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At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Animal evaluation of the prototype omnicath atherectomy catheter.

A prototype directional atherectomy catheter (Omnicath) was evaluated in four Yucatan microswines. Atherectomy was performed on iliac or aortic target lesions. After control angiography, the animals were sacrificed and the target arteries were examined histologically. Atherectomy resulted in arterial ruptures in three cases, and the track of the blade was measured to be of an average depth of 0.38 mm. Maneuverability was satisfactory but aspiration was not efficient. Precise localization of the atherectomy window was difficult. We conclude that modification of the catheter seems mandatory before use in humans.

Animals↗
PubMed1986

Testing of prototype antiepileptics in hippocampal slices.

The effects of six prototype anticonvulsant drugs, phenytoin, carbamazepine, midazolam, phenobarbital, ethosuximide and sodium valproate, were evaluated in two different experimental models of epileptiform activity using the in vitro slice preparation from the rat hippocampus. The relative potencies of the agents were determined: a) in the complete absence of synaptic transmission by recording spontaneous burst firing from the CA 1 pyramidal cell layer in a low calcium high magnesium solution and b) during blocked synaptic inhibition by observing the activity of each drug upon orthodromically evoked population spikes in penicillin containing medium. The rank order of potencies was a) in low Ca2+: carbamazepine, phenytoin, midazolam, phenobarbital, valproate, ethosuximide; b) in penicillin containing medium: midazolam, phenobarbital, carbamazepine, phenytoin, valproate, ethosuximide. These observations illustrate that the use of multiple paradigms is warranted when examining the mechanisms of action of new anticonvulsants.

Animals↗
PubMed1989

A generalized laboratory software package--a prototype approach.

A prototyped model of a generalized table-driven software package for laboratory testing and results registration is presented. The need to computerize dozens of laboratories performing hundreds of tests, called for a radical approach which would enable the quick addition of new laboratories to the system, as well as ease of maintenance. The generalized laboratory software package (GLAB) relies on a set of data tables, maintained by users, and a menu controlled environment interfacing GLAB with the rest of the hospital's systems.

Clinical Laboratory Information Systems↗
PubMed1980

A subtype of the prototypic karyotype in acute myeloid leukemia t (8; 21) (q22; q22), del 9 (q13; q23).

Two patients with acute myeloid leukemia are described in whom G- and C-banding analysis of bone marrow cells revealed, besides the translocation t(8;21), an additional structural anomaly characterized by the deletion of bands q13 to q23 of one chromosome no. 9. Findings in the literature support the proposal that this constellation represents a hitherto unreported subtype of the prototypic karyotype in AML.

Adult↗
PubMed1994

Evaluation of a portable prototype to analyze heart rate variability.

Power spectrum analysis of heart rate fluctuations provide a quantitative noninvasive means of assessing the functioning of the cardiovascular control system. Until now the equipment used to study heart rate variability (HRV) have been complicated systems utilized mostly in research centers. Simpler systems are needed for routine clinical application. We have evaluated, through clinical practice, the usefulness of prototype equipment which allows acquisition and analysis of ECG signals by a portable electrocardiograph and a personal computer in which sophisticated software is installed. We performed one hundred forty-five recordings in twenty-two patients admitted to ICU. With this technique two different predictive patterns were detected: one concerning survivors, the other concerning nonsurvivors. Reliability, portability, simplicity and quality results are the main advantages of the system. The disadvantage is that it is difficult to perform HRV analysis in patients with ECG arrhythmia. This is because the program does not allow the choice of an arrhythmia-free section of the tachogram to analyze.

Adolescent↗
PubMed1989

A new subgroup 2 bovine adenovirus proposed as the prototype strain 10.

A slowly growing subgroup 2 bovine adenovirus (BAV) strain designated Ruakura 78-5371 was isolated from a yearling heifer with systemic adenovirus infection. Cross neutralization tests and restriction endonuclease analysis of the viral DNA showed the virus to be distinct from the other 9 recognised types of BAV. It is proposed that this strain should be regarded as the prototype strain of the new type BAV-10.

Adenoviridae↗
PubMed1986

DNA restriction analysis of adenovirus prototypes 1 to 41.

DNA restriction patterns of all known human adenovirus prototypes (1 to 41), ordered according to subgenera A to F, are presented for restriction endonucleases BamHI, BglII, BstEII, HindIII, and SmaI. This catalogue is a prerequisite for typing of adenoviruses by DNA restriction analysis in diagnostic laboratories and for strain identification in reference laboratories. To determine the genetic relationship of human adenoviruses within a subgenus and between subgenera, a pairwise analysis of comigrating fragments was performed. Adenoviruses of subgenus C were closely related. Adenoviruses of subgenus B showed two related clusters of four types each, whereas the numerous serotypes of subgenus D did not show any corresponding clustering. Little comigration was observed between DNA restriction fragments from members of subgenus A or F respectively.

Adenoviruses, Human↗
PubMed1983

ABAC identibiogramme: prototype of an automated system for identification of enterobacteria.

The ABAC Identibiogramme, an automated, computerized system for the identification and antimicrobial susceptibility testing of the Enterobacteriaceae has been developed recently. The biological basis of the system resides in lyophilized, highly discriminating media enclosed in wells of an automatically inoculated disposable cartridge. The introduction of a suitable specimen rehydrates and inoculates the media in the wells. After incubation for 16 to 18 h at 37 degrees C and the addition of only one reagent (Kovacs reagent), the media changes and the results obtained are interpreted by an automated optical system and a computer. The antibiogram is also used by the computer to confirm the biochemical identification of the organism. The identification accuracy of a prototype of the ABAC Identibiogramme system was compared with that of API 20 E and conventional methods using a total of 1,290 clinical isolates. The ABAC Identibiogramme correctly identified 96.8% of the organisms tested, misidentified 2.4% and failed to identify 0.8%. The results demonstrate the high reliability and good identification performance of the ABAC Identibiogramme in comparison to API 20 E and conventional methods.

Enterobacteriaceae↗
PubMed1980

Development of prototype equipment for innovative employment of blind and partially sighted persons.

Sensory Aids Foundation of Palo Alto, California, has funded development of a number of microprocessor-based or computer-related sensory aids to enable blind and partially sighted persons to enter innovative areas of employment previously inaccessible to them. Three of these devices are discussed in this paper: the prototype TSPS (Traffic Service Position System) console for blind telephone operators; an Optacon Tracking Guide for CRT displays; and a Digital Indexing System for cassette audio recorders. In addition, three other microprocessor-based products recently acquired by Sensory Aids Foundation for placement with blind or partially sighted clients are briefly described: the Speech Annunciator for digital laboratory instruments; the Large Print Video Terminal; and the TIM-II (Talking Information Management System). A new grant received from the Department of Health, Education and Welfare, the Projects With Industry Section, has allowed expansion of services to develop computer-related jobs for blind, deaf, and orthopedically disabled persons.

Blindness↗
PubMed1992

Biochemistry and pharmacology of moclobemide, a prototype RIMA.

RIMA is a term for reversible inhibitors of monoamine oxidase (MAO) with preference for MAO-A; moclobemide is a prototype of this new class of antidepressants and is a highly selective inhibitor of MAO-A in vitro. This inhibition is reversible by dialysis in vitro, which accounts for the dose-dependent duration of in vivo enzyme inhibition of 12-24 h. Moclobemide increases the content of serotonin, noradrenaline and dopamine in the brain, and decreases that of their deaminated metabolites. Its biochemical, neurological and behavioural effects indicate that it increases the extracellular concentration of the classic monoamine neurotransmitters/neuromodulators - in particular 5-HT. Potentiation of the cardiovascular effects of tyramine is less pronounced after taking moclobemide than after irreversible MAO-A inhibitors. Understanding of the physiological role of MAO and of the events that link inhibition of the enzyme with modulation of neuronal activities in the CNS remains incomplete. A major physiological role of intraneuronal MAO is to keep cytosolic amine concentration very low, to enable the neuronal monoamine carriers to produce a net inward transport of monoamines, and thereby to act as the first step in the termination of action of extracellular monoamines. MAO is likely to have a similar function in non-monoaminergic cells with respect to the monoamine carriers they contain. In addition to the classic monoamines, "trace" amines may become functionally active after MAO inhibition. An alternative role for MAO is that of a scavenger, preventing natural substrates from accumulating in monoaminergic neurons and interacting with storage, release, uptake and receptor function of monoamines.

Animals↗
PubMed2000

New prototype NIRS instrument [corrected] to investigate multi-regional cerebral blood and tissue oxygenation and haemodynamics.

Near infra-red spectroscopy (NIRS) is a non-invasive optical technique used to assess blood and tissue oxygenation and haemodynamics in living tissue. It is presently used as a semi-continuous monitoring technique on a research basis. Multi-regional NIRS information could be beneficial for a better understanding of the development of cerebral injuries and the reduction of neurodevelopmental abnormalities in the human newborn. The paper presents the conversion of the continuous wave NIRS single-channel instrument (NIRDCU) into a prototype four-channel instrument which can be used to provide continuous multi-regional information regarding the cerebral blood oxygenation and haemodynamics in the frontal, left parietal, right parietal and occipital region of the neonatal brain. This has been achieved by attaching an optical multiplexing system to the NIRDCU to select different transmitting and receiving fibres, thus addressing different regions in the brain. Preliminary laboratory tests on a phantom and on the adult forearm are presented, illustrating the practicality of regional monitoring.

Adult↗
PubMedDate not supplied

Improved LAboratory Prototype ELectrolarynx (LAPEL): using inverse filtering of the frequency response function of the human throat.

The electrolarynx (EL) provides a valued means of verbal communication for people who have lost their larynx. Existing ELs have some drawbacks such as harsh, raucous, and unpleasant sound and the presence of background noise. This study presents an experimental analysis of two commercial ELs and describes the development and testing of an improved LAboratory Prototype ELectrolarynx (LAPEL) which more accurately simulates the sound of a natural larynx and has lower background noise. This natural sound is obtained by determining the frequency response function (FRF) of the tissue of the human neck and using this information to tailor the input signal to the EL by inverse filtering such that its output spectrum resembles that of the natural larynx. The result was subjectively judged to have a superior and more natural sound than existing electrolarynxes.

Humans↗
PubMedDate not supplied

Evaluation of a prototype steerable angioscopic laser catheter in a canine model: a feasibility study.

To overcome some of the persisting technical problems related to laser angioplasty, a new catheter was designed and investigated in a canine model. This 5F catheter contained a deflectable tip for steerability, an angioscope, and a laser fiber. Catheter steerability, angioscopic function, and the effects of a 480 nm flash lamp pumped pulsed dye laser on normal canine vessel walls were evaluated. Steering, angioscopic guidance, and application of laser energy were easy and fast to perform in a bloodless vessel segment. Maintaining a condition of bloodlessness at the target site, critical to angioscopic guidance, proved to be the most difficult part in this prototype evaluation. It was noted that the 480 nm pulsed dye laser did not cause macroscopic alterations or perforations to the normal vessel wall. We conclude that a relatively simple deflection mechanism of a small-caliber angioscope provides the kind of aiming ability requisite for precise endovascular therapy. Complete bloodlessness of the area is necessary for both viewing and laser ablation at 480 nm.

Angioplasty, Balloon, Laser-Assisted↗
PubMed2002

Beta-thalassaemia prototype of a single gene disorder with multiple phenotypes.

As the defective genes for more and more genetic disorders become unravelled, it is clear that patients with the same genotype can have many different clinical conditions even in monogenic disorders. The remarkable phenotypic diversity of the beta thalassaemias is prototypical of how the wide spectrum in disease severity can be generated. The most reliable and predictive factor of disease phenotype is the nature of the mutation at the beta-globin locus itself. However, relating phenotype to genotype is complicated by the complex interaction of the environment and other genetic factors at the secondary and tertiary levels, some implicated, and others, as yet unidentified. This article reviews the clinical and haematological diversity encountered in beta thalassaemia and their relationship with the underlying genotypes.

Alleles↗
PubMed1989

Digital image display station performance requirements based on physician experience with a prototype system.

The authors report on observations of and interviews with physicians using a prototype digital image display and reporting station. While the users generally agree that image quality is clinically satisfactory, they are unanimous in their opinion that improvements in the man-machine interface are required before case review by this mechanism is clinically acceptable in a production environment. A model image and information user interface is presented. It was developed in answer to the needs of radiologists and referring physicians operating in the imaging department of a community acute-care facility. In such an environment images and related information must be communicated quickly and often simultaneously to different parts of the department and hospital. The user interface with the management system and the management system itself must address the varied functions and the needs of both the medical and clerical staff. Image enhancement processes, for example, must be restricted to those that quickly provide significantly more perceivable diagnostic information. Little-used processes that may occupy significant portions of the display and the console's computing power must be trimmed or eliminated.

Computer Systems↗
PubMed1995

Opinion: a prototype for a computerized national mammography registry and tracking system using telecommunications and the Internet.

In this report, we analyze the feasability and discuss the potential benefits of using currently available technology for the wide-area registration and tracking of mammography patients. In our prototype, three dissimilar computer systems transmitted mammographic data (demographics and the results of mammograms) in a standardized format to a central data repository. Two of the three systems were dedicated computerized mammography systems and one was a general-purpose radiology information system. High-speed modems and the Internet were used to connect with the central repository, which could be queried in real time by remote users. Our results indicated that a busy mammography practice, using the slowest transmission method we tested (14-kilobaud modem), could transmit several days of mammographic data to a central repository in a matter of minutes. To implement systems that provide nation-wide mammographic tracking and follow up, more in-depth planning, development, and testing are necessary.

Computer Communication Networks↗
PubMed1991

A prototype of a high-resolution computerized radiology teaching file.

Computers provide an excellent tool for handling the task of organizing a radiology teaching file. Currently available computerized teaching files are either film-based, slide-based, or use laser-disc video technology for image display. There are obvious advantages to having the management of radiologic images under the control of a computer, and the need for a higher resolution alternative to video laser-disc technology becomes apparent when one tries to computerize a chest radiology teaching file. We describe the prototype of such a system, named MIRTLE, (the Mallinckrodt Institute of Radiology Teaching and Learning Environment) which was designed to integrate text under the control of a custom data base with high-resolution digital images from a Picture Archiving and Communications System. This system with its easy-to-use windows environment should allow a significant increase in the use of the radiology teaching file.

Computer Systems↗
PubMed2002

Gaucher disease: Perspectives on a prototype lysosomal disease.

Gaucher disease is an autosomal recessive trait and the most common lysosomal storage disease. The pathogenesis evolves from the diminished activity of the lysosomal hydrolase, acid beta-glucosidase and the resultant accumulation of glucosylceramide within lysosomes. The pathogenic mechanisms are poorly understood. During the past 2 decades, progress has been made in understanding the biochemical basis and molecular biology of the disease, but more fundamental knowledge is required to relate these advances to the cell and whole body phenotypes. Despite this lack of understanding, enzyme replacement therapy has proved a successful and effective management for Gaucher disease. However, basic details of this therapeutic efficacy require elucidation. Here, we review the current state of the molecular pathogenesis and provide our perspective of some major issues for continued advances in this prototype lysosomal storage disease.

Animals↗