Endothelin-1 derived from spleen-activated Rho-kinase pathway in rats with secondary biliary cirrhosis

AIM

  Splenectomy or partial splenic embolism has been reported to improve liver function in patients with hypersplenism and liver dysfunction. The aim of this study was to investigate the mechanism of improvement after splenectomy.

METHODS

  Liver cirrhosis was induced by bile duct ligation (BDL). Rats underwent sham operation, splenectomy (Sp group), BDL, or BDL plus splenectomy (BDL + Sp group), and were subjected to experiments at 2 weeks after the operation. Portal venous pressure (PVP) and hepatic tissue blood flow (HTBF) were measured in each group. The plasma concentration of endothelin-1 (ET-1) and endothelial nitric oxide synthase (eNOS), RhoA and Rho-kinase expressions were studied.

RESULTS

  There were significant differences in PVP (17.9 ± 0.91 vs 23.3 ± 3.91 cmH(2) O; P < 0.01) and HTBF (16.6 ± 1.72 vs 13.3 ± 1.82 mL/min; P < 0.01) between the BDL + Sp and BDL groups. In the liver of BDL rats, eNOS phosphorylation and NOx levels were decreased, accompanied by RhoA activation compared with the BDL + Sp group. Splenectomy decreased serum ET-1 levels, RhoA activation and consequently increased eNOS phosphorylation.

CONCLUSION

  ET-1 derived from the spleen might increase intrahepatic resistance by downregulating Rho signaling in liver cirrhosis. Splenectomy for splenomegaly in liver cirrhosis might partially improve liver function by enhancing intrahepatic microcirculation.

Rigid and flexible endoscopic rendezvous in spatium peritonealis may be an effective tactic for laparoscopic megasplenectomy: significant implications for pure natural orifice translumenal endoscopic surgery

BACKGROUND

We recently experienced 10 patients with cirrhosis who underwent laparoscopic splenectomy. A portion of these patients underwent dissection with a flexible endoscope in the peritoneal cavity. This pilot study mainly focused on the technical aspects and immediate results.

METHODS

From November 2009 to September 2010, 10 patients with cirrhosis and hypersplenism were entered into this pilot study. They were indicated to undergo laparoscopic splenectomy to treat portal hypertension and to facilitate initiation and completion of either interferon therapy for liver cirrhosis or anticancer therapy for hepatocellular carcinoma. To dissect the upper end of the gastrosplenic ligament and the marginal region between the left diaphragm and upper pole of the spleen, a flexible single-channel endoscope was introduced into the peritoneal cavity simultaneously with the use of a rigid laparoscope. Dissection with the flexible endoscope in the peritoneal cavity was performed using an insulation-tipped electrosurgical knife through the channel of the flexible endoscope.

RESULTS

The flexible endoscope offered a magnified operative view, a water-jet lens cleaner, and a powerful lavage and suction capability. The upper end of the gastrosplenic ligament and the marginal region between the left diaphragm and upper pole of the spleen were easily seen, and dissection of these critical regions was smoothly conducted with articulation of the tip of the flexible endoscope, even in patients with splenomegaly. No patient experienced major intraoperative complications or required conversion to open surgery.

CONCLUSIONS

Dissection with a flexible endoscope in the peritoneal cavity may be an effective tactic for laparoscopic megasplenectomy, and significant implications for pure natural orifice translumenal endoscopic surgery have been raised. Although future randomized controlled prospective studies are needed to confirm these findings, surgeons might find this to be a typical example of an appropriate strategy for high-risk patients.

Prediction of improved liver function after balloon-occluded retrograde transvenous obliteration: relation to hepatic vein pressure gradient

BACKGROUND AND AIMS

Balloon-occluded retrograde transvenous obliteration (B-RTO) is an effective treatment for gastric varices (GVx), as well as hepatic encephalopathy. The aim of this study was to examine the changes of the hepatic vein pressure gradient (HVPG) after B-RTO and determine the relation between the changes of HVPG and liver function.

PATIENTS AND METHODS

B-RTO was performed in 30 patients with GVx and hepatic encephalopathy. HVPG was measured in 19 of 30 patients both before and after B-RTO.

RESULTS

The B-RTO was successful in all patients. The GVx and hepatic encephalopathy were improved, and no recurrence or bleeding was observed within the follow- up period. The serum albumin and prothrombin activity were significantly improved 6 months after B-RTO in all patients. HVPG was elevated 44% above the baseline after B-RTO. Liver function significantly improved 6 months after B-RTO in patients whose HVPG increased ≥ 20% from baseline.

CONCLUSION

An elevated HVPG after B-RTO is one aspect of the effect of liver function, and an HVPG increase of ≥ 20% from baseline is a predictive factor for obtaining an improvement of liver function.

Nerve growth factor derived from bronchial epithelium after chronic mite antigen exposure contributes to airway hyperresponsiveness by inducing hyperinnervation, and is inhibited by in vivo siRNA

BACKGROUND

Bronchial asthma is a chronic allergic airway inflammatory disease. Neurotrophins, including nerve growth factor (NGF), play an important role in the pathogenesis of asthma. However, the effects of NGF derived from epithelium on airway hyperresponsiveness (AHR) after antigen sensitization/exposure remain uncertain.

OBJECTIVE

In this study, we examined the role of NGF on AHR after chronic antigen exposure and the effect of inhibiting NGF by in vivo siRNA on AHR exacerbation.

METHODS

We generated chronic mouse models of bronchial asthma using house-dust mite antigen (Dermatophagoides pteronyssinus; Dp). NGF concentrations in bronchoalveolar lavage fluid (BALF), lung histopathology, hyperresponsiveness, and related neuronal peptides and cytokines in supernatants of lung homogenates were determined.

RESULTS

NGF in BALF was increased in a dose- and time-dependent manner, and was expressed primarily in bronchial epithelium. Nerve fibres and substance P-positive fibres were detected in subepithelium of Dp-sensitized and challenged mice over 4 weeks of mite antigen exposure. AHR was positively correlated with NGF concentration and nerve fibre innervation. AHR, modulation of innervation, and increased substance P were inhibited by in vivo administration of siRNA that targeted NGF, although the inhibition of NGF did not affect allergic inflammation and subepithelial fibrosis.

CONCLUSION AND CLINICAL RELEVANCE

These findings suggest that NGF derived from bronchial and alveolar epithelium plays an important role in AHR after chronic exposure to mite antigen. NGF inhibition could potentially manage bronchial asthma, including AHR.

Biological significance of localized Type IV scirrhous gastric cancer

The prognosis of type IV scirrhous gastric cancer (SGC) is extremely poor. Linitis plastica (LP), the so-called 'leather bottle stomach', is believed to be a typical case of SGC, which is usually diagnosed as a far-advanced gastric cancer. The pathogenesis of this disease remains unclear. Although typical SGC often invades the entire stomach, atypical cases show SGC localized to one region of the stomach. The aim of the present study was to investigate localized SGC (LSGC) and its biological significance. A total of 509 patients with advanced gastric cancer who underwent gastrectomy were evaluated. These patients were divided into three groups as follows: 19 patients with type IV scirrhous lesions invading the whole stomach (defined as LP), 60 patients with type IV scirrhous lesions localized in less than two thirds of the stomach (defined as LSGC) and the remaining 430 patients with all other types of gastric cancer (OGC), and then clinicopathologically compared. Results showed that LP had deeper invasion (p=0.006), more frequent peritoneal dissemination including positive cytology (p=0.01 and p=0.018) and lower curability (p=0.03) compared with LSGC, whereas LSGC showed a higher malignant potential in a number of clinicopathological factors compared with OGC. Univariate analysis showed that survival in patients with LP was significantly poorer than in those with LSGC (p=0.002) whose survival was, in turn, inferior to those with OGC. By contrast, LSGC was not a prognostic factor in SGC according to the multivariate analysis. The findings of this study suggested that the malignant status of LSGC differs from that of LP, and that curative gastrectomy is effective in improving the outcome for LSGC but not for LP, as LSGC may represent the prelinitis condition.

IκB kinase β inhibitor IMD-0354 suppresses airway remodelling in a Dermatophagoides pteronyssinus-sensitized mouse model of chronic asthma

BACKGROUND

Nuclear factor (NF)-κB is a transcription factor that regulates cytokine and chemokine production in various inflammatory diseases, including bronchial asthma. IκB kinase (IKK) β is important for NF-κB activation in inflammatory conditions, and is possibly related to airway remodelling. Thus, inhibition of the IKKβ-NF-κB pathway may be an ideal strategy for the management of airway remodelling.

OBJECTIVE

We examined the effects of a newly synthesized IKKβ inhibitor, IMD-0354, in a chronic allergen exposure model of bronchial asthma in mice.

METHODS

A chronic mouse model was generated by challenge with house dust mite antigen (Dermatophagoides pteronyssinus). IMD-0354 was administrated intraperitoneally in therapeutic groups. Lung histopathology, hyperresponsiveness and the concentrations of mediators and molecules in supernatants of lung homogenates were determined.

RESULTS

NF-κB activation was inhibited by prolonged periods of IMD-0354 administration. IMD-0354 reduced the numbers of bronchial eosinophils. IMD-0354 also inhibited the pathological features of airway remodelling, including goblet cell hyperplasia, subepithelial fibrosis, collagen deposition and smooth muscle hypertrophy. Inhibition of these structural changes by IMD-0354 was the result of the suppressing the production and activation of remodelling-related mediators, such as TGF-β, via inhibition of IKKβ. IMD-0354 inhibited IL-13 and IL-1β production, and it restored the production of IFN-γ. It also ameliorated airway hyperresponsiveness.

CONCLUSION

IKKβ plays crucial roles in airway inflammation and remodelling in a chronic mouse model of asthma. A specific IKKβ inhibitor, IMD-0354, may be therapeutically beneficial for treating airway inflammation and remodelling in chronic asthma.

Liver regeneration is promoted by increasing serotonin content in rat liver with secondary biliary cirrhosis

AIM

  Liver cirrhosis clinically shows thrombocytopenia and hypersplenism. Although splenectomy is performed to achieve higher platelet count and better hemostasis, the effect of splenectomy for liver cirrhosis remains unclear. The aim of the present study that was focused on serotonin was to investigate the relationship between splenectomy and liver regeneration in rats with secondary biliary cirrhosis.

METHODS

  Liver cirrhosis was induced in Sprague-Dawley rats by bile duct ligation (BDL). In addition, splenectomy and administration of ketanserin, which selectively antagonizes 5-HT2A and 2B serotonin receptors, were performed. Three weeks after the interventions, whole blood, plasma, serum, and liver specimens were obtained for the following studies: peripheral platelet counts, hemodynamics of serotonin, histopathological examination, immunostaining, and quantification of mRNA expression.

RESULTS

  Splenectomy induced thrombocytosis, and increased serotonin content in cirrhotic liver. Stimulation of liver regeneration was indicated by the following parameters: hepatocyte ratio to the entire liver area, Ki67-positive hepatocyte count, and expression of phosphorylated extracellular signal-regulated kinases. This enhancement of liver regeneration was negated by ketanserin.

CONCLUSION

  Our results showed that splenectomy promoted liver regeneration by increasing serotonin content in liver even under cirrhotic conditions.

Modulation of CD4⁺ T cell responses following splenectomy in hepatitis C virus-related liver cirrhosis

Dysfunction of T cells is a common feature in chronic persistent viral infections, including hepatitis C virus (HCV), and although hepatic and peripheral T cells have been studied extensively in chronic HCV hepatitis, the role of splenic T cell responses in such patients is poorly defined. This is an important issue, as thrombocytopenia is a complication of HCV-related liver cirrhosis (LC), due to splenic platelet sequestration and bone marrow suppression; splenectomy has been proposed to treat such patients. Herein, we studied peripheral blood mononuclear cells (PBMC) and splenic lymphoid subpopulations from a total of 22 patients, including 15 with HCV-related LC with marked thrombocytopenia treated with splenectomy, and seven controls. CD4(+) T cells from peripheral blood and spleen were isolated and phenotype and function evaluated. Splenic CD4(+) T cells in patients with LC expressed molecules associated with inhibitory signalling, including increased frequency of negative markers such as cytotoxic T lymphocyte associated antigen-4 (CTLA-4) and programmed death 1 (PD-1) and decreased production of cytokines. Patients with LC manifest higher levels of splenic CD4(+) regulatory T cells and PD-L1- and PD-L2-expressing cells than controls. Blocking of PD-1/PD-1 ligand interaction reconstituted proliferative and cytokine responses of splenic mononuclear cells (SMC) from patients with LC. Splenectomy was followed by an increase in the ratio of interferon (IFN)-γ to interleukin (IL)-10 and a reduction of PD-1-expressing CD4(+) T cells in peripheral blood. Our data suggest that peripheral tolerance is promoted by the spleen in LC via the up-regulated expression of PD-1 ligands.

Blockade of Th1 chemokine receptors ameliorates pulmonary granulomatosis in mice

Sarcoidosis is a granulomatous disease of unknown aetiology. We identified immunological targets for the treatment of pulmonary granulomatosis using a murine model generated with Propionibacterium acnes. Sensitisation and challenge using heat-killed P. acnes and dendritic cells (DCs) were performed to produce pulmonary granulomatosis in C57BL/6 mice. Immunological analyses using ELISA as well as cDNA microarray analysis were used to search for cytokines or chemokines associated with the formation of granulomas in the lungs. Co-administration of P. acnes and DCs reproducibly induced the formation of pulmonary granulomas, which resembled sarcoid granulomas. The cDNA microarray assay demonstrated that the gene expression of CXCL9 and CXCL10, ligands for CXCR3, and of CCL4, a ligand for CCR5, was strongly upregulated during granulomatosis. ELISA confirmed that levels of CXCL9 and CXCL10 as well as T-helper (Th)1 cytokines and chemokines including tumour necrosis factor-α and interferon-γ were elevated in bronchoalveolar lavage fluid (BALF). The blockade of Th1 chemokine receptors using TAK-779, a dual blocker for CXCR3 and CCR5, led to reduced numbers of CXCR3+CD4+ and CCR5+CD4+ T-cells in BALF. Furthermore, administration of TAK-779 ameliorated the granulomatosis. The targeted inhibition of Th1 chemokines might be useful for inhibiting Th1-biased granulomatous diseases, including sarcoidosis.

Enhancement of osteoclastogenic activity in osteolytic prostate cancer cells by physical contact with osteoblasts

BACKGROUND

The interaction between prostate cancer cells and osteoblasts is critical for the development of bone metastasis. Metastatic cancer cells may physically contact osteoblasts in the bone microenvironment; however, the biological significance of this interaction is not fully understood.

METHODS

Human prostate cancer cells (the osteolytic cell line PC-3 and the osteoblastic cell line MDA-PCa 2b) and human osteoblasts (hFOB1.19) were cocultured under two different conditions (bilayer and contact conditions). Differential gene expression profiles of prostate cancer cells were then investigated using microarray analysis. Differentially expressed genes were analysed using RT-PCR and western blotting, and the effect of anti-cadherin neutralising antibodies on their expression was assayed. The osteoclastogenic activity of cells grown under these different conditions was also investigated using an in vitro assay.

RESULTS

When PC-3 or MDA-PCa 2b cells were cocultured with hFOB1.19 cells under contact conditions, the expression of eight genes was upregulated and that of one gene was downregulated in PC-3 cells compared with gene expression in bilayer culture. No differentially expressed genes were detected in MDA-PCa 2b cells. Four of the eight upregulated genes (interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), IL-6 and the third component of complement (C3)) have already been reported to participate in osteoclastogenesis. Indeed, a cell lysate of PC-3 cells grown under contact coculture conditions significantly enhanced osteoclastogenesis in vitro (P<0.005). neutralisation of cadherin-11 with a specific antibody inhibited upregulation of COX-2 and C3 mRNA in PC-3 cells. In contrast, neutralisation of N-cadherin induced upregulation of COX-2 mRNA.

CONCLUSION

Physical contact between osteolytic prostate cancer cells and osteoblasts may upregulate osteoclastogenesis-related gene expression in prostate cancer cells and enhance osteoclastogenesis. Additionally, cadherin-11 and N-cadherin are involved in this process. These data provide evidence supporting new therapies of prostate cancer bone metastasis that target direct cancer-cell-osteoblast cell-cell contact.

Value of laparoscopic splenectomy as salvage treatment for relapsed thrombocytopenia after partial splenic arterial embolization

BACKGROUND/AIMS

Recently, partial splenic arterial embolization (PSE) has become a supportive intervention for cirrhotic patients with hypersplenism in the administration of interferon therapy. However, relapsed thrombocytopenia is often observed in patients following PSE. This study aimed to report the clinical efficiency of laparoscopic splenectomy as a salvage treatment for relapsed thrombocytopenia following PSE.

METHODS

From 2005 to 2009, 6 patients with prior PSE treatment underwent laparoscopic splenectomy. We reviewed the surgical method of laparoscopic splenectomy and the peri- and postoperative outcomes.

RESULTS

Laparoscopic splenectomy effectively provided sufficient increases in patient platelet counts. In all patients, laparoscopic splenectomy was performed safely with no significant complications despite PSE-associated dense adhesion to the diaphragm and/or retroperitoneal attachments.

CONCLUSION

Laparoscopic splenectomy provides a sufficient increase in patient platelet counts in relapsed thrombocytopenia following PSE. Therefore, laparoscopic splenectomy appears to be a superior supportive therapy for the treatment of thrombocytopenia in cirrhotic patients.

The efficacy of balloon-occluded retrograde transvenous obliteration on small intestinal variceal bleeding

BACKGROUND

Small intestinal variceal bleeding is an unusual cause of gastrointestinal hemorrhaging of portal hypertensive patients, but once it occurs it may lead to life-threatening bleeding because this problem is difficult to diagnose and treat. This study investigated the efficacy of balloon occluded retrograde transvenous obliteration (B-RTO) to treat small intestinal variceal bleeding.

METHODS

From 2003 to 2007, 6 patients with small variceal bleeding were treated by B-RTO. The characteristics of the patients, B-RTO procedures, prognosis, and occurrence of risky esophageal and gastric varices were evaluated according to their medical records.

RESULTS

Three-dimensional (3-D) angiography by MD-CT was useful for the diagnosis of small intestinal varices and the draining vessels. In all cases, variceal bleeding was controlled by B-RTO treatment, although rebleeding was recognized in one patient after 30 months (16.6%). All patients were alive throughout the follow-up except 1 patient who died of liver failure (6-44 months). Risky esophageal varices and gastric varices occurred in 2 patients (33.3%) after B-RTO. However, no variceal bleeding occurred.

CONCLUSION

B-RTO was found to be an effective treatment modality which provided good initial hemostasis, thereby eradicating ectopic small intestinal varices.

Effect of laparoscopic splenectomy on portal hypertensive gastropathy in cirrhotic patients with portal hypertension

AIM

This study investigated the relationship between portal hypertensive gastropathy (PHG) and splenomegaly, and the effect of laparoscopic splenectomy on PHG in cirrhotic patients with portal hypertension.

METHODS

Seventy patients with liver cirrhosis and portal hypertension were prospectively studied. Indication for laparoscopic splenectomy was bleeding tendency in 10 patients, induction of interferon in 45, treatment of hepatocellular carcinoma in seven, and treatment for endoscopic injection sclerotherapy-resistant esophagogastric varices in eight. The severity of PHG was classified into none, mild, or severe according to the classification by McCormack et al. The severity of liver disease was classified using the Child-Pugh score. All patients underwent upper gastrointestinal endoscopy before and 1 month after the operation.

RESULTS

The prevalence of PHG was significantly correlated with the severity of liver disease using the Child-Pugh score. The severity of PHG was significantly correlated with the resected spleen volume. One month after the operation, PHG was improved in 16 of 17 patients with severe PHG and in 12 of 32 with mild PHG. The Child-Pugh score showed a significant improvement (6.8 +/- 1.4 to 6.2 +/- 1.2) at 3 months after laparoscopic splenectomy (P < 0.0001).

CONCLUSIONS

PHG may be associated with splenomegaly, and laparoscopic splenectomy may have a beneficial effect on PHG, at least for a short time.

Technical standardization of laparoscopic splenectomy harmonized with hand-assisted laparoscopic surgery for patients with liver cirrhosis and hypersplenism

BACKGROUND/PURPOSE

The aims of this study were to standardize the techniques of laparoscopic splenectomy (LS) to improve safety in liver cirrhosis patients with portal hypertension.

METHODS

From 1993 to 2008, 265 cirrhotic patients underwent LS. Child-Pugh class was A in 112 patients, B in 124, and C in 29. Since January 2005, we have adopted the standardized LS including the following three points: hand-assisted laparoscopic surgery (HALS) should be performed in patients with splenomegaly (> or =1,000 mL), perisplenic collateral vessels, or Child-Pugh score 9 or more; complete division and sufficient elevation of the upper pole of the spleen should be performed before the splenic hilar division; and when surgeons feel the division of the upper pole of the spleen is too difficult, conversion to HALS should be performed.

RESULTS

There were no deaths related to LS in this study. After the standardization, conversion to open surgery significantly reduced from 11 (10.3%) of 106 to 3 (1.9%) of 159 patients (P < 0.05). The average operation time and blood loss significantly reduced from 259 to 234 min (P < 0.01) and from 506 to 171 g (P < 0.01), respectively.

CONCLUSIONS

With the technical standardization, LS becomes a feasible and safe approach in the setting of liver cirrhosis and portal hypertension.

Value of FDG-PET/CT findings revised using an anthropomorphic body phantom for the evaluation of tumor malignancy grade in small-sized lung adenocarcinomas: A multicenter study

7573

Background: The malignant behavior of small lung adenocarinomas (AD), which have been detected with increasing frequency recently, has not yet been clearly evaluated, and an understanding of this biological characteristic is vital for selecting the appropriate therapeutic strategy. We examined the malignancy grade of small lung ADs using FDG-PET/CT (PET), in addition to high-resolution CT (HRCT) and pathologic evaluation in a multicenter setting. Methods: A total of 204 patients with cT1N0M0 AD underwent PET and HRCT, followed by complete resection with lymph node dissection. The associations between components of bronchioloalveolar carcinoma (BAC) on pathologic examination and maximum standardized uptake value (maxSUV) on PET, ground-glass opacity (GGO) ratio and tumor disappearance rate (TDR) on HRCT were examined, and these findings were analyzed in relation to pathologic features and surgical outcomes. To reduce the errors in PET machines used for this analysis, maxSUV data were adjusted using an anthropomorphic body phantom of the NEMA standards (corrected maxSUV). Results: Examination of tumor aggressiveness based on the presence of lymphatic, vascular and pleural invasion, and of nodal metastasis, showed that maxSUV, BAC ratio, TDR, and GGO ratio, in the order, can reflect the malignancy grade. MaxSUV and BAC ratio were also valuable prognostic predictors of the disease-free survival. There were no significant differences in the values between maxSUV and corrected maxSUV. Although BAC ratio was significantly associated with maxSUV, GGO ratio and TDR (all p<0.0001), the degree of association with maxSUV (R2=0.2533) was weaker than that with GGO (R2=0.5843) ratio or TDR (R2=0.5123). Conclusions: A higher maxSUV reflects an aggressive malignant behavior of cT1N0M0 ADs, independently of BAC component. Assessment by PET in addition to HRCT is useful for selection of the appropriate treatment strategy for small lung AD.

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No significant financial relationships to disclose.