Search PubMed⌕ Search

Biomedical subjects

A L Wright

Publications and source records attributed to A L Wright.

At least 73 records · Page 4Linked to original sources
PubMed1994

Evidence for Mendelian inheritance of serum IgE levels in Hispanic and non-Hispanic white families.

Considerable evidence is available suggesting a significant genetic component in the pathogenesis of asthma, but the mechanism of inheritance is not well understood. The main objective of this study was to assess if total serum IgE level, a known intermediate phenotype for asthma, is under the control of a major autosomal gene. We studied nuclear families participating in the Tucson Children's Respiratory Study in Tucson and originally selected because they belonged to a health maintenance organization. One hundred twenty-five Hispanic and 673 non-Hispanic White nuclear families were eligible; 50 Hispanic families (with 191 subjects) and 241 non-Hispanic White families (with 886 subjects) were included. Prevalence of asthma, hay fever, and parental smoking was similar among eligible families who were included and those who were not. Segregation analyses using regressive models for continuous traits showed that the best fit to the data was given by a model of Mendelian codominant inheritance of a major autosomal gene associated with higher serum IgE level. Log-likelihood for this model was not significantly different from that of the best-fitting ("unrestricted") model (P = .3) and was significantly better than log-likelihood for a dominant model (P < .0001) and a recessive model (P < .0001). An environmental model showed significant departure (P < .0001) from the unrestricted model. Tests for genetic heterogeneity showed no significant difference between the two ethnic groups. The data strongly suggest that total serum IgE levels are controlled by a major autosomal codominant gene.

Arizona↗
PubMed1993

Parental childhood respiratory illness and respiratory illness in their infants. Group Health Medical Associates.

Parental histories of childhood respiratory trouble (CRT) were examined as risk factors for lower respiratory tract illnesses in healthy infants enrolled in the Children's Respiratory Study, Tucson, Arizona. A parental history of childhood respiratory trouble before age 16 was a risk factor for infantile lower respiratory tract illnesses (LRIs). Early age of onset of the parental CRT and those illnesses described as asthma or bronchiolitis showed the greatest risk: odds ratio = 2.8, P < 0.05. After controlling for known and suspected confounders, a parental history of CRT described as asthma or bronchiolitis with onset before age 3 was associated with wheezing LRIs in their children, with an odds ratio of 2.6, P < 0.05. A parental history of CRT described as bronchitis/croup was associated with nonwheezing LRIs in their children: odds ratio = 2.2, P < 0.05. These findings suggest a familial component to childhood respiratory trouble which may have a hereditary basis.

Adolescent↗
PubMed1993

Emergency vehicle intervals versus collapse-to-CPR and collapse-to-defibrillation intervals: monitoring emergency medical services system performance in sudden cardiac arrest.

STUDY OBJECTIVE: To compare emergency vehicle response intervals with collapse-to-intervention intervals to determine which of these system data better correlated with survival after prehospital sudden cardiac arrest. STUDY DESIGN: A 22-month case series, collected prospectively, of out-of-hospital cardiac arrests. Times of collapse, dispatch, scene arrival, CPR, and initial defibrillation were determined from dispatch records, recordings of arrest events, interviews with bystanders, and hospital records. SETTING: Southwestern city (population, 400,000; area, 390 km2) with a two-tiered basic life support-advanced life support emergency medical services system. Emergency medical technician-firefighters without electrical defibrillation capability comprised the first response tier; firefighter-paramedics were the second tier. PATIENTS: One hundred eighteen cases of witnessed, out-of-hospital cardiac arrest in adults with initial ventricular fibrillation. MAIN OUTCOME MEASURES: Survival was defined as a patient who was discharged alive from the hospital. RESULTS: Eighteen of 118 patients (15%) survived. Survivors did not differ significantly from nonsurvivors in age, sex, or basic life support or advanced life support response intervals. Survivors had significantly (P < .05) shorter intervals from collapse to CPR (1.7 versus 5.2 minutes) and to defibrillation (7.4 versus 9.5 minutes). CONCLUSION: Collapse-to-intervention intervals, not emergency vehicle response intervals, should be used to characterize emergency medical services system performance in the treatment of sudden cardiac death.

Aged↗
PubMed1993

Acute lower respiratory illnesses during the first three years of life: potential roles for various etiologic agents. The Group Health Medical Associates.

Lower respiratory tract illnesses (LRIs) occurring during the first 3 years of life among children enrolled in the Tucson Children's Respiratory Study have been studied for evidence of viral, mycoplasmal and Chlamydia trachomatis infections. This report examines those from whom adequate acute and convalescent sera were available at the time of the LRI. Two groups were compared: those in whom culture and/or antigen detection yielded an etiologic agent (N = 110); and those who did not (culture negative, N = 124). Seroconversions (> or = 4-fold titer rise) to respiratory syncytial virus; influenza virus types A and B; parainfluenza virus types 1, 2 and 3; or adenovirus were found in only 0 to 5% of the culture negative group. No significant differences between groups with regard to frequencies of seroconversion to influenza type C, parainfluenza virus type 4, human coronaviruses 229E and OC43 or cytomegalovirus were detected, which suggests that these agents may not be frequent primary causes of LRIs among otherwise healthy children. Significant differences in seroconversions to Epstein-Barr virus were detected, suggesting that Epstein-Barr virus may contribute to LRI morbidity; however, its exact role remains to be defined.

Acute Disease↗
PubMed1993

Respiratory syncytial virus-associated lower respiratory illnesses: possible influence of other agents. The Group Health Medical Associates.

Acute lower respiratory illnesses were prospectively investigated in a cohort of 1246 healthy infants who were enrolled at birth in the Tucson Children's Respiratory Study and followed through the first 3 years of life. Respiratory syncytial virus (RSV) infection was documented by culture, antigen detection or both in 276 episodes. In 21 (7.6%) of these 276, other viruses were simultaneously detected. Further serologic studies of 50 episodes in which RSV had been found increased the apparent viral codetection rate to 24%. When culture results for Chlamydia trachomatis and Mycoplasma pneumoniae were also considered, the rate of codetection was found to be 10.9% (30 of 276); this increased to 28% for the subgroup of episodes (14 of 50) that was further studied serologically. Illnesses associated with more than one agent were not significantly different from those involving RSV alone, with respect to month of onset, age at illness, illness type or duration of illness. We conclude that when RSV has been detected in previously healthy infants, routine searches for the concomitant presence of other viruses are usually not warranted.

Child, Preschool↗
PubMed1993

Exclusive breast-feeding for at least 4 months protects against otitis media.

OBJECTIVE: This study was designed to assess the relation of exclusive breast-feeding, independent of recognized risk factors, to acute and recurrent otitis media in the first 12 months of life. METHODS: Records of 1220 infants who used a health maintenance organization and who were followed during their first year of life as part of the Tucson Children's Respiratory Study were reviewed. Detailed prospective information about the duration and exclusiveness of breast-feeding was obtained, as was information relative to potential risk factors (socioeconomic status, gender, number of siblings, use of day care, maternal smoking, and family history of allergy). Acute otitis media and recurrent otitis media, defined as three or more episodes of acute otitis media in a 6-month period or four episodes in 12 months, were the outcome variables. RESULTS: Of the 1013 infants followed for their entire first year, 476 (47%) had at least one episode of otitis and 169 (17%) had recurrent otitis media. Infants exclusively breast-fed for 4 or more months had half the mean number of acute otitis media episodes as did those not breastfed at all and 40% less than those infants whose diets were supplemented with other foods prior to 4 months. The recurrent otitis media rate in infants exclusively breast-fed for 6 months or more was 10% and was 20.5% in those infants who breast-fed for less than 4 months. This protection was independent of the risk factors considered. CONCLUSION: These findings suggest that exclusive breast-feeding of 4 or more months protected infants from single and recurrent episodes of otitis media.

Acute Disease↗
PubMed1993

Child day care, smoking by caregivers, and lower respiratory tract illness in the first 3 years of life. Group Health Medical Associates.

BACKGROUND: Day-care attendance has been associated with an increased risk of hospitalization for lower respiratory tract illnesses (LRIs). This study examines, in a health maintenance organization population of children, the associations between child day care and the occurrence of LRIs in the first 3 years of life. Smoking by caregivers and a possible protective effect of longer day-care enrollment in relation to LRIs are also addressed. METHODS: Information on day-care arrangements was elicited from 1006 parents of infants for five age intervals in the first 3 years of life: birth through 3 months, 4 to 6 months, 6 to 12 months, 1 to 2 years, and 2 to 3 years. Data on LRIs in the first 3 years of life were recorded by pediatricians at the time of the acute illnesses. RESULTS: After controlling for other risk factors, the presence of three or more unrelated children in the care setting was associated with significant risks of LRI of up to twofold or more from 4 months of age to 3 years. Type of care setting was not a significant risk factor during this time period. In the third year of life, the risk of wheezing LRI in the presence of a smoking caregiver was more than threefold for those in another residential home setting. No significant protective effect against LRIs in the third year of life associated with longer prior day-care enrollment was demonstrated. CONCLUSION: The presence of three or more unrelated children in the care setting and the presence of a smoking caregiver were significant independent risk factors for LRIs during the first 3 years of life. Prolonged day-care did not protect against LRIs in the third year of life.

Caregivers↗
PubMed1993

The relationship of family structure and perceived family support to length of hospital stay.

Membership in an extended family has been viewed as beneficial, particularly in time of crisis, because of the support and resources that can be provided a member. In an attempt to confirm this view of the family, a study was conducted among Navajo Indians at the time of hospitalization. Instruments assessed family characteristics regarding extended or nuclear structure and the amount of family support the patient perceived. Scores obtained were correlated with the patient's subsequent length of hospital stay. Perceived support was related to length of stay (r = .28, p < .001), while family structure was not (r = .10, p = .10). As hypothesized, greater perceived support was associated with longer length of stay. The results are consistent with other findings suggesting social systems gain importance from function, not structure. If these results are confirmed in other groups, use of a simple tool for assessing support may assist in predicting length of hospital stay.

Family↗
PubMed1992

Maternal age as a risk factor for wheezing lower respiratory illnesses in the first year of life.

Postneonatal mortality due to respiratory illnesses is known to be inversely related to maternal age, but the possible role of young motherhood as a risk factor for respiratory morbidity in infants has not been thoroughly explored. The authors studied the incidence of lower respiratory tract illnesses during the first year of life, as ascertained by health plan pediatricians, in over 1,200 infants enrolled at birth between 1980 and 1984 in Tucson, Arizona. The incidence of wheezing lower respiratory tract illnesses increased significantly (p = 0.005) with decreasing maternal age, whereas the incidence of nonwheezing lower respiratory tract illness was independent of maternal age. A logistic regression was used to control for the effects of several known confounding factors. When compared with infants of mothers aged more than 30 years, adjusted odds ratios were 2.4 (95% confidence interval 1.8-3.1) for infants whose mothers were less than age 21 years (p < 0.0001), 1.8 (95% confidence interval 1.4-2.3) for infants whose mothers were aged 21-25 (p < 0.0001); and 1.4 (95% confidence interval 1.1-1.6) for infants whose mothers were aged 26-30 (p < 0.001). These results suggest that young motherhood is an important risk factor for wheezing lower respiratory tract illnesses during the first year of life. Both biological and social factors related to maternal age may explain these findings.

Adult↗
PubMed1992

Case and survival definitions in out-of-hospital cardiac arrest. Effect on survival rate calculation.

OBJECTIVE: To determine the effect of different case and survival definitions of out-of-hospital cardiac arrest on survival rate calculations. DESIGN: A 22-month case series of nontraumatic, out-of-hospital cardiac arrests. SETTING: Southwestern city (population, 400,000; area, 390 km2) with a two-tiered emergency response system consisting of emergency medical technicians and paramedics. PATIENTS: A consecutive sample of 372 patients found without palpable pulse of spontaneous respiration. MAIN OUTCOME MEASURES: Survival rate after cardiac arrest was calculated using three case definitions of arrest and two definitions of survival. RESULTS: Twenty percent of all patients survived to hospital admission and 6% survived to hospital discharge. Twenty-six percent of adults whose collapse was witnessed survived to hospital admission, and 10% survived to hospital discharge. Patients whose collapse was witnessed and who experienced initial ventricular fibrillation survived to hospital admission in 38% and to hospital discharge in 15% of cases. CONCLUSIONS: The survival rate after out-of-hospital cardiac arrest varies widely depending on the case and survival definitions selected. To facilitate intersystem comparison and assessment of interventions designed to improve outcome, the Utstein Consensus Conference recommended that case and survival definitions should be adopted by all prehospital emergency systems.

Aged↗
PubMed1992

Life events and daily hassles and uplifts as predictors of hospitalization and outpatient visitation.

Increased occurrence of major life events and daily "hassles" and "uplifts" have been shown to be associated with several measures of health status and health care utilization. In order to test for such an association with hospital admission, a prospective study was designed. Navajo Indians presenting for either inpatient or outpatient health care at a U.S. Indian Health Service facility were questioned regarding the occurrence of major life events in the preceding six months and of hassles and uplifts in the preceding week. Two years later the subsequent numbers of outpatient visits and of hospital admissions were determined for each subject. An increased number of either major life events (relative risk 1.66) or daily hassles and uplifts (relative risk 1.87) was found to be associated with an increased risk of hospital admission. The effects of major and daily life events were additive on the risk of admission. In addition, hassles were predictive of subsequent outpatient utilization. While further demonstrating the influence of major and daily life occurrences on health care utilization, this study also shows their importance in an additional cultural setting.

Adult↗
PubMed1992

Nickel sensitivity: the influence of ear piercing and atopy.

In a group of 612 consecutive patients undergoing routine patch tests for suspected allergic contact dermatitis, more than four-fifths of the 364 women had had their ears pierced, over half gave a history of cutaneous reactions to metallic jewelery and almost one-third were sensitive to nickel. The increase in the frequency of nickel sensitivity in women with pierced ears compared to those with unpierced ears was highly significant (P less than 0.001). In men, nickel sensitivity was much less frequent; occupational factors were often implicated and few cases were related to ear piercing. Jewelery dermatitis was more frequent in atopic than non-atopic women but atopy did not appear to influence the propensity for developing nickel sensitivity in either sex. Ear piercing seems to induce nickel allergy which may result in lifelong morbidity and difficulty in employment. Jewelery suppliers should be encouraged to provide nickel-free earrings to reduce the frequency of this apparently avoidable problem.

Adult↗
PubMed1992

Lymphocyte subpopulation number and function in infancy.

Normal values for percentages of lymphocyte subpopulations and functional responses to mitogen stimulation in infancy are not well established. In the present study, lymphocyte subpopulations were examined in umbilical cord blood samples and in peripheral blood samples drawn before 7 and 24 months of age (mean age 10.4 months) from a healthy population of infants born in Tucson, Arizona. Results indicate significant increases occurred from birth to later infancy in the percentages of total T cells (CD3), T-cell subsets (CD4, CD8) and B cells (CD20). The CD4/CD8 ratio and the functional responses to ConA and PWM mitogens significantly decreased from birth to later infancy. PHA responsiveness did not show a significant change. Results from cross-sectional analyses (n = 271) were supported in a smaller longitudinal subset (n = 37). There were no detectable ethnic- or gender-related differences in cord blood or samples obtained in later infancy. The normal values established in this study will be useful in studies of immune-system maturation and in the clinical evaluation of newborns, infants, and toddlers suspected of either acquired or congenital immune-deficiency states.

Cell Count↗
PubMed1991

Risk factors for respiratory syncytial virus-associated lower respiratory illnesses in the first year of life.

The relation of breast feeding and other factors to the incidence of respiratory syncytial virus-associated lower respiratory tract illness (RSV-LRI) in the first year of life is examined. The study population is 1,179 healthy infants enrolled at birth between May 1980 and January 1984 into the Tucson Children's Respiratory Study, Tucson, Arizona. Each subject's data were assessed at each month of age during the first year of life, during those months when respiratory syncytial virus was isolated. A number of significant relations were observed, particularly between 1 and 3 months of age. At this age, the risk of having a RSV-LRI increased in association with less than 1-month or no breast feeding, with being male, and with increasing numbers of others sharing the child's bedroom. In multivariate analysis, only sex and the number of others sharing the room remained as significant direct effects. However, a significant interaction demonstrated that breast feeding has a protective role in relation to RSV-LRIs for those infants of mothers with a lower education level. The risk of having a RSV-LRI increases with combinations of risk factors. Being in day care was a significant risk factor in the 7- to 9-month age range. The RSV-LRI rate also varies by birth month. A separate case-control study assessed relations of RSV-LRIs with cord serum RSV antibody. Those with lower cord serum RSV antibody, who also have minimal breast feeding, were found to be especially at risk for RSV-LRIs in the first 5 months of life.

Antibodies, Viral↗
PubMed1991

Relationship of parental smoking to wheezing and nonwheezing lower respiratory tract illnesses in infancy. Group Health Medical Associates.

The relationship between parental smoking and lower respiratory tract illness (LRI) was studied in a large cohort of infants followed prospectively from birth. Illnesses were diagnosed by physicians using agreed-on criteria, and parental smoking histories were obtained by questionnaire. The LRIs were differentiated into wheezing and nonwheezing episodes, and the age at first illness of either type was evaluated in relation to smoking by parents. The odds of having an LRI were significantly higher in children whose mothers smoked (odds ratio 1.52; confidence interval 1.07 to 2.15). The odds were higher if the mother smoked a pack of cigarettes or more per day and if the child stayed home rather than attending day care (odds ratio 2.8; confidence interval 1.43 to 5.5). Logistic regression indicated that the LRI rate was significantly elevated both in children exposed to heavy maternal smoke in the absence of day care, and in those who use day care but were not exposed to maternal smoking of a pack or more per day. These findings could not be attributed to other confounding variables. Neither paternal smoking nor smoking by other household members was consistently related to the LRI rate. The relationship of maternal smoking to LRI rate was evident for both wheezing and nonwheezing illnesses. Maternal smoking of a pack or more per day was also related to an early age at first LRI, for both wheezing (p less than 0.05) and nonwheezing (p less than 0.002) illnesses. In sum, maternal smoking is associated with a higher rate of LRIs in the first year, particularly when mothers smoked a pack or more per day and when the child did not use day care.

Bronchial Diseases↗
PubMed1991

Computer-assisted image analysis of skin surface replicas.

Using a rubber-based dental impression material, negative surface impressions were made of demarcated areas of skin and prepared as dry specimens for scanning-electron microscopy. Electron micrographs were taken at low magnification and, using a programmed computer-assisted image analyser, it was possible to represent quantitatively the topography of that particular body site according to the degree of circularity of the various geometric subunits. This technique was most applicable to skin topography with a reliable geometrical pattern of triangles and squares, a feature of hair-bearing surfaces in general and in particular, the antecubital fossa. Using standardized trauma of various types the origin of skin surface markings were found to be located in the dermis. The technique was applied to the healing of experimental trauma produced by tape stripping, the resolution of clinical eczema and a comparison of steroid-treated and untreated tape-stripped skin.

Eczema↗