Efficacy of a half-grip technique using a fine tip LigaSure™, Dolphin Tip Sealer/Divider, on liver dissection in swine model.

BACKGROUND: Recently, a lot of energy devices in the surgical field, especially in the liver surgery, have been developed, and a fine tip LigaSure™, Dolphin Tip Sealer/Divider (DT-SD) also has been used frequently to dissect liver parenchyma as well as ultrasonically activated device (USAD). However, the utility of this instrument for liver dissection (LD) is still unknown. Moreover, to reduce bleeding during LD, a half-grip technique (HGT) was contrived. We herein report an experimental study in swine model to evaluate the feasibility and effectiveness of HGT using DT-SD for LD. METHODS: The swine model experiment was carried out under general anesthesia by veterinarians. LD was performed repeatedly by DT-SD with the HGT (Group A, n = 6), or the conventional clamp-crush technique (CCT) (Group B, n = 6), and by variable mode USAD (Group C, n = 6). The dissection length and depth (cm) as well as bleeding volume (g) were measured carefully, and the dissection area (cm(2)) and speed (cm(2)/min) were calculated precisely. Histological examinations of the dissection surfaces were also executed. Mann-Whitney's U test was used for Statistical analyses with variance at a significance level of 0.05. RESULTS: Among the three groups, the three averages of dissection lengths were unexpectedly equalized to 8.3 cm. The dissection area (cm(2)) was 9.9 ± 5.1 in Group A, 9.8 ± 4.7 in Group B, and 9.9 ± 4.5 in Group C. The mean blood loss during LD was 10.6 ± 14.8 g in Group A, 41.4 ± 39.2 g in Group B, and 34.3 ± 39.2 g in Group C. For Group A, the bleeding rate was the least, 0.9 ± 1.0 g/cm(2), and the average depth of coagulation was the thickest, 1.47 ± 0.29 mm, among the three groups (p < 0.05). The dissection speed in Group A (1.3 ± 0.3 cm(2)/min) was slower, than that in Group C (p < 0.05). CONCLUSIONS: This report indicates firstly that the HGT using DT-SD bring the least blood loss when compared with CCT or USAD. Although the HGT is feasible and useful for LD, to popularize the HGT, further clinical studies will be needed.

A novel p53-dependent apoptosis function of TARSH in tumor development.

A target of NESH-SH3/Abi3bp (TARSH) was originally identified as an SH3 domain-binding molecule of the NESH-SH3/Abi3 protein that is involved in Rac-dependent actin polymerization. In recent studies, TARSH gene expression was dramatically induced in mouse embryonic fibroblasts (MEFs) replicative senescence and suppressed in human lung carcinoma specimens and thyroid carcinomas. However, the molecular mechanism underlying the regulation of TARSH in tumorigenesis remains unclear. Here, we address a p53-dependent apoptosis function of the mouse TARSH gene using RNAi-mediated suppression of endogenous TARSH expression. Our results will be useful in the discovery of a novel therapeutic target in lung carcinoma.

Implication of p53-dependent cellular senescence related gene, TARSH in tumor suppression.

A novel target of NESH-SH3 (TARSH) was identified as a cellular senescence related gene in mouse embryonic fibroblasts (MEFs) replicative senescence, the expression of which has been suppressed in primary clinical lung cancer specimens. However, the molecular mechanism underlying the regulation of TARSH involved in pulmonary tumorigenesis remains unclear. Here we demonstrate that the reduction of TARSH gene expression by short hairpin RNA (shRNA) system robustly inhibited the MEFs proliferation with increase in senescence-associated beta-galactosidase (SA-beta-gal) activity. Using p53-/- MEFs, we further suggest that this growth arrest by loss of TARSH is evoked by p53-dependent p21(Cip1) accumulation. Moreover, we also reveal that TARSH reduction induces multicentrosome in MEFs, which is linked in chromosome instability and tumor development. These results suggest that TARSH plays an important role in proliferation of replicative senescence and may serve as a trigger of tumor development.

Generation and characterization of novel monoclonal antibodies against murine and human TARSH proteins.

TARSH/Abi3bp was originally isolated as a novel target of NESH-SH3 by a two-hybrid yeast system. We have already identified murine TARSH (mTARSH) as a cellular senescence-related gene because of its robust induction in the early phase of mouse embryonic fibroblast cellular senescence. We have also revealed that the expression of this gene was dramatically reduced in human lung cancer cell lines and primary lung tumor, while it was predominantly expressed in normal conditions. This evidence suggests that TARSH is involved in both stress-induced senescence and prevention of cancer development; however, little is known about its molecular mechanisms. To reveal the further physiological function of this molecule, we established rat anti-TARSH monoclonal antibodies (MAb). Recombinant His-tagged partial mouse TARSH protein was expressed in Escherichia coli, affinity purified and used as an antigen to immunize rats. Hybridomas were screened by enzyme-linked immunosorbent assay, and we generated six stable hybridoma cell lines that produced antibody against murine TARSH protein, including three clones that represented cross-reactivity with human TARSH. We determined their isotypes and further examined capabilities or limitations in immunoblotting, immunoprecipitation, and immunofluorescence microscopy, realizing the most suitable antibody for each application. These MAbs should therefore be very useful tools for the study of TARSH expression and for following biological function in cellular senescence and tumor suppression.

Expression of TARSH gene in MEFs senescence and its potential implication in human lung cancer.

To reveal the molecular mechanism of cellular senescence, we have surveyed the genes that are specifically upregulated via MEFs senescence by suppression subtractive hybridization method. We show here that mTARSH was induced particularly in the relative early phase of MEFs cellular senescence. Further structural analysis of mTARSH disclosed five splicing variants shared a common reading frame whose diversity was derived from the SH3-binding motif cluster in the middle of the gene. We also show that mTARSH mRNA predominantly expressed in lung and that conspicuous expression of TARSH was drastically declined in all several lung cancer cell lines we tested. Thus, TARSH presumably represents a trigger gene for evoking cellular senescence, which has also been suggested to be involved in the prevention of tumorigenesis.