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1.
Clin Neurol Neurosurg ; 175: 121-123, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30399602

RESUMO

OBJECTIVE: Utilization is an executive function disorder and implies an inappropriate response to external stimuli. The sunglasses test is a simple test to examine utilization by offering a pair of sunglasses to a patient without any instruction. PATIENTS AND METHODS: We performed a pilot study to examine the sunglasses test in 100 patients, of which 50 had cognitive symptoms and 50 did not have cognitive symptoms. When the patient put on the sunglasses, the test was considered positive. Cognitive dysfunction was based on the results of the MMSE, results of the clock test and neuropsychological examination (blinded). The final diagnosis was based on all results of the work-up (including MRI). RESULTS: Of the 50 patients with cognitive symptoms 30 had a positive test and 28 of them had cognitive dysfunction. Final diagnosis in most patients was Dementia due to probable Alzheimers disease, followed by Frontotemporal dementia. Seven of the 20 patients with a negative test also had cognitive dysfunction. None of the 50 patients without cognitive symptoms put on the sunglasses. Sensitivity of the sunglasses test to detect cognitive dysfunction was 80% and specificity was 97%, with a positive predictive value of 93%. CONCLUSION: Offering sunglasses is a simple test to screen for utilization. Putting on sunglasses without instruction to do so can be indicative for cognitive dysfunction and further cognitive evaluation should be considered. Future studies are needed in a larger group of patients and to determine the role of this test in different diseases with cognitive decline.


Assuntos
Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/psicologia , Dispositivos de Proteção dos Olhos , Testes de Estado Mental e Demência , Testes Neuropsicológicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos
2.
J Fish Dis ; 40(12): 1783-1790, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28493490

RESUMO

When challenged with atypical Aeromonas salmonicida subsp. salmonicida, exposure of the common carp (Cyprinus carpio L.) to different humic-rich compounds resulted in a significant reduction in infection rates. Specifically, in fish exposed to (i) humic-rich water and sludge from a recirculating system, (ii) a synthetic humic acid, and (iii) a Leonardite-derived humic-rich extract, infection rates were reduced to 14.9%, 17.0% and 18.8%, respectively, as compared to a 46.8% infection rate in the control treatment. An additional set of experiments was performed to examine the effect of humic-rich components on the growth of the bacterial pathogen. Liquid culture medium supplemented with either humic-rich water from the recirculating system, the synthetic humic acid or the Leonardite humic-rich extract resulted in a growth reduction of 41.1%, 45.2% and 61.6%, respectively, as compared to the growth of the Aeromonas strain in medium devoid of humic substances. Finally, in a third set of experiments it was found that while the innate immune system of the carps was not affected by their exposure to humic-rich substances, their acquired immune system was affected. Fish, immunized against bovine serum albumin, displayed elevated antibody titres as compared to immunized carps which were not exposed to the various sources of humic substances.


Assuntos
Aeromonas salmonicida/crescimento & desenvolvimento , Carpas/imunologia , Carpas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Substâncias Húmicas , Aeromonas salmonicida/efeitos dos fármacos , Ração Animal/análise , Animais , Carvão Mineral , Suplementos Nutricionais , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Água Doce/química , Infecções por Bactérias Gram-Negativas/imunologia , Imunidade Inata , Soroalbumina Bovina/imunologia , Esgotos/química
3.
Ned Tijdschr Geneeskd ; 161: D683, 2017.
Artigo em Holandês | MEDLINE | ID: mdl-28325156

RESUMO

In patients aged over 70 years, a non-functioning rotator cuff is an indication for a reversed shoulder prosthesis. Here we describe an 84-year-old woman with rotator cuff arthropathy and a 76-year-old man with a proximal humerus fracture, who both received a reversed shoulder prosthesis. This prosthesis decreases pain and improves the range of movement; however, the high risk of complications associated with this prosthesis should be taken into account and should be discussed preoperatively.


Assuntos
Amplitude de Movimento Articular/fisiologia , Lesões do Manguito Rotador/cirurgia , Fraturas do Ombro/cirurgia , Prótese de Ombro , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Prótese Articular , Masculino , Manguito Rotador , Articulação do Ombro , Resultado do Tratamento
4.
Water Res ; 108: 412-421, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27838024

RESUMO

Recirculating aquaculture systems (RAS), offering many economic and fish husbandry benefits, are characterized by an accumulation of dissolved organic matter (DOM) and, specifically, humic substances (HS). As reported in a number of studies, HS may affect biological activity in both invertebrates and vertebrates. Given the accumulation of HS in RAS, it is therefore of great interest to characterize DOM and, specifically, its HS fraction in the RAS. The present study was aimed at characterizing long-term changes in fluorescent DOM composition in the culture water of RAS systems, which were operated in a novel, zero water exchange mode. Two such zero-discharge recirculating systems (ZDS) were examined: a freshwater system, stocked with hybrid tilapia (Oreochromis aureus x Oreochromis niloticus) and a marine system, stocked with gilthead seabream (Sparus aurata). Excitation-emission matrices (EEMs) of fluorescence, coupled with parallel factor analysis (PARAFAC), were used to characterize and quantify the different DOM components in the ZDS. In the culture water, one tryptophan-like and four HS-like components were identified. The fluorescence intensities of three of the HS-like components as well as the tryptophan-like component increased at comparable rates during ZDS operation while a much slower accumulation of these compounds was observed in a parallel operated, flow-through, freshwater aquarium. The ZDS examined in this study comprised a sludge digestion stage where a considerable accumulation of all fluorescent components was detected. A HS-like components and a tryptophan-like component in blood of tilapia from the freshwater ZDS were similar to components found in the culture water. Blood levels of both components were higher in fish cultured in the DOM-rich ZDS than in fish raised in the control, flow-through freshwater aquarium. Fluorescence of the HS-like component found in the fish blood increased also with time of ZDS operation. The finding that fish blood contains a HS-like fluorescent component may have important implications for the understanding of the physiological effects of HS in fish and the possible benefits of these substances in aquaculture.


Assuntos
Substâncias Húmicas , Espectrometria de Fluorescência , Aquicultura , Análise Fatorial , Água Doce
5.
Water Res ; 56: 109-21, 2014 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24657541

RESUMO

Simultaneous removal of nitrogen and phosphorus by microbial biofilters has been used in a variety of water treatment systems including treatment systems in aquaculture. In this study, phosphorus, nitrate and sulfate cycling in the anaerobic loop of a zero-discharge, recirculating mariculture system was investigated using detailed geochemical measurements in the sludge layer of the digestion basin. High concentrations of nitrate and sulfate, circulating in the overlying water (∼15 mM), were removed by microbial respiration in the sludge resulting in a sulfide accumulation of up to 3 mM. Modelling of the observed S and O isotopic ratios in the surface sludge suggested that, with time, major respiration processes shifted from heterotrophic nitrate and sulfate reduction to autotrophic nitrate reduction. The much higher inorganic P content of the sludge relative to the fish feces is attributed to conversion of organic P to authigenic apatite. This conclusion is supported by: (a) X-ray diffraction analyses, which pointed to an accumulation of a calcium phosphate mineral phase that was different from P phases found in the feces, (b) the calculation that the pore waters of the sludge were highly oversaturated with respect to hydroxyapatite (saturation index = 4.87) and (c) there was a decrease in phosphate (and in the Ca/Na molar ratio) in the pore waters simultaneous with an increase in ammonia showing there had to be an additional P removal process at the same time as the heterotrophic breakdown of organic matter.


Assuntos
Aquicultura , Reatores Biológicos , Nitratos/química , Fósforo/metabolismo , Sulfatos/química , Águas Residuárias/química , Bactérias/química , Bactérias/metabolismo , Fósforo/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos
6.
Tijdschr Psychiatr ; 53(4): 245-50, 2011.
Artigo em Holandês | MEDLINE | ID: mdl-21506081

RESUMO

Neurosyphilis is a neuropsychiatric disorder which can be severely incapacitating and even fatal, but which has been associated historically with genius and artistic inspiration. We describe an artist with neurologic and psychiatric complaints who owed not only his disease symptoms, but possibly also his artistic talent to neurosyphilis. Gradually, our patient developed all the clinical symptoms of neurosyphilis. In addition, he turned out to suffer from AIDS. At a late stage, the clinical picture was complicated by opportunistic infections and epilepsy. Although the patient received the best possible treatment, he ultimately died from opportunistic infections.


Assuntos
Síndrome da Imunodeficiência Adquirida/diagnóstico , Síndrome da Imunodeficiência Adquirida/epidemiologia , Neurossífilis/diagnóstico , Neurossífilis/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/complicações , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Síndrome da Imunodeficiência Adquirida/complicações , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Fármacos Anti-HIV/uso terapêutico , Comorbidade , Progressão da Doença , Evolução Fatal , Humanos , Masculino , Pessoa de Meia-Idade , Neurossífilis/complicações , Neurossífilis/tratamento farmacológico
7.
J Hand Surg Am ; 35(4): 572-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20185250

RESUMO

PURPOSE: The purpose of this study was to evaluate a cemented prosthesis (Avanta SR TMC prosthesis; Avanta Orthopaedics, San Diego, CA) of the basal thumb joint on the outcomes of range of motion, strength, pain, function, and loosening. METHODS: Between July 2004 and December 2007, a total of 15 prostheses in 13 patients were implanted, with an average follow-up period of 36 months (range, 21-63 mo). Before and during the follow-up, the following scores were recorded: Kapandji-score (range of opposition), strength (hand dynamometer and pinch meter), pain (sequential occupational dexterity assessment [SODA], and Michigan Hand Outcomes Questionnaire [MHQ]) and function (9-hole peg test, SODA and MHQ). Radiographs taken before and after surgery were reviewed. RESULTS: The measurements of range of opposition and strength did not show any significant postoperative improvement. Pain during activities (SODA) decreased significantly, and the function with both hands (SODA and MHQ) improved significantly after surgery. The review of pre- and postoperative radiographs did not show any signs of implant loosening after surgery. One failure and one nerve injury occurred. CONCLUSIONS: In this group of patients, the Avanta SR TMC prosthesis provided statistically significant improvements in function with both hands and in pain during activity, but no significant change in range of motion, strength, or in function of the operated hand used alone. Prosthesis loosening was not detected.


Assuntos
Artroplastia de Substituição/métodos , Cimentos Ósseos/uso terapêutico , Articulações Carpometacarpais/cirurgia , Prótese Articular , Osteoartrite/cirurgia , Polegar/cirurgia , Idoso , Articulações Carpometacarpais/diagnóstico por imagem , Articulações Carpometacarpais/patologia , Cromo , Cobalto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/diagnóstico por imagem , Osteoartrite/fisiopatologia , Medição da Dor , Força de Pinça/fisiologia , Polietileno , Desenho de Prótese , Radiografia , Amplitude de Movimento Articular/fisiologia , Recuperação de Função Fisiológica , Inquéritos e Questionários , Polegar/diagnóstico por imagem , Polegar/fisiopatologia
8.
AJNR Am J Neuroradiol ; 29(9): 1768-74, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18583406

RESUMO

BACKGROUND AND PURPOSE: The long-term fate of coiled intracranial aneurysms is largely unknown, and prolonged imaging follow-up has been advocated. The yield of follow-up imaging in coiled aneurysms adequately occluded at 6 months is unknown. In such patients, we performed time-of-flight MR angiography (MRA) to assess the incidence and therapeutic consequences of reopening 5-11 years after coiling. MATERIALS AND METHODS: Between 1995 and 2002, 661 aneurysms in 607 patients were coiled in 3 participating centers. Six-month follow-up angiograms were obtained in 497 (75%) aneurysms, of which 316 (64%) in 297 patients were adequately occluded. Of 297 patients, 84 were excluded for various reasons and 73 could not be traced. Of 140 eligible patients, 104 (74%) with 111 aneurysms were studied with 3T MR imaging and high-resolution MRA at a mean of 6.0 years after coiling (median, 5.6 years; range, 5.0-10.6 years). RESULTS: The proportion of aneurysms with reopening was 3.6% (4/111; 95% confidence interval [CI], 1.1%-9.2%). One reopened aneurysm, which initially contained intraluminal thrombus, was additionally coiled (0.9%; 95% CI, 0.0%-5.4%). CONCLUSION: In intracranial aneurysms with adequate occlusion at 6 months after coiling, the proportion of reopening needing retreatment after >5 years is low. The number of reopened aneurysms with therapeutic consequences was too small to assess risk factors, but probably the presence of intraluminal thrombus is one such risk factor. Most patients with coiled intracranial aneurysms that are adequately occluded at 6 months might not need prolonged imaging follow-up.


Assuntos
Aneurisma Roto/terapia , Embolização Terapêutica , Aneurisma Intracraniano/terapia , Angiografia por Ressonância Magnética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Aneurisma Roto/diagnóstico , Estudos de Coortes , Feminino , Seguimentos , Humanos , Aneurisma Intracraniano/diagnóstico , Masculino , Pessoa de Meia-Idade , Recidiva , Retratamento
9.
AJNR Am J Neuroradiol ; 29(1): 134-9, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17928381

RESUMO

BACKGROUND AND PURPOSE: Our aim was to determine the diagnostic accuracy of multisection CT angiography combined with matched mask bone elimination (CTA-MMBE) for detection of intracranial aneurysms compared with digital subtraction angiography (DSA) and 3D rotational angiography (3DRA). MATERIALS AND METHODS: Between January 2004 and February 2006, 108 patients who presented with clinically suspected subarachnoid hemorrhage underwent both CTA-MMBE and DSA for diagnosis of an intracranial aneurysm. Two neuroradiologists, independently, evaluated 27 predefined vessel locations in the CTA-MMBE images for the presence of an aneurysm. After consensus, diagnostic accuracy of CTA was calculated per predefined location and per patient. Interobserver agreement was calculated with kappa statistics. RESULTS: In 88 patients (81%), 117 aneurysms (82 ruptured, 35 unruptured) were present on DSA. CTA-MMBE detected all ruptured aneurysms except 1. Overall specificity, sensitivity, positive predictive value, and negative predictive value of CTA-MMBE were 0.99, 0.90, 0.98, and 0.95 per patient and 0.91, 1.00, 0.97, and 0.99 per location, respectively. Sensitivity was 0.99 for aneurysms >/=3 mm and 0.38 for aneurysms <3 mm. Interobserver agreement for aneurysm detection was excellent (kappa value of 0.92 per location and 0.80 per patient). CONCLUSION: CTA-MMBE is accurate in detecting intracranial aneurysms in any projection without overprojecting bone. CTA-MMBE has limited sensitivity in detecting very small aneurysms. Our data suggest that DSA and 3DRA can be limited to the vessel harboring the ruptured aneurysm before endovascular treatment, after detection of a ruptured aneurysm with CTA.


Assuntos
Angiografia Digital/métodos , Angiografia Cerebral/métodos , Imageamento Tridimensional/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Crânio/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intensificação de Imagem Radiográfica/métodos , Reprodutibilidade dos Testes , Rotação , Sensibilidade e Especificidade , Técnica de Subtração
10.
Br J Radiol ; 79(941): 372-7, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16632616

RESUMO

Spiral CT is considered the best alternative for MRI in the evaluation of herniated discs. The purpose of this study was to compare radiological evaluation of spiral CT with MRI in patients suspected of herniated discs. 57 patients with lumbosacral radicular syndrome underwent spiral CT and 1.5 T MRI. Two neuroradiologists independently evaluated 171 intervertebral discs for herniation or "bulge" and 456 nerve roots for root compression, once after CT and once after MRI. We compared interobserver agreement using the kappa statistic and we performed a paired comparison between CT and MRI. For detection of herniated or bulging discs, we observed no significant difference in interobserver agreement (CT kappa 0.66 vs MRI kappa 0.71; p = 0.40). For root compression, we observed significantly better interobserver agreement at MRI evaluation (CT kappa 0.59 vs MRI kappa 0.78; p = 0.01). In 30 of 171 lumbar discs (18%) and in 54 of 456 nerve roots (12%), the observers disagreed on whether CT results were similar to MRI. In the cases without disagreement, CT differed from MRI in 6 discs (3.5%) and in 3 nerve roots (0.7%). For radiological evaluation of lumbar herniated discs, we found no evidence that spiral CT is inferior to MRI. For evaluating lumbar nerve root compression, spiral CT is less reliable than MRI.


Assuntos
Deslocamento do Disco Intervertebral/diagnóstico , Vértebras Lombares , Imageamento por Ressonância Magnética , Interpretação de Imagem Radiográfica Assistida por Computador , Tomografia Computadorizada Espiral , Adulto , Humanos , Disco Intervertebral/diagnóstico por imagem , Disco Intervertebral/patologia , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Síndromes de Compressão Nervosa/diagnóstico por imagem , Síndromes de Compressão Nervosa/patologia , Neurorradiografia , Variações Dependentes do Observador , Radiologia , Sensibilidade e Especificidade , Raízes Nervosas Espinhais/diagnóstico por imagem , Raízes Nervosas Espinhais/patologia
13.
Biotechnol Prog ; 19(3): 1019-21, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12790671

RESUMO

Biological denitrification of nitrate to nitrogen gas was examined in a freshwater and a marine aquarium. Nitrate removal in the aquarium water was accomplished with denitrifiers immobilized in a freeze-dried, alginate-starch matrix. Starch served as a bacterial carbon source and cellular matrix-strengthening filler. Freeze-dried beads were placed in canisters through which nitrate-rich aquarium water was recirculated. The freshwater aquarium (100 L) contained goldfish (Carassius auratus) at a total biomass of 390 g, whereas cichlids (Oreochromis mossambicus) were kept at a similar stocking density in the marine aquarium. Denitrification resulted in low ambient nitrate concentrations in both aquariums. The specific nitrate removal rate of the freshwater beads was significantly higher (50 microg of NO(3)-N/bead/day) than that of seawater beads (5 microg of NO(3)-N/bead/day). Differences in ambient nitrate concentrations between both aquariums and diffusion limitation of nitrate to the active denitrification sites within the beads might explain these observed differences.


Assuntos
Carpa Dourada/crescimento & desenvolvimento , Sistemas de Manutenção da Vida , Nitratos/metabolismo , Pseudomonas/metabolismo , Tilápia/crescimento & desenvolvimento , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Animais , Células Imobilizadas/fisiologia , Água Doce/microbiologia , Biologia Marinha/métodos , Microesferas , Pseudomonas/classificação , Pseudomonas/ultraestrutura , Ultrafiltração , Microbiologia da Água
14.
Environ Technol ; 24(2): 217-29, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12666791

RESUMO

A novel automated warning and removal system for hydrogen sulphide in aqueous flow-through systems has been developed based on the sulphidation of ferrihydrite sorbed to zeolite substrate. The system consists of a small flow-through reaction cartridge with photo-sensors positioned at the base. During the reaction, sulphide is initially oxidised to elemental sulphur by the ferrihydrite, and Fe2+ is subsequently released to solution. This Fe2+ then reacts with additional dissolved sulphide to form solid phase iron monosulphide. The colour change from orange ferrihydrite to black iron monosulphide is continuously monitored by the photo-sensors, which provide a rapid and reproducible response (via a voltage change) to pulses of sulphidic water. The response of the photo-sensors is linear with respect to inflowing sulphide concentration, while the most rapid response to dissolved sulphide occurs at a flow rate of approximately 200 ml min(-1) (equivalent to a hydraulic loading rate of 21 cm min(-1). The presence of phosphate in solution substantially decreases reaction rates due to adsorption to reactive surface sites. However, the response time of the photo-sensors remains sufficient to provide a rapid indication of sulphidic conditions even in systems with high concentrations of dissolved phosphate. The cartridge has the advantage of partially or completely removing sulphide (depending on flow rate and substrate mass) from an initial pulse of water. At the optimal flow rate for the successful use of the cartridge as a sulphide warning system (200 ml min(-1)), required substrate masses for the complete removal of dissolved sulphide (over the experimental range of 0-1000 microM) are relatively small (0.5-2 kg).


Assuntos
Sulfeto de Hidrogênio/isolamento & purificação , Eliminação de Resíduos Líquidos , Adsorção , Automação , Monitoramento Ambiental , Compostos Férricos/química , Resíduos Industriais , Fotoquímica , Sulfetos/química , Zeolitas
15.
Br J Cancer ; 88(3): 447-54, 2003 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-12569390

RESUMO

Cultured H35 hepatoma cells release a cytotoxic factor in response to irradiation with X-rays. When the conditioned medium from irradiated cells is given to nonirradiated cells, growth is inhibited and followed by cell death, possibly apoptosis, Analysis of the conditioned medium reveals a dramatic change in the ornithine (urea) cycle components after the irradiation. A strong decrease in medium arginine is accompanied with parallel increases in ornithine, citrulline and ammonia. The high level of ammonia appears to be largely responsible for the observed cytotoxicity. The development of hyperammonia by irradiated cells and the related toxicity depend on the radiation dose and the number of cells seeded thereafter for the medium conditioning. Development of cytotoxicity by irradiated cells is completely prevented with the arginase inhibitor L-norvaline, in arginine-deficient medium or when citrulline replaces arginine. These preventive measures result in subtoxic ammonia levels.


Assuntos
Carcinoma Hepatocelular/metabolismo , Meios de Cultivo Condicionados/farmacologia , Neoplasias Hepáticas/metabolismo , Ornitina/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Contagem de Células , Divisão Celular/efeitos dos fármacos , Divisão Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Neoplasias Hepáticas/patologia , Doses de Radiação , Ratos , Estatística como Assunto , Células Tumorais Cultivadas
16.
Environ Pollut ; 112(2): 99-106, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11234547

RESUMO

The relative abundance of the denitrifier, Pseudomonas sp. JR12, was examined in an alginate-based entrapment complex under non-sterile, denitrifying conditions. Immuno-labeling of the Pseudomonas inoculant followed by flow cytometry (FCM) was used for determination of the relative abundance of this bacterium under the various incubation conditions. Additional information on the relative abundance of the inoculant was obtained by a quantitative enzyme-linked immunosorbent assay (ELISA) and results obtained by FCM and ELISA were compared. Ambient nitrate levels controlled the successful, long-term proliferation of the inoculant. At low ambient nitrate levels, Pseudomonas sp. remained the dominant microorganism during incubation. Higher ambient nitrate concentrations, attained by either decreasing the inoculum size of Pseudomonas sp. or raising inlet nitrate concentrations of the medium supplied to the incubation vessels, resulted in a gradual shift toward other, nitrite-accumulating denitrifiers. Thus far, most studies on the use of entrapped microorganisms for bioremediation purposes have been conducted under controlled laboratory conditions. Based on this study, conducted under non-sterile laboratory conditions, it is concluded that in-situ bioremediation using entrapped target microorganisms is bound to fail without a proper understanding of the factors that cause the target microorganism to out-compete undesired microbial invaders. Furthermore, based on the close agreement between the two detection methods used, it is concluded that flow cytometry provides a rapid and accurate tool for the detection of the relative abundance of immuno-labeled target organisms in heterogeneous microbial populations.


Assuntos
Pseudomonas , Poluentes da Água , Monitoramento Ambiental/métodos , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Nitratos/metabolismo , Dinâmica Populacional
17.
Appl Environ Microbiol ; 66(12): 5236-40, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11097896

RESUMO

Phosphate uptake by the phosphate-accumulating denitrifier Pseudomonas sp. JR12 was examined with different combinations of electron and carbon donors and electron acceptors. Phosphate uptake in acetate-supplemented cells took place with either oxygen or nitrate but did not take place when nitrite served as the final electron acceptor. Furthermore, nitrite reduction rates by this denitrifier were shown to be significantly reduced in the presence of phosphate. Phosphate uptake assays in the presence of the H(+)-ATPase inhibitor N,N'-dicyclohexylcarbodiimide (DCCD), in the presence of the uncoupler carbonyl cyanide 3-chlorophenylhydrazone (CCCP), or with osmotic shock-treated cells indicated that phosphate transport over the cytoplasmic membrane of this bacterium was mediated by primary and secondary transport systems. By examining the redox transitions of whole cells at 553 nm we found that phosphate addition caused a significant oxidation of a c-type cytochrome. Based on these findings, we propose that this c-type cytochrome serves as an intermediate in the electron transfer to both nitrite reductase and the site responsible for active phosphate transport. In previous studies with this bacterium we found that the oxidation state of this c-type cytochrome was significantly higher in acetate-supplemented, nitrite-respiring cells (incapable of phosphate uptake) than in phosphate-accumulating cells incubated with different combinations of electron donors and acceptors. Based on the latter finding and results obtained in the present study it is suggested that phosphate uptake in this bacterium is subjected to a redox control of the active phosphate transport site. By means of this mechanism an explanation is provided for the observed absence of phosphate uptake in the presence of nitrite and inhibition of nitrite reduction by phosphate in this organism. The implications of these findings regarding denitrifying, phosphate removal wastewater plants is discussed.


Assuntos
Nitritos/metabolismo , Fosfatos/metabolismo , Pseudomonas/metabolismo , Transporte Biológico Ativo/efeitos dos fármacos , Reatores Biológicos , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Dicicloexilcarbodi-Imida/farmacologia , Transporte de Elétrons/efeitos dos fármacos , Cinética , Nitratos/metabolismo , Pseudomonas/efeitos dos fármacos , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/metabolismo
18.
AJR Am J Roentgenol ; 175(5): 1279-82, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11044022

RESUMO

OBJECTIVE: Important decisions are made on the basis of CT angiographic measurements of aneurysm size obtained after endovascular abdominal aortic aneurysm repair; however, little is known about the variability of these measurements. We evaluated the variability of CT angiographic measurements of aneurysm size obtained after endovascular abdominal aortic aneurysm repair. MATERIALS AND METHODS: Thirty CT angiographic data sets were randomly chosen from 91 sets, including preoperative, postoperative, and follow-up CT images. All images were obtained according to a standardized acquisition protocol. On a workstation, three parameters were measured: maximum aneurysm diameter, maximum aneurysm cross-sectional area, and aneurysm volume. All data sets were measured twice by two investigators in a random order. The difference of each pair of measurements was plotted against the mean value. The mean difference and its standard deviation were calculated with a repeatability coefficient. RESULTS: The intraobserver repeatability coefficient for observer 1 was 3.8 mm for diameter, 201.7 mm(2) for cross-sectional area, and 5.6 mL for volume. For observer 2, these figures were 3.0 mm, 219.0 mm(2), and 8.1 mL, respectively. The interobserver repeatability coefficients were 3.9 mm, 236.2 mm(2), and 10.3 mL. CONCLUSION: Determination of the repeatability coefficient of aneurysm size measurements obtained after endovascular abdominal aortic aneurysm repair provides a good description of precision.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Aortografia , Implante de Prótese Vascular , Tomografia Computadorizada por Raios X , Idoso , Anatomia Transversal , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aortografia/métodos , Prótese Vascular , Sistemas Computacionais , Meios de Contraste , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Variações Dependentes do Observador , Desenho de Prótese , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos
19.
Int J Hyperthermia ; 16(4): 305-18, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10949127

RESUMO

The purpose of this study is to reinvestigate the heat shock response in cells treated with the antimetabolite azetidine-2-carboxylic acid (azetidine), an analogue of proline. Previous studies could not clearly discriminate between the progressive thermosensitization caused by amino acid analogues and a parallel induction of thermotolerance by heat shock. Incubation of H35 cells with 2.5 mm azetidine causes an increasing thermosensitization which achieves a maximum after approximately 18-22 h. At this point, azetidine does not prevent the development of acute thermotolerance following a heat shock at 42.5 degrees C, or the simultaneous induction of chronic thermotolerance during mild hyperthermia at 38-41 degrees C. However, for both the acute and chronic heating conditions thermotolerance levels are reduced in proportion with azetidine-thermosensitization. Incorporation of azetidine causes an apparent downward temperature shift of approximately 1 degree C relative to the time-temperature relationships for normal, or following heat shocks, for thermotolerant cells. After 18 h of incubation with azetidine, protein synthesis is reduced by a factor of 4 and cells show a preferential synthesis of heat shock proteins (hsp). A heat shock then, although inducing thermotolerance, is not followed by any noticeable effect on the synthesis of hsps. It is shown that the combination of prolonged azetidine treatment and heat shock causes a persistent inhibition of protein synthesis. This is hypothesized to result in the development of hsp synthesis independent thermotolerance. Additional treatment following heat shock in azetidine-treated cells with the protein synthesis inhibitor cycloheximide does not affect the induction of thermotolerance. In contrast to the heat shock response, no thermotolerance induction is observed in azetidine-treated cells after an exposure to sodium arsenite.


Assuntos
Ácido Azetidinocarboxílico/farmacologia , Resposta ao Choque Térmico/efeitos dos fármacos , Animais , Arsenitos/farmacologia , Linhagem Celular , Cicloeximida/farmacologia , Proteínas de Choque Térmico/biossíntese , Inibidores da Síntese de Proteínas/farmacologia , Ratos , Compostos de Sódio/farmacologia
20.
Int J Radiat Oncol Biol Phys ; 47(3): 779-84, 2000 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10837964

RESUMO

PURPOSE: To investigate the effect of temozolomide, a 3-methyl derivative of mitozolomide in combination with X-rays in human glioma-derived cell lines. METHODS AND MATERIALS: Glioma cell lines D384 and U251 were treated with temozolomide for various periods of time in combinations with X-rays. Temozolomide administration was repeated every 24 h for exposures up to 96 h. Cytotoxicity was determined with a clonogenic assay. RESULTS: Incubation of D384 cells with temozolomide during 24 h prior to or following irradiation results in a moderate enhancement of the cytotoxicity. Prolonged treatment with temozolomide, i.e., 48-96 h before X-rays, causes a stronger potentiation. In contrast, no enhancement is observed in irradiated U251 cells in combination with 24-96 h temozolomide treatment. In addition to single-dose irradiation, we investigated the effect of temozolomide in D384 cells with concomitant fractionated irradiation. A 96-h exposure to temozolomide with simultaneous doses of 2 Gy X-rays at 24-h intervals, causes a significant further reduction in cell survival as compared to fractionated irradiation only. CONCLUSION: Depending on the cell line, treatment of glioma cells with temozolomide and X-rays can have either an additional effect or potentiate cell killing.


Assuntos
Antineoplásicos Alquilantes/farmacologia , Neoplasias Encefálicas , Dacarbazina/análogos & derivados , Glioma , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/radioterapia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Terapia Combinada , Dacarbazina/farmacologia , Glioma/tratamento farmacológico , Glioma/radioterapia , Humanos , Temozolomida , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/efeitos da radiação , Ensaio Tumoral de Célula-Tronco
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