The gut-brain axis is thought to play a significant role in the development and manifestation of neurologic diseases. This study reports significant alterations in the brain dopamine metabolism in mice infected with C. difficile , an important pathogen that overgrows in the gut after prolonged antibiotic therapy. Such alterations in specific brain regions may have an effect on the precipitation or manifestation of neurodevelopmental disorders in humans.

Plasmacytoid and rhabdoid variants of urothelial carcinomas (UCs) of the urinary bladder have been described in humans with plasma cell–like or rhabdoid cellular appearance and aggressive clinical outcome. Canine UC of the bladder is generally classified as papillary/nonpapillary and infiltrating/noninfiltrating with limited information regarding other histological patterns. We report 3 cases of UC of the urinary bladder showing a unique discohesive cellular morphology with malignant behavior resembling the human plasmacytoid and rhabdoid variants of UC, which may raise some difficulties in diagnosis. Epithelial-mesenchymal transition and reduced E-cadherin expression were revealed by immunohistochemistry in 2 cases, possibly explaining the discohesive and invasive behavior of the tumor cells. The findings broaden the morphological spectrum as well as the distinct clinical features of canine UC of the urinary bladder.

Swine dysentery (SD) is an enteric disease associated with strongly β-hemolytic Brachyspira spp. that cause mucohemorrhagic diarrhea primarily in grower-finisher pigs. We characterized alteration of colonic mucin composition and local cytokine expression in the colon of pigs with acute SD after B. hyodysenteriae (Bhyo) infection and fed either a diet containing 30% distillers dried grains with solubles (DDGS) or a control diet. Colonic tissue samples from 9 noninoculated pigs (Control, N = 4; DDGS, N = 5) and 10 inoculated pigs experiencing acute SD (Bhyo, N = 4; Bhyo-DDGS, N = 6) were evaluated. At the apex of the spiral colon, histochemical staining with high-iron diamine–Alcian blue revealed increased sialomucin (P = .008) and decreased sulfomucin (P = .027) in Bhyo pigs relative to controls, with a dietary effect for sulfomucin. Noninoculated pigs fed DDGS had greater expression of sulfomucin (P = .002) compared to pigs fed the control diet. Immunohistochemically, there was de novo expression of mucin 5AC (MUC5AC) in the Bhyo group while mucin 2 (MUC2) expression was not significantly different between groups. RNA in situ hybridization to detect the pro-inflammatory cytokine IL-1β often showed increased expression in the Bhyo group although without statistical significance, and this was not correlated with MUC5AC or MUC2 expression, suggesting IL-1β is not a major regulator of their secretion in acute SD. Expression of the anti-inflammatory cytokine TGF-β1 was significantly suppressed in the Bhyo group compared to controls (P = .005). This study reveals mucin and cytokine alterations in the colon of pigs with experimentally induced SD and related dietary effects of DDGS.

Purpose: Because surgery is the only potential cure for pancreatic cancer, high-risk premalignant pancreatic lesions often evade detection by palpation or white-light visualization, increasing the risk of recurrence. We asked whether near-infrared fluorescence imaging of tumor-associated inflammation could identify high-risk premalignant lesions, leveraging the tumor microenvironment as a sentinel of local disease and, thus, enhance surgery outcomes. Experimental Design: Fluorescence-guided surgery was performed on genetically engineered mice [Ptf1a-Cre; LSL-KrasG12D/+; Smad4flox/flox (KSC)] at discrete stages of disease progression, histologically confirmed high-risk, premalignant lesions in postnatal mice to locally advanced pancreatic tumors in adults, using the imaging agent V-1520, a translocator protein ligand. Age-matched wild-type littermates were used as controls, whereas Ptf1a-Cre; LSL-KrasG12D/+ mice modeled pancreatitis and precursors of low penetrance. Localization of V-1520 and tumor-associated macrophages among the tumor microenvironment was detected by immunofluorescence imaging. Results: V-1520 exhibited robust accumulation in the pancreata of KSC mice from the early postnatal stage. Increased accumulation was observed in the pancreata of adolescent- and adult-aged mice with greater ductal lesion and stromal burden. Confocal microscopy of ex vivo pancreas specimens co-localized V-1520 accumulation primarily with CD68-expressing macrophages in KSC mice. Unlike the pancreata of KSC mice, accumulation of V-1520 did not exceed background levels in the pancreata of Ptf1a-Cre; LSL-KrasG12D/+ mice with pancreatitis. Conclusions: V-1520 exhibited differential accumulation in pancreatic cancer–associated inflammation compared with pancreatitis. Given the robust tracer uptake in tissues associated with early yet high-risk lesions, we envision that V-1520 could enhance surgical resection and reduce the potential for recurrence from residual disease.

Supplementary Data1 from Preclinical Fluorescence-Guided Imaging Leveraging Surrounding Sentinel Tumor Microenvironment Identifies High-Risk Premalignant Pancreatic Lesions

Supplementary Data2 from Preclinical Fluorescence-Guided Imaging Leveraging Surrounding Sentinel Tumor Microenvironment Identifies High-Risk Premalignant Pancreatic Lesions