Morphological and serum hyaluronic acid, laminin and type Ⅳ collagen changes in dimethylnitrosamine-induced hepatic fibrosis of rats

AIM: To study the morphological and serum hyaluronic acid (HA), laminin (LN), and type Ⅳ collagen changes in hepatic fibrosis of rats induced by dimethylnitrosamine (DMN).METHODS: The rat model of liver fibrosis was induced by DMN. Serum HA, type Ⅳ collagen, and LN were measured by ELISA. The liver/weight index and morphological changes were examined under electron microscope on d 7, 14, 21, and 28 by immunohistochemical alpha smooth muscle actin α-SMA staining as well as Sirius-red and HE staining.RESUJLTS: The levels of serum HA, type Ⅳ collagen and LN significantly increased from d 7 to d 28 (P = 0.043).The liver/weight index increased on d 7 and decreased on d 28. In the model group, the rat liver stained with HE and Sirius-red showed evident hemorrhage and necrosis in the central vein of hepatic 10 lobules on d 7. Thin fibrotic septa were formed joining central areas of the liver on d 14. The number of α-SMA positive cells was markedly increased in the model group. Transitional hepatic stellate cells were observed under electron microscope.All rats in the model group showed micronodular fibrosis in the hepatic parenchyma and a network of α-SMA positive cells. Typical myofibroblasts were embedded in the core of a fibrous septum. Compared to the control group, the area-density percentage of collagen fibrosis and pathologic grading were significantly different in the model group (P＜0.05) on different d (7, 14, and 28). The area-density percentage of collagen fibrosis in hepatic tissue had a positive correlation with the levels of serum HA, LN, and type Ⅳ collagen.CONCLUSION: The morphological and serum HA, type Ⅳ collagen, and LN are changed in DMN-induced liver fibrosis in rats.     

Radiofrequence ablation of liver cancers

Primary and secondary malignant liver cancer are some of most common malignant tumors in the world. Chemotherapy and radiotherapy are not very effective against them. Surgical resection has been considered the only potentially curtive option, but the majority of patients are not candidates for resection because of tumor size, location near major intrahepatic blood vessels and bile ducts, precluding a margin-negative resection, cirrhotic, hepatitis virus infection or multifocial. Radiofrequence ablation (RFA), which is a new evolving effective and minimally invasive technique, can produce coagulative necrosis of malignant tumors. RFA should be used percutaneously, laparascopically, or during the open laparotomy under the guidance of ultrasound, CT scan and MRI. RFA has lots of advantages superior to other local therapies including lower complications, reduced costs and hospital stays, and the possibility of repeated treatment. In general, RFA is a safe, effective treatment for unresectable malignant liver tumors less than 7.0 cm in diameter. We review the principle, mechanism, procedures and experience with RFA for treating malignant liver tumors.     

Arrhythmogenesis Toxicity of Aconitine Is Related to Intracellular Ca2+ Signals

Aconitine is a well-known arrhythmogenic toxin and induces triggered activities through cardiac voltage-gated Na⁺ channels. However, the effects of aconitine on intracellular Ca²⁺ signals were previously unknown. We investigated the effects of aconitine on intracellular Ca²⁺ signals in rat ventricular myocytes and explored the possible mechanism of arrhythmogenic toxicity induced by aconitine. Ca²⁺ signals were evaluated by measuring L-type Ca²⁺ currents, caffeine-induced Ca²⁺ release and the expression of NCX and SERCA2a. Action potential and triggered activities were recorded by whole-cell patch-clamp techniques. In rat ventricular myocytes, the action potential duration was significantly prolonged by 1 µM aconitine. At higher concentrations (5 µM and 10 µM), aconitine induced triggered activities and delayed after-depolarizations (6 of 8 cases), which were inhibited by verapamil. Aconitine (1 µM) significantly increased the I_Ca-L density from 12.77 ± 3.12 pA/pF to 18.98 ± 3.89 pA/pF (n=10, p<0.01). The activation curve was shifted towards more negative potential, while the inactivation curve was shifted towards more positive potential by 1 μM aconitine. The level of Ca²⁺ release induced by 10 mM caffeine was markedly increased. Aconitine (1 µM) increased the expression of NCX, while SERCA2a expression was reduced. In conclusion, aconitine increased the cytosolic [Ca²⁺]_i by accelerating I_Ca-L and changing the expression of NCX and SERCA2a. Then, the elevation of cytosolic [Ca²⁺]_i induced triggered activities and delayed after-depolarizations. Arrhythmogenesis toxicity of aconitine is related to intracellular Ca²⁺ signals.     

Pelvic lipomatosis with cystitis glandularis managed with cyclooxygenase-2 inhibitor: A case report

BACKGROUNDPelvic lipomatosis (PL) is a rare benign condition with characteristic overgrowth of histologically benign fat and invasion and compression of pelvic organs, often leading to non-specific lower urinary tract symptoms (LUTS). Approximately 40% of patients with PL have cystitis glandularis (CG). The cause of PL combined with CG is poorly understood, and there is currently no effective treatment. Refractory CG with upper urinary tract obstruction even requires partial or radical bladder resection. CASE SUMMARYIn this case, a patient suffering from PL with CG was treated by transurethral resection of bladder tumour (TUR-BT) and oral administration of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor. The LUTS were alleviated, and the cystoscopy results improved significantly. Immunohistochemistry showed up-regulated COX-2 expression in the epithelium of TUR-BT samples, suggesting that COX-2 may participate in the pathophysiological process of PL combined with CG. CONCLUSIONWe report for the first time that celecoxib may be an effective treatment strategy for PL combined with refractory CG.     

Effects of the calcineurin dependent signaling pathway inhibition by cyclosporin A on early and late cardiac remodeling following myocardial infarction

BACKGROUND: The calcineurin-mediated signaling pathway has been implicated as one of the crucial pathways in cardiac hypertrophy. However, the role of calcineurin pathway on cardiac remodeling after myocardial infarction (MI) has not been well defined. METHODS: Infarcted rats (n = 45) were randomized into calcineurin inhibitor, cyclosporin A (CsA) or vehicle groups, 3 days after MI and treated for 2 weeks (early post-MI cardiac remodeling stage), or randomized 17 days after MI and treated for 2 weeks (late remodeling stage). RESULTS: Calcineurin pathway inhibition during the early cardiac remodeling stage attenuated the myocardial hypertrophy after MI (P < 0.05). However, left ventricular dimensions were further increased and fractional shortening deteriorated with calcineurin inhibition during this stage (P < 0.05, each). During late remodeling stage, CsA treatment did not affect myocardial hypertrophy and cardiac dilation following MI. CONCLUSION: Our results strongly support the hypothesis that calcineurin pathway mediates compensatory myocardial hypertrophy during the early remodeling stage after MI. However, the calcineurin pathway does not seem to affect the late remodeling after MI.     

Antigen-recognition sites of micromanipulated T cells in patients with acquired aplastic anemia

OBJECTIVE: Acquired aplastic anemia (AA) is a rare disorder characterized by pancytopenia and hypocellular bone marrow. Though experimental and clinical data suggest that AA represents a T cell-mediated disease, neither the immune response nor the nature of inciting antigen(s) have been characterized so far. The identification of a restricted T cell repertoire by PCR techniques in total lymphocyte populations supports an antigen-driven T cell response. In order to investigate the clonal composition, we analyzed the gene rearrangements of the T cell receptor (TCR) variable beta chain (Vbeta) at the single-cell level. PATIENTS AND METHODS: CD3(+) T lymphocytes were micromanipulated from peripheral blood and bone marrow samples of 8 AA patients and healthy controls. Subsequently amplified VDJ gene segments of the TCRVbeta chain were analyzed for functional rearrangements. More than 500 functionally rearranged TCR loci were studied for Vbeta/Jbeta gene segment usage and molecular composition of the complementary-determining region 3 (CDR3). RESULTS: In comparison to healthy controls, the Vbeta sequences confirmed a highly restricted T cell repertoire in AA patients at the single-cell level. Both in bone marrow and peripheral blood a predominance of Vbeta13 and Jbeta2S7 was observed. Furthermore, individual clonal T-cell expansion was identified in the majority of patients. However, deduced CDR3 amino acid sequences revealed a high variability without common motifs among the 8 patients. CONCLUSION: Individual clonal T-cell expansion with high diversity of the antigen-binding sites among the analyzed patients argues for the predominance of private inciting epitopes in AA.     

PCSK9 regulates apoptosis in human neuroglioma u251 cells via mitochondrial signaling pathways

Proprotein convertase subtilisin/kexin type 9 (PCSK9), belongs to a family of proprotein convertases (PCs), encodes a neural apoptosis-regulated convertase 1. However, the precise role of PCSK9 during glioma cells apoptosis has not been reported. Therefore, we examined the effects of knockdown and overexpression of PCSK9 on apoptosis of human neuroglioma U251 cells, and investigated the underlying mechanisms of apoptosis. We found that PCSK9 regulated cells proliferation as determined by CCK-8 and Hoechst staining analysis. In addition, western blot results showed that PCSK9 siRNA promote apoptosis via activation of caspase-3 and down-regulation of the anti-apoptotic proteins, XIAP and p-Akt, while PCSK9 overexpression inhibited apoptosis. Moreover, PCSK9 siRNA improved the ratio of Bax/Bcl-2 which leads to the release of cytochrome c, while PCSK9 overexpression decreased it. Taken together, these data demonstrate that PCSK9 may regulate apoptosis through mitochondrial pathway and is expected to be a promising therapeutic strategy for the malignant glioma.