Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “classifier”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,315 records · Page 73Linked to original sources
PubMed1998

The DNA content of chromosome division figures and interphase nuclei classifies ulcerative colitis.

Long-standing ulcerative colitis is considered to be a precancerous condition. Therefore, a practical and reliable method is required for monitoring the progress of the disease. Liberation of the S-phase from karyokinesis occurs in DNA amplification and endoreplication, producing nuclei with more than 4 c DNA. The amount of Feulgen DNA was quantified with an image microphotometer in 8 microns sections for interphase nuclei and in 15 microns sections for chromosome division figures (CDFs). Development of ulcerative colitis was investigated in low grade dysplasia (n = 93 cases; score 3-7) and high grade dysplasia (n = 22; score 8-10). Bacterial colitis (n = 34) and invasive adenocarcinoma (n = 26) provided a basis for data interpretation in dysplasia. Lymphocyte nuclei served as an internal DNA standard. CDFs represent a novel type of aberrant 'mitoses'; they are different from and much more frequent than figures with multipolar spindles. Endoreplication began with low grade dysplasia in interphase nuclei as well as with CDFs; it was fully established in high grade dysplasia and carcinoma. Endoreplicated interphase nuclei and CDFs represent an early morphological mosaic of genomic instability. Both characteristics support a reproducible two-level classification of low and high grade dysplasia in ulcerative colitis.

Cell Nucleus↗
PubMed2000

[The difficulty of defining and classifying status epilepticus].

Status epilepticus (SE) can theoretically be described using a simple definition based on physiopathological mechanisms: any seizure of epileptic nature, partial or generalized, convulsive or non-convulsive, lasting over a period of more than 30 minutes; or repeated seizures lasting for a period of over 30 minutes without recovery of consciousness. In the context of a historical review of various definitions, the validity of this definition is assessed and questioned. The heterogeneous nature of this condition is evidenced in daily clinical practice and by the results of epidemiologic studies. In the present study, the authors propose a more pragmatic and heuristic classification, taking into account not only clinical but also electroencephalographic data, as well as the particular nature of the epileptic syndrome when this is known.

Humans↗
PubMed2001

Precision and accuracy of commercial laboratories' ability to classify positive and/or negative allergen-specific IgE results.

BACKGROUND: Accurate and reliable evaluation of the presence or absence of allergen-specific IgE is important in the differential diagnosis of allergic disease. A variety of different commercial tests are available for this purpose. There are few data available to judge how the results of these different tests compare with one another in everyday use. OBJECTIVE: To examine prospectively the extent of comparability among specific IgE results from different laboratories. METHODS: Six diagnostic laboratories employing five different methods to assay specific IgE were selected. Aliquots from 26 serum samples that contained variable levels of IgE specific to 17 common aeroallergens were sent in triplicate to each study laboratory during a 6-week time period. Results were reported numerically and by class scores and then compared by examining their concordance using Kendall's W nonparametric statistical test. In addition, cut-off values were compared by a best agreement analysis using reported results. Reproducibility was determined using precision profiles based upon the coefficient of variation among triplicates for each allergen across the range of reported results. RESULTS: In all, 7,813 tests were analyzed. Concordance among different assays in commercial use with one exception was not good. This was particularly true around the cut-off region where most assays demonstrated high imprecision. The Pharmacia CAP System used by two different laboratories demonstrated highly comparable results with good precision. Some assays were reproducible but not accurate. Others were neither reproducible nor accurate. CONCLUSIONS: The results of this study indicate that not all commercial laboratories/assays for specific IgE provide reproducible and accurate data. Significant potential for misdiagnosis was detected for some reported results. Methods were identified that do give sensitive, accurate, and reproducible results.

Allergens↗
PubMed1997

Robustness metrics for measuring the influence of additive noise on the performance of statistical classifiers.

This paper presents a novel quality measure called robustness. The robustness measure quantifies the influence of measurement noise in the attribute values on the credibility of the classification of a case. It is assumed that the type of distribution of the noise-generating process is known. It is not simple to measure the robustness in the general situation where the noise-free distribution of the attributes is unknown. Therefore, two approximations are suggested and compared with the robustness measure based on the noise-free distribution of the attributes. The usefulness of the suggested robustness measure is explored in a simulation experiment.

Bayes Theorem↗
PubMed1999

Identification of hemifield single trial PVEP on the basis of generalized dynamic neural network classifiers.

This paper is concerned with the application of generalized dynamic neural networks for the identification of hemifield pattern-reversal visual evoked potentials. The identification process is performed by different networks with time-varying weights using signals from different electrode positions as external inputs. Since dynamic neural networks are able to process time-varying signals, the identification of the stimulated hemiretinae is performed without feature extraction. The performance of the method presented is compared with a reference method based on the values of instantaneous frequency at the occipital electrode positions at P100 latency.

Adult↗
PubMed2001

What's new in defining hypertension and classifying hypertensive disorders in pregnancy.

Hypertensive disorders are the most common medical problems encountered by women during pregnancy and remain a major cause of maternal and fetal mortality and morbidity throughout the world. This article provides an update on the definition and classifications of hypertension in pregnancy and discusses the recent consensus statement from the Australasian Society into the Study of Hypertension in Pregnancy (ASSHP). A review of the relevance of the traditional triad of symptoms in the assessment of women for hypertensive disorders in pregnancy is also presented. An understanding of these issues will help midwives accurately assess women and ensure that appropriate management of pregnancies complicated by hypertensive disorders occurs.

Blood Pressure Determination↗
PubMed2003

Classifying human cancer by analysis of gene expression.

With the development and application of DNA microarrays, the expression of almost all human genes can now be systematically examined in human malignancies. This can lead to the identification of candidate molecular targets for therapeutic intervention and biomarkers for early detection of these diseases. However, perhaps the most exciting result to come from this research has been the demonstration that patterns of gene expression can distinguish between tumors of different anatomical origin, and define new subgroups of cancer with similar histological appearance, but distinct molecular profiles. Some of these new molecular subclasses of tumor appear to correlate with clinical behavior. If substantiated in larger studies, this might form a basis for stratifying patients so that they receive optimal therapeutic treatment and follow-up.

Gene Expression Regulation, Neoplastic↗
PubMedDate not supplied

A tiered approach is more cost effective than traditional pharmacist-based review for classifying computer-detected signals as adverse drug events.

OBJECTIVE: To develop a cost-efficient method for identifying adverse drug events (ADEs) and medication errors (MEs) identified using outpatient electronic medical records within ambulatory settings. DESIGN: Comparison of sensitivity and cost of "traditional" pharmacist based approach to identifying ADEs and MEs during a 4 month period with a tiered approach. RESULTS: The proportion of computer generated signals analyzed identified as ADEs were similar using the two approaches while the number of MEs was nearly double with tiered reviews suggesting the same or better sensitivity. Traditional pharmacist review cost $68.70 US dollars to detect an ADE and tiered approach cost only $42.40. CONCLUSION: Tiered review of ADEs and MEs by personnel with increasing clinical capability is more cost-efficient than pharmacist review.

Adolescent↗
PubMedDate not supplied

Personnel resource distribution for nursing programs in Carnegie-classified Research I and II and Doctoral I institutions.

Increasingly, nursing education programs, like other major institutions in the United States, are being charged to "do more with less." How to acquire sufficient human and material resources is a continuing challenge in an era of economic constraint. Benchmark data on the distribution of personnel resources within nursing programs is nearly nonexistent. To assess the personnel resources of nursing programs of major size and stature within the United States, a Personnel Resource Survey was mailed to the universe of all nursing programs located in Carnegie-designated Doctoral I, Research II, and Research I universities and/or colleges in the United States (n = 96). The return rate was 58 per cent, with a useable survey rate of 51 per cent (n = 49). Comparative numbers and ratios of administrators, faculty, students, and various levels and types of support staff by Carnegie-type institutions are presented. Findings indicate that, overall, nursing programs in Research I universities had 1.5 to 2 times as many personnel resources per student than programs in Doctoral I and Research II institutions. Doctoral I and Research II programs closely resembled each other. The details of the data, as well as its standardization into full-time equivalents, are useful to both university and nursing administrators, faculty, and staff in their comparisons and procurement of needed resources.

Benchmarking↗
PubMed2000

The use of statistical classifiers for the discrimination of species of the genus Gyrodactylus (Monogenea) parasitizing salmonids.

This study applies flexible statistical methods to morphometric measurements obtained via light and scanning electron microscopy (SEM) to discriminate closely related species of Gyrodactylus parasitic on salmonids. For the first analysis, morphometric measurements taken from the opisthaptoral hooks and bars of 5 species of gyrodactylid were derived from images obtained by SEM and used to assess the prediction performance of 4 statistical methods (nearest neighbours; feed-forward neural network; projection pursuit regression and linear discriminant analysis). The performance of 2 methods, nearest neighbours and a feed-forward neural network provided perfect discrimination of G. salaris from 4 other species of Gyrodactylus when using measurements taken from only a single structure, the marginal hook. Data derived from images using light microscopy taken from the full complement of opisthaptoral hooks and bars were also tested and nearest neighbours and linear discriminant analysis gave perfect discrimination of G. salaris from G. derjavini Mikailov, 1975 and G. truttae Gläser, 1974. The nearest neighbours method had the least misclassifications and was therefore assessed further for the analysis of individual hooks. Five morphometric parameters from the marginal hook subset (total length, shaft length, sickle length, sickle proximal width and sickle distal width) gave near perfect discrimination of G. salaris. For perfect discrimination therefore, larger numbers of parameters are required at the light level than at the SEM level.

Animals↗
PubMed2000

A statistically derived index for classifying East Coast fever reactions in cattle challenged with Theileria parva under experimental conditions.

A statistically derived disease reaction index based on parasitological, clinical and haematological measurements observed in 309 5 to 8-month-old Boran cattle following laboratory challenge with Theileria parva is described. Principal component analysis was applied to 13 measures including first appearance of schizonts, first appearance of piroplasms and first occurrence of pyrexia, together with the duration and severity of these symptoms, and white blood cell count. The first principal component, which was based on approximately equal contributions of the 13 variables, provided the definition for the disease reaction index, defined on a scale of 0-10. As well as providing a more objective measure of the severity of the reaction, the continuous nature of the index score enables more powerful statistical analysis of the data compared with that which has been previously possible through clinically derived categories of non-, mild, moderate and severe reactions.

Animals↗
PubMed1976

A note on classifying phobia.

The increasing interest in the treatment of phobias underlines the need for clarifying their definition and classification. A brief historical note highlights some of the difficulties which have been, and still are, encountered.

History, 19th Century↗
PubMedDate not supplied

GABA sensitivity of spectrally classified horizontal cells in goldfish retina.

We studied the GABA sensitivity of horizontal cells in the isolated goldfish retina. After the glutamatergic input to the horizontal cells was blocked with DNQX, GABA depolarized the monophasic and biphasic horizontal cells. The pharmacology of these GABA-induced depolarizations was tested with the GABA receptor antagonists bicuculline-methiodide and picrotoxin, the GABA transporter agonist nipecotic acid, and the GABA transporter antagonist SKF 89976-A. The GABA-induced responses of monophasic horizontal cells consisted of two components; one with characteristics of GABA-gated chloride channels, and one with characteristics of GABA transporters. In biphasic horizontal cells, we only found evidence for GABA-gated chloride channels. The results show that monophasic horizontal cells in goldfish contain the two components of a positive feedback loop (GABA transporters and GABA-gated chloride channels), as described in salamander. Furthermore, our results indicate that the monophasic horizontal cells may project directly to the biphasic horizontal cells, via an excitatory GABAergic pathway. We propose that the function of these GABAergic systems in horizontal cells is to abolish cone dominance in bipolar cells surround in the dark-adapted retina.

6-Cyano-7-nitroquinoxaline-2,3-dione↗