Obtainment, selection and characterization of a mutant strain of Kluyveromyces marxianus that displays improved production of 2-phenylethanol and enhanced DAHP synthase activity.

AIMS: Yeasts produce 2-phenylethanol (2-PE) from sugars via de novo synthesis; however, its synthesis is limited due to feedback inhibition on the isofunctional 3-deoxy-d-arabino-heptulosonate-7-phosphate (DAHP) synthases (Aro3p and Aro4p). This work aimed to select Kluyveromyces marxianus mutant strains with improved capacity to produce 2-PE from sugars. METHODS AND RESULTS: Kluyveromyces marxianus CCT 7735 mutant strains were selected from UV irradiation coupled with screening of p-fluoro-dl-phenylalanine (PFP) tolerant strains on culture medium without l-Phe addition. Most of them produced 2-PE titres higher than the parental strain and the Km_PFP41 mutant strain stood out for displaying the highest 2-PE specific production rate. Moreover it showed higher activity of DAHP synthase than the parental strain. We sequenced both ARO3 and ARO4 genes of Km_PFP41 mutant and identified mutations in ARO4 which caused changes in both size and conformation of the Aro4p. These changes seem to be associated with the enhanced activity of DAHP synthase and improved production of 2-PE exhibited by that mutant strain. CONCLUSIONS: The Km_PFP41 mutant strain presented improved 2-PE production via de novo synthesis and enhanced DAHP synthase activity. SIGNIFICANCE AND IMPACT OF THE STUDY: The mutant strain obtained in this work may be exploited as a yeast cell factory for high-level synthesis of 2-PE.

High genetic variability in endophytic fungi from the genus Diaporthe isolated from common bean (Phaseolus vulgaris L.) in Brazil.

AIMS: The goals of the present study were to identify, to analyse the phylogenetic relations and to evaluate the genetic variability in Diaporthe endophytic isolates from common bean. METHODS AND RESULTS: Diaporthe sp., D. infecunda and D. phaseolorum strains were identified using multilocus phylogeny (rDNA ITS region; EF1-α, ß-tubulin, and calmodulin genes). IRAP (Inter-Retrotransposon Amplified Polymorphism) and REMAP (Retrotransposon-Microsatellite Amplified Polymorphism) molecular markers reveal the existence of high genetic variability, especially among D. infecunda isolates. CONCLUSIONS: It was concluded that the multilocus phylogenetic approach was more effective than individual analysis of ITS sequences, in identifying the isolates to species level, and that IRAP and REMAP markers can be used for studying the genetic variability in the genus Diaporthe particularly at the intraspecific level. SIGNIFICANCE AND IMPACT OF THE STUDY: The combined use of molecular tools such as multilocus phylogenetic approach and molecular markers, as performed in this study, is the best way to distinguish endophytic strains of Diaporthe isolated from common bean (Phaseolus vulgaris L.).

Increased expression of clp genes in Lactobacillus delbrueckii UFV H2b20 exposed to acid stress and bile salts.

The ability to survive in harsh environments is an important criterion to select potential probiotics strains. The objective of this study was to identify and carry out phylogenetic and expression analysis by quantitative real-time PCR of the clpP, clpE, clpL and clpX genes in the probiotic strain Lactobacillus delbrueckii UFV H2b20 exposed to the conditions prevailing in the gastrointestinal tract (GIT). Phylogenetic trees reconstructed by Bayesian inference showed that the L. delbrueckii UFV H2b20 clpP, clpL and clpE genes and the ones from L. delbrueckii ATCC 11842 were grouped. The exposure of cells to MRS broth of pH 3.5 for 30 and 60 min resulted in an increased expression of the four genes. Exposure of the L. delbrueckii UFV H2b20 cells for 30 and 60 min to MRS broth containing 0.1% bile salts increased the expression of the clpP and clpE genes, while the expression level of the clpL and clpX genes increased only after 30 min of exposure. The involvement of the studied genes in the responses to acid stress and bile salts suggests a possible central role of these genes in the survival of L. delbrueckii UFV H2b20 during the passage through the GIT, a characteristic necessary for probiotic strains.

Carboxyl ester hydrolase from Penicillium expansum: cloning, characterization and overproduction by Penicillium griseoroseum.

AIMS: In this study, a gene that encodes a carboxylesterase (carb) in Penicillium expansum GF was cloned, sequenced and overexpressed by Penicillium griseoroseum PG63, and the enzyme was characterized. METHODS AND RESULTS: The recombinant strain, P. griseoroseum T55, obtained upon transformation using the plasmid pAN-52-1-carb, showed integration of the carb gene into at least two heterologous sites of the genome by Southern blotting. Furthermore, the recombinant strain T55 exhibited almost a fourfold increase in carboxylesterase activity compared with PG63 strain when both were cultured without inducers. Based on the secondary structure and multiple sequence alignments with carboxylesterases, cholinesterase and lipase, a three-dimensional model was obtained. The α/ß barrel topology, that is typical of esterases and lipases, was indicated for the CARB protein with Ser(213)-Glu(341)-His(456) as the putative catalytic triad. CARB preferentially hydrolysed acyl chains with eight carbon atoms, and its activity was optimal at a pH of 7·0 and a temperature of 25°C. CARB exhibited stability in alkaline pH, high activity under mesophilic conditions and stability in organic solvents. CONCLUSION: The CARB protein is potentially useful in bioremediation, food and chemical/pharmaceutical industries. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to report the development of a recombinant strain superproducing a Penicillium sp. carboxylesterase.

Genetic diversity analysis of isolates of the fungal bean pathogen Pseudocercospora griseola from central and southern Brazil.

Planting resistant varieties is the most effective control measure against the angular leaf spot of dry beans, a fungal disease caused by Pseudocercospora griseola. However, dry bean varieties with durable resistance are not easily obtained. Knowledge about the genetic variability of the pathogen population is key for the success of dry bean breeding programs aimed at developing resistant materials, but finding suitable operationally simple and genetically accurate markers is not an easy task. The aim of this study was to assess the suitability of the ISSR-PCR technique to quantify the genetic variability of P. griseola isolates. Total DNA of 27 P. griseola isolates from Goiás, Minas Gerais, Espírito Santo, and Paraná States was extracted and amplified using specific primers for ISSR. Using cluster analysis, 27 genotypes were identified. The ISSR-PCR technique was suitable for assessing intraspecific variability of P. griseola. The ISSR-PCR marker was found to be highly sensitive to genetic variation and can aid in elucidating the genetic structure of the population of this plant pathogen as a support tool for the dry bean breeding programs.

Improved pectinase production in Penicillium griseoroseum recombinant strains.

AIMS: To obtain recombinant strains of Penicillium griseoroseum that produce high levels of pectin lyase (PL) and polygalacturonase (PG) simultaneously. METHODS AND RESULTS: A strain with high production of PL was transformed with the plasmid pAN52pgg2, containing the gene encoding PG of P. griseoroseum, under control of the gpd promoter gene from Aspergillus nidulans. Southern blot analysis demonstrated that all strain had at least one copy of pAN52pgg2 integrated into the genome. The recombinant strain P. griseoroseum T20 produced levels of PL and PG that were 266- and 27-fold greater, respectively, than the wild-type strain. Furthermore, the extracellular protein profile of recombinant T20 showed two protein bands of c. 36 and 38 kDa, associated with PL and PG, respectively. CONCLUSIONS: This recombinant strain T20 produces PL and PG using carbon sources of low costs, and an enzyme preparation that is free of cellulolytic and proteolytic activities. SIGNIFICANCE AND IMPACT OF THE STUDY: PL and PG play an important role in the degradation of pectin. Owing to their use in the juice and wines industries, there is a growing interest in the inexpensive production of these enzymes. This work describes an efficient system of protein expression and secretion using the fungus P. griseoroseum.

Differential expression of plg genes from Penicillium griseoroseum: plg1 a pectinolytic gene is expressed in sucrose and yeast extract.

AIMS: To study the regulation of the plg1 and plg2 genes of Penicillium griseoroseum, in order to identify the industrial potential of their products in alternative carbon sources that are cheaper and widely available in Brazil. METHODS AND RESULTS: RT-PCR and Northern blot were used to investigate if plg1 and plg2 expression is under influence of catabolic repression, ambient pH and cAMP. Results demonstrated that the genes were differentially regulated depending on the carbon sources in the culture medium and pH. Sucrose, a noninducing carbon source of the pectinolytic system, was able to promote plg1 transcription but only when yeast extract was added into the culture medium. CONCLUSIONS: The plg genes are differentially expressed. The plg1 gene is more attractive for industrial use due to its expression in alternative carbon sources like sucrose and yeast extract. SIGNIFICANCE AND IMPACT OF THE STUDY: In recent years, industries have been trying to replace the toxic conventional treatments employed in these processes by more eco-friendly enzyme treatment. Alternative carbon sources will be tested with the aim to reduce the costs associated to pectin lyase production in Brazil.

Histology of the synovial tissue: value of semiquantitative analysis for the prediction of joint erosions in rheumatoid arthritis.

OBJECTIVE: Routine histologic techniques are still the main procedure in the study of the synovial biopsy. The relationship between the typical histological changes of rheumatoid synovium and clinical manifestations has not been studied in detail. METHODS: With the aim of determining whether a simple semiquantitative method of evaluating the changes in closed synovial biopsies was of clinical value in assessing both the diagnosis and prognosis of rheumatoid arthritis (RA) patients, we evaluated retrospectively 72 synovial biopsy specimens (26 RA patients, 30 patients with other inflammatory diseases and 16 osteoarthritis patients). Scores (0-10) were assigned to each biopsy specimen for each of 6 histologic features: synoviocyte hyperplasia; fibrosis in the subsynovial layer; proliferating blood vessels; perivascular infiltrates of lymphocytes; focal aggregates of lymphocytes; and diffuse infiltrates of lymphocytes. Scores were compared between the 3 groups and also between the RA subgroups with early and late disease; positive and negative rheumatoid factor; with and without joint erosions; and with and without systemic disease. RESULTS: Significant differences in the mean global score (mean of the 6 scores) were found both between RA and osteoarthritis and between other inflammatory diseases and osteoarthritis (p < 0.01). The mean global score for RA was higher than the mean global score obtained for the other inflammatory diseases, but the difference was not significant. We found a significantly higher mean global score in the RA patients with erosions in comparison to the RA patients without erosions, this difference being particularly evident for the lymphocyte perivascular infiltrate (p < 0.05). There were no significant differences between the other RA subgroups. CONCLUSION: In this study we have identified differences, using routine histologic techniques, between the rheumatoid synovial membrane of patients with and without erosions. Based on our present observations we suggest that the intensity of inflammatory histological features and, in particular, a high percentage of vessels with perivascular lymphocyte infiltrate might be of prognostic value in RA.

Transformation of Penicillium griseoroseum nitrate reductase mutant with the nia gene from Fusarium oxysporum.

A heterologous transformation system for Penicillium griseoroseum has been developed. This system is based on nia, the structural gene from Fusarium oxysporum encoding nitrate reductase. Penicillium griseoroseum niaD mutants have been selected from chlorate-resistant colonies. Among 24 chlorate-resistant colonies analyzed, 2 were confirmed to be niaD mutants. Transformation frequencies of 8 transformants/microgram of DNA were obtained. DNA hybridization analyses of five transformants showed distinct integration patterns of the plasmid and in all of them the integration occurred at tandem arrays. The transformation system established in this work will be useful for genetic studies of the pectinolytic complex genes from P. griseoroseum.

Facioscapulohumeral dystrophy with myositis associated with rheumatoid arthritis.

We report a case of facioscapulohumeral dystrophy with myositis, rheumatoid arthritis and serologic findings suggestive of autoimmune disease. To our present knowledge this is the first time this association has been observed.

[Osteoporosis in adult men]. / A osteoporose no homem adulto.

Osteoporosis in men, despite being a less important public health problem than osteoporosis in women, should not be neglected as it has many deleterious effects as well as social and economic costs. Finding the cause of osteoporosis is more complex in men than in women, and prevention should be based on an early evaluation of the various possible risk factors and on taking up measures that tend to maximise the peak bone mass. Further studies need to be carried out in order to establish the differences and similarities that characterise this phenomenon when considering different sexes.

The sequence and binding specificity of UaY, the specific regulator of the purine utilization pathway in Aspergillus nidulans, suggest an evolutionary relationship with the PPR1 protein of Saccharomyces cerevisiae.

The uaY gene codes for a transcriptional activator mediating the induction of a number of unlinked genes involved in purine utilization in Aspergillus nidulans. Here we present the complete genomic and cDNA nucleotide sequence of this gene. The gene contains two introns. The derived polypeptide of 1060 residues contains a typical zinc binuclear cluster domain and shows a number of similarities with the PPR1 regulatory gene of Saccharomyces cerevisiae. These similarities are most striking in the putative linker and dimerization regions following the zinc cluster. Gel-shift and DNase I footprinting experiments have been carried out for three genes subject to UaY-mediated induction. The binding sequence is 5'-TCGG-6X-CCGA, which is identical to the proposed PPR1 binding sites. Nevertheless, the identity of the base immediately 3' of the 5'-TCGG sequence clearly affects the affinity of the site. The site upstream of the uapA gene has been shown to be active in vivo. Binding to this site has been analysed by a number of interference techniques. There is an interesting chemical similarity between the co-inducer of the purine utilization pathway (uric acid) and that of the genes of the pyrimidine biosynthetic pathway (dihydroorotic acid) and we show that dihydroorotic acid can act as a poor inducer of at least one activity under UaY control. These striking similarities, together with the unique pattern of regulation of pyrimidine biosynthesis in S. cerevisiae, suggest that PPR1 evolved through recruitment into the pyrimidine biosynthetic pathway of an ancestral gene related to uaY.

Transformation of Aspergillus nidulans by microprojectile bombardment on intact conidia.

This paper describes transformation of intact conidia of Aspergillus nidulans, auxotrophic for arginine, by using the biolistic process. The plasmid employed was pFB39, carrying the argB gene. The transformation frequency obtained was 81 transformants/microgram of DNA. Classical genetics and molecular analysis were conducted to analyse transformants and to determine in which chromosome integration took place.

[Systemic lupus erythematosus. Current treatment]. / Lupus eritematoso sistémico. Terapêutica actual.

The treatment of the systemic lupus erythematosus (S.L.E.) has been modified significantly during the last years, contributing decisively to a better prognosis, and an increase in the life expectancy of patients. In this issue of the Acta Médica Portuguesa, we divulge our personal experience; the most recent advances in the treatment of this disease and, also, some future therapeutic perspectives.

[Ischemic lesion of the CNS in patients with systemic lupus erythematosus]. / Lesão isquémica do SNC em doentes com lupus eritematoso sistémico.

UNLABELLED: In a review of 240 patients with Systemic Lupus Erythematosus we found 12 (5%) with cerebral infarctions. The average patient age was 38 years and no relation with the duration of lupus was found. The most common neurologic manifestations were hemiparesis (67%), language disturbances (25%) and ataxia (25%). Clinical signs of diffuse involvement of Central Nervous System (CNS) were also present in 1/3 of the patients. In 5 cases (42%) no signs of lupus activity were found. In the remaining 7 (58%), where other manifestations occurred, all presented cutaneous vasculitis. Known risk factors for atherosclerotic vascular disease were common and 58% of the patients had at least one risk factor. IN CONCLUSION: 1. Recent onset cutaneous vasculitis should alert the physician to the possibility of CNS ischemic lesion and 2. The presence of risk factors for cerebrovascular disease (steroid therapy, hypertension and hypercholesterolemia) is frequent and may be controlled.

Double-blind comparison of the efficacy of diclofenac/misoprostol and diclofenac in the treatment of rheumatoid arthritis.

A double-blind, randomised, parallel-group study was conducted in eight countries to compare the efficacy of a fixed combination of diclofenac sodium (50 mg) and misoprostol (200 mcg) with a fixed combination of diclofenac sodium (50 mg) and placebo in treating the signs and symptoms of rheumatoid arthritis (RA). A total of 346 patients with RA who had been stabilised on diclofenac for at least 30 days were randomly assigned to receive either diclofenac/misoprostol BID or TID (n = 177) or diclofenac/placebo BID or TID (n = 169) for 12 weeks. Primary analyses of efficacy, made upon admission and at 4-week intervals, consisted of physician's global assessment of the arthritic condition, patient's global assessment of the arthritic condition, patient's global assessment of joint tenderness/pain, and physician's assessment of joint swelling. In this study, the fixed combination tablet of diclofenac sodium 50 mg/misoprostol 200 mcg administered BID or TID demonstrated no statistically significant difference in efficacy in the treatment of the signs and symptoms of RA compared with diclofenac sodium 50 mg/placebo administered BID or TID.