Liver is one of the few organs that have the capacity to regenerate in response to injury. We carried out genome-wide miRNA microarray studies during liver regeneration in rats after 70% PH at early and mid-time points to more thoroughly understand their role. At 3, 12 and 18 hrs post-PH ~ 40% of the miRNAs tested were up-regulated. Conversely, at 24 hrs post-PH, ~ 70% of miRNAs were down-regulated. Further, we established that the genome-wide down-regulation of miRNA expression at 24 hrs was also correlated with decreased expression of genes such as Rnasen, Dgcr8, Dicer, Tarbp2 and Prkra that are associated with miRNA biogenesis. To determine if a potential negative feedback loop between miRNAs and their regulatory genes existed, 11 candidate miRNAs which were predicted to target the above genes were examined and found to be up-regulated at 3 hrs post-PH. Using reporter and functional assays, we determined that expression of these miRNA-processing genes could be regulated by a subset of miRNAs and some miRNAs could target multiple miRNA biogenesis genes simultaneously. We also demonstrated that over-expression of these miRNAs inhibited cell proliferation and modulated the cell cycle in both Huh-7 human hepatoma cells and primary rat hepatocytes. From these observations, we postulated that selective up-regulation of miRNAs in the early-phase after PH was involved in the priming and commitment to liver regeneration, while the subsequent genome-wide down-regulation of miRNAs was required for efficient recovery of liver cell mass.
Conclusion
Our data suggest that miRNA changes are regulated by negative feedback loops between miRNAs and their regulatory genes that may play an important role in the steady-state regulation of liver regeneration.
We present a 31-year-old woman who developed ascending colon intussusception several hours after a routine colonoscopy where random mucosal biopsies were obtained. She underwent an ileocolic resection, and pathology did not show an etiology for the intussusception. Colonic intussusception occuring without pathology and after minimal intervention is rare.
SUMMARYWhat is known and objective: The thiopurine medications are standard inflammatory bowel disease treatments. Therapeutic failure is observed, however, often because of variable drug metabolism. Allopurinol can enhance the potency of thiopurine treatment. Our objective is to review the relevant literature, and our own experience, to determine if allopurinol enhancement of thiopurine treatment is a reasonable therapeutic strategy. Comment: Published reports of, and our own experience using, allopurinol-thiopurine combination therapy indicate that the addition of allopurinol will enhance thiopurine treatment in up to 60% of patients. There are risks to this approach, but with appropriate monitoring, these risks should approximate those observed with thiopurine therapy alone.
Gastroesophageal reflux disease (GERD) is a common and progressive condition manifested by heartburn or regurgitation. Though Nissen fundoplication has been and remains the gold standard for procedural therapy for GERD, two newer interventions have gained popularity: magnetic sphincter augmentation (MSA), which entails the placement of a self expanding magnetic ring around the gastroesophageal (GE) junction, and transoral incisionless fundoplication (TIF), an endoscopic approach that creates a neogastroesophageal valve near the fundus. Collective data gathered from four studies published within the past year suggest that the three modalities share comparable effectiveness in pH monitoring and patient satisfaction, TIF may have a lower proton pump inhibitor cessation rate, and Nissen fundoplication required longer recovery time and had a more serious adverse effects profile. Large, prospective, randomized controlled studies are needed to reliably compare the three procedures.
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