The liver plays an important role in the regulation of somatostatin-14 in the rat.

Since little is known about the in vivo disposition of circulating somatostatin-14 (SRIF-14), we examined hepatic processing of SRIF-14 in the rat. Three minutes after the intraportal injection of iodine 125 (125I)-labeled SRIF-14, 16.0 +/- 2.0% of the injected dose is localized to the liver. In the presence of unlabeled SRIF-14, hepatic uptake can be decreased by 68%. Five minutes after the intraportal injection of 125I-SRIF-14, 9.5 +/- 1.4% of the tracer is localized to the liver, more than any other organ tested. Serial collections of bile reveal peak radioactivity at between 10 and 20 minutes. Simultaneous administration of unlabeled SRIF-14 decreases biliary radioactivity by 40%. HPLC analysis of radioactive bile reveals a chromatographic profile similar to that of intact SRIF and is 73% immunoprecipitable by an anti-SRIF antibody. Pretreatment with chloroquine, a lysosomal enzyme inhibitor, does not significantly decrease biliary radioactivity. We conclude that the data are consistent with saturable hepatic uptake and predominantly nonlysosomal transcellular transport.     

Mechanism of postoperative liver failure after excessive hepatectomy investigated using a cDNA microarray

Background/Purpose: Excessive hepatectomy often causes fatal liver failure. We have reported that this is mainly mediated by apoptosis, characterized pathologically by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) assay-positive hepatocytes and a ladder pattern in DNA fragmentation assays. Methods: To investigate the mechanism, we used cDNA microarray analysis to compare clearly differentiated rat partial hepatectomy (PHx) models (90%PHx, and 95%PHx). All 90%PHx rats survived, but the 95%PHx animals died of hepatic failure within 96 h. Remnant liver was obtained at four time points (1, 3, 12, and 24 h after PHx). After RNA extraction, two samples were labeled with different fluorescent dyes and hybridized to the Institute of Physical and Chemical Research (RIKEN) set of 18 816 full-length enriched mouse cDNA arrays. Scanning for fluorescent dye signals was performed, and the mRNA expression ratio of the two models was examined. Results: Genes of the p21 cyclin-dependent kinase (CDK) inhibitor, Fas, interleukin (IL)-18, and many caspases were upregulated at 1 h after PHx in the 95%PHx group. On the other hand, genes of Bcl-2, heat shock proteins, and glutathione-S-transferase were downregulated. Conclusions: We concluded that fatal hepatic failure after excessive hepatectomy was characterized by increased apoptosis and diminished liver regeneration. Received: July 25, 2001 / Accepted: November 16, 2001     

A good model of hepatic failure after excessive hepatectomy in mice

AIMS: This study was intended to establish in mice: 1) a safety limit for the extent of hepatectomy and 2) the extent of hepatectomy invariably causing fatal hepatic failure, to facilitate gene expression analysis. MATERIALS AND METHODS: In 70%-hepatectomy, the left lateral and median lobes were removed, and in 90%-hepatectomy, all lobes except the caudate were resected. One-week survival rates, serum concentrations of aspartate aminotransferase, alanine aminotransferase and total bilirubin were measured. Histological examinations were performed using hematoxylin and eosin staining, and immunohistochemical tests were done with antibody against Ki-67 antigen. RESULTS: All of the 70%-hepatectomized mice were alive at 1 week, but the 90%-hepatectomized mice all died within 24 h after hepatectomy. Serum aminotransferase and total bilirubin levels were significantly higher in the 90%-hepatectomized mice than in the 70%-hepatectomized mice. Liver histology revealed more prominent vacuolar degeneration in the former. Ki67-positive hepatocytes appeared and proliferated immediately after 70%-hepatectomy, but few were observed in the 70%-hepatectomized mice. CONCLUSION: We established 90%-hepatectomy as the safety limit for murine hepatectomy and as a model for liver regeneration, and 90%-hepatectomy as a "fatal hepatic failure level."     

Spleen plays an important role in maintaining tolerance after removal of the vascularized heart graft

BACKGROUND: This study addresses the question of the mechanism for maintaining tolerance to donor alloantigen in the absence of antigen and the role of secondary lymphoid tissues. METHODS: Depleting anti-CD4 antibody administration in conjunction with allogeneic heart transplantation generates donor-specific operational tolerance. Primary C57BL/6 heart grafts were transplanted into the neck cavity of the anti-CD4 antibody pretreated C3H/He mice. At day 50, functioning heart grafts were removed from tolerant mice. At day 100, a secondary C57BL/6 or a third-party heart was transplanted into the abdomen. RESULTS: Anti-CD4 antibody therapy induced CD4CD25 regulatory T cells by 50 days after transplantation, as depleting anti-CD25 treatment in tolerant mice abrogated graft prolongation when spleen leukocytes were adoptively transferred to syngeneic mice. Tolerance was maintained by CD4CD25 regulatory T cells via a CTLA-4 signal at 100 days, even after removal of the primary graft at day 50. Administration of anti-CD25 antibody immediately after removal of the primary graft did not break tolerance, as five out of six second allografts transplanted at day 100 were accepted. Anti-CD25 antibody therapy in conjunction with splenectomy, but not thymectomy, immediately after removal of primary heart grafts at day 50 broke tolerance at day 100; all allografts were rejected. CONCLUSION: The spleen is important in maintaining CD4CD25 regulatory T cells after primary allograft removal.     

Endotoxin-induced liver injury after extended hepatectomy and the role of kupffer cells in the rat

Liver injury by endotoxin given during regeneration following a 70% hepatectomy was examined in Wistar rats. The intravenous administration of endotoxin caused an elevation of the serum GPT level, and severe damage of the remnant liver showing centrilobular necrosis with microthrombi. The highest mortality was induced by the administration of endotoxin to rats 24h after hepatectomy. Kupffer cells in the regenerative phase of the liver showed an augmented in vitro production of both tumor necrosis factor (TNF) and interleukin-1 (IL-1). The simultaneous administration of heparin and prostagladin E₁ (PGE₁), which is known to suppress the production of TNF and IL-1, reduced the magnitude of liver injury and the mortality of these rats. The absence of any direct cytotoxic effect of TNF and IL-1 against liver cells suggested that the cytokines, produced by Kupffer cells, play an important but indirect role in the remnant liver injury induced by endotoxin after hepatectomy.     

Interleukin-17A plays a pivotal role after partial hepatectomy in mice

Background

Liver regeneration after partial hepatectomy (PH) is regulated by tumor necrosis factor (TNF)-α derived from the Kupffer cell. Furthermore, it was reported from our laboratory that interleukin (IL)-17A enhances the production of TNF-α by the Kupffer cell, suggesting that IL-17A may play a role in liver regeneration.

Objective

The purpose was to determine the role of IL-17A and the spleen in liver regeneration after PH.

Methods

Two mouse models including the wild-type (WT) mice or the IL-17A knockout (KO) mice underwent PH. Animals were killed at the designated time points; liver tissues were harvested for further investigation. Proliferation of hepatocytes was evaluated. Furthermore, the messenger RNA and protein expression of TNF-α and IL-6 were measured in the liver. In another set of experiments, the two animal models underwent splenectomy before PH. In an in vitro study, CD4-positive lymphocytes in the spleen were isolated from mice, and the number of IL-17A–positive cells was investigated.

Results

Liver regeneration was significantly impaired in the KO mice compared with the WT mice. This was associated with suppression of cell proliferation assessed by cell proliferation markers in the KO mice. In the WT mice that underwent splenectomy, liver regeneration was significantly delayed compared with animals without splenectomy. In contrast, splenectomy did not affect liver regeneration in the KO mice. IL-17A–positive lymphocytes increased significantly in the spleen in the WT mice after PH.

Conclusions

These results indicate that IL-17A derived from CD4-positive lymphocytes in the spleen is a key regulator in liver regeneration after PH.     

Preservation of the nuchal ligament plays an important role in preventing unfavorable radiologic changes after laminoplasty

STUDY DESIGN: Prospective study. OBJECTIVE: To examine whether preservation of the funicular section of the nuchal ligament attached to the C6 and C7 spinous processes could prevent unfavorable radiologic changes such as kyphotic deformity and destabilization at the C6/7 segment, and to investigate possible correlations between adverse radiologic changes and neurologic recovery or incidence of axial neck pain after laminoplasty in patients with cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: Adverse radiologic changes after cervical laminoplasty have been reported to result from detachment of cervical extensor muscles. METHODS: Subjects comprised 37 patients who underwent modified C3-6 laminoplasty. Our procedure preserves the funicular section of the nuchal ligament attached to the C6 and/or C7 spinous processes in addition to all muscles attached to the C2 and C7 spinous processes and the subaxial deep extensor muscles on the hinged side. The funicular section of the ligament attached only to the C7 spinous process was preserved in 18 patients (C7 group). This funicular section attaching both to the C7 and C6 spinous processes was preserved in 19 patients (C6+7 group). Radiologic and clinical data were prospectively collected. RESULTS: Postoperative loss of lordosis and destabilization at the C6/7 segment were significantly reduced in the C6+7 group compared with the C7 group. As of final follow-up, neurologic recovery was significantly poorer in the 3 patients with kyphosis than in the 34 patients with straight spinal alignment or lordosis. Frequencies of axial pain showed no significant differences between groups. This value did not vary with the differences in sagittal alignment. CONCLUSIONS: These results indicate that the preserved funicular section of the nuchal ligament attached both to the C6 and C7 spinous processes plays an important role in preventing undesirable radiologic changes after laminoplasty.     

ICAM-1 expressed on hepatic stellate cells plays an important role in immune regulation

The authors have demonstrated a strong T-cell inhibitory activity of hepatic stellate cells (HSC), which may participate in the establishment of hepatic tolerance. The underlying mechanism is not completely understood. This study showed that intercellular adhesion molecule 1 (ICAM-1) was constitutively expressed on HSC, and up-regulated upon activation. ICAM-1 knockout mice was used to analyze the role of ICAM-1 expressed on HSC, and showed that deficiency in ICAM-1 expression partially reverses HSC immune inhibitory activity both in vitro and in vivo, but did not significantly affect their capacity to induce T-cell apoptosis.     

小肝癌切除术后并发肝功能衰竭20例

目的 探讨小肝癌术后肝功能衰竭的原因和防治。方法 回顾性分析近3年我院小肝癌切除的临床资料。结果 近3年我院共行直径＜3cm小肝癌409例，术后发生肝功能衰竭者20例(4．89％)，其中行肿瘤切除附加门奇断流术者占85％。与无肝功能衰竭者相比，术后出现肝功能衰竭的病人术中出血量明显多于后者(P＜0．01)。结论 小肝癌术后肝功能衰竭的发生并不少见。小肝癌术后肝功能衰竭的原因除了本身有较重的肝硬化外，术中出血量多、附加其他手术致手术创伤大也是重要因素。因此，对小肝癌，尤其是合并门脉高压症者，不可盲目追求行根治性肿瘤切除术以及随意附加门脉高压症手术。     

Functional capacity of the cirrhotic liver after partial hepatectomy in the rat.

BACKGROUND: Posthepatectomy liver insufficiency is one of the most serious problems associated with a major hepatic resection, especially in the cirrhotic liver, which has less functional reserve than the normal liver. Evaluation of morphologic liver regeneration is important in cirrhotic rats, as well as in the normal liver, and assessment of functional capacity in cirrhosis is clinically important for preventing hepatic insufficiency of the remnant liver after hepatectomy. METHODS: We evaluated the functional capacity of the cirrhotic liver induced by carbon tetrachloride in rats and studied the correlation between morphologic and functional restoration of the liver after partial hepatectomy in comparison with healthy rats. Morphologic restoration of the liver after hepatectomy was evaluated on the basis of remnant liver weight, proliferating cell nuclear antigen labeling index, and the DNA content of the regenerating liver. Functional restoration was evaluated by the indocyanine green disappearance rate and serum aminopyrine clearance. RESULTS: Morphologic restoration in cirrhotic rats was delayed in comparison with healthy rats. Although functional capacity in the cirrhotic rats was diminished, functional restoration was advanced after a two-thirds hepatectomy, in comparison with morphologic restoration. CONCLUSIONS: Functional restoration in cirrhotic rats after partial hepatectomy is advanced in comparison with morphologic restoration.     

Stearoyl-CoA desaturase plays an important role in proliferation and chemoresistance in human hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is often diagnosed at an advanced stage, when it is not amenable for aggressive therapies such as surgical resection or liver transplantation. Current therapeutic options achieve clinical responses in only a small percentage of cases. As a consequence, effective approaches for prevention and treatment are greatly needed. Altered lipid metabolism has been recently linked to HCC pathogenesis. The aims of this study were to define the cellular and molecular mechanisms linking stearoyl-CoA desaturase (SCD), the rate-limiting enzyme and an essential regulator of lipid homeostasis in liver cells, to carcinogenesis in HCC.

Material and methods

HCC and normal liver specimens were collected. Human HCC cell lines: HepG2, Hep3B, and PLC/PLF/5 were used for immunoblot, cell viability, proliferation, and apoptosis assays. Small interfering RNAs were used for genetic inhibition, and 10, 12 conjugated linoleic acid was used for pharmacologic SCD inhibition.

Results

SCD was strongly expressed in surgically resected HCC (n = 64) and various human HCC cell lines (HepG2, Hep3B, and PLC/PLF/5). The levels of SCD negatively correlated with degree of tumor differentiation (P < 0.01). Treatment of these HCC cell lines with a panel of chemotherapeutic drugs resulted in a time-dependent, phosphatidylinositol 3 kinase- and c-Jun N-terminal kinases1/2–mediated upregulation of SCD expression, which paralleled the degree of resistance to drug-induced apoptosis. Specific genetic or pharmacologic SCD suppression resulted in inhibition of cell proliferation (P < 0.001) and significantly increased sensitivity to chemotherapy-induced apoptosis.

Conclusions

Our data suggest that increased SCD expression plays an important role in HCC development and resistance to chemotherapy-induced apoptosis, and this is in part mediated by phosphatidylinositol 3 kinase/c-Jun N-terminal kinases activation. Specific targeted interruption of this pathway in HCC could be a desirable approach in designing novel therapeutic strategies.     

Serum testosterone plays an important role in the metastatic ability of castration resistant prostate cancer

Purpose

Prostate cells are dependent on androgens for growth and proliferation. Androgen deprivation therapy is the recommended treatment for advanced/metastatic prostate cancer. Under this therapy, prostate cancer will inevitably progress to castration resistant prostate cancer (CRPC). Despite putative castration resistance, testosterone might still play a crucial role in the progression of CRPC. The goal of this study was to determine the role of testosterone in the formation of metastases of CRPC in both in vitro and in vivo settings.

Methods

In vitro, the effect of testosterone and the non-aromatizable androgen methyltrienolone on migration, invasion and proliferation of a castration-resistant prostate cancer rat cell line (Dunning R3327-MATLyLu) was assessed using a transwell assay and a sulforhodamine B assay and immunohistochemical detection of ki67. Androgen receptor status was determined using Western blot. In vivo, Copenhagen rats were divided in four groups (males, females, castrated males and females with testosterone suppletion) and inoculated with MATLyLu cells. Tumor size was assessed daily.

Results

Testosterone increased cell migration and invasion in a concentration-dependent manner in vitro. Testosterone did not affect in vitro cell proliferation. No difference was shown between the effect of testosterone and methyltrienolone. In vivo, in groups with higher levels of circulating testosterone, more rats had (micro)metastases compared with groups with low levels of testosterone. No effect was observed on primary tumor size/growth.

Conclusions

Despite assumed castration resistance, progression of prostate cancer is still influenced by androgens. Therefore, continuous suppression of serum testosterone in patients who show disease progression during castration therapy is still warranted.     

MSCs移植治疗肝切除术后肝衰竭的应用及进展

肝大部切除术后肝衰竭的病死率极高,是非常危重的肝脏手术并发症,并且尚无有效治疗手 段,目前仍然以控制症状为主。间充质干细胞（mesenchymal stem cells,MSCs）因免疫调节、减轻炎症反应 能力被广泛研究。此外,MSCs具有促增殖和抗凋亡的特性,可以促进肝脏的修复和再生。综上,MSCs移 植成为治疗肝大部切除术后肝衰竭的研究热点,本文对MSCs的治疗效果及其促进肝脏修复的机制作一综 述。