of both sexes. Sertaconazole in 2% dermatological cream form was compared with 5 other commercially available antimycotics (econazole, ketoconazole, bifonazole, clotrimazole and miconazole), using the excipient of the cream without sertaconazole and 2% sertaconazole in vaseline as controls. At the end of the trial, only miconazole showed a positive allergy (vesiculation) in two of the 78 individuals studied. The other substances did not demonstrate any sensitizing capacity, including sertaconazole and its excipient. This trial showed that sertaconazole in 2% dermatological cream form does not possess a sensitizing capacity for causing contact dermatitis which confirmed its excellent safety in topical use.

Adolescent↗
PubMed1992

Phase II study of the therapeutic efficacy and safety of the new antimycotic sertaconazole in the treatment of superficial mycoses caused by Candida albicans.

The activity of 7-chloro-3-[1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethoxy-methyl] benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) was studied in a randomized parallel double-blind clinical trial on 20 patients suffering from superficial mycosis caused by Candida albicans (confirmed microscopically and microbiologically). The patients were divided into two groups; one received sertaconazole 1% cream (10 patients) and the other received sertaconazole 2% cream (10 patients), over a period of 28 days. Clinical, microscopic and microbiological parameters were evaluated. Analytical parameters such as the appearance of possible undesirable effects (both local and general) were also monitored. The cure was total for 19 out of the 20 patients, demonstrating high efficacy. There were no relapses of infection in any of the cured patients. No local or general effects were recorded during the trial. The analytical parameters remained within normal limits. The clinical and microbiological cure, absence of relapses and the non-existence of local and general undesirable effects indicate that sertaconazole may represent an important advance in the therapy of superficial mycosis caused by Candida albicans.

Adult↗
PubMed1992

Therapeutic efficacy and safety of the new antimycotic sertaconazole in the treatment of cutaneous dermatophytosis.

7-Chloro-3-[1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethoxy-methyl] benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) is a new antimycotic which, in experimental infection studies, proved to possess potent antifungal activity. In a randomized, parallel, double-blind trial, the activity of sertaconazole cream was studied in 20 patients suffering from superficial mycoses caused by dermatophytes, confirmed by microscopic examination (KOH) and culture test. The patients, who were included in accordance with microbiological, microscopic and clinical criteria, were divided into two groups of 10 and were treated with sertaconazole 1% or sertaconazole 2% (cream) twice a day for 28 days. Both treatments achieved a total cure of the disease, with a cure being reached in a shorter time in the group of patients treated with sertaconazole 2%. No undesirable effects or statistically significant changes in the blood tests conducted at the end of the trial were observed. The results of the trial show that sertaconazole 2% cream is more effective. In view of the advantages offered by topical therapy over systemic therapy and of the good results obtained in patients with dermatophytosis, sertaconazole may represent an important advance in the therapy of superficial dermatophytoses.

Adult↗
PubMed1992

Therapeutic efficacy and safety of the new antimycotic sertaconazole in the treatment of Pityriasis versicolor.

The activity of 7-chloro-3-[1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl) ethoxy-methyl]benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32,2) was studied in a randomized parallel double-blind clinical trial on 21 patients suffering from Pityriasis versicolor (confirmed by KOH microscopic examination and exploration with Wood's light). The patients were divided into two treatment groups: one with 11 patients receiving sertaconazole 1% cream and the other with 10 patients receiving sertaconazole 2% cream. The cream was applied twice a day during 4 weeks. The data were assessed clinically and microscopically (optical and fluorescence). All the patients were cured (100% cure), showing excellent efficacy. A check-up performed after the end of the treatment showed no relapses of infection. The drug safety was optimum, since no local or general undesirable effects were recorded, nor were there any changes in the analytical parameters studied in the 21 patients. Because of its high antifungal activity and excellent safety, sertaconazole represents an important advance in the topical therapy of this disease.

Adult↗
PubMed1991

Two-neurons network. I. Integrate and fire pacemaker models.

The behavior of two pacemakers simulated by integrate and fire oscillators reciprocally connected by synapses is studied. The activation of each synapse produces a sudden potential shift in the post-synaptic neuron. Two sorts of behaviour may occur when at least one synapse is excitatory. Phase-locking occurs for almost every set of parameters, and given certain initial conditions. Repetitive patterns in indifferent equilibrium appear in the presence of a given set of parameters and certain other initial conditions. Quasi-periodic behaviour corresponds to almost every set of parameters when both synapses are inhibitory, although repetitive patterns of firing in indifferent equilibrium occassionally occur.

Biological Clocks↗
PubMed1991

Helminthfauna of Microtus (Microtus) cabrerae (Thomas, 1906) (Rodentia: Arvicolidae) in the Iberian peninsula: faunistic and ecological considerations.

Faunistic and ecological study of parasitic helminths of Microtus (Microtus) cabrerae (Thomas, 1906) (Rodentia: Arvicolidae) in the Iberian Peninsula. 70 specimens have been dissected, coming from 8 enclaves located in three Spanish provinces; 6 species of helminths have been detected (1 Digenetic Trematode, 4 Cestodes and 1 Nematode). Structure of helminthfauna of M. (M.) cabrerae in relation to remaining Iberian Arvicolids and the most conditioning ecological factors of the helminthfauna of the Rodent are analyzed.

Animals↗
PubMed1991

Enterotoxigenic Escherichia coli associated with infant diarrhoea in Galicia, north-western Spain.

To assess the role of enterotoxigenic Escherichia coli (ETEC) in infantile diarrhoea, 482 children with diarrhoea and 103 healthy controls, from three localities of Galicia, north-western Spain, were investigated between 1985 and 1988. Rotavirus (37.3%) and Salmonella spp. (12.8%) were the most common causal agents, followed by ETEC (3.9%), Campylobacter jejuni (2.3%), Shigella spp. (0.9%) and Yersinia enterocolitica (0.5%). ETEC were significantly more frequently isolated from children with diarrhoea who were under 1 month of age (26.5%) than from older diarrhoeic children (2.2%) (p less than 0.001) or from healthy children who were under 1 month of age (0%) (p less than 0.05). Among children who harboured ETEC, five of the nine children under 1 month of age developed diarrhoea in hospital, whereas none of the 10 children over 1 month of age did so. Seventeen ETEC isolates produced heat-stable enterotoxin (STa) only, four produced only heat-labile enterotoxin (LT), and two produced both toxins. Colonisation factor antigens CFA/I and CFA/II were detected in 11 (55.0%) of the 20 ETEC isolates that remained enterotoxigenic after maintenance in the laboratory. Most ETEC isolates belonged to serotypes O153:K-:H45 (nine STa+ CFA/I+ isolates), O27:K-:H7 (three STa+ isolates) or O6:K15:H16 (two LT+ STa+ CFA/II+ isolates). Our results suggest that ETEC constitute an important cause of neonatal diarrhoea in this part of Spain.

Antigens, Bacterial↗
PubMed1991

Clostridium difficile toxin A induces a specific antisecretory factor which protects against intestinal mucosal damage.

Peroral challenge with toxin A from Clostridium difficile induced the formation of antisecretory factor in rats. The animals were given 100 micrograms of the toxin, which was followed by a pronounced diarrhoea and by the appearance of antisecretory factor in the pituitary gland. In electrofocusing, the induced antisecretory factor separated in two peaks (pI 5.4 and 5.0); both fractions showed a lectin-like binding to agarose. The pI 5.4 fraction inhibited cholera toxin as well as toxin A induced fluid secretion, while pI 5.0 inhibited toxin A induced secretion only. Immunohistochemistry showed that an antisecretory factor of pI 5.0 protected the mucosa from the cytotoxic effect of toxin A, but did not affect the binding of toxin A to the intestinal epithelium. Sodium dodecyl-sulphate-polyacrylamide gel electrophoresis of the pI 5.0 protein showed two major fractions to be present, one of molecular weight 60 kDa, the other of 30 kDa, the latter probably being a degradation product of the former.

Animals↗
PubMed1991

Characterization of T- and B-cell epitopes of a simian retrovirus (SRV-2) envelope protein.

Synthetic envelope peptides of a simian retrovirus (SRV-2) were used to define both T- and B-cell epitopes of the envelope protein. The SRV-2 peptide 100-106 specifically blocks rhesus anti-SRV-2 neutralizing antibody activity, and a peptide 100-106 keyhole limpet hemocyanin conjugate induces a strong antipeptide antibody response. SRV-2 peptide 100-106 and 233-249 induces good T-cell proliferation of murine spleen cells immunized with the SRV-2 virus. Thus, SRV-2 envelope peptide 100-106 represents both a T- and B-cell epitope, and peptide 233-249 a T-cell epitope.

Amino Acid Sequence↗
PubMed1979

Single and divided doses of penbutolol.

Penbutolol, a nonselective beta-adrenoreceptor antagonist, induced reduction of exercise-induced heartbeats for at least 24 hr after a single 40-mg oral dose, and was equipotent with respect to a 2 X 20-mg regimen over the same period. Ingestion for 7 days did not influence the pharmacodynamics or pharmacokinetics of penbutolol, and there was no cumulation of drug in serum. A relationship was found between the logarithms of measurable serum concentrations of penbutolol and the percentage reduction of total heartbeats. Absorption of oral penbutolol appeared to be reduced when administered in the evening. Since beta-adrenoceptor activity was relatively unchanged between 13 and 24 hr after a single 40-mg dose of penbutolol, there is a possibility that an active metabolite or metabolites may contribute to prolonged duration of action.

Adult↗
PubMed1978

Analysis of intestinal cell proliferation after guanethidine-induced sympathectomy. I. Stathmokinetic, labelling index, mitotic index, and cellular migration studies.

Guanethidine-induced sympathectomy in the rat during the neonatal period (injection of 20 microgram/g body weight every 48 h from day of birth until day 14) produces an absolute reduction in the number of sympathetic ganglion cells, but no significant alteration of body weight. Superior cervical ganglia show 79.8% fewer cell bodies at 15 days and 92.3% at 45 days; coeliac ganglia exhibit an 81.0% reduction at 15 days and 89.6% at 45 days in guanethidine-treated rats as compared to normal controls. The sympathetic ganglion cells that remain after treatment have an abnormal morphological appearance with distended mitochondria and depletion of endoplasmic reticulum. Sympathectomy produces a prolongation of the generation cycle time (Tc) as measured by the colchicine-induced mitotic arrest technique, and a decrease in labelling, mitotic, and migration indices. In addition, sympathectomy suppresses the amplitude of the circadian rhythm in mitotic activity. The general suppression of this activity in the intestinal epithelium is more pronounced in the jejunum and ileum than in the duodenum. Variation in the effectiveness of sympathectomy on the inhibition of intestinal cell proliferation may be related to segmental differences in cell proliferation, to segmental differences in innervation, and/or to segmental variation in the effectiveness of guanethidine.

Animals↗
PubMed1978

Plasma cortisol levels in normal volunteers receiving either betamethasone valerate or desoximetasone by topical application.

Desoximetasone (Topisolon; Hoechst), a new topical steroid, and betamethasone 17-valerate were compared with respect to their effects on hypothalamic-pituitary-adrenal function as evidenced by plasma cortisol concentrations. Three grams of each test preparation were applied daily for 21 days to intact skin of the ventral aspects of alternate forearms of 15 normal volunteers. Five received betamethasone 17-valerate 0.1%, 5 desoximetasone 0.05%, and 5 desoximetasone 0.25%. Plasma cortisol levels were determined before and after the initial applications on days 1, 3, 10, 17, 22, 24 and 28. These values were compared with the mean control values by analysis of covariance. There was no significant difference in plasma cortisol levels. The value of performing similar studies on larger skin areas and with larger doses is discussed.

Administration, Topical↗