Laparoscopic treatment of a vesicointestinal fistula due to a Meckel's diverticulum: a case report and review of the literature.

While there have been numerous reports about colovesical fistulas and ruptured intestinal diverticula, there have been far fewer reports about vesicointestinal fistulas caused by Meckel's diverticula. Most Meckel's diverticula are asymptomatic. Furthermore, they seldom cause vesicointestinal fistulas, and the associated complications are non-specific. Thus, their preoperative diagnosis is difficult. We experienced a case in which a vesicointestinal fistula was caused by a Meckel's diverticulum and was treated with laparoscopic surgery. A 46-year-old male was referred to our hospital after exhibiting hematuria. Cystoscopy revealed a fistula between the small intestine and bladder. Contrast-enhanced computed tomography and magnetic resonance imaging showed a diverticulum in the ileum and a fistula between the ileum and bladder, which passed through the diverticulum. A Meckel's diverticulum was suspected. We conducted a laparoscopic operation. We dissected the Meckel's diverticulum with an automatic suturing device and removed it together with part of the ileum. The patient's postoperative course was good. We experienced a case in which a vesicointestinal fistula was caused by a Meckel's diverticulum and was successfully treated with laparoscopic surgery. In selected cases of Meckel's diverticulum, the dissection of the diverticulum with an automatic suturing device is appropriate.

Sphingosine 1-phosphate has anti-apoptotic effect on liver sinusoidal endothelial cells and proliferative effect on hepatocytes in a paracrine manner in human.

AIM: Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid metabolite released from erythrocytes and platelets, and is a potent stimulus for endothelial cell proliferation. However, the role of S1P on human liver sinusoidal endothelial cells (LSEC) remains unclear. The proliferation and inhibition of apoptosis in LSEC are involved in the promotion of liver regeneration and the suppression of liver injury after liver resection and transplantation. The aim of this study is to investigate the role of S1P on human LSEC and the interaction between S1P and LSEC in hepatocyte proliferation in vitro. METHODS: Immortalized human LSEC were used. LSEC were cultured with S1P, and the cell proliferation, anti-apoptosis, signal transductions and production of cytokines and growth factors were subsequently examined. To investigate the interaction between S1P and LSEC in hepatocyte proliferation, primary human hepatocytes were cultured with the supernatants of LSEC with and without S1P. DNA synthesis and signal transductions in hepatocytes were examined. RESULTS: S1P induced LSEC proliferation through activation of Akt and extracellular signal-related kinase pathways and suppressed LSEC apoptosis by affecting the expression levels of Bcl-2, Bax and cleaved caspase-3. S1P promoted interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) production in LSEC. The supernatants of LSEC cultured with S1P enhanced hepatocyte DNA synthesis more strongly than the supernatants of LSEC cultured without S1P through activation of the signal transducer and activator of transcription-3 pathway. CONCLUSION: S1P has proliferative and anti-apoptotic effects and promotes the production of IL-6 and VEGF in human LSEC, thereby promoting hepatocyte proliferation.

Signal transduction of platelet-induced liver regeneration and decrease of liver fibrosis.

Platelets contain three types of granules: alpha granules, dense granules, and lysosomal granules. Each granule contains various growth factors, cytokines, and other physiological substances. Platelets trigger many kinds of biological responses, such as hemostasis, wound healing, and tissue regeneration. This review presents experimental evidence of platelets in accelerating liver regeneration and improving liver fibrosis. The regenerative effect of liver by platelets consists of three mechanisms; i.e., the direct effect on hepatocytes, the cooperative effect with liver sinusoidal endothelial cells, and the collaborative effect with Kupffer cells. Many signal transduction pathways are involved in hepatocyte proliferation. One is activation of Akt and extracellular signal-regulated kinase (ERK)1/2, which are derived from direct stimulation from growth factors in platelets. The other is signal transducer and activator of transcription-3 (STAT3) activation by interleukin (IL)-6 derived from liver sinusoidal endothelial cells and Kupffer cells, which are stimulated by contact with platelets during liver regeneration. Platelets also improve liver fibrosis in rodent models by inactivating hepatic stellate cells to decrease collagen production. The level of intracellular cyclic adenosine monophosphate (cyclic AMP) is increased by adenosine through its receptors on hepatic stellate cells, resulting in inactivation of these cells. Adenosine is produced by the degradation of adenine nucleotides such as adenosine diphosphate (ADP) and adenosine tri-phosphate (ATP), which are stored in abundance within the dense granules of platelets.

(-)-Epigallocatechin-3-gallate suppresses liver metastasis of human colorectal cancer.

(-)-Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, has been shown to inhibit cell proliferation and induce apoptosis in several types of human tumors. The most common site of distant metastases in colorectal cancer is the liver. However, no previous studies have reported the ability of EGCG to suppress liver metastases of human colorectal cancer. The aim of the present study was to elucidate the potential use of EGCG as chemotherapy targeting liver metastases of human colorectal cancer. To assess the effect of EGCG on human colorectal cancer cell lines, RKO and HCT116, cell viability, cell proliferation and apoptosis were measured by cell counting kit-8, BrdU assay and TUNEL staining, respectively. Protein and gene expression were measured by western blot analysis and RT-PCR analysis, respectively. EGCG inhibited cell proliferation and induced apoptosis. EGCG dephosphorylated constitutively activated Akt and increased the activation of p38. EGCG also decreased the expression of vascular endothelial growth factor receptor 2. Additionally, the ability of EGCG to prevent the development of liver metastases of RKO tumors was evaluated in SCID mice. EGCG suppressed angiogenesis and induced apoptosis in liver metastases without associated body weight loss or hepatotoxicity. Furthermore, the liver metastatic area was significantly reduced by EGCG administration. Our findings indicate that EGCG may be useful in the treatment of liver metastases of human colorectal cancer.

Platelet transfusion improves liver function in patients with chronic liver disease and cirrhosis.

Chronic liver disease (CLD), such as hepatitis C, is a progressive disease consisting of the destruction and regeneration of the liver parenchyma, leading to fibrosis and cirrhosis. Platelets contain various growth factors and may play important roles in liver regeneration. Thus, to investigate whether platelet transfusion improves liver function in patients with CLD and cirrhosis, we conducted an exploratory clinical trial. The study included 10 patients with CLD and cirrhosis (Child-Pugh class A or B), who all presented thrombocytopenia (platelet counts between 50,000 and 100,000 /µl). The subjects received 10 units of platelet concentrate once a week for 12 weeks. They were followed up for 9 months after the last transfusion. One patient discontinued platelet transfusion because of pruritus, and 2 patients discontinued because of platelet transfusion refractoriness. One patient was excluded from the analysis for receiving a procedural treatment after 12 platelet transfusions. Thus, the remaining 6 patients were analyzed. The platelet count did not increase significantly after the last transfusion. Significant improvement of serum albumin was observed at 1 month and 3 months after the last transfusion. Serum cholinesterase improved significantly at 1 week, 3 months, and 9 months after the last transfusion. Serum hyaluronic acid showed a tendency toward improvement after the last transfusion. In conclusion, platelet transfusion improved some of the indicators of liver function in patients with CLD and cirrhosis, though adverse events related to platelet transfusion were observed in some patients. Platelet increment therapy could be a new strategy for treating CLD and cirrhosis.

Effects of thrombopoietin on growth of hepatocellular carcinoma: Is thrombopoietin therapy for liver disease safe or not?

AIM: Liver cirrhosis (LC) is the end stage of chronic liver disease. No definitive pharmacological treatment is currently available. We previously reported that thrombopoietin (TPO) promoted liver regeneration and improved liver cirrhosis by increasing platelet count. TPO is therefore considered to be a therapeutic agent for LC; however, it is unclear whether TPO has proliferative effects on hepatocellular carcinoma (HCC), which arises frequently in cirrhotic livers. In this study, we examined the effects of TPO on growth of HCC. METHODS: Expression of the TPO receptor, myeloproliferative leukemia virus oncogene (MPL) was examined in various liver tumor cell lines and liver cell types. In an in vitro study, the effects of TPO on signal transduction, cell proliferation, migration and invasion were examined in Huh7 cells, in which MPL is highly expressed. In an in vivo study, we subcutaneously transplanted Huh7 cells into nude mice that were divided into a TPO-treated group and a control group, and the tumor volume of each group was measured. RESULTS: MPL was expressed strongly in hepatocytes but not in other cell types. Among liver tumor cell lines, Huh7 showed the highest expression of MPL. In Huh7, the addition of TPO activated Akt phosphorylation but not cell proliferation, migration or invasion. In the mouse experiment, there was no significant difference in tumor volume between the two groups. CONCLUSION: TPO had no proliferative effect on HCC in vitro or in vivo, and could therefore be useful in the treatment of liver cirrhosis.

Human platelets promote liver regeneration with Kupffer cells in SCID mice.

BACKGROUND: Platelets contain several growth factors, including vascular endothelial growth factor (VEGF) and insulin-like growth factor. We examined the role of human platelets in liver regeneration with a focus on Kupffer cells (KCs). MATERIALS AND METHODS: Severe combined immunodeficiency mice were subjected to 70% hepatectomy and phosphate-buffered saline administration (PBS); 70% hepatectomy and human platelet transfusion (hPLT); 70% hepatectomy, KC depletion, and PBS administration (KD + PBS); 70% hepatectomy, KC depletion, and human platelet transfusion (KD + hPLT); or a sham operation and human platelet transfusion (sham). The groups were evaluated for liver regeneration, accumulation and activation of human platelets in the liver, and/or co-localization of platelets and KCs. RESULTS: The liver-to-body weight ratio was significantly higher 48 h post-transfusion in the hPLT group compared with the PBS, KD + PBS, and KD + hPLT groups. Human VEGF concentrations were higher in liver tissues from the hPLT group, whereas VEGF was not detected in the other groups. Hepatic levels of KC-derived cytokines were elevated in the hPLT group compared with the PBS group. Molecules in signaling cascades downstream of these cytokines were phosphorylated earlier and more robustly in the hPLT group than in the PBS group. Activated human platelets accumulated in livers in the hPLT group, whereas fewer platelets accumulated and many were not activated in the sham and KD + hPLT groups. In the hPLT group, most human platelets were attached to KCs. CONCLUSIONS: Human platelet transfusion promoted liver regeneration in severe combined immunodeficiency mice. Together, human platelets and KCs resulted in growth factor release and enhanced liver regeneration.

Platelet-derived adenosine 5'-triphosphate suppresses activation of human hepatic stellate cell: In vitro study.

AIM: Activated hepatic stellate cells (HSC) play a critical role in liver fibrosis. Suppressing abnormal function of HSC or reversion from activated to quiescent form is a hopeful treatment for liver cirrhosis. The interaction between platelets and HSC remains unknown although platelets go through hepatic sinusoids surrounded by HSC. This study aimed at clarifying the hypothesis that platelets control activation of HSC. METHODS: We used human platelets, platelet extracts, and primary or immortalized human HSC. We examined the effect of platelets on the activation, DNA synthesis, type I collagen production, and fibrosis-relating gene expressions of HSC. We investigated what suppressed activation of HSC within platelets and examined the mechanism of controlling activation in vitro. RESULTS: Platelets and platelet extracts suppressed activation of HSC. Platelets decreased type I collagen production without affecting DNA synthesis. Platelets increased the expression of matrix metallopeptidase 1. As platelet extracts co-cultured with an enzyme of degrading adenosine 5'-triphosphate (ATP) suppressed activation, we detected adenine nucleotides within platelets or on their surfaces and confirmed the degradation of adenine nucleotides by HSC and the production of adenosine. Adenosine and platelets increased the intracellular cyclic adenosine 5'-monophosphate (cAMP), which is important in quiescent HSC. A great amount of adenosine and ATP also suppressed activation of HSC. CONCLUSION: Activation of human HSC is suppressed by human platelets or platelet-derived ATP via adenosine-cAMP signaling pathway in vitro. Therefore, platelets have the possibility to be used in the treatment of liver cirrhosis.