38 Thus, a CAC score of zero is associated with a very low risk

of subsequent coronary events,38, 39 whereas an elevated CAC score is related to a stepwise increase in the risk of subsequent coronary events.11, 38 CAC scores have been shown to be highly predictive of future cardiovascular events independent of traditional risk click here factors.11, 40, 41 Thus, in this study, we used the CAC score as an outcome variable to predict future coronary heart disease in individuals with NAFLD. Currently, three published papers address the relationship between NAFLD and CAC. But, these results conflict with each other. As part of the Diabetes Heart Study, McKimmie et al.42 suggested that hepatic steatosis is less likely to be a direct mediator of cardiovascular disease and may be described as an epiphenomenon. The preponderance of diabetes (82.8%) and the nature of the Diabetes Heart Study as a family study, however, may limit the generalizability of these Z-IETD-FMK mw results. On the contrary, Chen et al.43 reported a significant relationship between NAFLD and CAC in Taiwan, but the possibility of selection bias was raised because of the exclusion of a large number of subjects without hepatic imaging. Jung et al.44 also suggested that hepatic steatosis and increased ALT are associated with CAC. They used less stringent

criteria to define ALT elevation for women and only a single cutoff point of CAC (>100). Importantly, 上海皓元医药股份有限公司 two studies did not include VAT data in multivariate analysis. Although the pathogeneses that relate NAFLD and coronary artery disease

have not been thoroughly investigated, several possible explanations have been offered. A low-grade systemic and hepatic inflammatory milieu may link NAFLD to atherosclerosis, which increases the risk of coronary artery disease.45, 46 In NAFLD, reactive oxygen radicals may induce the production of cytokines, such as tumor necrosis factor-α and interleukin-6,47 and add further atherogenic stimuli to the already high oxidative and proinflammatory status that is closely related to metabolic syndrome.48, 49 In addition, such conditions favor the up-regulation of hepatic C-reactive protein levels, which may link NAFLD to coronary atherosclerosis.45, 50 Furthermore, subjects with NAFLD have reduced serum adiponectin levels, which are inversely related to the severity of NAFLD histology.3, 51 Low serum adiponectin levels may also play an important role in the pathogenesis between NAFLD and subclinical coronary atherosclerosis. The strengths of our study are the use of CAC scores, CT-measured VAT, with a high degree of validity and reproducibility, high-quality data collected by trained personnel with a systematic protocol, a wealth of metabolic variables, and a large number of subjects. In addition, we simultaneously measured CAC, hepatic ultrasonography, and VAT on the same day.

5B-E). The reduction in desmin-positive HSC was due to decreased proliferation but not due to killing of the cells, as confirmed by absence of apoptotic cells using caspase staining (data not shown), whereas significant reduction in proliferating nuclei (stained with Ki67 antibody) was observed with targeted IFNγ construct (Supporting Fig. 5). In addition, the

HSC-targeted conjugate but this website not IFNγ and IFNγ-PEG significantly enhanced the MMP-13/TIMP-1 transcript ratio, implying activation of fibrolysis (Fig. 5E). Finally, the chemokine receptor CXCR4 and its ligand CXCL12/SDF1α, which were recently implicated in HSC activation,24 were significantly down-regulated by IFNγ-PEG-PPB (Fig. 5F), whereas IFNγ and IFNγ-PEG had no effect. Angiogenesis that is induced by hypoxia within an injured liver and appears to aggravate

hepatic fibrogenesis.25 Accordingly, using CD31 immunostaining, we noted significant neovascularization that was paralleled by an increased angiopoietin-1 and fibronectin expression26, 27 in livers of mice chronically treated with CCl4. All these parameters were http://www.selleckchem.com/products/napabucasin.html ameliorated by IFNγ and IFNγ-PEG treatment, but most dramatically by IFNγ-PEG-PPB (Fig. 6A,B). Because PDGF receptor blockade can also lead to antiangiogenic effects we administered higher doses of PPB coupled to a nonbioactive protein (albumin) and did not observe any reduction in CD31 staining in a chronic CCl4 model (Supporting Fig. 6). Liver fibrosis is also an inflammation-driven process28 and HSC can modulate the recruitment of inflammatory cells during fibrogenesis.5 Compared to PBS, IFNγ, and IFNγ-PEG, IFNγ-PEG-PPB showed a significant decrease in MIP2 (macrophage

inflammatory protein 2) expression and lower numbers of macrophages as evidenced by staining for F4/80, and CD68 and F4/80 RNA transcript levels (Fig. 6C,D). Additional effects on other inflammatory cells (neutrophils, CD4, CD8, and dendritic cells) were investigated but no significant differences were observed (Supporting Fig. 7). The main hurdles in IFNγ-based therapies are the adverse effects due to the proinflammatory activity 上海皓元 of IFNγ, one reason for its failures in clinical trials. To investigate whether targeting of IFNγ could ameliorate these IFNγ-mediated side effects, we focused on clinically relevant side effects such as fever, elevated plasma triglycerides, endothelial cell activation, proinflammatory cytokine release, and central nervous system (CNS) effects.29-31 Although IFNγ-PEG treatment induced a significant rise in body temperature, endothelial cell activation (eNOS), plasma TNF-α, and IL-6 levels (Fig. 7A-D), these side effects were completely absent in animals treated with HSC-targeted IFNγ-PEG-PPB (Fig. 7A-D).

18 These studies were approved by the Ethical Committee of the Second Military Medical University. The rat pluripotent LPC-like cell line WB-F34419, 20 was purchased from the Cell Bank of Type Culture Collection of Chinese Academy of Sciences and cultured in Dulbecco’s modified Eagle’s medium (DMEM; Invitrogen, Carlsbad, PD0325901 ic50 CA) supplemented with 0.5% fetal bovine serum (FBS; Gibco, Invitrogen). WB-F344 cells treated with TGF-β (Miltenyi Biotec, Auburn, CA) at 0.25 ng/mL or saline for 18 weeks were termed WB-TβLT or WB-CON

cells, respectively. The mouse liver progenitor cell line LEPC was cultured in DMEM supplemented with 10% FBS.21 Adenovirus encoding dominant-negative mutant of Akt (AdDN-Akt) and green fluorescent

protein (AdGFP) were generated using AdMax Adenovirus Vector (Microbix, Ontario, Canada). All human liver tissues were obtained from surgical resections of patients without preoperative treatment at the Eastern Hepatobiliary Surgery Hospital (Shanghai, China). (See Supporting Table 1 for detailed clinicopathologic information.) The procedure for human sample collection was approved by the Ethics Committee of Eastern Hepatobiliary Surgery Hospital. Formaldehyde-fixed, paraffin-embedded sections of liver tissue were subjected to hematoxylin and eosin (H&E) staining and immunohistochemistry following routine protocols MCE as described.22 selleck chemical The antibody information is provided in Supporting Table 2. Frozen sections of fresh human or rat liver

tissue were incubated with rabbit anti-CD133 (Abcam, Cambridge, MA) and mouse anti-OV-6 (R&D Systems, Minneapolis, MN), followed by fluorescent staining with Alexa Fluor 488-conjugated antimouse IgG and Alexa Fluor 555-conjugated antirabbit IgG (Invitrogen). Mice samples were stained by rabbit anti-A6 and FITC-conjugated antirabbit IgG (Invitrogen). Nuclear staining was performed by Hoechst 33342 in tissue samples. Rabbit anti-forkhead family of transcriptional regulators subfamily O, 3a (FOXO3a; Epitomics, Burlingame, CA) and Alexa Fluor 555-conjugated antirabbit IgG were used to detect the cellular localization of FOXO3a in WB-CON and WB-TβLT cells, and 4′,6-diamidino-2-phenylindole (DAPI) was applied to show the nucleus. Representative images were captured with an Olympus IX70. Quantitative PCR was performed using SYBR Green PCR Kit (Applied Biosystems, Foster City, CA) and ABI 7900HT Fast Real-Time PCR System (Applied Biosystems). The messenger RNA (mRNA) level of specific genes was normalized against β-actin. Primers used are listed in Supporting Table 3. Total RNAs were isolated using TriZol (Invitrogen). The level of microRNA (miRNA) was determined using specific primers (RiboBio Biotechnology, Guangzhou, China) and normalized against U6.

18 These studies were approved by the Ethical Committee of the Second Military Medical University. The rat pluripotent LPC-like cell line WB-F34419, 20 was purchased from the Cell Bank of Type Culture Collection of Chinese Academy of Sciences and cultured in Dulbecco’s modified Eagle’s medium (DMEM; Invitrogen, Carlsbad, PF-2341066 CA) supplemented with 0.5% fetal bovine serum (FBS; Gibco, Invitrogen). WB-F344 cells treated with TGF-β (Miltenyi Biotec, Auburn, CA) at 0.25 ng/mL or saline for 18 weeks were termed WB-TβLT or WB-CON

cells, respectively. The mouse liver progenitor cell line LEPC was cultured in DMEM supplemented with 10% FBS.21 Adenovirus encoding dominant-negative mutant of Akt (AdDN-Akt) and green fluorescent

protein (AdGFP) were generated using AdMax Adenovirus Vector (Microbix, Ontario, Canada). All human liver tissues were obtained from surgical resections of patients without preoperative treatment at the Eastern Hepatobiliary Surgery Hospital (Shanghai, China). (See Supporting Table 1 for detailed clinicopathologic information.) The procedure for human sample collection was approved by the Ethics Committee of Eastern Hepatobiliary Surgery Hospital. Formaldehyde-fixed, paraffin-embedded sections of liver tissue were subjected to hematoxylin and eosin (H&E) staining and immunohistochemistry following routine protocols medchemexpress as described.22 PXD101 The antibody information is provided in Supporting Table 2. Frozen sections of fresh human or rat liver

tissue were incubated with rabbit anti-CD133 (Abcam, Cambridge, MA) and mouse anti-OV-6 (R&D Systems, Minneapolis, MN), followed by fluorescent staining with Alexa Fluor 488-conjugated antimouse IgG and Alexa Fluor 555-conjugated antirabbit IgG (Invitrogen). Mice samples were stained by rabbit anti-A6 and FITC-conjugated antirabbit IgG (Invitrogen). Nuclear staining was performed by Hoechst 33342 in tissue samples. Rabbit anti-forkhead family of transcriptional regulators subfamily O, 3a (FOXO3a; Epitomics, Burlingame, CA) and Alexa Fluor 555-conjugated antirabbit IgG were used to detect the cellular localization of FOXO3a in WB-CON and WB-TβLT cells, and 4′,6-diamidino-2-phenylindole (DAPI) was applied to show the nucleus. Representative images were captured with an Olympus IX70. Quantitative PCR was performed using SYBR Green PCR Kit (Applied Biosystems, Foster City, CA) and ABI 7900HT Fast Real-Time PCR System (Applied Biosystems). The messenger RNA (mRNA) level of specific genes was normalized against β-actin. Primers used are listed in Supporting Table 3. Total RNAs were isolated using TriZol (Invitrogen). The level of microRNA (miRNA) was determined using specific primers (RiboBio Biotechnology, Guangzhou, China) and normalized against U6.

Db/db mice in a C57/BLKS background have less pronounced basal up-regulation of ER stress markers than those in a C57/BL6

background and were thus used in these experiments (Fig. S1). The link between ER stress and inflammation selleck compound is incompletely understood. Although CHOP expression was clearly higher in db/db mice compared to db/m mice fed the MCD diet, activation of NF-κB did not appear to completely account for the differential increase in inflammatory markers. There are many mechanisms by which activation of the UPR could differentially up-regulate inflammatory pathways in db/db mice fed the MCD diet. Other factors directly related to ATF-4, JNK, or through the generation of reactive oxygen species (ROS) due to prolonged ER stress can also activate inflammatory pathways.18 We propose that, in part, “chronic” ER stress may impair adaptation to acute MCD diet-induced stress. In vitro studies have shown that CHOP activation is a consequence of UPR signaling that will only remain elevated if salvage mechanisms are inadequate.28-30 Here we showed that the MCD diet

caused a sustained increase in CHOP protein expression only in db/db mice. Although persistent elevation of CHOP can be indicative of unresolved ER stress and has been shown to activate apoptosis, no discernable effect was noted on caspase 3 cleavage or transferase-mediated dUTP nick end labeling Dabrafenib in vitro (TUNEL) staining despite a modest increase in caspase-12 (data not shown). A potential explanation may be that, whereas CHOP activation is important in the propagation of the UPR and apoptotic signaling, such effects are more evident after a prolonged time as suggested by a delayed activation of UPR and ER stress in CHOP null mouse embryonic fibroblasts.29, 30 Furthermore, MCD induction of CHOP in

db/db mice was sufficient to propagate ER stress without prompting the feedback inhibition of GADD34. Unresolved ER stress can also further lower hepatic GADD34 levels. This contrasts with a more robust compensatory response seen in db/m mice, where attenuated 上海皓元医药股份有限公司 levels of CHOP and p-eIF2a were observed. A recent publication shows that in CH3 male mice the MCD diet only up-regulated p-eIf2α, and not other arms of the UPR. Furthermore, they suggest that CHOP was not essential for MCD-induced injury.31 The data presented here show that, whereas p-eIf2α and its downstream targets are most affected by the MCD diet, all three pathways are activated. Furthermore, not only are CHOP and important inflammatory mediators up-regulated, as we have previously shown, db/db mice fed an MCD develop more liver injury.4 Although it may be the case that in some mice the mechanism of liver injury is not directly related to the effect of the MCD diet on the UPR, these data suggest that in a diabetic milieu dysregulation of the UPR and unresolved ER stress do contribute to liver injury.

, 2011). Tests of verbal memory may be more sensitive (notwithstanding the issues described here with Names cued-recall test) than those designed www.selleckchem.com/PD-1-PD-L1.html to detect visual and visuo-spatial memory (e.g., the noted susceptibility

of the Shapes visual recall test to ceiling effects), which may be supported by verbal encoding strategies (deliberate or unintentional). A small number of studies describe patients who fail to conform to this pattern, with, for example, lateralized left- or right-sided lesions resulting in a global memory deficit. One important reason for such inconsistencies is the reliance on low-resolution brain imaging, which fails to identify bilateral thalamic damage. For instance, in the first of two studies on patient QX, Edelstyn et al. (2002) initially reported that his lesion was limited to the left MDT on the basis of a CT scan. However, subsequent scanning, using high-resolution MRI imaging, revealed the presence of bilateral pathology of the dorsolateral thalamic nuclei (Edelstyn et al., 2006). The important features of the present study are, therefore, the use of high-resolution brain imaging evidence showing that

our patients’ medial thalamic lesions, selleck and presumed partial disconnection of the MTT, are clearly lateralized to the left side (SM) and right side (OG). Secondly, this is the first report of a double dissociation between visual memory and verbal memory in two thalamic lesion patients using the same battery of neuropsychological tests, thereby supporting the proposal that the material-specific lateralization of long-term memory extends to the MDT and thalamic tracts. Before discussing some of the other implications of our study, the findings from the stereological volume estimation of medial temporal lobe memory areas and the lateral ventricles will be considered. Both patients show evidence of ventricular enlargement, for SM this is lateralized to the left ventricle on the same side as his thalamic lesion, whereas

for OG both ventricles showed enlargement. SM’s unilateral left ventricular enlargement is consistent with other reports of ex vacuo ventricular dilatation following 上海皓元医药股份有限公司 various types of thalamic pathology, where there is outward movement of the ventricles to fill the lacuna. However, this compensatory enlargement is not associated with cerebrospinal fluid (CSF)-compression on proximal structures and tracts (e.g., Weisberg & Dunn, 1983; Wood & Bigler, 1995), so should not contribute to any memory deficits. The presence of bilateral ventricular enlargement in the case of OG is unlikely to be caused by a ‘hidden’ left-sided lesion either at the level of the diencephalon or the cortex since the high-resolution MR imaging employed in this study would have picked up such damage. OG’s memory profile is also supportive of this view.

4 We hypothesize that these differences may be due in part to a dysregulation of

the UPR in db/db mice that discourages cellular recovery and promotes further injury. The present results suggest that activation of the UPR and initiation of downstream inflammatory pathways may play a significant role in MCD induced steatohepatitis in db/db mice. ALT, alanine aminotransferase; ATF-4, activating transcription factor 4; ATF-6, activating transcription factor 6; CHOP, C/EBP homologous transcription factor; EDEM, enhancing α-mannosidase-like protein; ER, endoplasmic reticulum; ERO-1, oxireductase endoplasmic reticulum oxidoreductin-1; GADD34, growth arrest and DNA damage 34; IRE1α, inositol requiring 1α; JNK, c-Jun N-terminal AZD9668 cost kinase; NF-κB, nuclear factor kappaB; MCD, methionine choline-deficient; Myd 116, myleloid differentiation response gene 116; NAFLD, nonalcoholic fatty liver disease; NASH, nonalcoholic steatohepatitis; PERK, PKR-like eukaryotic initiation factor 2 kinase; RT-PCR, real time quantitative polymerase chain reaction; TG, triglyceride; TNF-α, tumor necrosis

factor alpha; UPR, unfolded protein response. For all experiments, 8 to 10-week-old female db/db, db/m, and corresponding wildtype strain control C57BLKS/J VX-809 nmr or C57BL/6 (only for experiments done for Supporting Fig. S1), (Jackson Laboratory, Bar Harbor, ME) were used. All mice were maintained under 12-hour light/dark cycles with unlimited access to regular chow and water until MCE the first day

of the study. Mice then received the MCD diet or a nutritionally identical diet supplemented with methionine and choline to serve as the control. At the conclusion of each experiment mice were fasted for 4 hours and euthanized using CO2 narcosis. Whole blood was obtained from the right atrium by cardiac puncture and the livers were excised and weighed. Livers were flash-frozen in liquid nitrogen and stored at −70°C, with the exception of NF-κB experiments, in which nuclear extract was collected from fresh liver tissue. All animal experiments were approved by the Animal Care and Use Committee of Northwestern University Feinberg School of Medicine. Fasting blood glucose was measured by the glucose oxidase method using a reflectance glucometer (One Touch Ultra; LifeScan, Milpitas, CA). The determination of serum ALT was performed using a spectrophotometric assay kit on fresh plasma (Biotron, Hemet, CA). Triglyceride (TG) and cholesterol were measured enzymatically (Thermo Electron, Louisville, KY) on hepatic homogenate. Total RNA was extracted from liver by homogenizing snap-frozen liver tissue samples in TRIzol reagent (Invitrogen). Complementary DNA (cDNA) was synthesized from 2 μg of total RNA using the SuperScript First Strand System for real-time reverse-transcription PCR (RT-PCR) (Invitrogen), henceforth abbreviated RT-PCR, and random hexamer primers. The resulting cDNA was subsequently used as a template for quantitative RT-PCR.

4 We hypothesize that these differences may be due in part to a dysregulation of

the UPR in db/db mice that discourages cellular recovery and promotes further injury. The present results suggest that activation of the UPR and initiation of downstream inflammatory pathways may play a significant role in MCD induced steatohepatitis in db/db mice. ALT, alanine aminotransferase; ATF-4, activating transcription factor 4; ATF-6, activating transcription factor 6; CHOP, C/EBP homologous transcription factor; EDEM, enhancing α-mannosidase-like protein; ER, endoplasmic reticulum; ERO-1, oxireductase endoplasmic reticulum oxidoreductin-1; GADD34, growth arrest and DNA damage 34; IRE1α, inositol requiring 1α; JNK, c-Jun N-terminal R788 cost kinase; NF-κB, nuclear factor kappaB; MCD, methionine choline-deficient; Myd 116, myleloid differentiation response gene 116; NAFLD, nonalcoholic fatty liver disease; NASH, nonalcoholic steatohepatitis; PERK, PKR-like eukaryotic initiation factor 2 kinase; RT-PCR, real time quantitative polymerase chain reaction; TG, triglyceride; TNF-α, tumor necrosis

factor alpha; UPR, unfolded protein response. For all experiments, 8 to 10-week-old female db/db, db/m, and corresponding wildtype strain control C57BLKS/J Selleck Z VAD FMK or C57BL/6 (only for experiments done for Supporting Fig. S1), (Jackson Laboratory, Bar Harbor, ME) were used. All mice were maintained under 12-hour light/dark cycles with unlimited access to regular chow and water until MCE公司 the first day

of the study. Mice then received the MCD diet or a nutritionally identical diet supplemented with methionine and choline to serve as the control. At the conclusion of each experiment mice were fasted for 4 hours and euthanized using CO2 narcosis. Whole blood was obtained from the right atrium by cardiac puncture and the livers were excised and weighed. Livers were flash-frozen in liquid nitrogen and stored at −70°C, with the exception of NF-κB experiments, in which nuclear extract was collected from fresh liver tissue. All animal experiments were approved by the Animal Care and Use Committee of Northwestern University Feinberg School of Medicine. Fasting blood glucose was measured by the glucose oxidase method using a reflectance glucometer (One Touch Ultra; LifeScan, Milpitas, CA). The determination of serum ALT was performed using a spectrophotometric assay kit on fresh plasma (Biotron, Hemet, CA). Triglyceride (TG) and cholesterol were measured enzymatically (Thermo Electron, Louisville, KY) on hepatic homogenate. Total RNA was extracted from liver by homogenizing snap-frozen liver tissue samples in TRIzol reagent (Invitrogen). Complementary DNA (cDNA) was synthesized from 2 μg of total RNA using the SuperScript First Strand System for real-time reverse-transcription PCR (RT-PCR) (Invitrogen), henceforth abbreviated RT-PCR, and random hexamer primers. The resulting cDNA was subsequently used as a template for quantitative RT-PCR.

Thus, β-catenin

plays a key role in the integration of ethanol metabolism and oxidative-stress functions of the liver. Additonal Supporting Information may be found in the online version of this article. “
“We have developed a novel model for depleting mouse hepatic stellate cells (HSCs) that has allowed us to clarify their contributions to hepatic injury and fibrosis. Transgenic (Tg) mice expressing the herpes simplex virus thymidine kinase gene (HSV-Tk) driven by the mouse GFAP promoter were used to Apitolisib in vitro render proliferating HSCs susceptible to killing in response to ganciclovir (GCV). Effects of GCV were explored in primary HSCs and in vivo. Panlobular damage was provoked to maximize HSC depletion by combining CCl4 (centrilobular injury) with allyl alcohol (AA) (periportal injury), as well as in a bile duct ligation

(BDL) model. Cell depletion in situ was quantified using dual immunofluorescence (IF) for desmin and GFAP. In primary HSCs isolated from both untreated wild-type (WT) and Tg mice, GCV induced cell death in ∼50% of HSCs from Tg, but not WT, mice. In TG mice treated with CCl4+AA+GCV, there was a significant decrease in GFAP and desmin-positive cells, compared to WT mice (∼65% reduction; P < 0.01), buy NU7441 which was accompanied by a decrease in the expression of HSC-activation markers (alpha smooth muscle actin, beta platelet-derived growth factor receptor, and collagen MCE I). Similar results were observed after BDL. Associated with HSC depletion in both fibrosis models, there was marked attenuation of fibrosis and liver injury, as indicated by Sirius Red/Fast Green, hematoxylin and eosin quantification, and serum alanine/aspartate aminotransferase.

Hepatic expression of interleukin-10 and interferon-gamma was increased after HSC depletion. No toxicity of GCV in either WT or Tg mice accounted for the differences in injury. Conclusion: Activated HSCs significantly amplify the response to liver injury, further expanding this cell type’s repertoire in orchestrating hepatic injury and repair. (HEPATOLOGY 2013) Hepatic stellate cells (HSCs) are well-characterized nonparenchymal cells of the liver with established roles in fibrosis, repair, and immunity.1 During liver injury, quiescent HSCs undergo activation, secreting a repertoire of molecules involved in cell proliferation, chemotaxis, inflammation, and fibrosis, among others. Although their role in fibrogenesis is well established, the contributions of HSCs to acute hepatocellular damage and tissue homeostasis are not well understood. Models to manipulate HSC function or number offer an appealing strategy to clarify this issue. However, only two models have been established to deplete HSCs in vivo thus far, by using gliotoxin2 or gliotoxin-coupled antibodies (Abs) against synaptophysin.

In case of heterogeneity, meta-analysis was performed applying the random-effects model. In addition, an I2 value of less than 25% was defined to represent low heterogeneity, a value between 25 and 50% was defined as moderate heterogeneity, and a value of >50% was defined as high heterogeneity.36 Subgroup analyses, which considered more homogeneous

studies, were performed to identify subsets of patients more likely to benefit from the treatment and to assess the efficacy of different studies. To determine the extent to which the combined risk estimate might be affected by individual studies, sensitivity analysis was RG7204 performed by consecutively omitting every study from the meta-analysis (leave-one-out procedure). Funnel plots were used to screen for publication bias. Meta-analysis was conducted by Review Manager (RevMan) Meta-analysis software,

v. 5.1.6. The 95% CIs were calculated as estimates of precision for OR. The statistical tests were two-sided, and P < 0.05 was considered statistically significant. Detailed analytical methods can be found in the Supporting Algorithms for Data Combination in the Meta-analysis. Table 1 lists the characteristics of the included studies and details of the enrolled participants. Figure 1 illustrates the study screening and selection process. A total of 2,880 patients (simultaneous resection 1,015, delayed resection 1,865) from 17 see more studies were included. Synchronous metastases were defined as liver metastases diagnosed before colorectal resection or at the time of surgery, and patients scheduled for a so-called “two-stage hepatectomy” procedure (two sequential hepatectomies for bilateral metastases unresectable by a single resection) were excluded from the meta-analysis. Most studies were from Western Europe and North America in single-centers analyzed retrospectively and the

number of patients per study ranged from 36 to 610 (multicenter study for Reddy et al.).27, 39 Preoperative chemotherapy status was reported in five studies.27, 40, 42, 47, 49 Moreover, we observed that patients with restricted metastatic disease were more likely to undergo simultaneous resections, whereas extended MCE公司 and anatomical difficult resections were rather performed as staged procedures. Distributions of risk (Severity) characteristics for the included patients from each observational study are detailed in Supporting Table 1. The agreement between two reviewers for study selection was 0.94 and for quality assessment of trials was 0.89. We evaluated the risk of bias in the 17 observational studies by modification of the Newcastle-Ottawa scale (Table 2).32 Detailed descriptions of follow-up were available in most studies.