Do ES Stem Cells Prevent Heart Disease?

first_imgThe promise of stem cells, whether embryonic or adult, is in their power to differentiate into any type of somatic cell.  Although adult stem cells have racked up an impressive number of therapeutic successes,* embryonic (ES) stem cells have only been promised to do so – until now.  In Science Oct. 8,1 Cornell scientists coaxed embryonic stem cells to prevent a fatal heart defect in mouse embryos, but in an unusual way: they did not differentiate into heart tissues at all, but locally (in the blastocyst) and “from a distance” (via the mother’s circulatory system) secreted factors that stimulated the embryo to trigger the formation of its own cardiac cells.  Three UC San Diego scientists, in the same issue,2 explain:Unlocking the therapeutic potential of embryonic stem (ES) cells has remained a tantalizing but elusive goal.  In this new era of “regenerative medicine,” the central experimental game plan has been predicated on driving the differentiation of ES cells along specific cell lineages (for example, neural, cardiac, endocrine), expansion and purification of the cell type of interest, and in vivo repopulation of damaged or degenerating organs by ES cell-derived differentiated cells.  However, there are numerous hurdles to using ES cells as therapeutic tools.  These include the need for reliable ES cell differentiation protocols for different cell lineages, purification techniques for the differentiated progeny, as well as ways to circumvent the immunological rejection of transplanted cells.  Given the complexity of these multiple steps, it is not surprising that there are few clear examples of in vivo ES cell therapy for treating disease-related phenotypes. On page 247 of this issue, an exciting new study by Fraidenraich and co-workers1 expands the potential therapeutic repertoire of ES cells.  These investigators provide direct evidence that ES cells can rescue otherwise lethal cardiac defects in mouse embryos.  Intriguingly, the rescue effect is not subject to the differentiation of ES cells into the cardiac cell lineages that are normally associated with heart regeneration.  Rather, the therapeutic effect of the transplanted ES cells depends on their secretion of defined factors that act either locally within the embryonic heart, or at a distance via the maternal circulation, to trigger fetal myocyte proliferation in utero.Stem cells from an embryo face rejection because they do not belong to the individual being treated and are seen as invaders.  In addition, they have a tendency to produce deformed embryos when injected into a blastocyst.  Adult stem cells from the patient’s own tissues do not have the rejection problem, and undergo differentiation as expected.  So while adult stem cell therapies have already demonstrated the differentiation of cells into other types, these ES cells in this study did not – they merely secreted substances that caused a mutated mouse embryo, which otherwise would have died before birth, to grow its own cardiac cells.  In essence, the secreted factors only stimulated the mouse’s own genes to supply missing ingredients caused by the mutation.  Since stem cell differentiation was not involved, and the stem cells did not get incorporated into the mouse tissues, what kind of benefit does this study promise for human therapies?Given the potential of ES cells to induce the formation of teratomas (defective embryonic tissue), these findings do not necessarily suggest that administering ES cells to pregnant mothers will become a new therapeutic approach for treating congenital heart disease.  However, given that a subset of maternal factors can cross the placenta, there remains a possibility that a subset of embryonic cardiac defects could be partially corrected by the careful delivery of the necessary proteins in the maternal circulation.  Increasingly, congenital heart defects can be diagnosed accurately in utero with noninvasive imaging technology.  In addition, ES cell-based assay systems may ultimately allow for the identification of likely candidate maternal factors that could correct a subset of severe human congenital heart defects.The potential benefits of this study, therefore, appear tentative at best, while adult stem cells have a proven track record without ethical concerns.*For examples, use the Search box with the phrase adult stem cells.1Fraidenraich et al., “Rescue of Cardiac Defects in Id Knockout Embryos by Injection of Embryonic Stem Cells,” Science, Science, Vol 306, Issue 5694, 247-252, 8 October 2004, [DOI: 10.1126/science.1102612].2Chien, Moretti and Laugwitz, “ES Cells to the Rescue,” Science, Vol 306, Issue 5694, 239-240, 8 October 2004, [DOI: 10.1126/science.1104769].Big Science wants ES stem cell funding, and they jump on any tentative success with excitement unwarranted by the facts.  If the ES cells do not differentiate, and only treat an prenatal condition that otherwise would be fatal, then they not only hold promise for living children or adults, but instead provide a reason for not aborting the embryo, because the stem cells might save it.  Would the political liberals who support ES stem cell research want that?    In tonight’s second presidential debate, John Kerry dodged questions on both of these moral issues.  In one case, he was asked point blank why, if adult stem cells already show success, we need embryonic stem cell research (see article on WorldNetDaily).  He patronized the questioner with phony compassion about the deep moral convictions that motivated her question, then proceeded to ignore it.  The only reason he gave for supporting federal funds for ES stem cell research was that Big Science says it wants it, and he wants to be a president that supports “science”  (see 08/11/2004 editorial).  President Bush, in rebuttal, reiterated the principle that guided his difficult decision on stem cells: a life should not be created to be destroyed, even to assist another life (see 09/03/2004 headline).    In another case, a questioner asked what Kerry would say to a voter who did not want her tax dollars used to support abortion.  Again, he patronized the questioner but dodged the question.  He said although he personally disliked abortion because he is Catholic, he cannot as a legislator impose his moral values on others.  That was not what she asked.  She asked why others’ moral values should be used to force her to pay her tax dollars on something that violates her moral values.  For the questions Kerry should face without bluffing or dodging, read this article by Steven Ertelt on on LifeNews.com    Kerry also dodged the issue of his vote against the partial-birth abortion ban (six times), passed by both houses of Congress and signed by the President, but overruled by a federal judge.  He said he had to oppose it, because it did not contain a provision for the life of the mother, in spite of the fact that the carefully-worded law specifically made that provision (see ACLJ website for documentation and history of the bill).  The claim that the bill needed a provision for the “health of the mother” is a huge loophole.  Health could mean anything – mental health, hangnails or a cold – and there is never a health reason for the grisly practice of sucking the brains out of a baby halfway born.    So this is the kind of “science-friendly” president the liberals are promoting, for less than moral reasons (see 09/27/2004 headline).  Science and baloney do not go together.  They are supposed to be opposites.(Visited 6 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

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Think Diversity at Your Startup Will Improve as You Grow? Think Again

first_imgRemote Working Culture: The Facts Business Owne… Brad is the editor overseeing contributed content at ReadWrite.com. He previously worked as an editor at PayPal and Crunchbase. You can reach him at brad at readwrite.com. AI Will Empower Leaders, Not Replace Them Brad AndersonEditor In Chief at ReadWrite “It’ll fix itself as we grow” is a legitimate answer to many startup struggles. Talent acquisition, branding, and procurement all tend to be easier for larger firms than smaller ones. Diversity, however, is not.In a recently published research report, STELLARES, an AI-based talent acquisition platform, found that early-stage companies are just as homogeneous as enterprises. By collecting data on employees at more than 13,000 U.S.-based tech companies, STELLARES discovered that companies at the seed stage have the same proportion of female employees — 34 percent — as their post-IPO peers. In fact, companies at the seed, A, B, C, D, pre-IPO, and post-IPO stages differ by no more than 10 percentage points in terms of female employees, employees of color, females on the leadership team, and females on the extended leadership team.How does STELLARES explain those similarities? Roi Chobadi, CEO and co-founder, attributes it to “divertia,” which he defines as the momentum the early team’s demographic makeup generates for its subsequent hires. “Companies’ demographic DNA persists,” Chobadi says, pointing out that referrals and so-called “cultural fits” tend to look like existing team members. “It’s a perpetual cycle that keeps repeating until someone does something to stop it.”Conventional Silicon Valley wisdom focuses on execution, growth, and product-market fit in the earliest stages of startups, relegating diversity as something to go back and “fix” later. Chobadi argues that if diversity is a goal, you should do the opposite, and early-stage startups are at the ideal stage for solving diversity issues. “If all you need is 40 percent of headcount to be diverse — and then divertia will keep you on the path of diversity — you only need eight people if you’re a 20-person team,” he says. “But when you’re a 2,000-person company, meeting that same goal takes 800 hires, which is much harder.”Look Away From LookalikesSo how can entrepreneurs hire for heterogeneity? Four strategies stand out:1. Don’t default to your friends.Your inner circle may be the obvious place to look when you’re staffing your startup, but beware: Its members probably look an awful lot like you. Although the Public Religion Research Institute found that 75 percent of white Americans have an all-white social circle, the researcher noted similar tendencies among Americans of all racial and ethnic backgrounds. Before hiring a cast of your clones, fight the tendency to turn to your existing relationships. “Your commitment to diversity as a CEO needs to start at the very beginning, from your very first hire,” urges Manu Smadja, co-founder of edtech startup MPOWER Financing. “This is also when it’s hardest, because diverse and inclusive hiring rarely happens organically.” Although Smadja says that hiring from your inner circle has advantages like value alignment and an existing relationship, he points out that it’s possible to hire for vision and values outside your inner circle. Start by checking out startup job boards, where you can evaluate strangers to ensure an even playing field. 2. Hit up diversity hotspots.Rightly or not, a survey by venture group First Round Capital concluded that many tech entrepreneurs have given up hope on improving the industry’s diversity figures. A plurality of respondents said they think it will be 11 to 20 years before the tech sector looks like the general population across both race and gender. While most founders blamed the “pipeline problem,” with 36 percent attributing diversity issues to few minorities entering the industry, the second largest group attributed it to unconscious biases in hiring. A distant third set of founders cited non-diverse recruitment practices in university STEM programs.Whether the problem is one of pipelines, unconscious biases, or recruitment practices, the here-and-now solution for entrepreneurs is the same: Hire from historically black colleges and universities and traditional women’s colleges. When most of your interviewees come from underrepresented groups, chances are good that you’ll find the right person among them. 3. Retool your recruitment ads.If you post ads on job boards, take a look at them. Do they use masculine adjectives like “competitive,” “strong,” or “fearless”? If so, they may be bringing an outsized share of male applicants to your door. Research published by augmented writing platform Textio showed that the way in which a job ad is worded can dramatically affect the gender breakdown of its applicants. If you doubt that diction choices are that powerful, consider what Atlassian found when it tried Textio’s software on its own job ads. After replacing masculine terms in its job ads with more feminine ones, the Australian software company increased the number of women hired for technical positions by 80 percent over the course of a year. Want to put your own job ads to the test? Try the free gender decoder for job ads. The tool draws from the list of gender-biased words in a study published in the Journal of Personality and Social Psychology titled “Evidence That Gendered Wording in Job Advertisements Exists and Sustains Gender Equality.” 4. Make interviews more objective.What can you do to promote diversity beyond hiring from a more diverse pool of candidates? Leela Srinivasan, CMO at Lever, suggests standardizing the criteria used to evaluate those candidates. “It’s an ongoing source of astonishment to me that, given the widespread consensus that hiring is really important for success, startups spend comparatively little time, effort and resources training employees to make objective hiring decisions.” Thoughtful interviewing guidelines, Srinivasan argues, are a low-effort way to minimize the impact of hiring biases. Without those guidelines, she says many people unknowingly evaluate candidates in ways that inhibit diversity. “A prime example is choosing to reject a candidate because they don’t feel like ‘a culture fit’ for the organization, which is often code for ‘they didn’t really seem like us’ or ‘I wouldn’t enjoy hanging out with them,” she says. For each role that needs to be filled, create a guide that applies to all candidates. Don’t insist that interviewers use it as a word-for-word template — organic conversations are valuable sources of candidate information, too — but ask that they collect answers to the listed questions. Be sure, too, that your guide includes a rubric for evaluating their responses. How, for example, might an “A” answer about the applicant’s teamwork experiences differ from a “B” one?All too many founders assume that, as they grow their team roster, their diversity will naturally improve. In reality, companies build on what they have. That’s why the best time to dedicate your company to diversity was before your first hire; the second best time is before your next one. How to Make the Most of Your Software Developer… Related Posts Tags:#diversity#Diversity In Tech#hiring#inclusion#minorities in tech#Silicon Valley#women in tech What Nobody Teaches You About Getting Your Star…last_img read more

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