Jana Prokein

Publications of Jana Prokein

• Cochlear osteoneogenesis after meningitis in cochlear implant patients: a retrospective analysis.

  Authors: Martin Durisin, Soenke Bartling, Christoph Arnoldner, Melanie Ende, Jana Prokein, Anke Lesinski-Schiedat, Heinrich Lanfermann, Thomas Lenarz, Timo Stöver

  Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 09/2010; 31(7):1072-8.

  Retrospective clinical study. Academic tertiary referral center at the Medical University of Hannover. Computed tomographic findings of 126 patients (95 children and 31 adults) profoundly deafened byRetrospective clinical study. Academic tertiary referral center at the Medical University of Hannover. Computed tomographic findings of 126 patients (95 children and 31 adults) profoundly deafened by meningitis during a period of 20 years were evaluated. Children were defined as up to 12 years old at the onset of meningitis. No patients showed any relevant bilateral auditory brainstem response thresholds at the time of admission to our clinic. Patient histories, surgical findings, and imaging results were analyzed by experienced surgeons/neuroradiologists. Of 95 children, 30 (32%) displayed symptoms of labyrinthitis ossificans, whereas 11 (36%) of 31 adults showed changes of the bony structure of the cochlea. High-resolution computed tomography (HRCT) evaluation indicated that the ossification was detected more frequently if there was a larger time interval between onset of meningitis and high-resolution computed tomographic scan. Bilateral ossification at various stages was observed in 67% of children and 55% of adults with obliteration. In the comparison of cochlear ossification found in computed tomographic scans and intraoperative obliteration, HRCT showed a specificity of 73% and a sensitivity of 88%. The intraoperative evaluation revealed various stages of cochlear obliteration in 44% of children and 39% of adults. In our study, the earliest onset of labyrinthitis ossificans was found in high-resolution computed tomographic scans as early as 4 weeks after the onset of meningitis. In most cases, ossification occurred bilaterally with predominantly asymmetric involvement of both ears. The rate of osteoneogenesis increases significantly over time after meningitis. This leads to the conclusion that cochlear ossification can start very early and increase over time with unpredictable speed. Cochlear ossification typically develops bilaterally. From these results, we conclude that cochlear implantation should be performed bilaterally as soon as possible after meningitis and deafness have been diagnosed. HRCT offers good specificity but only limited sensitivity. Preoperative diagnostics should include magnetic resonance imaging to optimize preparation for cochlear implantation.

• Performance of a new quantitative method for assessing dural ectasia in patients with FBN1 mutations and clinical features of Marfan syndrome.

  Authors: Bahar Söylen, Kerstin Hinz, Jana Prokein, Hartmut Becker, Jörg Schmidtke, Mine Arslan-Kirchner

  Neuroradiology. 03/2009;

  INTRODUCTION: This study presents a comparison of established methods for measuring dural ectasia with a new quantitative method of assessing this clinical feature. METHODS: Seventeen patients withINTRODUCTION: This study presents a comparison of established methods for measuring dural ectasia with a new quantitative method of assessing this clinical feature. METHODS: Seventeen patients with an identified mutation in FBN1 were examined for dural ectasia. The results were compared with 17 age- and sex-matched controls. Our images were also evaluated using the two methods of quantifying dural ectasia, namely those of Ahn et al. and of Oosterhof et al. RESULTS: With our method, 80% MFS1 patients and 7% controls fulfilled the criterion for dural ectasia. Using the method of Oosterhof et al., dural ectasia was found in 88% patients with MFS1 and in 47% controls. Using the method of Ahn et al. 76% patients with Marfan syndrome and 29% controls showed dural ectasia. CONCLUSION: We present a novel quantitative method of evaluating MRT images for dural ectasia, which, in our own patient cohort, performed better than those previously described.

• Mice That Overexpress CC Chemokine Ligand 2 in Their Lungs Show Increased Protective Immunity to Infection with Mycobacterium bovis Bacille Calmette-Guérin.

  Authors: Olivia Schreiber, Kathrin Steinwede, Nadine Ding, Mrigank Srivastava, Regina Maus, Florian Länger, Jana Prokein, Stefan Ehlers, Tobias Welte, Michael D Gunn, Ulrich A Maus

  The Journal of infectious diseases. 11/2008; 198(7):1044-1054.

  Background. @nbsp; The acute phase of mycobacterial lung infection is characterized by a nearly exponential outgrowth of mycobacteria in the alveolar airspace and lung parenchymal tissue, suggestingBackground. @nbsp; The acute phase of mycobacterial lung infection is characterized by a nearly exponential outgrowth of mycobacteria in the alveolar airspace and lung parenchymal tissue, suggesting insufficient early protective immunity against mycobacterial challenge. In the current study, we tested the hypothesis that a CC chemokine ligand 2 (CCL2)-dependent increased mononuclear phagocyte subset accumulation in distal airspaces would improve the lungs' protective immunity to infection with Mycobacterium bovis bacille Calmette-Guérin (hereafter, "M. bovis BCG"). Methods. @nbsp; Wild-type mice and CCL2-overexpressing mice that exhibited increased pools of alveolar and lung mononuclear phagocytes-due to the lung-specific overexpression of human CCL2 in type-II alveolar epithelial cells-were infected intratracheally with M. bovis BCG and the developing lung inflammatory response was analyzed. Results. @nbsp; CCL2-overexpressing mice demonstrated significantly decreased mycobacterial loads in the bronchoalveolar space, lung parenchymal tissue, and spleen compared with wild-type mice, when both groups of mice were infected with M. bovis BCG. Moreover, in M. bovis BCG-infected mice, later-developing, accelerated resolution of lung granuloma formation was noted, particularly in CCL2-overexpressing mice as compared with wild-type mice. In addition, CCL2-overexpressing mice demonstrated an increased trafficking of mycobacteria-loaded dendritic cells towards lung-draining lymph nodes that was found to coincide with increased mycobacterial loads in this compartment. Conclusions. @nbsp; The data of the current study suggest that CCL2-dependent amplification of endogenous host-defense programs in the lung may improve the lungs' protective immunity against mycobacterial infections.

• Prediction of survival after liver transplantation by pre-transplant parameters.

  Authors: Tobias J Weismüller, Jana Prokein, Thomas Becker, Hannelore Barg-Hock, Jürgen Klempnauer, Michael P Manns, Christian P Strassburg

  Scandinavian journal of gastroenterology. 02/2008; 43(6):736-46.

  OBJECTIVE: Score-based medical urgency criteria are used for necessity-oriented liver transplantation (OLT) but lead to an increasing number of complications in patients with reduced post-OLTOBJECTIVE: Score-based medical urgency criteria are used for necessity-oriented liver transplantation (OLT) but lead to an increasing number of complications in patients with reduced post-OLT survival. A prediction of outcome would improve preoperative patient selection and management. MATERIAL AND METHODS: One-hundred-and-thirty-three consecutive adult patients (63.9% men, mean age 47.4+/-11.2 years) given transplants between May 2004 and November 2005 at the Hannover Medical School were analysed retrospectively using univariate and multivariate methods. RESULTS: Indications were: 27.1% viral hepatitis, 19.6% primary sclerosing cholangitis, 15.0% alcoholic liver disease, 7.5% metabolic liver disease, 6.8% primary biliary cirrhosis. Overall, 12-month patient survival was 81.2%. The mean MELD score at OLT was 14.5+/-5.3 and 12-month survival with MELD >16 (71.7%) and <16 (86.2%) differed significantly (p=0.041). Predictors of 12-month mortality included age (53.2+/-9.4 versus 46.1+/-11.2 years; p=0.004), lower cholinesterase (2.9+/-1.88 versus 3.7+/-2.02 kU/l; p=0.026) and serum creatinine (160.4+/-186.8 versus 77.7+/-31.6 micromol/l; p=0.007), with creatinine and cholinesterase as independent parameters. Based on these parameters, a model for predicting patient survival after liver transplantation was calculated and validated in a second independent cohort of 87 OLT patients. This score identified a high-risk group and a low-risk group (overall survival 47.4 versus 91.2%; p<0.001) with a specificity of 87.3% and a sensitivity of 68.75%. CONCLUSION: Age, pre-OLT creatinine and cholinesterase are predictors of short-term post-OLT survival and may be helpful as a bedside score in pre-OLT clinical management, outcome prediction and decision-making.