Both sides in the ongoing court case over government funded human embryonic stem cell research are sharpening their arguments this week and maneuvering for what could be a swift judgment in the coming days.

Yesterday, for example, Story Landis (pictured), the chair of the National Institutes of Health (NIH) Stem Cell Task Force filed a declaration that seems to directly answer assertions that the agency’s funding guidelines are providing an incentive for new stem cell lines to be derived, causing more embryos to be destroyed.

In fact, wrote Landis to the US District Court for the District of Columbia, of the 75 stem cell lines approved for use in NIH-funded research since July 2009, “73 were derived from embryos donated prior to the issuance of the Guidelines.”

In other words, the issuance of new NIH guidelines following a March 2009 executive order from US President Barack Obama has not hastened the creation of new stem cell lines but has merely opened the door for funding research on lines that, for the most part, already existed. The point speaks to the central question around which the case now revolves: is all work now conducted with a human embryonic stem cell line akin to the destruction of a human embryo? The NIH says no, as the derivation could have occured long before the research was even imagined, while the plaintiffs, who oppose the funding, say that it amounts to a financial inducement to destroy embryos.

The opposing views were on full display yesterday, during appeals court arguments about whether a temporary stay on last month’s court injunction that banned governement funded stem cell research should be upheld. If it is upheld, then the research can continue while the District Court deals with the case. If not, then the District Court’s injunction stopping federally funded human embryonic stem cell research will once again be in effect.

As if that didn’t provide enough action for one day, the US government also yesterday petitioned the District Court to decide the case without further courtroom arguments, a so-called motion for summary judgment. (The plaintiffs earlier this month asked for the same thing.)

In a supporting, 52-page memo, the Justice Department argued, again, that funding the research does not violate the Dickey-Wicker amendment, which prohibits government funding for research in which a human embryo is destroyed. (See the case history.) It also contested the plaintiffs’ argument that the NIH broke a policymaking law by ignoring thousands of comments submitted by opponents of the research.

The government wrote that, because the comments opposed the research overall, they weren’t relevant to the policymaking procedure that NIH was charged with under Obama’s executive order: to develop guidelines under which the funding of the research would proceed. “NIH was under no obligation to convert the subject matter of the Guidelines into a completely separate topic – the scientific merits of hESC research generally – simply because plaintiffs ignored the intended purpose of the Guidelines,” the Justice Department lawyers write.

Yesterday, the government also filed a response to the plaintiffs’ statement of facts, arguing in several cases that the plaintiffs’ attested facts are “vague and ambiguous.” For instance, they contest the assertion that Theresa Deisher, one of the two plaintiffs, “is in the process of applying for NIH funding and will continue to seek NIH grants in the future.“

“This assertion is vague and ambiguous,” the Justice Department lawyers write, “insofar as Dr. Deisher has claimed to be `in the process’ of applying for NIH funding for more than a year.”

Deisher, an adult stem cell researcher, has never applied for an NIH grant. She was granted legal standing in the case on the grounds that her chances for winning NIH grants are being hurt by NIH’s funding of human embryonic stem cell researchers.

For full coverage of this developing story see our online Stem Cell Injunction news special.