Biomedical subjects

Don Liu

Publications and source records attributed to Don Liu.

6 recordsLinked to original sources

PubMed2005

METRO taxonomy - progress report on assessment.

The Medical Education Taxonomy Research Organization (METRO) was formed to map and create terms to comprehensively describe the processes, procedures and concepts of medical education. The terms will be used in a variety of purposes, such as describing content for retrieval from e-learning environments, indexing literature in databases, and extracting and exchanging data for research, such as for BEME systematic reviews. METRO has now completed an extensive set of descriptors for assessment, which are freely available at http://metro2.blogspot.com. The organization welcomes the response and participation of all medical education professionals.

Databases, Factual↗

PubMed2005

A comparison of implant extrusion rates and postoperative pain after evisceration with immediate or delayed implants and after enucleation with implants.

PURPOSE: To examine implant extrusion rates after evisceration with immediate or delayed implants in patients with culture-proven endophthalmitis. To compare postevisceration and postenucleation pain. METHODS: This prospective, nonrandomized interventional case series included four groups of patients: group 1, 25 endophthalmitis patients undergoing evisceration with immediate implants; group 2, 15 endophthalmitis patients undergoing evisceration with delayed implants; group 3, 31 patients without endophthalmitis undergoing evisceration with immediate implants; and group 4, eight patients undergoing enucleations with implants. Standardized techniques and follow-up schedules were used. Postoperative pain was assessed by weighted frequency of pain medications used during two 48-hour periods. Statistical analysis was performed. Retrospective review of two series of patients undergoing evisceration was performed. RESULTS: No cases of implant extrusion occurred during an average follow-up of 37.9 months. Average implant size was 19.0 mm. Conjunctival dehiscence occurred in one patient. Average total pain scores were 20.8 in endophthalmitis patients with immediate implants; 22.1 in endophthalmitis patients with delayed implants; 20.3 in patients without endophthalmitis and with immediate implants; and 23.1 in patients with enucleations and immediate implant insertions. Retrospective review suggested possible causes of implant extrusion. CONCLUSION: Both immediate and delayed implant techniques appear safe in patients with endophthalmitis, with the former being simpler, more cost-effective, and perhaps less painful. Prolonged antibiotic therapy and smaller implants may render a false sense of security against implant extrusion; good surgical technique and meticulous postoperative wound care are essential. Postenucleation pain appears more severe than postevisceration pain.

Adolescent↗

PubMed2004

METRO--the creation of a taxonomy for medical education.

AIMS: There is a proven and immediate need for a shared vocabulary for medical education in the United Kingdom, both to support the practice of medical education and the research of medical education practice. It would be inefficient to create a complete and independent vocabulary from scratch, the proposed alternative being to create differential terms between the MeSH and BET vocabularies. METHODS: Existing schemas were reviewed against the needs of stakeholders. Seed terms were submitted to the METRO work environment, discussed, scoped and voted upon. RESULTS: A set of procedures, initial terms and recommendations for further development are the principal deliverables from METRO's first phase, while the ongoing second phase will see the creation and testing of an essential branch of descriptors for assessment. CONCLUSIONS: Further work in a number of areas will be required and long-term issues of resourcing and sustainability have yet to be substantially addressed to allow for full adoption by the user community.

Classification↗

PubMed2003

Silicone nasolacrimal intubation with mitomycin-C: a prospective, randomized, double-masked study.

OBJECTIVE: To determine if mitomycin-C (MMC) application during silicone intubation (SI) can effectively substitute for dacryocystorhinostomy (DCR) or Jones tube insertion. DESIGN: A prospective, randomized, double-masked study. PARTICIPANTS: Twenty-four patients (7 males, 17 females; aged 2-69 years) with 27 eyes (three bilateral cases) with an obstructed lacrimal system who were candidates for DCR or Jones tube. METHODS: All study patients underwent SI with application in a randomized, double-masked fashion of MMC or placebo, with the former receiving 0.2 mg/ml MMC for 2 minutes before SI. MAIN OUTCOME MEASURES: Clinical assessment of tearing and discharge; Schirmer I and II tests at 1, 3, 6, and 12 months; and the need for eventual DCR or Jones tube insertion. RESULTS: Follow-up ranged from 13 to 23 months (mean, 18 months; median, 17 months). Seven of the 12 eyes in the MMC group and 8 of the 15 eyes in the placebo group had a successful outcome and remained symptom free. The difference was not statistically significant (P = 0.79). Dacryocystorhinostomy or Jones tube was performed in five eyes in the MMC group and in seven eyes in the placebo group 3 to 18 months later; all had successful outcome and no complications. Untoward effects of MMC application included a slit canaliculus and a transient conjunctival injection. A successful outcome using this combined technique does not appear to correlate with age, gender, laterality, and intraoperative bleeding observed at the punctum or for the duration of symptoms. CONCLUSIONS: Mitomycin-C application during SI did not benefit outcome. Complications from such application were mild and infrequent.

Adolescent↗

PubMed2002

Retained orbital wooden foreign body: a surgical technique and rationale.

OBJECTIVE: To emphasize the potential complications of a retained orbital wooden foreign body (WFB) and the rationale of a surgical technique. DESIGN: Two interventional case reports. PARTICIPANTS: Two patients sustained an orbital WFB injury. Both patients had ocular complications despite repeated attempts to remove the suspected residues. INTERVENTION: Computed tomography and magnetic resonance imaging of both patients at different intervals revealed evidence of orbital foreign body migration toward the cranium. A surgical technique combing transcranial and orbital approaches was used to remove the residues. MAIN OUTCOME MEASURES: Preoperative and postoperative vision, proptosis, ocular motility, and various ocular symptoms and signs. RESULTS: In both patients, no postoperative complications were seen, and all preoperative symptoms and signs were resolved at 9- and 19-month follow-ups, respectively. CONCLUSIONS: A retained orbital WFB can cause early or late complications and is known to have the potential to migrate intracranially. In selected patients, a team approach may be the best technique to ensure complete removal.

Adult↗

PubMed2002

Reassessment of sphenoid dysplasia associated with neurofibromatosis type 1.

BACKGROUND AND PURPOSE: Sphenoid dysplasia associated with neurofibromatosis type 1 is classically thought to be primarily related to abnormal development of the sphenoid bone. We investigated the possibility that these changes may be progressive. METHODS: We conducted a retrospective review of sphenoid bone changes in all patients with craniofacial neurofibromatosis type 1 who had undergone CT (31 patients) and MR imaging (seven patients) at our facility. A review of repeat images of 20 patients permitted analysis of progressive sphenoid bone changes. RESULTS: Eighteen patients had abnormalities of the sphenoid wings, 13 of whom also had enlargement of the middle cranial fossa compatible with descriptions of classic sphenoid dysplasia. All the patients with sphenoid dysplasia had neurofibromas in the ipsilateral superficial temporal fossa that were often contiguous with a radiologically abnormal temporo-squamosal suture. All except one had tumor infiltration in the deep orbit, contiguous with the sphenoid wings. Four patients had radiologic evidence of progressive sphenoid bone changes over time. CONCLUSION: The origin of sphenoid bone changes may be multifactorial. A modified concept of sphenoid dysplasia is proposed that emphasizes interaction between neurofibromas and sphenoid bone during skull development.

Adolescent↗