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Biomedical subjects

M Vendrell

Publications and source records attributed to M Vendrell.

At least 19 recordsLinked to original sources
PubMed2005

Genotype-phenotype correlation for pulmonary function in cystic fibrosis.

BACKGROUND: Since the CFTR gene was cloned, more than 1000 mutations have been identified. To date, a clear relationship has not been established between genotype and the progression of lung damage. A study was undertaken of the relationship between genotype, progression of lung disease, and survival in adult patients with cystic fibrosis (CF). METHODS: A prospective cohort of adult patients with CF and two CFTR mutations followed up in an adult cystic fibrosis unit was analysed. Patients were classified according to functional effects of classes of CFTR mutations and were grouped based on the CFTR molecular position on the epithelial cell surface (I-II/I-II, I-II/III-V). Spirometric values, progression of lung disease, probability of survival, and clinical characteristics were analysed between groups. RESULTS: Seventy four patients were included in the study. Patients with genotype I-II/I-II had significantly lower current spirometric values (p < 0.001), greater loss of pulmonary function (p < 0.04), a higher proportion of end-stage lung disease (p < 0.001), a higher risk of suffering from moderate to severe lung disease (odds ratio 7.12 (95% CI 1.3 to 40.5)) and a lower probability of survival than patients with genotype I-II/III, I-II/IV and I-II/V (p < 0.001). CONCLUSIONS: The presence of class I or II mutations on both chromosomes is associated with worse respiratory disease and a lower probability of survival.

Adult↗
PubMed2000

Utility of the antibody response to a conjugated Haemophilus influenzae type B vaccine for diagnosis of primary humoral immunodeficiency.

Antibody response to an Haemophilus influenzae type b (Hib)-conjugated vaccine was studied in 59 healthy adults (mean age: 32 yr) and 22 patients with humoral immunodeficiencies (mean age: 32 yr) to determine its usefulness in the diagnosis of defective antibody formation. Twenty of the healthy adults and nine of the patients were also immunized with a pneumococcal vaccine. Serum specific antibodies were measured by ELISA. Adequate response to both vaccines was defined using the lower limit of the two-tailed 90% probability interval of postimmunization specific IgG of the healthy adults. By using this cutoff, responders were considered to be those with an absolute increase in anti-Hib IgG titers higher than 2.28 microgram/ml, and in anti-Streptococcus pneumoniae IgG higher than 395 arbitrary units/ml. With these criteria, 85% (50 of 59) of the healthy adults responded with anti-Hib IgG and 75% (15 of 20) with anti-pneumococcal IgG. All healthy adults receiving both vaccines responded to at least one. None of the patients with humoral immunodeficiencies responded to either vaccine. Evaluation of the antibody response to both the Hib and pneumococcal vaccines may facilitate the diagnosis of humoral immunodeficiency and selection of patients to receive immunoglobulin therapy.

Adolescent↗
PubMed1999

Relationships between volatile production, fruit quality, and sensory evaluation in Granny Smith apples stored in different controlled-atmosphere treatments by means of multivariate analysis.

Aroma compounds, quality parameters, and sensory evaluation of Granny Smith apples were analyzed after 3, 5, and 7 months of cold storage in three controlled-atmosphere (CA) treatments, in which oxygen and carbon dioxide were held at 1, 2, and 3%. During poststorage ripening, the apples were kept at 20 degrees C for 1, 5, and 10 days before analytical measurements were made. The highest volatile emission was obtained after 5 months of storage in all CA treatments, reaching its highest value when a low-oxygen CA (LO) was used. Ultralow-oxygen CA (ULO) showed the highest ability to maintain apple firmness. The correlation among analytical and sensory parameters suggests that ethyl 2-methylbutyrate, 1-butanol, pentyl acetate, and tert-butyl propionate are the aroma compounds with the highest influence in the sensorial score. Concerning CA treatments, LO and ULO appear to be very valuable technologies for maintaining the sensorial quality even after 7 months of storage.

Alcohols↗
PubMed1999

Characterization of two divergent endo-beta-1,4-glucanase cDNA clones highly expressed in the nonclimacteric strawberry fruit.

Two cDNAs clones (Cel1 and Cel2) encoding divergent endo-beta-1, 4-glucanases (EGases) have been isolated from a cDNA library obtained from ripe strawberry (Fragaria x ananassa Duch) fruit. The analysis of the amino acid sequence suggests that Cel1 and Cel2 EGases have different secondary and tertiary structures and that they differ in the presence of potential N-glycosylation sites. By in vitro translation we show that Cel1 and Cel2 bear a functional signal peptide, the cleavage of which yields mature proteins of 52 and 60 kD, respectively. Phylogenetic analysis revealed that the Cel2 EGase diverged early in evolution from other plant EGases. Northern analysis showed that both EGases are highly expressed in fruit and that they have different temporal patterns of accumulation. The Cel2 EGase was expressed in green fruit, accumulating as the fruit turned from green to white and remaining at an elevated, constant level throughout fruit ripening. In contrast, the Cel1 transcript was not detected in green fruit and only a low level of expression was observed in white fruit. The level of Cel1 mRNA increased gradually during ripening, reaching a maximum in fully ripe fruit. The high levels of Cel1 and Cel2 mRNA in ripe fruit and their overlapping patterns of expression suggest that these EGases play an important role in softening during ripening. In addition, the early expression of Cel2 in green fruit, well before significant softening begins, suggests that the product of this gene may also be involved in processes other than fruit softening, e.g. cell wall expansion.

Amino Acid Sequence↗
PubMed1999

Specific antibody response against the 23-valent pneumococcal vaccine in patients with alpha(1)-antitrypsin deficiency with and without bronchiectasis.

OBJECTIVE: To assess the specific antibody response against polyvalent pneumococcal vaccine in patients with alpha(1)-antitrypsin deficiency (AATD) and respiratory infections. DESIGN AND PARTICIPANTS: We investigated specific IgG, IgG1, and IgG2 antibody responses against the 23-valent antipneumococcal vaccine in 18 patients with AATD phenotype PiZZ, 9 of whom had bronchiectasis and 4 a history of recurrent pneumonia, and compared them with a control group of 40 healthy volunteers. INTERVENTIONS: Blood samples were drawn just prior to and 3 weeks after immunization. MEASUREMENTS AND RESULTS: Quantification of specific IgG and its subclasses was performed by an enzyme-linked immunosorbent assay. For patients with AATD, mean increases in specific antipneumococcal titers were 4.7-fold (25 to 75% quartiles, 2.5- to 6.8-fold) for total IgG, 3.2-fold (1.2- to 4.9-fold) for IgG1, and 2.1-fold (1.8- to 3.7-fold) for IgG2. For the control group, the values were 3.3-fold (1.8- to 5.8-fold) for total IgG, 2. 5-fold (1.9- to 3.4-fold) for IgG1, and 3.1-fold (1.9- to 4.5-fold) for IgG2; differences were not significant. Patients with bronchiectasis showed a tendency toward higher levels of IgG subclasses than both control subjects and patients without bronchiectasis; however, there was a tendency toward lower postvaccination serum levels of specific antipneumococcal IgG, IgG1, and IgG2 in patients with bronchiectasis compared with patients without bronchiectasis, but this trend did not reach statistical significance. Three of the four patients with recurrent pneumonia did not show an appropriate IgG2 response. CONCLUSIONS: These results suggest that, as a group, patients with AATD have a preserved antibody response against pneumococcal polysaccharides. Patients with bronchiectasis show a tendency toward a decreased antibody response, even with increased serum levels of most Ig types. Individuals with an impaired IgG2 response seem to be at increased risk of recurrent pneumonia. Considering the pernicious effect of pulmonary infections on these patients and the preserved antibody response in a majority of them, pneumococcal vaccination should be recommended to patients with AATD.

Adult↗
PubMed1998

A gene expression approach to mapping the functional maturation of the hippocampus.

Previous studies have shown an association among seizures, neuronal death and the expression of cellular immediate-early genes (cIEG). To understand further the relationship between these processes, we investigated the ability of kainic acid (KAI) to induce behavioral responses and gene expression in the hippocampus of developing fos-lacZ transgenic mice. Despite the fact that KAI elicited seizure-like activity from P2 onwards, Fos-lacZ was first detected at P5 in CA3 pyramidal neurons. Thus, intense behavioral responses were not invariably associated with fos-lacZ expression. Furthermore, while adult CA3 neurons are highly susceptible to KAI toxicity, they are resistant at P5. Therefore, the presence of Fos-lacZ in CA3 neurons is not necessarily predictive of their fate. By P10, Fos-lacZ was induced in CA3 neurons and in the most mature granule neurons of the dentate gyrus (DG). Between P15 and P20, KAI induced fos-lacZ in all CA1 and CA3 pyramidal neurons and most granule neurons of the DG. This stereotypical pattern of fos-lacZ expression mirrors the ontogeny of hippocampal circuitry and glutamate signalling. Thus the fos-lacZ mice can be used to map the functional maturation of the nervous system with single cell resolution. The scope of this approach was extended by administration of additional chemoconvulsants to fos-lacZ mice and by analysis of fos-lacZ transgenic mice with mutations in their FAP site. These additional studies revealed anatomical and mechanistic differences in glutamate receptor-mediated transcriptional responses in the nervous system.

Animals↗
PubMed1998

Influence of Different Oxygen and Carbon Dioxide Concentrations during Storage on Production of Volatile Compounds by Starking Delicious Apples.

Starking Delicious apples were cold-stored in semicommercial chambers in normal atmosphere and in different controlled atmospheres in which oxygen and carbon dioxide were held at 1%, 2%, and 3% for 3, 5, and 7 months. After storage, fruit was kept at ambient temperature (20 degrees C) for 1, 5, and 10 days. The volatile emission was collected and analyzed. After all storage periods and conditions, the total aromatic volatile emission was higher than at commercial harvest. The highest emission of volatile components was obtained after 5 months of storage, in which controlled-atmosphere conditions gave a lower concentration than normal cold storage. Esters were the main volatiles detected (>98%). Acetate ester concentrations after all storage periods assayed were higher at 3% and 2% O(2)/CO(2). The components that contributed most to the characteristic aroma of Starking Delicious were ethyl 2-methylbutyrate, ethyl butyrate, and ethyl hexanoate. Their concentrations were higher after 5 months of storage and also during poststorage at ambient temperature (20 degrees C).

Journal Article↗
PubMed1997

A cDNA clone highly expressed in ripe banana fruit shows homology to pectate lyases.

A cDNA clone (Ban17), encoding a protein homologous to pectate lyase, has been isolated from a cDNA library from climacteric banana fruit by means of differential screening. Northern analysis showed that Ban17 mRNA is first detected in early climacteric fruit, reaches a steady-state maximum at the climacteric peak, and declines thereafter in overripe fruit. Accumulation of the Ban17 transcript can be induced in green banana fruit by exogenous application of ethylene. The demonstrates that expression of this gene is under hormonal control, its induction being regulated by the rapid increase in ethylene production at the onset of ripening. The deduced amino acid sequence derived from the Ban17 cDNA shares significant identity with pectate lyases from pollen and plant pathogenic bacteria of the genus Erwinia. Similarity to bacterial pectate lyases that were proven to break down the pectic substances of the plant cell wall suggest that Ban17 might play a role in the loss of mesocarp firmness during fruit ripening.

Amino Acid Sequence↗
PubMed1997

Characterization of specific immunoglobulin G (IgG) and its subclasses (IgG1 and IgG2) against the 23-valent pneumococcal vaccine in a healthy adult population: proposal for response criteria.

The aim of the study was to standardize an enzyme-linked immunosorbent assay (ELISA) method for the quantification of immunoglobulin G (IgG) and its subclasses (IgG1 and IgG2) against the 23-valent pneumococcal vaccine and to establish the criteria for a normal response to the vaccine. Forty healthy individuals (20 women and 20 men; mean age, 29 years) were studied. All were vaccinated with the 23-valent pneumococcal vaccine; blood samples were drawn just prior to and 3 weeks after immunization. Quantification of specific IgG and its subclasses was performed by an ELISA with the vaccine as the antigen. The linearity of the ELISA method was demonstrated by the similar slopes of the linear regression lines generated from the titration of sera with different antibody concentrations. The specificity of the antibodies against the vaccine was demonstrated by (i) an absorption test with pneumococcal vaccine, (ii) a cross-reactivity experiment with Haemophilus influenzae type b polysaccharide, and (iii) affinity chromatography with protein A-Sepharose. Response to the vaccine was defined by using the lower level of the 90% probability interval (one-tailed) for postimmunization-specific IgG, IgG1, and IgG2. By using this cutoff, responders were considered to be those with an absolute increase in antibody titers higher than 395 arbitrary units/ml for IgG, 0.350 A450 units for IgG1, and 0.314 A450 units for IgG2. Overall, 20 (50%) subjects had IgG, IgG1, and IgG2 responses, 9 (22.5%) had IgG and IgG2 responses, 4 (10%) had IgG1 responses, 3 (7.5%) had IgG and IgG1 responses, and 4 (10%) were nonresponders. Ninety percent of our population responded to the 23-valent pneumococcal vaccine. Up to 10% of healthy individuals may respond to an IgG subclass without significant increases in total IgG titers. The ELISA method that is described may be useful for evaluating the specific antibody response against polysaccharides.

Adult↗
PubMed1997

Empiric treatments impair the diagnostic yield of BAL in HIV-positive patients.

OBJECTIVE: To investigate the influence of empiric treatments prior to fiberoptic bronchoscopy (FOB) on the diagnostic yield of BAL in HIV-positive patients with respiratory symptoms. METHOD: We studied 123 consecutive FOBs with BAL in HIV-positive patients; 101 of these patients (82%) had received previous antimicrobial treatment from 1 to 60 days. Diagnostic yield of BAL for Pneumocystis carinii, Mycobacterium tuberculosis, and bacterial pneumonia was compared between patients with and without previous empiric treatments. RESULTS: A diagnosis was obtained in 85 patients (69%), of whom 17 (20%) had multiple infections. Diagnostic yield was higher in patients without previous treatment, 91% (20/22) compared with 64% (65/101), p < 0.03. Diagnostic yield was also higher for bacterial pneumonia: seven isolations from 22 patients not receiving previous empiric treatment (32%), compared with 11 of those who had (11%; p < 0.02). The duration of empiric treatment against P carinii in patients in whom it was isolated was significantly shorter than in those in whom P carinii was not detected (3.5 +/- 1.8 days compared with 5.2 +/- 2.4 days; p = 0.003). FOB permitted a change in treatment in 62% of patients with a final diagnosis. CONCLUSION: This study demonstrates that empiric treatments prior to FOB significantly impair the diagnostic yield of BAL in detecting common pathogens in HIV-infected patients with respiratory symptoms.

AIDS-Related Opportunistic Infections↗
PubMed1996

[Theophyllines of 12- and 24-hour sustained-release. Comparative study].

To compare 24-h and 12-h delayed-release theophylline in asthmatic patients, in terms of clinical stability and respiratory function, side effects and required dose, clinical tolerance and plasma concentrations. Patients with bronchial asthma in stable phase taking theophylline every 12 h were selected. Each patient received 12-h (treatment A) and 24-h (treatment B) theophylline formulas in a prospective, cross-over study with paired data for periods of 15 days. We evaluated theophylline doses, blood levels, clinical course, lung function and side effects. Twenty patients were enrolled. No significant differences between the two treatments were observed in mean dose of theophylline per kg body weight required to obtain therapeutic plasma concentrations (treatment A: 9.36 +/- 1.88 mg/kg/day; treatment B: 9.6 +/- 1.7 mg/kg/day). Mean blood level just before administration of a the next dose was lower with the 24-h formula, but still within therapeutic margins (treatment A: 7.31 +/- 2.27 micrograms/ml; treatment B: 10.66 +/- 2.86 micrograms/ml; p = 0.002). There were no differences in side effects after the adjustment period or in FEV1 after each treatment period. Peak expiratory flow remained stable during the study. The 24-h delayed release theophylline formula was similar to the 12-h formula in dose required by asthmatic patients and in therapeutic plasma concentrations throughout the day.

Adult↗
PubMed1996

IgG subclass deficiencies associated with bronchiectasis.

Only a small number of patients with IgG subclass deficiencies (IgGSD) have been observed to have bronchiectasis. Moreover, in the series of patients with bronchiectasis, IgGSD have not been found at any frequency, and the etiology of bronchiectasis remains unclear in 29 to 49% of cases. Serum concentrations of total IgG, IgA, and IgG subclasses as well as pulmonary function were measured in 65 patients (aged: 10 to 74 yr) with bronchiectasis of unknown etiology. An ELISA test was performed to quantify subclasses 1 through 4 using subclass-specific antihuman monoclonal antibodies. IgG subclass estimation in a healthy population with age-stratified normal ranges was derived from 100 adults, 37 children aged between 10 and 12 yr, and 27 adolescents aged between 13 and 16 yr. Serum concentrations of specific IgG antibodies to Haemophilus influenzae type b capsular polysaccharide (Hib-PRP) were also assayed by an ELISA test in 19 of the patients (10 with IgGSD and nine with non-IgGSD) and in 58 healthy individuals before and 3 wk after immunization with Hib-PRP conjugated to meningococcal outer membrane protein complex (OMPC). Thirty-one patients (48%) had low serum concentrations of one or more IgG subclasses (19 IgG2 deficiencies, 2 IgG3 deficiencies, 3 IgG4 deficiencies, and 7 combined subclass deficiencies). All patients showed increased levels of total IgG, IgG1, and IgA, but this rise was significantly higher in patients without IgGSD. Patients with IgGSD showed impaired antibody response to Hib-PRP compared with patients with non-IgGSD and the control group. IgGSD, particularly IgG2 deficiency, are not an unusual cause of bronchiectasis. Therefore, serum levels of IgG subclasses must be assayed whenever other causes of bronchiectasis have been ruled out.

Adolescent↗