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1.  Water exchange screening colonoscopy with or without indigo carmine in detecting overall and proximal colon adenoma - a randomized controlled trial 
Background and study aims
Dye spray chromoendoscopy and water exchange method both increase adenoma detection rate (ADR). This study was performed to determine if combining indigo carmine with water exchange method will further enhance adenoma detection.
An IRB-approved randomized, controlled trial was performed in outpatients undergoing screening colonoscopy. The water exchange or combined method with 0.008% indigo carmine added was performed by two endoscopists. Randomization was by computer-generated codes contained in opaque sealed envelopes. High resolution colonoscopes were used. The water exchange method with or without added indigo carmine was performed as previously described. Upon seeing the appendix opening under water, water was suctioned and air was insufflated to facilitate inspection on scope withdrawal. The primary outcome was ADR.
There were no significant differences in mean age, gender distribution, BMI, and family history of colorectal cancer. Cecal intubation success rate was 100% in both groups. The primary outcome of overall ADR was 44.6% (water only) vs. 62% (combined method) (p=0.026). The secondary outcome of proximal ADR was 34.8% (water) vs. 53.3% (combined) (p=0.017) and adenoma per colonoscopy (APC) was 0.9 vs. 1.6 (p=0.0013) respectively. One cancer was detected in each group. The withdrawal inspection time in patients without polyps averaged 14 min in both groups.
This RCT showed that indigo carmine (0.008% concentration) added to the water exchange method significantly enhanced ADR further, both overall and in the proximal colon.
PMCID: PMC4059856  PMID: 24963458
colorectal cancer screening; optical colonoscopy; water method; indigocarmine; adenoma detection
2.  Validation of a novel method for analyzing video recordings of the withdrawal phase of air insufflation and water exchange colonoscopy - documentation of distractions from focused mucosal inspection 
Compared with air insufflation (AI), water-exchange (WE) colonoscopy increases adenoma detection rate (ADR) in the right colon. The impact of insertion methodological differences on withdrawal examination has not been studied.
To develop and validate a novel method for analyzing distractions from mucosal inspection, bowel preparation scores and yield of quality outcome in prerecorded videos.
Edited videos of the withdrawal phase of screening colonoscopies meeting inclusion criteria.
Two reviewers blinded to colonoscope insertion technique evaluated edited recordings using agreed upon criteria. Distractions from mucosal inspection were defined as colonic spasms, water infusion or suctioning to clean the mucosa. The total number and duration of each distraction were analyzed in the cecum, ascending, transverse, descending and rectosigmoid colon. Total withdrawal time, bowel preparation scores and withdrawal techniques were assessed. Yield (biopsy or polypectomy) was considered a quality outcome.
Fourteen videos were evaluated by both reviewers. Inter-rater reliability was assessed by the Shrout-Fleiss reliability index. Nine of the 13 outcome measures received substantial to perfect inter-rater reliability, with the remaining variables achieving fair reliability and one with slight agreement between reviewers.
Retrospective study with small numbers.
The data suggest that the devised criteria, based on review of the literature, set up to evaluate video recordings of the withdrawal phase of colonoscopy can be applied by independent reviewers, regardless of actual experience in colonoscopy. The instrument is appropriate for assessing the hypothesis that reduced distraction during withdrawal inspection results in significantly higher yield, e.g. increased adenoma detection.
PMCID: PMC4059857  PMID: 24963459
adenoma detection; water method; colon cancer screening; quality indicators; mucosal inspection
3.  Phenotypic Differences of Cryptococcus Molecular Types and Their Implications for Virulence in a Drosophila Model of Infection 
Infection and Immunity  2014;82(7):3058-3065.
Compared to Cryptococcus neoformans, little is known about the virulence of the molecular types in Cryptococcus gattii. We compared in vitro virulence factor production and survival data using a Drosophila model of infection to further characterize the phenotypic features of different cryptococcal molecular types. Forty-nine different isolates were inoculated into wild-type flies and followed for survival. In vitro, isolates were assessed for growth at 30 and 37°C, melanin production, capsule size, resistance to H2O2, and antifungal susceptibility. A mediator model was used to assess molecular type and virulence characteristics as predictors of survival in the fly model. VGIII was the most virulent molecular type in flies (P < 0.001). At 30°C, VGIII isolates grew most rapidly; at 37°C, VNI isolates grew best. C. gattii capsules were larger than those of C. neoformans (P < 0.001). Mediator model analysis found a strong correlation of Drosophila survival with molecular type and with growth at 30°C. We found molecular-type-specific differences in C. gattii in growth at different temperatures, melanin production, capsule size, ability to resist hydrogen peroxide, and antifungal susceptibility, while growth at 30°C and the VGIII molecular type were strongly associated with virulence in a Drosophila model of infection.
PMCID: PMC4097627  PMID: 24799631
4.  Evaluation of an Exercise Field Test Using Heart Rate Monitors to Assess Cardiorespiratory Fitness and Heart Rate Recovery in an Asymptomatic Population 
PLoS ONE  2014;9(5):e97704.
Measures of cardiorespiratory fitness (CRF) and heart rate recovery (HRR) can improve risk stratification for cardiovascular disease, but these measurements are rarely made in asymptomatic individuals due to cost. An exercise field test (EFT) to assess CRF and HRR would be an inexpensive method for cardiovascular disease risk assessment in large populations. This study assessed 1) the predictive accuracy of a 12-minute run/walk EFT for estimating CRF () and 2) the accuracy of HRR measured after an EFT using a heart rate monitor (HRM) in an asymptomatic population.
Fifty subjects (48% women) ages 18–45 years completed a symptom-limited exercise tolerance test (ETT) (Bruce protocol) and an EFT on separate days. During the ETT, was measured by a metabolic cart, and heart rate was measured continuously by a HRM and a metabolic cart.
EFT distance and sex independently predicted. The average absolute difference between observed and predicted was 0.26±3.27 ml·kg−1·min−1 for our model compared to 7.55±3.64 ml·kg−1·min−1 for the Cooper model. HRM HRR data were equivalent to respective metabolic cart values during the ETT. HRR at 1 minute post-exercise during ETT compared to the EFT had a moderate correlation (r = 0.75, p<0.001).
A more accurate model to estimate CRF from a 12-minute run/walk EFT was developed, and HRR can be measured using a HRM in an asymptomatic population outside of clinical settings.
PMCID: PMC4029765  PMID: 24848378
5.  Increase in proximal adenoma detection rate after transition from air to water method for screening colonoscopy in a community-based setting in the United States 
The water method of colonoscopy has been shown to increase adenoma detection rate in the United States veteran population, but this has not yet been demonstrated in a non-veteran community setting in the United States.
Our aim is to perform a retrospective study to compare adenoma detection rate between the air and the water colonoscopy methods for screening colonoscopies at a non-veteran community site.
We performed a retrospective review of 100 patients from before and after a single community endoscopist transitioned from air colonoscopy to water colonoscopy. The patients selected were the 50 most recent patients who presented for air colonoscopy and the first 50 patients who underwent water colonoscopy after the transition. Patients who presented for indications other than colon cancer screening or surveillance were excluded. The primary end point was overall adenoma detection rate; secondary end points included cecal intubation time, procedure time, polyp detection rate, proximal colon adenoma detection rate, and sedation requirement.
There was no significant difference between the two methods in total adenoma detection rate, polyp detection rate, cecal intubation time, total procedure time, or sedation requirement. However, there was a significantly higher proximal adenoma detection rate (34%) with the water method compared to the air method (18%), p=0.015.
In a non-veteran community setting, screening colonoscopy done with the water method resulted in a significantly higher proximal colon adenoma detection rate without significantly adding to total procedure time or sedation requirement.
PMCID: PMC3791525  PMID: 24147230
water colonoscopy; adenoma detection rate; community setting
6.  Medical students’ attitudes toward gay men 
BMC Medical Education  2012;12:71.
Healthcare providers’ attitudes toward sexual minorities influence patient comfort and outcomes. This study characterized medical student attitudes toward gay men, focusing on behavior, personhood, gay civil rights, and male toughness.
A cross-sectional web-based anonymous survey was sent to medical students enrolled at the University of California, Davis (N = 371) with a response rate of 68%.
Few respondents expressed negative attitudes toward gay men or would deny them civil rights. More negative responses were seen with respect to aspects of intimate behavior and homosexuality as a natural form of sexual expression. Men and students younger than 25 years old were more likely to endorse negative attitudes toward behavior as well as more traditional views on male toughness.
We show that an important minority of students express discomfort with the behavior of gay men and hold to a narrow construction of male identity. These findings suggest that competency training must move beyond conceptual discussions and address attitudes toward behaviors through new pedagogical approaches.
PMCID: PMC3460746  PMID: 22873668
Homosexuality; Medical students; Bias

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