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1.
Microb Ecol ; 87(1): 33, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38236289

RESUMO

The freshwater raphidophyte Gonyostomum semen forms extensive summer blooms in northern European humic lakes. The development of these blooms might be facilitated by a lack of natural top-down control, as few zooplankton species are able to prey on these large algal cells (up to 100 µm) that expel trichocysts upon physical stress. In this study, we describe a small ciliate species (< 17 µm) that preys on G. semen by damaging the cell membrane until cytoplasm and organelles spill out. Sequencing of clonal cultures of the ciliate tentatively identified it as the prostomatid species Urotricha pseudofurcata. Grazing experiments illustrated that feeding by U. cf. pseudofurcata can significantly reduce cell concentrations of the microalga. However, differences in cell size and growth rate between two investigated ciliate strains resulted in noticeably different grazing pressure. Environmental sequencing data from five different lakes supported potential interactions between the two species. Urotricha cf. pseudofurcata might, thus, play an important role in aquatic ecosystems that are regularly dominated by G. semen, reducing the abundance of this bloom-forming microalga and enabling transfer of organic carbon to higher trophic levels.


Assuntos
Cilióforos , Microalgas , Ecossistema , Sêmen , Carbono , Lagos
2.
Environ Microbiol ; 25(11): 2289-2302, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37381117

RESUMO

When bacterial communities mix, immigration history can fundamentally affect the community composition as a result of priority effects. Priority effects arise when an early immigrant exhausts resources and/or alters habitat conditions, thereby influencing the establishment success of the late arriver. The strength of priority effects is context-dependent and expected to be stronger if environmental conditions favour the growth of the first arriver. In this study, we conducted a two-factorial experiment testing the importance of nutrient availability and grazing on the strength of priority effects in complex aquatic bacterial communities. We did so by mixing two dissimilar communities, simultaneously, and with a 38 h time-delay. Priority effects were measured as the invasion resistance of the first community to the invading second community. We found stronger priority effects in treatments with high nutrient availability and absence of grazing, but in general, the arrival timing was less important than the selection by nutrients and grazing. At the population level, the results were complex, but priority effects may have been driven by bacteria belonging to for example, the genera Rhodoferax and Herbaspirillum. Our study highlights the importance of arrival timing in complex bacterial communities, especially if environmental conditions favour rapid community growth.


Assuntos
Ecossistema , Água Doce , Água Doce/microbiologia , Bactérias/genética , Nutrientes
3.
Mol Ecol ; 30(5): 1345-1356, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33448073

RESUMO

The immigration history of communities can profoundly affect community composition. For instance, early-arriving species can have a lasting effect on community structure by reducing the invasion success of late-arriving ones through priority effects. This can be particularly important when early-arriving communities coalesce with another community during dispersal (mixing) events. However, the outcome of such community coalescence is unknown as we lack knowledge on how different factors influence the persistence of early-arriving communities and the invasion success of late-arriving taxa. Therefore, we implemented a full-factorial experiment with aquatic bacteria where temperature and dispersal rate of a better adapted community were manipulated to test their joint effects on the resistance of early-arriving communities to invasion, both at community and population level. Our 16S rRNA gene sequencing-based results showed that invasion success of better adapted late-arriving bacteria equaled or even exceeded what we expected based on the dispersal ratios of the recipient and invading communities suggesting limited priority effects on the community level. Patterns detected at the population level, however, showed that resistance of aquatic bacteria to invasion might be strengthened by warming as higher temperatures (a) increased the sum of relative abundances of persistent bacteria in the recipient communities, and (b) restricted the total relative abundance of successfully established late-arriving bacteria. Warming-enhanced resistance, however, was not always found and its strengths differed between recipient communities and dispersal rates. Nevertheless, our findings highlight the potential role of warming in mitigating the effects of invasion at the population level.


Assuntos
Bactérias , Ecossistema , Bactérias/genética , RNA Ribossômico 16S/genética
4.
J Phycol ; 57(4): 1309-1322, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33749827

RESUMO

The bloom-forming freshwater alga Gonyostomum semen is associated with acidic, mesotrophic brown water lakes in boreal regions. However, researchers have been unable to conclusively link G. semen abundance and bloom formation to typical brown water lake traits, that is, high water color and DOC (dissolved organic carbon) concentrations. Iron is a main driver of water color in boreal lakes, and a recent study of lake monitoring data indicated a connection between lakes with high G. semen abundance and iron concentrations >200 µg · L-1 . Thus, iron may be the missing link in explaining G. semen abundance and growth dynamics. We experimentally assessed the effects of different iron concentrations above or below 200 µg · L-1 on the growth of G. semen batch monocultures. Iron concentrations <200 µg · L-1 limited G. semen growth, while iron concentrations >200 µg · L-1 did not. Moreover, the iron concentration of the medium required for growth was higher than for other common phytoplankton (Microcystis botrys and Chlamydomonas sp.) included in the experiment. These results indicate that G. semen requires high levels of iron in the lake environment. Consequently, this and previous findings using lake monitoring data support the hypothesis that high concentrations of iron favor the formation of high-density G. semen blooms in boreal brown water lakes. As lakes get browner in a changing climate, monitoring iron levels could be a potential tool to identify lakes at risk for G. semen blooms, especially among lakes that provide ecosystem services to society.


Assuntos
Ecossistema , Sêmen , Ferro , Lagos , Microcystis
5.
Ecol Lett ; 21(1): 21-30, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29106075

RESUMO

Ecological stability is the central framework to understand an ecosystem's ability to absorb or recover from environmental change. Recent modelling and conceptual work suggests that stability is a multidimensional construct comprising different response aspects. Using two freshwater mesocosm experiments as case studies, we show how the response to single perturbations can be decomposed in different stability aspects (resistance, resilience, recovery, temporal stability) for both ecosystem functions and community composition. We find that extended community recovery is tightly connected to a nearly complete recovery of the function (biomass production), whereas systems with incomplete recovery of the species composition ranged widely in their biomass compared to controls. Moreover, recovery was most complete when either resistance or resilience was high, the latter associated with low temporal stability around the recovery trend. In summary, no single aspect of stability was sufficient to reflect the overall stability of the system.


Assuntos
Biomassa , Ecossistema
6.
Acta Neuropsychiatr ; 30(3): 137-147, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28803577

RESUMO

OBJECTIVE: To evaluate the performances of two auditory brainstem response (ABR) profiling tests as potential biomarkers and diagnostic support for schizophrenia and adult attention-deficit hyperactivity disorder (ADHD), respectively, in an investigator-initiated blinded study design. METHOD: Male and female patients with schizophrenia (n=26) and adult ADHD (n=24) meeting Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM IV) diagnostic criteria and healthy controls (n=58) comprised the analysis set (n=108) of the total number of study participants (n=119). Coded sets of randomized ABR recordings were analysed by an independent party blinded to clinical diagnoses before a joint code-breaking session. RESULTS: The ABR profiling test for schizophrenia identified schizophrenia patients versus controls with a sensitivity of 84.6% and a specificity of 93.1%. The ADHD test identified patients with adult ADHD versus controls with a sensitivity of 87.5% and a specificity of 91.4%. CONCLUSION: The ABR profiling tests discriminated schizophrenia and ADHD versus healthy controls with high sensitivity and specificity. The methods deserve to be further explored in larger clinical studies including a broad range of psychiatric disorders to determine their utility as potential diagnostic biomarkers.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Esquizofrenia/fisiopatologia , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Biomarcadores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esquizofrenia/diagnóstico , Sensibilidade e Especificidade , Adulto Jovem
7.
Environ Microbiol ; 19(1): 251-260, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27871136

RESUMO

Dispersal can modify how bacterial community composition (BCC) changes in response to environmental perturbations, yet knowledge about the functional consequences of dispersal is limited. Here we hypothesized that changes in bacterial community production in response to a salinity disturbance depend on the possibility to recruit cells from different dispersal sources. To investigate this, we conducted an in situ mesocosm experiment where bacterial communities of an oligotrophic lake were exposed to different salinities (0, 18, 36 psu) for 2 weeks and subjected to dispersal of cells originating from sediments, air (mesocosms open to air deposition), both or none. BCC was determined using 454 pyrosequencing of the 16S rRNA gene and bacterial production was measured by 3 H leucine uptake. Bacterial production differed significantly among salinity treatments and dispersal treatments, being highest at high salinity. These changes were associated with changes in BCC and it was found that the identity of the main functional contributors differed at different salinities. Our results further showed that after a salinity perturbation, the response of bacterial communities depended on the recruitment of taxa, including marine representatives (e.g., Alphaproteobacteria Loktanella, Erythrobacter and the Gammaproteobacterium Rheiheimera) from dispersal sources, in which atmospheric deposition appeared to play a major role.


Assuntos
Bactérias/metabolismo , Lagos/microbiologia , Plâncton/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Ecossistema , Lagos/química , Plâncton/classificação , Plâncton/genética , Plâncton/isolamento & purificação , RNA Ribossômico 16S/genética , Salinidade
8.
Environ Microbiol ; 19(12): 5078-5087, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29124844

RESUMO

Aquatic environments are typically not homogenous, but characterized by changing substrate concentration gradients and nutrient patches. This heterogeneity in substrate availability creates a multitude of niches allowing bacteria with different substrate utilization strategies to hypothetically coexist even when competing for the same substrate. To study the impact of heterogeneous distribution of organic substrates on bacterioplankton, bioreactors with freshwater bacterial communities were fed artificial freshwater medium with acetate supplied either continuously or in pulses. After a month-long incubation, bacterial biomass and community-level substrate uptake rates were twice as high in the pulsed treatment compared to the continuously fed reactors even if the same total amount of acetate was supplied to both treatments. The composition of the bacterial communities emerging in the two treatments differed significantly with specific taxa overrepresented in the respective treatments. The higher estimated growth yield in cultures that received pulsed substrate inputs, imply that such conditions enable bacteria to use resources more efficiently for biomass production. This finding agrees with established concepts of basal maintenance energy requirements and high energetic costs to assimilate substrates at low concentration. Our results further imply that degradation of organic matter is influenced by temporal and spatial heterogeneity in substrate availability.


Assuntos
Acetatos/metabolismo , Bactérias/classificação , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Lagos/análise , Lagos/microbiologia , Organismos Aquáticos/microbiologia , Bactérias/crescimento & desenvolvimento , Carga Bacteriana , Biomassa , Plâncton/metabolismo , Plâncton/microbiologia
9.
Environ Microbiol ; 19(6): 2391-2404, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28401636

RESUMO

The diversity and composition of lake bacterial communities are driven by the interplay between local contemporary environmental conditions and dispersal of cells from the surroundings, i.e. the metacommunity. Still, a conceptual understanding of the relative importance of the two types of factors is lacking. For instance, it is unknown which sources of dispersal are most important and under which circumstances. Here, we investigated the seasonal variation in the importance of dispersal from different sources (mixing, precipitation, surface runoff and sediment resuspension) for lake bacterioplankton community and population dynamics. For that purpose, two small forest lakes and their dispersal sources were sampled over a period of 10 months. The influence of dispersal on communities and populations was determined by 454 sequencing of the 16S rRNA gene and SourceTracker analysis. On the community level direct effects of dispersal were questionable from all sources. Instead we found that the community of the preceding sampling occasion, representing growth of resident bacteria, was of great importance. On the population level, however, dispersal of individual taxa from the inlet could be occasionally important even under low water flow. The effect of sediment resuspension and precipitation appeared small.


Assuntos
Actinobacteria/metabolismo , Sedimentos Geológicos/microbiologia , Lagos/microbiologia , Microbiota/fisiologia , Plâncton/metabolismo , Proteobactérias/metabolismo , Actinobacteria/classificação , Actinobacteria/genética , Clima , Microbiota/genética , Plâncton/classificação , Plâncton/genética , Dinâmica Populacional , Proteobactérias/classificação , Proteobactérias/genética , RNA Ribossômico 16S/genética , Estações do Ano
10.
Platelets ; 27(1): 86-92, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25970449

RESUMO

Exocytosis of lysosomal contents from platelets has been speculated to participate in clearance of thrombi and vessel wall remodelling. The mechanisms that regulate lysosomal exocytosis in platelets are, however, still unclear. The aim of this study was to identify the pathways underlying platelet lysosomal secretion and elucidate how this process is controlled by platelet inhibitors. We found that high concentrations of thrombin induced partial lysosomal exocytosis as assessed by analysis of the activity of released N-acetyl-ß-glucosaminidase (NAG) and by identifying the fraction of platelets exposing the lysosomal-associated membrane protein (LAMP)-1 on the cell surface by flow cytometry. Stimulation of thrombin receptors PAR1 or PAR4 with specific peptides was equally effective in inducing LAMP-1 surface expression. Notably, lysosomal exocytosis in response to thrombin was significantly reduced if the secondary activation by ADP was inhibited by the P2Y12 antagonist cangrelor, while inhibition of thromboxane A2 formation by treatment with acetylsalicylic acid was of minor importance in this regard. Moreover, the NO-releasing drug S-nitroso-N-acetyl penicillamine (SNAP) or the cyclic AMP-elevating eicosanoid prostaglandin I2 (PGI2) significantly suppressed lysosomal exocytosis. We conclude that platelet inhibitors that mimic functional endothelium such as PGI2 or NO efficiently counteract lysosomal exocytosis. Furthermore, we suggest that secondary release of ADP and concomitant signaling via PAR1/4- and P2Y12 receptors is important for efficient platelet lysosomal exocytosis by thrombin.


Assuntos
Difosfato de Adenosina/sangue , Plaquetas/metabolismo , Acetilglucosaminidase/sangue , Difosfato de Adenosina/farmacologia , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Plaquetas/efeitos dos fármacos , Epoprostenol/sangue , Exocitose/efeitos dos fármacos , Humanos , Proteínas de Membrana Lisossomal/biossíntese , Proteínas de Membrana Lisossomal/sangue , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Receptor PAR-1/sangue , Trombina/farmacologia
11.
Environ Microbiol ; 17(7): 2275-87, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25367396

RESUMO

Effects of dispersal and the presence of predators on diversity, assembly and functioning of bacterial communities are well studied in isolation. In reality, however, dispersal and trophic interactions act simultaneously and can therefore have combined effects, which are poorly investigated. We performed an experiment with aquatic metacommunities consisting of three environmentally different patches and manipulated dispersal rates among them as well as the presence or absence of the keystone species Daphnia magna. Daphnia magna reduced both local and regional diversity, whereas dispersal increased local diversity but decreased beta-diversity having no net effect on regional diversity. Dispersal modified the assembly mechanisms of bacterial communities by increasing the degree of determinism. Additionally, the combination of the D. magna and dispersal increased the importance of deterministic processes, presumably because predator-tolerant taxa were spread in the metacommunity via dispersal. Moreover, the presence of D. magna affected community composition, increased community respiration rates but did not affect bacterial production or abundance, whereas dispersal slightly increased bacterial production. In conclusion, our study suggests that predation by a keystone species such as D. magna and dispersal additively influence bacterial diversity, assembly processes and ecosystem functioning.


Assuntos
Bactérias , Biodiversidade , Daphnia/fisiologia , Consórcios Microbianos , Comportamento Predatório/fisiologia , Zooplâncton/fisiologia , Animais
12.
Ecology ; 95(5): 1134-40, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-25000745

RESUMO

The spatial structure of ecological communities, including that of bacteria, is often influenced by species sorting by contemporary environmental conditions. Moreover, historical processes, i.e., ecological and evolutionary events that have occurred at some point in the past, such as dispersal limitation, drift, priority effects, or selection by past environmental conditions, can be important, but are generally investigated much less. Here, we conducted a field study using 16 rock pools, where we specifically compared the importance of past vs. contemporary environmental conditions for bacterial community structure by correlating present differences in bacterial community composition among pools to environmental conditions measured on the same day, as well as to those measured 2, 4, 6, and 8 d earlier. The results prove that selection by past environmental conditions exists, since we were able to show that bacterial communities are, to a greater extent, an imprint of past compared to contemporary environmental conditions. We suggest that this is the result of a combination of different mechanisms, including priority effects that cause rapid adaptation to new environmental conditions of taxa that have been initially selected by past environmental conditions, and slower rates of turnover in community composition compared to environmental conditions.


Assuntos
Bactérias , Microbiologia da Água , Ecossistema , Meio Ambiente , Oceanos e Mares
13.
Pharmacoepidemiol Drug Saf ; 23(3): 290-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24435842

RESUMO

PURPOSE: The aim of this study was to analyse prescription refill, re-hospitalisation, total mortality, mortality because of suicide and attempted suicide among patients who were taking various types of antipsychotics. METHODS: A population-based cohort study analysed all patients (n=26046) in Sweden who had been treated for schizophrenia from 2006 to 2009 with regard to re-hospitalisation and prescription refill for various types of antipsychotic treatment. A case-control study nested within the cohort analysed all-cause mortality, mortality because of suicide and attempted suicide in relation to antipsychotic use. The study adjusted for history of hospitalisation for psychiatric and medical care, attempted suicide and use of antidepressants. RESULTS: Aripiprazole users were the only ones who showed significantly lower all-cause risks of death, but so few events occurred among users of this relatively new drug that the results should be interpreted with caution. Clozapine users showed lower odds of death by suicide (odds ratio [OR]=0.45 [95%CI 0.20-0.98]) and of attempted suicide (OR=0.44 [0.28-0.70]) than haloperidol users after adjustment for age, sex and year of discharge. Olanzapine users showed approximately the same favourable pattern. Patients who used clozapine were most likely to refill prescriptions and had lower rates of re-hospitalisation. Only one death and 23 cases of agranulocytosis were reported compared with 223 suicides and 831 suicide attempts. An etiologic fraction calculation suggests that the use of clozapine rather than traditional drugs could have prevented 95 suicide attempts during the period. CONCLUSION: Clozapine and olanzapine reduce the risk of suicide, attempted suicide and re-hospitalisation.


Assuntos
Antipsicóticos/administração & dosagem , Clozapina/administração & dosagem , Prescrições de Medicamentos , Hospitalização , Tentativa de Suicídio/prevenção & controle , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Hospitalização/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Tentativa de Suicídio/psicologia , Suécia/epidemiologia , Adulto Jovem
14.
Platelets ; 25(2): 111-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23534390

RESUMO

The aim of the present study was to investigate the role of 12-lipoxygenase (12-LOX) on platelet-induced airway smooth muscle cell (ASMC) proliferation. Co-incubation of platelets and ASMC caused platelet activation as determined by morphological changes. Simultaneously, reactive oxygen species (ROS)-generation was detected and ASMC proliferation (measured by using the MTS assay) increased significantly. Furthermore, we found that the 12-LOX inhibitors cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC) and Baicalein prevented platelet activation in a co-cultures of platelets and ASMC. The inhibitory effect of CDC and Baicalein on platelets was also registered in a pure platelet preparation. Specifically, the 12-LOX inhibitors reduced collagen-induced platelet aggregation both in the presence and absence of external added fibrinogen. Importantly, platelet-induced ASMC proliferation and ROS production generated during the platelet/ASMC interaction was significantly inhibited in the presence of 12-LOX inhibitors. In conclusion, our findings reveal that 12-LOX is crucial for the observed enhancement of ASMC proliferation in co-cultures of platelets and ASMC. The present result suggests that 12-LOX activity is important in the initial step of platelet/ASMC interaction and platelet activation. Such action of 12-LOX represents a potential important mechanism that may contribute to platelet-induced airway remodelling.


Assuntos
Araquidonato 12-Lipoxigenase/metabolismo , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Inibidores de Lipoxigenase/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Remodelação das Vias Aéreas , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Ativação Enzimática , Humanos , Miócitos de Músculo Liso/metabolismo , Espécies Reativas de Oxigênio/metabolismo
15.
Nord J Psychiatry ; 68(8): 573-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24724929

RESUMO

OBJECTIVE: To investigate the association between the Positive and Negative Syndrome Scale (PANSS) cognitive factors and cognition assessed by neuropsychological tests. METHOD: Ninety patients with a psychotic illness, the majority having a schizophrenia diagnosis, were assessed with PANSS ratings and tested by a comprehensive computerized neuropsychological test battery, EuCog. RESULTS: Test performance was in the normal range for some of the cognitive indices, but substantially reduced for others, compared with norms, particularly speed-based indices. PANSS ratings were non-specifically associated with cognitive indices representing performance (speed and accuracy) and problem solving strategies (executive functions). There was no discriminant validity for the cognitive factor. A regression analysis suggested that the PANSS cognitive factors reflected verbal IQ but no other cognitive domain like memory, attention or speed. CONCLUSION: Cognitive test performance is associated with psychopathology as assessed by PANSS items but in a non-specific way. The PANSS cognitive subscale seems to reflect over-learned verbal skills rather than the cognitive domains, which are known to be specifically affected in schizophrenia and relevant for the prognosis. Consequently, PANSS ratings cannot replace the information inherent in neuropsychological test data. The extensive speed problem of patients with schizophrenia should be studied in more detail using test batteries that focus on that problem.


Assuntos
Transtorno Bipolar/diagnóstico , Transtornos Cognitivos/diagnóstico , Testes Neuropsicológicos/normas , Escalas de Graduação Psiquiátrica/normas , Transtornos Psicóticos/diagnóstico , Esquizofrenia/diagnóstico , Adulto , Transtorno Bipolar/complicações , Transtornos Cognitivos/etiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Transtornos Psicóticos/complicações , Esquizofrenia/complicações
16.
Exp Cell Res ; 318(5): 632-40, 2012 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-22227408

RESUMO

Hyaluronic acid (HA) is one of the main components of the extracellular matrix (ECM) and is expressed throughout the body including the lung and mostly in areas surrounding proliferating and migrating cells. Furthermore, platelets have been implicated as important players in the airway remodelling process, e.g. due to their ability to induce airway smooth muscle cell (ASMC) proliferation. The aim of the present study was to investigate the role of HA, the HA-binding surface receptor CD44 and focal adhesion kinase (FAK) in platelet-induced ASMC proliferation. Proliferation of ASMC was measured using the MTS-assay, and we found that the CD44 blocking antibody and the HA synthase inhibitor 4-Methylumbelliferone (4-MU) significantly inhibited platelet-induced ASMC proliferation. The interaction between ASMC and platelets was studied by fluorescent staining of F-actin. In addition, the ability of ASMC to synthesise HA was investigated by fluorescent staining using biotinylated HA-binding protein and a streptavidin conjugate. We observed that ASMC produced HA and that a CD44 blocking antibody and 4-MU significantly inhibited platelet binding to the area surrounding the ASMC. Furthermore, the FAK-inhibitor PF 573228 inhibited platelet-induced ASMC proliferation. Co-culture of ASMC and platelets also resulted in increased phosphorylation of FAK as detected by Western blot analysis. In addition, 4-MU significantly inhibited the increased FAK-phosphorylation. In conclusion, our findings demonstrate that ECM has the ability to influence platelet-induced ASMC proliferation. Specifically, we propose that HA produced by ASMC is recognised by platelet CD44. The platelet/HA interaction is followed by FAK activation and increased proliferation of co-cultured ASMC. We also suggest that the mitogenic effect of platelets represents a potential important and novel mechanism that may contribute to airway remodelling.


Assuntos
Plaquetas/fisiologia , Proliferação de Células , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/fisiologia , Miócitos de Músculo Liso/fisiologia , Sistema Respiratório/citologia , Anticorpos/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Quinase 1 de Adesão Focal/metabolismo , Humanos , Ácido Hialurônico/biossíntese , Ácido Hialurônico/farmacologia , Miócitos de Músculo Liso/metabolismo , Fosforilação
17.
Acta Neuropsychiatr ; 25(3): 165-74, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25287470

RESUMO

OBJECTIVE: To investigate gender differences in psychiatric comorbidity patients diagnosed with attention-deficit hyperactivity disorder (ADHD) as adults. METHODS: Interviews about current ADHD symptoms and psychiatric comorbidity on axis I and II (Structured Clinical Interview for DSM-IV axis I and axis II) were conducted in a clinical cohort of 168 patients (78 women, 90 men). Independent information on childhood and current symptoms was collected from parents, partners and patient files. RESULTS: The lifetime prevalence of psychiatric comorbidity on axis I reached 92%, and current comorbidity, including autism spectrum disorders and Tourette's syndrome, was 47%. Women had a higher lifetime prevalence of mood and eating disorders compared with men, where substance-use disorders were more frequent. Ten per cent of patients fulfilled diagnostic criteria for a personality disorder. When excluding the general diagnostic criteria, 46% of the patients endorsed the specific criteria for at least one personality disorder. Gender differences were identified with predominance of histrionic personality traits in women and conduct disorder in men. CONCLUSION: Patients diagnosed with ADHD as adults display an extremely high lifetime axis I comorbidity with a gender-specific pattern similar to the general population. No gender differences were identified with regard to personality disorders; however, an increased prevalence of deviant personality traits was confirmed. This study stresses the importance of evaluating comorbidity among patients diagnosed with ADHD as adults to secure optimal treatment.

18.
Sci Rep ; 13(1): 13503, 2023 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-37598248

RESUMO

Lakes located in the boreal region are generally supersaturated with carbon dioxide (CO2), which emerges from inflowing inorganic carbon from the surrounding watershed and from mineralization of allochthonous organic carbon. While these CO2 sources gained a lot of attention, processes that reduce the amount of CO2 have been less studied. We therefore examined the CO2 reduction capacity during times of phytoplankton blooms. We investigated partial pressure of CO2 (pCO2) in two lakes at times of blooms dominated by the cyanobacterium Gloeotrichia echinulata (Erken, Sweden) or by the nuisance alga Gonyostomum semen (Erssjön, Sweden) during two years. Our results showed that pCO2 and phytoplankton densities remained unrelated in the two lakes even during blooms. We suggest that physical factors, such as wind-induced water column mixing and import of inorganic carbon via inflowing waters suppressed the phytoplankton signal on pCO2. These results advance our understanding of carbon cycling in lakes and highlight the importance of detailed lake studies for more precise estimates of local, regional and global carbon budgets.


Assuntos
Desequilíbrio Ácido-Base , Fitoplâncton , Humanos , Dióxido de Carbono , Lagos , Fotossíntese
19.
Mult Scler ; 18(10): 1384-94, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22457343

RESUMO

BACKGROUND: The role played by genetic factors in influencing the clinical course of multiple sclerosis (MS) is not yet well established. OBJECTIVE: We aimed to identify genetic variants associated with progressive MS (PrMS). METHODS: We conducted a genome-wide association study (GWAS) in 197 patients with PrMS and 234 controls of Italian origin. We tested the top 20 single nucleotide polymorphisms (SNPs) with suggestive evidence of association (p-value<10(-4)) in two independent sets of primary progressive MS cases and controls. RESULTS: We identified a risk-associated SNP in the HLA region in linkage disequilibrium (LD) with DRB1*1501 and DQB*0602 loci, with genome-wide significance (rs3129934(T), p (combined)=6.7×10(-16), OR=2.34, 95% CI=1.90-2.87), and a novel locus on chromosome 7q35 with suggestive evidence of association (rs996343(G), p (combined)=2.4×10(-5), OR=0.70, 95% CI=0.59-0.83) which maps within a human endogenous retroviral (HERV) element. The new locus did not have a 'cis' effect on RNA expression in lymphoblastic cell lines, but pathway analyses of 'trans' effects point to an expression regulation of genes involved in neurodegeneration, including glutamate metabolism (p<0.01) and axonal guidance signalling (p<0.02). CONCLUSIONS: We have confirmed the established association with the HLA region and, despite the low statistical power of the study, we found suggestive evidence for association with a novel locus on chromosome 7, with a putative regulatory role.


Assuntos
Cromossomos Humanos Par 7/genética , Predisposição Genética para Doença/genética , Antígenos HLA/genética , Esclerose Múltipla Crônica Progressiva/genética , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
20.
Nord J Psychiatry ; 66(1): 8-13, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21958235

RESUMO

OBJECTIVE: To investigate a series of consecutive suicides at a psychosis clinic by using a psychological autopsy technique. METHOD: The clinic serves an adult population of 225,000 individuals, of whom 0.5% have regular contact with the clinic. During a 7½-year period, 23 men and nine women committed suicide, which corresponds to an odds ratio of 14. RESULTS: Most patients were schizophrenic, and 24 were outpatients. Suicide methods were violent in all but two cases. Nineteen had a history of at least one suicide attempt, and 24 were known to have had suicidal ideation. More than half had no social contacts over the last year except with psychiatric staff. The median time between the last contact with the psychiatric services and the suicide was 4 days. No warning signs were noted. At the time of death, 3 of the 24 who were prescribed antipsychotics, and none of the 10 who were prescribed antidepressants had plasma levels of the corresponding drug. CONCLUSION: Findings of special interest are the lack of forewarnings and the poor drug compliance. Patients appear to have played "business as usual" with the care-givers, and did it well. Is it a sign of health and despair, or illness?


Assuntos
Transtornos Psicóticos/psicologia , Suicídio/psicologia , Adulto , Idoso , Antidepressivos/uso terapêutico , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Transtornos Psicóticos/complicações , Transtornos Psicóticos/tratamento farmacológico , Esquizofrenia/complicações , Esquizofrenia/tratamento farmacológico , Isolamento Social , Adulto Jovem
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