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Biomedical subjects

J Torres

Publications and source records attributed to J Torres.

At least 163 records · Page 9Linked to original sources
PubMed1993

Production of cytotoxins and enterotoxins by strains of Shigella and Salmonella isolated from children with bloody diarrhea.

The role of toxins in the pathogenesis of bloody diarrhea caused by Shigella and Salmonella isolated from children with bloody diarrhea was studied for production of toxins active on cells in culture and in rat intestinal loops. Human epithelial cells from colon carcinoma (HT-29), Chinese hamster ovary cells (CHO) and kidney fibroblast from rhesus monkey (Vero) were used to detect cytotoxins. On HT-29 almost 50% of the Shigella and about 20% of the Salmonella strains caused rounding of cells; on CHO over 50% of Salmonella and 20% of Shigella strains caused elongation of cells, some strains caused also rounding of these cells whereas on Vero over 60% of Salmonella and 40% of Shigella strains caused rounding of cells. Cytotoxicity on Vero and CHO cells was strongly inhibited with cholera toxin antiserum, whereas that on HT-29 was inhibited with C. difficile toxin B antiserum. Cytotonic activity on CHO cells and rounding on Vero cells seem to be suitable models to detect toxins cross-reacting with cholera toxin. Both species, Shigella and Salmonella, produce cytotoxins and enterotoxins which could play a role in intestinal disease.

Animals↗
PubMed1993

Antisecretory activity in a lectin fraction of plasma from patients with acute diarrhea.

The present study describes the first attempt to detect antisecretory activity in a lectin fraction of plasma from patients with acute diarrhea. The plasma antisecretory protein (ASP) was purified by affinity chromatography in agarose, and its antisecretory activity tested in rats subjected to intestinal challenge with cholera toxin. During the first 24 h of the diarrheal episode, antisecretory activity in patients (median 0, range 0-25%) was lower than that seen in the asymptomatic group (median 10, range 0-30%); 3 days later, when diarrhea ceased in most of the patients, the ASP activity increased significantly (median 30, range 0-75%). However, 5 days later the activity decreased again (median 0, range 0-55%). No differences in ASP levels were found between cases associated with an enteropathogen and those where no pathogen was identified. These findings reveal an inverse relationship between the increase in ASP and the patient's intestinal secretion; suggesting that ASP plays a role in the compensatory mechanisms that occur in diarrhea in humans.

Acute Disease↗
PubMed1993

Bone morphology after bone marrow transplantation for Hodgkin's and non-Hodgkin's lymphoma.

The osteogenic consequences of bone marrow ablation followed by bone marrow transplantation for Hodgkin's and non-Hodgkin's lymphoma were examined. Pre- and post-transplantation iliac crest bone biopsies were reviewed for all patients undergoing transplantation at the Johns Hopkins Oncology Center between January 1981 and December 1989. Histomorphometric measurements included percentage of filled trabecular lacunae to estimate osteocyte viability, marrow cellularity and marrow fibrosis. A total of 37 non-Hodgkin's and 32 Hodgkin's patients had adequate biopsies for study inclusion. Twenty-seven received chemotherapy alone, while the remaining 42 had lethal total body irradiation plus chemotherapy. Twelve transplants were allogeneic. Estimated osteocyte viability was decreased for over 4 weeks after bone marrow transplantation. Continuing osteocyte dropout in the central regions of trabeculae was seen in conjunction with active new osteocyte formation along the periphery. Marrow fibrosis was significantly increased and marrow cellularity decreased. There were no major distinctions based on lymphoma type, pretransplant treatment regimen or type of bone marrow transplant. The results indicate that disruption of marrow hematopoiesis causes a diminution in osteocyte viability. Although there is an early appearance of new osteogenesis, the source of progenitor cells cannot be determined from this study.

Adolescent↗
PubMed1993

[Pleural empyema as a complication of the sclerotherapy of esophageal varices].

We present three patients developing pleural empyema after sclerotherapy of esophagic varixes. In all of them, the presence of persistent fever syndrome following the sclerotherapy, along with radiological images of pleural overflow, were the starting point of the patient's study. In the emergency esophagogrames, the extravasation of contrast outside the esophagus could not be confirmed. The treatment, which must be started as soon as possible, was based in conservative measures (drainage, antibiotics and a proper nutrition), given the poor general condition of these patients. Despite all these measures, the prognosis is poor, with two of the three patients dying despite the administration of the treatment. In conclusion, although its frequency is very low, pleural empiema is an extremely severe complication of the sclerotherapy of esophagic varixes. If this complication is suspected, the prognosis depends on a treatment that must be started as soon as possible.

Aged↗
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↗