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Biomedical subjects

D J Rothwell

Publications and source records attributed to D J Rothwell.

14 recordsLinked to original sources
PubMed1998

The SNOMED model: a knowledge source for the controlled terminology of the computerized patient record.

This article will present a description of the semi-implicit semantic properties of the Systematized Nomenclature of Human and Veterinary Medicine, also called SNOMED International. It will focus on the formalism of SNOMED and its computational properties using the disease definition as an example. Additional information will be provided in order to convert semi-implicit links found between SNOMED concepts into explicit computational semantic links.

Artificial Intelligence↗
PubMed1996

Managing information with SNOMED: understanding the model.

SNOMED is an inventory of medical terms and concepts. Each concept has a unique representation, it's primary termcode. The primary termcode carries hierarchical and inheritable information about each concept it represents. Additional hierarchical and inheritable information is carried by cross references linked to each concept. The cross references provide the defining characteristics for each concept thereby creating a computer readable definition for each SNOMED entry. These are some of the attributes that define the SNOMED model.

Subject Headings↗
PubMed1995

SNOMED-based knowledge representation.

A standardized vocabulary and a standardized representation for this vocabulary are necessary prerequisites for the development of a computer-based patient record. A standard conceptual scheme or data structure for this vocabulary must be in place to define clinical events and to share data. SNOMED International is a detailed, fine grained, semantically typed and comprehensive computer processable vocabulary encompassing both human and veterinary medicine. Each term is placed in a standardized data structure that shows the term relationship within its own and other related taxonomic hierarchies. SNOMED International is a standardized vocabulary and data structure suitable for use in the computer-based patient record.

Animals↗
PubMed1993

Developing a standard data structure for medical language--the SNOMED proposal.

The Systematized Nomenclature of Medicine, Third Edition, SNOMED International, is a comprehensive structured nomenclature of human and veterinary medicine, the terms of which are detailed, fine grained and semantically typed. Terms are assigned to eleven independent modules (fields), each of which is systematized. Terms may be linked to on another to represent complex entities or manifestations or alternately complex terms dissected into their elemental parts. Terms are illustrated utilizing a frame representation. Efforts are in progress to build both a conceptual graph and a frame-based semantic network encompassing each SNOMED term, effectively building a knowledge base. In this way, the knowledge contained in each alphanumeric representation is made explicit. SNOMED is a linked data structure capable of faithfully representing the activities, observations and diagnoses found in the medical record in a computer processable form.

Animals↗
PubMed1978

Relations between surface charge and in vitro lysis of red blood cells in paroxysmal nocturnal haemoglobinuria.

The effects of neuraminadase on the electrophoretic mobility and in vitro lysis of PNH, glutathione treated and normal erythrocytes was determined. Neuraminidase strongly affected the in vitro haemolysis of PNH and glutathione treated erythrocytes by substantially elevating the lysis in the Ham acid test while virtually eliminating lysis in the sucrose test. Findings suggest that membrane bound sialic acid or the level of cell surface charge may have a role in the susceptibility of PNH erythrocytes to complement mediated lysis.

Complement C4↗
PubMed1976

Surface charge of erythrocytes in paroxysmal nocturnal haemogloninuria.

The electrophoretic mobility of erythrocytes from 3 patients with PNH was measured by standard techniques. Erythrocyte mobility is a measure of the net negative surface charge of these cells. In each of the 3 patients studied in mobility was significantly increased over normal cells indicating that there is an increase in negative surface charge of PNH erythrocytes. Following the Ham's and sucrose lysis tests; surviving cells showed mean mobilities that were not statistically different from normal cells. This suggests that these cells with higher surface charge are vulnerable to complement lysis.

Cell Membrane↗
PubMed1976

Lactate dehydrogenase activities in serum and plasma.

We investigated lactate dehydrogenase activity in serum and plasma because of the conflicting data found in the literature. We assayed serum, platelet-rich, and platelet-poor plasma by two colorimetric endpoint methods and by an ultraviolet kinetic procedure. Platelet-poor plasma and serum had essentially the same activities by all three methods, whereas the activity in platelet-rich plasma plasma averaged fourfold that in platelet-poor plasma or serum when the assay was performed under conditions that result in lysis of platelets and release of their lactate dehydrogenase. When measurements were performed in platelet-rich plasma under conditions that prevented lysis of platelets, all three types of specimens gave the same results. This occurred when the osmolality of the reaction mixture was about 240 mOsm/kg of water. At an osmolality of about 120 mOsm, the activity of platelet-rich plasma was substantially lower than that of platelet-poor plasma or serum. If plasma must be used, the sample must first be centrifuged (3000 X g, 15 min) to provide a platelet-free plasma.

Blood Cell Count↗
PubMed1976

Venereal transmission of hepatitis B virus. The possible role of vaginal secretions.

The presence of Type B viral (Australia antigen related serum) hepatitis in vaginal specimens was investigated and compared with that in saliva specimens in a group of patients during the acute phase of their illness. Hepatitis B surface antigen was detectable in most vaginal and salivary secretions during the phase of antigenemia and not in hepatitis B surface antigen-negative controls. Despite care in collection, occult blood was detected in the majority of specimens, but the positivity for hepatitis B surface antigen did not depend on the presence of occult blood. Recovery studies were performed in both vaginal fluids and saliva to determine if inhibitors to hepatitis B surface antigen were similar to those observed in stool samples. Significant inhibition was not observed. Although infectivity of the specimens was not established from this study, handling of these specimens as potentially infective material is recommended.

Female↗
PubMed1975

Bone marrow granulomas and infectious mononucleosis.

Multiple discrete granulomas were found in bone marrow sections of a young woman who had the typical symptoms and laboratory evidence of infectious mononucleosis. I present a review of findings in this case, together with reports of experimentally induced granulomas mediated by an immunologic mechanism.

Adult↗
PubMed1975

The effect of heparin and EDTA on the NBT test.

Heparin precipitates nitroblue tetrazolium (NBT) in the absence of protein (plasma). This NBT-heparin precipitate, when presented to neutrophils, results in NBT scores higher than those obtained with NBT in solution. It is postulated that the high NBT scores obtained with increasing heparin concentrations are due to increased NBT precipitation and hence increased phagocytosis. It is proposed that the variability of NBT scores obtained when heparin is used as the anticoagulant is related to the amount of precipitate formed and to inhibition of phagocytosis by excess heparin. EDTA, in the presence of plasma and NBT, forms a precipitate consisting of protein and little, if any, NBT. In the presence of EDTA, NBT scores are lower than those obtained with heparin. EDTA, at concentrations used to prevent coagulation, inhibits phagocytosis and this could explain the low NBT scores. These observations provide a mechanism for entry of NBT dye into neutrophils and may help explain the inconsistent results found in both normal and disease states.

Bacterial Infections↗
PubMedDate not supplied

The classification-nomenclature issues in medicine: a return to natural language.

The subject is examined in accordance with recommendations made at two recent international conferences. The historical backgrounds of the International Classification of Diseases (ICD) and the Systematized Nomenclature of Medicine (SNOMED) are related to explain the current status and objectives of both as well as their structural differences. A Canadian alternative to the ICD is presented along with the reason for its non-acceptance. Finally, it is proposed that SNOMED and ICD be integrated in a practical way to obtain the benefits of a multiaxial nomenclature while retaining the equivalent ICD classes necessary for maintaining the continuity of statistical information. This approach would prepare the groundwork necessary for completely automated encoding in natural medical language for health care data banks, while providing ICD-based national and international statistics.

Artificial Intelligence↗
PubMedDate not supplied

Toward representations for medical concepts.

The authors characterize the problems inherent to mapping across or combining terms from different vocabularies, focusing especially on MeSH and SNOMED. They also describe the exploration of the development of a frame-based representation of SNOMED.

Classification↗