Biomedical subjects

Dongseok Choi

Publications and source records attributed to Dongseok Choi.

14 recordsLinked to original sources

PubMed2006

The Network for the Improvement of Addiction Treatment (NIATx): enhancing access and retention.

The Network for the Improvement of Addiction Treatment (NIATx) teaches participating treatment centers to use process improvement strategies. A cross-site evaluation monitored impacts on days between first contact and first treatment and percent of patients who started treatment and completed two, three and four units of care (i.e., one outpatient session, 1 day of intensive outpatient care, and 1 week of residential treatment). The analysis included 13 agencies that began participation in August 2003, submitted 10-15 months of data, and attempted improvements in outpatient (n=7), intensive outpatient (n=4) or residential treatment services (n=4) (two agencies provided data for two levels of care). Days to treatment declined 37% (from 19.6 to 12.4 days) across levels of care; the change was significant overall and for outpatient and intensive outpatient services. Significant overall improvement in retention in care was observed for the second unit of care (72-85%; 18% increase) and the third unit of care (62-73%; 17% increase); when level of care was assessed, a significant gain was found only for intensive outpatient services. Small incremental changes in treatment processes can lead to significant reductions in days to treatment and consistent gains in retention.

Humans↗

PubMed2006

The impact of the implementation of work hour requirements on residents' career satisfaction, attitudes and emotions.

BACKGROUND: To assess the impact of work hours' limitations required by the Accreditation Council for Graduate Medical Education (ACGME) on residents' career satisfaction, emotions and attitudes. METHODS: A validated survey instrument was used to assess residents' levels of career satisfaction, emotions and attitudes before and after the ACGME duty hour requirements were implemented. The "pre" implementation survey was distributed in December 2002 and the "post" implementation one in December 2004. Only the latter included work-hour related questions. RESULTS: The response rates were 56% for the 2002 and 72% for the 2004 surveys respectively. Although career satisfaction remained unchanged, numerous changes occurred in both emotions and attitudes. Compared to those residents who did not violate work-hour requirements, those who did were significantly more negative in attitudes and emotions. CONCLUSION: With the implementation of the ACGME work hour limitations, the training experience became more negative for those residents who violated the work hour limits and had a small positive impact on those who did not violate them. Graduate medical education leaders must innovate to make the experiences for selected residents improved and still maintain compliance with the work hour requirements.

Accreditation↗

PubMed2006

A mid year comparison study of career satisfaction and emotional states between residents and faculty at one academic medical center.

BACKGROUND: The Accreditation Council for Graduate Medical Education's (ACGME) new requirements raise multiple challenges for academic medical centers. We sought to evaluate career satisfaction, emotional states, positive and negative experiences, work hours and sleep among residents and faculty simultaneously in one academic medical center after implementation of the ACGME duty hour requirements. METHODS: Residents and faculty (1330) in the academic health center were asked to participate in a confidential survey; 72% of the residents and 66% of the faculty completed the survey. RESULTS: Compared to residents, faculty had higher levels of satisfaction with career choice, competence, importance and usefulness; lower levels of anxiousness and depression. The most positive experiences for both groups corresponded to strong interpersonal relationships and educational value; most negative experiences to poor interpersonal relationships and issues perceived outside of the physician's control. Approximately 13% of the residents and 14% of the faculty were out of compliance with duty hour requirements. Nearly 5% of faculty reported working more than 100 hours per week. For faculty who worked 24 hour shifts, nearly 60% were out of compliance with the duty-hour requirements. CONCLUSION: Reasons for increased satisfaction with career choice, positive emotional states and experiences for faculty compared to residents are unexplained. Earlier studies from this institution identified similar positive findings among advanced residents compared to more junior residents. Faculty are more frequently at risk for duty-hour violations. If patient safety is of prime importance, faculty, in particular, should be compliant with the duty hour requirements. Perhaps the ACGME should contain faculty work hours as part of its regulatory function.

Academic Medical Centers↗

PubMed2006

Condition-specific coregulation with cis-regulatory motifs and modules in the mouse genome.

Deciphering genetic regulatory codes remains a challenge. Here, we present an effective approach to identifying in vivo condition-specific coregulation with cis-regulatory motifs and modules in the mouse genome. A resampling-based algorithm was adopted to cluster our microarray data of a stress response, which generated 35 tight clusters with unique expression patterns containing 811 genes of 5652 genes significantly altered. Database searches identified many known motifs within the 3-kb regulatory regions of 40 genes from 3 clusters and modules with six to nine motifs that were commonly shared by 60-100% of these genes. The upstream regulatory region contained the highest frequency of these common motifs. CisModule program predictions were comparable with the results from database searches and found four potentially novel motifs. This result indicates that these motifs and modules could be responsible for gene coregulation of the stress response in the lacrimal gland.

Algorithms↗

PubMed2006

A comparison study of career satisfaction and emotional states between primary care and speciality residents.

OBJECTIVE: To evaluate career satisfaction, emotional states and positive and negative experiences among residents in primary care and speciality programmes in 1 academic medical centre prior to the implementation of the Accreditation Council for Graduate Medical Education's (ACGME) duty hour requirements. DESIGN: Cross-sectional survey. MEASUREMENTS: All 581 residents in the academic health centre were asked to participate voluntarily in a confidential survey; 327(56%) completed the survey. RESULTS: Compared to their primary care colleagues, speciality residents had higher levels of satisfaction with career choice, feelings of competence and excitement, lower levels of inferiority and fatigue and different perceptions of positive and negative training experiences. However, 77% of all respondents were consistently or generally pleased with their career choices. The most positive residents' experiences related to interpersonal relationships and their educational value; the most negative experiences related to interpersonal relationships and issues perceived to be outside of residents' control. Age and training level, but not gender also influenced career satisfaction, emotional states and positive and negative opinions about residency. CONCLUSIONS: Less satisfaction with career choice and more negative emotional states for primary care residents compared to speciality residents probably relate to the training experience and may influence medical students' selections of careers. The primary care residents, compared to speciality residents, appear to have difficulty in fulfilling their ideals of professionalism in an environment where they have no control. These data provide baseline information with which to compare these same factors after the implementation of the ACGME duty hours' and competency requirements.

Adult↗

PubMed2006

Measuring the influence of built neighborhood environments on walking in older adults.

There is a need for greater understanding of how perceptions and objective measures of the physical environment influence physical activity among seniors. The goal of this study was to examine the degree of association between perceived and objective characteristics of the neighborhood environment and the relation of each type of measurement to neighborhood walking in older adults. Data on self-reported frequency of walking in the neighborhood and perceived measures of neighborhood environment from 105 older adults were linked to objective measures assessed by geographic information systems and an audit instrument. Perceived and objective measurements of the built environment exhibited a low degree of agreement (kappas: <.20). After adjustment for education, age, and gender, presence of a mall was positively associated with neighborhood walking in both the objective and perceived models.

Aged↗

PubMed2006

A large GLC1C Greek family with a myocilin T377M mutation: inheritance and phenotypic variability.

PURPOSE: POAG is a complex disease; therefore, families in which a glaucoma gene has been mapped may carry additional POAG genes. The goal of this study was to determine whether mutations in the myocilin (MYOC) gene on chromosome 1 are present in two POAG families, which have previously been mapped to the GLC1C locus on chromosome 3. METHODS: The three exons of MYOC were screened by denaturing (d)HPLC. Samples with heteroduplex peaks were sequenced. Clinical findings were compared with genotype status in all available family members over the age of 20 years. RESULTS: A T377M coding sequence change in MYOC was identified in family members of the Greek GLC1C family but not in the Oregon GLC1C family. Individuals carrying both the MYOC T377M variant and the GLC1C haplotype were more severely affected at an earlier age than individuals with just one of the POAG genes, suggesting that these two genes interact or that both contribute to the POAG phenotype in a cumulative way.

Adult↗

PubMed2005

Standardizing global gene expression analysis between laboratories and across platforms.

To facilitate collaborative research efforts between multi-investigator teams using DNA microarrays, we identified sources of error and data variability between laboratories and across microarray platforms, and methods to accommodate this variability. RNA expression data were generated in seven laboratories, which compared two standard RNA samples using 12 microarray platforms. At least two standard microarray types (one spotted, one commercial) were used by all laboratories. Reproducibility for most platforms within any laboratory was typically good, but reproducibility between platforms and across laboratories was generally poor. Reproducibility between laboratories increased markedly when standardized protocols were implemented for RNA labeling, hybridization, microarray processing, data acquisition and data normalization. Reproducibility was highest when analysis was based on biological themes defined by enriched Gene Ontology (GO) categories. These findings indicate that microarray results can be comparable across multiple laboratories, especially when a common platform and set of procedures are used.

Gene Expression Profiling↗

PubMed2005

Predictive value of frequency doubling technology perimetry for detecting glaucoma in a developing country.

PURPOSE: To determine the feasibility and diagnostic precision of Frequency Doubling Technology (FDT) perimetry as a method to detect glaucoma in rural villages of a developing country. DESIGN: Cross-sectional study. METHODS: Testing included FDT perimetry (C-20-5 screening protocol), tonometry, anterior segment biomicroscopy, and dilated ophthalmoscopy in 296 rural, non-English speaking residents of Southern India over 35 years old. Participants repeated the FDT if they had a location with reduced sensitivity or an unreliable result. We defined an abnormal FDT as one location of reduced sensitivity present on both the initial and repeat examination. We determined the diagnostic precision of FDT separately for a glaucomatous optic disc, a cup to disc ratio (C/D) > or = 0.7, and a C/D > or = 0.8. RESULTS: Ninety-three percent of subjects were able to complete the test satisfactorily. With repeat FDT testing, 37% of eyes with abnormal FDT results subsequently converted to normal and 67% of eyes with unreliable results subsequently became reliable. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for a glaucomatous optic disc were 7%, 87%, 13%, 76%, and 69%, respectively; for a C/D > or = 0.7, they were 0%, 87%, 0%, 91%, and 81%, respectively; and for a C/D > or = 0.8, they were 0%, 87%, 0%, 99%, and 87%, respectively. CONCLUSION: Clinicians can use FDT perimetry to rapidly screen for glaucoma in rural villages of a developing country. FDT testing had high specificity and negative predictive value, but low sensitivity and positive predictive value. The low sensitivity suggests that FDT has limited applicability as the sole test for glaucoma screening in this population. Repeat testing of FDT results that are unreliable or suspected of being abnormal is beneficial for this screening procedure.

Adult↗

PubMed2005

A time course microarray study of gene expression in the mouse lacrimal gland after acute corneal trauma.

PURPOSE: To investigate the effect of corneal trauma on gene expression in the lacrimal gland and to assess how many genes and what specific genes are regulated in response to corneal trauma. METHODS: A mouse model with acute corneal trauma was created with a chemical burn to the cornea with silver nitrate. Sixty-four female BALB/c mice at 12 weeks of age were randomly divided into eight groups, eight mice per group. The corneas of four mice in each group were bilaterally cauterized with silver nitrate, and another four time-matched mice were used as the control. The total RNA of the lacrimal gland was then extracted, at eight time points--0.5, 1, 3, 8, 24, 72, 120, and 360 hours--after the corneal burn, and gene expression was examined with using cDNA microarray technology. RESULTS: Evaluation of 15,065 genes with multiple array replications showed significantly altered expression in 3,799 genes at one or more of the eight time points. Of those, 1,528 were known genes and 2,271 were unknown. The analysis of known genes showed broad and long-lasting gene suppression in most functional gene groups, including housekeeping, energy metabolism, protein degradation, DNA and protein synthesis, and apoptosis-associated genes. Heat shock genes were upregulated beginning at the 8-hour time point, indicating a stress response. CONCLUSIONS: This study demonstrates that corneal trauma has profound effects on the regulation of gene expression in the lacrimal gland and may provide genetic evidence for a cornea-to-lacrimal gland feedback mechanism in dry eye.

Acute Disease↗

PubMed2005

Causes of visual impairment and common eye problems in Northwest American Indians and Alaska Natives.

OBJECTIVES: Little information exists regarding the causes of visual impairment and the most common eye problems in American Indians/Alaska Natives. METHODS: We randomly sampled American Indians/Alaska Natives older than 40 years from 3 tribes within the Northwest region. RESULTS: We found a higher prevalence of visual impairment and normal-tension glaucoma, as well as a lower prevalence of ocular hypertension, in American Indians/Alaska Natives compared with previous results in other racial/ethnic groups. CONCLUSIONS: American Indians/Alaska Natives have a need for vision correction. Future interventions in American Indians/Alaska Natives should include providing spectacles for refractive error, detecting glaucoma, and preventing visual impairment from age-related maculopathy and cataracts.

Adult↗

PubMed2004

High-throughput identification of proteins and unanticipated sequence modifications using a mass-based alignment algorithm for MS/MS de novo sequencing results.

With the increasing availability of de novo sequencing algorithms for interpreting high-mass accuracy tandem mass spectrometry (MS/MS) data, there is a growing need for programs that accurately identify proteins from de novo sequencing results. De novo sequences derived from tandem mass spectra of peptides often contain ambiguous regions where the exact amino acid order cannot be determined. One problem this poses for sequence alignment algorithms is the difficulty in distinguishing discrepancies due to de novo sequencing errors from actual genomic sequence variation and posttranslational modifications. We present a novel, mass-based approach to sequence alignment, implemented as a program called OpenSea, to resolve these problems. In this approach, de novo and database sequences are interpreted as masses of residues, and the masses, rather than the amino acid codes, are compared. To provide further flexibility, the masses can be aligned in groups, which can resolve many de novo sequencing errors. The performance of OpenSea was tested with three types of data: a mixture of known proteins, a mixture of unknown proteins that commonly contain sequence variations, and a mixture of posttranslationally modified known proteins. In all three cases, we demonstrate that OpenSea can identify more peptides and proteins than commonly used database-searching programs (SEQUEST and ProteinLynx) while accurately locating sequence variation sites and unanticipated posttranslational modifications in a high-throughput environment.

Algorithms↗

PubMed2004

Cluster analysis of patients with ocular surface disease, blepharitis, and dry eye.

OBJECTIVE: To develop a classification system for blepharitis and dry eye based on a classification-tree model of a large group of subjects who were given a variety of objective physiologic tests. METHODS: We evaluated 513 subjects, some healthy and some with blepharitis and dry eye,with tests for tear volume, tear flow, and tear turnover and the Schirmer test for dry eye. Meibomian gland function was evaluated by meibomian gland lipid expression for lipid volume and lipid viscosity, evaporation, and eyelid transillumination for meibomian gland drop out. We subjected these data to cluster analysis and formulated a classification tree. MAIN OUTCOME MEASURE: The outcome measure of this study was the statistically valid groups of subjects with and without ocular surface symptoms identified by their physiologic characteristics. RESULTS: Cluster analysis most successfully grouped subjects by initially dividing them into 2 groups based on the presence or absence of gland drop out and then by lipid viscosity and volume, Schirmer test results, and evaporation. The analysis created 9 categories. This division created an objective classification system that was found to have clinical relevance. Normal subjects were distributed across several groups. CONCLUSIONS: Using a classification tree, blepharitis and dry eye can be classified with objective physiologic tests into clinically relevant groups that have common characteristics. The analysis establishes the central role of meibomian gland dysfunction in blepharitis and demonstrates the diverse characteristics of the normal population.

Adult↗

PubMed2003

Relationship of optic disk topography and visual function in patients with large cup-to-disk ratios.

PURPOSE: To determine if topographic differences exist between large cup-to-disk ratio (C/D) eyes with standard achromatic automated perimetry (SAP) abnormalities and those with only short-wavelength automated perimetry (SWAP) abnormalities. DESIGN: Cross-sectional study. METHODS: The setting was a referral university-based clinical practice. We selected one eye of 72 patients with a vertical C/D of at least 0.8 by ophthalmoscopy. Patients performed SWAP, SAP, and confocal scanning laser ophthalmoscopy. We compared optic disk topography in eyes with and without visual field abnormalities and controlled for the influence of disk area. RESULTS: Disk area was a confounder of many topographic measures. After controlling for disk area, eyes with abnormal SAP had differences in rim volume, cup shape, rim area, retinal nerve fiber layer thickness, and retinal nerve fiber layer cross-sectional area when compared with eyes with normal SAP (P <.05). Rim volume and rim area were different in the SWAP comparison (P <.05). CONCLUSIONS: Investigators should control for disk area when evaluating topographic measures by confocal scanning laser ophthalmoscopy. In eyes with a large C/D, optic disk topography is more glaucomatous in eyes with SAP abnormalities than in those with only SWAP abnormalities. Eyes with large C/D and only SWAP abnormalities may have fewer glaucomatous optic disk changes than such eyes with SAP abnormalities. This indicates that SWAP is likely to correspond to abnormalities in optic disk topography at an earlier stage of glaucomatous optic neuropathy than SAP. Therefore, clinicians should consider SWAP testing in glaucoma suspects to detect glaucomatous visual field loss at an earlier stage of structural loss.

Adult↗