204 research outputs found

    Root colonization by fungal endophytes in Trithrinax campestris (Arecaceae) from semiarid ecosystems from Central Argentine

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    En ecosistemas áridos y semiáridos las raíces de las plantas suelen formar simbiosis con hongos, los que les proporcionan nutrientes y agua. Poco se conoce sobre los hongos asociados a palmeras nativas y cómo éstos podrían estar relacionados entre ellos. Se describe y cuantifica la colonización radical de los simbiontes de Trithrinax campestris en poblaciones leve y fuertemente afectadas por el fuego. T. campestris fue colonizada por hongos micorrícico-arbusculares (HMA) y endófitos septados oscuros (ESO). La colonización por HMA fue del tipo intermedio entre los tipos Arum y Paris. La colonización por HMA y ESO y la producción de pelos radicales, presentó diferencias entre las poblaciones estudiadas. Los resultados sugieren que en T. campestris la relación entre hongos simbiontes/producción de pelos radicales podrían estar relacionada con su alta tolerancia al fuego y la aridez.In arid and semiarid ecosystems, roots frequently form symbiosis with fungi that provides access to nutrients and water. Knowledge regarding the study of fungal symbionts colonizing native palms roots is still scarce. We described, quantified and compared fungal colonization in roots of Trithrinax campestris from two environmental situations: population with weak-burning-signs and population with strong-burning-signs. T. campestris was colonized by arbuscular-mycorrhizal-fungi (AMF) and dark-septate-endophytes (DSE). AMF colonization was an intermediate type between Arum and Paris. The AMF and DSE colonization and root hair production differed between populations. Our results suggest that in T. campestris the relation between fungal-symbionts and root-hair-production might be related to tolerance to burning and aridity.Fil: Lugo, Mónica Alejandra. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Giordano, Paula Guillermina. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Urcelay, Roberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina; ArgentinaFil: Crespo, Esteban María. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Hongos asociados con dos poblaciones de Acromyrmex lobicornis (Formicidae) de San Luis, Argentina

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    Fungi associated with two populations of Acromyrmex lobicornis (Formicidae) from San Luis, Argentina. The ant genera Atta and Acromyrmex (Tribe Attini) include the mowers or trimmers of leaves called leaf-cutting ants, which are the only ants that show an obligate dependence of fungal symbionts as a food source. Fragments of plants collected by these ants are used to grow the fungal symbionts, which produce gongylidia for the larvae and queen of the colony to feed on. The aim of this study was to isolate and characterize both, genetically and taxonomically the fungi cultured by two populations of Acromyrmex lobicornis from San Luis province. Samples were collected from the most superficial chambers of the nests and fungal isolates were cultured in malt extract (ME) and potato dextrose agar (PDA) media. The fungal symbiont associated to A. lobicornis nests was identified as Leucoagaricus gongylophorus (Möller) Singer (Holobasidiomycetes, Agaricales) through its morpho-anatomic characteristics and sequencing of ITS1, ITS2 and 5.8S ribosomal gene. Fungal growth in ME was higher than in PDA, and symbiont isolates showed differential growth rates depending on ant populations from where they originated. Fungal symbiont nutritional features and distributional aspects are discussed.Los géneros Atta y Acromyrmex comprenden a las hormigas cortadoras o podadoras de hojas de la tribu Attini, único grupo de hormigas que presenta una dependencia obligada con simbiontes fúngicos como fuente de alimento. Los fragmentos de plantas recolectados por estas hormigas son utilizados para cultivar al simbionte fúngico, el que origina gongilidios de los cuales se alimentan las larvas y la reina de la colonia. El objetivo de este trabajo fue aislar y caracterizar genómica y taxonómicamente los hongos cultivados por dos poblaciones de Acromyrmex lobicornis de la provincia de San Luis. Para ello, se recolectaron muestras del simbionte de las cámaras de cultivo más superficiales de los nidos y se cultivaron en los medios de extracto de malta (EM) y agar papa dextrosa (APD). El simbionte fúngico se identificó como Leucoagaricus gongylophorus (Möller) Singer (Holobasidiomycetes, Agaricales) por sus características morfo-anatómicas en cultivo, las secuencias del gen 5.8S ribosomal y de los espaciadores ITS1 e ITS2. El diámetro de las colonias de los simbiontes fúngicos aislados fue mayor en EM; además, mostraron crecimiento diferencial entre las poblaciones de hormigas de las que fueron aislados. Se discuten posibles implicancias nutricionales y aspectos relacionados con la distribución de los simbiontes aislados.Fil: Lugo, Mónica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - San Luis. Instituto Multidiciplinario de Investigación Biológica de San Luis; Argentina;Fil: Crespo, Esteban María. Diversidad Vegetal I. Universidad Nacional de San Luis; Argentina;Fil: Cafaro, Matias Jose. Universidad de Puerto Rico; Puerto Rico;Fil: Jofre, Laura Elizabeth. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia; Argentina

    Diversidad diferencial de esporas de Glomeromycota en la rizosfera de bromeliáceas nativas del Parque Nacional Sierra de las Quijadas (San Luis, Argentina)

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    Los hongos micorrícicos arbusculares (HMA) están ampliamente distribuidos en distintos ambientes y forman con la mayoría de las plantas asociaciones simbióticas denominadas micorrizas arbusculares. Bromeliaceae es una familia americana que habita desde los trópicos hasta zonas templadas y áridas. En el Parque Nacional Sierra de las Quijadas (San Luis, Argentina) las especies terrestres de Bromeliaceae están colonizadas por HMA, presentando distintos grados de asociación. El objetivo de este trabajo fue estudiar la diversidad (riqueza y densidad) de esporas de HMA en el suelo rizosférico de tres especies nativas de Bromeliaceae del Parque Nacional Sierra de las Quijadas. Riqueza y densidad de esporas difirieron significativamente entre las especies de Bromeliaceae estudiadas, siendo siempre marcadamente menores los valores obtenidos en Bromelia urbaniana, mientras que Deuterocohnia longipetala y Dyckia floribunda presentaron los mayores valores y sólo difirieron entre sí en la riqueza de HMA. Esta diversidad diferencial de esporas de HMA observada, podría tener relación con la especie hospedante y a su vez, con los distintos grados de colonización radical de cada especie. La escasa riqueza y densidad de esporas de HMA en B. urbaniana podría deberse tanto a un efecto alelopático de esta planta como a su particular morfología radical.Fil: Rivero Mega, Maria Soledad. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Area Ecológica; ArgentinaFil: Crespo, Esteban María. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Area Ecológica; ArgentinaFil: Molina, M.G.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Area Ecológica; ArgentinaFil: Lugo, Mónica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis; Argentin

    Diversity of Arbuscular Mycorrhizal Fungi in the Caldenal, San Luis (Argentina)

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    Arbuscular mycorrhizal fungi (AMF) are biotrophic mutualistic symbionts of the 80% of the terrestrial plants; they increase the growth of their hosts through the contribution in the absorption of water and nutrients by means of its extensive network of mycelium in the soil. This hyphal network also contributes to the soil aggregation, prevents erosion and interconnects plants, redistributing resources in the community. Also, these fungi benefit their hosts by increasing the host resistance to drought and pathogens attacks. AMF mycelium and spores are common components of soil microorganisms communities in diverse ecosystems. In worldwide arid areas, mycorrhizal associations have been registered with species of the genus Prosopis (Fabaceae). Ecosystem services are the direct benefits to society obtained by the functioning of an ecosystem. Thus, the HMA constitute a key functional group in the soil with an important role as ecosystem services providers through the increase of plant productivity, soil formation and improvement of the soil conditions, the prevention against biotic and abiotic stress. Despite playing a key role in ecosystems, a gap in the knowledge of the diversity of the AMF in Argentina exists. Particularly, in the Caldenal, Fitogeographical Province of the Espinal, there are no records of the AMF diversity. Taking into account that the ?Caldén? forests (Prosopis caldenia Burkart, Fabaceae) are suffering a constant reduction in their distribution area, driven mainly by the advance of the agricultural-livestock border, the knowledge of the AMF diversity as a basic service ecosystem and as an indicator of the general health of the soil is of vital importance for the preparation of an adequate management plans for the forest and the microorganisms diversity conservation in the soil and for the maintenance and/or conservation of soil quality. The objective of this work was to determine the diversity of the AMF in the Northern limit of the ?Caldén? Forest natural distribution. The sampling sites were four forest in Villa Mercedes, San Luis; soil samples extraction and AMF diversity analysis were done with classic technics. The morphospecies were determined by observing the spores and sporocarps in the optical microscope. Ten morphospecies belonging to the genera were found preliminarily: Acaulospora, Claroideoglomus, Corymbiglomus, Entrophospora, Funneliformis, Gigaspora, Glomus, Paraglomus, Redeckera, Rhizoglomus, Rhizophagus, Sclerocystis and Septoglomus; showing a variation in the frequency of appearance of each taxa in the different plots. This work will serve as a starting point for later studies comparing the diversity of AMF between areas with different land uses and for the analysis of the potential ecosystem services of AMF in the Caldenal.Fil: Ontivero, Roberto Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Risio Allione, Lucia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Económico Sociales. Departamento de Ciencias Agropecuarias; ArgentinaFil: Crespo, Esteban María. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lugo, Mónica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaXIII Congreso Argentino de Microbiología GeneralSan LuisArgentinaAsociación Civil de Microbiología Genera

    Gasteroid mycobiota (Agaricales, Geastrales, and Phallales) from Espinal forests in Argentina

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    Sampling and analysis of gasteroid agaricomycete species (Phallomycetidaeand Agaricomycetidae) associated with relicts of native Espinal forests in the southeast region of Córdoba, Argentina, have identified twenty-nine species in fourteen genera:Bovista (4), Calvatia (2), Cyathus (1), Disciseda (4), Geastrum (7), Itajahya (1),Lycoperdon (2), Lysurus (2), Morganella (1), Mycenastrum (1), Myriostoma (1),Sphaerobolus (1), Tulostoma (1), and Vascellum (1). The gasteroid species from the sampled Espinal forests showed an overall similarity with those recorded from neighboringphytogeographic regions; however, a new species of Lysurus was found and is briefly described, and Bovista coprophila is a new record for Argentina.Fil: Hernández Caffot, María Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Broiero, Ximena A.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Fernández, María Emilia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Silvera Ruiz, Leda. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Crespo, Esteban María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnol.conicet - San Luis. Unidad de Adm.territorial; ArgentinaFil: Nouhra, Eduardo Ramon. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

    Arbuscular mycorrhizal fungi from argentinean highland puna soils unveiled by propagule multiplication

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    Low arbuscular-mycorrhizal (AM) sporulation in arid field soils limits our knowledge of indigenous species when diversity studies are based only on spore morphology. Our aim was to use different approaches (i.e., spore morphological approach and PCR–SSCP (single-strand-conformation-polymorphism) analysis after trap plant multiplication strategies to improve the knowledge of the current richness of glomalean AM fungi (Glomerales; Glomeromycota) from the Argentine Puna. Indigenous propagules from two pristine sites at 3870 and 3370 m of elevation were multiplied using different host plants; propagation periods (2–6 months), and subculture cycles (1; 2; or 3) from 5 to 13 months. The propagule multiplication experiment allowed the detection of different glomoid taxa of Funneliformis spp. and Rhizoglomus spp., which were considered cryptic species since they had never been found in Puna soils before. On the other hand; almost all the generalist species previously described were recovered from cultures; except for Glomus ambisporum. Both plant host selection and culture times are critical for Glomerales multiplication. The SSCP analysis complemented the morphological approach and showed a high variability of Glomus at each site; revealing the presence of Funneliformis mosseae. This study demonstrates that AMF trap culture (TC) is a useful strategy for improving the analysis of AM fungal diversity/richness in the Argentinean highlands.EEA BalcarceFil: Covacevich, Fernanada. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación Biológicas Aplicadas. Instituto de Investigaciones en Biodiversidad y Biotecnología; Argentina.Fil: Hernández Guijarro, Keren. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Crespo, Esteban. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina.Fil: Lumini, Erica. Institute for Sustainable Plant Protection of National Research Council; Italia.Fil: Rivero Mega, María Soledad. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina.Fil: Lugo, Mónica. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina.Fil: Lugo, Mónica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Luis; Argentina. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina

    Contact with nature and executive functions: A pilot study with Spanish preschoolers

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    In the last decades, studies have suggested that contact with nature might impact positively on children’s Executive Functions (EF), although results are not consistent across studies. The present research aimed to explore a set of contextual factors (family socioeconomic status, residential area, and contact with nature) and their relations with preschoolers’ EF. Specifically, the research proposed to examine whether there were differences in preschoolers’ EF between rural/urban environments, to analyze the relation between exposure to natural surroundings and EF, and the potential interaction between contact with nature and family socioeconomic status in explaining children’s EF. A total of 56 preschoolers (30 boys, 26 girls) aged 4-6 years (M = 4.86, SD = .82) participated in the study. Families reported children’s contact with nature and EF through validated questionnaires. Results suggested that rural/urban environments were not related to children’s EF, but preschoolers who had more contact with nature exhibited higher Working memory skills. Moreover, mothers’ lower education was related to more difficulties in preschoolers’ Working memory when they have less contact with nature, but spending more time in natural surroundings seems to buffer that negative relation between lower maternal education and children’s EF. These preliminary findings highlight the relevance of the exposure and contact with nature for early childhood years

    Hernias diafragmáticas traumáticas

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    The diafragm is a thin and flat musculo-fascial structure that separates the chest from the abdominal cavity.Traumatic diaphragmatic hernia is an infrequent and life-threatening injury that may happen in patients with severe blunt or penetrating thoracoabdominal trauma. Diaphragmatic rupture is an important indicator of the severity of the trauma.These ruptures may be recognized at the time of the initial trauma, but are diagnosed months or even years later during the follow-up for related symptoms. If it is not detected early, the mortality rate could increase due to severe complications.The diagnosis of traumatic diaphragmatic hernia is difficult and often missed, because it could be accompanied by injuries to other organs. Supine chest radiography, despite its known limitations, is the initial most commonly performed imaging test to evaluate a traumatic injury in the thorax. However, computed tomography (CT) is the imaging tool of choice, as it is the key element for the detection of diaphragmatic injury after trauma.In hemodynamically stable patients, either videolaparoscopy or videothoracoscopy are recommended for the diagnosis and repair of a missed diaphragmatic injury. The surgical repair with nonabsorbable simple sutures is adequate in most cases, and the use of mesh should be reserved for chronic and large defects.El diafragma es una estructura músculo-aponeurótica delgada y aplanada que separa la cavidad torácica de la abdominal. La hernia diafragmática traumática es una lesión poco frecuente y potencialmente mortal que puede presentarse en pacientes que han sufrido un traumatismo tóraco-abdominal tanto cerrado como penetrante. La ruptura diafragmática es un importante indicador de la gravedad del traumatismo. Suelen identificarse en el momento del traumatismo, pero en ocasiones pueden pasar desapercibidas y diagnosticarse meses, e incluso años, más tarde debido a la presencia de síntomas relacionados con las estructuras y órganos afectados. Si no se detecta a tiempo, la tasa de mortalidad puede aumentar debido a la aparición de graves complicaciones. El diagnóstico de la hernia diafragmática traumática es difícil y, a menudo, puede pasar desapercibido debido a la gravedad de las lesiones acompañantes. La radiografía de tórax en decúbito supino, a pesar de sus limitaciones, es el método de imagen más habitual y el más frecuentemente utilizado para evaluar los traumatismos torácicos. Sin embargo, la tomografía computarizada (TAC) es actualmente la exploración idónea y el principal método diagnóstico de las hernias diafragmáticas traumáticas. En pacientes hemodinámicamente estables la videolaparoscopia y la videotoracoscopia permiten el diagnóstico y en muchos casos el tratamiento de la lesión diafragmática. En la mayoría de los casos la sutura de los bordes de la herida diafragmática es suficiente para corregir la lesión. En los grandes defectos diafragmáticos puede ser necesario el uso de prótesis

    Comparison of primary models to predict microbial growth by the plate count and absorbance methods

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    The selection of a primary model to describe microbial growth in predictive food microbiology often appears to be subjective. The objective of this research was to check the performance of different mathematical models in predicting growth parameters, both by absorbance and plate count methods. For this purpose, growth curves of three different microorganisms (Bacillus cereus, Listeria monocytogenes, and Escherichia coli) grown under the same conditions, but with different initial concentrations each, were analysed. When measuring the microbial growth of each microorganism by optical density, almost all models provided quite high goodness of fit (r(2) > 0.93) for all growth curves. The growth rate remained approximately constant for all growth curves of each microorganism, when considering one growth model, but differences were found among models. Three-phase linear model provided the lowest variation for growth rate values for all three microorganisms. Baranyimodel gave a variation marginally higher, despite a much better overall fitting. When measuring the microbial growth by plate count, similar results were obtained. These results provide insight into predictive microbiology and will help food microbiologists and researchers to choose the proper primary growth predictive model.This research was financially supported by the Ministerio de Economia y Competitividad of the Spanish Government and Fondo Europeo de Desarrollo Regional (FEDER) through Projects AGL2010-19775 and AGL2013-48993-C2-1-R.Pla-Ferrando, L.; Oltra Crespo, S.; Esteban, M.; Andreu, S.; Palop, A. (2015). Comparison of primary models to predict microbial growth by the plate count and absorbance methods. BioMed Research International. 2015:1-14. https://doi.org/10.1155/2015/365025S114201

    Safety of statins when response is carefully monitored: a study of 336 heart recipients

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    [Abstract] Background. Statins are used as first-line drugs against hypercholesterolemia after heart transplantation. Randomized clinical trials have shown that they reduce cholesterol levels, and the incidence of rejection and coronary vasculopathy. Adverse effects have been related to the use of certain statins, high statin dosages, comorbidities, and coadministration with cyclosporine. However, estimation of the risk of adverse effects for a given patient is difficult. The aims of this study were to determine the incidence of various kinds of adverse effect of statins; to evaluate certain potential risk factors; and to assess the efficacy of early response to signs of adverse effects. Methods. Between April 1991 and December 2003, we retrospectively evaluated 336 heart transplant patients (including 55 women) with regard to the occurrence of possible adverse effects of statins (rhabdomyolysis, myalgia, hepatotoxicity, high CK without muscle symptoms, and others). Resolution on reduction of dosage or discontinuance and/or change of statin were deemed to constitute confirmation of cause. Relations were sought between adverse effects and age, sex, immunosuppressive therapy, kidney failure, body mass index (BMI), arterial hypertension, and diabetes mellitus. Results. Possible adverse events of statins were suffered by 60 patients, all of them men. The causal role of statins was confirmed in 41 (12.2% of all 336): hepatotoxicity was suffered by 13, high CK without muscle ache or weakness by 18, rhabdomyolysis by 5, myalgia by 3, and other effects by 2. The incidence of confirmed statin-related complications was higher among patients with BMI >29 kg/m2 than among those with lower BMI (P = .055). None of the patients with confirmed statin-related complications needed dialysis, none died, and permanent suspension of statin treatment was only necessary in 13 cases (3.9% of the 336). Conclusions. Some 10% to 20% of HT patients appear to suffer adverse side effects of initial statin therapy. However, early detection of such effects through diligent clinical and analytical monitoring allows the therapy to be modified in time to minimize the appearance of severe complications. In only a minority of cases permanent suspension of statin therapy is necessary
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