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Biomedical subjects

V Law

Publications and source records attributed to V Law.

8 recordsLinked to original sources
PubMed2001

Cupped lesions of early onset dental erosion in young southeast Queensland adults.

BACKGROUND: Dental erosion manifests as cupped lesions on cusp apices and in fissures of teeth in patients from southeast Queensland referred with excessive tooth wear. When found in young adults, these lesions may indicate early onset of active dental erosion. If the numbers and extent of cupped lesions increase with age, erosion may be a slow cumulative process. METHODS: This cross-sectional study recorded the presence or absence and the relative sizes of cupped lesions from all cusps and occlusal fissures on premolar and permanent molar teeth from study models by image analysis. Type-specimens of cupped lesions were examined. RESULTS: The incidence by tooth reflected time in the mouth, post-tooth emergence. A linear increase in lesion number and size, with age, was found. However, cupped lesions occurred on mandibular first molar cusp apices as often, and attained greater extent, in adults under 27 years compared with older subjects. CONCLUSION: Marked differences were found between lesion number and size, between maxillary and mandibular molar sites that reflect differences in salivary protection against dental erosion. The significance of this study is that the mandibular first permanent molar indicates the age of onset and severity of dental erosion.

Adolescent↗
PubMed1998

An evaluation of UMLS as a controlled terminology for the Problem List Toolkit.

We are developing a set of software components--the Problem List Toolkit (PL-Tk)--to support operations on clinical problem labels. An adaptation of the National Library of Medicine's Unified Medical Language System (UMLS) provides general vocabulary services to domain-specific software components. Our initial investigation centers on the inclusion in UMLS of problem labels used in the Beth Israel Deaconess Medical Center's Online Medical Record (OMR). We also explore the semantic typing of problem labels matched in UMLS. We have operationally defined a clinical problem to derive its semantic type from classes of terms representing findings or processes typically requiring diagnostic evaluation or therapeutic management in clinical practice. Of 1262 unique OMR problem labels, 999 terms (79%) have matches in UMLS. 986 of 999 terms (99%) map to the UMLS concept of the corresponding lexical match. 952 of 999 terms (95%) have semantic types that comply with our operational definition of clinical problems. These 952 terms (75%) constitute Version 1.0 of the problem list vocabulary B196. Matching terms with inappropriate semantic types raise issues regarding requirements for PL-Tk, typing of existing UMLS terms, and the adequacy of our operational definition for clinical problems. UMLS provides a large repertoire of pre-coordinated terms that are used as problem labels in a heavily used computer-based patient record system. The semantic type hierarchy provides a framework for the consistent use of clinical concepts in problem lists such that clinical problem labels represent "good" clinical problems.

Evaluation Studies as Topic↗
PubMed1998

Metaphrase: an aid to the clinical conceptualization and formalization of patient problems in healthcare enterprises.

Patient descriptors, or "problems," such as "brain metastases of melanoma" are an effective way for caregivers to describe patients. But most problems, e.g., "cubital tunnel syndrome" or "ulnar nerve compression," found in problem lists in an Electronic Medical Record (EMR) are not comparable computationally--in general, a computer cannot determine whether they describe the same or a related problem, or whether the user would have preferred "ulnar nerve compression syndrome." Metaphrase is a scalable, middleware component designed to be accessed from problem-manager applications in EMR systems. In response to caregivers' informal descriptors it suggests potentially equivalent, authoritative, and more formally comparable descriptors. Metaphrase contains a clinical subset of the 1997 UMLS Metathesaurus and some 10,000 "problems" from the Mayo Clinic and Harvard Beth Israel Hospital. Word and term completion, spelling correction, and semantic navigation, all combine to ease the burden of problem conceptualization, entry and formalization.

Humans↗
PubMed1998

A component-based problem list subsystem for the HOLON testbed. Health Object Library Online.

One of the deliverables of the HOLON (Health Object Library Online) project is the specification of a reference architecture for clinical information systems that facilitates the development of a variety of discrete, reusable software components. One of the challenges facing the HOLON consortium is determining what kinds of components can be made available in a library for developers of clinical information systems. To further explore the use of component architectures in the development of reusable clinical subsystems, we have incorporated ongoing work in the development of enterprise terminology services into a Problem List subsystem for the HOLON testbed. We have successfully implemented a set of components using CORBA (Common Object Request Broker Architecture) and Java distributed object technologies that provide a functional problem list application and UMLS-based "Problem Picker." Through this development, we have overcome a variety of obstacles characteristic of rapidly emerging technologies, and have identified architectural issues necessary to scale these components for use and reuse within an enterprise clinical information system.

Computer Systems↗
PubMed1998

Validation of clinical problems using a UMLS-based semantic parser.

The capture and symbolization of data from the clinical problem list facilitates the creation of high-fidelity patient resumes for use in aggregate analysis and decision support. We report on the development of a UMLS-based semantic parser and present a preliminary evaluation of the parser in the recognition and validation of disease-related clinical problems. We randomly sampled 20% of the 26,858 unique non-dictionary clinical problems entered into OMR (Online Medical Record) between 1989 and August, 1997, and eliminated a series of qualified problem labels, e.g., history-of, to obtain a dataset of 4122 problem labels. Within this dataset, the authors identified 2810 labels (68.2%) as referring to a broad range of disease-related processes. The parser correctly recognized and validated 1398 of the 2810 disease-related labels (49.8 +/- 1.9%) and correctly excluded 1220 of 1312 non-disease-related labels (93.0 +/- 1.4%). 812 of the 1181 match failures (68.8%) were caused by terms either absent from UMLS or modifiers not accepted by the parser; 369 match failures (31.2%) were caused by labels having patterns not recognized by the parser. By enriching the UMLS lexicon with terms commonly found in provider-entered labels, it appears that performance of the parser can be significantly enhanced over a few subsequent iterations. This initial evaluation provides a foundation from which to make principled additions to the UMLS lexicon locally for use in symbolizing clinical data; further research is necessary to determine applicability to other health care settings.

Medical Records Systems, Computerized↗
PubMed1996

In vitro uptake of bromodeoxyuridine by human nasopharyngeal carcinoma (NPC) and its relation to clinical findings.

A cell kinetic study of 27 newly diagnosed patients with nasopharyngeal carcinoma (NPC) using the in vitro bromodeoxyuridine (BrdU) technique was performed. The results were reproducible as demonstrated by three independent sections performed on each patient. No correlation between BrdU labelling index (LI) and Ho's clinical staging was found. A higher LI was associated with the development of distant metastases (P = 0.057). Statistically significant correlation was found between low LI and longer duration required to achieve complete remission in the primary site of disease (P = 0.026). This study suggests a potential role for in vitro BrdU labelling index as a prognosticator for NPC prior to treatment.

Adult↗
PubMed1994

Effects of streptozotocin-induced diabetes on lymphocyte POMC and growth hormone gene expression in the rat.

Diabetes in the rat is associated with a change in the profiles of several neuroendocrine hormones resulting in poor growth and decreased immune function. Since lymphocytes can also serve as a source of neuroendocrine hormones, we have examined whether the change in hormone profiles are accompanied by an impairment of lymphocyte GH and POMC gene expression in the immune system. Diabetes was induced by the administration of streptozotocin (STZ; 10 mg/100 g body weight) and 3 days later GH and ACTH protein and mRNA were determined. The results show a modest diminution of GH RNA in the spleen of diabetic animals whereas the expression of POMC mRNA and ACTH by the thymus was enhanced. The expression of POMC in the spleen appeared unaltered while the increase of POMC RNA in the thymus was evident after the first day of STZ treatment. STZ had no direct effect on GH or POMC expression in the spleen or thymus cells in vitro. Insulin does not appear to be involved in the expression of lymphocyte GH or POMC. The administration of insulin to the diabetic animals had no significant effect on the expression of GH or POMC by the immune cells. In addition, lymphocytes do not appear to serve as a source of insulin or are the expression of genes for lymphocyte GH or ACTH altered by insulin in vitro. Taken together, the findings are the first to report on the expression of neuroendocrine genes in lymphocytes during diabetes. The mechanism for the inhibition of GH and stimulation of POMC expression by lymphocytes in diabetic animals is unknown, but it is tempting to speculate an important role in the development of the autoimmunity that characterizes this complex disease.

Adrenocorticotropic Hormone↗