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1.
Lett Appl Microbiol ; 71(3): 303-310, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32449160

RESUMO

A strain named as Pseudomonas aeruginosa 2016NX1, which could produce phenazine and cereusitin, was isolated from the root of Millettia specisoa. Phenazines were extracted, isolated and purified by chloroform, thin-layer chromatography, column chromatography and high-performance liquid chromatography. Then the purified materials were identified by analysis of nuclear magnetic resonance. The major yellow component is 1-hydroxyphenazine and the minor blue component is cereusitin A. The tests of antimicrobial activity of yellow component showed that the growth of several common plant pathogenic fungi and bacteria (such as Cochliobolus miyabeanus, Diaporthe citri, Salmonella sp., Klebsiella oxytoca) could be strongly inhibited. This study suggested that Pseudomonas aeruginosa strain 2016NX1 had a significant potential for biological control of phytopathogenic fungi. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, one bioactive substance from Pseudomonas aeruginosa 2016NX1 was identified and its antimicrobial activity was verified. This study demonstrated that one bioactive substance from P. aeruginosa can strongly inhibit the growth of plant pathogenic fungi and bacteria. This study suggested that P. aeruginosa strain 2016NX1 has a significant potential for biological control of phytopathogenic fungi.


Assuntos
Anti-Infecciosos/farmacologia , Ascomicetos/efeitos dos fármacos , Klebsiella oxytoca/efeitos dos fármacos , Fenazinas/farmacologia , Pseudomonas aeruginosa/metabolismo , Salmonella/efeitos dos fármacos , Anti-Infecciosos/metabolismo , Antibiose/fisiologia , Ascomicetos/crescimento & desenvolvimento , Bipolaris , Klebsiella oxytoca/crescimento & desenvolvimento , Millettia/microbiologia , Fenazinas/metabolismo , Pseudomonas aeruginosa/isolamento & purificação , Salmonella/crescimento & desenvolvimento
2.
Allergy ; 73(9): 1801-1811, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29679487

RESUMO

BACKGROUND: Several studies have demonstrated that allergen-specific immunotherapy (SIT) can be an effective treatment for atopic dermatitis (AD). However, there is no relevant mouse model to investigate the mechanism and validate the novel modality of SIT in AD. METHODS: NC/Nga mice with induced AD-like skin lesions received a subcutaneous injection of SIT (an extract of the house dust mite Dermatophagoides farinae [DfE]) or placebo for 5 weeks). Clinical and histological improvements of AD-like skin lesions were examined. The responses of local and systemic regulatory T (Treg) cells, natural killer (NK) cells, B cells, serum immunoglobulin, and T-cell cytokine response to DfE were evaluated to determine the underlying mechanism of the observed results. RESULTS: Specific immunotherapy significantly improved AD-like skin lesions. Histologically, SIT decreased epidermal thickness and reduced inflammatory cell infiltration, especially that of eosinophils. Concomitantly, SIT suppressed Th2 responses and induced local infiltration of Treg cells into the skin. Also, SIT induced the immunoglobulin G4 and attenuated allergen-specific immunoglobulin E. Furthermore, SIT induced local and systemic IL-10-producing Treg cells and regulatory NK cells. CONCLUSION: We established a SIT model on AD mice and showed that our model correlates well with previous reports about SIT-treated patients. Also, we revealed NK cells as another possible resource of IL-10 in SIT. Based on our results, we suggest our SIT model as a useful tool to investigate mechanism of action of SIT and to validate the efficacy of new SIT modalities for the treatment of AD.

4.
Eur J Neurol ; 24(2): 341-348, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27943468

RESUMO

BACKGROUND AND PURPOSE: Mild cognitive impairment (MCI) is associated with pronounced grey matter atrophy in various brain regions. However, the association between atrophy patterns and progression from no cognitive impairment (NCI) to Parkinson's disease (PD)-MCI is not clearly known. We investigated the pattern and progression of atrophy in subcortical structures and its impact on cognition in patients with mild PD. METHODS: Sixty-five patients with mild PD with baseline and longitudinal clinical and neuropsychological assessments, and structural magnetic resonance imaging scans were studied. Movement Disorder Society Task Force criteria were used to classify patients with PD into PD-NCI (n = 54) and PD-MCI (n = 11). Based on progression over time, those who remained without cognitive impairment were classified as PD-stable (n = 42) and those who converted to MCI over 18 months were classified as PD-converters (n = 12). FreeSurfer was used to measure cortical thickness and subcortical volumes at baseline and follow-up. RESULTS: Parkinson's disease-MCI showed baseline thalamus atrophy and progressive atrophy in the thalamus, caudate, presubiculum, cornu ammonis 1 and 2-3, and significant memory and executive dysfunction compared with PD-NCI. PD-converters had greater accumbens atrophy at baseline and progressive atrophy in the thalamus, caudate and accumbens with dysfunctions in memory and executive domains. CONCLUSIONS: Progression of cognitive impairment in non-demented PD is associated with a specific pattern of subcortical atrophy. Findings from this study will allow future studies to investigate in the role of subcortical structures as a biomarker for PD dementia.


Assuntos
Córtex Cerebral/patologia , Transtornos Cognitivos/patologia , Transtornos Cognitivos/psicologia , Doença de Parkinson/patologia , Doença de Parkinson/psicologia , Idoso , Atrofia , Transtornos Cognitivos/etiologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/psicologia , Progressão da Doença , Função Executiva , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Memória , Pessoa de Meia-Idade , Testes Neuropsicológicos , Doença de Parkinson/complicações
6.
Am J Transplant ; 14(5): 1183-90, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24731148

RESUMO

BK viral infection is an important cause of renal transplant dysfunction and failure. Current strategies utilize surveillance for infection with DNA polymerase chain reaction assays and modulation of immunosuppression. Many viruses including polyomaviruses encode microRNAs (miRNAs). We have detected BK virus (BKV) encoded miRNAs in the blood of infected renal transplant recipients, and see a strong correlation between BKV encoded miRNA and BKV DNA in blood and a relationship between levels of bkv-miR-B1-5p and the presence of biopsy-proven BK viral nephropathy. Further research is needed to determine whether the detection of this and other virally encoded miRNAs may be useful in the diagnosis of active viral replication.


Assuntos
Vírus BK/genética , Nefropatias/diagnóstico , Transplante de Rim , MicroRNAs/sangue , Infecções por Polyomavirus/diagnóstico , Transplantados , Vírus BK/isolamento & purificação , Estudos de Casos e Controles , DNA Viral/genética , Feminino , Seguimentos , Regulação Viral da Expressão Gênica , Humanos , Nefropatias/sangue , Nefropatias/virologia , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Infecções por Polyomavirus/sangue , Infecções por Polyomavirus/virologia , Prognóstico , RNA Mensageiro/genética , RNA Viral/sangue , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Replicação Viral
8.
Intern Med J ; 43(7): 798-802, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23461391

RESUMO

BACKGROUND: Discharge against medical advice (DAMA) occurs when an in-patient chooses to leave the hospital before discharge is recommended by the treating clinicians. The long-term outcomes of patients who DAMA are not well documented. AIM: The objective of this long-term and hospital-wide study is to examine characteristics of patients who DAMA, their rates of readmission and mortality after self-discharge. METHODS: Administrative data of admissions to Flinders Medical Centre between July 2002 and June 2011 were used to compare readmissions and mortality among patients who DAMA with those who did not. The outcomes were adjusted for age, gender, emergency admission status, comorbidity, mental health diagnoses, and alcohol and substance abuse. RESULTS: In the study period, 1562 episodes (1.3%) of 121,986 admissions to Flinders Medical Centre were DAMA. Compared with those who did not leave against medical advice, these patients were younger, more often male, more likely of indigenous ethnicity and had less physical comorbidity, but greater mental health comorbidity. Half of the DAMA group stayed less than 3 days. In multivariate analysis, the relative risk for 7-day, 28-day and 1-year readmission in the DAMA group was 2.36 (95% confidence interval (CI), 1.99-2.81; P < 0.001), 1.66 (95% CI, 1.44-1.92; P < 0.001) and 1.31 (95% CI, 1.19-1.45; P < 0.001), respectively, compared with standard discharges. Furthermore, DAMA was associated with twofold (P = 0.02), 1.4-fold (P = 0.025) and 1.2-fold (P = 0.049) increase in 28-day, 1-year and up-to-9-year mortality, respectively, compared with non-DAMA. CONCLUSIONS: Patients who self-discharged against medical advice carry a significant risk of readmission and mortality. Patients with characteristics of 'at risk of DAMA' should have greater attention paid to their care before and especially after any premature discharge.


Assuntos
Cooperação do Paciente , Alta do Paciente/tendências , Readmissão do Paciente/tendências , Recusa do Paciente ao Tratamento , Adulto , Idoso , Estudos de Coortes , Feminino , Hospitalização/tendências , Hospitais Universitários/normas , Hospitais Universitários/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Alta do Paciente/normas , Readmissão do Paciente/normas , Resultado do Tratamento
9.
Malays J Pathol ; 35(1): 91-4, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23817400

RESUMO

We report an18-year-old girl with a four-year history of a slow-growing labial mass with a sudden increase in size in the last year. Examination revealed a large fleshy 20 cm perineal mass centering on the left labia majora and attached to it by a 1cm pedicle. It was associated with pain, ulceration and discharge. The lesion was excised via diathermy at the base of the stalk. The excised specimen weighed 1.112kg and measured 20.5 x 17 x 5cm. The lesion showed a solid, soft whitish, cut surface. Histology revealed a hypocellular tumour with focally oedematous fibrous stroma in which were scattered large and small blood vessels, mast cells and other chronic inflammatory cells. True myxoid matrix was not observed. The stromal cells had a spindle to stellate morphology. There was no significant cytological atypia, mitotic activity or necrosis. The tumour cells were negative for SMA, desmin, CD34, S100 protein, EMA and PR. The diagnosis was clinically and histologically challenging because various vulvovaginal soft tissue tumours often have overlapping clinicopathological features. However, based on strict histological criteria and the absence of worrisome cytological features, a diagnosis of fi broepithelial stromal polyp was rendered despite the unusual size. A review of the literature shows that whilst vulvovaginal fibroepithelial stromal polyps are well described, giant variants are rare. Awareness of the extraordinary size that can be attained by such polyps can facilitate swift clinical and histological diagnosis.


Assuntos
Neoplasias Fibroepiteliais/patologia , Pólipos/patologia , Neoplasias Vaginais/patologia , Adolescente , Feminino , Humanos
10.
Parasite Immunol ; 34(4): 183-98, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22224945

RESUMO

Giardia lamblia, a pathogen causing diarrhoeal outbreaks, is interesting how it triggers immune response in the human epithelial cells. This study defined the crucial roles of signalling components involved in G. lamblia-induced cytokine production in human epithelial cells. Incubation of the gastrointestinal cell line HT-29 with G. lamblia GS trophozoites triggered production of interleukin (IL)-1ß, IL-8 and tumour necrosis factor (TNF)-α. IL-8 production was not significantly decreased by physically separating the HT-29 cells and G. lamblia GS trophozoites. Indeed, treatment of HT-29 with G. lamblia excretory-secretory products (ESP) induced IL-8 production. Electrophoretic mobility gel shift and transfection assays using mutagenized IL-8 promoter reporter plasmids indicated that IL-8 production by G. lamblia ESP occurs through activation of two transcriptional factors, nuclear factor kappaB (NF-κB) and activator protein 1 (AP-1) in HT-29 cells. In addition, activation of two mitogen-activated protein kinases (MAPKs), p38 and ERK1/2, was also detected in the HT-29 cells stimulated with G. lamblia ESP. Selective inhibition of these MAPKs resulted in decreased production of ESP-induced IL-8. These results indicate that activation of p38, ERK1/2 MAPK, NF-κB and AP-1 comprises the signalling pathway responsible for IL-8 production by G. lamblia ESP.


Assuntos
Colo/imunologia , Giardia lamblia/patogenicidade , Interleucina-8/biossíntese , Proteínas de Protozoários/imunologia , Animais , Colo/citologia , Colo/parasitologia , Ativação Enzimática , Giardia lamblia/genética , Giardia lamblia/crescimento & desenvolvimento , Giardia lamblia/metabolismo , Células HT29 , Humanos , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Transdução de Sinais , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
11.
Intern Med J ; 42(2): 160-5, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21470353

RESUMO

BACKGROUND: In a rural Irish hospital, a simple clinical score (SCS) determined at the time of admission enabled stratification of acute general medical admissions into five categories that were associated incrementally with patients' immediate and 30-day mortality. The aim of this study was to examine the representative performance of this SCS in predicting the outcomes of general medical admissions to an Australian teaching hospital. METHODS: A retrospective chart review was undertaken of a representative sample from 480 admissions in 2007 to an urban university teaching hospital in Australia. The SCS was calculated and related to that patient's outcome in terms of mortality, length of stay, nursing home placement on discharge, the occurrence of medical emergency team call and intensive care unit transfer. These data were compared, where possible, with the outcomes reported in the Irish hospital. RESULTS: Four hundred and seventeen complete sets of data allowed calculation of the SCS. There were significant linear correlations of the SCS (divided into quintiles) and patients' in-hospital and 30-day mortality, their length of stay and their discharge to a nursing home. There was no association of the SCS and the patients' readmission rate, intensive care unit transfer rate or likelihood of a medical emergency team call. The significant trends replicated those from the Irish hospital. CONCLUSION: The SCS can predict significant outcomes for general medical admissions in an Australian hospital despite obvious differences to the hospital of its derivation. A wider study of Australasian hospitals and the performance of the SCS as a predictor of general medical admission outcomes is underway.


Assuntos
Mortalidade Hospitalar/tendências , Tempo de Internação/tendências , Admissão do Paciente/tendências , Índice de Gravidade de Doença , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Estudos de Coortes , Feminino , Hospitalização/tendências , Hospitais de Ensino/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
12.
Eat Weight Disord ; 17(2): e144-6, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23010786

RESUMO

Vitamin A deficiency (VAD) after bariatric surgery is recognised as a significant post-operative complication that can lead to visual impairment. We report two cases of night blindness and visual impairment caused by VAD after malabsorptive bariatric surgery. Both patients were treated with intramuscular vitamin A replacement and made near complete recovery in their vision. Ocular complications due to VAD should be diagnosed and treated promptly in patients after bariatric surgery because these complications are reversible.


Assuntos
Cirurgia Bariátrica/efeitos adversos , Cegueira Noturna/etiologia , Baixa Visão/etiologia , Deficiência de Vitamina A/complicações , Deficiência de Vitamina A/diagnóstico , Vitamina A/administração & dosagem , Vitaminas/administração & dosagem , Atrofia/etiologia , Esquema de Medicação , Feminino , Derivação Gástrica/efeitos adversos , Humanos , Injeções Intramusculares , Derivação Jejunoileal/efeitos adversos , Síndromes de Malabsorção/complicações , Síndromes de Malabsorção/diagnóstico , Pessoa de Meia-Idade , Cegueira Noturna/fisiopatologia , Obesidade Mórbida/cirurgia , Nervo Óptico/patologia , Fatores de Tempo , Baixa Visão/fisiopatologia , Visão Ocular , Deficiência de Vitamina A/tratamento farmacológico , Deficiência de Vitamina A/etiologia
13.
J Obstet Gynaecol ; 31(8): 746-50, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22085068

RESUMO

This study is a retrospective review of the transcervical fluoroscopy-guided fallopian tube recanalisation (FTR) procedures done in a multi-ethnic south-east Asian population, over 9 years. A total of 100 patients with infertility and documented proximal tubal obstruction (PTO) were referred for FTR. On-table hysterosalpingography under sedation demonstrated true PTO in 96 patients. At selective-salpingography, the PTO cleared in 16 patients; 78 required FTR and two had fimbrial blockage. The technical success rate of FTR was 86.8% and the post-FTR pregnancy rate was 36.84% at a mean follow-up interval of 12.2 months. There were no major, immediate procedure-related complications. There was an ectopic pregnancy in a single treated patient. Fluoroscopy-guided FTR is a safe treatment option in patients with infertility from PTO, with high technical success rate, low complication rate and increased chances of pregnancy; therefore it should be preferred before attempting more expensive and resource-intensive procedures.


Assuntos
Doenças das Tubas Uterinas/diagnóstico por imagem , Doenças das Tubas Uterinas/cirurgia , Tubas Uterinas/cirurgia , Fluoroscopia/métodos , Histerossalpingografia/métodos , Adulto , Sudeste Asiático , Cateterismo/métodos , Feminino , Humanos , Infertilidade Feminina/diagnóstico por imagem , Infertilidade Feminina/cirurgia , Gravidez , Estudos Retrospectivos , Adulto Jovem
14.
Sci Rep ; 10(1): 14736, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895429

RESUMO

Debate still exists for the management of choledocholithiasis. The purpose of this study is to quantify the rate of recurrent choledocholithiasis post choledochoscopic bile duct exploration (CBDE) in comparison to ERCP and sphincterotomy, and to demonstrate the feasibility of this approach in a busy metropolitan hospital. Data of patients undergoing CBDE from 2009-2014 at the Northern Hospital, Victoria, Australia, was collected retrospectively. Primary outcomes were bile duct clearance rate and rate of recurrent stones post-clearance. Secondary outcomes measured were post-operative complications, laparoscopic to open conversion rate and operative time. Data of patients undergoing ERCP at the same institution was collected and compared. In total, there were 4,091 cholecystectomy cases performed from 2009-2014, of which 260 (6.3%) of patients had an intraoperative cholangiography (IOC) indicating a common bile duct (CBD) stone. Two hundred and forty-eight patients (95.3%) had a CBDE. The remaining 12 patients (4.6%) had radiological clearance, which were excluded from the study. The overall clearance rate for patients undergoing CBDE was 84% (209/248). The risk of recurrent stones up to 8 years post clearance was 2% (4/209). In the same institution, and between 1998-2012, a total of 1,148 patients underwent ERCP, of which 571 had endoscopic sphincterotomy (ES). Forty-three patients required a repeat ERCP for recurrent CBD stones with a complication rate of 7.5%. Time to recurrence ranged from 6 months to 10 years with a mean of 4.5 years. The rate of recurrence was lower in the CBDE group compared to the patients who had an ERCP (8.9% vs. 2%). CBDE is a feasible and effective method for clearance of CBD stones at the time of laparoscopic cholecystectomy. This approach, although not widely used, reduces the need for ERCP, which has inherent complications. In the longer term, this series showed a significant reduction in the rate of CBD stone recurrence.


Assuntos
Colangiografia/métodos , Colangiopancreatografia Retrógrada Endoscópica/métodos , Ducto Colédoco/cirurgia , Cálculos Biliares/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cateterismo/métodos , Colecistectomia Laparoscópica/métodos , Coledocolitíase/cirurgia , Feminino , Humanos , Cuidados Intraoperatórios/métodos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Estudos Retrospectivos , Esfinterotomia Endoscópica/métodos , Adulto Jovem
16.
Retrovirology ; 5: 2, 2008 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-18186934

RESUMO

BACKGROUND: We previously identified unusual variants of Moloney and Friend ecotropic mouse gammaretroviruses that have altered host range and are cytopathic in cells of the wild mouse species Mus dunni. Cytopathicity was attributed to different amino acid substitutions at the same critical env residue involved in receptor interaction: S82F in the Moloney variant Spl574, and S84A in the Friend mouse leukemia virus F-S MLV. Because M. dunni cells carry a variant CAT-1 cell surface virus receptor (dCAT-1), we examined the role of this receptor variant in cytopathicity and host range. RESULTS: We expressed dCAT-1 or mCAT-1 of NIH 3T3 origin in cells that are not normally infectible with ecotropic MLVs and evaluated the transfectants for susceptibility to virus infection and to virus-induced syncytium formation. The dCAT-1 transfectants, but not the mCAT-1 transfectants, were susceptible to virus-induced cytopathicity, and this cytopathic response was accompanied by the accumulation of unintegrated viral DNA. The dCAT-1 transfectants, however, did not also reproduce the relative resistance of M. dunni cells to Moloney MLV, and the mCAT-1 transfectants did not show the relative resistance of NIH 3T3 cells to Spl574. Western analysis, use of glycosylation inhibitors and mutagenesis to remove receptor glycosylation sites identified a possible role for cell-specific glycosylation in the modulation of virus entry. CONCLUSION: Virus entry and virus-induced syncytium formation using the CAT-1 receptor are mediated by a small number of critical amino acid residues in receptor and virus Env. Virus entry is modulated by glycosylation of cellular proteins, and this effect is cell and virus-specific.


Assuntos
Transportador 1 de Aminoácidos Catiônicos/genética , Vírus da Leucemia Murina de Friend/patogenicidade , Células Gigantes/fisiologia , Vírus da Leucemia Murina de Moloney/patogenicidade , Polimorfismo Genético , Animais , Animais Selvagens , Transportador 1 de Aminoácidos Catiônicos/metabolismo , Linhagem Celular , Efeito Citopatogênico Viral , Glicosilação , Leucemia Experimental/virologia , Camundongos , Células NIH 3T3 , Infecções por Retroviridae/virologia , Transfecção , Infecções Tumorais por Vírus/virologia , Internalização do Vírus
18.
Gerontol Geriatr Med ; 4: 2333721418819532, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30574533

RESUMO

Exercise may be beneficial to older persons living with peripheral neuropathy (PN), but maintaining an exercise program is challenging. After participating in a 12-week tai chi (TC) study, 12 participants requested classes continue. A mixed-methods design was used to explore long-term engagement of older persons with bilateral PN enrolled in a TC class for 18 months beyond the original 3-month study. Pre- and posttest measures of functional status and quality of life (QOL) were conducted. Focus groups were held after 18 months of twice-weekly classes. Psychosocial support was critical to participants' long-term commitment to exercise. Participants reported, and objective assessments confirmed, increased strength, balance, and stamina beyond that experienced in the original 12-week study. Changes in QOL scores were nonsignificant; however, qualitative data supported clinical significance across QOL domains. Results from this study support psychosocial and physical benefits of TC to older persons.

19.
Front Microbiol ; 9: 1575, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30140256

RESUMO

Hydrogen sulfide production by sulfate reducing bacteria (SRB) is the primary cause of oil reservoir souring. Amending environments with chlorate or perchlorate [collectively denoted (per)chlorate] represents an emerging technology to prevent the onset of souring. Recent studies with perchlorate reducing bacteria (PRB) monocultures demonstrated that they have the innate capability to enzymatically oxidize sulfide, thus PRB may offer an effective means of reversing souring. (Per)chlorate may be effective by (i) direct toxicity to SRB; (ii) competitive exclusion of SRB by PRB; or (iii) reversal of souring through re-oxidation of sulfide by PRB. To determine if (per)chlorate could sweeten a soured column system and assign a quantitative value to each of the mechanisms we treated columns flooded with San Francisco bay water with temporally decreasing amounts (50, 25, and 12.5 mM) of (per)chlorate. Geochemistry and the microbial community structure were monitored and a reactive transport model was developed, Results were compared to columns treated with nitrate or untreated. Souring was reversed by all treatments at 50 mM but nitrate-treated columns began to re-sour when treatment concentrations decreased (25 mM). Re-souring was only observed in (per)chlorate-treated columns when concentrations were decreased to 12.5 mM and the extent of re-souring was less than the control columns. Microbial community analyses indicated treatment-specific community shifts. Nitrate treatment resulted in a distinct community enriched in genera known to perform sulfur cycling metabolisms and genera capable of nitrate reduction. (Per)chlorate treatment enriched for (per)chlorate reducing bacteria. (Per)chlorate treatments only enriched for sulfate reducing organisms when treatment levels were decreased. A reactive transport model of perchlorate treatment was developed and a baseline case simulation demonstrated that the model provided a good fit to the effluent geochemical data. Subsequent simulations teased out the relative role that each of the three perchlorate inhibition mechanisms played during different phases of the experiment. These results indicate that perchlorate addition is an effective strategy for both souring prevention and souring reversal. It provides insight into which organisms are involved, and illuminates the interactive effects of the inhibition mechanisms, further highlighting the versatility of perchlorate as a sweetening agent.

20.
Neuroscience ; 145(3): 1026-36, 2007 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-17291689

RESUMO

Ca(v)2.1 Ca(2+) channels (P/Q-type), which participate in various key roles in the CNS by mediating calcium influx, are extensively spliced. One of its alternatively-spliced exons is 37, which forms part of the EF hand. The expression of exon 37a (EFa form), but not exon 37b (EFb form), confers the channel an activity-dependent enhancement of channel opening known as Ca(2+)-dependent facilitation (CDF). In this study, we analyzed the trend of EF hand splice variant distributions in mouse, rat and human brain tissues. We observed a developmental switch in rodents, as well as an age and gender bias in human brain tissues, suggestive of a possible role of these EF hand splice variants in neurophysiological specialization. A parallel study performed on rodent brains showed that the data drawn from human and rodent tissues may not necessarily correlate in the process of aging.


Assuntos
Processamento Alternativo , Canais de Cálcio Tipo N/genética , Caracteres Sexuais , Envelhecimento , Animais , Éxons , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Íntrons , Masculino , Camundongos , Ratos , Ratos Endogâmicos F344 , Mapeamento por Restrição , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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