Connect with us

Tech

A mouse embryo has been grown in an artificial womb—humans could be next

Published

on

A mouse embryo has been grown in an artificial womb—humans could be next


“I do understand the difficulties. I understand. You are entering the domain of abortions,” says Hanna. However, he says he can rationalize such experiments because researchers already study five-day-old human embryos from IVF clinics, which are also destroyed in that process.

“So I would advocate growing it until day 40 and then disposing of it,” says Hanna. “Instead of getting tissue from abortions, let’s take a blastocyst and grow it.”

The research is part of an explosion of new techniques and ideas for studying early development. Today, in the same issue of Nature, two other research groups are reporting a leap forward in creating “artificial” human embryos.

Those teams managed to coax ordinary skin cells and stem cells to self-assemble into look-alike early human embryos they call “blastoids,” which they grew for about 10 days in the lab. Several kinds of artificial models of embryos have been described before, but those described today are among the most complete, because they possess the cells needed to form a placenta. That means they are a step closer to being viable human embryos that could develop further, even until birth.

Scientists say that they would never try to establish a pregnancy with artificial embryos—an act that would be forbidden today in most countries.

Instead, Hanna says, an obvious next step would be to add these embryo models to his system of spinning jars and see how much further they can develop. “It took six years of very intense work to get this system to where it is,” says Hanna. “We do have the goal to do it with synthetic embryos as well.”

Early days

For now, the artificial womb technology remains “complex and expensive,” says Martinez Arias. He does not believe many other labs will be able to use it, limiting its impact in the short term, and he is not in favor of growing human embryos this way: “It’s expensive and complicated, so we will have to see how useful it is.”

The mouse-in-a-jar technology needs other improvements, too, Hanna says. He was not able to grow the mice starting from a fertilized egg all the way to day 12. Instead, he collected 5-day-old embryos from pregnant mice and moved them into the incubator system, where they lived another week.

The issue is that currently, the mouse embryos develop correctly only if they can be attached to an actual mouse uterus, at least for a brief time. Hanna’s team is working on adapting the procedure so they can develop the mice entirely in vitro.

Hanna says he’s not interested in bringing mice to term inside the lab. His goal is to watch and manipulate early development. “I want to see how the program unfolds,” he says. “I have plenty to study.”

Banned?

Long-term studies of live human embryos developing in the lab are currently banned under the so-called 14-day rule, a guideline (and a law in some countries) according to which embryologists have been forbidden to grow human embryos more than two weeks.

However, a key scientific organization, the International Society for Stem Cell Research, or ISSCR, has plans to recommend rescinding the prohibition and allowing some embryos to grow for longer.

Hanna says that means he could grow human embryos in his incubator—so long as Israeli ethics boards sign off, something he thinks they would do.

“Once the guidelines are updated, I can apply, and it will be approved. It’s a very important experiment,” says Hanna. “We need to see human embryos gastrulate and form organs and start perturbing it. The benefit of growing human embryos to week three, week four, week five is invaluable. I think those experiments should at least be considered. If we can get to an advanced human embryo, we can learn so much.”

A system of rotating bottles developed in Israel can keep mouse embryos alive outside the womb. The embryos are exposed to pressurized oxygen for several days.

Hanna says to make such experiments more acceptable, human embryos could be altered to limit their potential to develop fully. One possibility would be to install genetic mutations in a calcium channel so as to prevent the heart from ever beating.

I asked Hanna if he had sought the advice of ethicists or religious figures. He said he has not. Instead, he is awaiting the advice of his professional body and ethics clearance from his university.

“The ISSCR is my rabbi,” he says.

There may be unexpected practical applications of growing human embryos in jars. William Hurlbut, a doctor and bioethicist at Stanford University, says the system suggests to him a way to obtain primitive organs, like liver or pancreas cells, from first-trimester human embryos, which could then be grown further and used in transplant medicine. Hanna agrees this is a potential direction for the technology.

“The scientific frontier is moving from molecules and test tubes to living organisms,” says Hurlbut. “I don’t think that organ harvesting is so far-fetched. It could eventually get there. But it’s very fraught, because one person’s boundary is not another person’s boundary.”

Tech

The quest to show that biological sex matters in the immune system

Published

on

Sabra Klein and Janna Shapiro look at a specimen on a lightbox.


She ultimately found a postdoctoral position in the lab of one of her thesis committee members. And in the years since, as she has established a lab of her own at the university’s Bloomberg School of Public Health, she has painstakingly made the case that sex—defined by biological attributes such as our sex chromosomes, sex hormones, and reproductive tissues—really does influence immune responses. 

Through research in animal models and humans, Klein and others have shown how and why male and female immune systems respond differently to the flu virus, HIV, and certain cancer therapies, and why most women receive greater protection from vaccines but are also more likely to get severe asthma and autoimmune disorders (something that had been known but not attributed specifically to immune differences). “Work from her laboratory has been instrumental in advancing our understanding of vaccine responses and immune function on males and females,” says immunologist Dawn Newcomb of the Vanderbilt University Medical Center in Nashville, Tennessee. (When referring to people in this article, “male” is used as a shorthand for people with XY chromosomes, a penis, and testicles, and who go through a testosterone-dominated puberty, and “female” is used as a shorthand for people with XX chromosomes and a vulva, and who go through an estrogen-dominated puberty.)

Through her research, as well as the unglamorous labor of arranging symposia and meetings, Klein has helped spearhead a shift in immunology, a field that long thought sex differences didn’t matter. Historically, most trials enrolled only males, resulting in uncounted—and likely uncountable—consequences for public health and medicine. The practice has, for example, caused women to be denied a potentially lifesaving HIV therapy and left them likely to endure worse side effects from drugs and vaccines when given the same dose as men.


Men and women don’t experience infectious or autoimmune diseases in the same way. Women are nine times more likely to get lupus than men, and they have been hospitalized at higher rates for some flu strains. Meanwhile, men are significantly more likely to get tuberculosis and to die of covid-19 than women. 

In the 1990s, scientists often attributed such differences to gender rather than sex—to norms, roles, relationships, behaviors, and other sociocultural factors as opposed to biological differences in the immune system.

For example, even though three times as many women have multiple sclerosis as men, immunologists in the 1990s ignored the idea that this difference could have a biological basis, says Rhonda Voskuhl, a neuroimmunologist at the University of California, Los Angeles. “People would say, ‘Oh, the women just complain more—they’re kind of hysterical,’” Voskuhl says. “You had to convince people that it wasn’t just all subjective or environmental, that it was basic biology. So it was an uphill battle.” 

Sabra Klein (left) and Janna Shapiro in Klein’s laboratory at Johns Hopkins University in Baltimore, Maryland.

ROSEM MORTON

Despite a historical practice of “bikini medicine”—the notion that there are no major differences between the sexes outside the parts that fit under a bikini—we now know that whether you’re looking at your metabolism, heart, or immune system, both biological sex differences and sociocultural gender differences exist. And they both play a role in susceptibility to diseases. For instance, men’s greater propensity to tuberculosis—they are almost twice as likely to get it as women—may be attributed partly to differences in their immune responses and partly to the fact that men are more likely to smoke and to work in mining or construction jobs that expose them to toxic substances, which can impair the lungs’ immune defenses. 

How to tease apart the effects of sex and gender? That’s where animal models come in. “Gender is a social construct that we associate with humans, so animals do not have a gender,” says Chyren Hunter, associate director for basic and translational research at the US National Institutes of Health Office of Research on Women’s Health. Seeing the same effect in both animal models and humans is a good starting point for finding out whether an immune response is modulated by sex. 

Continue Reading

Tech

Why can’t tech fix its gender problem?

Published

on

From left to right: Gordon MOORE, C. Sheldon ROBERTS, Eugene KLEINER, Robert NOYCE, Victor GRINICH, Julius BLANK, Jean HOERNI and Jay LAST.


Not competing in this Olympics, but still contributing to the industry’s success, were the thousands of women who worked in the Valley’s microchip fabrication plants and other manufacturing facilities from the 1960s to the early 1980s. Some were working-class Asian- and Mexican-Americans whose mothers and grandmothers had worked in the orchards and fruit can­neries of the prewar Valley. Others were recent migrants from the East and Midwest, white and often college educated, needing income and interested in technical work. 

With few other technical jobs available to them in the Valley, women would work for less. The preponderance of women on the lines helped keep the region’s factory wages among the lowest in the country. Women continue to dominate high-tech assembly lines, though now most of the factories are located thousands of miles away. In 1970, one early American-owned Mexican production line employed 600 workers, nearly 90% of whom were female. Half a century later the pattern continued: in 2019, women made up 90% of the workforce in one enormous iPhone assembly plant in India. Female production workers make up 80% of the entire tech workforce of Vietnam. 

Venture: “The Boys Club”

Chipmaking’s fiercely competitive and unusually demanding managerial culture proved to be highly influential, filtering down through the millionaires of the first semiconductor generation as they deployed their wealth and managerial experience in other companies. But venture capital was where semiconductor culture cast its longest shadow. 

The Valley’s original venture capitalists were a tight-knit bunch, mostly young men managing older, much richer men’s money. At first there were so few of them that they’d book a table at a San Francisco restaurant, summoning founders to pitch everyone at once. So many opportunities were flowing it didn’t much matter if a deal went to someone else. Charter members like Silicon Valley venture capitalist Reid Dennis called it “The Group.” Other observers, like journalist John W. Wilson, called it “The Boys Club.”

The men who left the Valley’s first silicon chipmaker, Shockley Semiconductor, to start Fairchild Semiconductor in 1957 were called “the Traitorous Eight.”

WAYNE MILLER/MAGNUM PHOTOS

The venture business was expanding by the early 1970s, even though down markets made it a terrible time to raise money. But the firms founded and led by semiconductor veterans during this period became industry-defining ones. Gene Kleiner left Fairchild Semiconductor to cofound Kleiner Perkins, whose long list of hits included Genentech, Sun Microsystems, AOL, Google, and Amazon. Master intimidator Don Valentine founded Sequoia Capital, making early-stage investments in Atari and Apple, and later in Cisco, Google, Instagram, Airbnb, and many others.

Generations: “Pattern recognition”

Silicon Valley venture capitalists left their mark not only by choosing whom to invest in, but by advising and shaping the business sensibility of those they funded. They were more than bankers. They were mentors, professors, and father figures to young, inexperienced men who often knew a lot about technology and nothing about how to start and grow a business. 

“This model of one generation succeeding and then turning around to offer the next generation of entrepreneurs financial support and managerial expertise,” Silicon Valley historian Leslie Berlin writes, “is one of the most important and under-recognized secrets to Silicon Valley’s ongoing success.” Tech leaders agree with Berlin’s assessment. Apple cofounder Steve Jobs—who learned most of what he knew about business from the men of the semiconductor industry—likened it to passing a baton in a relay race.

Continue Reading

Tech

Predicting the climate bill’s effects is harder than you might think

Published

on

Predicting the climate bill’s effects is harder than you might think


Human decision-making can also cause models and reality to misalign. “People don’t necessarily always do what is, on paper, the most economic,” says Robbie Orvis, who leads the energy policy solutions program at Energy Innovation.

This is a common issue for consumer tax credits, like those for electric vehicles or home energy efficiency upgrades. Often people don’t have the information or funds needed to take advantage of tax credits.

Likewise, there are no assurances that credits in the power sectors will have the impact that modelers expect. Finding sites for new power projects and getting permits for them can be challenging, potentially derailing progress. Some of this friction is factored into the models, Orvis says. But there’s still potential for more challenges than modelers expect.

Not enough

Putting too much stock in results from models can be problematic, says James Bushnell, an economist at the University of California, Davis. For one thing, models could overestimate how much behavior change is because of tax credits. Some of the projects that are claiming tax credits would probably have been built anyway, Bushnell says, especially solar and wind installations, which are already becoming more widespread and cheaper to build.

Still, whether or not the bill meets the expectations of the modelers, it’s a step forward in providing climate-friendly incentives, since it replaces solar- and wind-specific credits with broader clean-energy credits that will be more flexible for developers in choosing which technologies to deploy.

Another positive of the legislation is all its long-term investments, whose potential impacts aren’t fully captured in the economic models. The bill includes money for research and development of new technologies like direct air capture and clean hydrogen, which are still unproven but could have major impacts on emissions in the coming decades if they prove to be efficient and practical. 

Whatever the effectiveness of the Inflation Reduction Act, however, it’s clear that more climate action is still needed to meet emissions goals in 2030 and beyond. Indeed, even if the predictions of the modelers are correct, the bill is still not sufficient for the US to meet its stated goals under the Paris agreement of cutting emissions to half of 2005 levels by 2030.

The path ahead for US climate action isn’t as certain as some might wish it were. But with the Inflation Reduction Act, the country has taken a big step. Exactly how big is still an open question. 

Continue Reading

Copyright © 2021 Seminole Press.