First ‘haploid’ human stem cells could advance medical research
Scientists have succeeded in creating only haploid embryonic stem cells – containing a single set of chromosomes – in non-human mammals such as mice, rats and monkeys.
By JUDY SIEGEL-ITZKOVICHA researcher works with stem cells in a laboratory(photo credit: REUTERS)
Stem cell research – especially that involving human embryonic stem cells (ESCs) – holds huge potential for medicine and human health. In particular, ESCs are important because they have an ability to turn into any cell in the human body that could be used for the future treatment and prevention of disease.Most of the cells in our body are diploid, meaning that they carry two sets of chromosomes, one from each parent. Until now, scientists have succeeded in creating only haploid embryonic stem cells – containing a single set of chromosomes – in non-human mammals such as mice, rats and monkeys. However, scientists have long sought to isolate and replicate these haploid ESCs in humans, which would allow them to work with one set of human chromosomes as opposed to a mixture from both parents.This milestone was finally reached by Ido Sagi, working as a PhD student at the Hebrew University of Jerusalem’s Azrieli Center for Stem Cells and Genetic Research. Sagi led research that yielded the first successful isolation and maintenance of haploid embryonic stem cells in humans. Unlike in mice, these haploid stem cells were able to differentiate into many other cell types, such as brain, heart and pancreas, while retaining a single set of chromosomes.With Prof. Nissim Benvenisty, durector of the Azrieli Center, Sagi showed that this new human stem cell type will play an important role in human genetic and medical research, Sagi said.“It will aid our understanding of human development – for example, why we reproduce sexually instead of from a single parent. It will make genetic screening easier and more precise, by allowing the examination of single sets of chromosomes. And it is already enabling the study of resistance to chemotherapy drugs, with implications for cancer therapy.”Based on this research, Yissum, the university’s technology transfer arm, launched a company called NewStem, which is developing a diagnostic kit for predicting resistance to chemotherapy treatments. By amassing a broad library of human pluripotent stem cells with different mutations and genetic makeups, NewStem plans to develop diagnostic kits for personalized medication and future therapeutic and reproductive products.SEX APPEAL IN ADS DOESN’T SELLCould it be that sex actually does not sell? Surprisingly, an analysis of nearly 80 US advertising studies published over more than three decades suggests that’s the case.“We found that people remember ads with sexual appeals more than those without, but that effect doesn’t extend to the brands or products that are featured in the ads,” said the lead author, University of Illinois advertising Prof. John Wirtz, which was published recently in the International Journal of Advertising.Wirtz and his co-authors conducted a first-of-itskind meta-analysis of peer-reviewed studies looking at the effects of sexual appeals. Their research found that not only were study participants no more likely to remember the brands featured in ads with sexual appeals; they were more likely to have a negative attitude toward those brands, Wirtz said.Participants also showed no greater interest in making a purchase.“We found literally no effect on participants’ intention to buy products in ads with a sexual appeal,” Wirtz said. “This assumption that sex sells – well, no, according to our study, it doesn’t. There’s no indication that there’s a positive effect.”As defined in the research, sexual appeals included models who were partially or fully nude; models who were engaged in sexual touching or in positions that suggested a sexual encounter was imminent; sexual innuendoes; and sexual embeds, which are partially hidden words or pictures that communicate a sexual message.“The strongest finding was probably the least surprising, which is that males, on average, like ads with sexual appeals, and females dislike them,” Wirtz said. “However, we were surprised at how negative female attitudes were toward these ads.”The implications of the research for advertising practitioners are mixed, given that ads with sexual appeals are remembered more – and advertisers want people to remember their ads, Wirtz said – yet they don’t appear to help in selling brands or products.“Certainly the evidence indicates that the carryover effect to liking the ads doesn’t influence whether they’re going to make a purchase,” he said.THE POWER OF TINY BUBBLESAn innovative technique using light and tiny bubbles to propel microparticles at speeds many times greater than previously achieved has been developed by Ben-Gurion University of the Negev researchers.The new technique could have significant implications in the development of micromotors and optical devices for use in solar cell optics.“What we ultimately hope to achieve is a highly accurate, passive technology for use in a concentrated solar device that would follow the sun without the need for a mechanical tracking mechanism,” said Dr.Avi Niv, the study’s co-author.According to the findings published recently in Nature Scientific Reports, the researchers converted the energy created from light into kinetic motion using nano-sized, laser-generated bubbles. As the bubble expands, it acts as a propulsion mechanism for surrounding microparticles. Mechanical manipulation of micro- and nano-scaled objects is important in biology, surface science and microfluidics, and for micromachines in general.“In our study, a micron-sized object was propelled at unprecedented speeds of close to one meter per second, six times faster than what is common in present devices, while still maintaining motion direction control,” Niv explained.“After the bubble initiates movement and bursts, there is no trace of the vapor; the system returns to the original state and the same action can be initiated repeatedly, like a combustion engine.”COUNTING ON FINGERSIs it acceptable for children to count on their fingers? Generations of pupils have been discouraged by their teachers from using their hands when learning arithmetic. But a new research article, published in Frontiers in Education shows using fingers may be a much more important part of math learning than previously thought.The article, by Prof. Tim Jay of Sheffield Hallam University and independent researcher Dr Julie Betenson, confirms what parents have long felt instinctively, that the kinds of finger games children often play at home are central to their education.The researchers worked with 137 primary pupils aged six and seven. All the children were given different combinations of counting and number games to play, but only some were given exercises that involved finger training.Some pupils played games involving number symbols, such as dominoes, shut-the-box or snakes and ladders.Other pupils were asked to play finger games: such as being asked to hold up a given number of fingers, or numbering fingers from one to five and then having to match one of them by touching it against the corresponding finger on the other hand or tracing colored lines using a particular finger. Both these groups did a little better in math tests than a third group of pupils who had simply had “business as usual” with their teachers. But the group that did both the counting and the finger games fared significantly better.“This study provides evidence that fingers provide children with a ‘bridge’ between different representations of numbers, which can be verbal, written or symbolic. Combined finger training and number games could be a useful tool for teachers to support children’s understanding of numbers,” Jay said.
