Role of the spleen in liver fibrosis in rats may be mediated by transforming growth factor beta-1

BACKGROUND: The effect of the spleen on the cirrhotic liver is unknown. Transforming growth factor-beta 1 (TGF-beta 1), which plays a crucial role in the matrix production during liver fibrosis, is an inhibitory factor regarding the regeneration of hepatocytes. In this study, we investigated the TGF-beta 1 production in the spleen of cirrhotic rats and the effects of a splenectomy on the healing process from liver fibrosis. METHODS: Thirty-six Wistar male rats were used. Thioacetamide (TAA) was administered intraperitoneally for 24 weeks. The rats underwent either a sham operation (TAA + Sham) or a splenectomy (TAA + SPL). The improvements in liver fibrosis and liver regeneration were investigated 10, 30 and 60 days after the operations in each group. The effect of a splenectomy on the plasma concentration of TGF-beta 1 in the portal vein was investigated by ELISA. The TGF-beta 1 expressions in the spleen were measured using immunohistochemical staining and the degree of such expression was measured using RT-PCR. The activity of TGF-beta 1 in the portal vein of TAA + Sham and TAA + SPL was assessed by the inhibiting effect of rat parenchymal hepatocyte proliferation in primary culture. RESULTS: Liver regeneration (PCNA-labeling index) in the TAA + SPL rats was stimulated more at 10 and 30 days after the operation (P < 0.05) than in the TAA + Sham rats, and the improvement of liver fibrosis (fibrosis rate) in the TAA + SPL rats was higher at 60 days (P < 0.05) than in the TAA + Sham rats. The plasma concentration of TGF-beta1 of the portal vein in TAA + SPL rats was significantly lower than in the TAA + Sham rats for each period. Immunohistochemically, TGF-beta1-positive stained cells were recognized in the spleen macrophages in the red pulp of cirrhotic rats. The plasma of the TAA + Sham rats at 10 and 30 days after the operation was significantly stronger than that of the TAA + SPL rats in inhibiting the proliferation of rat hepatocytes of primary culture. Inhibitory effects were then dose-dependently neutralized by monoclonal TGF-beta 1 antibody. CONCLUSION: Spleen-derived TGF-beta 1 may thus play an inhibitory role in the healing of liver cirrhosis by inhibiting the regeneration of the damaged liver.     

Chronic salt loading upregulates expression of adrenomedullin and its receptors in adrenal glands and kidneys of the rat

The vasodilator peptide adrenomedullin (AM) elicits diuresis and natriuresis and inhibits aldosterone secretion. The aim of this study was to better understand the role of AM in maintaining water and electrolyte balance during chronic salt loading. Male Wistar rats were divided into a high salt (HS) group that received a diet containing 8% sodium chloride (NaCl) and a normal salt group that received a diet containing 0.4% NaCl. Plasma AM concentrations as well as expression of AM mRNA in the adrenal gland and kidney were then measured after 3, 7, 14, and 28 days. After 28 days, sodium and water excretion were significantly higher in HS rats than in control, although blood pressure and fluid volume were not significantly affected. Moreover, although plasma AM remained unchanged for up to 14 days, it was increased 2.5-fold in HS rats after 28 days on a high salt diet, and there were corresponding 3-fold and 1.5-fold increases in the levels of AM mRNA in the adrenal gland and kidney, respectively. At the same time, expression of calcitonin receptor-like receptor mRNA was significantly upregulated in both kidney and adrenal gland, as was expression of receptor activity-modify protein 1 (RAMP1) and RAMP2 mRNA in the adrenals and expression of RAMP3 in kidneys. Taken together, these results suggest that AM plays a role in the regulation of water and electrolyte balance in animals chronically ingesting high levels of salt.     

Efficacy of thromboelastography in the management of anticoagulation for veno-venous extracorporeal membrane oxygenation in a coronavirus disease 2019 patient: A case report

Rationale:In coronavirus disease 2019 (COVID-19) patients with acute respiratory distress syndrome refractory to optimal conventional management, we should consider the indication for veno-venous extracorporeal membrane oxygenation (V-V ECMO). Growing evidence indicates that COVID-19 frequently causes coagulopathy, presenting as hypercoagulation and incidental thrombosis. For these reasons, a multifactorial approach with several anticoagulant markers should be considered in the management of anticoagulation using heparin in COVID-19 patients on V-V ECMO.Patient concerns:A 48-year-old man was infected with COVID-19 with a worsening condition manifesting as acute respiratory distress syndrome.Diagnoses:He was refractory to conventional therapy, thus we decided to introduce V-V ECMO. We used heparin as an anticoagulant therapy for V-V ECMO and adjusted the doses of heparin by careful monitoring of the activated clotting time (ACT) and activated partial thromboplastin time (APTT) to avoid both hemorrhagic and thrombotic complications. We controlled the doses of heparin in the therapeutic ranges of ACT and APTT, but clinical hemorrhaging and profound elevation of coagulant marker became apparent.Interventions:Using thromboelastography (TEG; Haemonetics) in addition to ACT and APTT, we were able to clearly detect not only sufficient coagulability of COVID19 on V-V ECMO (citrated rapid thromboelastography-R 0.5 min, angle 75.5°, MA 64.0 mm, citrated functional fibrinogen-MA 20.7 mm) but also an excessive effect of heparin (citrated kaolin -R 42.7 min, citrated kaolin with heparinase 11.7 min).Outcomes:Given the TEG findings indicating an excessive heparin effect, the early withdrawal of ECMO was considered. After an evaluation of the patient''s respiratory capacity, withdrawal from V-V ECMO was achieved and then anticoagulation was stopped. The hemorrhagic complications and elevated thrombotic marker levels dramatically decreased.Lessons:TEG monitoring might be a useful option for managing anticoagulation in COVID-19 patients on V-V ECMO frequently showing a hypercoagulative state and requiring massive doses of heparin, to reduce both hemorrhagic and thrombotic complications.     

Deciphering Subtype-Selective Modulations in TRPA1 Biosensor Channels

The transient receptor potential (TRP) proteins are a family of ion channels that act as cellular sensors. Several members of the TRP family are sensitive to oxidative stress mediators. Among them, TRPA1 is remarkably susceptible to various oxidants, and is known to mediate neuropathic pain and respiratory, vascular and gastrointestinal functions, making TRPA1 an attractive therapeutic target. Recent studies have revealed a number of modulators (both activators and inhibitors) that act on TRPA1. Endogenous mediators of oxidative stress and exogenous electrophiles activate TRPA1 through oxidative modification of cysteine residues. Non-electrophilic compounds also activate TRPA1. Certain non-electrophilic modulators may act on critical non-cysteine sites in TRPA1. However, a method to achieve selective modulation of TRPA1 by small molecules has not yet been established. More recently, we found that a novel N-nitrosamine compound activates TRPA1 by S-nitrosylation (the addition of a nitric oxide (NO) group to cysteine thiol), and does so with significant selectivity over other NO-sensitive TRP channels. It is proposed that this subtype selectivity is conferred through synergistic effects of electrophilic cysteine transnitrosylation and molecular recognition of the non-electrophilic moiety on the N-nitrosamine. In this review, we describe the molecular pharmacology of these TRPA1 modulators and discuss their modulatory mechanisms.     

Interleukin‐8‐producing primary cardiac undifferentiated sarcoma in a child with sustained fever

We report the case of a 12‐year‐old boy with primary undifferentiated sarcoma of the left atrium. He had sustained fever during the clinical course and multiple lung and brain metastases. Chemotherapy and irradiation were ineffective; he died 41 days after hospitalization. On retrospective analysis, interleukin‐8 (IL‐8) was elevated; this was supported by immunohistochemistry and gene expression analysis of tumor samples. IL‐8 continued to increase with tumor progression accompanied by elevated neutrophil count and C‐reactive protein. IL‐8 is involved in malignant tumor proliferation, migration, and angiogenesis and may have been related to the clinical condition and prognosis in the present case.     

Liver with hypoechoic nodular pattern as a risk factor for hepatocellular carcinoma

Ultrasonography should be used for screening of hepatocellular carcinoma, but there are few reports on the relationship between liver ultrasonographic findings and the development of hepatocellular carcinoma (HCC). Using prospective follow-up studies, we examined the role of liver with a hypoechoic nodular pattern as a high-risk factor in HCC. The study was performed by follow-up on 593 patients with chronic liver disease recorded at our hospital. The ultrasonographic pattern of the liver parenchyma was classified either as a small or large hypoechoic nodular pattern or as a nonnodular pattern. Patients were followed up from the time of initial ultrasonographic examination (1985–1987) until January 1, 1991. During the follow-up period (average, 4.2 years, range, 0.3–6.0 years), 62 patients were found to have HCC (12%). Patients whose livers showed small or large hypoechoic nodular pattern had a significantly higher risk of HCC than did patients whose livers showed a nonnodular pattern (rate ratios were 14.0 and 20.0, respectively, adjusted for age, sex, hepatitis virus markers, ICG R15, α-fetoprotein concentration, and ultrasonographic pattern of the liver). Liver showing a hypoechoic nodular pattern is a major risk factor in HCC.