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Mario Castro

Publications and source records attributed to Mario Castro.

31 records · Page 2Linked to original sources
PubMed2005

Self-organized ordering of nanostructures produced by ion-beam sputtering.

We study the self-organized ordering of nanostructures produced by ion-beam sputtering of targets amorphizing under irradiation. By introducing a model akin to models of pattern formation in aeolian sand dunes, we extend consistently the current continuum theory of erosion by IBS. We obtain new nonlinear effects responsible for the in-plane ordering of the structures, whose strength correlates with the degree of ordering found in experiments. Our results highlight the importance of redeposition and surface viscous flow to this nanopattern formation process.

Journal Article↗
PubMed2005

Community Asthma Program improves appropriate prescribing in moderate to severe asthma.

Asthma guidelines, established by the National Asthma Education and Prevention Panel (NAEPP), seek to guide physicians in the appropriate assessment and treatment of asthma. Poor physician adherence to these guidelines has been documented because of a variety of reported barriers. We sought to test the efficacy of the Community Asthma Program (CAP), which was designed to help primary care physicians (PCP) assess asthma severity and to prescribe medications according to NAEPP guidelines. A prospective, observational study was conducted in 723 patients with asthma (aged < 1-85 years) in two primary care clinics. PCPs had access to patient responses to asthma symptom questions at each visit. The correlations between patient self-reported and PCP-classified asthma severity, treatment prescribed, and missed days from work or school were determined. The effect of the intervention on guideline adherence was assessed by asthma severity level and time. An overall moderate measure of agreement was found between patient self-reported and PCP-classified asthma severity (kappa = 0.48; p < 0.001) although this agreement decreased with increasing severity of asthma. Patient self-reported (r = 0.14; p < 0.001) and PCP-classified (r = 0.17; p < 0.001) asthma severity was weakly correlated with missed days from work or school. Those with severe persistent asthma were 89% less likely to be appropriately treated than the mild intermittent group (OR = 0.11; 95% CI-0.1-0.2). This relationship was not influenced by the different clinics or providers nor by the age of the patient. Over time, the CAP-trained PCPs were more likely to appropriately prescribe asthma medications for those with moderate to severe asthma (Mantel-Haenszel chi2 = 5.11; p = 0.02). Despite appropriate assessment of asthma severity, physicians are undertreating patients with severe asthma, the group with the highest health care use. Use of the CAP over time aided PCPs in appropriately medicating patients with moderate to severe asthma in accordance with guidelines.

Adolescent↗
PubMed2005

Severity of respiratory syncytial virus bronchiolitis is affected by cigarette smoke exposure and atopy.

OBJECTIVE: Respiratory syncytial virus (RSV) bronchiolitis is a common cause of hospitalizations in children and has been increasingly identified as a risk factor in the development of asthma. Little is known about what determines the severity of RSV bronchiolitis, which may be helpful in the initial assessment of these children. DESIGN: We evaluated a variety of environmental and host factors that may contribute to the severity of RSV bronchiolitis in the RSV Bronchiolitis in Early Life prospective cohort study. Severity of bronchiolitis was based on the quantization of lowest O(2) saturation and the length of stay. These factors included the child's and family's demographics, presence of household allergens (dust mite, cat, dog, and cockroach), peripheral blood eosinophil count, immunoglobulin E level, infant feeding, prior illnesses, exposure to intrauterine and postnatal cigarette smoke, and family history of atopy. PATIENTS: We prospectively enrolled 206 hospitalized infants, all under 12 months old (4.0 +/- 3.3 months old), with their first episode of severe RSV bronchiolitis (mean O(2) saturation: 91.6 +/- 7.3%; length of stay: 2.5 +/- 2.5 days; presence of radiographic opacities: 75%). Patients were excluded for a variety of reasons including previous wheezing, regular use of bronchodilator or antiinflammatory medications, any preexisting lung disease including asthma, chronic lung disease of prematurity/bronchopulmonary dysplasia, or cystic fibrosis; gastroesophageal reflux disease on medical therapy; or congenital anomalies of the chest or lung. RESULTS: Age was found to be a significant factor in the severity of infection. The younger an infant was, the more severe the infection tended to be as measured by the lowest oxygen (O(2)) saturation. We also found that infants exposed to postnatal cigarette smoke from the mother had a lower O(2) saturation than those not exposed. However, there was no significant difference in RSV bronchiolitis severity between infants exposed only to intrauterine smoke and those infants never exposed to cigarette smoke. Infants with a family history of atopy, especially a maternal history of asthma or hay fever, had a higher O(2) saturation. Although a history of maternal atopy seemed to be protective, there was no association between allergens and bronchiolitis severity, although 25% of households had elevated allergen levels. Black infants demonstrated less severe RSV bronchiolitis than their white counterparts. Multivariate analysis revealed age, race, maternal atopy, and smoking to be associated with severity of RSV bronchiolitis. CONCLUSION: The severity of RSV bronchiolitis early in life seems modified by postnatal maternal cigarette smoke exposure and atopy and age of the infant, not by levels of allergens in the home environment.

Age Factors↗
PubMed2004

Asthma exacerbations after glucocorticoid withdrawal reflects T cell recruitment to the airway.

We reasoned that a prospective assessment of glucocorticoid withdrawal in subjects with asthma would provide insight into the basis for flares of the disease. We therefore enrolled 25 subjects with moderate persistent asthma and treated them for 30 days with inhaled fluticasone propionate (1,760 microg/day) followed by a withdrawal period that lasted until peak expiratory airflow decreased by 25% and FEV(1) by 15% or 6 weeks elapsed. After glucocorticoid withdrawal, 13 of 25 subjects reached the target, whereas 12 subjects did not. The number of eosinophils in bronchial biopsies was increased by glucocorticoid withdrawal in both groups, but increases in airway T cells were found in only those with exacerbation. T-cell accumulation was a reflection of similar increases in both CD4(+) and CD8(+) T cells and was accompanied by increased expression of chemokine CCL5 (regulated upon activation, normal T cell expressed and secreted) in the airway epithelium without activation of the transcription factor nuclear factor-kappaB. The pattern of glucocorticoid-sensitive inflammation during an asthma exacerbation is more reminiscent of an antiviral response than an eosinophil-predominant response to allergen and implies an independent role for airway T cells in mediating asthma flares and in determining glucocorticoid efficacy in the treatment of this disease.

Adult↗
PubMed2004

Immune response to influenza vaccination in children and adults with asthma: effect of corticosteroid therapy.

BACKGROUND: Annual influenza vaccination is currently recommended as a preventative measure for all patients with asthma. However, the effect of maintenance corticosteroid therapy on the immune response to influenza vaccine has received limited evaluation. OBJECTIVE: In this study, we evaluated the effect of corticosteroid therapy on the immune response to influenza vaccine in children and adults with asthma. METHODS: This was a substudy of a larger multicenter, randomized, double-masked, placebo-controlled, crossover study investigating the safety of trivalent influenza vaccine in patients with asthma. At baseline, 294 subjects were randomized to receive either placebo first (n=139) or inactivated trivalent split-virus influenza vaccine first (n=155). Study subjects were categorized into 2 groups: subjects in group 1 (n=148) were receiving medium-dose or high-dose inhaled corticosteroids (ICSs) or oral corticosteroids, whereas subjects in group 2 (n=146) were not receiving corticosteroids or were receiving low-dose ICSs. Serum hemagglutination inhibition antibody titers for the vaccine antigens were measured before and 4 weeks after the administration of placebo or vaccine. RESULTS: Serologic responses to each influenza vaccine antigen were significantly higher in vaccine than in placebo recipients and were similar among influenza vaccine recipients in groups 1 and 2 for the following endpoints: rise in antibody titer, percent of participants who developed a serological response, and percent of subjects who developed a serum hemagglutination inhibition antibody titer > or =1:32. Post hoc subgroup analyses demonstrated an attenuated response to influenza B antigen in subjects receiving high-dose ICS compared with subjects who were steroid-naïve (P<.05). CONCLUSION: The immune response to the A antigens of the inactivated influenza vaccine in subjects with asthma is not adversely affected by ICS therapy. High-dose ICS therapy may diminish the response to the B antigen of the vaccine, an observation that needs further investigation.

Adolescent↗
PubMed2004

Delayed cardiac tamponade after penetrating thoracic trauma.

Acute cardiac tamponade is very common after penetrating injuries to the chest. However, delayed cardiac tamponade is a rare phenomenon that may appear several days after injury. This paper presents three cases of delayed cardiac tamponade diagnosed weeks after ice pick wounds to the back. These experiences and a review of the literature on the subject are discussed.

Adult↗
PubMed2003

Asthma intervention program prevents readmissions in high healthcare users.

The largest portion of the cost for asthma healthcare is due to hospitalizations. Improved methods of healthcare delivery for patients with asthma are needed to prevent readmissions. From 1996 to 1999, 96 adult subjects (predominantly young African American women) hospitalized with an asthma exacerbation, who had a history of frequent healthcare use, were randomized to an asthma nurse specialist intervention (n = 50) or a usual care group (n = 46) for 6 months. Our aim was to decrease rates of readmissions within 6 months of hospital discharge, to reduce cost, and to improve health-related quality of life. Our results demonstrate a 60% reduction in total hospitalizations (31 readmissions in the intervention group and 71 in the control group, p = 0.04), with no significant change in emergency department visits. Readmissions for asthma were reduced by 54% (21 vs. 42 in the control group; p = 0.04). We found a marked reduction in lost work or school days: 246 versus 1040 days in the control group (p = 0.02). The intervention resulted in a substantial reduction in direct and indirect healthcare costs, saving US dollars 6462 per patient (p = 0.03). A brief intervention program focusing on high healthcare users with asthma can result in improved asthma control and reduced hospital use with substantial cost savings.

Adult↗
PubMed2003

The role of viral respiratory infections in the pathogenesis and exacerbation of asthma.

Respiratory viral infections are implicated in both the pathogenesis and exacerbation of asthma. Infections with respiratory syncytial virus and parainfluenza virus are the major cause of wheezing-related respiratory infections early in life. Infections in early childhood affect the immune system and modify the risk for subsequent development of allergies and asthma. Later in life, rhinovirus and influenza are implicated frequently in the exacerbation of asthma. The management of respiratory viral infections includes adequate prophylaxis and treatment of acute infections. Insights into the mechanism of viral respiratory tract infections will provide therapeutic targets for treatment and possibly the prevention of virus-induced asthma.

Asthma↗
PubMed2003

Effect of different doses of vitamin E on the incidence of malformations in pregnant diabetic rats.

BACKGROUND/AIMS: Previously we have shown that administration of 150 mg of vitamin E (alpha-tocopherol) per day to rats having diabetes decreases the rate of embryo malformations and increases their maturation and size. The present study was addressed to determine the effects of different doses of vitamin E upon these parameters. METHODS: Female rats were made diabetic (D) with streptozotocin, and from day 0 of gestation they were treated daily with 25 (D+25), 50 (D+50), 100 (D+100), 150 (D+150), and 500 (D+500) mg of vitamin E administered orally and were compared with control (C) animals. RESULTS: On day 11.5 of gestation, crown-rump length, somite number, and protein and DNA levels were lower in D than in C embryos. Crown-rump length and somite number increased with 100 mg or higher doses of vitamin E, although the values observed in C embryos were not reached. The proportions of reabsorption and malformations were 24.7 and 50%, respectively, in D rats, and in the rats supplemented with vitamin E they decreased to 22.7 and 19% in D+25, 16.4 and 21.3% in D+50, 16.2 and 12% in D+100, 12.9 and 13.9% in D+150, and to 43.9 and 10.8% in D+500 rats, whereas the values were 6.8 and 4.9% in C animals. CONCLUSIONS: Administration of vitamin E to D rats decreases the rate of embryo malformations, dependent on the dose administered. However, high doses have a negative effect in the conceptus, as shown by the increased rate of reabsorptions in the D+500 group.

Animals↗
PubMed2002

Immunity, inflammation, and remodeling in the airway epithelial barrier: epithelial-viral-allergic paradigm.

The concept that airway inflammation leads to airway disease has led to a widening search for the types of cellular and molecular interactions responsible for linking the initial stimulus to the final abnormality in airway function. It has not yet been possible to integrate all of this information into a single model for the development of airway inflammation and remodeling, but a useful framework has been based on the behavior of the adaptive immune system. In that paradigm, an exaggeration of T-helper type 2 (Th2) over Th1 responses to allergic and nonallergic stimuli leads to airway inflammatory disease, especially asthma. In this review, we summarize alternative evidence that the innate immune system, typified by actions of airway epithelial cells and macrophages, may also be specially programmed for antiviral defense and abnormally programmed in inflammatory disease. Furthermore, this abnormality may be inducible by paramyxoviral infection and, in the proper genetic background, may persist indefinitely. Taken together, we propose a new model that highlights specific interactions between epithelial, viral, and allergic components and so better explains the basis for airway immunity, inflammation, and remodeling in response to viral infection and the development of long-term disease phenotypes typical of asthma and other hypersecretory airway diseases.

Animals↗
PubMedDate not supplied

Major depression and allergy: does neuroticism explain the relationship?

OBJECTIVE: To determine the association between major depression, neuroticism, and self-reported allergy among adults in the community. METHODS: Data were drawn from the Midlife Development in the United States Survey, a nationally representative sample of 3,032 adults age 25 to 74. ANOVA and multiple logistic regression analyses were used to determine the association between depression and allergy and the role of neuroticism in these relationships. These links were also examined by gender. RESULTS: Among adults in the community, major depression was associated with a significantly increased likelihood of allergy (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.14-1.98). Higher levels of neuroticism were also significantly associated with increased likelihood of allergy (OR, 1.22; 95% CI, 1.04-1.43). Among women, major depression was associated with a significantly increased likelihood of allergy (OR, 1.67; 95% CI, 1.15-2.41), and this relationship persisted after adjusting for demographic characteristics and neuroticism. Among men, there was no significant relationship between allergy and depression, yet neuroticism was related to allergy (OR, 1.42; 95% CI, 1.42-1.82), which persisted after adjustment for depression. CONCLUSION: These data are consistent with results of previous studies showing an association between major depression and allergy among adults and extend these data by providing preliminary evidence suggesting that this association is specific to women and independent of the effects of neuroticism among women. In addition, the data provide preliminary evidence that neuroticism may be related to allergy among men, though no link between depression and allergy was found among men. Future research with prospective, longitudinal studies is needed next to understand the possible biological underpinnings of these associations.

Adult↗
PubMedDate not supplied

Volumetric measurements of lung nodules with multi-detector row CT: effect of changes in lung volume.

OBJECTIVE: To evaluate how changes in lung volume affect volumetric measurements of lung nodules using a multi-detector row CT. MATERIALS AND METHODS: Ten subjects with asthma or chronic bronchitis who had one or more lung nodules were included. For each subject, two sets of CT images were obtained at inspiration and at expiration. A total of 33 nodules (23 nodules > or =3 mm) were identified and their volume measured using a semiautomatic volume measurement program. Differences between nodule volume on inspiration and expiration were compared using the paired t-test. Percent differences, between on inspiration and expiration, in nodule attenuation, total lung volume, whole lung attenuation, and regional lung attenuation, were computed and compared with percent difference in nodule volume determined by linear correlation analysis. RESULTS: The difference in nodule volume observed between inspiration and expiration was significant (p < 0.01); the mean percent difference in lung nodule volume was 23.1% for all nodules and for nodules > or =3 mm. The volume of nodules was measured to be larger on expiration CT than on inspiration CT (28 out of 33 nodules; 19 out of 23 nodules > or =3 mm). A statistically significant correlation was found between the percent difference of lung nodule volume and lung volume or regional lung attenuation (p < 0.05) for nodules > or =3 mm. CONCLUSION: Volumetric measurements of pulmonary nodules were significantly affected by changes in lung volume. The variability in this respiration-related measurement should be considered to determine whether growth has occurred in a lung nodule.

Adult↗