Sec16 and Sed4 interdependently function as interaction and localization partners at ER exit sites.

COPII proteins assemble at ER exit sites (ERES) to form transport carriers. The initiation of COPII assembly in the yeast Saccharomyces cerevisiae is triggered by the ER membrane protein Sec12. Sec16, which plays a critical role in COPII organization, localizes to ERES independently of Sec12. However, the mechanism underlying Sec16 localization is poorly understood. Here, we show that a Sec12 homolog, Sed4, is concentrated at ERES and mediates ERES localization of Sec16. We found that the interaction between Sec16 and Sed4 ensures their correct localization to ERES. Loss of the interaction with Sec16 leads to redistribution of Sed4 from the ERES specifically to high-curvature ER areas, such as the tubules and edges of the sheets. The luminal domain of Sed4 mediates this distribution, which is required for Sed4, but not for Sec16, to be concentrated at ERES. We further show that the luminal domain and its O-mannosylation are involved in the self-interaction of Sed4. Our findings provide insight into how Sec16 and Sed4 function interdependently at ERES.

Clathrin-mediated endocytosis is essential for the selective degradation of maternal membrane proteins and preimplantation development.

Fertilization triggers significant cellular remodeling through the oocyte-to-embryo transition. In this transition, the ubiquitin-proteasome system and autophagy are essential for the degradation of maternal components; however, the significance of degradation of cell surface components remains unknown. In this study, we show that multiple maternal plasma membrane proteins, such as the glycine transporter GlyT1a, are selectively internalized from the plasma membrane to endosomes in mouse embryos by the late two-cell stage and then transported to lysosomes for degradation at the later stages. During this process, large amounts of ubiquitylated proteins accumulated on endosomes. Furthermore, the degradation of GlyT1a with mutations in potential ubiquitylation sites was delayed, suggesting that ubiquitylation may be involved in GlyT1a degradation. The clathrin inhibitor blocked GlyT1a internalization. Strikingly, the protein kinase C (PKC) activator triggered the heterochronic internalization of GlyT1a; the PKC inhibitor markedly blocked GlyT1a endocytosis. Lastly, clathrin inhibition completely blocked embryogenesis at the two-cell stage and inhibited cell division after the four-cell stage. These findings demonstrate that PKC-dependent clathrin-mediated endocytosis is essential for the selective degradation of maternal membrane proteins during oocyte-to-embryo transition and early embryogenesis.

Improved low-invasive mRNA electroporation method into immature mouse oocytes visualizes protein dynamics during development.

One of the major causes of oocyte quality deterioration, chromosome segregation abnormalities manifest mainly during meiosis I, which occurs before and during ovulation. However, currently, there is a technical limitation in the introduction of mRNA into premature oocytes without impairing embryonic developmental ability. In this study, we established a low-invasive electroporation (EP) method to introduce mRNA into pre-ovulatory, germinal vesicle (GV) mouse oocytes in an easier manner than the traditional microinjection method. The EP method with an optimized impedance value resulted in the efficient introduction of mRNAs encoding enhanced green fluorescent protein (EGFP) into the GV oocytes surrounded by cumulus cells at a survival rate of 95.0%. Furthermore, the introduction of histone H2B-EGFP mRNA into the GV oocytes labeled most of the oocytes without affecting the blastocyst development rate, indicating the feasibility of the visualization of oocyte chromosomal dynamics that enable us to assay chromosomal integrity in oocyte maturation and cell count in embryonic development. The establishment of this EP method offers extensive assays to select pre-implantation embryos and enables the surveying of essential factors for mammalian oocyte quality determination.

Safety and effectiveness of SARS-CoV-2 vaccines for patients with intractable hepatobiliary diseases: A multicenter, questionnaire-based, cross-sectional study.

AIM: There are few data regarding the safety and effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients with intractable hepatobiliary diseases. We conducted a multicenter, questionnaire-based, cross-sectional study to determine the safety and effectiveness of the SARS-CoV-2 vaccines in Japanese patients with intractable hepatobiliary disease. METHODS: Patients aged ≥18 years with autoimmune hepatitis (AIH), primary biliary cholangitis, primary sclerosing cholangitis, Budd-Chiari syndrome, idiopathic portal hypertension, and extrahepatic portal vein obstruction at each center were consecutively invited to join the study. Participants were asked to complete a questionnaire regarding their characteristics, vaccination status, post-vaccination adverse effects, and SARS-CoV-2 infection. Additionally, liver disease status, treatment regimens, and liver function test values pre- and post-vaccination were collected. RESULTS: The survey was conducted from September 2021 to May 2022, and 528 patients (220 AIH, 251 primary biliary cholangitis, 6 AIH- primary biliary cholangitis/primary sclerosing cholangitis overlap, 39 primary sclerosing cholangitis, 4 Budd-Chiari syndrome, 5 idiopathic portal hypertension, and 3 extrahepatic portal vein obstruction) participated in the study. Post-vaccination adverse effects were comparable to those observed in the general population. Post-vaccination liver injuries classified as grade 1 or higher were observed in 83 cases (16%), whereas grades 2 and 3 were observed in only six cases (1.1%); AIH-like liver injury requiring treatment was not observed. Overall, 12 patients (2.3%) were infected with SARS-CoV-2, and only one patient was infected 6 months after the second vaccination. CONCLUSION: SARS-CoV-2 vaccines demonstrated satisfactory safety and effectiveness in Japanese patients with intractable hepatobiliary diseases.

Spontaneous Overactivation of Xenopus Frog Eggs Triggers Necrotic Cell Death.

The excessive activation of frog eggs, referred to as overactivation, can be initiated by strong oxidative stress, leading to expedited calcium-dependent non-apoptotic cell death. Overactivation also occurs spontaneously, albeit at a low frequency, in natural populations of spawned frog eggs. Currently, the cytological and biochemical events of the spontaneous process have not been characterized. In the present study, we demonstrate that the spontaneous overactivation of Xenopus frog eggs, similarly to oxidative stress- and mechanical stress-induced overactivation, is characterized by the fast and irreversible contraction of the egg's cortical layer, an increase in egg size, the depletion of intracellular ATP, a drastic increase in the intracellular ADP/ATP ratio, and the degradation of M phase-specific cyclin B2. These events manifest in eggs in the absence of caspase activation within one hour of triggering overactivation. Importantly, substantial amounts of ATP and ADP leak from the overactivated eggs, indicating that plasma membrane integrity is compromised in these cells. The rupture of the plasma membrane and acute depletion of intracellular ATP explicitly define necrotic cell death. Finally, we report that egg overactivation can occur in the frog's genital tract. Our data suggest that mechanical stress may be a key factor promoting egg overactivation during oviposition in frogs.

[Autoimmune hepatitis developed after COVID-19 vaccination and ameliorated temporarily but relapsed or stopped improving, and finally resolved by steroid therapy:a report of three cases].

The severe acute respiratory syndrome coronavirus 2 vaccine has contributed to infection control and the prevention of complications due to coronavirus disease 2019 (COVID-19). Conversely, the COVID-19 vaccine has been associated with adverse effects due to liver injury caused by autoimmunity or drugs. To date, Japanese journals have only published five reports of autoimmune liver damage associated with the COVID-19 vaccination. Although the pathogenic mechanism has not yet been fully elucidated, corticosteroids or azathioprine have shown effectiveness in certain patients. However, there have been cases of liver injury resulting in deaths. Here, we encountered three patients who developed autoimmune hepatitis (AIH) within 10 days following vaccination. All three patients were treated with prednisolone (PSL) and achieved remission. However, the serum alanine aminotransferase levels in all cases were observed to either increase or cease to improve during the therapeutic course before PSL administration. It is therefore imperative to closely monitor liver injury after the COVID-19 vaccination. In cases where AIH is suspected and a recurrence of liver dysfunction occurs, PSL may be administered. Future considerations should not only encompass the underlying mechanism by which autoimmunity contributes to the development of liver injury following COVID-19 vaccination but also the optimal treatment period for PSL and the long-term prognosis of AIH after COVID-19 vaccination.

Platinum-based anticancer drugs-induced downregulation of myosin heavy chain isoforms in skeletal muscle of mouse.

Cisplatin, a platinum-based anticancer drug used frequently in cancer treatment, causes skeletal muscle atrophy. It was predicted that the proteolytic pathway is enhanced as the mechanism of this atrophy. Therefore, we investigated whether a platinum-based anticancer drug affects the expression of the major proteins of skeletal muscle, myosin heavy chain (MyHC). Mice were injected with cisplatin or oxaliplatin for four consecutive days. C2C12 myotubes were treated using cisplatin and oxaliplatin. Administration of platinum-based anticancer drug reduced quadriceps mass and muscle strength compared to the control group. Protein levels of all MyHC isoforms were reduced in the platinum-based anticancer drug groups. However, only Myh2 (MyHC-IIa) gene expression in skeletal muscle of mice treated with platinum-based anticancer drugs was found to be reduced. Treatment of C2C12 myotubes with platinum-based anticancer drugs reduced the protein levels of all MyHCs, and treatment with the proteasome inhibitor MG-132 restored this reduction. The expression of Mef2c, which was predicted to act upstream of Myh2, was reduced in the skeletal muscle of mice treated systemically with platinum-based anticancer drug. Degradation of skeletal muscle MyHCs by proteasomes may be a factor that plays an important role in muscle mass loss in platinum-based anticancer drug-induced muscle atrophy.

Significant association between HLA-B*35:01 and onset of drug-induced liver injury caused by Kampo medicines in Japanese patients.

AIM: Drug-induced liver injury (DILI) is a severe and life-threatening immune-mediated adverse effect, occurring rarely among treated patients. We examined genomic biomarkers in the Japanese population that predict the onset of DILI after using a certain class of drugs, such as Kampo products (Japanese traditional medicines). METHODS: A total of 287 patients diagnosed as DILI by hepatology specialists were recruited after written informed consent was obtained. A genome-wide association analysis and human leukocyte antigen (HLA) typing in four digits were performed. RESULTS: We found a significant association (p = 9.41 × 10-10 ) of rs146644517 (G > A) with Kampo product-related DILI. As this polymorphism is located in the HLA region, we evaluated the association of HLA types and found that 12 (63.2%) of 19 Kampo-DILI patients contained HLA-B*35:01, whereas only 15.2% were positive for this HLA among healthy volunteers. The odds ratio was 9.56 (95% confidence interval 3.75-24.46; p = 2.98 × 10-6 , corrected p = 4.17 × 10-5 ), and it increased to 13.55 compared with the DILI patients not exposed to Kampo products. The individual crude drug components in the Kampo products, including Scutellaria root (ougon in Japanese), rhubarb (daiou), Gardenia fruit (sanshishi), and Glycyrrhiza (kanzou), were significantly associated with HLA-B*35:01. CONCLUSIONS: HLA-B*35:01 is a genetic risk factor and a potential predictive biomarker for Kampo-induced DILI in the Japanese population.

Effect of a Cyclooxygenase-2 Inhibitor in Combination with (-)-Epigallocatechin Gallate or Polyphenon E on Cisplatin-Induced Lung Tumorigenesis in A/J Mice.

We investigated the effects of celecoxib combined with (-)-epigallocatechin-3-gallate (EGCG) or polyphenon E in a cisplatin-induced lung tumorigenesis model. Four-week-old female A/J mice were divided into seven groups: (i) Control, (ii) 150 mg/kg celecoxib (150Cel), (iii) 1,500 mg/kg celecoxib (1500Cel), (iv) EGCG+150 mg/kg celecoxib (EGCG+150Cel), (v) EGCG+1,500 mg/kg celecoxib (EGCG+1500Cel), (vi) polyphenon E+150 mg/kg celecoxib (PolyE+150Cel), and (vii) polyphenon E+1,500 mg/kg celecoxib (PolyE+1500Cel). All mice were administered cisplatin (1.62 mg/kg of body weight, i.p.) 1×/week for 10 weeks and sacrificed at week 30; the numbers of tumors on the lung surface were then determined. The tumor incidence and multiplicity (no. of tumors/mouse, mean±SD) were respectively 95% and 2.15±1.50 in Control, 95% and 2.10±1.29 in 150Cel, 86% and 1.67±1.20 in 1500Cel, 71% and 1.38±1.24 in EGCG+150Cel, 67% and 1.29±1.38 in EGCG+1500Cel, 80% and 1.95±1.36 in PolyE+150Cel, and 65% and 1.05±0.10 in PolyE+1500Cel. The combination of high-dose celecoxib with EGCG or polyphenon E significantly reduced multiplicity in cisplatin-induced lung tumors.

Comparative Outcomes of Anterior and Posterior Plating for Distal-Third Humerus Shaft Fractures.

PURPOSE: When treating distal-third humerus shaft fractures (HSFs) surgically, the optimal approach for plating is controversial. We conducted a retrospective multicenter study to investigate and compare the clinical outcomes of anterior and posterior plating in distal-third HSFs and the incidence of complications including iatrogenic radial nerve palsy. METHODS: We identified 116 patients from our multicenter trauma database who were diagnosed as having distal-third HSFs and who underwent surgical treatment, including intramedullary nailing between 2011 and 2020. We analyzed 50 cases treated in one of two ways: open reduction internal fixation with anterior plating (group A: 20 cases) and open reduction internal fixation with posterior plating (group P: 30 cases). RESULTS: The findings were similar in terms of operation time, estimated bleeding, and clinical and radiographic outcomes between the groups. Postoperative radial nerve palsy occurred only in group P (4 cases) and never in group A. CONCLUSIONS: The results of this study suggest that the anterior approach is a safe and effective method for treating distal-third HSFs with satisfactory outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Reorganization, specialization, and degradation of oocyte maternal components for early development.

Background: Oocyte components are maternally provided, solely determine oocyte quality, and coordinately determine embryo quality with zygotic gene expression. During oocyte maturation, maternal organelles are drastically reorganized and specialized to support oocyte characteristics. A large number of maternal components are actively degraded after fertilization and gradually replaced by zygotic gene products. The molecular basis and the significance of these processes on oocyte/embryo quality are not fully understood. Methods: Firstly, recent findings in organelle characteristics of other cells or oocytes from model organisms are introduced for further understanding of oocyte organelle reorganization/specialization. Secondly, recent progress in studies on maternal components degradation and their molecular mechanisms are introduced. Finally, future applications of these advancements for predicting mammalian oocyte/embryo quality are discussed. Main findings: The significance of cellular surface protein degradation via endocytosis for embryonic development, and involvement of biogenesis of lipid droplets in embryonic quality, were recently reported using mammalian model organisms. Conclusion: Identifying key oocyte component characteristics and understanding their dynamics may lead to new applications in oocyte/embryo quality prediction and improvement. To implement these multidimensional concepts, development of new technical approaches that allow us to address the complexity and efficient studies using model organisms are required.

[A case of extensive digestive tract metastasis from invasive lobular carcinoma of the breast].

A 59-year-old female patient underwent surgery for invasive lobular carcinoma of the right breast 12 years ago. The final diagnosis was invasive lobular carcinoma (T4N1M0 stage IIIB). She underwent chemotherapy, radiotherapy, and hormonal therapy after surgery. She had abdominal bloating and vomiting 12 years after surgery. Contrast-enhanced computed tomography (CECT) and esophagogastroduodenoscopy showed edematous thickening from the stomach to the duodenum and moderate amounts of ascites. Lymph node metastasis was not observed. Biopsy specimens of the stomach revealed signet ring cell carcinoma. Immunochemical studies (ER, GCDFP-15, MUC1, MUC5AC, and MUC6) confirmed gastroduodenal metastasis of invasive lobular carcinoma. Ascites disappeared after she underwent chemotherapy with paclitaxel and bevacizumab; however, wall thickening had spread from the lower esophagus to the stomach, small intestine, colon, and rectum on the CECT. She died 7 months after the diagnosis of gastroduodenal metastasis. Herein, we report a case of invasive lobular carcinoma of the breast with extensive digestive tract metastasis.

Synthesis and maintenance of lipid droplets are essential for mouse preimplantation embryonic development.

Lipid droplets (LDs), which are ubiquitous organelles consisting of a neutral lipid core coated with a phospholipid monolayer, play key roles in the regulation of cellular lipid metabolism. Although it is well known that mammalian oocytes and embryos contain LDs and that the amount of LDs varies among animal species, their physiological functions remain unclear. In this study, we have developed a method based on two-step centrifugation for efficient removal of almost all LDs from mouse MII oocytes (delipidation). We found that delipidated MII oocytes could be fertilized in vitro, and developed normally to the blastocyst stage even when the embryos were cultured in the absence of a fatty acid supply. LDs were newly synthesized and accumulated soon after delipidation, but chemical inhibition of long chain acyl-CoA synthetases (ACSLs) blocked this process, resulting in severe impairment of early embryonic development. Furthermore, we found that overabundance of LDs is detrimental to early embryonic development. Our findings demonstrate the importance of synthesis and maintenance of LDs, mediated in part by ACSL activity, during preimplantation embryonic development.

Polarization-insensitive local-oscillator-carrier loopback modulation for a cost-effective and high-port-count wavelength-routing optical switch.

A wavelength-routing optical switch uses a wavelength-tunable laser at each input port, and this transmitter implements output port selection by tuning the wavelength that is associated with each output port. With coherent transmission, loopback modulation of a local oscillator (LO) carrier generated at the output port can eliminate the need for a wavelength-tunable laser. However, loopback modulation can be unstable since the power fluctuates because fiber traversal by the light creates polarization rotation. Here, we propose a simple polarization-alignment circuit and verify its effectiveness in creating a high-port-count optical switch system. The proposed circuit consists of passive components and aligns the polarization state of the supplied LO carrier to be linearly polarized along the x-direction of a TE-input dual-polarization (DP) IQ modulator. The circuit is shown to yield stable modulation with Q-variation of less than 0.8 dB, regardless of any birefringence along the transmission path. The proposal's effectiveness is verified in optical switch system experiments with DP-QPSK signals; 1,856 × 1,856 switch scale is achieved with loopback modulation.

Frequency of null genotypes of glutathione S-transferase M1 and T1 in Japanese patients with drug-induced liver injury.

AIM: Previous reports suggest that the null genotype (*0/*0) of glutathione S-transferase (GST) M1 and/or GSTT1 could be risk factors for drug-induced liver injury (DILI). However, multi-institutional pharmacogenetic research with various suspected drugs has rarely been performed in Japan. Therefore, the aim of this study was to investigate the role of GSTM1 and GSTT1 null genotype in the occurrence of DILI in Japanese patients. METHODS: Blood samples of 270 DILI patients from 23 hospitals throughout Japan collected between 2010 and 2018 were subjected to genotyping of null genotypes of GSTM1 and GSTT1 using the SmartAmp-2 method. We also collected information on DILI types, time to onset of DILI, pharmacological classification of suspected drugs and Digestive Disease Week-Japan score, as well as genotypes of GSTM1 and GSTT1 in each patient with DILI. RESULTS: The distribution of a combination of null genotypes of GSTM1 and GSTT1 in Japanese patients with DILI was significantly different from that reported in the general Japanese population. Notably, the incidence of the GSTM1 null genotype in patients with DILI was significantly higher than that of the control population. A significant relationship between the frequency of GSTM1 and GSTT1 null genotypes and pharmacological classification of suspected drugs, clinical laboratory data for liver function, time to onset of DILI, and Digestive Disease Week-Japan scores was not observed. CONCLUSIONS: The GSTM1 null genotype was associated with an increased incidence of DILI in Japanese patients.

Inhibition of Spred/Sprouty Expression in the Skin of a Contact Dermatitis-Like Model.

We have previously reported that swellings caused by haptens, such as 2,4,6-trinitrochlorobenzene (TNCB), may be associated with the extracellular signal-regulated kinase (ERK)-induced proliferation pathway. However, the involvement of the Spred/Sprouty family as critical negative regulators of the Ras/Raf/ERK signaling pathway at disease sites is not well-established. Thus, in the present study, the effects of hapten-challenge on the expression levels of genes and proteins associated with the Spred/Sprouty family in the ear of mice were investigated. The activation of ERK and epidermal growth factor receptor (EGFR) tyrosine kinase was inhibited by their selective inhibitors, namely, U0126 and PD168393, respectively. Twenty-four hours after the final challenge by the haptens TNCB, 2,4-dinitrofluorobenzene, or oxazolone, ear thickness was augmented by challenge with all haptens and the gene expression levels of Spred1, Spred2, Sprouty1, and Sprouty2 in swelling induced by all haptens were significantly decreased. Furthermore, Spred2, Sprouty1, and Sprouty2 genes were decreased in the epidermis and dermis of the TNCB-challenged ear. In conclusion, it is possible that the mechanism of hapten-challenge-induced skin thickening involves not only the enhancement of cell proliferative functions via the activation of ERK by EGFR tyrosine kinase activation but also the decreases expression of Spred/Sprouty family members.

Multiple roles of endocytosis and autophagy in intracellular remodeling during oocyte-to-embryo transition.

Fertilization is the starting point for creating new progeny. At this time, the highly differentiated oocyte and sperm fuse to form one zygote, which is then converted into a pluripotent early embryo. Recent studies have shown that the lysosomal degradation system via autophagy and endocytosis plays important roles in the remodeling of intracellular components during oocyte-to-embryo transition. For example, in Caenorhabditis elegans, zygotes show high endocytic activity, and some populations of maternal membrane proteins are selectively internalized and delivered to lysosomes for degradation. Furthermore, fertilization triggers selective autophagy of sperm-derived paternal mitochondria, which establishes maternal inheritance of mitochondrial DNA. In addition, it has been shown that autophagy via liquid-liquid phase separation results in the selective degradation of some germ granule components, which are distributed to somatic cells of early embryos. This review outlines the physiological functions of the lysosomal degradation system and its molecular mechanisms in C. elegans and mouse embryos.

Significance of the association between early embryonic development and endocytosis.

Fertilization triggers a process called maternal-to-zygotic transition, in which the oocyte undergoes oocyte-to-embryo transition, leading to massive intracellular remodeling toward early embryogenesis. This transition requires the degradation of oocyte-derived components; however, the significance and mechanism of degradation of cell surface components remain unknown. In this review, we focused on the dynamics of plasma membrane proteins and investigated the relationship between embryonic development and endocytosis. Our survey of the extant literature on the topic led to the conclusion that clathrin-mediated endocytosis is essential for the progression of early embryogenesis and selective degradation of oocyte-derived plasma membrane proteins in mouse embryos, as reported by studies analyzing maternal cellular surface proteins, including a glycine transporter, GlyT1a. Evaluation of such endocytic activity in individual embryos may allow the selection of embryos with higher viability in assisted reproductive technologies, and it is important to select viable embryos to increase the rates of successful pregnancy and live birth. Although the early embryonic developmental abnormalities are mainly accompanied with chromosomal aneuploidy, other causes and mechanisms remain unclear. This review summarizes molecular biological approaches to early embryonic developmental abnormalities and their future prospects.

[Successful treatment of secondary graft failure after allogeneic stem cell transplantation for aplastic anemia with eltrombopag].

Herein we report a case of successful treatment of secondary graft failure due to poor graft function (PGF) using eltrombopag. A 25-year-old woman with aplastic anemia (stage 3) underwent allogeneic bone marrow transplantation (BMT) from her HLA-matched brother. Neutrophil engraftment was achieved on day 17, but she remained dependent on platelet transfusion. Chimerism analysis showed complete donor type, but she also became dependent on red blood cell transfusion later. Eltrombopag was administered on day 253 after BMT, after which she exhibited hematopoietic recovery, resulting in the withdrawal of transfusion dependency. Blood counts continued to be stable after eltrombopag was discontinued. The use of eltrombopag enabled outpatient treatment and induced hematopoietic recovery without significant side effects. Eltrombopag may be an effective and safe option for PGF after BMT.

[Liver injury in patients with moderate II COVID-19 who received dexamethasone monotherapy].

We examined 171 patients with novel coronavirus disease 2019 (COVID-19) with liver injury in the respiratory failure groups and the nonrespiratory failure groups and investigated 41 patients with moderate II COVID-19 with respiratory failure who received dexamethasone (Dex) monotherapy in the liver injury group and the nonliver injury group at the time before treatment. The respiratory failure group had 64% more liver damage than the nonrespiratory failure group, was older, had more men, and had significantly more complications from lifestyle-related diseases such as hypertension and diabetes. Obesity was more common in the liver injury group prior to Dex monotherapy, and the liver CT value was significantly lower than in the nonliver injury group. Liver injury worsened in 41% of patients after Dex monotherapy, but there was no significant difference in the frequency before Dex monotherapy between the liver injury group and the nonliver injury group, and the degree of liver injury was mild in all cases, improving in 38% of the liver injury group. Dex monotherapy was a safe treatment for moderate II COVID-19, which frequently resulted in liver injury.