Long distance collaboration with a professor – wrote manuscript, getting ignored. What to do next? This summer I was involved in a long distance collaboration with a researcher at an institution for clinical research. I was essentially CC'd to this person via an old colleague who currently works with this professor as a faculty member when the professor I collaborated with apparently expressed to my colleague that they needed more manpower to finish writing a manuscript given their busy schedule.

Anyways, this researcher had me conduct a literature review for a series of rare, clinically related human disorders to serve as the base of a case report for a series of patients who presented at this institution for a clinical trial, as well as some basic statistical analyses. I essentially typed what would be the base of this paper. This institution is a top 20 NIH funded institution and my old colleague is very trustworthy, so I was very ecstatic to work on this project during the summer.  This researcher even speculated on specific journals we should target for publication. The researcher and I had good interactions via e-mail and after I was finished with "baking the cake" so to speak with the review, the researcher praised my work and said all that they had to do was pull up the patient demographics and specific presentations of the patients to input. I do not have access to that sensitive information as I am not affiliated with that institution, so I was dependent upon them for that.

The researcher did not reply for what was around a month, so I sent an update e-mail kindly inquiring on the status of the project, thanking the researcher for allowing me to work with them, saying I learned a lot conducting the literature review, etc.

Ignored for another month. At this point I am frustrated because at the time I did all this work in about 3 days with very, very little sleep knowing I had personal familial commitments to attend to and I would be away from a computer for an extended period of time (around a week or two) and I thought this researcher was adamant about needing the "manpower" as per my old colleague.

What do I do now? I'm assuming there's nothing much I can do. I live pretty far from this institution so it's not like I can drive up there for a meeting. Moreover, to walk in unannounced sounds very vulgar. I can't tattletale to my old colleague because why would I drag him into something he isn't a part of? I wanted to get this project to completion because I am looking to apply to this same exact institution for a fellowship later on in my career and am looking at this specific department. Moreover, I was genuinely passionate about the project and felt like authorship in that field would boost my morale. I also thought developing rapport with faculty would help my prospective academic career. I tried looking at my e-mails and even had friends look through my e-mails to see if I had inadvertently wrote something that could be interpreted aggressive, rude, or accidentally offensive (like calling them Mr./Ms. instead of Dr.) but I found nothing.
Since email isn't working, I see two alternatives. The simple one is to contact the person who originally got you involved to see if they know what the problem might be. Presumably this person knows both of you and may know the other person better than you do. 

The only other solution with a positive outcome is to contact the other party in person. Your question is "How shall we proceed?" not "What is the problem here?". There might be any number of things in the way, but you have no way to  know with a passive approach. 

It's not impossible that you are being used and therefore ignored. But you shouldn't conclude that without more information.