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PubMed1985

Computerized EEG pattern classification by adaptive segmentation and probability-density-function classification. Description of the method.

A phenomenological model for the representation of clinical EEGs is proposed. It assumes each individual record to consist of a few repetitive patterns which are described sufficiently by their power spectra. An algorithm for automatic EEG evaluation is described. It consists of two steps, a segmentation process which isolates the elementary patterns, and a clustering procedure which groups similar patterns with each other. Results are represented in graphical form. Diagnostic classification is not attempted. An appendix highlights the advantages of autoregressive modelling for EEG spectral analysis and, in particular, the estimation of the power contained in the various "rhythms".

Biometry↗

PubMed1985

Computerized EEG pattern classification by adaptive segmentation and probability density function classification. Clinical evaluation.

A series of 63 clinical EEGs showing a variety of normal and abnormal patterns was analysed by computer with particular reference to the different types of pattern within the same EEG. Boundaries between different patterns were established by means of adaptive segmentation, so that the duration of the resulting segments was determined by the particular EEG itself (thus the term 'adaptive'). Four channels from each EEG were analysed, paired (left and right) channels were simultaneously segmented and analysed interactively. Similar segments were then clustered without supervision by estimating a probability density function in a 2-dimensional 'feature space' having dimensions of mean frequency and mean power. Individual clusters emerged as well-defined peaks of the surface, individual segments or small groups of duration insufficient to constitute a separate cluster, being identified as 'singular events' (e.g., rare sharp waves, artifacts). The autocorrelation function was used to characterize the EEG both for the segmentation and for the subsequent clustering of the resulting segments. In confirmation of our previous work, adaptive segmentation based on the autocorrelation function of the EEG was found to be quite satisfactory. Unsupervised clustering by estimation of the probability density function in feature space was found to give the correct number of clusters (usually less than 5) in a majority of the records (65%), but in the remaining minority of cases (35%), either overclustering or underclustering occurred. Further, the 'singular events' were occasionally partly included in a formal cluster. Comparison of these results of EEG clustering by unsupervised probability density function estimation with earlier results obtained by supervised hierarchical clustering suggests that there may be subtle cues used by the electroencephalographer in the classification of EEG patterns which have not been adequately approximated by the computer algorithms thus far used in this work. Hence at least some minimal degree of supervision in the clustering process may be necessary, at least for the present. On the other hand, the method recommends itself for the representation of illustrative EEG summaries which, in conjunction with a short written report, would provide the clinical neurologist with a sufficient picture of the real EEG without, in most cases, the need to inspect the original record.

Action Potentials↗

PubMed2005

Classification of drugs in absorption classes using the classification and regression trees (CART) methodology.

Classification and regression trees (CART) were evaluated for their potential use in a quantitative structure-activity relationship (QSAR) context. Models were build using the published absorption values for 141 drug-like molecules as response variable and over 1400 molecular descriptors as potential explanatory variables. Both the role of two- and three-dimensional descriptors and their relative importance were evaluated. For the used dataset, CART models showed high descriptive and predictive abilities. The predictive abilities were evaluated based on both cross-validation and an external test set. Application of the variable ranking method to the models showed high importances for the n-octanol/water partition coefficient (logP) and polar surface area (PSA). This shows that CART is capable of selecting the most important descriptors, as known from the literature, for the absorption process in the intestinal tract.

Intestinal Mucosa↗

PubMed2001

Classification of posterior fracture dislocation of the hip joint: a modification of the Thompsen Epstein classification.

The purpose of this paper was to describe a classification of posterior fracture dislocations of the hip joint, which would highlight the important aspects of managing this injury and more closely correlate with the prognosis. During the period from July 1994 to September 1997, the senior author operated on 60 posterior fracture dislocations of the hip joint. The results of the surgery were scored according to our ability to accurately anatomically reconstruct the acetabulum. We found that the degree of comminution was a greater determent of whether we could achieve an anatomical reconstruction than the presence of an associated acetabular floor fracture. Epstein showed conclusively that type II and III injuries have significantly different outcomes, but then grouped them together as type IV injuries if there was an associated floor fracture. We felt it more appropriate to continue with Epstein's fundamental feature of ascribing a grade according to the comminution and subdivided his type IV injuries.

Fractures, Comminuted↗

PubMed1998

Diabetes in older adults: comparison of 1997 American Diabetes Association classification of diabetes mellitus with 1985 WHO classification.

BACKGROUND: We aimed to compare the prevalence of abnormal glucose tolerance identified by the 1985 WHO and the 1997 American Diabetes Association (ADA) diagnostic categories based on information collected in the Cardiovascular Health Study, an epidemiological study of elderly people. METHODS: We measured glucose concentrations during fasting and 2 h after a 75 g oral glucose-tolerance test in participants aged 65-100 years in the Cardiovascular Health Study. From a 1989 cohort, we analysed the glucose measurements of 4515 individuals without a previous diagnosis of diabetes and of 262 additional measurements from an African-American cohort recruited in 1992-93. FINDINGS: In the 1989 cohort, the prevalence of untreated diabetes with ADA diagnostic fasting criteria was 7.7% versus a prevalence of 14.8% by the WHO criteria. In the African-American cohort, the prevalence of untreated diabetes was 2.7% with ADA criteria and 11.8% with WHO criteria. 3509 (77.7%) of the 4515 participants in the 1989 cohort had normal glucose concentrations according to ADA fasting criteria, compared with 2401 (53.2%) according to WHO criteria. In the African-American cohort, the corresponding numbers were 239 (91.2%) versus 153 (58.4%). All differences in prevalence of abnormal glucose tolerance between ADA and WHO classifications were significant (p<0.0001). INTERPRETATION: Among elderly individuals, there was a significant difference in the prevalence of diabetes identified by the WHO diagnostic criteria based on oral glucose-tolerance test and the ADA fasting criteria. Consequently, many individuals currently classified as non-diabetic according to ADA criteria would previously have had a diagnosis of diabetes according to WHO criteria. Longitudinal studies are needed to assess the value of the criteria in the identification of individuals at increased risk of diabetes-associated chronic complications.

Black or African American↗

PubMed2001

Reexamination of interictal psychoses based on DSM IV psychosis classification and international epilepsy classification.

We sought to examine interictal psychoses based on the international epilepsy classification and DSM IV criteria, with special attention paid to epilepsy types as well as to subcategories of psychoses. One hundred thirty-two outpatients were studied, each with definite evidence of both epilepsy and interictal psychosis clearly demarcated from postictal psychosis. We compared them with 2,773 other epilepsy outpatients as a control. Risk factors for psychosis were examined within the temporal lobe epilepsy (TLE) group and the more extended group of symptomatic localization-related epilepsy. Further, nuclear schizophrenia and other nonschizophrenic psychotic disorders were compared. We confirmed a close correlation between TLE and interictal psychoses. Within the TLE group, only early epilepsy onset and a history of prolonged febrile convulsions were revealed to be significantly associated with interictal psychosis. Within the symptomatic localization-related epilepsy group, such parameters as complex partial seizures, autonomic aura, and temporal EEG foci were closely associated with psychoses. There was also a significant difference between groups as to ictal fear and secondary generalization. Whereas patients with early psychosis onset and a low intelligence quotient were overrepresented in the nuclear schizophrenia group, drug-induced psychosis and alternative psychosis were underrepresented. TLE proved to be preferentially associated with interictal psychoses. Within the TLE group, medial TLE in particular was found to be more closely associated with psychosis. Our data support the original postulation of Landolt, stating that alternative or drug-induced psychoses constitute a definite subgroup of interictal psychoses, which are different from chronic epileptic psychoses that simulate schizophrenia.

Adolescent↗

PubMed1994

Personality disorders: model for conceptual approach and classification. Part II: Proposed classification.

In Part II of this article we propose a model for classification of normal and deviant personality types. First, we outline a matrix that classifies normal and deviant behaviors by combining three levels of functioning (normal, neurotic, and borderline) with specific long term behavior types. Second, we describe in some detail eight discrete syndromes that meet criteria for PDs presented in Part I of the article (Vol. 47, No. 4, pp. 558-571, this Journal).

Humans↗

PubMed2006

Classification of torasemide based on the Biopharmaceutics Classification System and evaluation of the FDA biowaiver provision for generic products of CLASS I drugs.

The biopharmaceutical properties of an in-house developed new crystal modification of torasemide (Torasemide N) were investigated in comparison with the most well known crystal modification form of torasemide (Torasemide I) in order to classify the drug according to the Biopharmaceutics Classification System (BCS), and to evaluate the data in line with current US Food and Drug Administration (FDA) guidance (with biowaiver provision for Class I drugs) to determine if the biowaiver provision could be improved. The solubility profiles of Torasemide I and Torasemide N were determined, and tablets prepared from both forms of the drug were studied for in-vitro release characteristics in media recommended by the current FDA guidance for biowaiver of generic products, and in other media considered more appropriate for the purpose than the ones recommended by the FDA. Two separate bioequivalence studies in healthy humans (following oral administration) were performed with two test products (both prepared from Torasemide I) against a single reference product (prepared from Torasemide N). The absorption profiles of the drug from the tablets were determined by deconvolution for comparison with the in-vitro release profiles to determine the appropriateness of some dissolution media for predicting in-vivo performance and to determine the comparative rate and extent of absorption. The drug was absorbed from the tested products quickly and almost completely (about 95% within 3.5 h of administration). However, one test product failed to meet the bioequivalence criteria and had a significant initial lower absorption rate profile compared with the reference product (P< or =0.05), whereas the other product was bioequivalent and had a similar absorption profile to the reference product. A dissolution medium at pH 5.0, in which torasemide has minimum solubility, was found to be more discriminatory than the media recommended by the FDA. Torasemide has been classified as a Class I drug according to the BCS up to a maximum dose of 40 mg and the data suggest that the current FDA guidance could be improved by giving more emphasis to selection of appropriate dissolution media than is given in its current form for approving biowaiver to generic products of Class I drugs.

Area Under Curve↗

PubMed2004

Classification of loratadine based on the biopharmaceutics drug classification concept and possible in vitro-in vivo correlation.

Loratadine was studied both in vitro and in vivo (in healthy humans) to classify it according to the Biopharmaceutics Classification System (BCS) in order to gain more understanding of the reasons for its highly variable nature with respect to plasma time profiles, and to determine the most appropriate dissolution test conditions for in vitro assessment of the release profile of the drug from solid dose forms. Based on the solubility of loratadine determined under various pH conditions and its permeability through Caco-2 monolayers, loratadine was classified as a Class II drug. Plasma profiles were predicted by convolution analysis using dissolution profiles obtained under various pH and hydrodynamic conditions as the input function and plasma time data obtained from a syrup formulation as the weighting function. The predicted profiles based on dissolution studies done at gastric pH values were in reasonable agreement with the mean bio-data suggesting dissolution testing should be done at gastric pH values. However, the bio-data were highly variable and it is suggested this may be due, at least in part, to high individual gastric pH variability and dissolution occurring in the intestine on some occasions, and therefore, dissolution testing should also be done in simulated intestinal fluid.

Area Under Curve↗

PubMed1982

Symposium: classification of leukemia. 1. The classification of acute leukemia.

Two main forms of acute leukemia have been recognized by the French-American-British (FAB) group: myeloid (AML) and lymphoblastic (ALL). Some types of AML can be diagnosed on well prepared bone marrow films stained with May-Grünwald-Giemsa. Poorly differentiated types, myeloblastic (M1) and monoblastic (M5PD), need confirmation by positive cytochemical reactions (Sudan Black B, myeloperoxidase and non-specific esterase). There are 2 sub-types of promyelocytic leukemia: M3 typical, hypergranular and M3 variant, microgranular. The M3 variant has a more acute course, higher WBC and may require cytochemistry to demonstrate promyelocytic differentiation. Electron microscopic cytochemistry can also help in the classification of difficult AML cases; the 'platelet-peroxidase' reaction, for example, is essential for the diagnosis of megakaryoblastic leukemia, a disorder often presenting as 'acute' myelosclerosis. Three morphological types are seen in ALL: L1, predominantly in children, L2, more frequently in adults, and the relatively rare L3 or Burkitt type. Immunological and enzyme markers (ALL and la antigens, terminal transferase, etc.) help define the cell phenotype: (1) non-B, non-T ALL with 3 forms (common, null and pre-B), (2) T-ALL, related to but distinct from T-lymphoblastic lymphoma, and (3) B-ALL, usually with L3 morphology, There is growing evidence that the FAB morphological types correlate with prognosis in ALL independently of other factors. The immunologically defined types also correlate with prognosis but not as an independent variable.

Acute Disease↗

PubMed1999

Recognition of a protein fold in the context of the Structural Classification of Proteins (SCOP) classification.

A computational method has been developed for the assignment of a protein sequence to a folding class in the Structural Classification of Proteins (SCOP). This method uses global descriptors of a primary protein sequence in terms of the physical, chemical, and structural properties of the constituent amino acids. Neural networks are utilized to combine these descriptors in a way to discriminate members of a given fold from members of all other folds. An extensive testing of the method has been performed to evaluate its prediction accuracy. The method is applicable for the fold assignment of any protein sequence with or without significant sequence homology to known proteins. A WWW page for predicting protein folds is available at URL http://cbcg.lbl.gov/.

Amino Acids↗

PubMed2002

Nursing classifications: Home Health Care Classification System (HHCC): an overview.

This paper provides an overview of the Home Health Care Classification (HHCC) System focusing on its two interrelated taxonomies: HHCC of Nursing Diagnoses and HHCC of Nursing Interventions both of which are classified by 20 Care Components. It highlights the major events that influenced its development, current status, and future uses. The two HHCC taxonomies and their 20 Care Components are used as a standardized framework to code, index, and classify home health clinical nursing practice. Further, they are used to document, electronically track, evaluate outcomes and analyze home health care over time, across settings, population groups, and geographic locations.

Comprehensive Health Care↗

PubMed1992

[Histological classification of malignant non-Hodgkin's lymphomas and patient survival: the Kiel classification versus the working formulation].

In 163 out of 251 histologically classified malignant Non-Hodgkin's lymphomas, a comparison was made of the patient survival with respect to both histological type and malignant grade according to the Kiel Classification (KC) and the three prognostic groups of the Working Formulation (WF). As expected, the survival rate of 94 low-grade malignant lymphoma cases (KC) was significantly better than that of 69 high-grade cases (p < 0.0001). Similar results were found both for 46 low grade cases (WF) in comparison to 50 high grade cases (p < 0.001) and for 67 intermediate grade cases (WF) compared with the 50 high grade cases (p < 0.05). The survival rates of low and intermediate grade cases (WF), however, showed no statistically significant difference. The low- and high-grade malignant lymphoma entities of KC, which together constitute the intermediate grade of WF, differed significantly with respect to patient survival (p < 0.05). Therefore, it appears that an intermediate grade is not essential in the KC.

Humans↗

PubMedDate not supplied

[Transcultural adaptation of a translation into Portuguese of terms included in the International Classification for Nursing Practice and identified in the Classification of Nursing Practice in Community Health Project].

The nursing classification systems have contributed to delimit our professional domain, by identifying concepts that are part of our professional language, and by promoting the knowledge concerning those concepts meanings. In this work, the authors report the process of transcultural adaptation of 145 terms (or concepts) identified in the CIPESC project and already included in the axis Focus of nursing practice of the Nursing Phenomena Classification/ICNP--Beta version. The process of transcultural adaptation was done through the comparison of the translation of those 145 terms into the Portuguese of Brazil with the translation of the same terms into the Portuguese of Portugal, taking the original text in English as the basis of comparison.

Culture↗

PubMed1991

Hyperlipidemia, dyslipoproteinemia and apolipoproteinopathia--classification and risk of atheroslcerosis. Part I: Principles of classification and methods of dyslipoproteinemia determination.

This paper sums up new findings in the field of pathogenetic relations between lipid and lipoprotein metabolical disorders on the one hand and the risk of early forms of atherosclerosis on the other hand. Detail classification of disorders proceeds from precise clinical and biochemical criteria, genetic considerations and therapeutical aspects. It provides definitions of hyperlipidemia, hyperlipoproteinemia, normolipidemic (latent) dyslipoproteinemia, secondary hyperlipidemia, apolipoproteinopathia and relatively harmless (benign) hyperlipidemia. The paper provides detail tables and systematic graphs.

Adult↗

PubMedDate not supplied

Classification and prognostic evaluation in multiple myeloma. A retrospective study of relationship of survivals and responses to chemotherapy to immunological types, 20 single prognostic factors, 15 clinical staging systems, and 6 morphological classifications.

In a group of 136 completely followed up patients with multiple myeloma, the prognostic significance of the immunological myeloma types, of 20 different single prognostic factors, of 15 clinical staging systems, and of 6 morphological classifications was retrospectively investigated by means of the calculation of mean survivals, survival curves, and responses to chemotherapy. A univariate analysis was employed in order to correlate each prognostic parameter at presentation with the survival in the whole group; a multivariate analysis according to the Cox's hazards regression model was used in order to select the most powerful prognostic variables. The patients were grouped according to the myeloma immunological types, to the mean value of each single prognostic factor, and to each stage of the clinical and morphological systems. Causes of death were also related to immunological multiple myeloma types. All single variables, except age and serum calcium, presented a significant relationship with the survival, even if at different significance levels. Cox's regression model selected among them, serum levels of beta 2-microglobulin, percentage of bone marrow plasma cells, hemoglobinemia, lytic bone lesions, and Bence-Jones proteinuria as the most significant factors related to survival. Each clinical and morphological staging system divided groups of patients with significant differences in mean survivals, or in survival curves, or in response to therapy. Multiple myeloma type IgA and micromolecular, with Bence-Jones proteinuria, and type lambda were associated with a poor prognosis, with low therapeutical response, and with the development of fatal renal failure. All these parameters, together with new prognostic factors, are useful in the prognostic evaluation, and, when applied in different steps of the diagnosis and the therapy, allow of studying the clinical course of multiple myeloma under different perspectives, in order to have a more complete picture of the disease and of the single patient.

Adult↗

PubMed1990

The classification of anxiety disorders in current and future classifications.

Comments are made on the main categories by which specific states of morbid anxiety are classified in the ICD-9, ICD-10, DSM-III and DSM-III-R. The latest classifications, ICD-10 and DSM-III-R, contain many more such categories than ICD-9, and although they differ in the priority given to panic versus agoraphobia, the content is very largely similar. ICD-10 contains several categories of special interest to mental health workers in developing countries and primary health care.

Anxiety Disorders↗

PubMed1988

An International Classification of Retinopathy of Prematurity: development of the classification of the late stages of retinopathy of prematurity.

In another publication [6], an agenda for ROP was outlined for the future. High on that list was the completion of the task of classifying ROP. This has been accomplished, but it is obvious that no classification is any better than the use to which it is put. This is the case with this work. Its implementation in a prospective, controlled trial of surgical therapy of end-stage ROP will more than justify the labors of all who participated in its development.

Anterior Eye Segment↗