Search PubMed⌕ Search

Biomedical subjects

C Carmona

Publications and source records attributed to C Carmona.

48 records · Page 3Linked to original sources
PubMed1990

Fluorescence of harmol, harmalol and 2-hydroxycarbazole in concentrated hydroxide solutions.

Room temperature electronic absorption and fluorescence spectra of harmol, harmalol and 2-hydroxycarbazole have been obtained in concentrated aqueous potassium hydroxide solutions. The appearance of a new fluorescence band for all these compounds in media of H- greater than 16, has been ascribed to the emission of excited dianions formed by deprotonation. Acidity constants have been estimated from the Föster-Weller method.

Carbazoles↗
PubMed1987

Cloning, mapping and molecular analysis of the pyrG (orotidine-5'-phosphate decarboxylase) gene of Aspergillus nidulans.

We have modified the transformation procedures of Ballance et al. [Biochem. Biophys. Res. Commun. 112 (1983) 284-289] to give increased rates of transformation in Aspergillus nidulans. With the modified procedures we have been able to complement pyrG89, a mutation in the orotidine-5'-phosphate decarboxylase gene of A. nidulans, by transformation with a library of wild-type (wt) sequences in pBR329. We have recovered, by marker rescue from one such transformant, a plasmid (pJR15) that carries an A. nidulans sequence that complements pyrG89 efficiently. In three experiments, this plasmid gave an average of 1985 stable transformants/micrograms of transforming DNA. We have analyzed ten of these genetically and by Southern hybridization. In five transformants a single copy of the transforming plasmid had integrated at the pyrG locus, in one transformant several copies of pJR15 had integrated at this locus, in one transformant several copies of the plasmid had integrated into other sites, and in three transformants, the wt allele had apparently replaced the mutant allele with no integration of pBR329 sequences. Sequence and S1 nuclease protection analysis revealed that pJR15 contains a gene that predicts an amino acid sequence with regions of strong homology to the orotidine-5'-phosphate decarboxylases of Neurospora crassa and Saccharomyces cerevisiae. We conclude that this gene is the wt pyrG allele. Finally, we have compared the 5'- and 3'-noncoding sequences and intron splice sequences to other genes of A. nidulans and have mapped the pyrG locus to a region between the fpaB and galD loci on linkage group I.

Aspergillus nidulans↗
PubMed1986

Structural genes encoding the thermophilic alpha-amylases of Bacillus stearothermophilus and Bacillus licheniformis.

The genes encoding the thermostable alpha-amylases of Bacillus stearothermophilus and B. licheniformis were cloned in Escherichia coli, and their DNA sequences were determined. The coding and deduced polypeptide sequences are 59 and 62% homologous to each other, respectively. The B. stearothermophilus protein differs most significantly from that of B. licheniformis in that it possesses a 32-residue COOH-terminal tail. Transformation of E. coli with vectors containing either gene resulted in the synthesis and secretion of active enzymes similar to those produced by the parental organisms. A plasmid was constructed in which the promoter and the NH2-terminal two-thirds of the B. stearothermophilus coding sequence was fused out of frame to the entire mature coding sequence of the B. licheniformis gene. Approximately 1 in 5,000 colonies transformed with this plasmid was found to secrete an active amylase. Hybridization analysis of plasmids isolated from these amylase-positive colonies indicated that the parental coding sequences had recombined by homologous recombination. DNA sequence analysis of selected hybrid genes revealed symmetrical, nonrandom distribution of loci at which the crossovers had resolved. Several purified hybrid alpha-amylases were characterized and found to differ with respect to thermostability and specific activity.

Amino Acid Sequence↗
PubMed1986

Rapid automated synthesis via diisopropyl phosphoramidite in situ activation. Chemical synthesis and cloning of a calmodulin gene.

A gene coding for a calmodulin was synthesized and cloned. The chemical synthesis of the gene, coding for 149 amino acids, was achieved by the enzymatic ligation of 61 chemically synthesized DNA fragments. The DNA fragments were synthesized using a solid support with a diisopropyl phosphoramidite intermediate and in situ activation. The automated standard cycle time was 10 min/addition. The synthesizer was designed and constructed from inexpensive, readily available parts and controlled by a Commodore 64 computer. The gene possesses 27 unique, regularly spaced, restriction endonuclease cleavage sites to facilitate gene mutagenesis.

Amino Acid Sequence↗
PubMedDate not supplied

Immunodiagnosis of fasciolosis using recombinant procathepsin L cystein proteinase.

Cathepsin L1, a cysteine protease secreted by the gastrodermis of juvenile and adult Fasciola hepatica, was expressed in Escherichia coli as a fusion protein containing the proregion, supplied with six histidyl residues at the N-terminal end (rproCL1). In this study we tested its potential as antigen for the serologic diagnosis of F. hepatica infections by enzyme-linked immunosorbent assay (ELISA). The analyzed human sera included 16 positive samples, 99 negative controls and 111 from individuals affected by other parasitic and non parasitic diseases. The sensitivity and specificity of the rproCL1-ELISA were 100%. We also assessed the ability to detect antibodies in sera from 10 experimentally infected sheep, obtaining preliminary results that shown a response since the third week post infection in all the studied animals. Therefore, the recombinant rproCL1-based ELISA could be a standardized test for the accurate diagnosis of fasciolosis.

Amino Acid Sequence↗
PubMedDate not supplied

[Chronic asymptomatic intrahepatic cholestasis associated with Turner's syndrome].

Turner syndrome or the gonadal dysgenesis syndrome which is monosomic because of the lack of an X chromosome (45 X) is associated to a greater incidence of autoimmune, particularly thyroidal, disorders and inflammatory intestinal disease, but is rarely associated to hepatic disorders. A female patient with chronic asymptomatic intrahepatic cholestasis which, to our knowledge, is the first reported in Spain, is herein presented. The 40-year old patient with a 45 X karyotype, feminine phenotype was accidently found to have a chronic alteration in the hepatic profile. Hepatic biochemical tests revealed AST 59 U/L, ALT 90 U/L, GGT 201 U/L and alkaline phosphatase 320 U/L. Hepatic echography was normal. Percutaneous liver biopsy was performed demonstrating minimum changes consisting of sinusoidal dilatation and pigment accumulation in the hepatocyte biliary pole. Treatment with ursodeoxycholic acid 15 mg/kg/day was administered showing a marked decrease in the laboratory parameters during follow up. Different hypothesis which may explain the association between chronic asymptomatic intrahepatic cholestasis and Turner syndrome are discussed.

Adult↗
PubMedDate not supplied

[Verbal auditory agnosia: SPECT study of the brain].

Verbal auditory agnosia are rare in clinical practice. Clinically, it characterized by impairment of comprehension and repetition of speech but reading, writing, and spontaneous speech are preserved. So it is distinguished from generalized auditory agnosia by the preserved ability to recognize non verbal sounds. We present the clinical picture of a forty-years-old, right handed woman who developed verbal auditory agnosic after an bilateral temporal ischemic infarcts due to atrial fibrillation by dilated cardiomyopathie. Neurophysiological studies by pure tone threshold audiometry: brainstem auditory evoked potentials and cortical auditory evoked potentials showed sparing of peripheral hearing and intact auditory pathway in brainstem but impaired cortical responses. Cranial CT-SCAN revealed two large hypodenses area involving both cortico-subcortical temporal lobes. Cerebral SPECT using 99mTc-HMPAO as radiotracer showed hypoperfusion just posterior in both frontal lobes nect to Roland's fissure and at level of bitemporal lobes just anterior to Sylvian's fissure.

Adult↗