Albocycline- and carbomycin-type macrolides, inhibitors of human prolyl endopeptidases.
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Anti-Bacterial Agents↗
Biomedical subjects
A Taddei
Publications and source records attributed to A Taddei.
Glucocorticoids and the immune function in the human immunodeficiency virus infection: a study in hypercortisolemic and cortisol-resistant patients.
Immunological studies in human immunodeficiency virus (HIV)-positive patients suggest that the disease progression is accompanied by a defective production of type 1 cytokines (interleukin-2 (IL-2) and IL-12], an increased production of type 2 cytokines (IL-4, IL-6, and IL-10), and an increased production of IgE. HIV infection is also associated with activation of the hypothalamo-pituitary-adrenal axis function and increased plasma and urinary cortisol concentrations. As cortisol is involved in the physiological regulation of cytokines, a study was conducted to examine cytokine patterns in two groups of hypercortisolemic patients, one with normal sensitivity to glucocorticoids and the other with glucocorticoid resistance. Ten HIV-infected patients with normal receptor affinity to glucocorticoids (AIDS-C), 10 HIV-infected patients with low receptor affinity to glucocorticoids (AIDS-GR), and 20 healthy subjects were studied. Receptor characteristics of peripheral blood mononuclear cells were evaluated by [3H]dexamethasone binding. Serum cortisol and urinary free cortisol were measured by RIA. Serum ACTH and IgE were measured by immunoradiometric assay, and IL-2, IL-4, and IL-10 cytokines and interferon-gamma were measured by enzyme-linked immunosorbent assay. AIDS-C patients showed low IL-2 and high IL-4, IL-10, and IgE concentratios; conversely, AIDS-GR patients showed high IL-2 and low IL-4 and IgE concentrations. Thus, in HIV infection, elevated cortisol levels suppress cell-mediated immunity and stimulate humoral immunity, whereas this response is not detected in cortisol-resistant patients. These findings indicate that cortisol and its receptors are critically involved in the regulation of immune function in HIV infection.
Adrenocorticotropic Hormone↗
Biosynthesis of albocycline: origin of the carbon skeleton.
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Anti-Bacterial Agents↗
Classification of arrhythmic events in ambulatory electrocardiogram, using artificial neural networks.
We propose artificial neural networks (ANN) for ambulatory ECG arrhythmic event classification, and we compare them with some traditional classifiers (TC). Among them, the one based on the median method (heuristic algorithm) was chosen and taken as a quality reference in this study, while a back propagation based classifier, designed as an autoassociator for its peculiar capability of rejecting unknown patterns, was examined. Two tests were performed: the first to discriminate normal vs ventricular beats and the second to distinguish among three classes of arrhythmic events. The results show that the ANN approach is more reliable than the traditional classifiers in discriminating among many classes of arrhythmic events: 98% by ANN vs 99% by a TC for correctly classified normal beats, 98% by ANN vs 96% by TC for correctly classified ventricular ectopic beats, 96% by ANN vs 59% by TC for correctly classified supraventricular ectopic beats, and 83% by ANN vs 86% by median method for correctly classified aberrated atrial premature beats. This paper also tackles the problem of the management of classification uncertainty. Two concurrent uncertainty criteria have been introduced, to reduce the classification error of the unknown ventricular and supraventricular arrhythmic beats respectively. The error in ventricular beats case was kept close to 0% in average and for supraventricular beats was kept at 35% in average. So we can state that the ANN approach is powerful in classifying beats represented in the training set and that it manages the uncertainty in such a way as to reduce, in any case, the global error percentage.
Algorithms↗
Synthesis of C(10)-halogenated prostaglandins.
The synthesis of halogenated prostaglandins at position C(10), starting from prostaglandin A2, has been accomplished, as well as an efficient regioselective hydroxylation of the upper chain of the prostanoid structure. Evaluation of the inhibitory effects on the proliferation of the K-562 cell line in vitro is presented. When the prostaglandin was modified in the upper chain, the antimitotic activity for bromo derivatives 4b, c and iodo derivative 5b had shown substantial improvements in their activities according to their ID50 values (28, 25, and 22 micrograms/mL, respectively). Attention is called to the significance of chloro derivative 3a in terms of its high potency, determined by its ID50 value (0.06 micrograms/mL).
Acetylation↗
The European ST-T database: standard for evaluating systems for the analysis of ST-T changes in ambulatory electrocardiography.
The project for the development of the European ST-T annotated Database originated from a 'Concerted Action' on Ambulatory Monitoring, set up by the European Community in 1985. The goal was to prototype an ECG database for assessing the quality of ambulatory ECG monitoring (AECG) systems. After the 'concerted action', the development of the full database was coordinated by the Institute of Clinical Physiology of the National Research Council (CNR) in Pisa and the Thoraxcenter of Erasmus University in Rotterdam. Thirteen research groups from eight countries provided AECG tapes and annotated beat by beat the selected 2-channel records, each 2 h in duration. ST segment (ST) and T-wave (T) changes were identified and their onset, offset and peak beats annotated in addition to QRSs, beat types, rhythm and signal quality changes. In 1989, the European Society of Cardiology sponsored the remainder of the project. Recently the 90 records were completed and stored on CD-ROM. The records include 372 ST and 423 T changes. In cooperation with the Biomedical Engineering Centre of MIT (developers of the MIT-BIH arrhythmia database), the annotation scheme was revised to be consistent with both MIT-BIH and American Heart Association formats.
Algorithms↗
[Methods of the elaboration of data of the cardiological importance].
This paper deals with some introductory topics of signal processing and decision making in cardiology. In both instances the matter is referred to general schemes well suited to host different applications. Signal processing is divided in some phases: acquisition, storing, analysis and each of them is described with applications to specific signals. In a similar manner the methods for decision making have been simplified to a scheme including a "knowledge base" and an "inference method". The scheme is used to classify various implementations. Bayes analysis and expert systems have been introduced with some details.
Data Interpretation, Statistical↗
[Technical ambulatory ECG innovations in performance evaluation].
Evaluating the performances of the instrumentation for Ambulatory ECG (AECG) analysis is a need largely recognized by both manufacturers and users. The most generally accepted method is the beat-by-beat comparison with annotated data bases, representing the different ECG abnormalities. Available data bases are aimed at arrhythmias detection evaluation, while it is recognized that the AECG ST-T changes detection has a great relevance in the analysis of ischemic heart disease. A concerted action of the European Community on Ambulatory Monitoring has been approved for achieving a comprehensive reference standard for assessing the quality of AECG instrumentation. The European project has been concentrated on the problem of ST-T analysis. An annotated data base is being developed with the contribution of european experts. A pilot study has been performed for establishing the criteria related to the development and annotation; particularly the definition of significant ST-T changes has been established. The data base will include 2-hour double channel AECG records, which contain at least one ST-T episode. Each record is annotated beat by beat according to the established scheme, identifying arrhythmic beats, rhythm changes, ST-T changes and noisy segments. A coordinating center has been established for interacting with the participating groups and for performing the operations related to the generation and management of the data base. For the time being 14 Groups of 8 Countries are participating to the annotation of the data base. A minimum number of 100 records is planned within June 1988.
Algorithms↗
[Analysis of the market and future trends of the instrumentation for ambulatory electrocardiography].
An inquiry has been made among most manufacturers of ambulatory ECG instrumentation. Both playback and real time systems have been considered. The inquiry, based on a questionnaire, was mainly aimed at identifying possible standard technical solutions emerging from the analysis of various implementations, and at verifying whether techniques for performance evaluation are in common use. Main conclusions of this study include: playback systems are still in competition with real time systems; automatic analysis has not yet reached adequate accuracy; analysis of ST-T interval, while performed by most systems, is not evaluated because common standard of quality is lacking.
Algorithms↗
Electrocardiogram blood pressure and systolic time intervals long term monitoring in ambulant patients.
Ambulatory monitoring of the intra arterial blood pressure (IBP), through the Selyg-Oxford System, has been used so far primarily for studies on hypertension. Aim of our study is to explore the possibility of obtaining from IBP indications useful to extend its field of application. The study will investigate: the usefulness of the continuous monitoring of the systolic time intervals (STI), measured from IBP as ventricular performance indicators, the increasing of specificity of the ECG allowed by the simultaneous beat by beat estimate of the STI's, the possibility of achieving the same information from non invasive peripheral pressure transducers. In this paper we are presenting the results obtained from the combined analysis of the STI's, ECG and IBP in a first series of 13 patients, selected out of 50 on the basis of the highest number of episodes of IBP variations, to allow the evaluation of the algorithms performances in severe conditions.
Blood Pressure↗
[Anterior joints of the thoracic cage].
The chondro-sternal, interchondral, costo-chondral joints and the upper and lower sternal joints were studied in the thorax of 60 children and human adults. Chondro-sternal joints occur as frequent symphyses in the 5th, 6th and 7th joints or ellipsoid joints which are mainly found in the 2nd, 3rd and 4th joints. Diarthrosis frequency increases with age in every joint. An articular space appears particularly in the lower part of the 2nd, 3rd and 4th joints; in fewer cases a space is found in the upper part of the 5th, 6th and 7th joints. These partial spaces disappear with age and are replaced by spaces occupying the whole articulation. The first joint is a synchondrosis which does not vary with age. Interchondral joints are diarthrodial or trochoid joints from earliest childhood and their frequency increases with age. No direct articular contact was observed between the 9th and 10th costal cartilages. Costo-chondral joints are synarthrosis. The upper sternal joint, which is a synchondrosis in the child, may develop into a non-synovial cavity with age, or even turn into synostosis. The lower sternal joint is a synchondrosis which develops partially towards synostosis.
Adult↗
Viability studies on actinomycetes.
Eighty-nine Actinomycetes strains were tested for their viability, morphological and physiological characteristics after being kept under paraffin oil overlay and distilled water for a period between 10-30 years. Most of the studied strains belong to the "Lorenzo De Montemayor" collection. Almost all the recovered strains were 28-30 years old and had never been subcultured since the paraffin oil was overlaid. 71.4% of viable Streptomycetes strains had been kept on Sabouraud-dextrose agar and 28.6% were kept on Negroni and Bonfiglioli-medium. Streptomyces violaceusruber produced its characteristic pigment even after 28 years under these conditions. All of the recovered strains were tested for their biological activity, but only Streptomyces lavendulae showed growth-inhibition against Staphylococcus aureus and Bacillus subtilis.
Actinomycetales↗
Electrocardiographic and signal monitoring in ischaemic heart disease: state of the art and perspective.
The current role of ECG and signal monitoring in the diagnosis of Ischaemic Heart Disease is outlined in relation to imaging techniques giving accurate information on myocardial anatomy and function. ECG monitoring during stress testing remains the first step non-invasive method providing pathophysiological information. Long term continuous monitoring of the ECG and of other signals (e.g. arterial blood pressure and respiration) is commonly used to control patients with suspected or ascertained IHD. Progress of technology and of signal processing methods are driving the exploitation of signal information for diagnosis, prognosis and therapy control of ischaemic patients.
Electrocardiography↗
Imaging-documented cardiovascular signal database for assessing methods for ischaemia analysis.
A new database of cardiovascular signals has recently been developed at the CNR Institute of Clinical Physiology in a study based on patients admitted to the Coronary Care Unit for suspected ischaemic heart disease (IHD), who underwent both ECG effort stress test and echo or radionuclide diagnostic imaging procedures associated with pharmacological test of myocardial ischaemia. During stress testing, in addition to 12-lead ECG, arterial blood pressure and respiration signals are measured non-invasively and recorded. Signals and representative image frames at baseline and during ischaemia are stored in the database, which is planned to include 50 cases, annotated beat by beat and archived on CD-ROM. Each case also contains resting ECG and a comprehensive patient clinical record; if possible Holter ECG and coronary arteriography frames.
Blood Pressure Monitors↗
Oligodendroglioma: CD44 as a possible prognostic opportunity.
CD44, in its standard form as well in its isoforms, is a cell surface adhesion glycoprotein which occurs in a wide variety of non-neoplastic and neoplastic cells. CD44 has been considered to be implicated in tumoral growth and in metastatic potential. We studied the immunohistochemical expression of CD44 standard in 30 oligodendrogliomas (19 primary lesions and 11 recurrences) in order to verify its possible prognostic role. Twelve primary oligodendrogliomas (63%) and 8 recurrences (73%) were CD44-positive. Three of 9 (33%) primary oligodendrogliomas with a Smith grade A-B and 9 of 10 (90%) primary oligodendrogliomas with a Smith grade C-D were found to be in CD44H-positive (p = 0.020). Three of 9 (33%) primary oligodendrogliomas that had not relapsed and 9 of 10 (90%) successively relapsed primary lesions were found to be CD44H-positive (p = 0.020). Median survival of the patients with a CD44H-positive lesion was 84 months; median survival of the patients with a CD44H-negative lesion was 91 months. We conclude that CD44H could have prognostic value regarding the occurrence of relapses.
Adult↗
Inducible cyclooxygenase (COX-2) in glioblastoma--clinical and immunohistochemical (COX-2-VEGF) correlations.
Cyclooxygenase-2 (COX-2) is the inducible form of the enzyme responsible for the first step in the prostaglandin synthesis. COX-2 upregulation is demonstrated in different tumors. COX-2 products may modulate tumoral growth, apoptosis, metastasis, multidrug resistance and angiogenesis. Moreover, the antitumoral effect of the COX inhibitors has been documented. We studied the immunohistochemical expression and the prognostic value of COX-2 on 43 surgical specimens of glioblastoma-affected patients. Furthermore, we evaluated the correlation between the immunohistochemical expression of COX-2 and vascular endothelial growth factor (VEGF). Of the glioblastomas, 63% resulted as COX-2-positive. Median survival of the patients with COX-2-positive lesions was 10 months; median survival of the patients with COX-2 negative glioblastoma was 21 months (NS). All 4 patients who survived longer than 24 months had COX-2 negative lesions (p = 0.017). Concordance between COX-2 and VEGF was documented in 60% of the cases. Our findings show that glioblastoma can immunohistochemically express COX-2 and that its expression is unrelated with VEGF and significantly less frequent in the long survivors. Nevertheless, the absence of statistical correlation with survival time advises further studies on larger series to ascertain the concrete prognostic value of COX-2 in glioblastoma.
Aged↗