Biomedical subjects

Henry L Dorkin

Publications and source records attributed to Henry L Dorkin.

6 recordsLinked to original sources

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

Species-specific bacteria identification using differential mobility spectrometry and bioinformatics pattern recognition.

As bacteria grow and proliferate, they release a variety of volatile compounds that can be profiled and used for speciation, providing an approach amenable to disease diagnosis through quick analysis of clinical cultures as well as patient breath analysis. As a practical alternative to mass spectrometry detection and whole cell pyrolysis approaches, we have developed methodology that involves detection via a sensitive, micromachined differential mobility spectrometer (microDMx), for sampling headspace gases produced by bacteria growing in liquid culture. We have applied pattern discovery/recognition algorithms (ProteomeQuest) to analyze headspace gas spectra generated by microDMx to reliably discern multiple species of bacteria in vitro: Escherichia coli, Bacillus subtilis, Bacillus thuringiensis, and Mycobacterium smegmatis. The overall accuracy for identifying volatile profiles of a species within the 95% confidence interval for the two highest accuracy models evolved was between 70.4 and 89.3% based upon the coordinated expression of between 5 and 11 features. These encouraging in vitro results suggest that the microDMx technology, coupled with bioinformatics data analysis, has potential for diagnosis of bacterial infections.

Bacillus↗

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

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↗