Yearbook 0203


Thomas Dienstknecht
Home Institution Medizinische Hochschule Hannover Host Institution Center for Surgical Research, University of Alabama at Birmingham Research Mentor: Irshad H. Chaudry , M.D., Ph.D. E-Mail: Th.Dienstknecht@t-online.de
Research Topic see Abstract
Personal Reactions to the U.S. Experience Of course, this one page is much too short to express an overall idea of the adventure of this year. Honestly, my experiences during this year were other than expected. The first impression for me (I had never been to the US before) was, of course, overwhelming. Everything was bigger, faster, better organized and more professional. During my time here, I discovered that a lot of things were less ideal than they seemed and, especially compared to the upper east coast, the south is really different. Fortunately, my colleagues in the laboratory improved my life to a great extent and I enjoyed every day here.
Greatest Difficulties Encountered Here, in the deep south, a big issue is the language. For the first weeks I took always a "double surprise meal" at every food place I went. The first surprise was what I had to pay (because of some absolutely unreasonable taxes), the second surprise was, what really was in my brown bag. Why? Because even at big companies like "McDonalds" and "Burger King" it was nearly impossible to communicate with the people over the counter, and every sentence was one big word for me. But believe me, over the time it gets better. The second big problem here in Birmingham is the lack of any useful public transportation. Avoiding some quarters of this city, where you definitely "do not want to go," complicated things. Simple things like going to the supermarket became an arduous task. In a city with roads built only for cars, every Saturday morning became a hellish ride with my bike over the highway to the next "Food World" to get my supplies for the next week.
Most humorous incident During the first month here in Alabama it was often over 34º C with humidity in the high nineties. So whatever you do outside, you don't do it without sweating a lot. With this said, I discovered my favorite sign in the supermarket, "Buy one, get one free!" No one told me that this means here that every single item is on sale for half price. You DON'T really have to buy one pair, as is common in most bars. So, on a hot and humid September day, you could see a crazy German guy carrying two heavy cartons of detergent to his dorm. What fun for all those car drivers passing me and making humorous statements about my totally soaked t-shirt.
Helpful Hints for Future Students - Contact former BMEP students. They will give you a lot of helpful facts about your trip. - Start early to get your paperwork done. - Get yourself an accessible fax number. If you need to prove something, fax the documents and send an additional letter. This worked out well for me and you save some precious time. - Keep in touch with the person in charge. Especially as an international student, you have to be persistent. Otherwise, your paper ends up at the bottom of a huge pile, and will never been seen again. - Oh yeah, and always be friendly to the immigration officers. Failure to this might cost you some additional hours in the waiting area. Ask me, I know what I am talking about. Feel free to contact me via email for any question bothering you because I had a lot, too.
next entry table of contents

Abstract on Research Topic
Gender differences in immune reaction after trauma-hemorrhage

Authors
Thomas Dienstknecht, Shellie Hyde

Institution
Center for Surgical Research, University of Alabama at Birmingham , Birmingham, AL

Note: Because of possible interferences with ongoing experiments and submitted results, this abstract does not reflect one special project and should give a more overall idea of the work done by my host laboratory.

Purpose
Former studies show a significant difference between the outcome of patients after trauma and severe blood loss. Beside the impact of the underlying trauma, gender differences are obvious with a much better prognosis for females. In the past it was shown that, as well blocking testosterone receptors, the administration of estrogen improves the immune dysfunction after trauma-hemorrhage. Although these effects are well observed, the complete pathways remain to some extent unclear. The purpose of our studies here are to unravel those ways. Overall aim is to find ways of a beneficial treatment of patients after trauma and blood loss.

Materials and Methods
Different hormones were administered to mice using long lasting pellets. Fourteen days later, the animals underwent soft tissue trauma and hemorrhage. Briefly, the animals were anaesthetized and a midline laparotomy was performed (soft tissue trauma). After closing the incision aseptically, both femoral arteries were canulated using microsurgical procedures. One catheter was connected to a permanent blood pressure measurement, the other one was used to shed blood from the mouse. By this method the blood pressure was lowered to 35 ± 5 mmHG and maintained for 90 minutes. After this, the animals were resuscitated with four times the shed blood volume in Ringer`s lactate solution over 30 minutes. 24 hours after this the animals were sacrificed and whole blood, liver cells and the spleen were harvested. Different cell types were isolated and cultured. The ability to respond to specific stimulation reagent was measured by ELISA. Additionally RT-PCR and FACS scans were performed to further investigate different signaling pathways.

Results
Mice receiving estrogen treatment showed a better outcome compared to animals receiving testosterone. Metabolic measurements, plasma level of proinflammatory cytokines and cell responses to stimulation from estrogen groups nearly reached the level of control mice without any treatment whereas the testosterone groups parameters were depressed in many fields.

Conclusion
The results show a clear difference between the outcome of animals receiving estrogen compared to those who received testosterone. Those results are comparable to clinical observations and might provide a widely based knowledge of the influence of sex hormones to the immune function after trauma hemorrhage. This might lead to possible treatment of the large number of patients who suffer from trauma and subsequent severe blood loss.