拔牙窝炎性肉芽组织的转归和调控

牙周炎、根尖周炎常导致牙槽骨进行性吸收,是牙齿松动和缺失的主要原因。在局部炎性因素的长期作用下,毛细血管和成纤维细胞增生,中性粒细胞、淋巴细胞等炎细胞浸润,炎性肉芽组织替代周围骨组织,传统观念认为炎性肉芽组织属于病理性组织,应在拔除患牙的同时将其彻底刮除,以避免拔牙术后出血、感染、骨组织愈合不良等问题。虽然炎性肉芽组织的再生修复能力降低,但当机体抵抗力增强或病原刺激消除(拔除患牙、根管治疗等)后,炎性肉芽组织中纤维成分逐渐增多,浸润的炎细胞逐渐减少,最终转化为修复性肉芽组织进而成骨,且即刻种植中利用拔牙窝的炎性肉芽组织进行创口关闭或软组织重建亦获得良好的临床效果,同时组织学研究证实炎性肉芽组织含有间充质干细胞群体,因此炎性肉芽组织需要彻底刮除的传统观念需要改变。炎性肉芽组织在合适的干预措施下可进行成骨转化,调控炎性肉芽组织转化为修复性肉芽组织成骨再生成为牙槽骨炎性病损再生修复的新策略,具有广阔的临床应用前景,亦是未来重要的研究方向。针对拔牙窝炎性肉芽组织转化为修复性肉芽组织的关键调控因素如活性氧、NOD样受体热蛋白结构域相关蛋白3、组织蛋白酶K等,以及修复性肉芽组织成骨的关键调控因素如骨形态发生蛋白2、血管内皮生长因子等的分子机制研究将有助于筛选促进牙槽骨炎性病损修复的合适靶点以进行相关生物治疗技术和药物材料的研发,以期能为牙周炎等导致的牙槽骨炎性病损提供更微创、更有效的治疗方式,但目前该方面研究仍处于起步阶段,距离临床转化应用尚有距离。

Sclerosing cholangitis following severe trauma: Description of a remarkable disease entity with emphasis on possible pathophysiologic mechanisms

MM： Persistent cholestasis is a rare complication of severe trauma or infections. Little is known about the possible pathomechanisms and the clinical course.METHODS： Secondary sclerosing cholangitis was diagnosed in five patients with persistent jaundice after severe trauma （one burn injury, three accidents, one power current injury）. Medical charts were retrospectively reviewed with regard to possible trigger mechanisms for cholestasis, and the clinical course was recorded.RESULTS： Diagnosis of secondary sclerosing cholangitis was based in all patients on the primary sclerosing cholangitis （PSC）-Iike destruction of the intrahepatic bile ducts at cholangiography after exclusion of PSC. In four patients, arterial hypotension with subsequent ischemia may have caused the bile duct damage, whereas in the case of power current injury direct thermal damage was assumed to be the trigger mechanism. The course of secondary liver fibrosis was rapidly progressive and proceeded to liver cirrhosis in all four patients with a follow-up 〉2 years. Therapeutic possibilities were limited.CONCLUSION： Posttraumatic sderosing cholangitis is a rare but rapidly progressive disease, probably caused by ischemia of the intrahepatic bile ducts via the peribiliary capillary plexus due to arterial hypotension.Gastroenterologists should be aware of this disease in patients with persistent cholestasis after severe trauma.

Role of chemokines and their receptors in viral persistence and liver damage during chronic hepatitis C virus infection

Chemokines produced in the liver during hepatitis C virus(HCV) infection induce migration of activated T cells from the periphery to infected parenchyma.The milieu of chemokines secreted by infected hepatocytes is predominantly associated with the T-helper cell/Tc1 T cell(Th1/Tc1) response.These chemokines consist of CCL3(macrophage inflammatory protein-1α;MIP-1α),CCL4(MIP-1β),CCL5(regulated on activation normal T cell expressed and secreted;RANTES),CXCL10(interferon-γ-inducible protein-10;IP-10),CXCL11(interferon-inducible T-cell α chemoattractant;I-TAC),and CXCL9(monokine induced by interferon γ;Mig) and they recruit T cells expressing either CCR5 or CXCR3 chemokine receptors.Intrahepatic and peripheral blood levels of these chemokines are increased during chronic hepatitis C.The interaction between chemokines and their receptors is essential in recruiting HCV-specific T cells to control the infection.When the adaptive immune response fails in this task,non-specific T cells without the capacity to control the infection are also recruited to the liver,and these are ultimately responsible for the persistent hepatic damage.The modulation of chemokine receptor expression and chemokine secretion could be a viral escape mechanism to avoid specific T cell migration to the liver during the early phase of infection,and to maintain liver viability during the chronic phase,by impairing non-specific T cell migration.Some chemokines and their receptors correlate with liver damage,and CXCL10(IP-10) and CXCR3 levels have shown a clinical utility as predictors of treatment response outcome.The regulation of chemokines and their receptors could be a future potential therapeutic target to decrease liver inflammation and to increase specific T cell migration to the infected liver.

Pancreatic involvement in chronic viral hepatitis

AIM: To elucidate the frequency and characteristics of pancreatic disorders in the course of chronic viral hepatitis. METHODS: We prospectively assessed the serum pancreatic enzyme levels and imaging findings in patients with chronic viral hepatitis and healthy control subjects. RESULTS: Serum amylase (t-Amy), salivary amylase (s-Amy), pancreatic amylase (p-Amy) and serum lipase levels were higher in hepatitis patients in comparison to control subjects. However, in asymptomatic viral carriers, only the serum t-Amy levels were higher than those of the controls. The levels of each enzyme rose with the progression of liver disease in patients with hepatitis B or C; whereas the levels of each enzyme within the same clinical stage of the disease did not differ between patients diagnosed with either hepatitis B or hepatitis C virus. Imaging findings demonstrated chronic pancreatitis in only 1 out of 202 patients (0.5%).CONCLUSION: Our data suggest that serum levels of pancreatic enzymes increase with the progression of liver disease in patients diagnosed with viral hepatitis. Pancreatic disease, asymptomatic in most cases, may represent an extrahepatic manifestation of chronic viral hepatitis.

Involvement of autophagy in alcoholic liver injury and hepatitis C pathogenesis

This review describes the principal pathways of macroautophagy (i.e. autophagy), microautophagy and chaperone-mediated autophagy as they are currently known to occur in mammalian cells. Because of its crucial role as an accessory digestive organ, the liver has a particularly robust autophagic activity that is sensitive to changes in plasma and dietary components. Ethanol consumption causes major changes in hepatic protein and lipid metabolism and both are regulated by autophagy, which is significantly affected by hepatic ethanol metabolism. Ethanol exposure enhances autophagosome formation in liver cells, but suppresses lysosome function. Excessive ethanol consumption synergizes with hepatitis C virus (HCV) to exacerbate liver injury, as alcohol-consuming HCV patients frequently have a longer course of infection and more severe manifestations of chronic hepatitis than abstinent HCV patients. Alcohol-elicited exacerbation of HCV infection pathogenesis is related to modulation by ethanol metabolism of HCV replication. Additionally, as part of this mechanism, autophagic proteins have been shown to regulate viral (HCV) replication and their intracel-lular accumulation. Because ethanol induces autophagosome expression, enhanced levels of autophagic proteins may enhance HCV infectivity in liver cells of alcoholics and heavy drinkers.

Role of Kupffer cells in acute hemorrhagic necrotizing pancreatitis-associated lung injury of rats

AIM： To investigate the role of Kupffer cells （KCs） in acute hemorrhagic necrotizing pancreatitis-associated lung injury （AHNP-U）. METHODS： Forty-two rats were allocated to four groups [sham operation, AHNP model, gadolinium chloride （GdCl3） pretreatment, GdCl3 control]. In GdCl3 pretreatment group, GdCl3 was administered by caudal vein injection 24 h before the AHNP model induction. Blood from the iliac artery, alveolar macrophages and tissues from the pancreas and lung, were collected in six animals per group 3 and 6 h after acute pancreatitis induction. TNF-α, IL-1 of Lserum, myeloperoxidase （MPO） of lung tissue, NF-κB activation of alveolar macrophages were detected. Serum AST and ALT in sham operation group and GdCl3 control group were tested. In addition, histopathological changes of the pancreas and lung were observed under light microscope. RESULTS： MPO of lung tissue and TNF-α, IL-1 levels of serum were all reduced significantly in GdCl3 pretreatment group compared to those in AHNP group （P〈0.01）. NF-KB activation of alveolar macrophages was also attenuated significantly in GdCl3 pretreatment group compared to that in AHNP group （P〈0.01）. The pathological injury of the lung was ameliorated obviously in GdCl3 pretreatment group compared to that in AHNP group. Nevertheless, the serum amylase level did not reduce and injury of the pancreas was not prevented in GdCl3 pretreatment group. CONCLUSION： Pulmonary injury induced by AHNP is mediated by KC activation and AHNP-LI can be significantly ameliorated by pretreatment with GdCh and KCs play a vital role in AHNP-LI.

Role of interleukin 18 in acute lung inflammation induced by gut ischemia repeifusion

AIM: To study the changes of endogenous interleukin 18 (IL-18) levels and evaluate the role of IL-18 on lung injury following gut ischemia/reperfusion.METHODS: A superior mesenteric artery occlusion model was selected for this research. The mice were randomly divided into four groups: Sham operation (sham), ischemia (0.5 h) followed by different times of reperfusion (I/R),and I/R pretreated with exogenous IL-18 (I/R+IL-18) or IL-18 neutralizing antibody (I/R+IL-18Ab) 15 min before ischemia. Serum IL-18 levels were detected by Western blot and ELISA, and the levels of IL-18 in lung tissue were evaluated by immunohistochemical staining. For the study of pulmonary inflammation, the lung myeloperoxidase (MPO) contents and morphological changes were evaluated.RESULTS: Gut ischemia/reperfusion induced rapid increase of serum IL-18 levels, peaked at 1 h after reperfusion and then declined. The levels of IL-18 in lung tissue were gradually enhanced as the progress of reperfusion.Compared with I/R group, exogenous administration of IL-18 (I/R+IL-18) further remarkably enhanced the pulmonary MPO activity and inflammatory cell infiltration,and in I/R+IL-18Ab group, the content of MPO were significantly reduced and lung inflammation was also decreased.CONCLUSION: Gut ischemia/reperfusion induces the increase of IL-18 expression, which may make IL-18 act as an important proinflammatory cytokine and contribute to gut ischemia/reperfusion-induced lung inflammation.

Expression of macrophage inflammatory protein-1αin Kupffer cells following liver ischemia or reperfusion injury in rats

AIM： To explore the expression of macrophage inflammatory protein-1α （MIP-1α） in Kupffer cells （KCs） following liver ischemia/reperfusion injury IRI in rats. METHODS： Forty male SD rats were divided randomly into five groups. A model of partial warm ischemia/ reperfusion injury in the rat liver was established. KCs were isolated and incubated one hour, six hours, 12 h, and 24 h after the reperfusion. Tumor necrosis factor alpha （TNF-α） and interleukin-lbeta （IL-1β） in the supernatants were measured by ELISA. MIP-1α in KCs was detected by immunocytochemical and RT-PCR. RESULTS： No or few MIP-1α protein and mRNA were expressed in the KCs of the control group. Its expression in the IRI group had a significant increase after the reperfusion （P 〈 0.05）, which was contrary to the control group. CONCLUSION： The active behavior of the MIP-1α gene in KCs following liver ischemia/reperfusion injury is assumed to be one of the major causes for the hepatic ischemia/reperfusion injury.

Severe acute cholestatic hepatitis of unknown etiology successfully treated with the Chinese herbal medicine Inchinko-to (TJ-135)

Severe acute hepatitis of unknown etiology is difficult to treat and often progresses to subacute fulminant hepatitis or late-onset hepatic failure. A 45-year-old wellnourished, healthy man had progressive fatigue and his liver function tests showed severe liver dysfunction. The etiology of sever acute cholestatic hepatitis was unknown. The liver function tests normalized gradually, which excluded high persistent total bilirubin after starting on predonine. A liver biopsy showed chronic active hepatitis with mild f ibrosis (A2, F1). Oral Inchinko-to, a Chinese herbal medicine, at 7.5 g daily was prescribed. The treatment was effective with no adverse effects. We present a successfully treated case and discuss hepatoprotective and choleretic effects of Inchinko-to.

Replication of hepatitis B virus in primary duck hepatocytes transfected with linear viral DNA

AIM: To explore the expression and replication of hepatitis B virus (HBV) DNA in primary duck hepatocytes (PDHs).METHODS: Complete HBV genome was transfected into PDHs by electroporation (transfected group, 1.19×1012copies of linear HBV DNA/1×107 PDHs). After 1-5 d of transfection, HBsAg and HBeAg in the supernatant and lysate of PDHs were measured with the IMX System.Meanwhile, replicative intermediates of HBV DNA were analyzed by Southern blotting and Dot blotting. PDHs electroporated were used as control group.RESULTS: HBsAg in the hepatocyte lysates of transfected group was 15.24 (1 d), 14.55 (3 d) and 5.13 (5 d; P/N values, positive≥2.1) respectively. HBeAg was negative (＜2.1). Both HBsAg and HBeAg were negative in the supernatant of transfected group. Dot blotting revealed that HBV DNA was strongly positive in the transfected group and negative in the control group. Southern blot analysis of intracellular total DNA indicated that there were relaxed circular (rc DNA), covalently closed circular (ccc DNA), and single-stranded (ss DNA) HBV DNA replicative intermediates in the transfected group, there was no integrated HBV DNA in the cellular genome. These parameters were negative in control group.CONCLUSION: Expression and replication of HBV genes can occur in hepatocytes from non-mammalian species.HBV replication has no critical species-specificity, and yet hepatic-specific regulating factors in hepatocytes may be essential for viral replication.