Biomedical subjects

Ian Lee

Publications and source records attributed to Ian Lee.

4 recordsLinked to original sources

PubMed2006

Diverse membrane-associated proteins contain a novel SMP domain.

We have analyzed the sequence of a mitochondrial integral membrane protein, Mdm12, and found that it forms the prototype for a novel domain, designated the SMP domain, that is common to an extended family of membrane-associated proteins. Comprehensive sequence searches using protein alignment models of SMP proteins were cross-validated by statistical resampling; providing strong support for these relationships. No consensus of 3-dimensional structure was reached upon threading sequences through known folds. SMP proteins are widespread amongst eukaryotic species with a particular enrichment in plants and features suggestive of species-specific functional variations. Members of 2 SMP families, the mitochore and tricalbin proteins, are essential components of protein complexes involved in mitochondrial inheritance and receptor endocytosis while a third SMP protein family, HT008, is associated with the Rvs161-Rvs167 complex, a known regulator of sphingolipid metabolism. In addition, HT008 and PDZK8 SMP proteins possess additional protein-protein interaction domains in domain architectures that are typical of protein scaffolds and adaptors. We therefore predict that the SMP domain is an important link between these distinct membrane-associated proteins and a key regulatory hub for unidentified global regulators.-Lee, I., Hong, W. Diverse membrane-associated proteins contain a novel SMP domain.

Amino Acid Sequence↗

PubMed2005

Modeling gunshot bruises in soft body armor with an adaptive fuzzy system.

Gunshots produce bruise patterns on persons who wear soft body armor when shot even though the armor stops the bullets. An adaptive fuzzy system modeled these bruise patterns based on the depth and width of the deformed armor given a projectile's mass and momentum. The fuzzy system used rules with sinc-shaped if-part fuzzy sets and was robust against random rule pruning: Median and mean test errors remained low even after removing up to one fifth of the rules. Handguns shot different caliber bullets at armor that had a 10%-ordnance gelatin backing. The gelatin blocks were tissue simulants. The gunshot data tuned the additive fuzzy function approximator. The fuzzy system's conditional variance V[Y/X = x] described the second-order uncertainty of the function approximation. Handguns with different barrel lengths shot bullets over a fixed distance at armor-clad gelatin blocks that we made with Type 250 A Ordnance Gelatin. The bullet-armor experiments found that a bullet's weight and momentum correlated with the depth of its impact on armor-clad gelatin (R2 = 0.881 and p-value < 0.001 for the null hypothesis that the regression line had zero slope). Related experiments on plumber's putty showed that highspeed baseball impacts compared well to bullet-armor impacts for large-caliber handguns. A baseball's momentum correlated with its impact depth in putty (R2 = 0.93 and p-value < 0.001). A bullet's momentum similarly correlated with its armor-impact in putty (R2 = 0.97 and p-value < 0.001). A Gujarati-Chow test showed that the two putty-impact regression lines had statistically indistinguishable slopes for p-value = 0.396. Baseball impact depths were comparable to bullet-armor impact depths: Getting shot with a .22 caliber bullet when wearing soft body armor resembles getting hit in the chest with a 40-mph baseball. Getting shot with a .45 caliber bullet resembles getting hit with a 90-mph baseball.

Computer Simulation↗

PubMed2004

RAP--a putative RNA-binding domain.

A novel approximately 60-residue domain has been identified in Homo sapiens MGC5297 and various other proteins in eukaryotes. Sequence searches reveal that the domain is particularly abundant in apicomplexans and is predicted to be involved in diverse RNA-binding activities.

Amino Acid Motifs↗

PubMed2003

Chiari I malformation associated with thoracic epidural cord lesion: case report.

Many spinal cord lesions have been described previously, in association with Chiari I lesions. The authors report a unique case of a 29-year-old patient with a Chiari I malformation and an upper thoracic epidural lesion causing headaches, dysphagia and Brown-Sequard syndrome. The patient underwent a suboccipital decompression as well as a thoracic laminectomy and resection of the epidural lesion. Pathologic analysis revealed that the thoracic lesion was fibro-adipose tissue. A review of the literature failed to show any other similar cases. We discuss the possible etiologies of this case.

Adult↗