Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2014
2014
Elucidating genetic causes of cholestasis has proved to be important in understanding the physiology and pathophysiology of the liver. Here we show that protein-truncating mutations in the tight junction protein 2 gene (TJP2) cause failure of protein localization and disruption of tight-junction structure, leading to severe cholestatic liver disease. These findings contrast with those in the embryonic-lethal knockout mouse, highlighting differences in redundancy in junctional complexes between organs and species.
View on PubMed2014
2014
BACKGROUND
Artemisinin-based combination therapies, including artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP), are recommended to treat uncomplicated falciparum malaria. Sensitivities to components of AL and DP are impacted by polymorphisms in pfmdr1 and pfcrt. We monitored changes in prevalences of polymorphisms in Tororo, Uganda, from 2008 to 2012.
METHODS
Polymorphic loci in pfmdr1 and pfcrt were characterized in samples from 312 children randomized to AL or DP for each episode of uncomplicated malaria (50 samples per arm for each 3-month interval) utilizing a fluorescent microsphere assay. Treatment outcomes and impacts of prior therapies were also characterized.
RESULTS
Prevalence increased significantly over time for pfmdr1 N86 (AL: odds ratio [OR], 2.08 [95% confidence interval {CI}, 1.83-2.38]; DP: 1.41 [95% CI, 1.25-1.57]), pfmdr1 D1246 (AL: 1.46 [95% CI, 1.29-1.64]; DP: 1.36 [95% CI, 1.23-1.50]), and pfcrt K76 (AL: 3.37 [95% CI, 1.85-6.16]; DP: 5.84 [95% CI, 1.94-17.53], and decreased for pfmdr1 Y184 (AL: 0.78 [95% CI, .70-.86]; DP: 0.84 [95% CI, .76-1.50]); changes were consistently greater in the AL arm. Recent AL treatment selected for pfmdr1 N86, D1246, and 184F in subsequent episodes; DP selected for the opposite alleles.
CONCLUSIONS
Genotypes with decreased sensitivity to AL components increased over time. This increase was greater in children receiving AL, suggesting that the choice of treatment regimen can profoundly influence parasite genetics and drug sensitivity.
CLINICAL TRIALS REGISTRATION
NCT00527800.
View on PubMed2014
Little is known about how human genetic variation affects the responses to environmental stimuli in the context of complex diseases. Experimental and computational approaches were applied to determine the effects of genetic variation on the induction of pathogen-responsive genes in human dendritic cells. We identified 121 common genetic variants associated in cis with variation in expression responses to Escherichia coli lipopolysaccharide, influenza, or interferon-β (IFN-β). We localized and validated causal variants to binding sites of pathogen-activated STAT (signal transducer and activator of transcription) and IRF (IFN-regulatory factor) transcription factors. We also identified a common variant in IRF7 that is associated in trans with type I IFN induction in response to influenza infection. Our results reveal common alleles that explain interindividual variation in pathogen sensing and provide functional annotation for genetic variants that alter susceptibility to inflammatory diseases.
View on PubMed2014
2014
BACKGROUND AND STUDY AIMS
Biliary and pancreatic diseases are common in the elderly; however, few studies have addressed the occurrence of adverse events in elderly patients undergoing endoscopic retrograde cholangiopancreatography (ERCP). Our objective was to determine the incidence rates of specific adverse events in this group and calculate incidence rate ratios (IRRs) for selected comparison groups.
PATIENTS AND METHODS
Bibliographical searches were conducted in Medline, EMBASE, and Cochrane library databases. The studies included documented the incidence of adverse events (perforation, pancreatitis, bleeding, cholangitis, cardiopulmonary adverse events, mortality) in patients aged ≥ 65 who underwent ERCP. Pooled incidence rates were calculated for each reported adverse event and IRRs were determined for available comparison groups. A parallel analysis was performed in patients aged ≥ 80 and ≥ 90.
RESULTS
Our literature search yielded 7429 articles, of which 69 studies met our inclusion criteria. Pooled incidence rates for adverse events (per 1000 ERCPs) in patients aged ≥ 65 were as follows: perforation 3.8 (95 %CI 1.8 - 7.0), pancreatitis 13.1 (95 %CI 11.0 - 15.5), bleeding 7.7 (95 %CI 5.7 - 10.1), cholangitis 16.1 (95 %CI 11.7 - 21.7), cardiopulmonary events 3.7 (95 %CI 1.5 - 7.6), and death 7.1 (95 %CI 5.2 - 9.4). Patients ≥ 65 had lower rates of pancreatitis (IRR 0.3, 95 %CI 0.3 - 0.4) compared with younger patients. Octogenarians had higher rates of death (IRR 2.4, 95 %CI 1.3 - 4.5) compared with younger patients, whereas nonagenarians had increased rates of bleeding (IRR 2.4, 95 %CI 1.1 - 5.2), cardiopulmonary events (IRR 3.7, 95 %CI 1.0 - 13.9), and death (IRR 3.8, 95 %CI 1.0 - 14.4). Conclusions ERCP appears to be safe in elderly patients, except in the very elderly who are at higher risk of some adverse events. These data on adverse event rates can help to inform clinical decision-making, the consent process, and comparative effectiveness analyses.
View on PubMed2014
OBJECTIVE
To investigate the association between obesity and multiple sclerosis (MS) while accounting for established genetic and environmental risk factors.
METHODS
Participants included members of Kaiser Permanente Medical Care Plan, Northern California Region (KPNC) (1235 MS cases and 697 controls). Logistic regression models were used to estimate odds ratios (ORs) with 95% confidence intervals (95% CI). Body mass index (BMI) or body size was the primary predictor of each model. Both incident and prevalent MS cases were studied.
RESULTS
In analyses stratified by gender, being overweight at ages 10 and 20 were associated with MS in females (p<0.01). Estimates trended in the same direction for males, but were not significant. BMI in 20s demonstrated a linear relationship with MS (p-trend=9.60×10(-4)), and a twofold risk of MS for females with a BMI≥30kg/m(2) was observed (OR=2.15, 95% CI 1.18, 3.92). Significant associations between BMI in 20s and MS in males were not observed. Multivariate modelling demonstrated that significant associations between BMI or body size with MS in females persisted after adjusting for history of infectious mononucleosis and genetic risk factors, including HLA-DRB1*15:01 and established non-HLA risk alleles.
INTERPRETATION
Results show that childhood and adolescence obesity confer increased risk of MS in females beyond established heritable and environmental risk factors. Strong evidence for a dose-effect of BMI in 20s and MS was observed. The magnitude of BMI association with MS is as large as other known MS risk factors.
View on PubMed2014
A 64-year-old man was evaluated by a rapid response team for altered mental status shortly after an uncomplicated surgery. He was found to be hypotensive and bradycardic, and an emergent electrocardiogram showed extra "P" wave complexes, ultimately found to be piezoelectric artifacts from a fluid infusion pump. Equipment-related artifacts have been known to mimic arrhythmias prompting unnecessary therapeutic interventions including antiarrhythmics and direct current shocks. Timely recognition of the unusual properties of the complexes resulted in the avoidance of atropine, epinephrine, or transcutaneous pacing in a rapid response team scenario.
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