TASK DEFINITION: In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.
PROBLEM: Flexible endoscopy has become a valuable tool for the diagnosis of many small animal gastrointestinal (GI) diseases, but the techniques must be performed carefully so that the results are meaningful. This article reviews the current diagnostic utility of flexible endoscopy, including practical/technical considerations for endoscopic biopsy, optimal instrumentation for mucosal specimen collection, the correlation of endoscopic indices to clinical activity and to histopathologic findings, and new developments in the endoscopic diagnosis of GI disease. Recent studies have defined endoscopic biopsy guidelines for the optimal number and quality of diagnostic specimens from different regions of the gut. They also have shown the value of ileal biopsy in the diagnosis of canine and feline chronic enteropathies, and have demonstrated the utility of endoscopic biopsy specimens beyond routine hematoxylin and eosin histopathological analysis, including their use in immunohistochemical, microbiological, and molecular studies.

SOLUTION: Maximizing the diagnostic utility of endoscopic biopsy in dogs and cats with gastrointestinal disease.

PROBLEM: Hepatic stellate cells (HSCs) play critical roles in liver fibrosis and hepatocellular carcinoma (HCC). Vitamin D receptor (VDR) activation in HSCs inhibits liver inflammation and fibrosis. We found that p62/SQSTM1, a protein upregulated in liver parenchymal cells but downregulated in HCC-associated HSCs, negatively controls HSC activation. Total body or HSC-specific p62 ablation potentiates HSCs and enhances inflammation, fibrosis, and HCC progression. p62 directly interacts with VDR and RXR promoting their heterodimerization, which is critical for VDR:RXR target gene recruitment. Loss of p62 in HSCs impairs the repression of fibrosis and inflammation by VDR agonists. This demonstrates that p62 is a negative regulator of liver inflammation and fibrosis through its ability to promote VDR signaling in HSCs, whose activation supports HCC.

SOLUTION: p62/SQSTM1 by Binding to Vitamin D Receptor Inhibits Hepatic Stellate Cell Activity, Fibrosis, and Liver Cancer.

PROBLEM: Cigarette smoke and smokeless tobacco extracts contain multiple carcinogenic compounds, but little is known about the mechanisms by which tumors develop and progress upon chronic exposure to carcinogens such as those present in tobacco products. Here, we examine the effects of smokeless tobacco extracts on human oral fibroblasts. We show that smokeless tobacco extracts elevated the levels of intracellular reactive oxygen, oxidative DNA damage, and DNA double-strand breaks in a dose-dependent manner. Extended exposure to extracts induced fibroblasts to undergo a senescence-like growth arrest, with striking accompanying changes in the secretory phenotype. Using cocultures of smokeless tobacco extracts-exposed fibroblasts and immortalized but nontumorigenic keratinocytes, we further show that factors secreted by extracts-modified fibroblasts increase the proliferation and invasiveness of partially transformed epithelial cells, but not their normal counterparts. In addition, smokeless tobacco extracts-exposed fibroblasts caused partially transformed keratinocytes to lose the expression of E-cadherin and ZO-1, as well as involucrin, changes that are indicative of compromised epithelial function and commonly associated with malignant progression. Together, our results suggest that fibroblasts may contribute to tumorigenesis indirectly by increasing epithelial cell aggressiveness. Thus, tobacco may not only initiate mutagenic changes in epithelial cells but also promote the growth and invasion of mutant cells by creating a procarcinogenic stromal environment.

SOLUTION:
A role for fibroblasts in mediating the effects of tobacco-induced epithelial cell growth and invasion.