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Olivares J, González A, Andrade D, Vásquez M. Vertical Immobilization Method for Time-Lapse Microscopy Analysis in Filamentous Cyanobacteria. J Vis Exp 2023. [PMID: 37811947 DOI: 10.3791/65612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023] Open
Abstract
A main event in bacterial cell division is the septation process, where the protein FtsZ is the key element. FtsZ polymerizes forming a ring-like structure (Z-ring) in the middle of the cell that serves as a scaffold for other division proteins. Super-resolution microscopy in bacterial models Escherichia coli and Bacillus subtilis showed that the Z-ring is discontinuous, while live cell imaging studies demonstrated that FtsZ moves along the ring by a mechanism known as treadmilling. To study the dynamics of FtsZ in vivo, a special cell placement in a vertical position is necessary for imaging the complete structure of the ring in the XY plane. In the case of FtsZ imaging in multicellular cyanobacteria, such as Anabaena sp. PCC7120, maintaining the filaments in a vertical position is challenging because of the size of the cells and the filaments' length. In this article, we describe a method that allows the vertical immobilization of Anabaena sp. PCC 7120 filaments using low melting point agarose and syringes, to record the Z-ring in a mutant that expresses a FtsZ-sfGFP fusion protein. This method is a rapid and inexpensive way to register protein dynamics at the division site using confocal microscopy.
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Affiliation(s)
- Jorge Olivares
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile
| | - Annia González
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile
| | - Derly Andrade
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile; Laboratorio de Ciencias Omicas, Facultad de Ciencias de la Salud, Universidad Espíritu Santo
| | - Mónica Vásquez
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile;
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Uribe-San-Martín R, Ciampi E, Cruz J, Vásquez M, Cárcamo C. Refractory epilepsy associated with anti-ribosomal P antibodies successfully treated with topiramate. J Neuroimmunol 2020; 340:577144. [DOI: 10.1016/j.jneuroim.2020.577144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/03/2020] [Accepted: 01/06/2020] [Indexed: 10/25/2022]
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Aladrén BS, González-Lama Y, García-Alvarado M, Sierra M, Barrio JA, Vicente VP, Hernández L, Velayos B, Garcia LA, Relea L, Suarez P, Atienza R, Vásquez M, Fernández-Salazar L, Muñoz F. Even non-experts identify non-dysplastic lesions in inflammatory bowel disease via chromoendoscopy: results of a screening program in real-life. Endosc Int Open 2019; 7:E743-E750. [PMID: 31157291 PMCID: PMC6524993 DOI: 10.1055/a-0839-4514] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 01/02/2019] [Indexed: 02/08/2023] Open
Abstract
Background and study aims Chromoendoscopy with targeted biopsy is the technique of choice for colorectal cancer screening in longstanding inflammatory bowel disease. We aimed to analyze results of a chromoendoscopy screening program and to assess the possibility of identifying low-risk dysplastic lesions by their endoscopic appearance in order to avoid histological analysis. Materials and methods We retrospectively reviewed chromoendoscopies performed between February 2011 and June 2017 in seven Spanish hospitals in a standardized fashion. We analyzed the findings and the diagnostic yield of the Kudo pit pattern for predicting dysplasia. Results A total of 709 chromoendoscopies (569 patients) were reviewed. Median duration of disease was 16.7 years (SD 8.1); 80.4 % had ulcerative colitis. A total of 2025 lesions (3.56 lesions per patient) were found; two hundred and thirty-two lesions were neoplastic (11.5 %) (223 were LGD (96.1 %), eight were HGD (3.4 %), and one was colorectal cancer (0.5 %). The correlation between dysplasia and Kudo pit patterns predictors of dysplasia (≥ III) was low, with an area under the curve of 0.649. Kudo I and II lesions were correctly identified with a high negative predictive value (92 %), even by non-experts. Endoscopic activity, Paris 0-Is classification, and right colon localization were risk factors for dysplasia detection, while rectum or sigmoid localization were protective against dysplasia. Conclusions Chromoendoscopy in the real-life setting detected 11 % of dysplastic lesions with a low correlation with Kudo pit pattern. A high negative predictive value would prevent Kudo I and, probably, Kudo II biopsies in the left colon, reducing procedure time and avoiding complications.
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Affiliation(s)
| | | | | | | | | | | | - Luis Hernández
- Hospital Santos Reyes. Aranda de Duero, Castilla y León, Spain
| | - Benito Velayos
- Hospital Clínico Universitario de Valladolid, Valladolid, Spain
| | | | - Lucia Relea
- Hospital Universitario Puerta de Hierro, Madrid, Spain
| | | | - Ramón Atienza
- Hospital Universitario Río Hortega de Valladolid, Valladolid, Spain
| | - Mónica Vásquez
- Hospital Santos Reyes. Aranda de Duero, Castilla y León, Spain
| | | | - Fernando Muñoz
- Hospital Universitario de Salamanca, Castilla y León, Spain
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Osorio H, Jara C, Fuenzalida K, Rey-Jurado E, Vásquez M. High-efficiency nuclear transformation of the microalgae Nannochloropsis oceanica using Tn5 Transposome for the generation of altered lipid accumulation phenotypes. Biotechnol Biofuels 2019; 12:134. [PMID: 31168324 PMCID: PMC6545213 DOI: 10.1186/s13068-019-1475-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/23/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND One of the major problems in the production of lipids for biotechnological purposes using microalgae is maintaining a high productivity of these molecules without reducing cellular biomass. High production rates are usually obtained by cultivating microalgae under different stress conditions. However, many of these changes usually result in lower biomass productivity. Therefore, the optimization of the culture conditions and genetic modification techniques in these organisms is needed to generate robust new strains for profitable economic use. RESULTS In this work, we describe a new strategy for random mutation of genomic DNA in the microalgae Nannochloropsis oceanica by insertion of a Transposome complex Tn5. This complex contains an antibiotic-resistance cassette commanded by a CMV viral promoter that allows high efficiency of transformation and the generation of mutants. This strategy, complemented with a large-scale identification and selection system for mutants, such as flow cytometry with cell selection, allowed us to obtain clonal cultures of mutants with altered phenotypes in the accumulation of intracellular lipids. The characterization of some of these mutants uncovered new genes that are likely to be involved in the regulation of lipid synthesis, revealing possible cellular responses that influence the intracellular homeostasis of lipids. CONCLUSION The strategies proposed here are easy to implement in different types of microalgae and provide a promising scenario for improving biotechnological applications.
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Affiliation(s)
- Hector Osorio
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Carol Jara
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Karen Fuenzalida
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Emma Rey-Jurado
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Mónica Vásquez
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
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Urrejola C, Alcorta J, Salas L, Vásquez M, Polz MF, Vicuña R, Díez B. Genomic Features for Desiccation Tolerance and Sugar Biosynthesis in the Extremophile Gloeocapsopsis sp. UTEX B3054. Front Microbiol 2019; 10:950. [PMID: 31134010 PMCID: PMC6513891 DOI: 10.3389/fmicb.2019.00950] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 04/15/2019] [Indexed: 01/06/2023] Open
Abstract
For tolerating extreme desiccation, cyanobacteria are known to produce both compatible solutes at intracellular level and a copious amount of exopolysaccharides as a protective coat. However, these molecules make cyanobacterial cells refractory to a broad spectrum of cell disruption methods, hindering genome sequencing, and molecular studies. In fact, few genomes are already available from cyanobacteria from extremely desiccated environments such as deserts. In this work, we report the 5.4 Mbp draft genome (with 100% of completeness in 105 contigs) of Gloeocapsopsis sp. UTEX B3054 (subsection I; Order Chroococcales), a cultivable sugar-rich and hardly breakable hypolithic cyanobacterium from the Atacama Desert. Our in silico analyses focused on genomic features related to sugar-biosynthesis and adaptation to dryness. Among other findings, screening of Gloeocapsopsis genome revealed a unique genetic potential related to the biosynthesis and regulation of compatible solutes and polysaccharides. For instance, our findings showed for the first time a novel genomic arrangement exclusive of Chroococcaceae cyanobacteria associated with the recycling of trehalose, a compatible solute involved in desiccation tolerance. Additionally, we performed a comparative genome survey and analyses to entirely predict the highly diverse pool of glycosyltransferases enzymes, key players in polysaccharide biosynthesis and the formation of a protective coat to dryness. We expect that this work will set the fundamental genomic framework for further research on microbial tolerance to desiccation and to a wide range of other extreme environmental conditions. The study of microorganisms like Gloeocapsopsis sp. UTEX B3054 will contribute to expand our limited understanding regarding water optimization and molecular mechanisms allowing extremophiles to thrive in xeric environments such as the Atacama Desert.
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Affiliation(s)
- Catalina Urrejola
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jaime Alcorta
- Laboratorio de Ecología Microbiana de Sistemas Extremos, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Loreto Salas
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mónica Vásquez
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Martin F Polz
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Rafael Vicuña
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Beatriz Díez
- Laboratorio de Ecología Microbiana de Sistemas Extremos, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
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Fuentes-Valdés JJ, Soto-Liebe K, Pérez-Pantoja D, Tamames J, Belmar L, Pedrós-Alió C, Garrido D, Vásquez M. Draft genome sequences of Cylindrospermopsis raciborskii strains CS-508 and MVCC14, isolated from freshwater bloom events in Australia and Uruguay. Stand Genomic Sci 2018; 13:26. [PMID: 30344889 PMCID: PMC6186047 DOI: 10.1186/s40793-018-0323-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 09/24/2018] [Indexed: 12/28/2022] Open
Abstract
Members of the genus Cylindrospermopsis represent an important environmental and health concern. Strains CS-508 and MVCC14 of C. raciborskii were isolated from freshwater reservoirs located in Australia and Uruguay, respectively. While CS-508 has been reported as non-toxic, MVCC14 is a saxitoxin (STX) producer. We annotated the draft genomes of these C. raciborskii strains using the assembly of reads obtained from Illumina MiSeq sequencing. The final assemblies resulted in genome sizes close to 3.6 Mbp for both strains and included 3202 ORFs for CS-508 (in 163 contigs) and 3560 ORFs for MVCC14 (in 99 contigs). Finally, both the average nucleotide identity (ANI) and the similarity of gene content indicate that these two genomes should be considered as strains of the C. raciborskii species.
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Affiliation(s)
- Juan J Fuentes-Valdés
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, 8331150 Santiago, Chile
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, 7820436 Santiago, Chile
| | - Katia Soto-Liebe
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, 8331150 Santiago, Chile
| | - Danilo Pérez-Pantoja
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación, Universidad Tecnológica Metropolitana, 8940577 Santiago, Chile
| | - Javier Tamames
- Systems Biology Program, CNB, CSIC, Calle Darwin 3, 28049 Madrid, Spain
| | - Lucy Belmar
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, 8331150 Santiago, Chile
| | | | - Daniel Garrido
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, 7820436 Santiago, Chile
| | - Mónica Vásquez
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, 8331150 Santiago, Chile
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Alcamán-Arias ME, Pedrós-Alió C, Tamames J, Fernández C, Pérez-Pantoja D, Vásquez M, Díez B. Diurnal Changes in Active Carbon and Nitrogen Pathways Along the Temperature Gradient in Porcelana Hot Spring Microbial Mat. Front Microbiol 2018; 9:2353. [PMID: 30333812 PMCID: PMC6176055 DOI: 10.3389/fmicb.2018.02353] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 09/13/2018] [Indexed: 01/14/2023] Open
Abstract
Composition, carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon (H13CO3) and nitrogen (15NH4Cl and K15NO3) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58°C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66°C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48°C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin-Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48°C. At 66°C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.
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Affiliation(s)
- María E. Alcamán-Arias
- Department of Oceanography, Universidad de Concepción, Concepción, Chile
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center for Climate and Resilience Research, Universidad de Chile, Santiago, Chile
| | - Carlos Pedrós-Alió
- Programa de Biología de Sistemas, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Javier Tamames
- Programa de Biología de Sistemas, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Camila Fernández
- Department of Oceanography, Universidad de Concepción, Concepción, Chile
- Laboratoire d’Océanographie Microbienne, Observatoire Océanologique, Sorbonne Universités, Université Pierre-et-Marie-Curie, Centre National de la Recherche Scientifique, Banyuls-sur-Mer, France
- Fondap IDEAL, Universidad Austral de Chile, Valdivia, Chile
| | - Danilo Pérez-Pantoja
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación, Universidad Tecnológica Metropolitana, Santiago, Chile
| | - Mónica Vásquez
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Beatriz Díez
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center for Climate and Resilience Research, Universidad de Chile, Santiago, Chile
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Ciampi E, Uribe-San-Martin R, Vásquez M, Ruiz-Tagle A, Labbe T, Cruz JP, Lillo P, Slachevsky A, Reyes D, Reyes A, Cárcamo-Rodríguez C. Relationship between Social Cognition and traditional cognitive impairment in Progressive Multiple Sclerosis and possible implicated neuroanatomical regions. Mult Scler Relat Disord 2018; 20:122-128. [PMID: 29414284 DOI: 10.1016/j.msard.2018.01.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 11/16/2017] [Accepted: 01/16/2018] [Indexed: 01/12/2023]
Abstract
BACKGROUND Cognitive impairment is a relevant contributor of the medical and social burden in Progressive MS. Social Cognition, the neurocognitive processes underlying social interaction, has been explored mainly in European and North American cohorts, influencing social aspects of quality of life (QOL) of early MS patients and families. Few studies have studied Social Cognition in Progressive MS and the literature on its neuroanatomical bases or brain atrophy measurements is still scarce. OBJECTIVES To explore the relationship between Social Cognition performance and its correlations with traditional cognitive domains, brain atrophy and QOL in primary and secondary Progressive MS patients. METHODS Cross-sectional analysis including: mini-Social-Cognition-and-Emotional-Assessment (mini-SEA), neuropsychological battery, disability, depression, fatigue, QOL, and brain volume. RESULTS Forty-three MS patients, 23 primary and 20 secondary Progressive, 65% women, mean age and disease duration of 57.2 and 15.7 years, respectively, with high levels of disability (median EDSS 6.0) and a widespread impairment in traditional domains (mostly episodic verbal/visual and working memories) were assessed. The Mini-SEA score was correlated with executive functions (cognitive shifts Rho:0.55; p = 0.001) analyzing the whole group, and with visual episodic memory (Rho:0.58, p = 0.009) in the primary Progressive MS group. Mini-SEA score was also correlated with total normalized grey matter volume (Rho:0.48; p = 0.004). Particularly, atrophy within bilateral cortical regions of orbitofrontal, insula and cerebellum, and right regions of fusiform gyrus and precuneus were significantly associated with higher Social Cognition impairment. In this cohort, QOL was not correlated with Social Cognition, but with EDSS, fatigue and depression. CONCLUSIONS In Progressive MS, Social Cognition is directly correlated with traditional cognitive domains such as executive function and episodic memory. It is also associated with global grey matter atrophy and regional atrophy within associative visual and executive cortical areas, but no correlations with QOL were found in this cohort. These findings may contribute to the understanding of the pathological bases behind Social Cognition in Progressive MS.
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Affiliation(s)
- E Ciampi
- Neurology Department, Pontifical Catholic University of Chile, Santiago, Chile; Neurology, Hospital Sotero del Rio, Santiago, Chile.
| | - R Uribe-San-Martin
- Neurology Department, Pontifical Catholic University of Chile, Santiago, Chile; Neurology, Hospital Sotero del Rio, Santiago, Chile
| | - M Vásquez
- Neurology Department, Pontifical Catholic University of Chile, Santiago, Chile
| | - A Ruiz-Tagle
- Centre for Advanced Research in Education, University of Chile, Santiago, Chile
| | - T Labbe
- Pontifical Catholic University of Chile, Santiago, Chile
| | - J P Cruz
- Radiology Department, Pontifical Catholic University of Chile, Santiago, Chile
| | - P Lillo
- Neurology Department South, Faculty of Medicine, University of Chile, Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - A Slachevsky
- Centre for Advanced Research in Education, University of Chile, Santiago, Chile; Gerosciences Center for Brain Health and Metabolism, Santiago, Chile; Physiopathology Department, ICBM and East Neuroscience Department Faculty of Medicine University of Chile, Santiago, Chile; Cognitive Neurology and Dementia, Neurology Department, Salvador Hospital, Santiago, Chile; Neurology Service, Medicine Department, Alemana Clinic and Universidad del Desarrollo, Santiago, Chile
| | - D Reyes
- Faculty of Medicine, Pontifical Catholic University of Chile, Santiago, Chile
| | - A Reyes
- Neurology Department, Pontifical Catholic University of Chile, Santiago, Chile
| | - C Cárcamo-Rodríguez
- Neurology Department, Pontifical Catholic University of Chile, Santiago, Chile
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10
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Santibáñez M, Saavedra R, Vásquez M, Malano F, Pérez P, Valente M, Figueroa R. Optimization of the sensitivity/doses relationship for a bench-top EDXRF system used for in vivo quantification of gold nanoparticles. Appl Radiat Isot 2017; 129:19-27. [DOI: 10.1016/j.apradiso.2017.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 08/02/2017] [Accepted: 08/03/2017] [Indexed: 10/19/2022]
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Trigo C, Andrade D, Vásquez M. Protein Localization in the Cyanobacterium Anabaena sp. PCC7120 Using Immunofluorescence Labeling. Bio Protoc 2017; 7:e2318. [PMID: 34541082 PMCID: PMC8410318 DOI: 10.21769/bioprotoc.2318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/07/2017] [Accepted: 05/06/2017] [Indexed: 11/02/2022] Open
Abstract
Techniques such as immunoflorescence are widely used to determine subcellular distribution of proteins. Here we report on a method to immunolocalize proteins in Anabaena sp. PCC7120 with fluorophore-conjugated antibodies by fluorescence microscopy. This method improves the permeabilization of cyanobacterial cells and minimizes the background fluorescence for non-specific attachments. In this protocol, rabbit antibodies were raised against the synthetic peptide of CyDiv protein ( Mandakovic et al., 2016 ). The secondary antibody conjugated to the fluorophore Alexa488 was used due to its different emission range in comparison to the autofluorescence of the cyanobacterium.
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Affiliation(s)
- Carla Trigo
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Derly Andrade
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mónica Vásquez
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
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Ramos H, Linares P, Badia E, Martín I, Gómez J, Almohalla C, Jorquera F, Calvo S, García I, Conde P, Álvarez B, Karpman G, Lorenzo S, Gozalo V, Vásquez M, Joao D, de Benito M, Ruiz L, Jiménez F, Sáez-Royuela F, Asociación Castellano y Leonesa de Hepatología (ACyLHE). Interferon-free treatments in patients with hepatitis C genotype 1-4 infections in a real-world setting. World J Gastrointest Pharmacol Ther 2017; 8:137-146. [PMID: 28533924 PMCID: PMC5421113 DOI: 10.4292/wjgpt.v8.i2.137] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/14/2017] [Accepted: 02/13/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To investigated the real-world effectiveness and safety of various regimens of interferon-free treatments in patients infected with hepatitis C virus (HCV).
METHODS We performed an observational study to analyze different antiviral treatments administered to 462 HCV-infected patients, of which 56.7% had liver cirrhosis. HCV RNA after 4 wk of treatment and at 12 wk after treatment sustained virologic response (SVR) as well as serious adverse events (SAEs) was analyzed first for the whole cohort and then separately in patients who met or did not meet the inclusion criteria of a clinical trial (CT-met and CT-unmet, respectively).
RESULTS The most frequently prescribed treatment was simeprevir/sofosbuvir (36.4%), followed by sofosbuvir/ledipasvir (24.9%) and ombitasvir/paritaprevir/ritonavir (r)/dasabuvir (19.9%). Ribavirin (RBV) was administered in 198 patients (42.9%). SVRs occurred in 437/462 patients (94.6%). The SVRs ranged between 93.3% and 100% for genotypes 1-4. SVRs were achieved in 96.2% patients in the CT-met group vs 91.9% patients in the CT-unmet group (P = 0.049). Undetectable HCV RNA at week 4 occurred in 72.9% of the patients. In the univariate analysis, the factors associated with SVRs were lower liver stiffness, absence of cirrhosis, higher platelet count, higher albumin levels, no RBV dose reduction, undetectable HCV RNA at week 4 and CT-met group. In the multivariate analysis, only albumin was an independent predictor of treatment failure (P = 0.04). Eleven patients (2.4%) developed SAEs; 5.2% and 0.7% of the patients in the CT-unmet and CT-met groups, respectively (P = 0.003).
CONCLUSION A high proportion of patients with HCV infection achieved SVRs. For patients who did not meet the CT criteria, treatment regimens must be optimized.
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Alcamán ME, Alcorta J, Bergman B, Vásquez M, Polz M, Díez B. Physiological and gene expression responses to nitrogen regimes and temperatures in Mastigocladus sp. strain CHP1, a predominant thermotolerant cyanobacterium of hot springs. Syst Appl Microbiol 2016; 40:102-113. [PMID: 28081924 DOI: 10.1016/j.syapm.2016.11.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 11/16/2016] [Accepted: 11/21/2016] [Indexed: 11/26/2022]
Abstract
Cyanobacteria are widely distributed primary producers with significant implications for the global biogeochemical cycles of carbon and nitrogen. Diazotrophic cyanobacteria of subsection V (Order Stigonematales) are particularly ubiquitous in photoautotrophic microbial mats of hot springs. The Stigonematal cyanobacterium strain CHP1 isolated from the Porcelana hot spring (Chile) was one of the major contributors of the new nitrogen through nitrogen fixation. Further morphological and genetic characterization verified that the strain CHP1 belongs to Stigonematales, and it formed a separate clade together with other thermophiles of the genera Fischerella and Mastigocladus. Strain CHP1 fixed maximum N2 in the light, independent of the temperature range. At 50°C nifH gene transcripts showed high expression during the light period, whereas the nifH gene expression at 45°C was arrhythmic. The strain displayed a high affinity for nitrate and a low tolerance for high ammonium concentrations, whereas the narB and glnA genes showed higher expression in light and at the beginning of the dark phase. It is proposed that Mastigocladus sp. strain CHP1 would represent a good model for the study of subsection V thermophilic cyanobacteria, and for understanding the adaptations of these photoautotrophic organisms inhabiting microbial mats in hot springs globally.
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Affiliation(s)
- M Estrella Alcamán
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Libertador Bernardo O'Higgins 340, Casilla 144-D, C.P. 651 3677 Santiago, Chile.
| | - Jaime Alcorta
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Libertador Bernardo O'Higgins 340, Casilla 144-D, C.P. 651 3677 Santiago, Chile
| | - Birgitta Bergman
- Department of Ecology, Environment and Plant Sciences and Science for Life Laboratory, Stockholm University, S-10691 Stockholm, Sweden
| | - Mónica Vásquez
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Libertador Bernardo O'Higgins 340, Casilla 144-D, C.P. 651 3677 Santiago, Chile
| | - Martin Polz
- Environmental Science and Engineering, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology (MIT), 15 Vassar Street, Cambridge, MA 02139, USA
| | - Beatriz Díez
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Libertador Bernardo O'Higgins 340, Casilla 144-D, C.P. 651 3677 Santiago, Chile; Center for Climate and Resilience Research (CR)2, Chile.
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Elgueta D, Aymerich MS, Contreras F, Montoya A, Celorrio M, Rojo-Bustamante E, Riquelme E, González H, Vásquez M, Franco R, Pacheco R. Pharmacologic antagonism of dopamine receptor D3 attenuates neurodegeneration and motor impairment in a mouse model of Parkinson's disease. Neuropharmacology 2016; 113:110-123. [PMID: 27693549 DOI: 10.1016/j.neuropharm.2016.09.028] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 08/25/2016] [Accepted: 09/27/2016] [Indexed: 12/16/2022]
Abstract
Neuroinflammation involves the activation of glial cells, which is associated to the progression of neurodegeneration in Parkinson's disease. Recently, we and other researchers demonstrated that dopamine receptor D3 (D3R)-deficient mice are completely refractory to neuroinflammation and consequent neurodegeneration associated to the acute intoxication with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In this study we examined the therapeutic potential and underlying mechanism of a D3R-selective antagonist, PG01037, in mice intoxicated with a chronic regime of administration of MPTP and probenecid (MPTPp). Biodistribution analysis indicated that intraperitoneally administered PG01037 crosses the blood-brain barrier and reaches the highest concentration in the brain 40 min after the injection. Furthermore, the drug was preferentially distributed to the brain in comparison to the plasma. Treatment of MPTPp-intoxicated mice with PG01037 (30 mg/kg, administrated twice a week for five weeks) attenuated the loss of dopaminergic neurons in the substantia nigra pars compacta, as evaluated by stereological analysis, and the loss of striatal dopaminergic terminals, as determined by densitometric analyses of tyrosine hydroxylase and dopamine transporter immunoreactivities. Accordingly, the treatment resulted in significant improvement of motor performance of injured animals. Interestingly, the therapeutic dose of PG01037 exacerbated astrogliosis and resulted in increased ramification density of microglial cells in the striatum of MPTPp-intoxicated mice. Further analyses suggested that D3R expressed in astrocytes favours a beneficial astrogliosis with anti-inflammatory consequences on microglia. Our findings indicate that D3R-antagonism exerts a therapeutic effect in parkinsonian animals by reducing the loss of dopaminergic neurons in the nigrostriatal pathway, alleviating motor impairments and modifying the pro-inflammatory phenotype of glial cells.
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Affiliation(s)
- Daniela Elgueta
- Fundación Ciencia & Vida, Ñuñoa, Santiago 7780272, Chile; Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago 8370146, Chile
| | - María S Aymerich
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona 31008, Spain; Department of Biochemistry and Genetics, School of Science, University of Navarra, Pamplona 31008, Spain; IdiSNA, Navarra Institute for Health Research, Pamplona, 31008, Spain
| | | | - Andro Montoya
- Fundación Ciencia & Vida, Ñuñoa, Santiago 7780272, Chile
| | - Marta Celorrio
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona 31008, Spain
| | - Estefanía Rojo-Bustamante
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona 31008, Spain; Department of Biochemistry and Genetics, School of Science, University of Navarra, Pamplona 31008, Spain
| | | | - Hugo González
- Fundación Ciencia & Vida, Ñuñoa, Santiago 7780272, Chile
| | - Mónica Vásquez
- Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, Chile
| | - Rafael Franco
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Barcelona 08028, Spain; CIBERNED. Centro de Investigación en Red. Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, 28049, Madrid, Spain
| | - Rodrigo Pacheco
- Fundación Ciencia & Vida, Ñuñoa, Santiago 7780272, Chile; Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago 8370146, Chile.
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Hallam SJ, Vásquez M. Editorial overview: Remapping the body of the world: Exploring interactions at the interface of microbial ecology, biological engineering and information science. Curr Opin Microbiol 2016; 31:v-vii. [PMID: 27199093 DOI: 10.1016/j.mib.2016.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Steven J Hallam
- University of British Columbia, Department of Microbiology & Immunology, Life Sciences Institute, 2552-2350 Health Sciences Mall, Vancouver, BC, Canada V6 T 1Z3. http://hallam.microbiology.ubc.ca/
| | - Mónica Vásquez
- Pontificia Universidad Católica de Chile, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Santiago 8331150, Chile. http://www.ecomicrolab.cl/
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16
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Santibáñez M, Vásquez M, Figueroa R, Valente M. Evaluation of EDXRF configurations to improve the limit of detection and exposure for in vivo quantification of gadolinium in tumor tissue. Radiat Phys Chem Oxf Engl 1993 2016. [DOI: 10.1016/j.radphyschem.2016.01.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Mandakovic D, Trigo C, Andrade D, Riquelme B, Gómez-Lillo G, Soto-Liebe K, Díez B, Vásquez M. CyDiv, a Conserved and Novel Filamentous Cyanobacterial Cell Division Protein Involved in Septum Localization. Front Microbiol 2016; 7:94. [PMID: 26903973 PMCID: PMC4748335 DOI: 10.3389/fmicb.2016.00094] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/18/2016] [Indexed: 11/13/2022] Open
Abstract
Cell division in bacteria has been studied mostly in Escherichia coli and Bacillus subtilis, model organisms for Gram-negative and Gram-positive bacteria, respectively. However, cell division in filamentous cyanobacteria is poorly understood. Here, we identified a novel protein, named CyDiv (Cyanobacterial Division), encoded by the all2320 gene in Anabaena sp. PCC 7120. We show that CyDiv plays a key role during cell division. CyDiv has been previously described only as an exclusive and conserved hypothetical protein in filamentous cyanobacteria. Using polyclonal antibodies against CyDiv, we showed that it localizes at different positions depending on cell division timing: poles, septum, in both daughter cells, but also in only one of the daughter cells. The partial deletion of CyDiv gene generates partial defects in cell division, including severe membrane instability and anomalous septum localization during late division. The inability to complete knock out CyDiv strains suggests that it is an essential gene. In silico structural protein analyses and our experimental results suggest that CyDiv is an FtsB/DivIC-like protein, and could therefore, be part of an essential late divisome complex in Anabaena sp. PCC 7120.
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Affiliation(s)
- Dinka Mandakovic
- Fondap Center for Genome Regulation, Universidad de ChileSantiago, Chile; Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Carla Trigo
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Derly Andrade
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Brenda Riquelme
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Gabriela Gómez-Lillo
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Katia Soto-Liebe
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Beatriz Díez
- Laboratorio de Ecología Microbiana de Sistemas Extremos, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Mónica Vásquez
- Laboratorio de Ecología Microbiana y Toxicología Ambiental, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile Santiago, Chile
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Vásquez M, Uslar W, Farías H, Juri C. Neuropsychological assessment in a Chilean cohort of patients with Parkinson's disease. J Neurol Sci 2015. [DOI: 10.1016/j.jns.2015.08.208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Plominsky ÁM, Delherbe N, Mandakovic D, Riquelme B, González K, Bergman B, Mariscal V, Vásquez M. Intercellular transfer along the trichomes of the invasive terminal heterocyst forming cyanobacterium Cylindrospermopsis raciborskii CS-505. FEMS Microbiol Lett 2014; 362:fnu009. [DOI: 10.1093/femsle/fnu009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Stucken K, John U, Cembella A, Soto-Liebe K, Vásquez M. Impact of nitrogen sources on gene expression and toxin production in the diazotroph Cylindrospermopsis raciborskii CS-505 and non-diazotroph Raphidiopsis brookii D9. Toxins (Basel) 2014; 6:1896-915. [PMID: 24956074 PMCID: PMC4073136 DOI: 10.3390/toxins6061896] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 05/31/2014] [Accepted: 06/09/2014] [Indexed: 11/16/2022] Open
Abstract
Different environmental nitrogen sources play selective roles in the development of cyanobacterial blooms and noxious effects are often exacerbated when toxic cyanobacteria are dominant. Cylindrospermopsis raciborskii CS-505 (heterocystous, nitrogen fixing) and Raphidiopsis brookii D9 (non-N2 fixing) produce the nitrogenous toxins cylindrospermopsin (CYN) and paralytic shellfish toxins (PSTs), respectively. These toxin groups are biosynthesized constitutively by two independent putative gene clusters, whose flanking genes are target for nitrogen (N) regulation. It is not yet known how or if toxin biosynthetic genes are regulated, particularly by N-source dependency. Here we show that binding boxes for NtcA, the master regulator of N metabolism, are located within both gene clusters as potential regulators of toxin biosynthesis. Quantification of intra- and extracellular toxin content in cultures at early stages of growth under nitrate, ammonium, urea and N-free media showed that N-sources influence neither CYN nor PST production. However, CYN and PST profiles were altered under N-free medium resulting in a decrease in the predicted precursor toxins (doCYN and STX, respectively). Reduced STX amounts were also observed under growth in ammonium. Quantification of toxin biosynthesis and transport gene transcripts revealed a constitutive transcription under all tested N-sources. Our data support the hypothesis that PSTs and CYN are constitutive metabolites whose biosynthesis is correlated to cyanobacterial growth rather than directly to specific environmental conditions. Overall, the constant biosynthesis of toxins and expression of the putative toxin-biosynthesis genes supports the usage of qPCR probes in water quality monitoring of toxic cyanobacteria.
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Affiliation(s)
- Karina Stucken
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.
| | - Uwe John
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.
| | - Allan Cembella
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.
| | - Katia Soto-Liebe
- Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile.
| | - Mónica Vásquez
- Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile.
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Adem E, Burillo G, del Castillo L, Vásquez M, Avalos-Borja M, Marcos-Fernández A. Polyamide-6: The effects on mechanical and physicochemical properties by electron beam irradiation at different temperatures. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2013.11.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Leiva E, Mujica V, Orrego R, Wehinger S, Soto A, Icaza G, Vásquez M, Díaz L, Andrews M, Arredondo M. Subjects with impaired fasting glucose: evolution in a period of 6 years. J Diabetes Res 2014; 2014:710370. [PMID: 25215305 PMCID: PMC4158147 DOI: 10.1155/2014/710370] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/04/2014] [Accepted: 08/05/2014] [Indexed: 12/25/2022] Open
Abstract
AIM To study the evolution of impaired fasting glucose (IFG), considering glucose and HbA1c levels and risk factors associated, in a period of 6 years. METHODS We studied 94 subjects with impaired fasting glucose (IFG) that were diagnosed in 2005 and followed up to 2012. Glucose and HbA1c levels were determined. A descriptive analysis of contingence charts was performed in order to study the evolution in the development of type-2 diabetes mellitus (T2DM). RESULTS Twenty-eight of ninety-four subjects became T2DM; 51/94 remained with IFG; and 20/94 presented normal fasting glucose. From the 28 diabetic subjects, 9 had already developed diabetes and were under treatment with oral hypoglycemic agents; 5 were diagnosed with plasma glucose < 126 mg/dL, but with HbA1c over 6.5%. In those who developed diabetes, 15/28 had a family history of T2DM in first relative degree. Also, diabetic subjects had a BMI significantly higher than nodiabetics (t test: P < 0.01). The individuals that in 2005 had the highest BMI are those who currently have diabetes. CONCLUSION The IFG constitutes a condition of high risk of developing T2DM in a few years, especially over 110 mg/dL and in obesity patients.
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Affiliation(s)
- E. Leiva
- Programa de Investigación de Excelencia Interdisciplinaria en Envejecimiento Saludable (PIEI-ES), Departamento de Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud, Universidad de Talca, 3465548 Talca, Chile
- *E. Leiva:
| | - V. Mujica
- Facultad de Medicina, Universidad Católica del Maule, Avenida San Miguel 3605, 3480112 Talca, Chile
| | - R. Orrego
- Programa de Investigación de Excelencia Interdisciplinaria en Envejecimiento Saludable (PIEI-ES), Departamento de Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud, Universidad de Talca, 3465548 Talca, Chile
| | - S. Wehinger
- Programa de Investigación de Excelencia Interdisciplinaria en Envejecimiento Saludable (PIEI-ES), Departamento de Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud, Universidad de Talca, 3465548 Talca, Chile
| | - A. Soto
- Programa de Investigación de Excelencia Interdisciplinaria en Envejecimiento Saludable (PIEI-ES), Instituto de Matemáticas y Física, Universidad de Talca, Chile 2 Norte 685, 3465548 Talca, Chile
| | - G. Icaza
- Programa de Investigación de Excelencia Interdisciplinaria en Envejecimiento Saludable (PIEI-ES), Instituto de Matemáticas y Física, Universidad de Talca, Chile 2 Norte 685, 3465548 Talca, Chile
| | - M. Vásquez
- Programa de Investigación de Excelencia Interdisciplinaria en Envejecimiento Saludable (PIEI-ES), Departamento de Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud, Universidad de Talca, 3465548 Talca, Chile
| | - L. Díaz
- Programa de Investigación de Excelencia Interdisciplinaria en Envejecimiento Saludable (PIEI-ES), Departamento de Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud, Universidad de Talca, 3465548 Talca, Chile
| | - M. Andrews
- Laboratorio de Micronutrientes, INTA, Universidad de Chile, El Líbano 5524, Macul, 7830490 Santiago, Chile
| | - M. Arredondo
- Laboratorio de Micronutrientes, INTA, Universidad de Chile, El Líbano 5524, Macul, 7830490 Santiago, Chile
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Soto-Liebe K, López-Cortés XA, Fuentes-Valdes JJ, Stucken K, Gonzalez-Nilo F, Vásquez M. In silico analysis of putative paralytic shellfish poisoning toxins export proteins in cyanobacteria. PLoS One 2013; 8:e55664. [PMID: 23457475 PMCID: PMC3574068 DOI: 10.1371/journal.pone.0055664] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 12/29/2012] [Indexed: 11/19/2022] Open
Abstract
Paralytic shellfish poisoning toxins (PSTs) are a family of more than 30 natural alkaloids synthesized by dinoflagellates and cyanobacteria whose toxicity in animals is mediated by voltage-gated Na+ channel blocking. The export of PST analogues may be through SxtF and SxtM, two putative MATE (multidrug and toxic compound extrusion) family transporters encoded in PSTs biosynthetic gene cluster (sxt). sxtM is present in every sxt cluster analyzed; however, sxtF is only present in the Cylindrospermopsis-Raphidiopsis clade. These transporters are energetically coupled with an electrochemical gradient of proton (H+) or sodium (Na+) ions across membranes. Because the functional role of PSTs remains unknown and methods for genetic manipulation in PST-producing organisms have not yet been developed, protein structure analyses will allow us to understand their function. By analyzing the sxt cluster of eight PST-producing cyanobacteria, we found no correlation between the presence of sxtF or sxtM and a specific PSTs profile. Phylogenetic analyses of SxtF/M showed a high conservation of SxtF in the Cylindrospermopsis-Raphidiopsis clade, suggesting conserved substrate affinity. Two domains involved in Na+ and drug recognition from NorM proteins (MATE family) of Vibrio parahaemolyticus and V. cholerae are present in SxtF/M. The Na+ recognition domain was conserved in both SxtF/M, indicating that Na+ can maintain the role as a cation anti-transporter. Consensus motifs for toxin binding differed between SxtF and SxtM implying differential substrate binding. Through protein modeling and docking analysis, we found that there is no marked affinity between the recognition domain and a specific PST analogue. This agrees with our previous results of PST export in R. brookii D9, where we observed that the response to Na+ incubation was similar to different analogues. These results reassert the hypothesis regarding the involvement of Na+ in toxin export, as well as the motifs L398XGLQD403 (SxtM) and L390VGLRD395 (SxtF) in toxin recognition.
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Affiliation(s)
| | - Xaviera A. López-Cortés
- Nanobiotechnology Division at University of Talca, Fraunhofer Chile Research Foundation - Center for Systems Biotechnology, Talca, Chile
| | | | - Karina Stucken
- Institute of Molecular Evolution Heinrich-Heine, Universität Düsseldorf, Düsseldorf, Germany
| | - Fernando Gonzalez-Nilo
- Universidad Andres Bello, Center for Bioinformatics and Integrative Biology, Santiago, Chile
| | - Mónica Vásquez
- Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail:
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Plominsky ÁM, Larsson J, Bergman B, Delherbe N, Osses I, Vásquez M. Dinitrogen fixation is restricted to the terminal heterocysts in the invasive cyanobacterium Cylindrospermopsis raciborskii CS-505. PLoS One 2013; 8:e51682. [PMID: 23405062 PMCID: PMC3566145 DOI: 10.1371/journal.pone.0051682] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 11/05/2012] [Indexed: 12/02/2022] Open
Abstract
The toxin producing nitrogen-fixing heterocystous freshwater cyanobacterium Cylindrospermopsis raciborskii recently radiated from its endemic tropical environment into sub-tropical and temperate regions, a radiation likely to be favored by its ability to fix dinitrogen (diazotrophy). Although most heterocystous cyanobacteria differentiate regularly spaced intercalary heterocysts along their trichomes when combined nitrogen sources are depleted, C. raciborskii differentiates only two terminal heterocysts (one at each trichome end) that can reach >100 vegetative cells each. Here we investigated whether these terminal heterocysts are the exclusive sites for dinitrogen fixation in C. raciborskii. The highest nitrogenase activity and NifH biosynthesis (western-blot) were restricted to the light phase of a 12/12 light/dark cycle. Separation of heterocysts and vegetative cells (sonication and two-phase aqueous polymer partitioning) demonstrated that the terminal heterocysts are the sole sites for nifH expression (RT-PCR) and NifH biosynthesis. The latter finding was verified by the exclusive localization of nitrogenase in the terminal heterocysts of intact trichomes (immunogold-transmission electron microscopy and in situ immunofluorescence-light microscopy). These results suggest that the terminal heterocysts provide the combined nitrogen required by the often long trichomes (>100 vegetative cells). Our data also suggests that the terminal-heterocyst phenotype in C. raciborskii may be explained by the lack of a patL ortholog. These data help identify mechanisms by which C. raciborskii and other terminal heterocyst-forming cyanobacteria successfully inhabit environments depleted in combined nitrogen.
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Affiliation(s)
- Álvaro M. Plominsky
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - John Larsson
- Department of Botany, Stockholm University, Stockholm, Sweden
| | | | - Nathalie Delherbe
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Igor Osses
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mónica Vásquez
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
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Soto-Liebe K, Méndez MA, Fuenzalida L, Krock B, Cembella A, Vásquez M. PSP toxin release from the cyanobacterium Raphidiopsis brookii D9 (Nostocales) can be induced by sodium and potassium ions. Toxicon 2012; 60:1324-34. [PMID: 22983012 DOI: 10.1016/j.toxicon.2012.09.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 07/11/2012] [Accepted: 09/06/2012] [Indexed: 11/25/2022]
Abstract
Paralytic shellfish poisoning (PSP) toxins are a group of naturally occurring neurotoxic alkaloids produced among several genera of primarily freshwater cyanobacteria and marine dinoflagellates. Although saxitoxin (STX) and analogs are all potent Na(+) channel blockers in vertebrate cells, the functional role of these compounds for the toxigenic microorganisms is unknown. Based upon the known importance of monovalent cations (such as sodium) in the maintenance of cellular homeostasis and ion channel function, we examined the effect of high extracellular concentrations of these ions on growth, cellular integrity, toxin production and release to the external medium in the filamentous freshwater cyanobacterium, Raphidiopsis brookii D9; a gonyautoxins (GTX2/3) and STX producing toxigenic strain. We observed a toxin export in response to high (17 mM) NaCl and KCl concentrations in the growth medium that was not primarily related to osmotic stress effects, compared to the osmolyte mannitol. Addition of exogenous PSP toxins with the same compositional profile as the one produced by R. brookii D9 was able to partially mitigate this effect of high Na⁺ (17 mM). The PSP toxin biosynthetic gene cluster (sxt) in D9 has two genes (sxtF and sxtM) that encode for a MATE (multidrug and toxic compound extrusion) transporter. This protein family, represented by NorM in the bacterium Vibrio parahaemolyticus, confers resistance to multiple cationic toxic agents through Na⁺/drug antiporters. Conserved domains for Na⁺ and drug recognition have been described in NorM. For the D9 sxt cluster, the Na⁺ recognition domain is conserved in both SxtF and SxtM, but the drug recognition domain differs between them. These results suggest that PSP toxins are exported directly in response to the presence of monovalent cations (Na⁺, K⁺) at least at elevated concentrations. Thus, the presence of both genes in the sxt cluster from strain D9 can be explained as a selective recognition mechanism by the SxtF/M transporters for GTX2/3 and STX. We propose that these toxins in cyanobacteria could act extracellularly as a protective mechanism to ensure homeostasis against extreme salt variation in the environment.
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Affiliation(s)
- Katia Soto-Liebe
- Pontificia Universidad Católica de Chile, Facultad de Ciencias Biológicas, Alameda 340, 8331150 Santiago, Chile
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Carneiro RL, Dörr FA, Dörr F, Bortoli S, Delherbe N, Vásquez M, Pinto E. Co-occurrence of microcystin and microginin congeners in Brazilian strains ofMicrocystissp. FEMS Microbiol Ecol 2012; 82:692-702. [DOI: 10.1111/j.1574-6941.2012.01439.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Revised: 06/07/2012] [Accepted: 06/25/2012] [Indexed: 11/28/2022] Open
Affiliation(s)
- Ronaldo Leal Carneiro
- Departamento de Análises Clínicas e Toxicológicas; Faculdade de Ciências Farmacêuticas; Universidade de São Paulo; São Paulo; SP; Brazil
| | - Felipe Augusto Dörr
- Departamento de Análises Clínicas e Toxicológicas; Faculdade de Ciências Farmacêuticas; Universidade de São Paulo; São Paulo; SP; Brazil
| | - Fabiane Dörr
- Departamento de Análises Clínicas e Toxicológicas; Faculdade de Ciências Farmacêuticas; Universidade de São Paulo; São Paulo; SP; Brazil
| | - Stella Bortoli
- Departamento de Análises Clínicas e Toxicológicas; Faculdade de Ciências Farmacêuticas; Universidade de São Paulo; São Paulo; SP; Brazil
| | | | - Mónica Vásquez
- Pontificia Universidad Católica de Chile; Santiago; Chile
| | - Ernani Pinto
- Departamento de Análises Clínicas e Toxicológicas; Faculdade de Ciências Farmacêuticas; Universidade de São Paulo; São Paulo; SP; Brazil
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Pena C, Yezioro Rubinsky S, Bolaños P, Vásquez M, Rincón J. Management of secondary alveolar bone graft in the multidisciplinary group of cleft lip and palate in Fundacion Hospital de la Misericordia (follow-up 5 years). Int J Oral Maxillofac Surg 2011. [DOI: 10.1016/j.ijom.2011.07.623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Trefault N, Krock B, Delherbe N, Cembella A, Vásquez M. Latitudinal transects in the southeastern Pacific Ocean reveal a diverse but patchy distribution of phycotoxins. Toxicon 2011; 58:389-97. [DOI: 10.1016/j.toxicon.2011.07.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 06/20/2011] [Accepted: 07/12/2011] [Indexed: 11/16/2022]
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Soto-Liebe K, Murillo AA, Krock B, Stucken K, Fuentes-Valdés JJ, Trefault N, Cembella A, Vásquez M. Reassessment of the toxin profile of Cylindrospermopsis raciborskii T3 and function of putative sulfotransferases in synthesis of sulfated and sulfonated PSP toxins. Toxicon 2010; 56:1350-61. [DOI: 10.1016/j.toxicon.2010.07.022] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 07/28/2010] [Accepted: 07/29/2010] [Indexed: 11/24/2022]
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Morgante V, López-López A, Flores C, González M, González B, Vásquez M, Rosselló-Mora R, Seeger M. Bioaugmentation with Pseudomonas sp. strain MHP41 promotes simazine attenuation and bacterial community changes in agricultural soils. FEMS Microbiol Ecol 2010; 71:114-26. [PMID: 19889033 DOI: 10.1111/j.1574-6941.2009.00790.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Bioremediation is an important technology for the removal of persistent organic pollutants from the environment. Bioaugmentation with the encapsulated Pseudomonas sp. strain MHP41 of agricultural soils contaminated with the herbicide simazine was studied. The experiments were performed in microcosm trials using two soils: soil that had never been previously exposed to s-triazines (NS) and soil that had >20 years of s-triazine application (AS). The efficiency of the bioremediation process was assessed by monitoring simazine removal by HPLC. The simazine-degrading microbiota was estimated using an indicator for respiration combined with most-probable-number enumeration. The soil bacterial community structures and the effect of bioaugmentation on these communities were determined using 16S RNA gene clone libraries and FISH analysis. Bioaugmentation with MHP41 cells enhanced simazine degradation and increased the number of simazine-degrading microorganisms in the two soils. In highly contaminated NS soil, bioaugmentation with strain MHP41 was essential for simazine removal. Comparative analysis of 16S rRNA gene clone libraries from NS and AS soils revealed high bacterial diversity. Bioaugmentation with strain MHP41 promoted soil bacterial community shifts. FISH analysis revealed that bioaugmentation increased the relative abundances of two phylogenetic groups (Acidobacteria and Planctomycetes) in both soils. Although members of the Archaea were metabolically active in these soils, their relative abundance was not altered by bioaugmentation.
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Affiliation(s)
- Verónica Morgante
- Departamento de Química, Universidad Técnica Federico Santa María, Valparaíso, Chile
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Morgante V, López-López A, Flores C, González M, González B, Vásquez M, Rosselló-Mora R, Seeger M. Bioaugmentation withPseudomonassp. strain MHP41 promotes simazine attenuation and bacterial community changes in agricultural soils. FEMS Microbiol Ecol 2010. [DOI: 10.1111/j.1574-6941.2010.00834.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Stucken K, John U, Cembella A, Murillo AA, Soto-Liebe K, Fuentes-Valdés JJ, Friedel M, Plominsky AM, Vásquez M, Glöckner G. The smallest known genomes of multicellular and toxic cyanobacteria: comparison, minimal gene sets for linked traits and the evolutionary implications. PLoS One 2010; 5:e9235. [PMID: 20169071 PMCID: PMC2821919 DOI: 10.1371/journal.pone.0009235] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Accepted: 01/14/2010] [Indexed: 11/24/2022] Open
Abstract
Cyanobacterial morphology is diverse, ranging from unicellular spheres or rods to multicellular structures such as colonies and filaments. Multicellular species represent an evolutionary strategy to differentiate and compartmentalize certain metabolic functions for reproduction and nitrogen (N2) fixation into specialized cell types (e.g. akinetes, heterocysts and diazocytes). Only a few filamentous, differentiated cyanobacterial species, with genome sizes over 5 Mb, have been sequenced. We sequenced the genomes of two strains of closely related filamentous cyanobacterial species to yield further insights into the molecular basis of the traits of N2 fixation, filament formation and cell differentiation. Cylindrospermopsis raciborskii CS-505 is a cylindrospermopsin-producing strain from Australia, whereas Raphidiopsis brookii D9 from Brazil synthesizes neurotoxins associated with paralytic shellfish poisoning (PSP). Despite their different morphology, toxin composition and disjunct geographical distribution, these strains form a monophyletic group. With genome sizes of approximately 3.9 (CS-505) and 3.2 (D9) Mb, these are the smallest genomes described for free-living filamentous cyanobacteria. We observed remarkable gene order conservation (synteny) between these genomes despite the difference in repetitive element content, which accounts for most of the genome size difference between them. We show here that the strains share a specific set of 2539 genes with >90% average nucleotide identity. The fact that the CS-505 and D9 genomes are small and streamlined compared to those of other filamentous cyanobacterial species and the lack of the ability for heterocyst formation in strain D9 allowed us to define a core set of genes responsible for each trait in filamentous species. We presume that in strain D9 the ability to form proper heterocysts was secondarily lost together with N2 fixation capacity. Further comparisons to all available cyanobacterial genomes covering almost the entire evolutionary branch revealed a common minimal gene set for each of these cyanobacterial traits.
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Affiliation(s)
- Karina Stucken
- Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
- Millenium Nucleus EMBA, Santiago, Chile
| | - Uwe John
- Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
| | - Allan Cembella
- Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
| | - Alejandro A. Murillo
- Department of Molecular Genetic and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millenium Nucleus EMBA, Santiago, Chile
| | - Katia Soto-Liebe
- Department of Molecular Genetic and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millenium Nucleus EMBA, Santiago, Chile
| | - Juan J. Fuentes-Valdés
- Department of Molecular Genetic and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millenium Nucleus EMBA, Santiago, Chile
| | - Maik Friedel
- Leibniz Institute for Age Research-Fritz Lipmann Institute, Jena, Germany
| | - Alvaro M. Plominsky
- Department of Molecular Genetic and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millenium Nucleus EMBA, Santiago, Chile
| | - Mónica Vásquez
- Department of Molecular Genetic and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millenium Nucleus EMBA, Santiago, Chile
- * E-mail: (MV); (GG)
| | - Gernot Glöckner
- Leibniz Institute for Age Research-Fritz Lipmann Institute, Jena, Germany
- Institute for Biochemistry I, University of Cologne, Cologne, Germany
- Leibniz Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany
- * E-mail: (MV); (GG)
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Plominsky Á, Soto-Liebe K, Vásquez M. Optimization of 2D-PAGE protocols for proteomic analysis of two nonaxenic toxin-producing freshwater cyanobacteria:Cylindrospermopsis raciborskiiandRaphidiopsissp. Lett Appl Microbiol 2009; 49:332-7. [DOI: 10.1111/j.1472-765x.2009.02665.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Stucken K, Murillo AA, Soto-Liebe K, Fuentes-Valdés JJ, Méndez MA, Vásquez M. Toxicity phenotype does not correlate with phylogeny of Cylindrospermopsis raciborskii strains. Syst Appl Microbiol 2009; 32:37-48. [DOI: 10.1016/j.syapm.2008.10.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Accepted: 10/23/2008] [Indexed: 11/15/2022]
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Sánchez MA, Vásquez M, González B. A previously unexposed forest soil microbial community degrades high levels of the pollutant 2,4,6-trichlorophenol. Appl Environ Microbiol 2005; 70:7567-70. [PMID: 15574963 PMCID: PMC535199 DOI: 10.1128/aem.70.12.7567-7570.2004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
2,4,6-trichlorophenol (2,4,6-TCP) is a hazardous pollutant that is efficiently degraded by some aerobic soil bacterial isolates under laboratory conditions. The degradation of this pollutant in soils and its effect on the soil microbial community are poorly understood. We report here the ability of a previously unexposed forest soil microbiota to degrade high levels of 2,4,6-TCP and describe the changes in the soil microbial community found by terminal restriction fragment length polymorphism (T-RFLP) analysis. After 30 days of incubation, about 50% degradation of this pollutant was observed in soils amended with 50 to 5,000 ppm of 2,4,6-TCP. The T-RFLP analysis showed that the soil bacterial community was essentially unchanged after exposure to up to 500 ppm of 2,4,6-TCP. However, a significant decrease in richness was found with 2,000 and 5,000 ppm of 2,4,6-TCP, even though the removal of this pollutant remained high. The introduction of Ralstonia eutropha JMP134 or R. eutropha MS1, two efficient 2,4,6-TCP degraders, to this soil did not improve degradation of this pollutant, supporting the significant bioremediation potential of this previously unexposed, endogenous forest soil microbial community.
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Affiliation(s)
- M A Sánchez
- Departamento de Genética Molecular y Microbiología, Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Castro D, Vera D, Lagos N, García C, Vásquez M. The effect of temperature on growth and production of paralytic shellfish poisoning toxins by the cyanobacterium Cylindrospermopsis raciborskii C10. Toxicon 2004; 44:483-9. [PMID: 15450922 DOI: 10.1016/j.toxicon.2004.06.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2004] [Revised: 05/27/2004] [Accepted: 06/09/2004] [Indexed: 10/26/2022]
Abstract
Cylindrospermopsis raciborskii is a cyanobacterium which produces either cylindrospermopsine or paralytic shellfish poisoning (PSP) toxins. We studied the effect of temperature on growth and production of PSP toxins by C. raciborskii C10, isolated from a freshwater reservoir in Brazil. We analyzed the extracellular and intracellular content of PSP toxins at two different temperatures: 19 and 25 degrees C. C. raciborskii C10 produces STX, GTX2, and GTX3 at both temperatures. dcSTX was also detected at 25 degrees C in the intracellular extracts obtained at the end of the stationary phase. The growth achieved at 25 degrees C and estimated by optical density at 700 nm was three times greater than at 19 degrees C. However, no significant differences were observed in the content of PSP toxins in either the cells or the extracellular media. The kinetics of accumulation of PSP toxins within the cells rather than in the media suggests an active PSP toxins-export process that is not related to cell lysis. The extracellular accumulation of PSP toxins at 19 degrees C suggested a biotransformation of STX to the epimers GTX2 and GTX3. The stability of the PSP toxins produced by C. raciborskii C10 was high enough for them to remain active in the media after 30 days (at 25 degrees C) or after 50 days (at 19 degrees C).
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Affiliation(s)
- Daniela Castro
- Laboratorio de Biotecnología, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Av. Macul 5540, Casilla 138-11, Santiago
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Stuardo M, Vásquez M, Vicuña R, González B. Molecular approach for analysis of model fungal genes encoding ligninolytic peroxidases in wood-decaying soil systems. Lett Appl Microbiol 2004; 38:43-9. [PMID: 14687214 DOI: 10.1046/j.1472-765x.2003.01442.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Test the use of nondegenerated consensus polymerase chain reaction (PCR) primers targeting lip and mnp sequences to detect ligninolytic fungi in wood-decaying soil systems, avoiding the need for enrichment or isolation on traditional fungal media culture. METHODS AND RESULTS The PCR primers were tested with total DNA isolated from incubations of wood-soil systems inoculated or not with the white-rot fungi Phanerochaete chrysosporium, or a white-rot sample obtained from a Nothofagus forest. The PCR products for lip and mnp sequences were only obtained in soil with P. chrysosporium-colonized wood chips. In these soil samples, reverse transcription-PCR analysis of lip and mnp PCR products indicated expression of LipA, LipB, LipJ and MnP isoenzymes. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first assessment of the use of consensus PCR primers for direct detection of ligninolytic peroxidase genes in wood-decaying soil systems.
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Affiliation(s)
- M Stuardo
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile and Millennium Institute for Fundamental and Applied Biology, Santiago, Chile
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Romero J, Yañez C, Vásquez M, Moore ERB, Espejo RT. Characterization and identification of an iron-oxidizing, Leptospirillum-like bacterium, present in the high sulfate leaching solution of a commercial bioleaching plant. Res Microbiol 2003; 154:353-9. [PMID: 12837511 DOI: 10.1016/s0923-2508(03)00037-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Most copper bioleaching plants operate with a high concentration of sulfate salts, caused by the continuous addition of sulfuric acid and the recycling of the leaching solution. Since the bacteria involved in bioleaching have been generally isolated at low sulfate concentrations, the bacterial population present in the high-sulfate (150 gl(-1)) leaching solution, employed in a copper production plant, was investigated. The iron-oxidizing bacteria able to grow in the leaching solution were enriched by several batch cultivations and, after serial dilution, an abundant bacterial strain was isolated. This strain, called LA, exhibited a relatively constant rate of iron-oxidation in media containing sulfate ions at concentrations ranging from 10 to 150 gl(-1). Culture collection strains of Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans showed limited abilities to grow at sulfate ion concentrations higher than 70 gl(-1). In spite of its tolerance to high sulfate concentrations, strain LA was as sensitive to NaCl as A. ferrooxidans. Comparative sequence analysis of the 16S rRNA gene of strain LA indicated that it is phylogenetically related to strains described as Leptospirillum ferrooxidans. Bacterial community DNA restriction patterns of 16S rRNA genes suggested that strain LA was a minor component of the bacterial population present in leaching solution, but is abundant in ore leached with this solution.
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Affiliation(s)
- Jaime Romero
- Laboratorio de Biotecnologi;a, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Macul 5540, 138-11 Santiago, Chile.
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Vásquez M, Grüttner C, Möeller B, Moore ERB. Limited selection of sodium channel blocking toxin-producing bacteria from paralytic shellfish toxin-contaminated mussels (Aulacomya ater). Res Microbiol 2002; 153:333-8. [PMID: 12238500 DOI: 10.1016/s0923-2508(02)01328-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Paralytic shellfish toxins (PSTs) are sodium channel blocking (SCB) toxins, produced by cyanobacteria, as well as by marine dinoflagellates and their associated bacteria, and cause serious health and economic concern worldwide. In a previous study, approximately 70% of the bacteria enriched from PST-contaminated shellfish tissue and isolated on marine agar medium were observed to produce SCB toxins. In the study reported here, the high percentage of cultivable toxigenic bacteria is demonstrated to be obtained through a marked selection on marine agar medium. The cultivable as well as the total bacterial diversity associated with PST-contaminated shellfish collected from the Magallanes region in the south of Chile has been analysed. Approximately 80% of bacterial isolates, analysed by restriction analysis of PCR amplified ribosomal DNA (i.e., ARDRA fingerprinting), were limited to only two genotypic OTUs (operational taxonomic unit). Sequence determination and analysis of the 16S rDNA from representative isolates of both OTUs established them to be closely related to species of the Psychrobacter genus of the gamma-subclass of the Proteobacteria. The total bacterial diversity in the shellfish was further analysed, using a cultivation-independent strategy of extraction of total DNA from contaminated tissue, PCR-amplification of bacterial 16S rRNA genes, cloning of the PCR products and analysis of the cloned 16S rDNA sequence types by fingerprinting and sequencing. Only 2% of the cloned sequence types corresponded to species of the Psychrobacter genus. The 16S rDNA sequence types detected clustered with species of the y-Proteobacteria subclass, the Cytophaga-Flexibacter-Bacteroides (CFB), the Fusobacteria and the Firmicutes phyla. The level of diversity observed within the libraries of cloned 16S rDNA was markedly greater than that observed among isolates obtained through marine agar enrichment cultures from the same shellfish tissue. Additionally the predominant cloned 16S rDNA sequence types detected from samples of the surrounding seawater demonstrated no correlation with those observed in the PST-contaminated mussels.
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Affiliation(s)
- Mónica Vásquez
- Laboratorio de Biotecnología, INTA-Universidad de Chile, Santiago, Chile.
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Pérez B, Landaeta-Jiménez M, Vásquez M. [Adiposity distribution in adolescents by conicity index]. Acta Cient Venez 2001; 51:244-51. [PMID: 11460795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Body regional fat distribution has been linked with a metabolic atherogenic risk profile, that starts early in life. Data from a cross-sectional sample of 394 boys and girls, 11 to 16 years, who inhabit a slum sector of Caracas, Venezuela was studied using Conicity Index (C): [equation: see text] by means of Box-plot diagram, Levene, ANOVA, and Scheffé tests. The accepted level of significance was p < 0.05. Results showed significant differences in body fat distribution between age groups. Height and body mass index were used as control variables. C values ranged between (1.02-1.18) in boys and (0.99-1.14) in girls. Boys attained higher mean values. All groups showed variance homogeneity (p value > 0.05) and sexual dimorphism was found at 11, 12 and 13 years, that were removed after controlling for height and body mass index. Differences according to age groups in boys, were removed after controlling for height. Results found conicity index as an alternative method to assess abdominal fat distribution during adolescents years.
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Affiliation(s)
- B Pérez
- Universidad Central de Venezuela, Instituto de Investigaciones Económicas y Sociales
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Vásquez M, Calao E, Becerra F, Ossa J, Enríquez C, Fresneda E. Initial stress differences between sliding and sectional mechanics with an endosseous implant as anchorage: a 3-dimensional finite element analysis. Angle Orthod 2001; 71:247-56. [PMID: 11510633 DOI: 10.1043/0003-3219(2001)071<0247:isdbsa>2.0.co;2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Endosseous implants have been used as orthodontic anchorage in recent years. A 3-dimensional mathematical model was constructed that uses the finite element method, which simulated an endosseous implant and an upper canine with its periodontal ligament and cortical and cancellous bone. Levels of initial stress were measured during 2 types of canine retraction mechanics (friction and frictionless). The lower magnitude and more uniform stresses in the implant and its cortical bone were found to have a moment-force ratio (M/F) of 6.1:1, whereas the canine and its supporting structures exerted a M/F ratio of 10.3:1. On the basis of these results, when the anchor unit is an endosseous implant, it seems better to use a precalibrated retraction system without friction (T-loop) where a low load-deflection curve would be generated.
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Affiliation(s)
- M Vásquez
- Private practice orthodontist, Medellín, Colombia.
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Tápanes FJ, Vásquez M, Ramírez R, Matheus C, Rodríguez MA, Bianco N. Cluster analysis of antinuclear autoantibodies in the prognosis of SLE nephropathy: are anti-extractable nuclear antibodies protective? Lupus 2001; 9:437-44. [PMID: 10981648 DOI: 10.1191/096120300678828604] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
To investigate the possible role of anti-ENA autoantibodies in the pathogenesis of SLE nephropathy, we performed a cross sectional clustering study of 91 SLE patients using 75 clinical and laboratory variables examining the presence of anti-dsDNA and ENA autoantibodies by ELISA and Western blot. We applied principal component, hierarchical cluster, multiple correspondence and logistical regression analysis. Two polar forms of SLE nephropathy and five clinical groups were identified: group 1 without overt nephropathy (n = 37), group 2 with nephropathy and only proteinuria (n = 19), group 3 nephropathy and only hematuria (n = 11), group 4 with hematuria and proteinuria (n = 14) and group 5 on renal failure (n = 10). When analyzed individually, levels of anti-dsDNA and single anti-ENA antibodies did not allow us to differentiate between renal and non-renal groups. However, when the anti-ENA autoantibodies were analyzed as a cluster, a high predictive value for clinical nephropathy was obtained. Thus, the absence of ENA antibodies (ENA ve or Venezuelan cluster) increased eleven-fold the odds ratio to develop SLE nephropathy. We suggested that the ENA ve cluster may predict development of the most severe forms of renal lupus while the ENA Sm/RNP and the ENA Ro/La/Sm/RNP clusters could be associated with the absence and the most benign form of SLE nephropathy. It must be interesting to apply similar cluster methodology in an SLE population with different ethnic background.
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Affiliation(s)
- F J Tápanes
- Centro Nacional de Enfermedades Reumáticas, Ministerio de Salud y Desarrollo Social, Universidad Central de Venezuela.
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45
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Landolfi NF, Thakur AB, Fu H, Vásquez M, Queen C, Tsurushita N. The integrity of the ball-and-socket joint between V and C domains is essential for complete activity of a humanized antibody. J Immunol 2001; 166:1748-54. [PMID: 11160220 DOI: 10.4049/jimmunol.166.3.1748] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
AF2 is a high affinity murine Ab possessing potent neutralizing activity against human IFN-gamma. In carrying out the modifications to humanize this Ab, we discovered that an initial version displayed affinity for IFN-gamma that was slightly less than that of AF2, but exhibited IFN-gamma-neutralizing activity that was severely diminished. Characterization via site-directed mutagenesis revealed that the majority of this loss in IFN-gamma-neutralizing activity was due to altering the V(H) framework residue at position 11. V(H) position 11 is distal to the binding surface of the Ab; however, it, along with residues 110 and 112, have been identified as forming the socket of a molecular ball-and-socket joint between the V and C domains of the Ig Fab, which influences the elbow angle between these domains. To determine whether disrupting the structure of this joint was the basis for reduced IFN-gamma-neutralizing capacity, we altered residue 148 of C(H1), which with residue 149 comprises the corresponding ball portion of the joint. Changing this single C(H1) domain residue diminished the ability of the Ab to neutralize IFN-gamma to a level similar to that observed with the V(H) alteration. Thus, an intact ball-and-socket joint between the V and C domains in AF2 is required for potent neutralization of IFN-gamma. These results suggest the importance of the elbow angle between Ig V and C domains in Ab activity, and support the hypothesis that this joint can be an important functional element of Ab structure.
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46
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Barro M, Vásquez M, Spencer E. [Use of a simple polymerase chain reaction combined with a heteroduplex mobility assay to characterize the non coding 5' region of hepatitis C virus]. Rev Med Chil 1999; 127:783-90. [PMID: 10668285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
BACKGROUND One of the most used methods for the characterization of hepatitis C virus strains is the use of a nested polymerase chain reaction (PCR) with a restriction fragment length polymorphism (RFLP) assay. Sometimes, RFLP results do not differentiate new strains. There are other more complex methods and only the sequencing of the PCR fragment allows a correct characterization of the strain. AIM To report the detection of hepatitis C virus using a single PCR assay of the 5' non codifying region. MATERIAL AND METHODS Thirty five serum samples coming from patients with chronic hepatitis or blood donors were assayed for hepatitis C virus. RESULTS The reported method increases the PCR sensitivity through the combination of polyacrylamide gel electrophoresis and silver staining of amplified products. This allowed the semi quantitative estimation of viral load and the characterization of amplified products through their electrophoretic motility. These PCR products were used in a heteroduplex motility assay; allowing the discrimination between sequences of different genotypes. CONCLUSIONS Heteroduplex assays can be used to characterize the 5' non codifying region of the hepatitis C virus for routine laboratory purposes.
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Affiliation(s)
- M Barro
- Departamento de Ciencias Biológicas, Facultad de Química y Biología, Universidad de Santiago de Chile
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47
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Martín R, Sneige N, Vásquez M, Aragón-Flores M, Martín G, Marrón C, Santamaría L. Stereologic estimates of volume-weighted mean nuclear volume in aspiration smears of ductal breast carcinoma. Correlation with cytologic grade, tumor size and lymph node status. Anal Quant Cytol Histol 1999; 21:185-93. [PMID: 10560490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
OBJECTIVE To estimate cytologic volume-weighted mean nuclear volume and correlate it with other prognostic factors, such as tumor diameter and cytologic grading in relation to nodal infiltration. STUDY DESIGN The relationships between nodal status and nuclear VV, tumor diameter and cytologic grading, according to the modified Black nuclear grading system, were analyzed on fine needle aspirates of 49 cases of breast cancer by univariate and multivariate logistic regression. RESULTS Volume-weighted mean nuclear volume (nuclear VV) estimated on fine needle aspiration smears showed a significant correlation with grade of tumor differentiation. CONCLUSION Stereologic evaluation of nuclear size by nuclear VV is an objective method for the cytologic grading of ductal carcinoma of the breast and has independent prognostic value in relation to nodal status higher than those of tumor diameter and cytologic grade.
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Affiliation(s)
- R Martín
- Department of Pathology, School of Medicine, Autonomous University of Madrid, Spain
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48
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Blanco M, Gomez J, Negrín C, Blanco G, Rodriguez M, Torres M, Vásquez M, Alcalá I, Vargas R, Velasco M. Metoclopramide enhances labetalol-induced antihypertensive effect during handgrip in hypertensive patients. Am J Ther 1998; 5:221-4. [PMID: 10099062 DOI: 10.1097/00045391-199807000-00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effects of metoclopramide, labetalol, and metoclopramide plus labetalol treatments on baseline cardiovascular parameters and isometric handgrip-induced changes were evaluated in 11 hypertensive subjects. Although all treatments were effective in reducing resting systolic (SBP) and diastolic (DBP) blood pressures, the combination of metoclopramide and labetalol appeared to provide a greater decrease (changes in SBP/DBP: 15/11 mm Hg, P < 0.05; from 149 +/- 4/95 +/- 4 mm Hg to 134 +/- 5/84 +/- 3 mm Hg) than did labetalol alone (changes in SBP/DBP: 10/9 mm Hg, P < 0.05; from 149 +/- 4/95 +/- 4 to 139 +/- 4/86 +/- 3 mm Hg). At 2 minutes, handgrip increased blood pressure on placebo (changes in SBP/DBP: 34/7 mm Hg, P < 0. 001). In the presence of metoclopramide and metoclopramide plus labetalol, however, handgrip induced lesser increases in blood pressure (changes in SBP/DBP: 23/7 mm Hg, P < 0.01, and 18/4 mm Hg, P < 0.01, for metoclopramide and metoclopramide plus labetalol treatments). We conclude that (1) metoclopramide lowers blood pressure in hypertensive patients; (2) metoclopramide attenuates blood pressure response to isometric handgrip; and (3) both compounds, labetalol and metoclopramide, seem to have a pharmacologic interaction concerning blood pressure decrease. A clinical significance is suggested for the metoclopramide effect.
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Affiliation(s)
- M Blanco
- Clinical Pharmacology Unit, Vargas Medical School, Central University of Venezuela, Caracas, South America
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49
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Espejo RT, Feijóo CG, Romero J, Vásquez M. PAGE analysis of the heteroduplexes formed between PCR-amplified 16S rRNA genes: estimation of sequence similarity and rDNA complexity. Microbiology (Reading) 1998; 144 ( Pt 6):1611-1617. [PMID: 9639932 DOI: 10.1099/00221287-144-6-1611] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Analysis of the 16S rRNA genes retrieved directly from different environments has proven to be a powerful tool that has greatly expanded our knowledge of microbial diversity and phylogeny. It is shown here that sequence similarity between 80 and 100% among 16S rDNAs can be estimated by the electrophoretic migration of their heteroduplexes. This was measured by hybridization and electrophoresis in polyacrylamide gels of the product obtained after PCR amplification of almost the entire 16S rRNA gene from different bacterial species. These heteroduplexes were also observed after amplification of samples containing DNA from two or more bacterial species and a procedure was applied to identify reliably heteroduplexes among the amplification products. The electrophoretic migration of the heteroduplexes observed after PCR was used to detect the presence of 16S rDNAs with different sequences in DNA extracted from both a mixture of two bacterial species and samples containing a natural bacterial community.
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Affiliation(s)
- Romilio T Espejo
- Instituto de Nutrición y Tecnología de los Alimentos, University of Chile, Macul 5540, Santiago, Chile
| | - Carmen Gloria Feijóo
- Instituto de Nutrición y Tecnología de los Alimentos, University of Chile, Macul 5540, Santiago, Chile
| | - Jaime Romero
- Instituto de Nutrición y Tecnología de los Alimentos, University of Chile, Macul 5540, Santiago, Chile
| | - Mónica Vásquez
- Instituto de Nutrición y Tecnología de los Alimentos, University of Chile, Macul 5540, Santiago, Chile
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50
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Pérez BM, Vásquez M, Landaeta-Jiménez M, Rámirez G, Ledezma T. [Adiposity and fat distribution in preschool children from low socioeconomic levels in Caracas]. Arch Latinoam Nutr 1997; 47:38-43. [PMID: 9429639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Epidemiological studies suggest that body fat distribution in adults is associated with chronical nontransmissible diseases, less is known during the growing years. The current study was undertaken to explore the relationship between level of fatness, fat patterning and some socioenvironmental variables in a group of 449 children aged 3 to 6, living in Caracas, who belong to the poorest Venezuelan socio-economic stratum. Data was analyzed taking nutritional status (weight-for-age), an index of socioeconomic conditions (ICSA), sex and age, as control variables. Using a multivariate analysis we derived first, two groups of households (G1 and G2) as determined by socioeconomic variables, to which principal component analysis was applied to elicited fatness and relative fat patterning through six skinfolds. First component identify level of adiposity, second extremity/trunk fatness, and third upper/lower pattern. Comparison of normal children with those of low weight-for-age showed differences in adiposity and in the upper/lower patterning as detected by the skinfolds involved in the differences: subscapular (-0.53) and supraspinale (0.32) in children with low weight-for-age; triceps (-0.46) and thigh (0.29) in those classified as normal. We found that gender, nutritional condition, environmental variables and age, were significant predictors of the differences in adiposity level; while age and households conditions, appear to be related to upper/lower patterning. The data equally suggests that body fat is more centrally distributed in boys with low weight-for-age. Since these patterns are indicators of risk in the ongoing years, we call tha attention about environmental circumstances.
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Affiliation(s)
- B M Pérez
- Instituto de Investigaciones Económicas y Sociales, Universidad Central de Venezuela
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