ABSTRACT
Human beta-defensins are 2-5 kDa, cationic, microbicidal peptides, which represent the first-line host defense against several Gram-negative and Gram-positive bacteria, fungi and viruses. They contain a conserved disulfide-bridge pattern of three pairs of intramolecular cystine bonds. The well-known public health problem related with the growing number of multiresistant bacteria has driven research to look for novel antibiotics, such beta-defensins and a feasible way to produce them. Heterologous expression of beta-defensins could be one way to generate large quantities of beta-defensins for clinical research; however, heterologous expression of beta-defensins has some biochemical problems, such toxicity toward the host cell, peptide degradation by proteolytic cell enzymes, size, folding constrains and low recombinant peptide yields. In this communication, several heterologous systems for producing human beta-defensins are reviewed.
Subject(s)
Anti-Infective Agents/isolation & purification , Anti-Infective Agents/pharmacology , Gene Expression , Genetic Vectors/genetics , beta-Defensins/isolation & purification , beta-Defensins/pharmacology , Amino Acid Sequence , Anti-Infective Agents/chemistry , Anti-Infective Agents/metabolism , Genetic Vectors/metabolism , Humans , Molecular Sequence Data , Sequence Alignment , beta-Defensins/genetics , beta-Defensins/metabolismABSTRACT
A pathogen such as C. albicans needs an efficient mechanism of iron uptake in an iron-restricted environment such as is the human body. A ferric-reductase activity regulated by iron and copper, and analogous to that in S. cerevisiae, has been described in C. albicans. We have developed an in-plate protocol for the isolation of clones that complement an aft1 mutation in S. cerevisiae that makes cells dependent on iron for growth. After transformation of S. cerevisiae aft1 with a C. albicans library, we have selected clones that grow in conditions of iron deficiency and share an identical plasmid, pIRO1, with a 4500 bp insert containing the URA3 gene and an ORF (IRO1) responsible for the suppression of the iron dependency. IRO1 does not show homology with AFT1 or with other sequences in the databases. Northern analysis demonstrates constitutive expression of IRO1. CAI4, a C. albicans strain isolated as Deltaura3, also has a deletion of the 3' half of IRO1, and displays in YNB medium similar phenotypic characteristics to S. cerevisiae aft1 mutant strains. Therefore, we consider IRO1 as a gene of C. albicans involved in the utilization of iron. However, in extreme conditions of iron deprivation, CAI4 seems to activate alternative mechanisms of iron uptake that allow a better growth than the wild strain SC5314. Analysis of its predicted protein sequence is in agreement with a role of Iro1p as a transcription factor.
Subject(s)
Candida albicans/genetics , Fungal Proteins/genetics , Genes, Fungal , Iron/metabolism , Saccharomyces cerevisiae Proteins , Transcription Factors/genetics , Amino Acid Sequence , Candida albicans/cytology , Candida albicans/metabolism , Genetic Linkage , Molecular Sequence Data , Orotidine-5'-Phosphate Decarboxylase/genetics , Saccharomyces cerevisiae/genetics , Sequence Homology, Amino Acid , Suppression, GeneticABSTRACT
A rapid capillary electrophoresis method for the quantification of gabapentin, a new anticonvulsant drug, in serum was developed. The assay involves derivatization of gabapentin with fluorescamine to provide a chromophore for UV-fluorescence detection. The migration time is about 11 min. The assay was linear between 0 and 20 mg/l. No other therapeutic drugs or amino acids interfered with the gabapentin peak. The relative standard deviation is 2.4% at a mean of 11 mg/l (n = 17). The mean serum level for 52 patients on this drug was 5.2 mg/l with a range of 0-12 mg/l.
Subject(s)
Acetates/blood , Amines , Anticonvulsants/blood , Cyclohexanecarboxylic Acids , Electrophoresis, Capillary/methods , gamma-Aminobutyric Acid , Gabapentin , Humans , Spectrometry, Fluorescence , Spectrophotometry, UltravioletABSTRACT
Se realizó un estudio aplicando en una Cátedra Clínica de la carrera de odontólogo un sistema de regularidad y promoción por acumulación de puntos, resultantes de las calificaciones de los trabajos prácticos y de los exámenes parciales. Se tomó como grupo testigo un curso donde se alcanzaba la regularidad con un número de trabajos prácticos y un número de exámenes parciales aprobados. El procedimiento fue evaluado mediante un seminario docente, un seminario estudiantil y un estudio estadístico de la cantidad de trabajo por unidad de tiempo por cada alumno. Los resultados parecieron indicar que el sistema experimentado podría actuar como un elemento de motivación para un cambio positivo de actitudes en el estudiante. Se hacen necesarios otros estudios que amplíen los grupos experimentales y testigos en un mayor número de años para arribar a conclusiones más seguras (AU)
Subject(s)
Comparative Study , Humans , Education, Dental/standards , Educational Measurement/methodsABSTRACT
Se realizó un estudio aplicando en una Cátedra Clínica de la carrera de odontólogo un sistema de regularidad y promoción por acumulación de puntos, resultantes de las calificaciones de los trabajos prácticos y de los exámenes parciales. Se tomó como grupo testigo un curso donde se alcanzaba la regularidad con un número de trabajos prácticos y un número de exámenes parciales aprobados. El procedimiento fue evaluado mediante un seminario docente, un seminario estudiantil y un estudio estadístico de la cantidad de trabajo por unidad de tiempo por cada alumno. Los resultados parecieron indicar que el sistema experimentado podría actuar como un elemento de motivación para un cambio positivo de actitudes en el estudiante. Se hacen necesarios otros estudios que amplíen los grupos experimentales y testigos en un mayor número de años para arribar a conclusiones más seguras
Subject(s)
Humans , Education, Dental/standards , Educational Measurement/methodsSubject(s)
Adolescent , Humans , Male , Female , Adolescent , Social Adjustment , Chronic Disease , Physician-Patient RelationsSubject(s)
Adolescent , Humans , Male , Female , Adolescent , Chronic Disease , Physician-Patient Relations , Social AdjustmentABSTRACT
The results of a study of the effects of familiarity with the patient an patient socioeconomic status on pediatricians' responses to a case of apparent child abuse give insight into the bias that operates against full reporting of child abuse incidents.
