8765 Aero Drive Suite 130
San Diego CA 92123
Medical School: Meharry Medical College School Of Medicine - 1999
Accepts Medicare: Yes
Participates In eRX: No
Participates In PQRS: No
Participates In EHR: No
License #: A85613
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Enantioselective ruthenium-catalyzed carbonyl allylation via alkyne-alcohol C-C bond-forming transfer hydrogenation: allene hydrometalation vs oxidative coupling. - Journal of the American Chemical Society
Chiral ruthenium(II) complexes modified by Josiphos ligands catalyze the reaction of alkynes with primary alcohols to form homoallylic alcohols with excellent control of regio-, diastereo-, and enantioselectivity. These processes represent the first examples of enantioselective carbonyl allylation using alkynes as allylmetal equivalents.
Fabrication of Au/graphene-wrapped ZnO-nanoparticle-assembled hollow spheres with effective photoinduced charge transfer for photocatalysis. - ACS applied materials & interfaces
Heterostructures of gold-nanoparticle-decorated reduced-graphene-oxide (rGO)-wrapped ZnO hollow spheres (Au/rGO/ZnO) are synthesized using tetra-n-butylammonium bromide as a mediating agent. The structure of amorphous ZnO hollow spheres is found to be transformed from nanosheet- to nanoparticle-assembled hollow spheres (nPAHS) upon annealing at 500 Â°C. The ZnO nPAHS hybrids with Au/rGO are characterized using various techniques, including photoluminescence, steady-state absorbance, time-resolved photoluminescence, and photocatalysis. The charge-transfer time of ZnO nPAHS is found to be 87 ps, which is much shorter than that of a nanorod (128 ps), nanoparticle (150 ps), and nanowall (990 ps) due to its unique structure. The Au/rGO/ZnO hybrid shows a higher charge-transfer efficiency of 68.0% in comparison with rGO/ZnO (40.3%) and previously reported ZnO hybrids. The photocatalytic activities of the samples are evaluated by photodegrading methylene blue under black-light irradiation. The Au/rGO/ZnO exhibits excellent photocatalytic efficiency due to reduced electron-hole recombination, fast electron-transfer rate, and high charge-transfer efficiency.
Congenital microstomia in a neonate with impending respiratory compromise. - Case reports in anesthesiology
Microstomia is the term used to describe a reduction in the size of the oral aperture that is severe enough to compromise quality of life, nutrition, and cosmesis. Few cases of congenital microstomia have been reported as most microstomia cases are due to burn injuries. We are presenting a case of a neonate who was found to be in respiratory distress with severe congenital microstomia from no known cause. This case illustrates the rarity of this type of pathologic anatomy as well as the teamwork and tools necessary to treat these patients.
A new workflow for proteomic analysis of urinary exosomes and assessment in cystinuria patients. - Journal of proteome research
Cystinuria is a purely renal, rare genetic disease caused by mutations in cystine transporter genes and characterized by defective cystine reabsorption leading to kidney stones. In 14% of cases, patients undergo nephrectomy, but given the difficulty to predict the evolution of the disease, the identification of markers of kidney damage would improve the follow-up of patients with a higher risk. The aim of the present study is to develop a robust, reproducible, and noninvasive methodology for proteomic analysis of urinary exosomes using high resolution mass spectrometry. A clinical pilot study conducted on eight cystinuria patients versus 10 controls highlighted 165 proteins, of which 38 were up-regulated, that separate cystinuria patients from controls and further discriminate between severe and moderate forms of the disease. These proteins include markers of kidney injury, circulating proteins, and a neutrophil signature. Analysis of selected proteins by immunobloting, performed on six additional cystinuria patients, validated the mass spectrometry data. To our knowledge, this is the first successful proteomic study in cystinuria unmasking the potential role of inflammation in this disease. The workflow we have developed is applicable to investigate urinary exosomes in different renal diseases and to search for diagnostic/prognostic markers. Data are available via ProteomeXchange with identifier PXD001430.
Determining the role of metal binding in protein cage assembly. - Methods in molecular biology (Clifton, N.J.)
Assembly of protein cages may require structural metal ions to nucleate or stabilize association of protein subunits. We describe here an approach to establishing the role of metal ions in protein cage assembly and stability, focusing on detecting the presence of structural metal ions as well as establishing oligomeric state. A colorimetric assay for detection of metal is described, along with a gel filtration assay to assess protein cage assembly and a fluorescence-based method for determining protein stability.
Carbohydrate modified diet & insulin sensitizers reduce body weight & modulate metabolic syndrome measures in EMPOWIR (enhance the metabolic profile of women with insulin resistance): a randomized trial of normoglycemic women with midlife weight gain. - PloS one
Progressive midlife weight gain is associated with multiple adverse health outcomes and may represent an early manifestation of insulin resistance in a distinct subset of women. Emerging data implicate hyperinsulinema as a proximate cause of weight gain and support strategies that attenuate insulin secretion.To assess a previously reported novel hypocaloric carbohydrate modified diet alone (D), and in combination with metformin (M) and metformin plus low-dose rosiglitazone (MR), in diverse women with midlife weight gain (defined as >20lbs since the twenties), normal glucose tolerance, and hyperinsulinemia.46 women, mean age 46.6Â±1.0, BMI 30.5Â±0.04 kg/m2, 54.5% white, 22.7% black, 15.9% Hispanic, at 2 university medical centers.A dietary intervention designed to reduce insulin excursions was implemented in 4 weekly nutritional group workshops prior to randomization.Change in 6-month fasting insulin. Pre-specified secondary outcomes were changes in body weight, HOMA-IR, metabolic syndrome (MS) measures, leptin, and adiponectin.Six-month fasting insulin declined significantly in the M group: 12.5 to 8.0 ÂµU/ml, pâ€Š=â€Š.026. Mean 6-month weight decreased significantly and comparably in D, M, and MR groups: 4.7, 5.4, and 5.5% (p's.049, .002, and.032). HOMA-IR decreased in M and MR groups (2.5 to 1.6 and 1.9 to 1.3, p'sâ€Š=â€Š.054, .013). Additional improvement in MS measures included reduced waist circumference in D and MR groups and increased HDL in the D and M groups. Notably, mean fasting leptin did not decline in a subset of subjects with weight loss (26.15Â±2.01 ng/ml to 25.99Â±2.61 ng/ml, pâ€Š=â€Š.907. Adiponectin increased significantly in the MR group (11.1Â±1.0 to 18.5Â±7.4, p<.001) Study medications were well tolerated.These findings suggest that EMPOWIR's easily implemented dietary interventions, alone and in combination with pharmacotherapies that target hyperinsulinemia, merit additional investigation in larger, long-term studies.ClinicalTrials.gov NCT00618072.
Alkynes as allylmetal equivalents in redox-triggered C-C couplings to primary alcohols: (Z)-homoallylic alcohols via ruthenium-catalyzed propargyl C-H oxidative addition. - Journal of the American Chemical Society
The cationic ruthenium catalyst generated upon the acid-base reaction of H2Ru(CO)(PPh3)3 and 2,4,6-(2-Pr)3PhSO3H promotes the redox-triggered C-C coupling of 2-alkynes and primary alcohols to form (Z)-homoallylic alcohols with good to complete control of olefin geometry. Deuterium labeling studies, which reveal roughly equal isotopic compositions at the allylic and distal vinylic positions, along with other data, corroborate a catalytic mechanism involving ruthenium(0)-mediated allene-aldehyde oxidative coupling to form a transient oxaruthenacycle, an event that ultimately defines (Z)-olefin stereochemistry.
Eosinophils and type 2 cytokine signaling in macrophages orchestrate development of functional beige fat. - Cell
Beige fat, which expresses the thermogenic protein UCP1, provides a defense against cold and obesity. Although a cold environment is the physiologic stimulus for inducing beige fat in mice and humans, the events that lead from the sensing of cold to the development of beige fat remain poorly understood. Here, we identify the efferent beige fat thermogenic circuit, consisting of eosinophils, type 2 cytokines interleukin (IL)-4/13, and alternatively activated macrophages. Genetic loss of eosinophils or IL-4/13 signaling impairs cold-induced biogenesis of beige fat. Mechanistically, macrophages recruited to cold-stressed subcutaneous white adipose tissue (scWAT) undergo alternative activation to induce tyrosine hydroxylase expression and catecholamine production, factors required for browning of scWAT. Conversely, administration of IL-4 to thermoneutral mice increases beige fat mass and thermogenic capacity to ameliorate pre-established obesity. Together, our findings have uncovered the efferent circuit controlling biogenesis of beige fat and provide support for its targeting to treat obesity.Copyright Â© 2014 Elsevier Inc. All rights reserved.
Signaling by IL-6 promotes alternative activation of macrophages to limit endotoxemia and obesity-associated resistance to insulin. - Nature immunology
Obesity and resistance to insulin are closely associated with the development of low-grade inflammation. Interleukin 6 (IL-6) is linked to obesity-associated inflammation; however, its role in this context remains controversial. Here we found that mice with an inactivated gene encoding the IL-6RÎ± chain of the receptor for IL-6 in myeloid cells (Il6ra(Î”myel) mice) developed exaggerated deterioration of glucose homeostasis during diet-induced obesity, due to enhanced resistance to insulin. Tissues targeted by insulin showed increased inflammation and a shift in macrophage polarization. IL-6 induced expression of the receptor for IL-4 and augmented the response to IL-4 in macrophages in a cell-autonomous manner. Il6ra(Î”myel) mice were resistant to IL-4-mediated alternative polarization of macrophages and exhibited enhanced susceptibility to lipopolysaccharide (LPS)-induced endotoxemia. Our results identify signaling via IL-6 as an important determinant of the alternative activation of macrophages and assign an unexpected homeostatic role to IL-6 in limiting inflammation.
Redox-triggered C-C coupling of diols and alkynes: synthesis of Î²,Î³-unsaturated Î±-hydroxyketones and furans by ruthenium-catalyzed hydrohydroxyalkylation. - Angewandte Chemie (International ed. in English)
Direct ruthenium-catalyzed CC coupling of alkynes and vicinal diols to form Î²,Î³-unsaturated ketones occurs with complete levels of regioselectivity and good to complete control over the alkene geometry. Exposure of the reaction products to substoichiometric quantities of p-toluenesulfonic acid induces cyclodehydration to form tetrasubstituted furans. These alkyne-diol hydrohydroxyalkylations contribute to a growing body of merged redox-construction events that bypass the use of premetalated reagents and, hence, stoichiometric quantities of metallic by-products.
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