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Biomedical subjects

M Vendrell

Publications and source records attributed to M Vendrell.

At least 37 records · Page 2Linked to original sources
PubMed1995

[IgG subclasses in patients with symptomatic IgA deficiency].

BACKGROUND: Patients with IgA deficiency may be asymptomatic or may present recurrent infections mainly respiratory. A possible explanation for this variety of symptoms may be the association with a deficiency of IgG subclasses. METHODS: Twenty-five patients with a symptomatic IgA deficiency with a mean age of 18 +/- 12 years were studied. The quantification of the IgG subclasses was performed by ELISA test with antisubclass specific monoclonal murine antibodies. Serum from 100 healthy adults was collected to determine normal values of the IgG subclasses. RESULTS: Twenty-five (48%) had a deficiency of associated IgG subclasses (6 IgG2 deficiency, 1 IgG3, 3 IgG4 and 2 combined deficiency). The patient with a deficiency of associated IgG subclasses had more recurrent respiratory infections (chi 2, p < 0.03) and pneumonias (chi 2, p < 0.04). This group also had a greater FEV1 alteration (Student-t test, p < 0.04). CONCLUSIONS: Patients with symptomatic IgA deficiency frequently present IgG subclass deficiency and are more likely to have recurrent respiratory infections and greater changes in pulmonary function.

Adolescent↗
PubMed1995

[The use of human gamma globulin in the treatment of common variable immunodeficiency].

BACKGROUND: The indication for treatment with human gammaglobulin in patients with primary hypogammaglobulinemia is well established. Nonetheless, there are no uniform criteria with regard to dose, periodicity and route of administration. METHODS: Twenty-seven patients with common variable immunodeficiency (CVI) who received i.m. or i.v. treatment with gammaglobulin were studied, evaluating the secondary effects, stable levels of IgG achieved, control of symptomatology, clinical evolution and the need for adjuvant therapies. RESULTS: Intravenous administration was more effective than intramuscular administration to achieve higher total IgG serum levels (5.2 +/- 1.2 vs 3.5 +/- 1.6 g/l; p = 0.07) in a shorter period of time (2.1 +/- 1.6 months vs 6.3 +/- 2.8 months; p < 0.01) and with new few secondary effects. The dose and periodicity of the treatment was individualized in each patient on the basis of the needs of consumption and the speed of metabolism of the gammaglobulin, with patients with chronic bronchial suppuration and diarrhea being those requiring the greatest doses (p < 0.0001) and a short interdosis time interval (19.2 +/- 3.1 vs 23.6 +/- 3.6 days; p = 0.01). Treatment with human gammaglobulin allowed the control of recurrent bacterial infection; however, adjuvant treatment with respiratory physical measures and antibiotics were required in patients with chronic bronchial suppuration to avoid progressive alteration of respiratory function. CONCLUSIONS: The administration of human gammaglobulin at adequate doses and frequency is effective to control infection, avoid the development of chronic bronchial disease, alteration of pulmonary function and the appearance of other complications. Intravenous route is safer and produces fewer secondary effects than intramuscular administration with the doses and period of the treatment requiring individualization for each patient.

Adolescent↗
PubMed1995

Regulation of c-fos expression in transgenic mice requires multiple interdependent transcription control elements.

Transcription control regions of eukaryotic genes contain multiple sequence elements proposed to function independently to regulate transcription. We developed transgenic mice carrying fos-lacZ fusion genes with clustered point mutations in each of several distinct regulatory sequences: the sis-inducible element, the serum response element, the fos AP-1 site, and the calcium/cAMP response element. Analysis of Fos-lacZ expression in the CNS and in cultured cells demonstrated that all of the regulatory elements tested were required in concert for tissue- and stimulus-specific regulation of the c-fos promoter. This implies that the regulation of c-fos expression requires the concerted action of multiple control elements that direct the assembly of an interdependent transcription complex.

Animals↗
PubMed1995

[The use of fibrinogen-thrombin via endoscope in the treatment of massive hemoptysis].

We assessed the efficacy of fibrinogen-thrombin instillation through the fiberoptic bronchoscope to treat massive hemoptysis in patients to whom embolization of bronchial arteries was not available, was contraindicated or had failed. The fibrinogen-thrombin solution used was Tissucol, which in addition to 2% fibrinogen and 4 U/ml of thrombin, also contained factor XIII an aprotinin. The fibrinogen-thrombin solution was instilled with the aid of the Duplojec system and a 70 cm x 2 mm 4-way catheter. In 53 of the 628 fiberoptic bronchoscopies performed during the study, the indication was hemoptysis > or = 150 ml/12 h. Of these, bronchoscopic instillation of fibrinogen-thrombin was indicated in 5 cases because bronchial artery embolization was impossible. The point of bleeding was located by bronchoscopy in all cases and fibrinogen-thrombin instillation controlled hemoptysis immediately and throughout the follow-up period, which ranged 4 to 10 months. Morning expectoration of blood (< 10 ml) was observed in only 1 patient in the 3 days after treatment. The mean time taken for bronchoscopic exploration was 3 minutes (range, 2-7). In all cases fiberoptic bronchoscopy was performed without complications that might have required the procedure to be suspended. We conclude that the local use of fibrinogen-thrombin or fibrin glue instilled through the fiberoptic bronchoscope to the point of bleeding is a simple, fast and cheap way to control massive hemoptysis on a short and long-term basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Scintigraphy, angiography and computed tomography in unilateral hyperlucent lung due to obliterative bronchiolitis.

This study examines the value of different imaging methods in assessing the anatomic structures of unilateral hyperlucent lung due to obliterative bronchiolitis. We studied 9 patients, 5 males and 4 females, suffering from UHL (mean age 49 years). Ventilation-perfusion scan (VPS) and computed tomography (CT) of the chest were performed in all, and conventional angiography or digital substraction angiography (DSA) in 7 patients. The VPS showed the characteristic pattern of a matched ventilation-perfusion defect and considerable air trapping during the washout phase. Conventional angiography and DSA displayed a smaller pulmonary artery on the affected side, with a poor peripheral vasculature. CT displayed a loss of lung volume in all cases, with diminished mean attenuation values, a markedly diminished vasculature and integrity of the main airways. In contrast to other imaging modalities, CT imaged bronchiectasis, which was the cause of the patients' clinical symptoms of bronchorrhea and hemoptysis. We conclude that CT of the chest is the most valuable imaging method for evaluating unilateral hyperlucent lung, particularly in symptomatic patients.

Adult↗
PubMed1993

Continuous c-fos expression precedes programmed cell death in vivo.

The development of a multicellular organism involves a delicate balance among the processes of proliferation, differentiation and death. Naturally occurring cell death aids tissue remodelling, eliminates supernumerary cell populations and provides structural elements such as hair and skin. In the nervous system, selective cell death contributes to the formation and organization of the spinal cord and sympathetic ganglia, retina and corpus callosum. But cell death also occurs in several neuropathological conditions, such as amyelotrophic lateral sclerosis and Alzheimer's disease. Therefore an elucidation of the mechanisms responsible for cell death is critical for an appreciation of both normal development and neuropathological disorders. Using a fos-lacZ transgenic mouse, we provide evidence showing that the continuous expression of Fos, beginning hours or days before the morphological demise of the cell, appears to be a hallmark of terminal differentiation and a harbinger of death.

3T3 Cells↗
PubMed1993

Proto-oncogene c-fos induction in thiamine-deficient encephalopathy. Protective effects of nicardipine on pyrithiamine-induced lesions.

Treatment of rats with the central thiamine antagonist, pyrithiamine, results in severe neurological symptoms such as ataxia and convulsions. Induction of proto-oncogene c-fos expression, often related to seizure activity, has been detected in the brains of thiamine-deficient rats by means of Northern blot analysis and in situ hybridization. Region-selective increases of lactate observed following thiamine deficiency development are largely coincident with histologically vulnerable regions. When thiamine-deficient rats were treated with the calcium channel blocker, nicardipine, lesions associated with thiamine deficiency did not appear and there was no induction of c-fos mRNA expression. This suggests a neurocytoprotective role of nicardipine to neuronal cell damage in thiamine-deficient encephalopathy.

Animals↗
PubMed1993

Nuclear calmodulin-binding proteins in rat neurons.

By using a 125I-calmodulin overlay assay, three major high-affinity calmodulin-binding proteins, showing apparent molecular masses of 135, 60, and 50 kDa, have been detected in purified nuclear fractions isolated from rat neurons. It has been shown that after extraction of the nuclei with nucleases and high salt, all these proteins remain strongly associated with the nuclear matrix. The 60- and 50-kDa proteins have been previously identified as subunits of the calmodulin-dependent protein kinase II. We report here the immunoblot identification of the 135-kDa calmodulin-binding protein as myosin light chain kinase. We also show that the calmodulin-dependent protein phosphatase calcineurin is present in the neuronal nuclei and associated with the nuclear matrix. The nuclear localization of both calcineurin and myosin light chain kinase has been confirmed by immunocytochemical studies.

Animals↗
PubMed1993

Diagnostic value of bronchoalveolar lavage in peripheral lung cancer.

A prospective study has been performed to assess the value of the addition of bronchoalveolar lavage (BAL) to the routine bronchoscopic exploration with bronchial washing (BW) and postbronchoscopy sputum (PBS) procedures in the diagnosis of peripheral primary lung cancer not visible through bronchoscope when fluoroscopic guidance is not available. BW, BAL, and PBS were performed in 67 patients with suspected primary lung cancer by peripheral lung lesion on chest radiograph (39 nodules and 28 infiltrates) and nonendoscopically visible lesion. The sequence of procedures was in all cases BW, BAL, and post-bronchoalveolar lavage bronchoaspirate (PBBA). An attempt was made to collect early morning postbronchoscopy samples of sputum (PBS) on 3 consecutive days. BW and PBBA were collected in the same test tube, and the cytologic result was considered as BW diagnostic yield. If there were negative bronchoscopic results, either percutaneous fine-needle aspiration or open-lung biopsy were performed for diagnosis. Fifty-five patients were found to have malignant disease (23 adenocarcinomas, 22 squamous cell carcinomas, six small cell carcinomas, and four bronchioloalveolar cell carcinomas). BAL was positive in 18 of the 55 (33%) carcinomas, and it gave the only positive result in six (11%). BW was also positive in 18 of the 55 (33%), but it gave positive results in only 3 (5%). PBS was positive in 13 of the 43 (30%) patients from whom samples could be spontaneously obtained and were suitable for cytologic examination (not consisting of saliva), and gave the only positive result in three (7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Lindane-induced convulsions in NMRI and OF1 mice: antagonism with (+)MK-801 and voltage-dependent calcium channel blockers.

The convulsant profile of lindane was investigated in OF1 and NMRI mice lines in relation to other convulsants acting at the GABAA and NMDA receptor complexes. Thus, a specific GABA-gated chloride channel blocker, PTX, a GABAA receptor antagonist, PTZ, and an excitatory amino acid receptor agonist, NMDA, were used. Antagonism of the convulsant effects of each of these drugs was investigated with (+)MK-801, a blocker of the NMDA-operated cation channel, and with nifedipine, a voltage-dependent calcium channel antagonist. While no differences in potency for PTX or PTZ to induce seizures were observed between OF1 and NMRI mice, lindane was approximately 80 and 90% more potent in its ability to induce seizures and lethality, respectively, in OF1 than in NMRI mice. Brain lindane concentrations at the moment of convulsion, measured after ED100 doses of lindane (400 and 200 mg/kg for NMRI and OF1 mice, respectively), did not differ between OF1 and NMRI mice, suggesting that the different potency of lindane between these mouse lines is a consequence of pharmacokinetic factors. Furthermore, (+)MK-801 antagonized seizures induced by either lindane, PTX or PTZ with similar potencies in both mouse lines. These results, coupled with the different pharmacokinetics of lindane in OF1 and NMRI mice, suggest that the distinct effects of lindane in these mice are not mediated by different activities at either NMDA or GABAA receptor complexes. Nonetheless, nifedipine antagonized lindane-induced seizures with a three-fold higher potency in NMRI than in OF1 mice. In contrast, nifedipine failed to antagonize PTX and PTZ convulsions in both OF1 and NMRI mice. These results suggest that besides the GABAA receptor complex other mechanisms related to calcium mobilization may be involved in the convulsant action of lindane.

Animals↗
PubMed1992

Effect of different convulsants on calmodulin levels and proto-oncogene c-fos expression in the central nervous system.

In the present study, a relationship between convulsant activity and two cellular events, changes in calmodulin (CaM) concentration and proto-oncogene c-fos expression has been considered. c-fos has been found activated after the administration of the organochlorine insecticide lindane, the Ca2+ channel agonist Bay K, and N-methyl-D-aspartate (NMDA). The administration of the voltage-dependent Ca2+ channel antagonist nifedipine was able to block the expression elicited by lindane. The effect of lindane on c-fos expression could not be blocked by prior administration of MK-801, a non-competitive antagonist of the NMDA receptor. These results suggest a possible role for the voltage-dependent Ca2+ channels in the mechanism of action of lindane. By means of in situ hybridization, the different patterns of c-fos expression after the administration of the mentioned compounds have been described. A possible modification of the levels of CaM has also been investigated. Among all the subcellular fractions considered, only levels of nuclear CaM appeared to be affected after the different treatments. The changes observed seemed to follow a similar pattern to that described for c-fos induction. Calcium entry through these voltage-dependent calcium channels would be the link between membrane depolarizing events and expression of c-fos and/or increase in nuclear CaM.

Animals↗
PubMed1992

Differential Protein Accumulation in Banana Fruit during Ripening.

Banana (Musa acuminata, cv Dwarf Cavendish) proteins were extracted from pulp tissue at different stages of ripening and analyzed by two-dimensional electrophoresis. The results provide evidence of differential protein accumulation during ripening. Two sets of polypeptides have been detected that increase substantially in ripe fruit. These polypeptides were characterized as glycoproteins by western blotting and concanavalin A binding assays. Antibodies againts tomato polygalacturonase cross-react with one of these sets of proteins.

Journal Article↗
PubMed1992

c-fos expression as a model for studying the action of hexachlorocyclohexane isomers in the CNS.

The induction of protooncogene c-fos in the CNS after administration of several convulsants has been studied. The organochlorine insecticide gamma-hexachlorocyclohexane (gamma-HCH, lindane) has been shown to induce c-fos expression in different brain areas. Pentylenetetrazole and picrotoxin, a known gamma-aminobutyric acid-receptor antagonist, have also been considered. The administration of two nonconvulsant isomers of gamma-HCH, alpha-HCH, and delta-HCH, before the mentioned toxicants, affects the protooncogene expression in different ways. The differential pattern of expression displayed by c-fos after these treatments suggests the presence of diverse mechanisms of action for the compounds studied.

Animals↗
PubMed1992

Effect of gamma-hexachlorocyclohexane and its isomers on proto-oncogene c-fos expression in brain.

By means of in situ hybridization, the induction of proto-oncogene c-fos in rat brain after administration of several convulsants has been studied. The organochlorine insecticide gamma-hexachlorocyclohexane (lindane) has been shown to induce c-fos expression in a dose dependent manner. 30 mg/kg of lindane increased c-fos expression in cortical and hippocampal areas. The two non convulsant isomers of lindane, alpha- and delta-HCH, were not able to induce the expression of the proto-oncogene, but blocked that elicited by lindane. Pentylenetetrazole (PTZ) and picrotoxin (PTX), a known GABAA-receptor antagonist, have also been considered. Both of them were able to induce c-fos, although the pattern of expression was not the same in each case. alpha- and delta-HCH, were administered prior to the mentioned toxicants, affecting the proto-oncogene expression in different ways. We propose here that the distribution of c-fos mRNA after different treatments can be used as a marker of neurotoxic action.

Animals↗
PubMed1991

c-fos and ornithine decarboxylase gene expression in brain as early markers of neurotoxicity.

An increase of proto-oncogene c-fos expression in cerebral cortex of rats treated with subconvulsant doses of the pesticide organochlorine lindane (gamma-hexachlorocyclohexane) has been detected using Northern blots. Immunohistochemical studies show that Fos protein was already increased in neuronal nuclei 3 h after treatment. The administration of the benzodiazepine diazepam prior to lindane totally blocked the activation of this proto-oncogene expression. Parallel to this increased expression of c-fos an activation of the ornithine decarboxylase (ODC) gene and enzyme was also observed. High levels of ODC mRNA and increased enzyme activity in cortex were found in rats following lindane treatment. These changes were attenuated by prior treatment of animals with diazepam. The co-induction of c-fos and ODC suggests a potential link between the ODC/polyamine system and the short-acting proto-oncogenes in stimulus-transcription coupling events.

Animals↗
PubMed1991

Presence of calmodulin and calmodulin-binding proteins in the nuclei of brain cells.

The nuclear calmodulin levels have been measured in rat neurons and glial cells. The values are 1.0 and 1.1 micrograms/mg of protein, respectively. These levels are about threefold higher than those in the nuclei of rat liver cells. We have also investigated the presence of several calmodulin-binding proteins in the nuclei of both brain cellular types. As similarly observed in the nuclei of liver cells, we detected the presence of alpha-spectrin and a 62-kDa calmodulin-binding protein (p62) in the nuclei of neurons and glial cells by immunoblotting and immunocytochemical methods. Both proteins are enriched in the purified nuclear matrix samples from both cellular types. In contrast to that occurring in rat hepatocytes, we have not been able to detect, by immunoblotting methods, caldesmon in the nuclear matrices of neurons and glial cells. The immunocytochemical studies suggest, however, that caldesmon can be present in the nuclei but in a fraction distinct from the nuclear matrices.

Animals↗
PubMed1988

An improved procedure for the isolation of rat brown adipose tissue cells.

A method for the isolation of brown adipocytes free of fat interferences and sensitive to noradrenalin is presented. The cells were isolated from pieces of brown adipose tissue with a collagenase treatment. The cells were obtained in the presence of heparin, in order to free the lipoprotein lipase attached to the cell surface. The cells were isolated in the presence of Amberlite XAD-2 [polymeric hydrophobic absorbent beads], which retained most of the fat droplets, formed from broken cells, during the process of disaggregation. The combined use of heparin and Amberlite XAD-2 during the isolation procedure resulted in a lowered cell basal oxygen consumption rate when compared with that of cells isolated with standard methods. The treatment presented lowered the availability of extracellular fatty acids for the isolated brown fat cells, resulting in lower operation of the thermogenin shunt, and thence in decreased basal oxygen consumption and higher sensitivity to glucose and noradrenalin stimulation.

Adipose Tissue, Brown↗