Combinatorial Inhibition of Myostatin and Activin A Improves Femoral Bone Properties in the G610C Mouse Model of Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a collagen-related bone disorder characterized by fragile osteopenic bone and muscle weakness. We have previously shown that the soluble activin receptor type IIB decoy (sActRIIB) molecule increases muscle mass and improves bone strength in the mild to moderate G610C mouse model of OI. The sActRIIB molecule binds multiple transforming growth factor-β (TGF-β) ligands, including myostatin and activin A. Here, we investigate the musculoskeletal effects of inhibiting activin A alone, myostatin alone, or both myostatin and activin A in wild-type (Wt) and heterozygous G610C (+/G610C) mice using specific monoclonal antibodies. Male and female Wt and +/G610C mice were treated twice weekly with intraperitoneal injections of monoclonal control antibody (Ctrl-Ab, Regn1945), anti-activin A antibody (ActA-Ab, Regn2476), anti-myostatin antibody (Mstn-Ab, Regn647), or both ActA-Ab and Mstn-Ab (Combo, Regn2476, and Regn647) from 5 to 16 weeks of age. Prior to euthanasia, whole body composition, metabolism and muscle force generation assessments were performed. Post euthanasia, hindlimb muscles were evaluated for mass, and femurs were evaluated for changes in microarchitecture and biomechanical strength using micro–computed tomography (μCT) and three-point bend analyses. ActA-Ab treatment minimally impacted the +/G610C musculoskeleton, and was detrimental to bone strength in male +/G610C mice. Mstn-Ab treatment, as previously reported, resulted in substantial increases in hindlimb muscle weights and overall body weights in Wt and male +/G610C mice, but had minimal skeletal impact in +/G610C mice. Conversely, the Combo treatment outperformed ActA-Ab alone or Mstn-Ab alone, consistently increasing hindlimb muscle and body weights regardless of sex or genotype and improving bone microarchitecture and strength in both male and female +/G610C and Wt mice. Combinatorial inhibition of activin A and myostatin more potently increased muscle mass and bone microarchitecture and strength than either antibody alone, recapturing most of the observed benefits of sActRIIB treatment in +/G610C mice. © 2022 American Society for Bone and Mineral Research (ASBMR).     

鼠巨细胞病毒感染C57BL/6小鼠急性肝炎动物模型的建立与鉴定

目的：建立鼠巨细胞病毒（MCMV）感染C57BL/6小鼠急性肝炎模型并对其感染特点进行分析及鉴定。方法：将24 只C57BL/6小鼠随机分为阴性对照组（n =12）及病毒感染组（n =12），病毒感染组腹腔注射1.0×106 PFU（200 μL）MCMV悬液，阴性对照组注射等体积小鼠胚胎成纤维细胞（MEF）悬液。于感染后第3天和第7天取外周血分离血清检测谷丙转氨酶（ALT）及谷草转氨酶（AST）。同时进行肝组织病毒分离、组织病理学及MCMV IE和M55基因、细胞因子白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）、肿瘤坏死因子α（TNF-α）的检测。结果：病毒感染组肝组织匀浆病毒分离均为阳性，肝炎发生率为100%。在感染后第3天即发生肝炎病理改变，病毒感染组血清ALT及AST较阴性对照组明显升高（P ＜0.01）；病毒感染组肝脏HE染色第3天可见局灶性炎性细胞浸润及肝脏点灶状坏死，持续至第7天，Ishak评分较阴性对照组明显升高（P ＜0.01）；在感染后第3天病毒感染组肝组织内可检测到MCMV IE及M55基因，且在感染后第7天仍可测得IE基因；感染后第3天及第7天病毒感染组炎性细胞因子IL-6、TNF-α及IL-1β mRNA表达水平明显升高（P ＜0.05）。 结论：成功建立MCMV感染C57BL/6小鼠急性动物肝炎模型，其感染表现主要集中在急性感染前期。     

艾尔巴韦/格拉瑞韦治疗慢性丙型肝炎患者疗效初步观察

目的 初步探讨应用艾尔巴韦/格拉瑞韦治疗慢性丙型肝炎(CHC)患者的疗效。方法 2017年3月~2018年3月仙桃市第一人民医院感染病科收治的CHC患者82例,被随机分为对照组41例和观察组41例,分别给予聚乙二醇干扰素-α联合利巴韦林治疗和艾尔巴韦/格拉瑞韦治疗,两组均连续治疗24周。采用RT- PCR法检测血清 HCV RNA,采用全基因序列测定法行病毒基因分型。比较两组早期病毒学应答(EVR)、治疗结束时病毒学应答(ETVR)和持续病毒学应答(SVR)。结果 在治疗结束时,观察组血清丙氨酸氨基转移酶(ALT)水平为(47.9±19.7)U/L,显著低于对照组【(63.5±21.2)U/L,P<0.05】,天冬氨酸氨基转移酶(AST)水平为(55.5±22.3)U/L,显著低于对照组【(81.3±25.8)U/L,P<0.05】;观察组EVR、ETVR和SVR分别为48.8%、63.4%和70.7%,与对照组的41.5%、53.7%和65.8%比,无统计学差异(P>0.05);18例观察组非HCV Ⅰ型感染者EVR、ETVR和SVR分别为88.9%、94.4%和88.9%,显著高于同组23例HCV Ⅰ型感染者(分别为52.2%、60.9%和52.2%, P<0.05),而与对照组15例非HCV Ⅰ型感染者比,无统计学差异(分别为86.7%、93.3%和73.3%, P>0.05);观察组SVR₁₂为87.8%(36/41),显著高于对照组的73.2%(30/41,P<0.05)。结论 应用直接抗病毒(DAA)药物艾尔巴韦/格拉瑞韦治疗CHC患者近期疗效达到,但远期疗效似优于标准治疗方案, 值得临床进一步验证。     

Infección por el virus de la hepatitis C y nuevas estrategias de tratamiento

Hepatitis C is a major public health problem worldwide. This disease is caused by the hepatitis C virus, which is characterised by its genetic diversity. The infection is usually asymptomatic. However, between 60% and 80% of HCV-infected individuals will progress to chronic hepatitis, 20% to liver cirrhosis in the medium-to long-term and, each year, between 1% and 4% of these patients with cirrhosis will develop hepatocellular carcinoma (HCC). A Spanish consensus document has recently been drafted to diagnose hepatitis C in a single step, consisting of active investigation (antibodies and viremia) in a single sample, which according to the experts, would reduce the time to access treatment and avoid tracking losses. To definitively change the hepatitis C treatment paradigm, direct-acting antiviral drugs (DAAs) have been approved, whose development has been based on achieving cure rates close to 100% regardless of the genotype of the virus, ie, pangenotypes, with good tolerance and bioavailability. These drugs have constituted a real therapeutic revolution. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016», which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A.© 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved.     

Metabolism of deltamethrin and cis- and trans-permethrin by human expressed cytochrome P450 and carboxylesterase enzymes

1. The metabolism of the pyrethroids deltamethrin (DLM), cis-permethrin (CPM) and trans-permethrin (TPM) was studied in human expressed cytochrome P450 (CYP) and carboxylesterase (CES) enzymes.

2. DLM, CPM and TPM were metabolised by human CYP2B6 and CYP2C19, with the highest apparent intrinsic clearance (CL_int) values for pyrethroid metabolism being observed with CYP2C19. Other CYP enzymes contributing to the metabolism of one or more of the three pyrethroids were CYP1A2, CYP2C8, CYP2C9*1, CYP2D6*1, CYP3A4 and CYP3A5. None of the pyrethroids were metabolised by CYP2A6, CYP2E1, CYP3A7 or CYP4A11.

3. DLM, CPM and TPM were metabolised by both human CES1 and CES2 enzymes.

4. Apparent CL_int values for pyrethroid metabolism by CYP and CES enzymes were scaled to per gram of adult human liver using abundance values for microsomal CYP enzymes and for CES enzymes in liver microsomes and cytosol. TPM had the highest and CPM the lowest apparent CL_int values for total metabolism (CYP and CES enzymes) per gram of adult human liver.

5. Due to their higher abundance, all three pyrethroids were extensively metabolised by CES enzymes in adult human liver, with CYP enzymes only accounting for 2%, 10% and 1% of total metabolism for DLM, CPM and TPM, respectively.