RESUMO
Agri-environment schemes (AES) are key mechanisms to deliver conservation policy, and include management to provide resources for target taxa. Mobile species may move to areas where resources are increased, without this necessarily having an effect across the wider countryside or on populations over time. Most assessments of AES efficacy have been at small spatial scales, over short timescales, and shown varying results. We developed a survey design based on orthogonal gradients of AES management at local and landscape scales, which will enable the response of several taxa to be monitored. An evidence review of management effects on butterflies, birds and pollinating insects provided data to score AES options. Predicted gradients were calculated using AES uptake, weighted by the evidence scores. Predicted AES gradients for each taxon correlated strongly, and with the average gradient across taxa, supporting the co-location of surveys across different taxa. Nine 1 × 1 km survey squares were selected in each of four regional blocks with broadly homogenous background habitat characteristics. Squares in each block covered orthogonal contrasts across the range of AES gradients at local and landscape scales. This allows the effects of AES on species at each scale, and the interaction between scales, to be tested. AES options and broad habitats were mapped in field surveys, to verify predicted gradients which were based on AES option uptake data. The verified AES gradient had a strong positive relationship with the predicted gradient. AES gradients were broadly independent of background habitat within each block, likely allowing AES effects to be distinguished from potential effects of other habitat variables. Surveys of several mobile taxa are ongoing. This design will allow mobile taxa responses to AES to be tested in the surrounding countryside, as well as on land under AES management, and potentially in terms of population change over time. The design developed here provides a novel, pseudo-experimental approach for assessing the response of mobile species to gradients of management at two spatial scales. A similar design process could be applied in other regions that require a standardized approach to monitoring the impacts of management interventions on target taxa at landscape scales, if equivalent spatial data are available.
Assuntos
Agricultura , Borboletas , Animais , Biodiversidade , Aves , Ecossistema , Meio AmbienteRESUMO
The class Dothideomycetes (along with Eurotiomycetes) includes numerous rock-inhabiting fungi (RIF), a group of ascomycetes that tolerates surprisingly well harsh conditions prevailing on rock surfaces. Despite their convergent morphology and physiology, RIF are phylogenetically highly diverse in Dothideomycetes. However, the positions of main groups of RIF in this class remain unclear due to the lack of a strong phylogenetic framework. Moreover, connections between rock-dwelling habit and other lifestyles found in Dothideomycetes such as plant pathogens, saprobes and lichen-forming fungi are still unexplored. Based on multigene phylogenetic analyses, we report that RIF belong to Capnodiales (particularly to the family Teratosphaeriaceae s.l.), Dothideales, Pleosporales, and Myriangiales, as well as some uncharacterised groups with affinities to Dothideomycetes. Moreover, one lineage consisting exclusively of RIF proved to be closely related to Arthoniomycetes, the sister class of Dothideomycetes. The broad phylogenetic amplitude of RIF in Dothideomycetes suggests that total species richness in this class remains underestimated. Composition of some RIF-rich lineages suggests that rock surfaces are reservoirs for plant-associated fungi or saprobes, although other data also agree with rocks as a primary substrate for ancient fungal lineages. According to the current sampling, long distance dispersal seems to be common for RIF. Dothideomycetes lineages comprising lichens also include RIF, suggesting a possible link between rock-dwelling habit and lichenisation.
RESUMO
Defence in young trees has been much less studied than defence in older ones. In conifers, resin within ducts in bark is an important quantitative defence, but its expression in young trees may be influenced by developmental or physical constraints on the absolute size of the resin ducts as well as by differential allocation of resources to growth and resin synthesis. To examine these relationships, we used nitrogen fertilisation of 1- and 2-year-old pine and spruce to produce trees of different sizes and measured the effect on the number and size of resin ducts and the amount of resin they contained. All of these variables tended to increase with stem diameter, indicating a positive relationship between resin-based defence and growth of 1- and 2-year-old trees. In pine, however, the mass of resin flowing from severed ducts was much lower relative to duct area in 1- than in 2-year-old trees, suggesting that the older trees allocated a higher proportion of the carbon budget to resin synthesis. Resin-based defence in 1-year-old pines appears to be both positively related to growth and resource limited. In spruce, resin production was generally lower, and age-related differences were not observed, suggesting that resin-based defence is less important in this species. Bio-assays of 2-year-old trees with the pine weevil, Hylobius abietis, emphasised the importance of resin as a defence against this bark feeding insect. Nitrogen fertilisation had a limited influence on resistance expression. One-year-old trees remained susceptible because of their small size, low resin production and limited response to fertilisation. The strong growth response of 2-year-old trees to fertilisation increased resin-based defence, but most spruce trees remained susceptible, while most pines were resistant at all levels of fertilisation.
Assuntos
Picea/crescimento & desenvolvimento , Pinus/crescimento & desenvolvimento , Resinas Vegetais/metabolismo , Gorgulhos/fisiologia , Animais , Comportamento Alimentar , Fertilizantes , Nitrogênio/farmacologia , Picea/anatomia & histologia , Picea/efeitos dos fármacos , Pinus/anatomia & histologia , Pinus/efeitos dos fármacos , Análise de RegressãoRESUMO
BACKGROUND: Perioperative delirium is common in high-risk surgery and is associated with age, education, preoperative cognitive functioning, pre-existing medical conditions, and postoperative complications. We investigated these factors as well as lifestyle and demographic variables by using cognitive measures that were more sensitive than those used in previous studies. METHODS: Extensive medical and demographic data were collected on 102 patients between 41 and 88 years of age to identify comorbidities and lifestyle considerations preoperatively. Elective abdominal aortic aneurysm surgery was performed under combined general/epidural anesthesia with postoperative epidural analgesia. A battery of sensitive, cognitive measures was administered preoperatively, at the time of discharge from hospital, and 3 months postoperatively. Symptoms of delirium were assessed during the first 6 postoperative days using Diagnostic and Statistical Manual of Mental Disorders-4th Edition criteria. Intraoperative and postoperative data, including medications, vital signs, conduct of the surgery and anesthesia, complications, and details of pain control, were collected. RESULTS: Delirium occurred in 33% of the patients during the first 6 days after surgery. Longer duration of delirium was related to lower education, preoperative depression, and greater preoperative psychoactive medication use. Characteristics of the surgery and hospital stay were unrelated to the development of delirium. Patients who were diagnosed with delirium had lower cognitive scores during each of the three assessment periods, even when controlling for age and education. Logistic regression analysis indicated that the most powerful preoperative predictors of delirium were number of pack years smoked (P = .001), mental status scores (P = .003), and number of psychoactive medications (P = .005). CONCLUSION: A significant proportion of patients undergoing elective abdominal aortic aneurysm repair are susceptible to the development of delirium and are at risk for cognitive dysfunction after surgery. Our findings have implications for promoting long-term lifestyle changes, including smoking cessation and improved management of mental health as risk-reduction strategies.
Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Cognição/fisiologia , Delírio , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Delírio/epidemiologia , Delírio/etiologia , Delírio/psicologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
Young plants of Sitka spruce, Scots and Corsican pine were subject to high and low light, and high and low nitrogen treatments in a polyhouse experiment. The effect of treatments on resin duct size and nitrogen concentration in stem bark was determined together with feeding by Hylobius abietis Linnaeus on the stems of 'intact' plants and on 'detached' stems cut from the plant. Resin duct size was largest on Corsican pine and smallest on Sitka spruce and inherent variation in duct size between the three conifer species appears to determine the pattern of weevil feeding between species. Resin ducts and the flow of resin from them protect the stems of young conifers from weevil feeding not by affecting the total amount of bark eaten but by limiting the depth of feeding and so protecting the inner phloem and cambium. Shallow feeding may increase the likelihood of effective wound repair. Duct size was positively related to plant growth and in particular increased with bark thickness. Overall, ducts were largest in the high light treatment although species differed in their response to the treatment. It is suggested that the effects of plant size, growing conditions and transplantation on susceptibility to attack by H. abietis, reported in various studies, may be due to underlying variation in resin duct size or flow rate. The effect on weevils of superficial feeding on stems is to increase the time for reproductive maturation by reducing consumption of the inner bark which has a higher nitrogen content.
Assuntos
Comportamento Alimentar/fisiologia , Nitrogênio/farmacologia , Pinaceae , Casca de Planta/efeitos dos fármacos , Gorgulhos/fisiologia , Animais , Modelos Lineares , Nitrogênio/metabolismo , Casca de Planta/anatomia & histologia , Casca de Planta/metabolismo , Caules de Planta/anatomia & histologia , Reprodução/fisiologia , Fatores de Tempo , Reino UnidoRESUMO
"Psychromonas ingrahamii," named for John L. Ingraham, was isolated from sea ice from off Point Barrow, Alaska. This large rod-shaped bacterium belongs to the gamma-Proteobacteria. "P. ingrahamii" is a psychrophilic, heterotrophic bacterium that is gas vacuolate and nonmotile. "P. ingrahamii" is notable in that it grows at a temperature of -12 degrees C with a generation time of 240 h. This is the lowest growth temperature of any organism authenticated by a growth curve.
Assuntos
Gammaproteobacteria/genética , Gelo , Fenótipo , Filogenia , Água do Mar/microbiologia , Alaska , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Gammaproteobacteria/crescimento & desenvolvimento , Modelos Genéticos , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Fatores de TempoRESUMO
Nicotine and other constituents of tobacco smoke elevate dopamine (DA) and serotonin (5-HT) levels in brain and may cause homeostatic adaptations in DA and 5-HT transporters. Since sex steroids alter DA and 5-HT transporter expression, the effects of smoking on DA and 5-HT transporter availability may differ between sexes. In the present study, DA and 5-HT transporter availabilities were quantitated using single photon emission computed tomography (SPECT) imaging approximately 22 h after bolus administration of [123I]beta-CIT, an analog of cocaine which labels DA and 5-HT transporters. Forty-two subjects including 21 pairs of age-, race-, and gender-matched healthy smokers and nonsmokers (12 female and 9 male pairs) were imaged. Regional uptake was assessed by the outcome measures, V3", which is the ratio of specific (i.e., ROI-cerebellar activity) to nondisplaceable (cerebellar) activity, and V3, the ratio of specific to free plasma parent. Overall, striatal and diencephalic [123I]beta-CIT uptake was not altered by smoking, whereas brainstem [123I]beta-CIT uptake was modestly higher (10%) in smokers vs. nonsmokers. When subgrouped by sex, regardless of smoking status, [123I]beta-CIT uptake was higher in the striatum (10%), diencephalon (15%), and brainstem (15%) in females vs. males. The sex*smoking interaction was not significant in the striatum, diencephalon, or brainstem, despite the observation of 20% higher brainstem [123I]beta-CIT uptake in male smokers vs. nonsmokers and less than a 5% difference between female smokers and nonsmokers. The results demonstrate higher DA and 5-HT transporter availability in females vs. males and no overall effect of smoking with the exception of a modest elevation in brainstem 5-HT transporters in male smokers. Although these findings are preliminary and need validation with a more selective 5-HT transporter radiotracer, the results suggest that brainstem 5-HT transporters may be regulated by smoking in a sex-specific manner.
Assuntos
Proteínas de Transporte/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso , Caracteres Sexuais , Fumar , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Afeto/fisiologia , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/metabolismo , Cocaína/análogos & derivados , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina , Feminino , Humanos , Radioisótopos do Iodo , Masculino , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos , Proteínas da Membrana Plasmática de Transporte de SerotoninaRESUMO
One strain of bacteria, designated NCE312, was isolated from a naphthalene-digesting chemostat culture that was inoculated with creosote-contaminated marine sediment. The strain was isolated based on its ability to grow using naphthalene as a sole carbon source. In addition, the strain degraded 2-methylnaphthalene and 1-methylnaphthalene. Analysis of a 16S rRNA gene sequence from NCE312 placed the isolate in the genus Marinobacter. Degenerate PCR primers were used to amplify a fragment of a naphthalene 1,2-dioxygenase large subunit gene. A phylogenetic analysis indicated the Marinobacter naphthalene dioxygenase is similar to those from Pseudomonas and Burkholderia strains suggesting that the dioxygenase gene may have been transferred horizontally between these lineages of bacteria.
Assuntos
Gammaproteobacteria/enzimologia , Sedimentos Geológicos/microbiologia , Complexos Multienzimáticos/metabolismo , Naftalenos/metabolismo , Oxigenases/metabolismo , Biodegradação Ambiental , Dioxigenases , Gammaproteobacteria/classificação , Gammaproteobacteria/genética , Gammaproteobacteria/isolamento & purificação , Transferência Genética Horizontal , Genes Bacterianos , Genes de RNAr , Hidrocarbonetos Aromáticos/metabolismo , Filogenia , Pseudomonas/enzimologia , Pseudomonas/genética , RNA Ribossômico 16S/genética , Água do Mar , Análise de Sequência de DNA , Especificidade por SubstratoRESUMO
The test/retest reproducibility of brain measures of 5-HT2A receptors with positron emission tomography (PET) and [18F]deuteroaltanserin was examined in a group of eight healthy human subjects. PET measures of 5-HT2A receptors were obtained under an equilibrium paradigm, with a 40-min PET acquisition starting approximately at 300 min (308+/-11 min) after bolus plus constant infusion of the radiotracer. Three brain outcome measures were obtained at equilibrium, V(3) (ratio of specific brain uptake to free parent plasma concentration of radiotracer), V(3)' (ratio of specific brain uptake to total parent plasma concentration) and RT (ratio of specific to non-displaceable brain uptakes). V(3)' and RT had high test/retest reproducibility, as measured by mean intra-subject% change for cortical brain areas of 14.1 and 11.0%, respectively. They also had high reliability, as measured by mean intra-class correlation coefficients (ICC) for cortical brain areas of 0.86 and 0.88, respectively. V(3) had low test/retest reproducibility, due to high variability in the measures of free parent tracer in plasma. This study supports the feasibility of equilibrium imaging of 5-HT2A receptors with PET and [18F]deuteroaltanserin. The equilibrium imaging method with [18F]deuteroaltanserin allows a single acquisition and blood measurement to provide an image whose pixel values equal a receptor volume of distribution. Since the single image pixel values are proportional to receptor densities, the images can be used in pixel-by-pixel statistical methods, such as SPM, to assess the distribution and density of 5-HT2A receptors in neuropsychiatric disorders.
Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Radioisótopos de Flúor , Ketanserina/análogos & derivados , Modelos Neurológicos , Receptores de Serotonina/metabolismo , Tomografia Computadorizada de Emissão , Adulto , Idoso , Cromatografia Líquida de Alta Pressão , Estudos de Viabilidade , Feminino , Radioisótopos de Flúor/administração & dosagem , Radioisótopos de Flúor/sangue , Humanos , Infusões Intravenosas , Ketanserina/administração & dosagem , Ketanserina/sangue , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos TestesRESUMO
The regional distribution in brain, distribution volumes, and pharmacological specificity of the PET 5-HT(2A) receptor radiotracer [(18)F]deuteroaltanserin were evaluated and compared to those of its non-deuterated derivative [(18)F]altanserin. Both radiotracers were administered to baboons by bolus plus constant infusion and PET images were acquired up to 8 h. The time-activity curves for both tracers stabilized between 4 and 6 h. The ratio of total and free parent to metabolites was not significantly different between radiotracers; nevertheless, total cortical R(T) (equilibrium ratio of specific to nondisplaceable brain uptake) was significantly higher (34-78%) for [(18)F]deuteroaltanserin than for [(18)F]altanserin. In contrast, the binding potential (Bmax/K(D)) was similar between radiotracers. [(18)F]Deuteroaltanserin cortical activity was displaced by the 5-HT(2A) receptor antagonist SR 46349B but was not altered by changes in endogenous 5-HT induced by fenfluramine. These findings suggest that [(18)F]deuteroaltanserin is essentially equivalent to [(18)F]altanserin for 5-HT(2A) receptor imaging in the baboon.
Assuntos
Encéfalo/metabolismo , Radioisótopos de Flúor , Ketanserina/análogos & derivados , Receptores de Serotonina/metabolismo , Tomografia Computadorizada de Emissão , Análise de Variância , Animais , Deutério , Feminino , Radioisótopos de Flúor/metabolismo , Radioisótopos de Flúor/farmacocinética , Ketanserina/metabolismo , Ketanserina/farmacocinética , Papio , RadioquímicaAssuntos
Antimaláricos/uso terapêutico , Cloroquina/uso terapêutico , Malária Falciparum/tratamento farmacológico , Proteínas de Membrana/genética , Plasmodium falciparum/efeitos dos fármacos , Polimorfismo Genético , Animais , Antimaláricos/farmacologia , Cloroquina/farmacologia , Resistência a Medicamentos , Genes de Protozoários , Humanos , Malária Falciparum/parasitologia , Proteínas de Membrana Transportadoras , Testes de Sensibilidade Parasitária , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Proteínas de ProtozoáriosRESUMO
While some members of the ubiquitous DExD/H box family of proteins have RNA helicase activity in vitro, their roles in vivo remain virtually unknown. Here, we show that the function of an otherwise essential DEAD box protein, Prp28p, can be bypassed by mutations that alter either the protein U1-C or the U1 small nuclear RNA. Further analysis suggests that the conserved L13 residue in the U1-C protein makes specific contact to stabilize the U1 snRNA/5' splice site duplex in the prespliceosome, and that Prp28p functions to counteract the stabilizing effect of the U1-C protein, thereby promoting the dissociation of the U1 small nuclear ribonucleoprotein particle from the 5' splice site. Thus, in addition to unwinding RNA, the DExD/H box proteins may affect RNA-RNA rearrangements by antagonizing specific RNA-stabilizing proteins.
Assuntos
RNA Nucleotidiltransferases/genética , Splicing de RNA/fisiologia , Ribonucleoproteína Nuclear Pequena U1/genética , Ribonucleoproteínas Nucleares Pequenas/genética , RNA Helicases DEAD-box , Dados de Sequência Molecular , Mutação/genética , RNA Nucleotidiltransferases/metabolismo , Ribonucleoproteína Nuclear Pequena U1/metabolismo , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Proteínas de Saccharomyces cerevisiae , Homologia de Sequência de Aminoácidos , Supressão Genética/fisiologia , LevedurasRESUMO
Strain P-2P44T was isolated from creosote-contaminated marine sediments by using a most-probable number procedure in which phenanthrene was the sole carbon and energy source. Growth experiments showed that P-2P44T utilized several two- and three-ring polycyclic aromatic hydrocarbons (PAHs) as substrates, including naphthalene, 2-methylnaphthalene and phenanthrene. Additionally, gas-chromatography experiments showed that P-2P44T degraded several other PAHs, though it was unable to use them as sole sources of carbon and energy. Phylogenetic analyses confirmed that strain P-2P44T is a member of the genus Vibrio, most closely related to Vibrio splendidus. However, strain P-2P44T shared only 98.3% 16S rDNA identity and 35% DNA-DNA reassociation with the type strain of V. splendidus. Strain P-2P44T differed phenotypically from V. splendidus. Together, these differences indicated that strain P-2P44T represents a novel species in the genus Vibrio, for which the name Vibrio cyclotrophicus sp. nov. is proposed; the type strain is P-2P44T (= ATCC 700982T = PICC 106644T).
Assuntos
Sedimentos Geológicos/microbiologia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Vibrio/classificação , Poluição Química da Água , Técnicas de Tipagem Bacteriana , Biodegradação Ambiental , DNA Bacteriano/genética , DNA Ribossômico/genética , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Vibrio/genética , Vibrio/metabolismo , Vibrio/ultraestruturaRESUMO
The suitability of an (123)I-labeled form of the putative D(4) receptor ligand L750,667 as a radiotracer for single photon emission computed tomography imaging was assessed in nonhuman primates. [(123)I]L750,667, labeled by iododestannylation, was administered to baboons in bolus and bolus plus constant infusion paradigms and imaged for 6 h. Total [(123)I]L750,667 brain uptake peaked (2.3% injected dose) at 15 min postinjection. [(123)I]L750,667 uptake was observed in all brain regions measured including diencephalon, brainstem, basal ganglia, cingulate cortex, and cerebellum, and slightly lower levels were noted in the frontal, parietal, temporoinsular, and occipital cortices. Administration of the D(4) receptor antagonist NGD 94-1 (2 mg/kg) did not displace radioactivity from any of the brain regions examined. Thus, while L750,667 is selective for the D(4) receptor in vitro, because brain [(123)I]L750,667 uptake was not displaced by NGD 94-1 at receptor saturating doses, [(123)I]L750,667 does not appear to be a suitable radiotracer for in vivo imaging of the D(4) receptor.
Assuntos
Encéfalo/metabolismo , Antagonistas de Dopamina/farmacocinética , Antagonistas dos Receptores de Dopamina D2 , Piridinas/farmacocinética , Pirróis/farmacocinética , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Animais , Gânglios da Base/diagnóstico por imagem , Gânglios da Base/metabolismo , Ligação Competitiva/efeitos dos fármacos , Encéfalo/diagnóstico por imagem , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/metabolismo , Cerebelo/diagnóstico por imagem , Cerebelo/metabolismo , Lobo Frontal/diagnóstico por imagem , Lobo Frontal/metabolismo , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/metabolismo , Imidazóis/farmacologia , Radioisótopos do Iodo , Lobo Occipital/diagnóstico por imagem , Lobo Occipital/metabolismo , Especificidade de Órgãos , Papio , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/metabolismo , Piridinas/sangue , Pirimidinas/farmacologia , Pirróis/sangue , Receptores de Dopamina D4 , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/metabolismo , Distribuição TecidualRESUMO
OBJECTIVE: Evidence of a relationship between genotype and binding availability was assessed for the dopamine and serotonin transporter genes. METHOD: The authors assessed dopamine transporter genotype at the SLC6A3 3' variable number of tandem repeats (VNTR) polymorphism and serotonin transporter genotype at the SLC6A4 promotor VNTR polymorphism in 30 healthy subjects who also underwent single photon emission computed tomography with [(123)I]beta-CIT. RESULTS: Subjects homozygous for the 10-repeat allele at the SLC6A3 locus demonstrated significantly lower dopamine transporter binding than carriers of the nine-repeat allele. There was no effect of SLC6A4 genotype upon serotonin transporter binding. CONCLUSIONS: These findings suggest that genetic variation at the SLC6A3 3' VNTR polymorphism may modify dopamine transporter function.
Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Dopamina/genética , Dopamina/metabolismo , Genótipo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso , Adulto , Proteínas de Transporte/isolamento & purificação , DNA/genética , Proteínas da Membrana Plasmática de Transporte de Dopamina , Feminino , Humanos , Masculino , Glicoproteínas de Membrana/isolamento & purificação , Repetições Minissatélites/genética , Reação em Cadeia da Polimerase , Polimorfismo Genético/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Electron microscope grids were submerged in Lake Washington, Seattle, Wash., in June 1996 as bait to which Caulobacter sp. swarmers would attach and on which they would then reproduce in situ. Enumeration of bands in the stalks of attached cells implied that the caulobacters were completing approximately three reproductive cycles per day. A succession of morphological types of caulobacters occurred, as well as an episode of bacteriovore grazing that slowed the accumulation of caulobacters and prevented the aging of the population.
Assuntos
Caulobacter/crescimento & desenvolvimento , Água Doce/microbiologia , Aderência Bacteriana , Caulobacter/ultraestrutura , Microscopia EletrônicaRESUMO
OBJECTIVE: Recent work has underscored the role of serotonergic neurotransmission in chronic neural adaptations to cocaine dependence. The authors tested for evidence of serotonergic dysfunction during acute abstinence from cocaine, a period of high risk for relapse in cocaine dependence. METHOD: Binding availability of dopamine transporters and serotonin transporters was measured in 15 cocaine-dependent subjects during acute abstinence and in 37 healthy comparison subjects by using [(123)I]beta-CIT and single photon emission computed tomography. RESULTS: Significant increases in diencephalic and brainstem serotonin transporter binding (16.7% and 31.6%, respectively) were observed in cocaine-dependent subjects. Brainstem serotonin transporter binding was significantly inversely correlated with age across diagnostic groups. CONCLUSIONS: These findings provide further evidence of serotonergic dysfunction during acute abstinence from chronic cocaine use. Age-related decline in brainstem serotonin transporter binding may underlie the poor response to selective serotonin reuptake inhibitor antidepressants seen in some elderly depressed patients.
Assuntos
Encéfalo/metabolismo , Proteínas de Transporte/metabolismo , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso , Serotonina/metabolismo , Adulto , Fatores Etários , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/metabolismo , Tronco Encefálico/fisiopatologia , Proteínas de Transporte/fisiologia , Cocaína/análogos & derivados , Transtornos Relacionados ao Uso de Cocaína/diagnóstico por imagem , Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Diencéfalo/diagnóstico por imagem , Diencéfalo/metabolismo , Dopamina/metabolismo , Dopamina/fisiologia , Proteínas da Membrana Plasmática de Transporte de Dopamina , Feminino , Humanos , Radioisótopos do Iodo , Masculino , Glicoproteínas de Membrana/fisiologia , Recidiva , Fatores de Risco , Serotonina/fisiologia , Proteínas da Membrana Plasmática de Transporte de Serotonina , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Tomografia Computadorizada de Emissão de Fóton Único/estatística & dados numéricos , Resultado do TratamentoRESUMO
Pure bacterial cultures were isolated from a highly enriched denitrifying consortium previously shown to anaerobically biodegrade naphthalene. The isolates were screened for the ability to grow anaerobically in liquid culture with naphthalene as the sole source of carbon and energy in the presence of nitrate. Three naphthalene-degrading pure cultures were obtained, designated NAP-3-1, NAP-3-2, and NAP-4. Isolate NAP-3-1 tested positive for denitrification using a standard denitrification assay. Neither isolate NAP-3-2 nor isolate NAP-4 produced gas in the assay, but both consumed nitrate and NAP-4 produced significant amounts of nitrite. Isolates NAP-4 and NAP-3-1 transformed 70 to 90% of added naphthalene, and the transformation was nitrate dependent. No significant removal of naphthalene occurred under nitrate-limited conditions or in cell-free controls. Both cultures exhibited partial mineralization of naphthalene, representing 7 to 20% of the initial added (14)C-labeled naphthalene. After 57 days of incubation, the largest fraction of the radiolabel in both cultures was recovered in the cell mass (30 to 50%), with minor amounts recovered as unknown soluble metabolites. Nitrate consumption, along with the results from the (14)C radiolabel study, are consistent with the oxidation of naphthalene coupled to denitrification for NAP-3-1 and nitrate reduction to nitrite for NAP-4. Phylogenetic analyses based on 16S ribosomal DNA sequences of NAP-3-1 showed that it was closely related to Pseudomonas stutzeri and that NAP-4 was closely related to Vibrio pelagius. This is the first report we know of that demonstrates nitrate-dependent anaerobic degradation and mineralization of naphthalene by pure cultures.
Assuntos
Bactérias Anaeróbias/isolamento & purificação , Bactérias Anaeróbias/metabolismo , Naftalenos/metabolismo , Nitratos/metabolismo , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , Biodegradação Ambiental , Radioisótopos de Carbono/análise , Meios de Cultura , DNA Bacteriano/análise , DNA Bacteriano/genética , DNA Ribossômico/análise , DNA Ribossômico/genética , Hidrocarbonetos Aromáticos/metabolismo , Dados de Sequência Molecular , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Microbiologia da Água , Poluentes Químicos da Água/metabolismoRESUMO
OBJECTIVE: The purpose of this study was to define the effects of external beam radiation (EBR) on AlloDerm (LifeCell Corp) through the analysis of graft thickness, fibroblast recellularization, and neovascularization as a function of time. METHODS AND MATERIAL: Thirty-six male Sprague-Dawley rats (n = 36) were randomly assigned to 1 of 4 groups (A, B, C, and D). AlloDerm was implanted subcutaneously into the hind legs of each rat, and 20 Gy of EBR was administered to one side. Grafts harvested 1, 2, 4, and 12 weeks after radiation were subjected to blinded histologic analysis. RESULTS: In groups A, B, and C, the irradiated grafts showed a significant decrease in recellularization versus nonirradiated (P < 0.001). At 12 weeks (group D), recellularization equalized, but neovascularization was significantly less (P = 0.048) in the irradiated group. Graft thickness was unaffected. CONCLUSIONS: In the rat model, EBR of the implanted AlloDerm graft hinders recellularization in the early posttreatment period. However, EBR did not adversely affect graft thickness, recellularization or ultimate graft survival.