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PubMed1999

Some theoretical and practical considerations for multivariate statistical cell classification useful in autologous stem cell transplantation and tumor cell purging.

BACKGROUND: As flow cytometric data becomes more complex, it becomes increasingly difficult to classify cells using conventional flow cytometry data techniques based on visual classification of the data by user-drawn regions. This paper shows some simple applications of multivariate statistical classification to classify flow cytometric data. METHODS: Discriminant Function Analysis (DFA) and Logistic Regression (LR) analysis techniques were evaluated with respect to their potential utility in the problem of detecting human breast cancer cells within normal bone marrow cells. Data sets having defined properties were employed to evaluate the potential utility of these statistical classification techniques whose performance was measured by ROC analysis. RESULTS: Two extreme but reasonable situations are presented: (1) data where the separation of cells was obvious by visual inspection and (2) data where major overlaps in the values of the individual FCM parameters made intuitive classification improbable. Both DFA and LR analysis were able to classify the cells of each type with acceptable accuracy and yield. CONCLUSIONS: The excellent empirical performance of both DFA and LR techniques, suggests that they offer promising approaches for classifying multiparameter FCM data using objective rules that may represent an improvement over commonly employed ad hoc approaches.

Breast Neoplasms↗
PubMedDate not supplied

Assessment of statistical and neural networks methods in NMR spectral classification and metabolite selection.

Magnetic resonance spectroscopy opens a window into the biochemistry of living tissue. However, spectra acquired from different tissue types in vivo or in vitro and from body fluids contain a large number of peaks from a range of metabolites, whose relative intensities vary substantially and in complicated ways even between successive samples from the same category. The realization of the full clinical potential of NMR spectroscopy relies, in part, on our ability to interpret and quantify the role of individual metabolites in characterizing specific tissue and tissue conditions. This paper addresses the problem of tissue classification by analysing NMR spectra using statistical and neural network methods. It assesses the performance of classification models from a range of statistical methods and compares them with the performance of artificial neural network models. The paper also assesses the consistency of the models in selecting, directly from the spectra, the subsets of metabolites most relevant for differentiating between tissue types. The analysis techniques are examined using in vitro spectra from eight classes of normal tissue and tumours obtained from rats. We show that, for the given data set, the performance of linear and non-linear methods is comparable, possibly due to the small sample size per class. We also show that using a subset of metabolites selected by linear discriminant analysis for further analysis by neural networks improves the classification accuracy, and reduces the number of metabolites necessary for correct classification.

Animals↗
PubMed1977

STNMP: a new system for the clinico-pathological classification and identification of intra-oral carcinomata.

A new system for the notation of intra-oral carcinomata has been described. It differs from all previous TNM classifications in that both the site (S) and the pathology (P) have been taken into consideration in addition to the conventional tumour (T), node (N) and metastasis (M) generally used. Both of these additional features have been recognized as important factors in assessing the prognosis of the patient. This new system additionally functions as a means of disseminating the maximum of clinical information succinctly and in a readily communicable format. A further innovation has been the introduction of a means of quantitatively assessing the significance of particular clinical and pathological features and from these values predicting the prognosis. For comparative purposes we have defined four stages corresponding with the stages used in the conventional TNM classification. We have applied the STNMP classification to a random sample of 136 cases of intra-oral carcinomata with more than 5 years follow-up. Particularly in defining those patients with a good prognosis, i.e. 5 year plus survival, this system has proved to be considerably more accurate than the existing staging methods. We propose that for a trial period this system should be widely used in parallel with the conventional TNM classification and staging in order to evaluate its true worth in the clinical situation. With further use it will probably be necessary to adjust the numerical weighting given to particular features, but this can only be accurately assessed when a very large number of patients has been evaluated. Our figures support the clinical impression that patients with poorly differentiated squamous cell carcinomata have a shorter survival than those with well differentiated lesions and that the degree of differentiation of the tumour is directly proportional to the survival of the patient. When considering the site of the tumour we have based our grading on the known survival curves for squamous cell carcinomata at different sites.

Alveolar Process↗
PubMed1984

Improved diagnostic accuracy in laryngeal cancer using a new classification based on computed tomography.

The most commonly accepted classification of laryngeal cancer is based on the definition of regions formulated by the American Joint Committee on Laryngeal Cancer. The limitations of this classification are discussed. A new radiologic classification based on computed tomography (CT) is presented, its application illustrated, and its accuracy documented. This classification has the advantage that it provides information preoperatively which closely agrees with the pathologic facts seen postoperatively. It also helps to separate those tumors that tend to invade cartilage from those that do not.

Biopsy↗
PubMed1985

Classifications of childhood brain tumors.

Diagnostic classifications of brain tumors do not necessarily reflect natural orders in biology. They are hypothetic statements about relationships among histologic features within tumors that have been fabricated for the purposes of understanding, communicating, and predicting brain tumor biology. Historically, they have been constructed in response to specific needs and have changed to meet new needs. The classifications in use today are built on arbitrary a priori dicta and assumptions that may not stand scientific scrutiny and may obscure efforts of physicians at prognosis. Classifications ignore the influence of site and age upon prognosis. For future use, the differing goals of prognosis and genesis may require different classifications.

Age Factors↗
PubMed1985

An appraisal of the World Health Organization classification of tumors of the central nervous system.

An important development in the classification of tumors of the central nervous system was the nomenclature recommended by the World Health Organization in 1979. Since then, wide usage has suggested that the classification be modified to account for problems that neuropathologists have encountered. Although no classification is ideal, modification of certain tumor categories, particularly from the perspective of childhood brain tumors, is desirable. These are discussed in detail. Greater emphasis on standardization of the localization of brain tumors is also recommended. This appraisal suggests changes that will allow a consensus on nomenclature of central nervous system tumors so that a workable classification is the end product.

Brain Neoplasms↗
PubMed1993

The World Health Organization histological classification of tumours of the upper respiratory tract and ear. A commentary on the second edition.

The second edition of Histological Typing of Tumours of the Upper Respiratory Tract and Ear, in the World Health Organization series International Histological Classification of Tumours, provides a comprehensive classification of tumors and tumor-like lesions occurring in (1) the nasal cavity and paranasal sinuses; (2) the nasopharynx; (3) the larynx, hypopharynx, and trachea; (4) the external ear; and (5) the middle and inner ear. The classification includes several newly recognized entities and many that were omitted from the first edition on account of their rarity. The terminology and definitions of several tumor types have been revised in the light of experience gained during the past 12 years. This article discusses the revised classification with special reference to some of the major changes in the listings, terminology, and definitions.

Humans↗
PubMed2001

The predictive value of the 1997 American Joint Committee on Cancer stage classification in determining failure patterns in nasopharyngeal carcinoma.

BACKGROUND: A retrospective analysis of treatment outcomes in patients with nasopharyngeal carcinoma (NPC) was performed in which the newly revised 1997 American Joint Committee on Cancer (AJCC) stage classification was applied and compared with the 1988 AJCC and Ho stage classifications, with emphasis on the predictive value of different staging systems in determining failure patterns in NPC. METHODS: Three hundred and twenty-four patients with newly diagnosed NPC treated between September 1989 and August 1991 and originally staged according to Ho stage classification were re-staged according to the 1988 and 1997 AJCC stage classifications. In addition to stage grouping, patients were also classified into the following prognostic categories to study the failure patterns: early disease group (T1-2N0-1), advanced local disease group (T3-4N0-1), advanced nodal disease group (T1-2N2-3), and advanced locoregional disease group (T3-4N2-3). The overall survival (OAS), relapse-free survival (RFS), local relapse-free survival, nodal relapse-free survival, and distant metastases-free survival were compared among different stage groups and prognostic categories in the three staging systems. RESULTS: In the new AJCC system, the percentages of patients with Stage I, II, III, and IV disease were 15.1%, 31.5%, 28.1%, and 25.3%, respectively, whereas most patients were classified as having Stage IV disease (65.7%) in the old AJCC system and Stage II or III disease (74.1%) in the Ho system. The 5 year OAS rates in the 1997 AJCC Stage I, II, III, and IV disease were 97.7%, 78.7%, 79.5%, and 61.4%, respectively. The corresponding 5 year RFS rates were 95.7%, 64.7%, 54.5%, and 41.1%. Using the 1997 AJCC system to define the four prognostic categories, the early disease group had the lowest incidence of relapse (27.6%) and death (18.4%), whereas the advanced locoregional disease group had the highest incidence of relapse (61.4%) and death (43.2%). Both the advanced local disease group and the advanced nodal disease group had similar rates of relapse (46.7% vs. 47.2%), but local relapse was the major cause of failure in the former group (61.8%), whereas distant metastases was the major cause in the latter group (44%). CONCLUSIONS: Using the 1997 AJCC staging system, the authors observed a better distribution of patient numbers as well as segregation of survival curves among different stage groups. Moreover, prognostic categories with distinct prognosis and failure patterns were definable by the new system, which has important implications in selecting appropriate patient treatment strategies.

Adult↗
PubMed1981

Classification of tinnitus.

Classification in general serves a number of purposes. In relation to tinnitus there are particular problems because the cause in only rarely known and the mechanism is not known at all. This means that firm classifications tend to be misleading and serve little purpose other than to delude the doctor and the patient. The aim in this paper therefore is to examine the various ways in which information (whether scientific or clinical) about tinnitus can be organized so as to help diagnosis, management or research towards recognition of the fundamental abnormalities. Attempts at classification based on the site of the lesion and on speculation about its cause are described. Classification is analysed according to (1) patients' own reports, (2) doctors' clinical observations, (3) various techniques of measurement, (4) associated phenomena and (5) results of treatment. From these various aspects a pattern emerges which, though incomplete, at least exposes rather than obscures the gaps in our knowledge.

Humans↗
PubMed1975

Ridge course of the whorls: classification and methods.

In dermatoglyphic methodology the system of gross classification of digital pattern types needs modifications. More attention should be focussed on the study of minute morphological variations among pattern types in order to understand fully the genetic mechanisms involved in pattern variations. A systematic classification to record many of the morphological peculiarities is lacking. The paper proposes a classification and methods of identification of the direction of the course of the ridges inside the pattern area of true whorls. In all, nine ridge course types are identified, named and described. Data analysed on the basis of the above methods and classification reveal significant bilateral differences for clockwise and counter-clockwise types of ridge directions. Mode of inheritance, bisexual differences, etc., of the polymorphic course of these ridges should be studied. Its usefulness in the field of personal identification, population genetics and medicine should also be evaluated.

Dermatoglyphics↗
PubMed1978

The morphology and kinetics of spermatogonial degeneration in normal adult rats: an analysis using a simplified classification of the germinal epithelium.

The phenomena of spermatogonial degeneration have been studied in normal adult rat testes using a simplified classification of the germinal epthelium based upon the six types of differentiating spermatogonia. The following features distinguished this from schemes based on acrosome development. Rather than 14 states of unequal duration, there are only six stages, five of which are the same length. The classification starts at the beginning of spermatogenesis with A1 spermatogonia rather than at the onset of spermiogenesis. The classification is derived from acutal biological events in spermatogenesis, namely generation times of spermatogonia, rather than upon arbitrary events in acrosome development. Most importantly, this new classification can be used with most types of preparations and in most experimental conditions. Examination of tubular whole mounts reveals that degeneration preferentially occurs in types A2 and A3 and to a lesser extent A4 spermatogonia, and is rarely seen in generations of A1, In or B cells. Deterioration is first manifested in clusters of cells joined by the intercellular bridges as they complete DNA synthesis and enter the 2 phase of cell cycle. It is characterized by a denser staining of the nuclear membrane, coalescence of chromatin into several pyknotic bodies, and eventual extrusion of the nuclear mass, leaving a cytoplasmic ghost. The sequential steps in degeneration may often be traced from one end of a synctial chain to the other, suggesting that the process may start with just one cell and then spread via intercellular bridges to involve all spermatogonia within the clone. Quanitatively, degeneration is a relatively constant feature of spermatogonial development. Only 25% of the theoretically possible number of pre-leptotene spermatocytes are produced from th original population of A1 spermatogonia; most of this loss is incurred during the maturation of A2 and A3 generations. While the reason for spermatogonial degeneration in the normal generminal epithelium remain obscure, it is proposed that the numerical ratio of A spermatogonia to Sertoli cells may be a significant limiting factor.

Animals↗
PubMed1990

The American College of Rheumatology 1990 criteria for the classification of polyarteritis nodosa.

Criteria for the classification of polyarteritis nodosa were developed by comparing 118 patients who had this disease with 689 control patients who had other forms of vasculitis. For the traditional format classification, 10 criteria were selected: weight loss greater than or equal to 4 kg, livedo reticularis, testicular pain or tenderness, myalgias, mononeuropathy or polyneuropathy, diastolic blood pressure greater than 90 mm Hg, elevated blood urea nitrogen or serum creatinine levels, presence of hepatitis B reactants in serum, arteriographic abnormality, and presence of granulocyte or mixed leukocyte infiltrate in an arterial wall on biopsy. The presence of 3 or more of these 10 criteria was associated with a sensitivity of 82.2% and specificity of 86.6%. A classification tree was also constructed, with 6 criteria being selected. Three of these, angiographic abnormality, biopsy-proven granulocyte or mixed leukocyte infiltrate in arterial wall, and neuropathy, were criteria used in the traditional format. The other 3 criteria used in the tree format included the patient's sex, weight loss greater than 6.5 kg, and elevated serum aspartate aminotransferase or alanine aminotransferase levels above the range of normal. The classification tree yielded a sensitivity of 87.3% and a specificity of 89.3%.

Diagnosis, Differential↗
PubMed1990

The American College of Rheumatology 1990 criteria for the classification of Wegener's granulomatosis.

Criteria for the classification of Wegener's granulomatosis (WG) were developed by comparing 85 patients who had this disease with 722 control patients with other forms of vasculitis. For the traditional format classification, 4 criteria were selected: abnormal urinary sediment (red cell casts or greater than 5 red blood cells per high power field), abnormal findings on chest radiograph (nodules, cavities, or fixed infiltrates), oral ulcers or nasal discharge, and granulomatous inflammation on biopsy. The presence of 2 or more of these 4 criteria was associated with a sensitivity of 88.2% and a specificity of 92.0%. A classification tree was also constructed with 5 criteria being selected. These criteria were the same as for the traditional format, but included hemoptysis. The classification tree was associated with a sensitivity of 87.1% and a specificity of 93.6%. We describe criteria which distinguish patients with WG from patients with other forms of vasculitis with a high level of sensitivity and specificity. This distinction is important because WG requires cyclophosphamide therapy, whereas many other forms of vasculitis can be treated with corticosteroids alone.

Biopsy↗
PubMed1990

The American College of Rheumatology 1990 criteria for the classification of hypersensitivity vasculitis.

Criteria for the classification of hypersensitivity vasculitis were developed by comparing 93 patients who had this disease with 714 control patients with other forms of vasculitis. For the traditional format classification, 5 criteria were selected: age greater than 16 at disease onset, history of taking a medication at onset that may have been a precipitating factor, the presence of palpable purpura, the presence of maculopapular rash, and a biopsy demonstrating granulocytes around an arteriole or venule. The presence of 3 or more of these 5 criteria was associated with a sensitivity of 71.0% and a specificity of 83.9%. A classification tree was also constructed. The criteria appearing in the tree structure were the same as for the traditional format, except there were 2 pathology criteria: one required the presence of granulocytes in the wall of an arteriole or venule, and the other required the presence of eosinophils in the inflammatory exudate. The classification tree was associated with a sensitivity of 78.5% and a specificity of 78.7%.

Adolescent↗
PubMed1990

The American College of Rheumatology 1990 criteria for the classification of giant cell arteritis.

Criteria for the classification of giant cell (temporal) arteritis were developed by comparing 214 patients who had this disease with 593 patients with other forms of vasculitis. For the traditional format classification, 5 criteria were selected: age greater than or equal to 50 years at disease onset, new onset of localized headache, temporal artery tenderness or decreased temporal artery pulse, elevated erythrocyte sedimentation rate (Westergren) greater than or equal to 50 mm/hour, and biopsy sample including an artery, showing necrotizing arteritis, characterized by a predominance of mononuclear cell infiltrates or a granulomatous process with multinucleated giant cells. The presence of 3 or more of these 5 criteria was associated with a sensitivity of 93.5% and a specificity of 91.2%. A classification tree was also constructed using 6 criteria. These criteria were the same as for the traditional format, except that elevated erythrocyte sedimentation rate was excluded, and 2 other variables were included: scalp tenderness and claudication of the jaw or tongue or on deglutition. The classification tree was associated with a sensitivity of 95.3% and specificity of 90.7%.

Aged↗
PubMed1990

The American College of Rheumatology 1990 criteria for the classification of Takayasu arteritis.

Criteria for the classification of Takayasu arteritis were developed by comparing 63 patients who had this disease with 744 control patients with other forms of vasculitis. Six criteria were selected for the traditional format classification: onset at age less than or equal to 40 years, claudication of an extremity, decreased brachial artery pulse, greater than 10 mm Hg difference in systolic blood pressure between arms, a bruit over the subclavian arteries or the aorta, and arteriographic evidence of narrowing or occlusion of the entire aorta, its primary branches, or large arteries in the proximal upper or lower extremities. The presence of 3 or more of these 6 criteria demonstrated a sensitivity of 90.5% and a specificity of 97.8%. A classification tree also was constructed with 5 of these 6 criteria, omitting claudication of an extremity. The classification tree demonstrated a sensitivity of 92.1% and a specificity of 97.0%.

Adult↗
PubMed1990

The American College of Rheumatology criteria for the classification and reporting of osteoarthritis of the hand.

Clinical criteria for the classification of symptomatic idiopathic (primary) osteoarthritis (OA) of the hands were developed from data collected in a multicenter study. Patients with OA were compared with a group of patients who had hand symptoms from other causes, such as rheumatoid arthritis and the spondylarthropathies. Variables from the medical history, physical examination, laboratory tests, and radiographs were analyzed. All patients had pain, aching, or stiffness in the hands. Patients were classified as having clinical OA if on examination there was hard tissue enlargement involving at least 2 of 10 selected joints, swelling of fewer than 3 metacarpophalangeal joints, and hard tissue enlargement of at least 2 distal interphalangeal (DIP) joints. If the patient had fewer than 2 enlarged DIP joints, then deformity of at least 1 of the 10 selected joints was necessary in order to classify the symptoms as being due to OA. The 10 selected joints were the second and third DIP, the second and third proximal interphalangeal, and the trapeziometacarpal (base of the thumb) joints of both hands. Criteria derived using the "classification tree" method were 92% sensitive and 98% specific. The "traditional format" classification method required that at least 3 of these 4 criteria be present to classify a patient as having OA of the hand. The latter sensitivity was 94% and the specificity was 87%. Radiography was of less value than clinical examination in the classification of symptomatic OA of the hands.

Adult↗
PubMed1991

The European Spondylarthropathy Study Group preliminary criteria for the classification of spondylarthropathy.

Classification criteria for most of the disorders belonging to the spondylarthropathy group already exist. However, the spectrum of spondylarthropathy is wider than the sum of these disorders suggests. Seronegative oligoarthritis, dactylitis or polyarthritis of the lower extremities, heel pain due to enthesitis, and other undifferentiated cases of spondylarthropathy have been ignored in epidemiologic studies because of the inadequacy of existing criteria. In order to define classification criteria that also encompass patients with undifferentiated spondylarthropathy, we studied 403 patients with all forms of spondylarthropathy and 674 control patients with other rheumatic diseases. The diagnoses were based on the local clinical expert's opinion. The 403 patients included 168 with ankylosing spondylitis, 68 with psoriatic arthritis, 41 with reactive arthritis, 17 with inflammatory bowel disease and arthritis, and 109 with unclassified spondylarthropathy. Based on statistical analysis and clinical reasoning, we propose the following classification criteria for spondylarthropathy: inflammatory spinal pain or synovitis (asymmetric or predominantly in the lower limbs), together with at least 1 of the following: positive family history, psoriasis, inflammatory bowel disease, urethritis, or acute diarrhea, alternating buttock pain, enthesopathy, or sacroiliitis as determined from radiography of the pelvic region. These criteria resulted in a sensitivity of 87% and a specificity of 87%. The proposed classification criteria are easy to apply in clinical practice and performed well in all 7 participating centers. However, we regard them as preliminary until they have been further evaluated in other settings.

Europe↗