A simple noninvasive model to predict significant fibrosis in children with chronic hepatitis B.

ABSTRACT: To develop a noninvasive model to predict significant fibrosis in children with chronic hepatitis B (CHB).A total of 116 CHB pediatric patients who underwent liver biopsy were included in the study. Liver histology, which is the gold standard for assessing fibrosis, was performed. Blood routine examination, coagulation function, liver biochemistry, viral serology, and viral load were analyzed. Receiver operating characteristic curve analysis was used to analyze the sensitivity and specificity of all possible cut-off values.Based on the correlation and difference analyses, 7 available clinical parameters (total bile acid, gamma-glutamyl transpeptidase [GGT], aspartate transaminase, direct bilirubin to total bilirubin ratio, alanine aminotransferase, prealbumin [PA], and cholinesterase) were included in the modeling analysis. A model to predict significant liver fibrosis was derived using the 2 best parameters (PA and GGT). The original model was . After the mathematical calculation, the G index=600 × GGT/PA2 predicted significant fibrosis, with an area under the receiving operating characteristics (AUROC) curve of 0.733, 95% confidence interval (0.643-0.811). The AUROC of the G index (0.733) was higher than that of aminotransferase to platelet ratio index (APRI) (0.680) and Fibrosis index based on 4 factors (FIB-4) (0.601) in predicting significant fibrosis in children with CHB. If the values of the G index were outside the range of 0.28 to 1.16, 52% of children with CHB could avoid liver biopsy, with an overall accuracy of 75%.The G index can predict and exclude significant fibrosis in children with CHB, and it may reduce the need for liver biopsy in children with CHB.

Bloody Diarrhea Caused by Intestinal Myiasis in an Infant: A Case Report and Review of Pediatric Literature.

Intestinal myiasis caused by fly larvae parasitic in gastrointestinal tract was rare reported in children. We reported an infant with bloody diarrhea caused by intestinal myiasis. A 1 year and 7 months old boy presented with the only symptom of bloody diarrhea of unknown origin. In the second week of onset, numerous moving worms were observed in the bloody stool after bowel preparation with polyethylene glycol for colonoscopy. The bloody diarrhea disappeared after 1 week of combined therapy with albendazole and metronidazole. On follow-up after 6 months, the patient remained well without bloody diarrhea. In conclusion, intestinal myiasis being a rare disease that is very challenging to diagnose, physicians should remember it when they receive cases of bloody diarrhea with non-specific symptoms without any apparent cause.

The N-terminus of histone H3 is required for de novo DNA methylation in chromatin.

DNA methylation and histone modification are two major epigenetic pathways that interplay to regulate transcriptional activity and other genome functions. Dnmt3L is a regulatory factor for the de novo DNA methyltransferases Dnmt3a and Dnmt3b. Although recent biochemical studies have revealed that Dnmt3L binds to the tail of histone H3 with unmethylated lysine 4 in vitro, the requirement of chromatin components for DNA methylation has not been examined, and functional evidence for the connection of histone tails to DNA methylation is still lacking. Here, we used the budding yeast Saccharomyces cerevisiae as a model system to investigate the chromatin determinants of DNA methylation through ectopic expression of murine Dnmt3a and Dnmt3L. We found that the N terminus of histone H3 tail is required for de novo methylation, while the central part encompassing lysines 9 and 27, as well as the H4 tail are dispensable. DNA methylation occurs predominantly in heterochromatin regions lacking H3K4 methylation. In mutant strains depleted of H3K4 methylation, the DNA methylation level increased 5-fold. The methylation activity of Dnmt3a largely depends on the Dnmt3L's PHD domain recognizing the histone H3 tail with unmethylated lysine 4. Functional analysis of Dnmt3L in mouse ES cells confirmed that the chromatin-recognition ability of Dnmt3L's PHD domain is indeed required for efficient methylation at the promoter of the endogenous Dnmt3L gene. These findings establish the N terminus of histone H3 tail with an unmethylated lysine 4 as a chromatin determinant for DNA methylation.

Global reduction of the epigenetic H3K79 methylation mark and increased chromosomal instability in CALM-AF10-positive leukemias.

Chromosomal translocations generating fusion proteins are frequently found in human leukemias. The fusion proteins play an important role in leukemogenesis by subverting the function of one or both partner proteins. The leukemogenic CALM-AF10 fusion protein is capable of interacting with the histone H3 lysine 79 (H3K79)-specific methyltransferase hDOT1L through the fused AF10 moiety. This interaction leads to local H3K79 hypermethylation on Hoxa5 loci, which up-regulates the expression of Hoxa5 and contributes to leukemogenesis. However, the long latency of leukemogenesis of CALM-AF10 transgenic mice suggests that the direct effects of fusion oncogene are not sufficient for the induction of leukemia. In this study, we show that the CALM-AF10 fusion protein can also greatly reduce global H3K79 methylation in both human and murine leukemic cells by disrupting the AF10-mediated association of hDOT1L with chromatin. Cells with reduced H3K79 methylation are more sensitive to gamma-irradiation and display increased chromosomal instability. Consistently, leukemia patients harboring CALM-AF10 fusion have more secondary chromosomal aberrations. These findings suggest that chromosomal instability associated with global epigenetic alteration contributes to malignant transformation in certain leukemias, and that leukemias with this type of epigenetic alteration might benefit from treatment regimens containing DNA-damaging agents. This study is registered with www.clinicaltrials.gov as NCT00266136.