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Fernando Martinez

Publications and source records attributed to Fernando Martinez.

16 recordsLinked to original sources
PubMed2006

Selective modulation of protein kinase A I and II reveals distinct roles in thyroid cell gene expression and growth.

A global gene expression profiling of TSH stimulation on differentiated (FRTL5) and partially dedifferentiated [FRT/TSHR (TSH receptor)] rat thyroid cells was performed. A total of 123 TSH-regulated genes (95 newly described) were identified in FRTL5, whereas no significant transcriptional modifications were seen in FRT/TSHR cells. Because regulatory subunit IIbeta (RIIbeta) of protein kinase A (PKA), a key element downstream of cAMP, was expressed in FRTL5 but not in cAMP-refractory FRT/TSHR cells, we hypothesized that this gene may play an important role in TSH signaling. We therefore performed a series of experiments to investigate the involvement of RIIbeta and the different PKA isoforms. A positive effect of PKA II- but not of PKA I-selective activation on gene transcription and proliferation in FRTL5 cells, as well as an impairment of TSH nuclear effects after RIIbeta silencing were observed, suggesting that PKA II plays an essential role in TSH signaling. This view was supported by the restoration of TSH nuclear effects after reexpression of RIIbeta in FRT/TSHR cells. Because PKA I stimulation could increase iodide uptake in FRTL5 cells without affecting gene transcription, PKA I may mediate TSH actions at posttranscriptional levels. Analyses on three human cancer cell lines confirmed the possible loss of RIIbeta expression and antiproliferative activity of PKA I-selective cAMP analogs ( approximately 60% at 200 microm in BRAF-mutated cells). The inhibitory effect of PKA I apparently required constitutive MAPK activation and was associated with an inhibition of ERK phosphorylation. These findings may open new therapeutic perspectives in patients with thyroid cancer.

Animals↗
PubMed2006

A brief targeted review of susceptibility factors, environmental exposures, asthma incidence, and recommendations for future asthma incidence research.

Relative to research on effects of environmental exposures on exacerbation of existing asthma, little research on incident asthma and environmental exposures has been conducted. However, this research is needed to better devise strategies for the prevention of asthma. The U.S. Environmental Protection Agency (EPA) and National Institute of Environmental Health Sciences held a conference in October 2004 to collaboratively discuss a future research agenda in this area. The first three articles in this mini-monograph summarize the discussion on potential putative environmental exposure; they include an overview of asthma and conclusions of the workshop participants with respect to public health actions that could currently be applied to the problem and research needs to better understand and control the induction and incidence of asthma, the potential role of indoor/outdoor air pollutants in the induction of asthma), and biologics in the induction of asthma. Susceptibility is a key concept in the U.S. EPA "Asthma Research Strategy" document and is associated with the U.S. EPA framework of protecting vulnerable populations from potentially harmful environmental exposures. Genetics, age, and lifestyle (obesity, diet) are major susceptibility factors in the induction of asthma and can interact with environmental exposures either synergistically or antagonistically. Therefore, in this fourth and last article we consider a number of "susceptibility factors" that potentially influence the asthmatic response to environmental exposures and propose a framework for developing research hypotheses regarding the effects of environmental exposures on asthma incidence and induction.

Asthma↗
PubMed2005

Peribronchiolar metaplasia: a common histologic lesion in diffuse lung disease and a rare cause of interstitial lung disease: clinicopathologic features of 15 cases.

Peribronchiolar metaplasia (PBM) is a histologic lesion consisting of peribronchiolar metaplasia (PBM) of bronchiolar-type epithelium. Although widely recognized, PBM has received little attention in the pathologic literature and is not known to have clinical significance. We identified 15 cases in which PBM was the only major histologic finding in surgical lung biopsies from patients with interstitial lung disease (PBM-ILD), and we reviewed the clinical, imaging, and pathologic findings. The mean age was 57 years (range, 44-74 years) with 13 females and 2 males. One patient had been a welder with fume and asbestos exposure; another had pigeon exposure. Smoking history was available for 13 patients: three current smokers, one cocaine user, two former smokers, and seven never smokers. Three patients had collagen vascular disease. One had elevated serum antinuclear antibody titers. Pulmonary function data were available for 10 patients: one obstructive, five restrictive, two mixed obstructive and restrictive, and two normal. Computerized tomography in 7 patients showed mosaic attenuation in 3 patients and air trapping in 1 patient; no bronchiectasis, septal lines, or honeycombing were seen in any cases. All 11 patients with available follow-up are alive; 4 of them have experienced symptomatic improvement (follow-up, 0.6-6.9 years; mean, 2.4 years). PBM was found focally in other interstitial lung diseases, which were assessed for this lesion: 59% of usual interstitial pneumonia (17 of 29), 50% of nonspecific interstitial pneumonia (10 of 20), desquamative interstitial pneumonia (3 of 6), hypersensitivity pneumonitis (9 of 18), and 11% of respiratory bronchiolitis (2 of 18). In summary, PBM is a common histologic finding in various interstitial lung disorders. It is rarely the sole major lung biopsy finding in patients presenting with interstitial lung disease (PBM-ILD). Patients are mostly older women, with mild symptoms and CT findings. Survival appears to be favorable.

Adult↗
PubMed2003

A randomized trial comparing lung-volume-reduction surgery with medical therapy for severe emphysema.

BACKGROUND: Lung-volume-reduction surgery has been proposed as a palliative treatment for severe emphysema. Effects on mortality, the magnitude and durability of benefits, and criteria for the selection of patients have not been established. METHODS: A total of 1218 patients with severe emphysema underwent pulmonary rehabilitation and were randomly assigned to undergo lung-volume-reduction surgery or to receive continued medical treatment. RESULTS: Overall mortality was 0.11 death per person-year in both treatment groups (risk ratio for death in the surgery group, 1.01; P=0.90). After 24 months, exercise capacity had improved by more than 10 W in 15 percent of the patients in the surgery group, as compared with 3 percent of patients in the medical-therapy group (P<0.001). With the exclusion of a subgroup of 140 patients at high risk for death from surgery according to an interim analysis, overall mortality in the surgery group was 0.09 death per person-year, as compared with 0.10 death per person-year in the medical-therapy group (risk ratio, 0.89; P=0.31); exercise capacity after 24 months had improved by more than 10 W in 16 percent of patients in the surgery group, as compared with 3 percent of patients in the medical-therapy group (P<0.001). Among patients with predominantly upper-lobe emphysema and low exercise capacity, mortality was lower in the surgery group than in the medical-therapy group (risk ratio for death, 0.47; P=0.005). Among patients with non-upper-lobe emphysema and high exercise capacity, mortality was higher in the surgery group than in the medical-therapy group (risk ratio, 2.06; P=0.02). CONCLUSIONS: Overall, lung-volume-reduction surgery increases the chance of improved exercise capacity but does not confer a survival advantage over medical therapy. It does yield a survival advantage for patients with both predominantly upper-lobe emphysema and low base-line exercise capacity. Patients previously reported to be at high risk and those with non-upper-lobe emphysema and high base-line exercise capacity are poor candidates for lung-volume-reduction surgery, because of increased mortality and negligible functional gain.

Aged↗
PubMed2003

Single-nucleotide polymorphisms in the Toll-like receptor 9 gene (TLR9): frequencies, pairwise linkage disequilibrium, and haplotypes in three U.S. ethnic groups and exploratory case-control disease association studies.

TLR9 is a mammalian Toll-like receptor homologue that appears to function as an innate immune pattern recognition protein for motifs that are far more common in bacterial than in mammalian DNA. The gene was sequenced in 71 subjects from three self-identified U.S. ethnic groups to identify single-nucleotide polymorphisms (SNPs). A total of 20 SNPs were found of which only 20% were in the public dbSNP database. Four SNPs were relatively common in all three ethnic samples. Using these four SNPs, seven distinct haplotypes were statistically inferred, of which four accounted for 75% or more chromosomes. These four haplotypes could be distinguished from each other by the alleles of two SNPs (-1237 and 2848). Five exploratory nested case-control disease-association studies (asthma, DVT, MI, and COPD in European Americans and asthma in African Americans) were performed by genotyping DNA collected from four ongoing cohort studies. There was evidence suggesting increased risk for asthma with a C allele at -1237 (odds ratio 1.85, 95%CI 1.05 to 3.25) among European Americans (genotypes available from 67 cases and 152 controls). No other significant disease associations were detected. Replication of this finding in other, larger samples is needed. This study suggests that there is substantial diversity in human TLR9, possibly associated with asthma in Europeans but not African Americans. No association was detected with three other diseases potentially related to innate immunity.

Black People↗
PubMed2003

Phaeohyphomycosis of the central nervous system in immunocompetent hosts: report of a case and review of the literature.

BACKGROUND: Phaeohyphomycosis refers to infections caused by phaeoid fungi that can have an aggressive course in normal hosts. Involvement of the central nervous system may occur with a generally poor outcome. Clinical report and literature review: We report a case of Bipolaris sp. brain abscess in an immunologically competent host. We also review all previous cases of cerebral phaeohyphomycosis in normal hosts reported in the literature to date. CONCLUSIONS: Central nervous system phaeohyphomycosis remains an unusual disease; however, its incidence has been increasing in recent years. The prognosis of this condition is still poor, despite medical and surgical interventions. Aggressive diagnostic approaches and careful interpretation of cultures might modify the natural history of this disease.

Adult↗
PubMed2002

The burden of asthma in the United States: level and distribution are dependent on interpretation of the national asthma education and prevention program guidelines.

Asthma imposes a growing burden on society in terms of morbidity, quality of life, and healthcare costs. Although federally sponsored national surveys provide estimates of asthma prevalence, these surveys are not designed to characterize the burden of asthma by self-reported disease activity. We sought to characterize asthma burden in the United States. This study was based on a cross-sectional random-digit-dial household telephone survey designed to identify adult patients and parents of children with current asthma. Global asthma burden was comprised of three components: short-term symptom burden (4-week recall), long-term symptom burden (past year), and functional impact (activity limitation). Using this construct, only 10.7% of individuals were classified as having a global asthma burden consistent with mild intermittent disease, and 77.3% had moderate to severe persistent disease. These results suggest that a majority of the United States population with asthma experiences persistent rather than intermittent asthma burden. In addition, the discordance in type and distribution of asthma symptoms reported by individual subjects suggests that the exact estimate of the burden of asthma is related to how the National Asthma Education and Prevention Program classification is operationalized. Inquiry into recent day or nighttime symptoms alone underestimates the burden of asthma and may lead to inadequate treatment of asthma based on national guideline recommendations.

Adolescent↗
PubMed2002

Mantle wedge control on back-arc crustal accretion.

At mid-ocean ridges, plate separation leads to upward advection and pressure-release partial melting of fertile mantle material; the melt is then extracted to the spreading centre and the residual depleted mantle flows horizontally away. In back-arc basins, the subducting slab is an important control on the pattern of mantle advection and melt extraction, as well as on compositional and fluid gradients. Modelling studies predict significant mantle wedge effects on back-arc spreading processes. Here we show that various spreading centres in the Lau back-arc basin exhibit enhanced, diminished or normal magma supply, which correlates with distance from the arc volcanic front but not with spreading rate. To explain this correlation we propose that depleted upper-mantle material, generated by melt extraction in the mantle wedge, is overturned and re-introduced beneath the back-arc basin by subduction-induced corner flow. The spreading centres experience enhanced melt delivery near the volcanic front, diminished melting within the overturned depleted mantle farther from the corner and normal melting conditions in undepleted mantle farther away. Our model explains fundamental differences in crustal accretion variables between back-arc and mid-ocean settings.

Journal Article↗
PubMed2002

Single-nucleotide polymorphisms in the interleukin-10 gene: differences in frequencies, linkage disequilibrium patterns, and haplotypes in three United States ethnic groups.

Interleukin-10 (IL-10) is a cytokine that seems to function as a downregulator of the innate (nonadaptive) immune system. Approximately three-quarters of interindividual variability in human IL-10 levels has been attributed to genetic variation, and there is evidence suggesting a potential role for IL-10 in a range of human diseases. To provide a basis for haplotype analysis and future disease association studies, we characterized genetic variation in IL10 by sequencing all exons, and 2.5 kb of the 5'- and the 3'-flanking region in a panel of DNA samples from 24 African Americans, 23 European Americans, and 24 Hispanic Americans. The region sequenced was found to contain 28 single-nucleotide polymorphisms (SNPs), 16 with frequency >2% and 14 with frequency >5%. All SNPs with frequency >5% were present in subjects from all three populations. No SNP caused amino acid changes. Differences in pairwise linkage-disequilibrium (LD) patterns and in SNP and haplotype frequency distributions among the three populations may be of potential importance for disease association studies.

Bayes Theorem↗
PubMed2002

Contribution of donor age to the recent decrease in patient survival among HCV-infected liver transplant recipients.

Recurrent hepatitis occurs in the majority of patients undergoing liver transplantation for hepatitis C virus (HCV) cirrhosis, with progression to cirrhosis in up to 30% after 5 years. Based on these data, a decrease in survival can be anticipated with prolonged follow-up. Furthermore, posttransplantation HCV-fibrosis progression has been shown in recent years to increase. Our aims were (1) to describe the natural history of HCV-infected recipients, particularly to determine whether survival has decreased in recent years; (2) to compare this outcome with that observed in non-HCV-infected cirrhosis controls; and (3) to determine the factors associated with disease severity and survival. Among 522 cirrhotic patients undergoing transplantation between 1991 and 2000, 283 (54%) were infected with HCV. Yearly biopsies were performed in these recipients and at 1 and 5 years in the remainder. With similar follow-up, the percentage of deaths in the HCV(+) group was significantly higher than in the HCV- group (37% vs. 22%, P <.001), and patient survival was lower (77%, 61%, 55% vs. 87%, 76%, 70% at 1, 5, and 7 years, respectively; P =.0001). Although survival has increased in the HCV- group in recent years, it has significantly decreased in HCV recipients (P <.0001). The main cause of death among the latter was decompensated graft cirrhosis (n = 23/105, 22%), whereas that of HCV- patients was infections (n = 10/52, 19%). Reasons for the recent worse outcome in HCV+ recipients include the increased donor age and stronger immunosuppression. In conclusion, patient survival is lower among HCV+ recipients than among HCV- ones and has been decreasing in recent years. The aging of donors is a major contributor to this worse outcome.

Adult↗
PubMed2002

Inadequate use of asthma medication in the United States: results of the asthma in America national population survey.

BACKGROUND: Studies of the use of anti-inflammatory asthma therapy have been limited to selected populations or have been unable to assess the appropriateness of therapy for individuals. OBJECTIVE: We sought to describe the current use of asthma medication in the United States population and to examine the influence of symptoms and sociodemographics on medication use. METHODS: This study was based on a cross-sectional, national, random-digit-dial household telephone survey in 1998 designed to identify adult patients and parents of children with current asthma. Respondents were classified as having current asthma if they had a physician's diagnosis of asthma and were either taking medication for asthma or had asthma symptoms during the past year. RESULTS: One or more persons met the study criteria for current asthma in 3273 (7.8%) households in which a screening questionnaire was completed. Of these, 2509 persons (721 children <16 years) with current asthma were interviewed. Current use of anti-inflammatory medication was reported by 507 (20.1%). Of these, most were using inhaled corticosteroids (72.5%), with use of antileukotrienes reported by 11.4% and use of cromolyn-nedocromil reported by 18.6%. Of persons with persistent asthma symptoms in the past month, 26.2% reported current use of some form of anti-inflammatory medication. In bivariate analysis persons reporting lower income, less education, and present unemployment, as well as smokers, were significantly (P <.001) less likely to report current anti-inflammatory use than were other populations. In a multiple regression model nonsmokers and those of white, non-Hispanic ethnicity, as well as persons reporting less asthma control, were more likely to report current anti-inflammatory medication use. CONCLUSION: In the United States use of appropriate asthma therapy remains inadequate. Strategies to increase use of anti-inflammatory therapy among patients with asthma are needed. These might include methods to increase access to asthma care for minorities and the socioeconomically disadvantaged.

Adolescent↗
PubMed2002

Plasma cell granuloma of the thyroid.

Plasma cell granuloma of the thyroid is an uncommon lesion; only 6 cases have been reported in the English literature to date. All reported cases occurred in women, mostly after the age of 50 years. We report a case of plasma cell granuloma of the thyroid in a 46-year-old woman with a 20-year history of euthyroid goiter and a positive family history of goiter in 3 close relatives. The lesion was composed of sheets of plasma cells involving the entire parenchyma that histologically resembled plasmacytoma. Plasmacytoma was excluded by demonstration of polyclonal kappa/lambda light chain immunostaining and by lack of evidence of clonal bands by polymerase chain reaction for immunoglobulin heavy-chain gene rearrangement. Similarly, the predominant histologic pattern in all previously reported cases is that of marked plasma cell infiltration. A family history of thyroid disease (goiter, thyroiditis) was associated with diffuse involvement of the thyroid. Prognosis after surgery is excellent, and to our knowledge no cases of malignant transformation or recurrence have been described.

Antigens, CD↗
PubMed2001

Patients at high risk of death after lung-volume-reduction surgery.

BACKGROUND: Lung-volume-reduction surgery is a proposed treatment for emphysema, but optimal selection criteria have not been defined. The National Emphysema Treatment Trial is a randomized, multicenter clinical trial comparing lung-volume-reduction surgery with medical treatment. METHODS: After evaluation and pulmonary rehabilitation, we randomly assigned patients to undergo lung-volume-reduction surgery or receive medical treatment. Outcomes were monitored by an independent data and safety monitoring board. RESULTS: A total of 1033 patients had been randomized by June 2001. For 69 patients who had a forced expiratory volume in one second (FEV1) that was no more than 20 percent of their predicted value and either a homogeneous distribution of emphysema on computed tomography or a carbon monoxide diffusing capacity that was no more than 20 percent of their predicted value, the 30-day mortality rate after surgery was 16 percent (95 percent confidence interval, 8.2 to 26.7 percent), as compared with a rate of 0 percent among 70 medically treated patients (P<0.001). Among these high-risk patients, the overall mortality rate was higher in surgical patients than medical patients (0.43 deaths per person-year vs. 0.11 deaths per person-year; relative risk, 3.9; 95 percent confidence interval, 1.9 to 9.0). As compared with medically treated patients, survivors of surgery had small improvements at six months in the maximal workload (P= 0.06), the distance walked in six minutes (P=0.03), and FEV1 (P<0.001), but a similar health-related quality of life. The results of the analysis of functional outcomes for all patients, which accounted for deaths and missing data, did not favor either treatment. CONCLUSIONS: Caution is warranted in the use of lung-volume-reduction surgery in patients with emphysema who have a low FEV1 and either homogeneous emphysema or a very low carbon monoxide diffusing capacity. These patients are at high risk for death after surgery and also are unlikely to benefit from the surgery.

Aged↗