目的研究替米沙坦促进大鼠胰岛素分泌作用相关的信号通路。方法(1)分离成年Wistar大鼠胰腺获得胰岛和胰岛细胞,通过胰岛素分泌实验观察药物对胰岛素分泌的影响,通过钙成像实验和全细胞膜片钳技术观察药物对β细胞内Ca^(2+)浓度的变化和...目的研究替米沙坦促进大鼠胰岛素分泌作用相关的信号通路。方法(1)分离成年Wistar大鼠胰腺获得胰岛和胰岛细胞,通过胰岛素分泌实验观察药物对胰岛素分泌的影响,通过钙成像实验和全细胞膜片钳技术观察药物对β细胞内Ca^(2+)浓度的变化和对离子通道的作用。(2)使用过表达电压门控性钾(voltage-gated potassium channel,Kv)通道2.1亚型(Kv2.1)的慢病毒转染中国仓鼠卵巢(Chinese hamster ovary,CHO)细胞构建CHO-Kv2.1细胞系,使用膜片钳技术观察替米沙坦对Kv2.1通道的直接作用。结果缬沙坦和厄贝沙坦无类似替米沙坦的高糖浓度下促胰岛素分泌、升高β细胞内Ca^(2+)浓度和抑制β细胞的Kv通道等作用。过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)阻断剂GW9662亦未阻断替米沙坦的上述作用。而替米沙坦可以浓度依赖性地抑制CHO-Kv2.1细胞的Kv2.1通道电流。结论替米沙坦的促胰岛素分泌作用可能与血管紧张素Ⅱ-1型(angiotensin II type 1,AT-1)受体和PPARγ无关,但至少与对Kv2.1通道的直接抑制作用有关。展开更多
State Administration for Market Regulation and National Standardization Administration of China have approved the following 218 national standards and 1 national standard with amendment.
Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation...Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation. The immune evasion capability of JN.1 is a subject of scientific investigation. The US CDC used SGTF of TaqPath COVID-19 Combo Kit RT-qPCR as proxy indicator of JN.1 infections for evaluation of the effectiveness of updated monovalent XBB.1.5 COVID-19 vaccines against JN.1 and recommended that all persons aged ≥ 6 months should receive an updated COVID-19 vaccine dose. Objective: Recommend Sanger sequencing instead of proxy indicator to diagnose JN.1 infections to generate the data based on which guidelines are made to direct vaccination policies. Methods: The RNA in nasopharyngeal swab specimens from patients with clinical respiratory infection was subjected to nested RT-PCR, targeting a 398-base segment of the N-gene and a 445-base segment of the RBD of SARS-CoV-2 for amplification. The nested PCR amplicons were sequenced. The DNA sequences were analyzed for amino acid mutations. Results: The N-gene sequence showed R203K, G204R and Q229K, the 3 mutations associated with Omicron BA.2.86 (+JN.1). The RBD sequence showed 24 of the 26 known amino acid mutations, including the hallmark L455S mutation for JN.1 and the V483del for BA.2.86 lineage. Conclusions: Sanger sequencing of a 445-base segment of the SARS-CoV-2 RBD is useful for accurate determination of emerging variants. The CDC may consider using Sanger sequencing of the RBD to diagnose JN.1 infections for statistical analysis in making vaccination policies.展开更多
文摘目的研究替米沙坦促进大鼠胰岛素分泌作用相关的信号通路。方法(1)分离成年Wistar大鼠胰腺获得胰岛和胰岛细胞,通过胰岛素分泌实验观察药物对胰岛素分泌的影响,通过钙成像实验和全细胞膜片钳技术观察药物对β细胞内Ca^(2+)浓度的变化和对离子通道的作用。(2)使用过表达电压门控性钾(voltage-gated potassium channel,Kv)通道2.1亚型(Kv2.1)的慢病毒转染中国仓鼠卵巢(Chinese hamster ovary,CHO)细胞构建CHO-Kv2.1细胞系,使用膜片钳技术观察替米沙坦对Kv2.1通道的直接作用。结果缬沙坦和厄贝沙坦无类似替米沙坦的高糖浓度下促胰岛素分泌、升高β细胞内Ca^(2+)浓度和抑制β细胞的Kv通道等作用。过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)阻断剂GW9662亦未阻断替米沙坦的上述作用。而替米沙坦可以浓度依赖性地抑制CHO-Kv2.1细胞的Kv2.1通道电流。结论替米沙坦的促胰岛素分泌作用可能与血管紧张素Ⅱ-1型(angiotensin II type 1,AT-1)受体和PPARγ无关,但至少与对Kv2.1通道的直接抑制作用有关。
文摘State Administration for Market Regulation and National Standardization Administration of China have approved the following 218 national standards and 1 national standard with amendment.
文摘Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation. The immune evasion capability of JN.1 is a subject of scientific investigation. The US CDC used SGTF of TaqPath COVID-19 Combo Kit RT-qPCR as proxy indicator of JN.1 infections for evaluation of the effectiveness of updated monovalent XBB.1.5 COVID-19 vaccines against JN.1 and recommended that all persons aged ≥ 6 months should receive an updated COVID-19 vaccine dose. Objective: Recommend Sanger sequencing instead of proxy indicator to diagnose JN.1 infections to generate the data based on which guidelines are made to direct vaccination policies. Methods: The RNA in nasopharyngeal swab specimens from patients with clinical respiratory infection was subjected to nested RT-PCR, targeting a 398-base segment of the N-gene and a 445-base segment of the RBD of SARS-CoV-2 for amplification. The nested PCR amplicons were sequenced. The DNA sequences were analyzed for amino acid mutations. Results: The N-gene sequence showed R203K, G204R and Q229K, the 3 mutations associated with Omicron BA.2.86 (+JN.1). The RBD sequence showed 24 of the 26 known amino acid mutations, including the hallmark L455S mutation for JN.1 and the V483del for BA.2.86 lineage. Conclusions: Sanger sequencing of a 445-base segment of the SARS-CoV-2 RBD is useful for accurate determination of emerging variants. The CDC may consider using Sanger sequencing of the RBD to diagnose JN.1 infections for statistical analysis in making vaccination policies.
