Receptor activator of nuclear factor-B (RANKL)-
Although hemihepatic portal vein embolization (PVE) has been used preoperatively to extend indications for hepatectomy in patients with colorectal metastases, the effects of this procedure on tumor growth and outcome remain controversial. To address this issue, we assessed the proliferative activity of intrahepatic metastases after PVE and the long-term outcome of this procedure. Eighteen patients with colorectal metastases underwent preoperative PVE between 1996 and 2000 (PVE group). Twenty-nine patients who underwent major hepatic resection without PVE served as control (non-PVE group). The hepatic parenchymal fraction of the left lobe had significantly increased from 38.1 ؎ 3.2% to 45.9 ؎ 2.9% 3 weeks after PVE (؉20.5%, P < .0001). Tumor volume and percent tumor volume had also significantly increased from 223 ؎ 89 mL to 270 ؎ 97 mL (؉20.8%, P ؍ .016) and from 13.7 ؎ 4.3% to 16.2 ؎ 4.9% (؉18.5%, P ؍ .014), respectively. There was no apparent correlation between the increase in parenchymal volume and that in tumor volume. The Ki-67 labeling index of metastatic lesions was 46.6 ؎ 7.2% in the PVE group and 35.4 ؎ 12.6% in the non-PVE group (P ؍ .013). Long-term survival was similar in the PVE and non-PVE groups, however, disease-free survival was significantly poorer in the PVE group than in the non-PVE group (P ؍ .004). We conclude that PVE increases tumor growth and probably is associated with enhanced recurrence of disease. Although PVE is effective in extending indications for surgery, patient selection for PVE should be cautious. (HEPATOLOGY 2001;34:267-272.)Hepatic resection provides the only chance for cure in patients with colorectal metastases. To extend indications for hepatectomy, hemihepatic portal vein embolization (PVE) has been performed in selected patients. 1-3 PVE induces homolateral atrophy of the portion of the liver scheduled for resection and contralateral compensatory hypertrophy of the remnant liver, thus decreasing the risk of postoperative liver failure. PVE is indicated when the remnant liver is expected to be very small, i.e., about 40% smaller than preoperative liver volume, or when tumor spread requires a right hemihepatectomy with partial resection of the left side of the liver. 4,5 The positive effects of PVE on hepatic function must be weighed against recent evidence suggesting that this procedure may promote oncogenesis. Elias et al., have reported that after PVE liver metastases may grow more rapidly than liver parenchyma. 6 This assumption was based on a study of only 5 patients who had tumors in the nonembolized lobe of the liver, rather than the embolized lobe. In addition, they focused on tumor growth in the nonembolized lobe. Consequently, their findings were considered too premature to warrant contraindication of PVE in patients with colorectal metastases. 7,8 When used in combination with arterial chemoembolization, PVE suppresses growth of hepatocellular carcinoma (HCC). 9 Long-term results of HCC resection after PVE have recently been shown to be better than or...
The CD28 costimulation at TCR signaling plays a pivotal role in the regulation of the T cell response. To elucidate the role of T cells in periodontal disease, a system of cell transfer with TCR/CD28-dependent Th1 or Th2 clones was developed in rats. Gingival injection of specific Ag, Actinobacillus actinomycetemcomitans 29-kDa outer membrane protein, and LPS could induce local bone resorption 10 days after the transfer of Ag-specific Th1 clone cells, but not after transfer of Th2 clone cells. Interestingly, the presence of LPS was required not only for the induction of bone resorption but also for Ag-specific IgG2a production. LPS injection elicited the induction of expression of both B7-1 and B7-2 expression on gingival macrophages, which otherwise expressed only MHC class II when animals were injected with Ag alone. The expression of B7 molecules was observed for up to 3 days, which corresponded to the duration of retention of T clone cells in gingival tissues. Either local or systemic administration of CTLA4Ig, a functional antagonist of CD28 binding to B7, could abrogate the bone resorption induced by Th1 clone cells combined with gingival challenge with both Ag and LPS. These results suggest that local Ag-specific activation of Th1-type T cells by B7 costimulation appeared to trigger inflammatory bone resorption, whereas inhibition of B7 expression by CTLA4Ig might be a therapeutic approach for intervention with inflammatory bone resorption.
In March 2013, the world's first field trial of gas production from marine methane hydrate deposits was conducted in the Daini Atsumi Knoll area of the Eastern Nankai Trough off the Pacific coast of Japan as a process to bring gas hydrates under seafloor to valuable energy resource. The technique used to dissociate the ice-like material was "depressurization method" that had been applied in the previous production test in Mallik site, the Northwest Territories, Canada in 2007-2008. Japan Oil, Gas and Metals National Corporation (JOGMEC) as a part of MH21, the Research Consortium for Methane Hydrate Resources in Japan planed and supervised the project with the funding of the Ministry of Economy, Trade and Industry (METI), and scientific supports from the National Institute of Advance Industrial Science and Technology (AIST). One production well with two monitoring boreholes were drilled in the test site for the test. Along with the flow test operation, intensive data acquisition program was planned and implemented to understand behavior of methane hydrate dissociation- bearing sediments against depressurization. To realize high degree of drawdown in relatively shallow formation below deepwater, several downhole devices were designed and installed. The flow test started in the morning of March 12 and lasted until severe sand production forced to terminate the operation six days later. During the stable production term, gas flow rate was approximately 20,000m3 under atmospheric condition, and gas liquid ratio was larger than 100. A lot of data including formation temperatures, fluid pressure and temperature, and physical property changes in the formation were obtained. The data taken are under studies to verify applicability of the depressurization technique as a methane hydrate production technologies.
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