Related Concept Videos

Inhibitors of Bacterial DNA Synthesis01:28

Inhibitors of Bacterial DNA Synthesis

Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...
Inflammatory Bowel Disease III: Crohn's Disease01:25

Inflammatory Bowel Disease III: Crohn's Disease

Crohn’s disease is a chronic, relapsing form of inflammatory bowel disease characterized by segmental, transmural inflammation that can affect any part of the gastrointestinal tract. Its pathogenesis arises from a combination of genetic susceptibility, environmental exposures, epithelial barrier dysfunction, and immune dysregulation. Together, these factors lead to an exaggerated immune response against components of the gut microbiome.Genetic and Environmental InfluencesMultiple genetic...
Dysbiosis of the Gut Microbiota01:18

Dysbiosis of the Gut Microbiota

The human gut microbiome includes a diverse array of microbial species, including beneficial commensals and opportunistic pathogens, which interact to support host health. These microbes contribute to essential functions such as nutrient metabolism, immune system modulation, and maintenance of intestinal barrier integrity. However, disruptions to this equilibrium—referred to as dysbiosis—can have widespread physiological consequences.Dysbiosis is often characterized by reduced microbial...
Inflammatory Bowel Disease II: Crohn's Disease01:30

Inflammatory Bowel Disease II: Crohn's Disease

Introduction
Inflammatory bowel disease, commonly known as IBD, refers to a collection of disorders that lead to persistent inflammation of the gastrointestinal tract. The two types of IBD are ulcerative colitis, which impacts the colon, and Crohn's disease, which can involve any part of the gastrointestinal segment.
Crohn's disease
Crohn's disease is a chronic, systemic inflammatory bowel disease (IBD) that predominantly affects the gastrointestinal tract. It is marked by transmural...
Inflammatory Bowel Disease II: Ulcerative Colitis01:20

Inflammatory Bowel Disease II: Ulcerative Colitis

Ulcerative colitis is a chronic inflammatory disorder of the colon characterized by continuous mucosal inflammation that typically begins in the rectum and extends proximally in a uniform pattern. Its pathogenesis involves a complex interplay of genetic predisposition, immune dysregulation, and environmental influences. These factors converge to impair the colon’s epithelial defenses and promote an exaggerated inflammatory response against luminal contents.Breakdown of the Mucosal BarrierA...
Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents01:18

Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents

Acute diarrhea, a common gastrointestinal disturbance, is characterized by the rapid evacuation of fluid stools, leading to an excessive weight in fluid. This condition typically arises from disorders affecting intestinal water and electrolyte transport. It can be triggered by an increased osmotic load within the intestine, excessive secretion of electrolytes and water, mucosal exudation of protein and fluid, or altered intestinal motility. The primary risks of acute diarrhea are dehydration...