Faculty Bibliography

BACKGROUND AND AIMS:High sodium consumption has been associated with an increased risk of gastric cancer. The mean daily sodium intake in the United States substantially exceeds the national recommended amount. The low sodium-DASH diet has been shown to decrease the risk of cardiovascular disease in the United States, but its impact on gastric cancer has not been well studied. We therefore aimed to model the impact and cost-effectiveness of the low sodium-DASH diet for gastric cancer prevention in the U.S. POPULATION/: METHODS:A Markov cohort state-transition model was developed to simulate the impact of the low sodium-DASH diet on gastric cancer outcomes for the average 40-year-old in the United States compared to no intervention. Primary outcomes of interest were gastric cancer incidence and incremental cost-effectiveness ratios (ICER). RESULTS:Our model found that compared to the no intervention cohort, the risk of gastric cancer decreased by 24.8% for males and 21.2% for females on the low sodium-DASH diet. 27 cases and 14 cases per 10,000 individuals were prevented for males and females, respectively, in the intervention group. The ICER for the low sodium-DASH diet strategy was $287,726 for males and $423,878 for females compared to the no intervention strategy. CONCLUSIONS:Using a Markov model of gastric cancer risk, we found that adherence to a low sodium-DASH diet could decrease the risk of gastric cancer. This intervention was not cost-effective due to the high cost of a low sodium-DASH accordant diet, but significantly improved for high-risk populations and when the cost of the diet became slightly more affordable.

BACKGROUND:Racial/ethnic differences in mortality have not been well studied for either non-cardia gastric cancer (NCGC) or cardia gastric cancer (CGC). The aim of this study was to examine the US mortality rates for these cancer subtypes, as well as esophageal adenocarcinoma (EAC) as a comparator. METHODS:We identified 14 164 individuals who died from NCGC, 5235 from CGC, and 13 982 from EAC in the Surveillance, Epidemiology, and End Results database between 2004 and 2016. Age-adjusted incidence-based mortality rates and corresponding annual percent changes (APCs) were calculated. Analyses were stratified by race/ethnicity, age, and stage of disease at diagnosis. RESULTS:The mortality rate in NCGC was two- to threefold higher in blacks, Hispanics, and Asians/Pacific Islanders (PI) than non-Hispanic whites, and was significant across all age groups and stages of disease (P < .01). Mortality in CGC was higher in non-Hispanic whites than blacks and Asians/PI, particularly in individuals in the 50-64 year age group and those with stage IV disease. Mortality in EAC was two- to sixfold higher in non-Hispanic whites than all other groups across all age groups and stages of disease. From 2004 to 2016, mortality rates were stable across all racial/ethnic groups in NCGC and CGC, and in minority groups with EAC, but have been rising in non-Hispanic whites with EAC (APC 3.03, 95% CI 0.17-5.96). CONCLUSIONS:This is the largest study of incidence-based mortality in CGC and NCGC and demonstrates racial/ethnic differences in mortality between these subtypes. Mortality rates for NCGC are highest in minority groups, and have been stable in recent years despite declining incidence. Mortality rates for CGC are marginally higher in middle-aged non-Hispanic whites with advanced disease, though have remained stable. In contrast, mortality in EAC has been rising for non-Hispanic whites, in parallel to incidence. Further studies are needed to refine prevention strategies for high-risk individuals dying from these specific cancer subtypes.

Background and Aim/UNASSIGNED:Enteric tube (ET) placement is approached with caution in patients with esophageal varices (EV) due to concern of causing variceal bleeding. Data are limited on rates and predictors of gastrointestinal bleeding (GIB) in these patients. This study aims to assess the rate and predictors of bleeding from EV after ET placement. Methods/UNASSIGNED:test, and univariate logistic regression model. Results/UNASSIGNED:= 0.048). Conclusion/UNASSIGNED:ET placement in patients with EV is associated with low risk of bleeding. Elevated MELD-Na and lower EV location conferred a higher risk of bleeding after ET placement.

PURPOSE OF REVIEW/OBJECTIVE:Proton pump inhibitors (PPIs) are effective for many conditions but are often overprescribed. Recent concerns about long-term risks have made patients re-evaluate their need to take PPIs chronically, though these population-based studies have methodological weaknesses. The goal of this review is to provide evidenced-based strategies for discontinuation of PPI therapy. RECENT FINDINGS/RESULTS:Given that some patients experience rebound symptoms when abruptly stopping continuous PPI therapy due to its effect on hypergastrinemia, strategies focus on avoiding rebound. Tapering the PPI and then initiating a "step-down" approach with the use of alternative medications may be effective. "On-demand therapy" provides patients with the option to take intermittent PPI courses, reducing overall use and cost while preserving patient satisfaction. It is important for providers to consider ambulatory pH or pH/impedance testing to rule out diagnoses that may require alternative medications like neuromodulators. A number of studies reviewed here can provide guidance in counseling patients on PPI discontinuation. It is important for the provider to obtain a baseline needs assessment for PPI therapy and to elucidate predictors of difficulty in discontinuation prior to initiating a strategy.

Haematopoietic stem cells (HSCs) can convert between growth states that have marked differences in bioenergetic needs. Although often quiescent in adults, these cells become proliferative upon physiological demand. Balancing HSC energetics in response to nutrient availability and growth state is poorly understood, yet essential for the dynamism of the haematopoietic system. Here we show that the Lkb1 tumour suppressor is critical for the maintenance of energy homeostasis in haematopoietic cells. Lkb1 inactivation in adult mice causes loss of HSC quiescence followed by rapid depletion of all haematopoietic subpopulations. Lkb1-deficient bone marrow cells exhibit mitochondrial defects, alterations in lipid and nucleotide metabolism, and depletion of cellular ATP. The haematopoietic effects are largely independent of Lkb1 regulation of AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) signalling. Instead, these data define a central role for Lkb1 in restricting HSC entry into cell cycle and in broadly maintaining energy homeostasis in haematopoietic cells through a novel metabolic checkpoint.

Esophageal duplication cysts (EDCs) are well described within the literature, normally occurring within the mediastinum. Intra-abdominal EDCs are rare and typically occur near the intra-abdominal esophagus. Herein, we describe two cases of intra-abdominal EDCs: a 60-year-old man who was incidentally found to have a retro-duodenal cystic mass and a 50-year-old woman with a cystic lesion near the body and tail of her pancreas causing left flank pain. Both patients underwent enucleation of their respective masses. Pathology revealed ciliated pseudostratified columnar epithelium with scattered mucus-secreting cells and two smooth muscle layers in the cyst wall of both patients, consistent with EDCs. Although intra-abdominal EDCs have been reported in the literature, our two cases and a review of the literature indicate that these lesions are not always adherent to or even near the intra-abdominal esophagus.

Donor CD8(+) T cells can be potent mediators of graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation to either major histocompatibility complex (MHC) class I-or multiple minor histocompatibility antigen-mismatched recipients. To develop small molecular inhibitors of CD8(+) T-cell activity, theoretical structural analysis of the human CD8 alpha molecule was previously used to identify potential functional surface epitopes that interact with the MHC class I molecule. The DE loop (p71-78) was identified as such a target region, and a panel of synthetic cyclized peptide mimics of this region were tested for their inhibitory effects on cytotoxic T lymphocyte activity in human cell-mediated lympholysis assays. Peptide 1109 (CKRLGDTFVC) was most effective at inhibiting specific target cell lysis. Accordingly, studies were conducted to determine whether there was sufficient cross-species homology in the DE loop region and its nonpolymorphic interactive site on the beta(2)-microglobulin domain of the MHC class I molecule to allow similar inhibition of murine CD8(+) cytotoxic T lymphocyte activity. On the basis of strong in vitro inhibitory activity of 1109 in the murine system, the capacity of the peptide to inhibit in vivo CD8(+) T-cell effector functions in skin and hematopoietic stem cell transplantation models was examined. In the C57BL/6 anti-bm1 skin allograft rejection model, across an MHC class I barrier, a single injection of 1109 at the time of transplantation significantly prolonged graft survival. Moreover, 1109 administered at the time of transplantation in the multiple minor histocompatibility antigen-disparate B10.BR-->CBA GVHD model significantly prolonged the survival of lethally irradiated mice that underwent transplantation with donor bone marrow cells and CD8(+) T cells. Histopathologic analysis confirmed that mice treated with the synthetic peptide exhibited diminution of epithelial target cell injury. Specificity of the peptide effect was evidenced by draining lymph node cells from B10.BR mice that had been challenged with CBA lymphocytes and simultaneously treated with 1109. These cells could not generate secondary proliferative responses in vitro upon stimulation with CBA splenocytes but could respond to third-party C57BL/6 stimulation. Thus, the 1109 peptide has potential application in the prevention of CD8-mediated GVHD development.

Vascular cell adhesion molecule-1 (VCAM-1; CD106), the receptor for VLA-4, is an important mediator of adhesive and co-stimulatory interactions that govern cutaneous immune responses. Initial studies designed to elucidate temporal aspects of endothelial adhesion molecule induction in murine acute graft-versus-host disease (aGVHD) revealed unexpected and novel VCAM-1 expression by cutaneous and mucosal epithelial cells. Immunohistochemical techniques confirmed VCAM-1 staining as early as 7 days after transplantation in a distinctive subpopulation of squamous epithelial cells that normally occupy focal domains within the epidermal basal cell layer, the follicular infundibulum, and the dorsal lingual epithelium. Specifically, VCAM-1 expression was intimately associated with rete ridge-like prominences in footpad epidermis and in dorsal lingual epithelium. VCAM-1, as evaluated by serial section-labeling techniques, was preferentially expressed at sites of early epithelial infiltration by CD4(+) T cells. Western blot analysis confirmed expression of the 110-kd isoform of VCAM-1 in epithelium isolated from aGVHD animals, and immunoelectron microscopy demonstrated VCAM-1 reactivity restricted exclusively to epithelial cell plasma membranes. It is concluded that VCAM-1 is selectively expressed by discrete squamous epithelial subpopulations in murine aGVHD. As such, VCAM-1 may play a previously unrecognized role in mediating interactions between donor effector T lymphocytes and host epithelial cell targets.