Biomedical subjects
A Arnaud
Publications and source records attributed to A Arnaud.
Karyotype studies on different strains of Candida molischiana by pulsed-field gel electrophoresis.
We used pulsed-field gel electrophoresis to compare the electrophoretic karyotype of a Candida molischiana mutant, de-repressed for beta-glucosidase production, with a wild-type strain and a reference strain. The chromosomal organization in this mutant yeast was found to be quite different. Hybridization patterns and the relative fluorescence of all bands indicated eight chromosomes in the mutant strain and seven in the other two. All three strains seemed to be haploid, with an estimated genome size of 12 Mb; the beta-glucosidase gene was on the same chromosome in all of them and the SfiI restriction patterns of this chromosome indicated that it is not affected by the mutation.
Sizing of the Rhodococcus sp. R312 genome by pulsed-field gel electrophoresis. Localization of genes involved in nitrile degradation.
The two restriction enzymes AsnI and DraI were found to produce DNA fragment sizes that could be used for mapping the Rhodococcus sp. R312 (formerly Brevibacterium sp. R312) genome by pulsed-field gel electrophoresis. AsnI produced 24 fragments (4 to 727 kb) and DraI yielded 15 fragments (8.5 to 2400 kb). The fragment lengths in each digest were summed, indicating that the size of the chromosome ranged from 6.31 to 6.56 Mb, with a mean of 6.44 Mb. In addition, the wide-spectrum amidase gene (amiE) and the operon containing the enantiomer-selective amidase gene (amdA) and the nitrile hydratase structural gene (nthA, nthB) were localized on the AsnI and DraI fragments.
Allergy and intolerance to nonsteroidal anti-inflammatory agents.
Explore the source record for details and available documents.
Fibrinolytic and inflammatory processes in pleural effusions.
This study was designed to evaluate major fibrinolytic parameters in relation to parameters of inflammation associated with different kinds of pleural effusion. Sixty patients with pleural effusion were studied. The underlying aetiology was empyema in 10 cases, tuberculosis in 9, cancer in 31, cardiac failure in 7, and undetermined in 3. Plasminogen, plasminogen activator inhibitor 1 (PAI-1) and 2 (PAI-2), tissue type plasminogen activator (t-PA), urokinase (u-PA) and D-dimers (D-D) were quantified in plasma samples and pleural effusion specimens. These data were then correlated with inflammatory or infectious parameters, i.e. fibrinogen, von Willebrand factor (vWF), erythrocyte sedimentation rate (ESR), protein concentration, and white blood cell count. D-D levels were higher in pleural fluid than in plasma. D-D levels were not correlated with either plasminogen activator or plasminogen activator inhibitor levels, suggesting the presence of other fibrinolytic pathways. PAI levels (PAI activity, PAI-1 antigenicity, PAI-2 antigenicity) and vWF levels were significantly higher in patients with tuberculosis and empyema than in patients with cancer or cardiac failure. Regression analysis between inflammatory and fibrinolytic parameters showed that pleural PAI levels were significantly correlated with pleural neutrophil count, vWF levels, and plasma fibrinogen levels. D-D levels were correlated with blood ESR. No significant difference in pleural t-PA, u-PA and D-D levels was observed between aetiologies. The highest pleural t-PA and u-PA values were noted in patients with cancer, especially lymphoma. Plasma t-PA levels were higher inpatients with pleural effusion secondary to congestive heart failure, but this difference did not reach statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)
A very stable beta-glucosidase from a Candida molischiana mutant strain: enzymatic properties, sequencing, and homology with other yeast beta-glucosidases.
We purified a beta-glucosidase from the mutant strain Candida molischiana 35M5N. Analysis of the kinetic properties of this enzyme did not show any differences between the previously purified wild-type enzyme and that of the mutant. Nevertheless, a study of the stability of the enzyme at different pH levels and temperatures showed the increase resistance of this protein. This enzyme was found to be stable at pH 5 for 145 h and retained 78% of its initial activity after the same time at pH 3.5 (optimal pH) and 30 degrees C. This difference between the wild-type and the mutant enzyme could be explained by differences in the quantity or quality of glycosylation. This glycoprotein showed different forms after deglycosylation. Some peptides from this protein were also sequenced. An homology analysis found similarities between this beta-glucosidase and beta-glucosidases of Candida pelliculosa and Schizophyllum commune.
Kinetics of detection of antibodies to HIV-1 and plasma p24 antigens during a severe primary HIV-1 infection.
Explore the source record for details and available documents.
[Carboplatin-VP16 combination in non small cell lung cancers in the aged patient. A study of the French group in pneumology (GFPC)].
UNLABELLED: Between February 1992 and May 1993, 22 patients older than 75 years, with non small cell lung cancer, were treated with carboplatin and oral etoposide. There were 18 men and four women with a median age of 79 years. Fourteen patients had an epidermoid carcinoma: four had an adenocarcinoma and four had an undifferentiated carcinoma. Carboplatin was administered intravenously on day 1 at a dose of 300 mg/m2; oral etoposide was administered at a dose of 600 mg/m2 (two capsules daily) for 9, 10, 11, or 12 days according to body surface. Courses were repeated every 28 days for a total of three courses. TOXICITY: 15 patients (68%) had received previous chemotherapy. Myelosuppression was the main problem with one grade IV and five grade III hematologic toxicities. We observed one mild neurologic toxicity. RESULTS: 19 patients were evaluable for response. We observed one complete response (5%), five disease stabilizations (26%) and 13 disease progressions. Median survival was 5 months. These results led to discontinue this study.
[Clinical and psychological factors influencing the efficacy of botulinum toxin in the treatment of hemifacial spasm and blepharospasm].
We analyzed the influence of clinical and psychological factors on the long-term efficacy of botulinum toxin A (BTX) injections in 45 patients with blepharospasm and 66 patients with hemifacial spasm. Injections efficacy (respectively 94.3% and 95.7%) and duration of relief (respectively 14.8 and 18.7 weeks) remained stable over seven successive injections. Clinical improvement was not influenced by patients' sex, age, or disease duration but by psychological background (p < 0.001). Patients who failed to respond after repetitive injections had lower inter-injections intervals (p < 0.05). This data shows: (1) the importance of psychological contexte in subjective evaluation of treatment efficacy with BTX, (2) emphasizes the necessity of avoiding close injections.
Cloning of the wide spectrum amidase gene from Brevibacterium sp. R312 by genetic complementation. Overexpression in Brevibacterium sp. and Escherichia coli.
The amiE gene of Brevibacterium sp. R312 encoding wide spectrum amidase was isolated by complementation of a Brevibacterium sp. mutant using a plasmid gene bank of chromosomal DNA. The amiE structural gene and its promoter were localized on a 1.8-kb fragment by subsequent subcloning and complementation studies. Another promoter localized in the pSR 1 fragment of the cloning vector was shown to be able to control amiE gene expression. In Brevibacterium sp., the investigation of amidase activities related to one copy of the gene suggested that the regulation of the amiE gene expression was under negative control. High expression levels have been obtained in Brevibacterium sp. and, after substitution of the amiE promoter by the tac promoter, in Escherichia coli.
Application of high-performance liquid chromatography to the study of the biological transformation of adiponitrile.
A procedure for the assay of nitrile hydratase and amidase activity by high-performance liquid chromatography is described. The method can be used to assay the intermediate compounds resulting from the hydrolysis of adiponitrile into adipic acid, and to determine the kinetics of the hydrolysis of these compounds using whole cells and enzyme extracts. The precision of the method makes it suitable for the determination of the enzyme parameters: Km and Vm (nitrile hydratase and amidase). Using cyanovaleramide as substrate, Km and Vm were respectively 370 mM and 2060 U/mg for nitrile hydratase and 6.6 mM and 33 U/mg for amidase.
Selection and study of a Candida molischiana mutant derepressed for beta-glucosidase production.
A mutant strain of Candida molischiana was selected. Analysis of the exocellular activity of Candida molischiana 35M5N grown on different carbon sources revealed that the biosynthesis of beta-glucosidase is derepressed in this yeast strain. The strain is not a hyper-producer mutant. There were no observed differences in the endocellular and parietal activities of the wild and mutant strains. However, the mutant strain produced 35-fold more enzyme than the wild-type in the culture medium with glucose as carbon source. When glucose was used as carbon source, the mutant strain produced 90% more exocellular enzyme than when cellobiose was used as the carbon source.
Tissue-type plasminogen activator level is decreased in human seminal plasma with abnormal liquefaction.
OBJECTIVE: To determine plasminogen activators (PAs) and PA inhibitor levels in seminal plasma of patients attending an infertility clinic. DESIGN: Quantification by immunologic method of PAs in seminal plasma. SETTING: Patients of Department of Urology and Andrology, University Hospital, Nimes, France. PATIENTS: Ninety-two men attending for assessment because of infertility. INTERVENTIONS: Semen were collected by masturbation. Usual sperm parameters were determined; immediately after liquefaction, samples were snap-frozen at -85 degrees C until used for immunologic determination. MAIN OUTCOME MEASURES: Tissue-type PA antigen, urokinase-type PA antigen, and type 1 PA inhibitor antigen levels in seminal plasma. RESULTS: Median values of PA were 270 ng/mL (tissue-type PA) and 5.4 ng/mL (urokinase-type PA) in normozoospermia; 290 ng/mL (tissue-type PA) and 5.7 ng/mL (urokinase-type PA) in oligozoospermia; 325 ng/mL (tissue-type PA) and 3.5 ng/mL (urokinase-type PA) in oligoasthenozoospermia. Type 1 PA inhibitor antigen levels were often under detection limit. Tissue-type PA was 173.5 ng/mL in semen with abnormal liquefaction and 290 ng/mL in semen with normal liquefaction. CONCLUSION: The study confirmed the presence of both types of PAs in seminal plasma, tissue-type PA being largely predominant. No difference was found in tissue-type PA, urokinase-type PA, or type 1 PA inhibitor antigen levels between normal and oligozoospermic semen nor between normal and asthenozoospermic semen. On the other hand, semen with abnormal liquefaction had significantly lower tissue-type PA level than normal semen.
[Evaluation of three types of positive pressure ventilation in periodic respiration (CPAP, BiPAP, enhanced Morpheus)].
Explore the source record for details and available documents.
Relation between polysomnographic parameters and apnea index in obstructive sleep apnea syndrome.
We performed overnight polysomnography in 77 patients for diagnosis of sleep apnea syndrome (SAS) and assessment of severity. Patients were classified into 3 groups according to apnea index (AI): group 1 (G1; no SAS), AI < or = 10 (21 patients), group 2 (G2; moderate SAS), 10 < AI < 40 (34 patients), and group 3 (G3; severe SAS), AI > or = 40 (22 patients). In all 3 groups, 60% of the apneas were obstructive, but the proportion of mixed apnea increased from G1 to G3 (6% in G1, 12% in G2, and 24% in G3). The duration of REM sleep was shorter in G2 and G3 than in G1 (G1 61 min, G2 44 min, G3 41 min; p < 0.03). In G3 a dramatic decrease in deep sleep was noted in comparison with G1 and G2 (G1 29 min, G2 31 min, G3 10 min). The distribution of the apnea in the different sleep stages was similar in G3; in G2, 16 patients had a REM apnea predominance, but in this subgroup duration of REM sleep was longer and AI was lower than in the other 18 G2 patients. So, absence of sleep stage apnea predominance and high proportion of mixed apnea were observed in the most severe SAS.
Purification and characterization of the endocellular beta-glucosidase of a new strain of Candida entomophila isolated from fermenting agave (Agave sp.) juice.
A yeast strain isolated in the laboratory from fermenting agave (Agave sp.) juice was studied and classified as Candida entomophila. The beta-glucosidase of this yeast was purified by ion-exchange chromatography and gel filtration. Its molecular mass estimated by gel filtration was 400 kDa. The oligomeric structure was determined following treatment of the purified enzyme with SDS. Its optimum pH was between 5 and 6, and its optimum temperature was 60 degrees C. The enzyme was active against soluble glucosides with (1-->3)-beta, (1-->4)-beta and (1-->4)-alpha linkage configuration, and it possesses (1-->6)-alpha-arabinofuranosidase activity. It is competitively inhibited by glucose and by D-gluconic acid lactone. The enzyme was constitutive and a glucosyltransferase activity is observed in the presence of ethanol. Since the glycosides present in wines and fruit juices represent a potential source of aromatic flavour, the possible use of the yeast glucosidase for the liberation of the bound aroma is discussed.
Expression of a synthetic DNA region containing a consensus promoter and two lac operators in Brevibacterium sp.
The cat reporter gene was used to assess expression of two promoters, previously strongly expressed in Escherichia coli, in Brevibacterium sp. R312 strain. The tac promoter (de Boer et al., 1983, Proc. Natl. Acad. Sci. USA 80, 21-25) was poorly expressed in Brevibacterium sp. In contrast, the AatII-SalI fragment of plasmid pYEJ001 (Pharmacia LKB Biotechnology, Sweden) containing two lac operators, a consensus sequence promoter and the cat structural gene clearly revealed chloramphenicol acetyltransferase activity and the presence of a 25,600-kDa protein, corresponding to the monomeric CAT protein, in cell extracts.
N-terminal amino acid sequence of mutant strain Brevibacterium sp. adipamidase.
The adipamidase of a mutant strain Brevibacterium sp. R312 involved in the degradation of adiponitrile to adipic acid was purified. Its N-terminal amino acid sequence was shown to be identical to Brevibacterium sp. R312 enantio selective amidase and Rhodococcus sp. N-774 amidase.