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Results for “Multiple Classification Analysis”

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PubMed1989

[Cytologic differentiation between the autonomous and autoimmune type of diffuse hyperthyroid goiter: correlation with TSH receptor antibodies, microsomal antibodies and infiltrative ophthalmopathy].

A group of 101 patients with diffuse hyperthyroid goiter has been studied. Sixty-seven patients showed significantly increased level of antibodies to the TSH receptor (TBIAb), 48 patients had positive microsomal antibodies (MAb) and 41 patients had infiltrative ophthalmopathy. On the basis of cytologic analysis of the whole group, the patients were divided into two groups. Group A (n = 51, autonomous form?) was characterized by follicular cell proliferation, while group B (n = 50, autoimmune form?) was characterized by lymphocyte infiltration or follicular cell proliferation with lymphocyte traces. Cytologic findings were correlated with autoimmunity markers (TBIAb, MAb, infiltrative ophthalmopathy); multiple correlation factor was 0.17. In conclusion, cytologic classification into autonomous and autoimmune hyperthyroidism form, except by microsomal antibodies, is not followed by other autoimmunity markers.

Adolescent↗

PubMedDate not supplied

Alpha interferon treatment in chronic hepatitis C.

INTRODUCTION: Alpha interferon (alpha IFN) treatment normalizes serum ALT levels in at least half of all patients affected by chronic hepatitis C, but a reactivation of the disease is frequently observed after the end of therapy. Different regimens of alpha IFN therapy have been proposed but the optimal schedule is still controversial. Recently at least 6 different types of HCV have been identified and the HCV genotype has been proposed as an important factor influencing the response to alpha IFN therapy. OBJECTIVE: The aim of this study was to evaluate the efficacy of different regimens of alpha IFN in chronic hepatitis C, and to study the relationship between the response to treatment and HCV genotypes. METHODS: 160 consecutive patients affected by biopsy-proven chronic hepatitis C were randomly treated with different doses of lymphoblastoid alpha IFN [adjusted to the body surface area (m2)] and different durations of therapy, as follows: 2 MU/m2/t.i.w. for 6 or 12 months or 4 MU/m2/t.i.w. for 6 or 12 months. Biochemical and virological responses were studied: ALT levels were monitored monthly during and for at least 6 months after the end of treatment, and serum HCV RNA was assessed before and at the end of therapy, using nested RT-PCR. Biochemical responses were defined in advance as follows: non-response as maintenance of abnormal ALT levels during treatment; complete response as the normalization of ALT by the 4th month and lasting until the end of treatment; sustained response as a complete response lasting for at least 6 months after the end of therapy. The clearance of serum HCV RNA at the end of therapy was considered a virological response. In pre-treatment sera stored at-80 degrees, HCV genotyping was performed according to the method of Okamoto. The Chi square test and multiple stepwise logistic regression were used for the statistical analysis. RESULTS: A sustained biochemical response was significantly more frequent in patients treated for 12 than in patients treated for 6 months, independently of the dosage (45% vs 24% in patients treated with 2 MU/m2/tiw, and 55.5% vs 30% in those treated with 4 MU/m2/tiw). The distribution of HCV genotypes (according to the classification of Okamoto) was 9.8% type I, 45.5% type II, 37.1% type III and 7.6% type V. Both the biochemical and virological responses were significantly correlated to the HCV genotype, being significantly more frequent in patients infected with type III or V (71-60% biochemical and 48-50% virological response, respectively) than in patients with type I or II (15% biochemical and 18-21% virological response, respectively). CONCLUSIONS: 12 months of alpha IFN treatment seemed to be significantly more efficacious than 6 months of therapy, and a significant relationship between the HCV genotype and the biochemical and virological response to alpha IFN was found.

Adolescent↗

PubMedDate not supplied

[Clinico-radiological data of 48 cases of immunocompetent primary cerebral lymphoma].

In this article clinical and neuroradiological features from a cohort of 48 immunocompetent patients who have a histologically proved primary cerebral lymphoma are considered. Our series consisted of 27 men and 21 women with an average age of 59. The clinical results gave 73% patients with a focal deficit, 46% with deterioration of vigilance, 35% intracranial hypertension, and only 8% with epilepsy, which was never revealing. We observed 4 uveitis of which 3 revealed, and preceded by several months, the neuroradiological manifestations. Histological classification using the criterias of the Working Formulation showed that 92% of our patients had a large cell lymphoma (class G or H). Precise analysis of computed tomography features of 40 patients revealed 46 lesions (most of them were isodense) before contrast medium administration. In all the cases, the lesion enhancement was intense and homogeneous. In 50% of the cases, there were multiple lesions. Sixty lesions were of the supra tentorial compartment, lobar in 32 cases, deep in 28 cases. Fifteen were infratentorial. From our experience, we can put forward the following suggestions: 1) Neuroradiological aspects suggesting primary cerebral lymphomas exist but none of them are specific. 2) Research of an uveitis is important, as this makes the histological diagnosis more simple. 3)The prescription of corticosteroids should be delayed until the histological diagnosis is certain because the primary cerebral lymphoma, which is very corticosensitive, is likely to disappear with this treatment and then change the biopsy results.

Adrenal Cortex Hormones↗

PubMed1999

Fuzzy cluster analysis of positive stress tests: comparison with stress echocardiography and nuclear perfusion imaging in patients with triple vessel and left main coronary disease.

Fuzzy cluster analysis (FCA) was used to classify 166 outpatient positive treadmill stress tests as mildly, moderately, or severely abnormal. The method combines ST-segment change with five other stress test variables, and then computes a similarity measure to determine how closely each patient's stress test resembles a prototypical mildly, moderately, or severely abnormal stress test. All patients had coronary angiography within 1 month of their stress tests. For the 45 patients with triple vessel disease (TVD), FCA classified 34 of these stress tests as severely abnormal (sensitivity = 75%). For the 22 patients with left main disease (LM), FCA classified 19 stress tests as severely abnormal (sensitivity = 86%). For the combined group with high-grade disease (TVD + LM), the sensitivity was 79%. A literature review shows that for stress echocardiography, multiple exercise-induced wall motion abnormalities have a sensitivity in the 70-80% range for patients with high-grade disease. For nuclear stress testing, the high-risk pattern of multiple reversible defects, with or without increased lung uptake, has a sensitivity in the range of 70-80% for patients with high-grade disease. Thus classification of a positive stress test as severely abnormal by FCA has a sensitivity comparable to high-risk patterns on stress echocardiography and nuclear stress testing in patients with TVD or LM.

Adult↗

PubMed1995

Machine learning to support diagnostics in the domain of asymptomatic liver disease.

Machine learning procedures, in unsupervised and supervised manner, can enable their users to achieve knowledge hardly comprehensible by even the best experts. This is true also if the clinical knowledge has been carefully assembled in a prospective way. A data set including 165 patients with elevated routine laboratory tests was extensively studied according to clinical history, laboratory profile and liver biopsy. Unsupervised learning by Kohonen feature map disclosed 4 groups of patients: the largest one with no or slight histopathological changes (116) and three smaller, more homogenous, with more diseased patients. Standardized histopathological scorings of the liver specimens defined patients into two groups. Fifty-eight of them were, according to the analysis, recommended for a liver biopsy, due to more severe degrees of inflammation and fibrosis. One-hundred and seven of the patients, in whom liver biopsy was retrospectively considered unnecessary, had only minor degrees of inflammation, fibrosis and/or steatosis. Supervised learning, using the inductive systems based on Quinlan's ID3 and CART algorithms, extracted knowledge in the form of decision trees. This approach could define a need for biopsy either with a very few significant findings or by pathways containing quotients and multiplications of the different basic items. These procedures were analyzed and compared for their theoretical and applicative performances. The cluster and Fischerian discriminant analyses were performed in order to compare the classification performance. The medical appropriateness of the obtained results is satisfying, therefore decision support systems, outlined in this study, should be evaluated in wider clinical practice. To achieve this goal, an example of a Medical Logical Module (MLM), based on the Arden Syntax, is given.

Adult↗

PubMed1998

Arrhythmias and mortality after myocardial infarction in diabetic patients. Relationship to diabetes treatment.

OBJECTIVE: To assess the relationship between clinical course after acute myocardial infarction (AMI) and diabetes treatment. RESEARCH DESIGN AND METHODS: Retrospective analysis of data from all patients aged 25-64 years admitted to hospitals in Perth, Australia, between 1985 and 1993 with AMI diagnosed according to the International Classification of Diseases (9th revision) criteria was conducted. Short- (28-day) and long-term survival and complications in diabetic and nondiabetic patients were compared. For diabetic patients, 28-day survival, dysrhythmias, heart block, and pulmonary edema were treated as outcomes, and factors related to each were assessed using multiple logistic regression. Diabetes treatment was added to the model to assess its significance. Long-term survival was compared by means of a Cox proportional hazards model. RESULTS: Of 5,715 patients, 745 (12.9%) were diabetic. Mortality at 28 days was 12.0 and 28.1% for nondiabetic and diabetic patients, respectively (P < 0.001); there were no significant drug effects in the diabetic group. Ventricular fibrillation in diabetic patients taking glibenclamide (11.8%) was similar to that of nondiabetic patients (11.0%) but was lower than that for those patients taking either gliclazide (18.0%; 0.1 > P > 0.05) or insulin (22.8%; P < 0.05). There were no other treatment-related differences in acute complications. Long-term survival in diabetic patients was reduced in those taking digitalis and/or diuretics but type of diabetes treatment at discharge had no significant association with outcome. CONCLUSIONS: These results do not suggest that ischemic heart disease should influence the choice of diabetes treatment regimen in general or of sulfonylurea drug in particular.

Adult↗

PubMed1987

Cloacal exstrophy and cloacal exstrophy variants: a proposed system of classification.

A coding system that documents the abnormalities within the cloacal exstrophy complex is presented. Analysis allows the classification of these abnormalities into classical and variant series in a logical manner. The application of the coding system to selected reported material is described and it demonstrates the similarities between apparently divergent cases.

Abnormalities, Multiple↗

PubMed2000

Approximate Bayesian evaluation of multiple treatment effects.

We propose an approximate Bayesian method for comparing an experimental treatment to a control based on a randomized clinical trial with multivariate patient outcomes. Overall treatment effect is characterized by a vector of parameters corresponding to effects on the individual patient outcomes. We partition the parameter space into four sets where, respectively, the experimental treatment is superior to the control, the control is superior to the experimental, the two treatments are equivalent, and the treatment effects are discordant. We compute posterior probabilities of the parameter sets by treating an estimator of the parameter vector like a random variable in the Bayesian paradigm. The approximation may be used in any setting where a consistent, asymptotically normal estimator of the parameter vector is available. The method is illustrated by application to a breast cancer data set consisting of multiple time-to-event outcomes with covariates and to count data arising from a cross-classification of response, infection, and treatment in an acute leukemia trial.

Antineoplastic Agents↗

PubMed2005

On learning vector-valued functions.

In this letter, we provide a study of learning in a Hilbert space of vectorvalued functions. We motivate the need for extending learning theory of scalar-valued functions by practical considerations and establish some basic results for learning vector-valued functions that should prove useful in applications. Specifically, we allow an output space Y to be a Hilbert space, and we consider a reproducing kernel Hilbert space of functions whose values lie in Y. In this setting, we derive the form of the minimal norm interpolant to a finite set of data and apply it to study some regularization functionals that are important in learning theory. We consider specific examples of such functionals corresponding to multiple-output regularization networks and support vector machines, for both regression and classification. Finally, we provide classes of operator-valued kernels of the dot product and translation-invariant type.

Algorithms↗

PubMed2026

Responding to a protracted tuberculosis outbreak: lessons from multiple rounds of investigation in a Chinese boarding school.

PURPOSE: This study analysed a multi-semester pulmonary tuberculosis (PTB) cluster outbreak in a Chinese boarding school to provide evidence for future epidemic control. METHODS: Contacts were screened via symptoms, infection tests and chest radiography. Screening expanded progressively from close contacts to same-floor contacts, then all students and staff. Whole-genome sequencing (WGS) with single nucleotide polymorphism (SNP) and bioinformatics analysis was used for lineage classification, transmission clustering (≤12 SNPs defining a cluster) and drug resistance prediction. RESULTS: From 2020 to 2022, 20 students were diagnosed with PTB, half laboratory-confirmed. Most cases clustered in class 16 and were epidemiologically linked to the primary case (case 0), who had household PTB exposure. Case 0 and case 1 had diagnostic delays exceeding 3 and 6 months, respectively. WGS of five isolates (case 1, 3, 4, 9 and 10) collected over three semesters showed all belonged to lineage 2 and differed by ≤12 SNPs, confirming the same transmission chain. The infection rate in class 16 (46.34%) was significantly higher than other case classes (19.05%) and classes without cases (8.27%) (χ2 = 61.169, p < 0.001). No new cases were detected during a one-year follow-up of students involved in the outbreak after the final round of screening, nor among household contacts of all cases followed up to the present. CONCLUSIONS: Lack of entry health examinations facilitated the outbreak. Delayed diagnosis, incomplete contact screening and absence of preventive treatment led to cross-semester persistence. The infection rate disparity confirms class 16 as the outbreak epicentre. Improving community case management, extending contact follow-up and enhancing cluster outbreak measures are recommended to prevent future outbreaks.

Humans↗

PubMed2005

Are plant DNA barcodes a search for the Holy Grail?

In a recent study, Kress et al. compared two plant genomes to seek out plant DNA barcodes. Two promising markers balanced the variability that is needed to distinguish species with conserved primer regions that enable universal amplification. Although this study is the most rigorous effort to date, problems from earlier barcoding efforts, such as the use of non-evolutionary species concepts and differential sorting of genes and species, could reemerge. Single-gene barcoding might not be universally effective owing to inherent inaccuracies. Kress et al. suggest the use of multiple genes, reflecting an integrated approach that is likely to be the best answer to identifying species quickly and accurately.

Biodiversity↗

PubMed2025

Integrative multi-omics profiling deciphers tumor microenvironment heterogeneity and immunotherapy vulnerabilities in lung neuroendocrine carcinomas.

INTRODUCTION: Lung neuroendocrine carcinomas (Lu-NECs) are rare, highly aggressive lung tumors with poor prognosis and limited therapeutic options. Understanding the tumor immune microenvironment (TIME) is crucial towards personalized therapeutic strategies. OBJECTIVES: This study aims to systematically characterize the heterogeneity and complexity of the TIME in Lu-NECs by integrating proteomic, transcriptomic, and genomic data. METHODS: We performed comprehensive immune-proteomic profiling of 76 Lu-NECs across diverse histopathological subtypes to elucidate intra-tumoral TIME heterogeneity at the proteomic level. Validation was conducted in multiple independent cohorts, including 112 Lu-NECs using immunohistochemistry, 147 Lu-NECs, and 17 small cell lung carcinoma samples using transcriptomics. We integrated proteomic, transcriptomic, genomic, and clinical data to assess molecular, immunological, and clinical features, as well as therapeutic vulnerabilities across different immune subtypes. RESULTS: We delineated the immuno-proteomic landscape of Lu-NECs and identified two major immuno-proteomic clusters with distinct immunological, molecular, and clinical characteristics. IPC1 was characterized by high immune cell infiltration, while IPC2 exhibited sparse immune cell presence. Genomic analysis revealed distinct mutational patterns, with IPC1 showing a higher incidence of APOBEC-associated mutation signatures and IPC2 being enriched for mutations associated with defective DNA mismatch repair and tobacco-related mutagens. Functional analyses indicated that IPC1 was related to immune and oncogenic signaling activity, whereas IPC2 was associated with cancer stemness and proliferation-related features. Furthermore, IPC1 and IPC2 demonstrated histological subtype-specific clinical benefits from postoperative chemotherapy. Finally, we developed a machine learning model (iPROM) to predict Lu-NECs immune classification and improve risk stratification, which was validated across multiple independent cohorts. CONCLUSIONS: This study advances the understanding of the tumor immune microenvironment in Lu-NECs through multi-omics characterization and highlights potential personalized therapeutic vulnerabilities tailored to the specific immune landscapes of Lu-NECs.

Humans↗

PubMed2001

Asbestos exposure and malignant lymphomas--a review of the epidemiological literature.

There has been a significant number of case reports on the occurrence of lymphomas in people previously exposed to asbestos. This raises the question of whether corresponding results are available from analytical epidemiological studies. In the present review of the epidemiological literature, we describe the results of the six cohort and 16 case-control studies that - according to our research - were published up to 1999 and, directly or indirectly. shed light on the above question. In summarizing the results of these studies, we have distinguished between non-Hodgkin lymphoma (NHL), chronic lymphatic leukemia (CLL) and plasmocytoma/ multiple myeloma (MM). A causal relationship between asbestos exposure and the subsequent development of lymphomas cannot be derived from the available results. However, since quite a number of studies and the combined analysis indicate a (weakly) increased risk, this question should be considered directly in future epidemiological studies. Such studies should address separately the various sub-entities, employing the latest internationally agreed classification, and should also use the latest methods of quantifying exposure.

Asbestos↗

PubMed1996

Gender and age differences in the prevalence of specific fears and phobias.

Point prevalence of specific fears and phobias was determined in 704 respondents of 1000 randomly selected adults aged 18-70 yr. A phobia for lightning, enclosed spaces, darkness, flying, heights, spiders, snakes, injections, dentists and/or injuries was defined if subjects reported a fear that was out of conscious control, interfered with life and lead to the avoidance of the feared object [American Psychiatric Association, 1994. Diagnostic and statistical manual of mental disorders (4th edn). Washington, DC: American Psychiatric Press.] Fear intensity was assessed using visual analogue scales. A factor analysis generally supported the classification of fears and phobias into: (1) situational phobias (lightning, enclosed spaces, darkness, flying and heights); (2) animal phobias (spiders and snakes); and (3) mutilation phobias (injections, dentists, injuries). Total point prevalence of any specific phobia was 19.9% (26.5% for females and 12.4% for males). In total, 21.2% women and 10.9% men met criterias for any single specific phobia. Multiple phobias was reported by 5.4% of the females and 1.5% of the males. Animal phobia had a prevalence of 12.1% in women and 3.3% in men. Point prevalence of situational phobia was 17.4% in women and 8.5% in men. For mutilation phobia no gender difference was observed, being presented in 3.2% of the women and 2.7% of the men. Women as compared to men gave higher fear ratings for all objects and situations. Inanimate object fears and phobias were more common in older than younger individuals. Animal fears were more intense in younger than in older individuals. Fear of flying increased and fear of injections decreased as a function of age in women but not in men. Thus, specific fears and phobias are heterogeneous with respect to sex and age distribution.

Adolescent↗

PubMed2004

Probabilistic segmentation of white matter lesions in MR imaging.

A new method has been developed for fully automated segmentation of white matter lesions (WMLs) in cranial MR imaging. The algorithm uses information from T1-weighted (T1-w), inversion recovery (IR), proton density-weighted (PD), T2-weighted (T2-w) and fluid attenuation inversion recovery (FLAIR) scans. It is based on the K-Nearest Neighbor (KNN) classification technique that builds a feature space from voxel intensities and spatial information. The technique generates images representing the probability per voxel being part of a WML. By application of thresholds on these probability maps, binary segmentations can be obtained. ROC curves show that the segmentations achieve both high sensitivity and specificity. A similarity index (SI), overlap fraction (OF) and extra fraction (EF) are calculated for additional quantitative analysis of the result. The SI is also used for determination of the optimal probability threshold for generation of the binary segmentation. Using probabilistic equivalents of the SI, OF and EF, the probability maps can be evaluated directly, providing a powerful tool for comparison of different classification results. This method for automated WML segmentation reaches an accuracy that is comparable to methods for multiple sclerosis (MS) lesion segmentation and is suitable for detection of WMLs in large and longitudinal population studies.

Aged↗

PubMed2000

Refractory anemia with ringed sideroblasts with a low IPSS score progressed rapidly with de novo appearance of multiple karyotypic abnormalities and into acute erythroleukemia (AML-M6A).

We report here a case of refractory anemia with ringed sideroblasts (RARS) with a low risk group by the International Prognostic Scoring System (IPSS) at the time of diagnosis but had a rapid disease progression. Although the patient showed a normal male karyotype at the time of RARS diagnosis, his marrow cells had del(5)(q14) and add(17)(p12) abnormalities 2 months after the diagnosis, and later the marrow cells had multiple abnormalities and the patient expired 6 months after the initial diagnosis of RARS. The patient was diagnosed as having RARS with a low risk group by the IPSS classification, however, one should keep in mind that some patients with myelodysplastic syndromes with low risks by either the French-American-British (FAB) classification or the IPSS classification may have progressive disease and subsequential cytogenetic analysis could predict the disease progression.

Acute Disease↗

PubMed1993

Childhood asthma and indoor environmental risk factors.

In a case-control study carried out in Montréal, Québec, Canada, between 1988 and 1990, indoor environmental factors were studied in relation to the incidence of asthma among 3- and 4-year-old children. Cases (n = 457), whose parents were recruited at a hospital emergency room, were children who had a first-time diagnosis of asthma (International Classification of Diseases, Ninth Revision, code 493) made by a pediatrician. Controls (n = 457) were chosen from family allowance files and were matched with case children on age and census tract. A telephone interview was administered to the children's parents. A 20% feasibility subsample was chosen to wear a nitrogen dioxide monitoring badge during a 24-hour period. Multiple conditional logistic regression analysis showed that after personal susceptibility factors were controlled for, the following were independent risk factors for asthma: the mother's heavy smoking (odds ratio (OR) = 2.77, 95% confidence interval (CI) 1.35-5.66), use of a humidifier in the child's room (OR = 1.89, 95% CI 1.30-2.74), and the presence of an electric heating system in the home (OR = 2.27, 95% CI 1.42-3.65). The presence of other smokers in the home was not quite significant (OR = 1.82, 95% CI 0.98-3.38). A history of pneumonia, the absence of breast feeding, and a family history of asthma were also significant risk factors. In a separate unmatched multivariate analysis of subjects who had worn the nitrogen dioxide badge, there was a dose-response relation between nitrogen dioxide (in parts per billion) and asthma. These results confirm the role of susceptibility factors in asthma and show that indoor environmental factors contribute to the incidence of asthma.

Air Pollutants↗

PubMed1998

A comprehensive panel of near-full-length clones and reference sequences for non-subtype B isolates of human immunodeficiency virus type 1.

Non-subtype B viruses cause the vast majority of new human immunodeficiency virus type 1 (HIV-1) infections worldwide and are thus the major focus of international vaccine efforts. Although their geographic dissemination is carefully monitored, their immunogenic and biological properties remain largely unknown, in part because well-characterized virological reference reagents are lacking. In particular, full-length clones and sequences are rare, since subtype classification is frequently based on small PCR-derived viral fragments. There are only five proviral clones available for viruses other than subtype B, and these represent only 3 of the 10 proposed (group M) sequence subtypes. This lack of reference sequences also confounds the identification and analysis of mosaic (recombinant) genomes, which appear to be arising with increasing frequency in areas where multiple sequence subtypes cocirculate. To generate a more representative panel of non-subtype B reference reagents, we have cloned (by long PCR or lambda phage techniques) and sequenced 10 near-full-length HIV-1 genomes (lacking less than 80 bp of long terminal repeat sequences) from primary isolates collected at major epicenters of the global AIDS pandemic. Detailed phylogenetic analyses identified six that represented nonrecombinant members of HIV-1 subtypes A (92UG037.1), C (92BR025. 8), D (84ZR085.1 and 94UG114.1), F (93BR020.1), and H (90CF056.1), the last two comprising the first full-length examples of these subtypes. Four others were found to be complex mosaics of subtypes A and C (92RW009.6), A and G (92NG083.2 and 92NG003.1), and B and F (93BR029.4), again emphasizing the impact of intersubtype recombination on global HIV-1 diversification. Although a number of clones had frameshift mutations or translational stop codons in major open reading frames, all the genomes contained a complete set of genes and three had intact genomic organizations without inactivating mutations. Reconstruction of one of these (94UG114.1) yielded replication-competent virus that grew to high titers in normal donor peripheral blood mononuclear cell cultures. This panel of non-subtype B reference genomes should prove valuable for structure-function studies of genetically diverse viral gene products, the generation of subtype-specific immunological reagents, and the production of DNA- and protein-based subunit vaccines directed against a broader spectrum of viruses.

Adolescent↗