Research and Medical Services

Iowa City, IA, United States

Research and Medical Services

Iowa City, IA, United States

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Leung F.W.,Research and Medical Services | Leung F.W.,University of California at Los Angeles | Leung J.W.,University of California at Davis | Leung J.W.,Sacramento Veterans Affairs Medical Center | And 6 more authors.
Endoscopy | Year: 2011

Failure of cecal intubation when using air insufflation during scheduled unsedated colonoscopy in veterans prompted a literature search for a less uncomfortable approach. Water-related maneuvers as adjuncts to air insufflation were identified as effective in minimizing discomfort, although medication requirement was not reduced and willingness to repeat unsedated colonoscopy was not addressed. These adjunct maneuvers were combined with turning the air pump off to avoid colon elongation during insertion. Warm water infusion in lieu of air insufflation was evaluated in observational studies. Subsequent refinements evolved into the water method a combination of air exclusion by aspiration of residual air to minimize angulations at flexures and a dynamic process of water exchange to remove feces in order to clear the view and aid insertion. In subsequent randomized controlled trials, the water method significantly reduced medication requirement, increased the proportion of patients in whom complete unsedated colonoscopy could be achieved, reduced patient recovery time burdens (sedation on demand), decreased abdominal discomfort during and after colonoscopy, enhanced cecal intubation, and increased willingness to repeat the procedure (scheduled unsedated). Supervised education of trainees and self-learning by an experienced colonoscopist were feasible. Lessons learned in developing the water method for optimizing patient-centered outcomes are presented. These proof-of-principle observations merit further research assessment in diverse settings. © Georg Thieme Verlag KGStuttgart, New York.


Leung F.W.,Research and Medical Services | Leung F.W.,University of California at Los Angeles | Amato A.,Valduce Hospital | Ell C.,Dr Horst Schmidt Klinik | And 14 more authors.
Gastrointestinal Endoscopy | Year: 2012

Water-aided methods for colonoscopy are distinguished by the timing of removal of infused water, predominantly during withdrawal (water immersion) or during insertion (water exchange). To discuss the impact of these approaches on colonoscopy pain and adenoma detection rate (ADR). Systematic review. Randomized, controlled trial (RCT) that compared water-aided methods and air insufflation during colonoscope insertion. Patients undergoing colonoscopy. Medline, PubMed, and Google searches (January 2008-December 2011) and personal communications of manuscripts in press were considered to identify appropriate RCTs. Pain during colonoscopy and ADR. RCTs were grouped according to whether water immersion or water exchange was used. Reported pain scores and ADR were tabulated based on group assignment. Pain during colonoscopy is significantly reduced by both water immersion and water exchange compared with traditional air insufflation. The reduction in pain scores was qualitatively greater with water exchange as compared with water immersion. A mixed pattern of increases and decreases in ADR was observed with water immersion. A higher ADR, especially proximal to the splenic flexure, was obtained when water exchange was implemented. Differences in the reports limit application of meta-analysis. The inability to blind the colonoscopists exposed the observations to uncertain bias. Compared with air insufflation, both water immersion and water exchange significantly reduce colonoscopy pain. Water exchange may be superior to water immersion in minimizing colonoscopy discomfort and in increasing ADR. A head-to-head comparison of these 3 approaches is required. © 2012 American Society for Gastrointestinal Endoscopy.


Leung F.W.,Research and Medical Services | Leung F.W.,University of California at Los Angeles | Harker J.O.,Research and Medical Services | Jackson G.,Research and Medical Services | And 11 more authors.
Gastrointestinal Endoscopy | Year: 2010

Background: An observational study in veterans showed that a novel water method (water infusion in lieu of air insufflation) enhanced cecal intubation and willingness to undergo a repeat scheduled unsedated colonoscopy. Objective: To confirm these beneficial effects and significant attenuation of discomfort in a randomized, controlled trial (RCT). Design: Prospective RCT, intent-to-treat analysis. Setting: Veterans Affairs ambulatory care facility. Patients: Veterans undergoing scheduled unsedated colonoscopy. Interventions: During insertion, the water and traditional air methods were compared. Main Outcome Measurements: Discomfort and procedure-related outcomes. Results: Eighty-two veterans were randomized to the air (n = 40) or water (n = 42) method. Cecal intubation (78% vs 98%) and willingness to repeat (78% vs 93%) were significantly better with the water method (P < .05; Fisher exact test). The mean (standard deviation) of maximum discomfort (0 = none, 10 = most severe) during colonoscopy was 5.5 (3.0) versus 3.6 (2.1) P = .002 (Student t test), and the median overall discomfort after colonoscopy was 3 versus 2, P = .052 (Mann-Whitney U test), respectively. The method, but not patient characteristics, was a predictor of discomfort (t = -1.998, P = .049, R2 = 0.074). The odds ratio for failed cecal intubation was 2.09 (95% CI, 1.49-2.93) for the air group. Fair/poor previous experience increased the risk of failed cecal intubation in the air group only. The water method numerically increased adenoma yield. Limitations: Single site, small number of elderly men, unblinded examiner, possibility of unblinded subjects, restricted generalizability. Conclusions: The RCT data confirmed that the water method significantly enhanced cecal intubation and willingness to undergo a repeat colonoscopy. The decrease in maximum discomfort was significant; the decrease in overall discomfort approached significance. The method, but not patient characteristics, was a predictor of discomfort. (Clinical trial registration number NCT00747084). © 2010 American Society for Gastrointestinal Endoscopy.


Said H.,Research and Medical Services | Said H.,University of California at Los Angeles | Kaji I.,Research and Medical Services | Kaji I.,University of California at Los Angeles | And 2 more authors.
Current Opinion in Gastroenterology | Year: 2015

Purpose of review To highlight recent developments in the field of gastroduodenal mucosal defense with emphasis on lumen- gut interactions. Recent findings There has been a growing interest in the physiological functions of luminal chemosensors present from tongue to colon that detect organic molecules in the luminal content associated with nutrient ingestion, usually associated with specialized cells, in particular the enteroendocrine cells. These receptors transduce the release of peptide hormones, in particular proglucagon-derived products such as the glucagon-like peptides (GLPs), which have profound effects on gut function and on metabolism. Luminal chemosensors transduce GLP release in response to changes in the cellular environment, as part of the mechanism of nutrient chemosensing. GLP-2 has important trophic effects on the intestinal mucosa, including increasing the proliferation rate of stem cells and reducing transmucosal permeability to ions and small molecules, in addition to increasing the rate of duodenal bicarbonate secretion. GLP-1, although traditionally considered an incretin that enhances the effect of insulin on peripheral tissues, also has trophic effects on the intestinal epithelium. Summary A better understanding of the mechanisms that mediate GLP release can further illuminate the importance of nutrient chemosensing as an important component of the mechanism that mediates the trophic effects of luminal nutrients. GLP-1 and GLP-2 are already in clinical use for the treatment of diabetes and intestinal failure. Improved understanding of the control of their release and their end-organ effects will identify new clinical indications and interventions that enhance their release. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.


Leung F.W.,Research and Medical Services | Leung F.W.,University of California at Los Angeles | Aljebreen A.M.,King Khalid University
Saudi Journal of Gastroenterology | Year: 2011

Unsedated colonoscopy has been an evolving subject ever since its initial description four decades ago. Failure in unsedated diagnostic cases due to patient pain led to the introduction of sedation. Extension to screening cases, albeit logical, created a sedation-related barrier to colonoscopy screening. In recent years a water method has been developed to combat the pain during unsedated colonoscopy in the US. In randomized controlled trials the water method decreases pain, increases cecal intubation success, and enhances the proportion of patients who complete unsedated colonoscopy. The salvage cleansing of suboptimal bowel preparation by the water method serendipitously may have increased the detection of adenoma in both unsedated and sedated patients. The state-of-the-art lecture concludes that unsedated colonoscopy is feasible. The hypothesis is that recent advances, such as the development of the water method, may contribute to reviving unsedated colonoscopy as a potentially attractive option for colon cancer screening and deserves to be tested.


Stapleton J.T.,Research and Medical Services | Stapleton J.T.,University of Iowa | Martinson J.A.,Rush University | Klinzman D.,Research and Medical Services | And 5 more authors.
AIDS | Year: 2013

GB virus C (GBV-C), a pan-lymphotropic flavivirus capable of persistent infection, is associated with prolonged survival and reduced T-cell activation in HIV-infected patients. GBV-C was associated with reduced CD56brt/CD16 natural killer cell and monocyte activation, and a trend toward reduced B-cell activation by measuring cell surface activation markers or HIV entry coreceptors. The GBV-C association was independent of HIV viral load. Thus, GBV-C may influence non-T-cell immune activation in individuals with HIV infection. © 2013 Creative Common License.


Stapleton J.T.,Research and Medical Services | Stapleton J.T.,University of Iowa | Chaloner K.,University of Iowa | Martenson J.A.,Rush University | And 7 more authors.
PLoS ONE | Year: 2012

GBV-C infection is associated with prolonged survival and with reduced T cell activation in HIV-infected subjects not receiving combination antiretroviral therapy (cART). The relationship between GBV-C and T cell activation in HIV-infected subjects was examined. HIV-infected subjects on cART with non-detectable HIV viral load (VL) or cART naïve subjects were studied. GBV-C VL and HIV VL were determined. Cell surface markers of activation (CD38+/HLA-DR+), proliferation (Ki-67+), and HIV entry co-receptor expression (CCR5+ and CXCR4+) on total CD4+ and CD8+ T cells, and on naïve, central memory (CM), effector memory (EM), and effector CD4+ and CD8+ subpopulations were measured by flow cytometry. In subjects with suppressed HIV VL, GBV-C was consistently associated with reduced activation in naïve, CM, EM, and effector CD4+ cells. GBV-C was associated with reduced CD4+ and CD8+ T cell surface expression of activation and proliferation markers, independent of HIV VL classification. GBV-C was also associated with higher proportions of naïve CD4+ and CD8+ T cells, and with lower proportions of EM CD4+ and CD8+ T cells. In conclusion, GBV-C infection was associated with reduced activation of CD4+ and CD8+ T cells in both HIV viremic and HIV RNA suppressed patients. Those with GBV-C infection demonstrated an increased proportion of naive T cells and a reduction in T cell activation and proliferation independent of HIV VL classification, including those with suppressed HIV VL on cART. Since HIV pathogenesis is thought to be accelerated by T cell activation, these results may contribute to prolonged survival among HIV infected individuals co-infected with GBV-C. Furthermore, since cART therapy does not reduce T cell activation to levels seen in HIV-uninfected people, GBV-C infection may be beneficial for HIV-related diseases in those effectively treated with anti-HIV therapy.


PubMed | Research and Medical Services
Type: Journal Article | Journal: Gastrointestinal endoscopy | Year: 2012

Water-aided methods for colonoscopy are distinguished by the timing of removal of infused water, predominantly during withdrawal (water immersion) or during insertion (water exchange).To discuss the impact of these approaches on colonoscopy pain and adenoma detection rate (ADR).Systematic review.Randomized, controlled trial (RCT) that compared water-aided methods and air insufflation during colonoscope insertion.Patients undergoing colonoscopy.Medline, PubMed, and Google searches (January 2008-December 2011) and personal communications of manuscripts in press were considered to identify appropriate RCTs.Pain during colonoscopy and ADR. RCTs were grouped according to whether water immersion or water exchange was used. Reported pain scores and ADR were tabulated based on group assignment.Pain during colonoscopy is significantly reduced by both water immersion and water exchange compared with traditional air insufflation. The reduction in pain scores was qualitatively greater with water exchange as compared with water immersion. A mixed pattern of increases and decreases in ADR was observed with water immersion. A higher ADR, especially proximal to the splenic flexure, was obtained when water exchange was implemented.Differences in the reports limit application of meta-analysis. The inability to blind the colonoscopists exposed the observations to uncertain bias.Compared with air insufflation, both water immersion and water exchange significantly reduce colonoscopy pain. Water exchange may be superior to water immersion in minimizing colonoscopy discomfort and in increasing ADR. A head-to-head comparison of these 3 approaches is required.


PubMed | Research and Medical Services
Type: Journal Article | Journal: Saudi journal of gastroenterology : official journal of the Saudi Gastroenterology Association | Year: 2012

The impact of education on acceptance of unsedated colonoscopy by health care providers is unknown. To test the hypothesis that knowledge imparted by a lecture on unsedated colonoscopy is associated with its enhanced acceptance.At the State-of-the-Art Lecture on Unsedated colonoscopy: Is it feasible? presented at the 8 th Pan-Arab Conference on Gastroenterology, February, 2011, Riyadh, Saudi Arabia, a questionnaire survey of the audience was undertaken.An expectation questionnaire was administered before and after the lecture. Attendees responded anonymously.The responses of a convenient sample of 49 attendees who provided completed responses to the questionnaire both before and after the lecture were analyzed. Data are expressed as frequency counts and meansSEM. Repeated measures analysis of variance (ANOVA), ANOVA with contrasts and Chi-square analysis (Statview II Program for Macintosh computers) were used to assess the data. A P value of <0.05 is considered significant.The meanSEM credibility score (maximum possible score=50) was 25.8 1.8 before and 33.3 2.1 after the lecture, with a significant improvement in mean score of 7.5 1.3 (P=0.001, paired t test). Nineteen (39%) respondents were not willing to consider unsedated colonoscopy for themselves before the lecture. This number decreased to 13 (27%) after the lecture. Before the lecture only 4 (8%) respondents were willing to consider unsedated colonoscopy for themselves. After the lecture this number increased to 8 (16%). The data suggest education of healthcare professionals regarding the feasibility of unsedated colonoscopy appears to enhance its acceptance as a credible patient care option at a Pan-Arab Gastroenterology Conference.


PubMed | Research and Medical Services
Type: Journal Article | Journal: Biological trace element research | Year: 2013

Studies were conducted to determine the effects of zinc deficiency and excess zinc intake on the relative(65)Zn-binding activities of metallothionein (MT) and low-molecular-weight zinc-binding ligand (LMW-ZBL) in vitro and in vivo. Zinc-binding ligands of small intestine from four groups, each of five rats (normal, zinc-deficient, excess zinc injected, and excess zinc given orally), were separated by column chromatography on Sephadex G-75. The ratio of(65)Zn binding activities of MT to LMW-ZBL (MT/LMW-ZBL) in zinc-deficient rats was decreased both in vitro and in vivo compared to the control. When excess zinc was administered orally,(65)Zn-binding activity of MT was low in vitro and substantially increased in vivo. However, when excess zinc was injected intraperitoneally,(65)Zn-binding activity of MT in vitro greatly increased, but(65)Zn-binding activities of both MT and LMW-ZBL were significantly reduced in vivo as compared to the control. Based onA 280 readings of isolated MT and densities of protein bands in disc gel electrophoresis, the(65)Zn-binding activity of MT in vitro appeared to be proportional to the MT content. Hence, these data indicate that oral administration of excess zinc decreases MT whereas intraperitoneal injection of excess zinc stimulates its synthesis. Zinc deficiency has little to no effect on the intestinal MT metabolism. These results suggest that MT may be important in zinc secretion but not involved in zinc absorption; while LMW-ZBL participates both in zinc absorption and secretion.

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