scholarly journals Why Does SARS-CoV-2 Invade the Gastrointestinal Epithelium?

2020 ◽  
Vol 159 (4) ◽  
pp. 1622-1623 ◽  
Author(s):  
Yoshiharu Uno
Keyword(s):  
Gastrointestinal Epithelium

scholarly journals Combinations of Freeze-Dried Amorphous Vardenafil Hydrochloride with Saccharides as A Way to Enhance Dissolution Rate and Permeability

2021 ◽  
Vol 14 (5) ◽  
pp. 453
Author(s):  
Gabriela Wiergowska ◽  
Dominika Ludowicz ◽  
Kamil Wdowiak ◽  
Andrzej Miklaszewski ◽  
Kornelia Lewandowska ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Density Functional ◽  
Hydroxypropyl Methylcellulose ◽  
Fold Increase ◽  
Crystalline Form ◽  
Amorphous Form ◽  
Freeze Dried ◽  
Apparent Solubility ◽  
Gastrointestinal Epithelium ◽  
The Impact

To improve physicochemical properties of vardenafil hydrochloride (VAR), its amorphous form and combinations with excipients—hydroxypropyl methylcellulose (HPMC) and β-cyclodextrin (β-CD)—were prepared. The impact of the modification on physicochemical properties was estimated by comparing amorphous mixtures of VAR to their crystalline form. The amorphous form of VAR was obtained as a result of the freeze-drying process. Confirmation of the identity of the amorphous dispersion of VAR was obtained through the use of comprehensive analysis techniques—X-ray powder diffraction (PXRD) and differential scanning calorimetry (DSC), supported by FT-IR (Fourier-transform infrared spectroscopy) coupled with density functional theory (DFT) calculations. The amorphous mixtures of VAR increased its apparent solubility compared to the crystalline form. Moreover, a nearly 1.3-fold increase of amorphous VAR permeability through membranes simulating gastrointestinal epithelium as a consequence of the changes of apparent solubility (Papp crystalline VAR = 6.83 × 10−6 cm/s vs. Papp amorphous VAR = 8.75 × 10−6 cm/s) was observed, especially for its combinations with β-CD in the ratio of 1:5—more than 1.5-fold increase (Papp amorphous VAR = 8.75 × 10−6 cm/s vs. Papp amorphous VAR:β-CD 1:5 = 13.43 × 10−6 cm/s). The stability of the amorphous VAR was confirmed for 7 months. The HPMC and β-CD are effective modifiers of its apparent solubility and permeation through membranes simulating gastrointestinal epithelium, suggesting a possibility of a stronger pharmacological effect.

Biotransformations and cytotoxicity of graphene and inorganic two-dimensional nanomaterials using simulated digestions coupled with a triculture in vitro model of the human gastrointestinal epithelium

2021 ◽  
Author(s):  
Lila Bazina ◽  
Dimitrios Bitounis ◽  
Xiaoqiong Cao ◽  
Glen M. DeLoid ◽  
Dorsa Parviz ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Engineered Nanomaterials ◽  
Two Dimensional ◽  
Gastrointestinal Epithelium ◽  
Vitro Model ◽  
Human Gastrointestinal Epithelium

Background: engineered nanomaterials (ENMs) have already made their way into myriad applications and products across multiple industries.

scholarly journals Enteroviruses: A Gut-Wrenching Game of Entry, Detection, and Evasion

Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 460 ◽  
Author(s):  
Alexandra I. Wells ◽  
Carolyn B. Coyne
Keyword(s):  
Enterovirus 71 ◽  
Febrile Illness ◽  
Oral Route ◽  
Life Cycles ◽  
Innate Immune ◽  
Acute Flaccid Myelitis ◽  
Innate Immune Signaling ◽  
Intracellular Proteins ◽  
Enterovirus D68 ◽  
Gastrointestinal Epithelium

Enteroviruses are a major source of human disease, particularly in neonates and young children where infections can range from acute, self-limited febrile illness to meningitis, endocarditis, hepatitis, and acute flaccid myelitis. The enterovirus genus includes poliovirus, coxsackieviruses, echoviruses, enterovirus 71, and enterovirus D68. Enteroviruses primarily infect by the fecal–oral route and target the gastrointestinal epithelium early during their life cycles. In addition, spread via the respiratory tract is possible and some enteroviruses such as enterovirus D68 are preferentially spread via this route. Once internalized, enteroviruses are detected by intracellular proteins that recognize common viral features and trigger antiviral innate immune signaling. However, co-evolution of enteroviruses with humans has allowed them to develop strategies to evade detection or disrupt signaling. In this review, we will discuss how enteroviruses infect the gastrointestinal tract, the mechanisms by which cells detect enterovirus infections, and the strategies enteroviruses use to escape this detection.

scholarly journals Gastrointestinal synthetic epithelial linings

2020 ◽  
Vol 12 (558) ◽  
pp. eabc0441
Author(s):  
Junwei Li ◽  
Thomas Wang ◽  
Ameya R. Kirtane ◽  
Yunhua Shi ◽  
Alexis Jones ◽  
...  
Keyword(s):  
Drug Absorption ◽  
Ex Vivo ◽  
The Body ◽  
Proof Of Concept ◽  
Barrier Formation ◽  
Synthetic Biomaterial ◽  
Gastrointestinal Epithelium ◽  
Essential Enzyme ◽  
Directed Polymerization

Epithelial tissues line the organs of the body, providing an initial protective barrier as well as a surface for nutrient and drug absorption. Here, we identified enzymatic components present in the gastrointestinal epithelium that can serve as selective means for tissue-directed polymerization. We focused on the small intestine, given its role in drug and nutrient absorption and identified catalase as an essential enzyme with the potential to catalyze polymerization and growth of synthetic biomaterial layers. We demonstrated that the polymerization of dopamine by catalase yields strong tissue adhesion. We characterized the mechanism and specificity of the polymerization in segments of the gastrointestinal tracts of pigs and humans ex vivo. Moreover, we demonstrated proof of concept for application of these gastrointestinal synthetic epithelial linings for drug delivery, enzymatic immobilization for digestive supplementation, and nutritional modulation through transient barrier formation in pigs. This catalase-based approach to in situ biomaterial generation may have broad indications for gastrointestinal applications.

Ovarian Sertoli-Leydig cell tumor with heterologous gastrointestinal epithelium as a source of alpha-fetoprotein: A case report

2008 ◽  
Vol 34 (3) ◽  
pp. 418-421 ◽  
Author(s):  
Takafumi Watanabe ◽  
Hidekazu Yamada ◽  
Yutaka Morimura ◽  
Masafumi Abe ◽  
Teiichi Motoyama ◽  
...  
Keyword(s):  
Case Report ◽  
Leydig Cell ◽  
Leydig Cell Tumor ◽  
Cell Tumor ◽  
Alpha Fetoprotein ◽  
Gastrointestinal Epithelium

scholarly journals Microbe-Driven Genotoxicity in Gastrointestinal Carcinogenesis

2020 ◽  
Vol 21 (20) ◽  
pp. 7439
Author(s):  
Kimberly Hartl ◽  
Michael Sigal
Keyword(s):  
Colorectal Cancer ◽  
Virulence Factors ◽  
Acute Infection ◽  
Genomic Integrity ◽  
Mechanistic Studies ◽  
Gastrointestinal Malignancies ◽  
Barrier Integrity ◽  
Gastrointestinal Epithelium ◽  
Constant Exchange

The intestinal epithelium serves as a barrier to discriminate the outside from the inside and is in constant exchange with the luminal contents, including nutrients and the microbiota. Pathogens have evolved mechanisms to overcome the multiple ways of defense in the mucosa, while several members of the microbiota can exhibit pathogenic features once the healthy barrier integrity of the epithelium is disrupted. This not only leads to symptoms accompanying the acute infection but may also contribute to long-term injuries such as genomic instability, which is linked to mutations and cancer. While for Helicobacter pylori a link between infection and cancer is well established, many other bacteria and their virulence factors have only recently been linked to gastrointestinal malignancies through epidemiological as well as mechanistic studies. This review will focus on those pathogens and members of the microbiota that have been linked to genotoxicity in the context of gastric or colorectal cancer. We will address the mechanisms by which such bacteria establish contact with the gastrointestinal epithelium—either via an existing breach in the barrier or via their own virulence factors as well as the mechanisms by which they interfere with host genomic integrity.

Sign in / Sign up

Export Citation Format

Share Document