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Brian P O'Sullivan

Publications and source records attributed to Brian P O'Sullivan.

15 recordsLinked to original sources
PubMed2006

Potential utility of plasma fatty acid analysis in the diagnosis of cystic fibrosis.

BACKGROUND: An altered distribution of fatty acids in cells and tissues is found in patients with cystic fibrosis (CF). In this study, we assessed the potential role of plasma fatty acid analysis in the diagnosis of CF. METHODS: In this 2-part study, we first used gas chromatography-mass spectrometry to analyze fatty acids in plasma from 13 CF patients and 11 controls without CF. We then used the fatty acid distribution data to identify the fatty acids or multiple fatty acid calculations most effective in identifying CF patients. Part 2 of the study was a blinded analysis of 10 CF patients and 9 controls to directly test the effectiveness of the diagnostic parameters for CF identified from the plasma fatty acid analysis. RESULTS: In the nonblinded trial, the multiplication product of (18:2 n-6) x (22:6 n-3) (each as percentage of total plasma fatty acid) was the most effective indicator for distinguishing patients with CF from controls (P = 0.0003). In part 2 (the blinded trial), this multiplication product was also the most effective indicator for distinguishing CF patients from controls (P = 0.0008). CONCLUSIONS: The product of (18:2 n-6) x (22:6 n-3) is effective for distinguishing CF patients from persons without CF. This diagnostic marker may have value as an alternative to the sweat chloride test in selected patients being evaluated for CF.

Adolescent↗
PubMed2006

Early pulmonary manifestation of cystic fibrosis in children with the DeltaF508/R117H-7T genotype.

We report 3 cystic fibrosis newborn screen-positive infants with the DeltaF508/R117H-7T genotype who had Pseudomonas aeruginosa detected in oropharyngeal cultures early in life and a fourth who had pulmonary symptoms and Gram-negative growth on multiple oropharyngeal cultures. All 4 patients were followed prospectively from the time of genetic diagnosis. As many regions implement newborn screening for cystic fibrosis, there is concern regarding which mutations should be included in genetic panels used to make the cystic fibrosis diagnosis. Some have recommended that mutations not specifically associated with classic cystic fibrosis be excluded. Our cases highlight the importance of considering keeping so-called mild mutations on cystic fibrosis newborn screening panels and the need to follow children with these mutations closely.

Age of Onset↗
PubMed2005

The inflammatory role of platelets in cystic fibrosis.

Platelets are an important, albeit generally underappreciated, component of the inflammatory cascade. Platelets are known to contribute to inflammation in atherosclerosis, stroke, and asthma. They produce a large number of proinflammatory lipid mediators and cytokines, and play a vital role in recruitment of leukocytes into inflamed tissue. We review the role of platelets in inflammation, how they assist in the recruitment of leukocytes into lung tissue in asthma, and evidence of their dysfunction in cystic fibrosis (CF). Platelet dysfunction in CF could contribute to pulmonary inflammation and tissue destruction. We hypothesize that platelet activation is important in CF lung disease and suggest research avenues that might help elucidate the role of activated platelets in CF.

Biomedical Research↗
PubMed2005

Platelet activation in cystic fibrosis.

Cystic fibrosis (CF) is caused by a mutation of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). We examined platelet function in CF patients because lung inflammation is part of this disease and platelets contribute to inflammation. CF patients had increased circulating leukocyte-platelet aggregates and increased platelet responsiveness to agonists compared with healthy controls. CF plasma caused activation of normal and CF platelets; however, activation was greater in CF platelets. Furthermore, washed CF platelets also showed increased reactivity to agonists. CF platelet hyperreactivity was incompletely inhibited by prostaglandin E(1) (PGE(1)). As demonstrated by Western blotting and reverse-transcriptase-polymerase chain reaction (RT-PCR), there was neither CFTR nor CFTR-specific mRNA in normal platelets. There were abnormalities in the fatty acid composition of membrane fractions of CF platelets. In summary, CF patients have an increase in circulating activated platelets and platelet reactivity, as determined by monocyte-platelet aggregation, neutrophil-platelet aggregation, and platelet surface P-selectin. This increased platelet activation in CF is the result of both a plasma factor(s) and an intrinsic platelet mechanism via cyclic adenosine monophosphate (cAMP)/adenylate cyclase, but not via platelet CFTR. Our findings may account, at least in part, for the beneficial effects of ibuprofen in CF.

Adenylyl Cyclases↗
PubMed2005

Challenges in implementing a successful newborn cystic fibrosis screening program.

OBJECTIVE: To identify necessary components of a successful cystic fibrosis (CF) newborn screening (NBS) program. STUDY DESIGN: The approach to CF NBS used by the Massachusetts NBS program was examined. RESULTS: Several key components were identified that should be addressed when a state has made the decision to screen, and well in advance of actual implementation. These components include (1) inclusion of CF center directors in the development process; (2) logistics of choosing a screening algorithm relative to practices in place and community wishes; (3) projections of medical service needs from specific algorithms; (4) identification of critical reporting components; (5) identification of critical follow-up components; and (6) recognition of educational needs. CONCLUSIONS: Careful examination of a wide variety of issues is needed to ensure optimal implementation of NBS for CF.

Aftercare↗
PubMed2005

Communications systems and their models: Massachusetts parent compliance with recommended specialty care after positive cystic fibrosis newborn screening result.

OBJECTIVE: To evaluate compliance with recommendations for sweat testing/specialty evaluation and genetic counseling after a positive cystic fibrosis newborn screening (CF NBS) result. STUDY DESIGN: All infants with positive CF NBS results require a diagnostic sweat test at a CF center. Results that were "screen positive and diagnosis negative" prompted family genetic counseling. Parent compliance with follow-up protocol recommendations was retrospectively analyzed relative to the communications model in place at a particular CF Center. RESULTS: At each of the 5 MA CF centers, 95% of the CF NBS-positive infants completed recommended sweat testing. In contrast, there was wide disparity in compliance (32%-90%) with completion of genetic counseling between CF centers. CONCLUSION: CF centers that escorted parents through the 2 recommended follow-up steps in 1 day had higher compliance with the second step (genetic counseling) than centers that required a return visit for genetic counseling.

Aftercare↗
PubMed2005

Sweat testing infants detected by cystic fibrosis newborn screening.

OBJECTIVE: Describe and define limitations of early pilocarpine iontophoresis (sweat testing) for cystic fibrosis (CF) newborn screening (NBS). STUDY DESIGN: Population-based results from follow-up of CF NBS-positive newborns. RESULTS: Insufficient quantity of sweat is more likely if the sweat test is done too early, but testing is generally successful after 2 weeks of age. Sweat chloride levels drop over the first weeks of life. CF carriers have higher sweat chloride concentrations than non-carriers. CONCLUSIONS: Sweat testing can be performed effectively after 2 weeks of age for CF NBS-positive newborns. Earlier testing has a higher risk of insufficient sweat for completing testing.

Age Factors↗
PubMed2004

Association of cystic fibrosis with abnormalities in fatty acid metabolism.

BACKGROUND: Patients with cystic fibrosis have altered levels of plasma fatty acids. We previously demonstrated that arachidonic acid levels are increased and docosahexaenoic acid levels are decreased in affected tissues from cystic fibrosis-knockout mice. In this study we determined whether humans with mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene have a similar fatty acid defect in tissues expressing CFTR. METHODS: Fatty acids from nasal- and rectal-biopsy specimens, nasal epithelial scrapings, and plasma were analyzed from 38 subjects with cystic fibrosis and compared with results in 13 obligate heterozygotes, 24 healthy controls, 11 subjects with inflammatory bowel disease, 9 subjects with upper respiratory tract infection, and 16 subjects with asthma. RESULTS: The ratio of arachidonic to docosahexaenoic acid was increased in mucosal and submucosal nasal-biopsy specimens (P<0.001) and rectal-biopsy specimens (P=0.009) from subjects with cystic fibrosis and pancreatic sufficiency and subjects with cystic fibrosis and pancreatic insufficiency, as compared with values in healthy control subjects. In nasal tissue, this change reflected an increase in arachidonic acid levels and a decrease in docosahexaenoic acid levels. In cells from nasal mucosa, the ratio of arachidonic to docosahexaenoic acid was increased in subjects with cystic fibrosis (P<0.001), as compared with healthy controls, with values in obligate heterozygotes intermediate between these two groups (P<0.001). The ratio was not increased in subjects with inflammatory bowel disease. Subjects with asthma and those with upper respiratory tract infection had values intermediate between those in subjects with cystic fibrosis and those in healthy control subjects. CONCLUSIONS: These data indicate that alterations in fatty acids similar to those in cystic fibrosis-knockout mice are present in CFTR-expressing tissue from subjects with cystic fibrosis.

Arachidonic Acid↗
PubMed2004

Survey of breast-feeding practices and outcomes in the cystic fibrosis population.

The aim of this study was to survey cystic fibrosis (CF) patients to determine the frequency of breast-feeding and its association with onset and severity of CF symptoms. Three thousand, two hundred questionnaires were sent to 30 accredited CF centers for anonymous completion. Eight hundred and sixty-three questionnaires were returned and scanned into a database. All results were adjusted for age at time of filling out the questionnaire. Age at onset of symptoms, percent forced expired volume in 1 sec (FEV1%) predicted, and intravenous (IV) antibiotic use were analyzed based on breast-feeding history. Approximately 49% of respondents received human breast milk at some time, but only 18% were exclusively breast-fed. Breast-feeding exclusively for greater than 6 months was associated with a decrease in disease severity based on recent intravenous antibiotic use compared to no breast-feeding (P = 0.03). There was no statistically significant change in onset of symptoms in the setting of breast-feeding; however, a trend toward delayed onset was seen in those receiving human milk. Fifty-three percent of those who breast-fed exclusively > or = 6 months had FEV1% values > 90%, compared to 47% of those not breast-fed. This is a suggestive but not statistically significant difference. In conclusion, breast-feeding for > or = 6 months is associated with decreased use of intravenous antibiotics in the 2 years prior to administering the questionnaire. This survey indicates that breast-feeding is not harmful to children with CF, and may be beneficial.

Adolescent↗
PubMed2004

Interleukin 8 secretion from monocytes of subjects heterozygous for the deltaF508 cystic fibrosis transmembrane conductance regulator gene mutation is altered.

Patients with cystic fibrosis (CF) exhibit an excessive host inflammatory response. The aim of this study was to determine (i) whether interleukin 8 (IL-8) secretion is increased from monocytes from subjects heterozygous as well as homozygous for cystic fibrosis transmembrane conductance regulator (CFTR) mutations and (ii) whether this is due to increased cell surface lipopolysaccharide (LPS) receptors or, alternatively, increased activation of mitogen-activated protein kinases (MAPK). The basal level of IL-8 secretion was higher from monocytes from CF patients than from monocytes from healthy controls (P = 0.02) and obligate heterozygotes (parents of the CF patients). The 50% effective concentrations for LPS-induced IL-8 production for monocytes from both CF patients and obligate heterozygotes were 100-fold lower than those for monocytes from healthy controls (P < 0.05). No differences in the levels of IL-1beta production were seen between these groups. Expression of the LPS surface receptors CD14 and Toll-like receptor 4 were not different between CF patients and healthy controls. In contrast, phosphorylation of the MAPKs p38 and ERK occurred at lower doses of LPS in monocytes from patients heterozygous and homozygous for CFTR mutations. These results indicate that a single allelic CFTR mutation is sufficient to augment IL-8 secretion in response to LPS. This is not a result of increased LPS receptor expression but, rather, is associated with alterations in MAPK signaling.

Adult↗
PubMed2004

Use of nasopharyngoscopy in the evaluation of children with noisy breathing.

STUDY OBJECTIVE: To evaluate the practice of using nasopharyngoscopy without routine fiberoptic bronchoscopy for children presenting to a pediatric pulmonary practice with nonspecific noisy breathing. DESIGN: Retrospective chart review. Records of patients who underwent nasopharyngoscopy between January 1, 1990, and December 31, 1999, were reviewed. Follow-up was obtained by office records and direct contact with the patient's family and/or primary care physician. SETTING: Academic, tertiary care facility. RESULTS: Eighty-one children who underwent upper airway endoscopy to evaluate noisy breathing consistent with extrathoracic lesions were identified. One child had two evaluations separated by years for differing complaints, making a total of 82 procedures. Stridor was the chief complaint in three fourths of the children. Half of the children with stridor were found to have laryngomalacia. Long-term follow-up was available for 75 of 81 children, with median follow-up of 6 years (range, 1 to 13 years). No medical problems related to missed airway lesions developed in any infants initially evaluated using nasopharyngoscopy. CONCLUSIONS: Nasopharyngoscopy without lower airway endoscopy can be used safely for the initial evaluation of noisy breathing in infants and children provided excellent follow-up is available.

Adolescent↗
PubMed2004

Population-based newborn screening for genetic disorders when multiple mutation DNA testing is incorporated: a cystic fibrosis newborn screening model demonstrating increased sensitivity but more carrier detections.

OBJECTIVES: Newborn screening for cystic fibrosis (CF) provides a model to investigate the implications of applying multiple-mutation DNA testing in screening for any disorder in a pediatric population-based setting, where detection of affected infants is desired and identification of unaffected carriers is not. Widely applied 2-tiered CF newborn screening strategies first test for elevated immunoreactive trypsinogen (IRT) with subsequent analysis for a single CFTR mutation (DeltaF508), systematically missing CF-affected infants with any of the >1000 less common or population-specific mutations. Comparison of CF newborn screening algorithms that incorporate single- and multiple-mutation testing may offer insights into strategies that maximize the public health value of screening for CF and other genetic disorders. The objective of this study was to evaluate technical feasibility and practical implications of 2-tiered CF newborn screening that uses testing for multiple mutations (multiple-CFTR-mutation testing). METHODS: We implemented statewide CF newborn screening using a 2-tiered algorithm: all specimens were assayed for IRT; those with elevated IRT then had multiple-CFTR-mutation testing. Infants who screened positive by detection of 1 or 2 mutations or extremely elevated IRT (>99.8%; failsafe protocol) were then referred for definitive diagnosis by sweat testing. We compared the number of sweat-test referrals using single- with multiple-CFTR-mutation testing. Initial physician assessments and diagnostic outcomes of these screened-positive infants and any affected infants missed by the screen were analyzed. We evaluated compliance with our screening and follow-up protocols. All Massachusetts delivery units, the Newborn Screening Program, pediatric health care providers who evaluate and refer screened-positive infants, and the 5 Massachusetts CF Centers and their affiliated genetic services participated. A 4-year cohort of 323 506 infants who were born in Massachusetts between February 1, 1999, and February 1, 2003, and screened for CF at approximately 2 days of age was studied. RESULTS: A total of 110 of 112 CF-affected infants screened (negative predictive value: 99.99%) were detected with IRT/multiple-CFTR-mutation screening; 2 false-negative screens did not show elevated IRT. A total of 107 (97%) of the 110 had 1 or 2 mutations detected by the multiple- CFTR-mutation screen, and 3 had positive screens on the basis of the failsafe protocol. In contrast, had we used single-mutation testing, only 96 (87%) of the 110 would have had 1 or 2 mutations detectable by single-mutation screen, 8 would have had positive screens on the basis of the failsafe protocol, and an additional 6 infants would have had false-negative screens. Among 110 CF-affected screened-positive infants, a likely "genetic diagnosis" was made by the multiple-CFTR-mutation screen in 82 (75%) versus 55 (50%) with DeltaF508 alone. Increased sensitivity from multiple-CFTR-mutation testing yielded 274 (26%) more referrals for sweat testing and carrier identifications than testing with DeltaF508 alone. CONCLUSIONS: Use of multiple-CFTR-mutation testing improved sensitivity and postscreening prediction of CF at the cost of increased referrals and carrier identification.

Algorithms↗