PARIS: Scientists said Tuesday they had used stem cells to grow human heart tissue that contracted spontaneously in a petri dish — marking progress in the quest to manufacture transplant organs.
A team from the University of Pittsburgh, Pennsylvania, used induced pluripotent stem (iPS) cells generated from human skin cells to create precursor heart cells called MCPs.
iPS cells are mature human cells “reprogrammed” into a versatile, primitive state from which they can be prompted to develop into any kind of cell of the body.
The primitive heart cells created in this way were attached to a mouse heart “scaffold” from which the researchers had removed all mouse heart cells, they wrote in the journal Nature Communications.
The scaffold is a network of non-living tissue composed of proteins and carbohydrates to which cells adhere and grow on.
Placed on the 3D scaffold, the precursor cells grew and developed into heart muscle, and after 20 days of blood supply the reconstructed mouse organ “began contracting again at the rate of 40 to 50 beats per minute,” said a University of Pittsburgh statement.
“It is still far from making a whole human heart,” added senior researcher Lei Yang.
Ways have to be found to make the heart contract strongly enough to pump blood effectively and to rebuild the heart’s electrical conduction system.
“However, we provide a novel resource of cells — iPS cell-derived MCPs — for future heart tissue engineering,” Yang told AFP by e-mail.
“We hope our study would be used in the future to replace a piece of tissue damaged by a heart attack, or perhaps an entire organ, in patients with heart disease.”
According to the World Health Organization, an estimated 17 million people die of cardiovascular ailments every year, most of them from heart disease.
Due to a shortage of donor organs, “end-stage heart failure is irreversible,” said the study.
More than half of patients with heart disease do not benefit from drugs.
“Heart tissue engineering holds a great promise... based on the reconstruction of patient-specific cardiac muscle,” the researchers wrote.
Last month, scientists in Japan said they had grown functional human liver tissue from stem cells in a similar process.
Creating lab-grown tissue to replenish organs damaged by accident or disease is a Holy Grail for the pioneering field of stem cell research.
Until a few years ago, when iPS cells were created, the only way to obtain stem cells was to harvest them from human embryos.
This was controversial because it required the destruction of the embryo, a process to which religious conservatives and others object.
Scientists grow human heart tissue
Scientists grow human heart tissue
Apple to update EU browser options, make more apps deletable
- iPhone maker came under pressure from regulators to make changes after the EU’s sweeping Digital Markets Act took effect on March 7
- Apple users will be able to select a default browser directly from the choice screen after going through a mandatory list of options
STOCKHOLM: Apple will change how users choose browser options in the European Union, add a dedicated section for changing default apps, and make more apps deletable, the company said on Thursday.
The iPhone maker came under pressure from regulators to make changes after the EU’s sweeping Digital Markets Act took effect on March 7, forcing big tech companies to offer mobile users the ability to select from a list of available web browsers on a “choice screen.”
The new rules require mobile software makers to show the choice screen where users can select a browser, search engine and virtual assistant as they set up their phones, which earlier came with preferred options from Apple and Google.
In an update later this year, Apple users will be able to select a default browser directly from the choice screen after going through a mandatory list of options.
A randomly ordered list of 12 browsers per EU country will be shown to the user with short descriptions, and the chosen one will be automatically downloaded, Apple said. The choice screen will also be available on iPads through an update later this year.
Apple released a previous update in response to the new rules in March, but browser companies criticized the design of its choice screen, and the Commission opened an investigation on March 25 saying it suspected that the measures fell short of effective compliance.
The company said it has been in dialogue with the European Commission and believes the new changes will address regulators’ concerns.
It also plans to introduce a dedicated area for default apps where a user will be able to set defaults for messaging, phone calls, spam filters, password managers and keyboards.
Users will also be able to delete certain Apple-made apps such as App Store, Messages, Camera, Photos and Safari. Only Settings and Phone apps would not be deletable.
