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Biomedical subjects

F D Martinez

Publications and source records attributed to F D Martinez.

At least 73 records · Page 4Linked to original sources
PubMed1997

Cold air challenge at age 6 and subsequent incidence of asthma. A longitudinal study.

The aim of this study was to assess the relation between bronchial hyperresponsiveness to dry, cold air at age 6 and the subsequent incidence of asthma. The cumulative incidence of newly diagnosed asthma between ages 6 and 11 among 360 children included in this study was 12.0%. Survival analysis showed that hyperresponsiveness to cold air at age 6 was associated with an increased risk of developing subsequent asthma (hazard ratio = 2.6, 95% CI = 1.2-5.4; p = 0.01). However, after adjusting for potential confounders, only mild wheezing at age 6 (adjusted hazard ratio 7.5, 95% CI = 3.6-15.9; p < 0.001) and skin test reactivity to allergens at age 6 (adjusted hazard ratio 3.6, 95% CI = 1.5-8.5; p < 0.01), but not hyperresponsiveness to cold air (adjusted hazard ratio = 0.9, 95% CI = 0.4-2.2; p = 0.8), remained significant predictors of subsequent development of asthma. These findings were substantially confirmed after stratifying for wheezing illnesses before age 3. We conclude that hyperresponsiveness to cold air at age 6 was associated with subsequent development of a diagnosis of asthma but this effect was not independent of atopy and mild wheezing at age 6.

Age Factors↗
PubMed1997

Maternal risk factors in asthma.

There is now increasing evidence that maternal factors may play a role in the development of asthma and asthma-related syndromes in children. For years it has been known that younger mothers are more likely to have children who develop wheezing illnesses in early life. It has been suggested that the development of the lung may differ in children of younger mothers compared to that in children of older mothers, but the biology of this association is not well understood. Recent data suggest that there is a much stronger association of allergic conditions in early life with allergic disease in the mother than in the father. Maternal asthma is more strongly associated with childhood asthma than is paternal asthma. The influence of the pattern of immune responsiveness in the mother on the ontogeny of the immune system in children needs further exploration, and it may offer new clues as to the factors determining the development of asthma and allergy in children.

Asthma↗
PubMed1997

Definition of pediatric asthma and associated risk factors.

Significant advances have been made in recent years in understanding the different ways in which asthma is expressed during childhood. There is a large group of children (20% of the population) who present with wheezing during viral infections during the first 3 years of life but whose symptoms disappear after this age. These children do not have any of the important risk factors associated with asthma in later childhood (high serum IgE levels, bronchial hyperresponsiveness, family history of asthma). The main characteristic associated with this condition is reduced lung function, which can be detected before these illnesses develop. It has been suggested that there is nothing unusual or characteristic in the immune response to viruses in these children, but it would appear that these children have narrower intrapulmonary airways. A second group of young children (10% of the population), who also wheeze during viral infections, present with most of the risk factors associated with asthma in later childhood. In this group of children symptoms tend to persist with age. It appears that in these children the immune response to viruses is characterized by a predominance of TH2-like cells. This suggests that their early wheezing is the expression of asthma because a TH2-like response to allergens and viruses is a characteristic found in most asthmatic children. A better understanding of the different types of childhood asthma, together with development of accurate prognostic tests, may be decisive in determining adequate strategies for prevention and treatment of the condition.

Airway Resistance↗
PubMed1996

Relation of indoor heating with asthma, allergic sensitisation, and bronchial responsiveness: survey of children in south Bavaria.

OBJECTIVE: To investigate the relation between different types of heating and the prevalence of atopic diseases, skin test reactivity, and bronchial hyperresponsiveness. DESIGN: Cross sectional survey among school-children aged 9-11 years. Skin prick tests, pulmonary function tests, and bronchial challenge in the children and self completion of a written questionnaire by the children's parents. SUBJECTS: 1958 children in a rural area in southern Bavaria, Germany. MAIN OUTCOME MEASURES: Prevalence of asthma, hay fever, and atopic dermatitis as determined by parents' answers to a questionnaire; the atopic status of the child assessed by skin prick tests; and bronchial responsiveness to cold air challenge in the children. RESULTS: After possible confounders were controlled for, the risk of developing hay fever (odds ratio = 0.57; 95% confidence interval 0.34 to 0.98), atopy defined as at least one positive reaction to a panel of common aeroallergens (0.67; 0.49 to 0.93), sensitisation to pollen (0.60; 0.41 to 0.87), and of bronchial hyperresponsiveness (0.55; 0.34-0.90) was significantly lower in children living in homes where coal or wood was used for heating than in children living in homes with other heating systems. CONCLUSIONS: Factors directly or indirectly related to the heating system used in rural Bavarian homes decrease the susceptibility of children to becoming atopic and to developing bronchial hyperresponsiveness.

Asthma↗
PubMed1996

Evaporative cooling and other home factors and lower respiratory tract illness during the first year of life. Group Health Medical Associates.

Lower respiratory tract illness (LRI) is associated with exposure to various environmental factors. The relation between home environment and LRI in infants was studied with the use of data from the Children's Respiratory Study in Tucson, Arizona. Healthy infants from a health maintenance organization were recruited at birth (1980-1984). Analysis was restricted to one infant per family, and to those followed through the first year (n=936). Environmental data were collected at enrollment, and clinicians diagnosed LRI according to predetermined criteria. During the first year of life, 196 infants (21%) had wheezing LRI, and 60 (6%) had nonwheezing LRI. The risk of wheezing LRI was higher in infants with evaporative home cooling (24%) than in those without evaporative home cooling (15%) (odds ratio = 1.8, 95% confidence interval 1.1-3.0); this association was stronger among infants who lived with other children in the home. The risk of nonwheezing LRI was associated with parents' rating of neighborhood dustiness, ranging from 5% in the least dusty environments to 12% in the dustiest (p for trend = 0.002). Neither association could be explained by confounding factors. LRI was not related to the type of home heating, cooking fuel, or the numbers of indoor dogs or cats.

Air Conditioning↗
PubMed1996

The relation between physician-diagnosed sinusitis, asthma, and skin test reactivity to allergens in 8-year-old children.

The purpose of this study was to assess the prevalence of sinusitis in a nonselected sample of children, and the relation of sinusitis to allergic rhinitis (AR), atopy, asthma, and cough in the same population sample. Of 1246 children enrolled at birth in the Tucson Children's Respiratory Study, 835 were studied at a mean age +/-SD of 8.6 +/- 0.7 years. Questionnaires asking about MD-Sinusitis, MD-AR, MD-Asthma, and cough were completed by parents. Skin tests for seven common aeroallergens in the Tucson area had been performed in 630 of the participating children at the mean age +/-SD of 6.3 +/- 0.9 years. Prevalence of MD-Sinusitis was 13.1%; 78% of subjects with MD-Sinusitis also had MD-AR. Detailed analysis of the relation between MD-Sinusitis and individual environmental allergens tested for showed that only a response to Bermuda grass pollen was significantly associated with MD-Sinusitis after controlling for MD-AR [adjusted odds ratio 2.3 (95% CI 1.2-4.3)]. Having MD-Sinusitis was also significantly associated with MD-Asthma and cough [odds ratios 3.0 (95% CI 1.8-5.2)] and 2.5 (95% CI 1.6-3.8), respectively]. However, logistic regression demonstrated that, after controlling for MD-AR and skin test reactivity, MD-Sinusitis was no longer significantly associated with MD-Asthma or cough. We conclude that MD-Sinusitis is a common condition in childhood. The main independent risk factors in our community for MD-Sinusitis were grass pollen and current MD-AR. MD-Sinusitis was not associated with MD-Asthma or with cough after controlling for skin test reactivity and for MD-AR.

Allergens↗
PubMed1996

Early childhood respiratory symptoms and the subsequent diagnosis of asthma.

BACKGROUND: Respiratory symptoms are frequent in very young children, and the relation of these symptoms to later asthma in some of these children is unknown. OBJECTIVE: The aim of the study was to describe the natural history of respiratory symptoms in a community-based sample of young children who were prospectively observed for as long as 11 years. METHODS: Subjects were participants in the Tucson Epidemiologic Study of Airways Obstructive Disease. They were under 5 years of age at enrollment and were studied by means of a parent-administered mail survey instrument every 1 to 2 years for 3 to 11 years. RESULTS: Among subjects younger than 1 year of age, no single respiratory symptom, such as cough or wheeze only with colds, significantly increased the risk of a subsequent diagnosis of asthma. Among 1- and 2-year-olds, however, those with wheeze only with colds and those with attacks of shortness of breath with wheeze were more likely to be diagnosed with asthma later when compared with children without those symptoms (odds ration = 2.1; p < 0.05 for wheeze only with colds). At ages 3 to 4 years, symptoms were even more strongly associated with subsequent asthma (odds ratio = 7.2; p < 0.0001 for attacks of shortness of breath with wheeze). CONCLUSION: Although respiratory symptoms reported by parents very early in life are not significantly associated with future asthma, those symptoms that begin at or persist through ages 3 to 4 years are.

Adolescent↗
PubMed1996

Relapse after short-course chemotherapy of patients with sputum smear-positive pulmonary tuberculosis under routine conditions with additional information on side effects and contact tracing.

SETTING: The region of Leon/Chinandega in Western Nicaragua. OBJECTIVE: To assess the relapse rate after short course chemotherapy with thioacetazone in the continuation phase in patients with sputum smear-positive pulmonary tuberculosis. DESIGN: A cohort of 247 new sputum smear-positive patients with pulmonary tuberculosis, started on the national short-course treatment (2SRHZ/6TH) between October 1986 and April 1988 as part of the National Tuberculosis Programme, were followed up for 17-32 months after completion of treatment. Two thirds of the patients spent the first 2 months hospitalized, the rest received the whole treatment as out-patients. RESULTS: 204 (83%) completed treatment, seven failure cases were cured with retreatment, 24 defaulted, 10 were transferred out and two died. The patients who completed treatment continued to undergo smear examination for acid-fast bacilli every three months. Of the 204 patients who completed treatment, five died and 10 were lost to follow-up. The remaining 189 patients were followed up for a total of 388 person-years. Three relapses appeared (1.6%), one relapse during 129 person years of observation. Two of the relapse cases were hospitalized, and the third received the full treatment as an out-patient. In the 223 patients who first entered the study, contact tracing detected 24 new smear-positive and 43 smear-negative cases. Adverse reactions (jaundice) required suspension of treatment in one patient, but only temporarily. CONCLUSION: Short course chemotherapy with an ambulatory continuation phase with isoniazid and thioacetazone seems to have a low relapse rate under routine conditions and should continue to be used.

Adolescent↗
PubMed1996

Serum levels of the soluble low affinity receptor for IgE and soluble interleukin-2 receptor in childhood, and their relation to age, gender, atopy and allergic disease.

Identifying immune factors associated with the development of atopy can enhance our understanding of the in vivo mechanisms involved and may have utility in paradigms designed to prevent disease. Two candidates suggested for such roles are the soluble low affinity receptor for IgE (sCD23) and the soluble interleukin-2 receptor (sCD25). To assess serum levels of these factors blood samples were collected at birth and at age 6 in a large nonselected population from Tucson, AZ. Log mean sCD23 and sCD25 levels decreased from birth to age 6, (for sCD23 0.60 ffi 0.26pg/l, n = 340 and 0.53 + 0.28pg/l, n = 333 and for sCD25 1.95 i 0.14pM, n = 304 and 1.86 ffi 0.20pM, n = 327, for the two ages respectively. Anglo children had lower sCD23 levels at birth compared to Hispanic children (p < 0.01); no effect of gender was observed. Skin test reactivity at age 6 was directly related to sCD25 levels at age 6 (p = 0.007) and even levels at birth showed a similar trend (p = 0.06). These relations were distinct from any relation to total serum IgE. No relation was observed with sCD23 levels for either skin test reactivity or serum IgE. The prevalences of asthma, rhinitis and eczema by age 6 were unrelated to sCD25 or sCD23 levels. The results indicate that soluble CD23 and CD25 have higher levels at birth than later in childhood and that the development of skin test reactivity may be associated with regulatory mechanisms involving sCD25, whereas sCD23 was not similarly implicated.

Age Factors↗
PubMed1996

Recurrent cough in childhood and its relation to asthma.

Risk factors for recurrent cough (RC) in childhood, and its relation to asthma were investigated as part of the prospective, longitudinal Tucson Children's Respiratory Study. RC, defined as > or = 2 episodes of cough without a cold in the past year, was assessed by questionnaire in 987 children at age 6. Children having RC without wheeze (n = 154) did not differ from children with neither symptom (n = 610) in serum IgE levels, skin test response, size-corrected forced expiratory flow, or percentage of decline following cold air challenge. In contrast, children with both RC and wheeze (n = 116) had significantly more respiratory illness, more atopy, lower flow at end-tidal expiration (V'maxFRC), and greater declines in lung function following cold air challenge than children with neither symptom. Current parental smoking was a risk for RC without wheeze, whereas male gender, maternal allergy, wheezing lower respiratory tract illness (LRI) in early life, and high IgE were significant risks for RC with wheeze, compared with children having neither symptom. RC early in life resolved in the majority of children, between ages 2-3 yr and age 6, and between age 6 and age 11. High IgE and positive skin prick test were associated with persistence of RC to age 6 among children who wheezed, and markers of allergy were associated with persistence of RC between 6 and 11 yr. These findings suggest that recurrent cough in the absence of wheeze differs in important respects from classic asthma, and using the same label to refer to these distinct syndromes may obscure their diverse pathophysiologies.

Asthma↗
PubMed1996

Segregation analysis of physician-diagnosed asthma in Hispanic and non-Hispanic white families. A recessive component?

The inheritance of asthma, evident from its high family concordance, is not well understood. To investigate whether asthma may be inherited through a major gene with two alleles, segregation analyses were conducted in 3,369 individuals from 906 nuclear families enrolled, without selection, in a longitudinal study of respiratory health in Tucson, Arizona. Physician-diagnosed asthma and its age of onset were ascertained for each family member when children were at a mean age of 7 yr. Age of asthma diagnosis was allowed for in analyses, and the impact of the covariate total serum IgE level on age of onset was examined. Segregation analyses were conducted with and without residual family effects, with and without the covariate IgE. The hypothesis of a single two-allele locus for asthma was rejected. However, depending on the method of assessment of the residual familial effects, either a polygenic/multifactorial mode of inheritance alone, or an oligogenic model with some evidence of a recessive component present in the population with the high frequency of 0.67, were compatible with the data. Results were unchanged with the addition of the covariate IgE.

Adult↗
PubMed1995

Asthma and wheezing in the first six years of life. The Group Health Medical Associates.

BACKGROUND: Many young children wheeze during viral respiratory infections, but the pathogenesis of these episodes and their relation to the development of asthma later in life are not well understood. METHODS: In a prospective study, we investigated the factors affecting wheezing before the age of three years and their relation to wheezing at six years of age. Of 1246 newborns in the Tucson, Arizona, area enrolled between May 1980 and October 1984, follow-up data at both three and six years of age was available for 826. For these children, assessments in infancy included measurement of cord-serum IgE levels (measured in 750 children), pulmonary-function testing before any lower respiratory illness had occurred (125), measurement of serum IgE levels at nine months of age (672), and questionnaires completed by the children's parents when the children were one year old (800). Assessments at six years of age included measurement of serum IgE levels (in 460), pulmonary-function testing (526), and skin allergy testing (629). RESULTS: At the age of six years, 425 children (51.5 percent) had never wheezed, 164 (19.9 percent) had had at least one lower respiratory illness with wheezing during the first three years of life but had no wheezing at six years of age, 124 (15.0 percent) had no wheezing before the age of three years but had wheezing at the age of six years, and 113 (13.7 percent) had wheezing both before three years of age and at six years of age. The children who had wheezing before three years of age but not at the age of six had diminished airway function (length-adjusted maximal expiratory flow at functional residual capacity [Vmax FRC]) both before the age of one year and at the age of six years, were more likely than the other children to have mothers who smoked but not mothers with asthma, and did not have elevated serum IgE levels or skin-test reactivity. Children who started wheezing in early life and continued to wheeze at the age of six were more likely than the children who never wheezed to have mothers with a history of asthma (P < 0.001), to have elevated serum IgE levels (P < 0.01), to have normal lung function in the first year of life, and to have elevated serum IgE levels (P < 0.001) and diminished values for VmaxFRC (P < 0.01) at six years of age. CONCLUSIONS: The majority of infants with wheezing have transient conditions associated with diminished airway function at birth and do not have increased risks of asthma or allergies later in life. In a substantial minority of infants, however, wheezing episodes are probably related to a predisposition to asthma.

Algorithms↗
PubMed1995

Relationship of infant feeding to recurrent wheezing at age 6 years.

OBJECTIVES: To investigate the relationship of infant feeding to recurrent wheezing at age 6 years and to assess whether this relationship is altered by a history of wheezing lower respiratory tract illnesses. DESIGN: Prospective, longitudinal study of healthy infants followed up from birth to 6 years of age. SETTING: Nonselected health maintenance organization population in Tucson, Arizona. PARTICIPANTS: There were 1246 healthy infants enrolled at birth, 988 of whom had data on both infant feeding and wheezing at age 6 years. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Recurrent wheeze (four or more episodes in the past year) was assessed by a questionnaire that was completed by parents when the children were 6 years old. Children were classified by atopic status on the basis of skin prick tests. RESULTS: Breast-feeding information was collected prospectively, and lower respiratory tract illnesses in the first 3 years of life were diagnosed by the pediatrician. Being breast-fed was associated with lower rates of recurrent wheeze at age 6 years (3.1% vs 9.7%, P < .01) for nonatopic children; this relationship was not significant for atopic children. The relationship of breast-feeding with recurrent wheeze was apparent among nonatopic children both with and without a wheezing lower respiratory tract illness in the first 6 months of life. When potential confounders, including early wheezing lower respiratory tract illness, were included in a multivariate model, nonatopic children who had not been breast-fed had three times the odds of wheezing recurrently (odds ratio, 3.03; confidence interval, 1.06 to 8.69). Eleven percent of recurrent wheeze among nonatopic children could be attributed to not breast-feeding. CONCLUSIONS: Recurrent wheeze at age 6 years is less common among nonatopic children who were breast-fed as infants. This effect is independent of whether the child wheezed with a lower respiratory tract illness in the first 6 months of life.

Breast Feeding↗
PubMed1995

Association of interleukin-2 and interferon-gamma production by blood mononuclear cells in infancy with parental allergy skin tests and with subsequent development of atopy.

The mechanisms regulating the onset of atopic sensitization in human beings are not yet fully clarified. We assessed the capacity of mitogen-stimulated umbilical and peripheral blood mononuclear cells to produce interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) at birth and at 9 months of age in 159 infants. Mononuclear cell production of both IFN-gamma and IL-2 at 9 months, but not at birth, was found to be inversely related to parental immediate skin test reactivity to seven local aeroallergens. Skin test reactivity at the age of 6 years was also inversely related to IFN-gamma and IL-2 production at 9 months of age. However, no relationship was evident between total serum IgE levels at 6 years and production of these cytokines at 9 months. The proportions of circulating lymphocytes and CD4+ or CD8+ cells were also unrelated to skin test reactivity at the age of 6 years. These data suggest that mechanisms regulating skin test reactivity to inhaled allergens may involve deficient IFN-gamma production, deficient IL-2 production, or both during or preceding the time of initial sensitization and that additional mechanisms are involved in regulating total serum IgE level.

Adult↗
PubMed1995

Association of non-wheezing lower respiratory tract illnesses in early life with persistently diminished serum IgE levels. Group Health Medical Associates.

BACKGROUND: The role of lower respiratory tract illnesses (LRIs) in the development of allergies is not well understood. The relation of wheezing and non-wheezing LRIs to serum IgE levels and atopy was studied in 888 children. METHODS: Total serum IgE levels were measured at birth, nine months and six years of age; and interferon gamma production by blood mononuclear cells was measured at birth and nine months. Atopy was determined by skin prick tests at age six. Wheezing and non-wheezing LRIs up to age three were diagnosed by a physician. RESULTS: Cord serum IgE levels were similar between all LRI groups and the no LRI group. Children who had wheezing LRIs until the age of three had IgE levels at nine months and at six years within normal ranges for age. In contrast, children who had a non-wheezing LRI before the nine month IgE sample had lower IgE levels at nine months and six years (geometric mean 1.8 IU/ml and 9.9 IU/ml, respectively) compared with children who had no LRIs (3.9 IU/ml and 38.3 IU/ml, respectively). Children who had non-wheezing LRIs after the nine month IgE sample had normal nine month IgE levels (3.2 IU/ml) but decreased IgE levels at six years of age (15.7 IU/ml). Children with more than one non-wheezing LRI before the age of three were less likely to be atopic than those with no LRI (odds radio 0.2). Interferon gamma production was higher in the non-wheezing LRI group at nine months than in the no LRI or wheezing LRI groups. CONCLUSIONS: Non-wheezing LRIs are associated with subsequent depression of IgE levels and reduced skin test reactivity.

Child, Preschool↗