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A A Colin

Publications and source records attributed to A A Colin.

At least 19 recordsLinked to original sources

Relationship between insulin-like growth factor I, dehydroepiandrosterone sulfate and proresorptive cytokines and bone density in cystic fibrosis.

INTRODUCTION: Patients with cystic fibrosis (CF) are known to be at risk for early osteoporosis, and the mechanisms that mediate bone loss are still being delineated. The aim of the present investigation was to investigate if a correlation exists in these patients between skeletal measurements by dual-energy x-ray absorptiometry (DXA) and two anabolic factors, dehydroepiandrosterone (DHEA) and insulin-like growth factor I (IGF-I), and proresorptive factors such as the cytokines interleukin-1beta, tumor necrosis factor alpha, and interleukin-6. METHODS: We studied 32 outpatients (18 females; mean age: 26.2+/-7.9 years) at a tertiary care medical center. The subjects had venous samples obtained, underwent anthropometric and bone mineral density (BMD) measurements, and completed a health survey. Serum IGF-I concentrations were below the age-adjusted mean in 78% of the participants, and DHEA sulfate (DHEAS) concentrations were low in 72%. Serum concentrations of all cytokines were on the low side of normal; nonetheless, there was a modest inverse correlation between IL-1beta and BMD at all sites. RESULTS: In univariate analyses, IGF-I and DHEAS were significant correlates of BMD or bone mineral content. In final multivariate models controlling for anthropometric and other variables of relevance to bone density, only IGF-I was identified as a significant independent skeletal predictor. While alterations in DHEAS, IGF-I, and specific cytokines may contribute to skeletal deficits in patients with CF, of these factors a low IGF-I concentration appears to be most strongly correlated with BMD. CONCLUSIONS: These findings may have therapeutic implications for enhancing bone density in these patients.

Adolescent↗

Levalbuterol hydrochloride.

Racemic albuterol, a commonly used bronchodilator, is an exact 50:50 mixture of two enantiomers, R- and S-albuterol. Concern regarding increased mortality associated with the use of this beta-2 (beta 2) agonist triggered the study of both of these enantiomers separately. In vitro studies suggest that the two enantiomers have different binding affinities for beta-adrenoreceptors, may exert opposing effects on inflammation, demonstrate different effects on mucocilary transport, and display differing pharmacokinetics. Clinical studies comparing both enantiomers are few, of short duration, and often in small patient populations, and their results vary. R-albuterol has greater bronchodilatory effects than the racemate and may have anti-inflammatory properties. S-albuterol has markedly less affinity for the beta-adrenoreceptor. It was found to cause bronchoconstriction in animal models, but neither bronchoconstrictive nor pro-inflammatory effects have been conclusively demonstrated in human studies. The data available at present, while suggestive, are insufficient to conclusively recommend R-albuterol over the racemate. Further basic research and investigations in humans comparing both enantiomers at increasing doses over longer time periods are required to clarify the precise roles of R- and S-albuterol.

Adrenergic beta-Agonists↗

Respiratory diseases in the first year of life in children born to HIV-1-infected women.

Our objective was to describe the respiratory complications, clinical findings, and chest radiographic changes in the first year of life in infected and uninfected children born to HIV-1-infected women. We prospectively followed a cohort of 600 infants born to HIV-1-infected women from birth to 12 months in a multicenter study. Of these, 93 infants (15.5%) were HIV-1-infected, 463 were uninfected, and 44 were of unknown status prior to death or loss to follow-up. The cumulative incidence ( +/- SE) of an initial pneumonia episode at 12 months was 24.1 +/- 4.7% in HIV-1-infected children compared to 1.4 +/- 0.6% in HIV-1-uninfected children (P < 0.001). The rate of Pneumocystis carinii pneumonia (PCP) was 9.5 per 100 child-years. The HIV-1 RNA load was not higher in the group that developed pneumonia in the first year vs. those who did not. Children who developed lower respiratory tract infections or PCP had increased rates of decline of CD4 cell counts during the first 6 months of life. Lower maternal CD4 cell counts were associated with higher rates of pneumonia, and upper and lower respiratory tract infections. The rates of upper respiratory tract infection and bronchiolitis/reactive airway disease in infected children were not significantly different than in uninfected children. At 12 months, significantly more HIV-1-infected than uninfected children had tachypnea and chest radiographs with nodular and reticular densities. There was no relationship between cytomegalovirus infection in the first year of life and radiographic changes or occurrences of pneumonia. In conclusion, despite a low incidence of PCP, rates of pneumonia remain high in HIV-infected children in the first year of life. The incidence of pneumonia in uninfected infants born to HIV-1-infected mothers is low. Chest X-ray abnormalities and tachypnea suggest that subacute disease is present in infected infants. Further follow-up is warranted to determine its nature.

Adult↗

Reproductive and sexual health in males with cystic fibrosis: a case for health professional education and training.

PURPOSE: To survey the attitudes and clinical practice of health professionals to identify current practice and possible barriers to discussion of sexual and reproductive health issues in adolescent males with cystic fibrosis (CF). METHODS: An interview schedule was developed to seek information about attitudes to reproductive and sexual health in males with CF and to elicit details of reported professional practice of health care providers from four CF centers in Massachusetts. RESULTS: Of 32 health professionals interviewed, 66% informed parents about male infertility soon after diagnosis in infancy; 22% of those not informing parents at this time waited until later childhood or adolescence; and 12% reported they did not discuss these issues with parents during childhood or adolescence. All respondents reported they discuss infertility with male adolescents. The mean age thought most appropriate to discuss infertility was 13.8 (+/-2.2) years, although most do so at 15.2 (+/-2.8) years (p <.05). Fifty percent report routinely discussing that sexual performance is not affected by CF; 38% discuss the importance of condom use; 50% discuss normal sexual performance; 13% offer semen analysis to adolescents; and 3% inform males about small-volume ejaculates. Reproductive options are discussed with adolescents by 19% of clinicians. The themes of embarrassment, insufficient time, the difficulty of finding the "right" time, and insufficient training were identified as barriers to these discussions. CONCLUSIONS: Greater training for health professionals in the reproductive and sexual health issues of CF is a step to more complete, timely, and comfortable discussion of this area of health care.

Adolescent↗

Forced expiratory flow in uninfected infants and children born to HIV-infected mothers.

The Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV (P(2)C(2) HIV) Study is a multicenter study examining pulmonary and cardiac outcomes in offspring of HIV-infected mothers. This portion of the P(2)C(2) study tests the hypothesis that infants exposed to, but uninfected by, maternal HIV have normal maximal expiratory flow at functional residual capacity (V'max,(FRC)). We obtained 500 measurements of V'max,(FRC) by rapid thoracic compression in 285 children ages 6-30 mo in five U.S. centers. The data were compared with those from a healthy cohort of children described elsewhere. V'max,(FRC) rose with height in a linear relationship. The slope of the regression line in the exposed infants did not differ statistically from the slope in the comparison group, but the intercept was about 20% lower (p < 0.001). Height and weight were comparable in the two cohorts, and the differences between intercepts persisted after adjusting for birth weight and gestational age. However, maternal HIV infection cannot be assumed to be the cause as the cohorts may have differed in other variables, such as socioeconomic status and frequency of maternal smoking and drug use. Also, measurements varied substantially within and between our five centers, probably in part because of different racial and ethnic distributions. In summary, maternal HIV infection probably has only a modest effect, if any, on maximal expiratory flow at functional residual capacity in uninfected infants.

Age Factors↗

Passive respiratory mechanics: the occlusion techniques.

The aim of this position paper is to define quality control and acceptance criteria for measuring passive respiratory mechanics in infants using the occlusion techniques to ensure that valid results are obtained. These guidelines cover numerous aspects including: 1) terminology and definitions; 2) equipment; 3) data acquisition; 4) data handling and analysis; 5) reporting of results. Adherence to these guidelines should ensure that measurement of passive respiratory mechanics in infants in different lung function laboratories could be performed with an acceptable degree of safety, precision, and reproducibility. This will facilitate multi-centre collection of data and performance of clinical investigations.

Airway Resistance↗

Human immunodeficiency virus-related mortality in infants and children: data from the pediatric pulmonary and cardiovascular complications of vertically transmitted HIV (P(2)C(2)) Study.

OBJECTIVES: To identify the causes of mortality in children with vertically transmitted human immunodeficiency virus (HIV) infection and to study age-related mortality trends. METHODS: In the multicenter P(2)C(2) HIV Study, 816 children born to HIV-infected mothers were followed for a median of 3.6 years. Two hundred five study participants with HIV infection were enrolled at a median age of 23 months; 611 were enrolled either prenatally or in the neonatal period before their HIV infection status was known. There were 121 deaths in study patients. The cause of death for all patients, its relationship to HIV infection, and pulmonary or cardiac involvement were determined. Age trends in disease-specific mortality were summarized for the HIV-related deaths. RESULTS: Ninety-three children died of HIV-related conditions. Infection was the most prevalent cause of death for children under 6 years of age with 32.3% caused by pulmonary infection and another 16.9% caused by nonpulmonary infection. The frequency of pulmonary disease as the underlying cause of death decreased significantly with increasing age: 5/9 (55.6%) by age 1, 1/12 (8.3%) after age 10 years. The frequency of chronic cardiac disease as the underlying cause increased with age-0% by age 1 year, 3/12 (25.0%) after age 10 years, as did the frequency of wasting syndrome with disseminated Mycobacterium avium complex-0% by age 1 year, 6/12 (50.0%) after age 10 years. CONCLUSIONS: Children with HIV who survive longer are less likely to die of pulmonary disease or infection and more likely to die of cardiac causes or with wasting syndrome.pediatric acquired immunodeficiency syndrome, mortality, human immunodeficiency virus.

AIDS Dementia Complex↗

Mycobacterium abscessus infection in cystic fibrosis. Colonization or infection?

We present a case of a patient with cystic fibrosis who was thought to be colonized with Mycobacterium abscessus for 13 yr prior to developing clinically apparent mycobacterial infection. However, histologic evidence indicated that invasive mycobacterial disease was present from the onset. While accepting that chronic endobronchial colonization with atypical mycobacteria may occur in patients with cystic fibrosis, the repeated isolation of mycobacteria from the sputum of these patients should alert the clinician to the possibility of indolent disease. Early consideration of treatment for this infection should occur in any patient with cystic fibrosis in whom there is an unexplained deterioration in lung function. The recent introduction of high dose ibuprofen raises concerns about its possible contribution to the progression of the infection.

Adult↗

Thoracoabdominal compression and respiratory system compliance in HIV-infected infants.

The thoracoabdominal compression technique (TAC) is used to measure expiratory flow in infants. We investigated whether TAC caused a change in total thoracic compliance (Crs), resistance (Rrs), and respiratory system time constant (Trs). We studied 41 infants (mean age, 12.4 mo; SD, 7.5) from five centers studying longitudinal lung and cardiovascular function of infants from HIV-infected mothers. We measured Crs, Rrs, and Trs before and after TAC. Changes in Crs, Rrs, and Trs after TAC were not dependent on the length of time since TAC. Crs and Trs were reduced after TAC, p = 0.013 and p = 0.003, respectively, whereas Rrs did not change. When compared with uninfected infants, HIV-infected infants had a larger post-pre TAC percent decline in Crs (p = 0.003) and a post-pre TAC rise in mean Rrs (p = 0.03). These differences remained significant after adjusting for sex and age. When performing infant pulmonary function testing, TAC itself produces a temporary decrease in Crs and Trs that is more significant in infants at risk for abnormal lung volume or compliance. Therefore, the sequence of performing the infant lung function parameters should be the same each time the testing is repeated with TAC as the last parameter tested at each testing session.

Abdomen↗

Thoracoabdominal asynchrony and ratio of time to peak tidal expiratory flow over total expiratory time in adolescents with cystic fibrosis.

Thoracoabdominal asynchrony (TAA) and the ratio of time to peak tidal expiratory flow over total expiratory time (TME/TE) have been used to assess airway obstruction in infants and adults. We obtained these measurements using calibrated respiratory inductance plethysmography (RIP) on 15 adolescents and young adults with cystic fibrosis (CF) and varying disease severity. The measurements were then compared to 15 normal age-matched controls. TAA was expressed as a phase angle (phi) calculated from the abdominal (AB) and ribcage (RC) signals acquired from scalar strip chart recordings. Using CODAS (DATAQ Instruments, Akron, OH) software, the analog signals were digitized, and the differentiated sum (AB + RC) signal was used to calculate TME/TE. Forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1) were obtained using RIP in all subjects. Subjects with CF had a significantly higher mean phi than the control subjects (15 degrees vs. 8 degrees, respectively, P = 0.01). In the CF patients the specificity of a high phi as an indicator of abnormality was 80%, while the sensitivity was 65%. There was no correlation in the magnitude of phi and disease severity as assessed by FVC or FEV1. There was no significant difference in TME/TE between the groups. We conclude that RIP-acquired phi, but not TME/TE, is a simple and useful method to detect the presence of airway obstructive disease. We speculate that the sensitivity of this method will increase in younger patients with more compliant chest walls and less air trapping. Longitudinal studies of phi in infants and young children with lung disease could help in assessing disease severity and progression in this population, in whom repeated measures are few and complex.

Abdomen↗

Epidemiologic study of cystic fibrosis: design and implementation of a prospective, multicenter, observational study of patients with cystic fibrosis in the U.S. and Canada.

Cystic fibrosis (CF) is a complex illness characterized by chronic lung infection leading to deterioration in function and respiratory failure in over 85% of patients. An understanding of the risk factors for that progression and the interaction of these factors with current therapeutic strategies should materially improve the prevention of this progressive lung disease. The Epidemiologic Study of Cystic Fibrosis (ESCF) was therefore designed as a multicenter, longitudinal, observational study to prospectively collect detailed clinical, therapeutic, microbiologic, and lung function data from a large number of CF treatment sites in the U.S. and Canada. The ESCF also serves an important role as a phase-IV study of dornase alfa. To be eligible for enrollment, subjects must have the diagnosis of CF and receive the majority of their care at an ESCF site. In this paper, the authors present the ESCF study design in detail. Further, enrollment data collected at 194 study sites in 18,411 subjects enrolled from December 1, 1993 to December 31, 1995 are presented in summary form. This comprehensive study is unique in the detail of clinical data collected regarding patient monitoring and therapeutic practices in CF care. Two companion articles present data regarding practice patterns in cystic fibrosis care, including data on resource utilization and prescribing practices.

Adolescent↗

Lung abscess versus necrotizing pneumonia: implications for interventional therapy.

OBJECTIVE: To assess and contrast the role of interventional therapy for two types of cavitating pneumonias: lung abscess and necrotizing pneumonia. MATERIALS AND METHODS: We retrospectively reviewed the imaging, interventional therapy, and outcome of 14 children seen between February 1987 and January 1996 with lung abscess and 9 with necrotizing pneumonia. All children were treated with antibiotics prior to intervention. Pulmonary parenchymal fluid was percutaneously aspirated from ten lung abscesses and three necrotizing pneumonias. Percutaneous catheters drained five lung abscesses. Pleural drainage was performed for three lung abscesses and eight necrotizing pneumonias. RESULTS: All 14 children with lung abscesses had positive Gram stains of the pulmonary fluid; 13 cultures were positive. All 14 defervesced within 48 h of intervention. None developed a bronchopleural fistula. All nine necrotizing pneumonias were presumed to be sequelae of prior pneumonia. Streptococcus pneumoniae was the only organism as documented by pleural fluid latex fixation in three patients, gram stain in two, and culture in only one. Seven of these children developed pneumatoceles, five developed bronchopleural fistulae, and three required long-term chest tubes for persistent pneumothoraces. CONCLUSION: Aggressive interventional therapy can be diagnostic and therapeutic in the infected lung abscess. Interventional therapy can be harmful in postinfectious necrotizing pneumonia.

Adolescent↗

Allergic bronchopulmonary aspergillosis in cystic fibrosis: reported prevalence, regional distribution, and patient characteristics. Scientific Advisory Group, Investigators, and Coordinators of the Epidemiologic Study of Cystic Fibrosis.

OBJECTIVES: Using the large database from the Epidemiologic Study of Cystic Fibrosis (ESCF), the objectives of this study were to (1) estimate the reported prevalence of allergic bronchopulmonary aspergillosis (ABPA) in patients with cystic fibrosis (CF); (2) compare reported prevalence rates across geographic regions; (3) compare reported prevalence rates between patient subgroups based on demographic and disease characteristics; and (4) describe the ABPA group with regard to their sex, age, and disease severity. STUDY DESIGN: All patients > or = 5 years of age enrolled in ESCF between December 1993 and May 1996 were eligible. Criteria for the diagnosis of ABPA were defined by the ESCF guidelines. Prevalence rates for ABPA were calculated, and potential risk factors for the diagnosis of ABPA were analyzed, including sex, age, pulmonary function, diagnosis of asthma, presence of wheeze, and positive respiratory culture for Pseudomonas. RESULTS: There were 14,210 eligible patients enrolled in ESCF during this period, and ABPA was diagnosed in 281 patients (2%). Regional prevalence varied from 0.9% in the Southwest to 4.0% in the West. Increased prevalence rates occurred in female patients, the adolescent age group, and subjects with lower lung function, wheeze, asthma, and positive Pseudomonas cultures. Although most ABPA patients had evidence of airway obstruction, 10% had an FEV1 of > 100% of predicted. The rates of wheeze (17%) and asthma (30%) were lower than expected in the ABPA group. CONCLUSIONS: This observational study found a reported prevalence rate of ABPA of 2% of CF patients in a large database. This rate was lower than the 5 to 15% rate reported in smaller studies, suggesting that ABPA is underdiagnosed in the CF population. There was wide regional variation in reported prevalence rates, which is unexplained at this time. The characteristics of the patients with ABPA and the epidemiologic risk factors for diagnosis of ABPA were described. Simplified diagnostic criteria were adapted for ESCF with the intent of increasing awareness of ABPA among the participants in this study.

Adolescent↗

Unexpected non-HIV causes of death in children born to HIV-infected mothers. Pediatric Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection Study Group.

INTRODUCTION: A high incidence of sudden, unexplained deaths in infants born to HIV-infected mothers has been noted in several epidemiologic studies. During the course of a prospective study of heart and lung disease in children born to HIV-infected mothers, we noted that of 5 unexpected non-HIV-related deaths, 4 were attributed to traumatic events. METHODS: The Pediatric Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection (P2C2) study is a multicenter, prospective investigation of the incidence of heart and lung disease in HIV-infected children. A total of 805 children were enrolled and followed for 5 to 7 years with serial immunologic, pulmonary and cardiac function studies. During the study, a multidisciplinary committee was formed to review the cause of death for those patients who died. The committee used results of pulmonary, cardiac, and laboratory tests, hospital summaries, as well as autopsy and coroners' reports. The committee formed a consensus about the underlying and contributing causes of death for each subject using the definitions from the 1989 US Standard Certificate of Death. RESULTS: A total of 121 deaths occurred during the course of the P2C2 study. Of the 121 deaths, 5 were traumatic or sudden and unexpected and judged by the Mortality Review Committee to be unrelated to HIV infection. The median age at the time of death was 1.3 months and ranged from 1.2 to 37.8 months. Two infants died of trauma: a skull fracture and subdural hematoma in 1 infant and multiple skeletal fractures consistent with battered child syndrome in the other infant. The third infant died of accidental suffocation at home at 1.2 months of age. The fourth infant died suddenly and unexpectedly at home at 1.3 months of age. The autopsy showed no sign of HIV or other infection and was consistent with sudden unexpected death or SIDS. One non-HIV-related death occurred when a 38-month-old child died together with the mother in an unwitnessed drowning. The cumulative mortality rate attributable to trauma and sudden death at 4 months of age was 0.95% (95% CI: 0.02-1. 87%) and the infant mortality rate was 9.5/1000 live births. Three children were born prematurely at 30, 33, and 36 weeks' gestational age, respectively, and 3 mothers admitted using recreational drugs before or during pregnancy. DISCUSSION: These traumatic and sudden non-HIV-related deaths accounted for 4.1% (5/121) of the deaths during the entire P2C2 study period and for 20% (4/20) of the deaths in the first year of life. Four deaths were attributable to accidental and nonaccidental trauma rather than to other common causes of infant death. One death was a sudden unexpected death, similar to SIDS, a leading cause of infant death in the United States. The majority of previously reported non-HIV-related deaths in infants born to HIV-infected mothers have been attributed to SIDS or to unexplained sudden death. In contrast with other reports, 4 of the 5 children in our series died of accidental or nonaccidental trauma and only 1 was a sudden unexplained death. It is unlikely that HIV exposure is related directly to the deaths described in this report; however, maternal HIV infection may be a marker for factors that place the child at risk for sudden or traumatic death. SUMMARY: This report suggests that children born to HIV-infected mothers may be at increased risk for traumatic or sudden, unexplained, non-HIV-related death. These children seem to be at risk regardless of their own HIV infection status. Furthermore, 4 of the deaths in our study occurred within the first few months of life, suggesting that this is a period of increased vulnerability. Studies to identify associated risk factors for non-HIV-related deaths are needed to identify these high-risk infants. Children born to HIV-infected mothers may be more vulnerable than was recognized previously and may be in need of increased social services, especially in early infancy.

Cause of Death↗

Reproductive health in males with cystic fibrosis: knowledge, attitudes, and experiences of patients and parents.

Males with cystic fibrosis (CF) are generally infertile as a result of aberrant development of Wolffian duct derivitives. The personal significance of this and related reproductive and sexual health (RSH) issues is unknown. We set out to describe the knowledge, attitudes, and experiences regarding RSH in a group of adolescent and adult males with CF, as well as the knowledge and attitudes of parents. This descriptive study was based on a semi-structured interview utilizing in-depth interview techniques. Questions included aspects of knowledge, attitudes, and experiences. Adolescent (aged 14-17 years) and adult (at least 18 years) males attending the Children's Hospital Cystic Fibrosis Clinic, Boston, MA, USA, or hospitalized at the Children's Hospital over that period were eligible; the accompanying parent of the adolescent was also interviewed. Consecutive eligible males were interviewed over a 3 month period. Summary data are presented, attitudinal data are analyzed qualitatively, and a selection of representative transcript data are reported to describe the range of opinions. Fifty males (10 adolescents, 40 adults) participated; this constituted a consecutive sample of 44% of the eligible clinic population. Ninety percent of adults, 60% of adolescents, and 50% of parents knew of male infertility. The mean age (+/-SD) at which adults recalled first hearing this was 16.0 +/- 4.7 years and 13.9 +/- 1.6 years for those adolescents who knew of infertility. Nineteen (48%) of adults and 5 (83%) of adolescents first heard about infertility from their health care providers. Ninety percent reported no major distress upon first hearing about infertility during adolescence. Increasing significance of infertility with maturity was reported by 12 men (30%); only 4 adults (10%) reported that infertility was not a significant aspect of CF. Forty percent knew that males with CF have a small volume ejaculate, but none had been told this by a health care provider. Thirty percent of men had semen analysis performed and all were azoospermic. We conclude that the majority of males with CF know of likely infertility. The significance of this knowledge changes with time. Poor knowledge and confusion surround a range of RSH issues in males with CF.

Adolescent↗

Cystic fibrosis: a system for assessing and predicting progression.

OBJECTIVE: This study presents a radiography-based database scoring changes over time in a large population of patients with cystic fibrosis. The purpose of this database is to provide comparison for groups of patients undergoing experimental treatment to assess effect of the treatment. The data may also be used to compare individuals with their age-matched cohorts with cystic fibrosis. MATERIALS AND METHODS: From 230 patients, 3038 chest radiographs were scored using the Brasfield system. The scores from radiographs from all the patients were individually plotted for age, and a single age-based severity curve was created. The age-based severity curve was compared with similar curves derived from pulmonary function studies of a subset of the same patient population. RESULTS: We found high inter- and intraobserver reliability. The difference between the observers averaged 1.3 Brasfield points, the scale of which ranges up to 25 points. The age-based severity curve was presented as mean Brasfield scores versus age (birth to > 30 years) plotted with 95% confidence limits; the curve was also plotted in percentiles. The rate of decline of this curve was similar to the decline of pulmonary function studies in this patient population. CONCLUSION: The age-based curve, a structural anatomic parameter, differs from pulmonary function studies, which are functional. Thus the age-based severity curve provides an additional, independent basis for comparison between groups and individuals. It may be used for the initial assessment of lung disease and for gauging and predicting the rate of decline. The curve may be used as a long-range outcome criterion to evaluate new treatments in groups of patients with cystic fibrosis.

Adolescent↗