Expression of genes and processing of enzymes for the biosynthesis of penicillins and cephalosporins.

The genes pcbAB, pcbC and penDE encoding the enzymes (alpha-aminoadipyl-cysteinyl-valine synthetase, isopenicillin N synthase and isopenicillin N acyltransferase, respectively) involved in the biosynthesis of penicillin have been cloned from Penicillin chrysogenum and Aspergillus nidulans. They are clustered in chromosome I (10.4 Mb) of P.

Resolution of four large chromosomes in penicillin-producing filamentous fungi: the penicillin gene cluster is located on chromosome II (9.6 Mb) in Penicillium notatum and chromosome I (10.4 Mb) in Penicillium chrysogenum.

Four chromosomes were resolved by pulsed field gel electrophoresis in Penicillium notatum (10.8, 9.6, 6.

Gender differences in the EEG during cognitive activity.

EEG activity of 16 adult volunteers. 8 male and 8 females was monopolarly recorded at P3 and P4 at rest and during solution of three series of tasks: one analytic, one spatial and one mixed demanding both kinds of processing. The following main effects were observed: Men showed significantly higher beta relative power than women, while women showed significantly higher alpha relative power than men during all conditions.

The production of cephalosporin C by Acremonium chrysogenum is improved by the intracellular expression of a bacterial hemoglobin.

A DNA vector for expressing an oxygen-binding heme protein (Vitreoscilla hemoglobin, or VHb) in filamentous fungi was constructed and introduced into a cephalosporin C-producing strain of Acremonium chrysogenum. Expression of VHb in transformants was demonstrated by Western immunoblot analysis and by increased carbon monoxide binding activity of cell extracts. Several VHb-expressing transformants produced significantly higher yields of cephalosporin C than control strains in batch culture experiments.

The isopenicillin-N acyltransferase of Penicillium chrysogenum has isopenicillin-N amidohydrolase, 6-aminopenicillanic acid acyltransferase and penicillin amidase activities, all of which are encoded by the single penDE gene.

The isopenicillin-N acyltransferase of Penicillium chrysogenum catalyzes the conversion of the biosynthetic intermediate isopenicillin N to the hydrophobic penicillins. The isopenicillin-N acyltransferase copurified with the acyl-CoA:6-aminopenicillanic acid (6-APA) acyltransferase activity which transfers an acyl residue from acyl-CoA derivatives (e.g.

[Etiologic diagnosis of pneumonia in HIV-AIDS patients. Usefulness of fibrobronchoscopy].

Aim: to assess the usefulness of fiberoptic bronchoscopy in the etiologic diagnosis of pulmonary infiltrates in patients with AIDS.

Patients And Methods: in 25 patients with AIDS and pneumonia, 31 fiberoptic bronchoscopies with bronchoalveolar lavage were performed; in 11 occasions, a transbronchial biopsy was also performed.

Results: in 24 of the 31 procedures (77%) an etiologic diagnosis was made.

Biochemical characterization and molecular genetics of nine mutants of Penicillium chrysogenum impaired in penicillin biosynthesis.

Nine mutants of Penicillium chrysogenum (npe1 to npe8 and npe10) impaired in penicillin biosynthesis were screened after nitrosoguanidine mutation. Mutants npe1, npe4, npe5, npe6, npe7, npe8, and npe10 failed to synthesize significant levels of penicillin, whereas strains npe2 and npe3 synthesized about 20% of the penicillin level produced by the parental strain. Mutants npe5 and npe10 did not show alpha-aminoadipylcysteinyl-valine (ACV) synthetase activity in vitro and did not form ACV in vivo.

Resolution of chromosomes III and VI of Aspergillus nidulans by pulsed-field gel electrophoresis shows that the penicillin biosynthetic pathway genes pcbAB, pcbC, and penDE are clustered on chromosome VI (3.0 megabases).

An improved electrophoretic molecular karyotype of Aspergillus nidulans ATCC 28901 has been obtained by contour-clamped electric field gel electrophoresis, which separates seven chromosomal bands and allows resolution of chromosomes III and VI. The three genes of the penicillin biosynthetic pathway, pcbAB, pcbC, and penDE, encoding alpha-aminoadipyl-cysteinyl-valine synthetase, isopenicillin N synthase, and isopenicillin N acyltransferase, respectively, are clustered together on a chromosome of 3.0 Mg, corresponding to linkage group VI, whereas the argB gene was located on a chromosome of 3.

The cefG gene of Cephalosporium acremonium is linked to the cefEF gene and encodes a deacetylcephalosporin C acetyltransferase closely related to homoserine O-acetyltransferase.

The gene (cefG) encoding the acetyl coenzyme A:deacetylcephalosporin C acetyltransferase of Cephalosporium acremonium (synonym Acremonium chrysogenum) C10 has been cloned. It contains two introns and encodes a protein of 444 amino acids with an M(r) of 49,269 that correlates well with the M(r) deduced by gel filtration. The cefG gene is linked to the cefEF gene (encoding the bifunctional deacetoxycephalosporin C synthase/hydroxylase), but it is expressed in an orientation opposite that of the cefEF gene.

Characterization of the Cephalosporium acremonium pcbAB gene encoding alpha-aminoadipyl-cysteinyl-valine synthetase, a large multidomain peptide synthetase: linkage to the pcbC gene as a cluster of early cephalosporin biosynthetic genes and evidence of multiple functional domains.

A 24-kb region of Cephalosporium acremonium C10 DNA was cloned by hybridization with the pcbAB and pcbC genes of Penicillium chrysogenum. A 3.2-kb BamHI fragment of this region complemented the mutation in the structural pcbC gene of the C.

Expression of the penDE gene of Penicillium chrysogenum encoding isopenicillin N acyltransferase in Cephalosporium acremonium: production of benzylpenicillin by the transformants.

No DNA sequence homologous to the penDE gene of Penicillium chrysogenum was found in the genome of three different strains of Cephalosporium acremonium. The pcbC-penDE gene cluster of P. chrysogenum complemented the isopenicillin N synthase deficiency of C.

The cluster of penicillin biosynthetic genes. Identification and characterization of the pcbAB gene encoding the alpha-aminoadipyl-cysteinyl-valine synthetase and linkage to the pcbC and penDE genes.

Penicillium chrysogenum DNA fragments cloned in EMBL3 or cosmid vectors from the upstream region of the pcbC-penDE cluster carry a gene (pcbAB) that complemented the deficiency of alpha-aminoadipyl-cysteinyl-valine synthetase of mutants npe5 and npe10, and restored penicillin production to mutant npe5. A protein of about 250 kDa was observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels of cell-free extracts of complemented strains that was absent in the npe5 and npe10 mutants but exists in the parental strain from which the mutants were obtained. Transcriptional mapping studies showed the presence of one long transcript of about 11.

Cloning, characterization of the acyl-CoA:6-amino penicillanic acid acyltransferase gene of Aspergillus nidulans and linkage to the isopenicillin N synthase gene.

The penDE gene encoding acyl-CoA:6-amino penicillanic acid acyltransferase (AAT), the last enzyme of the penicillin biosynthetic pathway, has been cloned from the DNA of Aspergillus nidulans. The gene contains three introns which are located in the 5' region of the open reading frame. It encodes a protein of 357 amino acids with a molecular weight of 39,240 Da.

[Effect of position with respect to gravitational force on the hydrodynamics of an experimental model of saccular aneurysm].

We wish to confirm the hypothesis that the hydrodynamics of brain aneurysms depend partially on their position, with respect to the force of gravitation, and so developed an experimental model of latex aneurysms, which was subjected to a pulsatile flow. Four different registers were made with an injection of ink and radioisotopes. A physical model was designed which allowed a quantitative analysis of the results and which allows a mathematical analysis of the aneurysm's hydrodynamics.

[Value of laboratory tests and echography in the diagnosis of biliary disease in the initial phase of acute pancreatitis].

The aim of this study was to investigate the usefulness of serum bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (APh) and real time ultrasonography (US) in distinguishing between gallstone and non gallstone related acute pancreatitis (A.P.).

Analysis of supra-nucleosome particles from unfertilized eggs of sea urchins.

Two discrete supranucleosomal particles that differ in their electrophoretic migration on 1% agarose gels were isolated from unfertilized sea urchin eggs. Both particles contain the same complement of cleavage stage (CS) chromosomal proteins, which is identical to the complete set of basic proteins isolated directly from chromatin by extraction with 0.25 N HCl.

The pancreatic enzymes value in the diagnosis of acute pancreatitis and acute biliary tract diseases.

Unlabelled: The aim of this study was to investigate the usefulness of lipase and isoamylases in the diagnosis of acute pancreatitis and to determine if its use permits differential diagnosis between acute pancreatitis and acute biliary tract disease. Three groups of patients were studied. a)

Control: 60 patients without abdominal diseases.

EEG activity during performance of cognitive tasks demanding verbal and/or spatial processing.

EEG activity of 8 male volunteers was monopolarly recorded at P3 and P4 during four resting periods and during the performance of three series of cognitive tasks: one verbal, one spatial and one demanding verbal and spatial processing or "mixed" task. Beta, alpha and theta relative power were compared between successful and unsuccessful trials, between start and end of performance interval and among resting periods and tasks. There were no significant differences between successful and unsuccessful trials, nor between start and ending of performance period.

Interhemispheric correlation of EEG activity during successful and unsuccessful cognitive performance.

EEG activity of eight male volunteers was monopolarly recorded at P3 and P4 during an initial baseline and during performance of three series of cognitive tasks: one verbal, one spatial and one "mixed" demanding verbal and spatial processing. Interhemispheric correlation of the EEG activity was compared among tasks and between successful and unsuccessful trials. There was a significant main effect for success or failure of cognitive processing with increased interhemispheric correlation during unsuccessful trials regardless of their nature.

[Chronic calcified pancreatitis. Our experience].

Forty five cases of chronic pancreatitis have been diagnosed between January 1966 to July 1983 in the Hospital A. Posadas. The diagnosis was confirmed by the presence of one or more of the following data: pancreatic calcifications positive in 35, abnormal secretin test 37, ultrasonography and computed tomography pathological findings 10.