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PubMed1988

Computerized classification of two-dimensional gel electrophoretograms by correspondence analysis and ascendant hierarchical clustering.

A powerful data processing methodology for analysis and classification of two-dimensional gels is introduced. The approach is based on correspondence analysis (CA) and ascendant hierarchical classification (AHC), and significantly differs from the more classical principal-component decomposition. Starting with a series of gels, each having a large number of spots, CA allows their representation in a factorial space of reduced dimension; classification into meaningful groups is then performed using AHC. Simultaneous representation of both spots and gels in the same space can be done. This precisely indicates the key spots pertinent for the classification, and therefore the characteristic proteins representative of a particular class of gels (i.e. of a particular disease or biological status). In addition, knowledge of these characteristic spots greatly simplifies the screening of future gels. After a brief overview of the Mélanie system for analyzing 2D gels, the theory of correspondence analysis and ascendant hierarchical classification is summarized. Equations are given that are easily ammenable to computation. How classification of two-dimensional gel electrophoretograms is accomplished is then detailed. Experimental results support the power of this approach.

Cluster Analysis↗
PubMed1988

International statistical classification of diseases and related health problems. Tenth revision.

The International Classification of Diseases has, under various names, been for many decades the essential tool for national and international comparability in public health. This statistical tool has been customarily revised every 10 years in order to keep up with the advances of medicine. At first intended primarily for the classification of causes of death, its scope has been progressively widening to include coding and tabulation of causes of morbidity as well as medical record indexing and retrieval. The ability to exchange comparable data from region to region and from country to country, to allow comparison from one population to another and to permit study of diseases over long periods, is one of the strengths of the International Statistical Classification of Diseases, Injuries, and Causes of Death (ICD). WHO has been responsible for the organization, coordination and execution of activities related to ICD since 1948 (Sixth Revision of the ICD) and is now proceeding with the Tenth Revision. For the first time in its history the ICD will be based on an alphanumeric coding scheme and will have to function as a core classification from which a series of modules can be derived, each reaching a different degree of specificity and adapted to a particular specialty or type of user. It is proposed that the chapters on external causes of injury and poisoning, and factors influencing health status and contact with health services, which were supplementary classifications in ICD-9, should form an integral part of ICD-10. The title of ICD has been amended to "International Statistical Classification of Diseases and Related Health Problems"', but the abbreviation "ICD" will be retained.(ABSTRACT TRUNCATED AT 250 WORDS)

Disease↗
PubMed1988

[Film digital and texture analysis for digital classification of pulmonary spot opacities].

The study aimed at evaluating the effect of different methods of digitisation of radiographic films on the digital classification of pulmonary opacities. Test sets from the standard of the International Labour Office (ILO) Classification of Radiographs of Pneumoconiosis were prepared by film digitisation using a scanning microdensitometer or a video digitiser based on a personal computer equipped with a real time digitiser board and a vidicon or a Charge Coupled Device (CCD) camera. Seven different algorithms were used for texture analysis resulting in 16 texture parameters for each region. All methods used for texture analysis were independent of the mean grey value level and the size of the image analysed. Classification was performed by discriminant analysis using the classes from the ILO classification. A hit ratio of at least 85% was achieved for a digitisation by scanner digitisation or the vidicon, while the corresponding results of the CCD camera were significantly less good. Classification by texture analysis of opacities of chest X-rays of pneumoconiosis digitised by a personal computer based video digitiser and a vidicon are of equal quality compared to digitisation by a scanning microdensitometer. Correct classification of 90% was achieved via the discribed statistical approach.

Algorithms↗
PubMed1987

[Classification of injuries of the cervical spine].

Recent advances and the technical options that have lately become available in the surgical treatment of spinal injuries mean that clear definition of the indications is essential. Precise observation and classification of each injury to the cervical spine are of paramount importance for this purpose, to allow the comparison of proposed methods of treatment and of the results obtained with them. There are a number of classification systems for injuries to the cervical spine, none of which, however, is generally accepted. These classification systems are based on different criteria, such as nature of the accident at which the injury was sustained, neurologic deficits, morphological criteria, the concept of instability, and implications for treatment and prognosis. These criteria, however, hardly allow the classification of most of the injuries affecting the upper and those affecting the lower cervical spine in a single system. Therefore, the authors propose a system of their own, which draws on the principles of classification suggested by the ASIF for fractures of the extremities. According to this proposed new system, injuries are divided into those of the upper and those of the lower cervical spine, and each of these two main groups is further divided into three subgroups. In the case of the lower cervical spine, injuries are classed according as whether they affect the anterior or the posterior section of the spine more, or both to the same degree. Beyond this, injuries are subdivided with reference to whether they affect primarily bone, bone and ligament equally, or primarily ligament. Further subdivision by severity and implications for treatment allows more detailed differentiation. This classification system is based on the analysis of over 200 cases of injury to the cervical spine treated by the authors and of cases from the literature.

Axis, Cervical Vertebra↗
PubMed1986

[Evaluation of the hypertensive intracerebral hematoma based on the study of long-term outcome--Part III. Evaluation of neurological grading and CT classification].

It is very important to have a standard neurological grading system and CT classification for "putaminal hemorrhage" to compare, contrast and discuss the results and the surgical indications of various workers. We evaluated 355 cases of putaminal hemorrhage for their long-term outcome by using neurological grading and CT classification of Kanaya et al and compared it with our new classification based on the mode of hematoma extension. The long-term outcome (ADL) showed a better correlation with our new classification. While by using the earlier method (Kanaya et al), there was no significant statistical difference in the ADL between the patients of neurological grade IVb & grade V and also between the patients of CT class II and IIIa. In this classification, the definition of CT class V is not clear as the putaminal hemorrhage does not penetrate into the thalamus. It also ignores the upward or downward extension of the hematoma. Therefore, we emphasize the need for the modification of the presently existing neurological grading system and the CT classification for a better correlation with the long-term outcome.

Basal Ganglia Diseases↗
PubMedDate not supplied

Lymphoedema: pathophysiology and classification.

This paper reviews current knowledge and hypotheses about the physiology of lymph production and lymph flow and the aetiology and classification of lymphoedema. One of the earlier contributions in the 1930's by Allen suggested that primary lymphoedema was caused by congenital underdevelopment of lymph vessels. At that time he described two clinical varieties (congenital and praecox) but later suggested a further subdivision into inflammatory and non-inflammatory types of lymphoedema. Kinmonth in 1957 produced the first clinical classification dividing all cases into primary or secondary lymphoedema but at that time gave no indication as to the cause of the primary variety. In the 1950's Kinmonth also developed a radiological classification which has contributed considerably to our knowledge of the anatomical abnormalities of the lymphatic system in primary lymphoedema. However, despite the widespread use of Kinmonth's classification the lymphographic appearances in primary lymphoedema give little or no clue to the aetiology of the disease process. The aetiology of primary lymphoedema is not known. There are various descriptive classifications based on age of onset and radiological findings for instance, but none attempts to explain the pathophysiology of the disease. We have therefore described our current knowledge of the known physiology and the potential abnormalities of the collection and passage of lymph from the interstitial space to the blood system. Based on this we have presented a simple classification of the aetiology of lymphoedema. Thus primary lymphoedema may be defined as lymphoedema caused by a primary abnormality or disease of the lymph conducting elements of the lymph vessels or lymph nodes. Secondary lymphoedema is oedema caused by disease in the nodes or vessels that began elsewhere (e.g., neoplasia or filariasis), or lymphocytic proliferative disorders such as Hodgkin's disease or following surgical extirpation of lymph nodes or vessels. There are three groups of primary lymphoedema in which the functional abnormality and its cause are known; namely (a) large vessel abnormalities such as congenital aplasia of the thoracic duct or cysterna chyli, (b) congenital lymphatic valvular incompetence or congenital aplasia and (c) lymph node fibrosis. The remainder are characterised by a reduced number of lymphatics on lymphography. Such patients can be described as having obliterated lymphatics. If they present within a few years of birth they were probably born with too few lymphatics. However, those who present later in life may have acquired obliterative disease, the cause of which is still obscure.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMedDate not supplied

New directions in standard terminology and classifications for primary care.

Three documents that considerably facilitate primary care research have been produced in recent years. They are an international glossary of primary care health terms, an international classification of primary care health problems, and a primary care process classification. To describe the full spectrum of primary health care, however, additional classifications are needed that detail the reasons for encounters and indicate health status. Work on these several classifications is in progress and a set of primary care classifications has been proposed as a basis for the 10th revision of the International Classification of Diseases.

Diagnosis↗
PubMed1984

Evaluation of a histologic classification of mouse liver tumors based on pyruvate kinase isozymes and status of host lipids.

The histologic classification of mouse liver tumors, i.e., hepatic nodules type 1 and type 2 and hepatocellular carcinomas, was evaluated by a comparison of several biologic and biochemical markers that have been shown to be useful for the grading of tumor malignancy. The liver tumors were induced by N,N'-2,7-fluorenylenebisacetamide (CAS: 304-28-9; N,N'-fluoren-2,7-ylenebisacetamide) administration to male CD-1 mice. The ability to induce L-type pyruvate kinase activity in response to a high-carbohydrate diet disappeared in almost all the liver tumors. However, fairly good correlations were observed between the histologic classification and the relative weights of liver and intraperitoneal fat pads, between the histologic classification and the level of serum total cholesterol, and between the histologic classification and the K-type pyruvate kinase activity. The results suggest that the present histologic classification reflects the degree of tumor malignancy, and therefore, it would be useful for the classification of mouse liver tumors.

Animals↗
PubMed1982

Toxicological classification of pesticides.

The authors put forth their proposition for pesticide classification from the points of view of acute toxicity, skin irritation, skin toxicity 'resorption), cummulation coefficient and chronic effect--anticipated chronic risk. The proposition of this kind may be considered a priority in Czechoslovakia. It is confronted with the criteria for pesticide classification recommended by the WHO which it suitably completes. Acute toxicity makes it possible to classify pesticides into five classes: class I - highly toxic, class II - toxic, class III - moderately toxic, class IV - slightly toxic, class V - virtually non-toxic. Skin irritation enabled to classify pesticides as highly irritant, irritant, moderately irritant, slightly irritant and non-irritant. For skin toxicity 3 degrees were used: those of very good resorption, good resorption and low resorption. The proposition fr classification is supplemented by cummulation coefficient and the aspect of chronic effect. In the present study the authors call for further search for the criteria of pesticide classification and draw attention to some pesticides, discussing their re-classification into higher classification classes.

Animals↗
PubMed1993

Comparison of neural network and k-NN classification methods in medical image and voice recognitions.

We make a comparison of classification ability between BPN (Back Propagation Neural Network) and k-NN (k-Nearest Neighbor) classification methods. Voice data and patellar subluxation images are used. The result was that the average recognition rate of BPN was 9.2 percent higher than that of the k-NN classification method. Although k-NN classification is simple in theory, classification time was fairly long. Therefore, it seems that real time recognition is difficult. On the other hand, the BPN method is long in learning time but is very short in recognition time. Especially if the number of dimensions of the samples is large, it can be said that BPN is better than k-NN in classification ability.

Algorithms↗
PubMed1994

DNA sequence analysis using hierarchical ART-based Classification Networks.

Adaptive resonance theory (ART) describes a class of artificial neural network architectures that act as classification tools which self-organize, work in realtime, and require no retraining to classify novel sequences. We have adapted ART networks to provide support to scientists attempting to categorize tandem repeat DNA fragments from Onchocerca volvulus. In this approach, sequences of DNA fragments are presented to multiple ART-based networks which are linked together into two (or more) tiers; the first provides coarse sequence classification while the subsequent tiers refine the classifications as needed. The overall rating of the resulting classification of fragments is measured using statistical techniques based on those introduced by Zimmerman, et al. (1994) to validate results from traditional phylogenetic analysis. Tests of the Hierarchical ART-based Classification Network, or HABclass network, indicate its value as a fast, easy-to-use classification tool which adapts to new data without retraining on previously classified data.

Algorithms↗
PubMed1995

Automated chromosome classification limitations due to image processing.

Automated chromosome classification from metaphase spreads has been a difficult research problem over the past 30 years. Numerous techniques have been implemented to address the research problem. Image processing techniques support many methods utilized for automated and/or semiautomated karyotyping. Some current systems correctly classify individual chromosomes at high rates but lack the capability to properly classify chromosomes for entire cells consistently. Most systems attain high classification rates ignoring overlapping metaphase chromosomes for testing purposes. Chromosome classification depends on identifying features common to each chromosome class or number. Some of the common features incorporated into various chromosome classification systems include length, centromere location, banding pattern, and width. To complicate classification, chromosome features tend to vary not only between people but from cell to cell for the same person. Additionally, chromosomes found in metaphase spreads may have any orientation and virtually any degree of overlap with other chromosomes present. Besides the inherent barriers impeding chromosome classification, many systems perform image processing operations to the chromosomes for feature determination. Image processing operations, such as image rotation, that manipulate the chromosome grey-level information may distort the feature calculations utilized in karyotyping. Consequently, feature stability becomes an important issue for improving karyotyping capability.

Chromosomes, Human↗
PubMed1994

Some personal comments on the Sydney system for the classification of chronic gastritis.

The Sydney system for the classification of chronic gastritis is a system for describing the histopathological findings of a biopsy specimen. It involves the analysis of two to four biopsies of the gastric mucosa taken from arbitrary sites, which, taken alone, are insufficient for extrapolation to the diagnosis of the whole stomach. The system seems to be useful as a computer-oriented method fo documenting the histopathological analysis of the two to four biopsy specimens obtained from the arbitrary sites in the antrum or corpus. One biopsy specimen is obtained from the anterior wall of the antrum, the other from the posterior wall. They would be better obtained from the lesser and greater curvatures, which areas would provide more accurate data concerning the antrum or body. While this may be invaluable for researchers with particular interests, it is quite valueless for the majority of clinicians who must diagnose and treat their patients. When a classification is made, its purposes should, firstly, be clear and definite. Secondly, the classification should be simple and easy to use. If a classification is effective, it will be widely used. However, in this field, it is almost impossible to achieve a classification that will fully satisfy all practitioners and researchers with different interests. The Sydney system alone is not sufficient for the classification of chronic gastritis. It is merely a system for describing the histopathological findings of biopsy specimens. It does not allow for an integrated diagnosis of chronic gastritis of the entire stomach.

Adolescent↗
PubMed1994

Image analysis and diagnostic classification of hepatocellular carcinoma using neural networks and multivariate discriminant functions.

BACKGROUND: Hepatocellular carcinoma (HCC) is often difficult to diagnose in cytologic material and small tissue biopsies since histomorphologic information is minimal or absent. The potential for misdiagnosis is greatest in attempting to discriminate well-differentiated HCC from dysplastic hepatocytes in cirrhosis. We investigated the feasibility of developing artificial intelligence classification methods based on nuclear image analysis data for use as adjuncts to the morphologic diagnosis of HCC. EXPERIMENTAL DESIGN: Ninety hematoxylin-eosin stained histologic slides including 56 with well- to poorly differentiated HCC and 34 showing a morphologic continuum from normal to markedly dysplastic benign hepatocytes were assembled from four laboratories. A relatively inexpensive PC-based image analysis system was used to measure 35 nuclear morphometric and densitometric parameters of 100 nuclei in each specimen. The data were randomized into classification training and testing sets containing equal numbers of benign and HCC samples. Objective diagnostic classification criteria for HCC based on neural networks and multivariate discriminant functions (DFs) were developed for the most discriminatory subsets of morphometric, densitometric, and combined morphometric/densitometric variables as selected by stepwise discriminant analysis of training data. RESULTS: Morphometric parameters provided the best results with the following testing data positive and negative predictive values (PV+ and PV-) for HCC classification: 86.2% PV+ and 81.3% PV- for a linear DF, 85.7% PV+ and 76.5% PV- for a quadratic DF and 100% PV+ and 85.0% PV- for a neural network. CONCLUSIONS: Our results demonstrate that nuclear image analysis-based objective classification criteria for HCC can be developed using artificial intelligence methods and that histologic material prepared at different institutions can be reliably classified. Neural networks for HCC classification were superior to linear and quadratic DFs. Morphometric data yielded the best results compared with densitometric or combined morphometric/densitometric data.

Carcinoma, Hepatocellular↗
PubMed1994

[The new international psychiatric classification ICD-10. I. General principles and historical development].

The new international psychiatric classification, ICD-10, involves changes in the theoretical concept of the existing classification system. The change is associated with a shift of the general concept of medical classification which is influenced in particular by new research technologies, the development of programmes of extramural and social care and the penetration of computing technique into medical research. The contemporary psychiatric classification belongs to the agonistic (atheoretical) model which is typical by its pragmatic, clinical approach to diagnosis and classification. Phenomenology and an operational pattern of the classification is emphasized.

Humans↗
PubMed1993

Preconceived ideas in the classification of leukemia.

General biological classifications have theoretical aims regarding the natural order of things. Classification in pathology has basic pragmatic aims regarding diagnosis, prognosis and treatment. In history, leukemia classifications were mainly (but not exclusively) based on classification of normal cells. Clinical data were introduced mainly secondarily. For a long time, no treatment was available. Two questions are asked: might classification of leukemia help to understand the disease's mechanisms; might better classification eliminate unclassifiable leukemias?

Erythrocytes↗
PubMed1994

Jass' classification revisited.

BACKGROUND: In 1986, Jass and colleagues claimed to have improved on Dukes' classification of prognosis for carcinoma of the colon and rectum. To have clinical relevance, such results should be reproducible and confirmed by other institutions. STUDY DESIGN: Retrospective clinicopathologic study of 312 carcinomas of the colon and rectum to determine whether or not Jass' classification is superior to that of Dukes' as assessed by their relative reproducibility and prognostic significance. RESULTS: Dukes' classification had excellent intraobserver and interobserver reproducibility (kappa values of 0.86 and 0.93, respectively). In contrast, the reproducibility of variables assessed by Jass showed only slight to fair agreement (lymphocytic infiltration: intraobserver and interobserver kappa values of 0.08 and 0.05, respectively, growth pattern: intraobserver and interobserver kappa values of 0.37 and 0.41, respectively). Dukes' stage and patient age were the most important prognostic variables on multivariate regression analysis. Tumor differentiation, nuclear polarity, tubule configuration, and lymphocytic infiltration remained significantly related to survival in the presence of Dukes' stage and age. The model which best predicted prognosis was a combination of Dukes' stage, patient age and tumor differentiation. Further addition of the variables assessed by Jass to this model did not significantly improve the prediction of prognosis. CONCLUSIONS: Dukes' classification is of greater prognostic value and more reproducible than the components of Jass' classification. The continued use of Dukes' classification is, therefore, warranted for prognostic and therapeutic decisions in patients with carcinoma of the colon and rectum.

Colonic Neoplasms↗
PubMed1994

Classification of hip fractures.

Several classifications of hip fractures have been proposed in the literature. The usefulness of classifications of hip fractures was examined between Belgian Orthopaedic and General Surgeons. Garden's classification of subcapital fractures is the most widely adopted system. Simple anatomic identification is preferred by 64.9 per cent for intertrochanteric fractures and by 78.7 per cent for subtrochanteric fractures. Classifications of fractures for clinical research are considered necessary by 89.4 per cent but there is no universally accepted system. Radiographs of 5 hips were classified by 10 colleagues using the AO Classification system. No fracture was classified identical by all observers. This confirms earlier studies that observers had a poor ability to classify hip fractures according to a given classification system.

Femoral Neck Fractures↗