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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 325 records · Page 18Linked to original sources
PubMed1998

Lung inflammatory response in pneumonia.

In normal conditions, alveolar macrophages (AMs) are the main cells that respond to bacteria that reach lower airways. However, if the microbial inoculum is too high or too virulent to be stopped by AM alone, these cells recruit polymorphonuclear neutrophils (PMN) into the alveoli from the vascular compartment. Cytokines, such as tumour necrosis factor-alpha (TNF-alpha), interleukin-1-beta (IL-beta), interleukin-6 (IL-6), and interleukin-8 (IL-8), secreted by the AM are able to attract PMN enhanced for phagocytosis, ready to destroy the invading pathogens. However, excessive cytokine production has deleterious effects, with a systemic inflammatory response (sepsis) that can lead to multiorganic failure and death. Other cytokines, such as interleukin-10 (IL-10) balance this response, attenuating several inflammatory mechanisms. The inflammatory lung response in pneumonia has been well studied in animals, and more recently in humans, using bronchoalveolar lavage to measure some inflammatory mediators (TNF-alpha, IL-1 beta, IL-6, IL-8). From these studies, it seems that: 1) the inflammatory response to pneumonia is compartmentalized for most cytokines (in contrast to adult respiratory distress syndrome (ARDS)), except for IL-6 which is a general marker of inflammation. On the other hand, C-reactive-protein is an acute-phase protein synthesized by the liver through the stimulus of IL-6 that may also be an easy-to-measure marker of inflammation that is directly related to IL-6; 2) some of these cytokines may be useful as prognostic indices; 3) there is no clear relationship between the local lung bacterial burden and the intensity of the inflammatory response; and 4) the administration of granulocyte colony-stimulating factor (G-CSF) is a promising therapeutic approach that is still under clinical investigation. In the future, it is probable that the therapeutic goal in severe pneumonia will be to find the exact point at which inflammation is beneficial but not deleterious. The measurement of the inflammatory response may serve for this purpose.

Bronchoalveolar Lavage Fluid↗
PubMed1998

[Behavioral evaluation of the unilateral lesion model in rats using 6-hydroxydopamine. Correlation between the rotations induced by D-amphetamine, apomorphine and the manual dexterity test].

INTRODUCTION: Evaluation of rotatory activity induced by dopaminergic agonists is the most widely used test of conduct for the measurement of dopaminergic depletion of a unilateral lesion of the striatonigral pathway caused by 6-hydroxydopamine (6-OHDA) in rats, since it is quantitatively related to the extension of the dopaminergic denervation. OBJECTIVE: The objective of this study was to evaluate, from different angles, the changes in conduct seen in the model of unilateral lesion with 6-OHDA and to establish correlation with the rotation induced by D-amphetamine and by apomorphine and the ladder test. MATERIAL AND METHODS: Male Wistar rats were used. Lesions were produced in the SNpc by stereotactic injection of 6-OHDA into the right hemisphere and the effectiveness of the lesions was studied using the rotary conduct induced by D-amphetamine and apomorphine. The motor ability of the front legs was measured by the ladder test, carried out under standard and forced conditions. RESULTS: All the animals with lesions had difficulty in reaching food with both legs, although the most pronounced deficit was in the leg contralateral to the lesion. The ladder test correlated better with rotatory activity induced by apomorphine than by D-amphetamine. CONCLUSION: The animals with most dopamine loss showed most deficient use of their front legs.

Animals↗
PubMed1998

Health evaluation of free-ranging guanaco (Lama guanicoe).

Twenty free-ranging guanaco (Lama guanicoe) in Chubut Province, Argentina, were immobilized for health evaluations. All but two animals appeared to be in good condition. Hematology, serum chemistry, and vitamin and mineral levels were measured, and feces were evaluated for parasites. Serology tests included bluetongue, brucellosis, bovine respiratory syncitial virus, bovine viral diarrhea/mucosal disease, equine herpesvirus 1, infectious bovine rhinotracheitis, Johne's disease (Mycobacterium paratuberculosis), foot and mouth disease, leptospirosis (17 serovars), parainfluenza-3, and vesicular stomatitis. Blood samples from 20 domestic sheep (Ovis aries) maintained in the same reserve with the guanaco were also collected at the same time for serology tests. No guanaco had positive serologic tests. Sheep were found to have antibody titers to bovine respiratory syncytial virus, Johne's disease, leptospirosis, and parainfluenza-3. There was no apparent difference in external appearance or condition, or statistical difference in blood test values, between the animals that were positive or negative for parasite ova.

Analgesics, Opioid↗
PubMed1998

[Treatment of pneumonia caused by Legionella with azithromycin].

Nineteen patients with pneumonia caused by Legionella, who did not need to be admitted to ICU were treated with 500 mg/day of azithromycin. The etiological diagnosis was made retrospectively by detecting Legionella pneumophila in the urine of nine patients and/or by serology (seroconversion or single titer 1/256) in 19 cases. None of them met the criteria for ICU admittance nor had received prior treatment with antibiotics which were potentially active against L. pneumophila. Serology tests and radiography of the thorax were carried out on all the patients in the study during their convalescence period. The average age (+/- SD) of the group was 58.5 +/- 16.2 years. The average respiratory frequency (+/- SD) 26 +/- 6 breaths per minute; the radiologic extension was of one lobule in 18 cases and two lobules in one case. No patients showed bilateral disease. Arterial gasometry (FiO2 0.21) showed a pO2 average of (+/- SD) 53 +/- 14 mmHg and the hemogram an average of 6.700 leukocytes/mm3 (range: 4,200-41-800). All the patients progressed favorably. The average duration of fever was 1.8 days; the average stay (+/- SD) was 6.1 +/- 2 days. The treatment was well tolerated. One month after discharge radiographies were clear for all patients. There were no relapses. In conclusion, 3-day administration of azithromycin was found to be a useful guide in the treatment of community acquired pneumonia caused by Legionella in patients whose clinical situation does not require ICU administration and allows for oral administration.

Adult↗
PubMed1998

[A morphological and morphometric study of the testicle in the rat vasectomized by electrocautery technics].

OBJECTIVE: To evaluate the influence of vasectomy by different fulguration methods on the rat testicular structure. METHODS: Experimental vasectomy was performed in Wistar rats by means of the Shapiro and Silber, and the Schmidt cauterization techniques. The animals were orchidectomized between 7 days and 9 months following vasectomy. A morphological and morphometric study of the rat testes was performed. RESULTS: We have observed that both cauterization techniques do not produce sequelae in the rat testicular structure and its morphology is compatible with the normal. The morphometric study showed that both techniques produced a significant decrease (p > 0.05) of the area occupied by seminiferous epithelium within one month post-vasectomy; however, these values returned to normal three months thereafter. CONCLUSIONS: Vasectomy by different fulguration methods does not change the rat testicular structure.

Animals↗
PubMed1998

[Plastic reconstruction of the irradiated thoracic wall].

Chest-wall reconstruction following irradiation requires a surgical approach that addresses the specific healing disorders associated with irradiation: (1) biopsy of any open wound to rule out recurrence or persistence of tumor; (2) aggressive debridement of all necrotic or infected tissue, especially osteonecrosis of the chest wall; (3) reconstruction with well-vascularized muscle or musculocutaneous flaps. Coverage with muscle flaps provides a very reliable and effective single-stage reconstruction. Most types of flaps employed involve the latissimus, rectus abdominis and pectoralis muscle or musculocutaneous flaps. Rarely, stabilization of the thoracic wall is required, mostly facilitated by nonresorbable mesh. Respecting these principles, the irradiated chest wall can be reconstructed safely and with low morbidity. Plastic reconstructive techniques may also be employed safely to reconstruct the breast simultaneously in irradiated tissue by use of latissimus or rectus abdominis flaps.

Adult↗
PubMed1997

In-laboratory removal of femoral sheath following protamine administration in patients having intracoronary stent implantation.

Two hundred twenty-eight patients with successful coronary stent implantation were randomized either to protamine administration and femoral sheath removal (group I, n = 117) or no heparin neutralization and delayed sheath removal (group II, n = 111). The hospital stay after treatment was shorter in patients receiving protamine; therefore, protamine use for neutralizing circulating heparin may be safely administered immediately after stent implantation.

Anticoagulants↗
PubMed1997

'Wide-spectrum Ca2+ channel antagonists': lipophilicity, inhibition, and recovery of secretion in chromaffin cells.

Repetitive application of short depolarizing K+ pulses (70 mM K+, 2 mM Ca2+ Krebs-HEPES solution, for 10 s every 5 min) produced reproducible catecholamine secretory responses from superfused bovine chromaffin cells. At 10 microM for 15 min, the piperazine derivatives dotarizine, flunarizine and lidoflazine inhibited secretion by around 90%; cinnarizine halved the secretory response. Recovery of secretion after 30-min washout with Krebs-HEPES solution amounted to 75% in the case of dotarizine, 8% for flunarizine, 46% for lidoflazine and 21% for cinnarizine. The benzothiazol derivatives (10 microM) (+)-S-lubeluzole and R91154 (the (-)-R-enantiomer of lubeluzole) blocked the response by 75%; sabeluzole inhibited secretion by only 34% and R56865 (N-[1-(4-(4-fluorophenoxy)butyl]-4-piperidinyl-N-methyl-2-benzo-thiaz olamine) by 61%. Recoveries were around 70% in the case of these four benzothiazol derivatives. The diphenylbutyl-piperazine derivatives fluspirilene and penfluridol inhibited secretion by over 80%; no recovery was produced after 30-min washout. The inhibition of secretion was time dependent, as the recovery of the response was. Blockade of secretion by dotarizine and flunarizine occurred even in the absence of intermittent K+ stimulations of the cells. No obvious correlation was seen between the octanol/water partition coefficients of the ten compounds tested (that ranged between 6 and 4.61), the rate and extent of blockade of secretion, and the recovery of the secretory response upon washout. Rather than non-specific actions on ion channels (and secretion) due to their high lipophilicity, we believe that blockade of various Ca2+ channels relates to their binding properties to specific channel micro and macrodomains, as the case might be for 'narrow' (omega-conotoxin GVIA) and 'wide-spectrum' (omega-conotoxin MVIIC) peptide toxins.

Animals↗
PubMed1997

[Cardiopulmonary resuscitation in hospitalized patients in conventional units. Prospective study of 356 consecutive cases. Commission for Care of Cardiorespiratory Arrest].

BACKGROUND: Information regarding to the system functioning and to the outcome of patients in whom cardiopulmonary resuscitation (CPR) was performed during their in hospital period in non intensive care units are essentially lacking in Spain. The objectives of the present work were: 1) to define clinical and demographic characteristics of the patients who develop cardiopulmonary arrest in general hospitalization wards; 2) to analyze immediate and late (at discharge) survival rates as well as the frequency of severe sequelae in final survivors; 3) to identify prognostic factors in relationship to survival, and 4) to detect possible internal deficiencies in the organized system of CPR. PATIENTS AND METHODS: All patients who develop cardiac and pulmonary arrest through their hospitalization in general wards during a three year period, were prospectively included. Clinical and demographic data from all the patients as well as data related to the internal functioning of the system were recorded. RESULTS: From 356 included cases, 196 (55%) were initially recovered and 128 (36%) were discharged from the hospital. Among the latter group, 12.5% remained with severely disabling neurologic damage. Age under 80 years, resuscitation maneuvers for less than 20 minutes and respiratory arrest as the ultimate event leading to cardiopulmonary arrest were associated with better prognosis. The internal deficiencies most commonly recorded in the system were false calling to the emergency team, the wrong identification of the location in the hospitalization unit and several abnormalities in the content of CPR sets. CONCLUSIONS: With the currently available organized system directed towards CPR for patients admitted in general hospitalization wards, our rates of success are good and similar to those achieved in some intensive care units. Thus, a similar policy may be encouraged in large hospitals. Since most of the detected deficiencies in internal functioning are easy to rectify, a close monitoring is warranted in order to optimize the results.

Aged↗
PubMed1997

Thrombosis in primary antiphospholipid syndrome: a pivotal role for monocyte tissue factor expression.

OBJECTIVE: The antiphospholipid syndrome (APS) is a disorder of recurrent thrombosis, pregnancy loss, and thrombocytopenia associated with the production of anticardiolipin antibodies (aCL) and lupus anticoagulant (LAC). The mechanisms of thrombus formation remain unknown. Tissue factor (TF), an inducible cell glycoprotein, is a major initiator of coagulation in vivo. The present study was therefore undertaken to investigate TF expression and procoagulant activity on monocytes from patients with primary APS and its correlation with thrombotic events. METHODS: Three groups of patients were studied: group 1 comprised 23 primary APS patients with thrombosis, group 2 consisted of 10 primary APS patients without thrombosis, and group 3 contained 20 patients with thrombosis but without antiphospholipid antibodies. Twenty age- and sex-matched healthy blood donors were used as controls (group 4). Anticardiolipin antibodies were measured by enzyme-linked immunosorbent assay (ELISA) and LAC by standard methodology. Cell surface expression of TF on monocytes was assessed by flow cytometry. The amount of TF in cell lysates (TF(Ag)) and soluble TF(Ag) plasma levels were analyzed by ELISA, and the TF-related procoagulant activity (PCA-TF) on intact cells and cell lysates by a chromogenic assay. Levels of the cytokines that influence TF production, i.e., tumor necrosis factor alpha (TNF alpha) and interleukin-1beta (IL-1beta), were determined by ELISA. RESULTS: Cell surface expression of TF was increased in group 1 (mean +/- SEM 50.2 +/- 4% positive cells) compared with group 2 (14.6 +/- 1.6%), group 3 (16.8 +/- 3.7%), and group 4 (14.1 +/- 1.6%). TF(Ag) levels were also elevated in group 1 (215.8 +/- 11.2 pg/10(6)) compared with group 2 (150.8 +/- 15.2), group 3 (101.4 +/- 14.8), and group 4 (80.32 +/- 5.5). PCA-TF on intact cells and cell lysates was significantly increased in group 1 (148.8 +/- 16.3 units/10(5) lysate cells, compared with 54.5 +/- 11.5, 38.6 +/- 9.7, and 22.5 +/- 3.1 in groups 2, 3, and 4, respectively). Among group 1 patients, there was a significant increase in the degree of TF expression in those positive for IgG aCL, but not in those positive for IgM aCL or LAC. TNF alpha and IL-1beta plasma levels did not differ significantly between any of the groups. CONCLUSION: These results suggest that monocyte TF expression is directly involved in the pathogenesis of thrombotic complications in patients with the primary APS.

Adult↗
PubMed1997

[Definitive diagnosis of pulmonary sequestration using magnetic resonance. Description of 3 cases].

Pulmonary sequestration is a congenital malformation in which the pulmonary parenchyma is isolated from the rest of the lung and receives irrigation. Traditionally this malformation has been diagnosed by arteriography, but in recent years the usefulness of magnetic resonance, a technique that can probably substitute for arteriography on many occasions, has been emphasized. We report 3 cases of intralobar pulmonary sequestration diagnosed by magnetic resonance, a procedure that provided adequate presurgical assessment. The magnetic resonance images were later shown to be consistent with anatomical findings.

Adolescent↗
PubMed1997

Different behavior of lactotroph cell subpopulations in response to angiotensin II and thyrotrophin-releasing hormone.

1. In the present investigation we have extended the study of lactotroph subpopulations in primary pituitary cell cultures. Male rats with or without previous estrogenization followed by A-II or TRH treatments were selected as experimental models. 2. The TRH increased up to 50% the PRL released in both whole and OROX+EB rats (P < 0.05). In contrast, A-II treatment introduced no changes in PRL secretion from cell cultures derived from whole male rats but attained a significant augmentation (about 75%) of PRL secreted by ORQX+EB pituitary cells. 3. The addition of TRH and A-II to cultures of ORQX+EB-derived lactotrophs induced cytological changes compatible with a high secretory activity. In estrogen-treated rats the prevailing lactotroph subpopulation is type I. In cell cultures from control and A-II treated whole male pituitaries, the majority of lactotrophs consists of atypical subpopulations of II and III cells, with smaller secretory granules (between 150 and 300 nm in diameter). 4. Morphometry of immunostained lactotrophs performed on light microscopic preparations revealed that about 30-36% of the total cell count were lactotrophs. This percentage was fixed and did not change significantly after TRH and A-II treatments. 5. The present results confirm the presence of morphological and functional subtypes of lactotroph cells in rat pituitary. Typical PRL cell population shows the highest responsiveness to angiotensin II and TRH action. This functional heterogeneity of lactotroph subtypes may reflect an important and scarcely explored factor in the regulatory process of prolactin secretion.

Angiotensin II↗