PubMed Health⌕ Search

Biomedical subjects

J Lochner

Publications and source records attributed to J Lochner.

5 recordsLinked to original sources
PubMed2004

The concept of a clinical round as a virtual, interactive web-based, e-learning model for interdisciplinary teaching.

The demonstration of patient case reports in the course of a clinical round is an essential part of teaching medicine and dentistry. However, suitable live patients with particular problems are not always available at a time when teaching is taking place. This project therefore had the objective of establishing a web-based, virtual e-learning concept for demonstrating case reports independent of time and place, with the possibility of an interactive examination, diagnosis, and interdisciplinary therapy decision making for medical and dental students. Anonymized case reports of diseases in the oral and maxillofacial region and the interdisciplinary treatment were digitized and prepared in a web-based format. The technical aspect was based on connecting flash modules with videos and animation, and monitoring through HTML and Javascript. Due to the modular concept and the programming used, the learning environment was independent of platform and open. Independent formats (.swf, .avi, .mpeg, etc.) were integrated into the individual modules. According to a hierarchic decision system, the user was guided interactively to the diagnosis through a differential diagnostic exclusion process. Sound was digitized and integrated in mp3 compressed form in the 3D models for lip-synchronous speech output. The speech output was connected with a virtual 3D tutor that acted in an advisory capacity in reaching a diagnosis and determining therapy. Further sources of information and literature with abstracts or pdf files of the subject-related publications were inserted to ensure that the teaching was objective. To conclude the virtual clinical round, a check on learning success was conducted in the form of a multimedia multiple choice test.

Computer-Assisted Instruction↗
PubMed1995

A novel nerve growth factor-responsive element in the stromelysin-1 (transin) gene that is necessary and sufficient for gene expression in PC12 cells.

Stromelysin-1 (ST-1) is an extracellular matrix metalloproteinase whose expression is transcriptionally regulated by nerve growth factor (NGF) in the PC12 rat pheochromocytoma cell line. In this paper, we define sequences in the proximal ST-1 promoter that contain a novel NGF-responsive element(s). We show that this cis-acting promoter element can bind nuclear proteins from both untreated and NGF-treated PC12 cells in a specific and saturable manner and is sufficient to confer NGF-inducibility to a heterologous promoter. At least a portion of this NGF-responsive element lies within a 12-base pair region between positions -241 and -229 of the ST-1 promoter and bears no sequence homology to other known transcriptional elements. In contrast to what has been reported for fibroblasts, an AP1 site centered around position -68 does not seem to be involved in the growth factor regulation of ST-1 in PC12 cells. These results suggest that the NGF regulation of ST-1 gene expression involves different promoter elements, and possibly different transcription factors, from that described for ST-1 induction by other growth factors.

Animals↗
PubMed1995

The metalloproteinase stromelysin-1 (transin) mediates PC12 cell growth cone invasiveness through basal laminae.

Matrix metalloproteinases have been implicated in various extracellular matrix remodeling events that occur during normal development and in a number of pathologies. In previous work with PC12 rat pheochromocytoma cells, we found that the matrix metalloproteinase stromelysin-1 (ST1) was highly induced by nerve growth factor (NGF), but not by epidermal growth factor (EGF). Here, we show that ST1 immunoreactivity is present in growth cones of NGF-treated PC12 cells, but not EGF-treated or untreated cells. To determine whether ST1 expression confers neurite invasiveness, three lines of PC12 cells were produced that constitutively express ST1 antisense mRNA. These lines expressed and secreted significantly reduced levels of ST1 protein, as determined by immunoblot and immunocytochemical methods, but otherwise responded normally to NGF-treatment by elaborating neurites. We found, however, that the neurites of these ST1 antisense cells showed a significantly reduced ability to penetrate a Matrigel reconstituted basal lamina, as compared to the parental cells, suggesting that ST1 confers neurite invasiveness. Finally, we show that ST1 is also expressed in vivo in sections through Embryonic Day 15 rat embryos, including neurons of both the peripheral and central nervous systems. These data indicate that ST1 may play a role in axonal growth in vivo, including a role in growth cone invasiveness.

Animals↗