Effect of endotoxin on portal hemodynamic in rats

Noncirrhotic portal hypertension: current trends and future directions

PURPOSE OF REVIEW

Noncirrhotic portal hypertension (NCPH) comprises a diverse group of vascular liver disorders characterized by elevated portal pressure without cirrhosis. Due to overlapping clinical features, distinguishing NCPH from cirrhosis and porto-sinusoidal vascular disorder (PSVD) remains challenging. This review explores recent advancements in diagnosis, differentiation, and evolving treatment strategies.

RECENT FINDINGS

NCPH is characterized by preserved liver function and near-normal hepatic venous pressure gradients (HVPG). It shares risk factors with PSVD, including infections, drugs, toxins, and prothrombotic conditions. Diagnostic advancements, such as liver stiffness measurement (LSM) and splenic stiffness measurement (SSM), offer noninvasive differentiation from cirrhosis, while liver biopsy remains crucial for confirming PSVD and noncirrhotic portal fibrosis (NCPF). Imaging is reliable for diagnosing extrahepatic portal vein obstruction (EHPVO). Transjugular intrahepatic portosystemic shunts (TIPS) for refractory variceal bleeding or ascites, achieving rebleeding control in 72-80% of cases. Surgical shunts and splenectomy remain essential for uncontrolled bleeding and portal biliopathy, demonstrating excellent variceal control (93-95%).

SUMMARY

NCPH requires a high index of suspicion for diagnosis. Differentiation from cirrhosis and PSVD relies on clinical, histological, and hemodynamic assessments. Management focuses on endoscopic, interventional, and surgical strategies tailored to disease severity. Future research should standardize diagnostic criteria, explore targeted therapies, and refine prognostic tools to improve outcomes.

Cloning of human ABCB11 gene in E. coli required the removal of an intragenic Pribnow-Schaller Box before it's Insertion into genomic safe harbor AAVS1 site using CRISPR-Cas9

Background: Genomic safe harbors are sites in the genome which are safe for gene insertion such that the inserted gene will function properly, and the disruption of the genomic location doesn't cause any foreseeable risk to the host. The AAVS1 site is the genetic location which is disrupted upon integration of adeno associated virus (AAV) and is considered a 'safe-harbor' in human genome because about one-third of humans are infected with AAV and so far there is no apodictic evidence that AAV is pathogenic or disruption of AAVS1 causes any disease in man.  Therefore, we chose to target the AAVS1 site for the insertion of ABCB11, a bile acid transporter which is defective in progressive familial intra hepatic cholestasis type-2 (PFIC-2), a lethal disease of children where cytotoxic bile salts accumulate inside hepatocytes killing them and eventually the patient. Methods: We used the CRISPR Cas9 a genome editing system to insert the ABCB11 gene at AAVS1 site in human cell-lines. Results: We found that human ABCB11 sequence has a "Pribnow- Schaller Box" which allows its expression in bacteria and expression of ABCB11 protein which is toxic to E. coli; the removal of this was required for successful cloning. We inserted ABCB11 at AAVS1 site in HEK 293T using CRISPR-Cas9 tool.  We also found that the ABCB11 protein has similarity with E. coli endotoxin (lipid A) transporter MsbA. Conclusions: We inserted ABCB11 at AAVS1 site using CRISPR-Cas9; however, the frequency of homologous recombination was very low for this approach to be successful in vivo.