为什么心肌梗死后心脏几乎不能自我再生？
Why can the heart barely regenerate itself after a myocardial infarction?
成年人的心肌细胞出生后大多退出细胞周期，年更新率仅约百分之一，远不足以补充梗死区死亡的上亿个心肌细胞。修复过程因此以成纤维细胞增殖和胶原沉积形成瘢痕为主，虽能维持室壁完整、防止破裂，却不具备收缩和电传导功能，进一步引起心室重构、心律失常和心力衰竭。干细胞移植、心肌细胞周期重新激活和成纤维细胞直接重编程等再生策略仍处于试验阶段。
Adult human cardiomyocytes largely exit the cell cycle after birth, with an annual turnover of only about one percent, far too little to replace the hundreds of millions of cells lost in an infarct. Repair therefore proceeds mainly through fibroblast proliferation and collagen deposition to form scar, which preserves wall integrity and prevents rupture but cannot contract or conduct, driving ventricular remodelling, arrhythmia and heart failure. Regenerative strategies such as stem cell transplantation, reactivating cardiomyocyte proliferation and direct reprogramming of fibroblasts remain experimental.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Harrison's Principles of Internal Medicine 第20版,McGraw-Hill,2018
J. Loscalzo et al., Harrison's Principles of Internal Medicine, 20th ed., McGraw-Hill, 2018
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY ISBN 标识 9781259644047（按标识回读: Harrison's prin
#心肌再生 #瘢痕修复 #心室重构
用iPSC来源细胞治疗帕金森病目前进展到什么阶段？
How far has iPSC-derived cell therapy for Parkinson disease progressed?
研究者可将iPSC定向分化为中脑多巴胺能前体细胞并移植到纹状体，已有个案与小样本临床研究报告移植物存活、影像学多巴胺能信号改善以及运动症状的部分获益。关键挑战包括细胞纯度与批次一致性、残留未分化细胞的成瘤风险、免疫排斥（自体来源可减轻但成本高）以及需要多年随访确认疗效持久性。目前仍属研究性治疗，尚未成为常规临床方案，患者应通过正规注册的临床试验参与。
Investigators can differentiate iPSCs into midbrain dopaminergic progenitors and graft them into the striatum, and case reports and small clinical studies have described graft survival, improved dopaminergic imaging signal and partial motor benefit. Key challenges include cell purity and batch consistency, tumour risk from residual undifferentiated cells, immune rejection, which autologous sources reduce at high cost, and the need for years of follow-up to confirm durability. This remains investigational rather than routine care, and patients should participate only through properly registered clinical trials.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
《新英格兰医学杂志》(NEJM)（Schweitzer 等，自体iPSC来源多巴胺前体细胞治疗帕金森病，2020）
NEJM (Schweitzer et al., personalised iPSC-derived dopamine progenitor cells for Parkinson disease, 2020)
#iPSC移植 #多巴胺前体细胞 #成瘤风险
猪器官异种移植面临的主要障碍是什么？
What are the main obstacles to pig-to-human xenotransplantation?
首要障碍是免疫排斥：猪细胞表面的α-Gal、Neu5Gc等糖抗原会引发人体预存抗体介导的超急性排斥，需通过基因编辑敲除相关糖基转移酶并转入人补体调节蛋白。其次是猪与人凝血系统不匹配导致的血栓性微血管病，以及猪内源性逆转录病毒和潜在病原体带来的生物安全风险。已有基因编辑猪心脏和猪肾移植到人体的个案报告，患者存活时间有限，目前仍属高度试验性治疗。
The first barrier is immune rejection: carbohydrate antigens on pig cells such as alpha-Gal and Neu5Gc trigger hyperacute rejection by pre-existing human antibodies, which is why gene editing knocks out the relevant glycosyltransferases and adds human complement regulatory proteins. Next are coagulation incompatibilities between pig endothelium and human blood, which cause thrombotic microangiopathy, and biosafety concerns about porcine endogenous retroviruses and other latent pathogens. Case reports of gene-edited pig heart and kidney transplants in humans describe limited survival, so the field remains highly experimental.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
《新英格兰医学杂志》(NEJM)（Griffith 等，基因编辑猪心脏移植个案报告，2022）
NEJM (Griffith et al., genetically modified porcine-to-human cardiac xenotransplantation, 2022)
#异种移植 #基因编辑猪 #超急性排斥
诱导多能干细胞（iPSC）是什么？为什么意义重大？
What are induced pluripotent stem cells and why do they matter?
通过导入Oct4、Sox2、Klf4、c-Myc等少数转录因子，可将皮肤成纤维细胞或血细胞等成体细胞重编程为具有类似胚胎干细胞分化潜能的诱导多能干细胞。它绕开了使用人类胚胎的伦理争议，还能用患者自身细胞建立疾病模型、筛选药物并制备潜在的移植用细胞。这项工作使山中伸弥获得2012年诺贝尔生理学或医学奖。
Introducing a small set of transcription factors such as Oct4, Sox2, Klf4 and c-Myc can reprogramme adult cells like skin fibroblasts or blood cells into induced pluripotent stem cells with differentiation potential similar to embryonic stem cells. This avoids the ethical controversy of using human embryos and allows patient-derived cells to be used for disease modelling, drug screening and potentially for transplantable cell products. The discovery earned Shinya Yamanaka the 2012 Nobel Prize in Physiology or Medicine.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Harrison's Principles of Internal Medicine 第20版,McGraw-Hill,2018
J. Loscalzo et al., Harrison's Principles of Internal Medicine, 20th ed., McGraw-Hill, 2018
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY ISBN 标识 9781259644047（按标识回读: Harrison's prin
#诱导多能干细胞 #重编程 #疾病模型
组织工程通常需要哪三个基本要素？
What three basic elements does tissue engineering usually require?
一是具备增殖和分化能力的细胞，例如干细胞或原代细胞；二是提供三维空间与力学支撑并可逐步降解的支架材料；三是引导细胞增殖分化的生长因子及灌流、力学刺激等培养条件。三者配合才可能形成有一定功能和营养供应的组织。目前皮肤、软骨、骨和膀胱等结构相对简单的组织进展较快，肝、肾等需要复杂血管网络和多种细胞协同的实质器官仍是难题。
First, cells able to proliferate and differentiate, such as stem cells or primary cells; second, a scaffold that provides three-dimensional space and mechanical support and degrades progressively; third, signals and culture conditions including growth factors, perfusion and mechanical stimulation that guide cell behaviour. Only when all three fit together can functional tissue with adequate nutrient supply form. Relatively simple tissues such as skin, cartilage, bone and bladder have advanced fastest, while solid organs like liver and kidney, which need complex vasculature and multiple cooperating cell types, remain unsolved.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Harrison's Principles of Internal Medicine 第20版,McGraw-Hill,2018
J. Loscalzo et al., Harrison's Principles of Internal Medicine, 20th ed., McGraw-Hill, 2018
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY ISBN 标识 9781259644047（按标识回读: Harrison's prin
#组织工程 #支架材料 #生长因子
自体和异体造血干细胞移植有什么区别？
What is the difference between autologous and allogeneic haematopoietic stem cell transplantation?
自体移植先采集并冻存患者自身的造血干细胞，在大剂量化疗后回输以重建造血，不存在排斥和移植物抗宿主病，常用于淋巴瘤和多发性骨髓瘤，但缺少移植物抗肿瘤的免疫效应，复发风险相对较高。异体移植使用配型合适的供者细胞，供者免疫细胞可清除残留白血病细胞，代价是移植物抗宿主病和感染风险，需要较长期的免疫抑制与随访管理。具体选择取决于疾病类型、缓解深度、年龄合并症和供者可得性。
In autologous transplantation the patient's own stem cells are collected and stored, then reinfused after high-dose chemotherapy to restore haematopoiesis; there is no rejection or graft-versus-host disease, and it is commonly used in lymphoma and myeloma, but the lack of a graft-versus-tumour effect leaves a relatively higher relapse risk. Allogeneic transplantation uses cells from a matched donor whose immune cells can eliminate residual leukaemia cells, at the cost of graft-versus-host disease and infection risk, requiring prolonged immunosuppression and follow-up. The choice depends on disease type, depth of remission, age and comorbidity, and donor availability.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Harrison's Principles of Internal Medicine 第20版,McGraw-Hill,2018
J. Loscalzo et al., Harrison's Principles of Internal Medicine, 20th ed., McGraw-Hill, 2018
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY ISBN 标识 9781259644047（按标识回读: Harrison's prin
#造血干细胞移植 #移植物抗宿主病 #移植物抗肿瘤效应
类器官是什么？它能取代动物实验吗？
What are organoids, and can they replace animal experiments?
类器官是干细胞在三维培养中自组织形成的微型组织结构，能部分再现肠、脑、肝、肾、肺等器官的细胞组成和基本功能。它可用于研究发育与疾病机制、测试药物毒性，患者来源类器官还被尝试用于预测个体对化疗药物的反应。但类器官通常缺乏血管、免疫细胞和器官之间的相互作用，因此目前是动物实验的重要补充，而非完全替代。
Organoids are miniature tissue structures that stem cells self-organise into in three-dimensional culture, partly reproducing the cell composition and basic functions of organs such as intestine, brain, liver, kidney and lung. They are used to study development and disease mechanisms and to test drug toxicity, and patient-derived organoids are being explored for predicting individual responses to chemotherapy. Because they usually lack blood vessels, immune cells and inter-organ interactions, they currently complement rather than replace animal studies.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Harrison's Principles of Internal Medicine 第20版,McGraw-Hill,2018
J. Loscalzo et al., Harrison's Principles of Internal Medicine, 20th ed., McGraw-Hill, 2018
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY ISBN 标识 9781259644047（按标识回读: Harrison's prin
#类器官 #三维培养 #药物筛选
3D生物打印现在能打印出可以移植的器官吗？
Can 3D bioprinting already produce transplantable organs?
生物打印用含活细胞的生物墨水逐层构建三维结构，目前已能制备皮肤、软骨、骨和血管片段等相对简单的组织，并广泛用于制作药物筛选与病理研究模型。真正可移植的实体器官受限于血管网络构建、所需细胞数量与存活率、组织成熟化以及长期功能等难题。因此近期更现实的应用是组织修复补片、个体化手术模型和体外测试平台。
Bioprinting builds three-dimensional structures layer by layer from bioinks containing living cells, and it can already produce relatively simple tissues such as skin, cartilage, bone and vascular segments, and is widely used to make models for drug screening and disease research. Truly transplantable solid organs are limited by the need to build vascular networks, obtain enough viable cells, mature the tissue and sustain long-term function. Realistic near-term uses are repair patches, patient-specific surgical models and in vitro testing platforms.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Harrison's Principles of Internal Medicine 第20版,McGraw-Hill,2018
J. Loscalzo et al., Harrison's Principles of Internal Medicine, 20th ed., McGraw-Hill, 2018
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY ISBN 标识 9781259644047（按标识回读: Harrison's prin
#3D生物打印 #生物墨水 #血管化