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Biomedical subjects

F Rodríguez

Publications and source records attributed to F Rodríguez.

At least 91 records · Page 5Linked to original sources
PubMed1999

Dapsone prevents morphological lesions and lipid peroxidation induced by quinolinic acid in rat corpus striatum.

Increasing doses of dapsone were tested on rats administered intrastriatally with quinolinic acid in order to evaluate a possible protective action of this drug on the striatal lesions produced after the excessive activation of N-methyl-D-aspartate receptors. Morphological lesions were evaluated 7 days after the intrastriatal injection of quinolinate (240 nmol/microl) by light microscopy, and the ratio of neuronal damage per field was also estimated as a quantitative index of the striatal toxicity. Quinolinate alone produced extensive necrosis and loss of striatal neurons. No protective effects on the striatal tissue from quinolinate-treated rats were observed at lower doses of dapsone (6.25 and 9.375 mg/kg). However, at higher doses (12.5 and 25 mg/kg), dapsone prevented significantly the striatum from quinolinate toxicity. Dapsone alone had no effect on the striatal tissue from control rats. A single dose of dapsone (12.5 mg/kg) was tested also on the index of lipid peroxidation 2 h after the striatal injection of quinolinate, resulting in a significant protection (78% vs. QUIN). Findings of this study, in accordance with our previous reports, demonstrate the ability of dapsone to prevent the neuronal damage associated with the excitatory action of quinolinate via overactivation of NMDA receptors, and provide evidences to support the hypothesis that this drug is acting against the pattern of toxicity elicited by agonists of glutamate receptors.

Animals↗
PubMed1999

Regio- and Diastereoselective Aldol Products through Three-Component Coupling Reactions of Difluoroboroxy Fischer Carbene Molybdenum Complexes.

The reaction of difluoroboroxy Fischer carbene complexes, vinyl ketones, and aldehydes leads to the regioselective formation of aldol-like products (see reaction scheme). The reaction also shows a high degree of diastereofacial selectivity when chiral aldehydes are used. These results show that this is a very attractive process since the regioselective formation of aldols from nearly symmetrical ketones still remains an unsolved problem.

Journal Article↗
PubMed1999

Design and construction of African swine fever virus chimeras incorporating foreign viral epitopes.

In the present work we have studied the feasibility of introducing foreign epitopes into the African swine fever virus (ASFV) particle by genetic manipulation of the virus. For this purpose, we developed specific transfer vectors containing the gene encoding for the highly antigenic structural ASFV protein p54 in which foreign sequences were introduced. DNA sequences encoding continuous linear epitopes, the antigenic site A from foot-and-mouth disease virus (FMDV) VP1 protein and the DA3 antigenic determinant from transmissible gastroenteritis coronavirus (TGEV) nucleoprotein N, were separately cloned into the p54 gene, in a region encoding a non-essential domain of the protein. Chimeric p54 genes were inserted by homologous recombination into the thymidine kinase (TK) locus of ASFV genome. The resulting recombinant viruses efficiently expressed both chimeric proteins under transcriptional control of the p54 promoter, and the chimeric gene products were recognized by antibodies to both p54 and foreign epitopes. The modified p54 proteins were also found in the viral particles and complemented the function of the wild-type p54, since deletion of the p54 gene from recombinant viruses did not affected virus replication in Vero cells. This work demonstrates for the first time the feasibility of incorporating foreign amino acid sequences (up to 18 residues) into a protein component of the ASFV particle without affecting virus viability.

African Swine Fever Virus↗
PubMed1999

Conclusions of a national multicenter intercomparative study of in vitro cultures of human hematopoietic progenitors.

With the aim of developing a standardized program of clonogenic cultures, a multicenter intercomparative study of human CFU-GM, BFU-E and CFU-GEMM cultures was conducted. Aliquots of fresh mononuclear cord blood cells, as well as uniform culture materials and instructions for cell culture and for colony scoring were distributed to 28 national laboratories involved in hematopoietic research and transplantation. High interlaboratory coefficients of variation (CV) in the reported number of progenitors were found in our first intercomparative study (range 67-231%). To investigate the relevance of colony scoring in variations of the reported colony numbers, participants were invited to attend a meeting where a single culture dish was scored. In this case, the CVs ranged from 31% to 81%. A subsequent intercomparative assay was then conducted, and significant reductions in the inter-laboratory CVs were obtained with respect to the first study (CVs for colonies grown with two different media: CFU-GMs, 48% and 55%; BFU-Es, 70% and 62%; CFU-GEMMs, 70% and 51%; respectively). In most instances CVs were not significantly different from those obtained in the single plate scoring study, suggesting that the scoring process was the most relevant parameter accounting for variations in the reported colony numbers.

Cell Culture Techniques↗
PubMed1999

Coordinate expression of cytokeratins 7 and 20 in feline and canine carcinomas.

Forty-seven feline and 60 canine epithelial tumors were studied to test the coordinate expression of cytokeratin 7 (CK 7) and cytokeratin 20 (CK 20) using commercially available monoclonal antibodies and an avidin-biotin immunoperoxidase staining technique. Previously, the distribution of both cytokeratins was examined in normal tissues from 4 cats and 4 dogs. The pattern of distribution of CK 7 in normal tissues was similar, with minor differences, to that described in humans, whereas the reactivity pattern of CK 20 in cats and dogs was wider than that in humans. The subset of tumors strongly expressing CK 7 and CK 20 included pancreatic adenocarcinomas (100%), transitional cell carcinomas (75%), and endometrial carcinomas (67%) in the cat. None of the canine tumors had this immunophenotype. Feline (50%) and canine (56%) mammary gland carcinomas and canine cholangiocarcinomas (67%) were the only tumors presenting the CK 7 +/CK 20- immunophenotype, whereas the CK 7-/CK 20+ immunophenotype included thyroid carcinomas (100%), intestinal adenocarcinomas (60%), bronchioloalveolar carcinomas (50%), and renal carcinomas (50%) in the cat and intestinal adenocarcinomas (56%), gastric adenocarcinomas (50%), and ovarian carcinomas (50%) in the dog. The CK 7-/CK 20- immunophenotype included the rest of the analyzed tumors. The immunohistochemical evaluation of coordinate expression of both CK 7 and CK 20 in feline and canine carcinomas using monoclonal antibodies provides important information that can help to discriminate among carcinomas from different primary sites and could be particularly helpful in the determination of the primary site of origin of carcinomas presenting as metastatic disease.

Animals↗
PubMed1999

A method for measuring eye movements using Hall-effect devices.

A system for precise recording of eye position and movements in laboratory animals, by means of Hall-effect devices, is described. The system, useful in neurophysiological and neurobehavioral studies, allows the analysis of saccadic eye movements, optokinetic- and vestibular-induced nystagmus, slow tracking movements, eye vergences, and so forth. This small, light-weight, and inexpensive system uses a set of Hall-effect devices and associated electronics to sense variations in the position of high-power magnets fixed in the eye sclera or in scleral contact lenses. The output of the Hall-effect devices is amplified by operational amplifiers, collected through an A/D converter, and analyzed in a PC computer by specific software.

Animals↗
PubMed1999

[One year treatment with lamivudine in different hepatitis B virus related hepatic diseases].

BACKGROUND: Three month administration of lamivudine in patients with chronic hepatitis B produces a transitory inhibition of the DNA of the hepatitis B virus (HBV). AIM: The aim of this study was to evaluate the efficacy and safety of one year treatment with lamivudine in patients with chronic hepatitis B and liver transplantation (LTx) with recurrence of HBV infection. PATIENTS AND METHODS: Sixteen patients with chronic hepatitis B, 4 patients with decompensated hepatic cirrhosis and 4 patients having undergone LTx with recurrence of HVB infection were treated with the oral administration of 100 mg/day of lamivudine for one year. RESULTS: At 3 months of treatment, the HBV-DNA became negative in 94% of the cases of chronic hepatitis B, in 10% of those with decompensated hepatic cirrhosis and in 100% of the cases of LTx. At one year of treatment, the HBV-DNA was negative in 81% of the chronic hepatitis B, in 100% of the decompensated cirrhotics and in 100% of the LTX cases which survived. The tolerance to treatment was excellent in all the cases. In 34% of the cases, mutations were observed in the gene of the polymerase DNA at one year of treatment. CONCLUSIONS: Lamivudine produces intense, rapid inhibition in viral replication not only in chronic hepatitis B but also in cases of decompensated cirrhosis or recurrence following liver transplantation. Around 30% of the patients undergoing one year of treatment with lamivudine developed gene mutations of the HBV polymerase.

Adult↗
PubMed1999

[Laparoscopic adrenalectomy. Initial results of a Chilean experience].

BACKGROUND: Laparoscopic adrenal approach was introduced in 1992 and is becoming the surgical method of choice for several adrenal diseases. AIM: To report the initial Chilean experience in laparoscopic adrenalectomy. MATERIAL AND METHODS: A retrospective review of 17 patients subjected to the surgical procedure by the authors. RESULTS: The preoperative diagnosis were adenomas (8 patients), pheochromocytoma (3), cystic lesions (2), adrenal metastases (2), hyperaldosteronism (1) and a pituitary Cushing (1). The average lesion size was 5.4 cm, the operative time 2.5 hours and the hospital stay 2.5 days. Eight patients were discharged in less than 48 hours. Pain was managed with non steroidal antiinflammatory drugs in 14 patients. One subject required conversion to open surgery. Transfusions were required in complex cases with a diaphragmatic hamartoma, Cushing disease and in a combined adrenal and renal resection. One patient had to be re admitted due to a pancreatic pseudo cyst that was drained percutaneously. There have been no recurrences after a mean follow up of 2 years. CONCLUSIONS: This early experience with laparoscopic adrenalectomy shows good results. A good patient selection and experience with advanced laparoscopic surgery are requisites for a successful use of this surgical technique.

Adolescent↗
PubMed1999

[The bent spine syndrome: a focal axial myopathy of late onset].

The bent spine is a rare syndrome appearing at an advanced age which shows a posture of anterior flexion of the trunk, which is reducible and is often hereditary. It is caused by a paresia of the extensor musculature of the trunk by a focal axial myopathy of late onset. We herein describe the case of a 72-year-old woman with a progressive bent spine initiated at the age of 55. Family questioning showed vertical transmission of the process. On exploration paresis of the paravertebral musculature and to a lesser extent of both girdles was observed. Serum CK levels were normal. Vertebral CT showed atrophy with fatty substitution of the paravertebral musculature. EMG of the scapular and paravertebral muscles demonstrated a myopathic pattern. Deltoid muscle biopsy found atrophy of type II fibers and isolated broken red fibers. This case corroborates the myopathic nature of this syndrome. A review of the nosology of the syndrome is also presented.

Age Factors↗
PubMed1999

[Descriptive analysis (clinical and functional characteristics) of an asthmatic population in a health care district].

OBJECTIVE: To determine the social, demographic, clinical and lung function characteristics of the population of asthmatics living in Health Care District 2 of Madrid. STUDY DESIGN: Transversal (initial visit) phase of a primary care community intervention study. The target population consisted of all asthmatics in District 2 of Madrid who were registered at the public health clinics, were older than 14 and had experienced asthma symptoms within the past year. The selection of patients for the study was systematic (not probabilistic), such that all registered asthmatics seeking care and/or scheduled for check-ups were enrolled. Participation was 96.6% of those on file. We recorded social, demographic, clinical, and lung function variables as well as results of allergy studies, family histories of asthma and/or atopy and type of treatment. RESULTS: Six hundred fifty patients were enrolled, 238 men (36.7%) and 412 women (63.3%). Mean age was 45 +/- 28.1 yr, mean FEV1% was 87.2 +/- 26%. Mean course of disease was 16 +/- 14.6 yr and age of onset was 26 +/- 20 yr. Family history of asthma was present in 34% of cases and a family history of atopy was reported by 21%. Half had allergic rhinitis as an associated factor, with respiratory infections (62.4%) being the most common trigger, followed by pollen (25.3%) and exposure to tobacco smoke (20%). Active smokers accounted for 9.1% of the group, and ex-smokers for 21.6%. Short-term beta-adrenergic drugs on demand were used by 64% of patients, whereas 83.2% reported daily and long-term use of beta-2 drugs and 77% used inhaled steroids. Severity of disease differed significantly by age of patient, age at onset and predominance of perennial asthma (with older age and age of onset and greater seasonality observed among severely asthmatic patients). CONCLUSIONS: a) Most symptomatic asthmatic have mild disease. b) Rationally adjusted, appropriate drug treatment should be graded according to level of disease severity.

Adolescent↗
PubMed1998

[Acute renal failure in the allogeneic transplantation of hemopoietic progenitors. The clinical characteristics in a series of 92 patients].

BACKGROUND: Analysis of clinical characteristics of acute renal failure (ARF) after allogeneic bone marrow transplantation (BMT). PATIENTS AND METHODS: Analysis of 92 patients who developed ARF of 260 patients following BMT. RESULTS: ARF incidence was 35.4%. Sixty three percent of ARF occurred before day 20 after BMT. Duration of ARF was less of 10 days in 72.8%. ARF was non oliguric in the 80.4% of cases. Most common ARF etiologies were: multifactorial (37%), nephrotoxicity (NPH) (33.7%) and veno-occlusive disease of the liver (VOD) (14.1%). ARF secondary to VOD was the most severe: and the longest, where the secondary to NPH was less lever and shorter. Hemodialysis (HD) was necessary in 22.8% of ARF. Mortality in ARF group was 45.6%, higher in HD group (80.9%) than in non-HD group (35.2%) (p < 0.0002). CONCLUSIONS: ARF is a frequent complication following BMT. It occurs early, has short duration, is non oliguric, mainly hemodynamic and carries a whose prognosis.

Acute Kidney Injury↗
PubMed1998

The African swine fever virus proteins p54 and p30 are involved in two distinct steps of virus attachment and both contribute to the antibody-mediated protective immune response.

The nature of the initial interactions of African swine fever (ASF) virus with target cells is only partially known, and to date only the ASF virus protein p12 has been identified as a viral attachment protein. More recently, antibodies to viral proteins p54 and p30 have been shown to neutralize the virus, inhibiting virus binding and internalization, respectively. Therefore, we investigated the role of these proteins in the receptor-mediated ASF virus endocytosis in swine macrophages, the natural host cells. Proteins p54 and p30, released from ASF virus particles after treatment of virions with a nonionic detergent, bound to virus-sensitive alveolar pig macrophages. Binding of these proteins was found to be specifically inhibited by neutralizing antibodies obtained from a convalescent pig or from pigs immunized with recombinant p54 or p30 proteins. The baculovirus-expressed proteins p54 and p30 retained the same biological properties as the viral proteins, since they also bound specifically to these cells, and their binding was equally inhibited by neutralizing antibodies. Binding of 35S-labeled recombinant p54 and p30 proteins to macrophages was specifically competed by an excess of unlabeled p54 and p30, respectively. However, cross-binding inhibition was not observed, suggesting the existence of two different saturable binding sites for these proteins in the susceptible cells. In addition, protein p54 blocked the specific binding of virus particles to the macrophage, while protein p30 blocked virus internalization. Both proteins independently prevented virus infection and in a dose-dependent manner, suggesting that binding interactions mediated by both proteins are necessary to give rise to a productive infection. The relevance of blockade of virus-cell interactions mediated by p54 and p30 in the protective immune response against ASF virus was then investigated. Immunization of pigs with either recombinant p54 or p30 proteins induced neutralizing antibodies which, as expected, inhibited virus attachment or internalization, respectively. However, immunized pigs were not protected against lethal infection and the disease course was not modified in these animals. In contrast, immunization with a combination of p54 and p30 proteins simultaneously stimulated both virus neutralizing mechanisms and modified drastically the disease course, rendering a variable degree of protection ranging from a delay in the onset of the disease to complete protection against virus infection. In conclusion, the above results strongly suggest that proteins p54 and p30 mediate specific interactions between ASF virus and cellular receptors and that simultaneous interference with these two interactions has a complementary effect in antibody-mediated protection.

African Swine Fever↗