Changes in platelet Bax levels contribute to impaired platelet response to thrombin after cardiopulmonary bypass: prospective observational clinical and laboratory investigations

Background

Anucleate platelets can undergo apoptosis in response to various stimuli, as do nucleated cells. Cardiopulmonary bypass (CPB) causes platelet dysfunction and can also activate platelet apoptotic pathways. We therefore evaluated time-dependent changes in blood platelet Bax (a pro-apoptotic molecule) levels and platelet dysfunction after cardiac surgery.

Methods

We assessed blood samples obtained from subjects having on-pump or off-pump coronary artery bypass graft surgery ( n =20 each). We also evaluated the in vitro effects of platelet Bax increase in eight healthy volunteers.

Results

Thrombin-induced platelet calcium mobilisation and platelet-surface glycoprotein Ib (GPIb) expression were lowest at weaning from CPB and did not recover on postoperative day one. On-pump surgery increased platelet expression of Bax, especially the oligomerised form, along with translocation of Bax from the cytosol to mitochondria and platelet-surface tumour necrosis factor-alpha (TNF-α)-converting enzyme (TACE) expression. In contrast, mitochondrial cytochrome c expression was reduced. While similar in direction, the magnitude of the observed changes was smaller in patients having off-pump surgery. In vitro , a cell-permeable Bax peptide increased platelet Bax expression to the same extent seen during bypass and produced similar platelet changes. These apoptotic-like changes were largely reversed by Bcl-xL pre-administration, and were completely reversed by combined application of inhibitors that stabilise outer mitochondrial membrane permeability and TACE.

Conclusions

CPB increases platelet Bax expression, which contributes to reduced platelet-surface GPIb expression and thrombin-induced platelet calcium changes. These changes in platelet apoptotic signalling might contribute to platelet dysfunction after CPB.

Clinical trial registration

UMIN Clinical Trials Registry (number UMIN000006033).

Static and dynamic structures of liquid Ba8Ga16Sn30: a melt of the thermoelectric clathrate compounds

X-ray diffraction and inelastic x-ray scattering measurements of liquid Ba₈Ga₁₆Sn₃₀ have been carried out to investigate local structure and atomic dynamics in the liquid. The pair distribution function shows shorter and longer interatomic distances in the first coordination shell. The dynamic structure factor exhibits the inelastic excitations on both sides of the quasielastic central peak. The inelastic excitations disperse with increasing the momentum transfer, suggesting the longitudinal acoustic mode. We found a low energy excitation in addition to the longitudinal acoustic excitation in the dynamic structure factor and it reminds us a strong relationship with a rattling motion of a guest (Ba) atom in the solid state. The temperature dependence of the pair distribution function and the longitudinal acoustic excitation energy is very weak in a range from 600 to 900 °C. The result suggests that Ba and other atoms in the melt are located around minimum positions of the effective pair potential approximated as a harmonic one.

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10^{21} Protons on Target

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3}  eV^{2}/c^{4}.

Adult hepatocytes direct liver organogenesis through non-parenchymal cell recruitment in the kidney

BACKGROUND & AIMS

Since the first account of the myth of Prometheus, the amazing regenerative capacity of the liver has fascinated researchers because of its enormous medical potential. Liver regeneration is promoted by multiple types of liver cells, including hepatocytes and liver non-parenchymal cells (NPCs), through complex intercellular signaling. However, the mechanism of liver organogenesis, especially the role of adult hepatocytes at ectopic sites, remains unknown. In this study, we demonstrate that hepatocytes alone spurred liver organogenesis to form an organ-sized complex 3D liver that exhibited native liver architecture and functions in the kidneys of mice.

METHODS

Isolated hepatocytes were transplanted under the kidney capsule of monocrotaline (MCT) and partial hepatectomy (PHx)-treated mice. To determine the origin of NPCs in neo-livers, hepatocytes were transplanted into MCT/PHx-treated green fluorescent protein transgenic mice or wild-type mice transplanted with bone marrow cells isolated from green fluorescent protein-mice.

RESULTS

Hepatocytes engrafted at the subrenal space of mice underwent continuous growth in response to a chronic hepatic injury in the native liver. More than 1.5 years later, whole organ-sized liver tissues with greater mass than those of the injured native liver had formed. Most remarkably, we revealed that at least three types of NPCs with similar phenotypic features to the liver NPCs were recruited from the host tissues including bone marrow. The neo-livers in the kidney exhibited liver-specific functions and architectures, including sinusoidal vascular systems, zonal heterogeneity, and emergence of bile duct cells. Furthermore, the neo-livers successfully rescued the mice with lethal liver injury.

CONCLUSION

Our data clearly show that adult hepatocytes play a leading role as organizer cells in liver organogenesis at ectopic sites via NPC recruitment.

LAY SUMMARY

The role of adult hepatocytes at ectopic locations has not been clarified. In this study, we demonstrated that engrafted hepatocytes in the kidney proliferated, recruited non-parenchymal cells from host tissues including bone marrow, and finally created an organ-sized, complex liver system that exhibited liver-specific architectures and functions. Our results revealed previously undescribed functions of hepatocytes to direct liver organogenesis through non-parenchymal cell recruitment and organize multiple cell types into a complex 3D liver at ectopic sites. Transcript profiling: Microarray data are deposited in GEO (GEO accession: GSE99141).

Risk Factors for Postoperative Ascites in Patients Undergoing Liver Resection for Hepatocellular Carcinoma

BACKGROUND

Postoperative ascites is a common complication after liver resection. This study aimed to identify the risk factors for ascites in patients after liver resection and the relationship between postoperative ascites and other complications.

METHODS

We retrospectively analyzed data that were obtained from 266 patients who underwent liver resection for treating hepatocellular carcinoma between 2008 and 2015. Postoperative ascites was defined as a daily ascitic fluid drainage exceeding 500 mL on postoperative day 3 or later. The participants were categorized and analyzed with respect to the presence or absence of postoperative ascites.

RESULTS

Overall, 17 (6.4%) patients developed postoperative ascites. A multivariate analysis identified that three significant factors-serum albumin, platelet count, and operation duration-were associated with the development of postoperative ascites. Sixteen (94.1%) of the 17 patients with postoperative ascites experienced other associated complications. The patients with ascites had more pleural effusion (70.6 vs. 17.7%, P < 0.001) than the patients without ascites. Postoperative morbidity, except for pleural effusion, was similar between the groups. The postoperative hospital stay duration was significantly longer in patients with ascites than in those without ascites.

CONCLUSIONS

Postoperative ascites frequently occurred in patients with decreased liver functional reserve. Moreover, the presence of ascites was associated with significantly increased pleural effusion rates, and postoperative hospital stay duration was significantly prolonged.

Increased metabolite production by deletion of an HDA1-type histone deacetylase in the phytopathogenic fungi, Magnaporthe oryzae (Pyricularia oryzae) and Fusarium asiaticum

Histone deacetylases (HDACs) play an important role in the regulation of chromatin structure and gene expression. We found that dark pigmentation of Magnaporthe oryzae (anamorph Pyricularia oryzae) ΔMohda1, a mutant strain in which an orthologue of the yeast HDA1 was disrupted by double cross-over homologous recombination, was significantly stimulated in liquid culture. Analysis of metabolites in a ΔMohda1 mutant culture revealed that the accumulation of shunt products of the 1,8-dihydroxynaphthalene melanin and ergosterol pathways were significantly enhanced compared to the wild-type strain. Northern blot analysis of the ΔMohda1 mutant revealed transcriptional activation of three melanin genes that are dispersed throughout the genome of M. oryzae. The effect of deletion of the yeast HDA1 orthologue was also observed in Fusarium asiaticum from the Fusarium graminearum species complex; the HDF2 deletion mutant produced increased levels of nivalenol-type trichothecenes. These results suggest that histone modification via HDA1-type HDAC regulates the production of natural products in filamentous fungi.

SIGNIFICANCE AND IMPACT OF THE STUDY

Natural products of fungi have significant impacts on human welfare, in both detrimental and beneficial ways. Although HDA1-type histone deacetylase is not essential for vegetative growth, deletion of the gene affects the expression of clustered secondary metabolite genes in some fungi. Here, we report that such phenomena are also observed in physically unlinked genes required for melanin biosynthesis in the rice blast fungus. In addition, production of Fusarium trichothecenes, previously reported to be unaffected by HDA1 deletion, was significantly upregulated in another Fusarium species. Thus, the HDA1-inactivation strategy may be regarded as a general approach for overproduction and/or discovery of fungal metabolites.

Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW_{th} reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective ^{239}Pu fission fractions F_{239} from 0.25 to 0.35, Daya Bay measures an average IBD yield σ[over ¯]_{f} of (5.90±0.13)×10^{-43}  cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×10^{-43}  cm^{2}/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the ^{239}Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1σ. This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes ^{235}U, ^{239}Pu, ^{238}U, and ^{241}Pu. Based on measured IBD yield variations, yields of (6.17±0.17) and (4.27±0.26)×10^{-43}  cm^{2}/fission have been determined for the two dominant fission parent isotopes ^{235}U and ^{239}Pu. A 7.8% discrepancy between the observed and predicted ^{235}U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.

Genetic Modification of Hepatocytes towards Hepatocyte Transplantation and Liver Tissue Engineering

Cell-based therapies, including liver tissue engineering following hepatocyte transplantation, have therapeutic potential for several types of liver diseases. Modifications in the methodology to manipulate the donor hepatocytes in a more simple and timely manner prior to transplantation would enhance the therapeutic efficacy of this procedure. Conventional approach for vector-mediated gene transduction to the isolated hepatocytes has been performed under primary culture conditions that routinely require several days to complete. In our study, we have established a clinically feasible approach that requires only 1 h of infection time with an adenoviral vector system that results in an extremely efficient transduction efficiency (>80%). To optimize transduction efficiency and sustain normal cellular function, we determined that the isolated hepatocytes should be maintained in UW solution as a suspension medium and infected with adenoviral vectors (Ad) for no more than 1 h at a MOI of 1. To establish if the isolated hepatocytes could be used as a source for cell-based therapies, we transplanted the Ad-transduced hepatocytes into the liver or under the kidney capsule. When the cells were transplanted into the liver, Ad-transduced hepatocytes cultured in suspension conditions were found to have a significantly higher survival rate (p < 0.01) than Ad-transduced hepatocytes cultured under standard conditions. We also confirmed that these Ad-transduced hepatocytes have ability to survive long term and were able to engineer a biologically active hepatic tissue under the kidney capsule. Finally, we obtained high level of transduction into canine, porcine, and human isolated hepatocytes in a suspension solution mixed with Ad. In conclusion, the present studies demonstrate that isolated hepatocytes could be genetically modified using Ad when kept in a suspension solution. For this reason, this cell-modified technique could be used for the treatment of liver-targeted diseases and/or disorders.

Stability and Repeat Regeneration Potential of the Engineered Liver Tissues under the Kidney Capsule in Mice

Liver tissue engineering using hepatocyte transplantation has been proposed as a therapeutic alternative to liver transplantation toward several liver diseases. We have previously reported that stable liver tissue with the potential for liver regeneration can be engineered at extrahepatic sites by transplanting mature hepatocytes into an extracellular matrix. The present study was aimed at assessing the liver tissue persistence after induced regeneration by hepatectomy and repeat regeneration potential induced by repeat hepatectomy. Mouse isolated hepatocytes mixed in EHS extracellular matrix gel were transplanted under both kidney capsules of isogenic mice. The hepatocyte survival persisted for over 25 weeks. In some of the mice, we confirmed that the grafted hepatocytes developed a thin layer of liver tissues under the kidney capsule, determined by specific characteristics of differentiated hepatocytes in cord structures between the capillaries. We then assessed the regenerative potential and persistence of the exogenous liver tissue. To induce liver regeneration, we performed a two-thirds hepatectomy at 70 days after hepatocyte transplantation. Three weeks after this procedure, the engineered liver tissues showed active regeneration, reaching serum marker protein levels of 261 ± 42% of the prehepatectomy level. We found that the regenerated liver tissue was stably maintained for 100 days (length of the experiment). Repeat regeneration potential was established by performing a repeat hepatectomy (that had been two-thirds hepatectomized at day 70) 60 days after the initial hepatectomy. Again, the regenerated engineered liver tissues showed active regeneration as there was an approximately twofold increase in the serum marker protein levels. The present studies demonstrate that liver tissue, which was recognized as a part of the host naive liver in terms of the regeneration profile, could be engineered at a heterologous site that does not have access to the portal circulation.

Diagnostic test accuracy of antigenaemia assay for PCR-proven cytomegalovirus infection-systematic review and meta-analysis

OBJECTIVES

We aimed to assess diagnostic test accuracy of antigenaemia assay for PCR-proven cytomegalovirus (CMV) infection.

METHODS

We systematically searched studies that provide data both on sensitivity and specificity of the CMV antigenaemia assay using the PCR as the reference standard. Adults, children, infants, individuals who were immunocompromised for any reason, symptomatic patients and asymptomatic individuals were all included. A hierarchical summary receiver operating characteristics model was used for diagnostic meta-analysis. Study quality was assessed by Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies. Protocol registration identification is CRD42016035892.

RESULTS

We identified 75 eligible articles including 9058 CMV PCR-positive individuals and 22 232 PCR-negative individuals. The diagnostic odds ratio for positive antigenaemia was 30 (95% CI 24-38, I² = 28%) and the area under the hierarchical summary receiver operating characteristic curve was 0.86 (95% CI 0.83-0.88). The summary estimates of sensitivity and specificity were 0.65 (95% CI 0.59-0.70) and 0.94 (95% CI 0.93-0.95), respectively. The positive likelihood ratio of 10.9 (95% CI 8.5-14.0) suggested that a positive result from the antigenaemia assay greatly increased the probability of PCR-proven CMV infection, but a negative likelihood ratio of 0.38 (95% CI 0.32-0.44) indicated that a negative result led to a small decrease in the probability of PCR-proven CMV infection. Sensitivity and subgroup analyses replicated these results.

CONCLUSIONS

The antigenaemia assay overlooked 35% of PCR-proven CMV infections; hence, a negative result of an antigenaemia assay could not rule out a CMV infection.

Use of fondaparinux for thromboprophylaxis in an unfractionated heparin-intolerant pregnant woman with thrombotic predisposition

A 34-year-old primigravida who had undergone thrombectomy for deep venous thrombosis (DVT) in her leg and exhibited low protein S activity, indicating predisposition to thrombosis, developed DVT of the leg. No pulmonary embolism was detected. After anticoagulant therapy with unfractionated heparin was discontinued because of liver dysfunction, danaparoid treatment was administered in hospital. The patient had a normal delivery after 39 weeks' gestation with no recurrence of thrombosis. During her second pregnancy four years later, she gave herself fondaparinux injections. She delivered normally after 38 weeks' gestation without experiencing DVT. Fondaparinux may be a useful anticoagulant for heparin-intolerant pregnant women.

Overexpression of E3 ubiquitin ligase tripartite motif 32 correlates with a poor prognosis in patients with gastric cancer

Tripartite motif protein (TRIM) 32 belongs to the TRIM family, which is composed of RING finger, B-box and coiled-coil domains. TRIM32 has been reported to function as an enzyme 3 ubiquitin ligase and is overexpressed in numerous types of cancer. The present study evaluated the clinical significance of TRIM32 expression levels in gastric cancer. The current study also investigated the TRIM32 expression levels in 142 patients with gastric cancer using immunohistochemistry and examined its clinical importance and potential as a prognostic marker. Furthermore, the function of TRIM32 was examined in vitro. High TRIM32 expression levels were detected in gastric cancer tissues. The postoperative overall and relapse-free survival rates were significantly reduced in patients with tumors with high levels of TRIM32 expression compared with those with tumors expressing low levels of TRIM32. Tumors expressing high levels of TRIM32 were associated with an increased risk of postoperative recurrence, particularly hematogenous recurrence. Multivariate analysis identified TRIM32 status as an independent prognostic factor. Furthermore, TRIM32 gene silencing induced apoptosis and inhibited the proliferation of gastric cancer cells in vitro. Therefore, TRIM32 expression levels may be of potential prognostic value in gastric cancer.

Outcomes of Laparoscopic Liver Resection for Patients with Large Colorectal Liver Metastases: A Case-Matched Analysis

BACKGROUND

Despite the expansion of laparoscopic approach in the treatment of liver tumors, limited data have been reported regarding large colorectal liver metastases (CRLMs). This study aimed at assessing the short- and long-term outcomes after laparoscopic liver resection (LLR) for large (≥5 cm) CRLMs.

METHODS

This was a case-matched study (1:2) comparing patients with large (group L; ≥5 cm) and small (group S; <5 cm) CRLMs using demographic, tumor, and surgical characteristics as matching variables. Postoperative outcomes and survival data were compared in the 2 groups.

RESULTS

Forty patients who underwent LLR for large CRLMs were matched with 80 patients with tumors <5 cm. Major hepatectomy was performed with 75.0 % of patients in Group L and 66.3 % in group S (p = 0.403). Operative time was 300 min in group L and 240 min in group S (p = 0.059). The postoperative mortality and overall morbidity rates were comparable in the 2 groups (p = 1.000 and 0.170, respectively). Postoperative major complication (Dindo-Clavien ≥3) was similar between the two groups (p = 0.072). R0 resection was achieved in 92.5 % in the group L and in 95.0 % in the group S (p = 1.000). The 5-year overall survival and recurrence-free survival were better for group S than for group L (47.3 vs. 35.4 %, p = 0.044 and 27.3 vs. 14.9 %, p = 0.042, respectively). Multivariate analysis identified positive surgical margins and synchronous presentation as prognostic factors.

CONCLUSION

Since LLR was performed safely with favorable oncological adequacy in selected patients with large CRLMs, tumor size should not modify the surgical approach.

Correlation between luminescence intensity and cytotoxicity in cell-based cytotoxicity assay using luciferase

The luciferase reporter assay has become one of the conventional methods for cytotoxicity evaluation. Typically, the decrease of luminescence expressed by a constitutive promoter is used as an index of cytotoxicity. However, to our knowledge, there have been no reports of the correlation between cytotoxicity and luminescence intensity. In this study, to accurately verify the correlation between them, beetle luciferase was stably expressed in human hepatoma HepG2 cells harboring the multi-integrase mouse artificial chromosome vector. We showed that the cytotoxicity assay using luciferase does not depend on the stability of luciferase protein and the kind of constitutive promoter. Next, HepG2 cells in which green-emitting beetle luciferase was expressed under the control of CAG promoter were exposed to 58 compounds. The luminescence intensity and cytotoxicity curves of cells exposed to 48 compounds showed similar tendencies, whereas those of cells exposed to 10 compounds did not do so, although the curves gradually approached each other with increasing exposure time. Finally, we demonstrated that luciferase expressed under the control of a constitutive promoter can be utilized both as an internal control reporter for normalizing a test reporter and for monitoring cytotoxicity when two kinds of luciferases are simultaneously used in the cytotoxicity assay.

Serum ferritin level is a prognostic marker in patients with peripheral T-cell lymphoma

INTRODUCTION

The prognostic value of serum ferritin level in patients with peripheral T-cell lymphoma (PTCL) remains unknown.

METHODS

We retrospectively analyzed clinical data from 78 consecutive patients with newly diagnosed PTCL that were treated with anthracycline-containing regimens between 1998 and 2011.

RESULTS

The patients consisted of 50 males and 28 females with a median age of 64 years (range, 16-83 years). The subtypes of PTCL were 39 PTCL, not otherwise specified and 39 angioimmunoblastic T-cell lymphoma (AITL). The median observation period for the surviving patients was 50 months. The overall survival (OS) was poorer in patients with serum ferritin level above the upper normal limit (n = 28), compared with patients with serum ferritin level within normal range (n = 50; 4-year OS: 23% vs. 72%; P < 0.001). In the multivariate analysis, poor performance status (P = 0.006) and elevated serum ferritin level (P = 0.018) were independent risk factors for poor OS.

CONCLUSION

Serum ferritin level is a useful prognostic marker for PTCL.

Keratin 19 as a key molecule in progression of human hepatocellular carcinomas through invasion and angiogenesis

BACKGROUND

Keratin (K) 19-positive hepatocellular carcinoma (HCC) is well known to have a higher malignant potential than K19-negative HCC: However, the molecular mechanisms involved in K19-mediated progression of HCC remain unclear. We attempted to clarify whether K19 directly affects cell survival and invasiveness in association with cellular senescence or epithelial-mesenchymal transition (EMT) in K19-positive HCC.

METHODS

K19 expression was analysed in 136 HCC surgical specimens. The relationship of K19 with clinicopathological factors and survival was analysed. Further, the effect of K19 on cell proliferation, invasion, and angiogenesis was examined by silencing K19 in the human HCC cell lines, HepG2, HuH-7, and PLC/PRF/5. Finally, we investigated HCC invasion, proliferation, and angiogenesis using K19-positive HCC specimens.

RESULTS

Analysis of HCC surgical specimens revealed that K19-positive HCC exhibited higher invasiveness, metastatic potential, and poorer prognosis. In vitro experiments using the human HCC cell lines revealed that K19 silencing suppressed cell growth by inducting apoptosis or upregulating p16 and p27, resulting in cellular senescence. In addition, transfection with K19 siRNA upregulated E-cadherin gene expression, significantly inhibited the invasive capacity of the cells, downregulated angiogenesis-related molecules such as vasohibin-1 (VASH1) and fibroblast growth factor 1 (FGFR1), and upregulated vasohibin-2 (VASH2). K19-positive HCC specimens exhibited a high MIB-1 labelling index, decreased E-cadherin expression, and high microvessel density around cancer foci.

CONCLUSION

K19 directly promotes cancer cell survival, invasion, and angiogenesis, resulting in HCC progression and poor clinical outcome. K19 may therefore be a novel drug target for the treatment of K19-positive HCC.