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At least 451 records · Page 25Linked to original sources
PubMed2006

Clinical analysis of chronic obstructive pulmonary disease phenotypes classified using high-resolution computed tomography.

OBJECTIVE AND BACKGROUND: The present study was performed to clarify the clinical characteristics of patients with COPD classified into phenotypes according to the dominancy of emphysema and the presence of bronchial wall thickening (BWT) evaluated by chest high-resolution CT. METHODS: A total of 172 patients with stable COPD (FEV1<80%) were examined by chest high-resolution CT. Emphysematous changes and BWT were evaluated visually, and COPD patients were classified into three phenotypes: absence of emphysema, with little emphysema with or without BWT (A phenotype), emphysema without BWT (E phenotype) and emphysema with BWT phenotype (M phenotype). The clinical characteristics were compared among the three phenotypes. RESULTS: The A phenotype showed a higher prevalence of those who had never smoked and patients with wheezing both on exertion and at rest, higher values of BMI and diffusing capacity for carbon mononide (DLCO), milder lung hyperinflation, and greater reversibility of airflow limitation responsive to beta2-agonist as compared with the E phenotype. The M phenotype showed a higher prevalence of patients complaining of a large amount of sputum, productive cough and wheezing, higher rate of exacerbation or hospitalization and greater reversibility of airflow limitation responsive to beta2-agonist as compared with the E phenotype. CONCLUSIONS: These findings suggest that the morphological phenotypes of COPD show several clinical characteristics and different responsiveness to bronchodilators.

Adrenal Cortex Hormones↗
PubMed1994

Membrane properties of physiologically classified rat dorsal horn neurons in vitro: correlation with cutaneous sensory afferent input.

Dorsal horn neurons in the young rat spinal cord-hindlimb preparation were physiologically classified as wide dynamic range (WDR), nociceptive specific (NS) or low threshold (LT) according to their excitatory responses to low and high intensity mechanical stimuli applied to the hindlimb skin. Two additional types were classified: neurons displaying only sub-threshold excitations (SUB) and neurons displaying inhibitory events (INH), such as inhibitory post-synaptic potentials or interruption of spontaneous spiking following cutaneous stimulation. Direct intracellular current injection revealed four different patterns of spiking behaviour: group A neurons were characterized by tonic firing in response to depolarizing current pulses; group B neurons were strongly phasic, producing only one spike at the beginning of the pulse; group A-B neurons generated an early unsustained (< 300 ms) burst of spikes; and group C neurons exhibited anomalous rectification in response to hyperpolarizing current which was followed by a voltage-dependent rebound excitation. A statistically significant (P < or = 0.01) association existed between a neuron's physiological classification and its electrophysiological profile. The majority of WDR neurons responded with tonic firing and were assigned to group A, while NS neurons were strongly represented in group A-B. All INH neurons were assigned to group C. LT neurons were distributed between groups A and A-B, and SUB neurons were distributed between groups A and B. These data indicate, firstly, that dorsal horn neurons possess heterogeneous membrane properties and, secondly, that a relationship exists between a neuron's biophysical profile and its excitatory or inhibitory response to peripheral cutaneous afferent stimulation. The implications for dorsal horn somatosensory processing are discussed.

Animals↗
PubMedDate not supplied

Difficulties in classifying diabetes at presentation in the young adult.

All newly diagnosed diabetic patients in Sweden aged 15-34 years have been registered since 1983. In this study the clinical characteristics initially and after 2.5-3 years were evaluated by a questionnaire to the patient's physician and by non-fasting C-peptide. The study comprised patients registered 1983-84, and for 281 patients (37%), complete information was obtained. At diagnosis 75% were classified as Type 1, 19% as Type 2, and 6% as secondary diabetes or as uncertain by their physician. Twenty patients (7.1%) were reported to have ketoacidosis. Seventy-five percent were treated with insulin, 7% with oral hypoglycaemic agents (OHG), and 18% with diet alone. At follow-up 71% were classified as Type 1, 21% as Type 2, and 8% as secondary or uncertain while treatment was 82% insulin, 8% OHG, and 9% diet. During the follow-up period 42% of the initially non-insulin-treated patients were put on insulin whereas only a few stopped insulin treatment. Patients treated with diet or OHG at follow-up were older, had higher percent desirable weight, and lower blood glucose at diagnosis than patients treated with insulin. All except one patient had measurable random C-peptide at follow-up and mean values were for patients treated with insulin 0.55, OHG 1.41 and diet alone 1.29 nmol l-1. Random blood glucose results were similar. In conclusion the majority of newly diagnosed patients in the age group 15-34 years have the characteristics of Type 1 diabetes and Type 2 diabetes is rare before 25-30 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Magnetic resonance imaging may be an asset to diagnose and classify fluoroquinolone-associated Achilles tendinitis.

The aim of this study was to document the accuracy of magnetic resonance imaging (MRI) during fluoroquinolone-associated Achilles tendinitis. Fourteen Achilles tendons were examined by MRI (T1 and T2 or T2*-weighted sequences) in nine patients with typical tendinopathy (13 cases of tendinitis and 1 rupture) during fluoroquinolone therapy. Tendinous involvement was classified according to the prominence of intra- or peritendinous changes. The most typical feature was the presence of intratendinous changes, longitudinal or transversal, detected on T1 or T2-weighted sequences. Peritendinitis was most visible in two cases and nodular involvement in three cases. It was concluded that MRI appears a helpful and accurate method in identifying and classifying such iatrogenic tendinitis. In addition, MRI indicates orthopedic management when detecting risk of rupture.

Achilles Tendon↗
PubMed1990

Effects of antiarrhythmic agents classified as class III group on ischaemia-induced myocardial damage in canine hearts.

1. The cardioprotective effects of antiarrhythmic agents classified as class III, amiodarone, sotalol and E-4031, were investigated in anaesthetized dogs. 2. The left anterior descending coronary artery was occluded for 2 h. 3. Heart mitochondria were prepared from both the ischaemic and non-ischaemic areas, and their function was estimated polarographically. 4. Activities of the lysosomal enzymes, N-acetyl-beta-glucosaminidase and beta-glucuronidase, were measured in each fraction. 5. Two hour occlusion induced ventricular arrhythmias, and amiodarone, sotalol and E-4031 greatly suppressed the development of arrhythmias. 6. Amiodarone, sotalol and E-4031 significantly protected mitochondria against ischaemia, and prevented ischaemia-induced leakage of lysosomal enzymes. 7. Antiarrhythmic agents classified as class III show cardioprotective effects, which might participate in their antiarrhythmic effect.

Acetylglucosaminidase↗
PubMed1991

Comparison of two schema for classifying nursing research.

To examine trends in nursing research during the last five years of the 1980s and to test the reliability and validity of two taxonomic schemes to classify nursing research, 811 abstracts from three years of a national nursing research conference (Council of Nurse Researchers, 1983, 87, 89) were reviewed and classified independently by three investigators. Taxonomies were research topics as categorized in the Sigma Theta Tau International Directory of Nurse Researchers (STT) and the Classification of Nursing-Related Dissertations (DISSER). More than half of abstracts addressed clinical topics, and clinical research topics increased significantly over time (p less than .001). At least two of the three raters agreed on coding for 62.8 percent of abstracts with STT schemes, 70.9 percent with DISSER scheme (p less than .01). Additional testing and standardization of taxonomies for nursing research is needed to improve reliability and validity.

Clinical Nursing Research↗
PubMed1992

Tumours classified as "malignant histiocytosis" in children are T-cell neoplasms.

During the last five years increasing evidence has accumulated that many tumours classified as 'histiocytic' in the past do not originate from macrophages, but from transformed (or anaplastic) large lymphoid cells. Most of these studies have focused upon adult neoplasms. Knowledge concerning the lineage of 'histiocytic' tumours in the paediatric age group is more limited. In this study we have examined the clinical, morphological and immunophenotypical features of six childhood malignancies originally diagnosed as being of histiocytic origin. Three patients showed an aggressive course with involvement of internal organs and very short survival times. Two patients were brought into remission: one is alive without active disease after seven years; the other died after seven years due to treatment-related cardiomyopathy. The remaining patient had a protracted course for two and a half years, but subsequently deteriorated and died three years after diagnosis. The histomorphological features in five cases were those of anaplastic large cell lymphomas. The remaining case consisted of pleomorphic (rather than anaplastic) large lymphoid cells. In all cases the immunophenotypical examination showed features characteristic of activated T lymphocytes. All cases were positive for Ki-1 (CD30), and three were positive for epithelial membrane antigen (EMA). Histiocyte-associated markers were positive in residual reactive macrophages, but nowhere could unequivocal positivity for macrophage-associated markers be seen in the neoplastic cells. It is concluded that most childhood malignancies in the past classified as 'histiocytic' are examples of anaplastic large cell (Ki-1) lymphomas of T-cell type and that true histiocytic malignancies are exceedingly rare in the paediatric age group.

Antigens, CD↗
PubMed1981

Succinate dehydrogenase activity in fibres classified by myosin ATPase in three hind limb muscles of rat.

1. Succinate dehydrogenase (SDH) activity was assessed in situ in single fibres of cross-sectioned extensor hallucis longus, extensor digitorum longus, and soleus muscles of rat by means of microphotometric recordings of initial maximum reaction rates. 2. Each fibre assessed for SDH activity was subjectively classified into myosin subgroups by its histochemical reaction for myofibrillar actomyosin ATPase (myosin ATPase) following preincubation at pH 4.6 according to Brooke & Kaiser (1970). 3. The majority of fibres classified into myosin types I and IIa were highly reactive for SDH, such that those myosin groups could be interchangeable with the metabolic subgroups of Peter, Barnard, Edgerton, Gillespie & Stempel (1972); myosin I = slow-twitch oxidative, myosin IIa = fast-twitch oxidative glycolytic. 4. The myosin type IIb fibres, however, demonstrated marked variability in activity levels of SDH. Over 40% of those fibres had high SDH activity, and thus could not be equated with the metabolic subgroup fast-twitch glycolytic. 5. The histochemical reaction for myosin ATPase in muscle fibres therefore cannot be used as a reliable means to predict the fibres' metabolic characteristics.

Adenosine Triphosphatases↗
PubMed2001

Transforming echoes into pseudo-action potentials for classifying plants.

Animals perceive their environment by converting sensory stimuli into action potentials, or temporal point processes, that are interpreted by the brain. This paper investigates the information content of point processes extracted from echoes from in situ plants in an effort to understand how bats recognize landmarks in the field. A mobile sonar converts echoes into biologically similar temporal point processes. termed pseudo-action potentials (PAPs), whose inter-PAP interval relates to echo amplitude. The sonar forms a sector scan of an object to produce a spatial-temporal PAP field. Classifier neurons apply delays and coincidence detection to the PAP field to identify three distinct echo types, glints, blobs, and fuzz, which characterize plant features. Glints are large amplitude echoes exhibiting coherence over successive echoes in the sector scan, typically produced by favorably oriented isolated specular reflectors. Blobs are large echoes lacking coherence, typically bordering glints or formed by collections of interfering reflectors. Fuzz represents weak echoes, typically produced by collection of weak scatterers or by reflectors on the beam periphery. A small mirror reflector models a flat leaf surface and motivates the glint criteria. Classifiers are applied to experimental data from two types of tree trunks, a glint-producing sycamore (Platanus occidenatalis) and a glint-absent Norway maple (Acer platanoides) and two plants, a glint-producing rhododendron (Rhododendron maximus) and a glint-absent yew (Taxus media). We speculate that our narrow-band sonar models the activity of a single frequency bin in the frequency-modulated (FM) sweep emitted by bats, and that one function of the frequency bins in the FM sweep is to form a sector scan of the environment.

Animals↗
PubMed2004

Neuro-computational processing of moving sonar echoes classifies and localizes foliage.

Echoes from in situ tree trunks, similar to those observed by flying bats, are processed. A moving sonar converts echoes into spike sequences and applies neural-computational methods to classify objects and estimate passing range. Two classes of tree trunks act as retro-reflectors that generate strong echoes (SEs), identified by a locally dense spike pattern. Linear drive-by sonar trajectories cause SEs to follow hyperbolic curves specified by passing range. A glint is a collection of consecutive range readings matching expected values on a specific hyperbolic curve. Passing-range detectors compare successive SE data with expected values in a table and tally coincidences. Counters increment when coincidences occur and decrement when they do not. A glint terminates after tallying a sufficient number of coincidences and coincidence failure occurs in the maximum-count detector. Reflector roughness, deviations in sonar trajectory, and echo jitter necessitate a coincidence window to define matches. Short windows identify small glints over piecewise linear sonar trajectories, while long windows accommodate deviations in sonar speed and trajectory, and associate multiple glints observed with shorter windows. The minimum coincidence window size yielding glints classify smooth and rough retro-reflectors.

Acoustic Stimulation↗
PubMed1993

Use of repetitive sequences and the polymerase chain reaction technique to classify genetically related Bradyrhizobium japonicum serocluster 123 strains.

We have determined that repetitive (repetitive extragenic palindromic [REP] and enterobacterial repetitive intergenic consensus [ERIC]) sequences used in conjunction with the polymerase chain reaction technique (REP and ERIC PCR) provide an effective means of differentiating between and classifying genetically related Bradyrhizobium japonicum serocluster 123 strains. Analysis of REP and ERIC PCR-generated dendrograms indicated that this technique can effectively differentiate between closely related strains which were indistinguishable by using other classification methods. To maximize the genomic differences detected by REP and ERIC PCR fingerprint patterns, the REP and the ERIC data sets were combined for statistical analyses. REP-plus-ERIC PCR fingerprints were also found to provide a method to differentiate between highly diverse strains of Bradyrhizobium spp., but they did not provide an effective means for classifying these strains because of the relatively low number of REP and ERIC consensus sequences found in some of the bradyrhizobia. Our results also suggest that there is a relationship between nodulation phenotypes and the distribution of REP and ERIC consensus sequences within the genomes of B. japonicum serogroup 123 and 127 strains. Results obtained by restriction fragment length polymorphism hybridization analyses were correlated with the phylogenetic classification of B. japonicum serocluster 123 strains obtained by using REP and ERIC PCR.

Base Sequence↗
PubMed1964

QUICK SEROLOGICAL METHOD OF CLASSIFYING STRAINS OF RHIZOBIUM JAPONICUM IN NODULES.

Means, Ura M. (U.S. Department of Agriculture, Beltsville, Md.), Herbert W. Johnson, and R. A. Date. Quick serological method of classifying strains of Rhizobium japonicum in nodules. J. Bacteriol. 87:547-553. 1964.-A new method of classifying strains of Rhizobium japonicum serologically by utilizing the contents of nodules as antigens is described. The method differs from standard procedures only in the preparation of antigens, but it is less time-consuming. Agglutination reactions of culture and nodule antigens were identical for 15 of the 17 strains investigated. Nodule antigens of ineffective strain 24 failed to agglutinate with any of the 17 antisera employed, and nodule antigens of strain 46 reacted with two antisera in addition to the two with which the culture antigens reacted. Host genotypes affected the reactions of nodule antigens of strain 46, with the reactions ranging from those typical for culture antigens for some soybean (Glycine max) varieties to reactions with heterologous antisera only for other soybean varieties and six cowpea (Vigna sinensis) varieties. Although nodule antigens of most strains of R. japonicum reacted the same as culture antigens, the inconsistent reactions of nodule antigens of strain 46 suggest precautions in the general use of nodule antigens. Indicated precautions are discussed.

Agglutination Tests↗
PubMed1968

Genetic relationship among bacteria classified as vibrios.

Genetic relatedness among six bacterial strains currently classified as vibrios was determined by biochemical tests, deoxyribonucleic acid base composition analysis, and the detection of nucleic acid homology by the membrane filter method. Varying degrees of genetic homology existed among vibrios having similar base compositions. The bovine isolate which had a substantially different per cent guanine plus cytosine content was shown to be genetically different from the remaining vibrio strains. The use of nucleic acid homology studies in classifying vibrio strains is discussed.

Carbohydrate Metabolism↗
PubMed2003

Phylogeny of the genus Nocardia based on reassessed 16S rRNA gene sequences reveals underspeciation and division of strains classified as Nocardia asteroides into three established species and two unnamed taxons.

Conventional identification of Nocardia in the routine laboratory remains problematic due to a paucity of reliable phenotypic tests and due to the yet-unresolved taxonomy of strains classified as belonging to the species Nocardia asteroides, which comprises the type strain and isolates with drug pattern types II and VI. The 16S rRNA gene of 74 representative strains of the genus Nocardia, encompassing 25 established species, was sequenced in order to provide a molecular basis for accurate species identification and with the aim of reassessing the phylogeny of taxons assigned to the species N. asteroides. The result of this phylogenetic analysis confirms that the interspecies heterogeneity of closely related nocardial species can be considerably low (a sequence divergence of only 0.5% was found between N. paucivorans and N. brevicatena). We observed a sequence microheterogeneity (sequence divergence of fewer than five bases) in 8 of 11 species of which more than one strain in the species was studied. At least 10 taxons were found that merit description as new species. Strains previously classified as N. asteroides fell into five distinct phylogenetic groups: the type strain cluster (N. asteroides sensu strictu), N. abscessus, N. cyriacigeorgica, and two clusters closely related to N. carnea or N. flavorosea. The strains within the latter two groups probably represent new species, pending further genetic and phenotypic evaluation. Restricted phenotypic data revealed that N. abscessus, N. cyriacigeorgica, and the two Nocardia species taxons are equivalent to drug patterns I, VI, and II, respectively. In the future, these data will help in finding species-specific markers after adoption of a more precise nomenclature for isolates closely related to N. asteroides and unravel confusing phenotypic data obtained in the past for unresolved groups of strains that definitely belong to separate taxons from a phylogenetic point of view.

DNA, Bacterial↗
PubMed1998

An isolate of human immunodeficiency virus type 1 originally classified as subtype I represents a complex mosaic comprising three different group M subtypes (A, G, and I).

Full-length reference clones and sequences are currently available for eight human immunodeficiency virus type 1 (HIV-1) group M subtypes (A through H), but none have been reported for subtypes I and J, which have only been identified in a few individuals. Phylogenetic information for subtype I, in particular, is limited since only about 400 bp of env gene sequences have been determined for just two epidemiologically linked viruses infecting a couple who were heterosexual intravenous drug users from Cyprus. To characterize subtype I in greater detail, we employed long-range PCR to clone a full-length provirus (94CY032.3) from an isolate obtained from one of the individuals originally reported to be infected with this subtype. Phylogenetic analysis of C2-V3 env gene sequences confirmed that 94CY032.3 was closely related to sequences previously classified as subtype I. However, analysis of the remainder of its genome revealed various regions in which 94CY032.3 was significantly clustered with either subtype A or subtype G. Only sequences located in vpr and nef, as well as the middle portions of pol and env, formed independent lineages roughly equidistant from all other known subtypes. Since these latter regions most likely have a common origin, we classify them all as subtype I. These results thus indicate that the originally reported prototypic subtype I isolate 94CY032 represents a triple recombinant (A/G/I) with at least 11 points of recombination crossover. We also screened HIV-1 recombinants with regions of uncertain subtype assignment for the presence of subtype I sequences. This analysis revealed that two of the earliest mosaics from Africa, Z321B (A/G/?) and MAL (A/D/?), contain short segments of sequence which clustered closely with the subtype I domains of 94CY032.3. Since Z321 was isolated in 1976, subtype I as well as subtypes A and G must have existed in Central Africa prior to that date. The discovery of subtype I in HIV-1 hybrids from widely distant geographic locations also suggests a more widespread distribution of this virus subtype, or at least segments of it, than previously recognized.

Base Sequence↗
PubMed2007

Characteristics of youth soccer players aged 13-15 years classified by skill level.

OBJECTIVE: To evaluate the growth, maturity status and functional capacity of youth soccer players grouped by level of skill. SUBJECTS: The sample included 69 male players aged 13.2-15.1 years from clubs that competed in the highest division for their age group. METHODS: Height and body mass of players were measured and stage of pubic hair (PH) was assessed at clinical examination. Years of experience in football were obtained at interview. Three tests of functional capacity were administered: dash, vertical jump and endurance shuttle run. Performances on six soccer-specific tests were converted to a composite score which was used to classify players into quintiles of skill. Multiple analysis of covariance, controlling for age, was used to test differences among skill groups in experience, growth status and functional capacity, whereas multiple linear regression analysis was used to estimate the relative contributions of age, years of training in soccer, stage of PH, height, body mass, the height x weight interaction and functional capacities to the composite skill score. RESULTS: The skill groups differed significantly in the intermittent endurance run (p<0.05) but not in the other variables. Only the difference between the highest and lowest skill groups in the endurance shuttle run was significant. Most players in the highest (12 of 14) and high (11 of 14) skill groups were in stages PH 4 and PH 5. Pubertal status and height accounted for 21% of the variance in the skill score; adding aerobic resistance to the regression increased the variance in skill accounted for to 29%. In both regressions, the coefficient for height was negative. CONCLUSION: Adolescent soccer players aged 13-15 years classified by skill do not differ in age, experience, body size, speed and power, but differ in aerobic endurance, specifically at the extremes of skill. Stage of puberty and aerobic resistance (positive coefficients) and height (negative coefficient) are significant predictors of soccer skill (29% of the total explained variance), highlighting the inter-relationship of growth, maturity and functional characteristics of youth soccer players.

Adolescent↗
PubMed1999

Improving the discriminatory capabilities of a neural classifier by using a biased-wavelet layer.

In the context of wavelet neural networks (WNN's), two modifications to the basic training algorithms are proposed, namely the introduction of a bias component in the wavelets and the adoption of a weight decay policy. A problem of ECG segment classification is used for illustration purposes. Results suggest that bias improves the discriminatory capabilities of the WNN, which is also compared favourably to a conventional perceptron classifier. The use of weight decay during training, followed by pruning, resulted in a more parsimonious network, which also turned out to be a more conservative classifier. The knowledge embedded in the wavelet layer is interpreted with basis on the concept of super-wavelets.

Algorithms↗
PubMedDate not supplied

A method for rating charts to identify and classify patients with medically unexplained symptoms.

BACKGROUND: As part of conducting a randomized control trial (RCT) to treat chronically high utilizing patients with medically unexplained symptoms (MUS), we developed the chart rating method reported here to identify and classify MUS subjects. METHOD: Intended at this point only as a research tool, the method is comprehensive, uses explicit guidelines, and requires clinician raters. It distinguishes primary organic disease patients from those with primary MUS, quantifies medical comorbidities in primary MUS patients, and also distinguishes subgroups among MUS patients that we call somatization (resembles DSM-IV somatoform disorders) and minor acute illness (MAI) which differs from DSM-IV somatoform definitions. Scoring rules are used to generate the diagnoses above. The rules may be set according to the investigator's needs, from highly sensitive to highly specific. RESULTS: We found high levels of agreement with the gold standard for MUS vs. organic disease (97.6%) and among raters for the key individual chart elements rated (92-96%). The method identified 206 MUS subjects and the extent of their medical comorbidities for entry into a RCT. It also identified somatization and MAI; the latter supports the validity of this newly reported MAI syndrome. CONCLUSION: We concluded that this method offered research potential for identifying MUS patients, for quantifying their medical comorbidities, and for classifying MUS subgroups.

Comorbidity↗