Gastrointestinal tract and viral pathogens

Viral gastroenteritis is the most common viral illness that affects the gastro-intestinal(GI)tract,causing inflammation and irritation of the lining of the stomach and intestines.Common signs and symptoms associated with this condition include abdominal pain,diarrhea,and dehydration.The infections commonly involved in viral gastroenteritis are rotavirus,norovirus,and adenovirus,which spread through the fecal-oral and contact routes and cause non-bloody diarrhea.These infections can affect both immunocompetent and immunocompromised individuals.Since the pandemic in 2019,coronavirus gastroenteritis has increased in incidence and prevalence.Morbidity and mortality rates from viral gastroenteritis have declined significantly over the years due to early recognition,treatment with oral rehydration salts,and prompt vaccination.Improved sanitation measures have also played a key role in reducing the transmission of infection.In addition to viral hepatitis causing liver disease,herpes virus,and cytomegalovirus are responsible for ulcerative GI disease.They are associated with bloody diarrhea and commonly occur in im-munocompromised individuals.Hepatitis viruses,Epstein-Barr virus,herpesvirus 8,and human papillomavirus have been involved in benign and malignant diseases.This mini review aims to list different viruses affecting the GI tract.It will cover common symptoms aiding in diagnosis and various important aspects of each viral infection that can aid diagnosis and management.This will help primary care physicians and hospitalists diagnose and treat patients more easily.

Adenovirus induced acute hepatitis in non-human primates after liver-directed gene therapy

OBJECTIVE: To define the mechanism of acute hepatitis in non-human primates after liver directed gene therapy. METHODS: Differences in immune response exhibited by 8 rhesus monkeys receiving adenovirus (Ad) or lipofectamine-mediated gene transfer by various routes, the time course, and the nature of the specific immune responses to both adenoviral vectors and transgene products were studied using HE staining (H&E) and immunohistochemical staining. RESULTS: The monkeys developed mild to moderate acute hepatitis 1 to 3 weeks after intravenous or intrabiliary injection of first generation replication-defective adenoviruses carrying the Escherichia coli lacZ gene. This was accompanied by adenovirus-mediated T-cell proliferation and neutralizing antibodies to the adenovirus. Increased numbers of CD3(+), CD4(+) and CD8(+) T-lymphocytes were detected in the diseased livers, while B-lymphocytes were absent. Hepatocytes demonstrated increased expression of beta 2-microglobulins (beta 2-MG) and HLA-DR antigens in the plasma membranes. The development of acute hepatitis and the accompanying immune abnormalities were delayed in immunosuppressed monkeys until after the discontinuation of immunosuppressive therapy. The monkeys infused with Ad. CMVluc showed more significant and longer durations of hepatitis than the monkeys infused with adenoviruses carrying the lacZ gene. Lipofectamine-mediated gene transfer was inefficient. There was neither lacZ expression nor significant immune response in the liver of monkeys infused with lipofectamine via the portal vein or the common bile duct. CONCLUSION: Immune response to the hepatocytes in liver directed gene therapy is MHC class I restricted and T-cell mediated. Both adenoviral vectors and foreign genes are related to the liver damage. Mild to moderate hepatic inflammation seen with the E-1 deleted vector is reversible. Immunosuppression regimens may prolong transgene expression and delay the development of acute adenoviral hepatitis.