Factors Relating to Coagulation, Fibrinolysis and Hepatic Damage After Liver Resection

A survey of the blood of twenty-two patients who had undergone hepatic resection was performed. Serum levels of α-2 plasmin inhibitor-plasmin complex initially decreased from 1.58 ± 0.31 μg/ml on the preoperative day (PREOP), to 0.92 ± 0.14 μ/ml on the first postoperative day (POD 1), and then increased to 3.13 ± 0.92 μg/ml on the seventh postoperative day (POD 7) (mean ± SE)). Thrombin-anti-thrombin III complex (14.2 ± 4.3 ng/ml on PREOP and 26.0 ± 4.1 ng/ml on POD 7 (mean ± SE)) and D-dimer (335 ± 96 ng/ml on PREOP and 1859 ± 258 ng/ml on POD 7 (mean ± SE)) increased in the early postoperative stage. The level of 6-keto-prostaglandin F1α increased after the operations (from 13.2 ± 1.8 pg/ml on PREOP to 37.8 ± 12.8 pg/ml on POD 7 (mean ± SE)). The level of thromboxane B-2 decreased at first, and then gradually increased and returned to its preoperative level on POD 7 (144.7 ± 43.8 pg/ml on PREOP, 57.6 ± 27.5 pg/ml on POD1 and 152.5 ± 58.4 pg/ml on POD 7 (mean ± SE)). Superoxide dismutase activity increased at first, and then gradually decreased, postoperatively (2.8 ± 0.5 NU/ml on PREOP, 4.8 ± 0.8 NU/ml on POD1 and 2.6 ± 0.3 NU/ml on POD 7 (mean ± SE)). That is, biodefensive reactions which protect patients against the shift to disseminated intravascular coagulation (DIC) were inferred with by the increase in antiplatelet aggregation, despite the activation of coagulation and fibrinolytic mechanisms after hepatic resection

Differential impact of Ink4a and Arf on hematopoietic stem cells and their bone marrow microenvironment in Bmi1-deficient mice

The polycomb group (PcG) protein Bmi1 plays an essential role in the self-renewal of hematopoietic and neural stem cells. Derepression of the Ink4a/Arf gene locus has been largely attributed to Bmi1-deficient phenotypes in the nervous system. However, its role in hematopoietic stem cell (HSC) self-renewal remained undetermined. In this study, we show that derepressed p16Ink4a and p19Arf in Bmi1-deficient mice were tightly associated with a loss of self-renewing HSCs. The deletion of both Ink4a and Arf genes substantially restored the self-renewal capacity of Bmi1−/− HSCs. Thus, Bmi1 regulates HSCs by acting as a critical failsafe against the p16Ink4a- and p19Arf-dependent premature loss of HSCs. We further identified a novel role for Bmi1 in the organization of a functional bone marrow (BM) microenvironment. The BM microenvironment in Bmi1−/− mice appeared severely defective in supporting hematopoiesis. The deletion of both Ink4a and Arf genes did not considerably restore the impaired BM microenvironment, leading to a sustained postnatal HSC depletion in Bmi1−/−Ink4a-Arf−/− mice. Our findings unveil a differential role of derepressed Ink4a and Arf on HSCs and their BM microenvironment in Bmi1-deficient mice. Collectively, Bmi1 regulates self-renewing HSCs in both cell-autonomous and nonautonomous manners

Gastrointestinal Stromal Tumor in a Patient with Neurofibromatosis: Abscess Formation in the Tumor Leading to Bacteremia and Seizure

A 66-year-old woman with neurofibromatosis type 1 (NF1) was brought to the emergency room with seizures and high-grade fever. Seizure in adult NF1 patients raises concern for intracranial lesions. However, neurological examination and central nervous system imaging failed to detect any causative intracranial lesions for her seizure. Gram-positive cocci, Streptococcus anginosus, were detected by blood cultures. Abdominal computed tomography revealed a well-defined round mass 7 cm in diameter, which was found to be a small intestinal gastrointestinal stromal tumor (GIST) containing an abscess. There was fistula formation between the intestinal lumen and the abscess, in which there were numerous Gram-positive cocci. The seizure may have been caused by hypoosmolality (hyponatremia and hypoproteinemia), which may result from decreased food intake associated with high-grade fever and general malaise. In this case GIST originating from the small intestine was invaded by S. anginosus through a fistula, leading to abscess formation, bacteremia, high-grade fever, and seizure, which was the first clinical manifestation

Bmi1 Confers Resistance to Oxidative Stress on Hematopoietic Stem Cells

The polycomb-group (PcG) proteins function as general regulators of stem cells. We previously reported that retrovirus-mediated overexpression of Bmi1, a gene encoding a core component of polycomb repressive complex (PRC) 1, maintained self-renewing hematopoietic stem cells (HSCs) during long-term culture. However, the effects of overexpression of Bmi1 on HSCs in vivo remained to be precisely addressed.In this study, we generated a mouse line where Bmi1 can be conditionally overexpressed under the control of the endogenous Rosa26 promoter in a hematopoietic cell-specific fashion (Tie2-Cre;R26Stop(FL)Bmi1). Although overexpression of Bmi1 did not significantly affect steady state hematopoiesis, it promoted expansion of functional HSCs during ex vivo culture and efficiently protected HSCs against loss of self-renewal capacity during serial transplantation. Overexpression of Bmi1 had no effect on DNA damage response triggered by ionizing radiation. In contrast, Tie2-Cre;R26Stop(FL)Bmi1 HSCs under oxidative stress maintained a multipotent state and generally tolerated oxidative stress better than the control. Unexpectedly, overexpression of Bmi1 had no impact on the level of intracellular reactive oxygen species (ROS).Our findings demonstrate that overexpression of Bmi1 confers resistance to stresses, particularly oxidative stress, onto HSCs. This thereby enhances their regenerative capacity and suggests that Bmi1 is located downstream of ROS signaling and negatively regulated by it

Analysis of gut microbiome, host genetics, and plasma metabolites reveals gut microbiome-host interactions in the Japanese population

Interaction between the gut microbiome and host plays a key role in human health. Here, we perform a metagenome shotgun-sequencing-based analysis of Japanese participants to reveal associations between the gut microbiome, host genetics, and plasma metabolome. A genome-wide association study (GWAS) for microbial species (n = 524) identifies associations between the PDE1C gene locus and Bacteroides intestinalis and between TGIF2 and TGIF2-RAB5IF gene loci and Bacteroides acidifiaciens. In a microbial gene ortholog GWAS, agaE and agaS, which are related to the metabolism of carbohydrates forming the blood group A antigen, are associated with blood group A in a manner depending on the secretor status determined by the East Asian-specific FUT2 variant. A microbiome-metabolome association analysis (n = 261) identifies associations between bile acids and microbial features such as bile acid metabolism gene orthologs including bai and 7β-hydroxysteroid dehydrogenase. Our publicly available data will be a useful resource for understanding gut microbiome-host interactions in an underrepresented population.Tomofuji Yoshihiko, Kishikawa Toshihiro, Sonehara Kyuto, et al. Analysis of gut microbiome, host genetics, and plasma metabolites reveals gut microbiome-host interactions in the Japanese population. Cell Reports 42, 113324 (2023); https://doi.org/10.1016/j.celrep.2023.113324

A Novel Zinc Finger Protein Zfp277 Mediates Transcriptional Repression of the Ink4a/Arf Locus through Polycomb Repressive Complex 1

Polycomb group (PcG) proteins play a crucial role in cellular senescence as key transcriptional regulators of the Ink4a/Arf tumor suppressor gene locus. However, how PcG complexes target and contribute to stable gene silencing of the Ink4a/Arf locus remains little understood.We examined the function of Zinc finger domain-containing protein 277 (Zfp277), a novel zinc finger protein that interacts with the PcG protein Bmi1. Zfp277 binds to the Ink4a/Arf locus in a Bmi1-independent manner and interacts with polycomb repressor complex (PRC) 1 through direct interaction with Bmi1. Loss of Zfp277 in mouse embryonic fibroblasts (MEFs) caused dissociation of PcG proteins from the Ink4a/Arf locus, resulting in premature senescence associated with derepressed p16(Ink4a) and p19(Arf) expression. Levels of both Zfp277 and PcG proteins inversely correlated with those of reactive oxygen species (ROS) in senescing MEFs, but the treatment of Zfp277(-/-) MEFs with an antioxidant restored the binding of PRC2 but not PRC1 to the Ink4a/Arf locus. Notably, forced expression of Bmi1 in Zfp277(-/-) MEFs did not restore the binding of Bmi1 to the Ink4a/Arf locus and failed to bypass cellular senescence. A Zfp277 mutant that could not bind Bmi1 did not rescue Zfp277(-/-) MEFs from premature senescence.Our findings implicate Zfp277 in the transcriptional regulation of the Ink4a/Arf locus and suggest that the interaction of Zfp277 with Bmi1 is essential for the recruitment of PRC1 to the Ink4a/Arf locus. Our findings also highlight dynamic regulation of both Zfp277 and PcG proteins by the oxidative stress pathways

Metabolic syndrome is associated with incidence of deep cerebral microbleeds.

Metabolic syndrome (MetS) has been associated with silent brain lesions; however, there are no data on the relationship between MetS and the incidence of cerebral microbleeds (CMBs) in Asian populations. The aim of this study was to evaluate the longitudinal association between MetS and incidence of CMBs in the Japanese population. We performed a prospective cohort study involving 684 Japanese participants (mean age, 61.7 years) with a mean 6.5 ± 3.4 years follow-up. All participants underwent 1.5 T magnetic resonance imaging, and CMBs were classified by their locations. Logistic regression analyses were performed to examine the relationship of MetS and its components with the incidence of CMBs. MetS was observed in 7.5% of the study population. Forty-nine (7.2%) subjects (36 had new deep or infratentorial CMBs, 13 had new strictly lobar CMBs) developed new CMBs during the follow-up period. In multivariable analysis, MetS was significantly associated with the incidence of deep or infratentorial CMBs (odds ratio, 4.03; 95% confidence interval, 1.72-9.41), and the elevated blood pressure component was most robustly associated with the incidence of deep or infratentorial CMBs (odds ratio, 5.16; 95% confidence interval, 2.02-13.2). Increased body mass index was also associated with incidence of deep or infratentorial CMBs (odds ratio, 2.45; 95% confidence interval, 1.06-5.67). The present study showed that MetS predicts incidence of CMBs in the deep brain regions and high blood pressure is the most important among the MetS components

Association of Mild Kidney Dysfunction with Silent Brain Lesions in Neurologically Normal Subjects

Background: Chronic kidney disease (CKD) has been closely associated with stroke. Although a large number of studies reported the relationship between CKD and different types of asymptomatic brain lesions, few comprehensive analyses have been performed for all types of silent brain lesions. Methods: We performed a cross-sectional study involving 1,937 neurologically normal subjects (mean age 59.4 years). Mild CKD was defined as an estimated glomerular filtration rate between 30 and 60 ml/min/1.73 m2 or positive proteinuria. Results: The prevalence of mild CKD was 8.7%. Univariate analysis revealed an association between CKD and all silent brain lesions, including silent brain infarction, periventricular hyperintensity, subcortical white matter lesion, and microbleeds, in addition to hypertension and diabetes mellitus after adjusting for age and sex. In binary logistic regression analysis, the presence of CKD was a significant risk factor for all types of silent brain lesions, independent of other risk factors. Conclusions: These results suggest that mild CKD is independently associated with all types of silent brain lesions, even in neurologically normal subjects