Search PubMed⌕ Search

Biomedical subjects

J R Scherrer

Publications and source records attributed to J R Scherrer.

At least 109 records · Page 6Linked to original sources

Relationship between renin and intrarenal hemodynamics in hemorrhagic hypotension.

In order to investigate the possible role of the renin-angiotensin system in the regulation of intrarenal hemodynamics in hemorrhagic hypotension (HH), seven mongrel dogs have been studied under the following conditions: (a) Control, (b) HH (mean arterial pressure 70 mm Hg), and (c) HH + alpha adrenergic blockade by phenoxybenzamine (HH + POB). The following parameters were obtained for the right kidney: Intrarenal distribution of blood flow and local blood flow rates ((133)Xe washout technique); total renal blood flow (RBF) on the basis of the clearance and extraction ratio of PAH and the arterial hematocrit; plasma renin concentrations in the renal artery and vein by the method of Boucher and his associates; and renin release into the renal circulation. Alpha adrenergic blockade reverted the typical redistribution of intrarenal blood flow observed under HH. In hemorrhage, arterial and venous renin concentrations increased by a factor of 3.4 and 4.8 respectively. A further small increase was observed during HH + POB with the respective factors increasing to 4.8 and 5.3, as compared with control values. The renin release into the circulation increased by a factor of 1.2 in HH and 4.0 in HH + POB. Whereas in HH there seemed to be a relationship between increased renin concentrations or renin release, and the redistribution of blood flow, no such correlation was found during alpha-adrenergic blockade. From these observations it is concluded that renin alone is unable to maintain the typical redistribution of RBF seen during hemorrhage. Circumstantial evidence points to a permissive role of the renin-angiotensin system in the pathogenesis of the patchy cortical hypoperfusion caused by sympathoadrenergic mechanisms during hemorrhagic hypotension.

Angiotensin II↗

Digital image management and communication in medicine.

With the rapid development of digital imaging modalities in medicine, there is an increasing need for an efficient management and archival of medical images in digital form. Picture Archiving and Communication Systems (PACS) are becoming an essential component of medical imaging equipment, allowing for medical images to be accessed and stored directly in digital form. This paper describes a hospital-wide PACS currently under development at the University Hospital of Geneva, based on an open architecture, regrouping equipment from different vendors in a distributed topology. The image archival is organized in multiple locations geographically distributed in the hospital. The PACS database is fully integrated with the concurrent Radiology Information System (RIS) and Hospital Information System (HIS). A standard image storage format called the PAPYRUS format was developed for the storage of medical images from a variety of imaging modalities. To provide a more uniform user interface on a variety of different workstations, a common platform for image display and manipulation called OSIRIS was developed.

Computer Communication Networks↗

Object-oriented design of medical imaging software.

A special software package for interactive display and manipulation of medical images was developed at the University Hospital of Geneva, as part of a hospital wide Picture Archiving and Communication System (PACS). This software package, called Osiris, was especially designed to be easily usable and adaptable to the needs of noncomputer-oriented physicians. The Osiris software has been developed to allow the visualization of medical images obtained from any imaging modality. It provides generic manipulation tools, processing tools, and analysis tools more specific to clinical applications. This software, based on an object-oriented paradigm, is portable and extensible. Osiris is available on two different operating systems: the Unix X-11/OSF-Motif based workstations, and the Macintosh family.

Computer Communication Networks↗