Biomedical subjects
Publications and source records attributed to A Arnaud.
Primary pulmonary actinomycosis is a purulent bronchopulmonary disease mimicking tuberculosis. The histological lesions contain characteristic yellow granules. The organism most frequently responsible for the disease is Actinomyces israeli. We report the first case to our knowledge where Actinomyces odontolyticus seems to be involved.
It has been suggested that almitrine improves the local ventilation/perfusion ratio by enhancing hypoxic pulmonary vasoconstriction (HVC), leading to an increase in pulmonary vascular resistance (PVR) and PaO2. The goal of the present study was to determine if pulmonary vasodilation induced by nifedipine inhibits the enhancement of HVC (and consequently of PaO2), in patients suffering from chronic obstructive pulmonary disease (COPD). Two groups of 10 patients were compared in a controlled, double-blind study. Hemodynamics and blood gases were measured during continuous infusion of placebo or almitrine (8 micrograms/kg/min). Two hours after the onset of the infusion, a single dose of nifedipine (10 mg) was given sublingually. Almitrine infusion was followed by an increase in PaO2 (20%) and PVR (48%). In the almitrine group, after nifedipine, the PVR decreased 33% and PaO2 dropped to baseline while in the placebo group the PVR decreased 22% and PaO2 fell to 11% below baseline. In COPD patients, nifedipine inhibits almitrine-induced pulmonary vasoconstriction.
The endocellular enzyme beta-glucosidase of Candida cacaoi was purified by ion-exchange chromatography and gel filtration. The molecular weight was 220 +/- 10 kDa; its optimum pH was between 4 and 5.5 and its optimum temperature was 60 degrees C. This enzyme was active against soluble glucosides tested with beta(1-2), beta(1-3), beta(1-4) and even alpha(1-4) and alpha(1-6) and was inhibited by D-glucono-delta-lactone. The enzyme was constitutive but its synthesis was repressed by glucose.
The diagnosis of sleep apnea syndrome (SAS) requires expensive and complex instrumentation. The purpose of the present study was to determine the value of end-tidal CO2 (EtCO2) in screening for sleep apneas. Thirty-nine patients referred to our sleep laboratory because of suspected SAS and ten normal subjects were studied. The EtCO2 was measured using an infrared spectrometer (POET) designed for simultaneous measurement of CO2 and pulse oximetry. In 29 subjects, expired gas was sampled with a nasobuccal mask (Respiron) with lateral orifices. In the other 20 subjects, sampling was done with nasobuccal prongs (Criticare) comprising a four-channel plastic tube to the mouth and the nostrils. Data from an 8-h night were transferred the following day to a microcomputer (Apple Macintosh) for processing. Apnea was defined as an absence of detection of CO2 for more than 10 s. Conventional polysomnography was performed (Respisomnographe). The number of apneas in 8 h and the apnea index (number of apneas in 1 h) were calculated after visual analysis on the screen of the polysomnograph and also with EtCO2 analysis. For recordings made with a nasobuccal mask, the regression curve between the apnea indices computed with EtCO2 and polysomnography was an order 2 polynomial curve (r = 0.76; p < 0.001), with an inflection point at 39 apneas per hour. For recordings with nasobuccal prongs, the correlation was very significant (r = 0.95; p < 0.0001), and the regression curve was linear. The EtCO2 with nasobuccal prongs appears to be a simple and reliable method for screening for SAS.
We analyzed the hemoglobin patterns of all the adult patients whose hemograms, performed in the hematology laboratory of our hospital, indicated microcytosis (MCV < 82 fl). During a 6 weeks period, 43 cases of microcytosis were identified out of 1827 hemograms and, among them, 16 cases of beta-thalassemia trait were diagnosed, i.e., 0.88%. This rate can probably be extrapolated to the general population of this region. It is in agreement with results obtained by other authors from southeastern France. This frequency of heterozygous beta-thalassemia is non-negligible and strongly suggests that screening for the beta-thalassemia trait in the at risk populations should be undertaken to prevent homozygous forms.
A Brevibacterium sp. R312 DNA fragment encoding the wide-spectrum amidase (EC 3.5.1.4) has been cloned and sequenced, using limited amino acid (aa) sequence information obtained from the purified enzyme. The deduced aa sequence showed more than 80% strict identity with the Pseudomonas aeruginosa aliphatic amidase, the product of the amiE gene, suggesting a horizontal transfer of the gene during evolution between Gram+ and Gram- bacteria.
Nitrile hydratase from Brevibacterium sp. R312 was purified to homogeneity. The isoelectric point was 5.75. The two kinds of subunits were separated by reverse phase HPLC and their N-terminal amino acid sequences were found to be identical to those of Rhodococcus sp. N-774 nitrile hydratase.
Theophylline levels in plasma, erythrocytes and cantharides-induced blister fluid (BF) have been correlated with peak expiratory flow (PEF) in asthmatic patients. Nine asthmatic men received an IV infusion of 240 mg theophylline at a constant rate for 30 min. The theophylline concentrations in erythrocytes and blister fluid were 37% and 78% of those in plasma. There was not a strong correlation between erythrocyte or blister fluid penetration and the clinical effect of theophylline.
The plasma protein S (PS) system was studied in 120 HIV seropositive patients (CDC classification: group II: n = 35; group III: n = 6; groups IVA, IVC2 or IVE, n = 38; groups IVB, IVC1 or IVD, n = 41). Total PS antigen and C4b-binding protein (C4b-BP) values were not significantly different from control values. Free protein S levels assessed by an immunological method in the supernatant of PEG-precipitated plasma samples (PEG-fPS) were below the normal limit in 85 patients, lower values being found in patients with advanced HIV disease. No correlation was found between PEG-fPS levels and C4b-BP or total PS levels. At least 25 patients had a low functional PS value. Low functional levels of PS were found in each clinical group although there was no difference in the distribution of functional PS values among groups. Crossed immuno-electrophoresis showed an abnormal distribution of PS in some patients, but failed to confirm the marked decrease of free PS in patients with very low PEG-fPS. An impairment of the protein S system is observed in HIV-infected patients. However, the discrepancies found in some patients among the results of the various PS-related assays should lead to a cautious interpretation concerning the incidence of PS deficiency in HIV-infected patients.
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To clone the malolactic enzyme gene from Lactobacillus sp. 89, construction of a shuttle vector able to express itself in Lactobacillus sp. 89 and Escherichia coli was undertaken. The shuttle plasmid pLE16 resulted from the union of pBR328 and of the pLB10 plasmid extracted from Lactobacillus bulgaricus 10. The bacterial transformation in Lactobacillus sp. 89 was performed by electroporation, and the clones were selected on MRS medium with 30 micrograms.mL-1 chloramphenicol added. Fifty percent of the clones from Lactobacillus sp. 89 lost their resistance to chloramphenicol following 28 generations when the selection pressure was not maintained. The restriction map of pLE16 (7600 bp) was established using several restriction enzymes.
To achieve a rational basis for the use of deferoxamine (DFO) in aluminum (AL) -and iron (Fe)-overloaded uremic patients, important insights may be provided by the recently available micromethods to determine DFO and its metallochelates aluminoxamine (AlA) and feroxamine (FeA). With this procedure, AlA and FeA plasma kinetics were evaluated in a pilot study in 10 uremic patients during a whole week after a single DFO infusion performed during the first hour of the first standard bicarbonate hemodialysis (HD) of the week. Patients were divided into normal (n = 6) and high (n = 4) ferritin groups (1 and 2 respectively). Baseline Al concentrations were greater than 2 less than 6 in group 1 and less than 1.5 mumol/l in group 2. DFO was given at doses of 40, 20 and 10 mg/kg. AlA and FeA showed substantially different kinetics. AlA kinetics were similar in group 1 and 2: they reached their peak at the beginning of the 2nd HD, decreased during the 2nd and 3rd HD, and with the highest DFO dose still increased between the 2nd and 3rd HD. At similar pre-DFO Al values (greater than 2 less than 3.3 mumol/l), increased DFO doses produced increased AlA concentrations ranging from 95 to 40% of total plasma Al for all the week. At higher pre-DFO Al values (greater than 3.5 less than 6 mumol/l), even a DFO dose as low as 10 mg/kg was sufficient to form consistent AlA amounts (from 80 to 15% of total Al).(ABSTRACT TRUNCATED AT 250 WORDS)
The purpose of this study was to investigate the effect of a constant infusion rate of terbutaline on circadian bronchial peak expiratory flow rate (PEFR), heart rate and arterial pressure in patients with asthma exacerbation. Fifteen hospitalized asthmatic patients (6 females and 9 males, mean age 43.3 years, mean weight 67.0 kg) were included in this study. In order to reach the desired plasma concentrations of terbutaline immediately, a pharmacokinetic simulation was done. Based on the predicted values thus obtained, an initial 5-min bolus dose of 2.94 micrograms/kg was given to all patients at 7 a.m., i.e. at the beginning of the study. Over the following 24 h (7 a.m. to 7 a.m.), 33 micrograms/kg of terbutaline was infused intravenously at a constant rate with an electric pump. Since severe acute asthma requires corticosteroids, a 40-mg injection of methylprednisolone was given to all patients at 7 a.m. PEFR, heart rate, systolic arterial pressure, side effects and plasma terbutaline levels were recorded at 7 and 10 a.m., 1, 4, 7 and 11 p.m., and 3 and 7 a.m. the following morning. Terbutaline had a significant favorable effect on asthma exacerbation but no circadian rhythm was found in PEFR. Although terbutaline was infused at a constant rate, plasma levels depended on circadian variations.
Five patients developed neurological adverse effects as they were treated with amiodarone for 2 to 18 months. The daily maintenance dose did not exceed 400 mg. The neurological manifestations included tremor, ataxia, peripheral neuropathy, dyskinesia, myoclonic jerks, extrapyramidal hypertony, and altered mental status. These side effects resolved within 3 days to 3 months after amiodarone withdrawal. Advanced age, renal failure, diabetes mellitus, and alcoholism seemed to be risk factors for development of amiodarone neurotoxicity. Both peripheral and central nervous systems are involved in these amiodarone-induced complications.
A double blind multicentre study of seasonal rhinitis (108 patients) has compared Loratadine and Cetirizine. The results of clinical scores are significantly good for both products. Only tolerance is different and in favour of Loratadine, since sleepiness was found in 9.5% of patients treated with Cetirizine, and 3.6% with Loratadine.
Promoter sequences recognized by Escherichia coli RNA polymerase were isolated from Brevibacterium sp. R312, a coryneform strain producing nitrile hydratase and amidase. Ten Escherichia coli clones containing promoter sequences were selected for their ability to grow with chloramphenicol concentrations of up to 1500 micrograms/ml. The strength of these promoter sequences was determined. We carried out a preliminary study of the strongest promoter having a chloramphenicol acetyl-transferase/beta-lactamase activities ratio of 18.4.
Tissue-type plasminogen activator, von Willebrand factor, and plasminogen-activator inhibitor type 1 plasma levels were measured at first consultation in 85 consecutive patients infected with human immunodeficiency virus. Patients were assigned to three groups according to clinical status: mild disease group, intermediate group, and acquired immunodeficiency syndrome group. Significant differences were found in von Willebrand factor, tissue-type plasminogen activator, and plasminogen-activator inhibitor type 1 plasma levels among the three groups: severe clinical status was associated with higher von Willebrand factor, tissue-type plasminogen activator, and plasminogen-activator inhibitor type 1 plasma levels. Significant correlations were found among these three parameters, such known biologic prognostic indicators of human immunodeficiency virus infection as IgA, anti-p24 antibodies, p24 antigenemia, CD4+ lymphocytes, beta 2-microglobulin, and the clinical status. The prognostic relevance of plasma von Willebrand factor and tissue-type plasminogen activator levels at the time of entry into the study was then investigated in a cohort of 65 of the 85 patients who had follow-up during a median period of 22 months. The median survival time for all patients was 39 months after the first consultation. A plasma von Willebrand factor level greater than 200% of the control value had a positive predictive value of 86% for determining nonsurvivors; the median survival time for such patients was 9 months after the first consultation. A positive predictive value of 100% in recognizing nonsurvivors was found for tissue-type plasminogen factor plasma levels greater than 20 ng/ml; the median survival time for these patients was 2 months after the first consultation.(ABSTRACT TRUNCATED AT 250 WORDS)
The aim of the present work was to evaluate vasoreactivity in patients with pulmonary hypertension related to chronic obstructive lung disease. This was done by comparing haemodynamic data recorded while patients were breathing room air, and hypoxic and hyperoxic mixtures. We estimated the role of vasoconstriction in determining the level of pulmonary hypertension. This study included 26 patients with moderate pulmonary hypertension mean pulmonary arterial pressure (MPAP) = 27.3 +/- 1.2 mmHg) secondary to chronic obstructive lung disease (COLD), forced expiratory volume in one second (FEV1) = 0.95 +/- 0.13 l; arterial oxygen tension (PaO2) = 8.7 +/- 0.25 kPa). After insertion of a thermodilution catheter in the pulmonary artery and a cannula in the femoral artery, mixtures containing 15, 21, 30 and 100% oxygen were randomly administered for 20 min each. As fractional inspiratory oxygen (FIO2) increased, MPAP decreased relatively less than cardiac index. Cardiac output was at its highest during room air breathing and the hypoxic mixture did not lead to a further increase. Unlike normal subjects, in whom adjustment of cardiac output is achieved by heart rate alone, haemodynamic regulation in these patients also involved stroke volume. Variations in MPAP and cardiac index were strongly correlated with arterial oxygen saturation (SaO2). The greatest variations were noted in the patients with the highest pulmonary hypertension. Under normoxic and hyperoxic condition the relationship between pulmonary artery driving pressure and cardiac index was linear and its slope steeper in patients having the highest pulmonary hypertension at steady-state.(ABSTRACT TRUNCATED AT 250 WORDS)