Dynamic zonation of liver polyploidy

The liver is a polyploid organ, consisting of hepatocytes with one or two nuclei each containing 2, 4, 8 or more haploid chromosome sets. The dynamic changes in the spatial distributions of polyploid classes across the liver lobule, its repeating anatomical unit, have not been characterized. Identifying these spatial patterns is important for understanding liver homeostatic and regenerative turnover, as well as potential division of labor among ploidy classes. Here, we use single molecule-based tissue imaging to reconstruct the spatial zonation profiles of liver polyploid classes in mice of different ages. We find that liver polyploidy proceeds in spatial waves, advancing more rapidly in the mid-lobule zone compared to the periportal and perivenous zones. We also measure the spatial zonation profiles of S-phase entry at different ages and identify more rapid S-phase entry in the mid-lobule zone at older ages. Our findings reveal fundamental features of liver spatial heterogeneity and highlight their dynamic changes during development and aging.

Anthocyanin synthesis in native and wound periderms of potato

Skin color of red potatoes is due to accumulation of anthocyanins in the tuber periderm, a protective tissue that replaces the epidermis at an early stage of tuber development. The periderm consists of external layers of suberized phellem cells making up the skin, and internal layers of parenchyma-like phelloderm cells. Red pigmentation is an important marketing factor for red-skinned potatoes. However, injuries to the tuber surface, which are common in the potato industry, result in the development of a wound periderm that is devoid of the characteristic red coloration. To study the reason for these differences in anthocyanin accumulation, the expression level of anthocyanin biosynthesis genes and regulators was monitored in native and wound periderm using microarray analysis and quantitative polymerase chain reaction. We found significantly higher expression of the anthocyanin pathway in the phelloderm cells compared with the skin and tuber-flesh samples. However, in wound periderm, the anthocyanin pathway was strongly downregulated relative to the native periderm. This was true for two developmental stages of the native periderm--'immature', when the skin is prone to skinning injuries, and 'mature', following skin set--suggesting that anthocyanin synthesis continues postharvest. Wound-induced expression of steroidal glycoalkaloid glycosyltransferases, suberin-related 3-ketoacyl-CoA synthase and actin indicated that downregulation of the anthocyanin-specific pathway does not reflect global repression of the wound-periderm transcriptome. Loss of pigmentation may result from reduced expression of the Myb-bHLH-WD40 anthocyanin regulatory complex--a possible candidate might be the bHLH transcription factor JAF13.

Bursty gene expression in the intact mammalian liver

Bursts of nascent mRNA have been shown to lead to substantial cell-cell variation in unicellular organisms, facilitating diverse responses to environmental challenges. It is unknown whether similar bursts and gene-expression noise occur in mammalian tissues. To address this, we combine single molecule transcript counting with dual-color labeling and quantification of nascent mRNA to characterize promoter states, transcription rates, and transcript lifetimes in the intact mouse liver. We find that liver gene expression is highly bursty, with promoters stochastically switching between transcriptionally active and inactive states. Promoters of genes with short mRNA lifetimes are active longer, facilitating rapid response while reducing burst-associated noise. Moreover, polyploid hepatocytes exhibit less noise than diploid hepatocytes, suggesting a possible benefit to liver polyploidy. Thus, temporal averaging and liver polyploidy dampen the intrinsic variability associated with transcriptional bursts. Our approach can be used to study transcriptional bursting in diverse mammalian tissues.

Clinicopathological study of mucous pooling referred to as mucinous component (MUC) in colorectal submucosal invasive carcinomas

We investigated the significance of a pool of mucin, individually termed mucinous component (MUC), at the leading invasion edge of colorectal submucosal invasive carcinoma (SIC). In particular, we studied the correlation between pathological adverse prognostic factors and stainability of the mucosubstances and tumor-associated glycoconjugates in MUC. We demonstrated that MUCs were present in 21% of SICs, and 20% of SICs with MUC were involved in metastasis or recurrence, while only 6% of SICs without MUC were positive for it (p=0.005). SICs with MUC showed strong staining of carcinoembryonic antigen and Ulex europaeus I in the MUCs as well as in the cancer cells with high-grade atypia. Moreover, the mucins in MUCs predominantly stained for sialomucin. This study was the first to investigate the importance of mucous nodules in colorectal SIC. We concluded that MUC in SIC would be an important adverse prognostic factor, and that we should at least consider employing a similar treatment strategy for it to advanced colorectal carcinoma.

Abdominosacral repair for a rectovaginal fistula with anastomotic stenosis after low anterior resection report of a case

The management of a postoperative rectovaginal fistula after low anterior resection for rectal cancer is difficult and requires reconstruction of the anastomotic site and fistula. The results of reconstructive operation are often unsatisfactory. Herein, we describe our reconstruction technique using the posterior approach through the vaginal lumen for a high rectovaginal fistula repair. This reconstructive operation is useful for postoperative rectovaginal fistulas accompanied by severe stenosis of the anastomotic site following low anterior resection for rectal cancer.

Ileosigmoid anastomosis with exclusion of transected ileal loop for intestinal fistula following total cystectomy of bladder cancer. Report of a case

We report in this article a new technique of surgical treatment of enterocutaneous or enterovaginal fistula after total cystectomy for three cases of bladder cancer. The surgical outcome was successful in these patients, showing good performance status after this operation. It would seem that this technique is a good indication for enteric fistulas in the bottom of the pelvic cavity, which were difficult to be managed even under the control of total parenteral nutrition.