Current Role at Stanford
Education Development Specialist, Immersive & Simulation-Based Learning
Education & Certifications
BA, Stanford University, Human Biology (2003)
MD, Stanford School of Medicine, Medicine (2009)
Education Development Specialist, Immersive & Simulation-Based Learning
Medical education, surgical education, immersive and simulation-based learning, use of technology and media in education, curriculum design and implementation.
Zygomatic-maxillary (ZMC) complex fractures are a common consequence of facial trauma. In this retrospective study, we present a novel method of ZMC fracture pattern analysis, utilizing three-dimensional visualization of computed tomography (CT) images to record displacement of the malar eminence in a three-dimensional coordinate plane. The pattern of fracture was then correlated with treatment outcome. Facial CT scans were obtained from 29 patients with unilateral ZMC fractures and 30 subjects without fractures and analyzed. Briefly, displacement of the malar eminence (ME) on the fractured side was measured in medial-lateral (x), superior-inferior (y), and anterior-posterior (z) dimensions, as well as Euclidean distance, by comparison to ME location on the unfractured side. Baseline natural variance in asymmetry was accounted for by comparing ME location on the left and right sides in subjects without fractures. Patients who required open reduction and internal fixation (ORIF) to repair the ZMC fracture alone had significantly greater cumulative ME displacements than patients who did not require ORIF (p?=?0.02). Additionally, patients with a high fracture score of 3, 4, or 5 (assigned based on severity displacement in each dimension) had significantly higher rates of ORIF than patients with a low fracture score of 0, 1, or 2 (p?=?0.05). Severe displacement in one or more dimensions was associated with higher rates of ORIF than seen in patients with only neutral or mild displacements in all dimensions (p?=?0.05). Severe x displacement was most strongly correlated with surgical intervention (p?=?0.02). Overall, orbital floor repair was less strongly associated with most displacement measures than ZMC repair alone; however, patients requiring orbital floor repair had greater Euclidean ME displacements than patients who did not require orbital floor repair (p?=?0.02). Fracture severity, as determined by multiple parameters in this novel evaluation system, is associated with higher rates of ORIF in patients with unilateral ZMC fractures. Determination of ZMC fracture pattern may thus be informative when considering treatment options.
View details for DOI 10.1055/s-0030-1263082
View details for PubMedID 22110833
Noradrenaline plays a key role in the initiation of ovulation in nonprimate species. A similar noradrenaline role in the primate has not been established experimentally. We utilized the ovariectomized-oestrogen-supplemented (OVX + E) rhesus macaque to examine the effects of intravenous (i.v.) infusion of oestradiol-17beta (E2) on the activity of the brain noradrenaline system. Experiment 1 established the induction of a preovulatory surge-like release of luteinizing hormone in OVX + E monkeys by i.v. infusion of E2 (OVX + E + E2). In experiment 2, a marked increase in hypothalamic microdialysate noradrenaline concentrations occurred after identical E2 infusion into the OVX + E monkeys that were used in experiment 1. In experiment 3, tyrosine hydroxylase (TH) mRNA expression in the locus coeruleus of the brainstem increased at various times after E2 infusion as determined by semiquantitative in situ hybridization. The amount of TH mRNA in OVX + E + E2 animals was higher (P < 0.05) than that in either the OVX + E or OVX monkeys; no difference was found in the latter two groups. Moreover, selected locus coeruleus sections from E2-infused monkeys were examined for the localization of oestrogen receptors (ER) by in situ hybridization. Both ER-alpha and ER-beta mRNAs were expressed in the locus coeruleus, although the expression was greater for ER-alpha than for ER-beta. We conclude that i.v. infusion of E2, which induces a preovulatory surge-like release of LH, stimulates brain noradrenaline activity; this enhanced activity likely involves an ER-mediated process and is reflected by hypothalamic noradrenaline release and locus coeruleus TH mRNA expression. The results support the concept that noradrenaline can influence the E2-stimulated ovulation in nonhuman primates and that the brainstem is one of the components in this neuroendocrine process.
View details for Web of Science ID 000089054500010
View details for PubMedID 10971815
In 17beta-estradiol (E)-treated ovariectomized (OVX) rabbits, the coitus-induced luteinizing hormone (LH) surge is only one fourth that in ovarian-intact rabbits. In this study, we determined the pattern of the coitus-induced gonadotropin release, i.e., LH and follicle-stimulating hormone (FSH), in OVX + E animals without or with continuous 3-wk treatment of 20-alphahydroxypregn-4-en-3-one (20alphaP). For positive and negative experimental controls, ovarian-intact rabbits were either mated or sham mated, respectively. The pituitary hormones prolactin (PRL) and growth hormone (GH) were measured to serve as collateral controls for gonadotropins. The addition of continuous 20alphaP in OVX + E does fail to stimulate a coitus-induced LH surge equal in magnitude and duration to the LH surge in ovarian-intact rabbits. Postcoital levels of FSH were greater in OVX + E + 20alphaP animals than those in OVX + E rabbits. Coitus induced a PRL surge in ovarian-intact and OVX + steroid-treated females, but not in mated males, thereby suggesting a gender difference in this neuroendocrine circuit. Neither coitus nor steroids altered plasma GH values in female or male animals. We conclude that chronic administration of neither E nor E + 20alphaP can restore full-scale gonadotropin surges in OVX rabbits, whereas replacement of one or both of these steroids is sufficient for a coitus-induced PRL surge. Moreover, the presented observation that activin stimulates hypothalamic gonadotropin-releasing hormone (GnRH) release suggests a possible involvement of ovarian proteins in the production of a full-scale coitus-induced GnRH/LH surge.
View details for Web of Science ID 000089148600004
View details for PubMedID 11051044
The profound effects of estrogen on different tissues may involve at least two estrogen receptor (ER) subtypes, ERalpha and the recently discovered ERbeta. Where and how the two ER subtypes differentially or cooperatively mediate estrogen actions, however, are still unknown. In this study, we report the cloning of a specific ERbeta cDNA fragment and the expression of ERalpha and ERbeta mRNAs in various endocrine and non-endocrine tissues of male and female rhesus macaques. Total RNA from monkey tissues was isolated and subjected to reverse transcription-polymerase chain reaction (RT-PCR) using human-specific ERbeta primers. A 126 bp RT-PCR product was identified in ovarian tissue and subsequently transfected into pGEM-T vectors for DNA sequencing. The cloned rhesus monkey ERbeta fragment contained a sequence nearly identical to the corresponding sequence in the human (four mismatched nucleotides out of 126). Because complete monkey ERbeta and ERalpha DNA sequences have not been established, the expression of the ERbeta and ERalpha fragments in monkey tissues by RT-PCR reflects 'putative' ERbeta and ERalpha mRNA expression, respectively. Both ERbeta and ERalpha mRNAs were present in male and female reproductive organs, in several endocrine and non-endocrine tissues, and in various regions of the brain, whereas several tissues, including liver, frontal cortex, caudate nucleus, locus coeruleus and cerebellum, expressed only ERalpha message. In some brain regions, i.e. the putamen, internal capsule, hippocampus and paraventricular hypothalamus, the ERbeta fragment was expressed in the female but not in the male. These data suggest that ERalpha mRNA is widely distributed in both female and male tissues, while ERbeta mRNA is more widely distributed in female than in male brain.
View details for Web of Science ID 000077924200007
View details for PubMedID 10022763