Heavy metal capture by autochthonous yeasts from a volcanic influenced environment of Patagonia.

Heavy metals at elevated concentrations are a major threat to agricultural and human health. Typically, human activities tend to release these metals to the environment in aqueous solutions, generating high levels of pollution due to the mobility of the heavy metals. The aim of the present work was to assess heavy metal tolerance in yeasts isolated from Río Agrio - Lake Caviahue volcanic acidic aquatic environment and to evaluate the capacity of selected strains to capture metals in acidic culture media conditions. The ability of three yeast species, Cryptococcus agrionensis, Cryptococcus sp. 2, and Coniochaeta fodinicola, to tolerate and capture metals in live cultures has been evaluated. These three yeast species showed high tolerance to low pH and elevated concentrations of metals, thus implying their autochthonous status. Minimal inhibitory concentration (MIC) for growth obtained for these isolates showed elevated tolerance to the six heavy metals evaluated and were significantly higher than those registered for other microorganisms. C. agrionensis was able to capture 15.80 mg (g biomass)-1 of Cu2+ (MIC: 0.22 g L-1 ), Cryptococcus sp. 2 was able to capture 36.25 and 65.28 mg (g biomass)-1 of Ni2+ and Zn2+ , respectively (MIC: 0.56 and 1.68, respectively), and C. fodinicola was able to capture 67.11 mg (g biomass)-1 of Zn2+ (MIC: 3.75). This work reported the ability of yeasts to capture metals in acidic conditions for the first time. We hope that it represents the step-stone for future researches in the ability and metabolism of yeasts form acidic aquatic environment related to metal tolerance and capture.

Yeast diversity in the acidic Rio Agrio-Lake Caviahue volcanic environment (Patagonia, Argentina).

The Rio Agrio and Lake Caviahue system (RAC), in Northwestern Patagonia, is a natural acidic environment. The aims of this study were to characterize the yeast community and to provide the first ecological assessment of yeast diversity of this extreme aquatic environment. Yeast occurrence and diversity were studied at seven sites where the water pH varied between 1.8 and 6.7. Yeast CFU counts in the river ranged from 30 to 1200 CFU L(-1), but in the Lake the values were lower (30-60 CFU L(-1)). A total of 25 different yeast species were found, 11 of which belonged to undescribed taxa. Among these was an unusual strongly acidophilic Cryptococcus species. The RAC yeast community resembles that of acidic aquatic environments resulting from anthropic activities such as the São Domingos mines in Portugal and the Rio Tinto in Spain, respectively. The isolated yeast species were organized into different grades of adaptation to the RAC aquatic system. Based on the proposed grades, Rhodotorula mucilaginosa, Rhodosporidium toruloides and two novel Cryptococcus species were the most adapted species. These Cryptococcus species are apparently specialists of acidic aquatic environments, and might bear physiological features that possibly account for their ability to thrive in such extreme environments.

Cryptococcus spencermartinsiae sp. nov., a basidiomycetous yeast isolated from glacial waters and apple fruits.

Seven strains representing a novel yeast species belonging to the genus Cryptococcus were isolated from different substrates from Patagonia, Argentina, and The Netherlands. Three strains were isolated from a meltwater river draining from the Frias glacier at Mount Tronador situated in Nahuel Huapi National Park (Patagonia) and four were isolated from apple surfaces in Randwijk, The Netherlands. Analysis of the D1/D2 large-subunit rRNA gene and ITS region sequences indicated that these strains represent a single species that is distinct from other species of the Tremellales clade. The name Cryptococcus spencermartinsiae sp. nov. is proposed to accommodate these strains. The type strain is CRUB 1230(T) (=CBS 10760(T) =DBVPG 8010(T)).

Cryptococcus agrionensis sp. nov., a basidiomycetous yeast of the acidic rock drainage ecoclade, isolated from an acidic aquatic environment of volcanic origin.

Seventy-one strains were isolated from the River Agrio-Lake Caviahue acidic aquatic environment in Argentina. Strains were isolated mainly from the most acidic section of the river (pH 1.8-2.7). According to the mini/microsatellite-primed PCR technique and physiological data, these strains are representatives of a single novel species of the genus Cryptococcus. Analysis of the D1/D2 region of the large-subunit rRNA gene showed that the strains belong to the order Filobasidiales of the subphylum Agaricomycotina. The novel isolates formed a phylogenetic group with Cryptococcus ibericus, Cryptococcus aciditolerans and Cryptococcus metallitolerans, the most closely related species. This group, which is phylogenetically related to the Gastricus clade, is considered to be an ecoclade due to its peculiar ecology and physiology. The name Cryptococcus agrionensis sp. nov. is proposed to accommodate these isolates, with strain CRUB 1317(T) (=CBS 10799(T)=JCM 15321(T)) as the type strain.

Hematoma epidural cervical espontáneo / Spontaneous cervical epidural hematoma

Presentamos un caso tratado en nuestro hospital, de síndrome de compresión medular cervical originado por hematoma epidural espontáneo, analizando los diagnósticos diferenciales, los estudios complementario y los resultados de esta infrecuente patología. El síndrome de compresión medular cervical de presentación espontánea, comprendió una monoparesia braquial derecha de rápida instalación con déficit sensitivo asociado, observando en las imágenes de tomografía computada y resonancia magnética la presencia de de una masa epidural en situación posterior y derecha sobre la médula espinal extendida desde C2 hasta C6, se realizó laminectomía cervial bilateral con evacuación de hematoma epidural, confirmado macroscópicamente y microscópicamente. Son lesiones infrecuentes pero deben ser considerados entre los diagnósticos diferenciales en las compresiones medulares agudas. El abordaje neuroquirúrgico con laminectomía descomprensiva y evacuación del del hematoma epidural constituye el enfoque terapéutico óptimo que permite lograr la recuperación neurológica. (AU)

Hematoma epidural cervical espontáneo / Spontaneous cervical epidural hematoma

Presentamos un caso tratado en nuestro hospital, de síndrome de compresión medular cervical originado por hematoma epidural espontáneo, analizando los diagnósticos diferenciales, los estudios complementario y los resultados de esta infrecuente patología. El síndrome de compresión medular cervical de presentación espontánea, comprendió una monoparesia braquial derecha de rápida instalación con déficit sensitivo asociado, observando en las imágenes de tomografía computada y resonancia magnética la presencia de de una masa epidural en situación posterior y derecha sobre la médula espinal extendida desde C2 hasta C6, se realizó laminectomía cervial bilateral con evacuación de hematoma epidural, confirmado macroscópicamente y microscópicamente. Son lesiones infrecuentes pero deben ser considerados entre los diagnósticos diferenciales en las compresiones medulares agudas. El abordaje neuroquirúrgico con laminectomía descomprensiva y evacuación del del hematoma epidural constituye el enfoque terapéutico óptimo que permite lograr la recuperación neurológica.

Tulobuterol en pacientes pediátricos con asma bronquial: eficacia y seguridad de un nuevo beta2 agonista / Tulobuterol in pediatric patients with bronchial asthma efficiency ad safety of a new beta2 agonist

Se llevó a cabo una evaluación clínica en 30 niños de edad, con asma bronquial, para probar la eficacia del jarabe de tulobuterol, un nuevo agonista beta2. Las dosis administradas fueron de 30 y 40 mcg/kg dos veces al día, bajo un esquema especial que duró 21 días; se hicieron mediciones del fluxo máximo, capacidad vital forzado y volumen espiratorio forzado en un segundo, al inicio y a intervalos de una semana durante el tratamiento. El primero y último días de la administración de tulobuterol se valoró el efecto durante las primeras 9 horas después de administrar el medicamento. Para estudiar la seguridad del fármaco se hicieron determinaciones de laboratorio y se registraron los efectos colaterales. Los resultados observados comprobaron la eficacia broncodilatadora del tulobuterol, con mejoría de los síntomas, que permite la administración dada 12 horas. En ningún caso se suspendió el tratamiento por reacciones indeseables o efectos colaterales serios, por lo que también se comprobó buena tolerancia de tulobuterol. Se puede concluir que tulobuterol es un broncodilatador eficaz y seguro en niños con asma bronquial, bajo esquema de dosis de 2 veces al día