新型干细胞可降低引入移植瘤的风险

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2015年11月16日讯/生物谷BIOON/人类多能干细胞(hPSC) 在成年人的身体中可以发展成为任何类型的细胞， 它对心血管到阿尔茨海默氏症的疾病建模中进行的药物研发和创造替代细胞提供了巨大的潜力。6 [' S" ^& U4 C" W" _/ ^
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但这样会有风险：移植hPSCs也可能发展成为肿瘤。2015年11月10日发布的一项新的研究结果表明，新的“祖细胞能无限扩张和分化成成熟的肾脏细胞，但没有形成肿瘤的风险。”3 D  g3 \# ]# d. E

! f5 h  P3 a9 Z' [, y) G, PKarl Willert博士说， “这项工作在组织工程或重建功能器官中起到很好的补充作用，如我们所看到的微型肾，它代表了一种新型的细胞来源。”
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Willert设计了一种体外微环境，该环境可使早期胚胎发育的三个主要胚芽层之一的中胚层祖细胞hPSC同质扩张。胚芽层是一种在胚胎发生的主要层细胞。早期祖细胞是干细胞的后代，分化能力有限。
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分析表明，这些新创建的“中胚层祖细胞”缺乏肿瘤形成潜力，但保留分化成特定类型组织的能力，比如成人肾细胞。研究人员说生成祖细胞可扩展数量的能力， 通过未分化的人类干细胞的使用，有限的分化提供了几个优势：. a6 g! T$ C0 L8 E6 ?1 p: h7 e1 x& J

1 }( y7 [* M7 a1 y! n7 q& z首先，来源于后者的培养皿经常含有未分化细胞并保留肿瘤生长的潜力。, ]. q! i) i. K9 i; I# f

: _8 Q6 {% m0 ^, I+ _" F第二，发展和操纵限制性祖细胞不合理。它更容易为研究或治疗用途创建成熟的细胞群。
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$ A$ ~% o# [2 s第三，因为祖细胞受限于它们即将成为的某种细胞，它们不太可能分化成某种有害的细胞类型。
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“我们的细胞可以作为构建块生成肾脏，可能有一天会适合细胞替代和移植，”Willert说。“我认为这种治疗程序在未来几年中仍然持续，但设计出的肾组织可作为一种有力的模型系统来研究人类的肾脏如何与过滤器的药物相互作用，这样的应用程序将对医药行业有巨大的价值。”4 Y4 D9 U2 K2 m- q* ?$ k5 U
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Willert指出，开发的祖细胞可能能够分化成其他细胞类型的中间中胚层系，尤其在培养皿中的生殖细胞系可产生卵子和精子。“我们可以将他们潜在的特征分化成有助于肾脏的细胞。我们正在调查这些细胞多大程度上来源于中间的中胚层的其他组织和器官，包括生殖器官。”6 G" r9 D5 w( x1 D4 }) r" m

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Implantable cardiac defibrillators (ICDs) deliver an electric shock to the heart to correct life threatening heart beats.
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# y) c" \& L1 x* W" z% R7 xIn the study, 105 sexually active couples (average age 65 for patients and 63 for partners) answered questions when they left the hospital after the ICD implant procedure and again after three months. The survey consisted of eight questions in which they ranked their concerns about sexual activity after an ICD.# V/ {1 H; P& [; s  z5 W

# C! P' b+ A5 ^4 ~0 z+ \Participants' concerns included lacking interest in sex, fearing ICD discharge during sex, and worry about cardiac arrest happening during sex due to device malfunction. Concern levels for both dropped by three months. For partners, there was a nearly 50 percent drop in fears that the patient's heart would stop and about a two-thirds decline in fears that the ICD would accidentally fire off a cardiac shock. Patients experienced a similar reduction in concerns after 3 months; with the largest reduction being in the area of fear of an ICD shock during sex. The study adds to the growing body of research on sexual issues among heart patients and their partners.
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"We can't just focus on the patient," said Cynthia Dougherty, A.R.N.P., Ph.D., a Professor of Nursing at the University of Washington School of Nursing in Seattle, Washington. "An intimate partner's level of comfort is also important for recovery, and their concerns warrant attention from healthcare providers."
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0 R% c" Q2 S6 D9 x9 @For most people with an ICD, resuming sexual activity is OK once the surgical site is healed.
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0 S; c# n3 b4 x* I" M' v- _' YHeart patients and their partners' sexual concerns often aren't addressed by the provider, which affects recovery, emotional health and intimate relationships.4 s( Y8 @' s, b" Z8 \, s+ p7 M8 r
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Healthcare providers should discuss sexual activity with ICD patients and their partners to allay fears and to treat erectile dysfunction, Dougherty said.1 f# Z% f1 n4 R

: F3 s9 L6 \' D, s" o' d, Q$ H"This is an issue that patients are often reluctant to discuss and sometimes providers don't initiate these discussions as part of routine practice," she said. "But it shouldn't be taboo subject." * K9 p1 K5 h0 m( a% `