肥胖对男性更危险******
图片来源:pixabay
近日,英国科学家发表的一项研究揭示了肥胖相关疾病中性别差异的生物学基础。研究人员观察到,雄性与雌性小鼠脂肪组织中构建血管的细胞存在显著差异。相关研究近日发表于《交叉科学》。
约克大学运动与健康科学院教授Tara Haas说,男性比女性更容易患上与肥胖相关的疾病,如心血管疾病、胰岛素抵抗和糖尿病等。
“人们使用啮齿动物模型研究肥胖,以及与肥胖相关的疾病,如糖尿病。但他们通常只研究雄性啮齿动物,因为雌性对同样类型的疾病有抵抗力。”该研究负责人Haas说,“我们对探索这种差异非常感兴趣,这说明女性体内发生了一些可以保护自己的非常有趣的事。”
Haas团队在早期的一项研究中观察到,当小鼠变胖时,雌性会长出许多新的血管,为扩张的脂肪组织提供氧气和营养物质,而雄性新增的血管则很少。在最新研究中,Haas和约克大学博士生Alexandra Pislaru、助理教授Emilie Roudier等合作,重点研究了脂肪组织中血管内皮细胞的差异。
该团队使用软件筛选了数千个基因,以锁定与血管生长有关的基因。他们发现,雌性小鼠体内与新血管增殖相关的过程较多,而雄性小鼠体内则是与炎症相关的过程较多。Haas说:“其他研究表明,当内皮细胞有这种炎症反应时,雄性会出现功能异常,对刺激的反应也不正常。”
“通过观察,我们发现女性内皮细胞即使长期在高脂肪饮食的压力下仍能表现出持续的弹性,这令人兴奋。我们的研究结果可以帮助研究人员更好地理解为什么肥胖在男性和女性中表现不同。”该研究共同第一作者Pislaru说。
研究人员还检查了从人体内取出的内皮细胞在培养皿中的表现。Haas解释说:“即使把它们从体内取出来,没有了循环性激素或其他因素,男性和女性的内皮细胞仍有很大差异。”
女性内皮细胞复制更快,而男性内皮细胞对炎症刺激更敏感。通过与之前公布的数据集进行比较,研究人员发现,与雌性相比,老龄雄性小鼠的内皮细胞也表现出更多的炎症特征。
“不能假设两性对同一系列事件的反应是一样的。”Haas解释说,“这不仅是一个与肥胖有关的问题,而且是一个更广泛的概念性问题,包括老龄化对健康的影响。我们的研究结果意味着,在某些情况下,对男性理想的疗法对女性并不理想,反之亦然。”
虽然人类和小鼠有不同的基因,但Haas认为这些发现可能适用于未来的研究。他对在人身上研究这类细胞很感兴趣。(李木子)
中新网评:美国众议长选举“连续剧”暴露美式民主痼疾******
中新网北京1月9日电(蒋鲤)在15轮投票表决后,美国众议院议长选举这场“连续剧”终于落下帷幕,众议院共和党领袖凯文·麦卡锡最终成功当选第55任美国众议院议长。这是美国国会过去164年来耗时最久的一次议长选举记录,将美国“对抗式民主”的弊端暴露无遗。
资料图:美国众议院共和党领袖麦卡锡。中新社记者 沙晗汀摄
由于两党对立加剧、党派内斗、利益分配不均等因素,众议长选举陷入一场拉锯战。在此次众议长竞选中,美国民主党议员继续抱团,多轮投票中,一票不投麦卡锡,共和党右翼“强硬派”领头的约20人小团体也拒绝投票麦卡锡。
麦卡锡的当选之路一波三折,除了本人的“政治投机派”角色在国会不受欢迎外,与共和党内部政治分歧关系密切。
一方面,共和党党内反对者认为,麦卡锡对民主党态度过于软弱,无力对抗民主党控制的参议院和拜登政府,另一方面,因为共和党的多数优势微弱,党内一些影响力较小的派系的政治力量则被放大,有利于他们巩固自己的选票。
此外,党内反对者也认为,自己的选票没有换取更多利益,希望以此作为筹码换取麦卡锡更大的让步,比如让他们获得众议院重要委员会中的职务。
作为仅次于美国总统、副总统的政坛三号人物,众议院议长通常由众议院多数党领袖担任,选举几乎没有悬念。然而,麦卡锡此次为当选,不得不做出多个关键让步,其中可能包括恢复一项罢黜议长动议机制,使得众议长的权力被削弱,难以掌控众议院。
美国有线电视新闻网CNN称,麦卡锡在这场不合时宜的政治勒索中作出让步,这种绥靖政策只会让极端主义势力更加强大。
这场引发全世界围观的尴尬选举暴露出美国政治存在严重的对立和分化。在权力博弈思维的裹挟下,党派利益凌驾于国家和人民利益之上,美国两党相互拆台,陷入“为反对而反对”的无脑对垒。而即便是一党内,也会因为利益分配问题产生不同的小派系,相互对抗,选票变成了谋利益的工具。
从国会山骚乱到打破记历史记录的15轮众议长选举,“对抗式民主”让美国政治陷入瓶颈,长期对抗势必会让政客们丧失客观公正的判断能力,其政治阶层是否有能力治理国家也会引发质疑。
两党之争和党派内斗进一步放大了美国政治体制弊病,美国所谓的“民主”形象,让全世界大跌眼镜。鼓吹以选民利益为先的美式选举,变成了政客们利益置换的游戏,进一步彰显出美国“民主政治”日渐失能,不断极化的党争已使美国政治制度陷入死循环。
House speaker election reveals deep-rooted problems in U.S. democracy
(ECNS) -- The Republican leader Kevin McCarthy was elected as the 55th speaker of the U.S. House of Representatives after 15 ballots. As the most grueling House speaker election in the past 164 years, the election has highlighted the defects of the country’s "confrontational democracy".
The election once reached a stalemate due to intense partisan strife, inner-party struggle among the Republicans, uneven distribution of interests, and more. Democratic Party members forged a close alliance, refusing to vote for McCarthy, while about 20 Republicans also declined to cast ballots for the GOP leader.
Except for his unpopular role as a "political speculator" in Congress, McCarthy’s hard-won election can be attributed to turmoil within the Republican Party.
On the one hand, opponents in the Republican Party believe that the GOP leader's attitude toward the Democrats is too weak to confront the Senate controlled by Democrats and the Biden administration.
On the other hand, the political power of some less influential factions in the Republican Party has been amplified due to the Party’s weak majority advantage in the House of Representatives, which is conducive to consolidating their ticket warehouses.
Meanwhile, these opponents believe that their votes failed to win them more benefits, hoping to use this as a bargaining chip for McCarthy's further concessions, such as getting them positions in important House Committees.
As the third political figure after the President and Vice President of the U.S., the speaker, by tradition, is the head of the majority party in the House of Representatives.
But McCarthy has made many concessions in order to bring the ultra conservatives along, involving what’s known as the “motion to vacate,” a mechanism by which members can force a vote to depose the speaker. The reported concessions will empower individual members at the expense of McCarthy’s sway as speaker.
CNN thought the concessions he made during this unseemly political shakedown would only make the extremist faction more powerful.
This embarrassing election, which has drawn global attention, exposed the serious opposition and polarization in American politics. Both Democrats and Republicans put their interests before that of the country and its people, attacking and opposing each other irrationally.
Besides, different factions arise within a single party and confront each other because of the distribution of interests. Votes have become a tool to win more benefits.
From Capitol riots to the House Speaker election with record-breaking ballots, "confrontational democracy" has become a bottleneck of American politics. Long-term confrontation will surely impede politicians to think objectively and fairly while their capacity of governing the country will also raise doubts among the public.
Both parties’ struggle and infighting among the Republicans have further amplified the defects of the American political system, with its "democratic" image shocking the world.
The U.S.-style election, which advocates putting voters' interests first, has become a game of interest exchange among politicians. In addition, it further demonstrates the malfunction of American "democratic politics" and the constantly polarized party struggle that has trapped the American political system into an infinite cycle.
(文图:赵筱尘 巫邓炎)