Categories
Cardiovascular
Diagnostics
Endocrinology
Health Insurance
Medical Devices
Mental Health
Nutrition
Oncology
Public Health
Sexual Health
Popular Articles

Obama's Proposal To Redirect Abstinence-Only Funding Renews 'Culture-War Battle,' Washington Times Columnist States
President Obama is causing the "core culture-war battle" over sex education to "come full circle" by proposing to redirect funding for abstinence-only sex education to a new Teen Pregnancy Prevention Initiative that "rejects an abstinence-only approach," Washington Times columnist Cheryl Wetzstein writes. According to Wetzstein, Obama"s fiscal year 2010 budget plan "zeroed out" the Title V abstinence-only sex education grant program, set to expire on June 30, and the Community-Based Abstinence Education program. Wetzstein continues that groups supporting comprehensive sex education have "loathed Title V from its inception" because of its "prohibition on teaching teens how to use birth-control products (i.e., no condom demonstrations) and its eight-point definition that seemed utterly unrealistic to sex educators." For example, Title V"s definition said that the ""expected standard of human sexual activity"" was a ""mutually faithful, monogamous relationship in the context of marriage,"" which Wetzstein says she has "heard many times, was insulting to gay youth who couldn"t marry" and "insensitive to minority youth who grew up in neighborhoods where marriage was rare." Wetzstein asks, "What will happen to Title V?" She writes that opponents "are staying vigilant" and working to avoid "any last-minute, back-door revivals of this program." Groups that support abstinence-only sex education are "working the phones, too," Wetzstein reports. According to Wetzstein, Valerie Huber, executive director of the National Abstinence Education Association, noted that "[s]aving Title V will require some heavy lifting, but "it"s expired before and been retroactively renewed."" Wetzstein concludes that "we"ll soon see what happens with the new players in town" (Wetzstein, Washington Times, 6/23).

Jet-Propelled Imaging For An Ultrafast Light
John Spence, a physicist at Arizona State University, is a longtime user of the Advanced Light at Lawrence Berkeley National Laboratory, where he has contributed to major advances in lensless imaging. It"s a particularly apt propensity for someone who works with x-rays, since they can"t be focused with ordinary lenses.
News of the day
President Obama Receives Warm Welcome From AMA Physicians
The American Medical Association warmly welcomed U.S. President Barack Obama to its 158th annual meeting in Chicago. Like the president, the AMA is committed to health reform this year that provides all Americans with affordable, high-quality health coverage.
Endocrinology

Environmental Factors Instruct Lineage Choice Of Blood Progenitor Cells

The research team led by Dr. Timm Schroeder, stem cell researcher at Helmholtz Zentrum MÃønchen, has developed a new bioimaging method for observing the differentiation of hematopoietic progenitor cells (HPC) at the single-cell level. With this method the researchers were able to prove for the first time that not only cell-intrinsic mechanisms, but also external environmental factors such as growth factors can control HPC lineage choice directly. The findings, published in the current issue of the prestigious journal Science, provide an essential building block for understanding the molecular mechanisms of hematopoiesis and are an important prerequisite for optimizing therapeutic stem cell applications. For decades scientists from various disciplines have discussed to what respective extent genetic predisposition and environmental factors influence human development. Likewise, the same "nature vs. nurture" issue is debated by hematologists and stem cell researchers: Is multipotent progenitor cell differentiation influenced solely by cell-intrinsic mechanisms or is it also influenced by the environment of the cell? What role do growth factors such as cytokines play? Do they influence HPC lineage choice directly or do they merely regulate the survival of the cell after the lineage choice has been made? Despite the immense importance of cytokines for day-to-day clinical research - and not least their far-reaching significance commercially - this issue has been one of the key unknown factors in the stem cell biology of blood. "This is simply because until now we did not have the suitable technology to observe the processes of cell differentiation and to measure them quantitatively," explained Dr. Timm Schroeder, research group leader at the Institute of Stem Cell Research of Helmholtz Zentrum MÃønchen. "We didn"t know exactly what happens during this time span," Dr. Schroeder said. "That is why until now we could not prove what role cytokines play." With the new bioimaging techniques developed by Dr. Schroeder"s team, progenitor cells could be observed for a longer period and on the single-cell level. Depending on the kind of cytokines present, after a few days the HPC cultures contained only one cell type. The question remained unanswered whether this was a consequence of direct cytokine regulation or merely the result of sorting out "erroneously differentiated" cells by cell death. Using the new bioimaging techniques for continuous single-cell observation, Dr. Michael Rieger and students in Dr. Schroeder"s research group showed for the first time that no cell death could be detected during the entire cell differentiation process. This proves unambiguously that HPC lineage choices can be steered by external environmental factors such as in this case by cytokines. The hematopoietic progenitor cells are "instructed" by cytokines. "These findings confirm that signaling pathways that are activated by cytokine receptors influence the lineage choices of the cells," Dr. Schroeder said. "The new method offers us the unique chance to observe the effect of all the molecules involved in the differentiation process separately and to better understand their role. This is an important requirement for optimizing the therapeutic use of stem cells." Further information Original publication: Rieger MA, Hoppe PS, Smejkal BM, Eitelhuber AC & Schroeder T (2009): Hematopoietic cytokines can instruct lineage choice. Science 325:217-218 Sven Winkler Helmholtz Zentrum MÃønchen - German Research Center for Environmental Health


Add your comment:
Name:
Site address: http://
Your message:
Enter today\\\\'s date, 2 digits
(spam protection):

© Copyright 2009