Deacetylation of 4-(5-acetylamino-2-furyl)thiazole and formation of 1-(4-thiazolyl)-3-cyano-1-propanone by rat liver tissues

The reductive metabolism of the rat carcinogen 4-(5-nitro-2furyl)thiazole (NFT) to 1-4-thiazolyl)-3-cyano-1-propanone (TCP) is reported. Formation of TCP from NFT involved furan ring fission. This could have occurred through involvement of either aminofuran or N-hydroxylaminofuran as precursors. To examine if 4-(5-amino-2-furyl)thiazole is a precursor for TCP, a stable model compound, 4-(5-acetylamino-2-furyl)thiazole (AAFT), was prepared and subjected to enzymatic deacetylation, using rat liver tissue homogenates. AAFT was synthesized by catalytic hydrogenation of NFT with 5% palladium on activated carbon, followed by acetylation with acetic anhydride. AAFT, a white crystalline powder, melted at 168–170°, had an extinction coefficient of 17.9 mM^?1 cm^?1 at 293 nm in ethyl acetate, and exhibited spectroscopic and mass spectral characteristics consistent with the assigned structure. Incubation with rat liver 10,000 g supernatant preparations resulted in the biotransformation of AAFT as evidenced by a decrease in absorption at 290 nm. Incubation of ¹⁴C-labeled AAFT followed by extraction with chloroform-diethyl ether (1:1) resulted in the recovery of a major portion (56%) of the radioactivity in the organic phase when the label was at the 2-position of the thiazole ring, while the major amount (82%) of radioactivity was recovered in the aqueous phase when the 1-¹⁴C-acetyl group was labeled. The radioactivity from the aqueous phase was extractable into the organic phase following acidification to pH 1, an observation consistent with deacetylation. Furthermore, the deacetylation product exhibited a mass spectrum, and retention times in gas and high pressure liquid chromatography, similar to those of synthetic TCP. These data establish 4-(5-amino-2-furyl)thiazole, derived from AAFT by deacetylation, as a precursor for TCP.     

近10年来强直性脊柱炎的中医药临床研究进展

强直性脊柱炎是与感染、遗传和自身免疫功能障碍有关的一种病因尚未阐明的慢性进行性自身免疫性疾病,近年来诸医家运用中医药进行大量临床研究,并取得了一定疗效,本文就近10年来临床研究进行了综述。     

易黄汤临床新用的文献研究

笔者通过对近年有关易黄汤临床应用文献的研究发现,易黄汤不止限于治疗带下病,也被灵活运用于临床其他各种疾病的治疗中。文章对临床应用易黄汤治疗各种疾病进行概括总结,对其病机和作用机理进行了分析,并报道了易黄汤治疗的相关病例。     

五子衍宗丸药理作用及其临床研究进展

五子衍宗丸由五味子、枸杞子、菟丝子、覆盆子、车前子五味药组成,为补肾生精的代表药。就五子衍宗丸的药理作用及其机理、主要临床应用等进行综述,并探讨其临床应用的药理基础。     

小儿胸膜肺母细胞瘤临床特点及病理分析

目的探讨小儿胸膜肺母细胞瘤（pleuro．pulmonaryblastoma,PPB）的临床特点、病理学特征及早期诊治方法。方法对4例反复咳嗽,x线及CT检查发现胸腔内巨大占位性病变患儿的临床特点进行分析,l例放弃治疗,3例手术切除,病理学检查及免疫组化染色确诊为PPB,结合文献进行分析。结果肿瘤组织由原始胚胎小圆细胞及梭形细胞组成,核圆形或卵圆形,部分细胞呈巢状分布,原始细胞胞质空泡状,核深染,可见明显核分裂现象。免疫组化Vimentin（＋）,Desmin（＋）。结论 小儿胸膜肺母细胞瘤是罕见的肺间质恶性肿瘤,临床表现不典型,预后差,病理学检查和免疫组织化学检查有助于诊断,应及早完全手术切除,必要时辅以术后化疗。     

小儿返流性肾病31例临床分析

目的提高对小儿返流性肾病的认识,以早期诊断和治疗。方法收集３１例返流性肾病住院患儿的资料,进行临床分析和统计学处理。结果原发性返流占３５５％,继发性返流占６４５％;继发性返流起病早,部分患儿生后即可出现症状,而原发性返流患儿就诊晚,返流程度严重并且肾功能损害明显多于继发性返流患儿。结论小儿返流性肾病以继发性多见,男孩多见,且均继发于泌尿系统畸形;返流的严重程度与肾功能损害相关     

Hepatitis D: advances and challenges

Hepatitis D virus (HDV) infection causes the most severe form of viral hepatitis with rapid progression to cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Although discovered > 40 years ago, little attention has been paid to this pathogen from both scientific and public communities. However, effectively combating hepatitis D requires advanced scientific knowledge and joint efforts from multi-stakeholders. In this review, we emphasized the recent advances in HDV virology, epid...     

硝酸甘油用于高血压病人术中降压的临床观察

目的 :观察硝酸甘油在麻醉手术中控制血压的效果。方法 :46例病人均采用静脉复合麻醉 ,对在麻醉前和麻醉手术过程中血压过高者静脉滴注硝酸甘油观察血压下降的情况 ,并对用药量和用药前后血压、HR进行记录。结果 :用药3分钟血压开始下降 ,5分钟达到理想的范围 ,平均用量 (4±1 1)mg,部分病人心率加快 ,1例出现心动过速 ,静脉注射艾司洛尔20mg后降至正常范围。结论 :硝酸甘油降压可控性强 ,副作用少。