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In various eukaryotic kingdoms, long terminal repeat (LTR) retrotransposons repress transcription by infiltrating heterochromatin generated within their elements. In contrast, the budding yeast LTR retrotransposon Ty1 does not itself undergo transcriptional repression, although it is capable of repressing the transcription of the inserted genes within it. In this study, we identified a DNA region within Ty1 that exerts its silencing effect via sequence orientation. We identified a DNA region within the Ty1 group-specific antigen (GAG) gene that causes gene silencing, termed GAG silencing (GAGsi), in which the silent chromatin in the GAGsi region is created by euchromatin-specific histone modifications. A characteristic inverted repeat (IR) sequence is present at the 5' end of this region, forming a chromatin boundary between promoter-specific chromatin upstream of the IR sequence and silent chromatin downstream of the IR sequence. In addition, Esc2 and Rad57, which are involved in DNA repair, were required for GAGsi silencing. Finally, the chromatin boundary was required for the transcription of Ty1 itself. Thus, the GAGsi sequence contributes to the creation of a chromatin environment that promotes Ty1 transcription. [ABSTRACT FROM AUTHOR]

Juxta-articular myxoma (JAM) is a rare soft tissue tumour predominantly composed of mucinous tissue and usually found around large joints. We report a 73-year-old woman with a 5-year history of a soft tissue mass in the thenar eminence of the right wrist who presented to our department. An initial diagnosis of a ganglion cyst was made using magnetic resonance imaging (MRI) and the jellied content of the mass by aspiration. Two years after presentation, surgical treatment with tumour resection and carpal tunnel release via the radial approach was performed because the symptoms of carpal tunnel syndrome worsened, and the tumour invaded the carpal tunnel. Histopathological examination revealed a JAM. At the 1-year follow-up, the symptoms of carpal tunnel syndrome had resolved, and no recurrence was confirmed by MRI. Level of Evidence: Level V (Therapeutic) [ABSTRACT FROM AUTHOR]

Liver regeneration is a well-orchestrated compensatory process that is regulated by multiple factors. We recently reported the importance of the chromatin protein, a high-mobility group box 2 (HMGB2) in mouse liver regeneration. However, the molecular mechanism remains unclear. In this study, we aimed to study how HMGB2 regulates hepatocyte proliferation during liver regeneration. Seventy-percent partial hepatectomy (PHx) was performed in wild-type (WT) and HMGB2-knockout (KO) mice, and the liver tissues were used for microarray, immunohistochemistry, quantitative polymerase chain reaction (qPCR), and Western blotting analyses. In the WT mice, HMGB2-positive hepatocytes colocalized with cell proliferation markers. In the HMGB2-KO mice, hepatocyte proliferation was significantly decreased. Oil Red O staining revealed the transient accumulation of lipid droplets at 12–24 hr after PHx in the WT mouse livers. In contrast, decreased amount of lipid droplets were found in HMGB2-KO mouse livers, and it was preserved until 36 hr. The microarray, immunohistochemistry, and qPCR results demonstrated that the expression of lipid metabolism–related genes was significantly decreased in the HMGB2-KO mouse livers. The in vitro experiments demonstrated that a decrease in the amount of lipid droplets correlated with decreased cell proliferation activity in HMGB2-knockdown cells. HMGB2 promotes de novo lipogenesis to accelerate hepatocyte proliferation during liver regeneration: [ABSTRACT FROM AUTHOR]

Laparoscopic hepatectomy is safely performed with minimal invasiveness on patients with recurrent liver tumors after previous hepatectomy. However, it is still difficult to dissect and expose the operative field at the transected edge or plane after open right hepatectomy, even for limited resection by a laparoscopic approach, due to severe adhesion to the surrounding peritoneum or organs. We herein applied the retroperitoneal laparoscopic approach to limited resection of the dorsal surface at the transected edge of Couinaud's segment 6 after previous repeated hepatectomies in a patient with recurrent hepatocellular carcinoma (HCC) by avoiding severe intra‐abdominal adhesion. We safely resected recurrent HCC via the retroperitoneal space. This approach is a useful and alternative option for laparoscopy which minimizes the dissecting time and avoids organ injury on the right side of the transected area of the liver after hepatectomy in patients with liver malignancies. [ABSTRACT FROM AUTHOR]

Background. Oxaliplatin (OX)-based chemotherapy induces sinusoidal obstruction syndrome (SOS) in the nontumorous liver parenchyma, which can increase the risk of liver resection due to colorectal liver metastasis (CRLM). The extracellular volume (ECV) calculated from contrast-enhanced computed tomography (CT) has been reported to reflect the morphological change of hepatic fibrosis. The present retrospective study aimed to evaluate the ECV fraction as a predictive factor for OX-induced SOS. Methods. Our study included 26 patients who underwent liver resection for CRLM after OX-based chemotherapy with a preoperative dynamic CT of appropriate quality. We investigated the relationship between the pathological SOS grade and the ECV fraction. Results. Overall, 26 specimens from the patients were graded with the SOS classification of Rubbia-Brandt et al. as follows: grade 0, n = 17 (65.4%); grade 1, n = 4 (15.4%); and grade 2, n = 5 (19.2%). No specimens showed grade 3 SOS. In a univariate analysis, the ECV fraction in grade 0 SOS was significantly lower than that in grade 1 + 2 SOS (26.3 ± 3.4% vs. 30.6 ± 7.0%; P = 0.025). The cutoff value and AUC value of the ECV fraction to distinguish between grades 0 and 1 + 2 were 27.5% and 0.771, respectively. Conclusions. Measurement of the ECV fraction was found to be a potential noninvasive diagnostic method for determining early-stage histopathological sinusoidal injury induced by OX-based chemotherapy. [ABSTRACT FROM AUTHOR]

Background: Intra-articular fibromembranous septum in the radiocarpal joint can cause wrist contracture after distal radial fracture, but the mechanism underlying the formation of the septum is unknown. This study examined the clinical outcomes in patients treated with arthroscopic excision of the septum and the factors associated with formation of the septum in patients with and without a septum.Methods: Fifty-three patients (22 with septum and 31 without septum) treated for intra-articular distal radial fracture with arthroscopy using a volar locking plate and secondary removal of the plate were included. Clinical outcomes and radiological assessments were analyzed.Results: In patients with a septum, the range of wrist flexion and total wrist arc before the second operation were significantly more limited than in those without a septum (p < 0.01 and p = 0.03, respectively). The improvement rate (improvement in wrist arc divided by the wrist arc of the healthy side) after arthroscopic excision of the septum and plate removal was greater in patients with a septum than in those without a septum (6.1% vs. 2.0%, p = 0.08). The significant factors affecting formation of the septum were the residual articular gap and the height of the midradial ridge on computed tomography images.Conclusions: Intra-articular fibromembranous septum after surgically treated intra-articular distal radial fracture affects limited range of motion and secondary arthroscopic excision of the septum improves the wrist range of motion. Anatomical reduction and maintenance of the articular fragment, as well as anatomical characteristics might be causes of septum formation. [ABSTRACT FROM AUTHOR]