Jessica Wortmann

Home Institution
Medizinische Hochschule Hannover

Host Institution(s)
Mount Desert Island Biological Laboratory, Maine
Yale School of Medicine, New Haven, Connecticut
Research Mentors: Hermann Haller, M.D.; John Forrest, M.D.

E-Mail:
 Jessica.Wortmann@web.de

Research Topic
see Abstract
Personal Reactions to the U.S. Experience
As for myself, the decision to break out of the familiar environment and to make my own experience in extraordinary situations has always been my dream.
What strikes one most when coming to the U.S., especially from Europe? Optimism! Whereas in our country there is always a deep concern about every new technology, political concept, view of life, the American in general is more curious to actually give it a try. In Europe we debate, in the U.S. they learn by doing. Every medical student who comes to the U.S. for an elective knows what I am talking about. Even if I didn't agree with some of them, my ideas and objections were usually appreciated.
Greatest Difficulties Encountered
It wasn't too difficult for me to adjust myself to the new environment. After all, the East Coast is not much different from Europe. If asked to give an advice for future participants it would be to open up entirely without judgement and expectations other than optimism. Besides, asking foreign people about their story and to show interest in their life is the best way to get the same in return.
Personally, I never fell in love with the American food, something that really is better in Europe.
Thinking about it, I never had huge difficulties other than the VISA-application, something that really should be started months in advance, or problems that were home-made. The latter would be the difficulty to let go and to accept that research has its own life and that there are days when everything happens to go wrong. The typical answer given by my American colleagues: Stop whining and try it again. Last but not least I learned to be persistent. To stand up for myself and to verbalise concerns is not a problem anymore.
Most humorous incident
I should say, the most ironic incident: The very last day of my stay in Maine, I wanted to simply drop something of at a friend's house. I took my Professor's car. Since he wasn't in Maine for that time I was allowed to use it. Well, what can I say? The streets were icy and I couldn't help it. Or in other words - it was a total crash. Well, there are other ways to be memorable, but I guess I really wanted to make sure…

Helpful Hints for Future Students

  • Talk to former BMEP students.
  • Plan visa application well in advance and keep yourself updated about changes concerning the process (www.us-botschaft.de).
  • Keep in touch with the other applicants, some problems are ubiquitous.

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Abstract on Research Topic

Effects of Tissue Culture Media on the Aduld Little Skate (Leucoraja Erinacea) Kidney
Authors:
Jessica Wortmann, Jennifer Litteral (MDI Bio Lab, Maine, USA)
Institution:
Mount Desert Island Biological Laboratory, Salisbury Cove, Maine Yale School of Medicine, New Haven, Connecticut
Note: This abstract reflects my work in Maine. At Yale I was working at a different project.
Introduction:
Contrary to the mammalian kidney, nephrogenesis is known to occur in lower vertebrates throughout their lifetime. In the mammalian embryonic kidney, development of the kidney is dependent on interaction and signaling of the uretric bud and the surrounding mesenchyme; nephrogenesis is terminated shortly after birth. Elger et al. (JASN ,June 2003) have shown that nephrogenesis can be induced by partial nephrectomy in the little Skate (Leukoraja Erinacea).
Furthermore, a zone situated at the outer edge of the skate kidney had been characterized as the "developing-zone" consisting of stem cell like mesenchyme. Similarities between the adult skate nephrogenic zone and the developing mammalian kidney are suggested by histological similarities. Wnt4 and Pax2 are important genes in mammalian nephrogenesis and fragments of these genes have been detected in the developing zone of the skate kidney.
Objectives:
1) To determine differences between embryonic nephrogenesis and adult kidney regeneration by establishing a tissue culture to cultivate the developing zone of the adult little Skate.
2) To determine the expression Wnt4 and Pax2 under four media conditions.
Methods:
For culture, small tissue pieces out of the skate developing zone were micro-dissected and placed into 6-well culture plates with culture medium (VCM), (Valentich, J. Tissue Cult. Method 13:149-162,1991). In order to compare tissue culture to untreated tissue pieces, some dissected material was flash frozen in liquid nitrogen and kept at -80 Celsius. These pieces were labeled baselines (controls).The experimental conditions varied in culture medium (four different media: VCM, VCM and Shark serum, VCM and Insulin, VCM and Shark serum and Insulin), time of incubation (6h,24h,1week,2weeks,etc.) and special ingredients (beta-mercaptoethanol; PMA, a Proteinkinase-Inhibitor and onkogene) to enhance growth. After incubation RNA was extracted using Trizol reagent, Dnase digested and tranlated into cDNA. The ABI Prism 7700 TaqMan Real-Time PCR was utilized, using specific primers and TaqMan probes for Wnt4 and Pax2. The data was then imported into an Exel Spreadheet and analyzed.
Preliminary Results:
1) Both, the developing zone and the mature, adult kidney pieces could be maintained in Tissue culture for 20-30 days. Histologically, the developing zone showed all stages of kidney development, such as s-shaped bodies, condensing mesenchyme and tubule formation. The adult kidney showed mature nephrons without signs of developing stages.
2) The preliminary data suggest that there is little difference in Wnt4 and Pax2 expression tested between the four media. The highest level of Wnt4 was seen in the tissue before culture (baseline). The Valentich medium, when used without other ingredients, caused the tissue to undergo rescue-growth. Probably due to a lack of nutrients, the tissue piece showed macroscopic outgrowth of axon-like structures, which appeared to be fibroblastic filaments. However, there was no increase in the expression of Wnt4 in these tissue pieces. On the contrary, preliminary data suggest that the expression of Wnt4 and Pax2, very highly expressed in native developing tissue (baseline) is almost completely down regulated when kept in culture, independent of the media chosen.