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Biomedical subjects

F Moreno

Publications and source records attributed to F Moreno.

At least 271 records · Page 15Linked to original sources
PubMed1985

Cloning and mapping of the genetic determinants for microcin B17 production and immunity.

Plasmid pMccB17 (70 kilobases [kb]) codes for the production of microcin B17, a peptide that inhibits DNA synthesis, and for microcin B17 immunity. A BamHI-EcoRI fragment of 5.1 kb from pMccB17 was cloned into pBR322 in two steps. The resulting plasmid (pMM102) overproduced microcin B17 and expressed immunity against microcin. Mcc- and Mcc- Imm- mutants were isolated on plasmids pMccB17 and pMM102 by deleting various DNA fragments and by inserting different translocatable elements. Physical and phenotypic characterization of these mutants showed that a DNA region of 3.0 to 3.5 kb is required to produce microcin B17, whereas an adjacent region of about 1.0 kb is required to express microcin B17 immunity.

Bacteriocins↗
PubMed1985

Plasmid genes required for microcin B17 production.

The production of the antibiotic substance microcin B17 (Mcc) is determined by a 3.5-kilobase DNA fragment from plasmid pMccB17. Several Mcc- mutations on plasmid pMccB17 were obtained by both transposon insertion and nitrosoguanidine mutagenesis. Plasmids carrying these mutations were tested for their ability to complement Mcc- insertion or deletion mutations on pMM102 (pMM102 is a pBR322 derivative carrying the region encoding microcin B17). Results from these experiments indicate that at least four plasmid genes are required for microcin production.

Bacteriocins↗
PubMed1984

The transposon Tn5 carries a bleomycin-resistance determinant.

Transposon Tn5 carries a determinant for resistance to bleomycin (Bm). Deletion mapping and cloning experiments have shown that this determinant, gene ble, is located between the determinant for kanamycin (Km) and neomycin resistance (gene neo) and the determinant for streptomycin resistance (gene str). Genes neo, ble, and str belong to an operon controlled by the common promoter. The Mr of the ble product, as determined by polyacrylamide gel electrophoresis, is 12000 to 13000.

Bacterial Proteins↗
PubMed1984

[Right cervical aortic arch: report of 2 cases, one associated with aortic coarctation].

Cervical aortic arch is a rare congenital vascular anomaly. Usually it appears as an asymptomatic pulsatile cervical mass, but symptoms of tracheal and esophageal compression may be present in 25% of the patients. About 40% of cases are associated with vascular or heart abnormalities. Angiography provides definitive diagnosis. Authors report two patients with right cervical aortic arch, one of them associated with aortic coarctation, and review 52 published cases.

Aorta, Thoracic↗
PubMed1982

Gene ompR and regulation of microcin 17 and colicin e2 syntheses.

The production of microcin 17 is controlled by plasmid pRYC17. Chromosomal mutants unable to produce a normal amount of microcin were isolated in Escherichia coli. One of the mutations maps in the ompR locus, indicating that an active OmpR product is required for the synthesis of microcin 17. The same conclusion was obtained for the synthesis of colicin E2. Therefore, two new functions of the regulatory gene ompR have been revealed.

Anti-Bacterial Agents↗
PubMed1981

Hepatic microsomal ethanol-oxidizing system (MEOS): increased activity following propylthiouracil administration.

Treatment for 7 days with the thyreostatic drug propylthiouracil (5 mg/100 g of body weight) resulted in a hypothyroid hepatic state as shown by the marked decreased hepatic content of thyroxine and triiodothyronine. This regimen led to an enchanced activity of the microsomal ethanol-oxidizing system, whereas the activities of alcohol dehydrogenase and catalase remained unchanged. Moreover, a hyperthyroid hepatic state achieved following the daily administration of L-thyroxine (150 micrograms/100 g of body weight) or L-3,3', 5-triiodothyronine (10 micrograms/100 g body weight) for 7 days resulted in a similar increased activity of the microsomal ethanol-oxidizing system. Under these conditions, a decrease of alcohol dehydrogenase activity and an unaffected catalase activity was observed. These findings, therefore, show that the administration of either propylthiouracil or thyroid hormones results in an increased activity of the microsomal ethanol-oxidizing system, suggesting that the underlying mechanism for the induction of the microsomal ethanol-oxidizing system by propylthiouracil is independent of the action of thyroid hormones.

Alcohol Oxidoreductases↗
PubMed1980

Effects of 2-deoxy-D-glucose on the synthesis of RNA and protein in Saccharomyces carlsbergensis G-517.

When Saccharomyces carlsbergensis G-517 was grown in 10 mM galactose as the carbon source, the addition of 2-deoxy-D-glucose restricted the uptake of galactose, [3H]uridine and [3H]leucine, and restricted invertase synthesis (beta-D-fructofuranoside fructohydrolase; EC 3.2.1.26) for a period of 60-90 min. During this time, the radioactive antimetabolite was taken up by the cells; afterwards, invertase synthesis was enhanced, and the utilizaton rate of galactose, [3H]uridine and [3H]leucine increased until it reached that of the control culture. When glucose was used as a carbon source, sugar utilization and uptake of radioactive precursors were unaffected by addition of the deoxysugar.

Deoxy Sugars↗