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1.
Water Res ; 221: 118727, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35797818

RESUMO

Hypersaline endorheic aquatic systems (H-SEAS) are lakes/shallow playas in arid and semiarid regions that undergo extreme oscillations in salinity and severe drought episodes. Although their geochemical uniqueness and microbiome have been deeply studied, very little is known about the availability and quality of dissolved organic matter (DOM) in the water column.. A H-SEAS from the Monegros Desert (Zaragoza, NE Spain) was studied during a hydrological wetting-drying-rewetting cycle. DOM analysis included: (i) a dissolved organic carbon (DOC) mass balance; (ii) spectroscopy (absorbance and fluorescence) and (iii) a molecular characterization with Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). The studied system stored a large amount of DOC and under the highest salinity conditions, salt-saturated waters (i.e., brines with salinity > 30%) accumulated a disproportionate quantity of DOC, indicating a significant in-situ net DOM production. Simultaneously, during the hydrological transition from wet to dry, the DOM pool showed strong alterations of it molecular composition. Spectroscopic methods indicated that aromatic and degraded DOM was rapidly replaced by fresher, relatively small, microbial-derived moieties with a large C/N ratio. FT-ICR-MS highlighted the accumulation of small, saturated and oxidized molecules (molecular O/C > 0.5), with a remarkable increase in the relative contribution of highly oxygenated (molecular O/C>0.9) compounds and a decrease of aliphatic and carboxyl-rich alicyclic moleculesThese results indicated that H-SEAS are extremely active in accumulating and processing DOM, with the notable release of organic solutes probably originated from decaying microplankton under large osmotic stress at extremely high salinities.


Assuntos
Matéria Orgânica Dissolvida , Lagos , Hidrologia , Lagos/química , Espectrometria de Massas , Água
2.
Sci Total Environ ; 714: 136838, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32018979

RESUMO

Microbiota inhabiting the intermittent streambeds mediates several in-stream processes that are essential for ecosystem function. Reduced stream discharge caused by the strengthened intermittency and increased duration of the dry phase is a spreading global response to changes in climate. Here, the impacts of a 5-month desiccation, one-week rewetting and punctual storms, which interrupted the dry period, were examined. The genomic composition of total (DNA) and active (RNA) diversity, and the community level physiological profiles (CLPP) were considered as proxies for functional diversity to describe both prokaryotes and eukaryotes inhabiting the surface and hyporheic streambeds. Comparisons between the genomic and potential functional responses helped to understand how and whether the microbial diversity was sensitive to the environmental conditions and resource acquisition, such as water stress and extracellular enzyme activities, respectively. RNA expression showed the strongest relationship with the environmental conditions and resource acquisition, being more responsive to changing conditions compared to DNA diversity, especially in the case of prokaryotes. The DNA results presumably reflected the legacy of the treatments because inactive, dormant, or dead cells were included, suggesting a slow microbial biomass turnover or responses of the microbial communities to changes mainly through physiological acclimation. On the other hand, microbial functional diversity was largely explained by resources acquisition, such as metrics of extracellular enzymes, and appeared vulnerable to the hydrological changes and duration of desiccation. The data highlight the need to improve the functional assessment of stream ecosystems with the application of complementary metrics to better describe the streambed microbial dynamics under dry-rewet stress.


Assuntos
Microbiota , Biomassa , Hidrologia , Rios
3.
Sci Rep ; 9(1): 13506, 2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31534180

RESUMO

Stream microbes that occur in the Mediterranean Basin have been shown to possess heightened sensitivity to intensified water stress attributed to climate change. Here, we investigate the effects of long-term drought (150 days), storms and rewetting (7 days) on the diversity and composition of archaea, bacteria and fungi inhabiting intermittent streambed sediment (surface and hyporheic) and buried leaves. Hydrological alterations modified the archaeal community composition more than the bacterial community composition, whereas fungi were the least affected. Throughout the experiment, archaeal communities colonizing sediments showed greater phylogenetic distances compared to those of bacteria and fungi, suggesting considerable adaptation to severe hydrological disturbances. The increase in the class abundances, such as those of Thermoplasmata within archaea and of Actinobacteria and Bacilli within bacteria, revealed signs of transitioning to a drought-favoured and soil-like community composition. Strikingly, we found that in comparison to the drying phase, water return (as sporadic storms and rewetting) led to larger shifts in the surface microbial community composition and diversity. In addition, microhabitat characteristics, such as the greater capacity of the hyporheic zone to maintain/conserve moisture, tended to modulate the ability of certain microbes (e.g., bacteria) to cope with severe hydrological disturbances.


Assuntos
Hidrologia/métodos , Microbiota/fisiologia , Adaptação Biológica/genética , Archaea/classificação , Bactérias/classificação , Mudança Climática , Secas , Fungos/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Rios/microbiologia
4.
Sci Total Environ ; 669: 559-569, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30889445

RESUMO

Bioclogging is a main concern in infiltration systems as it may significantly shorten the service life of these low-technology water treatment methods. In porous media, biofilms grow to clog partially or totally the pore network. Dynamics of biofilm accumulation (e.g., by attachment, detachment, advective transport in depth) and their impact on both surface and deep bioclogging are still not yet fully understood. To address this concern, a 104 day-long outdoor infiltration experiment in sand tanks was performed, using secondary treated wastewater and two grain size distributions (GSDs): a monolayer system filled with fine sand, and a bilayer one composed by a layer of coarse sand placed on top of a layer of fine sand. Biofilm dynamics as a function of GSD and depth were studied through cross-correlations and multivariate statistical analyses using different parameters from biofilm biomass and activity indices, plus hydraulic parameters measured at different depths. Bioclogging (both surface and deep) was found more significant in the monolayer fine system than in the bilayer coarse-fine one, possibly due to an early low-cohesive biofilm formation in the former, driven by lower porosity and lower fluxes; under such conditions biomass is favorably detached from the top layer, transported and accumulated in depth, so that new biomass might colonize the surface. On the other hand, in the bilayer system, fluxes are highest, and the biofilm is still in a growing phase, with low biofilm detachment capability from the top sand layer and high microbial activity in depth, resulting in low bioclogging. Overall, the bilayer coarse-fine system allows infiltrating higher volume of water per unit of surface area than the monolayer fine one, minimizing surface and deep bioclogging, and thus increasing the longevity and efficiency of infiltration systems.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Biofilmes , Biomassa , Permeabilidade , Porosidade , Dióxido de Silício , Águas Residuárias , Movimentos da Água , Purificação da Água
5.
Environ Sci Technol ; 52(10): 5734-5743, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29672036

RESUMO

Infiltration systems are treatment technologies based on water percolation through porous media where biogeochemical processes take place. Grain size distribution (GSD) acts as a driver of these processes and their rates and influences nutrient accumulation in sediments. Coarse sands inhibit anaerobic reactions such as denitrification and could constrain nutrient accumulation in sediments due to smaller specific surface area. Alternatively, fine sands provide higher nutrient accumulation but need a larger area available to treat the same volume of water; furthermore, they are more susceptible to bioclogging. Combining both sand sizes in a bilayer system would allow infiltrating a greater volume of water and the occurrence of aerobic/anaerobic processes. We studied the performance of a bilayer coarse-fine system compared to a monolayer fine one-by triplicate-in an outdoor infiltration experiment to close the C-N-P cycles simultaneously in terms of mass balances. Our results confirm that the bilayer coarse-fine GSD promotes nutrient removal by physical adsorption and biological assimilation in sediments, and further it enhances biogeochemical process rates (2-fold higher than the monolayer system). Overall, the bilayer coarse-fine system allows treating a larger volume of water per surface unit achieving similar removal efficiencies as the fine system.


Assuntos
Nutrientes , Dióxido de Silício , Sedimentos Geológicos , Porosidade , Água
6.
Biofouling ; 34(2): 200-211, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29405091

RESUMO

Two non-destructive techniques, confocal laser scanning microscopy (CLSM) and planar optode (VisiSens imaging), were combined to relate the fine-scale spatial structure of biofilm components to real-time images of oxygen decay in aquatic biofilms. Both techniques were applied to biofilms grown for seven days at contrasting light and temperature (10/20°C) conditions. The geo-statistical analyses of CLSM images indicated that biofilm structures consisted of small (~100 µm) and middle sized (~101 µm) irregular aggregates. Cyanobacteria and EPS (extracellular polymeric substances) showed larger aggregate sizes in dark grown biofilms while, for algae, aggregates were larger in light-20°C conditions. Light-20°C biofilms were most dense while 10°C biofilms showed a sparser structure and lower respiration rates. There was a positive relationship between the number of pixels occupied and the oxygen decay rate. The combination of optodes and CLMS, taking advantage of geo-statistics, is a promising way to relate biofilm architecture and metabolism at the micrometric scale.


Assuntos
Biofilmes/crescimento & desenvolvimento , Processamento de Imagem Assistida por Computador , Microscopia Confocal , Oxigênio/análise , Biofilmes/classificação , Biopolímeros/análise , Clorófitas/química , Clorófitas/crescimento & desenvolvimento , Cianobactérias/química , Cianobactérias/crescimento & desenvolvimento , Espaço Extracelular/química
7.
Environ Sci Technol ; 51(11): 6110-6119, 2017 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-28481089

RESUMO

Physical heterogeneity determines interstitial fluxes in porous media. Nutrients and organic matter distribution in depth influence physicochemical and microbial processes occurring in subsurface. Columns 50 cm long were filled with sterile silica sand following five different setups combining fine and coarse sands or a mixture of both mimicking potential water treatment barriers. Water was supplied continuously to all columns during 33 days. Hydraulic conductivity, nutrients and organic matter, biofilm biomass, and activity were analyzed in order to study the effect of spatial grain size heterogeneity on physicochemical and microbial processes and their mutual interaction. Coarse sediments showed higher biomass and activity in deeper areas compared to the others; however, they resulted in incomplete denitrification, large proportion of dead bacteria in depth, and low functional diversity. Treatments with fine sediment in the upper 20 cm of the columns showed high phosphorus retention. However, low hydraulic conductivity values reported in these sediments seemed to constraint biofilm activity and biomass. On the other hand, sudden transition from coarse-to-fine grain sizes promoted a hot-spot of organic matter degradation and biomass growth at the interface. Our results reinforce the idea that grain-size disposition in subsurface sandy sediments drives the interstitial fluxes, influencing microbial processes.


Assuntos
Bactérias , Fósforo , Microbiologia da Água , Biomassa , Sedimentos Geológicos
8.
G Chir ; 38(6): 285-290, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29442059

RESUMO

AIM: The incidence of rectal cancer continues to rise. The functional results after complete Total Mesorectal Excision (TME) depend on the segment of colon used for reconstruction of colonic continuity and the form, the volume and the functional proprieties of the "neorectum". The aim of our study is evaluate the efficacy of our Modified Transverse Coloplasty Pouch (MTCP) after the treatment of low rectal cancer in terms of functional outcomes and quality of life. PATIENTS AND METHODS: The study included 136 patients, underwent TME from January 2007 to December 2016 with diagnosis of extraperitoneal carcinoma of the rectum. The average distance of the tumor from the dentate line was 5.6 cm. Our follow-up protocol included functional outcome evaluation at 7th post-operative day (POD), 2nd month, and 6th month after the surgery. RESULTS: All patients (M/F 84/52) underwent anterior rectal resection (TME) with MTCP. Frequency of bowel movements per 24 hours in the studied patients compared at 7th POD, 2 months, and 6 months. Since the first post-operative weeks there is an encouraging reduction of the frequency of bowel movements. CONCLUSION: Modified Transverse Coloplasty Pouch (MTCP) had better functional results and quality of life compared to patients with a Colonic J Pouch (CJP) and traditional Transverse Coloplasty Pouch (TCP).


Assuntos
Bolsas Cólicas , Neoplasias Retais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
9.
Water Res ; 99: 33-45, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27132197

RESUMO

Uncertainties exist regarding the magnitude of in situ dissolved organic matter (DOM) processing in lotic systems. In addition, little is known about the effects of extreme hydrological events on in-stream DOM retention or release during downriver transport. This study quantified the net in-stream retention/release efficiencies (η) of dissolved organic carbon (DOC) and its humic and protein-like fluorescent fractions along a Mediterranean river during drought, baseflow and flood conditions. High performance size exclusion chromatography was used to describe the apparent size distributions of the humic and protein-like DOM moieties. A snapshot mass balance allowed estimating the η values of DOC and humic and protein-like fractions. Significant DOM net retention (η < 0) was detected during the drought condition and the protein-like fraction was more retained than the humic-like fraction and bulk DOC. In addition, small substances were more efficiently retained than larger substances. DOC retention decreased under baseflow conditions, but it remained significant. The humic and protein-like net efficiencies exhibited high variability, but the net retention were not significant. From a longitudinal perspective, the entire fluvial corridor contributed net retention of DOC and humic and protein-like moieties net retention during drought condition. In contrast, net retention/release efficiencies exhibited spatial variability during baseflow condition. The flood preferentially mobilized large size DOM molecules and the fluvial corridor behaved as a homogeneous passive DOM (η = 0) conduit. This research highlights the relevance of hydrological extreme events on the magnitude of DOM retention/release mass balance and emphasizes the need to perform measurements during these conditions to quantify the impact of fluvial corridors on DOM fate and transport.


Assuntos
Hidrologia , Rios/química , Substâncias Húmicas
10.
Sci Total Environ ; 540: 20-31, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25900223

RESUMO

Water flowing through hyporheic river sediments or artificial recharge facilities promotes the development of microbial communities with sediment depth. We performed an 83-day mesocosm infiltration experiment, to study how microbial functions (e.g., extracellular enzyme activities and carbon substrate utilization) are affected by sediment depth (up to 50 cm) and different oxygen concentrations. Results indicated that surface sediment layers were mainly colonized by microorganisms capable of using a wide range of substrates (although they preferred to degrade carbon polymeric compounds, as indicated by the higher ß-glucosidase activity). In contrast, at a depth of 50 cm, the microbial community became specialized in using fewer carbon substrates, showing decreased functional richness and diversity. At this depth, microorganisms picked nitrogenous compounds, including amino acids and carboxyl acids. After the 83-day experiment, the sediment at the bottom of the tank became anoxic, inhibiting phosphatase activity. Coexistence of aerobic and anaerobic communities, promoted by greater physicochemical heterogeneity, was also observed in deeper sediments. The presence of specific metabolic fingerprints under oxic and anoxic conditions indicated that the microbial community was adapted to use organic matter under different oxygen conditions. Overall the heterogeneity of oxygen concentrations with depth and in time would influence organic matter metabolism in the sediment tank.


Assuntos
Sedimentos Geológicos/análise , Substâncias Húmicas , Oxigênio/análise , Eliminação de Resíduos Líquidos/métodos , Microbiologia da Água , Sedimentos Geológicos/microbiologia
11.
Environ Pollut ; 178: 220-8, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23583942

RESUMO

We investigated the effects of pharmaceuticals and pesticides detected in a Mediterranean river, on fluvial biofilms by translocation experiments performed under controlled conditions. Water was sampled from three sites along a pollution gradient. Biofilms grown in mesocosms containing relatively clean water were translocated to heavily polluted water. Several biofilm descriptors were measured before and after translocations. Fifty-seven pharmaceuticals and sixteen pesticides compounds were detected in river waters. The translocation from less to more polluted site was the most effective. Autotrophic biomass and peptidase increased while phosphatase and photosynthetic efficiency decreased. Multivariate analysis revealed that analgesics and anti-inflammatories significantly affected biofilm responses. Ibuprofen and paracetamol were associated with negative effects on photosynthesis, and with the decrease of the green algae/cyanobacteria ratio, while diclofenac was associated with phosphatase activity. The effects of these emerging compounds on biofilms structure and function may cause important alterations in river ecosystem functioning.


Assuntos
Biofilmes/efeitos dos fármacos , Praguicidas/toxicidade , Preparações Farmacêuticas/análise , Rios/microbiologia , Microbiologia da Água , Poluentes Químicos da Água/toxicidade , Ecossistema , Monitoramento Ambiental , Praguicidas/análise , Fotossíntese/efeitos dos fármacos , Rios/química , Poluentes Químicos da Água/análise
12.
Chemosphere ; 92(9): 1126-35, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23434260

RESUMO

Antibiotics are emerging contaminants, which wing to their bioactivity, may lead to short-term and long-term alterations of natural microbial communities in aquatic environment. We investigated the effects of antibiotics on biofilm bacterial communities in the Llobregat River (Northeast Spain). Three sampling sites were selected: two less polluted sites and one hotspot. River water was collected from each site and used both as inoculum and medium for growing biofilms in independent mesocosms. After 25d of biofilm colonization, we exposed the colonized biofilms to river waters from the downstream sites (progressively contaminated by antibiotics). A control from each site was maintained where the growing biofilm was always exposed to water from the same site. The bacterial community composition, bacterial live/dead ratio and extracellular enzyme activities of the biofilms were measured before and 9d after exposing the biofilms to increasing contaminated waters. Sixteen antibiotic compounds were detected in the water from the three sampling sites. At each site, the antibiotics present in the highest concentrations were sulfonamides, followed by quinolones and macrolides. Bacterial communities of biofilms grown with the three river waters differed markedly in their structure, but less so in terms of functional descriptors. After switching the medium water to increasing pollution, biofilms exhibited increased levels of actinobacteria (HGC), a trend that was associated to the higher antibiotic concentrations in the water. These biofilms also showed increased bacterial mortality, and decreased extracellular leucine-aminopeptidase and alkaline phosphatase. There was a significant correlation between antibiotic concentrations and biofilm responses. Our results indicate that the continuous entrance of antibiotics in running waters cause significant structural and functional changes in microbial attached communities.


Assuntos
Actinobacteria/fisiologia , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Rios/microbiologia , Poluentes Químicos da Água/farmacologia , Actinobacteria/enzimologia , Actinobacteria/isolamento & purificação , Fosfatase Alcalina/metabolismo , Antibacterianos/análise , Cromatografia Líquida de Alta Pressão , Hibridização in Situ Fluorescente , Leucil Aminopeptidase/metabolismo , Macrolídeos/análise , Quinolonas/análise , Espanha , Sulfonamidas/análise , Espectrometria de Massas em Tandem , Microbiologia da Água , Poluentes Químicos da Água/análise
13.
Aquat Toxicol ; 127: 36-45, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22310170

RESUMO

The consequences of global change on rivers include altered flow regime, and entrance of compounds that may be toxic to biota. When water is scarce, a reduced dilution capacity may amplify the effects of chemical pollution. Therefore, studying the response of natural communities to compromised water flow and to toxicants is critical for assessing how global change may affect river ecosystems. This work aims to investigate how an episode of drought might influence the response of river biofilms to pulses of triclosan (TCS). The objectives were to assess the separate and combined effects of simulated drought (achieved through drastic flow alteration) and of TCS exposure on biofilms growing in artificial channels. Thus, three-week-old biofilms were studied under four conditions: Control (normal water flow); Simulated Drought (1 week reduced flow+2 days interrupted flow); TCS only (normal water flow plus a 48-h pulse of TCS); and Simulated Drought+TCS. All channels were then left for 2 weeks under steady flow conditions, and their responses and recovery were studied. Several descriptors of biofilms were analyzed before and after each step. Flow reduction and subsequent interruption were found to provoke an increase in extracellular phosphatase activity, bacterial mortality and green algae biomass. The TCS pulses severely affected biofilms: they drastically reduced photosynthetic efficiency, the viability of bacteria and diatoms, and phosphate uptake. Latent consequences evidenced significant combined effects caused by the two stressors. The biofilms exposed only to TCS recovered far better than those subjected to both altered flow and subsequent TCS exposure: the latter suffered more persistent consequences, indicating that simulated drought amplified the toxicity of this compound. This finding has implications for river ecosystems, as it suggests that the toxicity of pollutants to biofilms may be exacerbated following a drought.


Assuntos
Biofilmes/efeitos dos fármacos , Secas , Triclosan/toxicidade , Poluentes Químicos da Água/toxicidade , Análise de Variância , Rios/microbiologia , Fatores de Tempo
14.
Minerva Chir ; 67(2): 165-73, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22487918

RESUMO

AIM: Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Surgery remains the elective treatment. We retrospectively compared two group of patients, who underwent surgery for GIST before and after Imatinib advent in order to analyze the recurrence and survival rate. METHODS: Two patient groups who underwent surgery for GIST, from January 1997 to December 2002 (Pre-Imatinib group) and from January 2003 to December 2008 (Post-Imatinib group) were compared. Patients were evaluated on the base of gender, age, clinical manifestations, primary location and metastasis positivity, tumor size, mitotic index, immunoreactivity for CD117 and the outcome, including date of death. RESULTS: In the Pre-IM group only one patient died for prostate cancer, 12 months after operation, the other died because of GIST with a 24.6 months of median survival rate (range 15-51). In the remaining 12 patients the median follow up period was 55 months (range 6-152 months). In the Post-IM group the mean follow up was 50.7 months (range 26-74) and they are still being assessed for oncological as well as surgical treatment. CONCLUSION: Early diagnosis and radical resection remain the standard of cure for GISTs. To date, the use of Imatinib lead to its utilization as adjuvant and neo-adjuvant therapy in adults. Our experience suggests that there is a correlation between the mutational status of KIT and clinical outcome. These aspects should be explored for targeted therapy that can effectively combine biological therapy to surgery.


Assuntos
Antineoplásicos/uso terapêutico , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/cirurgia , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Feminino , Humanos , Mesilato de Imatinib , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
Sci Total Environ ; 426: 180-7, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22503678

RESUMO

The regulation of large rivers to meet human requirements (e.g. hydroelectricity production, flood prevention, recreation activities) alters the longitudinal distribution of plankton communities and may affect their capacity to use nutrients and organic matter. Here we analyzed phosphorus (P) availability and use by phytoplankton and bacterioplankton in 6 upstream and 5 downstream sites from a reservoir system in the Ebro River (N Spain). Alkaline phosphatase activity (APA) was related to nutrient availability and biomass of both phytoplankton and bacterioplankton. During dry periods phytoplankton and bacterioplankton APA was inversely correlated to P availability in the water, but these patterns became less clear during wet periods. The phosphorus-APA patterns were more consistent in the upstream sites and especially during dry periods. Although phytoplankton APA was 6-40 times greater than that of bacterioplankton, APA per unit of biomass suggested that bacterioplankton was more efficient at utilizing dissolved organic phosphorus (DOP) in the upstream section during dry periods. Imbalanced N:P ratios in the particulate (N:P ranging 133-170) and dissolved (N:P ranging 301-819) water fractions confirmed the strong P limitation in these upstream communities. The phosphorus-APA patterns were weaker in the downstream section and during wet periods. The reservoirs caused a change in the downstream dynamics, where bacterioplankton biomass was positively correlated to APA but APA per unit of biomass decreased. Our findings reveal that river regulation drives changes in plankton use of organic phosphorus, especially during extreme dry periods.


Assuntos
Fósforo/metabolismo , Plâncton/crescimento & desenvolvimento , Rios/química , Poluentes Químicos da Água/metabolismo , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Monitoramento Ambiental , Fósforo/análise , Plâncton/metabolismo , Rios/microbiologia , Espanha , Poluentes Químicos da Água/análise
16.
Sci Total Environ ; 409(17): 3129-37, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21621820

RESUMO

The effects of the herbicide Diuron (DIU) and the bactericide Triclosan (TCS) were assessed on laboratory-grown stream biofilms. Four week-old biofilms were exposed in mesocosms to 48-hours of short pulses of either DIU or TCS. The direct and indirect effects of each toxicant on the biofilms, and the subsequent recovery of the biofilms, were evaluated according to structural and functional biomarkers. These parameters were analyzed immediately before exposure, immediately after exposure, and 9 and 16days post-exposure. DIU caused an increase in diatom mortality (+79%), which persisted until the end of the experiment. TCS also affected diatom mortality (+41%), although the effect did not appear until 1week post-exposure. TCS caused an increase in bacterial mortality (+45%); however, this parameter returned to normal values 1week post-exposure. TCS compromised the cellular integrity of the green alga Spirogyra sp., whereas DIU did not. TCS also strongly inhibited phosphate uptake (-71%), which did not return to normal values until 2weeks post-exposure. DIU directly affected algae, but barely affected the heterotrophs, whereas TCS seriously impaired bacteria (direct effect) as well as autotrophs (indirect effect). However, the biofilms recovered their normal structure and function within only a few days to a few weeks. These findings demonstrate the capacity of biofilms to cope with periodic inputs of toxicants, but also the risks associated to repeated exposure or multi-contamination in aquatic ecosystems.


Assuntos
Biofilmes/efeitos dos fármacos , Diurona/toxicidade , Resistência a Medicamentos/efeitos dos fármacos , Rios/química , Triclosan/toxicidade , Poluentes Químicos da Água/toxicidade , Anti-Infecciosos Locais/análise , Anti-Infecciosos Locais/toxicidade , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Clorófitas/efeitos dos fármacos , Clorófitas/crescimento & desenvolvimento , Clorófitas/metabolismo , Diatomáceas/efeitos dos fármacos , Diatomáceas/crescimento & desenvolvimento , Diatomáceas/metabolismo , Diurona/análise , Herbicidas/análise , Herbicidas/toxicidade , Fosfatos/análise , Fosfatos/metabolismo , Fotossíntese/efeitos dos fármacos , Rios/microbiologia , Triclosan/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo
17.
Arch Environ Contam Toxicol ; 58(4): 955-62, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20020116

RESUMO

Herbicides affect the structure and functional parameters of fluvial biofilm. Diuron is toxic to primary producers and disrupts endocrine activity. Here, we studied the interaction between this toxicant and several biological compartments in a simple food chain composed of herbivores (the snail Physella [Costatella] acuta) and biofilm. We used indoor experimental channels to which Diuron was added at a realistic concentration (2 mug/L). Bacterial survival and chlorophyll-a and photosynthetic activity were analyzed in the biofilm. We monitored biomass, mortality, reproduction, and motility as end points in the freshwater snail P. acuta. Our results showed that bacterial survival and photosynthetic activity were sensitive to Diuron. Snails were not affected by the herbicide at the concentration tested. No significant interactions between the toxicant and grazers were observed on the biofilm. Reproductive traits, however, were slightly affected, indicating a possible endocrine disruption.


Assuntos
Biofilmes/efeitos dos fármacos , Diurona/toxicidade , Comportamento Alimentar/fisiologia , Herbicidas/toxicidade , Lymnaea/crescimento & desenvolvimento , Poluentes Químicos da Água/toxicidade , Animais , Biofilmes/crescimento & desenvolvimento , Biomassa , Clorofila/análise , Clorofila A , Eucariotos/efeitos dos fármacos , Eucariotos/crescimento & desenvolvimento , Cadeia Alimentar , Modelos Biológicos , Fotossíntese/efeitos dos fármacos , Microbiologia da Água
18.
G Chir ; 29(11-12): 497-504, 2008.
Artigo em Italiano | MEDLINE | ID: mdl-19068188

RESUMO

BACKGROUND: In the last ten years the introduction of various open mesh and laparoscopic techniques has increased the interest in inguinal hernia surgery. Anyway controversy persists about the most effective inguinal hernia repair. The aim of this study was to compare the results of open mesh technique and laparoscopic transabdominal preperitoneal (TAPP) repair for inguinal hernia. PATIENTS AND METHODS: We considered 584 patients, 532 man and 52 woman, between 19 and 86 years: 332 (56.8%) had open mesh repair and 252 (43.2%) laparoscopic TAPP repair of groin hernia. Operative time, complications, recurrences and time to normal activities were recorded in both groups (range follow-up 1-10 years). RESULTS: The median operative time was 71 min for open group and 92 min for TAPP group. No intraoperative complications were observed. Postoperative complication rate was 4,5% in patients open group and 3% in TAPP group. The recurrence rate was less than 1% in both groups (0,6% for open repair and 0,4% for laparoscopic repair). Significant difference was observed in the median time to return to normal activities: 9,8 days in TAPP group versus 13,4 days in open approach. CONCLUSIONS: Our experience confirmed the safety and effectiveness of laparoscopic transabdominal preperitoneal (TAPP) approach to inguinal hernia repair as excellent alternative to conventional surgery. The reduction of operative time, complications and recurrences is correlated to the surgeon's experience and learning curve.


Assuntos
Hérnia Inguinal/cirurgia , Laparoscopia , Telas Cirúrgicas , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Procedimentos Cirúrgicos Operatórios/métodos , Adulto Jovem
19.
G Chir ; 29(10): 407-12, 2008 Oct.
Artigo em Italiano | MEDLINE | ID: mdl-18947462

RESUMO

The goal of this study was to evaluate the complication rate of reoperative thyroid surgery and to find out the way to minimize the morbidity associated with it. We reviewed our experience in 622 patients, who underwent thyroid operation from January 2000 to September 2007. Among these ones, 76 were the patients who underwent reoperative thyroid surgery. Prior surgery in the 76 reoperations was: nucleo-resection in 9 pts (12.9%), lobectomy in 43 pts (55.5%), lobectomy+isthmectomy in 7 pts (9.3%), subtotal thyroidectomy in 17 pts (22.2%). Histologic examination revealed: benign lesions in 67 pts (88.15%), papillary cancer in 4 pts (5.26%), follicular cancer in 2 pts (2.63%), follicular adenoma in 1 pt (1.32%) and Hashimoto thyroiditis in 2 pts (2.63%). Complications included: section of recurrent laryngeal nerve, that was reconstructed in the same operation, and bilateral palsy of the recurrent laryngeal nerve so that was necessary to make a tracheotomy. One of the patient at the first thyroid surgery had monolateral palsy of the recurrent laryngeal nerve with dyspnoea and dysphonia. Temporary hypoparathyroidism (Ca<8 mg/dl) occurred in 47.3% of the patients, who underwent reoperative thyroid surgery and in 45.2% of the patients, who underwent prior thyroid surgery. Conclusions. This study documents that reoperative thyroid surgery can be performed with little morbidity to the patient if precise operative rules are respected.


Assuntos
Doenças da Glândula Tireoide/cirurgia , Tireoidectomia , Adenocarcinoma Folicular/cirurgia , Adenoma/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/cirurgia , Feminino , Doença de Hashimoto/cirurgia , Humanos , Hipoparatireoidismo/etiologia , Complicações Intraoperatórias/etiologia , Traumatismos do Nervo Laríngeo , Masculino , Pessoa de Meia-Idade , Reoperação , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/efeitos adversos , Resultado do Tratamento , Adulto Jovem
20.
G Chir ; 28(3): 73-81, 2007 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-17419903

RESUMO

Primary adenocarcinoma of the appendix is a rare malignancy that constitutes less than 0.5% of all gastrointestinal neoplasms. Usually the diagnosis is made only after histological examination of surgically removed inflamed appendix. Alternatively represent an unexpected finding, confirmed by frozen section, during surgery performed for acute appendicitis or other non appendiceal pathologies. Natural history is strongly influenced by anatomic peculiarities of the appendix that predispose to early spread and perforation. Frequently is associated with synchronous and metachronous colorectal or extraintestinal cancers. The correct management is the right hemicolectomy as a primary procedure in the case of preoperatively or intraoperatively diagnosis or as secondary procedure, after two-three weeks from appendectomy, when the microscopic examination of specimen reveals the presence of adenocarcinoma. Right hemicolectomy is the best treatment for all histologic types (colonic, mucinous, adenocarcinoid), in presence of perforation and even in Dukes A tumors. A careful intraoperative search for synchronous lesions and a life-long program of surveillance for the detection of early stage metachronous carcinomas are recommended. The Authors report a case of primary adenocarcinoma of the appendix occurred in a 78 year-old female patient, diagnosed incidentally during surgery performed for ileus from suspected cecal neoplasm.


Assuntos
Neoplasias do Apêndice , Carcinoma de Células em Anel de Sinete , Idoso , Neoplasias do Apêndice/diagnóstico por imagem , Neoplasias do Apêndice/cirurgia , Carcinoma de Células em Anel de Sinete/diagnóstico por imagem , Carcinoma de Células em Anel de Sinete/cirurgia , Feminino , Humanos , Radiografia
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